Constructing Anode Ca-rich Protective Layer of for High Performance Aqueous Zinc-ion Batteries

Abstract

Zinc metal anodes (ZMA) are notable among aqueous ion battery anodes for their low cost, high specific capacity and low redox potential. However, zinc anodes still encounter many challenges such as hydrogen evolution reactions (HER), zinc dendrite and electrode corrosion, which can result in short circuits and pose serious safety risks.In this study, a calcium-rich (Ca 10 (OH) 2 (PO 4 ) 6 ) protective layer was constructed on the surface of zinc anode by a simple coating process, which aimed to regulate the homogeneous deposition of Zn 2+ , reduce the nucleation potential of Zn, and suppress zinc dendrite growth. Furthermore, the porous calcium-rich layer enhanced Zn 2+ migration, reduced water activity, mitigated side reactions at the electrode-electrolyte interface, and effectively prevented corrosion of the ZMA. Consequently, the Zn/Zn symmetric cell assembled based on the modified ZMA was able to cycle stably for 1180 h at 5 mA cm -2 . And the capacity of the NH 4 V 4 O 10 (NVO)/Zn full cell assembled based on the modified Zn anode was still 144.69 mAh g -1 after cycling for 700 at 1 A g -1 current density. This work provides a straightforward and effective approach for advancing stabilized ZMA.