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

Abstract

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.