Determination of Elements in Ternary Material Nickel-Cobalt-Manganese Hydride

Significance of the topic

Lithium nickel cobalt manganese oxide (NCM) cathode materials are central to high-energy-density lithium-ion batteries, powering electric vehicles and renewable energy storage. Accurate quantification of both major components and trace impurities in these ternary oxides is critical for performance, safety and regulatory compliance.

Objectives and study overview

This study aimed to develop and validate a rapid, reliable method for the simultaneous determination of 25 elements—including Al, As, Ba, Be, Ca, Cd, Cr, Cu, Fe, K, Mg, Mo, Na, P, Pb, S, Si, Sr, Ti, Zn, Zr and the four main constituents Ni, Co, Mn and Li—in NCM cathode materials. The method addresses limitations of traditional FAAS and titration by leveraging ICP-OES technology to improve sensitivity, range and throughput.

Methodology

Two commercial NCM samples (A and B) were digested in aqua regia under controlled heating. Digests were split into two solutions: one for trace impurity analysis and a 1:1 dilution for major element quantification. Standard addition calibration minimized matrix effects for trace elements, while conventional external calibration covered Ni, Co, Mn and Li.

Instrumentation

The analyses employed the Agilent 5110 Vertical Dual View ICP-OES equipped with a vertically oriented torch, SeaSpray concentric nebulizer, cyclonic spray chamber and Vista Chip II CCD detector. Dual viewing modes (axial for trace elements, radial for major elements) extended dynamic range and reduced interferences.

Main results and discussion

Calibration curves for all 25 elements exhibited excellent linearity (R² > 0.9995). Method detection limits ranged from 0.015 to 1.345 mg/kg for impurities and 0.143 to 1.161 mg/kg for major elements. Spike recoveries in both samples fell within 92–110%, confirming accuracy, except for As, and for Na, S and Si which exceeded spike levels. Long-term stability tests over 2.5 hours showed RSDs below 3.5% for impurities and under 1% for major elements.

Benefits and practical applications

• High sensitivity and wide linear range enable simultaneous trace and major element analysis without multiple dilutions.
• Reduced analysis time and labor compared to FAAS and titration.
• Robust performance on high-salt and high-lithium matrices supports fast quality control in battery production.

Future trends and applications

Advances in ICP-OES detector technology and plasma robustness will further lower detection limits and expand dynamic range. Integration with automation and chemometric tools may enable real-time process monitoring of cathode synthesis. Emerging battery chemistries will drive demand for multi-element profiling and rapid impurity assessment.

Conclusion

The Agilent 5110 VDV ICP-OES method provides a fast, precise and reliable approach for comprehensive elemental analysis of NCM cathode materials. High recoveries, low detection limits and excellent stability demonstrate its suitability for quality control and research in lithium-ion battery development.

References

1. Chinese standard YS/T 798-2012: Lithium nickel cobalt manganese oxide specification and impurity requirements.