fuel cell

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An electrochemical cell in which the energy of a reaction between a fuel, such as liquid hydrogen, and an oxidant, such as liquid oxygen, is converted directly and continuously into electrical energy.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An electrochemical device in which the intrinsic chemical free energy of fuel and oxidant is catalytically converted to direct current energy.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun cell that produces electricity by oxidation of fuel (hydrogen and oxygen or zinc and air); often used in electric cars