TY - CONF A1 - Graeber, Gustav T1 - Paste-like interlayers in alkali-metal battery anodes N2 - Giving an introduction to high-temperature batteries with molten alkali-metal anodes and solid electroyltes. Presenting the research on alkali-metal tensiometry and the study about wetting interactions between liquid alkali-metal alloys and porous carbon hosts. T2 - AG Christina Roth Seminar CY - Bayreuth, Germany DA - 16.07.2025 KW - Battery PY - 2025 AN - OPUS4-64069 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Graeber, Gustav T1 - Graeber Lab for Energy Research at Tag der Chemie in Adlershof N2 - Highlighting recent progress in the Graeber Lab for Energy Research in the areas of alkali-metal tensiometry, alkali-metal anodes in contact with solid electrolytes, sulfur cathodes and solid electrolyte synthesis. T2 - Tag der Chemie in Adlershof 2025 CY - Berlin, Germany DA - 03.07.2025 KW - Batterie PY - 2025 AN - OPUS4-64068 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Graeber, Gustav T1 - Paste-like alkali-metal anodes in contact with solid electroytes N2 - Explaining the motivation of the BMFTR ANaBatt project. Presenting recent advances in alkali metal tensiometry and characterization of alkali-metal wetting in porous carbon materials via X-ray computed tomography. T2 - Sodium Battery Symposium 6 CY - Dresden, Germany DA - 03.09.2025 KW - Battery PY - 2025 AN - OPUS4-64070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Graeber, Gustav T1 - Batterieforschung an der Humboldt-Universität zu Berlin - Selbstvorstellung beim KLiB N2 - Selbstvorstellung der Batterieforschungsaktivitäten der HU Berlin in Kooperation mit lokalen Partnern wie der BAM im Rahmen eines Netzwerktreffens. Fokus auf die Forschung in der Arbeitsgruppe Graeber zu Festkörperbatterien und der Arbeitsgruppe Adelhelm zu Natrium-Ionen-Batterien. T2 - KLiB Netzwerktreffen CY - Frankfurt, Germany DA - 26.03.2025 KW - Batterie PY - 2025 AN - OPUS4-63350 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Graeber, Gustav T1 - Graeber Lab for Energy Research - Overview N2 - Vorstellung der Forschungsaktivitäten der AG Graeber an der HU Berlin und an der BAM. Diese beinhalten die Erforschung grundlegender Benetzungsphänomene von Alkalimetallen, deren Anwendung in Festkörperbatterien mit pastenartigen Alkalimetallanoden, die Erforschung von Schwefelkathoden, die Synthese von Natrium-leitenden Festelektrolyten sowie die Entwicklung von Hydrogel-basierten Batterien. T2 - BMBF BattFutur NanoMatFutur Netzwerktreffen 2025 CY - Berlin, Germany DA - 24.02.2025 KW - Batterie PY - 2025 AN - OPUS4-63361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Qi, Naiyu A1 - Somaskandan, Rachana A1 - Graeber, Gustav T1 - High-Precision Surface Tension Measurements of Sodium, Potassium, and Their Alloys via Du Noüy Ring Tensiometry N2 - The development of post-lithium-ion batteries has sparked significant interest in alkali-metal anodes, particularly sodium (Na), potassium (K), and sodium−potassium (Na−K) alloys. Na−K alloys are promising for partially liquid anodes due to their unique low melting points. A critical factor influencing Na−K-based anode performance is wetting behavior, which governs electrical conductivity, mechanical contact, and long-term stability. At the heart of wetting lies surface tension, a fundamental property of solid−liquid− gas interactions. However, the surface tension of alkali metals and their alloys, particularly Na−K systems, remains poorly understood due to experimental and theoretical challenges. This study bridged these gaps by employing Du Noüy ring tensiometry for the first time in alkali-metal systems to measure the surface tension of Na, K, and Na−K alloys across temperatures from ambient to 180 °C. A key innovation in this work is the development of the push-in Du Noüy method, which provided significantly higher precision and reliability compared to the traditional pull-out technique, without requiring a correction factor. The measured surface tension decreased with increasing temperature for the studied Na−K alloys. For instance, for a eutectic Na−K