Co-MOF/polyaniline-based electrode material for high performance supercapattery devices

Abstract The supercapattery emerges as an ultimate energy storage device that synchronizes the excellent power density and rate capability of supercapacitors with the higher energy density of batteries. Metal organic framework (MOF) signifies a novel class of porous materials designed by the strong bonds between metal ions and organic linkers. By careful selection of ingredients, MOFs can display very high surface area, excellent chemical stability, and large pore volume. Here, we report cobalt intercalated MOF/PANI composite for the application of supercapattery devices. The MOF/PANI (50/50%) has shown a highest specific capacity of 154.9 C g−1 in cyclic voltammetry at 3 mV s−1, whereas 162.5 C g−1 at 0.4 A g−1. The MOF/PANI (50/50%) gave lowest ESR resistance in electrochemical impedance spectroscopy, that reveals enhancement in the conductivity after incorporation of PANI. The supercapattery (AC//MOF/PANI) was formed by coupling the activated carbon with MOF/PANI separated by porous membrane, MOF/PANI was given the positive potential whereas the activated carbon was utilized as the negative electrode. Supercapattery showed specific capacity of 104.5 C g−1 at a current density of 1.0 A g−1. Furthermore, this hybrid device provided excellent performance by expressing the notable performance with the energy density of 23.2 W h kg−1 in line with high power density of 1600 W kg−1 at 1.0 A g−1. The highest specific power sustained by the device is 4480 W kg−1 whereas excellent stability is expressed by subjecting the device to 3000 cycles of GCD at room temperature and sustain specific capacity of 146%.