▎ 摘　　要

NOVELTY - Preparation of flexible high-load sulfur, high-stability graphene-mesoporous carbon-sulfur film involves (s1) dispersing graphene oxide aqueous solution in oil-bath flask, and adding hydrazine hydrate solution in graphene oxide aqueous solution and washing with deionized water to obtain dispersed water-soluble graphene sheet dispersion, (s2) mixing aqueous ammonia and sucrose, reacting, soaking in hydrofluoric acid, and obtaining mesoporous carbon material (MC), (s3) mixing ammonium hexafluorophosphate and mesoporous carbon material (MC) with deionized water, and vacuum drying to form a nitrogen, phosphorus, and fluorine co-doped mesoporous carbon material (NPFMC), (s4) mixing NPFMC with native sulfur, and sealing to obtain nitrogen, phosphorus, and fluorine co-doped mesoporous carbon mesoporous carbon-sulfur nanomaterials (NPFMC-S), (s5) dispersing NPFMC-S with water-soluble graphene sheets, and vacuum filtering resulting mixture. USE - Preparation of flexible high-load sulfur, high-stability graphene-mesoporous carbon-sulfur film used as positive material for lithium-sulfur battery (all claimed). ADVANTAGE - The method can prepare mesoporous carbon by co-doping nitrogen, phosphorus, fluorine, and the porous structure provides sites for attachment of active sulfur, making the content of active sulfur up to 86%, interacting with active sulfur through the isolated sites formed by nitrogen, phosphorus, and fluorine elements on the interface of mesoporous carbon materials. Through the barrier effect of the graphene network, to overcome the low utilization rate of active sulfur species and volume expansion that lead to the collapse of the positive electrode structure and capacity fading. The shuttle effect of lithium polysulfides is adjusted, which is of great significance for the pursuit of high-performance lithium-sulfur batteries. DETAILED DESCRIPTION - Preparation of flexible high-load sulfur, high-stability graphene-mesoporous carbon-sulfur film involves (s1) dispersing graphene oxide aqueous solution in oil-bath flask at 60℃, and adding preset amount of hydrazine hydrate solution in graphene oxide aqueous solution in oil-bath flask, maintaining at 60℃ for 30 minutes, natural cooling, and washing with deionized water to obtain a uniformly dispersed water-soluble graphene sheet dispersion, (s2) mixing aqueous ammonia and sucrose, adding silicon dioxide (LSiO2) sol, and reacting in stainless steel reactor at 160℃ for 24 hours, cooling and drying, and soaking in hydrofluoric acid for 3 hours, washing with deionized water, and obtaining mesoporous carbon material (MC), (s3) mixing ammonium hexafluorophosphate and mesoporous carbon material (MC) with deionized water, and vacuum drying at 80℃, heat-treating obtained powder at 800℃ for 2 hours to form a nitrogen, phosphorus, and fluorine co-doped mesoporous carbon material (NPFMC), (s4) mixing nitrogen, phosphorus, and fluorine co-doped mesoporous carbon material (NPFMC) with native sulfur, and sealing in argon-saturated polytetrafluoroethylene reactor, heating at 170℃ for 24 hours, and natural cooling to obtain nitrogen, phosphorus, and fluorine co-doped mesoporous carbon mesoporous carbon-sulfur nanomaterials (NPFMC-S), (s5) dispersing the nitrogen, phosphorus, and fluorine co-doped mesoporous carbon mesoporous carbon-sulfur nanomaterials (NPFMC-S) with water-soluble graphene sheets, and stirring under predetermined conditions, vacuum filtering resulting mixture to obtain graphene-nitrogen, phosphorus, fluorine co-doped mesoporous carbon mesoporous carbon mesoporous carbon-sulfur nanomaterial (G-NPFMC-S). The predetermined conditions are a stirring speed of 300 rpm and ultrasonic treatment with power of 50 watts. The mass ratio of graphene oxide to hydrazine hydrate is 15:1.