MnO₂ Nanosheets Grown on Multichannel Carbon Nanofibers Containing Amorphous Cobalt Oxide as a Flexible Electrode for Supercapacitors

In this study, MnO2 nanosheets grown on the multichannel carbon nanofibers containing amorphous cobalt oxide (CoMCNFs@MnO2) are prepared via electrospinning technology followed by carbonization and a facile chemical bath deposition process. The as-obtained CoMCNFs@MnO2 shows flexible features, which could serve as freestanding electrodes applied in supercapacitors. As a result, CoMCNFs@MnO2-2.5 exhibits the specific capacitance of 265 F g–1 at 0.5 A g–1, which surpasses those of their individual counterparts (135 and 143 F g–1 at 0.5 A g–1 for MCNFs@MnO2 and CoMCNFs, respectively). Moreover, After 10000 cycles, the specific capacitance of CoMCNFs@MnO2-2.5 also maintained 98.7%. Most importantly, the asymmetric supercapacitor (ASC) is assembled with CoMCNFs@MnO2-2.5 and the electrospinning carbon nanofibers (CNFs), which exhibit a high E of 19.27 Wh kg–1 with a P of 217.51 W kg–1 at 0.3 A g–1 and outstanding cycle ability of capacitance retention of 94.9% after 10000 cycles. This work paves a way to develop high-performance wearable asymmetric supercapacitors.