mixture, the surface tension decreases from 121.7 mN m−1 to 112.2 mN m−1 when increasing the temperature from ambient to 180 °C. Additionally, this study presented the first use of Gibbs free energy minimization to model the surface tension of the Na−K system. The robust method significantly enhanced the predictive accuracy compared to the previous simplified model, reducing deviations from 25% to 2%. Our findings reveal that surface tension increases with sodium mole fraction in the bulk phase, yet the surface monolayer remains potassium-rich, indicating non-ideal surface behavior. This study deepens the understanding of alkali-metal wetting behavior, providing valuable insights for designing optimized interfaces in next-generation semi-solid alkali-metal batteries. KW - Sodium−potassium alloy KW - Liquid-metal anodes KW - Alkali metal KW - Batteries KW - Surface tension PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630102 DO - https://doi.org/10.1021/acsami.5c02183 SN - 1944-8252 VL - 17 IS - 17 SP - 25985 EP - 25995 PB - American Chemical Society (ACS) CY - Washington, DC AN - OPUS4-63010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wille, Frank T1 - Package safety evaluation in a rapidly changing world N2 - The presentation addressed the evolving challenges and developments in the safety evaluation of transport packages for radioactive materials, especially in light of changing technologies, regulations, and environmental conditions. A key focus was the current situation in Germany: following the final shutdown of commercial nuclear power plants in 2023, efforts are now concentrated on decommissioning, interim storage in dual-purpose casks (DPCs), and the ongoing site selection process for a repository for high-level waste. The expected duration of interim storage exceeds 100 years, demanding robust and sustainable safety strategies. One major topic was ageing management, which goes beyond technical measures to ensure transportability over long periods. It also includes preserving knowledge and expertise for future generations. The regulatory framework includes international standards such as IAEA SSR-6 and SSG-26, as well as national guidance like BAM-GGR 023. It was emphasized the growing role of Artificial Intelligence (AI) in safety evaluations. AI can enhance efficiency through automated document analysis and digital data structuring. However, final safety decisions remain the responsibility of human experts, especially given the complexity of documentation and the shortage of skilled personnel. The presentation also addressed changing transport technologies, such as the use of electric and hydrogen-powered vehicles. These vehicles behave differently in accidents, particularly in battery fires, which can reach temperatures above 1000 °C and last significantly longer than conventional fires. This raises the need to reassess existing fire test criteria. Environmental changes were another key point. With global temperatures rising by 0.26 °C per decade, local safety margin evaluations are becoming increasingly important. Existing regulatory assumptions, such as ambient temperatures of 38 °C, may no longer be sufficient. Finite Element Analysis (FEA) is increasing. AI can support model generation, but there is concern about potential skill fading among engineers. Physical testing, such as BAM’s drop towers (up to 200 tons), remains essential for public package safety acceptance. Key takeaways from the talk include: Ageing Management is also about preserving skills and knowledge. Changing technologies and environmental conditions impact package safety. AI can improve efficiency but must be used carefully to avoid skill loss. Physical testing continues to play a vital role in gaining public trust. T2 - PATRAM 2025 CY - San Antonio, Texas, USA DA - 27.07.2025 KW - Artificial Intelligence KW - Package KW - Ageing Management KW - Electric Vehicles KW - Testing PY - 2025 AN - OPUS4-63879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Graeber, Gustav T1 - Batterien und Elektrolyseure der nächsten Generation N2 - Übersichtvortrag zu