Hybrid Supercapacitors Are — Well — Super

Kurt.energy is promoting a new line of hybrid supercapacitors. By itself, that wouldn’t be very newsworthy, but the company claims these graphene-based supercapacitors merge the best features of both supercapacitors and lithium-ion batteries. Based on technology from a company called Shenzhen Toomen New Energy, the capacitors are optimized for either high energy or high power. They can reportedly charge and discharge 10-20 times faster than lithium-ion batteries. Of course, we’ve heard wild claims surrounding graphene capacitors before and, so far, they haven’t seemed very credible.

In addition to high performance, the company claims the capacitors are safe from overcharging, short circuit, and other safety issues that plague batteries. The devices are said to operate — including charging — from -40C to 80C. You can see a video from the company, below.


Assuming this all proves out, it seems like the devices would open up a lot of new design possibilities. Designs would no longer need complex charging systems, active thermal management, and would degrade gracefully and safely.

New Atlas has a good write up where they interview the Belgian engineer who saw the Toomen devices at a trade show and after testing them brought them to market with Kurt.energy. According to that article, the capacitor uses a graphene electrode and a metallic oxide material for the other electrode. The energy storage is like that of a capacitor — there is no chemical reaction generating electricity.

The capacitors aren’t in full production yet. There are a few scaling problems with charging at such fast rates, too. According to the New Atlas article, a 10 kWh pack charged in 5 minutes would require a 100 kW charger. However, the new capacitors could have big implications for hybrid cars and solar. We also remember a supercap-powered bicycle that didn’t turn out very well.

With limited production, the price is still somewhat high although that is offset by the simplistic power management system required as well as the lower weight and size of the units. The safety, temperature range, and rapid charging might also tip the balance against traditional components.

Extraordinary claims require extraordinary proof, of course, and we haven’t seen these in real life. We will be interested to see if the components live up to the hype. We’ve seen graphene supercapacitors show up before and it still makes us suspicious. What do you think? Is this the next power revolution or just another wild claim?

36 thoughts on “Hybrid Supercapacitors Are — Well — Super

  1. I’ve got a cold fusion reactor here if you would like to buy it. 100MW and you can pick it up with one hand. I’ll give you a special price if you buy two.. :-)

    ie until someone actually has one, and tests the marketing claims, it could (and often is) be complete fiction..

  2. >Designs would no longer need complex charging systems

    As stated in OP, a fast charging circuit still have to be a high power power supply. If you want speed and efficiency, that has to be a switch mode capable of delivering huge amount of current into anywhere from 0V to the full voltage. Been there, done that.

    It is still a capacitor, so the discharge cure is not flat like a battery. To maximize the energy coming *from* the capacitor, your power circuit needs to be able to handle a wider range of input voltage than from a battery.

    So nothing much has change to simplify the support circuits. The only thing is that it *might* have higher energy density, longer life and a bit safer.

    1. The catch is that if all this was actually true, we’d see more scientific papers about it and here from every car/electronics company on the planet about how they’re implementing it as soon as they can.

      1. Well yes, but it includes things that you would expect to be true. Like that graphene can give you a conductive plate only an atom thick, therefore you might be able to cram square miles of it into a small package. Also one might expect that a metallic oxide could be sprayed/sputtered or deposited from solution on such a surface in very thin layers, and would have similar properties to ceramics.

        1. The most important words as far as development goes.

          Sadly also why a lot of cool technologies aren’t on the market… (sometimes different parts of the same tech is spread between different organizations that all want a too big slice of the cake….)

      2. Kilowatt Labs have supercapacitor units in 500w, 1kw 12v ,3.5 kw and 7.1kw.They are manufactured in Dubai. There are already hundreds of succesful solar applications all over South Africa. No need for huge charging units at all.They can be fully charged in 30min without heat issues. Lifespan is 40 years or 1 million cycles.

        1. There’s a difference between “Supercapacitors” and “Supercapacitors with the same energy density as lithium ion cells”. Kurt energy is claiming the latter; which would indeed be unprecedented, in that nobody has been able to do this yet. The press release doesn’t drop any names at the university of Munich, and the company called Toomen doesn’t show up at all on a web search.

          Literally everyone is trying to make a supercap with battery energy density, and we’re being asked to believe that there’s been one in production since 2018 from a company nobody’s heard of except this other company that’s apparently the sole user of their product.

