ABSTRACT
As an extension of traditional “parallel-plate” capacitors, Electrochemical Capacitors (ECs) hold a transformative role in the area of energy storage. Whereas traditional capacitors operate by storing charges on two polarized plates, separated by a dielectric material, ECs operate on the formation of Electrical Double Layer (EDL) at each electrode surface, connected in series. The formation of EDLs allows for much greater amounts of energy to be stored. Of course, such improvements are only made possible through the use of the suitable electrode materials, which must display a high electrical conductivity, along with a high microporosity and the right amount of surface functional groups. Moreover, these materials must also be cost effective—which explains why this chapter focuses exclusively on carbon-based materials. Herein, we will first focus on theoretical principles by discussing the fundamental physical properties of capacitor materials, along with structure-property relationships of carbon materials and their electrochemical performance in ECs. The chapter will then introduce several synthetic techniques as well as the use of graphene in ECs. Lastly, the chapter will conclude with a discussion on pseudocapacitance and the effect of heteroatom doping in carbon in electrochemical performance. This work is intended to give interested audiences an introduction and a starting point towards the synthesis and use of carbon materials for use in ECs.
