rick@csd4.csd.uwm.edu (Rick Miller) (09/07/89)
I first heard of this gizmo on a T.V. program called "Beyond Tomorrow" and wasn't so sure I believed the power output they ascribed to it. Then I was browsing through my Chemistry book (I put off that 2nd semester as long as I could...) and there it was again. The details were scant, but interesting. The anode is pure aluminum, and air is bubbled through an "inert, porous metal" cathode. The electrolyte is either salt-water or sodium hydroxide solution (concentration not given). The aluminum anode is consumed by the reaction, producing a solid precipitate of aluminum hydroxide (1 Al and 3 OH's). The cell consumes the aluminum anode, water, and oxygen from the air. Recharging is done simply by replacing the anodes, dumping out the solid precipitate and adding water. I did a little figuring, and it comes to about one gram of aluminum for every 3 Amp-hours. Optimum cell voltage is about 2.7 Volts. So has anyone heard of this thing? Who makes them? (A commercial version was mentioned.) What about this "inert, porous metal" electrode... What metal is it, and how-do-I-make/where-do-I-get them? Rick Miller rick@csd4.csd.uwm.edu
estell@m.cs.uiuc.edu (09/08/89)
First, the aluminum air power cell is available through the Edmund Scientific catalog. You could also order directly (and ask for product info) from the manufacturer: ALUPOWER, Inc., 6 Claremont Road, Bernardsville, NJ 07924. In the literature I have, the process is explained as follows: "The ALUPOWER battery cell uses a special Aluminum alloy as an anode and Air as a cathode. The electrolyte is Salt Water." The Al reacts with H2O to produce Al(OH)3; the excess of electrons at the anode and O2 from the air reacts with H2O to form OH- , depleting electrons from the cathode. The "special Al alloy" obviously contains some sort of catalyst to speed up the reaction between the O2 and H2O, but I don't know what it is that they added.
ee5391aa@hydra.unm.edu (Duke McMullan n5gax) (09/14/89)
In article <21000041@m.cs.uiuc.edu> estell@m.cs.uiuc.edu writes: > "The ALUPOWER battery cell uses a special Aluminum alloy as an anode >and Air as a cathode. The electrolyte is Salt Water." The Al reacts with >H2O to produce Al(OH)3; the excess of electrons at the anode and O2 from the >air reacts with H2O to form OH- , depleting electrons from the cathode. > >The "special Al alloy" obviously contains some sort of catalyst to speed up >the reaction between the O2 and H2O, but I don't know what it is that >they added. Hey, I'd sure like to know. I've tried replacing the anodes with vanilla aluminum alloys, and the cell current drops considerably. (I've never measured the open-circuit voltage -- I ought to....) I'm messing with this cell to see if I can come up with something that's useful as a power source for caving. So far, the Al-O2 battery looks good chemically and electrically, but hasn't the physical durability to stand up to this sort of service. Imagine it: you lose your balance and land on a large rock. No injury, but the battery cathode diaphram got punctured. Oops. Or: you're crawling down a lemon-squeezer passage -- the sort where you have to exhale to move forward -- and the thing dips sharply downward. To go down, you have to invert that battery almost all the way. There isn't any way you can turn around, not even enough room to take the battery off your belt. Why does your belly seem wet? Because the electrolyte has drained out of the battery. Oops, again. Someday, perhaps. As it stands, I'm not much impressed by this particular cell chemistry. A shame, 'tis. Minding knows inquire to want, d Skinner's algorithm for squaring a number: Divide the number by its reciprocal. Duke McMullan n5gax nss13429r phon505-255-4642 ee5391aa@hydra.unm.edu
ee5391aa@hydra.unm.edu (Duke McMullan n5gax) (09/24/89)
In article <21000041@m.cs.uiuc.edu> estell@m.cs.uiuc.edu writes: > "The ALUPOWER battery cell uses a special Aluminum alloy as an anode >and Air as a cathode. The electrolyte is Salt Water." The Al reacts with >H2O to produce Al(OH)3; the excess of electrons at the anode and O2 from the >air reacts with H2O to form OH- , depleting electrons from the cathode. > >The "special Al alloy" obviously contains some sort of catalyst to speed up >the reaction between the O2 and H2O, but I don't know what it is that >they added. Hey, I'd sure like to know. I've tried replacing the anodes with vanilla aluminum alloys, and the cell current drops considerably. (I've never measured the open-circuit voltage -- I ought to....) I'm messing with this cell to see if I can come up with something that's useful as a power source for caving. So far, the Al-O2 battery looks good chemically and electrically, but hasn't the physical durability to stand up to this sort of service. Imagine it: you lose your balance and land on a large rock. No injury, but the battery cathode diaphram got punctured. Oops. Or: you're crawling down a lemon-squeezer passage -- the sort where you have to exhale to move forward -- and the thing dips sharply downward. To go down, you have to invert that battery almost all the way. There isn't any way you can turn around, not even enough room to take the battery off your belt. Why does your belly seem wet? Because the electrolyte has drained out of the battery. Oops, again. Someday, perhaps. As it stands, I'm not much impressed by this particular cell, physically. A shame, 'tis. Minding knows inquire to want, d -- Generic Apophthegmatic Statement -- Duke McMullan n5gax nss13429r phon505-255-4642 ee5391aa@hydra.unm.edu