▎ 摘　　要

NOVELTY - The preparation method involves (S1) mixing and reacting phosphorus pentoxide, expansion agent, graphite and sulfuric acid to prepare a mixture, and (S2) mixing and reacting the mixture with auxiliary expansion agent to prepare expanded graphite. The expansion agent is persulfate. The mesh number of the graphite is 32-10000 mesh. The preparation method of expanded graphite specifically comprises adding phosphorus pentoxide, expansion agent, graphite and sulfuric acid into the reaction vessel in sequence for mixing and reaction. The expansion agent is selected from hydrogen peroxide and water. The volume ratio of the expansion aid and sulfuric acid is (0.1-1):10. USE - Preparation method of expanded graphite made into graphite paper by calendering and used as precursor for preparation of graphene (all claimed). ADVANTAGE - The method can quickly synthesize chemical expansion graphite. The acid consumption is controllable. The energy consumption is low. The implementation process is simple and safe, which is suitable for mass production, does not need heating energy consumption, and quickly reacts at room temperature. The preparation time of the whole expanded graphite can be controlled within 10 minutes. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1)an expanded graphite; and (2) an application of the expanded graphite in preparing graphene. DESCRIPTION OF DRAWING(S) - The drawing shows a Raman diagram of expanded graphite. (Drawing includes non-English language text)