Simple MOF Composite Coating-Modified Zinc Metal Anode for Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries have been widely studied due to their high theoretical capacity and safety; however, zinc dendrite growth and severe side reactions limit their practical applications. In this article, a simple Zn/Cu composite metal–organic framework (MOF) coating-modified zinc anode (Zn@ZCM) has been prepared. The coating separates the zinc anode from the electrolyte, which can effectively inhibit side reactions. At the same time, it has good electrolyte wettability and promotes the diffusion of zinc ions. In addition, the MOF material itself has high porosity and good chemical stability, which can increase the specific surface area of the zinc anode, provide more active sites for zinc-ion deposition, promote uniform deposition of zinc ions, and reduce the growth of zinc dendrites. Zn@ZCM//NVO full cells have a capacity retention rate of 93.04% for 220 cycles at a low current (0.3 A g–1). Zn@ZCM symmetric cells show excellent cycle stability within 2275 h at a 1 mA cm–2 current density and a 1 mAh cm–2 area capacity.