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11-28-08, 03:18 PM #1
Texas Nano-Research May Have Yielded a Breakthrough in Energy Storage Devices
FYI, a less efficient version of this device (which stores electric power using static electricity instead of chemicals) is what that new 5.1.1. flashight uses, which can be completey charged in 90 seconds, but has a short run-time. This breakthrough may allow it to have a runtime equivalent to using chemical batteries, yet keeping weight down and up to 100,000 charge cycles, versus less a 1000 for chemical batteries.
Graphene Ultracapacitor Packs a Powerful Punch
November 20, 2008
Ultracapacitors--high-energy-density storage devices--may one day supplement, or even replace, batteries in mobile phones, laptops and other devices. Researchers at The University of Texas at Austin recently moved the technology a step closer to commercialization by using graphene--a one-atom thick structure--as a new material for storing an electrical charge in ultracapacitors.
The researchers feel that graphene--a form of carbon--could eventually double the capacity of existing ultracapacitors, which are currently manufactured using an entirely different form of carbon. "Through such a device, electrical charge can be rapidly stored on the graphene sheets and released from them as well for the delivery of electrical current and, thus, electrical power," says Rod Ruoff, a University of Texas at Austin mechanical engineering professor and a physical chemist. "There are reasons to think that the ability to store electrical charge can be about double that of current commercially used materials. We are working to see if that prediction will be borne out in the laboratory."
Two main methods exist to capture and store electrical energy: batteries and ultracapacitors, which are becoming increasingly commercialized but are not yet as popularly known. An ultracapacitor can be used in a wide range of energy capture and storage applications, either by itself as the primary power source or in combination with batteries or fuel cells. Advantages ultracapacitors have over batteries include a higher power capability, longer life, a wider temperature operating range, lighter and more flexible packaging and lower maintenance, Ruoff says.
Ruoff and his team prepared a chemically modified graphene material and, using several types of common electrolytes, constructed and electrically tested graphene-based ultracapacitor cells. The specific capacitance--the amount of electrical charge stored per weight--of the graphene material already rivals the values available in existing ultracapacitors, and the researchers' modeling suggests the possibility of doubling the capacity, Ruoff notes.
"Our interest derives from the exceptional properties of these atom-thick and electrically conductive graphene sheets, because in principle all of the surface of this new carbon material can be in contact with the electrolyte," Ruoff says. Graphene's surface area--almost the area of a football field in only about 1/500th of a pound of material--means that a greater number of positive or negative ions in the electrolyte can form a layer on the graphene sheets, "resulting in exceptional levels of stored charge," he adds
Mobile phones and other mobile devices stand to benefit from ultracapacitors' improved power delivery and lengthy lifetimes. This technology also promises to significantly improve the efficiency and performance of electric and hybrid cars, buses, trains and trams.
Funding and support for the project was provided by the Texas Nanotechnology Research Superiority Initiative, the University of Texas at Austin and a Korea Research Foundation Grant.
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11-28-08, 04:53 PM #2
It's always good to hear of breakthroughs. It's nice to know that despite some bad stuff in the world...we're still forging aheadArm the sheep!
01-02-09, 05:09 AM #3
Just what are you up to there in Texas, Charlie? I saw a story related to ultra/super capacitors, remembered this thread only to find out it's a different outfit. Aren't you supposed to be an oil state?
(Wiki) EEStor is a company based in Cedar Park, Texas, United States that has developed a type of capacitor for electricity storage, which EEStor calls 'Electrical Energy Storage Units' (EESU). ... According to its patent application, these units will use high-purity barium titanate coated with aluminum oxide and glass to achieve a level of capacitance claimed to be much higher than what is currently available in the market. The claimed energy density of the prototype is 1 MJ/kg; existing commercial supercapacitors typically have an energy density around 0.02 MJ/kg, while lithium ion batteries are around 0.54–0.72 MJ/kg.
Here's the new application part I ran across
Lockheed Martin Patent Application Includes EEStor EESU
Add another log to the rumors igniting around energy storage startup EEStor. According to a patent application with World Intellectual Property Organization that was recently published online (via bariumtitanate.blogspot.com), military-industrial giant Lockheed Martin is researching developing body armor and utility garments that could include using EEStor’s energy solution (page 7 of the application).
While Lockheed’s patent application references a more general rechargeable lithium-ion polymer battery being used with the garment, the application not only specifically refers to possibly using EEStor’s technology, but calls the general energy storage technology an “electrical energy storage unit,” precisely what EEStor calls the energy storage device on which it is working. A garment with an energy storage layer could help soldiers power electronics like a radio, flashlight, or GPS for longer periods of time — soldiers often carry a significant amount of weight in extra batteries to power such devices. (Hmm... Skipping ahead)
Lockheed patent says that an energy storage layer of the garment could have a thickness of .5 centimeters to 2 centimeters, and there could be multiple layers of energy storage units. The garment would include electrical connectors, electrical ports and an energy management system. Specifically Toby Thomas and David Hoelscher are named as inventors of the device. See images below: (more images at link)
Cool thing about this, beyond the increase in electricity reserve at a lower weight, is the capacitor layers would be integrated into the armor in such a way they would increase its effectiveness as armor.
01-02-09, 09:08 PM #4
On the podcast I listened to today, Security Now, Leo Laporte and Steve Gibson discussed that EEStor patent in a fair bit of depth. For the convenience I clipped out that discussion to make a small mp3 instead of fast forwarding 86 minutes in to get to it.
Whether you're an electrical engineer or generally avoid tech talk the way Steve explains the functions of capacitors and implications of this patent are easy listening. The file is a regular mp3, should work on any mp3 player, phone, etc.
If this ultracapacitor works as described and is able to be manufactured cheaply (both sound promising, but admittedly I'm wanting it to be so - see if you detect BS) the days of having to wait hours to charge your cellphone, laptop or anything else with a battery may be nothing more than a quaint memory in the not so distant future.
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