正极材料LiNi0.5Co0.5O2的电化学性能研究

以聚丙烯酰胺(PAM)为分散剂用微波—固相复合加热技术合成了层状锂离子电池正极材料LiNi0.5Co0.5O2。通过扫描电子显微镜(SEM)和X—射线粉末衍射(XRD)分析技术对材料的微观形貌和相结构进行了表征。恒电流充放电循环测试表明:材料的放电比容量高达154mAh/g,且有良好的循环性能。重点利用循环扫描伏安、计时电量和电化学交流阻抗测试技术,对材料在循环前后的电化学性能变化规律进行了探讨。结果表明,经过循环后材料的导电能力以及锂离子扩散能力都有了很大的提高。另外,材料中的锂含量对材料的导电能力也有很大的影响。

Study on electrochemical performances of cathode material LiNi0.5Co0.5O2

Layered cathode materials LiNi_(0.5)Co_(0.5)O_2 were prepared by microwave-solid calcined method for lithium ion batteries using ployacrylamide(PAM) as dispersant.The prepared materials were characterized for their morphologies,phase purity and structure features using SEM and X-ray diffraction(XRD) techniques.The results of the charge-discharge test show that the discharge capacity is up to 154mAh/g,and the material exhibits excellent cyclic reversibility.The changes of materials' electrochemical performance during charge-discharge cycles were studied using cyclic voltammetry,chronocoulometry and electrochemical impedance spectroscopy.The results indicate that the abilities of conductivity and Li diffusion will be improved by charge-discharge cycle.In addition,the Li content of material is corresponding to its conductive capability.