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Waiting for fuel cells to come to light will not help us in the present. Manufacturers are battling high electrode and PEM prices, with no low-cost alternatives to date. Most research has been geared toward electric vehicles, yet EVs remain underpowered, range limited, and prohibitively expensive. At the same time, we continue to burn fossil fuels, adding to the pollution of our planet. Even EVs derive their power from fossil sources- such as the burning of coal at the local power plant. Granted, there are ways to use purely green energy, such as solar and wind, but drawbacks, such as price, hinder their use. Silicon-based solar panels are energy negative, taking more energy to create than they can produce in a lifetime. Newer dye-sublimated Ti02 panels may correct this imbalance, but in the meantime, this page has been created to gather the various minds together to create a practical, easy power source, recycling materials that are readily available. The current version is very low power, but we hope to change that! If you would like to help, feel free to post to this site or email anytime. There are many thinkers in this world, but few putting thoughts into action! Join me!
The ideal solution will be usable in third world
countries, disaster-stricken zones, and as a temporary power source.
With the hurricanes, earthquakes, and tsunamis experienced lately, this
project will be very
beneficial. Once a high-current cell is operational, cells will
be chained in series to 12volts, followed by an inverter, allowing AC
power simulation and the use of appliances. This could also power
UV water purification lamps, which destroy harmful bacteria in water,
making it drinkable.
So what motivator
spawned the project? Driving a Heinzmann Estelle City Bike,
on a 10 mile commute, having to recharge twice daily,
despite pedaling half the time. Granted, it was
moderately hilly, but bicycle EVs must meet such demands to become
plausible alternatives to motor vehicles. A 20 to 30 mile
range and instant refueling would make ebikes more appealing. The
Estelle used a 4.4Ah, 36V Nickel Cadmium (NiCad) battery pack,
with the available alternatives Sealed Lead Acid (SLA),
larger capacity NiCads, Nickel Metal Hydride (NiMh), Nickel Zinc
(NiZn), and Lithium Ion/ Polymer (LiIon) batteries. Here is
a battery chemistry primer with the benefits and drawbacks of each cell
type: http://www.freewebs.com/alfuelcell/batterytypes.htm
Fuel Cells. A Solution?
We have heard great promises for fuel cells. NASA first
used them on space missions, then the media took over several years ago
claiming they would revolutionize our lives. But this has
been just talk. I have seen only one company that offers
usable hydrogen fuel cell kits to consumers http://www.fuelcellstore.com/.
However, there are many manufacturers for industrial applications, with
prices ranging from $7000 to $50,000 per kilowatt. The very first
hydrogen power station in the United States was installed in
Westerville, Ohio in November 2004. This 250kW unit cost $103
million and uses natural gas reformers to operate. That is enough
to power 180 homes. A 1000Watt
unit, enough for an environmentally-conscious household with many
power-saving features, sells for $10,000. Still
interested? If you get rid of your microwave, use LCD
monitors and televisions, replace all light bulbs with LED
and fluorescent units, and use gas heating and cooling,
this unit could work for your household. Don't
forget your cost of obtaining the hydrogen, which could be much
higher. Propane fuel cells would be a better bet for country
folks, since many already use propane for heating purposes.
You're on your own here! I haven't priced them. If anyone has
information of the pricing of these cells, please let me know.
If you were thinking about making your own hydrogen fuel cells,
think again. The Proton Exchange Membrane (PEM), the most
important and advanced cell component, must be purchased direct from a
manufacturer. I've emailed several, and they are not willing to
part with small amounts of material - they have too much invested in
research and development. On top of this, the catalyst
needed to use the cell at room temperature is platinum, which is
currently trading for $1200 per ounce! You may have also heard that the primary
source of hydrogen planned is hydrocarbon fuel - natural gas
reformers, gasoline, and diesel. This has some advantages, such
as utilizing the available fueling infrastructure, and
some extractions avoid polluting the air. As an alternative, a few people produce hydrogen
from water using electrolysis and solar or wind energy, which is
excellent, but entry costs are high. The crude hydrogen can be burned
directly in modified natural gas appliances. It is very simple
and more efficient than storing energy in batteries. The electrolysis
unit can be expensive however, and many fuel cells require very pure
gas input, which must be provided by a special tank or
filters, adding thousands more. Storage tanks add
additional costs, although hydrogen has been stored in steel containers
for years without trouble. Clean and progressive, but still not
practical for most of us.
