POLARIZATION BEHAVIOR OF LITHIUM ELECTRODE IN SOLID ELECTROLYTES CONSISTING OF A POLY(ETHYLENE OXIDE)-GRAFTED POLYMER

A complex of poly(ethylene oxide)-grafted poly(methyl)-methacrylate (PEO-PMMA) with a lithium salt has been examined as a solid electrolyte of an ambient-temperature rechargeable lithium battery. The electrolyte film was prepared by radical polymerization of PEO-grafted methacrylate which contained a lithium salt dissolved in poly(ethylene glycol) dimethyl ether. The resulting composite had a high conductivity of 10−4 S cm−1 at room temperature. The rate of charge transfer at the lithium electrode/polymeric electrolyte interface was high, and the ion transfer in the bulk electrolyte was rate-determining at high cathodic polarization. The coulombic efficiency of lithium during the charge-discharge cycle depended on the cycling current density. The average efficiency reached 88% at 50 µA cm−2 cycling when an A1 plate was used as a substrate. © 1990, The Electrochemical Society, Inc. All rights reserved.