Flexible and high energy density solid-state asymmetric supercapacitor based on polythiophene nanocomposites and charcoal

An asymmetric supercapacitor (ASC) was constructed using a polythiophene/aluminium oxide (PTHA) nanocomposite as an anode electrode and charcoal as a cathode electrode. The highest specific capacitance (C(sp)) of the PTHA electrode was found to be 554.03 F g(−1) at a current density (CD) of 1 A g(−1) and that of the charcoal electrode was 374.71 F g(−1) at 1.4 A g(−1), measured using a three electrode system. The maximum C(sp) obtained for the assembled PTHA//charcoal asymmetric supercapacitor (ASC) was 265.14 F g(−1) at 2 A g(−1). It also showed a high energy density of 42.0 W h kg(−1) at a power density of 735.86 W kg(−1) and capacitance retention of 94.61% even after 2000 cycles. Moreover, it is worth mentioning that the asymmetric device was used to illuminate a light emitting diode (LED) for more than 15 minutes. This PTHA//charcoal ASC also possesses stable electrochemical properties in different bending positions and hence finds a promising application in flexible, wearable and portable energy storage electronic devices.