Supercapacitor

SUPERCAPACITOR

1. SUPERCAPACITOR ANUSREE VIJAYAN E 2 nd year B.Ed KUTEC Dharmasala

2. capacitor A Capacitor (condenser) is a passive two terminal electrical component used to store energy in its electric field. The effect of a capacitor is known as capacitance. Electronic symbol of capacitor Unit of capacitance is Farad. Capacitor was invented by Ewald George von Kleist.

3. STRUCTURE Capacitors contain at least two electrical conductors often in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be a foil, thin film, sintered bead of metal, or an electrolyte. The nonconducting dielectric acts to increase the capacitor's charge capacity. Materials commonly used as dielectrics include glass, ceramic, plastic film, paper, mica, air, and oxide layers. Capacitors are widely used as parts of electrical circuits in many common electrical devices.

4. WORKING OF CAPACITOR When an electric potential, a voltage, is applied across the terminals of a capacitor, for example when a capacitor is connected across a battery, an electric field develops across the dielectric, causing a net positive charge to collect on one plate and net negative charge to collect on the other plate. No current actually flows through the dielectric. However, there is a flow of charge through the source circuit. If the condition is maintained sufficiently long, the current through the source circuit ceases. If a time-varying voltage is applied across the leads of the capacitor, the source experiences an ongoing current due to the charging and discharging cycles of the capacitor.

5. 1.1Video of charging and discharging of a capacitor Image showing charging and discharging of capacitor

6. Supercapacitor Also known as ultra capacitor/ Electric Double Layer Capacitor (EDLC) High capacity capacitor with a capacitance value much greater than other capacitor. Capacitance range from 100F-5KF

7. consist of two electrodes separated by an ion-permeable membrane (separator), and an electrolyte ionically connecting both electrodes.

8. WORKING OF SUPERCAPACITOR When the voltage is applied to positive electrode, it attracts negative ions from electrolytes. When the voltage is applied to negative electrode , it attracts positive ions from electrolytes. These ions are stored near the surface of electrode and this ions decreases the distance between the electrodes. Due to decrease of the distance between electrodes , the capacitance become very huge.

9. Materials used in supercapacitor 1. ELECTRODE Carbon nanotubes carbon aerogel used as electrode WHY? Carbon nanotubes greatly improve capacitor performance, due to the highly wettable surface area and high conductivity. Highly porous

10. 2. ELECTROLYTE Sodium perchlorate , Lithium perchlorate are used as electrolyte WHY? Wide working temperature (-90ºc to 400ºc) Non-flammable and low toxic Non-corrosive to electrode and packing component

11. 3.SEPARATOR Polyacrylonitrile is used as a separator (thickness 0.3nm to 0.8nm) WHY? Unique tensile strength (103MegaPascals) Electrical conductivity Not degraded easily

12. FEATURES OF SUPERCAPACITOR High capacitance. Low toxicity. Store high amount of energy compared to capacitor. High power density. Longer life. High cycle efficiency (95%)

13. APPLICATIONS OF SUPERCAPACITOR Hybrid electric vehicles(HEV) Military Aviation Medical Street lights Incorporation into batteries Energy harvesting Micro grids Voltage stabilizer etc.

14. High energy storage. Wide working temperature. Maximum life cycle. High cycle efficiency. Eco-friendly. Safe. Quick charging time. High self discharge rate. Low energy density. Can not be used in AC and high and high frequency spectrum. High cost. The voltage varies with energy stored. Individual cells have low voltage, and so series connections are needed to obtain higher voltages. DISADVANTAGES ADVANTAGES

15. reference https://www.sciencedirect.com/topics/chemistry/supercapacitors https://electricalfundablog.com/supercapacitor-ultracapacitor-characteristics-working/ https://batteryuniversity.com/learn/article/whats_the_role_of_the_supercapacitor https://www.engineersgarage.com/tutorials/articles-basic-electronics-super-capacitors-construction-working-advantages-applications/ https://www.explainthatstuff.com/how-supercapacitors-work.html https://www.electronics-tutorials.ws/capacitor/cap_1.html

16. Thank you