Supercapacitors, also commonly known as 'ultracapacitors', represent a promising alternative for meeting the escalating power demands of energy storage systems, particularly within the realm of portable electronic devices and batteries in the automotive sector. Their capacity to store and release energy at notably elevated rates, exceeding the capabilities of conventional batteries, stems from the fundamental charge-separation mechanism similar to that observed in traditional capacitors. In this scenario, the present study focuses on the development of environmentally friendly nanocomposites based on Poly(3,4-ethylene-dioxythiophene): polystyrene sulfonate (PEDOT:PSS) and Exfoliated Graphene (ExG) to produce electrodes for supercapacitor applications. The ExG-PEDOT:PSS nanocomposites were characterized via X-ray diffraction (XRD) and Raman analysis, revealing a uniform dispersion of ExG within the PEDOT:PSS matrix and providing evidence of electronic interactions between the two materials.

Subsequently, a morphological investigation combining XRD and TEM led to a comprehensive understanding of the structure of the inks. It was revealed that the materials combine perfectly into a homogenous mix with the polymer coating the graphene nanosheets. The interplay of the two materials leads to a boost of the performance when used in a capacitor. Thermogravimetric analysis (TGA) revealed an enhancement in thermal stability upon the incorporation of ExG, as evidenced by a higher residual mass for the ExG-PEDOT:PSS nanocomposite compared to pristine PEDOT:PSS. Moreover, scan rate-dependent cyclic voltammetry measurements were performed in phosphate buffer (PB) electrolyte; the incorporation of a small amount of ExG (1.4% wt/V) led to a 20 % increase in specific capacitance compared to pure PEDOT:PSS. Additionally, by repeating the CV tests for 1000 cycles under the same conditions, a higher capacitance retained ratio (96%) was observed for the ExG(1.4%)-PEDOT:PSS nanocomposite relative to pure PEDOT:PSS (90%). This advancement highlights the promising capabilities of these nanocomposites in developing electrodes for supercapacitors.