以β-Co(OH)_2为前驱体的锂离子电池正极材料LiCoO_2

Highly active cathode material LiCoO_2 for lithium ion battery through β-Co(OH)_2 as precursors

对ＬｉＣｏＯ２ 的结构与电化学性能进行了研究。采用控制结晶法合成出来的层状结构β－Ｃｏ（ＯＨ）２ 作为前驱体，和ＬｉＯＨ混和煅烧，制备出高活性的具有层状结构的锂离子电池正极材料ＬｉＣｏＯ２。试验中，通过差热 热重法分析了煅烧过程的反应机理； Ｘ 光衍射谱表明制得的ＬｉＣｏＯ２ 为α－ＮａＦｅＯ２ 层状结构的 ＨＴ－ＬｉＣｏＯ２； 扫描电镜照片显示β－Ｃｏ（ＯＨ）２ 是ＬｉＣｏＯ２ 优良的前驱体； 性能测试表明制得的ＬｉＣｏＯ２ 具有良好的电化学性能： 其首次充电容量为１５０．１ ｍ Ａｈ／ｇ， 放电容量为１４３．８ ｍ Ａｈ／ｇ， 充放电效率为９５．８％ 。

Structure and the electrochemical properties of LiCoO 2 were studied. Highly active layered LiCoO 2 powders, as the cathode materials for lithium ion battery, were synthesized through the layered β Co(OH) 2 as precursors, which were prepared by the controlled crystallization method. DTA/TGA (“differential thermal analysis” and “thermagravimetric analysis”) were employed to investigate the reaction mechanism. XRD (X ray diffraction) results show that the prepared LiCoO 2 is HT LiCoO 2 with α NaFeO 2 layer structure type. SEM photographs show that β Co(OH) 2 are the excellent precursors for LiCoO 2. Electrochemical test of constant current charge discharge proves that the LiCoO 2 powders prepared have excellent electrochemical property in laboratory coin cell: its initial charge capacity is 150.1 mAh/g, its initial discharge capacity is 143.8mAh/g and the coulomb efficiency is 95.8%.