3. It is of three types
› Electrolytic cell
› Fuel cell
› Galvanic cell
4. An electrolytic cell is an electrochemical cell that undergoes a
redox reaction when electrical energy is applied. It is most often
used to decompose chemical compounds, in a process called
electrolysis
An electrolytic cell has three component parts: an electrolyte
and two electrodes (a cathode and an anode). The electrolyte is
usually a solution of water or other solvents in which ions are
dissolved.
When driven by an external voltage applied to the electrodes,
the electrolyte provides ions that flow to and from the
electrodes, where charge-transferring (also called faradic or
redox) reactions can take place. Only for an external electrical
potential of correct polarity and sufficient magnitude can an
electrolytic cell decompose a normally stable, or inert chemical
compound in the solution.
5. A fuel cell is a device that converts the chemical energy from a fuel
into electricity through a chemical reaction with oxygen or another
oxidizing agent.[1] Hydrogen is the most common fuel, but
hydrocarbons such as natural gas and alcohols like methanol are
sometimes used.
Fuel cells are different from batteries in that they require a constant
source of fuel and oxygen/air to sustain the chemical reaction.
In 1838, German Physicist Christian Friedrich Schönbein invented
the first crude fuel cell.
The first commercial use of fuel cells was in NASA space programs to
generate power for probes, satellites and space capsules.
Fuel cells are used for primary and backup power .
They are used to power fuel cell vehicles, including automobiles,
buses, forklifts, airplanes, boats, motorcycles and submarines.
6. A galvanic cell, or voltaic cell, named
after Luigi Galvani, or Alessandro Volta
respectively, is an electrochemical cell
that derives electrical energy from
spontaneous redox reaction taking
place within the cell. It generally
consists of two different metals
connected by a salt bridge, or individual
half-cells separated by a porous
membrane.
Volta was the inventor of the voltaic
pile, the first electrical battery. In
common usage, the word "battery" has
come to include a single galvanic cell,
but a battery properly consists of
multiple cells.[1]
7. The cylindrical cell continues to be one of the
most widely used packaging styles for primary and
secondary batteries. The advantages are ease of
manufacture and good mechanical stability. The
tubular cylinder has the ability to withstand
internal pressures without deforming.
The cylindrical cell design has good cycling ability,
offers a long calendar life, is economical but is
heavy and has low packaging density due to space
cavities
The metallic cylinder measure 18mm in diameter
and 65mm the length. The larger 26650 cell
measures 26mm in diameter.
8. Smaller devices required a more compact cell
design, and the button cell met this need. The
desired voltage was achieved by stacking the
cells into a tube. Early cordless telephones,
medical devices and security wands at
airports used these batteries.
A drawback of the button cell is swelling if
charged too rapidly. Button cells have no
safety vent and can only be charged at a 10- to
16-hour charge.
Most button cells in use today are non-
rechargeable and can be found in medical
implants, watches, hearing aids, car keys and
memory backup.
9. The prismatic cell satisfies the demand for
thinner sizes and lower manufacturing costs.
Wrapped in elegant packages resembling a
box, prismatic cells make optimal use of space
by using the layered approach.
These cells are predominantly found in
mobile phones with lithium-ion.
The prismatic cell improves space utilization
and allows flexible design but it can be more
expensive to manufacture and have a shorter
cycle life than the cylindrical design.
The prismatic cell requires a slightly thicker
wall to compensate for the decreased
mechanical stability from the cylindrical
design, resulting in a small capacity drop.
10. In 1995, the pouch cell surprised the
battery world with a radical new design.
Rather than using a metallic cylinder and
glass-to-metal electrical feed-through for
insulation, conductive foil tabs welded to
the electrode and sealed to the pouch
carry the positive and negative terminals
to the outside.
11. The pouch cell offers a simple, flexible and lightweight
solution to battery design. Exposure to high humidity and
hot temperature can shorten service life.
The pouch cell makes the most efficient use of space and
achieves a 90 to 95 percent packaging efficiency, the
highest among battery packs.
No standardized pouch cells exist; each manufacturer
builds the cells for a specific application.
Pouch packs are commonly Li-polymer. Its specific energy
is often lower and the cell is less durable than Li-ion in
the cylindrical package.
12. Swelling can occur as part of gas
generation. Battery manufacturers are at
odds why this happens. A 5mm (0.2”)
battery in a hard shell can grow to 8mm
(0.3”), more in a foil package.
To prevent swelling, the manufacturer
adds excess film to create a “gas bag”
outside the cell.
During the first charge, gases escape into
the gasbag, which is then cut off and the
pack resealed as part of the finishing
process. Expect some swelling on
subsequent charges; 8 to 10 percent over
500 cycles is normal.
13. A solar cell (also called a photovoltaic cell) is an electrical
device that converts the energy of light directly into
electricity by the photovoltaic effect. It is a form of
photoelectric cell (in that its electrical characteristics—e.g.
current, voltage, or resistance—vary when light is incident
upon it) which, when exposed to light, can generate and
support an electric current without being attached to any
external voltage source.
A solar cell made from a monocrystalline silicon wafer with
its contact grid made from busbars (the larger strips) and
fingers the (smaller ones).
Solar cells can be used devices such as this portable
monocrystalline solar charger.