Biomimetic proton pocket and effective interfacial modulation for zinc metal anodes

Rechargeable aqueous zinc batteries（RAZBs） offer a promising solution for large-scale energy storage due to the abundance,low cost, and safety of Zn. However, practical applications are hindered by Zn anode instability, dendrite growth, and hydrogen evolution reactions（HER）. Chaotropic Zn（ClO4）2 electrolytes are favorable for low-temperature operations but exacerbate these issues due to their high acidity, leading to severe Zn corrosion and layered double hydroxide formation. We propose a biomimetic strategy using methylguanidoacetic acid（creatine） as a low-cost, eco-friendly additive to address these challenges. Creatine acts as a proton pocket to finely tune the p H of acidic Zn（ClO4）2 electrolytes for suppressing HER and stabilizing the Zn anode.Furthermore, the formed creatinine cations adsorb on the Zn surface, promoting highly controlled Zn deposition with a preferred（002） orientation. This approach significantly enhances battery cycling performance, with Zn||Zn cells demonstrating extended cycling stability at both low and high current densities. Zn||Cu cells exhibited improved Coulombic efficiency over thousands of cycles, indicating highly reversible Zn plating/stripping. Notably, stable cell operations were realized at the temperature as low as -35℃ without electrolyte freezing. Our findings highlight the potential of biomimetic proton regulation and interfacial modulation for improving the stability and reversibility of Zn plating/stripping in RAZBs.