Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Simpler Process to Grow Germanium Nanowires Could Improve Lithium-Ion Batteries

01.09.2014

Researchers at Missouri University of Science and Technology have developed what they call “a simple, one-step method” to grow nanowires of germanium from an aqueous solution. Their process could make it more feasible to use germanium in lithium-ion batteries.

The Missouri S&T researchers describe their method in a paper published Thursday (Aug. 28, 2014) on the website of the journal ACS Nano. The researchers’ one-step approach could lead to a simpler, less expensive way to grow germanium nanowires.


Jay A. Switzer/Missouri University of Science and Technology

Scanning electron micrograph image of germanium nanowires electrodeposited onto an indium-tin oxide electrode from an aqueous solution.

As a semiconductor material, germanium is superior to silicon, says Dr. Jay A. Switzer, the Donald L. Castleman/Foundation for Chemical Research Professor of Discovery at Missouri S&T. Germanium was even used in the first transistors. But it is more expensive to process for widespread use in batteries, solar cells, transistors and other applications, says Switzer, who is the lead researcher on the project.

Switzer and his team have had success growing other materials at the nanometer scale through electrodeposition – a process that Switzer likens to “growing rock candy crystals on a string.” For example, in a 2009 Chemistry of Materials paper, Switzer and his team reported that they had grown zinc oxide “nanospears” – each hundreds of times smaller than the width of a human hair – on a single-crystal silicon wafer placed in a beaker filled with an alkaline solution saturated with zinc ions.

But growing germanium at the nano level is not so simple. In fact, electrodeposition in an aqueous solution such as that used to grow the zinc oxide nanospears “is thermodynamically not feasible,” Switzer and his team explain in their ACS Nano paper, “Electrodeposited Germanium Nanowires.”

So the Missouri S&T researchers took a different approach. They modified an electrodeposition process found to produce germanium nanowires using liquid metal electrodes. That process, developed by University of Michigan researchers led by Dr. Stephen Maldonado and known as the electrochemical liquid-liquid-solid process (ec-LLS), involves the use of a metallic liquid that performs two functions: It acts as an electrode to cause the electrodeposition as well as a solvent to recrystallize nanoparticles.

Switzer and his team applied the ec-LLS process by electrochemically reducing indium-tin oxide (ITO) to produce indium nanoparticles in a solution containing germanium dioxide, or Ge(IV). “The indium nanoparticle in contact with the ITO acts as the electrode for the reduction of Ge(IV) and also dissolves the reduced Ge into the particle,” the Missouri S&T team reports in the ACS Nano paper. The germanium then “starts to crystallize out of the nanoparticle allowing the growth of the nanowire.”

The Missouri S&T researchers tested the effect of temperature for electrodeposition by growing the germanium nanowires at room temperature and at 95 degrees Celsius (203 degrees Fahrenheit). They found no significant difference in the quality of the nanowires, although the nanowires grown at room temperature had smaller diameters. Switzer believes that the ability to produce the nanowires at room temperature through this one-step process could lead to a less expensive way to produce the material.

“The high conductivity (of germanium nanowires) makes them ideal for lithium-ion battery applications,” Switzer says.

Switzer’s co-authors on the paper “Electrodeposited Germanium Nanowires” were lead author Naveen K. Mahenderkar, a Ph.D. candidate in materials science and engineering at Missouri S&T; Ying-Chau Liu, a Ph.D. candidate in chemistry at Missouri S&T; and Jakub A. Koza, a postdoctoral associate in Missouri S&T’s Materials Research Center.

Switzer’s research in this area is funded through a $1.22 million grant from the U.S. Department of Energy’s Office of Basic Energy Science.

Contact Information

Andrew Careaga
Communications Director
acareaga@mst.edu
Phone: 573-341-4328
Mobile: 573-578-4420

Andrew Careaga | newswise
Further information:
http://www.mst.edu

Further reports about: ACS Germanium Lithium-Ion Nano S&T Technology electrodeposition nanowires temperature zinc

More articles from Materials Sciences:

nachricht New nontoxic process promises larger ultrathin sheets of 2-D nanomaterials
26.07.2016 | DOE/Oak Ridge National Laboratory

nachricht Self-assembling nano inks form conductive and transparent grids during imprint
26.07.2016 | INM - Leibniz-Institut für Neue Materialien gGmbH

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Self-assembling nano inks form conductive and transparent grids during imprint

Transparent electronics devices are present in today’s thin film displays, solar cells, and touchscreens. The future will bring flexible versions of such devices. Their production requires printable materials that are transparent and remain highly conductive even when deformed. Researchers at INM – Leibniz Institute for New Materials have combined a new self-assembling nano ink with an imprint process to create flexible conductive grids with a resolution below one micrometer.

To print the grids, an ink of gold nanowires is applied to a substrate. A structured stamp is pressed on the substrate and forces the ink into a pattern. “The...

Im Focus: The Glowing Brain

A new Fraunhofer MEVIS method conveys medical interrelationships quickly and intuitively with innovative visualization technology

On the monitor, a brain spins slowly and can be examined from every angle. Suddenly, some sections start glowing, first on the side and then the entire back of...

Im Focus: Newly discovered material property may lead to high temp superconductivity

Researchers at the U.S. Department of Energy's (DOE) Ames Laboratory have discovered an unusual property of purple bronze that may point to new ways to achieve high temperature superconductivity.

While studying purple bronze, a molybdenum oxide, researchers discovered an unconventional charge density wave on its surface.

Im Focus: Mapping electromagnetic waveforms

Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.

Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...

Im Focus: Continental tug-of-war - until the rope snaps

Breakup of continents with two speed: Continents initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. The final speed can be up to 20 times faster than in the first, slow extension phase.phases

Present-day continents were shaped hundreds of millions of years ago as the supercontinent Pangaea broke apart. Derived from Pangaea’s main fragments Gondwana...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

GROWING IN CITIES - Interdisciplinary Perspectives on Urban Gardening

15.07.2016 | Event News

SIGGRAPH2016 Computer Graphics Interactive Techniques, 24-28 July, Anaheim, California

15.07.2016 | Event News

Partner countries of FAIR accelerator meet in Darmstadt and approve developments

11.07.2016 | Event News

 
Latest News

New movie screen allows for glasses-free 3-D

26.07.2016 | Information Technology

Scientists develop painless and inexpensive microneedle system to monitor drugs

26.07.2016 | Health and Medicine

Astronomers discover dizzying spin of the Milky Way galaxy's 'halo'

26.07.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>