New M.Tech. Thesis Submitted from Power

SUPERCAPACITOR PERFORMANCE EVALUATION by Sonam Khurana 

Abstract

Supercapacitor (SC) also popularly known as Ultracapacitor (UC) or Electric Double Layer Capacitor

(ELDC) is becoming one of the most attractive Energy Storage Device. Supercapacitors have capacity to store large amount of power as compared to traditional capacitors. It has high power density and large life cycle due to these properties it can be employed in many applications. In traditional capacitors capacitance value is in microfarads, picofarads and nanofarads. To get higher values of capacitance of the order of hundreds of farads supercapacitors have been employed. Supercapacitors have high porous electrodes and employs different kinds of materials for electrodes. Mainly carbon based electrodes have been used for electrodes as carbon has highly porous structure. In this activated carbon based electrode has been used for improving specific capacitance which has specific surface area approximately 1000-3000 m2/g and it provides encouraging results with higher specific capacitance when specific area of the electrodes has been increased. When distance between the electrodes is varied from 2nm to 10nm value of specific capacitance also changes. Barium titanate has been used as dielectric material whose dielectric constant is different for different temperatures and its specific capacitance value comes to be maximum at 25°C. Life expectancy of supercapacitor has been evaluated and comes out to be long and gives hundreds of cycles of life. Lifetime of supercapacitor gets double when ambient temperature of supercapacitor is decreased by 10°C. At 25°C expected lifetime of supercapacitor is 32000 hours and at 65°C expected lifetime is 2000 hours. Effect on Voltage and charge of supercapacitor has been evaluated when distance between the electrodes is increased.