Analyzing Battery Compounds with Raman Spectroscopy

By Owais AliReviewed by Lexie CornerFeb 13 2025

Raman spectroscopy has been a critical tool in battery research since the 1960s, originally used to identify spectral characteristics of battery materials. Its strength lies in detecting vibrational and rotational modes in the low-wavenumber region, typically accessible only through far-infrared measurements.¹

Image Credit: Allahfoto/Shutterstock.com

In recent years, Raman spectroscopy's role has expanded significantly, particularly with the growing demand for energy storage solutions driven by the increased use of renewable energy. It has become indispensable for characterizing novel anode and cathode materials, as it detects minute variations in molecular structure and chemical environment.

This makes it invaluable for developing, optimizing, and assessing battery materials, providing insights into changes that affect efficiency, stability, and longevity.²

Applications in Battery Analysis

Electrode Analysis in Batteries

Raman spectroscopy helps analyze electrodes in battery research, supporting manufacturing quality control and failure analysis.

Anode Analysis

Graphite is the most common anode material, and its structural integrity is crucial for battery performance. Raman spectroscopy evaluates graphite degradation by monitoring the intensity ratio of the D-band (1346 cm⁻¹) and G-band (1582 cm⁻¹), where an increase in D-band intensity indicates structural disorder.

In addition, Raman imaging provides spatial analysis of degradation patterns, revealing graphite deterioration and binder migration, contributing to electrode instability.^3,4

Cathode Analysis

In cathode analysis, Raman spectroscopy detects structural changes in materials like lithium cobalt oxide (LiCoO₂) during charge and discharge cycles, revealing transformations such as the formation of cobalt dioxide (CoO₂) due to overcharging or irreversible decomposition into lithium oxide (Li₂O) and cobalt oxide (CoO).

Similarly, it helps characterize structural variations in advanced cathode materials such as Li(Ni,Mn,Co)O₂, LiMn₂O₄, and Li₂TiO₃, aiding in material optimization for improved electrochemical stability.⁴

Impurity Detection

Raman spectroscopy is highly sensitive to lithium-based impurities, particularly hydrated lithium salts such as lithium hydroxide and lithium carbonate. A recent study using the Thermo Fisher Scientific DXR3 SmartRaman spectrometer has detected carbonate contamination through spectral variations below 2000 cm⁻¹ in batch analyses of battery-grade lithium hydroxide, highlighting its importance in ensuring material purity for high-performance batteries.³

Electrolyte Analysis

Electrolyte Degradation Analysis

Electrolytes facilitate charge transport between the cathode and anode, directly affecting ion mobility, electrode stability, and battery lifespan. Over time, common electrolytes like (LiPF₆) degrade, generating gaseous by-products such as hydrogen fluoride (HF), which accelerates electrode corrosion. Advanced monitoring techniques are essential to track these changes.

A study in Nature Communications used operando Raman spectroscopy to track carbonate-based electrolytes in lithium-ion batteries with a graphite anode and LiNi₀.₈Mn₀.₁Co₀.₁O₂ cathode. Using a hollow-core optical fiber probe in a pouch cell, the researchers captured real-time changes in solvent ratios and additives, providing insights into solvation dynamics and electrolyte degradation.⁵

Ion Association and Conductivity Analysis

Raman spectroscopy provides valuable insights into ion association, conductivity, and electrolyte stability by distinguishing between free ions, ion pairs, and aggregates, enhancing the understanding of charge mobility in battery systems. Advanced tools like the DXR3 Raman Microscope enable high-precision analysis of local chemical environments, facilitating the optimization of electrolyte formulations for more stable, high-performance batteries.

In solid polymer electrolytes (SPEs), Raman mapping reveals the distribution of additives and electrolytes within polymer matrices, helping optimize formulations for improved ionic conductivity. For instance, a study tracking a supramolecular additive (Cx₂) in a PEO-based SPE mapped the ratio of the 1598 cm⁻¹ peak (Cx₂) to the 840 cm⁻¹ peak (PEO), revealing variations in additive concentrations that are crucial for improving electrolyte formulations.⁶

Interface Monitoring and SEI Formation

The solid electrolyte interphase (SEI) layer is critical for lithium-ion and lithium-metal battery performance. It stabilizes the electrode surface during initial charge-discharge cycles, enabling reversible capacity. Understanding SEI formation and evolution is essential for battery stability, with Raman spectroscopy providing molecular-level insights into electrode-electrolyte interactions.

