Prepared by T Vigneshkumar S Vijayakumar SUPERCAPACITOR Prepared by T Vigneshkumar S Vijayakumar

Supercapacitor Supercapacitor is a high-capacity electrochemical capacitor Capacitance value 10,000 farads It is the bridge of the electrolytic capacitor and rechargeable batteries

Introduction Electric Double Layer Capacitor(EDLC) also known as ultra capacitor or super capacitor It is made up of two conductors which is separated by dielectric A dielectric can be made up of paper, mica, ceramic or a vacuum

Principle Energy is stored in a capacitor by polarising the electrolytic solution The charges are separated by electrode- electrolyte interface

Types of supercapacitors

Construction It consists of porous electrode, electrolyte and current collector There is a membrane which separates positive and negative plate is called separator

Working There are two carbon sheets separated by a separator It stores more energy than other electrolytic capacitor When voltage is applied to a positive terminal it attracts negative ions from the separator When voltage is applied to a negative terminal it attracts positive ion from the separator

The ions are stored near the surface of carbon The distance between the plates in order of angstroms Ultra capacitor stores energy via electrostatic charges on opposite surfaces of the electric double layer. The purpose of having separator is to prevent the charges moving across the electrodes.

Dielectric constant of medium X area of the plate Capacitance = ---------------------------------------------------------- Distance between the plates The amount of energy stored is very large as compared to a standard capacitor because of the enormous surface area created by the porous carbon electrodes and the small charge separation (10 angstroms) created by the dielectric separator

Rechargeable Battery vs Supercapacitor Supercapacitors Batteries Higher power density Much faster charge and discharge rate Environmentally friendly Extremely low internal resistance or ESR High efficiency(97-98%) Over a million charge-discharge cycle Have higher energy density Typically 200-1000 charge- discharge cycle Containing highly reactive and hazardous chemicals Negatively effected by low temperature

Advantages Long Life: It works for large number of cycle without wear and aging Rapid charging: It takes a second to charge completely Low cost: It is less expensive as compared to electrochemical battery High power storage: It stores huge amount of energy in a small volume Faster release: Release the energy much faster than battery

Disadvantages They have low energy density Individual cell shows low energy density Not all the energy can be utilized during discharge They have high self discharge as compared to battery Voltage balance is required when more than three capacitor connected in series

Applications They are used in electronic applications such as cellular electronics, power conditioning, Uninterruptible Power Supplies(UPS) They used in industrial lasers, medical equipment

Electric vehicles They are used electric vehicles for load levelling to extend the life of batteries It stores some energy from already moving vehicle So we don’t want to give external energy

Wireless systems They are used in wireless communication system for uninterrupted service They are used in VCRs CD players, electronic toys, security system and computers

Thank you