Chapter twelve - Analysis of supercapacitors

Supercapacitors are high-power density electrical energy storage devices with the ability to deliver electrical power instantly. To fulfill further enhanced performance requirements, especially higher energy densities due to increased energy requirements of modern-day systems, make specialized testing techniques incredibly crucial. There are a number of electrochemical performance characterization techniques that are extensively used to assess the suitability of these devices for particular applications. The primary electrochemical testing techniques include Galvanostatic charge-discharge, cyclic voltammetry, and electrochemical impedance spectroscopy. These techniques not only provide vital information about storage and delivery of electrical energy but also give insight into the fundamentals of charge storage (electric double layer or pseudo-capacitive), reaction kinetics (interaction between electrode and electrolyte), types of interfacial reactions, and equivalent series resistance. Likewise, there are a number of secondary testing approaches that can be used to analyze additional properties of these devices, including specific energy, specific power, self-discharge, cyclic stability, coulombic efficiency, and thermal stability. Combining primary and secondary characterization techniques not only helps in determining performance testing parameters precisely of capacitive devices but also distinguishes the correct testing approach for performance assessment and measurement.