TY - JOUR A1 - Lancaster, Shaun T. A1 - Sahlin, Eskil A1 - Oelze, Marcus A1 - Ostermann, Markus A1 - Vogl, Jochen A1 - Laperche, Valérie A1 - Touze, Solène A1 - Ghestem, Jean-Philippe A1 - Dalencourt, Claire A1 - Gendre, Régine A1 - Stammeier, Jessica A1 - Klein, Ole A1 - Pröfrock, Daniel A1 - Košarac, Gala A1 - Jotanovic, Aida A1 - Bergamaschi, Luigi A1 - Di Luzio, Marco A1 - D’Agostino, Giancarlo A1 - Jaćimović, Radojko A1 - Eberhard, Melissa A1 - Feiner, Laura A1 - Trimmel, Simone A1 - Rachetti, Alessandra A1 - Sara-Aho, Timo A1 - Roethke, Anita A1 - Michaliszyn, Lena A1 - Pramann, Axel A1 - Rienitz, Olaf A1 - Irrgeher, Johanna T1 - Evaluation of X-ray fluorescence for analysing critical elements in three electronic waste matrices: A comprehensive comparison of analytical techniques N2 - As the drive towards recycling electronic waste increases, demand for rapid and reliable analytical methodology to analyse the metal content of the waste is increasing, e.g. to assess the value of the waste and to decide the correct recycling routes. Here, we comprehensively assess the suitability of different x-ray fluorescence spectroscopy (XRF)-based techniques as rapid analytical tools for the determination of critical raw materials, such as Al, Ti, Mn, Fe, Co, Ni, Cu, Zn, Nb, Pd and Au, in three electronic waste matrices: printed circuit boards (PCB), light emitting diodes (LED), and lithium (Li)-ion batteries. As validated reference methods and materials to establish metrological traceability are lacking, several laboratories measured test samples of each matrix using XRF as well as other independent complementary techniques (instrumental neutron activation analysis (INAA), inductively coupled plasma mass spectrometry (ICP-MS) and ICP optical emission spectrometry (OES)) as an inter-laboratory comparison (ILC). Results highlighted key aspects of sample preparation, limits of detection, and spectral interferences that affect the reliability of XRF, while additionally highlighting that XRF can provide more reliable data for certain elements compared to digestion-based approaches followed by ICP-MS analysis (e.g. group 4 and 5 metals). A clear distinction was observed in data processing methodologies for wavelength dispersive XRF, highlighting that considering the metals present as elements (rather than oxides) induces overestimations of the mass fractions when compared to other techniques. Eventually, the effect of sample particle size was studied and indicated that smaller particle size (<200 μm) is essential for reliable determinations. KW - XRF KW - WEEE KW - PCB KW - Battery KW - LED KW - Recycling PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614060 DO - https://doi.org/10.1016/j.wasman.2024.10.015 VL - 190 SP - 496 EP - 505 PB - Elsevier B.V. AN - OPUS4-61406 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tatzel, Michael A1 - Oelze, Marcus A1 - Frick, Daniel A. A1 - Di Rocco, Tommaso A1 - Liesegang, Moritz A1 - Stuff, Maria A1 - Wiedenbeck, Michael T1 - Silicon and oxygen isotope fractionation in a silicified carbonate rock N2 - Silicon isotope fractionation during silicification is poorly understood and impedes our ability to decipher paleoenvironmental conditions from Si isotopes in ancient cherts. To investigate isotope fractionation during silica-for-carbonate replacement we analyzed the microscale Si and O isotope composition in different silica phases in a silicified zebra dolostone as well as their bulk δ18O and Δ’17O compositions. The subsequent replacement of carbonate layers is mimicked by decreasing δ18O and δ30Si. The textural relationship and magnitude of Si and O isotope fractionation is best explained by near-quantitative silica precipitation in an open system with finite Si. A Rayleigh model for silicification suggests positive Ɛ30/28Si during silicification, conforming with predictions for isotope distribution at chemical equilibrium from ab-initio models. Application of the modelled Ɛ30Si-T relationship yields silicification temperatures of approx. 