TY - JOUR A1 - Zhang, Wuyi A1 - Mehmood, Asad A1 - Ali, Ghulam A1 - Liu, Hui A1 - Chai, Liyuan A1 - Wu, Jun A1 - Liu, Min T1 - Nickel Nanocluster-Stabilized Unsaturated Ni–N3 Atomic Sites for Efficient CO2-to-CO Electrolysis at Industrial-Level Current N2 - Unsaturated Ni single-atom catalysts (SACs), Ni-Nx (x=1,2,3), have been investigated to break the conventional Ni-N4 structural limitation and provide more unoccupied 3d orbitals for CO2 reduction reaction (CO2RR) intermediates adsorption, but their intrinsically low structural stability has seriously hindered their applications. Here, we developed a strategy by integrating Ni nanoclusters to stabilize unsaturated Ni-N3 atomic sites for efficient CO2 electroreduction to CO at industrial-level current. Density Functional Theory (DFT) calculations revealed that the incorporation of Ni nanocluster effectively stabilizes the unsaturated Ni-N3 atomic sites and modulates their electronic structure to enhance the adsorption of the key intermediate *COOH during CO2RR. Guided by these insights, we prepared an optimal composite catalyst, Ni6@Ni-N3, which features a Ni6N6 nanocluster surrounded by six Ni-N3 single atoms sites, through low-temperature pyrolysis. The morphology and coordinative structure of Ni6@Ni-N3 were confirmed by an aberration-corrected transmission electron microscope (AC-TEM) and X-ray absorption spectroscopy (XAS). As a result, Ni6@Ni-N3 demonstrated a remarkably high CO Faradaic efficiency (FECO) of 99.7 % and a turnover frequency (TOF) of 83984.2 h−1 at 500 mA cm−2 under −1.15 VRHE, much better than those of Ni-N4 with a lower FECO of 86 % at 100 mA cm−2 and a TOF of 39309.9 h−1under identical potential. XAS analyses of Ni6@Ni-N3 before and after long-term CO2RR testing confirmed the excellent stability of its coordinative environment. This work highlights a generalizable approach for stabilizing unsaturated single-atom catalysts, paving the way for their application in high-performance CO2RR. KW - Electrochemical CO2 conversion KW - Single atom catalysts KW - CO2 electrolysis PY - 2025 DO - https://doi.org/10.1002/anie.202424552 SN - 1521-3773 VL - 64 IS - 13 SP - 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-62926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Braga, Daniel S. A1 - Pedersen, Angus A1 - Riyaz, Mohd A1 - Barrio, Jesús A1 - Bagger, Alexander A1 - Neckel, Itamar T. A1 - Mariano, Thiago M. A1 - Winkler, Manuel E. G. A1 - Stephens, Ifan E. L. A1 - Titirici, Maria‐Magdalena A1 - Nagao, Raphael T1 - Inside back cover image for the article "In situ structural evolution and activity descriptor of atomically dispersed catalysts during nitrate electroreduction" N2 - This cover illustrates the electrosynthesis of ammonia through the reduction of nitrate ions on metallic clusters formed from single atom catalysts. The artwork highlights the catalytic interface where molecular transformations occur, linking nanoscale reactions to sustainable fertilizer production. By converting pollutants into value-added products, this work envisions a green pathway toward circular nitrogen management and enhanced agricultural sustainability. More details can be found in the Research Article (DOI: 10.1002/advs.202510282) by Maria-Magdalena Titirici, Raphael Nagao, and co-workers. KW - Single atom KW - Nitrate reduction KW - In situ KW - Structure-activity-selectivity PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652626 DO - https://doi.org/10.1002/advs.71951 SN - 2198-3844 VL - 12 IS - 39 SP - 1 PB - Wiley-VCH CY - Weinheim AN - OPUS4-65262 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Low, Jian Liang T1 - 理论模拟与实验协同的材料表征与机理研究 T1 - Integrating modelling and experiment for synergistic material characterization and mechanism studies N2 - In this academic salon among Chinese-speaking researchers within Germany and EU, I presented my work on utilizing computational chemistry to support experimental characterization and mechanism studies. The discussion focused on metal- and nitrogen-doped carbon (M-N-Cs) with well-defined coordination geometry as an excellent reference material for synergistic theory-experimental research. Some key topics included the analysis of structural preferences of imprinting ions, spectroscopic characterization of specific active sites and mechanism studies pertaining oxygen reduction reaction and hydrogen peroxide chemistry at these active sites. T2 - 21st Koushare Workshop - European Materials Science: From Molecular Design to Material Applications CY - Berlin, Germany DA - 25.10.2025 KW - Metal- and Nitrogen Doped Carbon (M-N-C) KW - Active Site Characterization KW - Electrochemical mechanisms KW - Oxygen Reduction Reaction (ORR) PY - 2025 AN - OPUS4-65152 LA - zho AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gong, Mengjun A1 - Mehmood, Asad A1 - de Oliveira Guilherme Buzanich, Ana A1 - Fellinger, Tim-Patrick A1 - Jackson, Colleen A1 - Cui, Junyi A1 - Drazic, Goran A1 - Kucernak, Anthony T1 - Designing Co–N/C Cathode Catalysts with Dense Atomic Cobalt Sites for Enhanced PEMFC Performance N2 - Metal-nitrogen/carbon (M-N/C) catalysts, particularly those incorporating Fe,Co, or Mn, are among the most promising non-platinum group catalysts forthe acidic oxygen reduction reaction (ORR) in fuel cells. This study reports aCo-N/C catalyst featuring high (3 wt%) cobalt content exclusively present asatomic sites. Extended X-ray absorption fine structure analysis confirms atetrapyridinic Co-N4 coordination environment in the optimized (3.0)Co-N/C𝚫catalyst. The high cobalt loading leads to a significant density ofelectrochemically accessible active sites, 3.58 × 10 19 sites g−1 , quantified viathe nitrite stripping method. The catalyst demonstrates excellent ORR activityin a rotating ring-disk electrode setup, achieving a half-wave potential (E 1/2 ) of0.76 V at a low loading of 0.2 mg cm−2 and a mass activity of 3.5 A g−1 at 0.80VRHE . Single-cell hydrogen-oxygen PEMFC tests achieve a peak power densityexceeding 1.3 W cm−2 (iR-corrected). Under hydrogen-air condition, thecatalyst delivers 0.54 A cm−2 at 0.60 V (0.39 W cm−2 ). Despite the intrinsicallyhigher turnover frequency of Fe-based sites, the optimized(3.0)Co-N/C𝚫 catalyst achieves similar fuel cell performance to that of Fe-N/C,highlighting the critical role of site density in overall activity. KW - Fuel cells KW - Single atom catalysts KW - Oxygen reduction reaction KW - Non-precious catalysts PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-644276 DO - https://doi.org/10.1002/advs.202516060 SN - 2198-3844 SP - 1 EP - 11 PB - Wiley VHC-Verlag AN - OPUS4-64427 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Rieck, Arielle A1 - Low, Jian Liang A1 - Dietzmann, Simon A1 - Radnik, Jörg A1 - Teimouri, Zahra A1 - Higgins, Drew A1 - Hodoroaba, Vasile-Dan A1 - Mehmood, Asad A1 - Fellinger, Tim-Patrick T1 - Understanding the Activity Trade-Off between Tetrapyrrolic Fe-NCs and Co-NCs in the Alkaline Oxygen Reduction Reaction N2 - A water-free ionothermal synthesis of porous magnesium-imprinted nitrogen-doped carbon (Mg–NC) materials is introduced to prepare a platform material to investigate electrocatalytic structure-performance relations. Atomically dispersed Co- and Fe-NCs isomorphic to the pristine Mg-NCs are prepared by ion-exchange reactions. The current Mg-templating strategy enables relatively high pyrolysis product yields of up to 50 wt% and resultant Fe-NC and Co-NC catalysts contain high and comparable active metal loading of up to 2.52 wt% Fe and 2.29 wt% Co, respectively. A combination of X-ray spectroscopies with DFT studies reveals a tetrapyrrolic structure of the coordination sites, originating from a pyrolytic magnesium template ion reaction within the ionothermal synthesis. Two sets of highly active isomorphic tetrapyrrolic Fe-NCs and Co-NCs are utilized to understand the differences in intrinsic electrocatalytic performance of Co-NCs and Fe-NCs towards the alkaline oxygen reduction reaction (ORR). Despite their superior valence electronic properties to facilitate the initial outer-sphere electron transfer to O2, Co-NCs show significantly lower performance than Fe-NC with comparable loading. Although the generally discussed weaker binding of peroxide intermediates to CoN4 sites compared to FeN4 sites is evident, experimental and theoretical investigation reveal that it is the underlying peroxide oxidation activity that suppresses the oxygen reduction activity of M-NCs. The high peroxide oxidation activity of Co-NCs explains their reduced alkaline ORR relative to Fe-NCs, shedding light on the understated significance of controlling peroxide chemistry for the optimizing cathodic