Eira Tiberg North

• Dai, Tian; Ahmed, Razan M. N.; North, Eira Tiberg; Valldor, Björn Martin & Koposov, Alexey Y. (2026). Exploring Antiperovskite Cathodes for Na‐Ion Batteries. ChemSusChem. ISSN 1864-5631. 19(10). doi: 10.1002/cssc.70723. Fulltekst i vitenarkiv Vis sammendrag

  Recently discovered cathode materials with antiperovskite (AP) structure have shown a promising performance in Li‐ion batteries. However, their applicability in other battery chemistries have not been well explored. In this work, an AP‐based cathode material, Li 2 FeSeO, was systematically studied for application in Na‐ion batteries (NIBs). Delithiated Li 0.8 FeSeO was used as a precursor for preparing an Na‐ion analog. The electrochemical characterization of Na‐based AP cathode revealed a reversible galvanostatic cycling behavior with an initial capacity of 129 mA g −1 and a capacity retention of 57% after 200 cycles when cycled at a current density of 10 mA g −1 . Up to 0.75 Na + can be reversibly inserted into the AP framework. Synchrotron operando and ex situ X‐ray studies revealed a working mechanism based on a dual redox behavior including both Fe and Se, with Se being the main redox actor. The (de)sodiation capacity below expected value is possibly attributed to the formation of a core–shell structure formed due to kinetic limitation of Na + diffusion into bulk structure, thus preventing a full utilization of the available redox activity. These findings establish AP cathodes as viable candidates for NIBs and provide mechanistic insights that can guide their future structural optimization.

• Skurtveit, Amalie; North, Eira Tiberg; Berdiell, Izar Capel; Beek, Wouter Van; Wragg, David S. & Koposov, Alexey (2026). Operando X‐Ray Diffraction and Total Scattering Characterization of Battery Materials: Not Just a Pretty Picture. Advanced Energy Materials. ISSN 1614-6832. doi: 10.1002/aenm.202506777. Fulltekst i vitenarkiv Vis sammendrag

  The development of rechargeable batteries can be accelerated by the fundamental understanding of their chemistries. Multiple characterization techniques have been deployed to study the chemical processes in batteries, but structural studies at the atomic level using X‐ray diffraction (XRD) and total X‐ray scattering (TXS) show enduring popularity. These methods are relatively easy to apply in operando mode, where structural data is collected alongside electrochemical data under operating conditions. With a growing interest in this powerful methodology, it is important to review the general principles of operando XRD/TXS characterization and develop a set of guidelines for the collection, analysis, and presentation of data that are acceptable to the community and can lead to reliable, representative, and reproducible results that are easy to judge and compare. This Review aims to survey and discuss important steps in operando XRD and TXS. From cell and electrode design to data treatment, we survey the major experimental aspects of operando studies, pointing out potential pitfalls and identifying best‐practice. In addition, we review some unconventional experiments conducted in operando mode to illustrate how such methods can be used beyond studies of the early‐stage cycling mechanisms of battery active materials.

• North, Erlend Tiberg; Skautvedt, Casper; Thiagarajan, Abilash Kanish; Michiel, Marco Di; Checchia, Stefano & Koposov, Alexey [Vis alle 7 forfattere av denne artikkelen] (2025). X-ray Beam Damage Effects in a Lithium-Ion Battery Probed by Spatially Resolved X-ray Diffraction. ACS Energy Letters. 10(10), s. 4930–4932. doi: 10.1021/acsenergylett.5c02442. Fulltekst i vitenarkiv Vis sammendrag

  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.

• Skurtveit, Amalie; North, Erlend Tiberg; Park, Heesoo; Chernyshov, Dmitry; Wragg, David Stephen & Koposov, Alexey (2025). Stepwise Structural Relaxation in Battery Active Materials. ACS Materials Letters. 7(1), s. 343–349. doi: 10.1021/acsmaterialslett.4c02058. Fulltekst i vitenarkiv Vis sammendrag

  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.

