Accurate Identification of Binder Raw Materials for Li-Ion Battery Electrodes by FTIR

Significance of the Topic

Lithium-ion battery production depends on consistent raw materials quality and even small proportions of binders critically affect electrode integrity and long-term performance. Rapid binder verification enhances manufacturing yield and reliability.

Objectives and Study Overview

This study demonstrates a fast, reliable FTIR-based method using the Agilent Cary 630 spectrometer and MicroLab software to identify and verify binder materials in incoming lithium-ion battery raw streams. A spectral library was created for PVDF and PTFE binders, followed by automated analysis of unknown samples.

Used Instrumentation

• Agilent Cary 630 FTIR spectrometer with diamond ATR module
• Agilent MicroLab software

Methodology

A two-step workflow involved generating a reference library by collecting ATR-FTIR spectra of known PVDF and PTFE binders (4000–650 cm–1 range, 32 scans, 4 cm–1 resolution) and applying an automatic similarity search (Hit Quality Index thresholds: >0.95 high, 0.91–0.95 medium, <0.91 low). Four unknown binders were subsequently tested under identical conditions.

Main Results and Discussion

All unknown samples matched library entries, with high HQI values for two PVDF grades (>0.96) and PTFE (>0.98). One PVDF sample showed a medium confidence score (0.91), reflecting formulation differences. Color-coded indicators facilitated rapid interpretation. Additionally, FTIR analysis confirmed the α-phase of PVDF binders via characteristic absorption peaks near 763, 795, 855, 976, and 1149 cm–1, demonstrating phase identification capability relevant for materials development.

Benefits and Practical Applications

• Rapid on-site binder verification minimizing production disruptions
• Intuitive, pictorial software interface reducing training needs and errors
• Automated library management enabling swift adaptation to new materials
• Color-coded, pass/fail results for efficient quality control workflows

Future Trends and Opportunities

Integration of portable FTIR with automated material handling and online monitoring will further streamline QA/QC. Expansion of spectral libraries to new sustainable binder chemistries and incorporation of AI-driven analysis can enhance detection of formulation variants and contamination risks.

Conclusion

The Agilent Cary 630 FTIR spectrometer paired with MicroLab software provides a compact, user-friendly solution for fast identification of battery electrode binders, ensuring material consistency and supporting high-throughput lithium-ion battery manufacturing standards.

References

1. Cai, X.; Lei, T.; Sun, D.; Lin, L. A Critical Analysis of the α, β and γ Phases in Poly(Vinylidene Fluoride) using FTIR. RSC Advances 2017, 7(25), 15382–15389.