Improved composite materials for rechargeable lithium metal polymer batteries

The performance of several polymer electrolytes for lithium metal batteries for electric vehicle applications are reported. The best performing electrolyte is the composite PEO20LiCF3SO3-gamma LiAlO2, which was prepared by a solvent-free procedure. It showed coulombic efficiency values of the lithium deposition-stripping process of 94%-96%. Electrochemical tests of lithium polymer battery (LPB) prototypes based on a 3 V LiMn2O4 composite cathode material laminated together with the PEO20LiCF3SO3-gamma LiAlO2 electrolyte gave promising results for electric vehicle applications. Even under non-optimized battery design, the prototypes delivered, at the C/3 rate and at 94 degrees C, 40%-30% of theoretical capacity over 100 charge-discharge cycles. (C) 1999 Elsevier Science S.A. All rights reserved.