“You might get seven or eight hours out of your iPhone on one charge, maybe a day,” says Reza Shahbazian-Yassar, an associate professor of mechanical engineering at Michigan Technological University. “This is not enough for many of us. A fully electric car, like the Nissan Leaf, can go up to 100 miles on a single charge. To appeal to a mass market, it should be about 300 miles. We want to increase the power of these systems.”
Michigan Tech's Reza Shahbazian-Yassar has developed a device that allows scientists to watch lithium ions at work inside a battery, opening the door to better designs and materials. Above, (a), the nanobattery setup inside the aberration corrected scanning transmission electron microscope. Below, (b), atomic resolution imaging of the front line of lithium ions entering a tin oxide nanowire. The atomic resolution images show the parallel lithium-ion channels and the formation of dislocations at the tip of the channels.
To wring more power out of lithium ion batteries, scientists are experimenting with different materials and designs. However, the important action in a battery occurs at the atomic level, and it’s been virtually impossible to find out exactly what’s happening at such a scale. Now, Yassar has developed a device that allows researchers to eavesdrop on individual lithium ions—and potentially develop the next generation of batteries.
Batteries are pretty simple. They have three major components: an anode, a cathode and electrolyte between the two. In lithium batteries, lithium ions travel back and forth between the anode and cathode as the battery discharges and is charged up again. The anodes of lithium-ion batteries are usually made of graphite, but scientists are testing other materials to see if they can last longer.
“As soon as lithium moves into an electrode, it stresses the material, eventually resulting in failure,” said Yassar. “That’s why many of these materials may be able to hold lots of lithium, but they end up breaking down quickly.
“If we were able to observe these changes in the host electrode, particularly at the very early stage of charging, we could come up with strategies to fix that problem.”
Ten years ago, observing light elements such as lithium or hydrogen at the atomic level would have been out of the question. Now, however, it’s possible to see light atoms with an aberration corrected scanning transmission electron microscope (AC-STEM). Yassar’s team was able to use one courtesy of the University of Illinois at Chicago, where he is a visiting associate professor.
To determine how the host electrode changes as lithium ions enter it, the team built a nano-battery within the AC-STEM microscope using a promising new electrode material, tin oxide, or SnO2. Then, they watched it charge.
“We wanted to monitor the changes in the tin oxide at the very frontier of lithium-ion movement within the SnO2 electrode, and we did,” Yassar said. “We were able to observe how the individual lithium ions enter the electrode.”
The lithium ions moved along specific channels as they flowed into the tin oxide crystals instead of randomly walking into the host atoms. Based on that data, the researchers were able to calculate the strain the ions were placing on the electrodes.
The discovery has prompted inquiries from industries and national labs interested in using his atomic-resolution capability in their own battery-development work.
“It’s very exciting,” Yassar said. “There are so many options for electrodes, and now we have this new tool that can tell us exactly what’s happening with them. Before, we couldn’t see what was going on; we were just guessing.”
The work was supported by the National Science Foundation and the American Chemical Society Petroleum Research Fund.
An article on the research, “Atomic Scale Observation of Lithiation Reaction Front in Nanoscale SnO2 Materials,” was published online June 3 in ACS Nano. In addition to Yassar, the coauthors are mechanical engineering graduate student Hasti Asayesh-Ardakani and research associate Anmin Nie of Michigan Tech; Li-Yong Gan, Yingchun Cheng and Udo Schwingeschlogl of King Abdullah University of Science and Technology, Saudi Arabia; Qianquin Li, Cezhou Dong and Tao Wang of Zhejiang University, China; and Farzad Mashayek and Robert Klie of the University of Illinois at Chicago.
Marcia Goodrich | Newswise
Organic-inorganic heterostructures with programmable electronic properties
29.03.2017 | Technische Universität Dresden
Researchers use light to remotely control curvature of plastics
23.03.2017 | North Carolina State University
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences