In order to extremely retain the lattice structure of graphene so as to enhance its conductivity and simplify the synthesis process of transition metal oxides / graphene composites,Mn3O4/ graphene nanocomposites were successfully prepared through a hydrogen arc discharge method and a simple high-temperature treatment,and the proposed nanocomposites were used as the electrode of supercapacitor. The morphology,structure and composition of products were characterized by x-ray diffractometer( XRD),Raman spectro...