物理化学学报 >> 2012, Vol. 28 >> Issue (02): 343-348.doi: 10.3866/PKU.WHXB201111031

电化学和新能源 上一篇    下一篇

溶胶-凝胶法制备LiCoPO4及其电化学性能

王绍亮, 唐致远, 沙鸥, 闫继   

  1. 天津大学化工学院, 天津 300072
  • 收稿日期:2011-08-19 修回日期:2011-10-10 发布日期:2012-01-11
  • 通讯作者: 唐致远 E-mail:zytang@tju.edu.cn
  • 基金资助:

    国家自然科学基金(20973124)资助项目

Synthesis and Electrochemical Performance of LiCoPO4 by Sol-Gel Method

WANG Shao-Liang, TANG Zhi-Yuan, SHA Ou, YAN Ji   

  1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P. R. China
  • Received:2011-08-19 Revised:2011-10-10 Published:2012-01-11
  • Contact: TANG Zhi-Yuan E-mail:zytang@tju.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20973124).

摘要: 采用溶胶-凝胶法合成了高电位正极材料LiCoPO4, 并通过X射线衍射(XRD)、扫描电镜(SEM)以及充放电测试考察了不同烧结条件下产物的晶体结构、微观形貌以及电化学性能. 实验结果表明: 在650 °C下烧结12 h所制备的样品为单一橄榄石型结构的LiCoPO4, 产物颗粒细小(0.2-0.4 μm)且分布均匀, 同时具有最佳的电化学性能, 其在1C倍率下的放电比容量可达到122.7 mAh·g-1. 此外, 产物在充放电过程中均呈现两个电压平台, 且随着放电倍率的增加, 两个电压平台之间的区分逐渐明显, 分析认为, 这与充放电过程中锂离子的两步脱嵌行为有关.

关键词: 锂离子电池, LiCoPO4, 正极材料, 溶胶-凝胶法

Abstract: High potential cathode material LiCoPO4 was synthesized by sol-gel method. The effects of different sintering conditions on the crystal structure, surface morphology and electrochemical performance of LiCoPO4 were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and charge-discharge tests. The results show that the sample synthesized at 650 ° C for 12 h has a good crystalline orthorhombic olivine-type structure and a uniform particle distribution (0.2-0.4 μm), which delivers the best electrochemical performance. The discharge capacity of the sample at 1C rate can reach 122.7 mAh·g-1. Moreover, from the charge and discharge profiles, two charge/discharge plateaus are presented and they become more obvious with the increase of charge/discharge rate. This phenomenon can be interpreted by considering the two-step extraction/insertion behavior of Li+ in LiCoPO4.

Key words: Lithium-ion battery, LiCoPO4, Cathode material, Sol-gel method

MSC2000: 

  • O646