Featured Research

from universities, journals, and other organizations

Exposing the roots of the lithium battery problem

Date:
December 17, 2013
Source:
DOE/Lawrence Berkeley National Laboratory
Summary:
Researchers have discovered that the dendrite problem that can cause lithium-ion batteries to short-circuit, overheat and possibly catch fire originates below the surface of the lithium electrode and not at the surface as has been widely believed.

These 3D reconstructions show how dendritic structures that can short-circuit a battery form deep within a lithium electrode, break through the surface and spread across the electrolyte.
Credit: Image courtesy of DOE/Lawrence Berkeley National Laboratory

The lithium-ion batteries that power our laptops, smartphones and electric vehicles could have significantly higher energy density if their graphite anodes were to be replaced by lithium metal anodes. Hampering this change, however, has been the so-called dendrite problem. Over the course of several battery charge/discharge cycles, particularly when the battery is cycled at a fast rate, microscopic fibers of lithium, called "dendrites," sprout from the surface of the lithium electrode and spread like kudzu across the electrolyte until they reach the other electrode. An electrical current passing through these dendrites can short-circuit the battery, causing it to rapidly overheat and in some instances catch fire. Efforts to solve the problem by curtailing dendrite growth have met with limited success, perhaps because they've just been scratching the surface of the problem.

Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have discovered that during the early stages of development, the bulk of dendrite material lies below the surface of the lithium electrode, underneath the electrode/electrolyte interface. Using X-ray microtomography at Berkeley Lab's Advanced Light Source (ALS), a team led by Nitash Balsara, a faculty scientist with Berkeley Lab's Materials Sciences Division, observed the seeds of dendrites forming in lithium anodes and growing out into a polymer electrolyte during cycling. It was not until the advanced stages of development that the bulk of dendrite material was in the electrolyte. Balsara and his colleagues suspect that non-conductive contaminants in the lithium anode trigger dendrite nucleation.

"Contrary to conventional wisdom, it seems that preventing dendrite formation in polymer electrolytes depends on inhibiting the formation of subsurface dendritic structures in the lithium electrode," Balsara says. "In showing that dendrites are not simple protrusions emanating from the lithium electrode surface and that subsurface non-conductive contaminants might be the source of dendritic structures, our results provide a clear prescription for the path forward to enabling the widespread use of lithium anodes."

Balsara, who is a professor of chemical engineering at the University of California (UC) Berkeley, is the corresponding author of a paper describing this research in Nature Materials titled "Detection of subsurface structures underneath dendrites formed on cycled lithium metal electrodes." Co-authors are Katherine Harry, Daniel Hallinan, Dilworth Parkinson and, Alastair MacDowell.

The tremendous capacity of lithium and the metal's remarkable ability to move lithium ions and electrodes in and out of an electrode as it cycles through charge/discharge make it an ideal anode material. Until now, researchers have studied the dendrite problem using various forms of electron microscopy. This is the first study to employ microtomography using monochromatic beams of high energy or "hard" X-rays, ranging from 22 to 25 keV, at ALS beamline 8.3.2. This technique allows non-destructive three-dimensional imaging of solid objects at a resolution of approximately one micron.

"We observed crystalline contaminants in the lithium anode that appeared at the base of every dendrite as a bright speck," says Katherine Harry, a member of Balsara's research group and the lead author of the Nature Materials paper. "The lithium foils we used in this study contained a number of elements other than lithium with the most abundant being nitrogen. We can't say definitively that these contaminants are responsible for dendrite nucleation but we plan to address this issue by conducting in situ X-ray microtomography."

Balsara and his group also plan further study of the role played by the electrolyte in dendrite growth, and they have begun to investigate ways to eliminate non-conductive impurities from lithium anodes.


Story Source:

The above story is based on materials provided by DOE/Lawrence Berkeley National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Katherine J. Harry, Daniel T. Hallinan, Dilworth Y. Parkinson, Alastair A. MacDowell, Nitash P. Balsara. Detection of subsurface structures underneath dendrites formed on cycled lithium metal electrodes. Nature Materials, 2013; DOI: 10.1038/nmat3793

Cite This Page:

DOE/Lawrence Berkeley National Laboratory. "Exposing the roots of the lithium battery problem." ScienceDaily. ScienceDaily, 17 December 2013. <www.sciencedaily.com/releases/2013/12/131217134710.htm>.
DOE/Lawrence Berkeley National Laboratory. (2013, December 17). Exposing the roots of the lithium battery problem. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2013/12/131217134710.htm
DOE/Lawrence Berkeley National Laboratory. "Exposing the roots of the lithium battery problem." ScienceDaily. www.sciencedaily.com/releases/2013/12/131217134710.htm (accessed July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins