UNIVERSITY PARK, Pa. — Hongtao Sun, an expert in nanoscience and nanotechnology, will join the Penn State Harold and Inge Marcus Department of Manufacturing and Industrial Engineering as an assistant professor on Aug. 15. He is also a co-hire of the Materials Research Institute (MRI).
Sun’s research is at the intersection of energy science, functional materials and advanced manufacturing. He focuses on rational design and synthesis of functional nanoscale materials, such as graphene. Graphene is a single layer of carbon atoms bonded in a hexagonal lattice, and is the thinnest, strongest and stiffest known material, as well as an excellent conductor of heat and electricity.
In order to use these nanoscale properties in devices, Sun develops scalable manufacturing processes to assemble low-dimensional nanomaterials, like graphene nanosheets, into larger macroscopic structures. Before scaling, these nanosheets are less than a few nanometers in thickness, which is around one-ten-thousandth the width of a human hair. The macroscopic structures can be made into one-dimensional graphene fibers, two-dimensional graphene papers and three-dimensional graphene frameworks.
According to Sun, when the size of materials is reduced to the nanoscale dimension, various physical and chemical phenomena cause the material’s properties to dramatically differ from its larger counterpart. These phenomena affect how nanoscale materials transport, store, convert and dissipate energy. Sun is working to manufacture scaled technologies that retain the nanoscale properties, which could have a broad range of implications for various energy applications.
“These manufactured forms enable original innovations for energy conversion and storage, thermal management and advanced sensing and detection,” Sun said.
One such application is the development of cost-effective and energy-saving processes to manufacture high-performance energy-storage systems such as batteries.
However, key challenges exist in the effective assembly of these nanoscale electrode materials into macroscopic electrodes while maintaining high battery performance. The scaling up of nanomaterials is usually accompanied by the loss of exceptional nanoscale properties during assembling processes.
To address this issue, Sun found that assembling active nanomaterials into a 3D architecture allows them to facilitate a rapid charge transport and mitigate diffusion limitations while still working within a larger scale system, such as a large area and thick electrode in a commercial device. This is an essential step for the advancement of battery technologies and practical energy-storage device applications, according to Sun. He also noted that the resulting all-solid-state batteries could be further developed for safer energy-storage technology.
At Penn State, Sun plans to build an interdisciplinary laboratory to foster effective, collaborative research that could lead to diverse approaches to solve such challenges.
“I look forward to the potential collaboration with the Battery and Energy Storage Technology Center, Center for Innovative Materials Processing through Direct Digital Deposition within the Materials Research Institute, and the Center for Innovative Sintered Products,” Sun said.
Ling Rothrock, professor and interim department head of the Harold and Inge Marcus Department of Industrial and Manufacturing Engineering, said he is excited to see what Sun accomplishes through his research and collaborations.
“Hongtao is a wonderful addition to our department,” Rothrock said. “He brings a wealth of knowledge, and his collaboration with the Materials Research Institute will give us insight into the future of industrial and manufacturing engineering.”
Clive Randall, director of the Materials Research Institute and professor of materials science and engineering, was in agreement.
“I am very excited about having Hongtao Sun join the faculty at Penn State,” Randall said. “He has shown some very creative ways of scaling nanomaterials in a manufacturing process. I predict that he will have many fruitful collaborations with our faculty across the University.”
Sun previously worked as an assistant professor in the Department of Mechanical and Industrial Engineering at the New Jersey Institute of Technology (NJIT). Sun has published roughly 40 peer-reviewed papers in leading journals, including Science, Nature Reviews Materials, Nature Communications and Nature Catalysis, with a total citation number of more than 3,000. Prior to NJIT, Sun completed a postdoctoral fellowship at the University of California, Los Angeles. Sun received his doctorate in mechanical engineering from Rensselaer Polytechnic Institute in 2014.