High-density hybrid powercapacitors: A new frontier in the energy race
newatlas.com
newatlas.com
If you're highway bound often this may mean faster decay of battery throughout the decade because of which side gets cycled.
Although I was under the impression that the impact on lifespan is much greater the deeper you cycle the batteries, so it might be better to be perpetually topping them up.
You make me wonder if it would be better to charge every hundred miles in your 250mi range rated EV as a way to preserve long term battry health on a long interstate road trip.
EDIT: Maybe they could partner up with the capacitor-electrode-made-from-Durian people? https://arstechnica.com/science/2020/03/super-stinky-durian-...
Have a comparatively small capacitor sit as a "battery cache" for short (5-10 second) bursts of acceleration, and let the battery be the slow but efficient & steady main energy store. This would mitigate many potential downsides to capacitors (e.g. cost, leakage, energy density, etc etc).
Once you have enough battery cells, a large power draw (acceleration) or power feed (charging, deceleration) becomes a very small amount of current for each cell.
Acceleration today is mostly limited by available traction. It's not at all clear that a liveable car could get appreciably faster acceleration than we have today without a breakthrough in tire technology.
That should provide lots of traction.
Problem with wings is that they not only add drag but they are not affecting anything at launch. Maybe if you had a big electromagnet under the car and a steel path under the asphalt.
1. https://jalopnik.com/brabham-bt46b-fan-car-making-lemonade-f...
You get into the limits of being able to transfer the rotation of the axle to the tire patch.
Mental picture time, if you will: 1. Axle spins, which rotates the metal wheel |> since the metal wheel is metal to metal with the axle, we will consider it to be one unit, even though technically, it is not
2. Metal wheel rotates the part of the tire near the rim |> There is only so much force which can be applied to join the tire's bead to the metal of the wheel. "Bead locking" can be done, but this is esoteric and, at least in the US, is mostly not legal for road-going vehicles. Also, the amount of space necessary for bead locking components is a complex challenge for the passenger car wheels, and is usually reserved to far larger wheels found in off-road-like vehicles.
3. The tire rim has to transmit the rotation to the tire contact patch, which happens via the tire sidewall. |> This sidewall has to stay flexible otherwise the ride would be nigh impossibly jarring. Check videos of sidewall flex of drag tires for a practical example of this, a-la https://youtu.be/rw3LE78gwhg
There are plenty of other things in play, top, but these are the big limiting factors.
I believe with EVs, traction is not as much of an issue because the computer can adjust the torque output 1000 times per second, unlike an Internal Combustion Engine which takes eons to react and change it's power output. Obviously off the line it is, but certain as you get moving more you can dump a lot of torque into sticky rubber.
Tesla are having a "battery day" soon, and I for one suspect their new batteries (maybe just for the new Roadster, maybe for all their cars) will be some kind of hybrid capacitor, or at least have some of their capacity does that way.
Now I'm wondering what Elon will name his coffee roasting company.
Except it hasn't, because the production version does not exist. I don't even think the 1.9 second claim has been verified for the prototype.
I'm extremely excited, but as you said, it's still ~9 months away from being sold.
The problem I've always seen with supercapacitors is that their leakage current usually seems to increase as their ESR drops. So as they gain the ability to charge/discharge quickly, they lose the ability to hold charge over time.
I wonder if there are ways to mitigate that, but there are other problems like poor handling of high temperatures and mechanical vibrations / shocks; both are difficult tradeoffs for automotive parts.
They are proven solutions for buffering energy in EVs, but it's harder to justify the cost/weight in light passenger vehicles. That's why hybrid solutions like this are exciting.
These look cool - does anyone know if they have two or four dielectric layers? I can't quite tell from the article. IIRC Supercapacitors use four while traditional capacitors use two, and I feel like the self-discharge/ESR tradeoffs of supercapacitors might have a lot to do with the finnicky EDLC technology. If they've managed to make traditionally-structured capacitors with the Farad ratings of supercapacitors, that would be very cool.
Really only a problem for hybrids with only 8-16 cells. Power density of any serious EV battery pack is enough to melt car's motor.
Outside these two conditions, the only other thing is age, other than that, they tend to not explode.
source: https://www.vishay.com/docs/49268/tn0003.pdf other source: at $WORK we are having some problems with igniting tantal caps
A short dumps a pile of current across the capacitor. an open circuit usually just means your circuit doesn't work well.
