Atomic-Scale Characterization of Microscale Battery Particles Enabled by a High-Throughput Focused Ion Beam Milling...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Cathode materials in lithium-ion batteries (LIBs) face challenges like surface degradation and dendrite formation, impacting battery performance and lifespan.
• Surface coatings are crucial for enhancing cathode durability, but their characterization, especially uniformity and stability, is vital for performance assessment.
• Traditional transmission electron microscopy (TEM) techniques for microscale particle surface analysis are time-consuming and have low throughput, often requiring focused ion beam (FIB)-assisted lift-out.

Purpose of the Study:

• To develop a more efficient method for preparing microscale cathode materials for TEM analysis.
• To reduce the sample processing time for TEM characterization of coated LIB cathode materials.
• To enable high-throughput analysis of surface modifications in microscale battery materials.

Main Methods:

• A novel FIB technique was developed, directly supporting microscale cathode materials on a TEM grid.
• The workflow integrates air-liquid particle assembly, direct particle transfer to a TEM grid, FIB milling, and subsequent TEM analysis.
• Elemental composition mapping using energy-dispersive X-ray spectroscopy (EDS) was performed on cross-sections of microscale particles.

Main Results:

• The demonstrated FIB technique reduced sample processing time by 60-80% (from over 5 hours to approximately 1.5 hours).
• The method was successfully illustrated using lithium nickel cobalt aluminum oxide and lithium manganese nickel oxide cathode particles.
• High-throughput characterization of microscale particles and their coatings is now feasible.

Conclusions:

• The developed FIB workflow significantly enhances sample throughput and reduces preparation time for TEM analysis of LIB cathode materials.
• This method is extendable to various LIB cathode compositions, coatings, and end-of-life studies.
• The approach is applicable to the characterization of other microparticles and their coatings across diverse applications.