TY - JOUR A1 - Czeskleba, Denis A1 - Rhode, Michael A1 - Wandtke, Karsten A1 - Irfan, Muhammad Dary A1 - Kannengiesser, Thomas T1 - Hydrogen diffusion in thick-walled S690 SAW joints: part 2 – predictive modeling of heat input and microstructure influence N2 - High-strength low-alloy (HSLA) steels such as S690 are widely employed in thick-walled welded structures, where hydrogen-assisted cold cracking (HACC) remains a persistent concern. While microstructure-specific hydrogen diffusion coefficients (DH) for weld metal (WM), heat-affected zone (HAZ), and base material (BM) were experimentally established in Part 1 of this study, their quantitative influence on hydrogen accumulation and effusion has not yet been fully clarified. This work presents a transient, spatially resolved numerical model for simulating hydrogen transport in multi-pass submerged arc welds. The model integrates experimentally determined DH values with realistic thermal cycles and temperature-dependent boundary conditions. Developed in Python, the simulation tool is purpose-built for hydrogen diffusion in welded joints. It offers a focused, transparent alternative. It offers a focused, transparent alternative to general-purpose finite element platforms. Parametric analyses demonstrate that, although the diffusion coefficients vary by up to 50%, their impact on overall hydrogen retention is minor. In contrast, plate thickness, bead geometry, cooling time (t₈/₅), and interpass temperature exert a dominant influence on hydrogen distribution. Despite clear microstructural differences between the thermomechanically rolled (S690MC) and quenched and tempered (S690Q) variants, including opposite HAZ hardness responses (softening in S690MC, hardening in S690Q) in the (pen)ultimate weld bead, the simulations confirm that their diffusion behavior and hydrogen solubility are closely aligned. Consequently, differences in DH and solubility exert only a minor influence on hydrogen retention compared to thermal exposure and joint geometry. These findings support the interchangeable use of both steel grades in terms of HACC risk due to hydrogen diffusion kinetics under comparable welding conditions. KW - Hydrogen assisted cracking KW - Numerical simulation KW - Diffusion KW - Submerged arc welding PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655721 DO - https://doi.org/10.1007/s40194-026-02395-1 SN - 0043-2288 SP - 1 EP - 16 PB - Springer Science and Business Media LLC AN - OPUS4-65572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Sarah-K. T1 - Second Life Batterien - Alterungsverhalten und Brandversuche N2 - Der Vortrag gibt zunächst einen Themeneinstieg in den Bereich der Second-Life-Batterien sowie rechtliche und technische Grundlagen zu Lebenszyklus und Alterung. Im Weiteren werden experimentelle Ergebnisse aus Versuchen zum thermischen Durchgehen mit Batteriemodulen aus dem BMBF-Vorhaben SEE-2L vorgestellt. Darüber hinaus wird ein eigens entwickelter Ausbildungsdemonstrators vorgestellt, welcher einen wesentlichen Baustein des Ergebnistransfers aus dem Vorhaben darstellt. T2 - 19. Fachkonferenz Lithiumbatterien CY - Göttingen, Germany DA - 26.01.2026 KW - Auswirkungsbetrachtungen KW - Elektrische Energiespeicher KW - Lithium-Ionen-Batterie KW - Second Life KW - Thermisches Durchgehen PY - 2026 AN - OPUS4-65621 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayat, Mehmet Emin T1 - Traceable dynamic and gravimetric preparation of trace ammonia in hydrogen gas standards for ISO 14687 N2 - Trace ammonia impurities in hydrogen fuel poison proton-exchange-membrane fuel cells (PEMFC), causing irreversible performance degradation. Accurate quantification of ammonia in so-called Grade D hydrogen fuel is crucial for ensuring PEMFCs long-term operational stability and performance. According to ISO 14687 grade D hydrogen fuel sets a stringent threshold value of just 100 nmol/mol for ammonia impurities. Given the potential of an ammonia-based hydrogen supply chain, reliable quantification of ammonia contamination appears even more relevant. Hydrogen quality assessments for ammonia impurities typically employ techniques such as gas chromatography, cavity-enhanced absorption spectroscopy, or mass spectrometry. These techniques, however, require stable reference gases for calibration and long-term method validation. Typically, gravimetrically produced reference gases are used. However, ammonia poses unique challenges due to its chemical reactivity and stickiness. By applying (ultra )long-path Optical Feedback Cavity Enhanced Absorption Spectroscopy we observed that above a certain amount of ammonia, the gravimetric amount deviates from the analytically determined amount. This