    2. The catch is that this isn’t exactly better – they just make it sound good by omitting facts.

      For example, lithium batteries’ power density does not go down with their energy density – in fact they both increase, because the amount of energy per material goes up, so the relative internal resistance of the cell goes down. A higher capacity lithium-ion battery is able to deliver more power per unit mass and volume.

      Secondly, lithium batteries with comparable power densities already exist. The best types can be discharged at 50 C.

      Thirdly, a supercapacitor as an energy storage medium is absolutely bonkers because it’s a bomb. They behave worse than the worse li-poly batteries you might imagine, because storing energy in free electrostatic charges is inherently unstable. It also has very high self-discharge rate due to dielectric leakage.

  3. I’m always a bit cynical of “golden arrow” solutions. tekkineet already laid out the limitations that have always plagued capacitors as mass storage components. By the time you’ve had to add any balancing circuits, high current switching boost regulators and a monitoring circuit, you probably haven’t gained any simplicity. Supercaps are great for supplying massive current for short periods of time to “dumb” loads. They’re great for capturing energy surges to be transformed and used by other components. Their low rate of decay and subsequent resistance to chronic failure makes them ideal for some niche UPS applications…..
    But they’re lousy as a complete storage solution.
    I’d put the practical odds of them ousting active components, such as batteries or power cells, at nearly zero. They are likely to keep increasing their role of augmenting active power sources, but that’s where they’ll stay. That’s my six bits worth, anyway.

  4. If super capacitors are used with lithium batteries, surely the lithium batteries will still need a BMS. Hanging a bank of super capacitors off the side of a lithium battery is not going to remove the need for a BMS, so all the weight savings talked about in the video are just not going to happen.

  5. If this solves the plague of bulging caps (which mostly still exists because manufacturers are cheap), I’d be happy. I’ve got a pile of dead thinclients at work, all from one or two bulged capacitors that have died. I have neither the experience nor the steady hands to remove the dead ones and replace them. (They’re surface mount, which I have zero experience with)

    1. Mr Carlson of Mr Carlsons Lab on youtube had a good video showing how you can just twist the SMT caps off with no damage to the board.

      Then ypu can always just solder standard through-hole caps in their place, just bend the legs outwards at 90 degrees and snip them short to convert them to a makeshift surface mount part that can be soldered directly to the pads.

  6. Did not find anything about number of charge-discharge cycles, low temperatures efficiency, full discharge resistance and quick degradation in fully charged state – four main and awful drawbacks of typical rechargeable batteries. If that parameters are as low as for Lithium, there is nothing to see at all…

    As for power density and recharge speed, in any case, that properties of this invention are very far from methanol fuel cells, that was promised multiplie times by industry, but never hit the market due to unknown reasons (with small exception of Toshiba, but that device was also cut down very fast).

  7. Al Williams you should just stop writing articles all together it’s embarrassing. Hackaday when you want to hire someone to write these up for you that actually understands things go ahead and send me an email.

    “The energy storage is like that of a capacitor — there is no chemical reaction generating electricity.”

    These are HYBRID energy storage devices meaning there is a redox reaction at the cathode and a electrostatic interaction at the anode. There is a chemical reaction and an electrostatic one, and these have been around since 2003 meaning this “new technology” is complete bullshit.

  8. Hmm, wonder when this could be augmented for the home hobbyist to make their own, eg from a roll of butchers paper the size of a 1 metre tall cafe rubbish bin, that would pack a heap of charge. Starting with something like butchers packing paper with care I handling offers a cheap method and can be scaled up pretty straighforwardly to those 10m long several tonne newspaper rolls !
    Thanks for posting :-)

    1. Wow! I don’t believe it! Finally, after all these years… I once learned a fact, I thnk from an electronics kit I got as a kid. A very poor quality, rip-off one actually (Tree of Knowledge from Israel). But the book mentioned The Fact, which I haven’t been able to forget. It must be for now! It must be here…

      Did you know, that an ordinary paper capacitor of 1 Farad would take up the size of a kitchen?

      There! That’s it! You might have to actually connect a few in parallel if you’ve only got 1 metre sized paper. That’s fine though. Go for the farad! It will have a much better voltage capacity than 1.09V or whatever the pathetic little tubs are now. A real manly capacitor! And you can use foil from the kitchen for the plates, too.

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