• Chernyshov, Dmitry; Marshall, Kenneth P.; North, Erlend Tiberg; Fuller, Chloe A. & Wragg, David Stephen (2024). Instrumental broadening and the radial pair distribution function with 2D detectors. Acta Crystallographica Section A: Foundations and Advances. 80(5), s. 358–366. doi: 10.1107/S2053273324006569. Fulltekst i vitenarkiv Vis sammendrag

  The atomic pair distribution function (PDF) is a real-space representation of the structure of a material. Experimental PDFs are obtained using a Fourier transform from total scattering data which may or may not have Bragg diffraction peaks. The determination of Bragg peak resolution in scattering data from the fundamental physical parameters of the diffractometer used is well established, but after the Fourier transform from reciprocal to direct space, these contributions are harder to identify. Starting from an existing definition of the resolution function of large-area detectors for X-ray diffraction, this approach is expanded into direct space. The effect of instrumental parameters on PDF peak resolution is developed mathematically, then studied with modelling and comparison with experimental PDFs of LaB6 from measurements made in different-sized capillaries.

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• Skurtveit, Amalie; North, Erlend 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. Fulltekst i vitenarkiv
• 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. Fulltekst i vitenarkiv Vis sammendrag

  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.

• North, Erlend Tiberg; Chernyshov, Dmitry; Diadkin, Vadim; Koposov, Alexey; Svelle, Stian & Wragg, David Stephen (2022). Multivariate Analysis of Synchrotron X-ray Data for Battery Research. Fulltekst i vitenarkiv Vis sammendrag

  By utilizing multivariate analysis of x-ray operando data from working batteries one can separate and enhance scattering signals from specific components of the battery, identifying the critical responses that are connected to its performance and failure. This can enable faster and easier analysis of operando data, especially from complex materials that are difficult to analyze manually. In this poster I will present the preliminary results that we have obtained so far, focusing mainly on comparing analysis methods on simulated data sets, along with the current plan of the research project in my PhD.

• North, Erlend Tiberg; Nilsen, Ola & Hansen, Per-Anders Stensby (2022). Quinizarin as Organic Sensitizer in LnF3 Thin Films for Photon Upconversion. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  This thesis illuminates the opportunities for Quinizarin (Qz) as an organic sensitizer in LnF3 (Ln=Y, Nd, Tm, Yb) thin films for upconversion. Lanthanides show great promise as active materials for upconversion technologies, but struggle with very low absorption and thus, very low efficiency. We attempt to correct this by including a broad band absorber, in our case an organic dye. Atomic layer deposition (ALD) has been used to build the multilayered structures with control of the interatomic separations. The project has been divided into multiple parts, focusing first on Qz as sensitizer and its properties in solid state by ALD growth of Ln2Qz3. The ALD growth of LnF3 thin films was investigated and multilayered structures intended to show upconversion was made. Initial investigations of Qz show that as a dispersed molecule, its luminescence is heavily influenced by its environment, but indicates it could function as a sensitizer. When combined with Ln(thd)3 as a precursor in ALD growth, it shows exceptionally good growth with high growth rate, as well as high optical absorption. The growth and structure of LnF3 thin films using NH4F as fluorine source has been characterized using quartz crystal microbalance (QCM), with results indicating similar type of growth among all the tested lanthanides, apart for Nd, which proved more challenging. Uniform film with growth rates of around 0.6 Å/cycle were achieved, and NH4F has been proven a good fluorine source in LnF3 systems using Ln(thd)3. Qz has been successfully incorporated into these films with high absorption for high Qz-content, as characterized by using ultraviolet, visible and near infrared spectroscopy (UV-Vis). However, the films were not luminescent, as aimed for, proving that there is more work to be done to understand the quenching mechanisms involved. The upconversion structure itself has been investigated by growing and investigating multilayers of YbF3 with Nd3+ and Tm3+. Using cathodoluminescence (CL) both ions have been shown incorporated in the structure. The system shows different emission intensities depending on ion distance, with 0.8 nm being the most optimal for CL signal.

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