20090135548 | Positive Electrode for Electric Double Layer Capacitors, and Electric Double Layer Capacitors - The present invention provides a positive electrode for electric double layer capacitors which can improve basic characteristics, such as energy density, of electric double layer capacitors and also can improve electric double layer capacitors in useful life and stability under high temperatures. Provided is a positive electrode for electric double layer capacitors comprising as electrode active materials a carbonaceous material having a ratio of rhombohedral crystal structure to hexagonal crystal structure in crystal structure of carbon within the range of not less than 20%. | 05-28-2009 |