Interaction between dislocation mechanics on diffusion induced stress and electrochemical reaction in a spherical lithium ion battery electrode

摘要

The effect of coupling dislocation induced stress with electrochemical reaction in a spherical battery electrode is investigated. A new coupled model among diffusion, dislocation, reversible electrochemical reaction is established by combining diffusion induced stress (DIS), dislocation induced stress and forward reaction induced stress in the spherical electrode. The results of our model show that the interaction between dislocation induced stress and the forward reaction induced stress plays a significant role in decreasing the tensile stress and even the tensile state can be turned into the compressive stress, which may become a factor in resistance to fracture and decrepitation due to DIS. However, the electrochemical reaction results in the surface tangential stresses sharply increasing with a larger relative rate of reaction and diffusion. Therefore, we provide a new theoretical method to explain the volume change and understand the stress evolution in the electrode.