Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Is There a Micro-Supercapacitor in Your Future? Don’t Bet Against It

A technique in which high temperature chlorination is used to etch carbon electrodes into a film of titanium carbide has the potential to yield a supercapacitor compatible with the fabrication of a silicon microchip and boasting a high power density and practically infinite cycle life.
A technique in which high temperature chlorination is used to etch carbon electrodes into a film of titanium carbide has the potential to yield a supercapacitor compatible with the fabrication of a silicon microchip and boasting a high power density and practically infinite cycle life.

Abstract:
"Just think how often your fancy new mobile phone or computer has become little more than a paperweight because the battery lost its zeal for doing its job," says John Chmiola, a chemist with the Lawrence Berkeley National Laboratory (Berkeley Lab). "At a time when cellphones can do more than computers could do at the beginning of the Clinton presidency, it would be an understatement to say that batteries have not been holding up their end of the mobile device bargain."

Is There a Micro-Supercapacitor in Your Future? Don’t Bet Against It

Berkeley, CA | Posted on April 27th, 2010

Chmiola is a staff scientist in the Advanced Energy Technologies Department of Berkeley Lab's Environmental Energy Technologies Division. His research is aimed at addressing this problem of relatively short-lived portable energy storage devices. Chmiola believes he has found a solution in electrochemical capacitors, which are commonly referred to as "supercapacitors" because of their higher energy storage densities than conventional dielectric capacitors and higher abuse tolerance than batteries.

In a paper published in the April 23, 2010 issue of the journal Science, titled "Monolithic Carbide-Derived Carbon Films for Micro-Supercapacitors," Chmiola and Yury Gogotsi of Drexel University, along with other co-authors, describe a unique new technique for integrating high performance micro-sized supercapacitors into a variety of portable electronic devices through common microfabrication techniques.

By etching electrodes made of monolithic carbon film into a conducting substrate of titanium carbide, Chmiola and Gogotsi were able to create micro-supercapacitors featuring an energy storage density that was at least double that of the best supercapacitors now available. When used in combination with microbatteries, the power densities and rapid-fire cycle times of these micro-supercapacitors should substantially boost the performance and longevity of portable electric energy storage devices.

"The prospect of integrating batteries and supercapacitors with the micro-electromechanical systems (MEMS) they power represents a conceptual leap forward over existing methods for powering such devices," Chmiola says. "Furthermore, since the same fabrication processes that produced the devices needing the electrical energy also produced the devices storing that energy, we provide a framework for potentially increasing the density of microelectronic devices and allowing improved functionality, reduced complexity, and enhanced redundancy."

The two principal systems today for storing electrical energy are batteries and supercapacitors. Batteries store electrical energy in the form of chemical reactants and generally display even higher energy storage densities than supercapacitors. However, the charging and discharging of a battery exact a physical toll on electrodes that eventually ends the battery's life after several thousand charge-discharge cycles. In supercapacitors, energy is stored as electrical charge, which does not impact electrodes during operation. This allows supercapacitors to be charged and discharged millions of times.

"We have known for some time that supercapacitors are faster and longer-lasting alternatives to conventional batteries," Gogotsi says, "so we decided to see if it would be possible to incorporate them into microelectronic devices and if there would be any advantage to doing so."

Chmiola and Gogotsi chose titanium carbide as the substrate in this study because while all metal carbides can be selectively etched with halogens so that a monolithic carbon film is left behind, titanium carbide is readily available, relatively inexpensive and can be used at the same temperatures as other microfabrication processes.

"Plus, we have a body of work on titanium carbide precursor carbons that provided us with a lot of data to draw from for understanding the underlying science," Chmiola says.

The process started with titanium carbide ceramic plates being cut to size and polished to a thinness of approximately 300 micrometers. The titanium was then selectively etched from one face of the plate using chlorine at elevated temperatures, a process that is similar to current dry-etching techniques for MEMS and microchip fabrications.

Chlorinating the titanium removed the metal atoms and left in place a monolithic carbon film, a material with a proven track record in supercapacitors produced via the traditional "sandwich construction" technique.

