1.SUPERCAPACITOR As energy storage deviceNAME: Abdul Saleem Mir Enrollment Number: 49/2010 7th ELECTRICAL

2. Supercapacitor Definition Supercapacitors are electrochemical devices with following features: High energy density. High power density. High capacitance. Longer life2 3. HISTORY The first supercapacitor based on double layer mechanism was developed in 1957 by General Electric using porous electrode. Standard Oil Company Cleveland Ohio rediscovered this effect in 1966 & gave licensing to NEC in 1978 for market production.3 4. Principle Construction It consists of following components: Current collector: Metal contacts are used as current collectors .4 5. Polarized electrode: Highly activated carbon is used as electrode because of following reasons: It is highly porous It has extraordinarily high specific surface area It has good conductivity High temperature and chemical stability Corrosion resistant 5 6. Electrolyte It contains dissolved and solvated ions that migrate to and from the electrodes during charge and discharge respectively. Electrolytes are of two types: Water soluble Water insoluble 6 7. Separator It acts as mechanical separation between two electrodes. It must provide electronic insulation between the electrode of opposite polarization It must support ionic conduction from one electrode to another.7 8. WORKING8 9. Equivalent circuit9 10. Manufacturers & Specifications10 11. Advantages High energy storage Low ESR and hence high power density Appreciable operating temp.(-40C to 70C) Eco-friendly11 12. Disadvantages Low voltage per cell It can't be used in AC & high frequency circuits13 13. Comparison13 14. Applications Used in Diesel engine start up in submarines & tanks. Used to recover braking energy in HEV & modern trains and deliver the same during accelerating periods. Can be used in f &V control in power systems Used as backup energy source for GPS guided missiles 14 15. Flat style of super capacitor used for mobile devices.Typical knob capacitor For PCB mounting used for memory backupRadial style of lithiumIon capacitor for PCB mounting used for industrial applications15 16. 16 17. References R.Morrison, The chemical physics of surfaces New York: Plenum,1990. E.J.Dowgiallo & A.F.Bruke Ultracapacitors for electric and hybrid vehicles: A technology update. B.E.Conway, Electrochemical Supercapacitors, chemical industry press. IEEE transactions on industry applications, vol. 36. Transient analysis of pulsed charging in Supercapacitors IEEE documentation.17 18. End 18