SiO_2表面包覆锂离子电池阴极材料LiMn_2O_4及对其性能影响研究

Research on Surface Modification of Lithium-ion Battery Cathode Material LiMn_2O_4 by Coating SiO_2 and Difference on Their Electrochemical Performance

锰酸锂(LiMn2O4)是作为目前性价比最高的商业化锂离子电池正极材料,成为近年来电池研究的热点。但该材料在高温时,由于Mn离子较易溶解于电解液中,制约其广泛应用。本研究中,采用SiO2对其表面进行包覆,减少了活性材料与电解液的直接接触。并通过X-射线衍射、扫描电镜(SEM)、充放电循环测试对合成产物的组成、结构、形貌和电化学性能进行表征,进而研究影响产品的高温性能的主要因素,并筛选出较为合适的改性条件以提高锂电池正极材料LiMn2O4的电化学性能。

Lithium manganese oxide, as a future cathode material for Li-ion batteries, has become one of most focused material in recent years. But its poor high-temperature performance hinders its further application. In this research, SiO2 was used to modify the surface of this material. And X-ray diffraction （XRD）, scanning electron microscopy （SEM） and charge-discharge test were employed to examine the composition, structure, morphology and electrochemical performance of the modified product, then main factors to affect its high-temperature performance were studied, the suitable modification conditions were determined to improve the electrochemical performance of lithium nickel-manganese oxide （LiMn2O4） in the lithium-ion battery.