discrepancy most likely arises due to strong adsorption of ammonia onto the inner surface of the gas cylinder. Therefore, we investigated the lowest gravimetrically preparable amount of ammonia in hydrogen for which the analytically measured amount of the cylinder remains congruent with the gravimetric amount of substance. We further investigated the applicability of passivated cylinders for trace ammonia gas standards and compared their performance to aluminum alloy cylinders. To confirm reproducibility of our results, we conducted three independent gravimetric preparation campaigns, each employing optimizations, or changes in methodology, at different times. Finally, we investigated whether those gravimetrically prepared trace amounts of ammonia in hydrogen gas standards were long-term-stable. Beyond gravimetrically prepared gas standards, we evaluated how a cutting-edge dynamic dilution system could reliably extend trace-ammonia calibration down to the ISO limit of 100 nmol/mol. For this purpose, we developed an advanced dynamic dilution system capable of a one-in-a-billion dilution ratio, validated for its SI traceability, reproducibility, and operational limits by applying an internal standard. In summary, our results demonstrate that precise dynamic dilution, coupled with concentrated gravimetrically prepared ammonia gas mixture, provides a route to full SI-traceable trace-ammonia reference sample gases. T2 - Gas Analysis Symposium 2026 CY - Paris, France DA - 27.01.2026 KW - Ammonia KW - Hydrogen KW - Gravimetric preparation KW - OF-CEAS KW - ISO 14687 PY - 2026 AN - OPUS4-65620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gleim, Tobias T1 - Großbrandversuche von Elektrofahrzeugen zum Transport Gefährlicher Güter N2 - Der zunehmende Einsatz von batterieelektrischen Transportfahrzeugen (Battery Electric Transport Vehicles – BETVs) im Verkehrswesen wirft Sicherheitsfragen beim Transport gefährlicher Güter auf. Obwohl Batteriebrände auf Zell-, Modul- und Fahrzeugebene umfassend untersucht wurden, fehlen systematische Daten zu deren thermischen Auswirkungen auf Gefahrgutverpackungen. Um diese Lücke zu schließen, führt die Bundesanstalt für Materialforschung und -prüfung (BAM) auf ihrem Testgelände Technische Sicherheit (BAM-TTS) groß angelegte Brandtests durch, in denen konservative Unfallszenarien mit unterschiedlichen Zellchemien und -kapazitäten nachgestellt werden. Die Tests kombinieren fahrzeugbedingte Brandlasten mit standardisierten Propan-Referenzbränden und erfassen mittels hochauflösender Instrumente zentrale Messgrößen wie Wärmefluss, Temperatur und Strahlung. Der daraus entstehende Datensatz liefert erstmals eine direkte Quantifizierung der thermischen Auswirkungen von BETV-Bränden auf Verpackungen und unterstützt Expertengremien bei der Bewertung, ob bestehende regulatorische Anforderungen für alternative Antriebssysteme weiterhin angemessen sind. T2 - Informationsaustausch zur verkehrsrechtlichen Aufsicht bei der Beförderung radioaktiver Stoffe CY - Salzgitter, Germany DA - 03.02.2026 KW - Batteriebrand KW - IAEA KW - Gefahrgut KW - Transport PY - 2026 AN - OPUS4-65626 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rautenberg, Max A1 - Bhattacharya, Biswajit A1 - Das, Chayanika A1 - Emmerling, Franziska T1 - Mechanochemical Synthesis of Phosphonate-Based Proton Conducting Metal-Organic Frameworks N2 - Water-stable metal−organic frameworks (MOFs) with proton-conducting behavior have attracted great attention as promising materials for proton-exchange membrane fuel cells. Herein, we report the mechanochemical gram-scale synthesis of three new mixed-ligand phosphonate-based MOFs, {Co(H2PhDPA)(4,4′-bipy)H2O)·2H2O}n (BAM-1), {Fe(H2PhDPA)(4,4′-bipy) (H2O)·2H2O}n (BAM-2), and {Cu(H2PhDPA)(dpe)2(H2O)2·2H2O}n (BAM-3) [where H2PhDPA = phenylene diphosphonate, 4,4′-bipy = 4,4′-bipyridine, and dpe = 1,2-di(4-pyridyl)ethylene]. Single-crystal X-ray diffraction measurements revealed that BAM-1 and BAM-2 are isostructural and possess a three-dimensional (3D) network structure comprising one-dimensional (1D) channels filled with guest water molecules. Instead, BAM-3 displays a 1D network structure extended into a 3D supramolecular structure through hydrogenbonding and π−π interactions. In all three structures, guest water molecules are interconnected with the uncoordinated acidic hydroxyl groups of the phosphonate moieties and coordinated water molecules by means of extended hydrogen-bonding interactions. BAM-1 and BAM-2 showed a gradual increase in proton conductivity with increasing temperature and reached 4.9 × 10−5 and 4.4 × 10−5 S cm−1 at 90 °C and 98% relative humidity (RH). The highest proton conductivity recorded