Fuel cells were first invented in 1838 and were developed for commercial use in 1932. A fuel cell is an electrochemical device that combines hydrogen and oxygen to produce electricity, water, and heat. It operates like a battery but does not run down or need recharging as long as fuel is supplied. A common type is the hydrogen-oxygen fuel cell, which produces electricity through the chemical reaction of hydrogen and oxygen to form water. Fuel cells have advantages such as high efficiency, low emissions and noise, and modularity.

1. FUEL CELLS
BY
CHILUKURI PAVAN CHOWDARY
17321

2. HISTORY OF FUEL CELLS
 The first fuel cells were INVENTED by Sir WILLIAm GROVe in 1838.
 The invention of the hydrogen–oxygen fuel cell for
COMMERCIAL USE BY FRANCIs THOmAs BACON in 1932.

3.  WHAT IS A FUEL CELL ?
 A Fuel Cell is an electrochemical device that combines hydrogen and
oxygen to produce electricity, with water and heat as its by-product.
 It is an energy conversion device or electricity generator.
 It is an example for a primary cell.
 This is capable of supplying current as long as it is provided with the supply of
reactants.
 GENERAL EQUATION :
FUEL + OXYGEN →OXIDATION PRODUCTS + ELECTRICITY
(OXIDANT)

4. FUEL CELL

5. HOW DOES A FUEL CELL WORK
 It operates similarly to a battery, but it does not run down nor does it require
recharging
 As long as fuel is supplied, a Fuel Cell will produce both energy and HEAT
 A Fuel Cell consists of two catalyst coated electrodes surrounding an
electrolyte
 One electrode is an anode and the other is a cathode
 The process begins when Hydrogen molecules enter the anode
 The catalyst coating separates hydrogen’s negatively charged electrons
from the positively charged protons.

6. HOW DOES A FUEL
CELL WORK
 The electrolyte allows the protons to pass through to the cathode, but not
the electrons
 Instead the electrons are directed through an external circuit which
creates electrical current
 While the electrons pass through the external circuit, oxygen molecules
pass through the cathode
 There the oxygen and the protons combine with the electrons after they
have passed through the external circuit

7. HOW DOES A FUEL CELL WORK ???
 When the oxygen and the protons
combine with the electrons it
produces water and heat.
Picture of fuel cell

8. mOsT ImPORTANT CHARACTeRIsTICs
 High efficiency
 Low emission levels
 Low noise levels
 Fuel cells are free from vibration, heat transfer and
thermal pollution

9. EXAMPLES OF FUEL CELLS
 HYDROGEN-OXYGEN CELLS
Types of H2-O2 Fuel Cell
 Alkaline fuel cells (AFC)
 Phosphoric acid fuel cells(PAFC)
 Molten carbonate fuel cells(MCFC)
 Solid oxide fuel cells(SOFC)
 Proton exchange membrane fuel cells (PEMFC)

10. HYDROEN-OXYGEN FUEL CELL(H2-O2)
 A common type of fuel cell based on the combustion of hydrogen gas.
Equation : 2H2 + O2 2H2O
(g) (g) (l)

12.  consists two electrodes
 made up of graphite
 catalyst platinum or metal oxide
 placed in aqueous solution (KOH or NAOH)
 H2 Gas evolves in anode
 O2 Gas evolve in cathod
REACTION
 AT Anode
H2 + 2OH− → 2H2O + 2e−
(g) (aq) (L)
 AT CATHOD
O2(g) + 2H2O + 4e− → 4OH
(g) (l)
2H2 + O2 → 2H2O
(g) (g) (L)

13.  THE Standard EMF Of H2 – O2 CELLS
E° = E°(cathode) - E°(anode)

14. USES OF H2 – O2 CELLS
• used in space craft because of their high
efficiency, lightness
• used in submarines or other military vehicles
• used as the primary source of electrical energy
on the Apollo moon flights. Approximately 200
kg of fuel is sufficient for 11 days in space

15. ADVANTAGES OF FUEL CELLS
 The energy conversion (chemical into
electrical) is very high by fuel cells (75-82.8%).
 H2-O2 fuel cell produces H2O, which is used as
drinking purpose by astronauts
 Noise and thermal pollution are low.
 Such type of cells never becomes dead,
because of continuous supply of fuel

16. ADVANTAGES OF FUEL
CELLS
Modular and other parts of fuel cells
are exchangeable
Fuels cells having low maintenance
cost
Fuels cells saves fossil fuels.

17. Disadvantages of Fuel Cells
 High initial cost.
 Large weight and volume of gas-fuel storage
system.
 High cost of pure hydrogen.
Life-times of such type of cells are not
accurately known.