ABSTRACT
In this chapter, the basic working principles of supercapacitors and state-of-the-art functional materials for them are presented. It also discusses the structure and properties of the electrical double layer and its influence on the energy storage capacity and power of these devices. It also deals with the pseudocapacitive behavior of some reversible adsorption processes at the electrode surfaces, which can be used to increase the devices' total effective capacitance significantly. Further, some essential differences between supercapacitors and batteries are analyzed. Typical schemes for the development of efficient functional electrode materials and electrolytes for supercapacitors are considered. A brief discussion on the existing and possible applications of supercapacitors is also presented.
