Regulating solvation structure to stabilize zinc anode by fastening the free water molecules with an inorganic colloidal electrolyte

The main obstacle for developing aqueous zinc-ion batteries (ZIBs) with long-term stability lies in the suppression of side reactions and zinc dendrites, which are derived from decomposition of active water molecules belonging to Zn2+ solvation layer in the electrolyte. Herein, an inorganic colloidal electrolyte composed of lithium magnesium silicate and zinc sulfate (LMS+ZSO) is utilized to improve the reversibility of Zn plating/stripping behavior for high-performance ZIBs. As revealed by the experimental and theoretical results, LMS’s superior adsorption capacity for water molecules modulates the Zn2+ solvation structure via converting the free water molecules into adsorbed water of LMS and weakening the electrostatic coupling of anions and cations, thus restraining the corrosion, hydrogen evolution reaction and by-products. Concomitantly, the LMS lowers the energy barrier of de-solvation process to promote the Zn2+ ions transfer kinetics and induce the homogeneous deposition, thus inhibiting the dendrites formation. Consequently, the cycling stability of symmetric battery and zinc-based full battery are significantly boosted with LMS+ZSO electrolyte. This reasonable and effective strategy offers a promising prospect for developing long life ZIBs.