Batterien und Elektrolyseuren. Ausgehend vom Funktionsprinzip von klassischen Lithium-Ionen-Zellen wurde deren Aufbau und die verwendeten Aktivmaterialien eingeführt. Im Anschluss wurde auf nachhaltigere Alternativtechnologien wie Natrium-Ionen und Natrium-Schwefel eingegangen. Immer mit dem Fokus auf den verwendeten Materialien und den umweltrelevanten Aspekten. T2 - BAM UBA Behördenerfahrungsaustausch Anlagensicherheit 2025 CY - Berlin, Germany DA - 02.06.2025 KW - Batterie PY - 2025 AN - OPUS4-63355 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wille, Frank T1 - KI-Einsatz im gefahrgutrechtlichen Kontext N2 - Der Vortrag behandelt den Einsatz von Künstlicher Intelligenz im gefahrgutrechtlichen Kontext und beleuchtet deren Potenzial zur Effizienzsteigerung in ressourcenlimitierten Umgebungen. Anwendungsfelder an der BAM umfassen die Datenanalyse zur Verpackungssicherheit, die Automatisierung von Zulassungs- und Genehmigungsprozessen, die Unterstützung bei der Mitarbeit an Normen und Regelwerken sowie die Bearbeitung komplexer Forschungsfragen. Herausgestellt wird die wachsende Datenmenge und Komplexität in der Gremienarbeit (z. B. UN-Regelwerke), die manuelle Auswertung ineffizient macht. KI-gestützte Methoden wie LLM, RAG und Knowledge Graphs sollen digitale Qualitätsinfrastrukturen unterstützen, die Dokumenten- und Datenanalyse beschleunigen, ohne die menschliche Verantwortung für Sicherheitsbewertungen zu ersetzen. Zentrale Herausforderungen sind die Black-Box-Natur von KI, mögliche Halluzinationen, sowie die Sicherstellung von Reliabilität und Compliance. Ein innovativer Ansatz wird für die wiederkehrende Prüfung von Gasdruckspeichern vorgestellt: Durch die Kombination zerstörungsfreier Prüfungen mit ML-gestützter Datenanalyse können Sicherheitsreserven ausgewiesen und Kosten deutlich reduziert werden. T2 - 20. Gefahrgut-Technik-Tage CY - Berlin, Germany DA - 13.11.2025 KW - Artificial Intelligence KW - RAG KW - LLM PY - 2025 AN - OPUS4-64864 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Graeber, Gustav T1 - Using X -ray computed tomography to learn more about alkali -metal batteries: Trajectory towards operando analysis N2 - Here we discuss how X-ray computed tomography can be used to learn more about alkali-metal batteries. We show wetting phenomena in alkali-metal batteries, discuss various techniques to study them, and show our recent results obtained at DESY in Hamburg. T2 - Operando battery workshop at CSMB CY - Berlin, Germany DA - 17.09.2025 KW - Battery KW - X-ray computed tomography KW - Operando PY - 2025 AN - OPUS4-64468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Graeber, Gustav T1 - Wetting and phase change phenomena in alkali -metal batteries N2 - Presentation about the importance of wetting and phase change phenomena in batteries. Hihglighting our work on Du Noüy ring tensiometry of alkali metals and wetting studies of alkali metals in contact with porous carbon hosts in alkali metal batteries with solid electrolytes. T2 - International Battery Workshop (ASPIRE, TwinBat) CY - Berlin, Germany DA - 15.9.2025 KW - Battery KW - Sodium KW - Wetting PY - 2025 AN - OPUS4-64467 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baller, Johannes A1 - Hilger, André A1 - Qi, Naiyu A1 - Morini, Chiara A1 - Cornelio, Andrea A1 - Remhof, Arndt A1 - Osenberg, Markus A1 - Manke, Ingo A1 - Moosmann, Julian A1 - Beckmann, Felix A1 - Graeber, Gustav T1 - Wetting Interactions Between Porous Carbon Hosts and Liquid Sodium‐Potassium Alloys Toward Their Use in Negative Electrodes of Alkali‐Metal Batteries N2 - Batteries with liquid alkali‐metal negative electrodes offer a route to compact, high‐performance energy storage. Innovation in alkali‐metal management, i.e., controlled storage, release and transport of liquid alkali metal, can enable simpler and cheaper cell designs. Porous carbons have emerged as potential host materials for liquid alkali metals. Here, X‐ray computed tomography is used to study the wetting interactions between porous carbon hosts and liquid sodium‐potassium alloy (NaK) as a function of carbon host