Patent application number | Description | Published |
20080206124 | Method of producing nano-scaled graphene and inorganic platelets and their nanocomposites - Disclosed is a method of exfoliating a layered material (e.g., graphite and graphite oxide) to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm, and often between 0.34 nm and 1.02 nm. The method comprises: (a) subjecting the layered material in a powder form to a halogen vapor at a first temperature above the melting point or sublimation point of the halogen at a sufficient vapor pressure and for a duration of time sufficient to cause the halogen molecules to penetrate an interlayer space of the layered material, forming a stable halogen-intercalated compound; and (b) heating the halogen-intercalated compound at a second temperature above the boiling point of the halogen, allowing halogen atoms or molecules residing in the interlayer space to exfoliate the layered material to produce the platelets. Alternatively, rather than heating, step (a) is followed by a step of dispersing the halogen-intercalated compound in a liquid medium which is subjected to ultrasonication for exfoliating the halogen-intercalated compound to produce the platelets, which are dispersed in the liquid medium. The halogen can be readily captured and re-used, thereby significantly reducing the impact of halogen to the environment. The method can further include a step of dispersing the platelets in a polymer or monomer solution or suspension as a precursor step to nanocomposite fabrication. | 08-28-2008 |
20080220282 | Highly conductive, multi-layer composite precursor composition to fuel cell flow field plate or bipolar plate - This invention provides a moldable, multiple-layer composite composition, which is a precursor to an electrically conductive composite flow field plate or bipolar plate. In one preferred embodiment, the composition comprises a plurality of conductive sheets and a plurality of mixture layers of a curable resin and conductive fillers, wherein (A) each conductive sheet is attached to at least one resin-filler mixture layer; (B) at least one of the conductive sheets comprises flexible graphite; and (C) at least one resin-filler mixture layer comprises a thermosetting resin and conductive fillers with the fillers being present in a sufficient quantity to render the resulting flow field plate or bipolar plate electrically conductive with a conductivity no less than 100 S/cm and thickness-direction areal conductivity no less than 200 S/cm | 09-11-2008 |
20080248275 | Nano-scaled graphene plate films and articles - Disclosed is a nano-scaled graphene article comprising a non-woven aggregate of nano-scaled graphene platelets wherein each of the platelets comprises a graphene sheet or multiple graphene sheets and the platelets have a thickness no greater than 100 nm (preferably smaller than 10 nm) and platelets contact other platelets to define a plurality of conductive pathways along the article. The article has an exceptional thermal conductivity (typically greater than 500 Wm | 10-09-2008 |
20080258359 | Low-temperature method of producing nano-scaled graphene platelets and their nanocomposites - A method of exfoliating a layered material to produce separated nano-scaled platelets having a thickness smaller than 100 nm. The method comprises: (a) providing a graphite intercalation compound comprising a layered graphite containing expandable species residing in an interlayer space of the layered graphite; (b) exposing the graphite intercalation compound to an exfoliation temperature lower than 650° C. for a duration of time sufficient to at least partially exfoliate the layered graphite without incurring a significant level of oxidation; and (c) subjecting the at least partially exfoliated graphite to a mechanical shearing treatment to produce separated platelets. The method can further include a step of dispersing the platelets in a polymer or monomer solution or suspension as a precursor step to nanocomposite fabrication. | 10-23-2008 |
20080268318 | Carbon cladded composite flow field plate, bipolar plate and fuel cell - The present invention provides a carbon-cladded composite composition for use as a fuel cell flow field plate or bipolar plate. In one preferred embodiment, the composition comprises a core composite layer sandwiched between two clad layers, wherein (a) the clad layer comprises a conductive carbon or graphite material (e.g., carbon nano-tubes, nano-scaled graphene plates, graphitic nano-fibers, and fine graphite particles); (b) the core composite layer comprises a matrix resin and a conductive filler present in a sufficient quantity to render the composite layer electrically conductive with an electrical conductivity no less than 1 S/cm (preferably no less than 100 S/cm); and (c) the composition has a planar outer surface on each clad side having formed therein a fluid flow channel. | 10-30-2008 |
20080277628 | Exfoliated graphite composite compositions for fuel cell flow field plates - This invention provides an electrically conductive, less anisotropic, and structurally sound composite composition for fuel cell flow field plate or bipolar plate applications. The composition comprises: (a) expanded or exfoliated graphite; (b) particles of non-expandable graphite or carbon, wherein the particles are between 3% and 60% by weight based on the total weight of the particles and the expanded graphite; and (c) a binder or matrix material to bond the expanded graphite and the particles of non-expanded graphite or carbon for forming a highly conductive composite, wherein the binder or matrix material is between 3% and 60% by weight based on the total composite composition weight. The composite plate exhibits a thickness-direction conductivity typically greater than 35 S/cm, more typically greater than 50 S/cm, most typically greater than 100 S/cm, and a thickness-direction specific areal conductivity greater than 200 S/cm | 11-13-2008 |
20080279710 | Method of producing exfoliated graphite composite compositions for fuel cell flow field plates - A method of producing an electrically conductive composite composition, which is particularly useful for fuel cell bipolar plate applications. The method comprises: (a) providing a supply of expandable graphite powder; (b) providing a supply of a non-expandable powder component comprising a binder or matrix material; (c) blending the expandable graphite with the non-expandable powder component to form a powder mixture wherein the non-expandable powder component is in the amount of between 3% and 60% by weight based on the total weight of the powder mixture; (d) exposing the powder mixture to a temperature sufficient for exfoliating the expandable graphite to obtain a compressible mixture comprising expanded graphite worms and the non-expandable component; (e) compressing the compressible mixture at a pressure within the range of from about 5 psi to about 50,000 psi in predetermined directions into predetermined forms of cohered graphite composite compact; and (f) treating the so-formed cohered graphite composite to activate the binder or matrix material thereby promoting adhesion within the compact to produce the desired composite composition. Preferably, the non-expandable powder component further comprises an isotropy-promoting agent such as non-expandable graphite particles. Further preferably, step (e) comprises compressing the mixture in at least two directions. The method leads to composite plates with exceptionally high thickness-direction electrical conductivity. | 11-13-2008 |
20080279756 | Method of producing exfoliated graphite, flexible graphite, and nano-scaled graphene platelets - The present invention provides a method of exfoliating a layered material (e.g., graphite and graphite oxide) to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm. The method comprises (a) dispersing particles of graphite, graphite oxide, or a non-graphite laminar compound in a liquid medium containing therein a surfactant or dispersing agent to obtain a stable suspension or slurry; and (b) exposing the suspension or slurry to ultrasonic waves at an energy level for a sufficient length of time to produce separated nano-scaled platelets. The nano-scaled platelets are candidate reinforcement fillers for polymer nanocomposites. Nano-scaled graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers. | 11-13-2008 |
20080299419 | Laminated exfoliated graphite composite-metal compositions for fuel cell flow field plate or bipolar plate applications - An electrically conductive laminate composition for fuel cell flow field plate or bipolar plate applications. The laminate composition comprises at least a thin metal sheet having two opposed exterior surfaces and a first exfoliated graphite composite sheet bonded to the first of the two exterior surfaces of the metal sheet wherein the exfoliated graphite composite sheet comprises: (a) expanded or exfoliated graphite and (b) a binder or matrix material to bond the expanded graphite for forming a cohered sheet, wherein the binder or matrix material is between 3% and 60% by weight based on the total weight of the first exfoliated graphite composite sheet. Preferably, the first exfoliated graphite composite sheet further comprises particles of non-expandable graphite or carbon in the amount of between 3% and 60% by weight based on the total weight of the non-expandable particles and the expanded graphite. Further preferably, the laminate comprises a second exfoliated graphite composite sheet bonded to the second surface of the metal sheet to form a three-layer laminate. Surface flow channels and other desired geometric features can be built onto the exterior surfaces of the laminate to form a flow field plate or bipolar plate. The resulting laminate has an exceptionally high thickness-direction conductivity and excellent resistance to gas permeation. | 12-04-2008 |
20090020734 | Method of producing conducting polymer-transition metal electro-catalyst composition and electrodes for fuel cells - A method of producing an electro-catalyst composition for use as an electrode, gas diffusion layer-supported electrode, catalyst-coated solid electrolyte layer, and membrane-electrode assembly in a proton exchange membrane (PEM) type fuel cell. The method comprises: (a) preparing a proton- and electron-conducting polymer having an electronic conductivity no less than 10 | 01-22-2009 |
20090022649 | Method for producing ultra-thin nano-scaled graphene platelets - A method of producing ultra-thin, separated nano-scaled platelets having an average thickness no greater than 2 nm or comprising, on average, no more than 5 layers per platelet from a layered graphite material. The method comprises: (a) providing a supply of nano-scaled platelets with an average thickness of no more than 10 nm or having, on average, no more than 30 layers per platelet; and (b) intercalating the supply of nano-scaled platelets to produce intercalated nano platelets and exfoliating the intercalated nano platelets at a temperature and a pressure for a sufficient period of time to produce the ultra-thin nano-scaled platelets. The nano-scaled platelets are candidate reinforcement fillers for polymer nanocomposites. Nano-scaled graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers. | 01-22-2009 |
20090026086 | Electrochemical method of producing nano-scaled graphene platelets - A method of producing nano-scaled graphene platelets with an average thickness smaller than 30 nm from a layered graphite material. The method comprises (a) forming a carboxylic acid-intercalated graphite compound by an electrochemical reaction which uses a carboxylic acid as both an electrolyte and an intercalate source, the layered graphite material as an anode material, and a metal or graphite as a cathode material, and wherein a current is imposed upon the cathode and the anode at a current density for a duration of time sufficient for effecting the electrochemical reaction; (b) exposing the intercalated graphite compound to a thermal shock to produce exfoliated graphite; and (c) subjecting the exfoliated graphite to a mechanical shearing treatment to produce the nano-scaled graphene platelets. Preferred carboxylic acids are formic acid and acetic acid. The exfoliation step in the instant invention does not involve the evolution of undesirable species, such as NO | 01-29-2009 |
20090028777 | Environmentally benign chemical oxidation method of producing graphite intercalation compound, exfoliated graphite, and nano-scaled graphene platelets - A method of producing exfoliated graphite, flexible graphite, or nano-scaled graphene platelets. The method comprises: (a) forming a graphite intercalation compound by a chemical oxidation reaction which uses a combination of a carboxylic acid and hydrogen peroxide as an intercalate source; and (b) rapidly heating the graphite intercalation compound to a desired temperature for a length of time sufficient for producing exfoliated graphite. The method may further comprise a step of subjecting the exfoliated graphite to a mechanical shearing treatment to produce nano-scaled graphene platelets. Alternatively, the method may further comprise a step of compressing the exfoliated graphite to form a flexible graphite product. The exfoliation step in the instant invention does not involve the evolution of undesirable species, such as NO | 01-29-2009 |
20090028778 | Environmentally benign graphite intercalation compound composition for exfoliated graphite, flexible graphite, and nano-scaled graphene platelets - A carboxylic-intercalated graphite compound composition for the production of exfoliated graphite, flexible graphite, or nano-scaled graphene platelets. The composition comprises a layered graphite with interlayer spaces or interstices and a carboxylic acid residing in at least one of the interstices, wherein the composition is prepared by a chemical oxidation reaction which uses a combination of a carboxylic acid and hydrogen peroxide as an intercalate source. Alternatively, the composition may be prepared by an electrochemical reaction, which uses a carboxylic acid as both an electrolyte and an intercalate source. Exfoliation of the invented composition does not release undesirable chemical contaminants into air or drainage. | 01-29-2009 |
