| 摘要 |
PURPOSE:To provide a non-aqueous secondary battery at a low cost, which has high energy density, a small self-discharging factor, and offers long cycle charging/discharging, by occluding metal ions at the time of charging, and making a neg. electrode consisting of specified fiber-form carbon material which is capable of performing release at the time of discharging. CONSTITUTION:The fiber-form carbon material shall preferably have a dia. between 0.1-1.0mum, and further be favorable if the fiber is graphite type carbon fiber prepared by the gas phase growth method. The amount of fiber-form carbon material of a neg. electrode small be at least 20 wt.% in order to maintain the reversibility. In case graphite type carbon fiber is used to the neg. electrode of a battery, it is important to increase the bulk density of the electrode to a certain degree even for increasing the energy density. Examples of alkali metal to be occluded and released in/from the graphite type carbon fiber according to the present invention are Li, Na, and K, among which Na can less be occluded and released in/from the carbon fiber while K has a melting point of 64 deg.C which is considered to be too low. Therefore, the optimum alkali metal is Li. |
