In recent years, there has been a notable surge in efforts aimed at advancing lithium-ion batteries, crucial for electric vehicles, stationary storage technologies, and portable electronics. The lifespan of these batteries, particularly concerning capacity fade, hinges largely on electrode degradation and the deactivation of active materials. Additionally, a pivotal factor impacting both battery lifespan and performance is the solid electrolyte interphase (SEI). Yet, the task of selecting a suitable analytical technique to study lithium-ion battery degradation and SEI properties presents challenges, necessitating detailed insights into their structural and chemical composition, including light elements such as lithium, with high surface sensitivity.
In this investigation, we employed a novel approach utilizing a Scanning Electron Microscope coupled with a Focused Ion Beam (FIB-SEM) and a compact Time-of-Flight Secondary Ion Mass Spectrometer (ToF-SIMS) to scrutinize the topographical and chemical composition of both non-cycled and cycled lithium-ion battery electrodes. Our objective was to discern degradation mechanisms, including parasitic chemical reactions. By integrating SEM observations with ToF-SIMS and complementary analytical methods such as Energy Dispersive X-ray Spectroscopy (EDS) and Raman spectroscopy on the same FIB-SEM platform, we achieved comprehensive 2D and/or 3D characterization of lithium-ion battery materials. This multifaceted approach provides valuable insights into degradation processes, SEI properties, and electrode composition, enhancing our understanding of battery performance. It empowers researchers to optimize battery properties, prevent failures, and develop sustainable energy solutions by addressing material chemistry and processing challenges, ultimately guiding advancements in battery design and production.