Sciencemadness Discussion Board

Supercapacitor/battery (RMS - murray Smith like) with AC powder and MnO2

RogueRose - 17-5-2017 at 20:18

I'm attempting to reproduce RMS's activated carbon super capacitor setup where he got outrageous energy in the little thing. Full writup with pics & video tro follow.

I know there is a thread devoted to the RMS battery but it seemed to stray and got a little off topic at places. I'm trying to see if his ideas actually work and what is needed to test them.

Here is a video on making a super cap from activated carbon and graphene (oxide).
https://www.youtube.com/watch?v=1Ce2au3PWnI

video 2
https://www.youtube.com/watch?v=ftAPXujssr8

I powderd some AC and filtered through a coffee filter - whatever passed through I kept for using in the cap. I did the same thing with MnO2 from batteries (washed 6-7 times) and everything that passed through the filters was kept. So all this powder is very fine, I don't know mesh size.

He seems all over the place when talking about binders, how much, which ones, etc. In one sentence he says 5-10% weight of the electrode material (AC or MnO2) whatever keeps it on and doesn't interfere with conductivity.

He mentions PVA and IDK if that is polyvinyl alcohol or acetate or something else. I've also read that ABS works (I'm assuming the plastic??). So I decided to dissolve this in acetone. I took 50g of acetone and 5g of ABS - stirred and heated until small bubbles emerged - then backed off. It has stayed in solution since.

He also made it seem like acetone could be used as a binder, but IDK, I didn't think that was correct, I thought it was the carrier to spread the carbon.

I'm using Al foil (I have regular and heavy duty - about 1.5x thicker). I've cut 1", 2", 3" and 4" strips in 12" lengths - 8 of each - for future tests. I plan on using toilet paper, napkin, paper towel or similar for the dielectric.

As for the electrolyte, IDK what to use. I'm thinking NaCl or KCl (I have both) as well as MgCl2, CaCl2, MgSO4, K2CO3, and lots of other things available. I'm open to suggestions. Preferably something that doesn't dissolve the Al (like KOH or NaOH)..


I've mixed some AC powder into a 10ml vial with 5ml acetone. It is a thin sludge now and I can move some to another vial and mix with the acetone/ABS mix as needed. I need to figure out how much AC I added, but probably about .7-1.2g for 5ml acetone (AC dust is super light and fluffy!!). I just don't know how much to add or mix - seeking suggestions.

As for the MnO2, I found that the powder adheres to Al beautifully in water (hot water even better). I found this out while boiling the battery MnO2 trying to clean it. The Al pot has a permanent layer of brown MnO2 on the surface and it only comes off with sand paper or steel wire brush. IDK if the Al reduces the MnO2 as it seemed to bubble slightly and give silvery glint around the bubbles. I think this means that no binder maybe necessary to bind the MnO2 to Al foil - thoughts?

As for charging and testing capacitance, IDK how to do that. I have a standard multimeter ($50 Southwire from Lowes) so it isn't great and some harbor freight cheapies. The video shows charging at 1.2v (dc I'm guessing). I can do this with batteries and variations of 1.2 or 1.5v with diff batteries. I also have 3.3, 5 and 12 from a computer PSU. I'm not sure what to use or if I can damage them by putting too high a voltage. IDK how to measure amperage or ATM but I know my meter does it.

If anyone can help cover some of the issues i'm having I'd be very grateful! I'll post pics and a writeup of everything and if the performance is anything like what the video show (4.2F @ 1.2v for a 1cm^2 area - which I have great difficulty believing!!!!!!!) then this could be SUPERDUPER awesome!!! I'm happy to prove it either way and have people review to see if I did anything wrong or could improve.

Thanks!!

floridajohnny - 31-5-2017 at 13:08

Rogue -

Excellent post and images - very helpful and full of intriguing ideas and concepts. I have to ask - do you have a zoom in of the mesh that you mentioned? I am not sure what to think of this mesh as you mentioned the powder passing through is "very fine" - Is this a metal wire mesh? Can you count the wires going in each direction as they mention here ( http://www.bwire.com ) as the measuring method of wire cloth screen?

A close up photo or video posting would be amazing - thanks!