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From: ee5391aa@hydra.unm.edu (Duke McMullan n5gax)
Newsgroups: sci.electronics
Subject: Re: Al battery
Message-ID: <2933@ariel.unm.edu>
Date: 30 May 90 02:04:21 GMT
References: <12945@mcdphx.phx.mcd.mot.com>
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Organization: University of New Mexico, Albuquerque
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In article <12945@mcdphx.phx.mcd.mot.com> hbg6@citek.phx.mcd.mot.com writes:

>I recently read an article about aluminium/air batteries which
>was interesting but short on technical detail. Does anyone know
>how these things are made and is it possible to assemble one
>from readily available materials ( I have plenty of empty Coors
>cans and loads of air around here :-) ).

I played around with one (a kit from Edmund (Yuppy) Scientific), and came up
with the proverbial "mixed review". Messy, fragile, they eat Al alloy like
crazy, they make a lot of foam, and other problema variosae.

The fragile can be partly fixed. Still, the membrane which allows air to dif-
fuse to the anode (I THINK anode....) seems inherently fragile. It generates
a lot of foam internally which appears to make it useless as a power source
for caving, my main interest in the thing.

One thing's for certain: it's an odd (and undescribed) alloy of aluminum that
serves as the cathode (see parenthetical note above). I tried several other
aluminum sources, cleaning each very carefully, and the output voltage was 
MUCH lower.

I hypothesize...maybe I should say conjecture...naw, let's just call it a 
wild-ass guess...that the alloy is needed to prevent aluminum from forming
its (in)famous oxide film.

"It's easy to solder aluminum. It's a pain in the butt to solder aluminum
oxide." -- a friend

If anyone can find the details on this particular battery (it's patented; I
can't find the number) I'd like to know more about it.

We will reach the stars! Our power source will be sheer gumption and empty
beer cans!


						d


--
		"I love eating popcorn. I think of each
		kernel as the skull of a conquered enemy."
      Duke McMullan n5gax nss13429r phon505-255-4642 ee5391aa@hydra.unm.edu