As lithium-ion battery production scales to meet the growing demand for electric vehicles and energy storage systems, the need for precise, robust elemental analysis has never been greater. This article summarizes key learnings from a Separation Science webinar, in which experts Simon Nelms and Sukanya Senkupda from Thermo Fisher Scientific shared best practices and case studies highlighting the roles of Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in battery material analysis.
The Role of ICP Techniques in Battery Development
ICP-OES and ICP-MS play central roles in lithium-ion battery analysis, supporting testing across materials. "ICP-OES is well recognized as being a robust, accurate and sensitive elemental analysis technique, and has rapidly been accepted as a routine workhorse technology," advises Nelms. This makes it ideally suited for laboratories that need to perform high-throughput testing and handle complex matrices efficiently.
"ICP-MS provides much higher sensitivity and can achieve detection limits into the picogram per milliliter range," adds Nelms. This capability makes ICP-MS a powerful tool for detecting low-level contaminants, investigating degradation pathways, and quantifying residuals that may affect battery performance or longevity.
Together, these technologies help achieve the following:
- Verifying cathode compositions and identifying trace contaminants.
- Assessing electrolyte degradation and impurity levels.
- Analyzing anode materials for trace metals and aging products.
- Supporting quality control, failure analysis, and regulatory compliance.
The following three case studies discussed by Nelms and Senkupda illustrate how ICP-OES and ICP-MS are applied in real-world battery testing scenarios, each focused on a different component within lithium-ion cells.
Case Study 1: Elemental Testing of Cathode Materials
Cathode chemistry, particularly the ratios of lithium, nickel, cobalt, and manganese, plays a critical role in performance and thermal stability of batteries. To ensure optimal composition and purity, analysts perform bulk and impurity testing of cathode materials using ICP-OES systems capable of achieving detection limits in the low parts per million (ppm) to sub-ppm range.
In the first case study, presented by Senkupda, ternary cathode materials were analyzed for both bulk composition and 21 impurity elements using ICP-OES. Following acid digestion and dilution, samples were spiked with known concentrations of target elements, analyzed, and recoveries were calculated to assess accuracy in the complex matrix.
"The method achieved spike recoveries within ±10% and demonstrated excellent stability with very low standard deviations," notes Senkupda. This performance demonstrates that the ICP-OES method is both accurate and stable, making it well-suited for routine quality control and ensuring compliance with cathode material impurity standards.
Case Study 2: Electrolyte Analysis with ICP-OES and ICP-MS
Understanding degradation products and pathways is critical for improving battery durability and reducing failure risks, especially in electric vehicle and grid storage applications.
Electrolytes, particularly lithium hexafluorophosphate (LiPF6) solutions, present unique challenges due to their reactivity and matrix complexity. Due to the presence of HF and organic solvents in numerous electrolytes, safe sample handling protocols and HF-compatible components are essential when preparing and analyzing these samples. Analytical workflows using ICP-OES and ICP-MS address these through:
- Use of specialized sample introduction systems with HF-resistant materials.
- Calibration strategies for volatile matrices.
- Detection of degradation byproducts and trace impurities.
"The high flexibility of the ICP-OES Duo really helped us to develop a suitable method for these challenging LiPF6 electrolyte samples," Senkupda explains.
In this case study, electrolyte samples were analyzed, and trace impurities were detected at extremely low concentrations, levels that demonstrate the method's high detection capacity. "Excellent sensitivity was achieved for all target elements, with detection limits well below regulatory requirements," reveals Senkupda.
To further validate the method's reliability for high-volume use, robustness testing was performed over a seven-hour sequence with 150 samples. The results showed stable quality control recoveries and relative standard deviations (RSDs) between 1.5–4.7%, confirming the method’s suitability for high-sensitivity, routine testing.
These workflows align with moisture analysis and other lithium battery standards, supporting regulatory compliance for electrolyte materials. Additionally, complementary techniques such as GC-MS can be used alongside ICP-OES and ICP-MS to investigate electrolyte breakdown products, offering a more comprehensive view of degradation chemistry in gas analysis battery studies.
Case Study 3: Anode and Aging Studies
Assessing the purity and consistency of graphite anodes is critical to ensuring reliable lithium-ion battery performance. This is typically done using ICP-OES, which provides accurate measurements of both bulk and trace element concentrations.
In this case study, microwave digestion was used to prepare charcoal-based graphite anode samples before analyzing spike recoveries across 13 elements. Total impurity content ranged from sub-ppm to hundreds of ppm, and Senkupda noted from the results that, "Spike recoveries between 93% and 104% demonstrate the accuracy of the method,".
