温度及放电倍率对电池循环寿命的影响及预测

Effects of Temperature and Discharge Rate on Battery Cycle Life and Prediction

[目的]针对一种手持式电加热器具使用的锂离子电池样品进行了电池循环寿命加速实验,探究不同温度及放电倍率对电池循环寿命的耦合影响并提出一种高效预测电池循环寿命的方法。[方法]在不同温度(23℃、50℃、65℃)及不同放电倍率(1 C、2 C、3 C)条件下,对36个电池样品进行500次充放电循环,并对结果进行拟合形成云图以快速评估电池在不同工况下的循环寿命。[结论]①随温度上升,电池容量衰减呈指数性增长,衰减趋势符合Arrhenius公式。②放电倍率对电池容量衰减的影响与温度耦合相关:常温时,放电倍率对电池容量衰减影响不明显,温度越高,放电倍率对电池容量衰减的影响逐步增大。③采用线性拟合及三次样条插值云图的方法可在电池选型阶段快速预测常温、低倍率放电电池循环寿命,大大缩短实验周期。未来将结合该手持式电加热器具脉冲放电,高倍率快充等实际工况场景进一步更准确地评估其电池容量衰减以更好的服务该类产品研发及为该类产品电池循环寿命测试方法标准制定提供依据。

[Purpose]Accelerated cyclic life test of lithium-ion battery for handheld electric heating appliance was carried out to study the coupling effects of different temperatures and discharge rates on the cycle life of the battery and a method for efficiently predicting the cycle life of the battery was proposed.[Methods]36 batteries were charged and discharged for 500 times under different temperatures(23,50℃,65℃)and dischargeratios(1C,2C,3C);thebattery discharge capacities were fit to form a contour for rapid evaluation of the battery cycle life under different conditions.[Conclusions]with the increase of temperature,battery capacity decayed exponentially and the trend conformed to Arrhenius formula.②The influence of discharge rate on battery capacity decay was related to temperature,the influence was not obvious under room temperature and became larger with temperature increases.The method of linear fitting and cubic spline interpolation contour could be used to quickly predict the cycle life of batteries under room temperature and low discharge rate in the battery selection,which greatly shortened the test time.In the future,we will further evaluate the capacity decay of the handheld electric heating appliance's battery under real working conditions such as pulse discharge and high rate fast charge in order to obtain more accurate data to serve the research and provide a basis for the development of standard for battery cycle life testing methods for this type of product.