Modification and Application of Lithium Cobalt Dioxide in Li-ion Battery
Abstract:
The LiCoO 2 obtained has excellent physical and electrochemical properties after modification. The initial specific capacity and charge discharge efficiency are 150 mAh·g -1 and 95.8% respectively. When it is used in 063048 type battery as cathode, it shows good processing property. The initial battery capacity is 774 mAh·g -1 . The initial ratio of the discharge capacity more than 3.6 V to total discharge capacity is 89%; the retention of the discharge capacity after 300 cycles is 87% to the initial capacity; the ratio of the capacity more than 3.6 V to total capacity is 83.7% after 300 cycles. The battery also had good high and low temperature performances, excollant capacity retention and safety performance.
图1 不同试验点钴酸锂的首次比容量比较Fig.1 Initial specific capacity of different LiCoO2 samples
图2 不同试验点钴酸锂循环性能比较Fig.2 Cycle performances of different LiCoO2 samples
图3 不同试验点钴酸锂材料平台性能 (以金属锂为对电极和参比电极) Fig.3 Discharge capacity percentage more than 3.8 V of different LiCoO2 samples (Metal lithium as counter and reference electrode)
图4 不同试验点钴酸锂振实密度比较Fig.4 Tap densities of different LiCoO2 samples
表3 电池高低温和荷电保持性能Table 3Performances of high-low temperature and capacity retention of the battery
检测 项目
高温 (+60 ℃) 放电率/%
低温 (-20 ℃) 放电率/%
30 d荷电保持/%
性能
>90
>80
>90
图6 D50=6.26 μm材料的循环容量 (1) 和平台性能 (2) Fig.6 Cycle capacity and cycle capacity percentage more than 3.6 V of our LiCoO2 with medium particle size of 6.26 μ
图7 自产材料和日本A级材料循环容量 (a) 及平台性能 (b) 比较图 (1) 自产; (2) 日本A级产品Fig.7 Cycle performances of our product and A-grade LiCoO2 product of Japan and A grade product of Japan