50°C. To reconcile the δ18Ochert composition with these temperatures, the δ18O of the fluid must have been between -2.5 and -4 ‰, compositions for which the quartz phases fall close to the oxygen equilibrium fractionation line in three-isotope space. Diagenetic silica replacement appears to occur in O and Si isotopic equilibrium allowing reconstructions of temperatures of silicification from Si isotopes and derive the δ18O composition of the fluid – a highly desired value needed for accurate reconstructions of the temperature- and δ18O histories of the oceans. KW - Silicon isotopes PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603430 DO - https://doi.org/10.1016/j.chemgeo.2024.122120 SN - 0009-2541 VL - 658 SP - 1 EP - 13 PB - Elsevier B.V. AN - OPUS4-60343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bourgon, Nicolas A1 - Oelze, Marcus A1 - Roberts, Patrick T1 - Less is more: Limiting semi-invasive sampling for multi-isotope analyses and increasing data output from single aliquot samples N2 - Developments in multi-isotope applications now enable the production of direct and precise life history data of studied archeological and paleoanthropological specimens, with analysis of tooth enamel proving particularly powerful in deep-time preservation contexts. However, the increasing amount of sample material necessary too-often compromises the specimen's structural integrity. Finding ways of minimizing semi-invasive sampling while maximizing produced data thus becomes increasingly crucial. In this study, we examine ways of optimizing sample use for state-of-the-art isotope measurements of enamel-bound zinc (δ66Zn), an increasingly used method in multi-isotope archeological research. We show that certain desolvating nebulizer introduction systems can be used to measure δ66Zn with high efficiency and accuracy using less than half the usual sample size. Moreover, we demonstrate that remaining samples subjected to typical pretreatments used for tooth enamel carbonate (δ13C and δ18O) studies can be safely used without alterations to δ66Zn values. Similarly, we highlight that the often-discarded matrix fraction from zinc chromatography can be utilized for further analyses, such as measurements of 87Sr/86Sr ratios. Our results underscore the possibility of extracting the maximum information from specimens while altogether avoiding or significantly reducing semi-invasive sampling. KW - Multi-isotope KW - Zinc isotope analysis KW - Tooth enamel PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-637986 DO - https://doi.org/10.1016/j.jas.2025.106308 SN - 0305-4403 VL - 180 SP - 1 EP - 8 PB - Elsevier Ltd. AN - OPUS4-63798 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schannor, Mathias A1 - Oelze, Marcus A1 - Traub, Heike A1 - He, Yubei A1 - Schmidt, Robin A1 - Heidemann, Luisa A1 - Savic, Lynn Jeanette A1 - Vogl, Jochen A1 - Meermann, Björn T1 - Advancing Biomarker Research: In Situ Cu Isotope Analysis in Liver Tumors by LA-MC-ICP-MS N2 - Stable metal isotopes have received increasing attention as medical biomarkers due to their potential to detect changes in metal metabolism related to diseases. In particular, copper stable isotopes are a powerful tool to identify isotopic variation between tumors and healthy tissue, suggesting application in cancer diagnosis. However, potential mechanisms causing isotope fractionation, such as redox- or bond-forming reactions and interactions of metals during transmembrane import and export, are less well understood. Here, we established an in situ method using laser ablation-multicollector-inductively coupled plasma-mass spectrometry (LA-MC-ICP-MS) to advance our understanding of the underlying processes responsible for isotope fractionation between normal and diseased tissues. Gelatin-based bracketing standards and quality control reference materials, crucial for laser ablation analysis, were developed to allow correction for instrumentally induced isotope fractionation during LA-MC-ICP-MS