为了探究负极极片复合材料的切割性质, 采用有限元模型, 对激光切割锂离子电池负极极片复合材料温度场进行数值模拟计算。由温度场分布取得了负极切缝宽度与切缝深度的尺寸大小, 从中研究激光功率、切割速率和光斑半径对负极表层材料切缝宽度与切缝深度的影响。结果表明, 负极表层切缝宽度随激光功率和光斑半径的增加而增大, 随切割速率增大而减小;切缝深度随激光功率增加而增大, 随切割速率和光斑半径增大而减小。切割至中间铜箔后, 切缝深度变化速率趋缓, 负极材料的复合结构对切缝深度存在明显影响;在功率为170W、光斑半径为47μm、切割速率变化至600mm/s左右时,效果最为明显, 切割深度在该参量下达到60μm, 且突破这一阈值后增长速率得到明显提升直至极片完全切断。这一结果可为激光应用于锂离子电池极片复合材料切割提供参考。

In order to investigate cutting characteristics of negative plate composites, the temperature field of negative plate composite material of the lithium ion battery by laser cutting was numerically simulated based on finite element model. The size of the width and depth of the negative electrode slit was obtained from the temperature field distribution. The effect of laser power, cutting speed and spot radius on the slit width and depth of negative surface material was studied. The results show that, the width of the slit on the surface of the negative electrode increases with the increase of laser power and the radius of the spot. It decreases with the increase of cutting speed. The slit depth increases with the increase of laser power. It decreases with the increase of cutting speed and spot radius. After cutting to the middle copper foil, the change rate of the slit depth is slowing down. The composite structure of the negative electrode material has a significant effect on the depth of the slit. When the power is 170W, the radius of the spot is 47μm, and the cutting speed varies to about 600mm/s, the effect is most obvious. The cutting depth reaches 60μm under this parameter. After breaking through this threshold, the growth rate is increased significantly until the polar plate is completely cut off. The results can provide a reference for laser cutting of lithium ion battery plate composite material.