How does an aluminum-air battery work?
Aluminum-air batteries produce electricity from the reaction of oxygen in the air with aluminum. Battery uses a catalyst with a unique silver structure which allows oxygen in the battery cells to block the entry of carbon dioxide into the system.
The explanation of their functioning, for a better understanding, can be made metaphorically by the difference between the diver and the fish: the diver needs an oxygen tube when underwater (so an additional container), while the fish uses the same oxygen from the water. .
They have one of the highest energy densities of all batteries, but are not widely used due to high cost issues in the anode manufacturing process. This limited their use mainly to military applications.
Advantages and disadvantages of the Aluminum-air battery
An electric vehicle with aluminum batteries has the potential up to eight times greater than the autonomy of a lithium-ion battery and a significantly lower total weight.
Basically, this battery offers a very high efficiency. Theoretical, an aluminum-air battery with a mass of 100 kg can ensure a maximum autonomy of 3.000 km, while a lithium-ion battery weighs 5 times more to ensure 10 times less autonomy (eg the battery on the Tesla Model S).
What are Aluminum-air batteries?
Aluminum-air batteries they are primary cells, ie non-rechargeable. Once the aluminum anode is consumed by its reaction with atmospheric oxygen, the battery will no longer produce electricity.
However, "mechanical recharging" is possible of the battery with new aluminum anodes made from the recycling of hydrated aluminum oxide. Such recycling would be essential if aluminum-air batteries were mass-produced.
Are Aluminum-air batteries cost effective?
The final price of the battery is unknown, although previous estimates had set the cost of an Al-air system at about $ 1.1 per kg of aluminum anode.
This was not communicated in precise terms in relation to the cost of petrol again the weight of the aluminum anode in these batteries is also unknown.
But the team that performed the analysis noted that proper recycling would put Al-air in the same cost range as conventional internal combustion engines.
It remains to be seen whether car manufacturers will be interested in this technology. Car companies tend to be conservative while still using lithium-ion technology.