Sustainable Lithium-Ion Battery Recycling: Recovery of Metals in Green Solvents by ICP-OES

Importance of Topic

The rapid growth of lithium-ion battery demand in electric vehicles, electronics, and energy storage has heightened the need for sustainable recovery of critical metals such as lithium, cobalt, and nickel. Recycling spent batteries using green solvents like deep eutectic solutions supports a circular economy, stabilizes metal supply and prices, and reduces environmental impact.

Study Objectives and Overview

This study evaluates the performance of the Agilent 5800 Vertical Dual View ICP-OES equipped with an AVS 7-port switching valve for the rapid, accurate quantification of eight key metals in deep eutectic solvent (DES) leachates. The work employs spiked choline chloride:urea DES samples to simulate real leachates and explores advanced software tools for method development and interference correction.

Methodology and Instrumentation

• Instrumentation: Agilent 5800 VDV ICP-OES, AVS 7 switching valve, SPS 4 autosampler, SeaSpray nebulizer, double-pass glass cyclonic spray chamber, Easy-fit 1.8 mm injector torch
• Software: ICP Expert Pro with IntelliQuant Screening, Fitted Background Correction (FBC) and Fast Automated Curve-fitting Technique (FACT)
• Sample Preparation: ChCl:urea DES (1:2 molar ratio) diluted with 2% HNO₃; spiked solutions at low and high concentration levels; QC and internal standard solutions
• Calibration: Multielement calibration for Al, Co, Cu, Fe, Li, Mn, Ni, and P across 1–100 mg/L and higher ranges with correlation coefficients >0.9999
• Interference Management: FBC for background correction and FACT to resolve Li spectral overlap
• Analysis Workflow: Automated 41 s per sample cycle, reducing argon consumption by 50%

Main Results and Discussion

• Linearity and Precision: All elements showed linear calibration (R > 0.9999) and RSD ≤ 2.2% over seven-hour runs
• Detection Limits: Low LOQs and MDLs achieved for trace analysis after accounting for dilution
• Accuracy: Spike recoveries between 94% and 104% across low and high levels, confirming method reliability
• Stability: 645 analyses over 7 h with recoveries within ±10% and minimal drift
• Software Advantage: IntelliQuant Screening streamlined wavelength selection and calibration range setting

Benefits and Practical Applications

• Environmentally friendly recovery of critical metals using biodegradable solvents
• High-throughput, cost-effective multi-element analysis in complex DES matrices
• Reduced instrument wear and operational costs through automated valve cycling and optimized argon usage

Future Trends and Potential Applications

• Development of novel DES formulations for selective metal leaching
• Integration of inline ICP-OES monitoring in industrial recycling processes
• Creation of certified reference materials for DES matrices to standardize measurements
• Advancement of real-time interference correction and data analytics in complex samples

Conclusion

The Agilent 5800 VDV ICP-OES combined with AVS 7 and IntelliQuant Screening offers a robust, rapid, and precise method for quantifying critical battery metals in deep eutectic solvents, supporting sustainable lithium-ion battery recycling initiatives.

Reference

1. Grand View Research. Battery Market Size, Share & Trends Analysis Report, 2024.
2. Jin S.; Mu D.; Lu Z.; et al. A comprehensive review on the recycling of spent lithium-ion batteries: urgent status and technology advances. Journal of Cleaner Production, 340:130535 (2022).
3. Zhu A.; Bian X.; Han W.; et al. The application of deep eutectic solvents in lithium-ion battery recycling: a comprehensive review. Resources, Conservation and Recycling Advances, 188:106690 (2023).
4. Lu Q.; Chen L.; Li X.; et al. Sustainable and Convenient Recovery of Valuable Metals from Spent Li-Ion Batteries by a One-Pot Extraction Process. ACS Sustainable Chemistry & Engineering, 9(41):13851–13861 (2021).