DIY Supercapacitor Using Kitchen Materials

Robert Murray-Smith makes lots of different batteries so if you are interested in batteries, exploring his videos is enlightening.

In this one, he makes a supercapacitor. It is hard to follow the audio as the sound is low, but hang in there. It starts with “chalk talk” then moves to the lab. He starts with using a zeolite as a super electrolyte, (clay paste) then moves to seaweed (think sushi nori from the Asian grocer), then ends with a home made emulsion of sugar, salt, water in oil with a drop of emulsifying agent. Dish soap in this case. But I can’t help thinking that sounds a lot like cake frosting…. mostly fat with some salty sugar water emulsified into it. Vanilla anyone? Or a bit of egg yolk as emulsifier.

This is spread thinly on electrodes. First aluminum foil for the seaweed, then a stainless steel mesh for the “frosting”. Starting near pf theoretical ranges, he ends at about 0.3 Farads at about 1 Volt.

I find myself wondering if a bit of tissue paper would standardize the thickness? He has videos about a “hemp battery” that looks rather like a hemp carbon mat supercapacitor, and searching on hemp battery finds a lot of hemp supercapacitor pages. He also has one where he wraps one plate of a lead acid cell in carbon mat and dramatically extends battery life cycles (from about 500 to near 15,000). For hemp, the bast layer under the bark, roasted for hours in a 350 F oven, makes a material about the same as graphene, or better, for making supercapacitor devices.

So perhaps a very thin hemp carbon layer smeared with emulsion between two plates?

This also has implications for biology, as our cells are oil and sugar/salt water devices. Makes a fella go Hmmmm.

He also made a kind of graphene ink (if I heard correctly) that may have been where he started. Here he shows the effect of coating an electrode with it. A 128,000 time improvement over a simple capacitor.

This is revisiting the strange capacitive behaviour of graphene ink as a possible solid state storage device – here we use PET and concentrate on the plate material that doesn’t exclude the exotic dielectric materials to get further performance increases from this device.

Are hemp batteries about to change the world?

According to, fibres from hemp may have just as much energy storage capacity as graphene, an atom-thick material that can be made into electrodes. Graphene has been the favourite choice for use in supercapacitors.

Supercapacitors have the ability to charge up in a matter of seconds, unlike traditional rechargeable batteries that can take hours. They also have a large capacity for energy storeage than traditional batteries.
By heating the hemp fibres for 24 hours at 350 degrees Fahrenheit, scientists were able to produce carbon nanosheets, which was then used to build supercapacitors.

Fully assembled, the devices performed far better than commercial supercapacitors in both energy density and the range of temperatures over which they can work. The hemp-based devices yielded energy densities as high as 12 Watt-hours per kilogram, two to three times higher than commercial counterparts. They also operate over an impressive temperature range, from freezing to more than 200 degrees Fahrenheit.

Small-scale manufacturing of the hemp-based supercapacitors is due to begin soon.

Which points to a article.

His team found that if they heated the fibers for 24 hours at a little over 350 degrees Fahrenheit, and then blasted the resulting material with more intense heat, it would exfoliate into carbon nanosheets.

Mitlin’s team built their supercapacitors using the hemp-derived carbons as electrodes and an ionic liquid as the electrolyte. Fully assembled, the devices performed far better than commercial supercapacitors in both energy density and the range of temperatures over which they can work. The hemp-based devices yielded energy densities as high as 12 Watt-hours per kilogram, two to three times higher than commercial counterparts. They also operate over an impressive temperature range, from freezing to more than 200 degrees Fahrenheit.

“We’re past the proof-of-principle stage for the fully functional supercapacitor,” he says. “Now we’re gearing up for small-scale manufacturing.”

Though I’m sure there is a “some assembly required” issue…

Here’s the one where he shows how to upgrade a simple lead acid battery (and with much better sound):

Robert Murray-Smith
113K subscribers
An Ultrabattery is an Australian invention that is a mix of battery and supercapacitor designed to improve the qualities of lead acid batteries. They are stunningly easy to make and in this video I show you how. You can buy materials for your own experimenting from our webshop at

I like his attitude about risks ;-)

So as someone thinking about DIY power storage, I find these advances very interesting. From a simple lead-acid upgrade for very extended cycle life, to ultracapacitors made from farm waste and “frosting”, it looks like the science is still not quite settled ;-)

Then the notion that plant black carbon ink can make supercapacitors is rather shocking, as we’ve had carbon black ink and metals for thousands of years. One wonders if the archeologists looking at the Bagdad Battery looked for a carbon black layer?

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
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23 Responses to DIY Supercapacitor Using Kitchen Materials

  1. E.M.Smith says:

    Found out what that grafoil is that he uses:

    Graphite based foil…

  2. cdquarles says:

    Re: cells being super capacitors, consider that the across the 20 nm or so cell membrane, the potential is 40 mV, if I am remembering correctly; and that is from transporting as few as 4 ions (potassium in and sodium out).

  3. E.M.Smith says:

    This one is also interesting. He demonstrates making 2 different supercapacitor types using a nearly trivial method. Conductor sheet coated in a solution of goo, (activated cabon in acetone with binder ) with a bit of paper between them with salt water on it.

    I now have this urge to make one of a few feet cubed :-)

  4. E.M.Smith says:


    Kinda makes you wonder about all those ion channels and pumps, eh? Cells as electrochemical factories wrapped in supercapacitor interfaces…

    In this video, he remanufactures paper towels into supercapacitor paper by adding activated carbon and graphite. Lay it between two conductors and add salt water, get full Farads in a few cm^2. Just amazing.

