Guide to Lithium-ion Battery Solutions

Significance of the Topic

Lithium-ion batteries are core to modern portable electronics, electric vehicles, and grid storage. Characterizing component properties—mechanical, thermal, chemical, and structural—is essential to ensure cell performance, safety, and longevity.

Objectives and Overview of the Study

This guide compiles a suite of analytical methods for lithium-ion battery research and quality control. It covers material testing, thermal analysis, component analysis, internal structure evaluation, microanalysis, and particle characterization to provide a comprehensive evaluation framework.

Methodology and Instrumentation

• Mechanical testing: Micro Compression Tester (MCT series), AUTOGRAPH AGX-V universal tester, puncture tests, and digital image correlation (DIC).
• Thermal analysis: Differential Scanning Calorimeter (DSC-60 Plus), Thermogravimetric Analyzer (TGA-50), Thermomechanical Analyzer (TMA-60).
• Component analysis: Fourier Transform Infrared Spectrometer (IRSpirit), Ion Chromatograph (HIC-ESP), Gas Chromatograph-Mass Spectrometer (GCMS-QP2020 NX), Gas Chromatograph with BID detector (Nexis GC-2030).
• Structural imaging: Microfocus X-Ray CT (inspeXio SMX-225CT series).
• Microanalysis: Electron Probe Microanalyzer (EPMA-8050G), Scanning Probe Microscope/Atomic Force Microscope (SPM-Nanoa).
• Particle characterization: Laser Diffraction Particle Size Analyzer (SALD-2300), Dynamic Particle Image Analysis System (iSpect DIA-10).

Key Results and Discussion

• Compression testing showed LiCoO₂ particles fracture at ~73 MPa versus ~8 MPa for LiMn₂O₄, indicating stronger interparticle bonding in cobalt oxide.
• Separator tensile strength tests at 25–90 °C demonstrated maintained mechanical integrity with increased elongation at higher temperatures; puncture tests and DIC revealed stress concentration zones around damage sites.
• DSC identified separator melting and shrinkage onset between 100 °C and 140 °C, while TMA measured shrinkage beginning near 80 °C, with greater shrinkage in the machine direction.
• TGA quantified moisture content in electrode materials below 0.3 wt%, important for preventing electrolyte decomposition.
• In-glove-box FTIR detected carbonate solvent–Li⁺ solvation peaks (700–1000 cm⁻¹) without atmospheric water interference.
• Ion chromatography and GC-MS identified LiPF₆ hydrolysis products and solvent/additive profiles in fresh and aged electrolytes.
• BID-GC analysis of cell gases showed increasing hydrocarbon content and decreasing H₂ as capacity retention declined.
• X-ray CT non-destructively tracked electrode deformation during cycling (100–1500 cycles), visualized explosion damage, and compared pre- and post-cycle structures.
• EPMA mapping resolved micro-scale distributions of active material, binder, and conductive additive and detected Mn chemical state shifts between charged and initial states.
• SPM/AFM revealed local conductivity pathways and binder distribution on electrode surfaces; force-distance curves in electrolyte assessed binder rigidity.
• Particle size analysis via laser diffraction showed dispersion of carbon black aggregates into submicron ranges; DIA detected trace coarse particles in electrode powders to prevent performance issues.

Advantages and Practical Applications

• Comprehensive testing supports R&D, failure analysis, and quality assurance across battery materials and cells.
• Non-destructive and in-situ techniques allow time-resolved studies on the same sample, reducing variability.
• Multi-modal microanalysis links composition, structure, and mechanics at micro- and nano-scales for targeted optimization.
• Particle and component assessments guide formulation adjustments to enhance safety and performance.

Future Trends and Opportunities

Advancements in operando and real-time analytical methods (e.g., synchrotron X-ray, Raman) will deepen insights into dynamic cell processes.
Machine learning on combined mechanical, thermal, and imaging datasets can accelerate materials discovery and predictive maintenance.
Solid-state electrolytes and next-generation chemistries will drive development of specialized interface and dendrite characterization protocols.
Portable and field-deployable instruments will enable on-line manufacturing monitoring and rapid diagnostics in service.

Conclusion

This guide presents a systematic analytical toolkit for evaluating lithium-ion battery components. Integrating mechanical, thermal, chemical, and imaging methods enhances understanding of degradation mechanisms and informs design improvements. Continued innovation in analytical instrumentation and data integration is essential to advance battery technology and ensure reliable energy storage solutions.

Reference

• Shimadzu Corporation. Guide to Lithium-ion Battery Solutions. First Edition: June 2022.