Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

DNA triggers shape-shifting in hydrogels, opening a new way to make 'soft robots' September 21st, 2017

Physicists develop new recipes for design of fast single-photon gun Physicists develop high-speed single-photon sources for quantum computers of the future September 21st, 2017

GLOBALFOUNDRIES Announces Availability of mmWave and RF/Analog on Leading FDX™ FD-SOI Technology Platform: Technology solution delivers ‘connected intelligence’ to next generation high-volume wireless and IoT applications with lower power and significantly reduced cost September 20th, 2017

GLOBALFOUNDRIES Announces Availability of Embedded MRAM on Leading 22FDX® FD-SOI Platform: Advanced embedded non-volatile memory solution delivers ‘connected intelligence’ by expanding SoC capabilities on the 22nm process node September 20th, 2017

Laboratories

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Solar-to-fuel system recycles CO2 to make ethanol and ethylene: Berkeley Lab advance is first demonstration of efficient, light-powered production of fuel via artificial photosynthesis September 19th, 2017

New insights into nanocrystal growth in liquid: Understanding process that creates complex crystals important for energy applications September 14th, 2017

Ames Laboratory scientists move graphene closer to transistor applications August 30th, 2017

Imaging

Graphene based terahertz absorbers: Printable graphene inks enable ultrafast lasers in the terahertz range September 13th, 2017

Chemical hot spots: Scanning tunneling microscopy measurements identify active sites on catalyst surfaces September 7th, 2017

Phenom-World selects Deben to supply a tensile stage as an accessory to their range of desktop SEMs August 29th, 2017

Govt.-Legislation/Regulation/Funding/Policy

DNA triggers shape-shifting in hydrogels, opening a new way to make 'soft robots' September 21st, 2017

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Solar-to-fuel system recycles CO2 to make ethanol and ethylene: Berkeley Lab advance is first demonstration of efficient, light-powered production of fuel via artificial photosynthesis September 19th, 2017

New insights into nanocrystal growth in liquid: Understanding process that creates complex crystals important for energy applications September 14th, 2017

Discoveries

DNA triggers shape-shifting in hydrogels, opening a new way to make 'soft robots' September 21st, 2017

Physicists develop new recipes for design of fast single-photon gun Physicists develop high-speed single-photon sources for quantum computers of the future September 21st, 2017

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Solar-to-fuel system recycles CO2 to make ethanol and ethylene: Berkeley Lab advance is first demonstration of efficient, light-powered production of fuel via artificial photosynthesis September 19th, 2017

Announcements

DNA triggers shape-shifting in hydrogels, opening a new way to make 'soft robots' September 21st, 2017

Physicists develop new recipes for design of fast single-photon gun Physicists develop high-speed single-photon sources for quantum computers of the future September 21st, 2017

GLOBALFOUNDRIES Introduces New 12nm FinFET Technology for High-Performance Applications September 20th, 2017

Copper catalyst yields high efficiency CO2-to-fuels conversion: Berkeley Lab scientists discover critical role of nanoparticle transformation September 20th, 2017

Tools

Graphene based terahertz absorbers: Printable graphene inks enable ultrafast lasers in the terahertz range September 13th, 2017

Chemical hot spots: Scanning tunneling microscopy measurements identify active sites on catalyst surfaces September 7th, 2017

Phenom-World selects Deben to supply a tensile stage as an accessory to their range of desktop SEMs August 29th, 2017

New results reveal high tunability of 2-D material: Berkeley Lab-led team also provides most precise band gap measurement yet for hotly studied monolayer moly sulfide August 26th, 2017

Automotive/Transportation

GLOBALFOUNDRIES Announces Availability of Embedded MRAM on Leading 22FDX® FD-SOI Platform: Advanced embedded non-volatile memory solution delivers ‘connected intelligence’ by expanding SoC capabilities on the 22nm process node September 20th, 2017

GLOBALFOUNDRIES Introduces New 12nm FinFET Technology for High-Performance Applications September 20th, 2017

More durable, less expensive fuel cells: University of Delaware researchers have developed a new technology that could speed up the commercialization of fuel cell vehicles September 5th, 2017

High-tech electronics made from autumn leaves: New process converts biomass waste into useful electronic devices August 30th, 2017

Aerospace/Space

Leti Develops Proof of Concept to Test Wireless Systems in Aircraft: Will Present Results of Joint Project at AeroTech Conference And Exhibition in Fort Worth, Texas, Sept. 26-28 September 20th, 2017

A revolution in lithium-ion batteries is becoming more realistic September 5th, 2017

The July 23 close fly-by of asteroid 2017 BS5 is explored in a Q&A with Dr. John S. Lewis, chief scientist at Deep Space Industries July 23rd, 2017

National Space Society Governor Scott Pace Named to National Space Council as Executive Secretary July 18th, 2017

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

How to draw electricity from the bloodstream: A one-dimensional fluidic nanogenerator with a high power-conversion efficiency September 11th, 2017

A revolution in lithium-ion batteries is becoming more realistic September 5th, 2017

High-tech electronics made from autumn leaves: New process converts biomass waste into useful electronic devices August 30th, 2017

Candy cane supercapacitor could enable fast charging of mobile phones August 17th, 2017

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