集流体型电池模型的热特性模拟

Thermal characteristic simulation of current collector type battery model

以容量为12.5 Ah的三元正极材料软包装动力锂离子电池为研究对象,通过数值模拟,研究单体电池结构对电池热特性的影响。结合电池实际结构,对单体电池传统结构进行简化,分离集流体模块并建立集流体型电池模型;同时,基于电池内阻温升特性和正负极耳的热影响,建立电池时变内热源,分析不同充电倍率下的单体电池温度和热流密度分布。在4.2~2.5 V充电,集流体型电池模型在3 C时的温升、温差和热流密度较1 C时分别增加47.04℃、22.38℃和1.6 W/m 2。此时,集流体型电池模型温升速率较基准型电池模型提高30.5%,并且温差增加20.85℃。

The ternary cathode material soft pack power Li-ion battery with a capacity of 12.5 Ah was selected as research object.The influence of the structure of a single battery on its thermal characteristics was studied by numerical simulation.According to the actual structure of the battery,the traditional simplified structure of the single battery was improved,the current collector module was separated and a current collector battery model was built.At the same time,a time-varying internal heat source of the battery was established based on the temperature rise characteristics of the battery internal resistance and the thermal effects of the anode and cathode ears.The temperature and heat flux density distribution of the single battery at different charge rates were analyzed.When charged in 4.2-2.5 V,the temperature rise,temperature difference and heat flow density of the current collector battery model under 3 C were increased by 47.04℃,22.38℃and 1.6 W/m 2 compared with that at 1 C,respectively.At this time,the temperature rise rate of the battery current collector type was 30.5%,which was higher than that of the battery reference type;the temperature difference was also increased by 20.85℃.