Elemental Impurity Analysis of Lithium Ion Battery Anodes using Agilent ICP-MS

Importance of the Topic

Graphite anode purity impacts battery capacity efficiency and safety. Low-level elemental contaminants can degrade performance lead to capacity fading or safety risks in electric vehicles and consumer electronics. Accurate impurity profiling supports quality control and materials development.

Objectives and Study Overview

This study applied an advanced ICP-MS method to quantify 45 elements in graphite anode materials. Two industrial grade samples were investigated to evaluate trace contaminants far below limits of conventional ICP-OES. Key goals included method validation linearity detection limits and robustness over extended runs.

Methodology and Instrumentation

Aqua regia microwave digestion of 1 g graphite was followed by dilution to 40 mL. Analysis used the Agilent 7850 ICP-MS equipped with Ultra High Matrix Introduction and ORS4 collision reaction cell. A single He kinetically energy discriminated mode covered ng per liter to mg per liter. Samples were introduced via an autosampler with online internal standard addition. Calibration employed multielement and single element standards in mixed acid matrix. Detection limits were calculated from blank replicates and corrected for sample dilution.

Main Results and Discussion

Detection limits ranged from sub microgram per kilogram levels up to low milligrams per kilogram. Calibration regression coefficients exceeded 0.999. Drift in a 10 hour sequence of over 200 analyses remained below 1 percent for most elements. Replicate digests showed relative standard deviations below 5 percent. High concentrations of manganese iron cobalt nickel and copper were observed reflecting processing residues. Spike recovery studies yielded recoveries within 90 to 110 percent with precision under 5 percent validating accuracy and negligible matrix effects.

Benefits and Practical Applications

The ICP-MS procedure delivers much lower detection limits and broader elemental coverage than ICP-OES enabling control of ultratrace impurities. Routine robustness and simple sample preparation make this approach attractive for battery manufacturers quality assurance laboratories and research into advanced anode materials.

Future Trends and Opportunities

Increased interest in next generation anode chemistries will drive demand for even lower detection levels. Enhanced cell gas modes such as hydrogen or oxygen reactions can further reduce polyatomic interferences. Integration of automated sample preparation and data analysis will improve throughput. Coupling impurity profiles with electrochemical performance studies can guide tailored material design.

Conclusion

The Agilent 7850 ICP-MS method provides accurate precise and sensitive multielement impurity analysis of graphite anodes. Its high matrix tolerance and extended stability support reliable routine screening enabling manufacturers to optimize battery performance.

References

• Asenbauer J et al The success story of graphite as a lithium ion anode material Sustainable Energy Fuels 2020 4 5387 5416
• Zhang H Yang Y Ren D Graphite as anode materials energy storage fundamentals and advances Energy Storage Materials 2021 36 147 170
• Ni Y Feng W Determination of elemental impurities in graphite based anodes using ICP OES Agilent publication 5991 9508EN
• GB/T 24533 2019 Graphite negative electrode materials for lithium ion battery