Phase-field modeling of zinc dendrites growth in aqueous zinc batteries

The growth of zinc dendrites poses a major challenge in developing stable aqueous zinc batteries. It is crucial to understand the mechanism underlying dendrite growth and the influences of various factors on the process of dendrite growth. In this study, a phase field model is constructed to simulate the growth of zinc dendrite and investigate the temporal and spatial distributions of ions and electric potential in both static and flowing electrolytes. The influences of various critical factors, including overpotential, anisotropic strength and electrolyte flow rate, on the morphology evolution of electrodeposit are investigated. Results reveal that the surface morphology evolution is intimately dependent on the competition between ion transport and the electrochemical reaction, and it can be modulated by various parameters. In particular, flowing electrolyte not only enhances the convective ion transport but also suppresses the dendrite bifurcation on the surface, resulting in a uniform distribution of the concentration gradient and a compact deposit. However, nonuniformity induced by the flowing electrolyte from the inlet to outlet may impede the stable cycling of zinc anodes in the flow batteries. Therefore, further design and optimization of the flow field are desired for zinc-based flow batteries. This work provides insights into the growth process of zinc dendrites and the influences of several critical parameters, which could inform the design of stable aqueous zinc batteries.