空冷条件下18650锂电池温度场仿真分析

Simulation and Analysis of 18650 Lithium Battery Temperature Field with Air Cooling

对18650锰酸锂电池建立电化学-热耦合三维仿真模型。基于电化学理论建立单体电池模型,以充放电过程中释放的热量作为热模型中的热源;通过热模型仿真计算得到电池-空气系统的温度场,以其作为电化学计算过程中的温度参数,实现电化学模型与热模型的耦合。采用数值仿真方法,分析放电倍率为2C、3C、6C及空气流速在0.1~1.0m/s范围内电池温度的分布及特征。结果表明:放电倍率越大,电池温度越高,放电倍率为6C时电池的温度已超出正常工作温度范围;冷却空气流速在一定范围内对电池温度的降低有显著作用。

The electrochemical thermal coupling three-dimensional simulation model of 18650 lithium manganate battery is established.A cell model is built based on the electrochemical theory.The heat releasedduring the charging and discharging process is used as the heat source in the thermal model.The temperature field distribution of battery-air system is obtained through the simulation of thermal model,which is used as the temperature parameter in the process of electrochemical calculation.Thus the coupling of electrochemical model and thermal model is realized.With numerical simulation,the distribution and characteristics of temperature field under 2C,3C,6C discharge rate and inair velocity range of 0.1~1.0m/s are analyzed.The results show that the higher the discharge rate is,the higher the temperature of the battery is.The temperature of the battery has exceeded the normaltemperature scope when the discharge rate is 6C.Also the cooling air flow rate has a significant effect on the reduction of the battery temperature in a certain range.