In Situ PANI–Graphite Nanochain-like Structures and Their Application As Supercapacitive Electrodes

Composite materials based on polyaniline and graphite were prepared using in situ polymerization of an aniline monomer without any previous treatment. Three monomer/graphite weight ratios during polymerization were studied, which were 1:1, 1:2, and 1:3. The composite materials showed a nanochain-like structure whose dimensions vary with the graphite content. Materials were deposited over a fluorine-doped tin oxide (FTO) substrate to evaluate its capacitive performance. The electrochemical measurements carried out in a 0.1 M aqueous solution of H2SO4 showed that PANI-Gr1 composite electrode exhibits a capacitance of 238 F·g−1 at 0.5 A·g−1 within a potential window of 0–0.6 V vs. Ag/AgCl. At a current density of 4.0 A·g−1, the PANI-Gr1 composite shows an energy density of 3.0 Wh·kg−1 that is 30% higher than pure PANI, results due to an increase in electrical conductivity concomitant with the morphology change and surface area increase. Composite materials showed promising properties as easily processable and scalable electrodes for supercapacitors.