Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study sheds new light on why batteries go bad

15.09.2014

Rapid charging and draining doesn't damage lithium ion electrode as much as thought

A comprehensive look at how tiny particles in a lithium ion battery electrode behave shows that rapid-charging the battery and using it to do high-power, rapidly draining work may not be as damaging as researchers had thought – and that the benefits of slow draining and charging may have been overestimated.


This is an apparatus used to charge lithium ion coin cell batteries at various rates with different levels of current at the Stanford Institute for Materials Science and Engineering. The results indicate that the benefits of slow draining and charging may have been overestimated.

Credit: SLAC National Accelerator Laboratory

The results challenge the prevailing view that "supercharging" batteries is always harder on battery electrodes than charging at slower rates, according to researchers from Stanford University and the Stanford Institute for Materials & Energy Sciences (SIMES) at the Department of Energy's SLAC National Accelerator Laboratory.

They also suggest that scientists may be able to modify electrodes or change the way batteries are charged to promote more uniform charging and discharging and extend battery life.

"The fine detail of what happens in an electrode during charging and discharging is just one of many factors that determine battery life, but it's one that, until this study, was not adequately understood," said William Chueh of SIMES, an assistant professor at Stanford's Department of Materials Science and Engineering and senior author of the study. "We have found a new way to think about battery degradation."

The results, he said, can be directly applied to many oxide and graphite electrodes used in today's commercial lithium ion batteries and in about half of those under development.

His team described the study September 14, 2014, in Natural Materials. The team included collaborators from Massachusetts Institute of Technology, Sandia National Laboratories, Samsung Advanced Institute of Technology America and Lawrence Berkeley National Laboratory.

Watching Ions in Battery Slices

One important source of battery wear and tear is the swelling and shrinking of the negative and positive electrodes as they absorb and release ions from the electrolyte during charging and discharging.

For this study scientists looked at a positive electrode made of billions of nanoparticles of lithium iron phosphate. If most or all of these particles actively participate in charging and discharging, they'll absorb and release ions more gently and uniformly. But if only a small percentage of particles sop up all the ions, they're more likely to crack and get ruined, degrading the battery's performance.

Previous studies produced conflicting views of how the nanoparticles behaved. To probe further, researchers made small coin cell batteries, charged them with different levels of current for various periods of time, quickly took them apart and rinsed the components to stop the charge/discharge process. Then they cut the electrode into extremely thin slices and took them to Berkeley Lab for examination with intense X-rays from the Advanced Light Source synchrotron, a DOE Office of Science User Facility.

New Insights on Faster Discharging

"We were able to look at thousands of electrode nanoparticles at a time and get snapshots of them at different stages during charging and discharging," said Stanford graduate student Yiyang Li, lead author of the report. "This study is the first to do that comprehensively, under many charging and discharging conditions."

Analyzing the data using a sophisticated model developed at MIT, the researchers discovered that only a small percentage of nanoparticles absorbed and released ions during charging, even when it was done very rapidly. But when the batteries discharged, an interesting thing happened: As the discharge rate increased above a certain threshold, more and more particles started to absorb ions simultaneously, switching to a more uniform and less damaging mode. This suggests that scientists may be able to tweak the electrode material or the process to get faster rates of charging and discharging while maintaining long battery life.

The next step, Li said, is to run the battery electrodes through hundreds to thousands of cycles to mimic real-world performance. The scientists also hope to take snapshots of the battery while it's charging and discharging, rather than stopping the process and taking it apart. This should yield a more realistic view, and can be done at synchrotrons such as ALS or SLAC's Stanford Synchrotron Radiation Lightsource, also a DOE Office of Science User Facility. Li said the group has also been working with industry to see how these findings might apply in the transportation and consumer electronics sectors.

###

Research funding came from the Samsung Advanced Institute of Technology Global Research Outreach Program; the School of Engineering and Precourt Institute for Energy at Stanford; the Samsung-MIT Program for Materials Design in Energy Applications; and the U.S. Department of Energy; and the National Science Foundation.

SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the U.S. Department of Energy Office of Science.

The Stanford Institute for Materials and Energy Sciences (SIMES) is a joint institute of SLAC National Accelerator Laboratory and Stanford University. SIMES studies the nature, properties and synthesis of complex and novel materials in the effort to create clean, renewable energy technologies. For more information, please visit simes.slac.stanford.edu.

SLAC National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

Citation: W. Chueh et al., Nature Materials, 14 September 2014 (10.1038/NMAT4084)

Andrew Gordon | Eurek Alert!

Further reports about: Accelerator DOE Energy Engineering SIMES SLAC batteries battery electrode electrodes ions nanoparticles particles small

More articles from Power and Electrical Engineering:

nachricht Organic-inorganic heterostructures with programmable electronic properties
29.03.2017 | Technische Universität Dresden

nachricht Researchers use light to remotely control curvature of plastics
23.03.2017 | North Carolina State University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>