Another, more practical fuel cell is the Zinc-Air or Aluminum-Air variety. One product has been released to my knowledge, with many others awaiting release. They use a specially designed zinc or aluminum alloy to allow continuous power output. For aluminum cells, electricity is transferred when the aluminum is oxidized. The remaining substance is alumina, which is a hard, protective coating. This will stop the oxidation from occurring further - which is a problem with our project design. Our design uses aluminum cans, as they are cheap and readily available. Instead of using a special alloy, we use mechanical force to expose aluminum with a wire brush. Aluminum was chosen because electricity production is reportedly much higher than any other battery chemistries, with aluminum having 75 times the energy density of lithium ion cells. More information is available from this link, but be advised it is a press release for a company creating the product: http://www.aluminum-power.com/media/yahoo2.htm
Please see this excellent experiment below, where an aluminum air
battery is created from aluminum foil, activated charcoal, salt water,
a paper towel, and wire. It is safe and easy to complete in your
own home: http://isaac.exploratorium.edu/~pauld/activities/AlAirBattery/alairbattery.html
Note that the air electrode is activated charcoal, which can be
found at the grocery store and health food stores. An
interesting alternative is activated charcoal in textile
form, available as a gas mask filter and in other goods: http://www.conservation-by-design.co.uk/sundries/sundries49.html.
This may simplify the air battery further, reducing the profile.
This allows an easy burrito-style battery of high voltage or
current by alternating layers of charcoal and aluminum foil.
Salt water is used as the electrolyte for safety. Electrolytes contain hydrogen ions of different proportions. Better performing electrolytes commonly used in electrolysis are Potassium Hydroxide (KOH), available from chemical warehouses, followed by Sodium Hydroxide (NaOH), which is available as a drain cleaner called Red Devil Lye. You simply mix the KOH or NaOH with water and substitute for the salt water to get higher voltage and current readings. Alternatively, you can go to a local campsite and collect ashes. Soak them overnight in water, then filter and use the remaining yellow liquid. This method was taken from an old-fashioned recipe for soap, yielding KOH, NaOH, and some other things, called caustic potash. I cannot locate my texts which stated Aluminum + NaOH and Aluminum + KOH release hydrogen gas, but I do remember reading this, so be sure to do this outside. Note that lab safety requires you to have vinegar nearby, safety goggles, rubber gloves, and long pants and sleeves when using these chemicals. They are highly basic and will burn your skin without you feeling the damage. In case some does happen to fall on your skin, vinegar is rubbed over the area to make the basic chemical more alkaline. Here is a link that shows lye being used in the anodizing of aluminum parts http://www.focuser.com/atm/anodize/anodize.html . Lye slowly removes the oxidized layer, the alumina. This could be the key to a high powered cell, as the commercial manufacturer I spoke with suggested power is severly limited without adding a chemical to remove the oxidized layer. This also serves a dual purpose, eliminating the need to use a wire brush to expose aluminum.
Our first experiment used a can scraped with a wire brush which sat
inside a plastic cup. The cup was filled with hydrogen peroxide
3% solution, available from the pharmacy or supermarket, which is
usually used on cuts. I actually found mine for $1 at
the local dollar store. It releases oxygen, which oxidizes
the aluminum. Stronger concentrations can be purchased as hair
bleach, providing a higher current
output. We dissolved salt in it for the
electrolyte. The electrolyte can be absorbed into a
sponge to keep it from splashing out of the cup if you
prefer. Between the plastic cup and the can, I placed a wire
in a cotton ball. This was one electrode. Another
wire went to the top of the pop can and served as the other
electrode. The current flows between these
electrodes. Hook your voltmeter to these to
measure your output and send us the results! If you need a
voltmeter, Harbor Freight often has them for under $5 http://www.harborfreight.com/.
You can stack the cells in series to add the voltages of
the cells - just run a wire from the cotton of the first
cell to the can of the next cell. Then your
cotton wire of the second cell and the can of
the first cell form your two electrodes. Add as many
cans as you like in this manner to add voltages. If you get
a negative voltage, just reverse the wires. To raise the
output current, you connect the cotton wires of each cell
together, and separately, the can wires together. The
cottons and can wires serve as your electrodes in this parallel
configuration.
When the cells get weak, you'll have to scrape the cans with the
wire brush to expose more aluminum. You can do this until there
is no more can left. Note that if the hydrogen peroxide runs out
of bubbles, you will have to replace it with new solution and salt.
Future versions of the project aim to use an air electrode rather than hydrogen peroxide, and an automatic scraping mechanism for the cans. Lightly soaked thin sponges would allow air and electrolyte to make contact with the cans - the sponges soaked in salt water. Alternatively, the campfire method provides a free electrolyte, and prevents you from having to use salt. Just take ashes from a campfire, the black chars and a little grey ash, crush, and add water.
Ideally, we will find a high-power solution. But for now, it is still far away. Or is it? Have fun experimenting!
Our example cell is given on the Cell Pictures page.
UPDATE 7/21/2005
I connected 6 cells in series by chopping cans in half, then using the
top sections (the ones with the pull tabs still attached). The
cans were placed into coffee mugs. 5% salt water was added to
each cell. A copper 24 gauge wire connected the pull tab of one
can to the outside water/salt area of the next cell, between the can
and the mug. No air electrode is needed. Just run the
wire into the salt water. Total cell voltage came to 2.3V.
I took a 25% mixture of Red Devil Lye and H20 and added 2 teaspoons to each cell (equivalent to 1/2 teaspoon Lye per cell). The voltage instantly jumped to 5V, then leveled out at 4.4V. A light emitting diode (LED) lit with the cell, bright for a split second, then very dim. I was not able to make an amperage measurement for some reason. I imagine the power is in the neighborhood of 3-5mA. Imagine what a higher concentration of Lye would do for your cell??? Remember to add Lye to water SLOWLY, and not the other way around to prevent explosions. Keep water and vinegar around in case you get lye on your hands. And the lye will eat aluminum, so be careful with your voltmeter probes! Do this outside as there is hydrogen gas formed, which you will see when it starts bubbling! Enjoy.
UPDATE 8/15/2006Reader Richard H. did some testing of his own with these results:
Aluminum foil battery with 3% H2O2 and salt electrolyte: output between 0.4-0.6V at 17mW, 60mA. He calculated a possible total cell size of 3-6 gallons to power a 400W ebike. He also powered 3 LEDs for several minutes using 3 cells in series. More to come...
UPDATE 11/2/2006
Jasper H. from the Netherlands created a Zinc-Air cell with results of 1.3V and 120mA. He used activated charcoal as the electrode and NaOH as the electrolyte. If anyone is aware of products which come in Zinc cans, please let me know at nocman43202@yahoo.com and I'll post them here.
Some Study Resources:
Electrochemical Cell Reactions, Oxidation and Reductant tables.
Chemists, please review! From this chart, you can pick chemicals that will increase the cell voltage and current. Please email if you are familiar with a common chemical derived from this list that will increase our power rating. Thank you!
http://www.ausetute.com.au/calcelemf.html
Bulgarian Electrochemical Power Sources Laboratory site
Air Electrode Design
http://www2.electrochem.org/cgi-bin/abs?mtg=204&abs=0218
Carbon Pad Air Filters $50/ year supply, 10x20x1/4"
http://www.a1airfilters.com/oxyclean.htm
Will sell activated charcoal cloth if you contact them. Last priced at $10/foot
"Charcoal Like" Novel Air Electrode, not explained
http://www2.electrochem.org/cgi-bin/abs?mtg=204&abs=1021
Oxygen Reduction no Gas Diffusion Electrodes in Alkaline Solution - various metals/ carbon tested
http://www.aba-brno.cz/aba2003/abstracts/35-furuya.pdf
Best diagram of cell, explanation of chemical reactions, Hydrogen problem, must see!
http://www.ectechnic.co.uk/ALUMAIR.HTML
Least expensive platinum coated material - 18" stainless steel coated necklace! Use for electrodes, experiments
http://www.fareastjade.com/CH001.htm
Molecular Expressions, featuring a rope battery
http://micro.magnet.fsu.edu/electromag/electricity/batteries/metalair.html
Production Fuel Cell Types - with descriptions, technical data, operating temperatures
http://www.fuelcells.org/basics/types.html
Zinc Fuel Cells for EVs
http://www.powerzinc.com/en/index-2-c1.html
Al O2 Fuel Cell Experiment - simple chemistry lab
http://129.93.84.115/Chemistry/DoChem/DoChem117.html
Westerville, Ohio 250kW power station article
http://www.greenenergyohio.org/default.cfm?exec=Page.View&pageID=1077cfm?exec=Page.View&pageID=1077
Most of the information on this site is available elsewhere on the internet. I obtained it through reading books, manuals, physics and chemistry classes, and the like. I suggest you do your own reading; this will at least get you started. If you see anything that is incorrect, please email me at nocman43202@yahoo.com and I will fix it shortly. Thanks, and enjoy! Remember that we need participants in the project - any contribution is a worthwhile contribution.
Brought to you by Matt Slezak. If you are interested in joining him, feel free to contact him at the email address above.
