Hybrid supercapacitor offers NiMH energy density, charges much faster
newatlas.com
newatlas.com
This means that EVs of all kinds, could not only get crazy acceleration, but could also recover all the energy of regen. Even battery packs with a very good layout can absorb a fraction of the acceleration energy, and less or none when the battery is cold or at the upper range of capacity.
I remember reading an article about a porsche in a car magazine (many) years ago that discussed not the horsepower for acceleration but also the horsepower absorbed by the brakes to decelerate.
It might have been 500 horsepower to accelerate the car, but since the brakes were very good, it could absorb 900+ horsepower when bringing it to a halt.
http://st.motortrend.ca/uploads/sites/42/2017/02/2017-Tesla-...
The fastest braking from 60-0 is 16 meters (53 feet), according to https://fastestlaps.com/lists/top-quickest-stoppers-60mph
Using the physics calculator at https://www.calculatorsoup.com/calculators/physics/uniformly...
This gives a deceleration of 22.5 m/sec^2, or about 2.3 g.
I'm amazed it can go above 1 g, actually.
If you are the driver then being in control probably helps quite a lot. In a roller coaster you are always a passenger.
Years ago in Denver when they had F1 racing, I remember a news story about preparations the city had to do for the race, which included welding down the manhole covers. Because the amount of suction these cars make would pull the manhole covers off as cars drove over them.
Also, traction is more than just friction. There's a mechanical component to it, the scraping off of the rubber from the surface of the tire.
Also, as far as the 53 feet goes, remember that this car was extremely light, 1400lbs. The Tesla Model S weighs almost 5Klbs for comparison.
https://en.wikipedia.org/wiki/Chaparral_Cars#2J
Two fans adapted from a military tank engine were housed at the rear, driven by a single two-stroke twin-cylinder engine.
...
The skirting produced a zone within which the fans could create a vacuum producing downforce on the order of 1.25 to 1.50 G when the car was fully loaded
Maybe this sort of thing will make a comeback :)
That downforce drops to zero long before the car stops.
>Also, as far as the 53 feet goes, remember that this car was extremely light, 1400lbs. The Tesla Model S weighs almost 5Klbs for comparison.
It doesn't matter how much something weighs... the kinetic energy scales linearly with weight. The F-16 fighter can pull 9gs, and it weighs 20,300 lbs.
>It doesn't matter how much something weighs
Stopping distance is absolutely, 100%, impacted by the weight of the car.
Also, the power output of Li-ion batteries has gotten so high that the supercapacitors only offer power benefits for marginal use cases.
That said, while it's a completely and utterly different area, I've actually now experienced my first hybrid using equipment just a few weeks ago and it was pretty interesting: the latest Black Diamond avalanche airbag (JetForce Tour 26L). Avalanche airbags are now quite common safety tools for heavy snow back country or mountaineering, and in an avalanche can help keep a person from being completely buried (or at least keep them much much shallower). Fundamentally, they need to extremely rapidly inflate a significant volume with gas or air on demand, with long term reliability in standby, and while being part of a human portable backpack carrying other stuff and thus as light as feasible. It doesn't take much absolute energy, but inflating in a couple of seconds does take a huge amount of power.
The original ones used compressed air or small explosives, which obviously are consumable and present problems traveling by commercial air. They're also harder to test/practice with. Electric fan models came about like 5-6 years ago, but extremely high instantaneous power demands in this application meant big fat lithium ion batteries which are fairly heavy. Fine in a car, not so man portable.
The JetForce uses Alpride's E1 supercap design fan. The supercap can be charged off of USB or just a single pair of AA batteries in the field, and can hold charge for a good 2-3 months. It shaves a solid couple of pounds off the previous lithium ion design.
Anyway, niche application but it was pretty neat to me anyway to see some real practical gains come about from newer supercap work. I'll be curious if hybrid designs continue to make inroads in other places characterized by sharp power spikes with less overall energy demand.
If one could do both, that might be nice. But cutting charging time while maintaining most of the range makes more sense than having acceleration bursts to the wheels that never make it to the road.
It would be a buffered input to the battery no matter where the energy comes from.
EVs already use their friction brakes pretty rarely, so the potential gains aren't even that big.
If you want more power you can just put more batteries in parallel. Or use batteries with lower resistance (the flat ones).
As for gathering bursts of energy; Again the problem is energy capacity. The (potential) energy released by braking really hard is really high (per time).
You could use a flywheel battery for that. They can take it. They are even used in roller coasters just for that purpose (granted they use big flywheels).
Considering people usually break "softly", it is just not worth it.
Perhaps with some reconfiguration it would be possible in the future to give those old machines some additional oomph, as the discharge limit in their NiMH battery packs is way below the combined power of the two motor-generators(21kW vs 60kW).
Isn’t it a bit odd that no one talks about it? Though probably the fact is just that no one take stock Prius or Leaf seriously
I read that in the former case it's connected with the fact that the motor-generator attached to the sun gear has to start turning in the opposite direction to assist acceleration - the high-pitched whine of the inverter appears to support this theory.
As for talking about it: I guess people just assume all EVs have instant torque. I for one was surprised to learn that the Renault Zoe has a delay put there supposedly to emulate an automatic transmission.
