Teen's Invention Could Charge Your Phone in 20 Seconds - ott板

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發佈時間：2013-05-20

Teenager explains her award winning revolutionary invention. Teenager invents revolutionary device which has the potential to charge a cell phone within just 20 SECONDS. A California teen has attracted the attention of tech giants Google for her potentially revolutionary invention which charges a phone in 20 seconds flat.

The super-fast charging device has been dubbed a supercapacitor by 18-year-old Esha Khare, of Saratoga - as she took home $50,000 from the Intel International Science and Engineering Fair, which took place in Phoenix this week.

The device will make waiting hours for a phone to charge a thing of the past and the gizmo packs more energy into a smaller space than traditional phone batteries and holds the charge for longer.

So far, Khare has only used her supercapacitor to power a light-emitting diode or LED - but she sees a bright future that one day will see her invention powering cellphones, cars and any gadget that requires a rechargeable battery.

Heading to Harvard, Khare told CBS San Francisco that this is only the start and that she will 'be setting the world on fire' from here.

'My cellphone battery always dies,' she told NBC News when asked what inspired her to work on the energy-storage technology.

Specializing in nanochemistry allowed Khare to reduve the size of her invention. 'Really working at the nanoscale to make significant advances in many different fields.'

'It is also flexible, so it can be used in rollup displays and clothing and fabric,' Khare added.

'It has a lot of different applications and advantages over batteries in that sense.'

The supercapacitor is flexible and tiny, and is able to handle 10,000 recharge cycles, more than normal batteries by a factor of 10.

How an 18-year-old girl has managed to figure out something that multi-national corporations have not has led to her being flooded with offers for her amazing leap forward.

Google have been in contact with Khare to explore how she plans to change the makeup of cell phone battery life.
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發佈時間：2012-03-16

Imagine having an energy storage device that stores as much energy as a conventional battery, yet, can be charged 100 to 1000 times faster. Supercapacitors store charge in electrochemical double layers whereas batteries store charge through electrochemical reactions. Although supercapacitors can charge and discharge much faster than batteries, they are still limited by low energy densities and slow rate capabilities. Researchers at UCLA have successfully used an inexpensive precursor (graphite oxide) to produce high-performance graphene-based supercapacitors using a computerized LightScribe DVD drive. These devices exhibit ultrahigh energy density values in different electrolytes approaching those of batteries, yet they can be charged in seconds. The devices can be charged and discharged for more than 10,000 cycles without losing much in performance compared with a normal life-time of less than 1000 cycles typical for batteries. Additionally, the devices are completely flexible and maintain excellent performance under high mechanical stress.

Read more at Chemistry World http://www.rsc.org/chemistryworld/New...
©Science/AAAS

Scalable fabrication of high-power graphene micro-supercapacitors for flexible and on-chip energy storage

Maher F. El-Kady

& Richard B. Kaner

AffiliationsContributionsCorresponding author

Nature Communications 4, Article number: 1475 doi:10.1038/ncomms2446
Received 01 October 2012 Accepted 04 January 2013 Published 12 February 2013

Abstract

Abstract

Author information Supplementary information

The rapid development of miniaturized electronic devices has increased the demand for compact on-chip energy storage. Microscale supercapacitors have great potential to complement or replace batteries and electrolytic capacitors in a variety of applications. However, conventional micro-fabrication techniques have proven to be cumbersome in building cost-effective micro-devices, thus limiting their widespread application. Here we demonstrate a scalable fabrication of graphene micro-supercapacitors over large areas by direct laser writing on graphite oxide films using a standard LightScribe DVD burner. More than 100 micro-supercapacitors can be produced on a single disc in 30 min or less. The devices are built on flexible substrates for flexible electronics and on-chip uses that can be integrated with MEMS or CMOS in a single chip. Remarkably, miniaturizing the devices to the microscale results in enhanced charge-storage capacity and rate capability. These micro-supercapacitors demonstrate a power density of ~200 W cm−3, which is among the highest values achieved for any supercapacitor.

Subject terms:

(a) A digital photograph of the laser-scribed micro-devices with 4 (LSG-MSC4), 8 (LSG-MSC8) and 16 interdigitated electrodes (LSG-MSC16). (b) An optical microscope image of LSG-MSC16 shows interdigitated fingers with 150-μm spacings. The d…

Graphene micro-supercapacitors to replace batteries for microelectonics devices
Will power biomedical implants, active RFID tags, embedded micro-sensors, and flexible electronics
February 27, 2013

UCLA researchers have developed a groundbreaking technique that uses a DVD burner to fabricate miniature graphene-based supercapacitors — devices that can charge and discharge a hundred to a thousand times faster than standard batteries.