analysis. Using such matrix-matched standards, the method achieved intermediate precisions for delta values of better than 0.15 ‰ (2 s) for inorganic reference materials and of better than 0.17 ‰ (2 s) for biological reference materials. The developed routine was tested on rabbit VX2 liver tumor samples, a model system resembling human hepatocellular carcinoma (HCC) used to study liver cancer. In situ Cu isotope compositions between healthy (𝛿65/63NIST976(Cu) = −1.5 ‰ to 0.2 ‰) and tumorous (𝛿65/63NIST976(Cu) = 0.0 ‰ to 1.3 ‰) liver tissue show distinct differences in their isotope ratios. The observed isotopic dichotomy is consistent with previous solution-based MC-ICP-MS work, showing enrichment of heavy 65Cu in cancer biopsies relative to healthy tissue. KW - Biomarker KW - Laser Ablation KW - Reference Material PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626865 DO - https://doi.org/10.1021/acs.analchem.4c05626 SN - 1520-6882 VL - 97 IS - 8 SP - 4425 EP - 4432 PB - American Chemical Society (ACS) AN - OPUS4-62686 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Plouffe, A. A1 - Lee, R. G. A1 - Byrne, K. A1 - Kjarsgaard, I. M. A1 - Petts, D. C. A1 - Wilton, D.H.C. A1 - Ferbey, T. A1 - Oelze, Marcus T1 - Tracing Detrital Epidote Derived from Alteration Halos to Porphyry Cu Deposits in Glaciated Terrains: The Search for Covered Mineralization N2 - Distal alteration related to porphyry Cu mineralization is typically characterized by an abundance of green minerals, such as epidote, tremolite, and chlorite, within the propylitic and sodic-calcic alteration zones and extends far outside (>1 km) the mineralized zone(s). Glacial erosion and dispersal derived from rocks affected by propylitic and sodic-calcic alteration have resulted in the development of extensive dispersal trains of epidote in till (glacial sediment) that can reach 8 to 330 km2 as observed at four porphyry Cu study sites in the Quesnel terrane of south-central British Columbia: Highland Valley Copper, Gibraltar, Mount Polley, and Woodjam deposits. At each of these sites, epidote is more abundant in heavy mineral concentrates of till collected directly over and down-ice from mineralization and associated alteration. Epidote grains in till with >0.6 ppm Sb and >8 ppm As (as determined by laser ablation-inductively coupled plasma-mass spectrometry) are attributed to a porphyry alteration provenance. There is a greater abundance of epidote grains with high concentrations of trace elements (>12 ppm Cu, >2,700 ppm Mn, >7 ppm Zn, and >37 ppm Pb) in each porphyry district com� pared to background regions. This trace element signature recorded in till epidote grains is heterogeneously distributed in these districts and is interpreted to reflect varying degrees of metal enrichment from a porphyry fluid source. Tracing the source of the epidote in the till (i.e., geochemically tying it to porphyry-related propy� litic and/or sodic-calcic alteration), coupled with porphyry vectoring tools in bedrock, will aid in the detection of concealed porphyry Cu mineralization in glaciated terrains. KW - Indicator minerals KW - Porphyry Cu deposits KW - Epidote KW - Glaciated terrains KW - Propylitic alteration PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635209 DO - https://doi.org/10.5382/econgeo.5049 SN - 1554-0774 VL - 119 IS - 2 SP - 305 EP - 329 PB - Society of Economic Geologists, Inc. AN - OPUS4-63520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yu, Jialu A1 - Oelze, Marcus A1 - Schannor, Mathias A1 - Nordstad, Simon A1 - Vogl, Jochen T1 - New Potential Haematite and Magnetite Reference Materials for Iron Isotope Measurements by Solution Nebulisation MCICPMS and by In Situ nsLAMCICPMS N2 - Iron isotope ratios of haematite (Fe2O3) and magnetite (Fe3O4) provide insights into geochemical, environmental and planetary processes. In most studies, Fe isotope measurements are commonly performed using solution nebulisation multi-collector inductively coupled plasma-mass spectrometry (SN-MC-ICP-MS). Nanosecond laser ablation multi-collector inductively coupled plasma-mass spectrometry (ns-LA-MC-ICP-MS) requires minimal sample preparation, and provides spatially resolved variation of iron isotopes at micro-scale. However, homogeneous and matrix-matched haematite/magnetite reference materials are lacking for precise in situ isotopic measurement. The iron isotope ratios of two potential reference materials resembling natural haematite (HMIE-NP-B01) and natural magnetite (MAKP-NP-B01) were characterised. Size fractions between 5–63 μm of the powdered Fe oxides were milled to nanoparticles, freeze-dried, homogenised, and pressed into pellets. The materials were then evaluated using SN-MC-ICP-MS and LA-MC-ICP-MS. Sample powders of the two materials were measured by SN-MC-ICPMS after sample digestion and column separation and pressed pellets were analysed directly via ns-LA-MC-ICP-MS. In both cases iron isotope delta values are reported relative to the certified reference material IRMM-014, used as the bracketing standard (calibrator). The solution measurements yielded δ56Fe values of -0.25 ± 0.08‰ (N = 13, 2s) for HMIE-NP-B01, and -0.05 ± 0.09‰ (N = 12, 2s) for MAKP-NP-B01, considered as the preferred Fe isotope delta values. In situ isotopic analysis via ns-LA-MC-ICP-MS yielded δ56Fe values of -0.28 ± 0.28‰ (N = 19, 2s) for HMIE-NP-B01 and -0.12 ± 0.24‰ (N = 22, 2s) for MAKP-NP-B01, consistent with the solution Fe isotope data. The homogeneity of Fe isotopes of the pellets was evaluated by ns-LA-MC-ICP-MS analyses of three different positions to further confirm that both materials are isotopically homogeneous. Both materials can be considered as potential quality control and bracketing reference materials for Fe isotopic measurements by in situ ns-LA-MC-ICP-MS analysis. KW - Laser ablation KW - Fe isotope KW - Fe-oxides PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654755 DO - https://doi.org/10.1111/ggr.70037 SN - 1639-4488 SP - 1 EP - 12 PB - John Wiley & Sons Ltd. AN - OPUS4-65475 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Morcillo, Dalia A1 - Winckelmann, Alexander A1 - Oelze, Marcus A1 - Leonhardt, Robert A1 - Schmidt, Anita A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Vogl, Jochen A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - Exploring Age-Induced Lithium Isotope Fractionation in Lithium-Ion Batteries using Microwave-Induced Cold Nitrogen Plasma Mass Spectrometry N2 - This study explores Microwave-Inductively Coupled Atmospheric-pressure Plasma Mass Spectrometry (MICAP-MS) as a cost-effective alternative to Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS) for analyzing lithium isotopic composition in lithium-ion batteries (LIBs). We investigate the performance of MICAP-MS in measuring Li isotope ratios in new and aged commercial lithium cobalt oxide (LCO) batteries. Our results show that MICAP-MS, operating under cold plasma conditions at 800 W with an 8 mm torch position, achieves results metrologically compatible with MC-ICP-MS, with a precision ranging from 0.6‰ to 3.4‰ for δ7Li values. MICAP-MS benefits from a dielectric resonator for uniform plasma, better ion velocity control, and higher energy efficiency. Optimal settings were identified with dwell times of 10 ms for 6Li and 1 ms for 7Li. The study of LIBs revealed that 6Li migrates towards the anode over multiple charge–discharge cycles, causing 7Li to accumulate in the cathode, a fractionation effect that becomes more pronounced with prolonged cycling. MICAP-MS provides a cost-effective, precise alternative to MC-ICP-MS, with lower operational costs and enhanced portability, advancing the study of isotopic fractionation and aging in lithium-ion batteries. KW - MICAP-MS KW - Lithium KW - Battery aging KW - Lithium isotopes KW - Nitrogen plasma KW - Isotope fractionation KW - lithium cobalt oxide KW - LCO PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643777 DO - https://doi.org/10.1039/d4ja00324a SN - 0267-9477 SP - 1 EP - 11 PB - Royal Society