Chelation-Driven Effect on Electrolyte Modulation Toward Highly Reversible Zinc Metal Anode

Aqueous zinc metal-based batteries are emerging as a viable energy storage technology, but suffer from poor interfacial stability between Zn metal and aqueous electrolytes, leading to dendritic growth and hydrogen evolution. Here, a bidentate chelating ligand, bipyridine (BPY) bearing two nitrogen donor sites, is employed as an additive, preferentially coordinating with Zn^{2 +} to occupy the primary solvation shell, thereby expelling water molecules and facilitating the involvement of sulfate ions in the solvation structure. This chelation-driven modulated electrolyte enables sulfate ion reduction to form a robust, zincophilic, sulfide-rich solid electrolyte interphase (SEI) layer on the Zn surface without sacrificing the additive. Moreover, this electrolyte modulation also plays a crucial role in suppressing Zn corrosion while promoting a homogeneous Zn^{2 +} ion flux and smooth Zn morphology during deposition. As a result, Zn plating/stripping demonstrates ultrahigh stability for more than 3800 h, and the assembled Zn-iodine full cell delivers stable cycling performance over 10 000 at 3 A g^{- 1}, highlighting the practical applicability of the chelation-driven modified electrolyte.