Toward Operando Structural, Chemical, and Electrochemical Analyses of Solid-State Batteries Using Correlative Secondary Ion Mass Spectrometry Imaging

Abstract

The global transition from fossil fuels to green energy underpins the need for efficient and reliable energy storage systems. Advanced analysis and characterization of battery materials is not only important to understand fundamental battery properties but also crucial for their continued development. A deep understanding of these systems is often difficult to obtain through only pre-and/or post-mortem analyses, with the full complexity of a battery being hidden in its operational state. Thus, we have developed an operando methodology to analyze solid-state batteries (SSBs) structurally as well as chemically before, during, and after cycling. The approach is based on a specially designed sample holder, which enables a variety of electrochemical experiments. Since the entire workflow is performed within a single focused ion beam scanning electron microscope equipped with an in-house developed magnetic sector secondary ion mass spectrometer, we are able to pause the cycling at any time, perform analysis, and then continue cycling. Microstructural analysis is performed via secondary electron imaging, and the chemical mapping is performed using the secondary ion mass spectrometer. In this proof-of-concept study, we were able to identify dendrites in a short-circuited symmetric cell and to chemically map dendritic structures. While this methodology focuses on SSBs, the approach can directly be adapted to different battery systems and beyond. Our technique clearly has an advantage over many alternatives for battery analysis as no transfer of samples between instruments is needed and a correlation between the microstructure, chemical composition, and electrochemical performance is obtained directly.

Temperature-Tunable Operando Nondestructive Detection of Electronic and Geometrical Structures in Battery Electrodes

“…Several innovative setups and workflows have been developed in the field of in situ and/or operando research on batteries. − Umegaki et al proposed a new element analysis technique to detect lithium metal deposits on the working anode of lithium-ion batteries by microfocusing X-rays . Cressa et al developed a methodology for performing operando magnetic sector secondary ion mass spectrometry to analyze solid-state batteries structurally as well as chemically during cycling . According to our observation, most of the operando technologies developed at present are aimed at the observation and imaging of electrode morphology, and few pay attention to the evolution information on the electrode material structure during battery operation, which is the critical factor affecting battery performance.…”