for BAM-3 was 1.4 × 10−5 S cm−1 at 50 °C and 98% RH. Upon further heating, BAM-3 undergoes dehydration followed by a phase transition to another crystalline form which largely affects its performance. All compounds exhibited a proton hopping (Grotthuss model) mechanism, as suggested by their low activation energy. KW - Mechanochemistry KW - Metal-organic-frameworks KW - Proton conductivity PY - 2022 DO - https://doi.org/10.1021/acs.inorgchem.2c01023 VL - 61 SP - 10801 EP - 10809 PB - ACS Publications AN - OPUS4-55448 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ghazanfari, M. R. A1 - Vittadello, L. A1 - Al-Sabbagh, Dominik A1 - Santhosh, A. A1 - Frankcom, C. A1 - Fuß, F. A1 - von Randow, C. A. A1 - Siemensmeyer, K. A1 - Vrijmoed, J. C. A1 - Emmerling, Franziska A1 - Jerabek, P. A1 - Irmlau, M. A1 - Thiele, G. T1 - Remarkable Infrared Nonlinear Optical, Dielectric, and Strong Diamagnetic Characteristics of Semiconducting K3[BiS3] N2 - The ternary sulfido bismuthate K3[BiS3] is synthesized in quantitative yields. The material exhibits nonlinear optical properties with strong second harmonic generation properties at arbitrary wavelengths in the infrared spectral range and a notable laser-induced damage threshold of 5.22 GW cm−2 for pulsed laser radiation at a wavelength of 1040 nm, a pulse duration of 180 fs, and a repetition rate of 12.5 kHz. K3[BiS3] indicates semiconductivity with a direct optical band gap of 2.51 eV. Dielectric and impedance characterizations demonstrate κ values in the range of 6−13 at 1 kHz and a high electrical resistivity. A strong diamagnetic behavior with a susceptibility of −2.73 × 10−4 m3 kg−1 at room temperature is observed. These results suggest it is a promising nonlinear optical candidate for the infrared region. The synergic physical characteristics of K3[BiS3] provide insight into the correlation of optical, electrical, and magnetic properties. KW - Electrical properties KW - Insulators KW - Materials KW - Nonlinear optics KW - Quantum mechanics PY - 2022 DO - https://doi.org/10.1021/acs.jpclett.2c01689 VL - 13 IS - 30 SP - 6987 EP - 6993 PB - ACS Publications AN - OPUS4-55456 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Shu-Han T1 - MOF-derived Synthetic Carbon Anode Materials for Sodium-Ion Batteries N2 - Metal-organic frameworks (MOFs), particularly the zeolitic imidazolate framework (ZIF) family, are attractive precursors for advanced energy-storage materials. Upon pyrolysis, ZIFs can be transformed into electrically conductive carbon materials while preserving their original particle morphology, which is crucial for achieving high-performance sodium-ion battery anodes. Despite these advantages, large-scale implementation remains challenging due to the need for synthesis routes that balance performance, cost, and sustainability. The present study addresses these challenges by developing environmentally benign and economically feasible strategies for the scalable production of ZIF-8-derived carbon anodes suitable for industrial applications. T2 - Batterieforum Deutschland 2026 CY - Berlin, Germany DA - 20.01.2026 KW - Sodium-ion battery KW - Negative electrode KW - Metalorganic frameworks PY - 2026 AN - OPUS4-65644 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aliyah, K. A1 - Berger, A. A1 - Lazaridis, T. A1 - Appel, C. A1 - Prehal, C. A1 - Menzel, A. A1 - Guizar-Sicairos, M. A1 - Smales, Glen J. A1 - Pauw, Brian Richard A1 - Gasteiger, H. A. A1 - Gubler, L. A1 - Büchi, F. N. A1 - Eller, J. T1 - Impact of Microporous Layer Composition on the Water Content in the Membrane Electrode Assembly of Polymer Electrolyte Fuel Cells N2 - Polymer electrolyte fuel cells are paramount for future emission-free mobility. One of the vital challenges for prospering commercialization of PEFCs is water management in the cells. A microporous layer (MPL) is typically positioned between the gas Diffusion layer (GDL) and the catalyst layer (CL) to boost the cell performance and facilitate water management. In this study, three different MPLs were investigated, namely, carbon black-based MPLs with different PTFE binder contents (20 wt % PTFE as a base case and 40 wt % PTFE), as well as perforated MPLs with micron-sized pores coated on the same GDL- Substrate (Freudenberg H14). The water content in the membrane, catalyst layers (CL), and MPLs was explored using operando scanning small- and wide-angle X-ray scattering (S/WAXS). At Tcell = 80 °C, relative humidity = 100%, pabs = 3 bar, the MPL with larger pores exhibits slightly higher performance than the base case, while a considerably lower cathode CL and MPL saturation levels were observed for the MPL. In contrast, the MPL with higher amounts of PTFE binder shows lower performance than the base case, with considerably higher cathode CL and MPL saturation levels. 3D representations of how the pores could be filled in the cathode CLs were obtained from operando SAXS profiles using representative structure modeling for the different materials and operating conditions. KW - Polymer electrolyte fuel cell KW - Catalyst layer saturation KW - Microporous layer saturation KW - Membrane hydration KW - Small and wide-angle scattering KW - MOUSE KW - SAXS KW - X-ray scattering KW - Energy storage materials PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656691 DO - https://doi.org/10.1021/acsami.5c22540 SN - 1944-8244 SP - 1 EP - 17 PB - American Chemical Society (ACS) AN - OPUS4-65669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Berger, J. A1 - Zahedi-Azad, S. A1 - Voss, H. A1 - Ernst, O.C. A1 - Hammerschmidt, R. A1 - Boeck, T. A1 - Martin, J. A1 - Bonse, J. A1 - Krüger, J. A1 - Schmid, M. T1 - CuInSe2-based micro-concentrator solar cells fabricated from In islands grown by laser-assisted MO-CVD N2 - Micro-concentrator solar cells offer a promising route for reducing material usage in photovoltaics. For Cu(In,Ga)Se2, multiple micro-concentrator manufacturing methods have already been evaluated. All of them involve either high preparation complexity or post-processing to recycle unused precursor or absorber materials. In this work, a new method using laser-assisted metal-organic chemical vapor deposition (LA-MOCVD) was applied to directly grow arrays of indium micro-islands. These arrays are examined and further processed to CuInSe2 micro-solar cell arrays. The geometry and morphology of the islands were investigated and compared before and after absorber formation. The investigation shows that the absorber growth is limited to the vertical direction normal to the substrate surface and that the starting morphology is preserved. Furthermore, the absorber island arrays are processed into micro-modules and operational solar cells are achieved as a proof of principle. These not yet optimized arrays reach a conversion efficiency of 0.65% under 1 sun illumination. Under 17 suns of light concentration, the efficiency gain is between 60 and 250%. This work demonstrates the method's viability for the fabrication of micro-solar cell arrays, with clear potential for achieving higher conversion efficiencies through future optimization. KW - Micro-concentrator solar cells KW - Laser-assisted chemical vapor deposition KW - CISe KW - Bottom-up fabrication KW - Resource efficiency PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656711 DO - https://doi.org/10.1016/j.solmat.2026.114284 SN - 0927-0248 VL - 301 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-65671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ekici, Nilsah A1 - Sobol, Oded T1 - SHIMMER Database for Hydrogen Integration in European Gas Grids N2 - The integration of hydrogen into existing natural gas infrastructure is an important pathway for achieving the European Union’s climate neutrality goals. However, hydrogen blending in gas networks raises technical challenges related to material compatibility, operational safety, and the lack of harmonized assessment methodologies across Europe. These challenges are addressed within the Safe Hydrogen Injection Modelling and Management for European Gas Network Resilience (SHIMMER) project, funded by the Clean Hydrogen Partnership under the Horizon Europe programme. A key outcome of the project is the development of an openly accessible database designed to support the assessment of hydrogen readiness in European gas networks and to facilitate knowledge sharing. The database compiles infrastructure data provided by project partners, including several European transmission and distribution system operators. It contains detailed information on gas network components such as pipelines, valves, fittings, gaskets, and compressors. In addition, a new category has been introduced focusing on the hydrogen compatibility of gas grid components and materials. This section provides structured information linking infrastructure components with material types and their hydrogen compatibility, enabling more systematic evaluation of hydrogen injection scenarios. By organizing heterogeneous datasets into a harmonized and user-friendly structure, the SHIMMER database supports research, best-practice development, and the safe integration of hydrogen into existing European gas infrastructure. T2 - EHEC 2026 CY - Seville, Spain DA - 11.03.2026 KW - Database KW - Gas Grid KW - Hydrogen KW - Low-carbon KW - Pipeline Steel PY - 2026 AN - OPUS4-65683 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -