Hollow V2O5 nanospheres wrapped by activated carbon to confine polysulfides for lithium sulfur battery

The practical application of the Li-S battery is restrained by the severe lithium polysulfide shuttle and sulfur insulation. In this work, the hollow V2O5 nanospheres wrapped by activated carbon as the host material for sulfur were prepared. The results indicate that initial specific discharge capacity of the electrode is 972 mA h g−1 and it can be maintained at 730 mA h g−1 after 200 cycles at 0.2 C. The average decay rate of the capacity for the AC@V2O5/S only is 0.09% per cycle after 200 cycles at 0.5 C. This excellent performance could result from the polar hollow V2O5 nanospheres providing more adsorption sites, which are conducive to electrolyte diffusion and confine polysulfides during the reaction of sulfur and polysulfide. Furthermore, the activated carbon coated on the outer layer can provide the large specific surface as conductive network. Therefore, this design strategy could show significant prospects for Li-S battery.