Inorganic Hybrid Interfacial Layer for a Stable Zinc Metal Anode

In aqueous zinc-ion batteries (AZIBs), the zinc metal anode faces serious problems such as dendrite growth, interface corrosion, and byproduct accumulation, which hinder the commercialization process of AZIBs. Herein, an inorganic hybrid interfacial layer ZnF₂/ZnSe (ZnFS) including the insulating interfacial phase (ZnF₂) and conductive interfacial phase (ZnSe) has been manufactured. ZnF₂ provides excellent corrosion resistance, inhibiting the corrosion and passivation of the zinc metal anode to enhance interfacial stability. The conductive ZnSe can reduce the interfacial resistance and induce the rapid migration of Zn²⁺, leading to the uniform deposition of Zn to inhibit the dendrite growth. Consequently, the Zn/ZnFS//Zn/ZnFS symmetrical batteries can run stably for more than 2200 h at 1 mA cm^-2/1 mAh cm^-2 and over 700 h at 5 mA cm^-2/5 mAh cm^-2. At the same time, the average Coulombic efficiency of the Zn/ZnFS//Ti half batteries reaches 98.3% after 600 cycles (1 mA cm^-2/1 h), indicating that the reversibility of zinc was greatly improved. The full batteries based on the Zn/ZnFS anode and (NH₄)₂V₁₀O₂₅·8H₂O cathode perform a high capacity ratio of 73.4% after 620 cycles at 1 A g^-1. The concept of hybrid interface layer design can provide inspiration for the modification of metal anode.