This document discusses supercapacitors, also known as electric double layer capacitors or ultracapacitors. It defines supercapacitors as electrochemical capacitors that can store much higher energy than common capacitors. The document outlines the basic design of supercapacitors, including their electrodes, electrolyte, and separator. It describes the three main types - electrochemical double layer capacitors, pseudocapacitors, and hybrid capacitors - and their charge storage mechanisms. Applications, advantages over batteries, and disadvantages of supercapacitors are also summarized.

1. JIBIN RAJU
II MSc PHYSICS
CUSAT10/23/2016 1

2. OUTLINE
10/23/2016 2
 Introduction
 Basic design
 Applications
 Advantages
 Disadvantages
 Conclusions
 References

3. Introduction
CAPACITORS
 A capacitor (originally known as condenser) is a
passive two-terminal electrical component used to
store energy in its electric field.
 When a capacitor is attached across a battery, an electric
field develops across the dielectric, causing
positive charge +Q to collect on one plate and negative
charge −Q to collect on the other plate
10/23/2016 3

4. SUPERCAPACITORS
 A supercapacitor is an electrochemical capacitor that has
an very high energy density as compared to common
capacitors, about 100 times greater
 Supercapacitor is also known as Electric Double Layer
Capacitor(EDLC) or Ultra capacitor.
 The capacitance range is from 100 Farad to 10KFarad.
10/23/2016 4

5. HISTORY OF SUPERCAPACITORS
 In 1950s General Electric Engineers started experimenting
components using porous carbon electrodes for fuel
cells and rechargeable batteries.
 In 1957 H. Becker developed a "Low voltage electrolytic
capacitor with porous carbon electrodes".
 That capacitor came to known as Supercapacitor as it
stored very high amount of energy.
10/23/2016 5

6. BASIC DESIGN
10/23/2016 6

7.  Electrochemical capacitors (supercapacitors) consist of
two electrodes separated by an ion permeable membrane
(separator), and an electrolyte electrically connecting both
electrodes. When the voltage is applied, ions in the
electrolyte form electric double layers of opposite polarity
to the electrode's polarity.
10/23/2016 7
---
---
---
---
++
++
++
++
+
+








+
+
+
+
+
+
Electrolyte
Separator
Electric double layer
▬ +

8. TYPES OF SUPERCAPACITORS
Different types of supercapacitors, based on the type of
electrode are as follows.
I. Electrochemical double-layer capacitors (EDLCs):
 Have activated carbon electrodes or derivatives
 No charge-transfer, non Faradaic
Advantages:
Higher energy density than conventional capacitors,
comparable power densities, greater cycle stability
 Disadvantage:
Cannot match energy density of mid-level batteries
10/23/2016 8

9. II. Pseudocapacitors:
1. Have metal oxide or conducting polymer electrodes
2. Ions diffuse into pores, undergo fast, reversible surface
reactions(REDOX Reactions)
 Advantage:
 Higher energy density & capacitance than EDLCs
 Disadvantages:
 Lower power density than EDLCs, limited life cycle,
expensive electrode material
10/23/2016 9

10. III. Hybrid Capacitors:
 Combine the advantages & less disadvantages of the first
2 types
 3 types of electrodes: composite, asymmetric, battery-type
Advantages:
Most flexible performance, high energy and power density
without sacrifices in cycling stability
Disadvantages:
Relatively new and unproven, more research required
10/23/2016 10

11. 10/23/2016 11
c. Hybridcapacitor

12. Charge storing mechanism
Electric Double Layer Capacitor
AEDL formed with electrode
and electrolyte with solvent
molecules between as dielectric.
Store energy by adsorbing
electrolyte ions onto the surface
of the electrode
Fast acting. Low energy
potential, charge confined to
surface
10/23/2016 12

13. Pseudocapacitor
10/23/2016 13
Rely on redox reactions that take
place at the electrode.
Electrode materials typically
made up of transition metals,
conducting polymers, or compound
with O and N functional groups.
Higher Energy density but
lower cycling life.

14. Hybrid capacitors
A combination of EDLC and pseudocapacitors. Optimizes
power density of EDLC with energy density of
pseudocapacitor.
One common example is the Li ion capacitor which is a
current leader in the field.
10/23/2016 14

15. Application
 In start up mechanism for Automobiles.
 Supercapacitors are suitable temporary energy storage
devices.
 Supercapacitors provide backup or emergency shutdown
power to low-power equipment. e.g., ups.
 They used in industrial lasers, medical equipment.
 Large supercapacitors are used in wind turbines.
10/23/2016 15

16. Advantages relative to Batteries:
Very high rates of charge and discharge.
Little degradation over hundreds of thousands of cycles.
Wide working temperature
Good reversibility.
Low toxicity of materials used.
High cycle efficiency (95% or more).
10/23/2016 16

17. Supercapacitor Battery
10/23/2016 17
Layman example for difference
between
More power required for small
time interval in 200 m race
Constant but less power
required for large time in
20km race

18. Disadvantages
 Individual cells have low voltages, and so series
connections are needed to obtain higher voltages.
 Having high self – discharge rate.
 Cannot be used in AC and high frequency circuits.
 Cost is high.
10/23/2016 18

19. Conclusions
Supercapacitors may be used where high power or energy
storage is required that it will replace the batteries for
power storage.
Supercapacitors can be used widely because of their long
life & short charging time.
On the other hand it has limitations due to its high cost,
self discharge, packaging problems etc.
10/23/2016 19

20. References
 Avinash Balakrishnan, K. R. V. Subramanian, “Nanostructured
Ceramic Oxides for Supercapacitor Applications”, CRC press
2013
 Manisha Vangari,Tonya Pryor, and Li Jiang, “Supercapacitors:
Review of Materials and Fabrication Methods” 2013
 Simon, Patrice, Yury Gogotsi, and Bruce Dunn. “Where Do
Batteries End and Supercapacitors Begin?” Science 343, no.
6176 (March 14, 2014): 1210–11. doi:10.1126/science.1249625
 Wikipedia.org
10/23/2016 20

21. 10/23/2016 21