锂离子电池新型快充负极材料Li_4Ti_5O_(12)的改性研究

Modification Studies on the Novel Anode Material Li_4Ti_5O_(12) with Characteristic of Fleetly Charging for Lithium Ion Batteries

采用传统固相法制备尖晶石型Li4Ti5O12,在前驱物中掺杂聚合物裂解碳材料聚并苯(PAS).经四探针测试仪测量,电导率提高9个数量级.复合物的电化学性能测试结果表明,其循环性和高倍率性能得到了明显改善.

Spinel Li4Ti5O12 for the lithium ion battery was used as an anode material, during the process of Li^＋ intercalation and de-intercalation, its crystal structure did almost no change, so it is regarded as a ＂zero strain＂ material. But Li4Ti5O12 has a poor electric conductivity, only 10^-9 S/cm, which affects its cycling stability and high rate characteristics. Here,Li4Ti5O12 /polyacene （PAS） composite was prepared via a solidstate method using TiO2-anatase, Li2CO3, and polymer degradation carbonous—— Polyacene（PAS） as precursors. Doping with PAS greatly improved the electric conductivity and electrochemical performance over the pure Li4Ti5O12 . The conclusion, which was measured by four-probe apparatus, showed that electric conductivity of the composite was enhanced for nine-magnitude order. The electrochemical tests indicated that the Li4Ti5O12 doping with mass fraction of 10% of PAS exhibited the initial specific capacity is 137. 3 mA · h/g at 10C, and it is still 100 mA·h/g over 200 cycles.