This document provides an overview of fuel cell technology. It begins with an introduction that defines fuel cells as devices that convert chemical energy from fuels like hydrogen into electrical energy. It then discusses why fuel cells are useful by noting issues with conventional energy sources like pollution. The document proceeds to compare fuel cells to batteries and describe the basic construction and working of fuel cells. It outlines the main types of fuel cells and provides details on proton exchange membrane fuel cells. Applications and advantages of fuel cells are highlighted, with high efficiency and low emissions mentioned. The disadvantages of fuel cells like the difficulty of storing hydrogen are also noted.

2. Township Campus,Lahore
Submitted to: Dr.M.Iqbal
Submitted by: Muhammad Kashif Hanif
(mcf 1700986)
Programme: M.Sc Chemistry(E)
Semester I
Subject: Quantum chemistry
Course code: CHEM3113

3. Contents:
.Introduction
.Why to use fuel cells?
.Compared to battery
.Construction
.Working
.Types of fuel cell
.Applications
.Advantages
.Disadvantages
.References
“FUEL CELLS TECHNOL0GY”
Introduction:
Fuel cells are electrochemical devices that convert chemical
energy of fuels (usually hydrogen derived from natural gas or
biogas) into electrical energy, promising power generation with
high efficiency and low environmental impact.
The first fuel cells were invented in 1838 by William Robert
Groove [1].
Combustion is avoided in these cells so, fuel cells
produce power with minimal pollutants. They can vary from tiny
devices producing only a few watts of electricity like in phones
and
laptops right up to large power plants producing several mega-watts.

4. Why to use fuel cells?
The convential energy sources like coal, petroleum and
diesel etc that we are using today produce much amount of co2
which is major green house gas that is responsible for global warming
causing much threats both for environment and other organisms. Sea
level have risen about 7 inches in the previous 100 years which is
more than previous 2000 years.[2]
.
And according to UN IPCC(International Panal Climate Change)
report 2007 sea level will rise from 7-23 inches at the end of this
century due to global warming[3]
. Thus
contributing lot to air pollution, also these resource are limited and it is
much fear that they will be depleted in near future.About 100 Million
Barrel of oil is used daily(1 barrel=About 159 Liters).According to this
rate,it is fear that they will be depleted in next 900 years[4]
. So, we have
to find such ways of energy production that are more efficient and
environment friendly.One of these are fuel cells.They do not pollute the
environment in anyway as the by-product that is produced is clean
water and heat. More-ever,They can be practically 60% efficient as
compared to car fuel which is about 25% efficient while their
theoretical efficiency could be upto 80% approximately.

5. POSCO;Fuel cell power plant in Air pollution through other resources.
Vs
South Korya.
Compared to battery:
A battery uses closed store of energy within it and once this is
depleted the battery must be discarded or rechargerd by using an
external supply of electricity.While a fuel cell,on the other hand, usesan
external supply of chemical energy and can run indefinitely as long as it
is supplied with source of hydrogen and a source of oxygen (usually
air).Generally the source of hydrogen is referred as fuel and this gives
the fuel cell its name.

6. .
Working:
Fuel cells come in different varieties but they all work on same
general princile.They are all made up of three adjacent segments;
the anode,the electrolyte and the cathode.Two chemical reactions
occur at the interfaces of the three different segments.The net result of
the two reactions is that the fuel is consumed, water is produced,and
an electric current is generated,which can be used to power electrical
devices,normally referred as the load.
At the anode a catalyst oxidizes the fuel (i.e hydrogen) turning the
fuel into a positively charged ion and negatively charged
electron.The electrolyte is a substance specifically designed so ions
can pass through it easily but the electrons can not.The freed
electrons travel through a wire creating the electric current.The ions
travel through the electrolyte to the cathode.Once reaching the
cathode;the ions are reunited with the electrons and the two react with
third chemical usually oxygen to create water[1]
.

7. A typical fuel cell produces a voltage from 0.6 V to 0.7 V at full rated
load.They are arranged in series in the form of stacks to produce more
amount of energy[5]
.
Construction:
A fuel cell mainly consists of following components.
. The electrolyte substance. The electrolyte substance usually
defines the type of fuel cell.
. The fuel that is used,the most common fuel usedis
hydrogen.
. The anode catalyst breaks down the fuel into electrons and
ions.The anode catalyst is made up of very fine platinium powder.
. The cathode catalyst turns the ions into theproducts like water
or carbon dioxide.The cathode catalyst is made up of platinium or
platinium-group metals and it can also be made of non-platinium
metals such as iron[1]
.

8. Types of fuel cells[6]
:
Although there are many types of fuel cells todays used in different fields
of life,but six main and most used types are being discussed here:
. Proton exchange membrane fuel cell (PEMFC)
. Alkaline fuel cell(AFC)
. Phosphoric acid fuel cell(PAFC)
. Molten carbonate fuel cell(MCFC)
. Solid oxide fuel cell(SOFC)
. Direct methanol fuel cell(DMFC)

9. 1. PEMFC:
 These are also known as polymer elctrolyte membrane fuel
cells.
 The PEM fuel cell was invented in the early 1960 by W.T
Grubb and L.Niedrach of general electricity.
 In PEMFC the electrolyte used is a thin polymer
membrane such as perfluorosulphonic acid.
 Hydrogen flows into the fuel cell onto the anode and splits into
hydrogen ions and electrons.
 Hydrogen ions permeate across the electrolyte to the
cathode.
 Electrons flow through an external circuit and supply power.
 Oxygen is supplied to the cathode and this combines with
electrons and hydroegn ions to formwater.
 They operate at a temperature of about 800C.
 Electrolyte is present between the two field flow plates.
 Each cell produces about 0.7 V about,enough power to lighta
bulb.
 They can be used in vehicles,motor bikes,portable powers of
electricity,APUs(auxiliary power units),on smaller scale
stationary electricity generation.

