Abstract

Hybrid supercapacitors (HSCs) are made by the combination of electric double-layer capacitor (EDLC) materials, various types of pseudocapacitive, and battery-type materials. The progress made on the improvement of energy density without sacrificing the power density attracted the researchers to move toward HSC. The specific capacitance of the HSC showed a superior value than the EDLC or pseudocapacitance-based supercapacitors. Numerous advancements have been made on the HSCs with the development in preparation of electrode materials, electrolyte, formation of component, device structure, and the new mechanisms for the improvement of electrochemical characteristics. This chapter specifically emphasis the new development made on the HSCs based on the layered double hydroxides, metal–organic frameworks (MOFs), MOF-derived materials and their composites. The specific characteristics requirement of the electrode material, electrolyte, the substrate in support of electrode materials, and the progress made on them for smart supercapacitors are discussed.