新型锂蓄电池正极复合材料的制备和电化学性能研究

Preparation and Electrochemical Properties of Novel Composite Cathode Materials for the Advanced Lithium Rechargeable Batteries

摘要:

采用升华硫与多壁碳纳米管在一定条件下合成了一种新型纳米含硫复合材料。通过扫描电子显微镜（SEM）和BET比表面积等分析测试手段对复合材料的物理化学性能进行表征，利用循环伏安、交流阻抗和电池充放电对材料的电化学性能进行了测试。结果表明：此复合材料表现出了很好的电化学性能，其初始放电比容量达700mAh／g，在室温下经过60次循环之后电池放电比容量仍稳定在464mAh／g，容量保持率大于66％。

Abstract:

Novel nanosized sulfur-containing composite cathode materials were synthesized by heating the mixture of sublimed sulfur and multi-walled carbon nanotubes(MWNTs)in certain conditions.The structure and morphology of the composite cathode materials were determined by scanning electron microscopy.The electrochemical performances of the MWNTs-sulfur composite(MSC)were characterized by charge-discharge characteristic,cyclic voltammetry and electrochemical impedance spectroscopy.The results indicate that the MSC exhibits a good rate capability,a satisfactory capacity,and acceptable cycle-life characteristics.The specific capacity was more than 700 mAh/g for the first discharge,and remained at 464 mAh/g,just 34% less after 60 cycles at room temperature.