Modulating Solvation\nShell with Acrylamide Electrolyte\nAdditives for Reversible Zn Anodes

The reconsideration of aqueous zinc-ion batteries (ZIBs)\nhas been\nmotivated by the attractive zinc metal, which stands out for its high\ntheoretical capacity and cost efficiency. Nonetheless, detrimental\nside reactions triggered by the remarkable reactivity of H<sub>2</sub>O molecules and rampant dendrite growth significantly compromise\nthe stability of the zinc metal anode. Herein, a novel approach was\nproposed by leveraging the unique properties of acrylamide (AM) molecules\nto increase the driving force for nucleation and parasitic reactions.\nCombined with experimental data and theoretical simulations, it is\ndemonstrated that the incorporation of AM additive can reconstruct\nthe solvation shell around Zn<sup>2+</sup> and reduce the number of\nactive H<sub>2</sub>O molecules, thereby effectively reducing the\nH<sub>2</sub>O molecule decomposition. Consequently, the Zn//Zn symmetric\nbatteries with AM-containing ZnSO<sub>4</sub> electrolytes can attain\nexcellent long-term performances over 2000 h at 1 mA cm<sup>–2</sup> and nearly 500 h at 10 mA cm<sup>–2</sup>. The Zn//VO<sub>2</sub> full batteries still display improved cycling performances\nand a high initial discharging capacity of 227 mA h g<sup>–1</sup> at 3 A g<sup>–1</sup> compared to the ZnSO<sub>4</sub> electrolyte.\nThis electrolyte optimization strategy offers new insights for achieving\nlong-term ZIBs and advances the progress of ZIBs in energy storage.