How NMR Spectroscopy Enhances Lithium-Ion Battery InnovationHow NMR Spectroscopy Enhances Lithium-Ion Battery Innovation
Bruker BioSpin provides insights into how NMR spectroscopy enhances lithium-ion battery performance, safety, and sustainability for the EV industry.

As the automotive industry reinvents itself with the ultimate goal of achieving zero emissions, and alternative fuels like biofuels, e-fuels, or hydrogen remain unfeasible at the commercial scale, the global spotlight remains firmly on battery performance.
Lithium-ion batteries (LIBs) are widely used in electric vehicles (EVs) owing to lithium’s high energy density and electrochemical potential, and they are expected to remain the core technology for EVs in the next decade. Manufacturers are under pressure to optimize production efficiency, battery performance, cost, lifespan, and recyclability, with R&D efforts—and competition—intensifying. To develop and produce superior LIBs more cost-effectively, however, the underlying chemistry of the materials and how they interact must be well understood.
In the EU, road transport accounts for a quarter of emissions, and to achieve net zero emissions by 2050, the EU wants to have at least 30 million zero-emission cars on European roads by 2030. In the US, industrial pressure has led to reduced EV adoption targets, but current plans will see emissions cut by 49% by 2032 over 2026 levels.
Passport to net zero
In July 2023, the EU Battery Regulation Amendment was adopted by the EU Council. It requires all EV batteries over 2 kilowatt (KWh) hours sold in the EU to hold a unique ‘battery passport’ that provides information about the battery's composition and lifecycle. This digital record system will enable the transfer of key information about the battery for better traceability, transparency, and safety, which is especially important in the emerging used EV market. The US Inflation Reduction Act already requires manufacturers to produce a record of a battery’s composition and production history.
These regulations—and the pressure to innovate—mean EV battery manufacturers require advanced analytical techniques for both R&D and manufacturing. Developments in magnetic resonance spectroscopy, including nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy, are paving the way for progress in this field.
NMR spectroscopy steps up
NMR spectroscopy is a non-destructive technique that uses the inherent magnetic properties of specific atomic nuclei to characterize the molecular structure and makeup of a sample in solid-state or solution form.
NMR spectroscopy supports R&D scientists and production experts and offers many applications for spectroscopic experts and non-experts along the entire value chain. NMR is intrinsically quantitative, highly reproducible, and capable of detecting and quantifying components within mixtures while covering a wide concentration range. It can also be applied as a solid-state technique for analysis to provide detailed qualitative and quantitative molecular-level insights into areas such as battery failure.
Effective material analysis
Batteries' safety, service life, power density, and recharge efficiency are all defined by their components' physical and chemical properties – the cathodes, anodes, separators, and electrolytes, and foremost driven by their interaction.
Key aspects of LIB battery development and manufacturing benefit from material analysis by NMR:
Slurry formation:
Optimizing material formulation and consistency is key for electrode coatings with electro-chemically active materials. Key bulk parameters besides the electrochemical properties of the coating precursor, a suspension known as slurry or ink, must be optimized, maintained, and monitored to ensure an efficient coating process and an optimal performance characteristic of the final battery.
Time domain NMR (TD-NMR) spectroscopy can measure critical physical properties of a slurry over time, allowing early identification of sedimentation, solid/liquid component distribution, mixing and binder activity homogeneity, and viscosity. The sample requires no additions or preparation allowing for measurements in the original, unchanged state.
In LIB R&D, TD-NMR can help define the optimal slurry formulation matching all performance and process requirements. In process control environments, it can help quickly assess the current state of any given electrode slurry before the coating process.
Liquid electrolytes:
Electrolytes play a key role in lithium-ion diffusion but are subject to aging during charging/discharging cycles and storage. They are also sensitive to thermal effects and protic contamination, like water. The resulting reaction by-products can negatively impact the battery’s performance, lifetime, and operational safety, especially if hydrofluoric (HF) acid is present, which degrades the active ingredients of the electrolyte.
Understanding aging and degradation pathways and defining countermeasures within the chemical makeup or industrial production processes can enhance battery performance.
Multi-nuclear NMR spectroscopy provides a comprehensive picture of the range of components in pristine, aged, or recycled electrolytes. NMR spectra are easily accessible for identification and quantification of known components, such as 1H, 7Li, 13C, 19F, or 31P. If structure elucidation of unidentified components is required, a broad range of suitable experiments—pre-defined or custom-tailored—provide detailed information on the molecular structures.
Within an instant, the characteristic electrolyte solvent signals appear in the 1H-NMR spectrum and, if present, the water signature (Figure 1). The peak areas are used to determine the components’ concentrations.
This determines the baseline for further studies within R&D environments involving adjusted formulations or degradation pathways. This information can be useful for incoming goods, process intermediates, or final product quality control testing in production environments.

