Boosting Zinc‐Ion Batteries with Innovative Ternary Electrolyte for Enhanced Interfacial Electrochemistry and Temperature‐Resilient Performance

Abstract

AbstractThe practical application of Zn‐ion batteries (ZIBs) faces several challenges, particularly regarding poor reversibility and the reactivity of water in the electrolytes across a wide temperature range. Herein, this study presents the design of a ternary electrolyte with significant intermolecular interactions based on tetrahydrofurfuryl alcohol (THFA), H2O, and Zn(OTf)2 to address these challenges from −40 to 60 °C. The ether alcohol compound THFA effectively mitigates the side reactions about water, by disrupting and suppressing the reactivity of the dominant water‐based clusters. Through experimental and theoretical investigations, the structural and mechanistic insights of ternary solvation clusters are uncovered. The hydrogen‐bond‐induced interactions of THFA facilitate the participation of OTf− in solvation clusters and bidentate chelation coordination with Zn2+ ensures the formation of lean‐water solvation clusters. Furthermore, the interfacial electrochemistry on the Zn surface is also regulated to exhibit a preferential layer‐by‐layer (0 0 2) oriented deposition with a stable solid electrolyte interface (SEI). As a result, The Zn||VO2 battery using ternary electrolyte maintains a capacity of 237.5 mAh g−1 with an 86.71% retention after 500 cycles at 60 °C and 3 A g−1, while it exhibits stable cycle even at −40 °C over 200 cycles with almost no capacity decrease.