锂离子电池安全性能评估及过充电实例分析

Safety performance evaluation and overcharge case analysis of lithium-ion battery

锂离子电池在全生命周期使用过程中,不可避免地面临控制失效、外界碰撞、浸水等问题,导致电池出现电滥用、热滥用或机械滥用,严重时引发热失控,造成安全事故。现有电池安全评价方法仅用于研发阶段的定性测试,基于电池的安全状态与滥用程度成反比这一假定,提出一种电池安全性能实时量化评估方法。针对多类典型滥用模式展开分析并提出多种安全状态计算公式。开展了一款大容量三元电池的过充电热失控实验,基于温度和电压数据计算电池的安全状态变化曲线,有助于及时准确地实现电池安全预警。

Lithium-ion batteries inevitably face some problems such as control failure,external collision and water immersion during the entire life cycle of use,which lead to electrical,thermal,or mechanical abuse of the battery,in severe cases,causing thermal runaway and safety accidents.The existing battery safety assessment methods are only used for qualitative testing in the research and development stage.Based on the assumption that battery safety status is inversely proportional to the abuse,a real-time quantitative assessment method for battery safety performance was proposed.Based on the analysis of various typical forms of abuse,a variety of battery safety state calculation formulas were proposed.An overcharge thermal runaway experiment of a large-capacity ternary battery was carried out,and the safety state curves of the battery were calculated based on the battery temperature and voltage,which contributes to the timely and accurate battery safety warning.