Ensuring Battery Material Quality at Every Step

insights from industryChristina Drathen | Bart Cleeren | Simon WelzmillerThermo Fisher Scientific

In the race to build better batteries, quality control at every stage of the production process has become critical. In this interview, experts Bart Cleeren, Simon Wetzmiller, and Christina Drathen explore how analytical techniques like ion chromatography (IC), X-ray diffraction (XRD), and X-ray fluorescence (XRF) are helping manufacturers improve the quality of electrode powders and electrolytes.

Bart, can you start by explaining how ion chromatography is used in the battery industry?

Bart Cleeren: Absolutely. Ion chromatography is particularly useful for analyzing lithium salts and their associated impurities in electrolytes. We’ve looked at salts like lithium hexafluorophosphate, difluorophosphate, and several borate-based compounds. These compounds are critical for improving thermal stability, electrochemical performance, and the solid electrolyte interphase (SEI) structure.

However, they can be unstable and prone to hydrolysis, so careful quantification is key. IC allows us to separate and quantify these ions effectively, even in complex mixtures.

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What challenges do you face when analyzing these lithium salts?

Bart Cleeren: The biggest challenges are the sample complexity and the stability of the salts in aqueous media. Some salts hydrolyze almost instantly, which affects quantification. We also have to deal with polarizable ions like FSI and TFSI, which tend to stick to the stationary phase. To address these issues, we use organic modifiers like acetonitrile to reduce ion retention and improve separation.

You mentioned two main applications of IC. Can you elaborate?

Bart Cleeren: Sure. The first is a straightforward quality control use case. It involves monitoring common lithium salts with a compact IC system to ensure consistency in materials. The second is more advanced and geared toward impurity analysis. This approach uses a gradient method with acetonitrile and is coupled with a mass spectrometer to boost sensitivity and enable compound confirmation. It’s particularly valuable for detecting unknown contaminants and tracking material stability over time.

Simon, let’s move to you. How does X-ray diffraction contribute to battery manufacturing quality control?

Simon Welzmiller: XRD is all about understanding the crystalline structure of materials. In battery manufacturing, this helps ensure the correct phase composition and crystallinity of electrode materials like NMC 811 or graphite anodes. For instance, we use it to determine the degree of graphitization, lithium mobility through hexagonal ordering, and cation disorder in cathodes, all of which influence battery performance.

What kinds of samples can be analyzed using XRD, and how difficult is the process?

Simon Welzmiller: It’s surprisingly user-friendly. Our benchtop XRD system can analyze powders, slurries, or solids in just a few minutes. With features like one-click analysis and photon energy filtering, it’s optimized for both research and QA/QC labs. Plus, it requires only an electrical outlet—no special lab infrastructure needed.

And what about identifying trace components? Can XRD detect minor phases below 5%?

Simon Welzmiller: Yes, in many cases. The general detection limit is around 1%, depending on the material and scan conditions. We’ve been able to quantify manganese in NMC 811 at levels below 4%, for example. Advanced refinements, like full structural analysis, can even assess cation mixing and lattice parameters for deeper insights.

Christina, turning to X-ray fluorescence, how does XRF complement these other techniques in battery quality control?

Christina Drathen: XRF is an essential tool for elemental analysis, particularly of cathode materials. It’s a bulk technique that delivers fast, accurate quantification of major and minor elements like nickel, cobalt, manganese, and iron. We work with manufacturers who need to ensure strict material specifications at high throughput, and XRF excels here thanks to its ease of use, minimal sample prep, and robustness.

Can XRF replace wet chemistry techniques like ICP for some applications?

Christina Drathen: Yes, particularly when you're analyzing bulk elements. ICP offers lower detection limits for trace analysis, but for routine quality control of cathode compositions, XRF offers excellent repeatability, fewer sample prep steps, and faster turnaround. It's especially valuable for scaling operations, since it allows plant operators to run analyses without specialized training.

What kind of results are typical with XRF in a production setting?

Christina Drathen: In a recent implementation with a cathode manufacturer, we achieved repeatability below 0.2% for Ni, Co, and Mn—well within industry standards. Short-term and long-term reproducibility were also excellent, enabling customers to trust their results and confidently make real-time process adjustments.

Final thoughts—how do these techniques work together to support battery manufacturing?

Christina Drathen: Each technique brings something unique. IC helps track ionic impurities and electrolyte stability. XRD gives us insight into the structure and phase purity of electrode materials. And XRF provides fast, reliable elemental analysis. Together, they offer a comprehensive toolkit for battery manufacturers to monitor quality, troubleshoot issues, and innovate confidently.

Watch the Accompanying Webinar: Assuring the Quality of Battery Electrode Powders and Electrolytes

About the Speakers

Bart Cleeren is a Product Manager for Ion Chromatography at Thermo Fisher Scientific.

Simon Welzmiller is an Application Scientist specializing in X-ray diffraction.

Christina Drathen is a Product Management Leader for Metals and Mining at Thermo Fisher Scientific.

This information has been sourced, reviewed and adapted from materials provided by Thermo Fisher Scientific – Materials & Structural Analysis.

For more information on this source, please visit Thermo Fisher Scientific – Materials & Structural Analysis.