Facile electrodeposition of graphene/polyaniline film on flexible substrate for supercapacitor application

Composites of electrode materials are of interest to further improve the performance of supercapacitor devices. Among other materials, graphene/polyaniline composite is one of the most promising materials due to their synergistic charge storage mechanism in the form of electrical double layer capacitance and pseudocapacitance. This work presents a facile way to prepare graphene/polyaniline film on a flexible gold deposited PET substrate through a one-step potentiodynamic method. The composites are synthesized from a solution of aniline and graphene flakes in sulfuric acid solution by varying the deposition cycle during the potentiodynamic method. The composite film shows a better performance than the pristine polyaniline in terms of capacitance, rate retention and stability over numerous cyclic voltammetry scans. The maximum value of areal capacitance is achieved with the graphene/polyaniline electrode prepared from 15 deposition cycle with the value of 167.8 mF cm−2. The best rate retention (up to 24.6%) is acquired by the sample made with 10 deposition cycles. Furthermore, addition of graphene also helps to enhance the cycle life of the electrode as shown by the insignificant capacitance fading during 500 cycles of cyclic voltammetry test. This work illustrates a promising platform to fabricate a stable and high areal capacitance electrode of supercacitor device with flexible substrate.