NSF-DFG MISSION: In-situ Analysis of Li transport through solid state interfacial systems by neutron reflectometry measurements

• Applicant: Dr. Erwin Hüger
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 540944754

This project aims to investigate and understand how interfaces may accelerate Li transport in nano-scaled systems. This will be done within a collaborative work between U.S. (numerical modelling) and German (experiments) researchers. In-situ neutron reflectometry (NR) measurements and numerical modelling will be combined. Si/Li3NbO4 multilayers are chosen as a model system. The experimental technique of NR and the theoretical analysis of the measurement results will be further developed in order to track in-situ Li permeation through interfaces and thin layers during (i) temperature ramping, (ii) electron flooding, and (iii) flooding with Li+ ions by electrochemical lithiation. Characteristic activation energies controlling Li transport are extracted from temperature-dependent measurements. The multilayers will be used as active electrode material for lithium-ion battery (LIB) operation, and it will be tested whether the insights gained from the Li transport investigations correlate with the cycling performance of the multilayers. At all interfaces, mechanical stress and space charge zones may be present, which can modify the Li transport, charge transfer, and storage properties. The in-situ NR experiments will examine whether an additional interfacial Li+ storage mechanism is present. All experiments will be accompanied by numerical modelling to enable the analysis of the experimental data and to help to find the underlying mechanisms for the accelerated Li permeation. The results of the project can be used to design interfaces that are important for drug release in pharmaceuticals and/or electrodes in Li-ion batteries.

• DFG Programme: Research Grants
• International Connection: USA
• Partner Organisation: National Science Foundation (NSF)
• Co-Investigator: Professor Dr. Harald Schmidt
• Cooperation Partner: Professor Dr. Fuqian Yang