摘要
钛酸锂电池具有高安全、快速充放电能力以及长的循环寿命,在储能调频市场应用前景广阔。然而目前关于不同荷电状态下的高倍率循环老化研究较少。本工作面向短时高频次储能应用场景需求,以商用钛酸锂电池为研究对象,系统探究了在不同SOC区间上限和SOC区间下限循环条件下,以4 C倍率进行充放电循环老化的钛酸锂电池电化学性能演变规律,并通过容量增量曲线和电压微分曲线等无损分析手段,解析了钛酸锂电池容量热力学衰减的主导模式。实验结果表明,随着SOC区间上限条件的增加或SOC区间下限条件的降低,钛酸锂的循环容量显著降低。同时,高荷电区间下负极嵌锂深度的补偿以及恒压充电过程的修复作用,使得钛酸锂电池在高荷电区间的循环稳定性优于低荷电区间。对充电曲线的分析表明,钛酸锂电池容量衰减规律与SOC区间条件具有强相关性。活性锂损失是导致钛酸锂电池在(0~100%)SOC、(0~80%)SOC、(80%~100%)SOC区间循环发生容量衰减的主要因素。而(20%~100%)SOC区间循环的钛酸锂电池容量衰减主要由正极活性材料损失引起。这些工作揭示了SOC区间对钛酸锂电池高倍率循环容量衰减的影响规律,为推动钛酸锂电池在短时高频次储能场景的应用提供了理论指导。
Lithium titanium oxide(LTO)batteries offer high safety,rapid charge-discharge capabilities,and long cycle life,presenting significant potential for application in energy storage and frequency modulation markets.However,research on high-rate cyclic aging under different state-of-charge(SOC)ranges remains limited.This study addresses the requirements of short-term,high-frequency energy storage scenarios by investigating commercial LTO batteries.The evolution of electrochemical performance in LTO batteries cycled under different SOC upper and lower limit conditions at a rate of 4 C was examined.Using non-destructive analysis methods such as incremental capacity curves and differential voltage curves,the dominant mechanisms of thermodynamic capacity decay were analyzed.Experimental results indicate that as the upper SOC limit increases or the lower SOC limit decreases,the cycling capacity of LTO batteries significantly decreases.Meanwhile,the compensation of lithium insertion depth in the negative electrode within high SOC ranges and the repair effect during constant voltage charging improve cycling stability in high SOC ranges compared with low SOC ranges.Analysis of the charge curves reveals a strong correlation between capacity degradation and SOC interval conditions.The loss of active lithium is the primary factor contributing to capacity degradation during cycling in 0%—100%SOC,0—80%SOC,and 80%—100%SOC ranges.In contrast,in the 20%—100%SOC range,capacity degradation is mainly caused by the loss of active material in the positive electrode.When cycled in the low SOC range(0—20%),the contributions of active lithium loss and positive electrode active material loss to capacity decay are comparable.These findings elucidate the influence of SOC range on high-rate cycling capacity degradation in LTO batteries,providing theoretical guidance for their application in short-term,high-frequency energy storage scenarios.
作者
钟晓晖
李将渊
陆玮
张乾能
张辉
郑卓群
解晶莹
罗英
ZHONG Xiaohui;LI Jiangyuan;LU Wei;ZHANG Qianneng;ZHANG Hui;ZHENG Zhuoqun;XIE Jingying;LUO Ying(Ningbo Beilun Third Container Terminal Co.,Ltd.,Ningbo 315813,Zhejiang,China;Huzhou Yongxing Lithium Battery Technology Co.,Ltd.,Huzhou 313000,Zhejiang,China;State Key Laboratory of Space Power Sources,Shanghai Institute of Space Power-Sources,Shanghai 200245,China)
出处
《储能科学与技术》
北大核心
2025年第8期2960-2969,共10页
Energy Storage Science and Technology
基金
国家自然科学基金项目(U23B20171)。
关键词
钛酸锂电池
SOC区间
循环老化
容量衰减
lithium titanium oxide batteries
state-of-charge range
cyclic aging
capacity fade