performance. KW - Magnesium Imprinting KW - Tetrapyrrolic Sites KW - Metal- and nitrogen-doped carbon (M-N-C) KW - Oxygen Reduction Reaction (ORR) KW - Nitrogen doped Carbon PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651487 DO - https://doi.org/10.26434/chemrxiv-2025-s59s5 SP - 1 EP - 24 AN - OPUS4-65148 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Böttcher, Nils A1 - Sander, Luise A1 - Ulbricht, Alexander A1 - Widjaja, Martinus Putra A1 - Fellinger, Tim-Patrick A1 - Schmidt, Anita A1 - Krug von Nidda, Jonas T1 - Sodium-ion battery research @ BAM (I): investigating the thermal runaway behaviour of commercial sodium-ion battery cells N2 - Commercially available sodium-ion battery (SIB) cells, with energy densities comparable to lithium-ion battery (LIB) cells based on LiFePO4, were investigated regarding their safety behaviour under thermal abuse conditions. Tests were carried out in an inert atmosphere. The SIB-cells went into thermal runaway (TR), intriguingly, even at a rather low state of charge of 30%. The TR-event was coupled with a pronounced jelly roll ejection, challenging the interpretation of the TR-diagrams. These findings highlight the necessity of incorporating SIB-cells into the ongoing safety classification discussions for LIB-cells. KW - Sodium Ion Batteries KW - Thermal Runaway KW - Battery safety PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647652 DO - https://doi.org/10.1039/d5se00687b SN - 2398-4902 VL - 9 IS - 21 SP - 5832 EP - 5838 PB - Royal Society of Chemistry (RSC) AN - OPUS4-64765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Shu-Han T1 - Exploring Sodium Ion Storage: Combining a MOF Derived Carbon Core with a Sieving Carbon Shell to Illuminate Adsorptive Site Influences N2 - Unlike lithium-ion batteries (LIBs) where crystalline graphite is commonly used as the negative electrode material, disordered carbons are regarded as more promising forsodium-ion batteries (SIBs). However, further advances towards better reversibility and higher specific capacity are still needed to match or even exceed the properties of graphite in LIBs. The main challenge is the complex and unpredictable Na+ storage mechanism in disordered carbons. [1] Method: Recently, Matsukawa et al. have reported that the reversibility of (de)sodiation processes of disordered carbons is better for ultra microporous carbons.[2] Ultra micropores are accessible only to Na+ ions and not to solvent molecules. Therefore, the ultra micopores can be used for Na-storage, however, do not significantly contribute to side reactions caused by solid-electrolyte interphase (SEI) formation, which reduces the related irreversible capacity loss. Building on this concept, the origins of specific capacity and irreversible losses were further explored by modifying the chemical composition of zeolitic imidazolate framework (ZIF-8) derived carbons, while maintaining comparable porosity. This involved adjusting the nitrogen content through temperature variation. Additionally, these ZIF-8 derived carbons were enhanced with a protective ion sieving carbon shell formed by chemical vapor deposition. This shell enables effective distinction between reversible and irreversible Na+ storage. Results: The tailor-made core-shell carbons with higher nitrogen content demonstrate greater capacity in the sloping region, but lower capacity in the plateau region of the voltage profile. In addition, they show reduced specific capacities compared to materials with lower nitrogen content. Lastly, it is important to highlight that the incorporation of sieving carbons results in a significant overall increase in capacity compared to materials without sieving carbons. The highest capacities were obtained for the core shell carbon pyrolyzed at 1000°C reaching reversible capacities of 381 +/- 4 mAh g–1 . Discussion: The nitrogen active sites in the as-synthesized materials facilitate the adsorption of Na+ ions, indicating that Na+ ions preferentially adhere to these active sites during the sodiation process. Moreover, the relatively low capacity observed in materials with higher nitrogen content may be attributed to their lower electrical conductivity. T2 - Batterieforum 2025 CY - Berlin, Germany DA - 21.01.2025 KW - Sodium-ion batteries KW - Hard carbon KW - Core-shell materials PY - 2025 AN - OPUS4-65131 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn T1 - Characterization of Beta-Alumina Solid Electrolyte by Coin Cell Testing N2 - All solid-state batteries (ASSBs) are the subject of widespread research, one reason being their predicted increased safety [1]. Variants of beta-alumina solid electrolyte (BASE), a promising solid electrolyte for sodium ion batteries, exhibit ion conductivities up to 5 mS/cm at room temperature, which motivates targeted research and testing [2]. Dedicated measurement cells for conductivity measurements and cycling of ASSBs are available, providing even pressure and temperature control. However, these are often costly and thus unsuitable for long-term studies with many cells. In contrast, coin cells are a practical and scalable approach for such ASSB studies, despite poor pressure control and other influencing factors that may affect the reproducibility of results [3]. This study investigates the extent to which reliable measurement data can be obtained from symmetrical Na/BASE/Na coin cells. Therefore, several testing procedures and different cell architectures are considered. The experiments are supported by an electrical equivalent circuit model. The modeling approach and both measured and numerically simulated data are presented. The coin cell results are compared to data acquired using a designated ASSB setup (CompreCell and CompreFrame by RHD). T2 - XIXth Conference of the EuropeanCeramic Society / SBS6 InternationalSodium Battery Symposium CY - Dresden, Germany DA - 01.09.2025 KW - Beta aluminate solid electrolyte KW - Coin cell PY - 2025 AN - OPUS4-64055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Appel, Paul Alexander T1 - Probing Structural Changes in Sodium-Ion Battery materials with Operando SAXS N2 - Operando small-angle X-Ray scattering (SAXS) can provide direct insight into nanoscale structural changes occurring during electrochemical operation. This workshop will provide a general overview of the fundamentals of SAXS and highlight its potential on a range of case studies. This talk will highlight how operando SAXS complements conventional electrochemical characterization by revealing dynamic, irreversible structural processes that govern performance and stability in energy storage materials T2 - Operando Workshop CY - Berlin, Germany DA - 17.09.2025 KW - Small Angle X-Ray Scattering KW - Operando Measurments PY - 2025 AN - OPUS4-65119 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 - CONF A1 - Sander, Luise T1 - Links Between Electrode Properties and Cell Performance in Commercial Sodium-Ion Batteries N2 - Our latest results of commercially purchased cylindrical sodium ion battery (SIB) cells will be presented. Two different cell types were dissasembled and thouroughly characterized on electrode as well as on material level. Both cell types comprise aluminum current collectors for anode and cathode, respectively. Furthermore, geometric electrode parameters, such as electrode size, thickness and loading, will be presented and linked to the electrical data-sheet values. Further in-depth characterization on material level revealed that both cathode active materials are composed of a cobalt free Ni-Mn-Fe-oxide. Interestingly, the cathode particles significantly differ in shape and size between the two cell types. Both anode active materials are graphite-free, and the particle structure points in both cases to a biomass-derived hard carbon material. Based on gas chromatography mesaurements coupled with mass spectrometry (GC-MS), both cell types utilize a mixture of carbonates as electrolyte, however, contain different conductive salts. Moreover, the measured, characteristic electrical features, e.g., capacity, Coulombic efficiency, and initial cycle life, will be discussed. Intriguingly, the cycling stability greatly differs between the cell types. Presumably, this behaviour can be mainly linked to the different morphology of the cathode active material. Overall, the work can give important insights in the composition and electrical behabiour of currently available SIB-cells. T2 - Sodium Battery Symposium (SBS-6) CY - Dresden, Germany DA - 03.09.2025 KW - Battery KW - Sodium-Ion-Battery KW - Electrochemical Energy Storage KW - Energy Storage PY - 2025 AN - OPUS4-64411 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sander, Luise