Copper nanowire-derived one-dimensional hollow copper sulfides as electrode materials for sodium-ion batteries

Abstract

Copper sulfides (Cu_xS) have been considered promising candidates for sodium-ion battery (SIB) anodes because they are environmentally friendly and have large theoretical capacities. Herein, one-dimensional (1D) hollow Cu_xS nanotubes were obtained via a sacrificial template diffusion process by immersing 1D copper nanowires in thiourea solution. Pure CuS nanotubes were obtained with sulfurization times lasting up to 12 h. The electrochemical properties of the Cu_xS nanotubes with different sulfurization times were studied, which reveals the better cycling stability and capacity of the Cu_xS nanotubes with a sulfurization time of 3 h compared with the pure CuS nanotubes due to the larger specific area. However, after modification with CTAB, the hollow CuS nanotubes (with a sulfurization time of 12 h) were able to deliver a high reversible capacity of 470.6 mA h g⁻¹ at 0.2 A g⁻¹ for the 150th cycle due to the increased specific surface area brought about by CTAB modification.