Pyrolysis gas chromatography - high resolution Orbitrap mass spectrometry as a tool for Li-ion battery shred material forensics

Importance of the Topic

Recovery of critical metals from lithium ion batteries relies on efficient separation of all cell components. Organic binders in shredded battery material can impede metal extraction and reduce recycling efficiency. Rapid and accurate identification of these binders supports process optimization and resource sustainability.

Objectives and Study Overview

This study demonstrates the use of pyrolysis gas chromatography coupled with high resolution Orbitrap mass spectrometry to identify organic binders directly in lithium ion battery shred material. Double shot pyrolysis and high mass resolution analysis enable fingerprinting of polymeric binders without sample pretreatment.

Methodology and Instrumentation

Pyrolysis was performed in two steps at 200 °C for initial desorption and 600 °C for binder decomposition. Gas chromatographic separation used a capillary column with helium carrier gas and split injection. Mass analysis employed Thermo Fisher Scientific Orbitrap Exploris GC 240 at 60000 resolution under electron impact and positive chemical ionization modes. This combination allowed rapid switching between ionization techniques without breaking vacuum.

Main Results and Discussion

High resolution accurate mass analysis filtered isobaric interferences and simplified chromatograms. Polyvinylidene fluoride was identified by fluoroalkene markers such as tetrafluoroallylium cation at m z 113.0009. Styrene butadiene copolymer was detected by aromatic pyrolysis products including toluene at m z 92.0621. Positive chemical ionization provided molecular ion information that helped confirm binder structures within complex matrices.

Benefits and Practical Applications of the Method

• Direct analysis of shred material without pretreatment
• High selectivity reduces interferences and maintenance
• Reduced sample consumption limits introduction of corrosive decomposition products
• Rapid switching between ionization modes enables both fingerprinting and molecular confirmation

Future Trends and Potential Applications

Further developments may include automated binder libraries and machine learning for pattern recognition. Expansion to track binder degradation in aged electrodes and integration with inline quality control systems could enhance recycling workflows. Alternative ionization approaches and coupling with complementary detectors may improve polymer characterization.

Conclusion

Pyrolysis GC Orbitrap mass spectrometry offers a robust tool for identifying organic binders in lithium ion battery shred. High mass resolution and flexible ionization modes deliver fast and accurate results that support improved recycling efficiency and resource recovery.

References

1. Petranikova M., Naharro P. M., Vieceli N., Lombardo G., Burcak E. Recovery of critical metals from EV batteries via thermal treatment and leaching with sulfuric acid at ambient temperature. Waste Management 2022 140 164-172.
2. Tsuge S., Ohtani H., Watanabe C. Pyrolysis GC MS Data Book of Synthetic Polymers Pyrograms Thermograms and MS of Pyrolyzates Elsevier 2011.
3. Peschel C., van Wickeren S., Preibisch Y., Naber V., Werner D., Frankenstein L., Horsthemke F., Peuker U., Winter M., Nowak S. Comprehensive characterization of shredded lithium ion battery recycling material. Chem Eur J 2022 28 e202200485.
4. Cholewinski A., Si P., Uceda M., Pope M., Zhao B. Polymer binders characterization and development toward aqueous electrode fabrication for sustainability. Polymers 2021 13 631