An electrochemical device, similar to a battery in function, in which the chemical energy of a fuel, such as hydrogen, and an oxidant, usually oxygen, are converted directly into electrical energy. Unlike batteries, however, fuel cells do not store energy, and they never run down or need recharging as long as the fuel and oxidant are supplied continuously. The principle of fuel cell technology was discovered more than 100 years ago, but until recently it had found use only in laboratories and in space travel (the Apollo missions and the space shuttle). Today, large and small fuel cells are being developed that will power portable devices such as laptop computers and cellular phones, generate electricity and heat, and replace automotive combustion engines.
Produces electricity by oxidation of fuel (hydrogen-oxygen or zinc-air); for use in electric cars.
Cell converting chemical energy directly to electrical energy.
It works on the same principle as a battery but is continually fed with fuel, usually hydrogen. Fuel cells are silent and reliable (no moving parts) but expensive to produce.
Hydrogen is passed over an electrode (usually nickel or platinum) containing a catalyst, which strips electrons off the atoms. These pass through an external circuit while hydrogen ions (charged atoms) pass through an electrolyte to another electrode, over which oxygen is passed. Water is formed at this electrode (as a by-product) in a chemical reaction involving electrons, hydrogen ions, and oxygen atoms. If the spare heat also produced is used for hot water and space heating, 80% efficiency in fuel is achieved.