Featured Research

from universities, journals, and other organizations

Analytical theory may bring improvements to lithium-ion batteries

Date:
March 5, 2013
Source:
Purdue University
Summary:
Researchers have shown theoretically how to control or eliminate the formation of "dendrites" that cause lithium-ion batteries to fail, an advance that if realized would improve safety and might enable the batteries to be charged within a matter of minutes instead of hours.

Formations called dendrites grow in lithium-ion batteries and may continue to grow until causing an internal short circuit, which results in battery failure and possible fire. Researchers have now shown theoretically how to control or eliminate their formation.
Credit: Image courtesy of Quinn Horn, Exponent

Researchers have shown theoretically how to control or eliminate the formation of "dendrites" that cause lithium-ion batteries to fail, an advance that if realized would improve safety and might enable the batteries to be charged within a matter of minutes instead of hours.

The dendrites are lithium deposits that form on electrode surfaces and may continue to grow until they cause an internal short circuit, which results in battery failure and possible fire.

Researchers have created an analytical theory that shows how to design experiments to study ways of controlling dendrite growth, and results of the theory allow researchers to predict early stages of dendrite formation.

"We believe that this work is the first of its kind because, prior to its publication, work on this area had heavily relied on anecdotal evidence," said R. Edwin García, an associate professor of materials engineering at Purdue University. "While we have applied this theory to lithium-ion batteries, it was formulated so that it could be readily applied to other emerging battery chemistries, such as magnesium-ion and lithium-sulfur."

Findings were detailed in a research paper published in February in the Journal of the Electrochemical Society. The paper was written by postdoctoral researcher David Ely and García, and the work was funded by Toyota Motor Engineering & Manufacturing North America Inc.

The dendrites are lithium formations that grow like tumors while batteries are being recharged. Some of them add layers that when cut in half reveal an internal structure like tree rings, with each layer representing a single recharge. Because they grow faster when exposed to the high voltages needed for fast recharging, the dendrites limit recharging speed.

"You want your battery to recharge as fast as possible, in a matter of 10 minutes or so," García said. "This would be possible if we could better control or eliminate dendrite growth."

The batteries have two electrodes, called an anode and a cathode, separated by an insulating polymer that keeps the electrodes from touching. When the battery is recharged, lithium ions are shuttled from the cathode to the anode through a liquid or gel called an electrolyte, from which the dendrites draw material to build up on the anode's surface. The dendrites may grow large enough to penetrate the separating barrier and touch the cathode.

"The moment these touch, the battery is dead," García said. "Or worse, if you have too much current going through the dendrites while the battery is being charged, the battery can catch fire."

The researchers used their analytical model to identify behavior associated with formation of the dendrites and have proposed methods to suppress or control them.

One solution might be to engineer the anode's surface chemistry to inhibit the lithium's beading at the surface so that it wets the surface instead of nucleating into a dendrite.

Another potential approach is to induce lithium deposits to grow uniformly, instead of heterogeneously. The heterogeneous growth means the dendrites sprout unevenly at various locations on the electrode's surface. Some of the formations grow in needlelike spikes that quickly breach the barrier to the cathode. High voltage is required for fast charging, but heterogeneous dendrite formation restricts this fast charging. Having uniformly distributed lithium deposits with a uniform size could make fast charging possible by allowing higher voltage.

Another approach might be to charge the batteries using rapid pulses of electricity instead of a constant current.

"We have developed an analytical theory that identifies the different ways in which lithium-ion batteries can fail during recharge," García said. "Fundamentally, we proposed a universal roadmap that allows experimentalists and theoreticians to explore the different regimes of behavior during battery recharging. The proposed analytical roadmap enables researchers to identify the charging conditions that will completely suppress or at least minimize the formation of lithium dendrites."

Findings showed how to keep a dendrite from growing beyond its "critical kinetic radius," the size at which it will either shrink or continue to grow depending on how much current is applied.

Researcher Stephen J. Harris at Lawrence Berkeley National Laboratory has recorded dendrite growth in movies that the Purdue researchers studied for their simulation.

The Purdue researchers have found that the smaller dendrites may transfer their mass to larger ones, causing the larger dendrites to grow faster and more stably. The work was validated against available experimental data in the scientific literature.

"We also unified conflicting existing theories as they were reported in the 1990s and early 2000s," Garcia said.

The work is ongoing, with future research possibly aimed at learning more detail about dendrite behavior.

"The dendrites don't grow just everywhere, but at very specific locations on the anode," García said. "At the end of the day we want to model that. Such a comprehensive model would lead to advanced battery designs of improved performance and reliability."


Story Source:

The above story is based on materials provided by Purdue University. The original article was written by Emil Venere. Note: Materials may be edited for content and length.


Journal Reference:

  1. David R. Elyz and R. Edwin Garcıa. Heterogeneous Nucleation and Growth of Lithium Electrodeposits on Negative Electrodes. Journal of the Electrochemical Society, 2013

Cite This Page:

Purdue University. "Analytical theory may bring improvements to lithium-ion batteries." ScienceDaily. ScienceDaily, 5 March 2013. <www.sciencedaily.com/releases/2013/03/130305131400.htm>.
Purdue University. (2013, March 5). Analytical theory may bring improvements to lithium-ion batteries. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2013/03/130305131400.htm
Purdue University. "Analytical theory may bring improvements to lithium-ion batteries." ScienceDaily. www.sciencedaily.com/releases/2013/03/130305131400.htm (accessed July 28, 2014).

Share This




More Matter & Energy News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) — Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) — TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) — Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) — When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. 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