Surface Analysis of Engineered Particles for Improved Battery Performance and Stability

Next-generation battery materials are needed to achieve high energy density, fast charging times, and long device lifetimes while remaining reliable and low-cost. Lithium metal batteries are a promising alternative to lithium-ion batteries but face stability concerns such as unstable solid-electrolyte interphase (SEI) growth and Li dendrite formation. Similarly, high-energy-density cathode materials like nickel manganese cobalt (NMC) and nickel manganese oxide (LNMO) have stable performance at high potentials but are susceptible to cathode dissolution in the electrolyte as well as unstable SEIs. Engineered particles (Ep) can stabilize electrode interactions, improving battery safety, SEI formation, and performance. However, batteries are multi-layered, complex systems with many components and interfaces that are difficult to handle and characterize. Understanding the chemical composition, distribution, and morphology of Ep-treated anodes/cathodes is necessary to prepare uniform, well-dispersed, high-capacity electrodes for optimized performance.<br/><br/>Developments in X-ray photoelectron spectrometers open up new capabilities to address these challenges. X-ray photoelectron spectroscopy (XPS) is ideal for analyzing thin layers and interfaces of battery materials due to its surface (~10nm) and chemical state sensitivity. Multi-technique XPS instruments offer additional operating modes and analytical options to enable the thorough characterization of battery materials. In this talk, a fully automated, multi-technique scanning XPS/HAXPES microprobe was used to address many challenges of analyzing battery materials, including an inert environment transfer vessel for air-free handling; microprobe X-ray source with &lt;5µm spatial resolution for 100% certainty of area selection for small-area spectroscopic analysis and chemical mapping; and the hard X-ray source and cluster ion gun source for analyzing buried interfaces without damaging the chemistry. Combined, these powerful capabilities enable thorough characterization of macro- and microscopic battery materials for a direct link between the chemistry and performance of Ep-treated battery electrodes.