Bringing research-grade technology to industrial analysis

The lithium-ion battery (LIB) has set the foundation for a new wireless and fossil fuel-free society – and this game-changing technology is yet to reach its full potential. The global demand for LIBs is projected to increase seven-fold by 2030, largely through growth in the electric vehicle market, which accounted for more than 80 percent of LIB demand in 2024 alone¹. With the goal of net zero emissions approaching and the terms of the EU's ‘battery passport’ ² starting to bite, research into this critical resource continues to attract significant attention.

Electrode material and production waste are major cost factors in battery production. Improving electrode performance and cutting waste can lower costs and boost large-scale production. Manufacturers aim to enhance LIB performance in a sustainable manner within this competitive market.

In this guest editorial, Eduardo Nascimento, Solution Product Manager - Polymer & Battery Industry Markets at Bruker BioSpin, focuses on how nuclear magnetic resonance (NMR) spectroscopy, widely used throughout academic and laboratory research, is increasingly being adopted in the battery manufacturing industry as a quality control (QC) and performance optimization resource.

Introduction to NMR technology

The role that advanced analytical technologies have in supporting research and novel material development is highly acknowledged. Nevertheless, translating advanced methodologies that can be applied in the quality control and production optimization of battery cells remains challenging. Improving battery performance and energy storage reliability at competitive financial and environmental cost requires advanced technology automation, low-maintenance cost, ease-of-use, and validated results.

Once considered a high-end academic research technique, NMR spectroscopy has migrated to widespread use across industrial and applied environments, proving its worth in enhancing production throughout the battery manufacturing value chain. This non-destructive technique leverages the inherent magnetic properties of certain atomic nuclei to characterize the molecular structure, interactions, and dynamic processes in both solid-state and solution samples, offering significant time and cost savings in battery cell production.

NMR is a quantitative, highly reproducible technique capable of analyzing individual components within complex solution mixtures across a wide concentration range. It can also be applied to solid-state matter, providing both qualitative and quantitative insights that support key areas such as slurry mixing (solid suspensions), operando battery analysis (in situ), and failure analysis (ex situ).

A new analytical technology in battery cell manufacturing

NMR enables high-throughput, high-performance, and reliable testing throughout the battery cell manufacturing chain, from product development and process control to recycling and material waste reduction, through dedicated solutions that support data management. It provides detailed insights into the properties of battery materials, helping to advance battery technology.

The development of compact benchtop NMR systems has increased applications across the battery manufacturing chain, from QC of battery components to process monitoring of cell manufacturing. Benchtop NMR instruments are user-friendly, offering automated workflows that require minimal sample preparation and can be operated by non-experts, enabling real-time monitoring and rapid, informed decision-making in production environments.

By using NMR throughout the battery lifecycle, methods, data, and resources can be harmonized across an organization to enable significant improvements in workflow efficiency and product quality. For example, methods developed in research and development (R&D) on floor-standing instruments can be translated into manufacturing for use in QC on benchtop systems, streamlining method validation and helping to reduce time to market.

Scope of NMR’s application in battery cell analysis

Reduction of scrap rates: Linking failure analysis, R&D, and manufacturing processes helps reduce expensive materials waste through a better understanding of each stage, allowing corrective actions to be fed back into the production cycle for future implementation. NMR supports failure analysis of cells post-mortem to pinpoint issues caused during manufacturing.

Solid-electrolyte interphase (SEI) characterization: Solid-state NMR allows for the characterization of the SEI, providing valuable insights into its composition and structure, and enabling in-situ monitoring. NMR can identify and quantify the chemical species present in the SEI, including both organic and inorganic compounds, providing crucial insights into its formation and evolution during battery cycling.

Solid-state NMR provides detailed information about the molecular structure and dynamics of the SEI components. This includes insights into the arrangement of atoms and the interactions between different species within the SEI. NMR allows for real-time, non-destructive monitoring of the SEI formation and changes during battery operation. This facilitates the monitoring of SEI stability and effectiveness over time.

