有机聚硫化物正极活性材料的高放电比容量现象

High Specific Capacity of an Organodisulfide Polymer as Cathode Active Materials for Second Lithium Batteries

以聚六硫蒽为正极活性材料制作正极，锂片为负极，双三氟甲基磺酰亚胺锂为电解质，有机醚为溶剂，组装锂电池。活性材料的放电比容量最高达1236mAhg^-1；放电电压3．5—2．5V，放电比容量在前20周下降较快，至第20周时为600mAh／g。以后下降速度减慢，到50周时仍有比容量411mAh／g，库仑效率大于90％。这种实际放电容量远高于理论放电容量的现象还未见过文献报道。

Lithium second batteries were assembled, in which polysexathioanthrcene was used as the cathode active material, lithium film as the anode, lithium bis - trifluromethylsolfonic imine （LiTFSI） as the electrolyte, 1, 3 - dioxy - pentane and ethylene glycoldimethyl ether as the solvents, . The cathode active material had the specific capacity up to 1260mAhg^-1 at 3^rd cycle and 411mAh/g at the 50^th cycle at discharge voltage of 3.5 -2. 5V, current density of 40mA/g, with efficiency of 90%. The specific capacity is very higher than its theoretical capacity 440mAhg^-1 and the mechanism is under investigation.