Don't use tantalum without a careful plan to deal with this issue... why are you forced to use them instead of a modern electrolytic?
The reason is a mismanaged project. Power budget on a CR2032 is tight and initially a supercap with much bigger capacity was planned. The company producing those went out of business and people were forced to somehow get it to market, working. We did, but now those new tantal cap problems arrived.
I turn around and see my two class mates looking shocked and confused, covered in fine fur all over their upper bodies, along with the desk.
Never got around to understanding just how they managed it, but they most certainly did manage to blow up that capacitor in a spectacular way.
While they look fairly harmless, one should also never forget that capacitors are the most dangerous part of any electric circuit; they don't become safe if power is off and they have no limit to their current other than "what the wire can do", which is usually northwards of "the wire evaporates".
I've experienced various caps burn their legs and solderpoints in less than a millisecond without warning once a short was realized. And on top of that, the huge currents running through wires not intended for that will usually cause quite a bit of inductive backlash in nearby components.
I'm pretty much convinced this was not a mistake, it was a "Be really CAREFUL with this stuff!" object lesson.
Purposefully weakening the container can bring this sort of behavior out at lower levels.
Gasoline is flammable, but it needs the right fuel air mixture to actually explode. Car fires are relatively common, but as far as I know car explosions are not.
So, yes, they can explode. That's actually pretty much the point.
(I do not believe this will actually be a primary impediment to adoption of either Lithium Ion or Super Capacitors)
The Tesla battery stores 272 Wh/kg and produces 207 W/kg.
So this suggests the hybrid capacitor would charge 1.4 times faster.
Next question is the price, the article doesn't give a straight-forward answer other than that it's significantly more expensive. In theory (no hard proof) the hybrid capacitor would last longer.
Regardless, a promising development.
From the article:
> The power-focused variants were delivering densities of 80 and 100 Wh/kg, and were charging and discharging at 10 and 20C.
I don't think it is Celsius, and Coulombs (which would be the correct SI unit) doesn't really make sense. Some number of Amps would make sense, but 10 or 20 isn't very impressive.
Does any one know?
https://batteryuniversity.com/learn/article/what_is_the_c_ra...
[1] https://en.wikipedia.org/wiki/Battery_(electricity)#C_rate
After so many disappointments, I'm down to "Let me know when I can buy one at Fry's, until then, I am not holding my breath."
See their specs page[0] for energy density. 236 Wh/Liter compared to 250-730 Wh/Liter in Li-ion.
They would probably make arguments about cooling requirements damaging that value for Li-ion at pack scale however.
This company claims a hundredfold improvement in capacitor capacity! And yet they also claim to be drop-shipping from a Chinese company I cannot find anywhere but their website. Where is the Chinese media to stump for what would be quite possibly the greatest discovery in China since gunpowder? Where are the physics papers discussing the necessarily entirely new mechanism of storage in this device?
This situation is extremely suspicious.
_Theoretically, these power capacitors could be wrapped up into a big battery pack and used to power a long-range, super fast charging EV. The high-power versions can charge to 75 percent in five minutes, for example. But Verhulst doesn't believe this tech will flood the automotive market. "You need a charger that can handle it," he tells us. "A 10 kWh pack charged in five minutes means you'd need a 100 kW charger. If you then go to the big ones, say a 100 kWh battery, you'd need a megawatt charger. That's a lot. That's a whole power station. So scalability is still an issue."_
Using them in the grid itself is an even bigger aspect, either for simple storage that can act as a peak power plant or to act like a high frequency energy trader.
If these capacitors have lower internal resistance (and it sounds like they do) and last reliably for 10 years... yeah, I can see these being a next generation alternative to battery based storage at the grid level.
If they can manufacture them in a rectangular plate kind of form factor like a cell phone battery, I imagine there could be a huge benefit there. I think people would pay a premium to be able to charge their phone to last for 10 hours in 12 minutes (50C charging rate).
This is exciting. That they're in production and being tested by outside partners is a huge validation point that this is real.
Isn't that why the batteries have active cooling systems?
Mouser and other distributors even have a category for them: https://www.mouser.com/Passive-Components/Capacitors/Superca...
Sort by price descending to see some of the more interesting ones. The cheaper ones are still called supercapacitors but the delineation becomes a little meaningless at that range since regular capacitors have also improved significantly.
Edit: fix link