外载对球形颗粒电极锂化过程的扩散影响  

The diffusion effect of external loads on the lithiation process of spherical particle electrodes

作　　者：冯超 张锴[1] 郑百林[1] FENG Chao;ZHANG Kai;ZHENG Bailin(School of Aerospace Engineering and Applied Mechanics,Tong Ji University,Shanghai 200092,China)

机构地区：[1]同济大学航空航天与力学学院,上海200092

出　　处：《电源技术》2024年第5期829-834,共6页Chinese Journal of Power Sources

摘　　要：锂离子电池在使用过程中不可避免地受到外部机械载荷的作用,而这种载荷会对电池产生重要影响。基于小变形和线弹性等理论建立了在外部机械载荷作用下的球形颗粒电极锂化过程的力化耦合模型。计算结果表明,随着扩散持续,外部应力梯度对扩散过程的影响逐渐增大,稳态时球心处锂离子浓度低于球表面处浓度。正应力梯度对离子的扩散具有抑制作用。而对于复杂形式的外载,稳态时锂离子浓度沿径向呈现非线性不均匀分布状态。Lithium ion batteries are inevitably subjected to external mechanical loads,which can have a significant impact on the battery.In this paper,a chemomechnical coupled model for the lithiation process of a spherical particle electrode under external mechanical loads is established based on the theories of small deformation and linear elasticity.It is found that the influence of external stress gradient on diffusion process gradually increases as the diffusion processes,and the lithium ion concentration at the center of the sphere is lower than that at the surface of the sphere at the steady state.The positive stress gradient has an inhibitory effect on diffusion of lithium ion.For complex external loads,the lithium ion concentration shows a nonlinear and non-uniform distribution along the radial direction at the steady state.

关 键 词：锂离子电池 外部机械载荷 球形电极 扩散诱导应力 

分 类 号：TM912[电气工程—电力电子与电力传动]