Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Study Reveals New Factor that could Limit the Life of Hybrid and Electric Car Batteries

13.12.2012
A new study of the batteries commonly used in hybrid and electric-only cars has revealed an unexpected factor that could limit the performance of batteries currently on the road.

Researchers led by Ohio State University engineers examined used car batteries and discovered that over time lithium accumulates beyond the battery electrodes – in the “current collector,” a sheet of copper which facilitates electron transfer between the electrodes and the car’s electrical system.

This knowledge could aid in improving design and performance of batteries, explained Bharat Bhushan, Ohio Eminent Scholar and the Howard D. Winbigler Professor of Mechanical Engineering.

“Our study shows that the copper current collector plays a role in the performance of the battery,” he said.

The study, which appears in a recent issue of the journal Scripta Materialia, reflects an ongoing collaboration between Bhushan and Suresh Babu, professor of materials science and engineering and director of the National Science Foundation Center for Integrative Materials Joining for Energy Applications, headquartered at the university. The team is trying to determine the factors that limit battery life.

Lithium-ion batteries are the rechargeable batteries used in most hybrid-electric cars and all-electric cars as well. Inside, lithium ions shuttle back and forth between the anode and cathode of the battery – to the anode when the battery is charging, and back to the cathode when the battery is discharging.

Previously, the researchers determined that, during aging of the battery, cyclable lithium permanently builds up on the surface of the anode, and the battery loses charge capacity.

This latest study revealed that lithium migrates through the anode to build up on the copper current collector as well.

“We didn’t set out to find lithium in the current collector, so you could say we accidentally discovered it, and how it got there is a bit of a mystery. As far as we know, nobody has ever expected active lithium to migrate inside the current collector,” Bhushan said.

Shrikant Nagpure, now postdoctoral researcher at Ohio State, carried out this research as a part of his doctoral degree. He examined batteries that were aged in collaboration with the university’s Center for Automotive Research, where colleagues Yann Guezennec and Giorgio Rizzoni have studied battery aging for several years, in collaboration with the automotive industry.

Key to the discovery of lithium in the current collector was collaboration between the Ohio State team and Gregory Downing, a research chemist at the National Institute of Standards and Technology and an expert on a technique called neutron depth profiling (NDP), a tool for impurity analysis in materials.

Previously, the researchers used NDP to study the cathodes and anodes of six off-the-shelf lithium-ion car batteries – one new battery and five batteries which they aged themselves in the laboratory – and found that lithium builds up on the anode surface over time.

To understand more about how these batteries degrade, Bhushan and his colleagues have been studying the batteries further, at various scales ranging from the millimeter (millionths of a meter) down to the nanometer (billionths of a meter) with different techniques.

In the NDP technique, researchers pass neutrons through a material and capture the charged particles that emerge from the fission reaction between neutrons and lithium in the electrodes. Since different chemical elements emit a certain signature set of particles with specific energies, NDP can reveal the presence of impurities in a material.

In this latest study, NDP detected the presence of lithium in the copper current collector from one of the aged batteries. The detection was measured as a ratio of the number of copper atoms in the collector to the number of lithium atoms that had collected there. The test yielded a ratio of up to 0.08 percent, or approximately one lithium atom per 1250 copper atoms in the collector.

That’s a small number, but high enough that it could conceivably affect the electrical performance of the current collector – and, in turn, the performance of a battery, Bhushan said. He hopes that battery makers will further investigate this phenomenon and use the information to design new materials that might prevent lithium from escaping the electrode material.

Next, he and his colleagues will study the impedance, or internal electrical resistance, of lithium-ion batteries on the nanoscale.

Funding for this study came from the Institute for Materials Research at Ohio State.

Contact: Bharat Bhushan, (614) 292-0651; Bhushan.2@osu.edu
Written by Pam Frost Gorder, (614) 292-9475; Gorder.1@osu.edu

Pam Frost Gorder | EurekAlert!
Further information:
http://www.osu.edu

More articles from Materials Sciences:

nachricht World’s Highest Magnetic Field* (1,020MHz) NMR developed
03.07.2015 | National Institute for Materials Science

nachricht Diamond provides technical progress
03.07.2015 | Julius-Maximilians-Universität Würzburg

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Forschungsschiff Heincke seit 25 Jahren im Dienst der Wissenschaft

Ein Vierteljahrhundert alt, über 900.000 Kilometer (488.842 nautische Meilen) gefahren und trotzdem auf dem neuesten wissenschaftlichen und technischen Stand: Die Indienststellung des Forschungsschiffes Heincke jährt sich am 8. Juli 2015 zum 25. Mal.

Wissenschaftler des Alfred-Wegener-Instituts, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), das die Heincke betreibt, nehmen ebenso regelmäßig an...

Im Focus: Solardächer produzieren Strom für Fahrzeuge

Studentische Industriekooperation zwischen HAW Hamburg und Webasto erarbeitet Ergebnisse für EU-Zertifizierungsprozess von Solardächern zur Verbesserung der Öko-Bilanz von Fahrzeugen.

Unter der Leitung von Dr.-Ing. Volker Skwarek, Professor für technische Informatik an der HAW Hamburg, erarbeiteten sechs Studierende des...

Im Focus: Viaducts with wind turbines, the new renewable energy source

Wind turbines could be installed under some of the biggest bridges on the road network to produce electricity. So it is confirmed by calculations carried out by a European researchers team, that have taken a viaduct in the Canary Islands as a reference. This concept could be applied in heavily built-up territories or natural areas with new constructions limitations.

The Juncal Viaduct, in Gran Canaria, has served as a reference for Spanish and British researchers to verify that the wind blowing between the pillars on this...

Im Focus: Aus alt mach neu - Rohstoffquelle Elektroschrott

Der Markt für Unterhaltungselektronik boomt: Rund 60 Millionen Fernsehgeräte wurden im letzten Jahr in Europa verkauft. Früher oder später werden sie zurückkehren – als Elektroschrott.

Die Recycling-Industrie hat darauf reagiert: Kupfer, Aluminium, Eisen- und Edelmetalle sowie ausgewählte Kunststoffe werden bereits wiederverwertet. Allerdings...

Im Focus: Radar schützt vor Weltraummüll

Die Bedrohung im All durch Weltraummüll ist groß. Aktive Satelliten und Raumfahrzeuge können beschädigt oder zerstört werden. Ein neues, nationales Weltraumüberwachungssystem soll ab 2018 vor Gefahren im Orbit schützen. Fraunhofer-Forscher entwickeln das Radar im Auftrag des DLR Raumfahrtmanagement.

Die »Verkehrssituation« im All ist angespannt: Neben unzähligen Satelliten umkreisen Weltraumtrümmer wie beispielsweise ausgebrannte Raketenstufen und...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Aktuelles aus Forschung und Betrieb: 27. Deutscher Flammentag

02.07.2015 | Veranstaltungen

Call for ideas: Gute Ideen für bessere Städte

02.07.2015 | Veranstaltungen

Von Produktpiraterie bis Ideen-Schutz: Mit Experten über Patent- und Innovationsschutz diskutieren

02.07.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Demenz in der Petrischale

03.07.2015 | Biowissenschaften Chemie

Quantenpunkt-Spektrometer passt jetzt ins Handy

03.07.2015 | Biowissenschaften Chemie

Von guten und schlechten Quantenzuständen

03.07.2015 | Physik Astronomie