20090047579 | Carbon anode compositions for lithium ion batteries - A lithium secondary battery comprising a positive electrode, a negative electrode comprising a carbonaceous material which is capable of absorbing and desorbing lithium ions, and a non-aqueous electrolyte disposed between the negative electrode and the positive electrode. The carbonaceous material comprises a graphite crystal structure having an interplanar spacing d | 02-19-2009 |
20090057940 | Method of producing less anisotropic flexible graphite - This invention provides a method for recompressing expanded or exfoliated graphite to produce a less anisotropic, flexible graphite foil having a thickness-direction electrical conductivity no less than 15 S/cm. In one preferred embodiment, the method comprises: (a) providing a mixture of expanded or exfoliated graphite flakes and particles of non-expandable graphite or carbon, wherein the non-expandable graphite or carbon particles are in the amount of between about 3% and 70% by weight based on the total weight of the particles and the exfoliated graphite; (b) compressing the mixture in at least a first direction to a pressure within the range of from about 0.04 MPa to about 350 MPa into a first cohered mixture; and (c) compressing this first cohered mixture in a second direction, different from the first direction, to a pressure sufficient to produce said flexible graphite foil having a bulk density within the range of from about 0.1 g/cm | 03-05-2009 |
20090059474 | Graphite-Carbon composite electrode for supercapacitors - A composite composition for use in an electrode for electrochemical capacitors, comprising: (a) an electrochemically active material; and (b) exfoliated graphite flakes that are substantially interconnected to form a porous, conductive graphite network comprising pores, wherein at least a portion of the active material resides in a pore of the network. The composite composition is characterized by having liquid accessible pores which provide a surface area greater than about 200 m | 03-05-2009 |
20090061191 | Recompressed exfoliated graphite articles - This invention provides an electrically conductive, less anisotropic, recompressed exfoliated graphite article comprising a mixture of (a) expanded or exfoliated graphite flakes; and (b) particles of non-expandable graphite or carbon, wherein the non-expandable graphite or carbon particles are in the amount of between about 3% and about 70% by weight based on the total weight of the particles and the expanded graphite flakes combined; wherein the mixture is compressed to form the article having an apparent bulk density of from about 0.1 g/cm | 03-05-2009 |
20090061312 | Method of producing graphite-carbon composite electrodes for supercapacitors - A method of producing a composite electrode having a specific surface area of at least 100 m | 03-05-2009 |
20090072448 | Continious production of exfoliated graphite composite compositions and flow field plates - A process of continuously producing a more isotropic, electrically conductive composite composition is provided. The process comprises: (a) continuously supplying a compressible mixture comprising exfoliated graphite worms and a binder or matrix material, wherein the binder or matrix material is in an amount of between 3% and 60% by weight based on the total weight of the mixture; (b) continuously compressing the compressible mixture at a pressure within the range of from about 5 psi or 0.035 MPa to about 50,000 psi or 350 MPa in at least a first direction into a cohered graphite composite compact; and (c) continuously compressing the composite compact in a second direction, different from the first direction, to form the composite composition in a sheet or plate form. The process leads to composite plates with exceptionally high thickness-direction electrical conductivity. | 03-19-2009 |
20090090640 | Process for producing carbon anode compositions for lithium ion batteries - This invention provides a process for producing a lithium secondary battery. The process comprises: (a) providing a positive electrode; (b) providing a negative electrode comprising a carbonaceous material capable of absorbing and desorbing lithium ions, wherein the carbonaceous material is obtained by chemically or electrochemically treating a laminar graphite material to form a graphite crystal structure having an interplanar spacing d | 04-09-2009 |
20090092747 | Process for producing nano-scaled graphene platelet nanocomposite electrodes for supercapacitors - A process for producing meso-porous nanocomposite electrode comprising nano-scaled graphene platelets. The process comprises: (A) providing nano-scaled graphene platelets, wherein each of the platelets comprises a single graphene sheet or a stack of multiple graphene sheets, and the platelets have an average thickness no greater than 100 nm (preferably less than 5 nm and most preferably less than 2 nm in thickness); (B) combining a binder material, the graphene platelets, and a liquid to form a dispersion; (C) forming the dispersion into a desired shape and removing the liquid to produce a binder-platelet mixture; and (D) treating the binder material under a desired temperature or radiation environment to convert the binder-platelet mixture into a meso-porous nanocomposite electrode, wherein the platelets are bonded by the binder and the electrode has electrolyte-accessible pores characterized in that the nanocomposite has a surface area greater than about 100 m | 04-09-2009 |
20090117466 | Hybrid anode compositions for lithium ion batteries - The present invention provides an exfoliated graphite-based hybrid material composition for use as an electrode, particularly as an anode of a lithium ion battery. The composition comprises: (a) micron- or nanometer-scaled particles or coating which are capable of absorbing and desorbing alkali or alkaline metal ions (particularly, lithium ions); and (b) exfoliated graphite flakes that are substantially interconnected to form a porous, conductive graphite network comprising pores, wherein at least one of the particles or coating resides in a pore of the network or attached to a flake of the network and the exfoliated graphite amount is in the range of 5% to 90% by weight and the amount of particles or coating is in the range of 95% to 10% by weight. Also provided is a lithium secondary battery comprising such a negative electrode (anode). The battery exhibits an exceptional specific capacity, excellent reversible capacity, and long cycle life. | 05-07-2009 |
20090117467 | Nano graphene platelet-based composite anode compositions for lithium ion batteries - The present invention provides a nano-scaled graphene platelet-based composite material composition for use as an electrode, particularly as an anode of a lithium ion battery. The composition comprises: (a) micron- or nanometer-scaled particles or coating which are capable of absorbing and desorbing lithium ions; and (b) a plurality of nano-scaled graphene platelets (NGPs), wherein a platelet comprises a graphene sheet or a stack of graphene sheets having a platelet thickness less than 100 nm; wherein at least one of the particles or coating is physically attached or chemically bonded to at least one of the graphene platelets and the amount of platelets is in the range of 2% to 90% by weight and the amount of particles or coating in the range of 98% to 10% by weight. Also provided is a lithium secondary battery comprising such a negative electrode (anode). The battery exhibits an exceptional specific capacity, an excellent reversible capacity, and a long cycle life. | 05-07-2009 |
20090151847 | Process for producing laminated exfoliated graphite composite-metal compositions for fuel cell bipolar plate applications - A process for producing an electrically conductive laminate composition for fuel cell flow field plate or bipolar plate applications. The process comprises: (a) feeding a thin metal sheet, having a first surface and a second surface, into a consolidating zone; and (b) feeding a first exfoliated graphite composite sheet onto the first surface of the metal sheet to form a two-layer precursor laminate in this consolidating zone; wherein the exfoliated graphite composite sheet comprises (i) expanded or exfoliated graphite and (ii) a binder or matrix material to bond the expanded graphite to form a cohered. The process preferably further comprises (c) feeding a second exfoliated graphite composite sheet onto the second surface of the metal sheet to form a three-layer precursor laminate. Both the first and second exfoliated graphite composite sheet may further comprise particles of non-expandable graphite or carbon in the amount of between 3% and 60% by weight based on the total weight of the non-expandable particles and the expanded graphite. Surface flow channels and other desired geometric features can be built onto the exterior surfaces of the laminate to form a flow field plate or bipolar plate by a procedure such as in-line embossing or molding. The resulting laminate has an exceptionally high thickness-direction conductivity and excellent resistance to gas permeation. | 06-18-2009 |
20090155578 | Nano-scaled graphene platelets with a high length-to-width aspect ratio - This invention provides a nano-scaled graphene platelet (NGP) having a thickness no greater than 100 nm and a length-to-width ratio no less than 3 (preferably greater than 10). The NGP with a high length-to-width ratio can be prepared by using a method comprising (a) intercalating a carbon fiber or graphite fiber with an intercalate to form an intercalated fiber; (b) exfoliating the intercalated fiber to obtain an exfoliated fiber comprising graphene sheets or flakes; and (c) separating the graphene sheets or flakes to obtain nano-scaled graphene platelets. The invention also provides a nanocomposite material comprising an NGP with a high length-to-width ratio. Such a nanocomposite can become electrically conductive with a small weight fraction of NGPs. Conductive composites are particularly useful for shielding of sensitive electronic equipment against electromagnetic interference (EMI) or radio frequency interference (RFI), and for electrostatic charge dissipation. | 06-18-2009 |
20090155676 | Anode protective layer compositions for lithium metal batteries - The present invention provides a battery cell, comprising: (a) an anode comprising an active metal or a metal ion storage material (e.g., an intercalation compound that accommodates lithium ion); (b) a cathode structure; and (c) an ionically conductive protective layer on a surface of the anode and interposed between the anode and the cathode structure. This protective layer comprises a porous membrane having pores therein and a soft matter phase disposed in at least one of the pores, wherein the soft matter phase comprises oxide particles dispersed in a non-aqueous alkali, alkaline, or transition metal salt solution. Most preferably, this battery cell is a lithium metal secondary cell that is essentially free from dendrite and exhibits a safer and more stable cycling behavior. Such a high-capacity rechargeable battery is particularly useful for powering portable electronic devices and electric vehicles. | 06-18-2009 |
20090169467 | Production of ultra-thin nano-scaled graphene platelets from meso-carbon micro-beads - A method of producing nano-scaled graphene platelets (NGPs) having an average thickness no greater than 50 nm, typically less than 2 nm, and, in many cases, no greater than 1 nm. The method comprises (a) intercalating a supply of meso-carbon microbeads (MCMBs) to produce intercalated MCMBs; and (b) exfoliating the intercalated MCMBs at a temperature and a pressure for a sufficient period of time to produce the desired NGPs. Optionally, the exfoliated product may be subjected to a mechanical shearing treatment, such as air milling, air jet milling, ball milling, pressurized fluid milling, rotating-blade grinding, or ultrasonicating. The NGPs are excellent reinforcement fillers for a range of matrix materials to produce nanocomposites. Nano-scaled graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers. | 07-02-2009 |
20090169725 | Method of producing hybrid nano-filament electrodes for lithium metal or lithium ion batteries - Disclosed is a method of producing a hybrid nano-filament composition for use in a lithium battery electrode. The method comprises: (a) providing an aggregate of nanometer-scaled, electrically conductive filaments that are substantially interconnected, intersected, physically contacted, or chemically bonded to form a porous network of electrically conductive filaments, wherein the filaments comprise electro-spun nano-fibers that have a diameter less than 500 nm (preferably less than 100 nm); and (b) depositing micron- or nanometer-scaled coating onto a surface of the electro-spun nano-fibers, wherein the coating comprises an electro-active material capable of absorbing and desorbing lithium ions and the coating has a thickness less than 10 μm (preferably less than 1 μm). The same method can be followed to produce an anode or a cathode. The battery featuring an anode or cathode made with this method exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life. | 07-02-2009 |
20090169996 | Hybrid nano-filament anode compositions for lithium ion batteries - This invention provides a hybrid nano-filament composition for use as an electrochemical cell electrode. The composition comprises: (a) an aggregate of nanometer-scaled, electrically conductive filaments that are substantially interconnected, intersected, or percolated to form a porous, electrically conductive filament network comprising substantially interconnected pores, wherein the filaments have an elongate dimension and a first transverse dimension with the first transverse dimension being less than 500 nm (preferably less than 100 nm) and an aspect ratio of the elongate dimension to the first transverse dimension greater than 10; and (b) micron- or nanometer-scaled coating that is deposited on a surface of the filaments, wherein the coating comprises an anode active material capable of absorbing and desorbing lithium ions and the coating has a thickness less than 20 μm (preferably less than 1 μm). Also provided is a lithium ion battery comprising such an electrode as an anode. The battery exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life. | 07-02-2009 |