T1 - Linking Material and Electrode Properties to the Cell Performance of Two Types of Commercially Available SIBs N2 - As the first commercial sodium-ion-batteries (SIBs) are available for purchase, it is possible to investigate material composition. Gaining an insight into the material composition of these SIBs is of interest not only for the classification of possible safety risks and hazards, but also in regards to recycling. Herein we report the preliminary investigations of the chemical and structural composition of first commercial SIB-cells. Two different SIB-cell types were compared in terms of electrode size, thickness, loading etc. Furthermore, the composition of the active materials and electrolyte was investigated and compared. Finally, the gained results were linked to the different data sheet performance of the two cell types. T2 - WISPER - Women in Science Promoting Energy Research CY - London, UK DA - 21.05.2025 KW - Battery KW - Sodium-Ion-Battery KW - Electrochemical Energy Storage KW - Energy Storage PY - 2025 AN - OPUS4-63284 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Basics, Challenges and Trends in Electrochemical Energy Storage N2 - In this lecture the fundamental principles of batteries are briefly introduced aligned by the historical development of the technology. The introduction is continued with an overview on current challenges regarding performance, durability, sustainability, cost and safety. Lastly, research trend on approaches to tackle the challenges are discussed by selected examples. T2 - Basics, Challenges and Trends in Electrochemical Energy Storage CY - Cottbus, Germany DA - 15.09.2025 KW - Batteries KW - Electrochemistry KW - Energy Materials PY - 2025 AN - OPUS4-64919 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Core-shell type carbon anodes for na-ion batteries N2 - Increasing prices of the material basis for lithium-ion batteries caused by limited production capacities or resource abundance has led to a renewed interest in sodium ion batteries (SIBs). Therein, amorphous disordered carbons such as hard carbons (HCs) are promising candidates for high-capacity negative electrode materials in SIBs. Their high capacities, however, are often accompanied with high irreversible capacity losses during the initial cycles,[1] while low initial losses are mostly accompanied with moderate capacities.[2] In our research we are aiming at morphologically improved carbons to reduce irreversible losses using a core-shell concept, leading to spacial separation of the reversible storage and unfavorable side reactions.[3] We investigated different methods to obtain core-shell structures with improved interfaces to restrict SEI formation to the external particle surface, while leveraging the Na storage potential of porous carbon core materials. With a simple and scalable chemical vapour deposition we obtained a 190-fold decrease in surface roughness, resulting in drastically reduced first cycle losses. Interestingly, the sodiation capacity at the same time increased to 400 mAh/g revealing the interference of excessive SEI formation with the storage process within the particles. T2 - Research Seminar of the Dahn Labs at Dalhousie University CY - Halifax, Canada DA - 27.05.2025 KW - Natrium-Ionen-Batterien KW - Synthetische Anoden KW - Kohlenstoff PY - 2025 AN - OPUS4-64912 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Commercial State-of-the-Art Sodium-Ion Batteries and Perspectives for the Negative Electrode (Anode) N2 - The current strong interest in electromotive mobility and the need to transition to an energy grid with sustainable storage devices has led to a renewed interest in sodium ion batteries (SIBs). Chinese battery manufacturers marketed the first cells, which are commercially available now. We have purchased and investigated two of these early cells to understand their composition and be able to compare to the state-of-the-art in the scientific community. According to our results and the current literature, all commercial cells utilize carbon-based anodes, with the characteristic sloping charge-discharge profile. In the presentation the results will be discussed in context with safety aspect and space for improvement. The latter aspect will be focused on hard carbon anodes. Amorphous disordered carbons such as hard carbons (HCs) are promising candidates for high-capacity negative electrode materials in SIBs. Their high capacities, however, are often accompanied with high irreversible capacity losses during the initial cycles,[1] while low initial losses are accompanied with moderate capacities.[2] In our research we are aiming at morphologically improved carbons to reduce irreversible losses using a core-shell concept.[3, 4] T2 - Eco-Mat Conference 2025 CY - Istanbul, Türkiye DA - 29.07.2025 KW - Natrium-Ionen-Batterien KW - Synthetische Anoden KW - Kohlenstoff PY - 2025 AN - OPUS4-64908 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krug von Nidda, Jonas T1 - Developing Core-Shell Carbon Materials to Link Porosity Features to Sodium Storage Capacities N2 - Porous carbon materials play an important role for energy storage and conversion. One (re-)emerging research field is the ability of porous carbons to store sodium metal ions. Current results shows that internal pores – hence, pores which are not accessible for the electrolyte – allow to store large amounts of sodium at low potentials, yielding high energy sodium-ion battery (SIB) anodes. The common synthesis approach to gain carbons with internal pores involves the pyrolysis of a non-graphitizing precursor, resulting in a so-called hard carbon (HC). However, HC-materials frequently show substantial non-reversible initial capacity losses. Commonly, significant losses are associated with the creation of the solid electrolyte interphase (SEI) on the carbon’s surface that occurs during the initial sodium insertion. Intriguingly, large irreversible capacities are often found for samples with experimentally determined low specific surface area.[2] A more comprehensive understanding of the structure-property relations is essential for quantifying and grasping the potential of carbon materials in SIBs. However, the typical synthesis methods do not allow to individually tune the storage properties – mainly connected to the internal properties of the carbons – and the SEI-formation – primarily related to the surface properties. Hence, the objective of the present work is to develop a synthesis route which tackles this challenge. Herein, the main approach is to develop tailor-made core-shell carbon materials consisting of a highly porous carbon core and a quasi-non-porous carbon shell. For the core, two strategies are pursued: A) microporous carbon materials with varied porosity, however, similar chemistry, and B) microporous carbons with tuneable chemistry, but similar porosity. Approach A involves the selection of commercially available activated carbons (ACs). Strategy B is based on the modification of the chemical composition (i.e., amount and type of N-sites) of zeolitic imidazolate framework (ZIF-8) derived carbons. In both cases, the shell is realized by chemical vapour deposition (CVD). Different analytical methods, e.g., powder XRD, gas physisorption (N2, Ar, CO2), XPS, and SAXS are used to thoroughly characterize morphological and chemical features of the core as well as of the core-shell carbons. These features are linked to the electrochemical characteristics of the materials. After CVD-coating, all materials show a significant reduction in detectable surface area (up to a factor of up to 190x) by N2-physisorption. The coating technique is successfully applied to a range of AC-materials, enabling to link porosity features to Na-storage behavior. For the best performing AC-based material, the reversible capacity is increased from ~140 mAhg-1 to ~400 mAhg-1 while irreversible capacity is decreased from ~640 mAhg-1 to ~90 mAhg-1. The results of the coated ZIF-derived carbon reveal that a higher nitrogen content leads to a greater capacity in the sloping region, but to a lower capacity in the plateau region of the voltage profile. Generally, core-shell carbon anodes promise to enable high capacities accompanied with low irreversible losses. T2 - 36. Deutsche Zeolith-Tagung CY - Erlangen, Germany DA - 26.02.2025 KW - Battery KW - Anode KW - Hard Carbon PY - 2025 AN - OPUS4-64960 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Improved Hard Carbon Anodes for Na-ion Batteries by Interface Modification N2 - The current strong interest in electromotive mobility and the need to transition to an energy grid with sustainable storage devices has led to a renewed interest in sodium ion batteries (SIBs). Amorphous disordered carbons such as hard carbons (HCs) are promising candidates for high-capacity negative electrode materials in SIBs. Their high capacities, however, are often accompanied with high irreversible capacity losses during the initial cycles,[1] while low initial losses are accompanied with moderate capacities.