
High-density hybrid powercapacitors: A new frontier in the energy race - bornelsewhere
https://newatlas.com/energy/toomen-powercapacitors-kurt-energy-high-density-supercapacitors/
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easymovet
You don’t need a power plant to charge, you just need a bigger capacitor
sitting at the gas station that’s been filling up for a while and ready to
dump into your car.

~~~
moneytide1
And then you'll leave the station and stop/go/hills/regen further "flexes" a
similar dedicated powercapacitor bank onboard (separate from the Li/Co/Mn/Ni
long term reservoir which is expected to contain thousands of cycles whereas
capacitors are tested in the millions).

If you're highway bound often this may mean faster decay of battery throughout
the decade because of which side gets cycled.

~~~
AtlasBarfed
I thought brake regen to battery was already really high efficiency. Hm,
apparently it's 60-70%. capacitors might add a couple percent but I bet
there's inevitable heat loss from running the motor backward.

~~~
strbean
I think parent is more getting at component lifetime. Every charge/discharge
on the batteries is a bit of their lifespan gone.

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.

~~~
moneytide1
Yeah deeper cycle reduced life - highway static travel speed would idle
onboard capacitor bank.

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.

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solstice
They write that they'll be at the Battery Show 2020 in Stuttgart (28 to 30
April, Booth C229.): [https://kurt.energy/visit-us-at-the-battery-
show-2020-stuttg...](https://kurt.energy/visit-us-at-the-battery-
show-2020-stuttgart/)

EDIT: Maybe they could partner up with the capacitor-electrode-made-from-
Durian people? [https://arstechnica.com/science/2020/03/super-stinky-
durian-...](https://arstechnica.com/science/2020/03/super-stinky-durian-fruit-
could-charge-your-cell-phone-someday/)

------
Scene_Cast2
From what I keep hearing, current EV acceleration is limited by the battery
discharge rates. I haven't seen anyone talk about creating a multi-tiered
(hybrid) battery.

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).

~~~
djrogers
> From what I keep hearing, current EV acceleration is limited by the battery
> discharge rates

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.

~~~
etaioinshrdlu
Can't the tires just continue to get wider and wider until the rear tires are
even about 4 ft wide?

That should provide lots of traction.

~~~
culopatin
But friction is dependent on the pressure between the contact patches. More
area of contact reduces the pressure per unit of area. So you’d need more
pressure on said tires without augmenting mass (because then you’d need yet
more friction to accelerate that mass, that’s why wings are a thing, more
pressure on the tires without adding mass that you’d have to turn accelerate.

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.

~~~
magicalhippo
Just pack a giant fan onto it, kinda like an up-side-down hovercraft.

~~~
LargoLasskhyfv
Why not going full hovercraft? Use the obsolete tire technology only for
transition and slow speeds, thereby eliminating all that rubber dust!1!!

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bestouff
They say in the intro that capacitors don't explode. My past time as EE
student tends to prove otherwise.

~~~
zaarn
Usually a cap blows it's top if you either exceed it's voltage rating or it's
polarized and the voltage on the pins is the wrong polarity.

Outside these two conditions, the only other thing is age, other than that,
they tend to not explode.

~~~
zwirbl
Tantal capacitors can actually start burning

source:
[https://www.vishay.com/docs/49268/tn0003.pdf](https://www.vishay.com/docs/49268/tn0003.pdf)
other source: at $WORK we are having some problems with igniting tantal caps

~~~
neltnerb
Tantalum capacitors break to form a short while essentially any other option
breaks and becomes an open circuit.

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?

~~~
zwirbl
I am in the lucky position to develop the firmware for the device / not being
the electronics guy

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.

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scandum
If I read the article in the worst possible way it suggests the hybrid
capacitor stores 260 Wh/kg and produces 300 W/kg.

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.

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nickcw
What does C as a unit mean in this context?

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?

~~~
mmastrac
"A C-rate of 1C is also known as a one-hour discharge; 0.5C or C/2 is a two-
hour discharge and 0.2C or C/5 is a 5-hour discharge. Some high-performance
batteries can be charged and discharged above 1C with moderate stress."

[https://batteryuniversity.com/learn/article/what_is_the_c_ra...](https://batteryuniversity.com/learn/article/what_is_the_c_rate)

~~~
pixelbash
Racing drone batteries can be charged around 4C and discharged at close to
100C (Unsure how many of those C is marketing), but then I think they safely
qualify as high stress..

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aurizon
Something seems fishy. Capacitors voltage versus charge conforms to the
equation C= 1/2 _C_ V*V with half the voltage you have only 25% of the charge
remaining! With a battery, you have the 2 half cell potentials that sum to the
rated voltage. As you discharge, this is a flat line voltage until the charged
element is depleted and it goes to zero, (discharged). This has the ring of a
scheme to get investor $$

~~~
mikevp
Agreed. Stories like this keep popping up, because this is something the whole
world desperately needs. EEStor was one of the previous claimants to the
title, but they flew by night.

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."

~~~
aurizon
Can anything be bought at Fry's these days? I had heard they are in a serious
decline?

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pintxo
They did not mention volume, only weight. Or did I miss it? So they have a
good energy/weight ratio? But bad energy/volume?

~~~
nickparker
Yes that seems to be the trade-off.

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.

[0]
[https://kurt.energy/products/products_cells/](https://kurt.energy/products/products_cells/)

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jacknews
extraordinary claims

~~~
scythe
Not only that, but this article shows a major warning sign of a fake
breakthrough: [massive] understatement of the potential impact.

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.

------
overcast
Seems like an eternity we've been hearing/waiting for super capacitors to
become a thing. They seem to be the final puzzle piece in EV adoption. Not
having to wait hours to "fill up" at the recharging station will be huge.

~~~
solstice
The article talks a bit about this, and fast charging seems to bring some
problems with it, though:

_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."_

~~~
ricw
Electrify America / ionity / Tesla superchargers these days already output
250-350kWh. You could also use those super capacitors in the charging station
itself to level out demand.

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.

~~~
neltnerb
Battery backed renewable power is competing primarily with natural gas in
being able to absorb and release power. They have to last 10-20 years.
Batteries heat up when you charge or discharge them, which causes lifetime
decrease and efficiency losses.

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.

~~~
vardump
> Batteries heat up when you charge or discharge them, which causes lifetime
> decrease and efficiency losses.

Isn't that why the batteries have active cooling systems?

~~~
neltnerb
Yes, which in any fair analysis decreases their efficiency.

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gok
It's weird for someone selling an ostensibly breakthrough EV energy storage
system to say that he's mostly focusing on plugin hybrids. Batteries aren't
the major contributor to cost or complexity in PHEVs.

~~~
AtlasBarfed
But if the cost is higher than lithium battery cells, their better discharge
rate, (perhaps) regen efficiency, and cycle advantage would justify the
premium in hybrids.

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baybal2
Here is the actual manufacturer:

[http://www.sztoomen.com/](http://www.sztoomen.com/)

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jansan
260 Wh/kg sounds really impressive. I will keep an eye on this technology.

~~~
at_a_remove
EEStor was claiming 385 for that particular metric, over a decade ago. Has yet
to pan out.

~~~
aidenn0
EEStor was lying through there teeth and never allowed anyone outside the
company to directly measure ED, just gamable proxies for ED (such as
capacitance).

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candiodari
Lithium batteries don't explode. They melt down and then catch on fire when
pierced. You have plenty of time to get away, just don't get stuck right next,
under or above them.

~~~
jacquesm
Depends on how well encased they are. They can definitely build up enough
pressure to explode if internally shorted and not pierced.

