3-D nanomaterials being explored for high-efficiency batteries, fuel cells, and more
Schematic of a pillared-graphene system. Minimum interpillar distance (MIPD) was calculated as (system dimension along X-direction)/2 - CNT diameter. Pillar length (PL) was assumed to be the distance between two graphene sheets. (Air Force Research Laboratory)
A national team of experts will explore the promise of three-dimensional nanomaterials with the help of a recently awarded U.S. Department of Defense Multidisciplinary University Research Initiative grant totaling more than $7 million over five years.
The team—consisting of scientists from five universities, two government research institutes, and a private company—aims to produce new materials for various uses ranging from high-efficiency batteries, ultracapacitors, fuel cells, and hydrogen storage devices to lightweight thermal coatings for hypersonic jets, multifunctional materials for aerospace, and other applications.
The grant comes through the Air Force Office of Scientific Research, for which Joycelyn Harrison is the Program Manager. Ajit Roy from the Air Force Research Laboratory leads the technical advisory board.
Recent theoretical studies and computer modeling, carried out by Roy and co-workers at Wright-Patterson Air Force Base and others elsewhere, have predicted great promise for 3-D pillared carbon nanomaterials, but so far no one has been able to make them with controlled and repeatable junction properties, said Liming Dai, the Kent Hale Smith Professor of Macromolecular Science and Engineering at Case Western Reserve University, in a statement announcing the project.
“This requires a multi-university effort,” said Dai, who is also Director of the Center of Advanced Science and Engineering for Carbon (CASE4Carbon), and principal investigator on the grant.
Dai’s Center in the Department of Macromolecular Science and Engineering, The Great Lake Energy Institute, and The Institute of Advanced Materials, Case School of Engineering, at Case Western Reserve will develop technology needed to build carbon nanotubes and graphene sheets into nanoporous frameworks that would produce strong electrical and thermal conductivity and other properties in three dimensions.
The university explains that his team plans to build 3-D networks of alternating layers of carbon nanotubes, which are single rolled molecules that conduct strongly but only in one direction, and graphene, which is a one-atom-thick sheet of carbon and highly conductive in two directions along the plane of the sheet.
Timothy Fisher and Xiulin Ruan, professors of mechanical engineering at Purdue University, will conduct experimental studies and develop predictive models of thermally conductive nanomaterials, and they will also develop methods of creating and characterizing 3-D nanoporous materials.
Nanoporous materials made of boron-carbon-nitrogen nanotubes and/or nanosheets are far less orderly than the frameworks above and reportedly would perform better at high temperatures—such as on the leading wing edge of a jet flying at more than five times the speed of sound—and in such applications as thermal dissipation, mechanical, and sound damping.
“Both kinds of structures are porous—the density is very low—which is good for aerospace applications,” Dai said. “They have huge surface area compared to volume, which is good for energy storage.”
Zhenhai Xia, a professor of materials science and engineering at North Texas University, will guide development through extensive multi-scale computer modeling.
Also from Case Western Reserve, Chung-Chiun Liu, the Wallace R. Persons Professor of Chemical Engineering, will characterize the electrochemical properties of the materials, and Vikas Prakash, a professor of mechanical and aerospace engineering, will characterize mechanical properties and thermal and electrical transport in these nanostructures. He also will explore the use of mechanical strain in tuning electrical and thermal transport in these materials.
Once the basic materials are made, others will hybridize them for custom uses, according to Case Western Reserve.
Zhong Lin Wang, the Hightower Chair and Regents’ Professor of Materials Science and Engineering at Georgia Institute of Technology, will integrate zinc-oxide components to produce and characterize structure and property changes triggered by exposure to certain wavelengths of light, mechanical, or other stimuli.
Quan Li, Director of Organic Synthesis and Advanced Materials Laboratory at the Liquid Crystal Institute and an adjunct professor in the Chemical Physics Interdisciplinary Program at Kent State University, will tap his lab’s expertise in liquid crystals to develop multifunctional capabilities.
Researchers from Wright Patterson Air Force Base, Pacific Northwest National Laboratory, and Cleveland-based GrafTech Inc. will also contribute to the project.