ABSTRACT
Supercapacitors, as a crucial energy storage device, have gained important attention due to their high-power density and ideal cyclic stability. Here, this chapter provides the fundamentals of energy storage in the electrical double-layer capacitance and Faradaic pseudocapacitance, focusing on the difference between supercapacitors and batteries from kinetic and mechanism. Electrode materials are the most critical components in supercapacitor devices, and thus this chapter primarily summarizes the progress of various electrode materials (such as carbon materials, metal oxides, metal sulfides, conducting polymers, etc.), and elaborates on the relationship between the material features and capacitive properties, including surface area, electrical conductivity, surface functional groups, etc. In addition, the applications of supercapacitors are also discussed and the research direction has been extensively proposed. In this chapter, the authors have attempted to provide an overview of supercapacitors and their prospects for future development/applications.
