Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ion trek through polymer offers better batteries

21.03.2003


Cell phones, CD players and flashlights all wear down batteries far faster than we might wish. But there’s new hope, now that researchers at the Department of Energy’s Idaho National Engineering and Environmental Laboratory (INEEL) have overcome another barrier to building more powerful, longer-lasting lithium-based batteries.



The INEEL team, led by inorganic chemist Thomas Luther, discovered how lithium ions move through the flexible membrane that powers their patented rechargeable lithium battery. Research results are currently published online, and in the April 24, 2003, print issue of the Journal of Physical Chemistry B.

Luther calls their translucent polymer membrane an ’inorganic version of plastic kitchen wrap.’ The team, including chemists Luther, Mason Harrup and Fred Stewart, created it in 2000 by adding a ceramic powder to a material called MEEP ([bis(methoxyethoxyethoxy) phosphazene]), an oozy, thick oil. The resulting solid, pliable membrane lets positively charged lithium ions pass through to create the electrical circuit that powers the battery, but rebuffs negatively charged electrons. This keeps the battery from running down while it sits on the shelf-overcoming a major battery-life storage problem.


For years, rechargeable lithium battery performance has been disappointing because the batteries needed recharging every few days. After conquering the discharge challenge, INEEL’s team attacked the need for greater battery power to be commercially competitive. Their membrane didn’t allow sufficient passage of lithium ions to produce enough power, so they needed to understand exactly how the lithium ions move through the membrane on a molecular level.

First, they analyzed the MEEP membrane using nuclear magnetic resonance-the equivalent of a hospital MRI-to zero in on the best lithium ion travel routes. The results supported the team’s suspicion that the lithium ions travel along the ’backbone’ of the membrane. The MEEP membrane has a backbone of alternating phosphorus and nitrogen molecules, with oxygen-laden ’ribs’ attached to the phosphorus molecules.

Further analysis using infrared and raman spectroscopy (techniques that measure vibrational frequencies and the bonds between different nuclei) helped confirm that the lithium ions are most mobile when interacting with nitrogen. Lithium prefers to nestle into a "pocket" created by a nitrogen molecule on the bottom with oxygen molecules from a MEEP rib on either side.

Armed with this new understanding of how lithium moves through the solid MEEP membrane, the team has already starting making new membrane versions to optimize lithium ion flow. And that should make the team’s lithium batteries much more powerful.

The team’s research results are a major departure from the conventionally accepted explanation of lithium ion transport that proposed the lithium/MEEP transport mechanism as jumping from one rib to the next using the oxygen molecules as stepping stones.

Harrup, Stewart and Luther are optimistic their battery design will ultimately change the battery industry. The team projects that its polymer membrane will be so efficient at preventing battery run down, that batteries could sit unused for up to 500 months between charges with no loss of charge. Since the membrane is a flexible solid, it can be molded into any shape-which could open up new applications for batteries. And the membrane is very temperature tolerant-with the potential to solve portable power need problems in the frigid cold of space. The team is already working with several federal agencies on applications for its lithium battery designs.

The reference for the paper describing this research is "On the Mechanism of Ion Transport Through Polyphosphazene Solid Polymer Electrolytes: NMR, IR, and Raman Spectroscopic Studies and Computational Analysis of 15N Labeled Polyphosphazenes," Journal of Physical Chemistry B. INEEL authors include Thomas Luther, Fred Stewart, Randall A. LaViolette, William Bauer and Mason K. Harrup. The work was also supported by Christopher Allen of the University of Vermont in Burlington, Vt.


###
The INEEL is a science-based applied engineering national laboratory dedicated to supporting the U.S. Department of Energy’s missions in environment, energy, science and national defense. The INEEL is operated for the DOE by Bechtel BWXT Idaho, LLC.

Technical contact: Thomas A. Luther, (208) 526-0203, luthta@inel.gov; Mason K. Harrup, (208) 526-1356, harrmk@inel.gov.
Media contact: Deborah Hill, (208) 526-4723, dahill@inel.gov; Keith Arterburn, (208) 526-4845, artegk@inel.gov.


Deborah Hill | EurekAlert!
Further information:
http://www.inel.gov/

More articles from Power and Electrical Engineering:

nachricht Did you know that the wrapping of Easter eggs benefits from specialty light sources?
13.04.2017 | Heraeus Noblelight GmbH

nachricht To e-, or not to e-, the question for the exotic 'Si-III' phase of silicon
05.04.2017 | Carnegie Institution for Science

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>