  5. E.M.Smith says:

    Just OMG crazy. I don’t know what is in his magic ink, but this is crazy. He says “all carbon” so I suspect some kind of graphene or activated carbon, but really… Paint ink on two sides of paper, dry. Apply salt solution electrolyte, lay conductor on each side. Charge 10 seconds, run a 200 ma motor for almost 2 minutes. That’s amazing. That it goes start to end real time in minutes is crazy time amazing. They sell you the ink if you want to play too…

    Energy density better than lead acid…

    Might be interesting to make hemp paper and hemp activated carbon ink, then sell gizmos to the Whole Earth crowd ;-)

  6. Larry Ledwick says:

    They have used carbon based inks in electronics for at least 60 years. That is how the Victoreen company made their super high resistance resistors for radiation detectors.
    ( 2.2 x10^8 ohms to 2.2 x 10 11 ohms) They put them across the ion chambers and used the voltage drop from the minuscule current to determine the ionization generated by gamma radiation in the chamber.

    It was a ceramic element with a thin coating of the carbon ink enclosed in a glass envelope.

    These were the radiation detectors I used to repair and calibrate for the Civil Defense program.

  7. cdquarles says:

    It doesn’t make me wonder that much, though; since I did study it. I have been saying for some time that embodied life’s chemistry is a redox electrochemical fuel cell in fact, with capacitance. That’s why irreversible cessation of metabolism takes at least 1 hour to happen. Physical unconciousness is not the same thing as physical death. It is a bit faster for the brain/nervous system because that pumping is time limited if the redox chemistry is interrupted (calcium poisoning of mitochondria via saponification of its membranes is just one mechanism and it triggers apoptosis, which is how growth and development in a multicellular organism happens); yet you are not dead until you are warm and dead (seen plenty of it). And the span of a man’s years shall be 120.

  8. jim2 says:

    EMS @

    Have you found somewhere the metals used as the “current gathering” pieces?

    Here’s a salt electrolyte battery design that’s quit old:

  9. tom0mason says:

    Here’s some guy called ‘lasersaber’ making his version of a ‘Easy DIY Graphene SuperCapacitors’ from scratch — grind your own activated charcoal …

  10. E.M.Smith says:


    He uses several, from aluminum foil to stainless steel mesh to the “grafoil” sheets where I linked to a maker for a description of what it was…

  11. E.M.Smith says:

    The benzene ring structure is described as having 1 1/2 bonds between the carbons in a resonance structure. I wonder if that means you can shove in electrons to the double bond level, or suck them out to the single bond level, and the resonance structure just adapts?

    Would explain a lot… and it is already happily delocalizing both double and single bonds… so clearly can spread electrons around.

  12. jim2 says:

    My first thought is there will be an electrolytic chemical reaction when the device is charged. In this case with NaCl, chlorine and hydrogen are produced. If these were somehow captured in the “carbon” part, it might be possible to recombine them in the battery mode.

  13. jim2 says:

    In the case of benzene, the 1 1/2 bond concept is an approximation. There is literally a quantum “conductive pipe” above and below the plane of the ring, IIRC.

  14. cdquarles says:

    What seems to happen with aromatic compounds is that the overlapping pi orbitals allow electron mobility, akin to the same overlapping orbitals allow electron conductivity seen with ordinary metals. The orbitals, themselves, being a mathematical probability ‘surface’.

  15. p.g.sharrow says:

    This is interesting. A bit different then my investigations into making High Voltage (40,000v) capacitors. and using gravity to warp the dielectric instead of voltage potential. Everything hinges on getting strong atomic warpage in the dielectric, Much like loading a spring without a short caused conductive break down in the dielectric. …pg

  16. LG says:

    For those who may be interested, here’s a link to all his supercapacitor videos.

  17. steven Fraser says:

    @p.g.sharrow: Sounds to me like dialectrical materialism ;-)

    Cool stuff.

  18. p.g.sharrow says:

    a little back ground on this

  19. LG says:

    @Steven Fraser:

    “Sounds to me like dialectrical materialism”

    My thoughts exactly.
    :D :D :D

  20. p.g.sharrow says:

    The more I think about the possibilities involved in the construction of a super capacitor the more intrigued I get. Generally you store energy in the warpage of the dielectric and utilize thin foil metal plates to store the “electrons”or charge bodies on it’s surface as there is no room in the metal’s crystal lattice structure. In a super capacitor the charge bodies are stored on the surface of the filler materials of the charged plates.
    The only need for an electrolyte is to improve the conductivity within the materials of each of the compost plates. The capacitance warpage is in the material of the separators. Relatively slow migration of the charge bodies in and out of a plate’s material would be a feature in this case….pg

  21. p.g.sharrow says:

    jim2 is correct the possibility of setting up a galvanic condition is always there in this sort of experiment. The use of salts, water with metals means at best a short life to any device created and I don’t think are necessary for the function of a super capacitor…pg

  22. Steven Fraser says:

    @EM: The info in these vids… very interesting. My rant: The presentations are difficult to watch and hear, for a few reasons:

    1) No close-miking, so ambient room noise is distracting.
    2) He has a tendency to place items in front of him, between the camera and pieces of apparatus, obscuring view of what he is doing.
    3) The camera placement is too far from the action, so items and motion in the background detract from the content. If the camera were 6 inches higher and 1 foot closer, it could have been angled downward to create a better view of him, and of the work on the table.
    4) Needs a 2nd camera angle. This would have helped to create interest, and clarity of what was being done on the desktop. I would have placed the 2nd camera just out of view, above the edge of the table (from our POV, the right side) at about 7′, and angled down. Alternatively, directly above the worktable at about 7′, facing straight down, showing the entire table.

    Stepping down from the soapbox, now…

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