Achieving Uniform Deposition of Zn with Amide Additives for Metal Anodes Stabilization.

The practical applications of aqueous zinc-ion batteries (AZIBs) are hindered by detrimental effects such as dendrites formation at the Zn metal anode interface and parasitic side reactions induced by HO. Hence, we propose adding amide additives to the Zn sulfate electrolyte (ZSO) to regulate the composition and properties of the electrolytes, thereby stabilizing the Zn anode interface. Different amide molecules containing formamide (FA), acetamide (AA), or trifluoroacetamide (TFA) are discussed. The polar C═O group shared by amide molecules can interact with Zn, forming their solvation shells. The molecules can also facilitate the transport of Zn and increase the conductivity of the electrolytes. Additionally, amide molecules can interact with HO through hydrogen bonds to limit the erosion of active HO on the Zn anode. The unique -H, -CH, and -CF groups of the molecules result in different polarities and varying numbers of interaction sites with HO and Zn, leading to some differences in the protective effects of the Zn anode. The stability and lifespan of Zn||Zn batteries assembled with amide electrolytes have significantly improved, especially those with TFA. Moreover, the Zn||NHVO full cells demonstrate remarkable capacity retention, and the overall performance of the batteries has also been enhanced.