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 ZnSO 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 Zn ions. The large molecule structure also exhibits a steric hindrance effect, regulating the diffusion and reduction of Zn. 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.