High‐Acceptor Fluoroalcohol Mediated Anion‐Solvation Enables Durable Zn‐V Batteries

Abstract

Abstract Aqueous zinc batteries (AZBs) are promising low‐cost and safe energy storage devices, yet suffer from dendrite growth and parasitic reactions caused by H 2 O‐rich solvation structure in conventional electrolytes. While high donor number (DN) co‐solvent strategies effectively reduce the H 2 O molecules in Zn 2+ inner solvation sheath, they fail to facilitate Zn 2 ⁺ migration or de‐solvation. Herein, an anion‐solvation strategy using a high acceptor number (AN) co‐solvent, 2,2,3,3‐tetrafluoro‐1‐propanol (TFP), is proposed to address these challenges. Rationally, TFP with high AN strongly promotes TFP–anion and TFP–H 2 O interactions while reducing their interaction with Zn 2 ⁺, leading to a H 2 O‐poor Zn 2+ solvation sheath, which not only enhances Zn 2 ⁺ transference number and de‐solvation kinetics but also lowers H 2 O activity to suppress parasitic reactions and cathode dissolution. Hence, this anion‐solvation electrolyte bestows highly reversible Zn plating/striping over 9000 h with a high Coulombic efficiency of 99.8%. The Zn‐V full cell delivers outstanding cycling performance, maintaining 98.8% capacity after 200 cycles at 0.25 A g −1 and 96.3% capacity after 900 cycles at 1 A g −1 . This anion‐solvation strategy opens up a new frontier in electrolyte developments toward high‐performance aqueous batteries.