20090176159 | Mixed nano-filament electrode materials for lithium ion batteries - This invention provides a mixed nano-filament composition for use as an electrochemical cell electrode. The composition comprises: (a) an aggregate of nanometer-scaled, electrically conductive filaments that are substantially interconnected, intersected, or percolated to form a porous, electrically conductive filament network, wherein the filaments have a length and a diameter or thickness with the diameter/thickness less than 500 nm (preferably <100 nm) and a length-to-diameter or length-to-thickness aspect ratio greater than 10; and (b) Multiple nanometer-scaled, electro-active filaments comprising an electro-active material capable of absorbing and desorbing lithium ions wherein the electro-active filaments have a diameter or thickness less than 500 nm (preferably <100 nm). The electro-active filaments (e.g., nanowires) and the electrically conductive filaments (e.g., carbon nano fibers) are mixed to form a mat-, web-, or porous paper-like structure in which at least an electro-active filament is in electrical contact with at least an electrically conductive filament. Also provided is a lithium ion battery comprising such an electrode as an anode or cathode, or both. The battery exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life. | 07-09-2009 |
20090186276 | Hybrid nano-filament cathode compositions for lithium metal or lithium ion batteries - This invention provides a hybrid nano-filament composition for use as a cathode active material. The composition comprises (a) an aggregate of nanometer-scaled, electrically conductive filaments that are substantially interconnected, intersected, or percolated to form a porous, electrically conductive filament network, wherein the filaments have a length and a diameter or thickness with the diameter or thickness being less than 500 nm; and (b) micron- or nanometer-scaled coating that is deposited on a surface of the filaments, wherein the coating comprises a cathode active material capable of absorbing and desorbing lithium ions and the coating has a thickness less than 10 μm, preferably less than 1 μm and more preferably less than 500 nm. Also provided is a lithium metal battery or lithium ion battery that comprises such a cathode. Preferably, the battery includes an anode that is manufactured according to a similar hybrid nano filament approach. The battery exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life. | 07-23-2009 |
20090269511 | Process for producing hybrid nano-filament electrodes for lithium batteries - This invention provides a process for producing a hybrid nano-filament composition for use in a lithium battery electrode. The process comprises: (a) providing a porous aggregate of electrically conductive nano-wires that are substantially interconnected, intersected, physically contacted, or chemically bonded to form a porous network of electrically conductive filaments, wherein the nano-wires have a diameter or thickness less than 500 nm; and (b) depositing an electro-active coating onto a surface of the nano-wires, wherein the electro-active coating is capable of absorbing and desorbing lithium ions and the coating has a thickness less than 10 μm, preferably less than 1 μm. This process is applicable to the production of both an anode and a cathode. The battery featuring an anode or cathode made with this process exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life. | 10-29-2009 |
20090305135 | Conductive nanocomposite-based electrodes for lithium batteries - This invention provides a nanocomposite-based lithium battery electrode comprising: (a) A porous aggregate of electrically conductive nano-filaments that are substantially interconnected, intersected, physically contacted, or chemically bonded to form a three-dimensional network of electron-conducting paths, wherein the nano-filaments have a diameter or thickness less than 1 μm (preferably less than 500 nm); and (b) Sub-micron or nanometer-scale electro-active particles that are bonded to a surface of the nano-filaments with a conductive binder material, wherein the particles comprise an electro-active material capable of absorbing and desorbing lithium ions and wherein the electro-active material content is no less than 25% by weight based on the total weight of the particles, the binder material, and the filaments. Preferably, these electro-active particles are coated with a thin carbon layer. This electrode can be an anode or a cathode. The battery featuring such an anode or cathode exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life. | 12-10-2009 |
20100000441 | Nano graphene platelet-based conductive inks - A nano graphene platelet-based conductive ink comprising: (a) nano graphene platelets (preferably un-oxidized or pristine graphene), and (b) a liquid medium in which the nano graphene platelets are dispersed, wherein the nano graphene platelets occupy a proportion of at least 0.001% by volume based on the total ink volume. The ink can also contain a binder or matrix material and/or a surfactant. The ink may further comprise other fillers, such as carbon nanotubes, carbon nano-fibers, metal nano particles, carbon black, conductive organic species, etc. The graphene platelets preferably have an average thickness no greater than 10 nm and more preferably no greater than 1 nm. These inks can be printed to form a range of electrically or thermally conductive components. | 01-07-2010 |
20100021819 | Graphene nanocomposites for electrochemical cell electrodes - A composite composition for electrochemical cell electrode applications, the composition comprising multiple solid particles, wherein (a) a solid particle is composed of graphene platelets dispersed in or bonded by a first matrix or binder material, wherein the graphene platelets are not obtained from graphitization of the first binder or matrix material; (b) the graphene platelets have a length or width in the range of 10 nm to 10 μm; (c) the multiple solid particles are bonded by a second binder material; and (d) the first or second binder material is selected from a polymer, polymeric carbon, amorphous carbon, metal, glass, ceramic, oxide, organic material, or a combination thereof. For a lithium ion battery anode application, the first binder or matrix material is preferably amorphous carbon or polymeric carbon. Such a composite composition provides a high anode capacity and good cycling response. For a supercapacitor electrode application, the solid particles preferably have meso-scale pores therein to accommodate electrolyte. | 01-28-2010 |
20100044646 | Supercritical fluid process for producing nano graphene platelets - The present invention provides a process for producing pristine or non-oxidized nano graphene platelets (NGPs) that are highly conductive. The process comprises: (i) subjecting a graphitic material to a supercritical fluid at a first temperature and a first pressure for a first period of time in a pressure vessel and then (ii) rapidly depressurizing the fluid at a fluid release rate sufficient for effecting exfoliation of the graphitic material to obtain the NGP material. Conductive NGPs can be used as a conductive additive in transparent electrodes for solar cells or flat panel displays (e.g., to replace expensive indium-tin oxide), battery and supercapacitor electrodes, and nanocomposite for electromagnetic wave interference (EMI) shielding and static charge dissipation, etc. | 02-25-2010 |
20100055025 | Process for producing dispersible Nano Graphene Platelets from oxidized graphite - The present invention provides a process for producing nano graphene platelets (NGPs) that are dispersible and conducting. The process comprises: (a) preparing a graphite intercalation compound (GIC) or graphite oxide (GO) from a laminar graphite material; (b) exposing the GIC or GO to a first temperature for a first period of time to obtain exfoliated graphite; and (c) exposing the exfoliated graphite to a second temperature in a protective atmosphere for a second period of time to obtain the desired dispersible nano graphene platelet with an oxygen content no greater than 25% by weight, preferably below 20% by weight, further preferably between 5% and 20% by weight. Conductive NGPs can find applications in transparent electrodes for solar cells or flat panel displays, additives for battery and supercapacitor electrodes, conductive nanocomposite for electromagnetic wave interference (EMI) shielding and static charge dissipation, etc. | 03-04-2010 |
20100055458 | Dispersible and conductive Nano Graphene Platelets - The present invention provides a dispersible and electrically conductive nano graphene platelet (NGP) material comprising at least a single-layer or multiple-layer graphene sheet, wherein the NGP material has an oxygen content no greater than 25% by weight and no less than 5% by weight. This NGP material can be produced by: (a) preparing a pristine NGP material from a graphitic material; and (b) subjecting the pristine NGP material to an oxidation treatment. Alternatively, the production process may comprise: (A) preparing a graphite oxide (GO) from a laminar graphite material; (b) exposing the GO to a first temperature for a first period of time to obtain exfoliated graphite; and (c) exposing the exfoliated graphite to a second temperature in a protective atmosphere for a second period of time. Conductive NGPs can find applications in transparent electrodes for solar cells or flat panel displays, additives for battery and supercapacitor electrodes, conductive nanocomposite for electromagnetic wave interference (EMI) shielding and static charge dissipation, etc. | 03-04-2010 |
20100056819 | Process for producing dispersible and conductive Nano Graphene Platelets from non-oxidized graphitic materials - The present invention provides a process for producing nano graphene platelets (NGPs) that are both dispersible and electrically conducting. The process comprises: (a) preparing a pristine NGP material from a graphitic material; and (b) subjecting the pristine NGP material to an oxidation treatment to obtain the dispersible NGP material, wherein the NGP material has an oxygen content no greater than 25% by weight. Conductive NGPs can find applications in transparent electrodes for solar cells or flat panel displays, additives for battery and supercapacitor electrodes, conductive nanocomposite for electromagnetic wave interference (EMI) shielding and static charge dissipation, etc. | 03-04-2010 |
20100092723 | NANO-SCALED GRAPHENE PLATE-REINFORCED COMPOSITE MATERIALS AND METHOD OF PRODUCING SAME - Disclosed are a nano-composite composition and a method of making such a composite that is composed of a matrix material and dispersed reinforcement nano-scaled graphene plates (NGPs) that are substantially aligned along at least one specified direction or axis. The method comprises: (a) providing a mixture of nano-scaled graphene plates (NGPs) and a matrix material in a fluent state; (b) extruding the mixture to form a filament wherein NGPs are aligned along a filament axis; (c) aligning a plurality of segments of the filament in a first direction, or moving the filament back and forth along a first direction and its opposite direction, to form a NGP-matrix filament preform; and (d) consolidating the preform to form the nanocomposite material. Also disclosed is a method of making a nano-composite fiber. | 04-15-2010 |
20100120179 | Method of producing prelithiated anodes for secondary lithium ion batteries - A method of producing a lithium-ion battery anode comprising: (a) providing an anode active material; (b) intercalating or absorbing a desired amount of lithium into this anode active material to produce a prelithiated anode active material; (c) comminuting the prelithiated anode active material into fine particles with an average size less than 10 μm (preferably sub-micron and more preferably <200 nm); and (d) combining multiple fine particles of prelithiated anode active material with a conductive additive and/or a binder material to form the anode. The battery featuring such an anode exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life. | 05-13-2010 |
20100143798 | Nano graphene reinforced nanocomposite particles for lithium battery electrodes - A solid nanocomposite particle composition for lithium metal or lithium ion battery electrode applications. The composition comprises: (A) an electrode active material in a form of fine particles, rods, wires, fibers, or tubes with a dimension smaller than 1 μm; (B) nano graphene platelets (NGPs); and (C) a protective matrix material reinforced by the NGPs; wherein the graphene platelets and the electrode active material are dispersed in the matrix material and the NGPs occupy a weight fraction w | 06-10-2010 |
20100173198 | Secondary lithium ion battery containing a prelithiated anode - The present invention provides a lithium ion battery that exhibits a significantly improved specific capacity and much longer charge-discharge cycle life. In one preferred embodiment, the battery comprises an anode active material that has been prelithiated and pre-pulverized. This anode may be prepared with a method that comprises (a) providing an anode active material (preferably in the form of fine powder or thin film); (b) intercalating or absorbing a desired amount of lithium into the anode active material to produce a prelithiated anode active material; (c) comminuting the prelithiated anode active material into fine particles with an average size less than 10 μm (preferably <1 μm and most preferably <200 nm); and (d) combining multiple fine particles of the prelithiated anode active material with a conductive additive and/or a binder material to form the anode. Preferably, the prelithiated particles are protected by a lithium ion-conducting matrix or coating material. Further preferably, the matrix material is reinforced with nano graphene platelets. | 07-08-2010 |
20100176337 | Process for producing nano graphene reinforced composite particles for lithium battery electrodes - A process for producing solid nanocomposite particles for lithium metal or lithium ion battery electrode applications is provided. In one preferred embodiment, the process comprises: (A) Preparing an electrode active material in a form of fine particles, rods, wires, fibers, or tubes with a dimension smaller than 1 μm; (B) Preparing separated or isolated nano graphene platelets with a thickness less than 50 nm; (C) Dispersing the nano graphene platelets and the electrode active material in a precursor fluid medium to form a suspension wherein the fluid medium contains a precursor matrix material dispersed or dissolved therein; and (D) Converting the suspension to the solid nanocomposite particles, wherein the precursor matrix material is converted into a protective matrix material reinforced by the nano graphene platelets and the electrode active material is substantially dispersed in the protective matrix material. For a lithium ion battery anode application, the matrix material is preferably amorphous carbon, polymeric carbon, or meso-phase carbon. Such solid nanocomposite particles provide a high anode capacity and good cycling stability. For a cathode application, the resulting lithium metal or lithium ion battery exhibits an exceptionally high cycle life. | 07-15-2010 |
