Leakage current of super capacitors with age?

[cupoftea]

Hi,
We all know electrolytic capcitors have lots of leakage current if they are left uncharged for over 2 years.
Does this same situation exist for supercapacitors?
You woudl think so, since they are basically wet electrolytic capacitors.
But nowhere tells of any significant leakage with time stored at full discharge...
eg

https://www.cde.com/resources/technical-papers/Supercapacitor-Technical-Guide.pdf

...reveals little about them being like electrolytics.

 

[ELECTRONICIENSENIOR]

https://www.mouser.com/pdfDocs/KEMETSupercap_Leakage_Selfdischarge-Q3FY18.pdf

Supercapacitors Leakage Current (LC) | Nippon Chemi-Con Corporation

www.chemi-con.co.jp

 

[cupoftea]

Thanks, for those, they show that leakage current in Super caps does decrease over time with voltage applied.

However, it would be good to have a comparaiosn of this effect with Alu electrolytic capacitors...but such a comparison exists nowhere on the web.

I used to work at a cap charger/discharger place, and we always had to be sure that our big 600V, 470uF Alu electrolytics were purchased absolutely fresh off the production line, and not a day later......does this also apply to the same degree with super caps......?

With Alu electrolytic caps, theres actually a danger that if you power them up after 2 years in storeage, they can actually blow up........is this the case for super caps to

Super capacitor = Electric double layer capacitor

 

[mtwieg]

I would not assume that supercaps will have the same issues as normal electrolytics. AFAIK the electrochemistry is very different. I would contact a manufacturer with these questions (and would not assume their response applies to all supercap manufacturers).

 

[cupoftea]

Thanks, it does tend to be the general rule though, that the higher the energy density you can get in a cap, the higher is its leakage current....that seems to be a general rule......eg, ceramics have the lowest leakage current, and the lowest energy density.

I suspect the reason that supercaps are such low voltage is because otherwise the leakage current gets excessive.