Lightweight, flexible, wearable, and portable electronic gadgets have drawn significant attention in modern electronics industry. To power these gadgets, great efforts have been made to develop highly efficient energy-storage equipment. Among various power sources, a supercapacitor, acting as a bridge between the conventional battery and electrolytic capacitor, has been considered a promising portable energy storage device because of its high power density, fast charge/discharge rate, adequate operational safety, and excellent working lifetime. Hybrid supercapacitors, which combine redox materials with carbon-based materials, exhibit tremendous potential to fulfill the requirement of practical applications. In this chapter, we will review recent reports focusing on composite materials (i.e. metal oxide, metal hydroxide, and metal dichalcogenide composited with carbon materials) for the application in supercapacitors. The conclusion and futuristic prospects and challenges of highly efficient supercapacitors are briefly discussed.
Part of the book: Novel Nanomaterials
Iron oxide nanostructures have been considered very promising material as electrode in electrochemical energy storage devices because of their lower cost of synthesis and high theoretical charge storage capacity. Iron oxide nanoparticles and their nanocomposites have performed excellent in supercapacitor. Iron oxide as negative electrode has extended the working voltage window of a supercapacitor. The main problems associated with iron oxide based electrodes are their poor electrical conductivity and cycle stability. Therefore, a conductive carbon matrix has been added to the iron oxide based electrodes to improve the electrochemical performance. In this chapter, recent progress on iron oxide and its composite with different materials as electrode in supercapacitor is summarized. The various synergistic effects of nanocomposites and compositional engineering to enhance the electrochemical performance of iron oxide are also discussed.
Part of the book: Iron Oxide Nanoparticles