基于电芯温差优化的热管理设计

Thermal management design based on optimization of temperature difference for the cell

电芯大倍率充放电,采用液冷进行散热时,会在电芯冷却方向上产生较大温度梯度。基于减少冷却方向温差的目的,通过在已有电芯大面添加散热铝片和石墨烯两种高导热材料的方式,以及优化处于设计阶段电芯的尺寸和直接提高导热系数的方式来提高单电芯在冷却方向上的导热速率。并通过仿真手段研究了上述方式对电芯冷却方向上温差的影响,结果显示:对于三元软包电芯,每个电芯添加一片散热铝片及两片石墨烯时,冷却方向上温差降幅达42%;对于三元方形电芯,每个电芯添加两片石墨烯时,温差降幅达24%。若同时优化处于设计阶段的三元软包电芯的尺寸和导热系数,温差降幅可达75%。

When cooling the cells which is charged and discharged at a large rate with liquid,a large temperature gradient will be generated in the cooling direction of the cell.Based on the purpose of reducing the temperature difference in the cooling direction,thermal conductivity of the cell in cooling direction was increased by adding two high thermal conductivity materials of aluminum(Al)sheet and graphene on the large surface of the cell,as well as by optimizing the size and directly increasing the thermal conductivity of the cell at the design stage.The effect of the above methods on the temperature difference in the cooling direction of the cell was studied by simulation.The results show that the temperature difference in the cooling direction decreases by 42%when one Al sheet and two graphene are added to each cell for pouch NCM cell and decreases by 24%when two graphene are added to each cell for prismatic NCM cells.And the temperature difference can be reduced by 75%when the size and thermal conductivity of the pouch NCMcell in the design stage are optimized at the same time.