“Water‐in‐Deep Eutectic Solvent” Electrolytes for High‐Performance Aqueous Zn‐Ion Batteries

作者：Jinqiang Shi, Tianjiang Sun, Junquan Bao, Shibing Zheng, Haihui Du, Lin Li, Xuming Yuan, Tao Ma, Zhanliang Tao · 发表于：Advanced Functional Materials · 年份：2021 · DOI：10.1002/adfm.202102035 · 被引用次数：282 · 研究领域：Advanced battery technologies research、Advanced Battery Materials and Technologies、Advancements in Battery Materials

Abstract Aqueous Zn‐ion batteries have been considered as promising alternatives to Li‐ion batteries due to their abundant reserves, low price, and high safety. However, Zn anode shows poor reversibility and cycling stability in most conventional aqueous electrolytes. Here, a new type of aqueous Zn‐ion electrolyte based on ZnCl2–acetamide deep eutectic solvent with both environmental and economic friendliness has been prepared. The water molecule introduced in the “water‐in‐deep eutectic solvent” electrolyte could reduce the Zn2+ desolvation energy barrier by regulating Zn2+ solvation structure to promote uniform Zn nucleation. Zn anode shows improved electrochemical performance (≈98% Coulombic efficiency over 1000 cycles) in the electrolyte whose molar ratio of ZnCl2:acetamide:H2O is 1:3:1. The assembled full battery composed of phenazine cathode and Zn anode could stably cycle over 10 000 cycles with a high capacity retention of 85.7%. Overall, this work offers new insights into exploring new green electrolyte systems for Zn‐ion batteries.