Defense

July 15, 2013

Air Force supports new generation of lithium-ion batteries

A few months back, the Air Force Office of Scientific Research was proud to publish an article regarding a research accomplishment by Dr. Jim Tour and his research team at Rice University.

AFOSR, along with other funding agencies, supported Dr. Tour’s research effort to make graphene suitable for a variety of organic chemistry applications – especially the promise of advanced chemical sensors, nanoscale electronic circuits and metamaterials.

Four years ago, Tour’s research team demonstrated that they could chemically unzip cylindrical shaped carbon nanotubes into soluble graphene nanoribbons without compromising the electronic properties of the graphitic structure. A recent paper by the Tour team, published in IEEE Spectrum and partially funded by AFOSR, showed that GNR can significantly increase the storage capacity of lithium ion (Li-ion) by combining graphene nanoribbons with tin oxide.

By producing GNR in bulk, a necessary requirement for making this a viable process, the Tour team mixes GNR and 10 nanometer wide particles of tin oxide to create a slurry. By adding a cellulose gum binding agent and water, the mixture is then applied to a capacitor, which is then fitted to a button-style lithium-ion battery.

In the Tour lab tests, the prototype battery had an initial charge capacity of more than 1,520 milliamp hours per gram (mAh/g). After repeated charge-discharge cycles that number began to plateau at about 825 mAh/g, but after 50 discharge cycles, the batteries retained far more capacity – more than double – that of Li-ion batteries that employ standard graphite anodes.

The critical key that makes the increase in battery capacity possible is the significant improvement in flexibility that graphene nanoribbons lend to the anode. By comparison, conventional Li-ion batteries with graphite anodes break down and lose efficiency because of their inability to flex, as they expand and contract, with repeated charge and discharge cycles; over time the graphite cracks and the battery cannot charge. Conversely, anodes with a graphene nanoribbon platform allow the tin oxide particles to maintain a consistent size, rather than expanding and contracting, and thus eliminating the brittleness and cracking associated with a graphite-based anode.

This breakthrough may very well lead to the next generation of the lithium-ion battery – a promising new platform for creating more durable, lightweight and efficient lithium-ion power.

 




All of this week's top headlines to your email every Friday.


 
 

 
Navy photograph

Triton UAS conducts first flight with search radar

Navy photograph The MQ-4C Triton unmanned aircraft takes off from Naval Air Station Patuxent River, Md., April 16, to conduct its first flight from the naval base. The aircraft began sensor testing on April 18 and flew with its...
 
 
Army photograph

Innovative technology destroys old munitions

Army photograph The Explosive Destruction System is a safe and effective means of destroying chemical munitions. The blast, vapor and fragments are all contained inside the stainless steel chamber. Army officials have brought a...
 
 

Navy names littoral combat ship

Secretary of the Navy Ray Mabus announced April 17 that the next Freedom-variant littoral combat ship (LCS) will be named USS St. Louis. The future USS St. Louis, designated LCS 19, will be the seventh ship to bear the name. The first St. Louis, a sloop of war, was launched in 1828. It spent the...
 

 
Luke Lightning strikes at Nellis

F-35 program on right track, director says

Luke Lightning strikes at Nellis Air Force photograph by Senior Airman Thomas Spangler An F-35A Lightning II assigned to the 61st Fighter Squadron, Luke Air Force Base, Ariz., taxis to the runway for a training exercise at Nell...
 
 
Army photograph

Army plans intelligence system to be lighter weight, easier to use

Army photograph During a media day, a soldier, with the Army’s intelligence community, demonstrates use of a portion of the Distributed Common Ground System – Army system on Fort Belvoir, Va., May 16, 2013. Future v...
 
 
Navy photograph

Closing the curtain on NAVAIR’s desert depot

An MV-22 gets ready for takeoff following repair at NAVAIR’s Forward Deployed Combat Repair facility in Afghanistan. The FDCR mission ended in June 2014, and was primarily led by NAVAIR reservists with artisans from Fleet...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>