Trace Element Detection in Large Area Samples of Graphite Battery Electrode with EDS Mapping

Trace elements and contaminants present in battery components can significantly influence battery performance. Electrode sheets may be investigated in top view to detect impurities and contaminant particles on both cathode and anode surfaces. However, large-area mappings performed with conventional EDS detectors often lack sufficient count statistics to reliably detect small particles.

This case study demonstrates that the XFlash^® FlatQUAD EDS detector can efficiently localize and identify individual contamination particles on large electrode samples using automatic SEM stage control. Contaminant elements in a graphite electrode were successfully mapped and identified across a very large area (18 × 18 mm²) within 120 minutes, including particles only a few pixels in size. 270 single fields of more than 18 million points in total were automatically measured at a pixel step size of 4.75 µm. The EDS count rate at a 3 nA beam current reached 1,120,000 counts per second.

The high signal yield and detection efficiency enabled the identification of micrometer-sized particles on the specimen surface, with sensitivity of X-ray fluorescence detection methods.