锂离子动力电池液体冷却实验研究

Experimental investigation of lithium-ion power battery liquid cooling

提出采用电子冷却液NOVEC 7000为工质的电池液体冷却实验系统,开展实验研究。研究结果表明,该系统具有良好的电池冷却效果。实验结果表明,产热机理不同,不同倍率放电时,电池呈现出不同的温度变化特性。发现温度对电池性能有着双重影响:尽管采用热管理手段能够降低电池表面温度,提高电池安全性,但是相应的电池电化学性能严重下降。质量流量的增大能够有效地降低电池表面最大温度,但在热管理系统的设计中必须考虑质量流量增大造成的附加功率(如泵功率)的消耗。在持续充放电过程中,NOVEC 7000工质的沸腾将电池的表面最大温度稳定地维持在34~36℃之间。而以乙二醇溶液为工质时,温度则保持持续增大的趋势。基于微细通道内沸腾换热的电池热管理系统,可以在保证电池热安全性的同时,有效提高系统经济性。

A battery liquid cooling system which uses new electronic cooling fluid NOVEC 7000 as the working medium was proposed and some experimental investigation was carried out.The results showed that this system had excellent cooling effect.Temperature variation showed different regularities when the battery was discharged at different rates due to the different heat generation mechanisms.The effect of temperature on battery was bidirectional.Although the battery thermal management system effectively decreased the battery temperature and improved the thermal safety,the electrochemical performance declined as well.The maximum temperature of battery surface was effectively reduced with the increase in mass flow rate,but parasitic power resulting from the increase in mass flow rate,such as pump power consumption,should be considered.During cyclic charging/discharging,because of the boiling phenomenon,the maximum temperature of battery surface could be stably maintained between 34℃ and 36℃ when NOVEC 7000 was used as working medium.However,the temperature kept rising tendency while glycol was used as cooling medium.So,designing a battery thermal management system,based on flow boiling in mini/micro-channel,will effectively improve the thermal safety of batteries as well as the economy.