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EEStor Issued a Patent For Its Supercapacitor 603

Posted by kdawson
from the if-it-sounds-too-good-to-be-true dept.
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."
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EEStor Issued a Patent For Its Supercapacitor

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  • by Arancaytar (966377) <arancaytar.ilyaran@gmail.com> on Monday December 22, 2008 @06:27AM (#26198397) Homepage

    What's the benefit of a patent for something that doesn't exist yet? At most, they're issued for things that are obvious or have existed for decades. ;)

  • Hmmm (Score:3, Funny)

    by Anonymous Coward on Monday December 22, 2008 @06:30AM (#26198415)
    I wonder what they will charge for this?
  • by Khyber (864651) <techkitsune@gmail.com> on Monday December 22, 2008 @06:34AM (#26198425) Homepage Journal

    Let's see. 50kwh. That would run my computer for...two days no problem with monitor and broadband modem included.

    Gimme two of these and some high-efficiency photovoltaics and good-bye power grid. I don't care if my house is ugly, cover the entire thing with HEPV.

    • Re: (Score:3, Informative)

      by erayd (1131355) *
      That's a bloody inefficient computer!
    • The worst, most inefficient computer in my house uses roughly 250Wh in continuous draw (less if the monitor is off, which it usually is). Relatively modern machine too (Pentium 4, lots of disks, etc).

      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'.
      • Re: (Score:3, Interesting)

        I hate to tell you but a P4 isn't modern any more. Not even "relatively" modern.

        But your point is valid, especially as the P4s were some of the most power-hungry desktop CPUs ever made.
        I've measured my pc at 200 W draw under normal use, most of which will be the graphics card. It probably goes up to 300 W when gaming.

        That cell would last me about 10 days of continuous use at 200W if I used it as a UPS. That's crazy.

        Now for the important bit. For a car:
        Wikipedia says cars use between 0.17 to 0.37 kWÂh/m

        • by compro01 (777531) on Monday December 22, 2008 @09:43AM (#26199379)

          The range would depend mostly on how fast you're going. The relationship between power use and speed is (generally) cubic, due to the equation for energy loss to drag.

          IIRC, when I was running numbers in a previous discussion here about the smart fourtwo car, I came up with something like 37.5HP (~28KW) needed to maintain 80MPH (Highest speed limit in the US, AFAIK). That would give you a bit less than 160 miles on that thing. Slow that down some and the range significantly increases though.

  • 52 kilowatt Hours? (Score:5, Interesting)

    by MichaelSmith (789609) on Monday December 22, 2008 @06:36AM (#26198433) Homepage Journal

    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.

    • by Joce640k (829181) on Monday December 22, 2008 @06:53AM (#26198501) Homepage

      A capacitor has the ability for almost all braking energy to be fed back into it.

      In stop-go traffic this could make a massive difference in mileage compared to a conventional battery.

      • by evanbd (210358) on Monday December 22, 2008 @11:31AM (#26200733)

        You can do that with a good battery pack, too. The Tesla does so, in fact (as do most hybrids). The only real requirement is that the power converter be capable of running backwards, which isn't all that hard if it's a design requirement. Some extra power capacity in the batteries helps, since most cars can brake faster than they can accelerate, and you don't want to charge the batteries too fast. Fortunately, in this application the batteries are designed around capacity, and have lots of extra power capability available.

    • by RedWizzard (192002) on Monday December 22, 2008 @07:32AM (#26198659)

      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: (Score:3, Insightful)

        by zigziggityzoo (915650)
        You can't triple its range if the *size* of the capacitor is the same as the battery. Just because it weighs less doesn't mean it has the same density.
    • by knarf (34928) on Monday December 22, 2008 @08:34AM (#26198915) Homepage

      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.

      • by Kupfernigk (1190345) on Monday December 22, 2008 @08:38AM (#26198937)
        Lead acid batteries start to degrade quickly once taken below 60% of nominal capacity, and car batteries may only stand 30-40 cycles of discharge below 50%. My marine batteries weigh a total of about the same as the EEStor claimed device, and have a real-world capacity of 1.5kW/hour, if I don't want to replace them every 3 years. This is a ratio more like 30 to 1.
    • Petrol contains about 34Mega-Joules of energy per litre. For a standard 60 litre tank, that's pretty close to 2GJ of energy.

      Now, using 1 Joule == 1 Watt for 1 Second, that comes out to 566kWh, roughly 10 times what this (and other) electrically powered vehicles can manage.

      Looks like they have a long way to go before they have enough juice for mainstream use.

      • by mevets (322601) on Monday December 22, 2008 @09:14AM (#26199143)

        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.

  • by dangitman (862676) on Monday December 22, 2008 @06:43AM (#26198465)

    the present invention provides a unique lightweight electric-energy storage unit that has the capability to store ultrahigh amounts of energy

    Can't you express these things in units we all all understand, like jigawatts per nanofornight?

    • Re: (Score:3, Informative)

      by edman007 (1097925)
      gigawatt is correctly pronounced, "jigawatt", the "giga" pronunciation only became popular when computers became common
      Anyways, if you want it in those units, well:
      52220 kWh = 155,416.667 GWnFn (gigawatt-nanoFortnights)
  • Check out the patent (Score:5, Informative)

    by shadester (196414) on Monday December 22, 2008 @06:50AM (#26198487)

    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.

