Pseudocapacitance: Fundamentals to Advanced Applications

The electrochemical energy storage advancement requires the use of either high-power density (like batteries) or high-energy density (like electrochemical capacitors) devices. For both current and upcoming applications, materials that can give high energy densities as well as high power densities in a single package are in increased demand. The faradaic process of power involves surface or near-surface redox processes. It provides a way for doing so by employing high charge–discharge rates and high-power densities. The focus of this chapter is on the pseudocapacitive characteristics of transition metal oxides. Pseudocapacitance will be explained in length in this chapter before going over its electrochemical properties. The following section of this chapter will be a review of the most prominent pseudocapacitive elements found in both aqueous & non-aqueous electrolytes. Near the end, there is a full discussion of the key problems with pseudocapacitive materials and a look into the future.