The IONIQ hybrid on the other hand, which I've test driven, has to react like a regular automatic because the electric motor is sandwiched between the engine and the transmission. I was meaning to get it after my first Toyota hybrid got stolen, but the way it reacted to throttle input turned out to be a deal breaker for me.
So, no, this isn't useful for battery electric vehicles. Hybrids, maybe, for vehicles with an underpowered main engine and electric boost for acceleration.
... retaining 90 percent of their initial storage capacity after 10,000 full charge/discharge cycles.
So, not a good power supply filter either. 10,000 cycles of the power line rectified to DC is under a minute and a half.
There are applications for big pulsed power sources, but not that many of them. Flashguns for cameras. Aircraft carrier catapults. Nuclear weapons detonators. Railguns. Big spark generators. Most of the applications that need a huge power spike are military.
Consider weight and volume isn't a concern for Grid Scale Energy Storage I assume this is a good fit?
Not to mention for something like AirPod....... no more throwing them away due to absurd Battery degradation, at the expense or lower connection time.
This is absolutely useful for anything with a high momentary power draw. Even with the quarter of the energy density. These aren't going to supply all the energy, just the peak power. The main pack can be sized for slightly above the average power draw, and it can charge the boost pack that needs to get you up to speed or handle the surge current sink from braking.
Who would use a multifarad capacitor for filtering a rectified AC line? Why is this an argument? This isn't a capacitor, it is a battery with capacitor qualities.
I feel like the internet was built for arm chair generals to attempt to rain on parades.
The article says the energy storage is "mostly capacitive", so it's reasonable to compare this with ultracapacitors.
[1] https://www.forbes.com/sites/billroberson/2019/12/22/nawas-r...
If these were integrated into exiting lion packs, it would extend life while supplying much higher instantaneous peak currents.
Are batteries involved in this used in such a way that they undergo a full charge/discharge cycles for every cycle of the incoming AC power?
But as power delivery for drones and rail guns these could be game changing.
For drones I don't understand why supercapacitors with equal energy density would be beneficial? I don't own a drone, but is charge time an issue?
Whether it makes much of a difference who knows, but it may open up different chemistries or whatever.
There's been a few times I've driven by a car fire, and even from the opposite side of a divided 4-lane highway, the heat I felt was impressive.
Fire requires fuel, oxygen and ignition (heat). Liquid fuels require external ignition. Batteries do not. But you also have to pump liquid fuels around and generally handle them more to make them do work.
Batteries are more dangerous on a fundamental/conceptual level because they have everything they need to release their energy all at once. So we build them with hard casings for the same reason we build large safety factors into pressurized gas containers so in practice it doesn't really matter.
Batteries and liquid fuels aren't really better or worse than each other from a "much safety or "won't somebody think of the children" point of view. They just require slightly different engineering considerations for an equivalent level of safety.
This is directed just as much (ore maybe even more) at the parent comment as it is at you.
And cars have come along way in the ability to protect the occupants. That same protection measures can be applied to the battery compartment if necessary (steal roll cage, elastic restraint system, air bags). Yes, these things need to be thought about, and yes we do have agencies such as the NTSB and insurance standards that will solve the problem.
Look up the definition of an explosion. I’m super excited about super capacitors - I think they are going to be required in order to make electric cars truly feasible - but the concerns around the safety of them should be dismissed just because they might hold up progress!
I'm dismissing these concerns not because they might hold up progress but because they're well withing what Donald Rumsfeld would call a "known known" of engineering difficulties.
That isn't to say gasoline isn't dangerous. However it isn't quite as dangerous as you seem to think.
Many people will stop only for fuel every 3 hours, and try to get everything they need to do (restroom, buy snacks, eat...) in the amount of time it takes the pump to fill the tank. This isn't a good idea, but it is what people in the real world do.
Gas cars don't have the advantage of being able to charge overnight when you're sleeping, or during the day when you're in meetings or hacking away on something - so in this sense, it's a solid 'pro' for electric vehicles.
It would be pretty easy to setup large scale energy buffers at the equivalent of an electric gas station - from stationary li-ion battery banks, to flywheel energy storage, to supercaps - if spikes were a major issue.
With California (and others) having excess capacity during the day due to Solar, it also allows better arbitrage opportunities, though not clear it would offset the costs.
You have to provision vehicles based off outlier usage (I've used zipcar, normal car rental services, etc. - they are terrible during exactly the times I would need them most, like holidays and months it's good to travel or visit somewhere, and are not reliable), and try to not ruin too badly your 90% pctile usage efficiency while doing so.
If a vehicle is a huge hassle (or impossible) to use for what I'd want to do 5% of the year, I either need a second vehicle for that 5% of the year (even more expensive and maintenance heavy), or a single vehicle that can cover 100% of my usage.
It shouldn't take hours to charge with specialized stations. Sure, the capacitors will give you a charge in minutes, but a supercharger station will give you a charge in about 1-1.5hr. Timing that with bathroom and food breaks should work well.
The capacitor charge stations would need to be more numerous for the decreased mileage. And with the ability to charge at home except for road trips, what makes that model viable?