of Chemistry (RSC) AN - OPUS4-64377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völzke, Jule L. A1 - Smatty, Sarah A1 - Döring, Sarah A1 - Ewald, Shireen A1 - Oelze, Marcus A1 - Fratzke, Franziska A1 - Flemig, Sabine A1 - Konthur, Zoltán A1 - Weller, Michael G. T1 - Efficient Purification of Polyhistidine-Tagged Recombinant Proteins Using Functionalized Corundum Particles N2 - Immobilized metal affinity chromatography (IMAC) is a widely used technique for purifying polyhistidine-tagged recombinant proteins. However, it often has practical limitations that require complex optimizations and additional steps for purification. In this study, we introduce functionalized corundum particles as a novel, efficient, and economical method for purifying recombinant proteins in a column-free format. The corundum surface is modified with amino silane APTES, followed by EDTA dianhydride, and then loaded with nickel ions. We used the Kaiser test to monitor the modification process and ICP-MS to quantify the metal-binding capacity. To evaluate the system, we used His-tagged protein A/G (PAG) mixed with bovine serum albumin (BSA). The corundum particles exhibited a binding capacity of approximately 3 mg of protein per gram of corundum or 2.4 mg per 1 mL of corundum suspension. We also examined cytoplasm obtained from different E. coli strains as an example of a complex matrix. Varying the imidazole concentration in the loading and washing buffers showed that higher concentrations during loading improved purity. Even with sample volumes as large as one liter, we successfully isolated recombinant proteins down to a concentration of 1 µg/mL. We found higher purity levels with corundum when comparing the corundum material to standard Ni–NTA agarose beads. We successfully purified His6-MBP-mSA2, a fusion protein comprising monomeric streptavidin and maltose-binding protein, from E. coli cytoplasm, demonstrating the method's applicability. We also purified SARS-CoV-2-S-RBD-His8 expressed in human Expi293F cells, confirming its suitability for mammalian cell culture supernatants. The material cost of the nickel-loaded corundum material (without regeneration) is estimated to be less than 30 cents per gram of functionalized support or 10 cents per milligram of isolated protein. Another advantage of this system is the exceptional physical and chemical stability of corundum particles. Overall, we have demonstrated that this novel material offers an efficient, robust, and cost-effective purification platform for His-tagged proteins, even in challenging, complex matrices and large sample volumes with low product concentrations. This method has potential applications in both small laboratories and large-scale industrial settings. N2 - Die immobilisierte Metallaffinitätschromatographie (IMAC) ist eine weit verbreitete Technik zur Reinigung von rekombinanten Proteinen mit Polyhistidin-Markierung. Sie hat jedoch oft praktische Einschränkungen, die komplexe Optimierungen und zusätzliche Schritte für die Aufreinigung erfordern. In dieser Studie stellen wir funktionalisierte Korundpartikel als neuartige, effiziente und wirtschaftliche Methode zur Reinigung rekombinanter Proteine in einem säulenfreien Format vor. Die Korundoberfläche wird mit dem Aminosilan APTES und anschließend mit EDTA-Dianhydrid modifiziert und dann mit Nickelionen beladen. Wir haben den Kaiser-Test zur Überwachung des Modifizierungsprozesses und ICP-MS zur Quantifizierung der Metallbindungskapazität verwendet. Zur Charakterisierung des Systems verwendeten wir His-markiertes Protein A/G (PAG) in Kombination mit Rinderserumalbumin (BSA). Die Korundpartikel wiesen eine Bindungskapazität von etwa 3 mg Protein pro Gramm Korund oder 2,4 mg pro 1 ml Korundsuspension auf. Als Beispiel für eine komplexe Matrix untersuchten wir auch Zytoplasma, das aus verschiedenen E. coli-Stämmen gewonnen wurde. Die Variation der Imidazolkonzentration in den Lade- und Waschpuffern zeigte, dass höhere Konzentrationen beim Laden die Reinheit verbesserten. Selbst bei einem Probenvolumen von bis zu einem Liter konnten wir rekombinante Proteine von 1 µg/mL isolieren. Beim Vergleich des Korundmaterials mit Standard-Ni-NTA-Agarose-Beads stellten wir einen höheren Reinheitsgrad mit Korund fest. Wir reinigten erfolgreich His6-MBP-mSA2 aus E. coli-Zytoplasma, ein Fusionsprotein, das aus monomerem Streptavidin und Maltose-bindendem Protein besteht. Wir reinigten auch SARS-CoV-2-S-RBD-His8, das in humanen Expi293F-Zellen exprimiert wurde, und bestätigten damit die Eignung des Materials für Zellkulturüberstände von Säugetieren. Die Materialkosten für nickelbeladenen Korund (ohne Regenerierung) werden auf weniger als 30 Cent pro Gramm funktionalisierten Trägers oder 10 Cent pro Milligramm isolierten Proteins geschätzt. Ein weiterer Vorteil dieses Systems ist die außergewöhnliche physikalische und chemische Stabilität der Korundpartikel. Insgesamt haben wir gezeigt, dass dieses neuartige Material eine effiziente, robuste und kostengünstige Reinigungsplattform für His-markierte Proteine bietet, selbst bei schwierigen, komplexen Matrices und großen Probenmengen mit niedrigen Produktkonzentrationen. Diese Methode könnte sowohl in kleinen Labors als auch in der Großindustrie eingesetzt werden. KW - Aluminum oxide KW - Sapphire KW - Ethylenediaminetetraacetic acid KW - Nickel chelate KW - EDTAD KW - HexaHis-Tag KW - His6 KW - 6xHis KW - His8 KW - Bioseparation KW - IMAC purification KW - Immunocapture KW - Affinity chromatography KW - Carrier KW - Nickel KW - Recombinant protein KW - Escherichia coli KW - Bacterial lysates KW - Cytoplasm KW - Polishing KW - Downstream processing PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575672 DO - https://doi.org/10.3390/biotech12020031 VL - 12 IS - 2 SP - 1 EP - 18 PB - MDPI CY - Basel, Schweiz AN - OPUS4-57567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Morcillo, Dalia A1 - Oelze, Marcus A1 - Seena Prem, Pranav A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska A1 - Recknagel, Sebastian A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - Lithium isotope fractionation as an early indicator of degradation mechanisms in lithium-ion batteries N2 - Aging in lithium-ion batteries (LIBs) degrades performance and hinders sustainability, demanding advanced diagnostics for early failure prediction. We investigate lithium isotope fractionation (LIF) as an innovative probe of degradation in lithium cobalt oxide (LCO) coin cells aged over 0−700 cycles. High-precision multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) quantified δ7Li variations across cell stages: non-cycled (0 cycles), newly formed (5 cycles), semi-aged (250 cycles), and fully aged (700 cycles). During early cycling (≤ 45 cycles), chemical processes drive 7Li enrichment at the anode (δ7Li vs LSVEC = +12 ‰) through solid electrolyte interphase (SEI) formation, while the cathode depletes in 7Li (δ7Li vs LSVEC = −0.7 ‰). Beyond 45 cycles, electric field-induced migration predominates, promoting 6Li intercalation into the anode and increasing the δ7Li of the cathode by 8.1 ‰. Mass balance verifies isotope conservation, attributing shifts to redistribution and trapping. Complementary electrochemical impedance spectroscopy (EIS) and X-ray absorption spectroscopy and diffraction confirm SEI expansion, cobalt oxidation, lattice shrinkage, and changes in electrode structure, corroborating LIF trends. Notably, a δ7Li inflection at approximately 270 cycles anticipates end-of-life by 70 cycles, surpassing traditional methods in sensitivity. LIF emerges as a predictive indicator of aging mechanisms, informing optimized designs for durable LIBs. KW - Lithium isotope fractionation KW - Lithium-ion batteries KW - Degradation mechanisms KW - LiCoO2 cathodes KW - LCO KW - Isotopic tracing KW - Lithium isotopes PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650945 DO - https://doi.org/10.26434/chemrxiv-2025-16lvq SP - 1 EP - 19 AN - OPUS4-65094 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -