基于参比电极的析锂电池安全充电控制

Charging performance of precipitating lithium batteries based on reference electrodes

电池系统是支撑下一代新型电网的关键,然而不合理的充放电策略会使电池发生析锂副反应,导致电池充放电性能大幅减弱。因此,文中针对三元锂离子电池,基于参比电极揭示了析锂后电池的充电性能变化情况,并对其安全充电电流进行控制。首先,设计不同温度下的充放电循环实验,得到低温循环与高温循环后的电池;其次,通过植入参比电极标定安全充电曲线对比电池的负极电位,发现高温循环后的电池发生了析锂,且平均充电电流相比新电池降低了61.7%;最后,对析锂后的电池建立安全充电荷电状态-温度-电流等高线图,对比新电池等高线图后发现,200 A以上的充电电流区域减少了69.84%。文中提供了一个析锂后电池充电性能衰减的量化指标,需要在实际的锂离子电池全寿命周期管理中予以考虑。

The battery system is the critical component to supporting the next generation of advanced power grids.However,parasitic lithium plating reactions can be triggered by improper charging and discharging strategies,leading to a significant compromise of the charge-discharge performance of batteries.Centered on ternary lithium-ion batteries,the degradation of charge performance due to lithium plating is elucidated through the utilization of a reference electrode-based approach in this study,followed by the implementation of measures to regulate safe charging currents.Diverse temperature-dependent charge-discharge cycling experiments are initially designed to evaluate batteries under both low-temperature and high-temperature cycling.Subsequently,the calibration of safe charging curves is conducted using a reference electrode,and the negative electrode potential of batteries undergoing high-temperature cycling is analyzed.The occurrence of lithium plating in batteries subjected to high-temperature cycling is identified,resulting in an average charging current reduction of 61.7% compared to pristine cells.Furthermore,a comprehensive charge state-temperature-current contour map is established for batteries with lithium plating.A reduction of 69.84% in the charging current region above 200 A is demonstrated through comparative analysis with the contour map of pristine batteries.A quantitative metric for assessing the degradation of charge performance in batteries with lithium plating is provided by this study,underscoring the necessity of considering these factors in the comprehensive lifecycle management of lithium-ion batteries.