Polypyrrole-coated hierarchical porous composites nanoarchitectures for advanced solid-state flexible hybrid devices

Design and fabrication of advanced functional materials is essential but still a challenge for current energy storage devices. Herein, polypyrrole coated highly porous vanadium oxide (V2O5@Ppy) nanorod and nanoplate arrays with large mass loadings, have been successfully constructed on carbon felt (CF) via a facile solvothermal reaction followed by in-situ polymerization technique. Interestingly, the structure of the V2O5 thin films can be simply tuned from porous nanoplates to nanorods with controlled calcination time. In addition, MnO2 nanowires with Ppy coating were also grown on the CF substrates to form MnO2 Ppy/CF electrode through the similar method. As integrate electrodes for energy storage devices, V2O5@Ppy/CF nanorods demonstrate more superior electrochemical properties compared to V2O5@Ppy/CF nanoplates. By virtue of their intriguing structural features and uniformly Ppy coating, a solid-state flexible hybrid device (SFHD) based on V2O5@Ppy/CF and MnO2 Ppy/CF as the negative and positive electrode, respectively, manifests outstanding cycling stability (approximately 89% retention even after 20,000 cycles), excellent mechanical flexibility, and remarkable energy density (28.6 W h kg(-1) at power density of around 200 W kg(-1)), which makes it hold great potential to be unexceptionably flexible devices for portable and wearable electronics. (C) 2015 Elsevier Ltd. All rights reserved.