Hydrogen Bond Network Regulation in Electrolyte Structure for Zn-based Aqueous Batteries

Abstract

Electrolyte regulation in Zn-based aqueous batteries (ZABs) has been extensively reported, and a broad range of strategies has been proposed. However, there is currently a lack of systematic summaries and a comprehensive understanding of the impact of hydrogen bond (H-bond) networks on electrolyte performance. This work presents the electrolyte structure model, encompassing solvation structure, electrolyte/Zn anode interface, and H-bond network. Through emphasizing and summarizing the reconstruction, strengthening, and breaking of the H-bond network within the electrolyte structure, various specific regulation strategies are identified, such as high Gutmann donor number solvent, organic co-solvent, molecular crowding additives, structure-breaking ions, and solid-state design. A critical appraisal is then provided on the key performance metrics influenced by these regulation methods, including Coulomb efficiency, voltage hysteresis, freezing point, and lifespan. This work is expected to illustrate electrolyte structure design to improve the comprehensive performance of ZABs. Last, a data-driven summary and outlook on hydrogen bond network regulation in electrolyte structure is provided, to objectively evaluate the overall performances of ZABs.