Figure 1: H-NMR spectrum at 400MHz of an electrolyte solution: A = full spectrum, B = y-zoomed cutouts of the EC (ethylene carbonate) and DEC (diethyl carbonate) signals. Credit: Bruker BioSpin.
NMR can provide a rapid assessment of electrolyte composition, plus water and/or HF quantification.
If routinely used as an automated raw material control in battery cell manufacturing, NMR-based electrolyte analysis creates a trackable baseline of this key component over time. Post-mortem NMR-based failure analysis of formation-failed cells can be linked back to this baseline, and corrective measures can be taken based on analytical evidence.
Ion mobility and ion diffusion in the electrolyte phase
Mobility of the ions and ion diffusion in the electrolyte phase affects the charge/discharge rate, energy density, and electrical conductivity. To increase battery performance, it is critical to characterize the mobility of ions in the electrolyte.
The suitability of an electrolyte can be evaluated by measuring the mobility of the solvent as well as the mobility of the dissolved Li+ and PF6.
Diffusion ordered spectroscopy (DOSY) is an experimental NMR technique that measures the self-diffusion coefficient, D, of the molecular species in solid-state or in liquid samples. It helps answer the questions, “Does my electrolyte effectively conduct electricity?”, and “To which extent did cycling influence the conductivity?”
Using information from DOSY NMR measurements, the properties of the electrolyte can be optimized and the electrolyte contribution to the total performance of the cell can be determined. Electrolytes extracted from cycled test cells can also be investigated after the formation process, to help better understand structural changes.
Failure analysis – minimizing scrappage rates:
Failure analysis is important for optimizing the production line, and NMR can provide critical information about the physical and chemical properties of the components present.
During the first charging cycle of a LIB, when lithium-ions travel through the electrolyte towards the anode, some react with the electrolyte's degradation products and form insoluble deposits on the anode. These deposits build up to form the solid-electrolyte interphase (SEI), which prevents the anode material from decomposing and negatively impacts the battery's long-term operation.
With solid-state NMR, the material characteristics of the SEI can be analyzed to understand its composition and how it formed. This helps reduce the scrap rate, as analysts can better understand and influence the formation step.
During charging, when lithium-ions move towards the anode, they may undergo plating or lead to the formation of dendrites. These finger-like projections can build up and impact battery performance. If the dendrites reach as far as the cathode, the battery may short- circuit and even ignite.
Measuring the build-up of dendrites during cell operation is challenging but is necessary for the continued investigation of alternative LIB designs and materials. In addition to NMR, EPR spectroscopy is well suited to studying the evolution of metallic lithium species. Compared with NMR, EPR has a higher surface selectivity due to the low penetration depth of microwaves into the bulk, enabling differentiation between bulk and fine structured lithium dendrites (Figure 2).

Figure 2: Different lithium morphologies detected with a Bruker E540 ELEXSYS X-band spectrometer equipped with a 4108 TMHS resonator. Top: dendritic lithium (green). Middle: mossy lithium (blue). Bottom: bulk lithium (red). Courtesy of Council of the EU in accordance with Creative Commons Attribution 4.0 International License.
As the automotive industry looks to battery manufacturers to develop safe, efficient, recyclable batteries with long lifespans at lower cost, the race is on to enhance lithium-ion based electrochemistry. With formulations of new active ingredients being developed and tested and production lines being optimized, there is unprecedented demand for fast, effective material analysis.
NMR spectroscopy is increasingly being relied upon to analyze the chemical and electrochemical processes and resulting reaction products of LIBs in real time. With this technique, it is possible to extrapolate information on stable and transient chemical species being produced within the materials and interfaces of battery cells, their concentration, mobility, and reaction rates. Thanks to this insight, NMR is contributing to the development and optimization of batteries, ultimately advancing battery technology and promoting sustainable energy solutions.
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