Linking Interfacial Hydrogen‐Bond Network to Electrochemical Performance of Zinc Anode in Aqueous Solution

Abstract Water‐induced parasitic reaction, e.g., spontaneous corrosion and hydrogen evolution reaction, has been widely recognized as a culprit of the poor electrochemical performance of Zn anode in aqueous electrolyte. Nevertheless, how the interfacial water, the pertinent participant of the Zn electrochemistry, affects the parasitic reaction occurring on Zn anode remains incompletely understood. Herein, a step forward toward understanding the relationship of the hydrogen‐bond network of interfacial water and the electrochemical performance of Zn anode is reported, where the structure of interfacial water can be regulated by (aminomethyl)phosphonic acid (AMPA), a molecular additive that can specifically adsorb on Zn surface. Direct spectral evidence coupled with theoretical calculation reveals that the AMPA preferentially adsorbs on the Zn anode surface that serves as a shield for water dissociation (i.e., spontaneous corrosion). Moreover, AMPA can promote interfacial water toward ordered H‐bond network with high electrochemical stability at electrified interface. As a result, water‐induced parasitic reaction has been significantly suppressed, enabling a dendrite‐free Zn 2+ deposition, an exceptional high coulombic efficiency, prolonged longevity of model Zn/Zn cells, and improved Zn//NH 4 V 4 O 10 full battery. The results presented here underscore the ramifications of interfacial water structure and provide design criteria for versatile electrolytes of rechargeable Zn batteries.