Multifunctional MoSe2@rGO coating on the cathode versus the separator as an efficient polysulfide barrier for high-performance lithium-sulfur battery.

The close interfacial contact between the MoSe 2 @rGO cathode coating and the sulfur cathode provided an efficient electron transfer pathway, thereby ensuring significant improvements in the recycling of the adsorbed active materials. The MoSe 2 @rGO cathode coating efficiently enhanced the cycling performance and stability of the lithium-sulfur batteries. • The MoSe 2 @rGO composite with a unique cotton-like porous structure is synthesized. • The MoSe 2 @rGO composite is excellent in electron transfer and polysulfide anchoring. • The MoSe 2 @rGO cathode coating is superior to the separator coating counterpart. • The MoSe 2 @rGO cathode coating serves as an efficient polysulfide barrier. The practical applications of high-performance lithium-sulfur batteries are severely hindered by the insulating nature of sulfur and intractable shuttling of the polysulfide intermediates. In this work, we report a novel MoSe 2 @rGO cathode coating consisting of two-dimensional MoSe 2 and reduced graphene oxide (rGO) as a multifunctional barrier to suppress polysulfide shuttling. Few-layered MoSe 2 nanosheets are in situ grown on the rGO surface by basal plane contact. Besides, some cotton-like MoSe 2 nanospheres assembled from porous nanosheets are decorated on the surface of rGO nanosheets. Benefitted from the strong chemical adsorption of polar MoSe 2 and excellent electrical conductivity of rGO, the MoSe 2 @rGO coatings exhibit highly efficient polysulfide anchoring and significantly enhanced electrocatalytic chemistry. Moreover, the MoSe 2 @rGO cathode coatings are much superior to its separator coatings in the recycling of the adsorbed active materials because of good interfacial conductivities. The cell with the MoSe 2 @rGO cathode coating delivers a high reversible capacity up to 1216 mAh g−1 at 0.2 C and outstanding cycling stability with a low capacity fading rate of 0.03% at 1 C over 1000 cycles. [ABSTRACT FROM AUTHOR]