▎ 摘　　要

NOVELTY - Preparing magnesium fluoride nanocrystalline doped nitrogen-doped graphene hollow nanosphere comprises compounding graphene hollow nanosphere and magnesium fluoride nanocrystalline on the inner wall of the graphene hollow nanosphere, where the graphene hollow nanosphere is made of nitrogen-doped graphene, (1) preparing a silicon dioxide ball template by using an improved method, using ammonia as a catalyst and tetraethyl orthosilicate as a silicon source in a solution containing isopropanol and water, using tetraethyl orthosilicate as a silicon source, using a sol-gel method to obtain white floccules, and finally centrifuging and drying to obtain silicon dioxide powder, (2) preparing silicon dioxide doped magnesium oxide by adding the silicon dioxide powder prepared in the step (1) into a reaction chamber, taking water and methyl ferrocene as a precursor, taking nitrogen as a carrier gas, alternately introducing into a cavity in a pulse form. USE - The magnesium fluoride nanocrystalline doped nitrogen-doped graphene hollow nanosphere material is used for a lithium metal battery negative electrode material (claimed). DETAILED DESCRIPTION - Preparing magnesium fluoride nanocrystalline doped nitrogen-doped graphene hollow nanosphere comprises compounding graphene hollow nanosphere and magnesium fluoride nanocrystalline on the inner wall of the graphene hollow nanosphere, where the graphene hollow nanosphere is made of nitrogen-doped graphene, specifically (1) preparing a silicon dioxide ball template by using an improved method, using ammonia as a catalyst and tetraethyl orthosilicate as a silicon source in a solution containing isopropanol and water, using tetraethyl orthosilicate as a silicon source, using a sol-gel method to obtain white floccules, and finally centrifuging and drying to obtain silicon dioxide powder, (2) preparing silicon dioxide doped magnesium oxide by adding the silicon dioxide powder prepared in the step (1) into a reaction chamber, taking water and methyl ferrocene as a precursor, taking nitrogen as a carrier gas, alternately introducing into a cavity in a pulse form, and preparing a magnesium oxide coating layer on the surface of the silicon dioxide particle to obtain silicon dioxide doped magnesium oxide, preparing silicon dioxide doped magnesium oxide doped nitrogen-doped graphene by placing the silicon dioxide doped magnesium oxide prepared in the step (2) in a crucible, introducing argon and hydrogen gas for mixing, heating to a reaction temperature, introducing argon to load a carbon source and a liquid of a nitrogen source, carrying out a reaction, continuously coating the silicon dioxide doped magnesium oxide with a nitrogen-doped graphene layer to obtain a silicon dioxide doped magnesium oxide doped nitrogen-doped graphene material, stopping ventilation after coating is completed, and cooling and taking out the product material, (4) etching silicon dioxide doped magnesium oxide doped nitrogen-doped graphene sphere by placing the product material prepared in the step III in a hydrofluoric acid solution having a concentration of not less than 1 mol/l, performing a conversion reaction and etching, removing the silicon dioxide template and forming magnesium fluoride nanocrystalline, and finally performing centrifugal operation to obtain the magnesium fluoride nanocrystalline doped nitrogen-doped graphene hollow nanosphere material.