基于参比电极的析锂电池安全充电控制

电池系统是支撑下一代新型电网的关键,然而随着使用次数增加电池性能会逐渐衰减,导致充放电能力大幅减弱。因此,本文针对三元锂离子电池,通过制备参比电极,揭示了不同温度充放电循环后电池充电性能变化。首先,设计了不同温度下的充放电循环实验,得到低温循环与高温循环两种状态下的电池；其次,通过植入参比电极标定安全充电曲线对比不同状态电池的负极电位情况,发现高温循环后的电池发生了析锂,并且在300 A电流充电持续时间上对比新鲜电池降低了76.19%；最后,对析锂后的电池建立了安全充电荷电状态-温度-电流等高线图。对比新鲜电池后发现,相同温度和荷电状态区间电池200A以上的充电能力减少了69.84%。电池发生析锂副反应后会严重影响电池充电性能,需要在实际的锂离子电池全寿命周期管理中予以考虑。

Study on the charging performance of precipitating lithium batteries based on reference electrodes

The battery system is the key to support the next generation of new power grid, however, the battery performance will gradually decay with increasing usage, resulting in a significant weakening of the charge and discharge capacity. Therefore, in this paper, for ternary lithium-ion batteries, the changes of battery charging performance after different temperature charging and discharging cycles are revealed by preparing reference electrodes. Firstly, the experiments of charge/discharge cycles at different temperatures were designed to obtain the battery in two states of low-temperature cycle and high-temperature cycle; secondly, the negative electrode potential of the battery in different states was compared by implanting the reference electrode to calibrate the safe charging curve, and it was found that the lithium precipitation occurred in the battery after high-temperature cycle, and the charging duration of 300 A current was reduced by 76.19% compared with that of the fresh battery; finally, the safe charging curve of the battery after high-temperature Finally, a safe charge state-temperature-current contour plot was established for the battery after high-temperature cycling. Finally, a safe charge-current contour plot was established for the battery after high-temperature cycling, and it was found that the charging capacity of the battery above 200 A was reduced by 69.84% in the same temperature and charge state range compared to the fresh battery. The occurrence of lithium precipitation side reactions in batteries can seriously affect the battery charging performance and needs to be considered in the actual whole life cycle management of Li-ion batteries.