LiMn2O4 for 4 V lithium-ion batteries

LiMn2O4 spinel samples, synthesized by the reaction of Li2CO3 and MnCO3 in air in several steps, have been evaluated as the electrode materials in 4 V lithium-ion cells. It was shown that the synthesis in the temperature range 500-750 degrees C leads to compounds with very poor electrochemical behavior. This is explained by a model of the chemistry of LiMn2O4 preparation proposed by Howard. On the basis of this model a new scheme of LiMn2O4 preparation is proposed. It was established experimentally that compounds with very high electrochemical characteristics can be obtained by a stepwise synthesis process, proceeding at three narrow temperature intervals.