Carbon aerogel is commonly used as the electrode material in supercapacitors due to its high surface area, which allows supercapacitors to store more electrical charge. Supercapacitors consist of two carbon aerogel electrodes separated by an ion-permeable membrane and immersed in an electrolyte. They provide high power density and can charge and discharge quickly, making them useful for applications requiring brief bursts of energy like camera flashes or backup power sources. However, supercapacitors also have lower energy density than lithium-ion batteries and higher self-discharge rates. Recent innovations include using supercapacitors to provide quick charging for electric bus stops and mobile phone batteries.

2. CONTENTS:
• INTRODUCTION
• CONSTRUCTION
• WORKING
• AEROGEL
• WHY CARBON AEROGEL?
• ADVANTAGES&DISADVANTAGES
• APPLICATIONS
• INNOVATIONS

3. INTRODUCTION
• Definition: Supercapacitor is an electrical component capable of
holding hundreds of times more electrical charge quantity than a
standard capacitor. This characteristic makes them useful in devices
that require relatively little current and low voltage.
• Supercapacitor cells are able to fill the gap between conventional
capacitors and batteries by providing high power performance in a
compact design.
• Supercapacitors are also known as Supercap, Pseudocapacitors, Gold
Cap or Ultracapacitors, Electric Double-Layer Capacitor (EDLC).

4. CONSTRUCTION:
• Supercapacitors are constructed with two metal foils (current
collectors), each coated with an electrode material like activated carbon.
• The collectors serve as the power connection between the electrode
material and the external terminals of the capacitor.
• Both the electrodes are then separated by an ion
permeable membrane(separator) used as an insulator to protect the
electrodes against direct contact forcing short circuits.
• This construction is subsequently rolled or
folded into a cylindrical shaped aluminum can.
1.Terminals, 2.Safety vent, 3.Sealing disc,
4.Aluminum can, 5.Positive pole,
6.Separator, 7.Carbon electrode,
8.Collector, 9.Carbon electrode,
10.Negative pole

5. WORKING
• Supercapacitors consist of two electrodes separated by an ion
permeable membrane (separator), and an electrolyte connecting
electrically the both electrodes.
• By applying a voltage to the capacitor an electric double layer at
both electrodes is formed, which has a positive or negative layer of
ions deposited in a mirror image on the opposite electrode.
1. power source, 2. collector,
3.polarized electrode, 4. Helmholtz
double layer, 5. electrolyte having
positive and negative ions, 6.
Separator.

6. Aerogel:
 The most commonly used electrode material for
supercapacitors is carbon aerogel.
 Small pieces of cellulose nanofibers were trimmed, freeze-
dried and then pyrolyzed at 1300 degrees Celsius under
argon to convert the cellulose into ultralight nanofibrous
carbon aerogel.
 This substance has a density only one sixth of that of the air.

7. One of the major interests in carbon aerogels is making
electrical conductors with high surface areas.
The equation that governs how much energy a capacitor can
store is
C = εA/d
where C is the capacitance, ε is the dielectric constant of the
separator between the plates, A is the surface area of the plates,
and d is the distance between the plates. The larger A is in this
equation, the more energy the capacitor can store-and for
applications where infinitely-large plates are too cumbersome
to carry around, high-surface-area conductors like carbon
aerogels are very important materials.
WHY CARBON AEROGEL?

8. Function Supercapacitor Lithium-ion (general)
Charge time
Cycle life
Cell voltage
Specific energy (Wh/kg)
Specific power (W/kg)
Cost per Wh
Service life (in vehicle)
Charge temperature
Discharge temperature
1–10 seconds
1 million or 30,000h
2.3 to 2.75V
5 (typical)
Up to 10,000
$20 (typical)
10 to 15 years
–40 to 65°C
–40 to 65°C
10–60 minutes
500 and higher
3.6 to 3.7V
100–200
1,000 to 3,000
$0.50-$1.00 (large system)
5 to 10 years
0 to 45°C
–20 to 60°C

9. ADVANTAGES:
DISADVANTAGES:
 High power density.
 The supercapacitor can be
charged and discharged
virtually an unlimited
number of times.
 Under normal conditions, a
supercapacitor fades from
the original 100 percent
capacity to 80 percent in 10
years.
 Low impedance
 No chemical actions.
 Low energy density
(6Wh/Kg).
 High self discharge rate
much higher than
batteries.
 Linear discharge voltage
characteristic prevents use
of all the available energy
in some applications.
 Power is available only for
a very short duration.
 Low cell voltage.

10. APPLICATIONS:
 Power back-up for memory functions in a wide range
of consumer products such as mobile phones ,
laptops and radio tuners.
 To provide fast acting short term power back up for
UPS applications.
 Energy storage for solar panels, and motor starters.
 In camera flashes to enable discharging enough
charge to produce a quick but bright flash of light.

11. INNOVATIONS:
 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. In 2006, two commercial
bus routes began to use supercapacitor buses, one of them
is route 11 in Shanghai.
 Recently in the university of California, a girl from India
has invented a device made of super capacitor which
charges the mobile phone battery in just 30 seconds.

12. Queries…??