ORNL demonstrates road to supercapacitors for scrap tires

September 25, 2015, Oak Ridge National Laboratory
Instead of ending up in landfills, old tires can supply a key ingredient for supercapacitors to help power the nation. Credit: ORNL

Some of the 300 million tires discarded each year in the United States alone could be used in supercapacitors for vehicles and the electric grid using a technology developed at the Department of Energy's Oak Ridge National Laboratory and Drexel University.

By employing proprietary pretreatment and processing, a team led by Parans Paranthaman has created flexible polymer composite films as electrodes for supercapacitors. These devices are useful in applications for cars, buses and forklifts that require rapid charge and discharge cycles with high power and high energy density. Supercapacitors with this in electrodes saw just a 2 percent drop after 10,000 charge/discharge cycles.

The technology, described in a paper published in ChemSusChem by Wiley-VCH, follows an ORNL discovery of a method to use scrap tires for batteries. Together, these approaches could provide some relief to the problems associated with the 1.5 billion tires manufacturers expect to produce annually by 2035.

"Those tires will eventually need to be discarded, and our supercapacitor applications can consume several tons of this waste," Paranthaman said. "Combined with the technology we've licensed to two companies to convert scrap tires into carbon powders for batteries, we estimate consuming about 50 tons per day."

While that amount represents just a fraction of the 8,000 tons that need to be recycled every day, co-author Yury Gogotsi of Drexel noted that other recycling companies could contribute to that goal.

"Each tire can produce carbon with a yield of about 50 percent with the ORNL process," Gogotsi said. "If we were to recycle all of the scrap tires, that would translate into 1.5 million tons of carbon, which is half of the annual global production of graphite."

To produce the carbon composite papers, the researchers soaked crumbs of irregularly shaped tire rubber in concentrated sulfuric acid. They then washed the rubber and put it into a tubular furnace under a flowing nitrogen gas atmosphere. They gradually increased the temperature from 400 degrees Celsius to 1,100 degrees.

After several additional steps, including mixing the material with potassium hydroxide and additional baking and washing with deionized water and oven drying, researchers have a material they could mix with polyaniline, an electrically conductive polymer, until they have a finished product.

"We anticipate that the same strategy can be applied to deposit other pseudocapacitive materials with low-cost tire-derived activated carbon to achieve even higher electrochemical performance and longer cycle life, a key challenge for electrochemically active polymers," Gogotsi said.

Explore further: Rubber meets the road with new ORNL carbon, battery technologies

More information: The paper, titled "Waste Tire Derived Carbon–Polymer Composite Paper as Pseudocapacitive Electrode with Long Cycle Life," is available at dx.doi.org/10.1002/cssc.201500866

Related Stories

Toward tires that repair themselves

September 23, 2015

A cut or torn tire usually means one thing—you have to buy a new one. But some day, that could change. For the first time, scientists have made tire-grade rubber without the processing step—vulcanization—that has been ...

Hertz to recycle all its tires

November 6, 2012

Do you have any idea what happens to the tires when you junk your car? I didn't think so. What about the 1.2 million tires on the 300,000 cars that are in the Hertz rental car fleet at any one time? I didn't think you had ...

New 'designer carbon' boosts battery performance

May 29, 2015

Stanford University scientists have created a new carbon material that significantly boosts the performance of energy-storage technologies. Their results are featured on the cover of the journal ACS Central Science.

Recommended for you

Two new planets discovered using artificial intelligence

March 26, 2019

Astronomers at The University of Texas at Austin, in partnership with Google, have used artificial intelligence (AI) to uncover two more hidden planets in the Kepler space telescope archive. The technique shows promise for ...

Infertility's roots in DNA packaging

March 26, 2019

Pathological infertility is a condition affecting roughly 7 percent of human males, and among those afflicted, 10 to 15 percent are thought to have a genetic cause. However, pinpointing the precise genes responsible for the ...

Facebook is free, but should it count toward GDP anyway?

March 26, 2019

For several decades, gross domestic product (GDP), a sum of the value of purchased goods, has been a ubiquitous yardstick of economic activity. More recently, some observers have suggested that GDP falls short because it ...

Droughts could hit aging power plants hard

March 26, 2019

Older power plants with once-through cooling systems generate about a third of all U.S. electricity, but their future generating capacity will be undercut by droughts and rising water temperatures linked to climate change. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.