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
Pebble CEO turns back clock
December 09, 2013
The night before Eric Migicovsky opened a door to what would become a $10 million windfall, he was sitting in his living ...
Tyndall National Institute captures snapshots of moving atoms under bursts of light
Measurement technique allows survey of 3D micro objects
Qualcomm to evaluate CEA-Leti’s sequential 3D transistor technology
Thermoelectronic generator design improves efficiency of heat and solar energy into electricity
Multithreading boosts ThreadX on MIPS cores
December 06, 2013
Imagination Technologies and Express Logic have expanded their support of the ThreadX real time operating system on Imagination’s ...
UK distribution sees 5% growth in 2014
Global M2M innovations design contest
PHI Group plans acquisition Nord Energy to extend LED street lighting offering
- 3mm × 3mm QFN IC Directly Monitors 0V to 80V Supplies
- UltraCMOS® Semiconductor Technology Platforms: A Rapid Advancement of Process & Manufacturing
- Adaptive Cell Converter Topology Enables Constant Efficiency in PFC Applications
- Isolated 4-Channel, Thermocouple/RTD Temperature Measurement System with 0.5°C Accuracy
InterviewPerformance monitoring solution helps provide intelligent control of high power systems
A performance monitoring solution designed to enable companies to monitor high power IGBT module systems in locomotive, wind turbine, High Voltage DC and industrial drive applications was unveiled this ...
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
Internet of Things (IoT) manufacturer Ciseco has launched the Raspberry Pi ‘Wireless Inventors Kit’ (RasWIK), featuring 88 pieces to provide everything a Pi owner needs to follow a series of step-by-step projects or to create their own wireless devices, without the need for configuration or even writing code.
RasWIK has been designed to be highly accessible, demystifying the dark art of wireless and enabling anyone with basic computing skills to begin building wireless devices with a Raspberry Pi. You can create anything from a simple traffic light, to a battery monitor, or even a temperature gauge that sends data to the Xively IoT cloud so billions can access the data.This month, Ciseco is giving away twelve Raspberry Pi Wireless Inventors kits, worth £49.99 each for EETimes Europe's readers to win.
And the winners are...
In our previous reader offer, Farsens was giving away five kits for EEtimes Europe readers to evaluate its FenixVortex, Kineo and X1 wireless, battery free sensor tags.
Lucky winners include Mr A. Neil from the UK, Mr. E. Delvaux from Belgium, Mr Lengal from the Czech Republic, Mr H. Bijlsma from the Netherlands, and Mr G. Pfaff from Germany. All should be receiving their packages soon. Lets wish them some interesting findings with their projects.
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.