锂离子电池电极片的激光清洗理论与实验研究

Theoretical and experimental study on laser cleaning of cathode from lithium- ion batteries

随着电动汽车的广泛应用,大量废旧锂离子电池不仅严重污染了环境而且造成能源和资源的极大浪费。提出了利用激光清洗的方式对废旧的车用锂离子电池进行再制造的方法。利用Nd:YAG固体脉冲激光器为光源,对造成电池容量衰退的磷酸铁锂电池正极表面积聚的固体电解质中间相界面(SEI,solid electrolyte interface)膜进行清洗,从而达到废旧电池电极片的再制造。建立了热传导模型,得到在清洗过程中的温度分布函数,通过扫描电镜及傅里叶红外光谱实验结果分析确定在当前实验环境中的最佳脉冲激光能量密度为0.142 J/mm2。

With the wide use of electric vehicles,a great deal of spent lithium- ion batteries not only seriously pollute the environment and cause great waste of energy and resources. The method of laser cleaning is proposed for re manufacturing cathode from end- of- life of lithium- ion batteries in this paper. Deposition of passive solid electrolyte interface（ SEI） layers on the electrodes of electric vehicle battery（ EVB） causes fast capacity loss and recharge- ability reduction of the battery. Nd： YAG pulsed solid state laser was used to ablate SEI from surfaces of the electrodes. This paper has established the heat conduction model and obtained the temperature distribution function during the cleaning process. The experimental results show that the optimal pulse laser energy density is 0. 142 J / mm^2 under current experimental conditions.