Polyaniline-based composites for supercapacitive performance for sustainable development: Recent materials and components

The use of polyaniline (PANI) as an energy storage material, either directly as an electroactive material or as a conducting agent, has been the subject of extensive investigation inthe last several decades. The detailed explanation of the supercapacitive properties, like specific capacitance, energy density, and power density of PANI-based supercapacitors, new materials have been found to be a better option. These materials include metal oxides, carbon materials, and new types of materials (metal oxide frameworks) with excellent specific surface area, exposure to active sites, porous structures, and good conductivity, like those of carbon materials and metals. The synthesis of PANI through environmentally benign methods, along with its recyclability and minimal toxicity, aligns with the principles of green chemistry and circular economy. Scholarly attention has been drawn to fuel cells, supercapacitors, and batteries as viable and sustainable energy storage devices because of their high energy and power densities, long cycle lifetimes, and environmental friendliness. This extensive review examines the field of PANI-based composites for supercapacitor performance to provide a state-of-the-art investigation and educate the broader materials community. PANI is well-known for its versatility and has garnered a lot of attention due to its ability to be used in a variety of applications, including energy storage and environmental remediation. Providing a comprehensive overview of PANI-based composites for supercapacitor applications, classifying supercapacitors according to their mechanisms and materials (such as EDLC, pseudocapacitors, and hybrid capacitors), developing new materials (MOFs and MXene) to improve supercapacitor performance, and briefly outlining the fundamental requirements of supercapacitors (such as maximum charge storage space, large surface area, rapid charge transport, electrodes, and separator) are the goals of this paper. Finally, briefly describe the various synthesis methods of PANI-based composites, including chemical oxidative polymerization, in situ polymerization, interfacial polymerization, rapid polymerization, electrochemical, wet chemical, pseudo-high dilution, template-free solid state method, electrodeposition, free-standing, wet spinning probe sonication/ultrasound-assisted synthesis, microwave-assisted synthesis, and hydrothermal synthesis methods. The role of electrolytes in improving supercapacitor performance is also discussed. This review provides valuable information for future advancements and studies in this ever-evolving field. It also emphasizes current problems, suggestions, and prospects for the future.