▎ 摘　　要

NOVELTY - Lewis acid is mixed with protonic acid to form electrolyte. Graphite as positive electrode is immersed in electrolyte and intercalated, to obtain intercalated graphite paper. The intercalated graphite paper as positive electrode is immersed in solution containing sulfate ions or phosphate ions. The intercalated graphite paper is peeled off to form flaky or granular expanded graphite slurry. The graphite slurry is washed and filtered. The graphite slurry is mixed with pure water, stripped, filtered and dried, to obtain graphene powder. USE - Electrochemical preparation of graphene (claimed). ADVANTAGE - The method enables preparation of graphene by simple and economical method, without using strong acid, strong oxidizing agent or expensive toxic organic solvent. DETAILED DESCRIPTION - Lewis acid is mixed with protonic acid to form electrolyte. Graphite as positive electrode is completely immersed in electrolyte and intercalated, to obtain intercalated graphite paper with expanded volume. The intercalated graphite paper as positive electrode is immersed in solution containing sulfate ions or phosphate ions, and voltage is applied to continue expansion of intercalated graphite paper. The intercalated graphite paper is gradually peeled off to form flaky or granular expanded graphite slurry. The graphite slurry is washed with pure water and filtered. The graphite slurry is mixed with pure water, to obtain thin slurry. The thin slurry is ultrasonically stripped, filtered and dried, to obtain graphene powder.