Li Yong, Huang He, Zhang Kai, Hou Mi, Yang Fuqian
School of Intelligent Manufacturing and Control Engineering, Shanghai Polytechnic University, Shanghai 201209, China.
Jiangsu Key Laboratory of Engineering Mechanics, School of Civil Engineering, Southeast University, Nanjing, Jiangsu 210096, China.
iScience. 2023 Oct 10;26(11):108174. doi: 10.1016/j.isci.2023.108174. eCollection 2023 Nov 17.
Lithium trapping, which is associated with the immobilization of lithium and is one of key factors contributing to structural degradation of lithium-ion batteries during electrochemical cycling, can exacerbate mechanical stress and ultimately cause the capacity loss and battery failure. Currently, there are few studies focusing on how lithium trapping contributes to mechanical stress during electrochemical cycling. This study incorporates the contribution of lithium trapping in the analysis of mechanical stress and mass transport in the framework of finite deformation. Two de-lithiation scenarios are analyzed: one with a constant concentration of trapped lithium and the other with inhomogeneous distribution of trapped lithium. The results show that the constant concentration of trapped lithium increases chemical stress and the inhomogeneous distribution of trapped lithium causes the decrease of chemical stress. The findings can serve as a basis for developing effective strategies to mitigate the lithium trapping and improve the battery performance.
锂捕获与锂的固定化有关，是导致锂离子电池在电化学循环过程中结构退化的关键因素之一，它会加剧机械应力并最终导致容量损失和电池失效。目前，很少有研究关注锂捕获在电化学循环过程中如何导致机械应力。本研究在有限变形框架内，将锂捕获的影响纳入机械应力和质量传输分析中。分析了两种脱锂情况：一种是捕获锂浓度恒定，另一种是捕获锂分布不均匀。结果表明，捕获锂浓度恒定会增加化学应力，而捕获锂分布不均匀会导致化学应力降低。这些发现可为制定有效策略以减轻锂捕获并改善电池性能提供依据。
