Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > 'Popcorn' particle pathways promise better lithium-ion batteries

These are LFP particles as seen by a transmission electron microscope with overlay of the chemical information as seen by a scanning transmission X-ray microscope. The red represents lithium iron phosphate while green represents iron phosphate, or LFP without lithium.

Credit: Sandia National Laboratories
These are LFP particles as seen by a transmission electron microscope with overlay of the chemical information as seen by a scanning transmission X-ray microscope. The red represents lithium iron phosphate while green represents iron phosphate, or LFP without lithium.

Credit: Sandia National Laboratories

Abstract:
Researchers at Sandia National Laboratories have confirmed the particle-by-particle mechanism by which lithium ions move in and out of electrodes made of lithium iron phosphate (LiFePO4, or LFP), findings that could lead to better performance in lithium-ion batteries in electric vehicles, medical equipment and aircraft.

'Popcorn' particle pathways promise better lithium-ion batteries

Livermore, CA | Posted on June 11th, 2013

The research is reported in an article entitled, "Intercalation Pathway in Many-Particle LiFePO4 Electrode Revealed by Nanoscale State-of-Charge Mapping" in the journal Nano Letters, 2013, 13 (3), pp 866-872. Authors include Sandia physicist Farid El Gabaly and William Chueh of Stanford University.

LFP, a natural mineral of the olivine family, is one of the newer materials being used in lithium-ion batteries and is known to be safer and longer-lasting than the lithium cobalt oxide (LiCoO2) compound used in smart phones, laptops and other consumer electronics.

While LFP material is intriguing to researchers and battery manufacturers for those reasons, the process by which lithium ions move in and out of LFP as the battery stores and releases its energy is not well understood. This has proven to be a barrier to the material's widespread adoption.

Cathode materials like LFP are critical in the search for higher-capacity, long-life, lithium-ion batteries for applications where batteries can't be replaced as easily or as often as they are in consumer electronics. Larger applications where lithium cobalt oxide cells eventually could be replaced by LFP batteries include electric vehicles and aircraft.

Popcorn-like particle movements seen via microscopy technique

By observing complete battery cross-sections, the researchers have provided key insights on a controversy over the process that limits the battery charging and discharging rates.

Previous attempts to optimize the charging/discharging speed have included coating the particles to increase their electrical conductivity and reducing particle size to speed up their transformation, but have overlooked the initiation process that may well be the critical rate-limiting step in the way that lithium moves from a particle's exterior to its interior.

By using X-ray microscopy to examine ultrathin slices of a commercial-grade battery, Sandia researchers found evidence that charging and discharging in LFP is limited by the initiation of phase transformation, or nucleation, and is unaffected by particle size.

The LFP electrode forms a mosaic of homogeneous particles that are in either a lithium-rich or lithium-poor state. The Sandia research confirms the particle-by-particle, or mosaic, pathway of phase transformations due to insertion of lithium ions into the cathode. The findings contradict previous assumptions.

"One propagation theory said that when all the particles were exposed to lithium, they would all start discharging slowly together in a concurrent phase transformation," said El Gabaly. "We've now seen that the process is more like popcorn. One particle is completely discharged, then the next, and they go one-by-one like popcorn, absorbing the lithium."

Slicing-and-dicing helps understanding of lithium-ion charging

Lithium ions move in and out of battery electrode materials as they are charged and discharged. When a rechargeable lithium-ion battery is charged, an external voltage source extracts lithium ions from the cathode (positive electrode) material, in a process known as "delithiation." The lithium ions move through the electrolyte and are inserted (intercalated) in the anode (negative electrode) material, in a process known as "lithiation." The same process happens in reverse when discharging energy from the battery.

"We observed that there were only two phases, where the particle either had lithium or it didn't," said El Gabaly. "In many previous studies, researchers have focused on understanding the charging process inside one particle."

El Gabaly and his Sandia colleagues took a slice just a bit thicker than a human hair from a commercial-grade battery, just one layer of LFP particles, and mapped the locations of the lithium in about 450 particles when the battery was at different states of charge.

"Our discovery was made possible by mapping the lithium in a relatively large particle ensemble," he said.

Many tools, facilities contribute to research

The researchers were able to build a commercial-grade coin-cell battery from raw materials using Sandia's cell battery prototyping facility in New Mexico, which is the largest Department of Energy facility equipped to manufacture small lots of lithium-ion cells. The battery was then charged, tested for normal behavior, and disassembled at Sandia's Livermore, Calif., facility through a new method of slicing layers that conserved the spatial arrangement from the cathode to the anode.

The Sandia researchers went to Lawrence Berkeley National Laboratory to characterize the materials with state-of-the-art scanning transmission X-ray microscopy (STXM) at the Advanced Light Source (ALS), and then returned to Sandia's California site for study by transmission electron microscopy (TEM).

"The X-ray spectroscopy from the ALS tells you what's inside an individual particle, or where the lithium is, but it has low spatial resolution. We needed the electron microscopy of the same slice to tell us where all the particles were distributed across the entire layer of the battery," said Chueh, a former Sandia Truman Fellow who is lead author of the journal article and an assistant professor and center fellow at the Precourt Institute of Energy at Stanford University.

