Recent advances in polyaniline/graphene nanocomposites for supercapacitor applications: Synthesis, properties, and future directions

Electrochemical capacitors or supercapacitors have attracted the attention of researchers and industries in the recent past because of the differences in the features and potential applications in comparison to the Li-ion batteries. Supercapacitors have been one of the most investigated applications in literature based on graphene-related materials. This review aims to provide the most recent advancement on the use of graphene and polyaniline (PANI) nanocomposite towards enhancing the supercapacitor properties. The synthesis methods of the graphene and PANI nanocomposite, the characteristics of the nanocomposite and its utilization in supercapacitors are discussed. Graphene and PANI are both well-known materials that possess fascinating physical and electrochemical characteristics, and in the last several years, they have been investigated for numerous applications by many researchers. Together with such advantages as enhanced physical and electrochemical characteristics, mechanical strength, and density, composites of both materials can be a potent material for supercapacitor usage. The preparation methods of graphene, PANI, and its composites described by the authors of the research article include in-situ polymerization, chemical vapor deposition, and hydrothermal-assisted polymerization. These characterization techniques include SEM, TEM, FTIR, XRD, DSC, and TGA to determine other properties of the nanocomposite which shows enhanced properties of graphene and PANI. The electrochemical properties of the nanocomposites are evaluated through cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) and the achieved values indicate high specific capacitance, cycling stability, and charge-discharge abilities. These outcomes demonstrate the excellent applicability of PANI/graphene nanocomposites as high-performance supercapacitors and encourage the confidence in the effectiveness of the study. Several factors affecting properties of the nanocomposites have been reported in the previous studies, and it is clear from this study how various properties and their relation affects the overall performance of the nanocomposite. Altogether, PANI/graphene nanocomposites have the potential to be used as next-generation supercapacitors, which is still unexplored fully to meet the demands to enhance the high-performance energy storage devices. • PANI/graphene composites achieve high specific capacitance (∼994 F/g) and stability. • SEM/TEM show uniform graphene coating, enhancing electrochemical activity. • FTIR confirms strong PANI-graphene interactions, critical for supercapacitor efficiency. • Galvanostatic charge-discharge shows >80% capacitance retention after 1000 cycles.