磷酸铁锂动力电池备电工况寿命试验研究及分析

Cycle life test and analysis of lithium iron phosphate based traction batteries

随着新能源汽车使用周期的增长,车用动力电池逐渐进入报废阶段。本工作以电动汽车用磷酸铁锂动力电池为研究对象,基于通信基站备电工况,开展了温度和恒压充电电压双因素工况的可用周期试验验证工作。研究结果表明,当备电工况的环境温度增高时,样品的性能衰减明显加速,出现非线性加速衰减的趋势;当备电工况的恒压充电电压变化时,样品的可用容量衰减趋势差异较小,放电直流内阻的变化差异明显。研究结果说明,当磷酸铁锂动力电池在备电工况再利用时,需要根据实际工况需求控制环境温度和恒压充电电压。

With the extension of the life cycle of electric vehicles, the traction battery has gradually entered the scrapping stage. In this paper, the lithium iron phosphate chemistry traction battery is taken as the research object. Based on the electrical conditions of the communication base station, the available cycle test verification of the temperature and constant voltage charging is carried out. The research results show that when the ambient temperature of the standby electrical condition increases,the performance degradation of the sample is obviously accelerated, and the trend of nonlinear acceleration attenuation occurs. When the constant voltage charging of the standby electrical condition changes, the difference in the available capacity attenuation trend of the sample is small, and the variation of the internal resistance of the discharge DC is significant. The research results show that when the lithium iron phosphate traction battery is reused in the standby electrical condition, it is necessary to control the ambient temperature and the constant voltage charging according to the actual working conditions.