Advancing Battery Diagnostics in Industrially-relevant Cells
A new generation of diagnostic tools for full–format cells are bridging the gap between academic research and industry development, offering new insights in battery performance and manufacturing.
Image: Spatial mapping of multi-layered pouch cells in ESRF. Image credit Ashok Menon.
A team led by WMG, University of Warwick, has advanced X-ray and neutron diagnostic techniques, enabling the study of battery behaviour during operation, including capabilities for spatial mapping across cells of different formats.
The insights gleaned have accelerated progress across the Faraday Institution research portfolio, influenced research strategy in several industry organisations and could present opportunities as a quality control and diagnostic tool in battery manufacturing.
By using pilot-line-built cells, leveraging high-throughput data reduction methods including the use of advanced machine learning algorithms, and collaborating with beamline scientists at national facilities, the team has redefined what is possible for operando diagnostic techniques. This research paves the way for use of the technique by other groups and is an exemplar of impactful and collaborative translational science.
| By the numbers | |
|---|---|
| 18 | citations for the Joule paper despite only being published in January 2025 |
| Other | |
| 3 | industry partners working on projects with WMG using the technique |
| 3 weeks | time for data analysis compared to 6 months previous to Finden's involvement in the project |
| 200+ | pouch cells investigated using the newly-developed method |
| 2-3 Ah | increased capacity of the A7 pouch cells being tested using this method (multi-layer cells with 10 anode/cathode pairs) |
| 600+ | cycles over which analysis has been performed |
| 1C | industry-relevant charge rate |
Previous successes
Researchers at WMG, University of Warwick previously pioneered X-ray methods to directly study unmodified pilot-line-built single-layer pouch cells during real operating conditions, something not previously possible in laboratory settings.
Unlike earlier operando methods, this approach allows the study of industrially relevant cells without modification, using lab-based X-ray techniques including diffraction, absorption spectroscopy and small-angle X-ray scattering. The cell does not need to be adapted to include “windows” for X-rays to probe the active material. The approach also supports cycling at industry-relevant rates and for long durations. The technique has been used to shine light on degradation mechanisms for automotive OEMs and helped accelerate development cycles.
With expert guidance from Dr David Walker and Dr Steven Huband at the University of Warwick’s X-ray Diffraction Research Technology Platform this capability has been incorporated into the X-ray research facilities on campus.
Read the previous success story published in September 2024.
The continued achievements of the development team were recognised in September 2025, when they were awarded the Faraday Institution Community Award for Innovation. Main contributors to the development team from the FutureCat project were:
- Professor Louis Piper – Professor of Battery Innovation at WMG and Principal Investigator of FutureCat
- Dr Ashok Menon – Research Assistant Professor at WMG and Project Leader of FutureCat
- Dr Gaurav Pandey – Research Fellow at WMG
- Dr Gabriel Perez – Instrument Scientist, ISIS Neutron and Muon Source
- Dr Philip Chater – Crystallography Science Group Leader, Diamond Light Source
- Dr Stephen Price – Industry Research Fellow at Finden Ltd and University of Sheffield (CMBE)
Picture of the award winners at the Faraday Institution Conference 2025. From left to right: Georgia Mann from Withers & Rogers (Award sponsor), Dr Gabriel Perez, Dr Gaurav Pandey, Dr Stephen Price, Dr Ashok Menon, ProfLouis Piper and Prof Martin Freer (Faraday Institution CEO).
Further technique development unlocks spatial mapping and operando neutron studies
Over the past year, the team has expanded the technique’s capabilities, applying it to a wide range of battery chemistries – including NMC811, LNO, LMFP, blended NMC/LMFP, mixed graphite/silicon anodes, and anodeless formats—to support improvements in electrode coatings and to better understand various degradation mechanisms.
The most significant recent advance is the transfer of the technique back to national facilities such as the European Synchrotron Radiation Facility (ESRF), where the high beam intensities, detector improvements and shorter data collection times have enabled spatially-resolved mapping studies.
