Fuel cell

A fuel cell is an electrochemical device similar to a battery, but differing from the latter in that it is designed for continuous replenishment of the reactants consumed; i.e. it produces electricity from an external fuel supply of hydrogen and oxygen as opposed to the limited internal energy storage capacity of a battery. Additionally, the electrodes within a battery react and change as a battery is charged or discharged, whereas a fuel cell's electrodes are catalytic and relatively stable.

Related Topics:
Electrochemical - Battery - Hydrogen - Oxygen

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Typical reactants used in a fuel cell are hydrogen on the anode side and oxygen on the cathode side (a hydrogen cell). In contrast, conventional batteries consume solid reactants and, once these reactants are depleted, must be discarded, recharged with electricity by running the chemical reaction backwards, or, at least in theory, by having their electrodes replaced. Typically in fuel cells, reactants flow in and reaction products flow out, and continuous long-term operation is feasible virtually as long as these flows are maintained.

Related Topics:
Reactant - Hydrogen - Anode - Oxygen - Cathode - Electricity

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Fuel cells are often considered to be very attractive in modern applications for their high efficiency and ideally emission-free use, in contrast to currently more common fuels such as methane or natural gas that generate carbon dioxide. The only by-product of a hydrogen fuel cell is water vapor. There is concern, however, about the energy-consuming process of manufacturing the hydrogen, which may still generate pollution and still requires either fossil fuel, nuclear power generation, or as yet undeveloped alternative generation. In this regard, hydrogen fuel technology itself cannot be said to reduce fossil fuel dependence.

Related Topics:
Methane - Natural gas - Carbon dioxide - By-product - Water vapor

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