A wire-shaped flexible asymmetric supercapacitor based on carbon fiber coated with a metal oxide and a polymer

Abstract

Due to high capacitance resulting from the redox character of the MnO₂–PPy–carbon and V₂O₅–PANI–carbon fiber composites, a flexible wire-shaped fiber asymmetric supercapacitor (WFASC) was fabricated using these materials as the positive and negative electrodes, respectively. Especially, the large work function difference between MnO₂ and V₂O₅ help the device to exhibit a wide potential window of 2.0 V and a high areal capacitance of 0.613 F cm⁻². As a result, the WFASC showed a maximum energy density of 0.340 mW h cm⁻² at a power density of 1.5 mW cm⁻² and a maximum power density of 30 mW cm⁻² at an energy density of 0.294 mW h cm⁻². Furthermore, the device exhibited a perfect stability after 5000 cycles at a current density of 30 mA cm⁻², meanwhile, it could withstand the bending test and drive a LED under bending states. All of the above results prove the potential application of WFASC devices.