[2] In our research we are aiming at morphologically improved carbons to reduce irreversible losses using a core-shell concept.[3] We investigated different methods to obtain core-shell structures with improved interfaces to restrict SEI formation to the external particle surface, while leveraging the Na storage potential of porous carbon core materials. With a simple and scalable chemical vapour deposition we obtained a 190-fold decrease in surface roughness, resulting in drastically reduced first cycle losses. Interestingly, the sodiation capacity at the same time increased revealing the interference of excessive SEI formation with the storage process within the particles. T2 - ECS Spring Meeting 2025 CY - Montreal, Canada DA - 18.05.2025 KW - Natrium-Ionen-Batterien KW - Synthetische Anoden KW - Kohlenstoff PY - 2025 AN - OPUS4-64911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Designing Core-Shell Carbon Materials for High-Performance Sodium-Ion Battery Anode N2 - Increasing prices of the material basis for lithium-ion batteries caused by limited production capacities or resource abundance has led to a renewed interest in sodium ion batteries (SIBs). Therein, amorphous disordered carbons such as hard carbons (HCs) are promising candidates for high-capacity negative electrode materials in SIBs. Their high capacities, however, are often accompanied with high irreversible capacity losses during the initial cycles,[1] while low initial losses are mostly accompanied with moderate capacities.[2] In our research we are aiming at morphologically improved carbons to reduce irreversible losses using a core-shell concept, leading to spacial separation of the reversible storage and unfavorable side reactions.[3] We investigated different methods to obtain core-shell structures with improved interfaces to restrict SEI formation to the external particle surface, while leveraging the Na storage potential of porous carbon core materials. With a simple and scalable chemical vapour deposition we obtained a 190-fold decrease in surface roughness, resulting in drastically reduced first cycle losses. Interestingly, the sodiation capacity at the same time increased to 400 mAh/g revealing the interference of excessive SEI formation with the storage process within the particles. T2 - International Carbon Conference 2025 CY - Saint Malo, France DA - 29.06.2025 KW - Sodium-Ion-Batteries KW - Hard Carbons KW - Synthetic Anodes KW - Carbon PY - 2025 AN - OPUS4-64907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Sustainable energy materials and circularity N2 - Li-ion batteries (LIB) are the dominant energy storage technology and present in electrified transportation, electronic devices as well as robotics. This is due to their high energy density (300 watt-hours per kilogram), low self-discharge (1.5-2% per month), long storage life (10 years) and cyclability (500-2000 cycles). Unfortunately, these batteries require the use of scarce, toxic and unethically resourced materials for their fabrication. Furthermore, it is expected an increase of 26 million units of LIB on electric vehicles by 2030 generating a large amount of waste in a very near future. However, those end-of-life batteries can be considered an important source of metals and materials (electrolytes, binders, anodes) to be reused in other applications or incorporated in the battery supply chain. This also pushes the need to redesign the LIB components and other sustainable technologies using low-cost materials. The focus of this symposium is to bring together experts from around the world to discuss the latest advancements in sustainability of battery technologies and their impact on the future landscape of our society and environment. During the symposium, speakers will present recent research and developments in solving future and present problems derived from the exponential demand of LIB manufacturing T2 - Mat-Sus Spring Meeting 2025 CY - Sevilla, Spain DA - 03.03.2025 KW - CRM-free KW - Sustainability KW - Energy Materials PY - 2025 AN - OPUS4-64915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Molekularsiebende Kohlenstoffe als hochkapazitive und stabile Anoden in Natrium-Ionen-Batterien N2 - In dem Vortrag wird ein Fortschrittsbericht über die laufenden Arbeiten im BMBF-geförderten Verbundprojekt „Dialysorb“ gegeben. Nach einer kurzen Schilderung der Arbeitspaketstruktur und den Arbeitspaketinhalten werden einzelne wissenschaftliche Ergebnisse genannt und kurz diskutiert. So gelang es hier u.a. hochporöse Materialien mittels Gasphasenabscheidung von Kohlenstoffverbindungen derart zu modifizieren, dass nur noch ein Bruchteil der Porosität mittels Gassorption messbar ist. Elektrochemische Sodiierungs-/Dessodiierungsergebnisse deuten darauf hin, dass die Porosität im Kern der Materialien erhalten ist, da die reversible Sodiierungskapazität deutlich erhöht ist. Abschließend werden folgende Arbeitschritte erläutert und der Vortrag zur Diskussion gestellt. T2 - BMBF-Statusmeeting B@TS 2025 CY - Cologne, Germany DA - 07.04.2025 KW - Natrium-Ionen-Batterien KW - Synthetische Anoden KW - Kohlenstoff PY - 2025 AN - OPUS4-64906 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Leveraging the Potential of Na-Ion-Batteries with Tailormade Anodes N2 - Research progress on synthetic hard carbon anodes was suggested as key technology to leverage the potential of sodium ion batteries. The background, progress and market size of sodium ion batteries was presented and the relevance of producing such materials in terms of a business case was suggested. T2 - HWR Entrepreneural Workshop 2025 CY - Berlin, Germany DA - 18.10.2025 KW - Natrium-Ionen-Batterien KW - Synthetische Anoden KW - Kohlenstoff PY - 2025 AN - OPUS4-64909 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lee, Woojin T1 - Impact of Coating and Drying on Electrochemical Properties of Core-Shell Carbon Materials N2 - Due to the heavy overuse of fossil energy sources since the last couple of centuries, a range of serious concerns such as depletion of fossil fuels and climate change that is driven by extensive carbon dioxide (CO2) emission has risen. Rechargeable batteries have surged as eco-friendly and sustainable energy source alternative. Lithiumion batteries (LIBs) have been the most successful rechargeable battery since their commercialization. However, owing to exhaustion and instability in price of scarce raw materials, sodium-ion batteries (SIBs) have emerged as the most attractive alternative to LIBs. Nonetheless, there are still burdens to overcome for SIBs to achieve competitiveness over LIBs, particularly in improving their energy density. To address the burdens, diverse materials have been studied to date. Yet, progress and development on achieving high performance negative electrode for SIBs still remain as a key object. Hard carbon (HC) has been considered as attractive candidate, because of its high capacity and low production cost. Despite the attractiveness, inherent limitations of HCs such as excessive formation of solid-electrolyte interphase (SEI) and large irreversible capacity loss have hindered their applications. To confront this challenge, core-shell concept has been suggested by the team of Division 3.6 at BAM. The concept is to create carbon coating (shell structure) around the core material in order to mitigate formation of excessive SEI and enhance performance of the negative electrode. Shu-Han Wu and Paul Alexander Appel from Division 3.6 at BAM have synthesized various core-shell materials and have observed promising results. They made great progress in the research of core-shell materials, for example improving initial coulombic efficiency from 31% to 68%. However, there are still room for improvement. The task of this bachelor thesis work is to enhance the electrochemical performance of the core-shell materials and to investigate a more effective carbon coating method on the core material by exploring various coating parameters and different drying procedures. In this bachelor thesis, Shu-Han Wu’s synthesis precedure was repeated, ZIF-8 was pyrolyzed at 1000°C with a consequent treatment with HCl gas and washed with de� ionised water. The material (ZIF8_1000_HCl gas_H2O) was re-synthesized. Increasement in N2 Physisorption was observed