The Importance of Crystallinity in Electrode Powder Characterization

The Battery Experts video series with Anthony Chalou from Anton Paar examines the crucial role of crystallinity in characterizing cathode and anode powders for lithium-ion batteries. In this video, Anthony highlights the importance of measuring crystalline properties, particularly for graphite materials used for anodes.

These properties, including the degree of crystallinity and graphitization, directly affect lithium ion mobility within the battery cell.

X-Ray diffraction (XRD) is the preferred technology for analyzing electrode powders' crystal structure, crystallite size, and phase purity.

Anthony explains the selection of appropriate sample holders based on material sensitivity and quantity. A front-loading type holder is sufficient for most electrode powders. Ensuring the powder is flat in the holder is essential to avoid errors during analysis.

Anthony details the setup of the XRD instrument, including the choice of X-Ray wavelengths (commonly copper for battery materials), goniometer radius, and beam geometries like Bragg-Brentano and parallel beam mirrors. These configurations influence the sensitivity and accuracy of measurements.

During the analysis, parameters such as the scan type, two-theta range, and time-per-step are adjusted based on the sample type.

For graphite samples, the two-theta range is typically set between 10 and 80 degrees. Parallel beam mirrors are particularly useful for solid electrode powders, compensating for potential peak shifts due to deep X-Ray penetration.

By comparing measurements with different geometries, Anthony demonstrates how peak positions can vary and how these shifts can be corrected using reference materials.

Accurately measuring the degree of crystallinity and graphitization is vital in the early stages of electrode manufacturing, ensuring optimal performance of the final battery product.

Video Credit: Anton Paar GmbH

This information has been sourced, reviewed and adapted from materials provided by Anton Paar GmbH.

For more information on this source, please visit Anton Paar GmbH.