Sandia's research team and others presented their technical findings at the recent Materials Research Society Spring Meeting in San Francisco. As a result of that presentation, El Gabaly said, other researchers are using the results to validate theoretical models. The team also may partner with industry, as one company has already indicated a strong interest in Sandia conducting similar studies on different, more complex battery materials.

The research team at Sandia has been funded internally, including support from the Sandia Truman Fellowship in National Security Science and Engineering, and by the Department of Energy's Office of Science, which also supports the ALS.

####

About DOE/Sandia National Laboratories
Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin company, for the U.S. Department of Energy's National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies and economic competitiveness.

For more information, please click here

Contacts:
Mike Janes

925-294-2447

Copyright © DOE/Sandia National Laboratories

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

Draw out of the predicted interatomic force August 30th, 2015

Iranian Scientists Use Artemisia Annua Plant to Produce Breast Cancer Drugs August 29th, 2015

Small but heading for the big time: Nanobiotix half year results for the six months ended 30 June 2015, in line with expectations: Major clinical achievements and corporate developments August 28th, 2015

A new technique to make drugs more soluble August 28th, 2015

Imaging

Nanolab Technologies LEAPS Forward with High-Performance Analysis Services to the World: Nanolab Orders Advanced Local Electrode Atom Probe (LEAP®) Microscope from CAMECA Unit of AMETEK Materials Analysis Division August 27th, 2015

50 Years of Scanning Electron Microscopy from ZEISS: ZEISS celebrates the birth of the first commercial scanning electron microscope in 1965 August 26th, 2015

Announcing Oxford Instruments and School of Physics signing a Memorandum of Understanding August 26th, 2015

Kwansei Gakuin University in Hyogo, Japan, uses Raman microscopy to study crystallographic defects in silicon carbide wafers August 25th, 2015

Laboratories

Major innovation in molecular imaging delivers spatial and spectral info simultaneously: Berkeley Lab scientist invents technique to combine spectroscopy with super-resolution microscopy, enabling new ways to examine cell structures and study diseases August 17th, 2015

Drexel engineers 'sandwich' atomic layers to make new materials for energy storage August 15th, 2015

Surprising discoveries about 2-D molybdenum disulfide: Berkeley Lab researchers use award-winning campanile probe on promising semiconductor August 15th, 2015

New ORNL hybrid microscope offers unparalleled capabilities August 10th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Draw out of the predicted interatomic force August 30th, 2015

These microscopic fish are 3-D-printed to do more than swim: Researchers demonstrate a novel method to build microscopic robots with complex shapes and functionalities August 26th, 2015

Glitter from silver lights up Alzheimer's dark secrets August 25th, 2015

Southampton scientists find new way to detect ortho-para conversion in water August 25th, 2015

Discoveries

Draw out of the predicted interatomic force August 30th, 2015

Iranian Scientists Use Artemisia Annua Plant to Produce Breast Cancer Drugs August 29th, 2015

A new technique to make drugs more soluble August 28th, 2015

Nanocatalysts improve processes for the petrochemical industry August 28th, 2015

Announcements

Draw out of the predicted interatomic force August 30th, 2015

Iranian Scientists Use Artemisia Annua Plant to Produce Breast Cancer Drugs August 29th, 2015

Small but heading for the big time: Nanobiotix half year results for the six months ended 30 June 2015, in line with expectations: Major clinical achievements and corporate developments August 28th, 2015

A new technique to make drugs more soluble August 28th, 2015

Tools

Nanolab Technologies LEAPS Forward with High-Performance Analysis Services to the World: Nanolab Orders Advanced Local Electrode Atom Probe (LEAP®) Microscope from CAMECA Unit of AMETEK Materials Analysis Division August 27th, 2015

Nanometrics to Participate in the Citi 2015 Global Technology Conference August 26th, 2015

50 Years of Scanning Electron Microscopy from ZEISS: ZEISS celebrates the birth of the first commercial scanning electron microscope in 1965 August 26th, 2015

Announcing Oxford Instruments and School of Physics signing a Memorandum of Understanding August 26th, 2015

Automotive/Transportation

CWRU researchers efficiently charge a lithium-ion battery with solar cell: Coupling with perovskite solar cell holds potential for cleaner cars and more August 27th, 2015

Lehigh University-DuPont tribology research seeks to reduce wear and waste August 13th, 2015

Flexible dielectric polymer can stand the heat August 6th, 2015

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Aerospace/Space

National Space Society Welcomes Janet Ivey As New NSS Governor: Janet Ivey of Janet's Planet is NOW IN ORBIT as a member of the Board of Governors of the National Space Society August 27th, 2015

National Space Society Welcomes Geoff Notkin As New NSS Governor August 26th, 2015

A thin ribbon of flexible electronics can monitor health, infrastructure August 17th, 2015

Lehigh University-DuPont tribology research seeks to reduce wear and waste August 13th, 2015

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

CWRU researchers efficiently charge a lithium-ion battery with solar cell: Coupling with perovskite solar cell holds potential for cleaner cars and more August 27th, 2015

'Diamonds from the sky' approach turns CO2 into valuable products August 19th, 2015

Drexel engineers 'sandwich' atomic layers to make new materials for energy storage August 15th, 2015

Flexible, biodegradable device can generate power from touch (video) August 12th, 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







Car Brands
Buy website traffic