EEStor Issued a Patent For Its Supercapacitor 603
An anonymous reader sends us to GM-volt.com, an electric vehicle enthusiast blog, for the news that last week EEStor was granted a US patent for their electric-energy storage unit, of which no one outside the company (no one who is talking, anyway) has seen so much as a working prototype. We've discussed the company on a number of occasions. The patent (PDF) is a highly information-rich document that offers remarkable insight into the device. EEStor notes "the present invention provides a unique lightweight electric-energy storage unit that has the capability to store ultrahigh amounts of energy." "The core ingredient is an aluminum coated barium titanate powder immersed in a polyethylene terephthalate plastic matrix. The EESU is composed of 31,353 of these components arranged in parallel. It is said to have a total capacitance of 30.693 F and can hold 52.220 kWh of energy. The device is said to have a weight of 281.56 pound including the box and all hardware. Unlike lithium-ion cells, the technology is said not to degrade with cycling and thus has a functionally unlimited lifetime. It is mentioned the device cannot explode when being charge or impacted and is thus safe for vehicles."
No, it's killowatt-hours. (Score:2, Informative)
Re: can hold 52.220 kWh (Score:5, Informative)
How do you figure?
The patent specifically mentions kW*H in reference to the 52.220 number.
I assume you were just trying to be smart and correct the summary thinking it was a typo. However, a kW*H is a valid unit of measurement.
In fact you could use them interchangably but it would give the very wrong idea as they measure different things.
A watt is one joule of energy flow over a second. so a KW would be 1000 joules of energy flow over 1 second.
A KW*H is a flow of a kilowatt continuously over an hour, therefore it would be a flow of 1000 joules over 3600 seconds.
So to recap:
1 kw = 1000 joules/sec
1 kw*h = 1000 joules/sec * 3600 seconds
If you were just going to measure the total energy usage, you'd have to keep it just in joules, in which case 52.220 KWH would be 187,992,000.
So yeah, big difference caused by little changes in notation. Of course i haven't done electricity in ages so i probably oversimplified somewhere and fubar'd up.
Re:Good enough for a couple days at home. (Score:3, Informative)
Only a couple of days? (Score:3, Informative)
Unless you have some seriously fucked up computer with hairdryers instead of heatsinks or a g'damned Cray as your desktop I can't see how you'd use that cell up in a 'couple of days'.
Check out the patent (Score:5, Informative)
A lot of cool data in the patent filing.
3-6 minutes charge time for 52 kWh. 286 lbs for that compared to 752 for a Li-Ion battery. And the Li-Ion takes 6h to charge.
Re:Use standard units, damnit! (Score:3, Informative)
Anyways, if you want it in those units, well:
52220 kWh = 155,416.667 GWnFn (gigawatt-nanoFortnights)
Re:Cannot explode but can be used in cars? (Score:4, Informative)
Re:Cannot explode but can be used in cars? (Score:1, Informative)
It's actually difficult to make gasoline explode- it needs just the right amount of air. Too little and it won't combust, too much and it burns instead of exploding. That's why you rarely see car explosions outside of movies- they may catch fire, but they won't explode.
By the way, you don't really want gas to explode in the engine either- that damages it. In fact, gasolines have a rating called knock which measures it's likelihood of explosion. That's whats measured by the octane of the fuel. Modern cars want very low knock.
Cannot explode but can be used in Fords? (Score:3, Informative)
It's only in Hollywood gasoline make cars explode with impact (or rather just before).
Sure they don't. [fordpinto.com]
Re:Use standard units, damnit! (Score:2, Informative)
If you are looking for Gigawatt Nanofortnights then the answer is 1.74x10^-11.
Interesting specifications (Score:5, Informative)
No one has noted yet that these caps also have insane *individual* unit specs! They're rated for 3500 V, have about 1 milli Farad and weight about *5 grams* each. This is absolutely unheard of. Normally you have to choose two from: small size, high voltage and high capacitance.
