Guide to Lithium-ion Battery Solutions

Importance of the Topic

The structural, mechanical and chemical integrity of lithium-ion battery components directly impacts performance, safety and lifetime. Comprehensive evaluation of electrode materials, separators, electrolytes and complete cells by advanced analytical techniques is essential for quality control, failure analysis and design optimization.

Objectives and Overview

This guide presents a systematic suite of test methods and instruments for characterizing lithium-ion battery materials and cells. It outlines evaluation of mechanical strength, thermal behavior, chemical composition, gas generation and internal structure, illustrating typical results and their relevance to practical battery development.

Methodology and Instrumentation

• Mechanical Tests: Micro Compression Tester (MCT) for electrode and solid electrolyte compression; AGX-V Universal Tester for separator tensile, puncture and DIC strain mapping.
• Thermal Analysis: DSC for melting and decomposition; TGA for moisture content; TMA for separator shrinkage profiles.
• Chemical Analysis: FTIR in argon for solvent solvation; Ion Chromatography for electrolyte salt degradation; GC-MS for solvent/additive identification; GC-BID for internal gas analysis.
• Imaging: Microfocus X-Ray CT for non-destructive cell inspection under cycling, explosion and mechanical loads.
• Microanalysis: EPMA for element mapping and bonding state of electrode particles; SPM/AFM for surface topography and local conductivity in electrolyte environment.
• Particle Characterization: Laser diffraction (SALD) for carbon black dispersion; Dynamic Image Analysis (DIA) for coarse particle detection and shape verification.

Main Results and Discussion

Compression tests differentiated LiCoO₂ (≈72 MPa) and LiMn₂O₄ (≈8 MPa) strength. Separator tensile and puncture data revealed temperature-dependent elongation and failure behavior, with DIC mapping local strain around damage. DSC identified separator melting at 100-140 °C and electrode decomposition peaks after charge. TGA measured sub-percent moisture levels; TMA showed shrinkage onset near 80-100 °C. FTIR detected solvated carbonate-lithium interactions under argon. IC and GC-MS traced LiPF₆ hydrolysis and additive profiles. GC-BID highlighted increasing hydrocarbon gas formation with capacity fade. X-Ray CT visualized collector deformation and cell expansion during cycling and failure. EPMA and SPM correlated element distribution and conductive pathways at micrometer scale. Particle analyzers quantified aggregate breakup and isolated contaminants.

Benefits and Practical Applications

This integrated approach enables targeted material selection, process control, early detection of defects, and safety assessment. Non-destructive imaging permits time-resolved monitoring of the same cell. Correlated chemical and mechanical data improve predictive models and guide formulation of electrodes and separators.

Future Trends and Possibilities

Emerging directions include operando techniques coupling real-time spectroscopy with electrochemical cycling, AI-driven multi-modal data integration, higher-resolution 3D imaging, in-line process analytics and miniaturized portable instruments for field diagnostics.

Conclusion

The combination of mechanical, thermal, chemical and imaging analyses provides a holistic understanding of lithium-ion battery behavior. Implementing these methods supports resilient cell design, enhances safety and accelerates innovation in energy storage.

Used Instrumentation

• Micro Compression Tester (MCT)
• AUTOGRAPH Precision Universal Tester (AGX-V)
• Differential Scanning Calorimeter (DSC-60 Plus)
• Thermogravimetric Analyzer (TGA-50 series)
• Thermomechanical Analyzer (TMA-60)
• FTIR Spectrophotometer (IRSpirit)
• Ion Chromatograph (HIC-ESP)
• GC-MS (GCMS-QP2020 NX)
• Gas Chromatograph with BID Detector (Nexis GC-2030)
• Microfocus X-Ray CT System (inspeXio SMX-225CT)
• Electron Probe Microanalyzer (EPMA-8050G)
• Scanning Probe Microscope / Atomic Force Microscope (SPM-Nanoa)
• Laser Diffraction Particle Size Analyzer (SALD-2300)
• Dynamic Particle Image Analysis System (iSpect DIA-10)