Graphene supercapacitor holding promise for portable electronics
March 19, 2012 // Julien Happich
Electrochemical capacitors (ECs), also known as supercapacitors or ultracapacitors, differ from regular capacitors that you would find in your TV or computer in that they store sustantially higher amounts of charges. They have garnered attention as energy storage devices as they charge and discharge faster than batteries, yet they are still limited by low energy densities, only a fraction of the energy density of batteries.
An EC that combines the power performance of capacitors with the high energy density of batteries would represent a significant advance in energy storage technology. This requires new electrodes that not only maintain high conductivity but also provide higher and more accessible surface area than conventional ECs that use activated carbon electrodes.
Now researchers at UCLA have used a standard LightScribe DVD optical drive to produce such electrodes. The electrodes are composed of an expanded network of graphene a one-atom-thick layer of graphitic carbon that shows excellent mechanical and electrical properties as well as exceptionally high surface area. UCLA researchers from the Department of Chemistry and Biochemistry, the Department of Materials Science and Engineering, and the California NanoSystems Institute have demonstrated high-performance graphene-based electrochemical capacitors that maintain excellent electrochemical attributes under high mechanical stress. The paper is published in the journal Science.
The process is based on coating a DVD disc with a film of graphite oxide that is then laser treated inside a LightScribe DVD drive to produce graphene electrodes. Typically, the performance of energy storage devices is evaluated by two main figures, the energy density and power density. Suppose we are using the device to run an electric car the energy density tells us how far the car can go a single charge whereas the power density tells us how fast the car can go. Here, devices made with Laser Scribed Graphene (LSG) electrodes exhibit ultrahigh energy density values in different electrolytes while maintaining the high power density and excellent cycle stability of ECs. Moreover, these ECs maintain excellent electrochemical attributes under high mechanical stress and thus hold promise for high power, flexible electronics.All news
Google locks future wearable IP with smart lens patents
April 16, 2014
Yesterday, 15th of April, US-based Google fans were granted the privilege to exchange $1500 for a ďpairĒ of Google Glass. ...
Porsche connects infotainment to cloud with HTML5
Anglia signs with DEM Manufacturing
RFMW Ltd to distribute Aviacommís transceivers
Sensors, actuators market on 11% CAGR to 2018
Additional conference complements Sensor + Test trade fair
April 15, 2014
As an add-on to the Sensor + Test trade fair later this year in Nuremberg (Germany), the organizer plans to launch the European ...
End of Windows XP boosted 1Q14 PC sales, says Gartner
Global HB LED market set to shine by 2018
Chinese smartphone maker undercuts western companies
- USB 5V 2.5A Output, 42V Input Synchronous Buck with Cable Drop Compensation
- Measurement applications across multiple test platforms
- Supplying DC input power to string inverters
- Supplying DC input power for HEV testing
InterviewHeartbleed challenges the Internet of Thing
The Heartbleed security bug is a key example of the fundamental security challenge for the Internet of Things says Green Hills Software as it launches a new security group.
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, Arrow Electronics is giving away ten XMC1200 lighting application kits, worth 100 Euros each, for EETimes Europe's readers to win.
Each kit combines Infineon’s brightness and colour control XMC1200 CPU board to drive flicker free LED dimming and colour changing, together with a colour LED card and a white LED card.
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.