Abstract:

In situ characterization techniques have become indispensable across many research fields for probing and understanding chemical reactions in real time. In electrochemical energy storage and conversion, methods such as in situ X-ray diffraction (XRD) are now central to both materials design and mechanistic insight. Since 2014, Dr. Chen’s group has developed a comprehensive suite of in situ XRD tools for diverse synthesis methods (including solid-state, hydrothermal, molten salt, and electrodeposition), as well as operando XRD platforms for functioning batteries and other electrochemical systems, using synchrotron, laboratory X-ray, and neutron sources. These capabilities have enabled influential advances in Li-ion, Na-ion, Li-metal, and solid-state batteries, as well as in alloy electrodeposition.

In this talk, Dr. Chen will first present early work combining in situ XRD and DFT calculations to study hydrothermal synthesis of cobalt nanoparticles, revealing formation pathways and polymorph selection rules. This led to the construction of a “nanometric phase diagram” of cobalt, markedly different from its conventional bulk phase diagram. He will then discuss recent studies using variable-temperature in situ synchrotron and neutron diffraction to resolve the detailed crystal structures of halide solid electrolytes, and how these insights informed the design of new materials with record-high room-temperature ionic conductivity. Finally, the talk will highlight the group’s latest advance, the first high-throughput in situ XRD tool for electrodeposition, and its application to uncover unprecedented mechanisms of Zn deposition and crystal growth, with important implications for the development of durable aqueous Zn-ion batteries.       

Bio:

Dr. Hailong CHEN is currently an Associate Professor at the Woodruff School of Mechanical Engineering at Georgia Tech with a courtesy appointment at the School of Materials Science. He received his BS degree in Materials Science and Engineering in 1999 and MS degree in Chemistry in 2002, respectively, from Tsinghua University, China. He earned his PhD degree in Chemistry at the State University of New York-Stony Brook. Before joining the faculty of Georgia Tech in November 2013, he conducted postdoctoral research at MIT in the Department of Materials Science and Engineering

His research interest focuses on understanding the formation mechanism of solid-state materials and the structure-property relationship. His research group at Georgia Tech has been working on the development of state-of-the-art X-ray-based in situ and operando characterization methods, such as synchrotron X-ray-based in situ XRD, PDF, SAXS, and XAS, and solid-state NMR, etc. The ongoing projects include design, synthesis, testing, and characterization of new materials for Li-ion, Na-ion, and all-solid-state batteries, as well as metals and alloys as functional and structural materials.