morphology and surface functionalization. While as‐received carbon samples show no affinity toward NaK, heat‐treated carbon is spontaneously infiltrated with NaK filling almost the entire pore volume. It is explored how forced wetting partially fills pores of NaK‐repellant hosts, showing large differences in pore filling based on the average pore size of the host material. In electrochemical discharge experiments, it is shown that both as‐received and heat‐treated carbon felt enable high areal capacities beyond 40 mAh cm−2. However, the heat‐treated carbon shows ten times lower overpotential. Finally, it is demonstrated how heat‐treated carbon felt can enable capillary transport of NaK. In summary, this study elucidates important aspects of the interactions between liquid alkali metals and porous carbon hosts, generating insights into possible applications in liquid alkali‐metal batteries. KW - Battery KW - Solid electrolyte KW - Sodium KW - Wetting PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-644663 DO - https://doi.org/10.1002/adfm.202523169 SN - 1616-301X SP - 1 EP - 10 PB - Wiley VHC-Verlag AN - OPUS4-64466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cornelio, Andrea T1 - NASICON Electrolytes for Room-Temperature Sodium-Sulfur Batteries with NaK Alloy Negative Electrode Interface N2 - The aim of the research is to develop a novel NASICON (NA Super Ionic CONductor) electrolyte for room-temperature (RT) sodium-sulfur (Na-S) cells employing a liquid sodium-potassium (NaK) alloy at the negative-electrode interface. The NaK alloy can improve the interfacial contact between the sodium-metal electrode and the solid electrolyte. The synthesized NASICON material must be stable with the alkali-metal alloy and provide good electrochemical performance at RT. T2 - 6th Sodium Battery Symposium CY - Dresden, Germany DA - 03.09.2025 KW - Solid Electrolyte KW - NASICON KW - Solid-state batteries KW - Sodium conductors KW - Material synthesis PY - 2025 AN - OPUS4-64080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nitz, Phillip D. H. A1 - Rosaz, Paul A1 - Kreysina, Daniela A1 - Kasprzak, Dawid A1 - Qi, Naiyu A1 - Baller, Johannes A1 - Graeber, Gustav T1 - Water-in-Salt Electrolytes Embedded in Polyacrylamide Hydrogels: A First Step toward Deformable Sodium-Ion Batteries N2 - The development of flexible, safe, and sustainable Energy storage systems is critical for next-generation technologies, including wearable electronics, biomedical devices, and soft robotics. In this work, we provide a systematic investigation of sodium perchlorate-based water-in-salt (WIS) electrolytes embedded in polyacrylamide (PAM) hydrogels as a potential platform for deformable sodium-ion batteries or aqueous supercapacitors. Using Raman spectroscopy, we track the transition from free to intermediate water states with increasing salt concentration, identifying the onset of the WIS regime around 10 mol kg−1. Electrochemical measurements reveal that both the aqueous and hydrogel-based electrolytes exhibit a broadened electrochemical stability window (ESW) at higher salt concentrations, reaching up to 2.75 V. Impedance spectroscopy shows that while aqueous electrolytes achieve higher peak conductivity (156 mS cm−1), hydrogel-based electrolytes offer greater stability across a range of concentrations. This observation was supported by cyclic voltammetry, as it showed enhanced electrochemical stability of the PAM hydrogel compared to the aqueous electrolyte. This comprehensive and systematic study demonstrates that highly concentrated WIS electrolytes can be successfullyembedded into PAM hydrogels, while preserving good electrochemical stability and ionic conductivity. This could make them a promising foundation for all-hydrogel, sodium-based energy storage devices that are safe, sustainable, and mechanically compliant. KW - Battery PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653156 DO - https://doi.org/10.1021/acsapm.5c03031 SN - 2637-6105 SP - 1 EP - 8 PB - American Chemical Society (ACS) AN - OPUS4-65315 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -