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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: RK1992 on October 10, 2010, 02:29:07 PM

Title: Recharging an electrochemical cell
Post by: RK1992 on October 10, 2010, 02:29:07 PM

If you want to recharge an elctrochemical cell, which electrode do you supply with more electrons?

My thinking was:

There was a P.D. between the elctrodes but now that the cell is spent, the P.D. is lower. To create a P.D. again, you must make the negative electrode more nagative or the positive electrode more positive.

You could do this either by giving the negative electrode more electrons making it more negative (so you could connect the electrode to the positive terminal of the mains which will deliver electrons making the electrode more negatively charged), or you could strip the positive electrode of electrons making it more positive (this is harder to do).

So am I right in saying that to recharge a fuel cell, you supply the electrode which was originally negative with more electrons creating a greater P.D. and thus a current again.

If not, could you explain the flaw in my thinking. :)

Thanks.

Title: Re: Recharging an electrochemical cell
Post by: onenameless on October 14, 2010, 06:36:17 PM

Yes, that would work if you attached some kind of battery to the two cells which will deliver electrons to the negative electrode and that will increase the potential again getting the same flow of electrons from the negative electrode to the positive electrode as it once was.