SEI Evolution in Solid-State Lithium-Ion Batteries

A study in Batteries & Supercaps used in-situ Raman spectroscopy to track SEI degradation in solid-state batteries. Researchers detected Li₂S, polysulfides, and P₂S_x species forming during charging cycles, revealing interfacial degradation pathways. These findings inform strategies for stabilizing ASSBs, improving interfacial management, and extending cycle life.⁷

SEI Monitoring in Lithium Metal Batteries

In lithium metal batteries, particularly anode-free designs, SEI formation occurs dynamically on both the copper current collector and deposited lithium. Traditional techniques often struggle to track these processes due to the complexity of the SEI, which includes nanometric decomposition products from the electrolyte.

Depth-sensitive plasmon-enhanced Raman spectroscopy (DS-PERS) addresses this limitation by integrating surface-enhanced Raman spectroscopy (SERS) with shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). Using nanostructured Cu, shell-isolated Au nanoparticles, and Li deposits, DS-PERS amplifies Raman signals, enabling real-time molecular analysis of SEI evolution.⁸

Solid-State Battery Applications

Mapping Ionic Pathways in Solid Fast-Ion Conductors

In solid-state batteries, solid fast-ion conductors (SFICs) offer liquid-like ion conduction within a solid framework, making them promising candidates for replacing traditional liquid electrolytes. However, the ionic conductivity of these materials can vary significantly within the same material class.

A study used Raman spectroscopy to map ionic conductivity pathways in Li₁₀Ge_1−xSnxP₂S₁₂ by examining the effects of substituting Ge with Sn. The substitution altered the chemical bonding within the electrolyte's host framework, impacting Li-ion transport. By combining Raman spectra with neutron diffraction and density functional theory (DFT) calculations, researchers identified structural factors that influence ion conduction.^9,10

Chemical Compatibility in Thin-Film ASSBs

Thin-film ASSBs are promising for ultra-small devices, with in-situ Raman spectroscopy providing insights into interface compatibility, ion transfer, and stress development during cycling.

A study examining Li_xCoO₂ cathodes used Raman spectral shifts correlated with the state of charge, revealing insights into ion transfer and material stress. Additionally, in-situ Raman spectroscopy tracked phase transitions in LiMn₂O₄ cathodes during lithiation, observing distinct Raman spectra during the α-phase to β-phase to λ-MnO₂ transition.

This non-destructive method provided insights into lithium diffusion, phase changes, and material stress.¹¹

Unique Advantages for Battery Analysis

Non-Destructive In-Situ Analysis

Raman spectroscopy enables real-time, non-destructive monitoring of lithium-ion battery materials, capturing phase transitions, intercalation processes, and electrode degradation during charge-discharge cycles.

A study using the Thermo Scientific DXRxi Raman Imaging Microscope analyzed a graphite anode, revealing lithiation-induced spectral shifts—the disappearance of the G-band (1580 cm⁻¹) and the emergence of a new peak at 1590 cm⁻¹. These findings underscore Raman spectroscopy’s ability to detect subtle structural changes in battery operation.¹

Operando and Ex-Situ Measurements

In addition to in-situ measurements, ex-situ Raman mapping helps understand discharge products and their distribution across cathodes. The Stephenson Institute for Renewable Energy combined in-situ Raman spectroscopy with electrochemical cells to study oxygen reduction and evolution reactions in lithium-ion and sodium-ion cells, providing insights into intermediate species and reaction mechanisms during cycling.

Moreover, it helps examine electrode materials through the electrolyte, offering high spatial resolution and sensitivity without disrupting electrochemical processes.¹²

Spatial Resolution and Chemical Mapping

Raman imaging offers a unique advantage in spatially resolving material behavior across electrode surfaces, enabling the investigation of heterogeneities within electrode materials. The technique allows spectra collection from areas as small as 30 µm × 30 µm with sub-micron resolution, providing insights into localized material changes. In graphite anode studies, Raman imaging revealed shifts in the G-band during lithiation, shedding light on electrochemical processes at different voltages.

Additionally, its sensitivity to local variations led to the detection of previously unreported spectral features, such as a new peak at 154 cm⁻¹ at low voltages, highlighting its capacity to uncover new information during battery operation.^1,13

Conclusion and Further Resources

Raman spectroscopy provides critical insights into battery chemistry, structure, and degradation, making it indispensable for advancing energy storage technologies. As battery research evolves, integrating real-time imaging and advanced characterization techniques will be key to improving performance, safety, and longevity.

For a deeper dive into battery diagnostics and imaging techniques, explore the following:

• Exploring the Changing Microstructure of Lithium Metal During Cell Battery Cycling
• Real-Time Imaging of Lithium Plating for Improved Battery Diagnostics
• The Use of Operando Imaging for Battery Analysis
• How do CT Instruments Help with Battery Analysis?
• Using Cryo-EM to Analyze Batteries

References and Further Reading

1. Dick Wieboldt, Ines Ruff, & Matthias Hahn. (2022). In situ Raman Analysis of Lithium-Ion Batteries. [Online]. Available from: https://assets.thermofisher.com/TFS-Assets/MSD/Application-Notes/an52676-e-0215m-in-situ-lithium-ion.pdf
2. Adams, R. A., Li, B., Kazmi, J., Adams, T. E., Tomar, V., & Pol, V. G. (2018). Dynamic impact of LiCoO2 electrodes for Li-ion battery aging evaluation. Electrochimica Acta, 292, 586-593. https://doi.org/10.1016/j.electacta.2018.08.101
3. Bruno Beccard & Shaileshkumar N. Karavadra. (2022). Lithium-Ion Battery Manufacturing and Quality Control: Raman Spectroscopy, an Analytical Technique of Choice. https://doi.org/10.56530/spectroscopy.sx2271c5
4. Renata Lewandowska, Miyoko Okada, & Tomoko Numata. (2025). Raman Spectroscopy Applied to the Lithium-ion Battery Analysis. Available from:  https://www.horiba.com/int/scientific/applications/energy/pages/raman-spectroscopy-applied-to-the-lithium-ion-battery-analysis/
5. Miele, E., Dose, W. M., Manyakin, I., Frosz, M. H., Ruff, Z., De Volder, M. F., Grey, C. P., Baumberg, J. J., & Euser, T. G. (2022). Hollow-core optical fibre sensors for operando Raman spectroscopy investigation of Li-ion battery liquid electrolytes. Nature Communications, 13(1), 1-10. https://doi.org/10.1038/s41467-022-29330-4
6. Robert Heintz. (2022). Raman analysis of lithium-ion battery components-Part III: Electrolytes. Available from: https://assets.thermofisher.com/TFS-Assets/MSD/Application-Notes/AN52445-raman-analysis-lithium-ion-battery-components-electrolytes.pdf
7. Zhou, Y., Doerrer, C., Kasemchainan, J., Bruce, P. G., Pasta, M., & Hardwick, L. J. (2020). Observation of interfacial degradation of Li6PS5Cl against lithium metal and LiCoO2 via in situ electrochemical Raman microscopy. Batteries & supercaps, 3(7), 647-652. https://doi.org/10.1002/batt.201900218
8. Gu, Y., You, E., Lin, J., Wang, J., Luo, S., Zhou, R., Zhang, C., Yao, J., Li, H., Li, G., Wang, W., Qiao, Y., Yan, J., Wu, D., Liu, G., Zhang, L., Li, J., Xu, R., Tian, Z., . . .  Mao, B. (2023). Resolving nanostructure and chemistry of solid-electrolyte interphase on lithium anodes by depth-sensitive plasmon-enhanced Raman spectroscopy. Nature Communications, 14(1), 1-11. https://doi.org/10.1038/s41467-023-39192-z
9. Sau, K., Takagi, S., Ikeshoji, T., Kisu, K., Sato, R., Dos Santos, E. C., Li, H., Mohtadi, R., & Orimo, S. (2024). Unlocking the secrets of ideal fast ion conductors for all-solid-state batteries. Communications Materials, 5(1), 1-27. https://doi.org/10.1038/s43246-024-00550-z
10. Krauskopf, T., Culver, S. P., & Zeier, W. G. (2018). Bottleneck of diffusion and inductive effects in Li10Ge1–x Sn x P2S12. Chemistry of Materials, 30(5), 1791-1798. https://doi.org/10.1021/acs.chemmater.8b00266
11. Kuwata, N., Matsuda, Y., Okawa, T., Hasegawa, G., Kamishima, O., & Kawamura, J. (2022). Ion dynamics of the LixMn2O4 cathode in thin-film solid-state batteries revealed by in situ Raman spectroscopy. Solid State Ionics, 380, 115925. https://doi.org/10.1016/j.ssi.2022.115925
12. Technology Networks. (2018). Raman Spectroscopy Helps Battery Research. Available from:  https://www.technologynetworks.com/analysis/news/raman-spectroscopy-helps-battery-research-295907
13. Baddour-Hadjean, R., & Pereira-Ramos, J. P. (2010). Raman microspectrometry applied to the study of electrode materials for lithium batteries. Chemical reviews, 110(3), 1278-1319. https://doi.org/10.1021/cr800344k

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