The electrochemical and mechanical performance of lithium-ion batteries is greatly affected by the porous electrode materials and dislocation effect. A diffusion-mechanical coupling model of porous electrode particle with dislocation effect is developed under potentiostatic operation in this work. Then, the distributions of lithium-ion concentration, volumetric strain and stress in the electrode particles with/without dislocation effect are analyzed. Finally, the influences of porosity and tortuosity on the lithium-ion concentration, volumetric strain, radial stress, hoop stress and strain energy are numerically discussed, respectively. The results show that dislocation effect retards the diffusion and relieves the electrode particle expansion and stresses. Moreover, larger porosity or smaller tortuosity can enhance the charge efficiency and avoid electrode particle damage or crack nucleation and propagation by reducing the stress and strain energy. Finally, from the perspective of fracture, dislocation effect can resist the crack propagation or avoid the formation of cracks during charge. This work will provide some theoretical guidance to improve the charge efficiency and prolong battery life.

锂离子电池的电化学和机械性能受多孔电极材料和位错效应的影响很大。本工作建立了恒电位操作下具有位错效应的多孔电极颗粒的扩散-机械耦合模型。然后，分析了有/无位错效应的电极颗粒中锂离子浓度、体积应变和应力的分布。最后，分别数值讨论了孔隙率和弯曲度对锂离子浓度、体积应变、径向应力、环向应力和应变能的影响。结果表明，位错效应阻碍了扩散并减轻了电极颗粒的膨胀和应力。此外，较大的孔隙率或较小的弯曲度可以提高充电效率，并通过降低应力和应变能来避免电极颗粒损坏或裂纹成核和扩展。最后，从断裂的角度来看，位错效应可以抵抗裂纹的扩展或避免充电过程中裂纹的形成。这项工作将为提高充电效率、延长电池寿命提供一定的理论指导。