Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

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

UC research partnership explores how to best harness solar power March 2nd, 2015

Researchers turn unzipped nanotubes into possible alternative for platinum: Aerogel catalyst shows promise for fuel cells March 2nd, 2015

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

New Hopes for Treatment of Intestine Cancer by Edible Nanodrug March 2nd, 2015

Possible Futures

European roadmap for graphene science and technology published February 25th, 2015

Quantum research past, present and future for discussion at AAAS February 16th, 2015

World’s first compact rotary 3D printer-cum-scanner unveiled at AAAS by NTU Singapore start-up: With production funded by crowdsourcing, the first unit will be delivered to the United States in March February 16th, 2015

Nanotechnology Electric Vehicle (EV) Market Analysis Report 2015: According to Radiant Insights, Inc February 13th, 2015

MEMS

MEMS/Sensors Drive IoT/E Innovation in Europe: MEMS Executive Congress Europe Speakers Explore Internet of Things/Everything in Automotive, Consumer, Industrial Markets, 9-10, March in Copenhagen February 9th, 2015

STMicroelectronics Leads European Research Project to Develop Next-Generation Optical MEMS: Extension to a project launched in 2013 builds on current efforts to enable technologies for next-generation applications February 4th, 2015

Entegris Launches Dispense System Optimized for 3D and MEMS Applications: New IntelliGen® MV system delivers process efficiencies and defect reduction in dispensing mid-viscosity fluids February 3rd, 2015

CNSE's Smart System Technology & Commercialization Center Successfully Recertifies as ISO 9001:2008 January 12th, 2015

Announcements

UC research partnership explores how to best harness solar power March 2nd, 2015

Researchers turn unzipped nanotubes into possible alternative for platinum: Aerogel catalyst shows promise for fuel cells March 2nd, 2015

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

New Hopes for Treatment of Intestine Cancer by Edible Nanodrug March 2nd, 2015

Energy

UC research partnership explores how to best harness solar power March 2nd, 2015

New nanowire structure absorbs light efficiently: Dual-type nanowire arrays can be used in applications such as LEDs and solar cells February 25th, 2015

Learning by eye: Silicon micro-funnels increase the efficiency of solar cells February 25th, 2015

Magnetic nanoparticles enhance performance of solar cells X-ray study points the way to higher energy yields February 25th, 2015

Battery Technology/Capacitors/Generators/Piezoelectrics/Thermoelectrics/Energy storage

Scientific breakthrough in rechargeable batteries: Researchers from Singapore and Québec Team Up to Develop Next-Generation Materials to Power Electronic Devices and Electric Vehicles February 28th, 2015

In quest for better lithium-air batteries, chemists boost carbon's stability: Nanoparticle coatings improve stability, cyclability of '3DOm' carbon February 25th, 2015

Dendrite eraser: New electrolyte rids batteries of short-circuiting fibers: Solution enables a battery with both high efficiency & current density February 24th, 2015

New Paper-like Material Could Boost Electric Vehicle Batteries: Researchers create silicon nanofibers 100 times thinner than human hair for potential applications in batteries for electric cars and personal electronics February 20th, 2015

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 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE