Fuel Cells

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Fuel Cells
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A Fuel Cell
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How they work

• Fuel cells are electrochemical cells, but they
  operate like a battery. A fuel cell consists of
  two electrodes sandwiched around an electrolyte.
  Oxygen passes over one electrode and hydrogen
  over the other, generating electricity, water,
  and heat.
• A fuel cell operates like a battery. But unlike a
  battery, a fuel cell does not run down or require
  recharging. It will produce energy in the form of
  electricity and heat as long as fuel is supplied.

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A Fuel Cell
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Whats a PEM?

• Proton Exchange Mechanism
• Suited for cars where a quick start is needed
• Thin plastic sheet allows hydrogen ions to pass
  through
• Coated on both sides with highly dispersed metal
  alloy particles (mostly platinum) that are active
  catalysts

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How do PEMs work?

• Hydrogen is fed to the anode side of the fuel
  cell where the catalysts encourages the hydrogen
  atoms to release electrons and become hydrogen
  ions (protons)
• Electrons travel in the form of an electric
  current that can be utilized before it returns to
  the cathode side of the fuel cell where oxygen
  has been fed.

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Moving Fuel Cells

• Fuel Cells

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Proton Exchange Membrane

• Anode
• H2(g) ? 2H(aq) 2e-
• Eº 0.00 V
• Cathode
• O2(g) 4H(aq) 4e- ? 2H2O(l)
• Eº 1.23 V

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Proton Exchange Membrane

• Total Reaction
• 2H2(g) O2(g) ? 2H2O(l)
• Eº 1.23 V
• Note The above reaction IS spontaneous.

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Safety

• Hydrogen has a very high energy content and
  therefore must be handled with extreme care, just
  like oil and gasoline. Hydrogen is no more
  dangerous than any other fuel, just different.
• In fact, hydrogen is as safe, if not safer, than
  conventional fuels on the market today.
• Automobile manufacturers constructed hybrid cars,
  which utilize hydrogen fuel cells. They are
  really neat. Theyre environmentally friendly,
  too. Which is nice.

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THE END!