Stories
Slash Boxes
Comments

News for nerds, stuff that matters

Slashdot Log In

Log In

Create Account  |  Retrieve Password

A Non-Toxic, Paper Battery / Supercapacitor

Posted by kdawson on Tue Aug 14, 2007 05:09 AM
from the i'll-take-a-ream dept.
jcr writes "Researchers at Rensselaer Polytechnic Institute have developed a combination battery/capacitor by infusing carbon nanotubes and electrolytes into a paper substrate. The material can be folded, rolled up, or molded to any convenient shape with no effect on power capacity. Operating temperature range is -100 to 300 degrees F. One of the co-authors is quoted: 'We're not putting pieces together — it's a single, integrated device. The components are molecularly attached to each other: the carbon nanotube print is embedded in the paper, and the electrolyte is soaked into the paper. The end result is a device that looks, feels, and weighs the same as paper.'" The researchers haven't yet developed a high-volume way to manufacture the devices. They envision ultimately printing sheets between rollers like newsprint.
+ -
story

Related Stories

This discussion has been archived. No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
 Full
 Abbreviated
 Hidden
More
Loading... please wait.
  • So... (Score:5, Funny)

    by What the Frag (951841) on Tuesday August 14 2007, @05:16AM (#20222681) Journal
    Instead of a paper-cut you get a electric paper-shock?
    • Re:So... (Score:5, Funny)

      by Linker3000 (626634) on Tuesday August 14 2007, @05:21AM (#20222703)
      Science labs around the world will soon migrate from the 'leave a charged capacitor lying around' trick to the 'can you take that note over there to Mr Smith' trick.
    • by Anonymous Coward on Tuesday August 14 2007, @06:19AM (#20222939)
      Power capacity. Keith Dawson, it's anything BUT that. Power capacity would be the ability to discharge. The poster is probably thinking of energy density. PLEASE READ THE SUBMISSIONS (and maybe try to understand them if you can) BEFORE YOU POST THEM ON THE FRONT PAGE.
    • Re:So... (Score:5, Funny)

      by hcdejong (561314) <acme AT xmsnet DOT nl> on Tuesday August 14 2007, @06:51AM (#20223103)
      Think of the things you can do with a paper airplane...
    • by Simonetta (207550) on Tuesday August 14 2007, @09:24AM (#20224457)
      Where are the numbers? As in how many microFarads per cubic centimeter does this material hold? As in how many milliAmp/hours? Without any numbers this is just science fiction, or a slow day at journalism school.
      • Re: (Score:3, Informative)

        by Anonymous Coward
        "By putting two sheets of paper together with the cellulose side facing inwards (and a drop of electrolyte on the paper), a supercapacitor is formed. These supercapacitors retain the flexibility of normal paper, but they have a rating that is comparable to that of standard commercial hardware--a 100g sheet could replace a 1300mAh battery. Because the medium is flexible, the researchers say you could shape batteries of all sizes for very specific use.

        It doesn't stop there, however. By putting a drop of elect
        • Re: (Score:3, Insightful)

          "So far, the researchers have achieved power densities of 1.5 kilowatts per kilogram in the supercapacitor version and tested it over 100 cycles of discharge and recharge, well short of the million or so typical for current commercial capacitors."

          Somebody correct me if I'm wrong, but that just refers to charge/discharge rate, rather than storage capacity, right? I mean, they don't say how long it can sustain 1.5 kilowatts. If it can put out 1.5 kw for a femtosecond, that's naturally less significant than

  • I wonder how hard nanotubes are to create. Are they totally unnatural and that's why we don't see exactly this sort of thing in nature?
    • Re: (Score:2, Informative)

      by Anonymous Coward
      imperfect ones are found in ordinary soot. Their effectiveness drops of rapidly if even just a few flaws are introduced and as far as I'm aware the only way of geting them with a really low flaw-count is to deliberately manufacture them.
    • by KrugalSausage (822589) on Tuesday August 14 2007, @05:54AM (#20222841)
      I do some research with CNTs, so maybe I can help answer this.

      Carbon nanotubes are not completely unnatural, there is probably a very small percentage found in your fireplace (if you are burning carbon based wood, is there another kind? ;) ).

      Most methods of production involve taking some form of carbon and applying enough energy to it break it up and allowing it to reform. In the 1950's, some Russian researchers were first publishing about these very small and strange carbon rods that they found in their powder. Going from memory (don't know russian), I believe they started with some electrodes with carbon on them. After applying high voltage to them, a discharge (lightning) forms and breaks down the carbon. In this soot, some of these carbon nanotubes were found. They were unaware of the significance of their discovery at the time.

