A HKUST-1 coating with copper metal active site enables stabilized zinc metal anode

Abstract

Aqueous zinc-ion batteries (AZIBs) are considered to be one of the alternatives for large-scale energy storage devices due to unique advantages. However, the harmful Zn dendrites generation of Zn anodes seriously hinders the development of AZIBs. Herein, Cu(BTC) (HKUST-1) as a compact functional interface layer on the surface of bare Zn foil is shown to improve the reversibility of Zn-plating/stripping process. Interestingly, HKUST-1 possesses high porosity, large number of water molecule vacancies, and Cu active center, which help to enhance the diffusion kinetics of Zn and reduce the surface free energy of Zn electrode. Combining theoretical calculations with experiments, the HKUST-1 can contribute to the desolvation process of Zn[(HO)] and balance Zn concentration, which thus accelerate Zn transfer kinetics, lower interfacial energy, and homogenize ion-distribution. Attributed to these superiorities, the HKUST-1@Zn symmetric cells demonstrate excellent stable plating/stripping for over 250 h under ultra-high current density (20 mA/cm and 20 mAh/cm). Furthermore, a HKUST-1@Zn||MnO full cell exhibits an enhanced long-cycling performance with a discharge capacity of 114 mAh/g after undergoing 500 cycles. All results demonstrate the potential application of HKUST-1 coating in AZIBs.