The energy that a cap contains is written as E = U^2*C, so it's obvious that scaling up the voltage gives you high rewards very rapidly. The problem has been that the insulating layers inside caps cannot handle high voltages without being made very thick. This means less capacitance since ideally the plates should be as large as possible and as close as possible.
The bill of materials looks nice too: Aluminum, Barium, Titanium, simple plastic. If they can actually produce the goods, this could be very cheap to mass produce.
If they can commercialise this, it *will* revolutionarise portable power (3500 V inside your iPod?;). But until they show a working prototype I'd hold my horses and not bet on this to solve our energy storage problems.
Re:Highly unlilkely (Score:1, Informative)
they would also need a breakthrough in matirials as the force exerted by the electric feild in such a small capacitor would rip it apart.
Re:Highly unlilkely (Score:2, Informative)
well, your calculations match the numbers that they show in the patent application.
they specificity are claiming a breakthrough in high voltage capability
Re:Comparison with gasoline (Score:5, Informative)
In their favour, an electric motor is much more energy efficient than an internal combustion engine. 20% seems to be the maximum for a practical internal combustion engine. Electric motors should easily be able to reach 90% efficiency, with the record being 98% efficiency [csiro.au]. Thus that 4.5 litres of petrol (1.2 US gallons of gas) becomes 20 litres. Not too bad for a first attempt, given that a small car (eg. Toyoto Echo/Yaris) typically takes 30-35 litres of petrol on a fill.
Yaris and their ilk aren't the model of efficiency in their design. Surely it wouldn't be too hard to make a Yaris type car use 35% less energy, resulting in a capacitor powered electric car with similar range to a petrol equivalent?
Re:52 kilowatt Hours? (Score:5, Informative)
TFA:
52.220 kWh of energy
A single car battery is about 200 watt hours. The batteries in the Tesla Roadster holds 53 kWÂh according to Wikipedia.
Now thats an interesting coincidence. I wonder if they just worked out how much capacitor would be needed for the power plant of the Tesla.
If they can bring it to market at the stated weight (130kg) it'll makes things very interesting. The Tesla's current battery pack weighs 450kg so you could triple its range. Or cut the vehicles weight by 25% (current weight is about 1200kg).
Re: can hold 52.220 kWh (Score:5, Informative)
It's NOT KW*H! It isn't kw either, nor is it kw*h.
It is however kWh, meaning kilowatt hour, and it is a unit of energy.
Start getting you units right, and capitalization DOES matter. M = mega, m = milli.
More details. (Score:2, Informative)
I've checked it out about once a week, for updates on it, but over the past year, it's heading towards vaporware.
Re:Cannot explode but can be used in cars? (Score:5, Informative)
A combustion event, aka 'explosion' occurs at the beginning of every power stroke in a reciprocating internal combustion engine. When an engine 'knocks' there is a combustion event as well. What makes it a 'knock' instead of a normal part of the power cycle is that it occurs at the wrong time. Knocking indicates perhaps a spark timing issue or the use of a fuel with an improper octane rating (which indicates resistance to knock). Octane ratings describe the resistance of the fuel to spontaneous ignition relative to a mixture of iso-octane (by definition Octane rating of 100) and n-heptane (by definition an octane rating of 0). Extrapolation is what allows for an octane rating of greater than 100. Diesel fuel has a similar concept, a Cetane number which indicates susceptibility to "spontaneous" combustion, since diesels use compression to ignite combustion events rather than an electrical spark.
Modern cars do depend on a much higher octane rating than historical vehicles. This allows for running on a much higher compression ratio and/or the use of turbo-chargers which allow for an engine that is thermodynamically more efficient (as compression ratio approaches infinity, thermodynamic efficiency approaches unity). This is one reason why diesels (compression ratios in the 20's rather than 5-10 for gasoline vehicles) get better mileage for a comparable vehicle/power output.
