MoreIsLess Design of electrodes for Li-ion batteries with optimized balance of energy and power

• North, Erlend Tiberg; Skautvedt, Casper; Thiagarajan, Abilash Kanish; Michiel, Marco Di; Checchia, Stefano & Koposov, Alexey [Show all 7 contributors for this article] (2025). X-ray Beam Damage Effects in a Lithium-Ion Battery Probed by Spatially Resolved X-ray Diffraction. ACS Energy Letters. 10(10), p. 4930–4932. doi: 10.1021/acsenergylett.5c02442. Full text in Research Archive Show summary

  The use of synchrotron radiation has become common for probing the structural changes in rechargeable batteries, particularly for operando analysis. Herein, we report the exposure of the electrode to high photon flux during an operando study shutting down electrochemical transformations in the irradiated area of an electrode and causing a gradient of lithiation around the operando beam position. We rationalize such beam damage through radiation induced ionization and, consequently, electrolyte decomposition.

• Wind, Julia & Vie, Preben Joakim Svela (2025). Entropy Profiles for Li-Ion Batteries—Effects of Chemistries and Degradation. Entropy. 27(4). doi: 10.3390/e27040364. Full text in Research Archive
• Ezeigwe, Ejikeme Raphael; Dunne, Ronan Njøs; Solberg, Simon Birger Byremo; Lamb, Jacob Joseph; Wind, Julia & Burheim, Odne Stokke (2025). Manufacturing techniques for improved rate capacity of thick electrodes by tailored electrode structures. Journal of Energy Storage. ISSN 2352-152X. 109. doi: 10.1016/j.est.2024.115253. Full text in Research Archive Show summary

  Increasing the specific energy of Lithium-ion batteries (LIBs), has been improved by increasing the portion of active mass and pre-lithiation. The former consists of both increasing the cell size and electrode layer thickness. Increasing the electrode thickness typically comes at the expense of lowered power capacity. This is because the capacity during high-intensity cycling (high c-rates) is limited for thicker electrodes compared to thinner ones. This is typically seen by studying capacity retention. Several efforts have been made to improve thick electrode power density by designing electrodes with novel architecture, designing porosity gradients, and, thereby, tortuosity. This paper summarises the different types of efforts made to design porosity gradients. Here, we present a comprehensive review of such efforts with a particular focus on manufacturing techniques for making corrugations in the electrodes.

• Skurtveit, Amalie; North, Eira Tiberg; Park, Heesoo; Chernyshov, Dmitry; Wragg, David Stephen & Koposov, Alexey (2025). Stepwise Structural Relaxation in Battery Active Materials. ACS Materials Letters. 7(1), p. 343–349. doi: 10.1021/acsmaterialslett.4c02058. Full text in Research Archive Show summary

  Whenever the cycling of Li-ion batteries is stopped, the electrode materials undergo a relaxation process, but the structural changes that occur during relaxation are not well-understood. We have used operando synchrotron X-ray diffraction with a time resolution of 1.24 s to observe the structural changes that occur when the lithiation of graphite and LiFePO4 electrodes are interrupted. Assessing the kinetics of the relaxation processes coupled with molecular dynamics simulations allows us to identify three relaxation stages in graphite. The atomistic origin for the relaxation process within the partially lithiated graphite structure is driven by the reorganization of Li ions into Li clusters. Relaxation in LiFePO4 electrodes is considerably slower than for graphite, but the observed structural changes is also attributed to reorganization of Li ions. These insights highlight the nature of the structural changes that occur during relaxation and the importance of using operando structural studies to avoid misleading conclusions about the reaction mechanisms in battery materials.

