Pseudocapacitance in Double Perovskite Material

Double perovskite materials (DPMs) with the formula of A2BB′O6 have gained much attention as supercapacitor materials due to their compositional characteristics that improve the properties of conventional perovskite structure ABO3 to gain higher electroactivity, conductivity, and faradic redox activity, in addition to their conventional structural stability. These advanced properties recently made DPMs promising materials for supercapacitor application, and they could show relatively high specific capacitance and specific energy density (Ed) at high specific power density (Pd). At the beginning of this chapter, the DPMs will be introduced in detail from a chemical perspective to address their chemical composition, common morphology, electrochemical characteristics, and the effect of oxygen intercalation on their electrochemical properties. Then, the electrochemical energy storage mechanism in DPMs will be discussed from the electrochemical interactions point of view, and the pseudocapacitive behavior will be explained through simple kinetics and thermodynamics concepts. After that, the recent developments in DPMs design and the correlation between the structural improvements and the change in the pseudocapacitance performance will be addressed. Finally, the pros and cons of using double perovskite as pseudocapacitive material will be discussed alongside future developments and directions in this type of pseudocapacitive material.