Elemental Analysis of Intermediate Feedstock Chemicals for Li-Ion Batteries (LIBs) by ICP-OES

Significance of the topic

The recovery and analysis of lithium ion battery feedstock chemicals are critical to sustainable battery production and resource reuse in a closed loop process. Precise elemental analysis of intermediate feedstock materials such as lithium hydroxide and metal sulfates plays a key role in quality assurance, process control and environmental safety. Ensuring low levels of impurities supports battery performance, extends lifecycle and reduces reliance on primary mining.

Objectives and study overview

This study evaluates the Agilent 5800 Vertical Dual View ICP Optical Emission Spectrometer for the quantitative analysis of 21 elements in intermediate lithium, nickel, manganese and cobalt salts recovered from spent lithium ion batteries. The method aims to demonstrate robust quantification of both major elements at high concentration and trace impurities in solutions with high total dissolved solids. Screening functions are used to select optimal wavelengths and calibration ranges.

Methodology and instrumentation

Sample preparation included acid digestion of recycled cathode materials and ten fold dilution in 5 percent nitric acid. Calibration standards and quality control solutions were prepared using certified multielement and single element stock solutions. The Agilent 5800 VDV ICP OES was equipped with a solid state radio frequency generator, cooled cone interface and SeaSpray nebulizer. A vertical plasma configuration and dual view optics enabled axial measurements for trace level elements and radial measurements for major components. IntelliQuant screening and Intelligent Rinse routines were employed to optimize wavelength selection and minimize carryover between samples

• Axial view for trace elements with fitted background correction and curve fitting techniques
• Radial view for high concentration elements using selected secondary wavelengths
• Automated rinse control based on signal threshold for consistent washout and throughput

Main results and discussion

Calibration curves for all analytes showed linearity with a correlation coefficient above 0.999 across the selected ranges. Method detection limits in high salt matrices were below 7 micrograms per liter for primary elements and below 2 micrograms per liter for most impurities. Spike recoveries of 50 micrograms per liter on diluted salt samples were within 100 ± 15 percent for all 21 elements, confirming minimal matrix interference. An eight hour stability test with a continuing calibration verification solution indicated recoveries within 10 percent, demonstrating reliable long term operation.

Benefits and practical applications of the method

The validated ICP OES method enables fast and accurate quality control of unrefined battery feedstock chemicals. Automated screening and rinse features reduce method development time and sample carryover. The approach supports closed loop recycling of lithium ion battery materials, enhances process efficiency and reduces environmental impact by ensuring feedstock purity.

Future trends and potential applications

Advances in spectroscopic software will further streamline screening and interference correction. Integration with robotics and data analytics could enable real time monitoring of recycling processes. Expansion of the method to include additional elements and speciation analysis may support next generation battery chemistries and industrial scale quality assurance.

Conclusion

The Agilent 5800 Vertical Dual View ICP OES method provides robust, sensitive and high throughput analysis of both major and trace elements in high matrix lithium, nickel, manganese and cobalt salt solutions. The technique is well suited for quality control of recycled battery feedstocks and supports sustainable lithium ion battery manufacturing.

References

1 Deng J Bae C Denlinger A Miller T Electric vehicles batteries requirements and challenges Joule 2020 4 511-515
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4 Agilent Innovative Freeform Optical Design Improves ICP OES Speed and Analytical Performance Agilent publication 5994-5891EN