• Wind, Julia; Ulvestad, Asbjørn; Abdelhamid, Muhammad & Mæhlen, Jan Petter (2024). Cellpy – an open-source library for processing and analysis of battery testing data. Journal of Open Source Software (JOSS). 9(97). doi: 10.21105/joss.06236. Full text in Research Archive
• Wind, Julia & Vie, Preben Joakim Svela (2024). Revisiting Pulse-Based OCV Incremental Capacity Analysis for Diagnostics of Li-Ion Batteries. Batteries. 10(8). doi: 10.3390/batteries10080277. Full text in Research Archive Show summary

  This paper presents the concept of applying incremental capacity analysis (ICA) on the OCV curve in the SoC space. The OCV curve can be obtained from any sequence of discharge or charge current or power pulse with a necessary rest period to allow the cell to reach a pseudo-OCV after each pulse. With a high resolution (>100 pulses) in the full SoC window, an OCV-vs.-SoC curve can be obtained with sufficient accuracy to perform an ICA on the obtained OCV curve. ICA as a diagnostic technique has commonly been applied on Li-ion cells with constant charge and discharge at slow currents. However, a slow controlled constant current charge or discharge is normally not feasible and cannot be easily applied to a battery in an application. Here, we revisit pulse-based ICA to supplement the conventional constant-current-based technique. Based on actual ageing data, we show that ICA performed on a selection of high-resolution OCV curves is comparable or better than conventional ICA with constant current. The main advantage of OCV-ICA is that it can be applied to most cells and systems without a significant interruption of normal cell operation. OCV-ICA can provide valuable insights into ageing mechanisms as well as, e.g., detailed information on changes in internal resistance.

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• Wind, Julia; Ostrander, John; Hassani, Alireza; Lian, Torleif; Wragg, David Stephen & Vie, Preben Joakim Svela (2025). DETAILED CHARACTERIZATION AND PARAMETERIZATION OF A LARGE STATE-OF-THE-ART COMMERCIAL LI-ION POUCH CELL. Full text in Research Archive
• Ostrander, John; Wragg, David Stephen & Vie, Preben Joakim Svela (2025). On the Development of Post-Mortem Analyses and Techniques in a Dynamic and Emerging Battery Industry. Full text in Research Archive Show summary

  The rapid pace of battery production presents new challenges when batteries reach the end of their primary service life or become unserviceable. Post-mortem analysis of batteries and battery materials is a developing field of study that needs to advance for efficient and reliable assessments of used batteries from the cell to pack level. Presently there is a push towards ontology based approaches which would facilitate upscaling and automation1 that might eventually adapt to the many different battery types and formats which are in production2. Extensive information can be obtained characterizing cells during operation, providing data to diagnose and determine a battery’s state of health. However, confirmation by physical sampling and direct characterization through various electrochemical, x-ray, and microscopy methods is still necessary to complete the story of the effects of battery aging, abuse, and which ageing mechanisms that have contributed to the battery’s end of life. Here we examine methodology for cell disassembly and some post-mortem analyses used in cell characterization including electrochemical testing, imaging, and x-ray analysis (EDX, XRD, XRCT, etc.). We also discuss results from selected commercial cells. An overview of disassembly techniques highlights considerations for preserving sample integrity and will be compared to procedures described in recent literature for large format pouch cells, high capacity prismatic cells, and 21700 cylindrical cells. Some of the applications of interest are the use in electric vehicles (EVs), as components in larger stationary energy storage units, and for use in the maritime industry in Norway. 1. Yu, J., et al., J. of Manufacturing Systems., 2022. 62: p. 347-366. 2. Baazouzi, S., et al., Batteries, 2023. 9(6): p. 309.

• Wind, Julia; Ostrander, John; Wragg, David Stephen; Hassani, Alireza; Lian, Torleif & Gilljam, Martin [Show all 7 contributors for this article] (2025). Detailed Characterization and Parameterization of a Large State-of-the-Art Commercial Li-Ion Pouch Cell. Full text in Research Archive Show summary

