Electrochemical Properties of LiCoO2-Coated LiMn2O4 Prepared by Solution-Based Chemical Process

Abstract

In order to enhance both the cycle stability at elevated temperatures and the rate capability of LiMn2O4, the surface of LiMn2O4 was covered with fine LiCoO2 particles prepared by a solution-based chemical process. The amount of LiCoO2 measured with inductively coupled plasma was about 7 mol %. LiCoO2-coated LiMn2O4 had an excellent cycle stability at 65 degreesC compared to pure LiMn2O4. This can be explained by suppression of the Mn dissolution. The rate capability of. LiCoO2-coated LiMn2O4 improved significantly. The improved rate capability may be attributed to a decrease in the passivation film that acts as an electronic insulating layer and interparticle contact resistance. Consequently, it is proposed that the surface encapsulation of LiMn2O4 with LiCoO2 improves its rate capability and cycling stability at high temperatures. (C) 2001 The Electrochemical Society.