    • by TapeCutter (624760) on Monday December 22, 2008 @07:28AM (#26198637) Journal
      3-6 minutes charge time for 52 kWh.

      Better use the heavy duty extention cord.
  • by Chris_Jefferson (581445) on Monday December 22, 2008 @06:50AM (#26198493) Homepage
    It's things like this that convince me that while patents need some serious fixing, they shouldn't be abolished. While we haven't seen all the details, it looks like genuinely interesting and original to me and a step beyond the currently available state-of-the-art. Of course, only time will tell if this is really a good patent, and if the product is really any good in practice. It's easy to make things that look good in the lab but don't do so well in real usage.
  • Highly unlilkely (Score:5, Insightful)

    by pdxdada (684092) on Monday December 22, 2008 @07:11AM (#26198573) Homepage
    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)/52.22)
    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.
    • Re: (Score:3, Informative)

      by RedWizzard (192002)

      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.

    • Re:Ignorant parent. (Score:4, Informative)

      by YetAnotherBob (988800) on Monday December 22, 2008 @01:51PM (#26202897)

      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.

  • by Anonymous Coward on Monday December 22, 2008 @07:18AM (#26198603)

    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.

  • Oh, this is clever. (Score:5, Interesting)

    by jcr (53032) <jcr@NoSPaM.mac.com> on Monday December 22, 2008 @07:27AM (#26198635) Journal

    At first I wasn't getting why this would have better capacitance than conventional materials. Then around page 6, I realized that they're laying down a lot of layers. Like, a micron of conductor and nine microns of dielectric in each pass.

    This is what patents are really for.

    -jcr

  • Instant stats (Score:4, Informative)

    by Twinbee (767046) on Monday December 22, 2008 @08:25AM (#26198885) Homepage

    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

  • by Pedrito (94783) on Monday December 22, 2008 @10:01AM (#26199559) Homepage

    It is mentioned the device cannot explode when being charge or impacted and is thus safe for vehicles.

    It may not explode when you hit it, and I'm not genius with electricity, but can't capacitors discharge their energy pretty quickly? Wouldn't 52kWh discharged through a pile of metal with people trapped inside be somewhat less than safe?

    • Re: (Score:3, Funny)

      by rossz (67331)

      Not a big deal. Back when I used to work on high powered lasers I accidentally used myself to discharge a bank of 30kv capacitors and it didn' t affect affect affect affect me one little b-b-b-b-b-bit.

      Kidding aside, every single muscle in my body hurt like hell. Muscles I didn't know I had hurt.

  • by Animats (122034) on Monday December 22, 2008 @12:42PM (#26201849) Homepage

    Back to basics. A capacitor is an insulator between two conductors. The key concept here is that their insulator has an insanely high breakdown voltage, which is why they can supposedly make an ultracapacitor that operates around 500V instead of the usual 5V or so.

    The patent says "The alumina-coated calcined CMBT powder and the poly(ethylene terephthalate) plastic have exceptional high-voltage breakdown and when used as a composite with the plastic as the matrix the average voltage breakdown was 5.57 * 10^6 V/cm or higher. The voltage breakdown of the poly(ethylene terephthalate) plastic is 580 V/micrometer at 23 degrees C. and the voltage breakdown of the alumina-coated CMBT powders is 610 V/micrometer at 85 degrees C."

    Note how many different units they use. Conventionally, dielectric strength is quoted as KV/mm. So we have

    • Their new composite: 5.57 * 10^6 V/cm = 5.57 * 10 ^ 3 KV/cm = 5.57 * 10 ^ 2 KV/mm = 557 KV/mm
    • PET: 580 V/micrometer = 580 KV/mm
    • Alumina-coated CMBT powders: 610 V/micrometer = 610 KV/mm

    First, why did they make a composite that's worse than either of its components? This would be obvious if they used the same units for all their breakdown voltages in the patent.

    Second, those are unreasonably good numbers. The usual breakdown voltage for PET [azom.com] as used in Mylar capacitors is only 17 KV/mm. Why is their PET 35 times as good as everybody else's?

    (Check this, please. Look at the actual patent image. [pat2pdf.org] The searchable text version at the USPTO doesn't show math symbols very well.)

    • by ivan256 (17499) on Monday December 22, 2008 @05:34PM (#26205347)

      The thing that's odd to me about the patent is how much marketing data is in there. It talks about potential to revolutionize the EV industry, and compares the technology to batteries... Everything you put in your claims that doesn't need to be there limits the scope. The only reason to put that crap in there is if you're planning on trying to trick somebody into believing it simply because the patent was granted. Any patent attorney with half a brain would have stripped that stuff out of there lest it be used to limit the scope of the patent in the future.

      The whole thing screams "investment scam".

      (The screen printing process they describe for creating the dielectric layer seems like it would result in a large percentage of the dielectric being made of the nitrocellulose binding resin for the dielectric "ink", rather than their CMBT/PET combo. The "jet milling" process they describe to mill the powders seems like it would introduce significant impurities in the powders. It also seems comical to me that they could achieve a sufficiently uniform dielectric layer through screen printing...)

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