Print  |  Send  |   

Graphene supercapacitor holding promise for portable electronics

March 19, 2012 // Julien Happich

Graphene supercapacitor holding promise for portable electronics

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.


Page 1 of 4

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.

1 | 2 | 3 | 4 | Next page

All news

Passives components,Power components

Follow us

Fast, Accurate & Relevant for Design Engineers only!

Technical papers     

Linear video channel

READER OFFER

Read more

This month, Arrow Electronics is giving away ten BeMicro Max 10 FPGA evaluation boards together with an integrated USB-Blaster, each package being worth 90 Euros, for EETimes Europe's readers to win.

Designed to get you started with using an FPGA, the BeMicro Max 10 adopts Altera's non-volatile MAX 10 FPGA built on 55-nm flash process.

The MAX 10 FPGAs are claimed to revolutionize...

MORE INFO AND LAST MONTH' WINNERS...

Design centers     

Automotive
Infotainment Making HDTV in the car reliable and secure

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.

 

You must be logged in to view this page

Login here :