Achieving Highly Reversible Zinc Anodes via N, N-Dimethylacetamide Enabled Zn-Ion Solvation Regulation

Although aqueous zinc-ion batteries (ZIBs) are promising for scalable energy storage application, the actual performance of ZIBs is hampered by the irreversibility. Optimization of electrolyte composition is a relatively practical and facile way to improve coulombic efficiency (CE) and Zn plating/stripping reversibility of ZIBs. N,N-Dimethylacetamide (DMA) has a higher Gutmann donor number (DN) than that of H₂ O, abundant polar groups, and economic price. Herein, a mixture electrolyte containing 10 vol% DMA and ZnSO₄ , which has an enhanced Zn reversibility almost fourfold higher than that of pure ZnSO₄ electrolyte, is demonstrated. The density functional theory (DFT) calculation and spectroscopic analysis reveal DMA has the ability to reconstruct the solvation structure of Zn²⁺ and capture free water molecules via forming Hbonds. The inhibited dendrite growth on Zn anode is further clarified by an in situ characterization. This work provides a feasible way for the development of long-lifespan ZIBs.