20100222482 | MASS PRODUCTION OF NANO-SCALED PLATELETS AND PRODUCTS - Disclosed is a process for exfoliating a layered material to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm, and often between 0.34 nm and 1.02 nm. The process comprises: (a) charging a layered material to an intercalation chamber comprising a gaseous environment at a first temperature and a first pressure sufficient to cause gas species to penetrate into the interstitial space between layers of the layered material, forming a gas-intercalated layered material; and (b) operating a discharge valve to rapidly eject the gas-intercalated layered material through a nozzle into an exfoliation zone at a second pressure and a second temperature, allowing gas species residing in the interstitial space to exfoliate the layered material to produce the platelets. The gaseous environment preferably contains only environmentally benign gases that are reactive (e.g., oxygen) or non-reactive (e.g., noble gases) with the layered material. The process can additionally include dispersing the platelets in a matrix material to form a nanocomposite. The process also can include an additional process of re-compressing the nana-scaled platelets into a product such as a flexible graphite sheet. | 09-02-2010 |
20110017585 | Mass production of pristine nano graphene materials - The present invention provides a method of producing pristine or non-oxidized nano graphene platelets (NGPs) that are highly conductive. The method comprises: (a) providing a pristine graphitic material comprising at least a graphite crystallite having at least a graphene plane and an edge surface; (b) dispersing multiple particles of the pristine graphitic material in a liquid medium containing therein no surfactant to produce a suspension, wherein the multiple particles in the liquid have a concentration greater than 0.1 mg/mL and the liquid medium is characterized by having a surface tension that enables wetting of the liquid on a graphene plane exhibiting a contact angle less than 90 degrees; and (c) exposing the suspension to direct ultrasonication at a sufficient energy or intensity level for a sufficient length of time to produce the NGPs. Pristine NGPs can be used as a conductive additive in transparent electrodes for solar cells or flat panel displays (e.g., to replace expensive indium-tin oxide), battery and supercapacitor electrodes, and nanocomposites for electromagnetic wave interference (EMI) shielding, static charge dissipation, and fuel cell bipolar plate applications. | 01-27-2011 |
20110017587 | Production of chemically functionalized nano graphene materials - Provided in this invention is a process for producing chemically functionalized nano graphene materials, known as nano graphene platelets (NGPs), graphene nano sheets, or graphene nano ribbons. Subsequently, a polymer can be grafted to a functional group of the resulting functionalized NGPs. In one preferred embodiment, the process comprises (A) dispersing a pristine graphite material and an azide or bi-radical compound in a liquid medium comprising to form a suspension; and (B) subjecting the suspension to direct ultrasonication with to ultrasonic waves of a desired intensity or power level for a length of time sufficient to produce nano graphene platelets and to enable a chemical reaction to occur between the nano graphene platelets and the azide or bi-radical compound to produce the functionalized nano graphene material. Concurrent production and functionalization of NGPs directly from pristine graphitic materials can be achieved in one step and in the same reactor. | 01-27-2011 |
20110017955 | Nano graphene-modified curing agents for thermoset resins - The present invention provides a modified curing agent for a thermosetting resin, such as epoxy resin. As one example, the epoxy curing agent comprises: (a) multiple nano graphene platelets; (b) a chemical functional group having multiple ends with a first end being bonded to a nano graphene platelet and at least a second end reactive with the epoxy resin; and (c) reactive molecules acting as a primary cross-linking agent for the epoxy resin; wherein the nano graphene platelet content is no less than 0.01% by weight based on the total weight of the modified curing agent. A modified curing agent containing reactive molecule-functionalized NGPs enable excellent dispersion of NGP in a resin matrix and the resulting nanocomposites exhibit much better properties than those of corresponding nanocomposites prepared by directly mixing dried NGPs with the thermosetting resins. | 01-27-2011 |
20110046027 | Nano graphene-modified lubricant - A lubricant composition having improved lubricant properties, comprising: | 02-24-2011 |
20110046289 | Pristine nano graphene-modified tires - A tire or tire lining comprising a rubber composite, comprising at least one rubber or elastomer matrix and pristine nano graphene platelets dispersed in the matrix. The pristine nano graphene-modified tire or tire lining has a significantly enhanced thermal conductivity. | 02-24-2011 |
20110104571 | Nano-structured anode compositions for lithium metal and lithium metal-air secondary batteries - This invention provides a nano-structured anode composition for a lithium metal cell. The composition comprises: (a) an integrated structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising interconnected pores, wherein the nano-filaments have a transverse dimension less than 500 nm; and (b) micron- or nanometer-scaled particles of lithium, a lithium alloy, or a lithium-containing compound wherein at least one of the particles is surface-passivated or stabilized and the weight fraction of these particles is between 1% and 99% based on the total weight of these particles and the integrated structure together. Also provided is a lithium metal cell or battery, or lithium-air cell or battery, comprising such an anode. The battery exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life. | 05-05-2011 |
20110133132 | Chemically functionalized submicron graphitic fibrils, methods for producing same and compositions containing same - The present invention provides a chemically functionalized submicron graphitic fibril having a diameter or thickness less than 1 μm, wherein the fibril is free of continuous thermal carbon overcoat, free of continuous hollow core, and free of catalyst. The fibril is obtained by splitting a micron-scaled carbon fiber or graphite fiber along the fiber axis direction. These functionalized graphitic fibrils exhibit exceptionally high electrical conductivity, high thermal conductivity, high elastic modulus, high strength and good interfacial bonding with a matrix resin in a composite. The present invention also provides several products that contain submicron graphitic fibrils: (a) paper, thin-film, mat, and web products; (b) rubber or tire products; (c) energy conversion or storage devices, such as fuel cells, lithium-ion batteries, and supercapacitors; (d) adhesives, inks, coatings, paints, lubricants, and grease products; (e) heavy metal ion scavenger; (f) absorbent (e.g., to recover spill oil); (g) sensors; (h) friction and brake components; (i) radiation-shield components; (j) catalyst carrier; and (k) composite materials. | 06-09-2011 |
20110135925 | Submicron-scale graphitic fibrils, methods for producing same and compositions containing same - The present invention provides a submicron-scaled graphitic fibril having a diameter or thickness less than 1 μm, wherein the fibril is free of continuous thermal carbon overcoat, free of continuous hollow core, and free of catalyst. The fibril is obtained by splitting a micron-scaled carbon fiber or graphite fiber along the fiber axis direction. The diameter or thickness is preferably less than 500 nm and can be greater or less than 100 nm. These graphitic fibrils exhibit exceptionally high electrical conductivity, thermal conductivity, elastic modulus, and strength. The present invention also provides several products that contain submicron graphitic fibrils: (a) paper, thin-film, mat, and web products; (b) rubber or tire products; (c) energy conversion or storage devices, such as fuel cells, lithium-ion batteries, and supercapacitors; (d) adhesives, inks, coatings, paints, lubricants, and grease products; (e) heavy metal ion scavenger; (f) absorbent (e.g., to recover spill oil); (g) sensors; (h) friction and brake components; (i) radiation-shield components; and (j) nanocomposite materials. | 06-09-2011 |
20110136007 | Submicron-scale and lower-micron graphitic fibrils as an anode active material for a lithium ion battery - The present invention provides a lithium ion battery anode material comprising a submicron-scaled graphitic fibril having a diameter or thickness less than 1 μm but greater than 100 nm, wherein the fibril is obtained by splitting a micron-scaled carbon fiber or graphite fiber along the fiber axis direction. This type of graphitic fibril exhibits exceptionally high electrical conductivity, thermal conductivity, elastic modulus, and strength. The anode material exhibits a high reversible capacity and good charge/discharge cycling stability for both low and high charge rate conditions. Another preferred embodiment of the present invention is an anode active material containing a graphitic fibril with a diameter greater than 1 μm but less than 6 μm obtained by splitting a carbon fiber or graphite fiber of at least 6 μm in diameter. | 06-09-2011 |
20110143022 | HIGHLY CONDUCTIVE COMPOSITES FOR FUEL CELL FLOW FIELD PLATES AND BIPOLAR PLATES - This invention provides a fuel cell flow field plate or bipolar plate having flow channels on faces of the plate, comprising an electrically conductive polymer composite. The composite is composed of (A) at least 50% by weight of a conductive filler, comprising at least 5% by weight reinforcement fibers, expanded graphite platelets, graphitic nano-fibers, and/or carbon nano-tubes; (B) polymer matrix material at 1 to 49.9% by weight; and (C) a polymer binder at 0.1 to 10% by weight; wherein the sum of the conductive filler weight %, polymer matrix weight % and polymer binder weight % equals 100% and the bulk electrical conductivity of the flow field or bipolar plate is at least 100 S/cm. The invention also provides a continuous process for cost-effective mass production of the conductive composite-based flow field or bipolar plate. | 06-16-2011 |
20110157772 | Spacer-modified nano graphene electrodes for supercapacitors - A surface-modified nano graphene platelet (NGP), comprising: (a) a nano graphene platelet having a thickness smaller than 10 nm; and (b) discrete, non-continuous, and non-metallic bumps or nodules bonded to a surface of the graphene platelet to serve as a spacer. When multiple surface-modified NGP sheets are stacked together to form an electrode, large numbers of electrolyte-accessible pores are formed, enabling the formation of large amounts of double layer charges in a supercapacitor, which exhibits an exceptionally high specific capacitance. | 06-30-2011 |
20110159372 | Conductive graphene polymer binder for electrochemical cell electrodes - The present invention provides an electrically conductive electrode comprising particles of an electroactive material and a conductive graphene polymer binder that bonds multiple particles of the electroactive material together, wherein the binder is in an amount of from 0.01% to 90% by weight based on the total electrode weight. Also provided are (a) a precursor solution or suspension to the graphene polymer binder for the electrode; (b) a paste containing electroactive particles and a graphene polymer dispersed in a liquid; (c) a method of producing the electrode from the precursor paste; and (d) an electrochemical cell (a battery or supercapacitor) containing such an electrode. | 06-30-2011 |
20110165321 | Continuous process for producing spacer-modified nano Graphene electrodes for supercapacitors - A specific embodiment of the present invention is a process for continuously producing a porous solid film of spacer-modified nano graphene platelets for supercapacitor electrode applications. This process comprises: (a) dissolving a precursor material in a solvent to form a precursor solution and dispersing multiple nano graphene platelets into the solution to form a suspension; (b) continuously delivering and forming the suspension into a layer of solid film composed of precursor material-coated graphene platelets overlapping one another, and removing the solvent from the solid film (e.g., analogous to a paper-making, mat-making, or web-making procedure); (c) continuously converting the precursor material into nodules bonded to surfaces of graphene platelets to form a porous solid film composed of spacer-modified graphene platelets; and (d) continuously collecting the porous solid film on a collector (e.g., a winding roller). The roll of porous solid film (mat, paper, or web) can then be cut into pieces for used as supercapacitor electrodes. | 07-07-2011 |
20110165462 | Anode compositions for lithium secondary batteries - A lithium secondary battery comprising a cathode, an anode, and a separator-electrolyte assembly or electrolyte layer disposed between the cathode and the anode, wherein the anode comprises: (a) an integrated nano-structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising interconnected pores, wherein the filaments have a transverse dimension less than 500 nm; and (b) a foil of lithium or lithium alloy as an anode active material. The battery exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life. | 07-07-2011 |
