Determination of Elemental Impurities in Graphite-based Anodes using the Agilent 5110 ICP-OES

Importance of the topic

Graphite-based anode materials are critical for lithium-ion battery performance and cycle life. Trace elemental impurities can degrade stability and charge transfer, necessitating sensitive and reliable analytical methods.

Objectives and study overview

This study presents a rapid and accurate procedure for quantifying 18 impurity elements (Fe, Al, As, Ba, Be, Cd, Co, Cr, Cu, K, Mg, Mn, Na, Ni, Pb, Sr, V, Zn) in graphite-based anode materials using the Agilent 5110 Vertical Dual View ICP-OES. The method follows China’s GB/T 24533-2009 standard.

Used Instrumentation

• Agilent 5110 VDV ICP-OES with Vista Chip II detector and solid state RF power supply
• SeaSpray concentric glass nebulizer and double-pass glass cyclonic spray chamber
• Milestone ETHOS ONE microwave digester for sample digestion

Methodology

• Sample digestion: 0.5 g graphite material spiked or unspiked digested with 5 mL aqua regia in microwave (150–180 °C program), diluted to 50 mL
• Calibration: multi-element standard prepared at 10–200 µg/L in 2% HNO₃, linearity (R²>0.9995) across all elements
• ICP-OES parameters: axial view, 1.2 kW RF power, plasma 12 L/min, auxiliary 1.0 L/min, nebulizer 0.65 L/min, read time 10 s, triplicate readings

Main results and discussion

• Calibration curves exhibited excellent linearity (R²>0.9995)
• Method detection limits ranged from 0.010 to 0.188 mg/kg based on 0.5 g sample
• Spike recovery for sample B was 90–110% for all elements, demonstrating accuracy
• Long-term stability over 2.5 h showed RSD <1.6% for all impurities, confirming robustness

Benefits and practical applications

• High sensitivity and wide dynamic range enable reliable detection at trace levels
• Robust solid state RF system ensures stability during extended analyses
• Applicable for quality control and grading of high-purity graphite anode materials in battery manufacturing

Future trends and applications

Adoption of such ICP-OES methods may expand towards on-line process monitoring, speciation of impurities, and integration with other techniques (e.g., ICP-MS) for comprehensive quality assessment of next-generation battery materials.

Conclusion

The Agilent 5110 VDV ICP-OES method provides accurate, precise, and stable quantification of 18 elemental impurities in graphite-based anodes, supporting stringent quality requirements in lithium-ion battery production.

References

• GB/T 24533-2009 Lithium-ion battery graphite anode material