      In 1991, Iijima published their 'new' discovery (not knowing about the Russian paper, language barrier and all) of the CNT and since then, research has exploded into finding and refining new ways to make them. Their method of production involved laser ablation, where a carbon target is hit with a laser. The hot debris is carried by an inert gas and while it cools some nanotubes are formed.

      The three main methods are chemical vapor deposition http://en.wikipedia.org/wiki/Chemical_vapor_deposi tion [wikipedia.org] , laser ablation http://en.wikipedia.org/wiki/Laser_ablation [wikipedia.org] and arc discharge http://en.wikipedia.org/wiki/Arc_discharge [wikipedia.org].

      Now there are companies that can send you a black powder that is >95% carbon nanotubes. At our lab, we take these and mix them with a surfactant to make a CNT solution. If you filter this solution, the CNTs accumulate on top of the filter and form a black sheet of carbon nanotubes. This paper paper goes by the name of buckypaper. In the article, it seems that instead of a surfactant they are using cellulose. If you want them to align while they are forming the paper, all one has to do is apply an external electric field. The quasi-one dimensional nature of the CNTs gives them a higher magnetic susceptibility along their axis than perpendicular to it. This helps them align along the magnetic field lines.

    • Re: (Score:3, Informative)

      Carbon nanotubes are usually manufactured by vaporising graphite impregnated with metal particles. The carbon condenses on the metal, forming tubular molecules. There's more information on the process here [azonano.com].
  • e-ink (Score:5, Interesting)

    by SharpFang (651121) on Tuesday August 14 2007, @05:17AM (#20222687) Homepage Journal
    Now it would be interesting, so far power supply for e-ink was big and bulky. There is already a technology of printing ICs on paper, meaning - electronic paper is at hand's reach.
  • kWh/kg and kWh/$? (Score:3, Interesting)

    by DamonHD (794830) <d@hd.org> on Tuesday August 14 2007, @05:18AM (#20222689) Homepage
    Hi,

    Just as an alternative ultracapacitor this sounds interesting: I'm going hunting for the efficiency numbers above, though they're going to be hard to gauge at this stage I guess!

    Rgds

    Damon
  • Like the sound of an mp3 player getting a paper jam.
  • by maroberts (15852) on Tuesday August 14 2007, @05:20AM (#20222701) Homepage Journal
    They combust at Farenheit 451 [wikipedia.org]
    • FTA: "Another key feature is the capability to use human blood or sweat to help power the battery."

      Human blood to power batteries? Oh shit... beware the machines!
  • Power specs? (Score:5, Insightful)

    by strredwolf (532) on Tuesday August 14 2007, @05:22AM (#20222711) Homepage Journal
    Come on? What's the volt/amp specs per square inch? "Oh we got a paper-thin battery that's flexible" is all fair and good, but until we get full specs on it, we can't plan on replacing our iPhones any time soon with Earth: Final Conflict style devices.
    • Re:Power specs? (Score:4, Interesting)

      by pragma_x (644215) on Tuesday August 14 2007, @09:28AM (#20224503) Journal
      Good point. For all we know, the capacitance of this stuff could be no better than building up a static charge with a balloon and your cat.

      Honestly, I think the more impressive stat is the one given in the summary: operating range of -100 to +300 degrees.

      Most batteries are only viable in temperatures where water can stay liquid. Were something like this made commercially viable, you could do things like run electric vehicles in the arctic w/o needing to keep the battery warm.
      • Honestly, I think the more impressive stat is the one given in the summary: operating range of -100 to +300 degrees.

        Most batteries are only viable in temperatures where water can stay liquid. Were something like this made commercially viable, you could do things like run electric vehicles in the arctic w/o needing to keep the battery warm. (emphasis added)

        I would suggest that we could use this to run electric vehicles in space w/o needing to keep the battery warm.

        NOTE: By "space" I mean not only the big, empty expanse around us, but also on the Moon, on Mars, etc. Even if the extremes there exceed that of this battery, the energy required to keep this battery within specs would be much less than for our current crop.

        IIRC, wasn't one of the big concerns about the Mars landers (Opportunity and Spirit) during the big dust storm that insufficient sunlight

        • Re: (Score:3, Insightful)

          You're pretty much on the money for this being good for space tech. I forgot about that particular cold frontier in my post. I guess you can paint me fixated on how the current crop of electric/hybrid cars will never catch on in places like Alaska, despite people painting them as some sort of panacea.

