Make an Aluminum Air Battery

Uploaded by NurdRage on 08.01.2011

Greetings fellow nerds. Time to make another simple battery, today
will be the aluminum-air battery with household materials.
We start with about 60 grams of table salt and add in 300 milliliters of water. Stir
it up until most of it dissolves. If it doesn't completely dissolve that's fine.
Now we get ourselves a couple of square feet of aluminum foil.
This will serve as our anode or negative electrode. Bunch it up into a ball but don't pack it
too tightly yet. Now get a needle or sharp rod and poke holes
through it. The idea is that we don't want it to trap
air when we put it into the salt water. Set that aside and now get some steel wool.
Fluff it up a bit so it's slightly larger than the mouth of the container you're using.
This will serve as our cathode, or positive electrode.
Now get some wires with alligator clips and attach them to each electrode material.
Now stuff the aluminum into the bottom of the salt water and pack it down.
Next, get a paper towel and lay it over the aluminum, this will serve a separator between
the electrodes. Make sure that the aluminum is completely
covered as well as the metal part of the alligator clip.
Now stuff the steel wool on top. And that is a simple aluminum air battery.
What's happening is that the iron catalyzes the reaction of oxygen with water to make
hydroxide while the aluminum reacts with the hydroxide to form aluminum oxide.
Overall the reactants are the aluminum metal and the oxygen in the air.
So let's check its output with this multimeter. Connecting it up to the clips.
We can see the voltage is around 0.23 volts give or take.
The current is pretty low at less than 20 milliamps.
This is because we're using a crude homemade setup.
A more advanced cell uses aluminum metal alloys and better chemicals for more voltage and
current. But you can see the basic chemistry here.
In an upcoming video, I'm going to make a much better zinc-air battery so please subscribe,
like and comment.