Electrochemical properties of LiCoO2-coated LiMn2O4 prepared by solution-based chemical process

In order to enhance both the cycle stability at elevated temperatures and t he 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 %. LiCo O2-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 passivatio n film that acts as an electronic insulating layer and interparticle contac t resistance. Consequently, it is proposed that the surface encapsulation o f LiMn2O4 with LiCoO2 improves its rate capability and cycling stability at high temperatures. (C) 2001 The Electrochemical Society.