锂离子电池耐过放性能的改善

Improvement of overdischarge resistance ability of Li-ion battery

采用磁控溅射法在负极集流体铜箔表面镀上一层致密的钛膜,以石墨为活性物质制备成扣式电池进行了对比实验。实验结果表明以铜箔为集流体制备的石墨半电池4次过充之后比容量衰减了120 m Ah/g(全电池的过放过程对应着石墨半电池的过充过程),以表面镀钛铜箔为集流体,4次过充之后比容量只衰减了25 m Ah/g。循环伏安曲线和交流阻抗分析表明铜箔表面镀一层钛膜,可有效地提高铜箔的电化学抗腐蚀性能,进而提高锂离子电池的耐过放性能。

In order to improve the overdischarge resistance ability of Li-ion battery,the Ti films were coated on the copper current collector by magnetron sputtering.After having been overcharged four times,the graphite half-cell with copper current collector reduced 120 mAh/g while the graphite half-cell with Ti-coated copper current collector only reduced 25 mAh/g.This suggested plating a titanium film can improve the resistance of the copper foil to the electrochemical corrosion effectively.