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
Failed merger talks won't stop Dialog
July 23, 2014
AMS, formerly known as Austriamicrosystems, and Dialog Semiconductor couldn't agree the terms of a merger, which feels like ...
XCore architecture attracts Bosch investment
Steep growth for thermoelectric energy harvesting, says Infinergia Consulting
AMS, Dialog merger talks fail
MIT wrist-robot adds extra fingers
Li-ion batteries market for EVs to quadruple in a decade
July 22, 2014
Worldwide revenues from Li-ion batteries for all consumer EVs will grow from $5.7 billion in 2014 to $24.1 billion in 2023, ...
Monolithic Power Systems signs with Avnet Memec
Thoughts on energy harvesting for wearable equipment
Will laser ignition replace the venerable spark plug?
- Testing GPS with a Simulator
- DSM presents: Select the best plastic for DDR4
- Dual 13A μModule Regulator with Digital Interface for Remote Monitoring & Control of Power
- Exploring the Business Model Evolution of High-Tech Equipment Manufacturers
InterviewCEO interview: China, not Apple, is way to go, says mCube CEO
Ben Lee, CEO of MEMS startup mCube, explains why he wants to spend $37 million on being a supplier of sensors to Chinese ODMs and avoiding a design win with Apple or Samsung.
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, Altium Ltd is offering EETimes Europe's readers the chance to win one TASKING VX-Toolset for ARM Cortex-M Premium Edition, normally licensed for 2.395 Euros, for ultra-rapid prototyping and code development around ARM Cortex-M based microcontrollers.
The VX-toolset for ARM is the first TASKING compiler suite to receive the Software Platform technology, which is seamlessly...Read more
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.