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A fuel cell is a device that generates electricity by a chemical reaction.
A fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, the anode (which is positively charged) and the cathode (which is negatively charged)Ryan O'Hayre, Suk-Won Cha, Whitney Colella, Fritz B. Prinz (2009) “Fuel Cell Fundamentals” , 2nd Edition, John Wiley and Sons. ISBN-13: 978-0470258439Ryan O'Hayre, Suk-Won Cha, Whitney Colella, Fritz B. Prinz (2009) “Fuel Cell Fundamentals” , 2nd Edition, John Wiley and Sons. ISBN-13: 978-0470258439Ryan O'Hayre, Suk-Won Cha, Whitney Colella, Fritz B. Prinz (2009) “Fuel Cell Fundamentals” , 2nd Edition, John Wiley and Sons. ISBN-13: 978-0470258439. The reactions that produce electricity take place at the two electrodes. Every fuel cell also has an electrolyte, which carries electrically charged particles from one electrode to the other, and a catalyst, which speeds the reactions at the electrodesXianguo Li, (2006) “Principles of Fuel Cells”, Edition 1. Taylor & Francis Group, 2006, ISBN-13: 978-1591690221 Xianguo Li, (2006) “Principles of Fuel Cells”, Edition 1. Taylor & Francis Group, 2006, ISBN-13: 978-1591690221 . Multiple fuel cells are usually assembled into a stack and generate direct current (DC).
Hydrogen is the basic fuel for fuel cells, but fuel cells also require oxygenSmithsonian Institution, (2008) “Fuel Cell Basics”, http://americanhistory.si.edu/fuelcells/basics.htmSmithsonian Institution, (2008) “Fuel Cell Basics”, http://americanhistory.si.edu/fuelcells/basics.htm.
There are several kinds of fuel cells, and each operates a bit differently. But, in general terms, hydrogen atoms enter a fuel cell at the anode where a chemical reaction strips them of their electrons. The hydrogen atoms are now "ionized," and carry a positive electrical charge. The negatively charged electrons provide the current through wires to do work. If alternating current (AC) is needed, the DC output of the fuel cell must be routed through a conversion device called an inverter.
Oxygen enters the fuel cell at the cathode and, in some cell types, it combines with electrons returning from the electrical circuit and hydrogen ions that have traveled through the electrolyte from the anode. In other cell types the oxygen picks up electrons and then travels through the electrolyte to the anode, where it combines with hydrogen ions.
The electrolyte plays a key role. It must permit only the appropriate ions to pass between the anode and cathode. If free electrons or other substances could travel through the electrolyte, they would disrupt the chemical reaction.
Whether they combine at anode or cathode, together hydrogen and oxygen form water, which drains from the cell. As long as a fuel cell is supplied with hydrogen and oxygen, it will generate electricity.
Types of Fuel Cells
Since fuel cells create electricity chemically, rather than by combustion, they are not subject to the thermodynamic laws that limit a conventional power plant (known as the Carnot Limit). Therefore, fuel cells are more efficient in extracting energy from a fuel. Waste heat from some cells can also be harnessed, boosting system efficiency still further.
Fuel cells are employed in stationary power generation, portable power supply and transportation. Small, stationary power generators provide 0.5 kW to 10 kW uninterrupted power supply to households, shopping malls and data centers. Grid-scale fuel cell generation is also in development. Portable fuel cells are best suited for auxiliary power units (APU), portable devices, PC, smart-phone etc.
The application of fuel cells in transportation represents the future for the automotive and computation industries. Buses, light vehicles (cars), UAVs and trains will soon be running on fuel cells.
Another great appeal of fuel cells is that they generate electricity with very little pollution–much of the hydrogen and oxygen used in generating electricity ultimately combine to form a harmless byproduct, namely water. However, obtaining hydrogen is a challenge and can be energy intensive.
Despite its many advantages, the commercialization of fuel cell technology faces many technical and economic challenges. The durability and cost of fuel cell systems represent the biggest barriers. Fuel cells are still in the ‘technology development phase’. Efforts are being made to reduce the cost and improve durability of fuel cells.
Sorry, we do not yet have a video specifically for Fuel Cell. We are adding new videos to StudentEnergy.org weekly, but in the meantime check out this video on Hydrogen.
Hydrogen is a gaseous element that is both odourless and colourless, hydrogen contains a large amount of energy in its chemical bond giving it potential as an energy carrier.
Electricity is the physical flow of electrons, referred to as an electrical current.