Determination of Carbonate Solvents and Additives in Lithium Battery Electrolyte Using the Agilent 5977B GC/MSD

Importance of Analyzing Lithium Battery Electrolytes

This study addresses the critical need to characterize the organic composition of lithium battery electrolytes. Accurate profiling of cyclic and linear carbonate solvents, along with performance-enhancing additives and potential impurities, underpins improvements in energy density, cycle life and operational safety. A reliable analytical workflow ensures consistent product quality and accelerates development of advanced electrolyte formulations.

Study Objectives and Overview

The primary objective was to establish a gas chromatography/mass spectrometry (GC/MS) method using an Agilent 7890B GC coupled to a 5977B single quadrupole MSD. The protocol focuses on simultaneous quantitation of 15 target carbonate solvents and additives over a 10–500 mg/L range, while retaining the capacity to detect and identify unknown species present in electrolyte samples.

Methodology and Instrumentation

• Sample Preparation: Electrolytes diluted 1 000× in dichloromethane, followed by direct 1 µL split injection (20:1).
• Chromatography: Agilent J&W DB-1701 capillary column (30 m × 0.25 mm, 0.25 µm); initial hold at 40 °C for 3 min, ramp to 160 °C at 10 °C/min, hold 2 min; helium carrier gas at 1 mL/min.
• Mass Spectrometry: Electron ionization mode; source 280 °C; quadrupole 150 °C; interface 250 °C; full-scan acquisition (35–450 amu); electron multiplier voltage 1 137 V.
• Quantitation Strategy: External standard calibration with five concentration levels; each analyte defined by specific quantitative and qualitative ions.

Key Results and Discussion

Separation of all 15 analytes was achieved within 17 min, demonstrating baseline resolution on the DB-1701 column. Instrument detection limits were below 1.3 mg/L for each compound, and repeatability studies (n=8) yielded peak area RSDs under 5 %. Calibration curves exhibited excellent linearity (R² > 0.997). Analysis of practical electrolyte samples confirmed accurate quantification of major solvents (e.g., EMC at 455 g/L, DEC at 276 g/L, EC at 192 g/L). Full-scan data also facilitated the identification of unknown additives, including propene-1,3-sultone in sample B.

Practical Benefits and Applications

This GC/MS method provides a streamlined, high-sensitivity approach for routine quality control and research applications in battery manufacturing. Its quantitative precision and qualitative screening capability support comprehensive profiling of electrolyte formulations and trace impurity detection.

Future Trends and Potential Applications

Emerging trends include faster GC/MS platforms with automated sampling, enhanced column chemistries for complex mixtures, and advanced deconvolution software for unknown identification. Integration with real-time battery performance monitoring and machine-learning-driven data analysis will further optimize formulation development.

Conclusion

The presented Agilent 7890B/5977B GC/MS method delivers reliable, high-throughput analysis of carbonate solvents and additives in lithium battery electrolytes. Its balance of sensitivity, reproducibility and qualitative insight makes it an effective tool for both R&D and industrial quality assurance of next-generation battery systems.