Flexible coaxial-type fiber supercapacitor based on NiCo2O4 nanosheets electrodes

Fiber electronic devices show advantages for the direct use as wearable and embedded device units or integrated textile modules. We successfully developed a coaxial-type flexible fiber supercapacitor by using NiCo2O4 nanosheets grown on Ni wire as the fiber electrodes. The volume capacitance of the fiber-shaped supercapacitor reached 10.3 F/cm(3) at a current of 0.08 mA and outstanding cycling stability. An energy density of 1.44 mWh cm(-3) and a power density of up to 17W cm(-3) were also obtained for the fiber supercapacitor, which are almost 48-fold higher than the previous values. Furthermore, the coaxial-type fiber supercapacitor does not show any apparent degradation in the bending test, illustrating the promise for use as electrodes for portable and wearable energy storage. (C) 2014 Elsevier Ltd. All rights reserved.