10. 2. Alkaline Fuel cells(AFC):
 Invented by Francis Thomas Bacon in 1959.
 Electrolyte used for this device is aquous solution of KOH or
NaOH solution.
 Compressed H2 and O2 fuel is used.
 Approximately 70 % efficiency.
 Operating temp.is around 1500C to 2000C
 300W to 5kW out put requires pure hydrogen fuel and
platinium catalyst
 Used on NASA shuttles throughout the space programme.

11. 3. Phosphoric acid fuel cell (PAFC):
 Introduced in 1961 by G.V Elmore & H.ATanner
 H+ move from anode to cathode
 Molten phosphoric acid (H3PO3) is used as an electrolyte
 Operating temperature about 150 to 2000
C
 Efficiency up to 55% but can be enhance up to 80%
 11MV units have been tested
 Sulphur free gasoline can be used as fuel
 Can be used on commercial scale
=> Disadvantages:
 Electrolyte is very corrosive
 Platinium catalyst is very expensive

12. 4. Molten Carbonate Fuel cell (MCFC)[7]
:
 Molten alkaline carbonate such as lithium potassium
carbonate is used as an eletrolyte
 In this fuel cell CO3
2- ions
move from cathode to anode
 Produce power up to 100MW
 Can be used as high power generators
 Can be operated at high temperature up to 6500
C
 Their Nickel catalyst are not so expensive and hence can be
used on commersial scale
 Efficiency up to 55%
=> Disadvantages:
 Shorter life spane
 Slow start up time
 Corrosion of electrodes

13. 5. Solid Oxide Fuel Cell (SOFC):
 Hard ceramic compound of metal oxide such as calcium
oxide or zirconium oxide is used as an electrolyte
 O2- move from cathode to anode
 Operating temperature range from 800 to 10000
C
 Popular in stationary power generation
 Slow start up time
 Cells output is about 100 kW.

14. 6. Direct methanol fuel Cell(DMFC):
 Polymer membrane is used as an electrolyte
 Use a platinium-ruthenium catalyst on the anode and a
platinium catalyst on the cathode.
 This catalyst can withdraw hydrogen atoms from liquid
methanol,which is used as fuel instead of hydrogen,giving
the cell its name.
 Operate in the range from 600
C to 1300
.
 They are convenient for portable power applications with
outputs generally less than 250 W.

15. Applications of Fuel Cells[1]
:
 Can be used as power sources in remote areas
 Can be used to provide off-grid power supplies
 Can be applicable in both hybrid and electric vehicles
 Waste water treatment plant and land fill
 Can be used in cellular phones , laptops and computers
 Can be used in hospitals,credit card centers and police
stations
 In buses (in august 2011 there were only 100 FC buses in
entire world)[1],cars (like Toyota mirai,Mercedes Benz,Honda
FCX,Audi company FCV and BMW FCV)[1]
,planes First test
flight was done in Feb 2008 in Europe), boats (named as Hydra
generating about 6.5 kW net output)[1],
fork lifts (in 2013, 4000
were present in US)[1]
and trains,and submarines(like Type 212
submarines of the German and Italian navies)
 As vacuum cleaners
 In telecommunications and mp3 players etc

16. Advantages of Fuel Cells[8]
:
 Only clean water is discharged
 Higher efficiency than convential engines
 Zero emission and combustion
 Long operated period between failure
 No rotating parts in the main hardware components
· Negligible noise pollution
Fuel cells for laptop Fuel cell rechagers

17. Boeing company FCP A FCV bus
Hydra;Fuel cell boatFuel cell fork lift
Toyota FCV Car
Disadvantages of fuel Cells:
 Pure hydrogen is difficult to handle and store as it is very
inflammable
 Only little higher efficiency than other resources
 They are very expensive,the price of stationary fuell cell has droped
from $600000 per kW(when fuel cell was being used by NASA) to
$4500 today[9]
.
Fuel cell smartphone

18. References:
1.Wikipedia.org/Fuel cells
2.https://climate.nasa.gov/evidence/
3.https://climate.nasa.gov/evidence/
4.https://www.quora.com/When-is-the-earth-supposed-to-run-
out-of-oil
5.Nice,Karim,Stricland and Jonathan“How fuel cells
work”.How stuff works,accessed in 4 august 2011.
6.Fuel cell handbook(seventh edition) by EG &G
technical services,Inc,in november 2004
7.Molten carbonate fuel cell technology.U.S
Department of energy,9 august 2011
8.https://google.com/Fuel cells slideshare
9.Fuel cells.briefing papers for state policy makers publishedin
august 2011 by CESA(Clean Energy States Alliance)