预处理流程对磷酸铁锂动力电池性能的影响

Influence of pretreatment process on LiFePO_4 power battery performance

考察预化成工艺、高温存储对20 Ah磷酸铁锂动力电池性能的影响,分析不同预处理流程处理后负极极片状态、电池容量、电池厚度、内阻,总结在电池水分较高时的预处理工艺。研究结果表明,高温静置8 h后的电池容量为20.623 Ah,小于未高温静置的电池容量(20.700 Ah);化成截止电压为3.9 V时,电池厚度小于截止电压为3.65 V时的厚度;截止电压为3.9 V时,极片未出现析锂状况。因此在电池水分较高时,提高截止电压可以提高电池容量、降低电池厚度、避免死区。

The effects of pretreatment process and high temperature storage on the performance of lithium ion battery were analyzed with the 20 Ah LiFePO_4 power battery. The anode morphology, battery capacity, thickness and resistance were studied. The results show that the battery capacity decreases from 20.700 to 20.623 Ah after high temperature storage, the thickness of the battery is thinner at cut-off voltage of 3.9 V than that at 3.65 V, and when the cut-off voltage increases from 3.65 to 3.9 V, the lithium can＇t precipitate out. Therefore, the higher battery capacity, thinner thickness and better cathode morphology can be found by increasing the cut-off voltage under high moisture condition.