POLYMER ELECTROLYTES REINFORCED BY CELGARD(R) MEMBRANES

Solid polymer electrolytes have been prepared by encapsulating plastic ized polymer electrolytes based on poly(tetraethylene glycol diacrylat e) into the pores of Celgard(8) microporous membranes. Electrolyte mem branes with thicknesses of similar to 40 mu m have been prepared. The conductivity of the electrolyte is determined by the porosity of the m embrane. and a conductivity of similar to 2 x 10(-4) Ohm(-1) . cm(-1) at room temperature has been demonstrated. These electrolytes showed g ood compatibility with Li and an electrochemical stability window span ning the range of 0.0 to similar to 4.5 V vs. Li+/Li. The excellent ch emical and electrochemical stabilities enabling the use of the membran es in rechargeable Li batteries have been confirmed by the discharge/c harge cycling of Li/solid polymer electrolyte/LiMn2O4 cells at room te mperature.