Incorporation of graphene-Mn₃O₄ core into polyaniline shell: supercapacitor electrode material

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. [Figure not available: see fulltext.].