Featured Research

from universities, journals, and other organizations

Engineer making rechargeable batteries with layered nanomaterials

Date:
January 16, 2013
Source:
Kansas State University
Summary:
A researcher is developing more efficient ways to save costs, time and energy when creating nanomaterials and lithium-ion batteries.

A Kansas State University researcher is developing more efficient ways to save costs, time and energy when creating nanomaterials and lithium-ion batteries.

Gurpreet Singh, assistant professor of mechanical and nuclear engineering, and his research team have published two recent articles on newer, cheaper and faster methods for creating nanomaterials that can be used for lithium-ion batteries. In the past year, Singh has published eight articles -- five of which involve lithium-ion battery research.

"We are exploring new methods for quick and cost-effective synthesis of two-dimensional materials for rechargeable battery applications," Singh said. "We are interested in this research because understanding lithium interaction with single-, double- and multiple-layer-thick materials will eventually allow us to design battery electrodes for practical applications. This includes batteries that show improved capacity, efficiency and longer life."

For the latest research, Singh's team created graphene films that are between two and 10 layers thick. Graphene is an atom-thick sheet of carbon. The researchers grew the graphene films on copper and nickel foils by quickly heating them in a furnace in the presence of controlled amounts of argon, hydrogen and methane gases. The team has been able to create these films in less than 30 minutes. Their work appears in the January issue of ACS-Applied Materials and Interfaces in an article titled "Synthesis of graphene films by rapid heating and quenching at ambient pressures and their electrochemical characterization."

The research is significant because the researchers created these graphene sheets by quickly heating and cooling the copper and nickel substrates at atmospheric pressures, meaning that scientists no longer need a vacuum to create few-layer-thick graphene films and can save energy, time and cost, Singh said.

The researchers used these graphene films to create the negative electrode of a lithium-ion cell and then studied the charge and discharge characteristics of this rechargeable battery. They found the graphene films grown on copper did not cycle the lithium ions and the battery capacity was negligible. But graphene grown on nickel showed improved performance because it was able to store and release lithium ions more efficiently.

"We believe that this behavior occurs because sheets of graphene on nickel are relatively thick near the grain boundaries and stacked in a well-defined manner -- called Bernal Stacking -- which provides multiple sites for easy uptake and release of lithium ions as the battery is discharged and charged," Singh said.

In a second research project, the researchers created tungsten disulfide nanosheets that were approximately 10 layers thick. Starting with bulk tungsten disulfide powder -- which is a type of dry lubricant used in the automotive industry -- the team was able to separate atomic layer thick sheets of tungsten disulfide in a strong acid solution. This simple method made it possible to produce sheets in large quantities. Much like graphene, tungsten disulfide also has a layered atomic structure, but the individual layers are three atoms thick.

The researchers found that these acid-treated tungsten disulfide sheets could also store and release lithium ions but in a different way. The lithium is stored through a conversion reaction in which tungsten disulfide dissociates to form tungsten and lithium sulfide as the cell is discharged. Unlike graphene, this reaction involves the transfer of at least two electrons per tungsten atom. This is important because researchers have long disregarded such compounds as battery anodes because of the difficulty associated with adding lithium to these materials, Singh said. It is only recently that the conversion reaction-based battery anodes have gained popularity.

"We also realize that tungsten disulfideis a heavy compound compared to state-of-the-art graphite used in current lithium-ion batteries," Singh said. "Therefore tungsten disulfide may not be an ideal electrode material for portable batteries."

The research appeared in a recent issue of the Journal of Physical Chemistry Letters.

Both projects are important because they can help scientists create nanomaterials in a cost-effective way. While many studies have focused on making graphene using low-pressure chemical processes, little research has been tried using rapid heating and cooling at atmospheric pressures, Singh said. Similarly, large quantities of single-layer and multiple-layer thick sheets of tungsten disulfide are needed for other applications.

"Interestingly, for most applications that involve this kind of battery research and corrosion prevention, films that are a few atoms thick are usually sufficient," Singh said. "Very high quality large area single-atom-thick films are not a necessity."

Other Kansas State University researchers involved in the projects include Romil Bhandavat and Lamuel David, both doctoral students in mechanical engineering, India, and Saksham Pahwa, a visiting undergraduate student, India. The graphene research involved University of Michigan researchers, including Zhaohui Zhong, assistant professor of electrical engineering and computer science, andGirish Kulkarni, doctoral candidate in electrical engineering.

Singh's work has been supported by the National Institute of Standards and Technology and the Kansas National Science Foundation Experimental Program to Stimulate Competitive Researchprogram.

Singh plans future research to study how these layered nanomaterials can create better electrodes in the form of heterostructures, which are essentially three-dimensional stacked structures involving alternating layers of graphene and tungsten or molybdenum disulfide.


Story Source:

The above story is based on materials provided by Kansas State University. Note: Materials may be edited for content and length.


Journal Reference:

  1. R. Bhandavat, L. David, G. Singh. Synthesis of Surface-Functionalized WS2Nanosheets and Performance as Li-Ion Battery Anodes. The Journal of Physical Chemistry Letters, 2012; 3 (11): 1523 DOI: 10.1021/jz300480w

Cite This Page:

Kansas State University. "Engineer making rechargeable batteries with layered nanomaterials." ScienceDaily. ScienceDaily, 16 January 2013. <www.sciencedaily.com/releases/2013/01/130116102018.htm>.
Kansas State University. (2013, January 16). Engineer making rechargeable batteries with layered nanomaterials. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2013/01/130116102018.htm
Kansas State University. "Engineer making rechargeable batteries with layered nanomaterials." ScienceDaily. www.sciencedaily.com/releases/2013/01/130116102018.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gulfstream G500, G600 Unveiling

Gulfstream G500, G600 Unveiling

Flying (Oct. 20, 2014) Watch Gulfstream's public launch of the G500 and G600 at their headquarters in Savannah, Ga., along with a surprise unveiling of the G500, which taxied up under its own power. Video provided by Flying
Powered by NewsLook.com
Japanese Scientists Unveil Floating 3D Projection

Japanese Scientists Unveil Floating 3D Projection

Reuters - Innovations Video Online (Oct. 20, 2014) Scientists in Tokyo have demonstrated what they say is the world's first 3D projection that floats in mid air. A laser that fires a pulse up to a thousand times a second superheats molecules in the air, creating a spark which can be guided to certain points in the air to shape what the human eye perceives as an image. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
What We Know About Microsoft's Rumored Smartwatch

What We Know About Microsoft's Rumored Smartwatch

Newsy (Oct. 20, 2014) Microsoft will reportedly release a smartwatch that works across different mobile platforms, has a two-day battery life and tracks heart rate. Video provided by Newsy
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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