20110165466 | Lithium metal-sulfur and lithium ion-sulfur secondary batteries containing a nano-structured cathode and processes for producing same - An electrochemical cell comprising an anode, electrolyte or an electrolyte/separator combination, and a nano-structured cathode, wherein the cathode comprises: (a) an integrated nano-structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising pores with a size smaller than 100 nm (preferably smaller than 10 nm), wherein the filaments have a transverse dimension less than 500 nm (preferably less than 100 nm); and (b) powder or salt of lithium-containing sulfide (lithium polysulfide) disposed in the pores, or a thin coating of lithium-containing sulfide deposited on a nano-scaled filament surface wherein the lithium-containing sulfide is in contact with, dispersed in, or dissolved in electrolyte liquid and the lithium-containing sulfide-to-filament weight ratio is between 1/10 and 10/1 which is measured when the cell is in a fully discharged state. The cell exhibits an exceptionally high specific energy and a long cycle life. | 07-07-2011 |
20110183180 | Flexible asymmetric electrochemical cells using nano graphene platelet as an electrode material - A flexible, asymmetric electrochemical cell comprising: (A) A sheet of graphene paper as first electrode comprising nano graphene platelets having a platelet thickness less than 1 nm, wherein the first electrode has electrolyte-accessible pores; (B) A thin-film or paper-like first separator and electrolyte; and (C) A thin-film or paper-like second electrode which is different in composition than the first electrode; wherein the separator is sandwiched between the first and second electrode to form a flexible laminate configuration. The asymmetric supercapacitor cells with different NGP-based electrodes exhibit an exceptionally high capacitance, specific energy, and stable and long cycle life. | 07-28-2011 |
20110190435 | METHOD OF PRODUCING NANO-SCALED GRAPHENE AND INORGANIC PLATELETS AND THEIR NANOCOMPOSITES - Disclosed is a method of exfoliating a layered material (e.g., graphite and graphite oxide) to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm, and often between 0.34 nm and 1.02 nm. The method comprises: (a) subjecting the layered material in a powder form to a halogen vapor at a first temperature above the melting point or sublimation point of the halogen at a sufficient vapor pressure and for a duration of time sufficient to cause the halogen molecules to penetrate an interlayer space of the layered material, forming a stable halogen-intercalated compound; and (b) heating the halogen-intercalated compound at a second temperature above the boiling point of the halogen, allowing halogen atoms or molecules residing in the interlayer space to exfoliate the layered material to produce the platelets. Alternatively, rather than heating, step (a) is followed by a step of dispersing the halogen-intercalated compound in a liquid medium which is subjected to ultrasonication for exfoliating the halogen-intercalated compound to produce the platelets, which are dispersed in the liquid medium. The halogen can be readily captured and re-used, thereby significantly reducing the impact of halogen to the environment. The method can further include a step of dispersing the platelets in a polymer or monomer solution or suspension as a precursor step to nanocomposite fabrication. | 08-04-2011 |
20120007913 | NANO GRAPHENE PLATELET-BASED CONDUCTIVE INKS AND PRINTING PROCESS - A nano graphene platelet-based conductive ink comprising: (a) nano graphene platelets (preferably un-oxidized or pristine graphene), and (b) a liquid medium in which the nano graphene platelets are dispersed, wherein the nano graphene platelets occupy a proportion of at least 0.001% by volume based on the total ink volume and a process using the same. The ink can also contain a binder or matrix material and/or a surfactant. The ink may further comprise other fillers, such as carbon nanotubes, carbon nano-fibers, metal nano particles, carbon black, conductive organic species, etc. The graphene platelets preferably have an average thickness no greater than 10 nm and more preferably no greater than 1 nm. These inks can be printed to form a range of electrically or thermally conductive components or printed electronic components. | 01-12-2012 |
20120021293 | Method of producing nano-scaled inorganic platelets - The present invention provides a method of exfoliating a layered material (e.g., transition metal dichalcogenide) to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm. The method comprises (a) dispersing particles of a non-graphite laminar compound in a liquid medium containing therein a surfactant or dispersing agent to obtain a stable suspension or slurry; and (b) exposing the suspension or slurry to ultrasonic waves at an energy level for a sufficient length of time to produce separated nano-scaled platelets. The nano-scaled platelets are candidate reinforcement fillers for polymer nanocomposites. | 01-26-2012 |
20120021294 | Graphite or carbon particulates for the lithium ion battery anode - This invention provides a graphite or graphite-carbon particulate for use as a lithium secondary battery anode material having a high-rate capability. The particulate is formed of a core carbon or graphite particle and a plurality of satellite carbon or graphite particles that are each separately bonded to the core particle wherein the core particle is spherical in shape, slightly elongate in shape with a major axis-to-minor axis ratio less than 2, or fibril in shape, and wherein the satellite particles are disc-, platelet-, or flake-like particles each containing a graphite crystallite with a crystallographic c-axis dimension Lc and a lateral dimension. Preferably, Lc is less than 100 nm and the flake/platelet lateral dimension is less than 1 μm. The core particle may be selected from natural graphite, artificial graphite, spherical graphite, graphitic coke, meso-carbon micro-bead, soft carbon, hard carbon, graphitic fibril, carbon nano-fiber, carbon fiber, or graphite fiber. Preferably, the flat-shaped particles are randomly oriented with respect to one another. | 01-26-2012 |
20120026643 | Supercapacitor with a meso-porous nano graphene electrode - A supercapacitor comprising a two electrodes, a porous separator disposed between the two electrodes, and an ionic liquid electrolyte in physical contact with the two electrodes, wherein at least one of the two electrodes comprises a meso-porous structure being formed of a plurality of nano graphene platelets and multiple pores having a pore size in the range of 2 nm and 25 nm, wherein the graphene platelets are not spacer-modified or surface-modified platelets. Preferably, the graphene platelets are curved, not flat-shaped. The pores are accessible to ionic liquid molecules, enabling the formation of large amounts of electric double layer charges in a supercapacitor, which exhibits an exceptionally high specific capacitance and high energy density. | 02-02-2012 |
20120045688 | Lithium super-battery with a functionalized nano graphene cathode - An electrochemical energy storage device, lithium super-battery, comprising a positive electrode, a negative electrode, a porous separator disposed between the two electrodes, and a lithium-containing electrolyte in physical contact with the two electrodes, wherein the positive electrode comprises a plurality of chemically functionalized nano graphene platelets (f-NGP) or exfoliated graphite having a functional group that reversibly reacts with a lithium atom or ion. In a preferred embodiment, a lithium super-battery having a f-NGP positive electrode and Li | 02-23-2012 |
20120058397 | Graphene-Enhanced cathode materials for lithium batteries - A nano graphene-enhanced particulate for use as a lithium battery cathode active material, wherein the particulate is formed of a single or a plurality of graphene sheets and a plurality of fine cathode active material particles with a size smaller than 10 μm (preferably sub-micron or nano-scaled), and the graphene sheets and the particles are mutually bonded or agglomerated into an individual discrete particulate with at least a graphene sheet embracing the cathode active material particles, and wherein the particulate has an electrical conductivity no less than 10 | 03-08-2012 |
20120064409 | Graphene-enhanced anode particulates for lithium ion batteries - A nano graphene-enhanced particulate for use as a lithium-ion battery anode active material, wherein the particulate is formed of a single sheet of graphene or a plurality of graphene sheets and a plurality of fine anode active material particles with a size smaller than 10 μm. The graphene sheets and the particles are mutually bonded or agglomerated into the particulate with at least a graphene sheet embracing the anode active material particles. The amount of graphene is at least 0.01% by weight and the amount of the anode active material is at least 0.1% by weight, all based on the total weight of the particulate. A lithium-ion battery having an anode containing these graphene-enhanced particulates exhibits a stable charge and discharge cycling response, a high specific capacity per unit mass, a high first-cycle efficiency, a high capacity per electrode volume, and a long cycle life. | 03-15-2012 |
20120077080 | Lithium super-battery with a chemically functionalized disordered carbon cathode - An electrochemical energy storage device, lithium super-battery, comprising a positive electrode, a negative electrode, a porous separator disposed between the two electrodes, and a lithium-containing electrolyte in physical contact with the two electrodes, wherein the positive electrode comprises a disordered carbon material having a functional group that reversibly reacts with a lithium atom or ion. The disordered carbon material is selected from a soft carbon, hard carbon, polymeric carbon or carbonized resin, meso-phase carbon, coke, carbonized pitch, carbon black, activated carbon, or partially graphitized carbon. In a preferred embodiment, a lithium super-battery having a functionalized disordered carbon cathode and a Li | 03-29-2012 |
20120164539 | Surface -controlled lithium ion-exchanging energy storage device - A surface-controlled, lithium ion-exchanging battery device comprising: (a) A positive electrode (cathode) comprising a first functional material having a first lithium-capturing or lithium-storing surface; (b) A negative electrode (anode) comprising a second functional material having a second lithium-capturing or lithium-storing surface; (c) A porous separator disposed between the two electrodes, and (d) A lithium-containing electrolyte (preferably liquid or gel electrolyte) in physical contact with the two electrodes; wherein at least one of the two electrodes contains therein a lithium source (e.g., lithium foil, lithium powder, stabilized lithium particles, etc) prior to the first charge or the first discharge cycle of the battery device. This new generation of energy storage device exhibits the best properties of both the lithium ion battery and the supercapacitor. | 06-28-2012 |
20120171574 | Partially and fully surface-enabled metal ion-exchanging energy storage devices - A surface-enabled, metal ion-exchanging battery device comprising a cathode, an anode, a porous separator, and a metal ion-containing electrolyte, wherein the metal ion is selected from (A) non-Li alkali metals; (B) alkaline-earth metals; (C) transition metals; (D) other metals such as aluminum (Al); or (E) a combination thereof; and wherein at least one of the electrodes contains therein a metal ion source prior to the first charge or discharge cycle of the device and at least the cathode comprises a functional material or nano-structured material having a metal ion-capturing functional group or metal ion-storing surface in direct contact with said electrolyte, and wherein the operation of the battery device does not involve the introduction of oxygen from outside the device and does not involve the formation of a metal oxide, metal sulfide, metal selenide, metal telluride, metal hydroxide, or metal-halogen compound. This energy storage device has a power density significantly higher than that of a lithium-ion battery and an energy density dramatically higher than that of a supercapacitor. | 07-05-2012 |
20120321953 | Graphene-enabled vanadium oxide cathode and lithium cells containing same - A nano graphene-enabled vanadium oxide composite composition for use as a lithium battery cathode active material, wherein the composite composition is formed of one or a plurality of graphene, graphene oxide, or graphene fluoride sheets or platelets and a plurality of nano-particles, nano-rods, nano-wires, nano-sheets, and/or nano-belts of a vanadium oxide with a size smaller than 100 nm (preferably smaller than 20 nm, further preferably smaller than 10 nm, and most preferably smaller than 5 nm), and wherein the graphene, graphene oxide, or graphene fluoride (having a thickness <20 nm, preferably <10 nm, further preferably <5 nm, and being most preferably of single-layer or less than 5 layers) is in an amount of from 0.01% to 50% (preferably <10%) by weight based on the total weight of graphene, graphene oxide or graphene fluoride and the vanadium oxide combined. This electrode material exhibits an unprecedented combination of outstanding specific capacity, capacity retention, and rate capability characteristics. | 12-20-2012 |
20130001068 | Production process for chemically functionalized nano graphene materials - A combined production-functionalization process for producing a chemically functionalized nano graphene material from a pre-intercalated, oxidized, or halogenated graphite material, comprising: (A) Producing exfoliated graphite from the pre-intercalated, oxidized, or halogenated graphite material, wherein the graphite material is selected from the group consisting of natural graphite, artificial graphite, highly oriented pyrolytic graphite, carbon fiber, graphite fiber, carbon nano-fiber, graphitic nano-fiber, meso-carbon micro-bead, graphitized coke, and combinations thereof; (B) Dispersing the exfoliated graphite and an azide or bi-radical compound in a liquid medium to form a suspension; (C) Subjecting the suspension to ultrasonication with ultrasonic waves of a desired intensity for a length of time sufficient to produce nano graphene platelets and to enable a chemical reaction to occur between the nano graphene platelets and the azide or bi-radical compound to produce the functionalized nano graphene material. | 01-03-2013 |
20130005917 | Process for producing chemically functionalized nano graphene materials - Provided in this invention is a process for producing chemically functionalized nano graphene materials, known as nano graphene platelets (NGPs), graphene nano sheets, or graphene nano ribbons. Subsequently, a polymer can be grafted to a functional group of the resulting functionalized graphene. In one preferred embodiment, the process comprises a step of mixing a starting nano graphene material having edges and two primary graphene surfaces, an azide or bi-radical compound, and an organic solvent in a reactor, and allowing a chemical reaction between the nano graphene material and the azide compound to proceed at a temperature for a length of time sufficient to produce the functionalized nano graphene material. | 01-03-2013 |
20130045427 | Prelithiated current collector and secondary lithium cells containing same - The present invention provides a battery or supercapacitor current collector which is prelithiated. The prelithiated current collector comprises: (a) an electrically conductive substrate having two opposed primary surfaces, and (b) a mixture layer of carbon (and/or other stabilizing element, such as B, Al, Ga, In, C, Si, Ge, Sn, Pb, As, Sb, Bi, Te, or a combination thereof) and lithium or lithium alloy coated on at least one of the primary surfaces, wherein lithium element is present in an amount of 1% to 99% by weight of the mixture layer. This current collector serves as an effective and safe lithium source for a wide variety of electrochemical energy storage cells, including the rechargeable lithium cell (e.g. lithium-metal, lithium-ion, lithium-sulfur, lithium-air, lithium-graphene, lithium-carbon, and lithium-carbon nanotube cell) and the lithium ion based supercapacitor cell (e.g, symmetric ultracapacitor, asymmetric ultracapacitor, hybrid supercapacitor-battery, or lithium-ion capacitor). | 02-21-2013 |
20130059174 | Partially surface-mediated lithium ion-exchanging cells and method for operating same - A lithium super-battery cell comprising: (a) A cathode comprising a cathode active material having a surface area to capture or store lithium thereon, wherein the cathode active material is not a functionalized material and does not bear a functional group; (b) An anode comprising an anode current collector; (c) A porous separator disposed between the two electrodes; (d) A lithium-containing electrolyte in physical contact with the two electrodes, wherein the cathode active material has a specific surface area of no less than 100 m | 03-07-2013 |
20130087446 | One-step production of graphene materials - A method of producing exfoliated graphite or graphene from a graphitic or carbonaceous material. The method includes: (a) dispersing a graphitic material in a liquid intercalating agent to form a suspension; and (b) subjecting the suspension to microwave or radio frequency irradiation for a length of time sufficient for producing the exfoliated graphite or graphene. In one preferred embodiment, the intercalating agent is an acid or an oxidizer, or a combination of both. The method enables production of more electrically conducting graphene sheets directly from a graphitic material without going through the chemical intercalation or oxidation procedure. The process is fast (minutes as opposed to hours or days of conventional processes), environmentally benign, and highly scalable. | 04-11-2013 |
20130162216 | Stacks of internally connected surface-mediated cells and methods of operating same - An energy storage stack of at least two surface-mediated cells (SMCs) internally connected in parallel or in series. The stack includes: (A) At least two SMC cells, each consisting of (i) a cathode comprising a porous cathode current collector and a cathode active material; (ii) a porous anode current collector; and (iii) a porous separator disposed between the cathode and the anode; (B) A lithium-containing electrolyte in physical contact with all the electrodes, wherein the cathode active material has a specific surface area no less than 100 m | 06-27-2013 |
20130171502 | Hybrid electrode and surface-mediated cell-based super-hybrid energy storage device containing same - The present invention provides a multi-component hybrid electrode for use in an electrochemical super-hybrid energy storage device. The hybrid electrode contains at least a current collector, at least an intercalation electrode active material storing lithium inside interior or bulk thereof, and at least an intercalation-free electrode active material having a specific surface area no less than 100 m | 07-04-2013 |
20130190956 | Surface-mediated cell-powered vehicles and methods of operating same - This invention provides a vehicle powered by a surface-mediated cell (SMC)-based power source, comprising a vehicle frame, at least a wheel supporting the frame or a propeller connected to the frame, a drive unit connected to the wheel or propeller, and a power source electrically connected to the drive unit, wherein the power source contains at least a surface-mediated cell. The vehicle can be a micro-EV (using the SMC for the stop-start function), HEV, plug-in HEV, all-electric vehicle, power-assisted bicycle, scooter, motorcycle, tricycle, automobile, wheelchair, fork lift, golf cart, specialty vehicle, bus, truck, train, rapid-transit vehicle, boat, or air vehicle. The ultra-high power density enables the SMC to provide pulsed power or increased current demands when the vehicle is accelerating or hill-climbing. The SMC also enables the power source to recuperate the braking energy when the vehicle decelerates, brakes, or simply moves down-hill. | 07-25-2013 |
20130202945 | Surface-mediated cells with high power density and high energy density - A surface-mediated cell (SMC) comprising: (a) a cathode comprising a carbon-based cathode active material having a surface area to capture or store lithium thereon; (b) an anode comprising an anode current collector alone, or combined anode current collector and anode active material; (c) a porous separator disposed between the anode and the cathode; (d) a lithium-containing electrolyte, wherein the anode and/or cathode active material has a specific surface area no less than 100 m | 08-08-2013 |
20130212409 | Surface-mediated cell-powered portable computing devices and methods of operating same - This invention provides a portable computing device powered by a surface-mediated cell (SMC)-based power source, the portable device comprising a computing hardware sub-system and a rechargeable power source electrically connected to the hardware and providing power thereto, wherein the power source contains at least a surface-mediated cell. The portable computing device is selected from a laptop computer, a tablet, an electronic book (e-book), a smart phone, a mobile phone, a digital camera, a hand-held calculator or computer, or a personal digital assistant. | 08-15-2013 |
20130213677 | Surface-mediated cell-driven power tools and methods of operating same - A portable power tool comprises an electric motor, actuator, or light-emitting hardware and a rechargeable power source connected to the electric motor, actuator, or light-emitting hardware, wherein the power source contains at least a surface-mediated cell (SMC). The power tools include, but are not limited to, impact driver, air compressor, alligator shear, angle grinder, band saw, belt sander, biscuit joiner, ceramic tile cutter tile saw, chainsaw, circular saw, concrete saw, cold saw, crusher, diamond blade, diamond tools, disc sander, drill, floor sander, grinding machine, heat gun, impact wrench, jackhammer, jointer, jigsaw, lathe, miter saw, nail gun, needle scaler, torque wrench, powder-actuated tools, power wrench, radial arm saw, random orbital sander, reciprocating saw, rotary reciprocating saw, rotary tool, sabre saw, sander, scroll saw, steel cut off saw, table saw, thickness planer, trimmer, wall chaser, wood router, or flashlight. | 08-22-2013 |
20130216894 | Inorganic nano sheet-enabled lithium-exchanging surface-mediated cells - An inorganic material based surface-mediated cell (SMC) comprising (a) a cathode comprising a non-carbon-based inorganic cathode active material having a surface area to capture and store lithium thereon; (b) an anode comprising an anode current collector alone or both an anode current collector and an anode active material; (c) a porous separator; (d) a lithium-containing electrolyte in physical contact with the two electrodes, wherein the cathode has a specific surface area no less than 100 m | 08-22-2013 |
20130224603 | Lithium-ion cell having a high-capacity anode and a high-capacity cathode - A lithium-ion cell comprising: (A) a cathode comprising graphene as the cathode active material having a surface area to capture and store lithium thereon and wherein said graphene cathode is meso-porous having a specific surface area greater than 100 m | 08-29-2013 |
20130236715 | Graphene oxide gel bonded graphene composite films and processes for producing same - Disclosed is a graphene composite thin film composition composed of nano graphene platelets (NGPs) bonded by a graphene oxide binder, wherein the NGPs contain single-layer graphene or multi-layer graphene sheets having a thickness from 0.335 nm to 100 nm. The NGPs occupy a weight fraction of 1% to 99.9% of the total composite weight. The graphene oxide binder, having an oxygen content of 1-40% (preferably <10%) by weight based on the total graphene oxide weight, is obtained from a graphene oxide gel. The composite forms a thin film with a thickness no greater than 1 mm, but preferably no greater than 100 μm and no less than 10 μm. This composition has a combination of exceptional thermal conductivity, electrical conductivity, and mechanical strength unmatched by any thin-film material of comparable thickness range. | 09-12-2013 |
20130260246 | Lithium-ion cell having a high energy density and high power density - A lithium-ion cell comprising: (A) a cathode comprising graphene as the cathode active material having a surface area to capture and store lithium thereon and wherein said graphene cathode is meso-porous having a specific surface area greater than 100 m | 10-03-2013 |
20130264041 | Thermal management system containing an integrated graphene film for electronic devices - Disclosed is a graphene-based heat dissipation system for an electronic device, comprising: (a) an electronic device comprising a heat source, wherein the heat source transmits heat to a second component or an external surface of the electronic device; (b) a heat-conducting layer comprising two major surfaces, the heat-conducting layer being positioned such that one of its major surfaces is in operative contact with the heat source such that it is interposed between the heat source and the second component or the external surface of the electronic device; wherein the heat-conducting layer comprises at least one sheet of integrated graphene film which thermally shields the second component or the external surface of the electronic device from heat generated by the heat source. | 10-10-2013 |
20130271085 | Method of operating a lithium-ion cell having a high-capacity cathode - A method of operating a lithium-ion cell comprising (a) a cathode comprising a carbon or graphitic material having a surface area to capture and store lithium thereon; (b) an anode comprising an anode active material; (c) a porous separator disposed between the two electrodes; (d) an electrolyte in ionic contact with the two electrodes; and (e) a lithium source disposed in at least one of the two electrodes to obtain an open circuit voltage (OCV) from 0.5 volts to 2.8 volts when the cell is made; wherein the method comprises: (A) electrochemically forming the cell from the OCV to either a first lower voltage limit (LVL) or a first upper voltage limit (UVL), wherein the first LVL is no lower than 0.1 volts and the first UVL is no higher than 4.6 volts; and (B) cycling the cell between a second LVL and a second UVL. | 10-17-2013 |
20130302697 | Rechargeable magnesium-ion cell having a high-capacity cathode - A magnesium-ion cell comprising (a) a cathode comprising a carbon or graphitic material as a cathode active material having a surface area to capture and store magnesium thereon, wherein the cathode forms a meso-porous structure having a pore size from 2 nm to 50 nm and a specific surface area greater than 50 m | 11-14-2013 |
20130309561 | Rechargeable lithium cell having a phthalocyanine-based high-capacity cathode - A rechargeable lithium cell comprising: (a) an anode; (b) a cathode comprising a hybrid cathode active material composed of a graphene material and a phthalocyanine compound, wherein the graphene material is in an amount of from 0.1% to 99% by weight based on the total weight of the graphene material and the phthalocyanine compound combined; and (c) a porous separator disposed between the anode and the cathode and electrolyte in ionic contact with the anode and the cathode. This secondary cell exhibits a long cycle life and the best cathode specific capacity and best cell-level specific energy of all rechargeable lithium-ion cells ever reported. | 11-21-2013 |
20130319870 | Rechargeable dual electroplating cell - A dual electroplating cell comprising: (a) an electrolyte component containing therein ions of a first metal; (b) a porous cathode current collector having surface areas to capture and store metal ions directly thereon, wherein the cathode current collector has a specific surface area greater than 100 m | 12-05-2013 |
20130329366 | INTEGRATED GRAPHENE FILM HEAT SPREADER FOR DISPLAY DEVICES - Disclosed is an integrated graphene film-enhanced display device, comprising: (a) a display device which comprises one or multiple heat sources and a back surface where a localized area is at a higher temperature than an adjacent area; and (b) a heat spreader which comprises at least one sheet of integrated graphene film having two major surfaces, wherein one of the major surfaces of the heat spreader is in thermal contact with one or multiple heat sources and further wherein the heat spreader itself reduces the temperature difference between locations on the display device. The integrated graphene film, either a graphene film obtained from a graphene oxide gel or a graphene composite film formed of graphene oxide gel-bonded nano graphene platelets (NGPs), exhibits highest thermal conductivity and highest effectiveness in reducing hot spots in various kinds of display devices. | 12-12-2013 |
