▎ 摘　　要

Hybrid supercapacitor is an important next-generation energy storage system. In order to enhance the specific capacitance of graphene-manganese oxide composite (GR-Mn3O4), polyaniline was introduced to GR-Mn3O4 (PANI-GR-Mn3O4) by sonochemical polymerization method. Formation of composites was confirmed from IR, XRD, and FE-SEM analyses. PANI-GR-Mn3O4 was used as binder-free electrode material in the supercapacitor symmetric cell and its electrochemical performances in terms of specific capacitance, energy, and power densities were compared with that of its constituents PANI-GO-Mn3O4, PANI-Mn3O4, and GR-Mn3O4. GR-Mn3O4 composite specific capacitance was boosted from 44 to 660 F g(-1) with the encapsulation of polyaniline. The specific capacitance retention of PANI-GR-Mn3O4 was 89% with that of its original amount of 460 F g(-1) with energy density is 23 W h kg(-1) and power density 600 W kg(-1) at 1 A g(-1) for 4000 charge-discharge cycles.