1. SUPERCAPACITOR
S
By- Poorva Sharma
(E.C.)

2. Outline questions
 What is Capacitors?
 What are Supercapacitors?
 History of Supercapacitors.
 Advantages relative to Batteries
 Why they can store more energy, and why the mechanism
of energy storage is so fast?
 Why supercapacitors?
 Disadvantage
 Applications.

3. What is Capacitor?
 A capacitor (originally known as condenser) is
a passive two-terminal electrical component used to
store energy in an electric field.
 When there is a potential difference (voltage) across the
conductors, a static electric field develops across the
dielectric, causing positive charge to collect on one plate
and negative charge on the other plate. Energy is stored
in the form of electrostatic field.

4. What is Supercapacitor
 A supercapacitor or ultracapacitor is an
electrochemical capacitor that has an
unusually high energy density when compared
to common capacitors. They are of particular
interest in automotive applications for hybrid
vehicles and as supplementary storage for
battery electric vehicles

5. History
 The first supercapacitor based on a double layer
mechanism was developed in 1957 by General Electric
using a porous carbon electrode [Becker, H.I., “Low
voltage electrolytic capacitor”, U.S. Patent 2800616, 23
July 1957].
 It was believed that the energy was stored in the carbon
pores and it exhibited "exceptionally high capacitance",
although the mechanism was unknown at that time. It
was the Standard Oil Company, Cleveland (SOHIO) in
1966 that patented a device that stored energy in the
double layer interface [Rightmire, R.A., “Electrical energy
storage apparatus”, U.S. Patent 3288641, 29 Nov 1966.].

6. Advantages relative to Batteries:
 Very high rates of charge and discharge.
 Little degradation over hundreds of
thousands of cycles.
 Good reversibility.
 Low toxicity of materials used.
 High cycle efficiency (95% or more).

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

8. Specific power against specific energy
Ragone plot

9. Electrochemical double layer capacitors (EDLC)
• Store energy using ion adsorption (no faradaic (redox) reaction)
• High specific surface area (SSA) electrodes (carbon)
100 – 120 F/g
(nonaqueous electrolyte)
150 – 300 F/g (aqueous
electrolyte)

10. Market Opportunity
World Supercapacitors Market, $ mln.
$560 mln.
Obstacles to
600
500
grow
254.4
400 • Relatively high cost
$272 mln.
• Competition with batteries well established on
300 the market
89.6 161.4 • Consumer conservatism
200
111.4
100
0
70.8
144.8
Factors to growth
2006 2011
• New market opportunities like HEVs, Smart Grid,
Alternative/Renewable Energy
Electronics UPS and power tools Transportation
• Growing ecology restrictions for competitors
Fig. 5. Annual Sales divided by segments • Operation in a wide temperature range
(Ultracapacitors - A Global Industry and Market
Analysis, Innovative Research and Products , Inc. 2006)
• Good prospects or a combined power supply

11. Why supercapacitors?
Supercapacitors are known for over 50 years
(patent of General Electric, 1957).
Capacitance
Supercapacitor are able to store and deliver of Earth is
energy at relatively high rates (beyond those 0.0007 F
accessible with batteries).
A specific power of 5 000 W/kg can be reached.
Supercapacitor exhibit very high degree of
reversibility in repetitive charge-discharge cycling.
Cycle life over 500 000 cycles demonstrated.

12. Applications in Public Transport
 China is experimenting with a new form of electric bus
that runs without powerlines using power stored in large
onboard supercapacitors, which are quickly recharged
whenever the electric bus stops at any bus stop, and
get fully charged in the terminus. A few prototypes were
being tested in Shanghai in early 2005. In 2006, two
commercial bus routes began to use supercapacitor
buses, one of them is route 11 in Shanghai.
 In 2001 and 2002, VAG, the public transport operator in
Nuremburg, Germany tested a bus which used a diesel-
electric drive system with supercapacitors .

13.  Since 2003 Mannheim Stadtbahn in
Mannheim, Germany has operated an LRV (light-rail
vehicle) which uses supercapacitors. In this
presentation, there is additional information about
that project by the builder of the Mannheim
vehicle, Bombardier Transportation, and the possible
application of the technology for DMUs (Diesel
Multiple Unit) trains.
 Other companies from the public transport
manufacturing sector are developing supercapacitor
technology: The Transportation Systems division of
Siemens AG is developing a mobile energy storage
based on double-layer capacitors called Sibac
Energy Storage. The company Cegelec is also
developing a supercapacitor-based energy storage
system.

14. Features
 Such energy storage has several advantages
relative to batteries.
 Very high rates of charge and discharge.
 Little degradation over hundreds of thousands
of cycles.
 Good reversibility
 Low toxicity of materials used.
 High cycle efficiency (95% or more).

15. Technology
 Carbon nanotubes and certain conductive
polymers, or carbon aerogels, are practical for
supercapacitors. Carbon nanotubes have
excellent nanoporosity properties, allowing tiny
spaces for the polymer to sit in the tube and act as
a dielectric. Some polymers (eg. polyacenes)
have a redox (reduction-oxidation) storage
mechanism along with a high surface area. MIT's
Laboratory of Electromagnetic and Electronic
Systems (LEES) is researching using carbon
nanotubes [1].

17. Supercapacitors are also being made of carbon
aerogel. Carbon aerogel is a unique material
providing extremely high surface area of about
400-1000 m2/g. Small aerogel supercapacitors
are being used as backup batteries in
microelectronics, but applications for electric
vehicles are expected.

19.  The electrodes of aerogel supercapacitors are
usually made of non-woven paper made from
carbon fibers and coated with organic
aerogel, which then undergoes pyrolysis. The paper
is a composite material where the carbon fibers
provide structural integrity and the aerogel provides
the required large surface.
 The capacitance of a single cell of an
ultracapacitor can be as high as 2.6 kF (see photo
at the beginning).

20. Disadvantage
 The amount of energy stored per unit weight is
considerably lower than that of an electrochemical
battery (3-5 W.h/kg for an ultracapacitor compared to
30-40 W.h/kg for a battery). It is also only about
1/10,000th the volumetric energy density of gasoline.
 The voltage varies with the energy stored. To effectively
store and recover energy requires sophisticated
electronic control and switching equipment.
 Has the highest dielectric absorption of all types of
capacitors.

21. Applications:
 Maintenance free applications
 Public transportation, HEVs, Start-Stop System
 Back-up and UPS systems
 Systems of Energy Recuperation
 Consumer electronics