A review on supercapacitor & its application

Abstract

Capacitors are commonly used in electronic resonance circuits; however, capacitors have not been used for storing large amounts of electrical energy in electrical circuits. Also they are not known to be long lasting. Thus appears the need of supercapacitor with variety of electrodes, offering high power density, fast charging & elongated life-cycle. Highly conducting and porous carbon nanotube (CNT) networks are popular as the sole electron conducting material in supercapacitors. The high conductivity of CNT networks and the high surface area allow the replacement of both the metallic current collector and the active material that forms one side of the electrochemical double layer. The combination of both functions in one single layer leads to lightweight charge storage devices that can be manufactured using simple and cheap room temperature methods. In case of solid-state supercapacitor, device fabrication is done by a simple vacuum thermal evaporation method, which allows not only a multilayer stacking structure to further enhance the capacitance, but also permits the supercapacitor to be easily incorporated with other electronic devices, showing interesting characteristics for both fundamental study and practical applications. supercapacitors are being used to increase the efficiency of hybrid electric vehicles in several ways. Aging of a capacitor is a topic to be concerned about. The voltage difference in cells and temperature tend to shorten the life span. Methods are being developed to tackle this problem. Until recently, supercapacitors were relegated to fairly mundane applications such as memory protection and internal battery backup, but in the last few years the application space has broadened significantly into hybrid vehicles, smartphones, and energy harvesting. New technologies on the horizon promise to bring supercapacitors into full competition with rechargeable batteries