Interface engineering design of three-phase cobalt selenide/zinc selenide/cobalt iron alloy heterostructure to enhance the performance of zinc-air batteries

The synergistic integration of multiple active groups and heterostructure engineering play a crucial role in optimizing reaction kinetics and enhancing the intrinsic activity of heterojunction electrocatalysts. Here, a three-phase nanocomposite heterojunction system of CoSe 2 /ZnSe/CoFe was successfully constructed via hydrothermal and selenization methods. Experimental results demonstrate that the designed CoSe 2 /ZnSe/CoFe@NCNTs/CC composite electrode exhibits outstanding bifunctional properties in electrocatalytic performance testing: in the oxygen evolution reaction (OER), it exhibits a low potential of 1.513 V at a current density of 10 mA cm −2 , while in the oxygen reduction reaction (ORR), the half-wave potential is 0.887 V. Further studies indicate that this self-supporting CoSe 2 /ZnSe/CoFe@NCNTs/CC cathode material exhibits outstanding performance in aqueous and flexible zinc-air batteries (ZABs), featuring high power density, excellent specific capacity, and exceptional cycling stability. Its outstanding electrocatalytic performance primarily stems from the following synergistic effects: first, the abundant distribution of active sites, including CoFe alloy with adsorption free energy and nitrogen-doped carbon nanotubes (NCNTs); Second, the multiphase coupled interface formed by the heterojunction between the biphasic selenide and the CoFe alloy, combined with the material's inherent superhydrophobic properties, jointly optimizes the oxygen diffusion kinetics at the three-phase interface. This innovative heterostructure design concept provides new research insights and technical pathways for developing efficient multifunctional electrocatalysts and advanced energy conversion devices.