Improved Elevated Temperature Cycling of LiMn[sub 2]O[sub 4] Spinel Through the Use of a Composite LiF-Based Electrolyte

Abstract

A composite electrolyte containing LiF and a tris(pentafluorophenyl)borane (TPFPB) anion complexing agent displays superior thermal and electrochemical stability compared to commercial -based electrolytes. Severe capacity fading of a cell, with a commercial electrolyte, was observed when cycled at 55°C. The capacity fading was attributed to acidic products, from salt hydrolysis and decomposition of the solvent, which degraded electrode. The composite electrolyte containing LiF and TPFPB is not moisture sensitive and does not produce acidic species. At room temperature, the composite electrolyte shows an improvement in capacity maintenance with cycling. However, at 55°C the improvement is much greater. © 2001 The Electrochemical Society. All rights reserved.