Effects of Hydrostatic Stress and Concentration-Dependent Elastic Modulus on Diffusion-Induced Stresses in Cylindrical Li-Ion Batteries

The effects of hydrostatic stress and concentration-dependent elastic modulus on diffusion-induced stress (DIS) in a cylindrical Li-ion battery are studied. It is found that the hydrostatic stress has little effect on the distribution of stresses but the change of elastic modulus has a significant effect on the distribution of stresses. The hydrostatic stress has little effect on the location of maximum hoop stress in active layer. The change of elastic modulus can slow down the trend with closing to the inner surface for the location of the maximum hoop stress in active layer with the thicker current collector or larger modulus of current collector and speed up the trend with closing to the outer surface with the smaller ratio of electrode radius to thickness. The current collector should be as thin and soft as possible when its premise strength is satisfied. The ratio of electrode radius to thickness should be preferably larger than 15.