Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Battery boost

This schematic shows a silicon-carbon nanocomposite granule formed through a hierarchical bottom-up assembly process. Annealed carbon black particles are coated by silicon nanoparticles and then assembled into rigid spheres with open interconnected internal channels. Credit: Courtesy of Gleb Yushin
This schematic shows a silicon-carbon nanocomposite granule formed through a hierarchical bottom-up assembly process. Annealed carbon black particles are coated by silicon nanoparticles and then assembled into rigid spheres with open interconnected internal channels. Credit: Courtesy of Gleb Yushin

Abstract:
High-Performance Lithium-Ion Anode Uses "Bottom Up, Self-Assembled" Nanocomposite Materials to Increase Capacity

By John Toon

Battery boost

Atlanta, GA | Posted on March 15th, 2010

A new high-performance anode structure based on silicon-carbon nanocomposite materials could significantly improve the performance of lithium-ion batteries used in a wide range of applications from hybrid vehicles to portable electronics.

Produced with a "bottom-up" self-assembly technique, the new structure takes advantage of nanotechnology to fine-tune its materials properties, addressing the shortcomings of earlier silicon-based battery anodes. The simple, low-cost fabrication technique was designed to be easily scaled up and compatible with existing battery manufacturing.

Details of the new self-assembly approach were published online in the journal Nature Materials on March 14.

"Development of a novel approach to producing hierarchical anode or cathode particles with controlled properties opens the door to many new directions for lithium-ion battery technology," said Gleb Yushin, an assistant professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. "This is a significant step toward commercial production of silicon-based anode materials for lithium-ion batteries."

The popular and lightweight batteries work by transferring lithium ions between two electrodes - a cathode and an anode - through a liquid electrolyte. The more efficiently the lithium ions can enter the two electrodes during charge and discharge cycles, the larger the battery's capacity will be.

Existing lithium-ion batteries rely on anodes made from graphite, a form of carbon. Silicon-based anodes theoretically offer as much as a ten-fold capacity improvement over graphite, but silicon-based anodes have so far not been stable enough for practical use.

Graphite anodes use particles ranging in size from 15 to 20 microns. If silicon particles of that size are simply substituted for the graphite, expansion and contraction as the lithium ions enter and leave the silicon creates cracks that quickly cause the anode to fail.

The new nanocomposite material solves that degradation problem, potentially allowing battery designers to tap the capacity advantages of silicon. That could facilitate higher power output from a given battery size - or allow a smaller battery to produce a required amount of power.

"At the nanoscale, we can tune materials properties with much better precision than we can at traditional size scales," said Yushin. "This is an example of where having nanoscale fabrication techniques leads to better materials."

Electrical measurements of the new composite anodes in small coin cells showed they had a capacity more than five times greater than the theoretical capacity of graphite.

Fabrication of the composite anode begins with formation of highly conductive branching structures - similar to the branches of a tree - made from carbon black nanoparticles annealed in a high-temperature tube furnace. Silicon nanospheres with diameters of less than 30 nanometers are then formed within the carbon structures using a chemical vapor deposition process. The silicon-carbon composite structures resemble "apples hanging on a tree."

Using graphitic carbon as an electrically-conductive binder, the silicon-carbon composites are then self-assembled into rigid spheres that have open, interconnected internal pore channels. The spheres, formed in sizes ranging from 10 to 30 microns, are used to form battery anodes. The relatively large composite powder size - a thousand times larger than individual silicon nanoparticles - allows easy powder processing for anode fabrication.

The internal channels in the silicon-carbon spheres serve two purposes. They admit liquid electrolyte to allow rapid entry of lithium ions for quick battery charging, and they provide space to accommodate expansion and contraction of the silicon without cracking the anode. The internal channels and nanometer-scale particles also provide short lithium diffusion paths into the anode, boosting battery power characteristics.

The size of the silicon particles is controlled by the duration of the chemical vapor deposition process and the pressure applied to the deposition system. The size of the carbon nanostructure branches and the size of the silicon spheres determine the pore size in the composite.

Production of the silicon-carbon composites could be scaled up as a continuous process amenable to ultra high-volume powder manufacturing, Yushin said. Because the final composite spheres are relatively large when they are fabricated into anodes, the self-assembly technique avoids the potential health risks of handling nanoscale powders, he added.

Once fabricated, the nanocomposite anodes would be used in batteries just like conventional graphite structures. That would allow battery manufacturers to adopt the new anode material without making dramatic changes in production processes.

So far, the researchers have tested the new anode through more than a hundred charge-discharge cycles. Yushin believes the material would remain stable for thousands of cycles because no degradation mechanisms have become apparent.

"If this technology can offer a lower cost on a capacity basis, or lighter weight compared to current techniques, this will help advance the market for lithium batteries," he said. "If we are able to produce less expensive batteries that last for a long time, this could also facilitate the adoption of many 'green' technologies, such as electric vehicles or solar cells."

In addition to Yushin, the paper's authors included Alexandre Magasinki, Patrick Dixon and Benjamin Hertzberg - all from Georgia Tech - and Alexander Kvit from the Materials Science Center and Materials Science Department at the University of Wisconsin-Madison, and Jorge Ayala from Superior Graphite. The paper also acknowledges the contributions of Alexander Alexeev at Georgia Tech and Igor Luzinov from Clemson University.

The research was partially supported by a Small Business Innovation Research (SBIR) grant from the National Aeronautics and Space Administration (NASA) to Chicago-based Superior Graphite and Atlanta-based Streamline Nanotechnologies, Inc.

####

About Georgia Institute of Technology
The Georgia Institute of Technology is one of the nation's top research universities, distinguished by its commitment to improving the human condition through advanced science and technology.

