Sciencemadness Discussion Board

Daniell cell secondary?

froot - 19-1-2011 at 00:36

This is something that's been bugging me to the point where I've looked, found nothing and I have to ask.
Back to the basic Zn-Cu cell and all the explanations on how it produces current flow while the redox reactions occur - fine.

But what stands in the way of it being electrically rechargeable?

There must be a crucial piece of theory here that I'm completely missing.

bquirky - 19-1-2011 at 03:44

Nothing.

They are rechargeable

But what happens over time is that the zinc electrode changes shape and looses structural integrity

Ive built one and cycled it about 20 times.

I found that the mossy bits of zinc fall down from the electrodes into the Copper sulfate and turn back in to Cu and Zinc Sulfate



[Edited on 19-1-2011 by bquirky]

froot - 19-1-2011 at 04:44

Fantastic. That was the only answer that made sense to me, thanks.

How did it perform? In terms of internal resistance, self discharge, comparative amount of energy it stored?

[Edited on 19-1-2011 by froot]

bquirky - 19-1-2011 at 05:20

yeah the internal resistance was quite high.

It put out about 100ma but it supplied that for hours and hours on end

oh and i made it in a 200ml beaker to give you some idea of size

[Edited on 19-1-2011 by bquirky]

froot - 19-1-2011 at 07:14

Great, thanks.