Tea polyphenol-zinc ion complexes synergize with ZnSO4 electrolyte to stabilize zinc ion battery anode

In aqueous zinc-ion batteries, the growth of dendrite, hydrogen evolution reaction, and corrosion on the Zn anode result in rapid performance degradation and poor cycling stability, which significantly impede their commercial application. Herein, a tea polyphenol-zinc ion complex (denoted as Tp-Zn) is used as an electrolyte additive to reshape the Zn 2+ solvation structure and guide uniform zinc deposition. Tp-Zn interacts with water molecules via hydrogen bonding of hydroxyl groups, weakening the Zn 2+ -H 2 O solvation sheath and suppressing water-related side reactions. Moreover, Tp-Zn induces preferential Zn deposition, contributing to homogeneous zinc deposition. As a result, the Zn//Zn symmetric cell assembled with Tp-Zn achieves an ultra-long cycle life of over 4000 h at 0.5 mA cm −2 and more than 1300 h at 2.0 mA cm −2 . The Zn//Cu asymmetric cell can maintain stable plating and stripping for more than 900 cycles at 1.0 mA cm −2 , and the Zn//NaVO full cell maintains high specific capacity during stable cycling. This green and non-toxic Tp-Zn additive effectively stabilizes the Zn anode interface and enhances cycling durability, providing a new reference for the exploration of the commercialization of ZIBs.