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

The formation of dendrite on zinc (Zn) metal anode has limited its practical applications on aqueous batteries. Herein, an artificial composite protective layer consisting of nano-sized metal-organic frameworks (MOFs) to improve the poor wetting effect of aqueous electrolytes on Zn anode, is proposed to reconstruct the Zn/electrolyte interface. In this layer, hydrophilic MOF nano-particles serve as inter-connecting electrolyte reservoirs enabling nano-level wetting effect as well as regulated 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 over-potentials in a Zn/MnO2 aqueous battery during cycling. The proposed principle and method in this work demonstrates an effective way to reconstruct a stable interface on metal anodes (e.g. Zn) where a conventional solid-electrolyte interface (SEI) cannot be formed.