High areal capacitance and enhanced cycling stability of binder-free, pristine polyaniline supercapacitor using hydroquinone as a redox additive

Lightweight, high-performance supercapacitors are in great demand in applications including hybrid electric vehicles and wearable electronics. Electrode materials play a very decisive role in determining the electrochemical performance as well as the mass of the supercapacitor. Electronically conducting polymers based pseudocapacitors have commanded much interest in the quest for the realisation of flexible, lightweight devices with high specific capacitance. Reports on the use of pristine polyaniline (PANI) electrodes for supercapacitors are rare due to their low cycling stability. Here, we report the synthesis of pristine crystalline PANI by selfstabilised dispersion polymerisation (SSDP) and its use as electrodes for supercapacitors using a redox-active electrolyte. The SSDP PANI electrode exhibits a gravimetric capacitance of 437.8 F g-1 at a current density of 0.5 A g-1 in the H2SO4-hydroquinone electrolyte. The pristine PANI supercapacitor exhibits a capacitance retention of 98.3 % even after continuous 8500 charge-discharge cycles performed at a current density of 5 A g-1. The incredibly high areal capacitance of 875.6 mF cm-2 at 1 mA cm-2 and long cycling stability observed in these lightweight pristine polymer supercapacitors can be used to power up wearable integrated devices.