STABILIZED OXYGEN STOICHIOMETRIC LITHIUM MANGANESE SPINEL CATHODES (Li, Mn, M)_3O_(4+δ) AT ELEVATED TEMPERATURES

摘要

A new type of oxygen stoichiometric metal-doped LiMn2O4 spinel materials were prepared with an optimized "two-step" method: first, the mixtures of LiOH, manganese and other metal oxides were calcinated at temperatures above 900℃ to get an intermediate product with slightly oxygen defect; then the intermediate product was heat treated at 600～800℃ after mixed and ground with an extra LiOH to obtain the final product of oxygen stoichiometric. The role of heat treatment with LiOH is to control the oxygen content in the spinel structure, and the oxygen defect in the intermediate product would be removed. This new kind materials exhibited greatly improved cycle performance and reduced Mn dissolution at elevated temperatures for promising application in practical Li-ion Batteries.