Introduction to Ultracapacitors

1. Ultracapacitors
“The unique attributes
of ultracapacitors often
complement the
weaknesses of other
power sources like
batteries and fuel
cells.”

2. History
 The concept of storing electrical energy in the electric
double layer that is formed at the interface between an
electrolyte and a solid has been known since the late
1800s.
 The first electrical device using double-layer charge
storage was reported in 1957 by H.I. Becker of General
Electric.

3. Capacitors v/s Ultracapacitors
 Capacitor is a device to store the charge in an electric
circuit.
 Basically, a capacitor is made up of two conductors
separated by an insulator called dielectric.
 Ultracapacitors can be defined as a energy storage
device that stores energy electrostatically by polarizing an
electrolytic solution.
 Ultracapacitors are also known as double-layer
capacitors or supercapacitors.
v/s

4.  Energy is stored in ultracapacitor by polarizing the
electrolytic solution.
 The charges are separated via electrode-electrolyte
interface.
Principle

5. Construction
 Porous electrode
 Electrolyte
 A current collector
(metal plates)
 A membrane, which
separates, positive
and negative plated
is called separator
Ultracapacitor consist of

6. Working
 There are two carbon sheet separated by separator.
 The geometrical size of carbon sheet is taken in such
a way that they have a very high surface area.
 The highly porous carbon can store more energy than
any other electrolytic capacitor.
 When the voltage is applied to positive plate, it attracts
negative ions from electrolyte.
 When the voltage is applied to negative plate, it
attracts positive ions from electrolyte.

7. Different styles of supercapacitors
Flat style Knob capacitor
Radial style

8. Advantage
 Long life: It works for large number of cycle without
wear and aging.
 Rapid charging: it takes a second to charge
completely
 Low cost: it is less expensive as compared to
electrochemical battery.
 High power storage: It stores huge amount of energy
in a small volume.
 Faster release: Release the energy much faster
than battery.

9. Disadvantage
 They have Low energy density
 Individual cell shows low voltage
 Not all the energy can be utilized during discharge
 They have high self-discharge as compared to battery.
 Voltage balancing is required when more than three
capacitors are connected in series.

10. Applications
 vehicle
 wireless communication system
 electronic applications