The Role of UV-Vis and ICP-OES Spectroscopy in Lithium-Ion Battery Recycling Methods

Importance of the Topic

Recycling lithium-ion batteries is essential to secure critical raw materials such as lithium, cobalt, nickel, and manganese while reducing environmental impact. The development of sustainable, cost-effective recycling methods supports a circular economy, addresses growing battery waste, and ensures resource availability for electric vehicles and energy storage.

Study Objectives and Overview

This work evaluates a one-step hydrometallurgical approach based on contact-electro-catalytic (CEC) technology, which merges pretreatment and leaching to recover Li, Co, Ni, and Mn from spent cathode materials. UV-Vis spectroscopy and ICP-OES are employed to optimize process parameters, monitor radical generation and metal dissolution in real time, and verify product purity.

Methodology and Instrumentation

• Sample Preparation: NCM cathode sheets were cut, then leached with malic or citric acid and SiO₂ catalyst under ultrasound (40 kHz, 300 W) at 80 °C for 6 h.
• CEC Process: Electron transfer at the liquid–solid interface generates radicals (superoxide and hydroxyl) that degrade binders and promote metal release.
• Instrumentation:
• UV-Vis Spectroscopy: Agilent Cary 3500 Multicell Peltier with Multizone control and Cary UV Workstation to track Ni²⁺ (390 nm), Co²⁺ (508 nm), Mn²⁺ (660 nm) and radical indicators.
• ICP-OES: Agilent 730 and Agilent 5800 Vertical Dual View for simultaneous, sensitive quantification of Li, Co, Ni, Mn, and trace impurities.

Main Results and Discussion

• Optimization: 80 mg SiO₂, 1 M malic acid, 80 °C, 6 h achieved maximum leaching.
• Recovery Rates: Li 99.6 %, Ni 98.3 %, Co 99.4 %, Mn 97.4 % under optimized conditions.
• UV-Vis Data: Real-time absorbance changes confirmed radical formation and metal ion release kinetics.
• ICP-OES Purity Assessment: Trace metals Al, Ca, Mg, Na < 0.03 wt %; regenerated NCM622 composition matched target molar ratio Li:Co:Ni:Mn = 10.1:2.1:6:2.

Benefits and Practical Applications

• Single-Step Efficiency: Simplifies traditional multistep hydrometallurgy.
• Eco-Friendly Catalyst: Recyclable SiO₂ reduces waste and operating cost.
• Real-Time Control: UV-Vis enables dynamic monitoring and process adjustment.
• Quality Assurance: ICP-OES ensures battery-grade material recovery suitable for new cathode fabrication.

Future Trends and Opportunities

• Scale-Up: Integration with continuous flow reactors and automated control systems.
• Broader Chemistries: Application to diverse battery cathode formulations.
• Green Catalysts: Exploration of alternative recyclable catalysts and benign solvents.
• Lifecycle Analysis: Comprehensive environmental and economic assessments for industrial deployment.

Conclusion

The combination of CEC-assisted one-step hydrometallurgical recycling with UV-Vis and ICP-OES analysis offers a sustainable, efficient solution for lithium-ion battery waste. High recovery rates and material purity validate its potential to close the resource loop and support green battery manufacturing.

References

1. Zhu A.; Bian X.; Han W.; et al. Resources, Conservation and Recycling Advances 2023.
2. Jin S.; Mu D.; Lu Z.; et al. Journal of Cleaner Production 2022.
3. Li H.; et al. Journal of Hazardous Materials 2025.
4. Li H.; Berbille A.; Zhao X.; et al. Nature Energy 2023.
5. Agilent Technologies. A Practical Guide to Elemental Analysis of Lithium-Ion Battery Materials Using ICP-OES, 2023.