微电滥用条件下磷酸铁锂和三元锂离子电池的性能衰减研究  

Performance degradation investigation of lithium iron phosphate and ternary lithium-ion batteries under slight electrical abuse condition

作　　者：魏港 黄冉军 姜波 蔡吉祥[1,2] 许文韬 朱建功 王学远[1,2] 魏学哲[1,2] 戴海峰[1,2] WEI Gang;HUANG Ranjun;JIANG Bo;CAI Jixiang;XU Wentao;ZHU Jiangong;WANG Xueyuan;WEI Xuezhe;DAI Haifeng(School of Automotive Studies,Tongji University,Shanghai,201804,China;Clean Energy Automotive Engineering Center,Tongji University,Shanghai,201804,China)

机构地区：[1]同济大学汽车学院,上海201804 [2]同济大学新能源汽车工程中心,上海201804

出　　处：《电池工业》2025年第2期110-121,共12页Chinese Battery Industry

基　　金：国家自然科学基金(52207242);国家自然科学基金(52307248)。

摘　　要：当前锂离子电池被广泛应用于清洁交通和规模储能场景中,然而由于电池制造单体一致性以及服役容量衰减速度的固有差异性,电池在运行过程中常出现轻微过度充电这一电滥用工况。进一步的滞后维护会带来循环积累效应,对电池的规模成组应用造成可靠性挑战和安全隐患。因此对主要电池类型在所述工况下的性能衰减特性进行研究具有重要意义。本文以磷酸铁锂和镍钴锰三元锂离子电池为研究对象,开展了正常循环老化和微过充循环老化试验。结果显示,磷酸铁锂电池在两种循环工况下的性能衰减特性差异较小,而三元电池在微过充循环工况下的性能衰减速度显著快于正常循环工况。结合电化学阻抗测试,通过等效电路模型和弛豫时间分布等分析方法,揭示了微过充循环工况下三元电池健康状态显著下降的主要原因:固体电解质界面膜等效电阻和传荷电阻的增长导致更严重的锂库存损失。相比之下,磷酸铁锂电池对微电滥用循环工况的抗性更为优异,固体电解质界面膜等效电阻和传荷电阻变化较小,相应的锂库存损失有限,因此在设定的循环圈数内,其性能衰减幅度与正常循环工况相比并未显著增加。Currently,lithium-ion batteries are widely used in clean transportation and scale energy storage applications,however,due to the inherent variability in the consistency of batteries manufacture and the capacity degradation rate in service,the batteries are often subjected to slight overcharge during operation,and the cyclic accumulation effect caused by further delayed maintenance will pose the reliability challenge and safety hazard to the large-scale group application of batteries,therefore it is valuable to investigate the performance degradation of the main battery types under the mentioned conditions.In this paper,normal cycle aging and slight overcharge cycle aging tests were conducted on lithium iron phosphate and nickel-cobalt-manganese ternary lithium-ion batteries.The results show that the performance degradation characteristics of lithium iron phosphate batteries under two cycle conditions are quite small,while the performance degradation of ternary batteries under slight overcharge cycle condition is much faster than that under normal cycle condition.Combined with electrochemical impedance tests and analysis methods such as equivalent circuit models and distribution of relaxation times,it is revealed that the main cause of the significant degradation of state of health for ternary batteries under the slight overcharge cycle condition is the more severe loss of lithium inventory due to the increase of the solid electrolyte interphase equivalent resistance and the charge transfer resistance.In contrast,the lithium iron phosphate batteries are more tolerant to the slight abuse cycle condition,with little change in the solid electrolyte interphase equivalent resistance and charge transfer resistance,and limited loss of lithium inventory,resulting in no more serious performance degradation compared with the normal cycle condition for the set number of cycles.

关 键 词：锂离子电池 微电滥用 过充循环 性能衰减 电化学阻抗 等效电路模型 弛豫时间分布 

分 类 号：TM912[电气工程—电力电子与电力传动]