▎ 摘　　要

NOVELTY - Two-dimensional composite material is prepared by intercalating titanium dioxide between titanium carbide and graphene on both sides, and forming sandwich structure. USE - Two-dimensional composite material as negative electrode material for lithium ion capacitor (claimed). ADVANTAGE - The two-dimensional composite material has intercalated structure to prevent self-stacking of graphene and two-dimensional transition metal carbide sheets and sheets, and increase its active site of capacitance. The thermal reduction process generates a small amount of titanium oxide which provides embedded pseudocapacitance activity. The large-sized graphene sheet layer can enhance the conductivity between the two-dimensional transition metal carbide sheets, and further improve the electrochemical performance of the composite material and performance of the lithium ion capacitor. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of two-dimensional composite material, which involves (1) dissolving the fluoride salt in 9 M hydrochloric acid solution, stirring and dissolving, adding a two-dimensional ceramic phase precursor MAX phase to the above solution, etching the above mixture at 25-90 degrees C, washing thoroughly with deionized water, obtaining a two-dimensional transition metal carbide material, mixing in a ratio of two-dimensional transition metal carbide material to water of 1 g: 200-1000 mL at 3500 rpm for 2 hours, ultrasonically dispersing, taking the supernatant, obtaining a two-dimensional transition metal carbide dispersion, the mass to volume ratio of fluoride salt, hydrochloric acid and two-dimensional ceramic phase precursor MAX phase is 1 g: 20 mL: 1 g, (2) mixing graphene oxide dispersion with two-dimensional transition metal carbide dispersion obtained in step (1), filtering, drying, obtaining graphene oxide/two-dimensional transition metal carbide, annealing at 550 degrees C, obtaining a two-dimensional composite material. The mass ratio of the graphene oxide to the two-dimensional transition metal carbide is 1: 9-99.