          Anyway, the heater for the electronics in the Mars rovers(and by extension, probably some spacecraft) is nothing more than a boring slug of plutonium (or something else radioactive). The problem with dust co
  • by headkase (533448) <pickett.bill@gmail.com> on Tuesday August 14 2007, @05:29AM (#20222741)
    As an aside, announcements of technologies such as this are becoming more frequent. As Alvin Toffler [wikipedia.org] was talking about many years ago, we have entered the period of "Future Shock". Development and change in general is undergoing a period doubling. Not only are these new technologies amazing, but also the technologies they enable will also be amazing. So it begs the question: what do we - as a species - want to do? Because unless a mass extinction occurs we will probably be able to choose from an unimaginable menu of options about fifty years from now.
    • So it begs the question: what do we - as a species - want to do?
      I suppose I can't answer for everyone, but to me, the choice is clear: Make a flying car.
      • Re: (Score:3, Insightful)

        Make a flying car.

        Are you crazy? Have you been out on a road recently?

        The vast majority of drivers can't handle two dimensions confined largely by concrete and steel barriers and you want them to be able to (try and) navigate in three dimensions? While diddling with their cell phones and bog-knows what else?

        You're either on some powerful medications or you have a very high tolerance for pain.

    • by Anonymous Coward on Tuesday August 14 2007, @05:38AM (#20222783)
      no, it doesn't. It might raise the question, but most definitely does not beg.
    • what do we - as a species - want to do?
      If the new technology is used in the future the same way it was used in the past, the first priority is probably to make better porn.
    • by Stefanwulf (1032430) on Tuesday August 14 2007, @07:09AM (#20223195)

      Development and change in general is undergoing a period doubling. Not only are these new technologies amazing, but also the technologies they enable will also be amazing.
      I'm trying to think of a period in human history when this wasn't true, at least for some area of the globe. Imagine when people first developed language, or writing, or math, or agriculture. Or more recently the printing press, more effective plows, the scientific method, the telegraph, or even steam-powered ships and locomotives. In each case the immediate practical benefits were augmented by an increase in the rate of future discoveries, either directly (as from the scientific method or writing), or indirectly (as from greater food production allowing a class of people who weren't subsistence farmers to develop, or faster travel allowing a more rapid exchange and synthesis of information)

      Technology has never been changing as fast as it is now, but that's also been true for as far back as I'm aware...each generation just doesn't seem to see the trend of acceleration that came before them because it all seems so slow compared to what's happening just then.
      • by The Monster (227884) on Tuesday August 14 2007, @09:13AM (#20224329) Homepage

        Technology has never been changing as fast as it is now, but that's also been true for as far back as I'm aware...each generation just doesn't seem to see the trend of acceleration that came before them because it all seems so slow compared to what's happening just then.

        This simply isn't true. There have been periods in history when generations would pass without any discernable technological improvements. There have also been things called Dark Ages where technology actually recedes. (I guess that's still change, though.)

        We have had steadily-accelerating technological progress for the last two centuries or so, which covers our memories and the stories passed down for a few generations. That's apparently enough to make people think it's been that way for all time.

        Now the rate of change is so great that people factor it into their decision-making. We just assume that the computers we buy two years from now will be twice as powerful as the ones sold today. We fully expect our next cell phone will do more for less power and money, and we're actually a bit miffed that we don't have our flying cars yet.

      • by mike2R (721965) on Tuesday August 14 2007, @09:56AM (#20224909)
        While technological advances have occured during most times, what has changed a lot is the perception of them (this is western Europe specific): until about the mid-eighteenth century western European thought did not really encompass the concept of Progress - by which I mean the concept (which is so embedded into our current thought as to be an axiom) of idea building on idea, and Mankind slowly improving itself.

        On the contary, the philosophical underpinnings of western European thought where Chrtistian - they looked back towards perfection before the Fall (and also towards Roman times), rather than forwards.

        The concept of progress was a big deal at the time - the core of what came to be known as the Enlightenment. This is not to say that there weren't technological advances during medeival times, just that the idea of progress; of things being better than they were in the past, and of getting better in the future, was not part of the contemporary mindset.
  • in SI units (Score:4, Informative)

    by Anonymous Cowpat (788193) on Tuesday August 14 2007, @05:35AM (#20222769) Journal
    thats -73.3 C to 148.8 C.

