锰酸锂动力电池高低温性能的研究

Research on high/low temperature performance of LiMn_2O_4 power battery

研究锰酸锂(LiMn2O4)动力电池在高低温(-20、40、65℃)条件下的充放电性能。结果表明:(1)在-20℃时,锰酸锂动力电池的极化严重,相应的电压变化也比较大,充放电效率降低,使得电池在低温环境下充放电容量均有大幅降低;(2)在40℃和65℃时,由于电解质的阻值和极化的增加,同时大量气体的产生使电极发生变化,导致了电池容量下降,性能降低;(3)低温和高温情况均加速了锰酸锂动力电池电极的极化,造成随着充放电循环次数的增加,充放电容量持续衰减;(4)在-20℃锰酸锂动力电池的恒流充电时间相对变短而恒压充电时间相对变长,与40℃和65℃时电池恒流充电的温升速率相比,锰酸锂动力电池在-20℃时恒流充电的温升速率最大。

The charge and discharge characteristics of power battery at different temperatures（-20,40 ℃ and 65 ℃）were investigated.The results show as follows：（1） at-20 ℃,the polarization of cathode materials is serious,the corresponding voltage change is large,and the charge-discharge efficiency is reduced,which make the battery charge and discharge capacity fading;（2）at 40 ℃ and 65 ℃,the resistance and polarization of LiMn2O4/electrolyte is increased,and the structure of active materials is changed resulting from a mass of gas produced,which is the responsible for the fading of capacity;（3） low temperature or high temperature accelerates the polarization of cathode materials,with increase of charge-discharge cycle,the charge and discharge capacity sustaining fading;（4） comparing with 40 ℃ and 65 ℃,at-20 ℃,the time of constant current charge is relative short,that of constant voltage charge is relative long,and the temperature rise rate of constant current charge is the largest.