Novel polymer electrolytes for rechargeable lithium-ion polymer batteries

Lithium-ion polymer cells employing a carbon anode, a gel polymer electroly te (GPE), and a lithium cobalt oxide cathode were assembled, and their char ge-discharge cycling characteristics were investigated. Gel polymer electro lytes were prepared by encapsulating an organic electrolyte solution in an acrylonitrile-methyl methacrylate-styrene terpolymer. A small amount of gam ma-butyrolactone was added to a gel polymer electrolyte containing an LiBF4 -ethylene carbonate-dimethyl carbonate electrolyte solution in order to imp rove the GPE ionic conductivity. Results showed a significant enhancement i n rate capability, whereas cycling efficiency and cyclability were little c hanged. (C) 1999 The Electrochemical Society. S1099-0062(99)01-018-4. All r ights reserved.