Aluminium Oxidation: Reusable Portable Circuit Solutions

AI Thread Summary
The discussion revolves around the feasibility of using aluminum air batteries by storing aluminum in a vacuum and exposing it to oxygen to initiate oxidation. The concept involves using a high surface area aluminum plate connected to a load via a copper lead, with the potential for rapid oxidation upon breaking the vacuum. A key point raised is the challenge of closing the circuit in a portable application, as traditional grounding methods may not be applicable. The conversation touches on the behavior of zinc-air batteries, noting their limited operational lifespan once exposed to air, regardless of load conditions. The importance of separating half reactions in battery chemistry is emphasized, as well as the misconception about charge development on oxidized aluminum surfaces. The response highlights the need for a foundational understanding of redox reactions to clarify these concepts.
Samson4
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I have watched many videos of aluminium air batteries and it got me wondering. Could this same process work if you stored the aluminum in vacuum and exposed it to oxygen? For example:

A high surface area aluminium plate is in a glass bulb under high vacuum. A copper lead connects to the aluminium to a load. If we break the bulb the aluminium will rapidly oxidize. How do you close the circuit? I know you could ground it but what about in aportable application? Reusability and controlled current flow are of no concern.
 
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My hearing aids run on zinc-air batteries, which are analogous. They are tiny. They have the strange property for batteries that once exposed to the air, they run out in 8 days regardless of how much electric power is supplied to the load. Full load, zero load, still lasts 8 days.
 
Samson4 said:
How do you close the circuit?

In what you described the circuit is already closed.

Whole trick with every battery is to have both half reactions separated so that electrons can flow through an external circuit, instead of jumping from one atom/ion/molecule to another directly.
 
If we released pure oxygen inside an aluminium sphere, a charge would develope on its surface correct?
 
I guess a better question would be; when 1 side of an aluminium plate is oxidized, does a charge develop on the opposite side?
 
Samson4 said:
I guess a better question would be; when 1 side of an aluminium plate is oxidized, does a charge develop on the opposite side?

No. I told you how it works. Please read any general chemistry book on redox reactions and cells and you will see what it is all about, right now you are just wild guessing.
 
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