after the acid treatment, consistent to Shu-Han Wu’s syntheis. The as-synthesized material was used as core material throughout this bachelor work. Moreover, 4 different core-shell carbon materials were synthesized by using chemical vapor deposition (CVD) and ball milling as synthesis methods. was used as core material and toluene was used as carbon precursor for CVD. CVD displayed an effective formation of shell structure evidenced by steep reduction in specific surface area (SSABET) from N2 physisorption characterization. Ball milling revealed to cause defects in shell structure, which was noticeable on increase in SSABET (from 14 to 379 m2 g-1) and pore size distribution characterization. Drying of powder material prior to CVD process did not exhibit a difference in porosity on the final product after CVD. From the galvanostatic cycling tests at a current density of 20 IVmA g⁻¹, it was evident that formation of shell structure enhances the performance of the material. Among the synthesized core-shell materials, the material double 1.5 h CVD with no ball milling in between exhibited the most excellent performance (ICE 60.1%). Powder drying prior to CVD showed a positive influence on improving the electrochemical performance (ICE improved from 45.1% to 51.9%). Increasing drying temperature of electrode resulted in increasements of performance, where the peak performance was reached at drying at 200°C (ICE 57.7%). The investigations of impacts of coating and drying on electrochemical properties of core-shell carbon materials would provide basis and motivation for further development of advanced negative electrode materials for SIBs. KW - Sodium-ion batteries KW - Hard carbon KW - Core-shell materials PY - 2025 SP - 1 EP - 39 CY - TU Berlin AN - OPUS4-65130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Bioinspired Electrode Materials N2 - Porous carbon materials are known for their applicability in important areas such as sorption, catalysis and electrochemistry (e.g. fuel cell catalysts, supercapacitor or battery electrodes). It was shown that nitrogen doped carbons (NDCs) act as an inexpensive and highly active non-metal catalyst in the oxygen reduction reaction (ORR), with the potential to reach performances of practical need one day. A key strategy towards improvement for this aim comprises the generation of advantageous porosity, which typically means high surface area and mass transport pores as well as the control over the chemistry of catalytically active sites. My group developed novel sol-gel type strategies that are using molten salts or molten acids as unconventional reaction medium for the porogenesis in doped carbons, thereby revisiting classic activation techniques. Carbon materials with extra high surface area of ~2800 m2 g-1 and pore volumes, up to four times as high as in commercial activated carbons, are obtained. Hierarchical pore systems, like used in nature (leaves, lungs, etc.) facilitate some of the electrochemical performances. Moreover, because of the elements also defining organic matter, also binding motifs can be realized that are reminiscent of proteins/enzymes. We established the pyrolytic template-ion reaction using cations like Mg2+ and Zn2+ to imprint tetrapyrrolic N4 sites (like in the heme molecule), embedded into the carbon structure. The imprinted structure may be utilized as catalytically active site by performing ion-exchange reactions. This way catalytic activity can be tuned for different societal important reactions, but also the defined catalysts structure allows the assignment of structure-performance relations. Other “tricks” that nature uses, are to influence the passage of ions through cell walls, or to expel water molecules from catalytically active sites. I will show some recent work on carbon electrodes used as battery active materials that utilizes similar pathways. T2 - Kolloquium des Instituts für Anorganische und Allgemeine Chermie der Universität Freiburg CY - Freiburg, Germany DA - 04.12.2025 KW - Carbon KW - M-N-C KW - Fuel cell KW - Core-shell KW - Sodium ion battery PY - 2025 AN - OPUS4-65021 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Design, Structure and Performance of Fe-N-C Catalysts Based on Active-Site Imprinting N2 - Atomically dispersed M-N-C catalysts such as Fe-N-Cs are most promising alternatives for precious metal-based catalysts for several energy conversion reactions. Early reports on such materials date back to the 1960´s, when Jasinski pioneered the research based on tetrapyrrolic phthalocyanine macrocycles which were inspired by natural transition metal porphyrin complexes present in enzyme active sites. For decades, the selective synthesis of these catalysts was complicated by the formation of side phases due to the harsh reaction conditions facilitating side phase formation. In 2018, we introduced a mild procedure, which is conservative toward the carbon support and leads to atomically dispersed Fe-N4 site formation at temperatures as low as 80 °C in a wet-chemical step, essentially decoupling the preparation of the N-C backbone from the preparation of the active sites. The key concept therein is the so-called active-site imprinting into the N-C backbone using pyrolytic template ion reactions, allowing for high concentrations of N4 sites resulting in more than 3 at.% of Fe in atomically dispersed phase. Using the same precursor that is used for the preparation of phthalocyanines, we were able to produce atomically-dispersed single-site Fe-N-Cs that consist of tetrapyrrolic FeN4 complexes. The tetrapyrrolic Fe-N-C derivatives are highly active and extraordinary selective electrocatalysts for the oxygen reduction reaction. The well-defined and homogeneous active site structure allows to quantify the intrinsic catalytic activity of the materials in acid and base, reveal insights into the electrocatalytic mechanism and to reveal distinct degradation mechanism upon storage and electrochemical cycling. Herein, the general synthetic strategy of active-site imprinted catalysts will be discussed mainly based on both Mg-ion and Zn-ion templating towards “designed” Fe-N-C catalysts. The tetrapyrrolic active sites will be discussed regarding structure, activity, selectivity and durability. This hopefully stimulates a fruitful discussion of the perspectives in the field. T2 - Chemical Engineering Research Seminar of Higgins Group of McMaster University CY - Hamilton, Canada DA - 29.05.2025 KW - Carbon KW - M-N-C KW - Electrocatalysis KW - Fuel cells PY - 2025 AN - OPUS4-64913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krug von Nidda, Jonas T1 - Tetrapyrrolic Nitrogen Doped Carbons by Pyrolytic Template Ion Reactions as Platform for Electrocatalysis N2 - Atomically dispersed M-N-C catalysts such as Fe-N-Cs are most promising alternatives for precious metal-based catalysts for energy conversion reactions. Early reports on such materials date back to the 1960´s, when Jasinski pioneered the research based on tetrapyrrolic phthalocyanine macrocycles which were inspired by natural transition metal porphyrin complexes present in enzyme active-sites. For decades, the selective synthesis of these catalysts was complicated by the formation of side phases due to the harsh reaction conditions facilitating side phase formation. In 2018, we introduced a mild procedure, which is conservative toward the carbon support and leads to atomically dispersed Fe-N4 site formation at temperatures as low as 80 °C in a wet-chemical step, essentially decoupling the preparation of the nitrogen-doped carbon (NDC) backbone from the preparation of the active-sites. The key concept therein is the so-called active-site imprinting into the NDC backbone using pyrolytic template ion reactions, allowing for high concentrations of N4 sites resulting in more than 3 at.