Triple-function Hydrated Eutectic Electrolyte for Enhanced Aqueous Zinc Batteries.

Aqueous rechargeable zinc-ion batteries (ARZBs) are impeded by the mutual problems of unstable cathode, electrolyte parasitic reactions, and dendritic growth of zinc (Zn) anode. Herein, a triple-functional strategy by introducing the tetramethylene sulfone (TMS) to form a hydrated eutectic electrolyte is reported to ameliorate these issues. The activity of H O is inhibited by reconstructing hydrogen bonds due to the strong interaction between TMS and H O. Meanwhile, the preferentially adsorbed TMS on the Zn surface increases the thickness of double electric layer (EDL) structure, which provides a shielding buffer layer to suppress dendrite growth. Interestingly, TMS modulates the primary solvation shell of Zn ultimately to achieve a novel solvent co-intercalation ((Zn-TMS) ) mechanism, and the intercalated TMS works as a "pillar" that provides more zincophilic sites and stabilizes the structure of cathode (NH V O , (NVO)). Consequently, the Zn||NVO battery exhibits a remarkably high specific capacity of 515.6 mAh g at a low current density of 0.2 A g for over 40 days. This multi-functional electrolytes and solvent co-intercalation mechanism will significantly propel the practical development of aqueous batteries.