LiCoO_2的形貌与结构对其电化学性能的影响

Influence of morphology and structure of LiCoO_2 on its electrochemical performance

研究了对电极界面状态有重要影响的LiCoO2物理参数如粒径分布、比表面积及表面形貌等对LiCoO2电化学性能的影响。研究结果表明:粒径及比表面积对LiCoO2电极的容量循环稳定性及电压循环稳定性有较大的影响;适宜的粒径分布有助于提高LiCoO2电极的循环稳定性,过大的比表面积会使电极循环稳定性急剧下降;随着晶块尺寸的减小,LiCoO2材料在大电流下的放电性能得到改善;在优化条件下合成的LiCoO2样品具有最佳的高倍率性能、较高的容量及电压循环稳定性。

The influence of physical parameters, such as particle distribution, specific surface area and morphology, which play an important role on the electrochemical behavior of LiCoO_2 was investigated. The results show that the particle size and specific surface area have a great effect on the stability of capacity and voltage cycling performance of LiCoO_2. A narrow particle size distribution is favorable for the improvement of cycling performance of LiCoO_2, while too large specific surface area can sharply deteriorate its performance. With the decrease of the crystal size, the charge/discharge performance in heavy drain is improved. Under the optimum conditions, the synthesized LiCoO_2 shows excellent high rate performance, high capacity and stable voltage performance.