Emerging Materials for High-Performance Supercapacitors

The most widely studied and exploited carbon forms are activated carbons or engineered carbon, carbon nanotubes, carbon nanofiber, and graphene, for the electrochemical capacitor application. Electrode materials are categorized based on three main classes: carbonaceous materials, transition metal oxides, and conducting polymers. Depending upon the number of carbon layers, they are classified as single-walled carbon nanotubes, double-walled carbon nanotubes, and multi-walled carbon nanotubes. The method often offers favorable mechanical performance; the electrochemical performance is satisfactory even though it offers favorable mechanical performance whereas the second one showed good electrochemical behavior. The scientific research communities and industries have started working on a clean renewable energy source instead of fossil fuels that cause environmental pollution, global warming, and rapid resource depletion. Pseudocapacitor materials include metal oxides, hydroxides, nitrides, intercalating materials, and polymers. The electrode materials should have a high areal and volumetric capacity, which represents their ability to supply high energy within a confined space.