Bioderived Monosaccharides as Green and Scalable Electrolyte Additives for Durable Aqueous Zinc–Metal Batteries

Aqueous zinc-metal batteries (AZMBs) face challenges involving dendrite growth, corrosion, and side reactions on the Zn anode side, stemming from unstable Zn²⁺ solvation and interfacial instability. Here, d-(+)-galactose (GAL), a bioderived monosaccharide with a unique hydroxyl configuration and oxygen-rich framework, is introduced as a sustainable electrolyte additive. GAL coordinates with zinc ions to partially replace H₂O in the primary solvation sheath, reorganizing the hydrogen-bonding network to enhance Zn²⁺ transport, facilitate desolvation, and suppress dendrites. In parallel, GAL exhibits zincophilicity and selectively adsorbs onto Zn surfaces, replacing water molecules and triggering the in situ construction of a robust hybrid SEI, which protects against corrosion and directs uniform Zn deposition. Accordingly, Zn//Zn cells cycle stably for 3500 h; Cu//Zn cells achieve 99.8% Coulombic efficiency over 700 cycles, and MnO₂//Zn full cells retain 84% capacity after 300 cycles. This work proposes a sustainable strategy employing bioderived monosaccharides to stabilize Zn anodes and advance high-performance AZMBs.