▎ 摘　　要

NOVELTY - Boron-nitrogen-doped three-dimensional graphene block preparation involves mixing biomass material, boron oxide, nitrogen precursor, metal catalyst precursor and solvent with stirring at 80-100 degrees C to obtain precursor solution. The biomass material, boron oxide precursor, nitrogen, catalyst precursor and metal mass in a ratio of 1:0.5-2:0-2:0.5-2. The solvent is water or a mixed solution of water and ethanol. The resulting precursor solution is cooled to form a three-dimensional gel. USE - Method for preparing boron-nitrogen-doped three-dimensional graphene block used in lithium-sulfur battery (claimed). ADVANTAGE - The method prepares the boron-nitrogen-doped three-dimensional graphene block in a simple and cost-effective manner. DETAILED DESCRIPTION - Boron-nitrogen-doped three-dimensional graphene block preparation involves mixing biomass material, boron oxide, nitrogen precursor, metal catalyst precursor and solvent with stirring at 80-100 degrees C to obtain precursor solution. The biomass material, boron oxide precursor, nitrogen, catalyst precursor and metal mass in a ratio of 1:0.5-2:0-2:0.5-2. The solvent is water or a mixed solution of water and ethanol. The resulting precursor solution is cooled to form a three-dimensional gel. The resulting three-dimensional gel is freeze-dried to obtain boron and nitrogen co-doped three-dimensional graphene block. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the Brunauer-Emmett-Teller test pattern of the boron-nitrogen-doped three-dimensional graphene block. (Drawing includes non-English language text).