% of Fe in atomically dispersed phase. Using the same precursor that is used for the preparation of phthalocyanines, we were able to produce tetrapyrrolic NDCs as a materials platform to synthesize atomically-dispersed single-site Fe-N-Cs comprising tetrapyrrolic FeN4 complexes by ion-exchange reactions. The tetrapyrrolic Fe-N-C derivatives are highly active and extraordinary selective electrocatalysts for the oxygen reduction reaction in acidic. The mere tetrapyrrolic NDC are likewise highly active ORR-catalysts in alkaline. The well-defined and homogeneous active-site structure allows to quantify the intrinsic catalytic activity of the materials in acid and base, reveal insights into the electrocatalytic mechanism and to reveal distinct degradation mechanism upon storage and electrochemical cycling. Herein, the general synthetic strategy will be discussed mainly based on Zn-ion templating towards Fe-N-C catalysts. The catalytic active-sites will be discussed regarding structure and potential as fuel cell catalyst. T2 - Carbon Conference 2025 CY - Saint-Malo, France DA - 29.06.2025 KW - Electrocatalysis KW - Oxygen Reduction Reaction KW - Noble Metal Free KW - Nitrogen Doped Carbon PY - 2025 AN - OPUS4-64968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Shu-Han T1 - Sodium Storage Mechanisms and Performance Improvement of Synthetic Hard Carbon Materials N2 - Hard carbons (HCs) are promising anodes for sodium-ion batteries (SIBs) due to their high capacity and low cost. However, their broader use is limited by an incomplete understanding of sodium storage mechanisms. Internal porosity is key to high capacity, but tuning its chemical functionality remains challenging. In this study, we designed core–shell carbon materials featuring closed pores and tailored surface chemistry to distinguish reversible sodium storage from irreversible capacity losses associated with solid electrolyte interphase (SEI) formation. Our results reveal that external porosity can be clearly converted into internal porosity, leading to enhanced sodium storage performance, with capacities exceeding those of lithium in graphite. T2 - Advanced Automotive Battery Conference (AABC) 2025 CY - Mainz, Germany DA - 23.06.2025 KW - Sodium-ion batteries KW - Hard carbon KW - Core-shell materials PY - 2025 AN - OPUS4-65133 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Appel, Paul Alexander T1 - Linking Porosity to Storage Capacity: Core-Shell Carbon Materials as High-Capacity Anodes for Sodium Ion Batteries N2 - Hard carbons (HCs) are currently one of the most promising anode materials for sodium-ion batteries (SIBs). However, the Na storage mechanism remains controversial, leaving the theoretical limits of carbon anodes unclear. To deconvolute the specific capacity from irreversible capacity losses, resulting from the formation of solid electrolyte interphase (SEI), core-shell carbon materials were synthesized. Based on these core-shell materials, an investigation of the storage mechanism of sodium is possible. T2 - Advanced Battery Power 2025 CY - Aachen, Germany DA - 01.04.2025 KW - Electrochemical Energy Materials KW - Negative Electrodes KW - Sodium Ion Batteries PY - 2025 AN - OPUS4-65114 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Appel, Paul Alexander T1 - Developing Tailor-Made Core-Shell Carbon Negative Electrode Materials for Sodium Ion Batteries N2 - Hard carbons (HCs) are currently one of the most promising anode materials for sodium-ion batteries (SIBs). However, the Na storage mechanism remains controversial, leaving the theoretical limits of carbon anodes unclear. To deconvolute the specific capacity from irreversible capacity losses, resulting from the formation of solid electrolyte interphase (SEI), core-shell carbon materials were synthesized. Based on these core-shell materials, an investigation of the storage mechanism of sodium is possible. T2 - Sodium Battery Symposium CY - Dresden, Germany DA - 03.09.2025 KW - Electrochemical Energy Materials KW - Negative Electrodes KW - Sodium Ion Batteries PY - 2025 AN - OPUS4-65116 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krug von Nidda, Jonas T1 - Porous „Ionophoric“ Carbon Materials: Synthesis Routes and Electrochemical Applications N2 - Porosity tuning and “doping” with heteroatoms and/or transition metals are key strategies to improve the performance of porous carbons. Nitrogen doped carbons (NDCs) with macrocyclic functionalities and the respective M-coordinated NDCs (M-N-Cs) containing FeN4 sites, are very promising electrodes for Na-storage and electrocatalytic conversions. Their functional groups are reminiscent of those in biomolecules like e.g. hemoglobin. The materials can carry ions and can be regarded as “ionophoric” carbons. T2 - AKK-Herbsttagung 2025 CY - Mainz, Germany DA - 22.09.2025 KW - Electrocatalysis KW - Energy Storage KW - Noble Metal Free KW - Nitrogen Doped Carbon PY - 2025 AN - OPUS4-64969 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dietzmann, Simon T1 - X-ray Absorption Spectroscopy to Uncover the Structure of Metal and Nitrogen Doped Carbon Electrocatalysts N2 - High-performance electrocatalysts and sodium-ion (Na+) storage materials for Na-ion batteries are essential for efficient energy conversion and storage. Metal and nitrogen enriched carbons (M–N–Cs) are promising candidates due to their intrinsic conductivity and tunable properties through targeted modification. To understand and optimize the catalytically active sites at the pseudo-molecular level, detailed structural characterization is crucial. T2 - Bessy User Meeting CY - Berlin, Germany DA - 03.12.2025 KW - Elechtrochemistry KW - XAS KW - Single atom catalysts PY - 2025 AN - OPUS4-65010 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sturm, Anna T1 - Tayloring Accessible Surfaces of Activated Carbons via Mechanochemical Processing N2 - Controlling the external accessibility of porous carbons without compromising their internal microporous network is essential for material functionality. Hard Carbons (HC) were ball milled in the presence of aromatic compounds, forming a disordered surface barrier that partially blocks pore entrances. This selectively reduces their external specific surface area (SSA) while preserving internal storage capacity. T2 - Income 2025 CY - Berlin, Germany DA - 14.09.2025 KW - Ball Milling KW - Sealed Porosity KW - Mechanochemistry PY - 2025 AN - OPUS4-65117 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Deciphering Structure-Performance Relations of PGM-Free Fe-N-C Electrocatalysts Based on Synthetic Materials Design N2 - Fe-N-C electrocatalysts are very promising alternatives for precious metal-based catalysts for energy conversion reactions.[1-3] Early reports on such materials date back to the 1960´s, when Jasinski pioneered the research based on tetrapyrrolic phthalocyanine macrocycles which were inspired by natural transition metal porphyrin complexes present in enzyme active sites.[3] For decades, the synthesis of these catalysts with a high iron loading was complicated by the formation of side phases due to the harsh reaction conditions facilitating side phase formation. In 2018, we introduced a mild procedure, which is conservative toward the carbon support and leads to active-site formation at low temperatures in a wet-chemical step, essentially decoupling the preparation of the N-C backbone from the preparation of the active sites.[4, 5] The key concept therein is the so-called active-site imprinting into the N-C backbone using pyrolytic template ion reactions.[4][5] Using the same precursor that is used for the preparation of phthalocyanines, we were able not only to produce atomically-dispersed single-phase Fe-N-Cs with a high iron loading, but were also able to selectively form tetrapyrrolic Fe-N4 complexes.[6] The tetrapyrrolic Fe-N-C derivatives are highly active and extraordinary selective electrocatalysts for the oxygen reduction reaction. Deconvolution of morphological effects on the performance allowed to quantify the intrinsic catalytic activity of the materials in acidic and alkaline conditions and gives new insights into the reaction mechanism in alkaline.[7, 8] A distinct degradation mechanism upon storage was found for the tetrapyrrolic sites and new insights on degradation upon fuel cell operation could be obtained.[9, 10] Herein, the general synthetic material design strategy for atomically dispersed catalysts will be discussed based on tetrapyrrolic Fe-N-C catalysts, which will be analyzed for their potential as PGM-free fuel cell catalysts. T2 - Research Seminar of National Institute of Chemical Physics and Biophysics CY - Tallinn, Estonia DA - 29.09.2025 KW - Carbon KW - M-N-C KW - Electrocatalysis KW - Fuel cells PY - 2025 AN - OPUS4-64916 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Low, Jian Liang T1 - Active Site Determination in Pyrolyzed M-N-C Electrocatalysts by Gas-sorption N2 - Metal and nitrogen-doped carbons (M-N-Cs) with M-N4 moieties as the generally accepted active sites, have gradually reached promising levels of activity towards crucial electrochemical reactions like the oxygen reduction reaction (ORR) and carbon dioxide reduction reaction (CO2RR). Even the metal-free counterparts, the nitrogen-doped carbons (NDCs), are common and well-studied electrocatalysts for ORR in alkaline media. In these disordered porous materials, the characterization and quantification of (M)N4 sites can be challenging and time-consuming, with many spectroscopic methods drastically overestimating their site accessibility for catalytic applications. In this study, we explore an alternative approach towards active site characterization and quantification in M-N-Cs based on multi-Langmuir analysis of CO2-sorption isotherms at low pressures, with support fromelectronic DFT calculations. T2 - Electrolyser and Fuel Cell Forum 2025 CY - Lucerne, Switzerland DA - 01.07.2025 KW - Metal- and Nitrogen Doped Carbon (M-N-C) KW - Active Site Characterization KW - Gas sorption KW - Active-Site Imprinting PY - 2025 AN - OPUS4-65147 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Design Structure and Performance of FeNC Catalysts N2 - Atomically dispersed M-N-C catalysts such as Fe-N-Cs are most promising alternatives for precious metal-based catalysts for energy conversion reactions.