Battery

[m.s.j]

In a battery, after finishing its construction of the positive & negative electrode creation, why will we need an external electrical lead (for example copper wires) for transmission of energy between two poles?

Why is there no short circuit between the positive and negative electrodes through the battery electrolyte and why is the electrical potential difference stable in the battery?



By the way for similar problem you can refer to persian-english weblog http://electrical-riddles.blogfa.com

[hj]

1. Are you really looking for a answer?
2. Is this a test?
3. Is this a question on a test that you don't know the answer to?

[BrianJohn]

While I am no engineer here is the short answer as I understand batteries, in particular lead acid batteries.

Batteries are electrochemical devices comprised of positive and negative plates separated by micro-porous insulators the plates are joined at collector bus commonly called post. During charge or discharge acid circulates between the plates through the microporous separators as electrons flow from the charger or load through the plates and back to the charger or load completing the circuit. As a lead acid battery discharges the sulfur in the acid is deposited on the plates and the acid changes to water, during recharge this is reversed and the sulfur in driven off the plates back into the acid.

Should the micro-porous separators fail there will be an internal short in the cell. As cells age from discharging and recharging, long time on float charge and heat the plates will deteriorated, depositing once active material in the bottom of the cell, should the deposited material reach a level where it comes in contact with the plates this will also result in a short.

Internal shorts usually result in excessive heat and the cell is no longer usable, though cells seldom explode. It is possible for a cell to reverse and this can result in spewing of the acid.

[jwelectric]

There has to be a complete path for current to flow.

In a battery there is no complete path unless there is a bank of cells as described above in which case one cell can then short out completing the path as was explained.

[m.s.j]

In the battery, the positive and negative polarities are relative concepts. In deed, in battery system one of the two poles is for example negative and the other is more negative in comparison with the electrolyte material.
In fact, in a separated battery bank after electrochemical stability, the charge transmissions between electrolyte media and both of two electrodes will be stopped and opposite transmission current will be impossible.
A similar mechanical phenomenon is heat transmission between two metal rods with different thermal conductivity coefficiency that are connected to a very hot metal plate. The thermal difference at the end of rods can cause the heat transfer through a metal wire between them, but the heat transmission between two rod is impossible through the hot metal plate because the plate is warmer than both of them.

[hj]

An excellent example of the classic statement, that to ask a good question you must know at least part of the answer. In this case, it appears you knew the entire answer to start with.

[Cass]

Which begs the question...why, m.s.j., was the question asked in the first place?

[Pewterpower]

Apparently for no other reason than to direct you to that website. Hopefully we're not all loaded up good with spyware now. :rolleyes:

[jwelectric]

In the battery, the positive and negative polarities are relative concepts.

Is not the whole of your post a concept?

Rethink what you have said and then apply the laws of electrical physics and you will have a different outcome.