In the lab, the technique would only collect a single spectra or diffraction pattern from one region of the cell during cycling, which may not represent average cell behaviour. Different regions in a cell can show varying degrees of electrochemical activity due to factors like particle cracking or electrolyte depletion, which can worsen battery performance over time.
A Chem Comms paper demonstrates that operando synchrotron X-ray diffraction (XRD) mapping can quantifiably track differences in the crystal lattice across the cell, revealing inhomogeneities.
Louis Piper explains,
We’re pushing the envelope of what’s possible. Access to the WMG battery pilot line has been key to opening up the field.
“Some believed that operando XRD could not be performed on non-adapted multi-layer pouch cells using X-rays, arguing that copper current collectors are too opaque to X-rays. And while that’s true for typical academic-built cells with thick copper layers, we use thin copper foils, very similar to what’s used in commercial batteries, making these studies possible.
“Similarly, operando neutron studies of laboratory-scale cells were once considered largely impossible due to the presence of hydrogen and lithium species that worsen data quality. By taking advantage of the specialised cold-neutron diffractometer WISH at ISIS we can now use the same tricks with neutrons as we have done with X-rays.”
X-rays and neutrons interact differently with different elements making up battery materials: neutrons are sensitive to lithium, while X-rays are better at detecting heavier elements like nickel and cobalt. Using both techniques on identical cells enables researchers to build a comprehensive picture of the behaviour of all elements at multiple positions in a battery, unlocking many new insights.
Stephen Price and Ashok Menon performing operando XRD experiments at ESRF. Image credit: Harry Gillions (WMG).
The benefits of machine learning in unexpected places
Data processing has been a significant challenge in using this operando technique for mapping. Recent developments in machine learning, new algorithms and custom software have dramatically improved the speed and efficiency of data analysis.
Louis explains,
We can measure data faster than we process it. Before, we might have had hundreds of diffraction patterns per cycle. Now, with spatial mapping, we have to process hundreds of thousands of patterns for the same cycling. New data reduction methods and analysis tools including advanced machine learning algorithms, developed by Finden Ltd, have been instrumental in managing the sheer volume of data, and correcting the artefacts inherent in data from large format cylindrical cells.”
Stephen Price continues,
When you are dealing with terabytes of data, data reduction is crucial, and we rely heavily on scripts to do that. The data we’re getting from testing multi-layered pouch cells and 21700 cylindrical cells from the WMG pilot line is so clean that it is much easier to process. So much so that we’ve been able to automate much of the processing. Our improved methods mean that future users of this technique will be able to accelerate data processing even further. It’s a virtuous cycle.”
Louis concludes,
Finden has massively accelerated the data processing. What used to take six months now takes three weeks. Stephen has helped us up that learning curve.”
Embedding skills, knowledge and tools at national facilities
This sector-focused collaboration is pushing the boundaries of the battery research that can be achieved at beamlines. Expertise has been embedded in beamline scientists like Gabriel Perez and Phil Chater, making it easier for other groups to adopt these technique at national facilities. Louis explains,
ISIS and Diamond are race tracks. With our pilot-line-built cells, we bring a racing car. We are pushing the instruments further and faster, and using better detectors. We’ve helped the central facilities with cycling protocols and now the limitation on data collection speed is the speed of the motor that drives the sample holder.”
Beyond improvements in data processing, several other legacies have emerged from this work:
A dedicated cell holder has been developed, enabling precise and reliable control of stack pressure during long-duration operando studies on multi-layer pouch cells. This advancement supports more consistent and reproducible results in extended experiments.
An expensive and time-consuming sample preparation step has been eliminated. Traditionally, operando experiments at neutron sources required draining the electrolyte and replacing it with a deuterated version—a costly and time-consuming process. The team demonstrated that, when performing experiments on pilot-line-produced, industry relevant cells with high active material content, this step can be avoided entirely, streamlining the process.
Louis continues,
Gabriel and Phil have been huge advocates for us at the central facilities. Their willingness to have a go, see what works, carve out time to try things, and push the boundaries of what’s possible has been greatly appreciated. It’s been a terrific example of a productive industry-relevant, academic-led collaboration with central facilities, which has leveraged the best of all parties.”
Single-layer pouch cells on I11 beamline at Diamond for long-duration studies. Image credit: Ashok Menon
Single-layer pouch cell prior to measurement on the WISH diffractometer (ISIS). Image credit: Ashok Menon.
New insights on research directions and manufacturing imperfections
The new characterisation method enables real-time tracking of degradation processes—including oxygen loss, structural densification, and phase transitions—in layered oxide cathodes like NMC and LNO. It has revealed new redox couplings and structural instability thresholds, providing mechanistic insights that challenge existing models of battery degradation.
The previous case study has shown, through experiments on single-crystal NMC811-graphite, the importance of cathode surface passivation to prevent a restructuring of the cathode’s surface that causes degradation by slowing lithium-ion transport.
Beyond guiding research directions, this technique holds promise as a quality control tool on battery manufacturing lines, helping to understand manufacturing imperfections and their impact on battery performance.
Louis Piper explains,
The technique can pinpoint how degradation is occurring in the battery and distinguish whether it is a manufacturing issue or a fundamental materials issue. It could be used in quality control on manufacturing lines to identify which stage of the process is contributing to unexpected performance loss. It’s far more sensitive than visual inspection.”
Shaping the research strategies of industry organisations
Insights from these new diagnostic techniques have catalysed progress across the Faraday Institution research portfolio – especially in the FutureCat and Degradation projects – and are influencing the research strategies at multiple industry organisations.
For example, WMG researchers are working with Elysia Battery Intelligence by Fortescue ZERO on a Faraday Institution Industry Sprint, using the technique to develop a validated physics-based model of cell degradation for a particular battery chemistry. If successful, these advancements will be commercialised through integration into Elysia’s products. Read more about the Sprint.
Louis elaborates on the link between the technique and battery modelling,
The technique allows us to directly observe electrochemical reactions – and how fast lithium is being transported and quantify them. We can measure the intercalation reactions and compare actual performance to the behaviour predicted by the equations in the models, and suggest changes to parameters accordingly.”
The development of operando XRD studies of pouch cells under real operating conditions presents new opportunities to link physics-based degradation models to cell production variables. We are exploring this exciting area of R&D with Louis in our industry sprint project.”
Tom Maull, Principal Product Manager – Innovation & Enabling Tech, Fortescue ZERO
The development of operando XRD studies of pouch cells under real operating conditions is helping to further validate the benefits of Forge Nano’s powder ALD technology.”
Dr Barbara Hughes, VP of Energy Storage, Forge Nano (Forge Nano is a US-based materials science company specialising in the development of Atomic Layer Deposition equipment and processes.)
Want to know more?
- Read the original PRX Energy on the technique, which was highlighted by editorial staff in an APS Physics article.
- Metal-ligand redox in layered oxide cathodes for Li-ion batteries – ScienceDirect
- Nature of the Oxygen-Loss-Induced Rocksalt Layer and Its Impact on Capacity Fade in Ni-Rich Layered Oxide Cathodes | ACS Energy Letters
- Advancing Battery Diagnostics through Operando Neutron Diffraction of Unmodified Non-deuterated Li-ion Single-layer Pouch Cells | Energy | ChemRxiv | Cambridge Open Engage
- Spatially Resolved Operando X-ray Diffraction for Mapping Heterogeneities in Li-ion Single-Layer Pouch Cells | Energy | ChemRxiv | Cambridge Open Engage
- Diamond celebrates 14,000th paper – A breakthrough in lithium-ion battery research – – Diamond Light Source
Case study published September 2025.