Dendrite growth in the recharging process of zinc-air batteries

To improve the cycling performance of rechargeable zinc-air batteries, the dendritic morphology of electrodeposited zinc should be effectively controlled. It is of crucial importance to understand the formation mechanism of the zinc dendritic structure. Here we show that an electrochemical phase-field model is established to simulate dendrite growth of electrodeposited zinc, and several measures including the pulsating current and the electrolyte flow are taken to suppress dendrite growth in the charging process. The results demonstrate that dendrite propagation is mainly controlled by diffusion dependent on overpotential and surface energy anisotropy, and dendritic morphology can also give rise to non-uniform distribution of the electric field and ion concentration in the electrolyte. The proposed model and solutions will be available for studying dendrite growth of metal-air batteries as well as metal electrodeposition.