Fuel Cells: Combustion-Free Electricity Generation From Fuels
Fuel cells are electrochemical conversion devices that generate electricity by chemically combining fuel and oxidant in the presence of an electrolyte, where the fuel and oxidant are replehished as they are consumed.
The most common and easily-described type of fuel cell is the hydrogen–oxygen proton exchange membrane fuel cell (PEMFC). In it, a polymer membrane forms the proton-conducting electrolyte that separtes the anode and cathode sides. During operation, hydrogen gas and oxygen gas are continuously supplied to channles on the anode and cathode sides, respectively, and generated water is continuoulsy exhausted from channels on the cathode side.
Other types of fuel cells employ hydrocarbon fuels such as methanol and diesel, instead of hydrogen, and exhaust carbon dioxide in addition to water. 1