CuO nanowire arrays synthesized at room temperature as a high-performance anode material for Li/Na-ion batteries

Abstract CuO nanowire arrays with thin nanowires and large interspaces grown on copper foil are prepared by a one-step room temperature solution approach without subsequent annealing. As the anodes for Li/Na-ion batteries, the large empty spaces between the nanowires enable Li/Na ions to diffuse into the electrode quickly. Due to the narrow diameter of the nanowire, the volume could expand in a timely manner, and the large interspace between the nanowires could accommodate the expansion effectively; thus, an undamaged framework is maintained. The one-dimensional nanowire and the tight contact between the nanowire and substrate favor electron delivery. A high discharge-charge capacity (i.e., at 100 mA g−1 it was 760 mAh g−1 for the Li-ion batteries and 351 mAh g−1 for the Na-ion batteries), excellent rate performance and long cycling life are obtained. This one-step synthesis route at room temperature is straightforward and industrially scalable. These factors, combined with the excellent electrochemical performance, make CuO nanowire arrays a promising anode for Li/Na-ion batteries.