Georgia Tech's campus occupies 400 acres in the heart of the city of Atlanta, where 20,000 undergraduate and graduate students receive a focused, technologically based education.

For more information, please click here

Contacts:
John Toon

404-894-6986

Abby Vogel
404-385-3364

Copyright © Georgia Institute of Technology

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

New Biological Nano-Fertilizers Presented in Iran as Appropriate Replacements for Chemical Fertilizers April 18th, 2015

Iranian Foodstuff, Agricultural Industries Welcome Nanotechnology Packaging Bags April 18th, 2015

Nanocomposites Play Effective Role in Production of Smart Fibers April 18th, 2015

Dais Analytic Corporation Appoints Eliza Wang to Board of Directors: Company's Newest Director Brings Expertise in Commercial and Legal Matters Both in the United States and China; Joins on the Heels of Successful Business Development Trade Mission to China April 18th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Engineer improves rechargeable batteries with MoS2 nano 'sandwich' April 18th, 2015

New Biological Nano-Fertilizers Presented in Iran as Appropriate Replacements for Chemical Fertilizers April 18th, 2015

Beyond the lithium ion -- a significant step toward a better performing battery April 18th, 2015

Oxford Instruments commissions high field outsert magnet system for the National High Magnetic Field Laboratory 32 Tesla magnet program April 17th, 2015

Possible Futures

A glass fiber that brings light to a standstill: By coupling photons to atoms, light in a glass fiber can be slowed down to the speed of an express train; for a short while it can even be brought to a complete stop April 9th, 2015

Nanotechnology in Medical Devices Market is expected to reach $8.5 Billion by 2019 March 25th, 2015

Nanotechnology Enabled Drug Delivery to Influence Future Diagnosis and Treatments of Diseases March 21st, 2015

Nanocomposites Market Growth, Industry Outlook To 2020 by Grand View Research, Inc. March 21st, 2015

Academic/Education

JPK reports on the use of the NanoWizardŽ 3 AFM system at the Hebrew University of Jerusalem April 14th, 2015

UK National Graphene Institute Selects Bruker as Official Partner: World-Leading Graphene Research Facility Purchases Multiple Bruker AFMs April 7th, 2015

SUNY Poly CNSE and Title Sponsor SEFCU Name Capital Region Teams Advancing to the Final Round of the 2015 New York Business Plan Competition March 30th, 2015

LAMDAMAP 2015 hosted by the University March 26th, 2015

Self Assembly

Carnegie Mellon chemists create tiny gold nanoparticles that reflect nature's patterns April 9th, 2015

DWI scientists program the lifetime of self-assembled nanostructures April 9th, 2015

In situ production of biofunctionalised few-layer defect-free microsheets of graphene April 7th, 2015

Designer's toolkit for dynamic DNA nanomachines: Arm-waving nanorobot signals new flexibility in DNA origami March 27th, 2015

Discoveries

Optical resonance-based biosensors designed for medical applications April 18th, 2015

Iranian Foodstuff, Agricultural Industries Welcome Nanotechnology Packaging Bags April 18th, 2015

Nanocomposites Play Effective Role in Production of Smart Fibers April 18th, 2015

Protein Building Blocks for Nanosystems: Scientists develop method for producing bio-based materials with new properties April 17th, 2015

Announcements

New Biological Nano-Fertilizers Presented in Iran as Appropriate Replacements for Chemical Fertilizers April 18th, 2015

Iranian Foodstuff, Agricultural Industries Welcome Nanotechnology Packaging Bags April 18th, 2015

Nanocomposites Play Effective Role in Production of Smart Fibers April 18th, 2015

Dais Analytic Corporation Appoints Eliza Wang to Board of Directors: Company's Newest Director Brings Expertise in Commercial and Legal Matters Both in the United States and China; Joins on the Heels of Successful Business Development Trade Mission to China April 18th, 2015

Energy

Dais Analytic Corporation Appoints Eliza Wang to Board of Directors: Company's Newest Director Brings Expertise in Commercial and Legal Matters Both in the United States and China; Joins on the Heels of Successful Business Development Trade Mission to China April 18th, 2015

Major advance in artificial photosynthesis poses win/win for the environment: Berkeley Lab researchers perform solar-powered green chemistry with captured CO2 April 16th, 2015

Newly-Developed Nanocatalysts Increase Performance of Fuel Cells April 16th, 2015

Graphenea embarks on a new era April 16th, 2015

Automotive/Transportation

Nanocomposites Play Effective Role in Production of Smart Fibers April 18th, 2015

Beyond the lithium ion -- a significant step toward a better performing battery April 18th, 2015

Newly-Developed Nanocatalysts Increase Performance of Fuel Cells April 16th, 2015

Cobalt film a clean-fuel find: Rice University discovery is efficient, robust at drawing hydrogen and oxygen from water April 15th, 2015

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

Engineer improves rechargeable batteries with MoS2 nano 'sandwich' April 18th, 2015

Beyond the lithium ion -- a significant step toward a better performing battery April 18th, 2015

Harvesting energy from electromagnetic waves: In the future, clean alternatives such as harvesting energy from electromagnetic waves may help ease the world's energy shortage April 15th, 2015

A KAIST research team develops a hyper-stretchable elastic-composite energy harvester April 13th, 2015

Research partnerships

Beyond the lithium ion -- a significant step toward a better performing battery April 18th, 2015

Light in a spin: Researchers demonstrate angular accelerating light April 15th, 2015

Graphene pushes the speed limit of light-to-electricity conversion: Researchers from ICFO, MIT and UC Riverside have been able to develop a graphene-based photodetector capable of converting absorbed light into an electrical voltage at ultrafast timescales April 14th, 2015

Scientists create invisible objects without metamaterial cloaking April 14th, 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