Fuel cells have received so much attention of late from the media, public and even some politicians. Back in 2003 President Bush announced the Hydrogen Fuel Initiative during the State of the Union Address. His main goal was that one day we can be able to use hydrogen as fuel for our cars. Is this achievable? Well, I will take my time in this article to explain how fuel cells work and their basic components.
These devices convert chemical energy into electrical energy. They use hydrogen and oxygen as the chemicals to produce electricity and water. This makes them a good source of energy. These cells have four basic components which include; an anode, a cathode, an electrolyte and a catalyst. I will describe each of them in detail below.
The anode
This is the negative element of the cell. It conducts the electrons that are released from the hydrogen molecules to an external circuit. It also disperses the hydrogen gas equally over the surface of the catalyst.
The cathode
This is the positive element of the cell. It channels the electrons from the external circuit to the catalyst, where they are recombined with the hydrogen ions and oxygen to form water. It also distributes the oxygen to the surface of the catalyst.
The electrolyte
This is the proton exchange membrane. This is a special material which only conducts positively charged ions. The membrane is there to block the electrons. This membrane must always be hydrated in order to function and remain stable.
The catalyst
This is the material that facilitates the reaction of oxygen and hydrogen. It is made of platinum nano-particles which are thinly coated onto a carbon paper or cloth. Catalysts are usually made rough and porous so that the maximum surface area of the platinum can be exposed to the hydrogen or oxygen. The platinum-coated side of the catalyst faces the membrane mentioned above.
How do fuel cells work?
The pressurized hydrogen gas enters the cell on the anode side of the cell. This gas is channeled through the catalyst by the pressure. When hydrogen comes in contact with the platinum on the catalyst, it splits into two hydrogen ions and two electrons. These electrons are conducted through the anode, where they are ported into the external circuit and return to the cathode side of the cell. The released electrons produce the electricity required to turn the motor.
On the cathode side of the cell, the oxygen is being forced through the catalyst, where it is separated into two oxygen atoms. These atoms have a strong negative charge. This negative charge attracts the two hydrogen ions through the membrane. When the hydrogen and oxygen combine, they form water. This makes the cells friendly to the environment.
This reaction in a single cell typically produces 0.7 volts. To increase the voltage, many separate cells must be combined to form a fuel-cell stack. Depending on what the cell will be used for, different combinations will be used to produce different voltages.
It is important to note that there are many types of fuel cells that work differently from the one I have described above. However this is the basics of how they work. Other fuel cells split hydrogen gas into HHO gas or oxyhydrogen, which is used to boost power for car engines.
For an expert review on other types of fuel cells, visit hydrogen fuel cells. You can also visit hydrogen cars for more information.
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