Co/SiO_x/C复合负极材料的制备及电化学性能研究

Preparation and electrochemical performance of Co/SiO_x/C composite as anode material for lithium-ion batteries

以CoCl2·6 H2O、正硅酸乙酯(TEOS)、蔗糖为原料,水热法制备Co/SiO_x/C复合负极材料,采用X射线衍射(XRD)、扫描电子显微镜(SEM)及恒电流充放电测试等方法研究了热处理温度和Co/Si摩尔比对复合材料组成、颗粒形貌和电化学性能的影响。结果表明,煅烧温度为500℃、Co/Si摩尔比为1/5时制备的复合材料表现出优异的循环性能和较高的比容量,50次循环后可逆比容量保持在763.1 m Ah/g。随钴元素含量的增加,复合材料的首次库仑效率有所提高。

The Co/SiO_x/C composite anode materials were prepared via hydrothermal method using TEOS,Co Cl2·6 H2 O and sucrose.The effects of the heat-treatment temperature and mol ratio of Co/Si on the phase composition,particle morphology,structure and electrochemical performance of the prepared Co/SiO_x/C composites were investigated by SEM,XRD and constant current charge-discharge tests.The results reveal that the Co/SiO_x/C composite synthesized by the Co/Si mol ratio of 1/5 at 500 ℃ exhibits excellent specific capacity.The reversible specific capacities remain 763.1 m Ah/g after 50 cycles.The first coulombic efficiency of the composites increases with the increase of the concentration of Co.