Anionic flip induced gating effect enables high stability of zinc metal anode

Abstract

The persistent issues of zinc dendrite and water-induced side reactions continue to compromise the stability of the anode/electrolyte interface. Herein, the gating mechanism based on interfacial ion flipping is proposed to stabilize the anode interface, suppress side reactions and facilitate dendrite-free Zn deposition. Under the specific adsorption of anions, water molecules are effectively expelled by hydrophobic cyclohexyl, thereby mitigating corrosion. Moreover, under the influence of electric field, negatively charged anions undergo flipping, enhancing cation transfer. Sodium ions preferentially adsorb at the electrode protrusions, creating an electrostatic shielding effect. Simultaneously, Zn ions redistribute spatially, thereby achieving uniform Zn deposition. Through the synergistic effect of anion flipping, a distinctive gating mechanism is established within the electric double layer, which precisely modulates the distribution and behavior of cations, water molecules, and anions at the interface. This dynamic regulation mechanism provides continuous protection for the Zn metal anode, ensuring its electrochemical stability. Accordingly, a high average coulombic efficiency of 99.79 % is obtained during 2250 cycles, demonstrating outstanding plating/stripping reversibility. Moreover, Zn//NVO full cell exhibits well-improved capacity retention with long cycling lifespan of 5000 cycles at 5 A g^-1. The successful application of the anion flipping effectively presents a novel paradigm for stabilizing Zn anodes.