Edit for sidenote: wilderness areas don't allow motorized vehicles, so maybe that doesn't matter.
Even here in overdeveloped California, the majority of the Sierra Nevada and Northern Coastal range easily counts, as does the ranges in the Mojave.
Federal wilderness designation is an administrative one to apply certain rules to a portion of federally controlled land, not a classification of the remoteness of something or a statement of how untouched it is. Technically the moment you step off Yosemite valley floor you’re in federal wilderness - try to not get distracted by the 1500 tourists staring at you or the 10 giant busses idling in traffic 100 feet away.
The area immediately around the roads are not wilderness in Yosemite, according to their maps.
The charging rate is limited both by the charging controller on the car, and the controller on the charging station. The standards for both of these are developed in consortia that include representatives of utilities and grid operators, so these things get taken into consideration at a very early stage.
> Unless you limit the rate, but then what's the benefit
Yes, as you say, specialized stations that have a buffer between themselves and the grid.
Also, regenerative braking requires storage systems to absorb much higher instant power than plug in charging. If the round trip efficiency of these is better than existing battery tech, that would also improve overall range.
> but then what's the benefit?
Braking and fast charging.
I'm not sure if I believe the above, but it is a good argument.
Over all, I think supercapacitors will be a good option in the future, but not at the current energy density. Especially if they're relying on graphene and the fast charging will essentially require a second one to act as a buffer for the grid.
Again, really good discovery, even if capacity is not on par with current batteries, making it practical would allow for more reusable energy storage.
Not saying it should preclude them from use; indeed I think super capacitors are the only thing that will make electric cars acceptable. Just saying that it’s something that needs to be addressed as part of their design.
Huge amounts of energy that have the potential to be released instantaneously should ALWAYS be respected/considered and not glossed over, especially for something intended to be deployed widely in vehicles where accidents/physical destruction does happen.
You said everything and I am sure they will come up with some technological way how handle discharge in case of accident, in case capacitor batteries become a thing.
I know they are talking about feed back from very large multi-phase motors but...
I wonder if they could leverage the power from electrical storms? Literally lightning in a bottle?
Yeah ok cool, join the giant pile of revolutionary battery designs and remind me when it's a physical product, tested, verified and ready for mass production.
https://cleantechnica.com/2020/02/19/bloombergnef-lithium-io...
There's a long road between the lab and production, but having all this cool stuff in the lab suggests that the long-term trend can continue for a good while.
https://data.energizer.com/pdfs/l91.pdf
But the problem isn't just capacity its maintaining the traditional zinc-carbon voltage profile. There were a bunch of much higher capacity Li/AA batteries from various manufactures that used buck converters inside the "cell" but they have fairly short lifespans, and efficiency loss due to the electronics.
For a lot of cases, companies just abandoned the AA form factor and embedded a rechargeable battery.
https://ceramics.org/ceramic-tech-today/energy-1/pursuing-a-...
> ...the Democratic Republic of the Congo (DRC), a country that produces more than 60% of the world’s cobalt. A significant amount of cobalt in the DRC is mined by children...
Then, the whole of world's refining, and relevant battery chemical industry is in China.
The parent’s linked article claims that a significant amount of the largest cobalt producing area is mined by children. The source article states that industrial-scale output dwarfs the production of the more than 100,000 so-called artisanal cobalt miners which include an unknown number of children.
I can’t say that I’m not saddened by thinking of kids, mine or others, mining for a living. The first image that comes to my mind is b/w pictures of Welsh coal mining kids. Stepping outside of my frame of reference, I can see the set of interests that bring about children mining in the DRC.
Congolese activists working to end child labor say poverty has driven up the numbers. “Because of the economic crisis, there are about 10,000 of them,” says Hélène Kayekeza Mutshaka, who coordinates a monitoring program in Kolwezi that the government began last year, to try to stop children from mining cobalt. Mutshaka says she faces strong resistance from poor families, who have long sent their children to dig for minerals in order to supplement their meager earnings. “They believe they can try to make it into the middle class if they work as artisanal miners,” Mutshaka says.
I’m less sanguine than the article about getting less child labor by moving on from cobalt. The likely scenario is that the industry moves to another similarly rar-ish element and the child miners in DRC move in to another hazardous occupation since the perceived rewards outweigh the risks.
0. https://fortune.com/longform/blood-sweat-and-batteries/
1. https://pulitzercenter.org/reporting/blood-sweat-and-batteri...
Very well put, and often overlooked. As is the road to actual viable commercialization.
Every time this happens I swear it is a glitch in the matrix or something.
Anyone know if any product with graphene as a main component ever been mass produced?
So I imagine that is not a huge issue.
[1]: https://onlinelibrary.wiley.com/doi/10.1002/adma.202004560 (pdf at the bottom)
When many labs will efficiently produce graphene, we will have made a step towards small-scale industrial production. Not yet, AFAICT.
Basically, every few months, a company comes out with claims that battery tech or e-waste has been revolutionized, but it’s always a bunch of bunk claims made using a multitude of weasel words.
Revolutions do happen, of course. But incremental improvement is both necessary and often overlooked.