Coupling Effect between Zn ²⁺ Solvation Structure Modulation and Electrochemical Reversibility Enabled by Glucose Additive

Aqueous zinc-based batteries (AZBs) are considered promising for grid-scale energy storage owing to their low cost, safety, and eco-friendliness. The practical applications, however, are limited by zinc dendrite growth and parasitic side reactions at the anode. This work presents a strategy of employing glucose as an electrolyte additive to tailor the Zn2+ solvation environment. This modification successfully suppresses dendrite growth and improves the electrochemical reversibility of Zn plating/stripping. Mechanistically, glucose disrupts the hydrogen-bond network among water molecules and attenuates the hydration of Zn2+, leading to an optimized solvation structure. The electrolyte with 150 mM glucose, Zn||Cu cells achieve a high Coulombic efficiency of 98.8% and sustain 450 stable cycles at 1 mA cm–2. Correspondingly, Zn||Zn symmetric cells exhibit dendrite-free operation for over 1050 h with a low overpotential of 40 mV. Furthermore, Zn||V2O5 full cells deliver outstanding cycling stability, retaining a capacity of 68 mAh g–1 after 1000 cycles at 1C. This study offers a general and effective additive approach for developing advanced electrolytes in aqueous ZIBs.