Electric Double Layer Regulator Design through a Functional Group Assembly Strategy towards Long-Lasting Zinc Metal...

Regulating the electric double layer (EDL) structure of the zinc metal anode by using electrolyte additives is an efficient way to suppress interface side reactions and facilitate uniform zinc deposition. Nevertheless, there are no reports investigating the proactive design of EDL-regulating additives before the start of experiments. Herein, a functional group assembly strategy is proposed to design electrolyte additives for modulating the EDL, thereby realizing a long-lasting zinc metal anode. Specifically, by screening ten common functional groups, N, N-dimethyl-1H-imidazole-1-sulfonamide (IS) is designed by assembling an imidazole group, characterized by its high adsorption capability on the zinc anode, and a sulfone group, which exhibits strong binding with Zn²⁺ ions. Benefiting from the adsorption functionalization of the imidazole group, the IS molecules occupy the position of H₂O in the inner Helmholtz layer of the EDL, forming a molecular protective layer to inhibit H₂O-induced side reactions. Meanwhile, the sulfone group in IS, acting as a binding site to Zn²⁺, promotes the de-solvation of Zn²⁺ ions, facilitating compact zinc deposition. Consequently, the utilization of IS significantly extending the cycling stability of Zn||Zn and Zn||NaV₃O₈ ⋅ 1.5H₂O full cell. This study offers an innovative approach to the design of EDL regulators for high-performance zinc metal batteries.