Difference between revisions of "Build a Fuel Cell"
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| − | A fuel cell is a way to convert a fuel such as hydrogen or methane directly into electricity through a chemical reaction called electrolysis.<ref>http://sci-toys.com/scitoys/scitoys/echem/fuel_cell/fuel_cell.html</ref> Each fuel cell contains two electrodes, one positively charged (the anode) and one negatively charged (the cathode), and an electrolyte that carries charged particles from one electrode to the other.<ref>http://americanhistory.si.edu/fuelcells/basics.htm</ref> There is also a catalyst that increases the rate of the reaction at the electrodes. Fuel cells that use hydrogen react with oxygen to form the byproduct of water, making them useful for high tech applications where clean power is needed. To understand how a fuel cell works, you can build a simple electrolytic cell with mostly common household materials. | + | A fuel cell is a way to convert a fuel such as hydrogen or methane directly into electricity through a chemical reaction called electrolysis.<ref name="rf1">http://sci-toys.com/scitoys/scitoys/echem/fuel_cell/fuel_cell.html</ref> Each fuel cell contains two electrodes, one positively charged (the anode) and one negatively charged (the cathode), and an electrolyte that carries charged particles from one electrode to the other.<ref name="rf2">http://americanhistory.si.edu/fuelcells/basics.htm</ref> There is also a catalyst that increases the rate of the reaction at the electrodes. Fuel cells that use hydrogen react with oxygen to form the byproduct of water, making them useful for high tech applications where clean power is needed. To understand how a fuel cell works, you can build a simple electrolytic cell with mostly common household materials. |
[[Category:Science]] | [[Category:Science]] | ||
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== Steps == | == Steps == | ||
=== Building the Fuel Cell === | === Building the Fuel Cell === | ||
| − | # Gather all of the necessary materials. To build a simple household fuel cell, you will need a 12 inches of platinum or platinum-coated wire, a popsicle stick, a 9-volt battery and battery clip, clear tape, a glass of water, salt (optional), and a volt meter.<ref | + | # Gather all of the necessary materials. To build a simple household fuel cell, you will need a 12 inches of platinum or platinum-coated wire, a popsicle stick, a 9-volt battery and battery clip, clear tape, a glass of water, salt (optional), and a volt meter.<ref name="rf1" />,<ref name="rf3">http://mad-science.wonderhowto.com/how-to/diy-hydrogen-fuel-cell-create-fuel-future-home-0134598/</ref> |
#* A 9-volt battery and battery clip can be purchased at an electronics or hardware store. | #* A 9-volt battery and battery clip can be purchased at an electronics or hardware store. | ||
# Cut two 6-inch (15-centimeter) strips of platinum or platinum-coated wire. You will need to purchase this wire from an electronics supply store, as platinum isn't used for common wiring purposes. The platinum serves as the catalyst for this reaction. | # Cut two 6-inch (15-centimeter) strips of platinum or platinum-coated wire. You will need to purchase this wire from an electronics supply store, as platinum isn't used for common wiring purposes. The platinum serves as the catalyst for this reaction. | ||
| − | #* Platinum wires are recommended because other substances, such as copper, will react with the oxygen or the salt to pollute your solution with the products of this reaction.<ref>http://www.rmcybernetics.com/projects/DIY_Devices/hho-hydrogen-water-fuel-cell.htm</ref> | + | #* Platinum wires are recommended because other substances, such as copper, will react with the oxygen or the salt to pollute your solution with the products of this reaction.<ref name="rf4">http://www.rmcybernetics.com/projects/DIY_Devices/hho-hydrogen-water-fuel-cell.htm</ref> |
| − | #* High quality stainless steel can also be used as it will not react as readily.<ref | + | #* High quality stainless steel can also be used as it will not react as readily.<ref name="rf4" /> |
# Wind each wire strip around a thin metal rod to shape it into a spring. These two springs will serve as the fuel cell's electrodes. Take the end of the wire and wrap it tightly around your shaping rod to form a coil. Remove the first wire from the shaping rod and wrap the second wire. | # Wind each wire strip around a thin metal rod to shape it into a spring. These two springs will serve as the fuel cell's electrodes. Take the end of the wire and wrap it tightly around your shaping rod to form a coil. Remove the first wire from the shaping rod and wrap the second wire. | ||
#* The shaping rod can be a nail, pick, wire coat hanger or lead on a battery tester. | #* The shaping rod can be a nail, pick, wire coat hanger or lead on a battery tester. | ||