[1-3] Early reports on such materials date back to the 1960´s, when Jasinski pioneered the research based on tetrapyrrolic phthalocyanine macrocycles which were inspired by natural transition metal porphyrin complexes present in enzyme active sites.[3] For decades, the selective synthesis of these catalysts was complicated by the formation of side phases due to the harsh reaction conditions facilitating side phase formation. In 2018, we introduced a mild procedure, which is conservative toward the carbon support and leads to atomically dispersed Fe-N4 site formation at temperatures as low as 80 °C in a wet-chemical step, essentially decoupling the preparation of the N-C backbone from the preparation of the active sites.[4, 5] The key concept therein is the so-called active-site imprinting into the N-C backbone using pyrolytic template ion reactions, allowing for high concentrations of N4 sites resulting in more than 3 at.% of Fe in atomically dispersed phase.[4-6] Using the same precursor that is used for the preparation of phthalocyanines, we were able to produce atomically-dispersed single-site Fe-N-Cs that consist of tetrapyrrolic FeN4 complexes.[6] The tetrapyrrolic Fe-N-C derivatives are highly active and extraordinary selective electrocatalysts for the oxygen reduction reaction. The well-defined and homogeneous active site structure allows to quantify the intrinsic catalytic activity of the materials in acid and base,[7, 8] reveal insights into the electrocatalytic mechanism and to reveal distinct degradation mechanism upon storage and electrochemical cycling.[9, 10] Herein, the general synthetic strategy of active-site imprinted catalysts will be discussed mainly based on Zn-ion templating towards tetrapyrrolic Fe-N-C catalysts. The catalytic active sites will be discussed regarding structure, activity, selectivity and durability, hence the potential as fuel cell catalyst. T2 - ECS Spring Meeting 2025 CY - Montreal, Canada DA - 18.05.2025 KW - Fuel Cell KW - ELectrocatalyst KW - Fe-N-C KW - Carbon PY - 2025 AN - OPUS4-64910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Shu-Han T1 - Revealing the Impact of Nitrogen Sites on the Sodium Storage Mechanism in Carbon Electrodes N2 - Unlike lithium-ion batteries (LIBs), where crystalline graphite is commonly used as the negative electrode material, disordered carbons are regarded as more promising for sodium-ion batteries (SIBs). However, further advances towards better reversibility and higher specific capacity are still needed to match or even exceed the properties of graphite in LIBs. The main challenge is the complex and unpredictable Na-storage mechanism in disordered carbons. Recently, Matsukawa et al. have reported that the reversibility of (de)sodiation processes of ultra microporous carbons is higher compared to carbon materials with larger pore sizes.[2] Ultra micropores are accessible only to Na+-ions and not to solvent molecules. Therefore, ultra micropores can be used for Na-storage, however, do not significantly contribute to side reactions caused by solid-electrolyte interphase (SEI) formation, which reduces the related irreversible capacity loss. Building on this concept, the origins of specific capacity and irreversible losses were further explored in the current work by modifying the chemical composition of zeolitic imidazolate framework (ZIF-8) derived carbons, while maintaining comparable porosity. This involved adjusting the nitrogen content as well as the types of nitrogen sites through temperature variation. Subsequently, these ZIF-8 derived carbons were modified with a protective ion-sieving carbon shell formed by chemical vapor deposition (CVD). This synthesis methodology enables effective distinction between reversible Na-storage and irreversible processes, e.g., SEI-formation. The former and later are mainly dictated by the properties of the ZIF-derived carbon core and the CVD based shell, respectively. The structure and morphology of the materials were characterized by electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy. In addition, different gas sorption techniques were carried out to analyze the porosity, pore sizes and specific surface areas. The electrochemical performance of the prepared materials was evaluated in coin cells vs. Na-metal. The results of the tailor-made core-shell carbons reveal that a higher nitrogen content leads to a greater capacity in the sloping region, but to a lower capacity in the plateau region of the voltage profile. In addition, the overall capacity is higher for materials with lower nitrogen content. Lastly, it is important to highlight that the incorporation of ion-sieving carbon shell results in a significant overall increase in capacity compared to materials without a carbon shell. The highest reversible capacities (i.e., 381 +/- 4 mAh g–1) were obtained for the core-shell carbon comprising a ZIF-derived core pyrolyzed at 1000°C. Apparently, the N-sites in the as-synthesized materials facilitate the adsorption of Na+ ions, indicating that Na+ ions preferentially adhere to these active sites during the sodiation process. It is worth noting that these results were observed while minimizing side reactions, making them more reliable and providing conclusive evidence for the long-debated Na-storage mechanism. Moreover, the lower capacity observed in materials with higher nitrogen content may be attributed to a lower electrical conductivity. T2 - Advanced Battery Power Conference 2025 CY - Aachen, Germany DA - 02.04.2025 KW - Sodium-ion batteries KW - Hard carbon KW - Core-shell materials PY - 2025 AN - OPUS4-65132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sander, Luise T1 - Commercially Available Sodium-Ion Cells: Links between Material and Electrode Properties and the electrochemical Performance N2 - As the first commercial sodium-ion-batteries (SIBs) are available for purchase, it is possible to investigate material composition. Gaining an insight into the material composition of these SIBs is of interest not only for the classification of possible safety risks and hazards, but also in regards to recycling. Herein we report the preliminary investigations of the chemical and structural composition of first commercial SIB-cells. Two different SIB-cell types were compared in terms of electrode size, thickness, loading etc. Furthermore, the composition of the active materials and electrolyte was investigated and compared. Finally, the gained results were linked to the different data sheet performance of the two cell types. T2 - MATSUS Conference 2025 CY - Sevilla, Spain DA - 03.03.2025 KW - Battery KW - Sodium-Ion-Battery KW - Electrochemical Energy Storage KW - Energy Storage PY - 2025 AN - OPUS4-62932 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sander, Luise T1 - Linking Material and Electrode Properties to the Cell Performance of Commercially Available SIBs N2 - As the first commercial sodium-ion-batteries (SIBs) are available for purchase, it is possible to investigate material composition. Gaining an insight into the material composition of these SIBs is of interest not only for the classification of possible safety risks and hazards, but also in regards to recycling. Herein we report the preliminary investigations of the chemical and structural composition of first commercial SIB-cells.