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|fuel cell |
A device that produces electricity by combining a fuel, usually hydrogen, with oxygen. In this reaction, electrons are freed from the hydrogen in the fuel cell by a catalyst, and gain energy from the chemical reaction binding hydrogen and oxygen; this provides a source for electric current. The exhaust of hydrogen fuel cells consists simply of water. Fuel cells are currently used in spacecraft, and increasingly in ground transportation, with potential use everywhere electricity is required.
An electrochemical device where a chemical reaction produces energy that is converted directly into electricity. Once used primarily in space travel, fuel cells are now being considered for use in cars. Unlike internal-combustion engines, fuel cells do not pollute the environment.