Subscribe to our free daily newsletters
  Energy News  




Subscribe to our free daily newsletters



ENERGY TECH
Scientists get first close-ups of finger-like growths that trigger battery fires
by Staff Writers
Menlo Park CA (SPX) Oct 30, 2017


This image of a lithium metal dendrite, taken with cryogenic electron microscopy or cryo-EM, shows that freezing has preserved its original state, revealing that it's a crystalline nanowire with six well-defined facets. Dendrites can pierce the barrier between battery chambers and trigger fires; cryo-EM is the first technique that can image them in atomic detail without damaging them. (Y. Li et al., Science)

Scientists from Stanford University and the Department of Energy's SLAC National Accelerator Laboratory have captured the first atomic-level images of finger-like growths called dendrites that can pierce the barrier between battery compartments and trigger short circuits or fires.

Dendrites and the problems they cause have been a stumbling block on the road to developing new types of batteries that store more energy so electric cars, cell phones, laptops and other devices can go longer between charges.

This is the first study to examine the inner lives of batteries with cryo-electron microscopy, or cryo-EM, a technique whose ability to image delicate, flash-frozen proteins and other "biological machines" in atomic detail was honored with the 2017 Nobel Prize in chemistry.

The new images reveal that each lithium metal dendrite is a long, beautifully formed six-sided crystal - not the irregular, pitted shape depicted in previous electron microscope shots.

The ability to see this level of detail for the first time with cryo-EM will give scientists a powerful tool for understanding how batteries and their components work at the most fundamental level and for investigating why high-energy batteries used in laptops, cell phones, airplanes and electric cars sometimes fail, the researchers said. They reported their findings in Science.

"This is super exciting and opens up amazing opportunities," said Yi Cui, a professor at SLAC and Stanford and investigator with the Stanford Institute for Materials and Energy Sciences (SIMES) whose group did the research.

"With cryo-EM, you can look at a material that's fragile and chemically unstable and you can preserve its pristine state - what it looks like in a real battery - and look at it under high resolution," he said. "This includes all kinds of battery materials. The lithium metal we studied here is just one example, but it's an exciting and very challenging one."

Fickle Fingers of Failure
Cui's lab is one of many developing strategies to prevent damage from dendrites, like adding chemicals to the electrolyte to keep them from growing or developing a "smart" battery that automatically shuts off when it senses that dendrites are invading the barrier between the battery's chambers.

But until now, scientists have not been able to get atomic-scale images of dendrites or other sensitive battery parts. The method of choice - transmission electron microscopy, or TEM - was too harsh for many materials, including lithium metal.

"TEM sample preparation is carried out in air, but lithium metal corrodes very quickly in air," said Yuzhang Li, a Stanford graduate student who led the work with fellow grad student Yanbin Li. "Every time we tried to view lithium metal at high magnification with an electron microscope the electrons would drill holes in the dendrite or even melt it altogether."

"It's like focusing sunlight onto a leaf with a magnifying glass. But if you cool the leaf at the same time you focus the light on it, the heat will be dissipated and the leaf will be unharmed. That's what we do with cryo-EM. When it comes to imaging these battery materials, the difference is very stark."

Batteries Take a Freezing Dip
In cryo-EM, samples are flash-frozen by dipping them into liquid nitrogen, then sliced for examination under the microscope. You can freeze a whole coin-cell battery at a particular point in its charge-discharge cycle, remove the component you're interested in and see what is happening inside that component at an atom-by-atom scale. You could even create a stop-action movie of battery activity by stringing together images made at different points in the cycle.

For this study, the team used a cryo-EM instrument at Stanford School of Medicine to examine thousands of lithium metal dendrites that had been exposed to various electrolytes. They looked not only at the metal part of the dendrite, but also at a coating called SEI, or solid electrolyte interphase, that develops as the dendrite reacts with the surrounding electrolyte. This same coating also forms on metal electrodes as a battery charges and discharges, and controlling its growth and stability are crucial for efficient battery operation.

They discovered, to their surprise, that the dendrites are crystalline, faceted nanowires that prefer to grow in certain directions. Some of them developed kinks as they grew, but their crystal structure remained surprisingly intact in spite of the kinks.

A Zoom Lens for Atoms
Zooming in, they used a different technique to look at the way electrons bounced off the atoms in the dendrite, revealing the locations of individual atoms in both the crystal and its SEI coating. When they added a chemical commonly used to improve battery performance, the atomic structure of the SEI coating became more orderly, and they think this may help explain why the additive works.

"We were really excited. This was the first time we were able to get such detailed images of a dendrite, and we also saw the nanostructure of the SEI layer for the first time," said Yanbin Li. "This tool can help us understand what different electrolytes do and why certain ones work better than others."

Going forward, the researchers say they plan to focus on learning more about the chemistry and structure of the SEI layer.

ENERGY TECH
When humidity benefits batteries
Montreal, Canada (SPX) Oct 26, 2017
Sometimes you can find simple solutions to complex problems, as demonstrated by the team of INRS's Dr. Lionel Roue, which cleverly improved the performance of silicon-based electrodes for lithium-ion batteries. It is well known that the robustness of the electrodes in these batteries, which are used in a host of devices, is key to their useful life. According to the team's paper published ... read more

Related Links
SLAC National Accelerator Laboratory
Powering The World in the 21st Century at Energy-Daily.com


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

ENERGY TECH
Japan faces challenges in cutting CO2, Moody's finds

IEA: An electrified world would cost $31B per year to achieve

'Fuel-secure' steps in Washington counterintuitive, green group says

SLAC-led project will use AI to prevent or minimize electric grid failures

ENERGY TECH
Electronic entropy enhances water splitting

Scientists solve a magnesium mystery in rechargeable battery performance

Ames UConn team discover superconductor with bounce

Plastic and metal-organic frameworks partner for sensing and storage

ENERGY TECH
Construction to begin on $160 million Industry Leading Hybrid Renewable Energy Project

A kite that might fly

Scotland outreach to Canada yields wind energy investment

First floating wind farm starts operation in Scotland

ENERGY TECH
New fractal-like concentrating solar power receivers are better at absorbing sunlight

German utility sees potential in rooftop solar

Recurrent Energy Announces Commercial Operation of 71 MW North Carolina Solar Project

Transparent solar technology represents 'wave of the future'

ENERGY TECH
South Korea to push ahead with nuclear power plants

AREVA NP awarded contract for safety upgrades in seven reactors

AREVA NP installs a system allowing flexible electricity generation at Goesgen nuclear power plant

Dessel: a new step forward with the dismantling of the site

ENERGY TECH
Expanding Brazilian sugarcane could dent global CO2 emissions

Stiff fibers spun from slime

Converting carbon dioxide to carbon monoxide using water, electricity

Separating methane and CO2 will become more efficient

ENERGY TECH
Oil prices stand still in market push-pull

Amid energy spats, Ukraine's economy showing resilience

Iran says it's signed its first agreement tied to LNG

Hearings cancelled over Minnesota oil pipeline

ENERGY TECH
IMF chief warns of 'dark future' over climate change

GAO finds big U.S. costs from climate change

US ocean observation critical to understanding climate change

Nicaragua signs Paris climate agreement




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement