Enhanced cyclability and thermal stability of LiCoO2 coated with cobalt oxides
Enhanced cyclability and thermal stability of LiCoO2 coated with cobalt oxides
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DOI：
10.1016/j.surfcoat.2004.06.007
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发表时间：
2005-02
影响因子：
5.4
通讯作者：
G. Fey;Y. Lin;T. P. Kumar
中科院分区：
文献类型：
--
作者：
G. Fey;Y. Lin;T. P. Kumar
采用湿法化学方法对钴氧化物包覆licoo2的循环性能和热稳定性进行了改进。XRD研究表明，涂层改变了晶格参数a和c的值，表明煅烧后表面可能形成了取代化合物。0.3 wt的透射电镜研究。%钴氧化物涂层的licoo2表明，钴氧化物在正极材料上形成了均匀的涂层。SEM图像、XRD研究的r因子值和恒流循环研究表明，0.3 wt.%的涂层水平在容量和循环性能方面具有最佳性能。循环伏安曲线表明，与Li+/Li相比，该涂层抑制了4.1 V以上电位下发生的循环限制性相变。用0.3 wt进行充放电研究。%氧化钴涂层的licoo2材料的可循环性提高了12倍。差示扫描量热数据显示涂层阴极材料具有较高的热稳定性。
Improved cycling properties and thermal stability of LiCoO2coated with cobalt oxides by a wet chemical process are described. XRD studies showed that the values of the lattice parameters, a and c, were altered by the coating, indicating that substitutional compounds might have formed on the surface upon calcination. TEM studies on 0.3-wt.% cobalt oxide-coated LiCoO2suggested that cobalt oxides formed a uniform coating over the cathode material. SEM images, R-factor values from XRD studies and galvanostatic cycling studies indicated that a coating level of 0.3 wt.% produced optimal performance in terms of capacity and cyclability. Cyclic voltammetric curves suggested that the coating suppressed the cycle-limiting phase transitions that occur at potentials above 4.1 V vs. Li+/Li. Charge–discharge studies with a 0.3-wt.% cobalt oxide-coated LiCoO2material showed a 12-fold improvement in cyclability. Differential scanning calorimetric data revealed the higher thermal stability of the coated cathode materials.