LiCoO_2表面沉积ZrO_2涂层的结构和电化学性能

为了提高LiCoO2材料的电化学性能,采用浸渍的方法,在LiCoO2的表面沉积纳米ZrO2涂层.将Zr(OH)x(CH3COO)y溶解在去离子水中,然后浸入LiCoO2,经超声波处理,蒸发溶剂,最后高温焙烧后,得到产物.用X射线吸收近边光谱(XANES)对涂层后的LiCoO2结构进行测试,检测涂层对其结构的作用效果.循环伏安实验结果表明,涂层对电极材料的氧化和还原行为有影响.恒电流充放电结果表明,LiCoO2沉积ZrO2涂层后,常温下性能改变较小,但是可以提高其在较高温度(如55℃)下的充放电性能.

On the Structure and Electrochemical Properties of LiCoO2 with Nanograde ZrO2 Coating

To improve the electrochemical properties of LiCoO2, a nanograde ZrO2 coating was deposited on it via impregnation. With the Zr(OH)x (CH3COO)y dissolved in deionized water,the LiCoO2 powder was immersed in the solution. Then, the LiCoO2 with ZrO2 coating was obtained after ultrasonic agitation, solvent evaporation and calcination at high temperature. X-ray absorption near edge spectrum(XANES)was used to investigate the structure of coated LiCoO2 and check the effect of the coating on the structure. The results of cyclic voltammogram testing showed that the ZrO2 coating can affect both the oxidation and reduction processes of LiCoO2.The results of charge/discharge tests revealed that the electro chemical properties of LiCoO2 change little at normal temperature after coating, but its charging/discharging efficiency can be improved at higher temperature, e.g. ,55℃.