基于电化学模型的车用锂离子电池安全快速充电算法

摘要

Although traditional fast charging methods can increase charging time of lithium ion battery,they are usually detrimental to battery life and causes safety problem.A control-oriented electrochemical model of lithium ion battery was used to develop a novel model-based fast charging algorithm to solve the problem of accelerated degradation or safety issues during the fast charging.The algorithm was validated by charging a commercial Li(NiMnCo)O2 (NMC) cathode battery of 42 Ah.The effect of the key parameters of the strategy on the algorithm performance,such as threshlod potential and initial charging rate,were also discussed.The results show that safe fast charging was achieved and charging rate was enhanced by 20.5％.As the critical parameters in the algorithm,threshold potential and initial charging rate influenced the charging time and anode overpotential during charging.%传统的快充方法可提升锂离子电池充电速度,但容易损害电池寿命,甚至造成安全问题.基于面向控制的锂离子电池电化学机理模型,提出了全新的快速充电算法.针对一款42Ah镍钴锰(NMC)三元锂离子电池,采用该算法进行了快速充电测试,讨论了开发策略中关键参数阈值电势、初始充电倍率的取值对算法效果的影响.结果表明:该方法实现了该款锂离子电池的安全快速充电,在保持电池不析锂情况下将电池充电速度提高了20.5％;算法中的阈值电势主要影响充电时间,而初始充电倍率影响负极过电势最低值.