Role of Stress Concentrations on the Electrochemical Response of a Li-Ion Battery Anode Particle

Abstract

© The Author(s) 2019. Several numerical voltammetry simulations are used to evaluate the role of stress concentrations on the electrochemical response of an anode particle with geometric discontinuities. The effect of two-way stress-diffusion interaction, on the magnitudes of the mechanical stresses induced, is also estimated. Effects of stresses on electrochemical response increases (decreases) with the sweep rate when the particle was first discharged (charged). Stress concentrations are analyzed for several particle and hole sizes, and hole locations. It was found that the dependence of electrochemical response on stress is influenced more by the size of the hole rather than its position. When two-way interactions between stresses and diffusion were considered, the peak stresses induced were found to be 0.3 to 0.5 times the value induced when the influence of stress on diffusion was neglected. Overall, the study shows that stress-concentrations significantly affects the electrochemical behavior of a particle. Further, numerical modeling should include a two-way interaction between stress and diffusion so as to not overpredict stresses in an electrode particle.