Aluminum air battery

by shadfurman

I was playing with different electrolytes with a copper aluminum battery; penny wrapped in a paper towel wrapped in aluminum foil. I dumped out a failed mixture of who God knows what, everything I added made it worse, and had it hanging over the edge of the sink; as it dripped I noticed the voltage increasing. I have read about carbon aluminum air batteries but have yet to try one. In about a minute it stabilized at about 700 mV and 300 uA. I replaced the paper towel with a dry one and wrapped another penny and aluminum on for just under 1.4 V with two cells and an air electrolyte. I think the aluminum wrapping around the back may be canceling out the voltage some; since the air is the electrolyte they aren’t really separate cells, just high resistance between them, but since the current flow comes from oxidizing of the aluminum (I think) I’m not sure if it matters. Supposedly potassium hydroxide in water as an electrolyte will accelerate the reaction as well as produce hydrogen… Which could be used as a burn assist in a gasoline engine? If I can get the necessary amperage I may have to try that in my car.