Construction of copper oxynitride nanoarrays with enhanced lithiophilicity toward stable lithium metal anodes

Abstract Lithium metal is considered as the ultimate anode material for next-generation high-energy-density batteries. However, it remains to be a formidable challenge to develop a dendrite-free and highly reversible lithium metal anode. Herein, we design and construct a three-dimensional (3D) copper oxynitride (CuON) nanoarray on a copper foam (CuON/CF) as an advanced current collector to modulate lithium electro-plating/stripping behavior. The nitrogen-implanted nanoarray is of great benefit for improving the surface lithiophilicity and electron/ion conductivity to induce uniform lithium nucleation/growth with a reduced overpotential. Additionally, the hierarchical architecture could provide enlarged surface area for delocalizing current density and well-defined diffusion channels for homogenizing Li ion flux during lithium plating. Consequently, the as-designed 3D CuON/CF host enables dendrite-free deposition of lithium, high coulombic efficiency, and impressive cycling stability at various current densities. Symmetric cells based on the composite anodes could manifest an ultralong lifespan of 2100 h with an ultralow overpotential of 5 mV. This work will provide a new insight into the design of lithiophilic oxynitrides for stable lithium metal anodes.