研究生体験記 アラゴン・ナノ科学・材料研究所 / サラゴサ大学Pedro氏
【テーマ：Study of battery materials by means of small- and wide-angle neutron scattering】
Aragon Nanoscience and Materials Institute, CSIC-University of Zaragoza
Pedro Antonio Alonso Sánchez
My name is Pedro Alonso Sánchez and I am a PhD student at the Aragon Nanoscience and Materials Institute, join research center between the CSIC and the University of Zaragoza, under the supervision of Prof Javier Campo and Dr Federico Cova. I carried out a research stay at CROSS from October 21st to December 20th, 2024, under the supervision of Dr. Kazuki Ohishi.
The main objective of the stay was to prepare and optimize an accepted operando neutron scattering experiment for battery systems using Small and Wide-Angle Neutron Scattering (SANS/WANS) with the aim of studying the evolution of morphology and porosity in diatom algae used as silicon source for anodes in Li-ion batteries. The experiment was planned to be performed at the TAIKAN beamline of the Materials and Life Science Experimental Facility (MLF) after the stay.
During the stay, the MLF source was temporarily unavailable due to technical issues. As a result, the work, initially focused on performing SANS/WANS measurements of different battery components to optimize the cell configuration for the operando experiment, shifted towards theoretical preparatory aspects of the experiment. In particular, a solid understanding of neutron scattering techniques, especially SANS was developed. Theoretical calculations of the scattering contributions and transmission of components in different cells to evaluate the most suitable configuration for future neutron experiments was performed. Based on this analysis, optimized cells configurations, including the selection of appropriate windows and current collectors were proposed.
In addition, I acquired expertise with a SANS-adapted operando cell that was being developed by Dr. Kazuki Ohishi for sodium-ion batteries. Previously acquired SANS data studying the structural evolution of hard carbon used as electrode in sodium batteries were analyzed. This allowed me to gain useful insights into the interpretation of operando scattering results. Subsequently, preliminary electrochemical tests using the operando cell in Li-ion configuration, in order to evaluate the performance and reliability of the cell under working conditions were performed. This work contributed to assessing the applicability of the cell design for future neutron experiments.
Besides, I gained experience in the treatment and analysis of SANS data using the software tools commonly employed at MLF, which provided me with practical skills for future SANS experiments.
Finally, I had the opportunity to attend “The 8th Neutron and Muon School”, where I acquired a broad overview of neutron- and muon-based techniques for the study of energy and magnetic related materials. As part of this school, I participated in a hands-on training using the muon spin relaxation (μSR) technique on the chiral magnet MnSi, where we investigated the transition from the paramagnetic phase to the helical magnetic phase under low magnetic field conditions.
