Advances in Electrochemical Energy Storage Device: Supercapacitor

The storage of electrical energy is an essential technology in recent years. It builds an application with future renewable energy-based technology, hybrid electric vehicles, and the manufacturing of portable electronic devices. The supercapacitor is an important energy storage device due to its rapid charge-discharge process, longer cycle life (>100000 cycles), and high power density compared to rechargeable batteries and more energy density than the conventional capacitors. A supercapacitor stores electrical charge by electrostatic ion adsorption process and pseudocapacitance process involving fast surface redox reaction. However, getting the energy density performance of a supercapacitor close to the rechargeable batteries is still challenging. Better energy storage performance can be achieved by developing new nanostructure electrode materials (having both capacitive type and battery type property), using stable electrolytes with high cell potential and design of hybrid supercapacitor device. This chapter provides an overview of the basic concept and principle of electrochemical energy storage devices (supercapacitor) along with the advancement of the materials developed, properties, and applications.