Can you make an electrophoresis battery?

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Discussion Overview

The discussion revolves around the feasibility of creating an electrophoresis battery that generates current through the separation of ions in an electrolyte under an external electric field, without relying on galvanic potential or chemical interactions at the electrodes. Participants explore theoretical implications, thermodynamic principles, and the nature of energy sources in this context.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant proposes the idea of using an external electric field to separate ions in an electrolyte, suggesting that this could lead to current flow without chemical reactions at the electrodes.
  • Another participant questions the source of energy for the proposed system, implying that the concept may not account for energy conservation principles.
  • A different viewpoint suggests that heating the electrolyte could provide energy for dissociation, potentially allowing for current flow as ions interact with the electrodes.
  • One participant challenges the notion by referencing thermodynamic laws, suggesting that the proposed system resembles a perpetuum mobile, which would violate the second law of thermodynamics.
  • Another participant seeks clarification on how the proposed system would violate thermodynamic principles, arguing that increased entropy from heating could provide Gibbs energy for work.
  • A later reply emphasizes the limitations of the system, stating that the external electric field is the only energy source and cannot be modified or utilized from within the isolated system.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of the proposed electrophoresis battery, with some questioning the energy sources and thermodynamic implications, while others explore the theoretical possibilities without reaching a consensus.

Contextual Notes

There are unresolved assumptions regarding the energy dynamics of the system, the role of thermodynamic laws, and the implications of heating the electrolyte. The discussion does not clarify the mathematical or physical principles governing the proposed interactions.

michaelm700
Can you immerse an electrolyte in an external electric field such that the ions are separated to a point that you could introduce electrodes and produce current in a load solely by virtue of the established charge distribution without electrode chemical interaction or galvanic potential as shown in the picture below?

That is, electrons on the anions will travel through the load and reduce the cations on the other side of the container. For instance, say the electrolyte was salt water. Would the Cl- ions oxidize to chlorine gas at the anode and furnish electrons to reduce H+ producing hydrogen gas at the cathode. The process would continue by virtue of the applied electric field and continued Na, Cl dissociation to replace the lost Chlorine? The potential for current flow is caused by the charge distribution from the field rather than a galvanic potential.

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Many ways to skin that cat ;)

Try to think this way: where would the energy to light the bulb come from?
 
I'm thinking from heat of the fluid perpetuating the dissociation as ions are netrualized.
 
Are you suggesting it is a perpetuum mobile?

If so, thermodynamics tells us it won't work and you don't have to waste time analyzing it any further.
 
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This is where I can't connect the dots. How does it violate the 2nd law? If the electrolyte is heated, the increase in entropy will provide an increase in available Gibbs energy for work after paying the enthalpy price for dissociation for NaCl. I would assume this would be added to the kinetic energy of the ions which on average would tend to be influenced by the field.

I was thinking one the ions made contact with the electrode, current would flow like discharging a capacitor. Is there some way to show chemically that electrons could not do this?
 
michaelm700 said:
If the electrolyte is heated

By what?

You have an external, static electric field. Battery it is connected to is the only source of energy. You can't modify this field, nor use energy it has, from the inside, being isolated from the external electrodes.
 

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