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Aluminum Air Batteries are the most energy dense chemical battery currently known at ~1300-6000 W·h/kg (compared to lithium ion at ~100-265 W·h/kg), however they are considered primary batteries meaning that once discharged, they cannot be electrically recharged (however, mechanically recharging is possible by replacing the consumed electrode).

Aluminum reacts with hydrogen and oxygen to create aluminum hydroxide and electrons that generates a voltage potential (using saltwater, a nominal voltage of 0.7V is achieved, whereas using potassium hydroxide would produce 1.2V. Only saltwater was used in this project).

Aluminum air batteries can be used in electric vehicles as a substitute for a combustion engine or as a more mechanical solution to the issue of electrically rechargable batteries (commonly used ones are LiFePo cells), by allowing the operator to "mechanically recharge" the vehicle, it could be a solution to both gasoline and to inefficient secondary cells.

The design for the battery is extremely simple and safe using aluminum, salt water, and activated charcoal, meaning that it is environmentally friendly in the event of an accident. And while the battery "burns" fuel, similar to a petrol based engine, this uses solid fuel and the waste is also solid (there are no gaseous emissions) and can be recycled back into pure aluminum.

The design is extraordinarily simple and can be made easily with household supplies. With the first iteration, I made an outer case of aluminum foil. I then made a rectangular pouch with a coffee filter and filled it with activated charcoal (~20% full). Activated charcoal is used because it is extremely porous and has a large interior surface area (so has a lot of internal air trapped inside), but it is also conductive due to the carbon.

After making the pouch, I cut a small hole in the top and inserted a threaded core wire (salvaged from a computer power cable). I then inserted the filter pouch into the aluminum foil shell and taped the ends.

After sealing it all but on the top, I added salt water to the mix (in the same opening as the filter pouch). I saturated the water with salt to be as conductive as possible (allowing the electrons to flow easier). After adding the water, I sealed the top and hooked it up to a volt meter, and lo-and-behold 0.7V came out. It's not shown in the video, but I was able to get up to 0.75V after moving the water around over the electrodes.

The next stage for the project will be to design a container to allow for parallel cells and to capture the dissolved Al(OH)₃, as well as provide a pumping mechanism to allow the salt water to constantly cycle over the electrodes thus keeping them free of any particles that may build up and impede current flow.