Hydrogen peroxide promotes zinc deposition nucleation and boosts the reversibility of aqueous rechargeable zinc-ion batteries

Aqueous zinc-ion batteries are a promising option for rechargeable energy storage devices. However, their performance is limited by the growth of zinc dendrites that can cause short circuits. Our research shows that adding a certain percentage of hydrogen peroxide solution to the electrolyte can effectively inhibit the irregular and non-planar growth of zinc dendrite crystals. This additive alters the deposition pattern of zinc and reduces surface roughness. Our experimental results indicate that the electrolyte with H2O2 can increase the cycle life by about 13 times compared to the electrolyte without the additive, extending it to 1057 h. The mechanism analysis reveals that H2O2 replaces H2O in forming hydrated zinc ions and facilitates zinc deposition during charging. Additionally, H2O2 significantly lowers the over-potential for zinc dendrite nucleation and suppresses the tip effect, leading to a uniform zinc morphology. This simple and eco-friendly electrolyte additive provides a strategy to regulate the deposition behavior of zinc.