Hydrofluoric acid (HF) monitoring in electrolyte: Monitoring HF in battery electrolyte analyses is crucial for evaluating electrode degradation, performance impact, safety concerns, and QC. HF can degrade electrode materials, particularly the cathode, leading to reduced battery capacity and efficiency. This degradation can also cause heat release, increasing the risk of thermal-runaway scenarios.

HF acts as a contaminant in the electrolyte, negatively affecting the overall performance of the battery. It can lower the efficiency of the electrodes over time, which is why it is often referred to as 'battery poison'. The presence of HF can compromise the safety of the battery.

HF formation typically occurs when water hydrolyses compounds like lithium hexafluorophosphate (LiPF₆), and its presence can lead to hazardous conditions. Regular monitoring of HF levels is essential for maintaining the quality and consistency of battery cells. This helps ensure that batteries meet the required specifications and deliver reliable performance.

By controlling HF levels, manufacturers can improve the longevity of batteries. Lower HF concentrations contribute to a more stable and durable electrolyte, enhancing the overall lifespan of the battery.

Improved battery performance:

Slurry stability analysis: Monitoring stability and understanding the physical properties of slurries is vital for improving performance. Slurry homogeneity is critical to achieving high-quality, consistent, cost-effective electrode coating and battery cell production.

NMR supports the optimization of the electrode coating process by assessing the physical and chemical properties of the slurries and ensuring their homogeneity and particle distribution. A homogeneous slurry ensures the electrode coating is uniform, which is essential for consistent electrochemical performance. It also prevents uneven current distribution, which affects the battery’s efficiency and lifespan.

Electrolyte conductivity: Electrolyte conductivity is essential for LIB performance. It facilitates efficient ion transport, reduces internal resistance, enhances thermal stability, prolongs cycle life, and maintains safety by reducing the risk of overheating and structural failures.

NMR can measure the diffusion coefficients of ions in the electrolyte. These coefficients are directly related to ionic conductivity, providing insights into how well ions move through the electrolyte. By analyzing the diffusion behavior of various ionic species, NMR enables the determination of overall electrolyte ionic conductivity – an essential factor in optimizing composition to improve battery performance.

Long-term aging studies: NMR is an invaluable tool for enhancing the durability and performance of LIBs through detailed, long-term analysis. NMR can monitor the chemical changes within battery cells over extended periods. This includes observing the formation and degradation of compounds in the electrolyte and electrodes.

As a non-destructive method, NMR allows for non-invasive, real-time monitoring of battery cells. This is crucial for understanding how batteries age under actual operating conditions. NMR provides detailed information about the molecular structure and dynamics of materials within the battery, aiding in the identification of the mechanisms behind aging and degradation.

NMR can evaluate the impact of various additives on the aging process. For example, it can track how certain additives might reduce the formation of detrimental compounds, thereby extending battery life. By examining interactions between battery materials, NMR supports the optimization of component composition and design to enhance battery longevity.

Looking ahead: Automated process

In today's fast-paced scientific and industrial environments, efficiency, accuracy, connectivity, and sustainability are paramount. NMR has proven to be a versatile analytical tool throughout the battery lifecycle, and contributes significantly to cost optimization, improved sustainability, streamlined processes and the overall performance and reliability of rechargeable batteries for EVs and large-scale energy storage.

The development of user-friendly benchtop NMR systems has facilitated its widespread adoption across the battery manufacturing chain to help optimize next-generation battery development. With further advances in automated processes, using innovative analytical technologies, sample creation, formulation, preparation, and handling have the potential to be automated – delivering precision and consistency while freeing up valuable human resources for more complex tasks.

References:

1. Statista, Lithium-ion batteries: statistics and facts, accessed 28 March 2025. https://www.statista.com/topics/2049/lithium-ion-battery-industry/#topicOverview

2. European Commission, Circular economy: New law on more sustainable, circular and safe batteries enters into force, August 2023, accessed 28 March 2025. https://environment.ec.europa.eu/news/new-law-more-sustainable-circular-and-safe-batteries-enters-force-2023-08-17_en