Water‐Deficient Interface Induced via Hydrated Eutectic Electrolyte with Restrictive Water to Achieve High‐Performance Aqueous Zinc Metal Batteries

Authors: Ping Luo, Yuyuan Wang, Wenwei Zhang, Zhen Huang, Feiyang Chao, Yuxin Yuan, Yipeng Wang, Yufan He, Gongtao Yu, Dongyao Zhu, Zhaoyang Wang, Han Tang, Qinyou An

Published: 2025-01-23

DOI: 10.1002/smll.202410946

Source: Full article


Abstract

AbstractThe development of aqueous zinc metal batteries (AZMBs) is hampered by dendrites and side reactions induced by reactive H2O. In this study, a hydrated eutectic electrolyte with restrictive water consisting of zinc trifluoromethanesulfonate (Zn(OTf)2), 1,3‐propanediol (PDO), and water is developed to improve the stability of the anode/electrolyte interface in AZMBs via the formation of a water‐deficient interface. Additionally, PDO participates in the Zn2+ solvation structure and inhibits the movement of water molecules. PDO also preferentially adsorbs along the Zn (100) plane, thereby inducing the formation of the organic/inorganic SEI layer that enables the cycle life of a Zn//Zn symmetric cell to reach 3000 h at 1 mA cm−2 and 1 mAh cm−2. Further, interfacial modulation by the eutectic electrolyte improves the cycling stability of Zn//V2O5 and Zn//VO2 cells. Particularly, the specific capacity of a Zn//V2O5 cell with the eutectic electrolyte is 1.7 times that of a cell with the 2M Zn(OTf)2 electrolyte, with a capacity retention of 93% after 100 cycles at 0.5 A g−1. This study provides a new perspective on the electrolyte modification strategies for AZMBs, highlighting the potential of PDO‐8 electrolyte in developing aqueous energy storage devices with excellent cycling stability.