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# Tape the electrodes to a popsicle stick or dowel rod. The popsicle stick needs to be longer than the mouth of the container holding the water so it can rest on top. Tape the electrodes so that they hang down, away from the stick and can be easily submerged into the water. | # Tape the electrodes to a popsicle stick or dowel rod. The popsicle stick needs to be longer than the mouth of the container holding the water so it can rest on top. Tape the electrodes so that they hang down, away from the stick and can be easily submerged into the water. | ||
#* You can use clear plastic tape or electrical tape. It doesn’t matter as long as the electrodes are firmly attached to the stick. | #* You can use clear plastic tape or electrical tape. It doesn’t matter as long as the electrodes are firmly attached to the stick. | ||
| − | # Fill the glass with tap water or salt water. In order to get a good reaction, the water solution needs electrolytes.<ref | + | # Fill the glass with tap water or salt water. In order to get a good reaction, the water solution needs electrolytes.<ref name="rf2" /> Distilled water does not work well for this because there are no impurities to serve as electrolytes. Salt and baking soda dissolved in water serve as good electrolytes for the reaction. |
#* Regular tap water has impurities in it such as minerals that can serve as electrolytes if you don’t have any salt handy. | #* Regular tap water has impurities in it such as minerals that can serve as electrolytes if you don’t have any salt handy. | ||
#* Add a tablespoon of salt or baking soda for each cup of water. Stir until fully dissolved. | #* Add a tablespoon of salt or baking soda for each cup of water. Stir until fully dissolved. | ||
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=== Activating the Fuel Cell === | === Activating the Fuel Cell === | ||
| − | # Touch the 9-volt battery terminals to the battery clip for one to two seconds. The battery is needed only to send an initial current through the wire to cause the hydrogen in the water molecules touching the electrodes to separate from the oxygen, forming bubbles around the electrodes.<ref | + | # Touch the 9-volt battery terminals to the battery clip for one to two seconds. The battery is needed only to send an initial current through the wire to cause the hydrogen in the water molecules touching the electrodes to separate from the oxygen, forming bubbles around the electrodes.<ref name="rf1" /> This process is called electrolysis. |
#* Notice the bubbles forming around each electrode. One electrode has bubbles of hydrogen, while the other electrode has oxygen bubbles. | #* Notice the bubbles forming around each electrode. One electrode has bubbles of hydrogen, while the other electrode has oxygen bubbles. | ||
#* The battery source does not need to be completely attached the clip, just touched to the battery terminals to begin the reaction. | #* The battery source does not need to be completely attached the clip, just touched to the battery terminals to begin the reaction. | ||
| − | # Remove the battery. The battery is only needed to initiate the reaction. The separated hydrogen and oxygen will recombine into water, releasing the energy originally used to split them as electricity.<ref | + | # Remove the battery. The battery is only needed to initiate the reaction. The separated hydrogen and oxygen will recombine into water, releasing the energy originally used to split them as electricity.<ref name="rf2" /> The platinum in the electrode coils serves as a catalyst to speed the recombination of the hydrogen and oxygen into water molecules. |
# Read the output on the voltmeter. Initially, the output may be as great as two volts, but will decline as the hydrogen bubbles dissipate, quickly at first and then gradually as the last of the bubbles pop. | # Read the output on the voltmeter. Initially, the output may be as great as two volts, but will decline as the hydrogen bubbles dissipate, quickly at first and then gradually as the last of the bubbles pop. | ||
#* A light bulb or LED may appear bright initially, but will quickly dim and then gradually fade away. | #* A light bulb or LED may appear bright initially, but will quickly dim and then gradually fade away. | ||
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== Tips == | == Tips == | ||
* Individual fuel cells produce only a small amount of electricity, much like the fuel cell described above. Commercially, many individual fuel cells are assembled into stacks. | * Individual fuel cells produce only a small amount of electricity, much like the fuel cell described above. Commercially, many individual fuel cells are assembled into stacks. | ||
| − | * Although this fuel cell used water as the electrolyte, commercial fuel cells use potassium hydroxide (the type used in the Apollo space program), phosphoric acid, molten sodium or magnesium carbonate at high temperature or special polymers.<ref | + | * Although this fuel cell used water as the electrolyte, commercial fuel cells use potassium hydroxide (the type used in the Apollo space program), phosphoric acid, molten sodium or magnesium carbonate at high temperature or special polymers.<ref name="rf2" /> |
== Warnings == | == Warnings == | ||