To extend the case study beyond raw material testing, the analysis also included post-mortem studies of aged lithium-ion cells. Samples from calendar-aged and cycle-aged cells were prepared by leaching the graphite anodes with deionized water, followed by filtration and dilution steps to ensure accurate analysis. These extracts were then analyzed using ICP-MS to assess trace elemental migration. In this context, ICP-MS workflows enable degradation mapping by:
- Measuring metal migration from cathode to anode.
- Quantifying phosphorus, manganese, cobalt, and lithium in leached samples.
- Differentiating between calendar-aged and cycle-aged degradation pathways.
As the analysis revealed, "Aged anode samples showed increased amounts of manganese, cobalt, and nickel, illustrating migration from the cathode to the anode".
Understanding elemental migration and degradation is essential to help manufacturers improve battery lifetime, reduce failure risks, and meet performance expectations for electric vehicle and energy storage systems. Such degradation mapping also plays a critical role in preventing catastrophic failure modes and ensuring compliance with rigorous safety standards.
Operational Insights from Quality Control Labs
During the webinar Q&A, Nelms and Senkupda offered practical troubleshooting advice, which included:
- Using clean labware to minimize contamination and ensure accurate results
Senkupda advised, "If you don't have clean labware, your calibration blanks will be variable, and you won't get good linearity,".
- Performing careful sample preparation to improve calibration accuracy.
- Optimizing instrument parameters to prevent plasma instability when analyzing complex electrolyte samples.
Nelms commented, "Choosing the right nebulizer and torch and carefully balancing gas flows are key to stabilizing the plasma,".
- Developing and optimizing sample introduction systems and calibration strategies to overcome matrix challenges and ensure reproducible results during extended testing sequences.
- Ensuring reliable and scalable performance in high-throughput laboratory environments.
Senkupda reiterated that "we successfully ran an uninterrupted measurement sequence for up to 7 hours with consistent performance and minimal signal drift throughout," demonstrating the method's robustness and suitability for extended, routine operations.
Together, these practical insights and best practices help laboratories optimize battery materials analysis workflows, ensuring accuracy, consistency, and confidence in results.
Final Takeaways from ICP-OES and ICP-MS in Battery Analysis
Drawing on expert insights from Simon Nelms and Sukanya Senkupda, the following takeaways highlight how ICP-OES and ICP-MS support battery research, manufacturing, and quality control across all stages of the battery lifecycle:
- ICP-OES and ICP-MS provide the sensitivity, accuracy, and throughput required to support high-quality lithium-ion battery development, from raw material verification through end-of-life recycling. These techniques help manufacturers ensure raw material purity, monitor degradation mechanisms, and maintain consistent product quality.
- Complementary methods, such as Ion Chromatography and Gas Chromatography–Mass Spectrometry (GC-MS), offer valuable insights, particularly for investigating complex degradation products and electrolyte breakdown pathways.
- Analytical workflows also play a growing role in battery recycling and environmental testing, where the ability to detect contamination and verify material purity is increasingly critical.
- For particularly challenging analyses, such as interference-heavy cathode materials or complex electrolyte solutions, advanced instrumentation such as Triple Quadrupole ICP-MS may be required. This technology, as discussed in the webinar, enables precise measurements by eliminating spectral interferences.
To explore these methods in greater detail and hear directly from the experts, watch the full on-demand webinar.
Meet the Experts
Simon Nelms, Global Product Manager for Metals Analysis at Thermo Fisher Scientific
Simon Nelms is a former ICP-OES and ICP-MS applications specialist who’s been part of the Thermo Fisher Scientific team for more than 20 years. He is now a Vertical Marketing Manager, with a particular focus on the battery and renewable energy markets. Simon holds a BSc in Analytical Chemistry and a PhD in research involving ICP-MS method development from the University of Hull, UK.
Sukanya Senkupda, Senior Applications Specialist at Thermo Fisher Scientific
Sukanya Senkupda applies advanced analytical techniques to address real-world challenges, providing critical support and training to laboratories. She helps optimize workflows for high-sensitivity applications, including lithium-ion battery analysis and regulatory compliance. After earning her Master’s in Applied Geology in Calcutta, India, in 2011, she pursued doctoral and postdoctoral research in Ingham, Germany, focusing on triple oxygen isotope compositions to study early Earth processes. Since 2020, she has served as an Application Specialist for ICP-OES and ICP-MS at Thermo Fisher Scientific in Bremen, specializing in trace elemental analysis and method development.