Molecular Key Tuned Steric-Hindrance Effect Toward Zn (100) Facet Texture Anode

Electrolyte additive is one of the most effective strategies to optimize Zn anode in aqueous zinc ion batteries (AZIBs). Few reports are available on the influence of spatial-hindrance effect on Zn2+ deposition behavior. Herein, the environmentally safe aspartame (Asp) and neotame (Neo) are selected to finely tune the molecular structure, thereby affecting molecular adsorption behavior as well as Zn2+ diffusion and deposition behavior, and the molecular structure regulation strategy is proposed to achieve the optimization of Zn anode. According to theoretical calculations and experimental conclusions, Asp acts as the molecular robot to uniformly adsorb on Zn anode surface via oxygen-containing functional groups, capture Zn2+ via −NH2, homogenize Zn2+ flux, and catalyze Zn2+ desolvation, resulting in Zn2+ oriented deposition to form Zn (100) facet texture. Benefited from the molecular structure regulation strategy, Zn anode exhibits an ultra-long lifespan of more than 4600 h and an extremely high cumulative plated capacity of 11.7 Ah cm−2. Furthermore, Zn anode operates stably for more than 270 h under 80% depth of discharge and possesses a high coulombic efficiency of 99.8% in Zn||Cu half cells. This strategy provides a new perspective on selecting additives.