Simultaneous Analysis of 19 Organic Solvents and Additives in Lithium-Ion Battery Electrolytes Using GC-MS

Significance of the Topic

The precise composition of lithium-ion battery electrolytes is critical to ensuring cell safety, performance and lifetime. Organic solvents facilitate lithium-ion transport, while functional additives stabilize electrode interfaces and suppress degradation. Trace impurities or incorrect additive levels can compromise battery efficiency and pose safety risks, driving the need for rapid and reliable analytical methods.

Study Objectives and Overview

This work presents the development and validation of a simultaneous GC-MS approach capable of quantifying 19 common organic solvents and additives in lithium-ion battery electrolytes. By coupling the Shimadzu Nexis GC-2030 gas chromatograph with the QP2020 NX single quadrupole mass spectrometer, the authors aimed to reduce total analysis time, improve throughput and deliver accurate results for both research and quality-control laboratories.

Materials and Methodology

A panel of 19 target compounds, including esters, carbonates, fluorinated solvents and specialized additives, was selected. Individual stock solutions (1 000 μg/mL) were prepared in dichloromethane, combined into a multi-standard (50 μg/mL each) and serially diluted to produce calibration standards ranging from 0.1 to 10 μg/mL. Commercial electrolyte samples were diluted 1 000-fold in solvent, with further 10- or 100-fold dilutions applied for high-concentration species. All solutions were injected under split mode conditions.

Used Instrumentation

• Gas Chromatograph: Shimadzu Nexis GC-2030
• Carrier Gas: Helium (99.999 %) at constant linear velocity (36 cm/s)
• Column: SH-1701 (30 m × 0.25 mm ID, 0.25 μm film)
• Oven Program: 35 °C (3 min) → 10 °C/min → 240 °C (5 min)
• Mass Spectrometer: QP2020 NX in EI-SIM mode
• Ion Source/Interface Temperatures: 250 °C / 300 °C

Main Results and Discussion

Under the optimized conditions, all 19 analytes were baseline separated and detected in selected-ion monitoring (SIM) mode. Retention times spanned 2.8 to 17.0 minutes. Calibration curves exhibited excellent linearity (R² > 0.999) across all compounds. Application to a commercial electrolyte containing LiFSI, LiPF₆, EC, EMC, DMC and additives (VC, FEC, PS, SN) demonstrated accurate quantification: DMC (471.1 mg/mL), EMC (497.4 mg/mL), EC (193.7 mg/mL), VC (30.6 mg/mL), FEC (13.5 mg/mL), PS (3.9 mg/mL) and SN (13.4 mg/mL).

Benefits and Practical Applications

The simultaneous analysis of 19 analytes in a single GC-MS run reduces sample throughput time and minimizes solvent usage. The method supports routine quality control of electrolyte formulations, aids research into additive performance and enables rapid screening for impurities or degradation products in battery manufacturing and R&D settings.

Future Trends and Opportunities

Emerging directions include coupling GC-MS methods with high-resolution mass spectrometry to identify unknown degradation products, integrating automated sample preparation for increased throughput, and applying machine learning for chromatogram deconvolution and predictive maintenance. Expanding the analyte scope to include emerging electrolyte solvents and next-generation additives will further enhance battery characterization workflows.

Conclusion

A fast, robust GC-MS method for the simultaneous quantification of 19 organic solvents and additives in lithium-ion battery electrolytes has been developed and validated. With excellent linearity, precision and applicability to real samples, the approach offers a reliable analytical tool for battery research, formulation development and quality control.

References

1. Analysis of Carbonic Esters and Additives in Lithium Ion Battery Electrolytes, Shimadzu Application News No. 01-00708-EN