Operando soft x-ray spectroscopy investigation of interfacial chemical transformation of energy-storage materials

Jinghua Guo

Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA

Advanced energy technology arises from the understanding in fundamental science, thus rest in large on in-situ/operando characterization tools for observing the physical and chemical interfacial processes. The energy materials and devices have been largely limited in a framework of thermodynamic and kinetic concepts or atomic and nanoscale. Synchrotron based x-ray spectroscopic techniques offers unique characterization in many important energy materials of energy conversion, energy storage and catalysis in regards to the functionality, complexity of material architecture, chemistry and interactions among constituents within. However, it is challenging to reveal the real mechanism of the chemical processes. In the operando soft x-ray spectroscopy characterization of interfacial phenomena in energy materials and devices, it has been found that the microstructure and composition of materials as well as the microstructure evolution process have a great influence on performances in a variety of fields, e.g., energy conversion and energy storage materials, chemical and catalytic processes. This presentation will show how to best use the in-situ/operando soft x-ray spectroscopy characterization techniques, including soft x-ray absorption spectroscopy (XAS) and resonant inelastic soft x-ray scattering (RIXS) to investigate the real electrochemical mechanism during the operation. The experimental results show how in-situ/operando soft x-ray spectra characterization techniques uncover the phase conversion, chemical and environmental change of elements and other very important information of solid/gas and solid/liquid interfaces in real time, thus further enhance the understanding of real reaction mechanism.

 

Jinghua Guo is Senior Scientist in the Advanced Light Source at Lawrence Berkeley National Laboratory and Adjunct Professor in the Department of Chemistry and Biochemistry at University of California, Santa Cruz. He received his B.S. from Zhejiang University in 1985, M.S. from Shanghai Institute of Optics and Fine Mechanics in 1988, and Ph.D. from Uppsala University in 1995. He continued as postdoctoral researcher in the Department of Physics at Uppsala University in 1995-1997 and Assistant Professor in 1997-2001 before joined the ALS as Staff Scientist in 2001. His research interest focuses on the nano-structured materials, battery and hydrogen-storage materials, catalysis, and environmental sciences with emphasis on the physical and chemical properties using in-situ/operando soft x-ray spectroscopy to investigate the charge transfer processes at the interfaces. He has pioneered the use of in-situ/operando soft X-ray spectroscopy for characterization of electronic structure properties of molecules solutions, energy materials and electrochemical and catalytic interfaces. He has developed the in-situ soft X-ray spectroscopy for characterization of solid/liquid interface in nanostructure materials and electrochemical interfaces in battery and photocatalysis, and made a range of in-situ/operando cells to handle special sample environments for operando studies of, e.g., electrochemical process of batteries and photocatalysis, catalysis and hydrogen storage applications. He published over 480 peer-reviewed papers with a H-index of 91, and received the MRS Innovation in Materials Characterization Award (2020) and David A. Shirley Award for Outstanding Scientific Achievement at the ALS (2022).