  Lithium-ion batteries (LIBs) serve a critical role in modern technology, powering portable electronics, electric vehicles, and energy storage systems essential for renewable energy integration. The LIB market is rapidly expanding, offering diverse battery cells with specific advantages and trade-offs due to variations in cell chemistry and design. However, manufacturers often provide limited information on cell characteristics, particularly regarding cell chemistries, electrode designs, and cell architecture. This knowledge is crucial for understanding the complex relationships between cell chemistry, design, and performance, and for advancing LIB technology. Here we present the thorough characterization and parameterization of a large-scale 64 Ah Lithium-ion pouch cell with NMC/graphite chemistry, optimized for high-power applications and frequently used e.g. in maritime applications and large-scale energy storage systems. This work contributes to the understanding of properties and design of state-of-the-art cells, and support the modelling on several levels, in addition to setting the benchmark for further work on ageing, degradation and safety on this cell. Extensive characterization on the cell level: The battery cells were characterized on the full cell level. This included charge/discharge capacities, advanced pulsing protocols, internal resistances, entropy measurements and estimations of the cell’s open-circuit voltage profile. The rate capability and corresponding temperature evolution across the cells surface was studied. The characterization of a total of 140 cells further allowed for a statistical analysis of initial capacities and internal resistances. Cell teardown: Details on cell architecture and electrode design were extracted as part of a cell teardown. Cells were carefully opened and disassembled, the individual cell components were counted, weighed and prepared for subsequent characterization. Materials characterization: Detailed analysis of the extracted cell parts with respect to their composition, including not only electrodes, but also separator, electrolyte, tabs and pouch materials. The extracted electrodes were reassembled into coin cells and characterized electrochemically. This included advanced cycling protocols such as GITT, and electrochemical impedance spectroscopy at various temperatures. The electrodes’ microstructure was assessed by SEM imaging and porosimetry measurements. Model parameterization: The collected data was compiled into a full P2D parameter set. The obtained parameters were compared to and supplemented by established literature values. Selected parameters were optimized, and the obtained parameter set was validated against experimental full cell data for a range of different conditions. A full parameter set ready for use within the Python Battery Mathematical Modelling framework PyBaMM was established [1]. References Sulzer, V., et al., Python Battery Mathematical Modelling (PyBaMM). Journal of Open Research Software, 2021.

• Visser, Nienke; Wind, Julia; Gilljam, Martin & Vie, Preben Joakim Svela (2025). End-of-Life Gassing and Electrochemical Degassing in Aged Li-Ion Cells. Full text in Research Archive Show summary

  The safety of the Li-ion battery is known to be a critical issue due to its high energy density and the high flammability of most of its components. Here we report on observations of significant gassing in large commercial Li-ion pouch cells during end-of-life (EoL) storage at supposedly ideal storage temperature, as well as the possibility to remove the evolved gasses through electrochemical degassing. One known safety hazard in Li-ion batteries is gas evolution. Significant gas evolution can lead to an overpressure build-up in the cell, causing significant cell expansion, venting or bursting in the worst case. Many studies with respect to gas formation in Li-ion batteries have focused on gassing during formation cycling (SEI formation), or gas evolution under extreme conditions (e.g., abuse tests, thermal runaway).Reports on gas evolution under “normal” operation or storage are scarce. The evolved gases and their compositions might be different compared to gases commonly released during a thermal event in the Li-ion battery. This study is based on large-format pouch cells (>60 Ah) from a renowned Li-ion cell manufacturer, cycled to EoL between 60 and 80% remaining capacity (SoH). Already during cycling, the thickness of some of the pouch cells increased by up to 50% by the time they reached EoL without gassing. In addition to the swelling during cycling, more than a third of the tested cells started to evolve significant amounts of gas during EoL storage at 5°C, i.e. after the cycling was finished and the cells had reached the planned lower remaining capacity. This gas evolution was further analyzed to scrutinize the causes of this gassing. The analysis revealed that more than 95 % of the gas within the cell was comprised of hydrogen, methane and ethane, with hydrogen being the largest contributor. Small amounts of electrolyte solvents (EMC and DMC) were found, as expected due to the low vapor pressure at low temperatures. CO and CO2 levels were found to be below 1 %. Correlations between cell thickness increase, SoH and methane:hydrogen ratio were observed. Selected gassed cells were carefully cycled to check their functionality and estimate their remaining capacity. During this process we observed that at specific conditions it was possible to electrochemically consume the evolved gasses within the cell. Figure: Three stages in gassing of a stored Li-ion cell. A) Cell swelled with no gassing to 150% @ EoL. B) Cell gassed in cold storage to 250%. C) Cell degassed through electrochemical cycling.

