Elemental composition analysis of Nickel-Manganese-Cobalt Cathodes

von Umesh Tiwari, Thursday, 31st October 2024

Lithium-ion batteries have revolutionized the energy storage landscape, becoming the powerhouse behind portable electronics, electric vehicles (EVs), and renewable energy systems. Among the various types of lithium-ion batteries, lithium nickel manganese cobalt oxide (Li-NMC) batteries have emerged as a preferred choice for high-performance applications. Their unique combination of nickel, manganese, and cobalt allows for fine-tuning battery properties such as energy capacity, stability, and thermal safety. This balance makes NMC cathodes particularly suitable for manufacturers aiming to create customized batteries tailored to diverse applications.

Elemental Composition Analysis in NMC cathode optimization

A crucial aspect of optimizing NMC cathodes is accurate elemental composition analysis. The relative concentrations of nickel, manganese, and cobalt significantly influence the electrochemical performance, longevity, and overall stability of the batteries. Therefore, precise determination of these elements is essential for ensuring consistent quality during the production process.

Several analytical techniques exist for analysing elemental composition, with Inductively Coupled Plasma and X-ray Fluorescence being the most prominent. While ICP is a widely respected method, XRF offers several advantages, including quicker analysis times and the ability to provide high-quality results with less sample preparation. The Epsilon 4 ED-XRF spectrometer exemplifies this technology, making it a practical solution for process and quality control in the production and recycling of battery cathodes.

Certified Reference Materials in NMC cathode measurement

To achieve reliable measurements, calibration of XRF instruments is essential. Malvern Panalytical has addressed the gap in the availability of calibration materials by developing a set of Nickel-Manganese-Cobalt Certified Reference Materials (CRMs). This package consists of 12 synthetic mixes designed specifically for XRF calibration, ensuring that measurements of NMC cathodes are both accurate and repeatable.

These CRMs are manufactured from pure chemicals using a gravimetric approach, which enhances metrological traceability and adherence to ISO 17034 standards. By providing a well-defined framework for calibration, these materials allow manufacturers to obtain consistent results that can be relied upon for quality control in battery production.

Advanced Spectrometry and Sample Preparation

The Epsilon 4 spectrometer stands out for its high-performance capabilities, equipped with state-of-the-art detection technology. It is designed to analyse a wide range of materials, from solids and liquids to powders and filters. The spectrometer’s metal-ceramic X-ray tube and high-resolution silicon-drift detector enable it to deliver precise results across the periodic table.

For sample preparation, the lithium borate fusion technique is recommended, ensuring that the specimens used for analysis are uniformly mixed and accurately represent the elemental composition. This method typically involves a dilution ratio of 1:10, where one part of the sample is fused with ten parts of lithium borate flux, resulting in highly homogeneous fused beads for XRF analysis.

Implications for Battery Development

With the rising demand for efficient, reliable lithium-ion batteries, advancements in elemental composition analysis are critical for future innovations in battery technology. The combination of XRF and the use of NMC CRMs not only enhances the accuracy of elemental measurements but also streamlines the production process. As manufacturers focus on developing batteries that meet increasingly stringent performance standards, these analytical techniques will play a pivotal role in achieving those goals.

To understand how much accurate elemental composition can be on an Epsilon 4 EDXRF calibrated with NMC CRMs, download our application note from our website.

Further reading

Read the application note