Comprehensive H2O Molecules Regulation via Deep Eutectic Solvents for Ultra-Stable Zinc Metal Anode

The corrosion, parasitic reactions, and aggravated dendrite growth severely restrict development of aqueous Zn metal batteries. Here, we report a novel strategy to break the hydrogen bond network between water molecules and construct the Zn(TFSI)(2)-sulfolane-H2O deep eutectic solvents. This strategy cuts off the transfer of protons/hydroxides and inhibits the activity of H2O, as reflected in a much lower freezing point (<-80 degrees C), a significantly larger electrochemical stable window (>3 V), and suppressed evaporative water from electrolytes. Stable Zn plating/stripping for over 9600 h was obtained. Based on experimental characterizations and theoretical simulations, it has been proved that sulfolane can effectively regulate solvation shell and simultaneously build the multifunctional Zn-electrolyte interface. Moreover, the multi-layer homemade modular cell and 1.32 Ah pouch cell further confirm its prospect for practical application.

Automated summary

A novel strategy was reported to break the hydrogen bond network between water molecules and construct the Zn(TFSI)(2)-sulfolane-H2O deep eutectic solvents. This strategy effectively cuts off the transfer of protons/hydroxides and inhibit the activity of H2O, resulting in improved stability and performance of aqueous Zn metal batteries.