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

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.