• Wragg, David Stephen (2025). Synchrotron radiation for understanding and developing batteries. Full text in Research Archive
• Wind, Julia & Vie, Preben Joakim Svela (2024). Revisiting pseudo-OCV pulse-based incremental capacity analysis. Full text in Research Archive
• Wind, Julia; Ostrander, John; Shearing, Paul Robert; Mæhlen, Jan Petter & Vie, Preben Joakim Svela (2024). A Direct Comparison of a Power and an Energy-optimized Li-ion Pouch Cell: Characterization, Ageing and Modelling. Full text in Research Archive
• Wind, Julia; Ostrander, John; Shearing, Paul Robert; Mæhlen, Jan Petter & Vie, Preben Joakim Svela (2024). A Direct Comparison of a Power and an Energy-optimized Li-ion Pouch Cell: Characterization, Ageing and Modelling. Full text in Research Archive
• Wind, Julia; Ostrander, John; Shearing, Paul Robert; Mæhlen, Jan Petter & Vie, Preben Joakim Svela (2024). A Direct Comparison of a Power and an Energy-optimized Li-ion Pouch Cell: Characterization, Ageing and Modelling. Full text in Research Archive
• Skurtveit, Amalie; North, Eira Tiberg; Park, Heesoo; Chernyshov, Dmitry; Wragg, David Stephen & Koposov, Alexey (2024). Elucidating relaxation mechanisms in Li-ion batteries through operando X-ray diffraction: Spontaneous Li-ion clustering as a structural origin of relaxation in battery electrodes. Full text in Research Archive
• Wind, Julia; Mæhlen, Jan Petter & Ulvestad, Asbjørn (2024). Cellpy – An Open-Source Python Library for Processing and Analysis of Battery Testing Data. Full text in Research Archive
• Ezeigwe, Ejikeme Raphael; Dunne, Ronan H; Bua, Tone G; Solberg, Simon Birger Byremo; Lamb, Jacob Joseph & Wind, Julia [Show all 7 contributors for this article] (2024). Investigation of Rate Capability and Mass Transfer Dynamics in Lithium-Ion Batteries. Meeting Abstracts - The Electrochemical Society [ECS]. ISSN 1091-8213. Full text in Research Archive
• North, Erlend Tiberg; Skautvedt, Casper; Thiagarajan, Abilash Kanish; Checchia, Stefano; Koposov, Alexey & Wragg, David Stephen (2024). Spatially Resolved Beam Damage on a Graphite Anode in Operando. Full text in Research Archive Show summary

  Modern synchrotron beam lines can offer higher luminance and energy, providing more opportunities for scientists performing structural analysis of materials. However, this benefit comes with a risk of questionable results as continual exposure can lead to damage to the studied materials. This effect is well established in protein crystallography but has recently gained attention in the field of material science including operando studies of battery materials. We have investigated the electrochemical cycling of a graphite-based anode for Li-ion batteries under continuous exposure to high-energy X-ray radiation, exploring the consequences of the exposure on the structure and cycling capabilities. We analyze damage by correlating the dose of radiation to the inhibition of electrochemistry.

• Wind, Julia; Vie, Preben Joakim Svela; Ostrander, John & Mæhlen, Jan Petter (2024). A DIRECT COMPARISON OF A POWER AND AN ENERGY-OPTIMIZED LI-ION POUCH CELL: CHARACTERIZATION, AGEING AND MODELLING. Full text in Research Archive
• Ezeigwe, Ejikeme Raphael; Erichsen, Lene Therese Backus; Wahl, Markus Solberg; Wind, Julia; Vie, Preben Joakim Svela & Burheim, Odne Stokke (2023). The Study of High-Energy Lithium Polymer Cells for Second-Life Applications. Full text in Research Archive
• Vie, Preben Joakim Svela; Wind, Julia & Lian, Torleif (2023). Kan brukte litium-ion-batterier fra elbiler brukes om igjen? Teknisk Ukeblad. ISSN 0040-2354. Full text in Research Archive
• Wind, Julia & Vie, Preben Joakim Svela (2023). Økt forståelse av sikkerheten til maritime Li-ion batterier. Skipsrevyen. ISSN 0800-2282. 12. Full text in Research Archive

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