Dual Organic Solvents Enable Stable Zn Anodes via Simultaneous Electrolyte Structure and Interface Chemistry...

Metallic Zn is an exceptionally promising anode material for aqueous batteries due to its inherent safety, low cost, and high theoretical capacity. However, its widespread application has been severely limited by persistent challenges, including water-induced parasitic reactions and uncontrolled dendritic growth. Herein, a hydrous dual organic electrolyte system with modulated bulk electrolyte structures and anode-electrolyte interfacial chemistry has been developed to address the above obstacles, featuring Zn trifluoromethanesulfonate (Zn(OTf)₂) dissolved in 1,2-dimethoxyethane (DME) and 1,4-dioxane (DX). In such a system, DME can effectively disrupt the hydrogen bond network of water molecules through its electron-donating properties, thereby significantly suppressing water activity and associated side reactions, while DX preferentially adsorbs at the anode/electrolyte interface to facilitate Zn²⁺ desolvation and promote the preferential growth of (002)-oriented Zn crystals. The optimized electrolyte system endows Zn anodes with exceptional electrochemical performance, demonstrating unprecedented cycling stability (4000 hours at 1 mA cm^-2/1 mAh cm^-2) in the Zn//Zn cell and outstanding Coulombic efficiency (CE) (99.8% over 2000 cycles) in the Zn//Cu cell. Moreover, the full battery paired with Na₂V₆O₁₆ (NVO)demonstrates excellent cycling stability with 79.0% capacity retention at 5 A g^-1 after 2000 cycles.