You are, however, entirely correct about the relative difficulty of causing a gasoline burn or explode. Only the vapor state is flammable and only at a narrow range of particle size.
Re:Highly unlilkely (Score:3, Informative)
Ok, I have not read tfa (in this case tfp), but I do know a bit about capacitors. Follow along with me here: You can calculate the energy stored in a capacitor (in Joules) by E = .5*CV^2 where C = capacitance (in Farads) and V = voltage, or
--> V = sqrt((2E)/C)
--> 3500 = sqrt((2*187992000)/30.7)
3500v is a lot. Up until now most comercially available supercapacitors do 5.5v or less and tend to leak energy over time. It's possilbe these guys have really made a stunning break through (the fact they filed for a patent is sure something), but the numbers set off my bullshit detector.
TFA (or TFP if you prefer) does indeed state 3500v. The patent also claims leakage of only 0.1% per 30 days. So, big claims. Hopefully they're for real. We'll just have to wait and see.
Instant stats (Score:4, Informative)
The stats are awesome for this if it's true. Here's a quick lowdown. Full stats are below (taken from PDF doc).
The weight is more than twice as light as Lithium Ion
The volume is 20% smaller than Lithium Ion
The charging time is 60x faster than Li-ion (15x faster than NiMH)
-----, EESU, NiMH, LA (Gel), Ni-Z, Li-Ion
Weight (pounds), 286.56, 1716, 3646, 1920, 752
Volume (inch^3), 4541, 17881, 43045, 34780, 5697
Discharge rate/30 days, 0.1%, 5%, 1%, 1%, 1%
Charging time, 3-6 min, 1.5h, 8h, 1.5h, 6h
Life reduced with deep cycle use, none, moderate, high, moderate, high
Hazardous materials, none, yes, yes, yes, yes
Re:52 kilowatt Hours? (Score:5, Informative)
That is an anemic car battery you have there... Take a car battery rated 12 V, capacity 60 Ah. This battery can keep up a current of 60A for about one hour (actual capacity depends on discharge rate, lower rate equals higher capacity - up to a point). 60A * 12V DC = 720W. It can do that for about an hour -> capacity 720Wh or about 0.72 KWh. The 12V battery in my tractor has a capacity of 180 Ah which roughly translates to (12 * 180 =) 2.16 KWh. It weighs some 60kg. This EEStor maybe-real-soon-now device has a claimed weight of 128 kg. You'd get about 5 KWh worth of Lead-Acid capacity for that weight, meaning this device - if it ever sees the light of day - has about 10 times more capacity per kg.
It's a lot better than that (Score:5, Informative)
Re:Cannot explode but can be used in Fords? (Score:3, Informative)
Inside the box is a 52,000 kwh electric charge. Huge difference there. The correct unit for magnetic field strength is Telsa btw.
Re:that's *nothing* compared to a tank of petrol (Score:5, Informative)
According to the great wiki god, ic engines average 18-20% efficiency, and peak at 37%; so a tank is between 100..210 kWh usable. Presuming the 18% is around city, and the more direct applicability of regenerative braking, the difference shrinks considerably.
Re: can hold 52.220 kWh (Score:3, Informative)
You misunderstood my flame. * is ok. But the letters are wrong.
k = kilo, not K
W = Watt, not w
h = hour, not H
Re:No, it's killowatt-hours. (Score:5, Informative)
Actually the watt-hour is a measure of (electrical, in this case) energy. It's an awkward convention, but it makes sense when you realize that Watts are equal to Joules over time and that multiplying time back in leaves you with Joules.
