Suppression of zinc dendrites via electrolyte and anode interfacial modification in Zinc-air battery: simulation and experiment

The formation and distortion of zinc dendrites significantly degrade the cycle life of zinc-air batteries. In this study, we developed and experimentally validated a phase-field model to simulate zinc dendrite growth. The model shows strong agreement with experimental data, with an average relative error of 8.51%. Key factors influencing dendrite morphology and vertical growth during charging were systematically investigated, including charging duration, anode surface anisotropy (strength and modulus), surface diffusion coefficient, and electrolyte temperature. Based on these findings, strategic approaches, particularly the modulation of surface anisotropy through zinc anode alloying, were experimentally validated. The results indicate that reducing surface anisotropy strength and enhancing anisotropy modulus, achieved by alloying with Zn-3.5%In, Zn-6.5%Yb, or Zn-5%Mg, effectively suppress dendritic growth. Additionally, lowering concentration polarization though increasing the anode surface diffusion coefficient by alloying with Zn-3.5%In or raising electrolyte temperature to 323-343 K can also reduce zinc dendrite growth. Finally, electrolyte flow of 35-40 mL/min can further suppress dendrite proliferation.