锂电池性能与温度相关性的基础实验研究

Experimental Research on the Correlation of Lithium-Ion Battery Performance with Temperature Condition

为综合分析影响电池性能的热环境因素,利用恒温油浴工况、近似绝热工况分别模拟有无热管理措施的动力电池组工作热环境,对松下18650锂电池进行了充放电性能与温度相关性的基础测试,研究了电池工作热条件、电池状态及放电倍率对其充放电性能的影响。研究结果表明:无论在何种热条件下,电池充电容量总是小于上次放电容量;当充电温度低于20℃时,电池充电容量随着充电温度的降低迅速衰减,若前一次放电倍率为0.5C、充电温度从20℃降至-10℃时,充电容量衰减12%;较高的放电温度能有效抵消电池大倍率放电引起的容量损失,当电池在40℃环境中以2C倍率电流放电时,其容量衰减仅为3.7%;当电池放电倍率较小,且工作温度高于30℃时,温度对电池放电性能的影响逐渐减小;环境温度较低时,电池放电容量随温度降低迅速衰减,当电池放电温度为-10℃时,其2C倍率放电容量衰减高达50%。本研究期望对高效、可靠及合理的电池热管理系统的设计提供理论依据。

To achieve a comprehensive understanding of the thermal effects on battery performance,the charging and discharging performances of Panasonic 18650 lithium battery were tested under constant temperature and approximate adiabatic conditions to simulate the battery operating conditions with and without thermal management strategies,respectively.The tested items include battery operating temperature,battery state and discharge rate.It was found that the charge capacity of the battery is always smaller than the previous discharge capacity regardless of thermal conditions,and when the operating temperature is below 20℃,the charge capacity decreases dramatically,e.g.,it decays 12% within the charging temperature range from20℃to-10℃in contrast to the previous discharge rate of 0.5 C.High operating temperaturecould offset the battery discharging capacity loss due to the large discharge rate.The battery discharge capacity loses only 3.7% when it discharges at the rate of 2 Cat 40℃.The study shows that the battery discharging performance decreases gradually when the operating temperature rises up to 30℃ and that the battery discharge capacity decreases rapidly with the temperature drop.When the operating temperature is-10℃,the 2 Cdischarge capacity fade can be as much as 50%.It is expected that the above results could provide a support for the design of an efficient,reliable and reasonable battery thermal management system.