Terminals when recharging cells?

[AnonymousLover]

What terminals of the battery do you connect the anode and cathode in i) galvanic cells, ii) electrolytic cells??

[tony3272]

There seems to be a little bit of confusion here.
In a galvanic cell you are not connecting a battery to the system because you are producing electrical energy rather than supplying it. Therefore the anode will be at whichever electrode oxidation occurs and the cathode is at the electrode where reduction occurs.
If you're drawing a diagram for a galvanic cell, put in something such as an ammeter or light bulb along the wire.

In an electrolytic cell the electrons will pass through the negative cathode which is reduced, and through to the positive anode, which is oxidised and then back to the other terminal of the battery. Because electrons travel from negative to positive, the negative terminal is placed at the cathode and the positive terminal is place at the anode.

[AnonymousLover]

Understood. But what I meant was, which battery terminals do you connect to the anode/cathode when youre RECHARGING a galvanic cell, ie: a recharable battery....

[geoff_821]

When recharging a battery, Positive to positive electrode, negative to negative electrode. correct me if I have misunderstood the question

[ARMYMAN0010]

To recharge a secondary cell, you need to 'reverse' the main reaction which has occurred in the cell. Where oxidation has occurred, ie, the loss of electrons, you must "force" electrons back in to reverse that reaction. Since oxidation occurs at the anode, to force electrons back in, you place the negative terminal of your power supply there. The opposite is true for the cathode- since reduction has occurred there, ie, a gain in electrons, a reversal of that reaction would require the opposite. Hence we conntect the positive terminal there to "suck up"  the electrons, thereby reversing the reaction (electrons are attracted to the +).

[flynny93]

negative terminal connects to the negative electrode (cathode in electrolysis/recharging)
positive terminal connects to the positive electrode (anode in electrolysis/recharging)

[AnonymousLover]

Cheers guys!

[tony3272]

When you are recharging the battery it becomes the same as an electrolytic cell. So cathode to negative, anode to positive. But remember, the anode and cathode for discharging energy is not the same as when recharging.

[Zebra]

how would you guys explain why the charge applied needs to be greater than the 'natural' charge?

( please correct my wording if i'm wrong)

[BoredSatan]

how would you guys explain why the charge applied needs to be greater than the 'natural' charge?

( please correct my wording if i'm wrong)

because the natural charge occurs spontaneously..

so in order to reverse this, a greater amount of energy is needed to force the electrons to go the other way..