Fuel Cell Vehicles

By:

Dan Grove and Karen Brunetti

Scientific Concepts

• A fuel cell is a device that converts the chemical energy of a fuel and an oxidant into electricity.

• A fuel cell is much like a battery, but it does not run down or require recharging.

• It will generate electricity as long as the fuel and the oxidant are supplied.

Scientific Concepts (cont.)

• Fuel cells chemically combine the molecules of a fuel and an oxidant.

• Fuel – hydrogen, oxidant – oxygen (air)• The hydrogen passes over the anode, while the

oxygen passes over the cathode, which are separated by electrolytes.

• This causes the molecules to split into individual atoms.

• When the hydrogen atoms meet the oxide atoms, they combine to create water molecules, which then generate electricity and heat.

Calculations and Data

• Because hydrogen is not a readily available source, fossil fuels are converted into hydrogen by a process called fuel reforming.

• The chemical formula for this reaction (with CH4) is: CH4 + 2H2O => CO2 + 4H2

• In high temperature fuel cells, CO acts as the fuel. CO + H2O => CO2 + H2

Reactions and Equations

• Anode Reaction: 2H2 => 4H+ + 4e-• Cathode Reaction: O2 + 4H+ + 4e- => 2H2O• Overall Cell Reaction: 2H2 + O2 => 2H2O• Electrical Power Produced: Power (Watts) = Voltage (Volts) X Current

(Amps)

Experiments and Testing

• In 1893, Friedrich Ostwald experimentally determined the interconnected roles of the various components of the fuel cell: electrodes, electrolyte, oxidizing and reducing agents, anions, and cations.

• In the late 1930s, Sir Francis Bacon managed to figure out how to put fuel cells into Royal Navy submarines.

• Safety Considerations:– Hydrogen is very flammable, and the gas must not leave the

vicinity of the fuel cell.– Hydrogen is highly reactive with metals, so stainless steel is the

best choice for fuel cells.

• Grove discovered that by arranging two platinum electrodes with one end of each immersed in a container of sulfuric acid and the other ends separately sealed in containers of oxygen and hydrogen, a constant current would flow between the electrodes. The sealed containers held water as well as the gases, and he noted that the water level rose in both tubes as the current flowed. By combining several sets of these electrodes in a series curcuit, he created what he called a "gas battery"- the first fuel cell.

History of Fuel Cells

• 1800 – British scientists William Nicholson and Anthony Carlisle had described the process of using the energy source of electricity to decompose water into hydrogen into water.

• 1838 – The first fuel cell was invented by Sir William Grove

• 1950s – NASA began to research and figure out how to use fuel cells to help supply electricity in their space missions

• 1966 GM Electrovan was the first hydrogen fuel cell vehicle.

How Fuel Cells Works.mp4

Social Impact

Sources

• http://www.fctec.com/fctec_basics.asp•

http://www.princeton.edu/~chm333/2002/spring/FuelCells/images/fuelcell_bocarsly.gif

• http://www.fueleconomy.gov/feg/fuelcell.shtml• http://www.howstuffworks.com/fuel-cell.htm• http://www.grc.nasa.gov/WWW/

Electrochemistry/doc/fuelcell.html