Chemical Forums
Specialty Chemistry Forums => Other Sciences Question Forum => Topic started by: cestlavie on May 23, 2013, 10:47:41 AM
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Hello guys, I am a microelectronics student and I've recently started learning about supercapacitors and their principles for an internship im doing right now and I had trouble understanding the seperator which is a porous membrane and its main function is to stop electronic conduction between the capacitor electrodes and prevent a short circuit but allow ionic conduction.
So if it is ion permeable why does it stop electrons from passing through as they comparatively smaller than the electrolyte ions. Most of the commercial seperator membranes right now are made from cellulose derivatives or porous polypropylene.
Does it have to do anything with the material properties of the membrane? or is it something else?
and sorry if this is a newbie question but I'm having a hard time figuring how this membrane works!
https://en.wikipedia...yer_capacitor-->basic idea of supercapacitor working mechanism.
Any help would be greatly appreciated.
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Generally speaking there is no such thing as freely floating electrons in water solutions.
(Well... solvated electrons do exist, but they are quite unstable, so in typical situations all conduction is through ions).
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Hmm thanks for that Borek, I did not know about the stability of the solvated electrons. Could you name some books or some good links from where I can learn more about this?
You mentioned that in typical situations only ionic conduction exists. So there can be a minute probability that this is not true in a special situation?
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Sorry, I don't have much more info, you will have to google for that. All I remember at the moment is that half life of the solvated electrons in water is several orders of magnitude below ms. They are quite stable in ammonia.
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Allright I'll start googling about it . And thanks again!