NiCo2O4 Nanosheet-Decorated Carbon Nanofiber Electrodes with High Electrochemical Performance for Flexible Supercapacitors

Carbon fiber-based electrodes decorated with binary metal oxides hold great promising for flexible and high performance supercapacitor applications. Herein, a poly (acrylonitrile-co-methylhydrogen itaconate) copolymer (P(AN-co-MHI)) was synthesized for flexible carbon nanofiber (CNF) by electrospinning. Then the nanostuctured NiCo2O4 was coated on nanofibers by a facile one-pot hydrothermal method. The obtained NiCo2O4/CNF composite showed unique hierarchical structure, in which the NiCo2O4 nanosheets were uniformly grown on the CNF and exhibited a high capacitance of 620.23 F g−1 at 0.5 A g−1 with great bending duration of almost 92.5% capacitance retention under 180° bending angle. Moreover, the symmetric solid-state supercapacitor was assembled, which demonstrated a maximum energy density of 36.68 Wh kg−1 and a power density of 2504.3 W kg−1. Considering the advantages of flexibility and excellent electrochemical performance, this NiCo2O4/CNF composite is promising great potential in the application of wearable and portable supercapacitor devices.