Chemical replacement route to Cu2−xSe-coated CuO nanotube array anode for enhanced performance in lithium ion batteries

Abstract

The utilization of well-aligned hybrid one-dimensional hollow nanostructured arrays is a promising strategy for the development of transition metal oxides as high-cycle-life stability and high-rate performance electrode materials for lithium ion batteries. Here we report a chemical replacement route to prepare well-aligned Cu_2−xSe-coated CuO nanotube arrays with diameters of 400 nm and length of several micrometers, based on Cu(OH)₂ nanotube arrays grown on a copper substrate as precursors. As an integrated anode for lithium ion batteries, the Cu_2−xSe-coated CuO nanotube array on a copper substrate is capable of delivering a high cycling capacity of 764 mA h g⁻¹ after 100 cycles at a current density of 0.08 mA cm⁻² (0.1 C), and retains a discharge capacity of 382.5 mA h g⁻¹ and 94.5 mA h g⁻¹ at current densities of 10 mA cm⁻² (12.5 C) and 20 mA cm⁻² (25 C), respectively, exhibiting superior performance to the bare CuO nanotube array film. The synergistic effect of the successful integration of the CuO nanotubes with the Cu_2−xSe semiconducting coating layer significantly contributes to the enhanced electrochemical properties of the Cu_2−xSe-coated CuO nanotube array anode.