Synthesis of CuxS/Cu Nanotubes and Their Lithium Storage Properties

Novel Cu x S/Cu (1 < x <2) nanotubes were prepared by a facile wet chemical approach in polyethylene glycol (PEG). Here, Cu nanowires were presynthesized and then converted to nanotubes via a mass diffusion process. A thin PEG layer is physically adsorbed on the nanotube surface. The obtained Cu x S/Cu nanotubes show good Li storage properties with stable cyclability upon Li ion insertion/extraction, which is attributed to the existence of the PEG capping and the reduced dissolution of Li polysulfides into the electrolytes. Furthermore, Cu x S/Cu nanotubes with 10 wt % Cu show promising rate capabilities (a fifth-cycle discharge capacity of 282 mA h g –1 at a current density of 5 A g –1 ) due to the enhanced kinetics of charge transfer.