It's not so awkward if you consider typical domestic usages: since most appliances have power consumption in the order of watts and kilowatts, and typical usages are in the hour (not second) timescale, it's much more comfortable to use: after all, 1 J = 1 W*s, so you'd need 3.6 MJ to describe the energy consumed by a 1 kW boiler functioning for 1 hour ... much more comfortable to just say it's 1 kWh
Re:Energy density (Score:3, Informative)
True, but you can't turn kinetic energy into fuel-gas (i.e. regenerative braking), and your I/C engine is wasting >65% of the energy anyway, so as part of an overall system, energy density isn't the whole story.
Re:Entropy be damned (Score:3, Informative)
How many times you can charge/discharge a storage medium without it degrading is no way related to thermodynamics. Now if they claimed %100 efficiency, you'd have something to complain about.
Re:that's *nothing* compared to a tank of petrol (Score:3, Informative)
Not unless you have a small power plant just for that purpose.
Using 20A at 220V (typical maximum draw for a household) it'll take you 11 hours to charge.
Even if you somehow have infinite power available, you still have to account for the "interesting" requirements of high power densities. To charge in 1 hour, you'd need 200A. 6 minutes, 2000A. Doubt that's going to happen with any sort of manageable cabling. Switching to increasing volts (let's assume you can actually get such a supply from somewhere) you start having to deal with the interesting issues of high voltage feeds, such as arcing and proper insulation, not to mention safety.
Electric cars will never charge faster than their hydrocarbon-consuming buddies. Replacing the entire battery pack with a charged one sounds like a much more viable option.
Re:Cannot explode but can be used in cars? (Score:3, Informative)
The gas back then often got high octane ratings by using a lead additive. Increased environmental regulations for leaded gas are one reason why engine efficiency dropped so badly in the '70s (most because lead doesn't work with catalytic converters rather than regulating lead directly).
Blending in some kind of alchol may get us 120 octane pump gas once again. Another problem solved by booze!
Re:Cannot explode but can be used in cars? (Score:5, Informative)
If we really want to split hairs, we should note that "explode" and "detonate" are two different concepts. Some explosions are detonations, and others are simple deflagration where the fuel burns rapidly but evenly over some period of time.
The physics of the two is vastly different. A detonation denotes an event where the material burns at a rate that is supersonic, and a deflagration is subsonic.
In a detonation, an instantaneous pressure jump moves through the material faster than the material's normal speed of sound. This produces instantaneous pressures that can go into the millions of PSI. A strong enough shock will shatter any material.
Occasionally, the fuel/air mixture in an automobile cylinder will partially detonate. These cause weak shocks that we notice as "knocks" and "pings" - and which over time will destroy the pistons in the engine. High compression, low octane fuel, and local hotspots in the cylinders are the usual reason for this.
As a side note, even smokeless gunpowder doesn't detonate, it just deflagrates on a time scale of 0.5 - 3 milliseconds. If it did detonate, the gun would quite spectacularly imitate a fragmentation grenade.
From the perspective of an observer outside the combustion both can produce similar effects, though detonations are much more spectacular.
Re:Cannot explode but can be used in Fords? (Score:5, Informative)
IIRC, Pintos didn't actually "explode" (except in the movie "Top Secret"). Instead, they poured the entire contents of their tank onto the ground in the case of a rear collision. The big gasoline puddle could then catch fire.
There's a video here [youtube.com]. Lots of flames, no flying shrapnel :)
Re:Cannot explode but can be used in Fords? (Score:2, Informative)
Re:Cannot explode but can be used in cars? (Score:3, Informative)
It was only later that gasoline demand started getting high enough that they started running short on the higher octanes, and needed to mix in lesser octane hydrocarbons.
Nope, it was the EPA making the refiners stop using lead. [wikipedia.org] Otherwise you are correct, gasoline used to have a much higher octane rating.
Re:Cannot explode but can be used in Fords? (Score:3, Informative)
Re: can hold 52.220 kWh (Score:4, Informative)
Re:But How To Charge It? (Score:4, Informative)
Approximately 3000 amps. 460 volt/ 3 phase: about 830 amps.
