Stress induced by diffusion and local chemical reaction in spherical composition-gradient electrodes

Abstract

Composition-gradient electrodes with their excellent electrochemical performance and mechanical durability are superior to homogeneous ones. In this work, taking into account the local solid reaction and composition-gradient electrode, a generalized diffusion–deformation–reaction model with E, D, and $$\Omega $$-dependent r under potentiostatic operation is developed. Then, some numerical simulations are performed to obtain the evolutions of concentration, radial stress, and tangential stress. The influences of Thiele number and reaction order on the concentration and stresses are also discussed. Finally, some comparisons between composition-gradient electrodes and homogeneous ones are made to show that the composition-gradient electrode is more helpful to improve the mechanical durability of Li-ion batteries than the homogeneous one.