Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




NANO TECH
Engineer making rechargeable batteries with layered nanomaterials
by Staff Writers
Manhattan KS (SPX) Jan 18, 2013


File image.

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 in an article titled "Synthesis of surface-functionalized WS2 nanosheets and performance as Li-ion battery anodes."

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.

.


Related Links
Kansas State University
Nano Technology News From SpaceMart.com
Computer Chip Architecture, Technology and Manufacture






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





NANO TECH
New Research Gives Insight into Graphene Grain Boundaries
Chicago IL (SPX) Jan 17, 2013
Using graphene - either as an alternative to, or most likely as a complementary material with - silicon, offers the promise of much faster future electronics, along with several other advantages over the commonly used semiconductor. However, creating the one-atom thick sheets of carbon known as graphene in a way that could be easily integrated into mass production methods has proven difficult. ... read more


NANO TECH
US, Europe team up for moon fly-by

Russia to Launch Lunar Mission in 2015

US, Europe team up for moon fly-by

Mission would drag asteroid to the moon

NANO TECH
Choosing the right people to go to Mars

ChemCam follows the 'Yellowknife Road' to Martian wet area

Mars image suggests ancient water flow

NASA Mars Rover Preparing to Drill Into First Martian Rock

NANO TECH
Mathematical breakthrough sets out rules for more effective teleportation

Orion Teamwork Pays Off

Unilever Buys 22 Flights On XCOR Lynx Suborbiter For AXE Campaign

Iran renews plan to send monkey into space: reports

NANO TECH
China to launch 20 spacecrafts in 2013

Mr Xi in Space

China plans manned space launch in 2013: state media

China to launch manned spacecraft

NANO TECH
ESA workhorse to power NASA's Orion spacecraft

Competition Hopes To Fine Tune ISS Solar Array Shadowing

Embassy Gathers Elite Group of Space Policy Chiefs

NASA, Bigelow Officials to Discuss ISS Expandable Module

NANO TECH
Africasat-1a to launch on first Ariane 5 launch in 2013

Roscosmos Releases Report On Proton Launch Anomaly

Russia plans replacement for Soyuz rocket

Arianespace's industry leadership will continue with 12 launcher family missions planned in 2013

NANO TECH
Earth-size planets common in galaxy

NASA's Hubble Reveals Rogue Planetary Orbit For Fomalhaut B

NASA, ESA Telescopes Find Evidence for Asteroid Belt Around Vega

Kepler Gets a Little Help From Its Friends

NANO TECH
New surfaces repel most known liquids

Sustainable reinforcement for concrete has newly discovered benefits

ECAPS signs contract with Skybox for complete propulsion system

Boeing Grows Composite Manufacturing Capability in Utah




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement