NONAQUEOUS SECONDARY-BATTERY

摘要

PURPOSE:To improve the electric charging and discharging cycle characteristics of a nonaqueous secondary-battery by using as a binding agent for the positive electrode of the nonaqueous secondary-battery a material whose heat-resisting temperature is not less than the characteristic temperature and which has rubber elasticity. CONSTITUTION:A nonaqueous secondary-battery has a negative electrode using as its active material a material which can reversibly store and emit lithium or its ion, and a positive electrode having an intercalating type active material which can be reversibly charged and discharged with the lithium ion. As a binding agent for the positive electrode is used a material which has rubber elasticity and whose heat- resisting temperature is not less than 200 degrees Centigrade. A material being used for the binding agent is fluororubber consisting mainly of a copolymer consisting of hexafluoropropylene and vinylidene fluoride, or another fluororubber consisting mainly of a copolymer consisting of trifluorochloroethylene and vinylidene fluoride. Thus contact between the positive electrode active-material and a conducting agent or between the positive electrode and a current collector can be kept in its excellent condition so as to effectively use the positive electrode active-material without lowering the binding characteristic of the binding agent even if electric charge-and-discharge causes the expansion and construction of active-material grains.