Helmholtz Plane Reconfiguration Enables Robust Zinc Metal Anode in Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries are promising for next-generation energy storage systems. However, the zinc dendrite growth, corrosion, and hydrogen evolution reaction at the electrochemical interface severely impede their further development. Herein, a Zn2+-rich and H2O-poor Helmholtz plane is constructed to regulate the electrochemical interface between the zinc anode and the electrolyte. Electrochemical and in situ spectroscopy characterizations reveal that the designed electric double layer with abundant Zn2+ coordination sites and less H2O content can facilitate rapid electron transfer, homogenize Zn2+ deposition, and alleviate the side reactions induced by active H2O. Benefiting from the high reversibility and stability of zinc anode, the Zn||Zn symmetric cell can be cycled over 1000 h at 1 mA cm-2 and the Zn||NH4V4O10 full cell can maintain a capacity of 85.23% for 1000 cycles at 3 A g-1. This work aims at Helmholtz plane reconfiguration and provides a realizable strategy in interface construction for other similar systems. A Zn2+-rich and H2O-poor Helmholtz plane designed by 3-mercapto-1-propanesulfonate (MPS) facilitates rapid electron transfer, homogenizes Zn2+ deposition, and alleviates the side reactions induced by active H2O, further enables robust zinc metal anode in cycling. Therefore, the Zn||Zn symmetric cell and Zn||NH4V4O10 full cell can exhibit excellent electrochemical performance in the electrolyte with MPS. image