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This simple foil and saltwater cell can be wired in series or in parallel to provide a scalable Al/Air fuel cell.
You can't read the numbers very well but the meter is showing .999 ( I think I caught that ). These pictures will probably get updated with better shots.
The body of the cell is a plastic water or soft drink bottle. A hole is cut into the bottle and piece of carbon paper is taped over it. The bottle is filled with an electrolyte (in this case saltwater) and an aluminum electrode is inserted into ti.
The carbon paper has a wax backing and provides a water proof (hydrophobic) barrier but is porous enough to allow air to pass. This air is absorbed by the electrolyte solution and the dissolved O2 is converted back to water by the fuel cell. This allows the creation of a very efficient yet simple cell design.
According to Wikipedia Aluminum has a potential energy density of 3.5 kW-h/kg and is one of the most readily available scrap materials around.
You can't read the numbers very well but the meter is showing .999 ( I think I caught that ). These pictures will probably get updated with better shots.
The body of the cell is a plastic water or soft drink bottle. A hole is cut into the bottle and piece of carbon paper is taped over it. The bottle is filled with an electrolyte (in this case saltwater) and an aluminum electrode is inserted into ti.
The carbon paper has a wax backing and provides a water proof (hydrophobic) barrier but is porous enough to allow air to pass. This air is absorbed by the electrolyte solution and the dissolved O2 is converted back to water by the fuel cell. This allows the creation of a very efficient yet simple cell design.
According to Wikipedia Aluminum has a potential energy density of 3.5 kW-h/kg and is one of the most readily available scrap materials around.
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Signing UpStep 1Bill of Materials
This is a really simple project, at least for an individual cell. Once you begin scaling up either in volume or quantity new challenges will present themselves.
For each cell you'll need:
A soda or water bottle. Try to go with smaller bottles as you work out the size and fabrication issues.
A sheet of carbon paper. Depending on what size bottles you use a single sheet will provide multiple electrodes.
Tape - I'm using Scotch brand cellophane tape which works okay. You'll want something that secures the carbon paper to the bottle and provides an easy water tight seal. I'm experimenting with other solutions.
Aluminum - I'm using aluminum foil, the electrode could easily be cut from an aluminum can. If you use a can you must scrape the anti-oxidant from the surface with a wire brush or something.
A replacement power brush from Ace Hardware used to tap the carbon electrode. Any number of alternatives can be used but I like the power brush electrodes so...nyahh!
Electrolyte - I'm using salt. Other alternatives which will produce higher power outputs but which have not been tested in this apparatus include Hydrogen Peroxide ( 3% solution from the drug store ), Chlorine bleach, vinegar (with or without salt) and Lye.
You'll need some scissors, an X-Acto knife or both for cutting a hole in the side of the bottle and trimming the carbon paper.
Okay, got everything? Then we're off...
For each cell you'll need:
A soda or water bottle. Try to go with smaller bottles as you work out the size and fabrication issues.
A sheet of carbon paper. Depending on what size bottles you use a single sheet will provide multiple electrodes.
Tape - I'm using Scotch brand cellophane tape which works okay. You'll want something that secures the carbon paper to the bottle and provides an easy water tight seal. I'm experimenting with other solutions.
Aluminum - I'm using aluminum foil, the electrode could easily be cut from an aluminum can. If you use a can you must scrape the anti-oxidant from the surface with a wire brush or something.
A replacement power brush from Ace Hardware used to tap the carbon electrode. Any number of alternatives can be used but I like the power brush electrodes so...nyahh!
Electrolyte - I'm using salt. Other alternatives which will produce higher power outputs but which have not been tested in this apparatus include Hydrogen Peroxide ( 3% solution from the drug store ), Chlorine bleach, vinegar (with or without salt) and Lye.
You'll need some scissors, an X-Acto knife or both for cutting a hole in the side of the bottle and trimming the carbon paper.
Okay, got everything? Then we're off...
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why not use silicon caulking for this purpose?
also, i was wondering if anyones done a stress test on the battery (heat production etc.)
In the area of microbial fuel cells a number of researchers have suggested titanium might make a good catalyst. There are caulks which are blended with titanium ( try Ace Hardware ) that could be used to test with.
Pour boiling water into the pop bottle, seal the pop bottle (i.e. put the cap back on it) and swirl it around until the glue starts to let go. The label can then be removed and once cool, the glue is still viable, with no scrap label in the way!
"Aluminium batteries or aluminum batteries are commonly known as aluminium-air batteries or Al-air batteries, since they produce electricity from the reaction of oxygen in the air with aluminium. They have one of the highest energy densities of all batteries, but they are not widely used because of previous problems with cost, shelf-life, start-up time and byproduct removal, which have restricted their use to mainly military applications. An electric vehicle with aluminium batteries could have potentially ten to fifteen times the range of lead-acid batteries with a far smaller total weight"
For more information start with the Wikipedia link:
http://en.wikipedia.org/wiki/Aluminium_battery