Mechanisms for the evolution of cell-to-cell variations and their impacts on fast-charging performance within a lithium-ion battery pack  

作　　者：Yufang Lu Xiaoru Chen Xuebing Han Dongxu Guo Yu Wang Xuning Feng Minggao Ouyang 

机构地区：[1]State Key Laboratory of Intelligent Green Vehicle and Mobility,School of Vehicle and Mobility,Tsinghua University,Bejing 100084,China [2]Research Institute of Tsinghua University in Shenzhen,Shenzhen 518057.Guangdong,China [3]Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology.Department of Chemical Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Journal of Energy Chemistry》2024年第12期11-22,共12页能源化学（英文版）

基　　金：supported by the National Natural Science Foundation of China under No. 52177217;the Postdoctoral Innovative Talents Support Program under No. BX20240232。

摘　　要：Cell-to-cell variations(CtCV) compromise the electrochemical performance of battery packs, yet the evolutional mechanism and quantitative impacts of CtCV on the pack's fast-charging performance remain unexplored. This knowledge gap is vital for the proliferation of electric vehicles. This study underlies the relationship between CtCV and charging performance by assessing the pack's charge speed, final electric quantity, and temperature consistency. Cell variations and pack status are depicted using 2D parameter diagrams, and an m PnS configured pack model is built upon a decomposed electrode cell model.Variations in three single electric parameters, i.e., capacity(Q), electric quantity(E), and internal resistance(R), and their dual interactions, i.e., E-Q and R-Q, are analyzed carefully. The results indicate that Q variations predominantly affect the final electric quantity of the pack, while R variations impact the charge speed most. With incremental variances in cell parameters, the pack's fast-charging capability first declines linearly and then deteriorates sharply as variations intensify. This research elucidates the correlations between pack charging capabilities and cell variations, providing essential insights for optimizing cell sorting and assembly, battery management design, and charging protocol development for battery packs.

关 键 词：Lithium-ion battery Battery pack Cell-to-cell variation Fast charging Performance evaluation 

分 类 号：TM912[电气工程—电力电子与电力传动]