高能量密度锂离子电池老化半经验模型  

Semi-empirical degradation model of lithium-ion battery with high energy density

作　　者：祝庆伟 俞小莉[2] 吴启超 徐一丹 陈芬放 黄瑞[2] ZHU Qingwei;YU Xiaoli;WU Qichao;XU Yidan;CHEN Fenfang;HUANG Rui(Polytechnic Institute,Zhejiang University,Hangzhou 310015,Zhejiang,China;College of Energy Engineering,Zhejiang University,Hangzhou 310027,Zhejiang,China)

机构地区：[1]浙江大学工程师学院,浙江杭州310015 [2]浙江大学能源工程学院,浙江杭州310027

出　　处：《储能科学与技术》2022年第7期2324-2331,共8页Energy Storage Science and Technology

基　　金：浙江省自然科学基金项目(LQ20E060008);浙江大学实验技术研究项目(SYB202109)。

摘　　要：电池循环老化过程中容量会不断衰退,内阻也会逐渐增长,从而影响电池的使用寿命与性能表现。为建立电池容量衰退与内阻增长半经验模型,缩短探究电池老化特性所需的实验时间,采用具有高能量密度的21700锂离子电池,在0℃、23℃和40℃条件下结合1 C和2 C两种放电倍率组成了六种工况,对电池进行循环老化实验,分析温度等因素对电池容量衰退与内阻增长特性的影响规律。在结合Arrhenius方程建立电池容量衰退半经验模型时,额外引入了两个关于循环次数的幂函数和常数项,拓展了容量衰退半经验模型的适用性,使其能够适用于不同温度下表现出的不同容量衰减趋势。采用双指数函数累乘的公式形式建立了电池内阻增长的半经验模型,能够有效地预测内阻在不同工况下的增长规律。并利用交叉验证的方法证明了容量衰退与内阻增长半经验模型的准确性,能够用于预测电池在其他温度条件下的老化规律。最后利用建立的电池老化半经验模型,预测了该电池在15℃、30℃和45℃的容量与内阻变化情况,有助于更全面地了解电池的老化特性,并避免了大量重复实验,有利于提高研究效率。The capacity of the battery will continue to fall as the cycle ages, and the internal resistance will progressively grow, affecting the battery’s service life and performance. To establish the semi-empirical model of capacity decline and internal resistance growth and shorten the time required to investigate the battery aging characteristics, the 21700 lithium-ion battery with high energy density is adopted to conduct the cycle aging experiment of the battery under six working conditions at 0 ℃, 23 ℃, and 40 ℃ combined with 1 C and 2 C discharge rates. The effect of temperature and other environmental conditions on battery capacity reduction and internal resistance increase is investigated.When the semi-empirical model of battery capacity decline is created by combining the Arrhenius equation, an additional power function and a constant term about the number of cycles are introduced, which can broaden the model’s applicability and make it suitable for different capacity decline trends at different temperatures. A semi-empirical model of battery internal resistance growth is developed using the double exponential function multiplication formula, which can effectively predict the law of internal resistance growth under various working conditions. The cross-validation approach is used to demonstrate the accuracy of semiempirical models of capacity decrease and internal resistance increase, which may be used to forecast the aging law of batteries at various temperatures. Finally, the semi-empirical model of battery aging is used to predict the capacity and internal resistance of the battery at 15 ℃,30 ℃, and 45 ℃, allowing for a better understanding of the battery’s aging characteristics while avoiding a large number of repeated experiments and increasing research efficiency.

关 键 词：锂离子电池 容量衰退 内阻增长 老化半经验模型 

分 类 号：TM911[电气工程—电力电子与电力传动]