"By using microfabrication techniques to produce our supercapacitors we avoided many of the pitfalls of the traditional method," says Chmiola, "namely poor contact between electro-active particles in the electrode, large void spaces between particles that don't store charge, and poor contact between the electro-active materials and the external circuitry."

The electrical charge storage densities of the micro-supercapacitors were measured in two common electrolytes. As promising as the results were, Chmiola notes the impressive figures were achieved without the "decades of optimization" that other electronic devices have undergone. This, he says, "hints at the possibility that the energy density ceiling for microfabricated supercapacitors is, indeed, quite high."

Adds Gogotsi, "Given their practically infinite cycle life, micro-supercapacitors seem ideal for capturing and storing energy from renewable resources and for on-chip operations."

The next step of the work is to scale down the size of the electrodes and improve the dry etching procedure for removing metal atoms from metal carbides to make the process even more compatible with commercial microfabrication technology. At Berkeley Lab, Chmiola is working on the development of new electrolytes that can help increase the energy storage densities of his micro-supercapacitors. He is also investigating the factors that control the usable voltage window of different electrolytes at a carbon electrode.

"My ultimate goals are to increase energy stored to levels closer to batteries, and preserve both the million-plus charge-discharge cycles and recharge times of less than five minutes of these devices," says Chmiola. "I think this is what the end users of portable energy storage devices really desire."

Co-authoring the Science paper with Chmiola and Gogotsi were Celine Largeot, Pierre-Louis Taberna and Patrice Simon of Toulouse University in France.

####

About Berkeley Lab
Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California.

For more information, please click here

Contacts:
Lynn Yarris
(510) 486-5375

Copyright © Berkeley Lab

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

FEI adds Phase Plate Technology and Titan Halo TEM to its Structural Biology Product Portfolio: New solutions provide the high-quality imaging and contrast necessary to analyze the 3D structure of molecules and molecular complexes July 28th, 2014

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

Bruker Announces Acquisition of High-Speed, 3D Super-Resolution Fluorescence Microscopy Company Vutara July 28th, 2014

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Possible Futures

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Surface Characteristics Influence Cellular Growth on Semiconductor Material March 12th, 2014

MEMS

Carbyne morphs when stretched: Rice University calculations show carbon-atom chain would go metal to semiconductor July 21st, 2014

Leti to Present Technological Platforms Targeting Industry’s Needs for the Future at Semicon West Workshop: Presentation at STS Session to Focus on Leti Advanced Lithography Programs for 1x Nodes and on Silicon Photonics at TechXPot June 25th, 2014

Mirrorcle Technologies Opens New Company Headquarters May 27th, 2014

Ziptronix and EV Group Demonstrate Submicron Accuracies for Wafer-to-Wafer Hybrid Bonding: Enables Fine-Pitch Connections for 3D Applications, Including Image Sensors, Memory and 3D SoCs May 27th, 2014

Announcements

FEI adds Phase Plate Technology and Titan Halo TEM to its Structural Biology Product Portfolio: New solutions provide the high-quality imaging and contrast necessary to analyze the 3D structure of molecules and molecular complexes July 28th, 2014

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

Bruker Announces Acquisition of High-Speed, 3D Super-Resolution Fluorescence Microscopy Company Vutara July 28th, 2014

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Energy

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Steam from the sun: New spongelike structure converts solar energy into steam July 21st, 2014

3-D nanostructure could benefit nanoelectronics, gas storage: Rice U. researchers predict functional advantages of 3-D boron nitride July 15th, 2014

Nanotechnology that will impact the Security & Defense sectors to be discussed at NanoSD2014 conference July 8th, 2014

Battery Technology/Capacitors/Generators/Piezoelectrics/Thermoelectrics

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Nano-supercapacitors for electric cars July 25th, 2014

Compact Vibration Harvester Power Supply with Highest Efficiency Opens Door to “Fix-and-Forget” Sensor Nodes July 23rd, 2014

UCF Nanotech Spinout Developing Revolutionary Battery Technology: Power the Next Generation of Electronics with Carbon July 23rd, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE