High-performance flexible supercapacitors based on mesoporous carbon nanofibers/Co3O4/MnO2 hybrid electrodes

Abstract

In this work, self-standing Co₃O₄ doped CNF (CNFs/Co₃O₄) membranes were prepared through a facile sol–gel electrospinning and high-temperature carbonization process, followed by a subsequent in situ redox reaction in KMnO₄ solution to obtain mesoporous MnO₂ sheets coated CNFs/Co₃O₄/MnO₂ composite membranes. The as-fabricated flexible CNFs/Co₃O₄/MnO₂ membrane electrodes exhibit superior capacitive performance compared to CNFs/MnO₂ membranes, with a high specific capacitance of 840 F g⁻¹ at a scan rate of 5 mV s⁻¹ (based on the mass of MnO₂) which is ascribed to the electrochemically active and electrically conductive CNF backbone contributed by Co₃O₄ doping and the efficient electron transportation and ion diffusion derived from the highly dispersed mesoporous MnO₂ nanosheets. Furthermore, a flexible supercapacitor device using CNFs/Co₃O₄/MnO₂ membranes as two symmetric electrodes has also been demonstrated, which exhibits good flexibility and remarkable capacitive performance as well.