20130330611 | Rechargeable lithium cell having a meso-porous conductive material structure-supported phthalocyanine compound cathode - A rechargeable lithium cell comprising: (a) an anode comprising a prelithiated lithium storage material or a combination of a lithium storage material and a lithium ion source; (b) a hybrid cathode active material composed of a meso-porous structure of a carbon, graphite, metal, or conductive polymer and a phthalocyanine compound, wherein the meso-porous structure is in an amount of from 1% to 99% by weight based on the total weight of the meso-porous structure and the phthalocyanine combined, and wherein the meso-porous structure has a pore with a size from 2 nm to 50 nm to accommodate phthalocyanine compound therein; and (c) an electrolyte or electrolyte/separator assembly. This secondary cell exhibits a long cycle life and the best cathode specific capacity and best cell-level specific energy of all rechargeable lithium-ion cells ever reported. | 12-12-2013 |
20140030590 | Solvent-free process based graphene electrode for energy storage devices - Disclosed is an electrode for an electrochemical energy storage device, the electrode comprising a self-supporting layer of a mixture of graphene sheets and spacer particles and/or binder particles, wherein the electrode is prepared without using water, solvent, or liquid chemical. The graphene electrode prepared by the solvent-free process exhibits many desirable features and advantages as compared to the corresponding electrode prepared by a known wet process. These advantages include a higher electrode specific surface area, higher energy storage capacity, improved or higher packing density or tap density, lower amount of binder required, lower internal electrode resistance, more consistent and uniform dispersion of graphene sheets and binder, reduction or elimination of undesirable effect of electrolyte oxidation or decomposition due to the presence of water, solvent, or chemical, etc. | 01-30-2014 |
20140072871 | Rechargeable lithium cell having a chemically bonded phthalocyanine compound cathode - A rechargeable lithium cell comprising: (a) an anode comprising an anode active material; (b) a cathode comprising a hybrid cathode active material composed of an electrically conductive substrate and a phthalocyanine compound chemically bonded to or immobilized by the conductive substrate, wherein the phthalocyanine compound is in an amount of from 1% to 99% by weight based on the total weight of the conductive substrate and the phthalocyanine compound combined; and (c) electrolyte or a combination of electrolyte and a porous separator, wherein the separator is disposed between the anode and the cathode and the electrolyte is in ionic contact with the anode and the cathode. This secondary cell exhibits a long cycle life, the best cathode specific capacity, and best cell-level specific energy of all rechargeable lithium-ion cells ever reported. | 03-13-2014 |
20140072879 | Encapsulated phthalocyanine particles, high-capacity cathode containing these particles, and rechargeable lithium cell containing such a cathode - Disclosed is an electrode material comprising a phthalocyanine compound encapsulated by a protective material, preferably in a core-shell structure with a phthalocyanine compound core and a protective material shell. Also disclosed is a rechargeable lithium cell comprising: (a) an anode; (b) a cathode comprising an encapsulated or protected phthalocyanine compound as a cathode active material; and (c) a porous separator disposed between the anode and the cathode and/or an electrolyte in ionic contact with the anode and the cathode. This secondary cell exhibits a long cycle life, the best cathode specific capacity, and best cell-level specific energy of all rechargeable lithium-ion cells ever reported. | 03-13-2014 |
20140098461 | Spacer-modified graphene electrode for supercapacitor - A spacer-modified nano graphene platelet electrode, comprising: (a) multiple nano graphene platelets or sheets having an average thickness smaller than 10 nm; and (b) discrete, non-metallic nano-scaled particles that are disposed between two graphene platelets or sheets to serve as a spacer. In such a spacer-modified graphene electrode, large amounts of electrolyte-accessible pores are formed, enabling the formation of large amounts of electric double layer charges in a supercapacitor, which exhibits an exceptionally high specific capacitance. | 04-10-2014 |
20140124176 | Thermal management system containing a graphene oxide-coated graphitic foil laminate for electronic device application - A heat dissipation system, comprising: (a) an electronic device comprising a heat source, wherein the heat source transmits heat to a second component or an external surface of the device; (b) a heat-conducting layer being positioned such that one of its major surfaces is in operative contact with the heat source such that it is interposed between the heat source and the second component or the external surface. The heat-conducting layer comprises at least one graphene oxide-coated graphitic foil laminate which thermally shields the second component or the external surface from heat generated by the heat source, and wherein the laminate is composed of a graphitic substrate/core layer with at least one primary surface coated with a graphene oxide coating layer. This graphene oxide-coated laminate exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface hardness, and scratch resistance, making this the most effective heat dissipation system. | 05-08-2014 |
20140127488 | Graphene oxide-coated graphitic foil and processes for producing same - A graphene oxide-coated graphitic foil, composed of a graphitic substrate or core layer having two opposed primary surfaces and at least a graphene oxide coating layer deposited on at least one of the two primary surfaces, wherein the graphitic substrate layer has a thickness preferably from 0.34 nm to 1 mm, and the graphene oxide coating layer has a thickness preferably from 0.5 nm to 1 mm and an oxygen content of 0.01%-40% by weight based on the total graphene oxide weight. The graphitic substrate layer may be preferably selected from flexible graphite foil, graphene film, graphene paper, graphite particle paper, carbon-carbon composite film, carbon nano-fiber paper, or carbon nano-tube paper. This graphene oxide-coated laminate exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface smoothness, surface hardness, and scratch resistance unmatched by any thin-film material of comparable thickness range. | 05-08-2014 |
20140147648 | Unitary graphene layer or graphene single crystal - A unitary graphene layer or graphene single crystal containing closely packed and chemically bonded parallel graphene planes having an inter-graphene plane spacing of 0.335 to 0.40 nm and an oxygen content of 0.01% to 10% by weight, which unitary graphene layer or graphene single crystal is obtained from heat-treating a graphene oxide gel at a temperature higher than 100° C., wherein the average mis-orientation angle between two graphene planes is less than 10 degrees, more typically less than 5 degrees. The molecules in the graphene oxide gel, upon drying and heat-treating, are chemically interconnected and integrated into a unitary graphene entity containing no discrete graphite flake or graphene platelet. This graphene monolith exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface smoothness, surface hardness, and scratch resistance unmatched by any thin-film material of comparable thickness range. | 05-29-2014 |
20140154941 | Unitary graphene matrix composites containing carbon or graphite fillers - A unitary graphene matrix composite comprising: (a) a unitary graphene matrix containing an oxygen content of 0.001% to 10% by weight, obtained from heat-treating a graphene oxide gel at a temperature higher than 100° C. and contains no discrete graphene platelets derived from the graphene oxide gel; (b) a carbon or graphite filler phase selected from carbon or graphite fiber, carbon or graphite nano-fiber, carbon nano-tube, carbon nano-rod, meso-phase carbon particle, meso-carbon micro-bead, exfoliated graphite flake with a thickness greater than 100 nm, exfoliated graphite or graphite worm, coke particle, needle coke, carbon black or acetylene black particle, activated carbon particle, or a combination thereof. The carbon or graphite filler phase is preferably in a particulate, filamentary, or rod-like form dispersed in and bonded by the unitary graphene matrix. This composite exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface hardness, and scratch resistance. | 06-05-2014 |
20140182830 | Graphene composite hand-held and hand-heated thawing tool - The present invention provides a hand-held and hand-heated thawing tool comprising a handling portion and a functional portion wherein one or both portions comprises a composite material comprising 1-90% by weight of a conductivity-enhancing graphene phase dispersed in or bonded by a matrix material of 10-99% by weight based on a total composite weight, and wherein the handling portion, when being held by a human hand, transfers heat from the hand to the functional portion for thawing or melting a food item, such as butter and ice cube. By holding such a tool, a person can use his or her own body heat to rapidly thaw a slice of butter, or melt and cut through a block of ice without the assistance of any other heating tool (e.g. an oven). | 07-03-2014 |
20140190676 | Unitary graphene material-based integrated finned heat sink - A unitary graphene-based integrated heat sink comprising a heat collection member (base) and at least one heat dissipation member (e.g. fins) integral to the baser, wherein the base is configured to be in thermal contact with a heat source, collects heat therefrom, and dissipates heat through the fins. The unitary graphene material is obtained from heat-treating a graphene oxide gel at a temperature higher than 100° C., 500° C., 1,250° C., or 2,000° C., and contains chemically bonded graphene molecules having inter-graphene distance of 0.3354-0.4 nm (preferably <0.337 nm). The unitary graphene material is a graphene single crystal, a poly-crystal with incomplete grain boundaries, or a poly-crystal having large grain sizes (e.g. >mm or cm), exhibiting a degree of graphitization preferably from 1% to 100% and a Mosaic spread value less than 0.7 (preferably no greater than 0.4). The finned heat sink may also be made from a filler-reinforced graphene matrix composite. | 07-10-2014 |
20140209168 | Inorganic coating-protected unitary graphene material for concentrated photovoltaic applications - This invention provides an inorganic coating-protected unitary graphene material article for concentrated photovoltaic cell heat dissipation. The article comprises at least a layer of unitary graphene material having two primary surfaces and an electrically non-conducting layer of inorganic coating deposited on at least one of the primary surfaces, wherein the unitary graphene material is obtained from heat-treating a graphene oxide gel at a heat treatment temperature higher than 100° C. and contains chemically bonded graphene molecules or chemically merged graphene planes having an inter-graphene spacing no greater than 0.40 nm, preferably less than 0.337 nm, and most preferably less than 0.3346 nm. | 07-31-2014 |
20140231718 | Process for Producing Highly conducting and Transparent Films From Graphene Oxide-Metal Nanowire Hybrid Materials - A process for producing a transparent conductive film, comprising (a) providing a graphene oxide gel; (b) dispersing metal nanowires in the graphene oxide gel to form a suspension; (c) dispensing and depositing the suspension onto a substrate; and (d) removing the liquid medium to form the film. The film is composed of metal nanowires and graphene oxide with a metal nanowire-to-graphene oxide weight ratio from 1/99 to 99/1, wherein the metal nanowires contain no surface-borne metal oxide or metal compound and the film exhibits an optical transparence no less than 80% and sheet resistance no higher than 300 ohm/square. This film can be used as a transparent conductive electrode in an electro-optic device, such as a photovoltaic or solar cell, light-emitting diode, photo-detector, touch screen, electro-wetting display, liquid crystal display, plasma display, LED display, a TV screen, a computer screen, or a mobile phone screen. | 08-21-2014 |
20140235123 | Highly conducting and transparent film and process for producing same - An optically transparent and electrically conductive film composed of metal nanowires or carbon nanotubes combined with pristine graphene with a metal nanowire-to-graphene or carbon nanotube-to-graphene weight ratio from 1/99 to 99/1, wherein the pristine graphene is single-crystalline and contains no oxygen and no hydrogen, and the film exhibits an optical transparence no less than 80% and sheet resistance no higher than 300 ohm/square. This film can be used as a transparent conductive electrode in an electro-optic device, such as a photovoltaic or solar cell, light-emitting diode, photo-detector, touch screen, electro-wetting display, liquid crystal display, plasma display, LED display, a TV screen, a computer screen, or a mobile phone screen. | 08-21-2014 |
20140242275 | Process for producing unitary graphene materials - A process for producing a unitary graphene material, comprising: (a) preparing a graphene oxide (GO) gel having GO molecules dissolved in a fluid medium wherein the GO molecules contain higher than 20% by weight of oxygen; (b) dispensing and depositing a layer of GO gel onto a surface of a substrate to form a layer of deposited GO gel thereon, wherein the dispensing and depositing procedure includes shear-induced thinning; (c) removing the fluid medium from the deposited GO gel to form a GO layer having an inter-plane spacing d | 08-28-2014 |
20140272172 | Method for producing conducting and transparent films from combined graphene and conductive nano filaments - A method of producing a transparent and conductive film, comprising (a) forming aerosol droplets of a first dispersion comprising a first conducting nano filaments in a first liquid; (b) forming aerosol droplets of a second dispersion comprising a graphene material in a second liquid; (c) depositing the aerosol droplets of a first dispersion and the aerosol droplets of a second dispersion onto a supporting substrate; and (d) removing the first liquid and the second liquid from the droplets to form the film, which is composed of the first conducting nano filaments and the graphene material having a nano filament-to-graphene weight ratio of from 1/99 to 99/1, wherein the film exhibits an optical transparence no less than 80% and sheet resistance no higher than 300 ohm/square. | 09-18-2014 |
