Effect of electrochemical reaction on diffusion-induced stress in hollow spherical lithium-ion battery electrode

Abstract

During the process of lithium-ion intercalation and de-intercalation, the electrode undergoes huge volumetric change. Diffusion-induced stress (DIS) has been investigated in solid and hollow spherical electrode. In this work, a new coupled model is established in a hollow spherical electrode to analyze the DIS with electrochemical reaction. The result shows that electrochemical reaction has a significant influence on the distribution of DIS, which can make the tensile stress decline and even convert the stress from tension to compression. The tendency to avoid the electrode fracture and failure induced by DIS is thus beneficial. Compared to stress evolution in solid and hollow sphere electrode, electrochemical-induced stress in solid electrode is much smaller than that in hollow electrode. Also, reaction-induced stress will keep increasing with the wall thickness decreases. Finally, a new strategy is put forward to optimize the reaction-induced stress and the electrode thickness, which may ultimately extend the overall battery life.