Combining Zn0.76Co0.24S with S-doped graphene as high-performance anode materials for lithium- and sodium-ion batteries

An easy and facile hydrothermal method is presented to synthesize hybrid materials of hollow mesoporous Zn0.76Co0.24S nanospheres anchored on reduced graphene oxide (rGO) sheets (Zn0.76Co0.24S@N/S-rGO), in which the obtained Zn0.76Co0.24S nanospheres are composed of numerous nanoparticles. Being evaluated as anode materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), the Zn0.76Co0.24S@N/S-rGO composites exhibited a high reversible capacity of 804 and 605 mA h g−1 at the current density of 1 A g−1 after 500 cycles for LIBs and SIBs, respectively. The excellent electrochemical performance of Zn0.76Co0.24S@N/S-rGO composites originates from the synergistic effect between hollow Zn0.76Co0.24S nanospheres and reduction graphene, as well as the void spaces between the neighbouring nanoparticles of Zn0.76Co0.24S providing large contact areas with electrolyte and buffer zone to accommodate the volume variation during the cycling process.