20140272199 | Ultrasonic spray coating of conducting and transparent films from combined graphene and conductive nano filaments - An ultrasonic spray coating method of producing a transparent and conductive film, comprising (a) operating an ultrasonic spray device to form aerosol droplets of a first dispersion comprising a first conducting nano filaments in a first liquid; (b) forming aerosol droplets of a second dispersion comprising a graphene material in a second liquid; (c) depositing the aerosol droplets of a first dispersion and the aerosol droplets of a second dispersion onto a supporting substrate; and (d) removing the first liquid and the second liquid from the droplets to form the film, which is composed of the first conducting nano filaments and the graphene material having a nano filament-to-graphene weight ratio of from 1/99 to 99/1, wherein the film exhibits an optical transparence no less than 80% and sheet resistance no higher than 300 ohm/square. | 09-18-2014 |
20140308449 | Process for producing continuous graphitic fibers from living graphene molecules - A process for producing a continuous graphitic fiber, comprising: (a) preparing a graphene oxide gel having living graphene oxide molecules or functionalized graphene chains dissolved in a fluid medium; (b) depositing at least a continuous filament of graphene oxide gel onto a supporting substrate under a condition of stress-induced molecular alignment of living graphene oxide molecules along a filament axis direction; (c) removing the fluid medium to form a continuous graphene oxide fiber, having an inter-plane spacing d | 10-16-2014 |
20140308517 | Continuous graphitic fibers from living graphene molecules - A unitary graphene-based continuous graphitic fiber comprising at least 90% by weight of graphene planes that are chemically bonded with one another having an inter-planar spacing from 0.3354 to 0.4 nm and an oxygen content of 0.01 to 5% by weight, wherein the graphene planes are parallel to one another and parallel to a fiber axis direction and the graphitic fiber contains no core-shell structure, have no helically arranged graphene domains, and have a porosity level less than 5% by volume. This fiber can be produced by a continuous filament of graphene oxide gel having living graphene oxide molecules or functionalized graphene chains dissolved in a fluid medium. The filament is deposited onto a supporting substrate under a molecule-aligning stress condition along the filament axis direction and then subjected to drying and heating treatments. | 10-16-2014 |
20140315100 | Rechargeable lithium-sulfur battery having a high capacity and long cycle life - A rechargeable lithium-sulfur cell comprising an anode, a separator and/or electrolyte, a sulfur cathode, an optional anode current collector, and an optional cathode current collector, wherein the cathode comprises (a) exfoliated graphite worms that are interconnected to form a porous, conductive graphite flake network comprising pores having a size smaller than 100 nm; and (b) nano-scaled powder or coating of sulfur, sulfur compound, or lithium polysulfide disposed in the pores or coated on graphite flake surfaces wherein the powder or coating has a dimension less than 100 nm. The exfoliated graphite worm amount is in the range of 1% to 90% by weight and the amount of powder or coating is in the range of 99% to 10% by weight based on the total weight of exfoliated graphite worms and sulfur (sulfur compound or lithium polysulfide) combined. The cell exhibits an exceptionally high specific energy and a long cycle life. | 10-23-2014 |
20140342209 | Lithium-sulfur secondary battery containing gradient electrolyte - A rechargeable lithium-sulfur cell comprising a cathode, an anode, a separator electronically separating the two electrodes, a first electrolyte in contact with the cathode, and a second electrolyte in contact with the anode, wherein the first electrolyte contains a first concentration, C | 11-20-2014 |
20140342249 | Lithium secondary batteries containing lithium salt-ionic liquid solvent electrolyte - A rechargeable lithium metal or lithium-ion cell comprising a cathode having a cathode active material and/or a conductive supporting structure, an anode having an anode active material and/or a conductive supporting nano-structure, a porous separator electronically separating the anode and the cathode, a highly concentrated electrolyte in contact with the cathode active material and the anode active material, wherein the electrolyte contains a lithium salt dissolved in an ionic liquid solvent with a concentration greater than 3 M. The cell exhibits an exceptionally high specific energy, a relatively high power density, a long cycle life, and high safety with no flammability. | 11-20-2014 |
20140363746 | Lithium secondary batteries containing non-flammable quasi-solid electrolyte - A rechargeable lithium cell comprising a cathode having a cathode active material, an anode having an anode active material, a porous separator electronically separating the anode and the cathode, a non-flammable quasi-solid electrolyte in contact with the cathode and the anode, wherein the electrolyte contains a lithium salt dissolved in a first organic liquid solvent with a concentration sufficiently high so that the electrolyte exhibits a vapor pressure less than 0.01 kPa when measured at 20° C., a flash point at least 20 degrees Celsius higher than the flash point of the first organic liquid solvent alone, a flash point higher than 150° C., or no flash point. This battery cell is non-flammable and safe, has a long cycle life, high capacity, and high energy density. | 12-11-2014 |
20150021196 | Electrochemical method of producing nano graphene platelets - A method of producing nano-scaled graphene platelets with an average thickness smaller than 30 nm from a layered graphite material. The method comprises (a) forming a carboxylic acid-intercalated graphite compound by an electrochemical reaction; (b) exposing the intercalated graphite compound to a thermal shock to produce exfoliated graphite; and (c) subjecting the exfoliated graphite to a mechanical shearing treatment to produce the nano-scaled graphene platelets. Preferred carboxylic acids are formic acid and acetic acid. The exfoliation step in the instant invention does not involve the evolution of undesirable species, such as NO | 01-22-2015 |
20150024121 | Process for producing non-flammable quasi-solid electrolyte and electrolyte-separator for lithium battery applications - A process for producing a separator-electrolyte layer for use in a lithium battery, comprising: (a) providing a porous separator; (b) providing a quasi-solid electrolyte containing a lithium salt dissolved in a first liquid solvent up to a first concentration no less than 3 M; and (c) coating or impregnating the separator with the electrolyte to obtain the separator-electrolyte layer with a final concentration ≧the first concentration so that the electrolyte exhibits a vapor pressure less than 0.01 kPa when measured at 20° C., a vapor pressure less than 60% of that of the first liquid solvent alone, a flash point at least 20 degrees Celsius higher than a flash point of the first liquid solvent alone, a flash point higher than 150° C., or no detectable flash point. A battery using such a separator-electrolyte is non-flammable and safe, has a long cycle life, high capacity, and high energy density. | 01-22-2015 |
20150024248 | Non-flammable quasi-solid electrolyte-separator layer product for lithium battery applications - A separator-electrolyte layer product for use in a lithium battery, comprising: (a) a porous thin-film separator selected from a porous polymer film, a porous mat, fabric, or paper made of polymer or glass fibers, or a combination thereof, wherein the separator has a thickness less than 500 μm; and (b) a non-flammable quasi-solid electrolyte containing a lithium salt dissolved in a liquid solvent up to a concentration no less than 3 M; wherein the porous thin-film separator is coated with the quasi-solid electrolyte so that the layer product exhibits a vapor pressure less than 0.01 kPa when measured at 20° C., a vapor pressure less than 60% of the vapor pressure of the liquid solvent alone, a flash point at least 20 degrees Celsius higher than a flash point of the first liquid solvent alone, a flash point higher than 150° C., or no detectable flash point. | 01-22-2015 |
20150028263 | Methods for mass-producing silicon nano powder and graphene-doped silicon nano powder - Disclosed is a facile and cost effective method of producing nano silicon powder or graphene-doped silicon nano powder having a particle size smaller than 100 nm. The method comprises: (a) preparing a silicon precursor/graphene nano composite; (b) mixing the silicon precursor/graphene nano composite with a desired quantity of magnesium; (c) converting the silicon precursor to form a mixture of graphene-doped silicon and a reaction by-product through a thermal and/or chemical reduction reaction; and (d) removing the reaction by-product from the mixture to obtain graphene-doped silicon nano powder. | 01-29-2015 |
20150037530 | Impregnated continuous graphitic fiber tows and composites containing same - An impregnated fiber tow comprising multiple unitary graphene-based continuous graphitic fibers impregnated with a matrix material, wherein at least one of the continuous graphitic fibers comprises at least 90% by weight of graphene planes that are chemically bonded with one another having an inter-planar spacing d | 02-05-2015 |
20150038041 | Fabric of continuous graphitic fiber yarns from living graphene molecules - Multi-functional and high-performing fabric comprising a first layer of yarns woven to form the fabric wherein the yarns comprise at least one unitary graphene-based continuous graphitic fiber comprising at least 90% by weight of graphene planes that are chemically bonded with one another having an inter-planar spacing d | 02-05-2015 |
20150044556 | Cathode active material-coated discrete graphene sheets for lithium batteries and process for producing same - The present invention provides a cathode (positive electrode) of a lithium battery and a process for producing this cathode. The electrode comprises a cathode active material-coated graphene sheet and the graphene sheet has two opposed parallel surfaces, wherein at least 50% area (preferably >80%) of one of the two surfaces is coated with a cathode active material coating. The graphene material is in an amount of from 0.1% to 99.5% by weight and the cathode active material is in an amount of at least 0.5% by weight (preferably >80% and more preferably >90%), all based on the total weight of the graphene material and the cathode active material combined. The cathode active material is preferably an inorganic material, an organic or polymeric material, a metal oxide/phosphate/sulfide, or a combination thereof. The invention also provides a lithium battery, including a lithium-ion, lithium-metal, or lithium-sulfur battery. | 02-12-2015 |
20150044564 | Anode containing active material-coated graphene sheets and lithium-ion batteries containg same - The present invention provides an anode electrode of a lithium-ion battery, comprising an anode active material-coated graphene sheet, wherein the graphene sheet has two opposed parallel surfaces and at least 50% area of one of the surfaces is coated with an anode active material and wherein the graphene material is in an amount of from 0.1% to 99.5% by weight and the anode active material is in an amount of at least 0.5% by weight (preferably at least 60%), all based on the total weight of the graphene material and the anode active material combined. | 02-12-2015 |
20150044565 | Anode active material-coated graphene sheets for lithium batteries and process for producing same - The present invention provides a process for producing a graphene-enhanced anode active material for use in a lithium battery. The process comprises (a) providing a continuous film of a graphene material into a deposition zone; (b) introducing vapor or atoms of a precursor anode active material into the deposition zone, allowing the vapor or atoms to deposit onto a surface of the graphene material film to form a sheet of an anode active material-coated graphene material; and (c) mechanically breaking this sheet into multiple pieces of anode active material-coated graphene; wherein the graphene material is in an amount of from 0.1% to 99.5% by weight and the anode active material is in an amount of at least 0.5% by weight, all based on the total weight of the graphene material and the anode active material combined. | 02-12-2015 |
20150064574 | Non-flammable quasi-solid electrolyte and non-lithium alkali metal or alkali-ion secondary batteries containing same - A non-flammable quasi-solid electrolyte and a rechargeable non-lithium alkali metal cell containing this electrolyte. The electrolyte comprises an alkali metal salt dissolved in an organic liquid solvent with a concentration higher than 2.5 M (preferably >3.5 M) or a molecular ratio greater than 0.2 (preferably >0.3), wherein the alkali metal is selected from Na, K, a combination of Na and K, or a combination of Na and/or K with Li. The alkali metal salt concentration is sufficiently high so that the electrolyte exhibits a vapor pressure <0.01 kPa when measured at 20° C., a vapor pressure <60% of the vapor pressure of thet organic solvent when measured alone, a flash point at least 20 degrees Celsius higher than a flash point of the organic liquid solvent when measured alone, a flash point higher than 150° C., or no detectable flash point. | 03-05-2015 |
20150064575 | Lithium-Selenium secondary batteries having non-flammable electrolyte - A rechargeable lithium-selenium cell comprising a cathode having a cathode active material selected from Se or Se | 03-05-2015 |
20150086881 | Large-grain graphene thin film current collector and secondary batteries containing same - A unitary graphene-based current collector in a battery or capacitor. The current collector is or contains a unitary graphene layer that is composed of closely packed and chemically bonded parallel graphene planes having an inter-graphene plane spacing of 0.335 to 0.40 nm and an oxygen content less than 5% by weight (more typically 0.001% to 1%), an average grain size larger than 5 μm (more typically >100 μm; some as large as >cm), a physical density higher than 1.8 g/cm | 03-26-2015 |