Polyhydroxy starch with abundant hydroxyls and a unique structure enables uniform Zn deposition

Zinc metal is a promising anode material for zinc-ion batteries (ZIBs), but severe side reactions and dendrite formation hinder its commercialization. In this study, starch is introduced into the ZnSO₄ electrolyte for stabilizing the Zn anode. With abundant hydroxyl groups, starch can reconstruct the H-bond system in the electrolyte, suppressing side reactions. Moreover, the unique ring and double-helix structures of starch show strong interactions with Zn²⁺ ions. The large molecule structure also exhibits a steric hindrance effect, regulating the diffusion and reduction of Zn²⁺. Additionally, starch molecules can adsorb onto the Zn anode, promoting the formation of a solid-electrolyte interphase (SEI) and resulting in uniform Zn deposition along the (002) plane. Consequently, this approach enhances the stability and reversibility of the Zn anode.