Researchers produce nanostructures with potential to advance energy devices


August 29, 2013

New types of nanostructures have shown promise for applications in electrochemically powered energy devices and systems, including advanced battery technologies.

One process for making these nanostructures is dealloying, in which one or more elemental components of an alloy are selectively leached out of materials. portrait of ASU engineer Karl Sieradki Download Full Image

Arizona State University researchers Karl Sieradzki and Qing Chen have been experimenting with dealloying lithium-tin alloys, and seeing the potential for the nanostructures they are producing to spark advances in lithium-ion batteries, as well as in expanding the range of methods for creating new nanoporous materials using the dealloying process.

Their research results are detailed in a paper they co-authored that was recently published on the website of the prominent science and engineering journal Nature Materials (Advance online publication). Read the article abstract.

Sieradzki is a materials scientist and professor in the School for Engineering of Matter, Transport and Energy, one of ASU’s Ira A. Fulton Schools of Engineering.

Chen earned his doctoral degree in materials science at ASU last spring and is now a postdoctoral research assistant.

Nanoporous materials made by dealloying are comprised of nanometer-scale zigzag holes and metal. These structures have found application in catalysis (used to increase the rate of chemical reactions), as well as actuation (used to mechanically move or control various mechanisms or systems) and supercapacitors (which provide a large amount of high electrical capacity in small devices). They could also improve the performance of electrochemical sensing technology and provide more resilient radiation damage-resistant materials.

The nanostructures that Sieradzki and Chen have produced by dealloying lithium-tin alloys allow for more efficient transport and storage of the electric charge associated with lithium, while the small size prevents fracture of the tin reservoir that serves as a storage medium for lithium.  

Lithium-ion batteries are one of the leading types of rechargeable batteries. They are widely used in consumer products, particularly portable electronics, and are being increasingly used in electric vehicles and aerospace technologies.

Sieradzki and Chen say that with more research and development, the porous nanostructures produced by dealloying lithium alloys could provide a lithium-ion battery with improved energy-storage capacity and a faster charge and discharge – enabling it to work more rapidly.

One major advantage is that the porous nanostructures providing this electrochemical power boost can evolve spontaneously during tunable dealloying processing conditions. This, Sieradzki explains, opens up possibilities for developing new nanomaterials that could have a multitude of technological applications.

“There are a lot of metals that scientists and engineers have not been able to make nanoporous,” he says. “But it turns out that with lithium you can lithiate and de-lithiate a lot of materials, and do it easily at room temperature. So this could really broaden the spectrum for what’s possible in making new nanoporous materials by dealloying.”

Joe Kullman

Science writer, Ira A. Fulton Schools of Engineering

480-965-8122

Rep. Grijalva visit to school highlights success of ASU Teachers College grant


August 29, 2013

While trying to figure out the best strategy for teaching “inferencing” to the students at Ed Pastor Elementary School in San Luis, Ariz., the school’s leadership team looked around the table of educators and realized a bigger, internal problem: there were at least five different interpretations of inferencing amongst its own teachers. 

“We would always find out what the kids need and present to the teachers, but we never took the time to check out what the teachers need,” said Cindy Sanchez, a former principal at Ed Pastor, who is now principal at Arizona Desert in Gadsden. Rep. Grijalva, ASU and Gadsden Download Full Image

Through the Arizona Ready-for-Rigor Program, a $43.8 million federal Teacher Incentive Fund grant awarded to Arizona State University, the school’s leadership team worked with the district to identify what the teachers need by utilizing the TAP System for Teacher and Student Advancement.

“That (realization) was huge for us. It was a total change of the paradigm for all of us,” Sanchez shared with U.S. Rep. Raul Grijalva during a visit earlier this month to Desert View Elementary to highlight the Gadsden Elementary School District’s successful partnership with ASU’s Mary Lou Fulton Teachers College, which administers the grant.

For the 2012-2013 academic year, Ed Pastor Elementary was one of three schools out of the eight in the Gadsden Elementary School District to receive an A rating through the A-F letter grades distributed through the Arizona Department of Education. The other five Gadsden schools received B grades.

“That’s why the Teacher Incentive Fund [grant] and what TAP System is doing, what the school district was willing to be open to do in terms of ASU, and what they brought into here, is the future,” said the Arizona congressman.

Developed by the National Institute for Excellence in Teaching, the TAP system is a data-driven program that focuses on increasing teacher and administrative effectiveness by providing all educators mentor and peer support groups, opportunities to advance in the profession without leaving their classrooms, continuous professional development based on their individual needs and a performance-based compensation system.

“The TAP system that the TIF funding has allowed the district to put into place has really formed the components that put together a structure that is a different way of looking at how to run schools,” said Ann Nielsen, Arizona TAP director. “A key component is weekly professional development with their peers based on the needs of their students.”

Each classroom teacher is paired with a mentor teacher who is available for guidance and support. A leadership team – comprised of the school principal, master and mentor teachers, and all career teachers – meets regularly to ensure the group is meeting its school-wide goals and to adjust any individual plans.

“When we have confident teachers, we have confident students who are able to excel,” said Linda Coronado, master teacher at Southwest Junior High, another Gadsden school participating in the grant.

The five-year AZRfR Project, which began during the 2010-2011 school year and is currently in 60 schools within 11 Arizona districts, is making an impact in the educational systems by developing and rewarding teachers and administrators. Throughout the state, along with school rankings improving through better student achievement results, the participating schools are increasing their teacher evaluation and observation scores and retaining more effective educators. Additionally, more than $5 million has been awarded to 2,250 Arizona educators during the past two years in performance-based incentives.

“We recognize the single most important characteristic in schools that affects student achievement and schools is the quality of the teacher,” said Virginia McElyea, AZRfR executive director. “So if we’re going to be successful in school reform, if we’re going to give kids access to the American dream, we have to have a quality teaching force. That’s what this grant is all about.”

Within the project, the TAP System has realigned the roles of educators to provide opportunities for them to differentiate levels of support for teachers. Within TAP schools, leadership teams follow research-based protocols to review data, provide professional development and support teachers.

“There is now a great system in place for getting the data. In the past we didn’t have a system where we would collaboratively look at a piece of data and make decisions that would impact our students,” said Coronado, the master teacher. “But with the TAP program and system it has allowed all of our teachers and administrators and master teachers to make the decisions to impact student achievement.”

The Gadsden district is seeing the results of their hard work and they’re committed to continue working just as hard.

“Our goal is to get all eight A’s, and we’re getting there,” said Ray Aguilera, Gadsden Elementary School District superintendent . “And it will be with the big help of a big team here.”