Highly Stable Aqueous Zinc Anodes Enabled by Synergistic Modulation of Interface and Solvation Structures

ABSTRACT The stability of aqueous Zn 2+ batteries is severely hindered by parasitic reactions at the Zn anode/electrolyte interface. Herein, itaconic acid (IA) is introduced as an effective electrolyte additive to achieve a highly stable zinc anode. Remarkably, IA concurrently modulates both the zinc anode/electrolyte interfacial structure and the Zn 2+ solvation structure, thereby synergistically enhancing battery stability. Specifically, IA reconstructs the Zn anode/electrolyte interfacial configuration via specific adsorption, thereby forming a functional interface to suppress interfacial parasitic reactions and homogenize the local Zn 2+ flux. Additionally, IA participates in the Zn 2+ solvation sheath, which significantly reduces the desolvation energy barrier, thereby accelerating interfacial charge transfer kinetics. As a result, the Zn||Zn battery presents outstanding cycling performance over 2200 h at 5 mA cm −2 and 1 mAh cm −2 and stably cycles for more than 700 h at 10 mA cm −2 and 10 mAh cm −2 . Even at 85% depth of discharge, the Zn||Zn battery exhibits excellent cycling performance of over 200 h. The capacity retention of the Zn||I 2 full battery is 91.91% after 15,000 cycles. The Zn||I 2 pouch battery with a discharge capacity of 130 mAh demonstrates a long cycling lifespan of over 530 cycles.