Graphene supercapacitor breaks storage record
December 10, 2010 // Julien Happich
Researchers in the US have made a graphene-based supercapacitor that can store as much energy per unit mass as nickel metal hydride batteries - but unlike batteries, it can be charged or discharged in just minutes or even seconds. The new device has a specific energy density of 85.6 Wh/kg at room temperature and 136 Wh/kg at 80 °C. These are the highest ever values for "electric double layer" supercapacitors based on carbon nanomaterials.
The new device was made by Bor Jang of US-based Nanotek Instruments and colleagues. It has electrodes made of graphene mixed with 5wt% Super P (an acetylene black that acts as a conductive additive) and 10wt% PTFE binder. A sheet of carbon just one atom thick, graphene is a very good electrical conductor as well as being extremely strong and flexible.The researchers coat the resulting slurry onto the surface of a current collector and assemble coin-sized capacitors in a glove box. The energy density values of the supercapacitor are comparable to that of nickel metal hydride batteries. "This new technology makes for an energy storage device that stores nearly as much energy as in a battery but which can be recharged in seconds or minutes," Jang explained. "We believe that this is truly a breakthrough in energy technology." The device might be used to recharge mobile phones, digital cameras and micro-EVs, he adds.
The team, which includes scientists from Angstron Materials in the US and Dalian University of Technology in China, are now working hard to further improve the energy density of the device. "Our goal is to make a supercapacitor that stores as much energy as the best lithium-ion batteries (for the same weight) but which can still be recharged in less than two minutes," said Jang.
His team first discovered that graphene could be used as a supercapacitor electrode material in 2006. Since then, scientists around the world have made great strides in improving the specific capacitance of these electrodes but the devices still fall short of the theoretical capacitance values of 550 F/g.
"Despite the theoretically high specific surface area of single-layer graphene (which can reach up to 2.675 m2/g), a supercapacitance of 550 F/g has not been reached in a real device because the graphene sheets tend to re-stack together," explained Jang. "We are trying to overcome this problem by developing a strategy that prevents the graphene sheets from sticking to each other face-to-face. This can be achieved if curved graphene sheets are used instead of flat ones."
Curved graphene sheets: Source Physicsworld
Graphene bandgap opened by vapor
Silicon Europe grows to cover 12 regions
October 13, 2015
The Silicon Europe project – set up in 2012 to link four regional clusters for electronics research and business development ...
More-than-Moore will lead, argues GloFo's Wijburg
Startup pitch-fest opens Semicon Europa show
MEMS, sensors get four sessions at IEDM 2015
Image sensors get seven papers at IEDM 2015
Nanohoops: A new approach to energize future devices
October 12, 2015
Researchers at the University of Oregon have shown that nanohoops can be made using a variety of atoms, not just those from ...
Melexis preps Sony sensor deal
Calibration reveals order of magnitude better accuracy, says Yokogawa
What's your definition of 'autonomous' car?
- Determine Balancing Current for the LTC3305 Lead-Acid Battery Balancer
- 3 Ways to Simplify Medical Device Testing
- Thread Networking Protocol Simplifies Connecting “Things” in the Home and Beyond
- High Voltage CMOS Amplifier Enables High Impedance Sensing with a Single IC
InterviewMEMS platforms are way to go, says Bosch's Finkbeiner
In the two years since we last interviewed Stefan Finkbeiner, CEO of Bosch Sensortec, the company has taken over from STMicroelectronics as the leading global supplier of MEMS components. Here he explains ...
Filter WizardCheck out the Filter Wizard Series of articles by Filter Guru Kendall Castor-Perry which provide invaluable practical Analog Design guidelines.
Linear video channel
READER OFFERRead more
This month, LabNation is giving away three of its SmartScope open source USB oscilloscopes, worth 229 Euros each, for EETimes Europe's readers to win.
Successfully funded through Kickstarter last year, the SmartScope is claimed to be the world's first test equipment designed to run on multiple operating systems and platforms such as smartphones, tablets and PCs. It is powered directly from... MORE INFO AND LAST MONTH' WINNERS...
December 15, 2011 | Texas instruments | 222901974
Unique Ser/Des technology supports encrypted video and audio content with full duplex bi-directional control channel over a single wire interface.