Artificial Solid-Electrolyte Interface Facilitating Dendrite-Free Zinc Metal Anodes via Nanowetting Effect.

Abstract

The formation of dendrites on a zinc (Zn) metal anode has limited its practical applications on aqueous batteries. Herein, an artificial composite protective layer consisting of nanosized metal-organic frameworks (MOFs) to improve the poor wetting effect of aqueous electrolytes on the Zn anode is proposed to reconstruct the Zn/electrolyte interface. In this layer, hydrophilic MOF nanoparticles serve as interconnecting electrolyte reservoirs enabling nanolevel wetting effect as well as regulating an electrolyte flux on Zn anode. This zincophilic interface exhibits significantly reduced charge-transfer resistance. As a result, stable and dendrite-free Zn plating/stripping cycling performance is achieved for over 500 cycles. In addition, especially at higher C-rates, the coating layer significantly reduces the overpotentials in a Zn/MnO2 aqueous battery during cycling. The proposed principle and method in this work demonstrate an effective way to reconstruct a stable interface on metal anodes (e.g., Zn) where a conventional solid-electrolyte interface (SEI) cannot be formed.