    <\karma whore>
  • by Ancient_Hacker (751168) on Tuesday August 14 2007, @05:43AM (#20222801)
    This is a pointless announcement. Anybody can make a capacitor with two conducting surfaces separated by an insulator. A good, useful, and economical capacitor is something else. Questions like capacitance, capacitance per unit area, capacitance per unit volume, voltage rating, Q, stability, cost per unit, testability, long-term stability and reliability, manufacturability, testability, structural strength, vibration effects, electromigration, overvoltage resistance, pinhole noise, dielectric drift, leakage current, leakage drift, stray inductance, longevity, temperature range, polarization, memory effect, moisture resistance, solvent resistance, altitude effects, and more are significant parameters. A useful new capacitor design would have to have some significant advantages over current designs.
    • by gone.fishing (213219) on Tuesday August 14 2007, @08:13AM (#20223735) Journal
      Research, pure or practical is what advances technology and indeed the whole human race. While very few products make it beyond the lab information learned may be applied elsewhere.

      While I may agree that this particular product may never make it out of the lab perhaps someone will read the announcment and have an eureka moment of their own and be able to apply something that they learned from this research to whatever it is that they are working on.

      I actually do hope that this research (or more accurately a product derived from this research) makes it out of the lab. I think there is room in this world for non-toxic, compostable capacitor-batteries.

      Pointless? I think a better word may be inspirational.
  • biodegradeable? (Score:3, Interesting)

    by Sibko (1036168) on Tuesday August 14 2007, @05:55AM (#20222845)
    It's 90% paper, so from the sounds of it, it'll biodegrade pretty much like paper. Which doesn't seem so great if you want to start putting it in cars or aeroplanes. I can't help but be reminded of Larry Niven's Ringworld, where a bacteria [I think it was a bacteria] evolved to consume certain high-tech gear. So not only will our batteries have the lifetime of regular paper, but things that eat regular paper will be able to eat our batteries too.
    • I have not read the article, so shame on me if this is incorrect. It sounded, however, like the paper was only being used as an inexpensive and flexible substrate. It would be neat to use regular paper if you actually wanted to print these, as described in the summary. On the other hand, if greater durability is required, I imagine that you could use cardstock, fabric, or some hybrid, like the paper used to make money.
  • I'm assuming since this is essentially a high tech capacitor it will probably withstand many more recharge cycles than a lithium ion or nickle metal hydride battery?
  • by ScrewMaster (602015) on Tuesday August 14 2007, @06:19AM (#20222943)
    It's a battery. It's a capacitor. It's the battacitor!
  • by Sabathius (566108) on Tuesday August 14 2007, @06:26AM (#20222979)

    Another key feature is the capability to use human blood or sweat to help power the battery.
    Jesus Christ! Has anyone else noticed the alarming trend of devices made to run on human fluids!
  • I can't find the paper yet at pnas.org, and as usual, TFA is light on details. Where and how is the energy stored? Capacitance between individual nanotubes? Or between sides of the paper? Or a chemical process?

    What happens when you fold the paper? Wouldn't you short-circuit it?

    How well does the carbon adhere to the paper? Pencil strokes always flake off a bit over time.
  • Scary fuel (Score:3, Funny)

    by Alain Williams (2972) on Tuesday August 14 2007, @07:00AM (#20223149) Homepage

    Another key feature is the capability to use human blood or sweat to help power the battery.

    I can see Stephen King starting on a new novel ...

  • by hcdejong (561314) <acme AT xmsnet DOT nl> on Tuesday August 14 2007, @07:36AM (#20223377)
    does it flux?
    • Re: (Score:3, Insightful)

      Each time I hear about things like this, I become less and less impressed. You said it yourself: "Announcements", while all these breakthroughs are occurring in the lab, the We hear so much about nano-technology and all these brilliant ground breaking devices, only to... never actually see them. Granted things like nano-tech are in their infancy, I dont actually see any of this technology they keep announcing. It is not like we are making great leaps and bounds. When I look around I do not see too much o
      • Re: (Score:3, Insightful)

        Each time I hear about things like this, I become less and less impressed. You said it yourself: "Announcements", while all these breakthroughs are occurring in the lab, the We hear so much about nano-technology and all these brilliant ground breaking devices only to... never actually see them.

        Of course, most of the time, those announcements are not sitting on a working prototype. They're trying to raise money for development.

        This is a new idea in academia. That's a totally different thing. It's either a hoax (which, in this case is incredibly easy to prove, so it probably isn't), or it's really something that's useful. Hopefully it'll spawn a bunch of research into similar approaches for nanotech batteries so that eventually we have something really awesome that does this.