Re:Cannot explode but can be used in cars? (Score:3, Informative)
Welcome to the wonderful world of internal resistance.
Wikipedia files it under output impedance, although no one outside of maybe textbooks refers to it that way
Impedance acts exactly like resistance, except it's only for alternating currents. Run 5v DC through a coil and it will still be 5v. Run 5v AC through a coil and your output voltage will go down. That's called impedance; impedance impeded AC while letting DC pass. The higher current's frequency the more it is impeded.
Wikipedia is correct; DC current cannot pass through a capacitor, so it is indeed impedance rather than resistance.
Detonate vs Deflagrate (Score:3, Informative)
See http://en.wikipedia.org/wiki/Detonation [wikipedia.org]
What should be happening in your engine is deflagration. I am not positive, but I think knocking is detonation not deflagration.
Re:Cannot explode but can be used in Fords? (Score:3, Informative)
News flash, Europe and US use different 'thousands' separator.
Correct, but news flash: who knows who proofread what. The simple fact is that 52 kWh is about enough to power a car for a fairly reasonable range. 52 MWh would be enough to run an 18 wheeler from coast to coast.
Re:Cannot explode but can be used in cars? (Score:3, Informative)
A combustion event, aka 'explosion' occurs at the beginning of every power stroke
It's not an explosion. It's rapid, but controlled, combustion (burning).
When an engine 'knocks' there is a combustion event as well.
Nope. Knocking is preignition or detonation (explosion).
Re:Cannot explode but can be used in cars? (Score:5, Informative)
A combustion event, aka 'explosion' occurs at the beginning of every power stroke in a reciprocating internal combustion engine. When an engine 'knocks' there is a combustion event as well. What makes it a 'knock' instead of a normal part of the power cycle is that it occurs at the wrong time
This is incorrect. When things are functioning normally, the fuel burns by deflagration, the reaction front is propagated subsonically by conductive heating of adjacent material. If you have knocking, what's going on is detonation, where the reaction front is propagated supersonically by compressive heating of adjacent material. Both deflagration and detonation are combustion reactions, but the latter is more powerful, less efficient, and far more destructive to your pistons. It's not just the same reaction occurring too early.
Re:Convert to real-world (Score:3, Informative)
PS: (52.220 kWh * 98%) / (36.6 kWh/US gallon * 30%) = 4.7 gallon but you can probably use more efficient regenerative breaks because you can charge faster.
Re:Ignorant parent. (Score:4, Informative)
Speaking as a Professional Engineer, there are capacitors that are not the simple dual plate (ceramic or electrolytic) you seem to think is the norm. Most utilities use capacitors with ratings up to several hundred thousand volts. they use (mostly) similar in concept designs to what you are used to, but spacings and insulators differ. Charge/discharge times differ too. the larger capacity units are physically quite large. Speed of light, internal reactance, etc. will limit how rapidly the charge can go in or out. Utilities use these units to adjust the power factor of a line to limit losses.
The unit under discussion seems to be a mix or matrix of small spheres coated in a conductor, suspended in an insulating matrix. similar designs have been proposed and made in laboratories since the time of Tesla (Nikolai, not the car). Most didn't work. This one is claimed to work in the lab. Each small sphere is a separate charge holder. As long as the insulator is thick enough, the unit should hold. The voltage is probably the highest they could get in the lab. That's to keep the KWH up. There will need to be a high voltage power supply, with a bleed off down to the voltage used by the motor. (Two way I hope). It'll take a lot of electronics to make this thing really work. There will be some power loss in the matrix. Some leakage, as well as some internal impedances to deal with. The car engineers should take care of that. If they can't, then it will just be another unfulfilled promise. The last hundred years is littered with those.
If that voltage could be raised an order of magnitude, I could use a couple of these on a substation I'm working on. If they are suitable for 60 Hz, that is.
Re:that's *nothing* compared to a tank of petrol (Score:3, Informative)