Hollow graphene spheres coated separator as an efficient trap for soluble polysulfides in Li S battery

Abstract

Hollow graphene spheres are successfully prepared and employed as the separator coating materials for lithium-sulfur batteries. The hollow graphene spheres coated separator has been proven an efficient trap to adsorb and block polysulfide, greatly alleviating the shuttle effect. In the case of using elemental sulfur as cathode active material and the weight of the diaphragm is only increased by 10.3%, the lithium-sulfur battery with hollow graphene spheres coated separator delivers a high initial specific capacity of 1172.3 mAh g −1 at the current density of 0.2 C, and the discharge capacity remains at 829.6 mAh g −1 after 200 cycles with a capacity decay of 0.146% per cycle, showing excellent electrochemical performance.