Freestanding N-Doped Carbon Coated CuO Array Anode for Lithium-Ion and Sodium-Ion Batteries

Considering the market demand for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) as energy storage devices, it is necessary to find a negative electrode material with low cost, high specific capacity, and long cycle life. CuO has a high theoretical specific capacity and therefore has broad application prospects. This study reports a freestanding nitrogen-doped carbon-coated CuO array (NC-CuO)-based anode obtained by synthesizing CuO nanorods on a Cu net and depositing nitrogen-doped carbon on the surface of the nanorods. The NC-CuO array anode fully utilizes the synergistic advantages of the 3D array and the outer N-doped carbon layer, which effectively enhance the electronic conductivity of the metal oxide and alleviate the volume change during Li/Na ion insertion and extraction. It is found that the NC-CuO array as the anode material for LIBs has a capacity of 562.5 mAhg⁻¹ and a cycle stability of more than 200 cycles even at a high current density of 500 mAg⁻¹. SIBs with the NC-CuO array anode also exhibit excellent electrochemical performance.