These micro-supercapacitors, made from a one-atom–thick layer of carbon, can be easily manufactured and readily integrated into small devices, such as next-generation pacemakers.

The new cost-effective fabrication method holds promise for the mass production of these supercapacitors, which have the potential to transform electronics and other fields.

“The integration of energy-storage units with electronic circuits is challenging and often limits the miniaturization of the entire system,” said Richard Kaner, a member of the California NanoSystems Institute at UCLA, a professor of chemistry and biochemistry, materials science, and engineering at UCLA’s Henry Samueli School of Engineering and Applied Science. “This is because the necessary energy-storage components scale down poorly in size and are not well suited to the planar geometries of most integrated fabrication processes.”

How it works

Fabrication process for micro-supercapacitors. (a) A grapene-based film supported on a sheet is placed on a DVD media disc. The disc is inserted into a LightScribe DVD drive and a computer-designed microcircuit is etched onto the film at precise locations to produce graphene circuits. (b) Copper tape is applied along the edges to improve the electrical contacts, and the interdigitated area is defined by polyimide (Kapton) tape. (c) An electrolyte overcoat is then added. Result is (d,e) a planar micro-supercapacitor. (Credit: UCLA)

“Traditional methods for the fabrication of micro-supercapacitors involve labor-intensive lithographic techniques that have proven difficult for building cost-effective devices, thus limiting their commercial application,” said Maher El-Kady, a graduate student in Kaner’s laboratory.

“Instead, we used a consumer-grade LightScribe DVD burner to produce graphene micro-supercapacitors over large areas at a fraction of the cost of traditional devices. Using this technique, we have been able to produce more than 100 micro-supercapacitors on a single disc in less than 30 minutes, using inexpensive materials.”

The process of miniaturization often relies on flattening technology, making devices thinner and more like a geometric plane that has only two dimensions. In developing their new micro-supercapacitor, Kaner and El-Kady used a two-dimensional sheet of carbon, known as graphene, which only has the thickness of a single atom in the third dimension.

Kaner and El-Kady took advantage of a new structural design during the fabrication. For any supercapacitor to be effective, two separated electrodes have to be positioned so that the available surface area between them is maximized. This allows the supercapacitor to store a greater charge.

In their new design, the researchers placed the electrodes side by side using an interdigitated pattern, akin to interwoven fingers. This helped to maximize the accessible surface area available for each of the two electrodes while also reducing the path over which ions in the electrolyte would need to diffuse. As a result, the new supercapacitors have more charge capacity and rate capability than their stacked counterparts.

The researchers found that by placing more electrodes per unit area, they boosted the micro-supercapacitor’s ability to store even more charge.

Could be made at home with DVD burner and graphite oxide in water

Kaner and El-Kady were able to fabricate these intricate supercapacitors using an affordable and scalable technique that they had developed earlier. They glued a layer of plastic onto the surface of a DVD and then coated the plastic with a layer of graphite oxide.

Then, they simply inserted the coated disc into a commercially available LightScribe optical drive — traditionally used to label DVDs — and took advantage of the drive’s own laser to create the interdigitated pattern. The laser scribing is so precise that none of the “interwoven fingers” touch each other, which would short-circuit the supercapacitor.

“The process is straightforward, cost-effective and can be done at home,” El-Kady said. “One only needs a DVD burner and graphite oxide dispersion in water, which is commercially available at a moderate cost.”

Flexible electronics uses

The new micro-supercapacitors are also highly bendable and twistable, making them potentially useful as energy-storage devices in flexible electronics like roll-up displays and TVs, e-paper, and even wearable electronics.

The micro-supercapacitors can also be fabricated directly on a chip using the same technique, making them highly useful for integration into micro-electromechanical systems (MEMS) or complementary metal-oxide-semiconductors (CMOS).

These micro-supercapacitors show excellent cycling stability, an important advantage over micro-batteries, which have shorter lifespans and which could pose a major problem when embedded in permanent structures — such as biomedical implants, active radio-frequency identification tags and embedded micro-sensors — for which no maintenance or replacement is possible.

As they can be directly integrated on-chip, these micro-supercapacitors may help to better extract energy from solar, mechanical and thermal sources and thus make more efficient self-powered systems. They could also be fabricated on the backside of solar cells in both portable devices and rooftop installations to store power generated during the day for use after sundown, helping to provide electricity around the clock when connection to the grid is not possible.

Sheet of micro-supercapacitors (credit: UCLA)

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