锂离子电池高温贮存容量衰减分析  

Capacity fading analysis of lithium-ion battery after high temperature storage

作　　者：程广玉[1] 刘新伟 梅悦旎 顾洪汇[1] 杨丞[1] 王可[1] CHENG Guangyu;LIU Xinwei;MEI Yueni;GU Honghui;YANG Cheng;WANG Ke(State Key Laboratory of Space Power Technology,Shanghai Institute of Space Power Sources,Shanghai 200245,China;Shanghai Power&Energy Storage Battery System Engineering Tech.Co.Ltd.,Shanghai 200241,China)

机构地区：[1]空间电源技术国家重点实验室,上海空间电源研究所,上海200245 [2]上海动力储能电池系统工程技术有限公司,上海200241

出　　处：《储能科学与技术》2022年第5期1339-1349,共11页Energy Storage Science and Technology

摘　　要：为了探究锂离子电池高温贮存后的容量衰减因素,研制了额定容量1.6 Ah的18650锂离子电池,并且负极采用预锂化技术。对比分析了电池常温及70℃分别满电贮存5个月后的容量损失、恢复容量、微分容量、电化学阻抗谱、形貌、结构、元素含量及热分析等。结果表明,电池70℃搁置后放电容量仅为25℃搁置后容量的79.14%,其中可逆容量损失占比为52.8%。电池的不可逆容量衰降源于严重的正负极失衡,其中未预锂化电池主要为负极损失,而预锂化电池由于负极锂过量主要表现为正极损失。70℃搁置电池内阻更高,特别是负极增加明显。70℃负极表面更多的“死锂”,更高的氧含量,意味着表面更多的副反应。此外,高温搁置并未对材料结构造成影响。A 1.6 Ah 18650 lithium-ion nominal capacity battery with a prelithiation process was developed to determine the capacity fading factors of lithium-ion batteries after high-temperature storage.Comparative analysis of the capacity loss,capacity recovery,d Q/d V,EIS,SEM,XRD,EDS,ICP,and thermal analysis of the battery storage under RT and 70℃after five months at100%SOC,respectively.The results demonstrate that the battery’s discharge capacity at70℃is only 79.14%of its capacity at 25℃,and the reversible capacity loss accounts for52.8%.The irreversible capacity loss is primarily due to the severe imbalance between the cathode and anode.The nonprelithium battery is subjected to anode fading,whereas the prelithium battery undergoes cathode fading due to the excessive lithium in the anode.Furthermore,the internal resistance of the battery storage under 70℃is greater than that under 25℃,particularly when the anode quantity increases.There is significantly more"dead lithium"on the surface of the anode for the battery storage under 70℃and more oxygen content was observed,meaning more side reactions on the surface.Moreover,high-temperature storage did not affect the structure of the electrode materials.

关 键 词：高温贮存 容量衰减 自放电 预锂化 锂离子电池 

分 类 号：TM912.9[电气工程—电力电子与电力传动]