Mechanochemical synthesis and electrochemical properties of LiMn2O4

Abstract

Spinel LiMn2O4 as a cathode material for lithium secondary batteries has been synthesized by a mechanochemical process, and its electrochemical properties have been characterized. Highly disordered nanocrystalline LiMn2O4 powders have been prepared by the mechanochemical processing of Li2O and MnO2 powder mixtures for 24 h. Electrochemical characterization of mechanochemically processed powder has shown that the intercalation of Li+ takes place with an initial capacity of 167 mA.h/g in the 2.5-4.3 V range and has better capacity retention as compared to the well-ordered crystalline LiMn2O4 powders. The better capacity retention of the mechanochemically processed LiMn2O4 powder may be attributed to the highly disordered structure that could accommodate the Jahn-Teller distortion of the spinel structure during Li+ intercalation around the 3 V region.