过渡金属氧化物Co_3O_4的嵌锂性能及其改性

Intercalation Behavior and Modification of Transition-Metal Oxide Co_3O_4

采用机械球磨制备了一定粒度的锂离子电池负极材料Co3O4 。电化学性能测试结果表明Co3O4 首次嵌锂容量为 990mAh·g- 1 ,脱锂容量为 3 95mAh·g- 1 。通过添加石墨类材料对Co3O4 进行了改性研究。充放电测试表明 :通过长时间机械混合球磨处理后的一定粒度的改性材料首次脱锂容量可提高到 63 2mAh·g- 1 ,充放电循环 15周后 ,容量保持在 40 8mAh·g- 1 ,电化学性能优于单纯的Co3O4 。由此可见通过添加石墨类材料并进行机械球磨以改变材料的微观结构不仅可以提高材料Co3O4 的可逆容量 ,而且改善了其循环寿命。

The negative electrode materials Co 3O 4 with constant particle size for lithium ion battery were prepared by mechanical milling of Co 3O 4. Through examining their electrochemical properties, it is found that the initial discharge capacity is 990 mAh·g -1 and the reversible capacity is 395 mAh·g -1 . In order to improve the electrochemical performance of Co 3O 4, we adopted to modify the Co 3O 4 by graphite MPG. The tests show that modified materials which ballmilled for a long time can increase the reversible capacity to 632 mAh·g -1 . After 15 charge/discharge cycles the reversible capacity of modified materials is 408 mAh·g -1 . These results indicate that the reversible capacity and cycle life of Co 3O 4 can be improved by adding MPG and mechanical milling of graphite and Co 3O 4 mixtures. These modified materials appear to be promising candidates for negative electrodes in lithium ion rechargeable batteries.