| 摘要 |
PROBLEM TO BE SOLVED: To prevent deterioration of the strength of a positive electrode due to repetition of charge and discharge, by using a fluororubber having rubber-elasticity and having a specific heat-resisting temperature, as a positive-electrode binder mixed with a positive-electrode active material of an intercalation-type lithium-manganese oxide capable of reversibly charging/discharging lithium ions, and pressed and then heat-treated. SOLUTION: Because a positive-electrode binder has rubber-elasticity, when it is used with a large-capacity intercalation-type positive-electrode active material and particles thereof are expanded/contracted by charge/discharge, its binding property is not lowered and contact is kept satisfactory between the active material and a conductive agent and between a positive electrode and a collector. Its heat-resisting temperature is adapted to be 200 deg.C or more that is higher than the heat-treatment temperature of the positive electrode, and therefore the binder is not deteriorated by heating and water does not remain in the positive electrode. Preferably, a fluororubber has, as a main constituent, a copolymer of hexafluoropropylene or hexafluorochloroethylene and vinylidene fluoride. A negative electrode includes a material capable of reversibly storing/releasing lithium or lithium ions. |
