摘要
近年来,随着气候变化和化石资源的匮乏,汽车工业重心逐渐由内燃机车转变到新能源汽车上。其中,电动汽车因其绿色、清洁和环保的特性得到迅猛发展,锂离子电池以其高能量密度、高功率密度、低自放电率等特性,成为商业化电动汽车首选的动力来源之一。尤其在市场需求驱动下,电动汽车续航里程逐步增长,锂离子电池不仅需要具备较高的电池容量,还需具备快速充电的能力,这对动力电池系统的安全、长寿命运行提出了更高的要求。锂离子电池的衰减老化是造成电动汽车“里程焦虑”的根源,也是电动汽车安全事故发生的重要原因,尤其在较低温度和大功率充电的条件下会引起电池的容量和输出功率等性能加速衰减的问题。本文着眼于现有文献的回顾与总结,针对锂离子电池在快速充电的条件下析锂机制、模型和快速充电的优化策略进行了综合分析总结,以期为高效无损快充的实现提供参考。
Reducing environment pollution and greenhouse gas emission can be the greatest challenge for the technological innovation and development of the automobile industry. Therefore,new energy to replace the traditional fossil fuels is needed to be devoloped,so as to alleviate the problem. Electric vehicles have attracted more and more attention due to their advantages of simple structure,high energy efficiency,low noise and no pollution,at present,the development of electric vehicles has become an inevitable trend.The lithium-ion battery is one of the most commonly used power source in the electric vehicles since its performance of high energy density,long cycle life and low self-discharge. However,for electric vehicles,the problems such as short driving range and long charging time are still to be solved,and the battery life cannot fully meet the needs of uses,which limits the further development of electric vehicles. Nowadays,researchers have done many research on the fast charging of electric vehicles,and have made great process,but most of the experiments were still in the laboratory stage. Relevant research showed that many side reactions happened in the process of fast charging,which included lithium plating,solid electrolyte interphase(SEI)growth and gas generation. Therein,this work first analyzed the mechanism and model of lithium plating. Lithium plating was a representative aging phenomenon of lithium-ion batteries,which usually occured during charging at low temperatures,high SOC(state of charge)and high charge rates. These factors might lead to high polarization of the negative electrode,namely,poor electrode kinetics,which forced the graphite potential below 0 V(vs. Li/Li+),thus causing the lithium plating phenomenon of the lithium-ion batteries. On one hand,the instant detection methods played a vital role in batteries safety,commonly used detection methods included scanning electron microscopy(SEM),transmission electron microscopy(TEM),nuclear magnetic resonance(NMR)and X-ray diffraction(XRD). Nevertheless,these methods generally required the battery to have a special structure or be specially disassembled. On the contrary,the used non-destructive methods did not make special requirements for the cell,which included aging rates,voltage plateaus exhibited during lithium stripping,model-based prediction. In the other hand,models tocharacterize lithium plating included the pseudo-two-dimensional(P2D)model,reduced-order model,electrochemical model and others were introduced. Besides,the method for fast charging of lithium-ion batteries to suppress lithium plating was introduced. Generally speaking,the types of charging protocols for fast charging could be divided into constant currentconstant voltage(CC-CV),multistage constant current(MCC),boost charging,variable current profile(VCP),constant power-constant voltage(CP-CV)and pulse charging. This paper mainly summarized the common strategies of fast charging to suppress lithium plating,which included two kinds of inhibition strategies,one was lithium plating inhibition based on electrolyte additives,the other was lithium plating inhibition based on fast charging strategy. Wherein,the relevant research indicated that the electrolyte additives could effectively inhibit the phenomenon of lithium plating,for example the bisfluoroacetamide(BFA)was used as the electrolyte additive for the construction of gradient SEI structure that could endow the homogeneous deposition of Li ions and the generation of lithium dendrite was reduced. Additionally,the inhibition of lithium plating could be realized by optimization based on physical characteristics and models. The physical strategy could evaluate the degree of lithium plating inside the battery by measuring the electrode thickness and the hybrid finite volume-spectral scheme. Furthermore,the charging strategy could be optimized by establishing equivalent circuit models(ECM),which were reformulated and embedded into single-objective or multi-objective constrained optimization problems,side reactions such as battery aging caused during charging could be embedded into basic ECM through the electrothermal aging coupling model to reduce the battery temperature rise and aging phenomenon. In addition,the Arrhenius formula could simulate the aging phenomenon well on the basis of combining the total discharge,charging rate and capacity of the battery. As mentioned above,by establishing a framework for optimization problems and combining constraints,a suitable fast charging control algorithm could be developed to reduce side reactions such as lithium plating and aging during fast charging. The traditional controlalgorithms included:dynamic programming,Pontiac minimum principle,genetic algorithm,Legendre-Gauss-Radau(LGR)pseudo-spectral method,and minimum-maximum strategy. Moreover,the electrochemical models could be used to estimate the internal state of the battery,because they could predict the side effects during the charging process. At present,the most widely used electrochemical model was the P2D model,and the other model included full order model(FOM),single particle(SP)model and reduced order model(ROM). Finally,according to the future development trend,the online monitoring algorithm of battery lithium plating could be combined with cloud computing. The integration of historical data and real-time data,equivalent circuit model and electrochemical model could be realized in the cloud,which was expected to develop advanced real-time lithium plating monitoring technology.
作者
梁峰伟
夏煜华
张玉龙
赵树朋
杨世春
刘新华
Liang Fengwei;Xia Yuhua;Zhang Yulong;Zhao Shupeng;Yang Shichun;Liu Xinhua(School of Mechanical and Electrical Engineering,Hebei Agricultural University,Baoding 071001,China;School of Earth Sciences and Engineering,Imperial College London,London SW72AZ,UK;School of Transportation Science and Engineering,Beihang University,Beijing 100191,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2022年第9期1235-1243,共9页
Chinese Journal of Rare Metals
基金
国家重点研发计划“新能源汽车”重点专项项目(2018YFB0104001)
国家新能源汽车重大专项项目(2018YFB0105400)资助。
关键词
锂离子电池
快充
析锂
模型
优化策略
lithium-ion battery
fast charging
lithium plating
model
optimization strategy
作者简介
梁峰伟(2000-),男,河南安阳人,本科生,研究方向:车辆工程,E-mail:LFW20000316@163.com;通信作者:张玉龙,副教授,电话:18311401318,E-mail:zhangyulong@hebau.edu.cn。
