Do electrons flow through a battery or is it something else?

In summary: As you said, electrons reach the positive terminal due to the current in the rest of circuit. If these electrons didn't flow -through the electrolyte - to the negative terminal then the charge of the positive terminal would become zero or negative after sometime. Similarly for the negative terminal if it would keep releasing electrons to the rest of circuit, it would become zero charged or positively charged unless of course electrons reach to it from the positive terminal through the electrolyte.I certainly believe that electrons flow through the battery. I don't know how the complex chemical reaction inside the battery works. But according to the law of conservation of charge, if electrons flowing into the positive electrode do not flow out of the negative electrode, where do those
  • #36
jbriggs444 said:
Have you looked at the electron drift velocity for a wire, divided the wire length by the drift velocity and compared the result to the discharge lifetime of the battery at the current in question?

Wikipedia has a numerical example for drift velocity.
Drift velocity is of the order ##10^{-5} m/s##, so it's extremely small. So, what you're saying is that the speed of electrons flow is too less for all the conductor electrons to reach the +ve terminal of battery. Right? It's like the electrons drift i.e. move forward in current direction at an extremely slow pace.
 
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  • #37
At the cathode of a cell some positive ion from the solution (electrolite) gets neutralized by "capturing" electrons. These electrons are from the metallic cathode which is part of the circuit. I suppose these electrons are from the conduction band of the cathode even though I did not find this explicitly stated. On the other hand, at the anode metallic atoms go into solution as positive ions and they "leave behind" some electrons in the process. So overall, the number of conduction electrons in the external circuit remains the same. It is not a change in the nuber of electrons that drives the current but the potential differences created at each interface electrode-solution. Oberall, the battery does not provide any charge to the external circuit and it does not store charge, of course.
 
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  • #38
vcsharp2003 said:
Drift velocity is of the order ##10^{-5} m/s##, so it's extremely small. So, what you're saying is that the speed of electrons flow is too less for all the conductor electrons to reach the +ve terminal of battery. Right? It's like the electrons drift i.e. move forward in current direction at an extremely slow pace.
Yes, that is the idea.

They move in the opposite direction of the "conventional current". If the wire is short and the battery has a large capacity (high amp-hours), electrons may be able to make the trip. If the wire is long and the battery has a low capacity (low amp-hours), electrons may not be able to make the trip before the battery is drained.

None of which matters. Electrons are, as far as we know, indistinguishable. Which ones are passing a particular point is irrelevant.
 
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  • #39
jbriggs444 said:
Yes, that is the idea.

They move in the opposite direction of the "conventional current". If the wire is short and the battery has a large capacity (high amp-hours), electrons may be able to make the trip. If the wire is long and the battery has a low capacity (low amp-hours), electrons may not be able to make the trip before the battery is drained.

None of which matters. Electrons are, as far as we know, indistinguishable. Which ones are passing a particular point is irrelevant.
The speed due to drift velocity seems to be less than even snail pace. ##10^{-5} m/s ## is equivalent to ##0.000022 mph## or ## 0.000036 km/h##.
And if we assume a conducting wire of 0.5 m length connecting the battery terminals, then it would take an electron to complete the full circuit about 13.89 hours which is a very long time.

I used to think that electrons are traveling very fast in a wire when a current flows.
 
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  • #40
And what electrons lack in speed they make up for in quantity.

One Ampere is defined as 6.28 ×1018 electrons per second.
(6 280 000 000 000 000 000 per second)
 
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  • #41
Tom.G said:
And what electrons lack in speed they make up for in quantity.

One Ampere is defined as 6.28 ×1018 electrons per second.
(6 280 000 000 000 000 000 per second)
Very interesting facts about electric current. Even 1 billion electrons per second is too small for above quoted number.
 
  • #42
vcsharp2003 said:
if we assume a conducting wire of 0.5 m length connecting the battery terminals, then it would take an electron to complete the full circuit about 13.89 hours which is a very long time.
A 12 volt automotive battery can deliver about 48 amp-hours of charge. So one of those could drive its electrons all the way through that 0.5 meter wire before running out of charge.

The electrons still would not complete a full circuit, however. Each one of the six series-connected cells in a car battery has the ability to absorb the entire 48 amp-hours of charge.
 
  • #43
jbriggs444 said:
The electrons still would not complete a full circuit, however. Each one of the six series-connected cells in a car battery has the ability to absorb the entire 48 amp-hours of charge.
Then where would they congregate?
 
  • #44
I think we do no service by re-enforcing a picture of electrons, each apparently having a name (but no possible nametag) marching single file through the circuit. I understand it is the simplified picture we likely all learned in primary school, but it leads to ill-conceived notions. The fields carry the energy and the wires guide the fields. There is no FILO (first in last out) requirement for them.
As to the OP:

Do electrons flow through a battery or is it something else?​

The correct answer is "yes"

/
 
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  • #45
Tom.G said:
Then where would they congregate?
They would not congregate anywhere. However, each cell has many moles of lead and acid. Plenty to absorb electrons on one side and emit on the other. All without any net charge accumulating anywhere.
 

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