2. Contents
History of fuel cell
Fuel cell introduction
Different types of Fuel cell
Overview of PEMFC
PEMFC basis
3. Contents
Basic Elements in a PEMFC
How PEM Fuel Cell Works
Comparison with IC engine and battery
PEM FUEL CELL Applications
The Current PEM Market
Part II
4. History of PEM Fuel Cell
PEM technology was invented at General Electric through the
1960 work of Thomas Grubb and Leonard Niedrach.
GE developed a small fuel cell for a program with the U.S. Navy's
Bureau of Ships (Electronics Division) and the U.S. Army Signal
mid-1960s
Corps. The unit was fueled by hydrogen generated by mixing water
and lithium hydride.
GE developed PEM water electrolysis technology for
mid-1970s undersea life support, leading to the US Navy Oxygen
Generating Plant.
1980s The British Royal Navy adopted this technology in early 1980s for
their submarine fleet.
1990s Los Alamos National Lab and Texas A&M University
experimented with ways to reduce the amount of platinum
required for PEM cells.
5. Fuel cell introduction
A fuel cell is an
They are being
electrochemical
publicized as a source of
conversion device.
energy of tommorow.
6. Different Types of Fuel Cell
Description:
PAFC - uses phosphoric acid as the
electrolyte.
(MCFC) uses high-temperature compounds
of salt (like sodium or magnesium)
carbonates (chemically, CO3) as the
electrolyte.
PROTON
EXCHANGE (AFC) operates on compressed hydrogen
and oxygen. They generally use a solution
MEMBRANE
of potassium hydroxide (chemically, KOH)
in water as their electrolyte.
(SOFC) uses a hard, ceramic compound of
metal (like calcium or zirconium) oxides
(chemically, O2) as electrolyte.
(PEM) works with a Proton Exchange
Membrane in the form of a thin, permeable
sheet.
7. Proton Exchange Membrane FC
- consists of an membrane sandwiched between an anode
(negative electrode) and a cathode (positive electrode).
Description
- a thin, solid, organic compound, typically the consistency of plastic
wrap and about as thick as 2 to 7 sheets of paper. This membrane
functions as an electrolyte: allows the solution to conduct electricity
Concept
PEM fuel cells work with a polymer electrolyte in the form of a thin,
permeable sheet and allow hydrogen protons to pass through but
prohibit the passage of electrons and heavier gases.
8. A PEM fuel cell uses hydrogen and oxygen to
produce electricity .
9. -A thin, solid, organic compound known
as Nafion.
-the consistency of plastic wrap and
about as thick as 2 to 7 sheets of paper.
-This membrane functions as an
gateway, allowing only +ive ions
(protons) to pass through it.
10. 1
Fuel cells are operationally equivalent to a battery.
4
2 Polymer Electrolyte Membrane
The reactants or fuel in a fuel cell (PEM) type cells are the standard
can be replaced unlike a standard devices.
disposable or rechargeable battery.
5
For automotive applications
3 hydrogen is the fuel choice.
Theoretically the maximum voltage
that this reaction can generate is
1.2 V. However, in practice the cell 6
usually generates about 0.7 V to Electrochemical energy comes
0.9 V of power. from the reaction: ½ H2 +
½ O2 → H2O.
11. Basic Elements of PEMFC
-It conducts the electrons that are freed from the
Anode hydrogen molecules so that they can be used in an
external circuit.
-has channels etched into it that distribute the oxygen
to the surface of the catalyst.
Cathode
-conducts the electrons back from the external circuit
to the catalyst, where they can recombine with the
hydrogen ions and oxygen to form water
Anode Reaction Cathode Reaction
H2 → 2H+ + 2e- O2 + 4H+ + 4e- → 2H2O
12. Basic Elements of PEMFC
-This specially treated material, which looks something
like ordinary kitchen plastic wrap, only conducts
Electrolyte positively charged ions.
- The membrane blocks electrons.
- It is usually made of platinum powder very thinly
coated onto carbon paper or cloth.
- The catalyst is rough and porous so that the maximum
Catalyst surface area of the platinum can be exposed to the
hydrogen or oxygen.
- The platinum-coated side of the catalyst faces the
PEM.
16. Energy Efficient
Rapid load
Zero following
emission capability
ADVANTAGES
High power No Internal
density combustion
The Proton Exchange Membrane (PEM)
system allows compact designs and achieves a
high energy to weight ratio. In comparison, the
internal compaction motor has an efficiency of
about 15%. More then internal combustion
engines.
17. HIGH
Needs Pure
Manufacturing
Hydrogen
Cost
Disadvantages
Complex Heat
Heavy Auxiliary
and Water
Equipment
Management
Start and stop conditions induce drying and wetting, which contributes
to membrane stress. If run continuously, the stationary stack is
estimated at 40,000 hours. Stack replacement is a major expense.
18. The first viable Decentralized
electric alternative power generation
On board
to the internal for industrial and
auxiliary power
combustion engine domestic
units (APUs) for
for vehicles aircraft applications.
land and air
and UAVs.
transportation.
PEM Fuel Cell.Applications
Portable generation systems for Small scale power packs for
domestic, industrial application remote, unattended and
military application