[1,2] Two different SIB-cell types were compared in terms of electrode size, thickness, loading etc. Furthermore, the composition of the active materials and electrolyte was investigated and compared. Finally, the gained results were linked to the different data sheet performance of the two cell types. T2 - Advanced Battery Power 2025 CY - Aachen, Germany DA - 01.04.2025 KW - Battery KW - Sodium-Ion-Battery KW - Electrochemical Energy Storage KW - Energy Storage PY - 2025 AN - OPUS4-62924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sander, Luise T1 - Comparison of Commercially Available SIBs: Linking Material and Electrode Properties to Cell Performance N2 - As the first commercial sodium-ion-batteries (SIBs) are available for purchase, it is possible to investigate material composition. Gaining an insight into the material composition of these SIBs is of interest not only for the classification of possible safety risks and hazards, but also in regards to recycling. Herein we report the preliminary investigations of the chemical and structural composition of first commercial SIB-cells. Two different SIB-cell types were compared in terms of electrode size, thickness, loading etc. Furthermore, the composition of the active materials and electrolyte was investigated and compared. Finally, the gained results were linked to the different data sheet performance of the two cell types. T2 - Batterieforum 2025 CY - Berlin, Germany DA - 21.01.2025 KW - Battery KW - Sodium-Ion-Battery KW - Electrochemical Energy Storage KW - Energy Storage PY - 2025 AN - OPUS4-62921 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pedersen, Angus T1 - Coupling Single Atom Electrocatalysts with a Bioreactor for CO2 to C2+ Conversion N2 - To alleviate CO2 emissions impact on climate change, and close the carbon cycle, converting carbon dioxide into valuable products such as multi-carbon organic chemicals is of great importance. Each approach offers distinct merits but also certain challenges in terms of process efficiency, product selectivity and implementation at scale. Developing coupled CO2 conversion systems, for instance bio-electrochemical reactors, can address some of the challenges.[1] Precious-metal free biocompatible single atoms in N-doped C (M-N-C, where M = Fe, Ni, Co) electrocatalysts, based on Mg active site imprinting of bioinspired MN4 sites,[2][3] have shown state-of-the-art activity and selectivity for conversion of CO2 to CO.[4] Pyrolysis of Mg-N-C is carried out in a salt-melt at high temperatures (≥ 800 oC) and followed by an exchange with stoichiometric amounts of Ni or Co at low temperatures. N2-sorption of the materials reveal a micro-mesoporous structure with high surface areas (> 1000 m2 g-1) and a mass-transport enabling pore system. Extended X-ray absorption fine structure reveal the existence of atomically dispersed single atom active sites with defined active site structure. These catalysts were implemented in a home-made bio-electrocatalytic system (BES) consisting of a bioreactor coupled to a CO2 electrolysis cell.[5] Here, CO2 is first electrochemically converted to CO in the electrolysis cell which is then directly fed to bacteria (Clostridium ragsdalei) in the bioreactor which further metabolize it to valuable carbon compounds, such as acetate. An acetate formation rate of 1.8 mg L-1 h-1 was achieved and an acetate concentration of 0.103 g L-1, corresponding to acetate formation rate of 0.73 mmol d-1. We have successfully demonstrated the validity of a coupled bio-electrocatalytic system operating with resource efficient single atom Co- and Ni-N-C electrocatalysts for CO2 conversion. T2 - Electrifying Organic Synthesis CY - Mülheim an der Ruhr, Germany DA - 03.09.2025 KW - Single atom KW - Electrochemical CO2 conversion KW - Bioelectrolysis PY - 2025 AN - OPUS4-64037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mehmood, Asad T1 - ZIF-derived Atomically Dispersed Non-precious Metal Catalysts (M-N-C) for Electrochemical Energy Applications N2 - Zeolitic imidazolate frameworks (ZIFs) which are a subtype of metal organic frameworks (MOFs) have been extensively used to prepare catalyst materials for a variety of electrochemical reactions for energy conversion and storage applications. Most notable examples of ZIFs used for that purpose include ZIF-8 and ZIF-67 etc. Particularly ZIF-8 with its high surface area, defined pore structure and tunable particle size is widely utilized as a platform material to prepare so-called metal- and nitrogen-doped carbon (M-N-C) catalysts with M= Co, Fe, Ni, Zn etc., which are an emerging class of catalyst materials and consist of nitrogen-doped porous carbon matrix hosting atomically distributed active metal sites.[1, 2] The active sites in M-N-Cs ideally have M-N4 coordination resembling to metal centres in macromolecules such as porphyrins and phthalocyanines.[3] Most representative examples of M-N-Cs include Fe-N-Cs, Co-N-Cs and Ni-N-Cs etc. which are showing promising activities for a variety of electrochemical reactions e.g. oxygen reduction reaction (ORR), carbon dioxide reduction reaction (CO2RR) and hydrogen evolution reaction (HER). The structures of M-N-C catalysts are quite complex and require a fine balance between morphological, electronic, and chemical properties to reach optimal electrocatalytic activities. In this talk, I will present our activities on (i) preparation of phase-pure M-N-C catalysts derived from ZIF-8 via active-site imprinting [4, 5] and highlight the benefits of our strategy to achieve high density of active sites and enhanced electrochemical performance levels [6] and (ii) feasibility of using gas physisorption techniques as a new approach to quantify active sites in M-N-Cs. The challenges of maximizing active site utilization and eliminating unfavourable mass-transport characteristics faced by ZIF-8 derived M-N-Cs in electrochemical energy devices e.g. fuel cells will also be briefly discussed. T2 - Materials for Sustainable Development Conference (MAT-SUS) CY - Sevilla, Spain DA - 03.03.20225 KW - Electrochemical energy conversion KW - Single atom catalysts KW - Electrochemical CO2 reduction KW - Fuel cells KW - Electrolyzers PY - 2025 DO - https://doi.org/https://doi.org/10.29363/nanoge.matsusspring.2025.251 AN - OPUS4-62927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Batteries: Basics, Challenges and Trends N2 - In this lecture the fundamental principles of batteries are briefly introduced aligned by the historical development of the technology. The introduction is continued with an overview on current challenges regarding performance, durability, sustainability, cost and safety. Lastly, research trend on approaches to tackle the challenges are discussed by selected examples. T2 - 2025 Scientific and Technological Training Course "Design and Evaluation Methods of Fire Safety Engineered Materials" CY - Hefei, China DA - 20.10.2025 KW - Fundamentals of Batteries KW - Safety KW - Active Materials KW - Research Topics PY - 2025 AN - OPUS4-64917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Appel, Paul Alexander T1 - Connecting Porosity to Storage Capacity: Core-Shell Carbon Material As High-Capacity Negative Electrodes for Sodium Ion Batteries N2 - Due to abundant raw materials, low costs and promising high reversible specific capacities, hard carbons (HCs) are a common choice for commercially manufactured anodes in sodium-ion batteries (SIBs). Despite their potential and extensive use, the storage mechanism is still under debate. The non-stoichiometric adsorption mechanism also means that the search for an upper limit for the reversible capacity is ongoing. There is a strong requirement for synthetic anodes that enable a better understanding of the theoretical capacity associated with HC-anodes. We have developed core-shell carbon anodes consisting of a highly porous carbon core and (almost) non-porous shell. Thus, the reversible capacity can be deconvoluted from irreversible capacity losses, arising from the formation of the solid electrolyte interphase (SEI). Moreover, the porosity of the carbon-core can be linked to the reversible capacities gained. A range of microporous activated carbons were coated via an optimized chemical vapour deposition technique.[1][2] These materials were characterised using a range of techniques including powder x-ray diffraction, small angle x-ray diffraction (SAXS), gas physisorption (N2, CO2) measurements and electrochemical characterisation at coin cell level. After coating, the material showed a significant reduction in detectable surface area (up to a factor of 192x) by N2-physisorption. The tailor-made shell allows the stable cycling of a carbon anode vs metallic Na-electrode in coin cells at room temperature. For the best performing material, the reversible capacity increased from 139 ± 2 mAhg-1 to 396 ± 2 mAhg-1 while irreversible capacity is decreased from 636 ± 3 mAhg-1 to 89 ± 3 mAhg-1 (see Figure 1). After initial stabilization, a CE of 99% was achieved. The coating technique was usefully applied to a range of materials. [3] The successful formation of core-shell structures with high capacities enables separation of the storage mechanism from SEI-formation. In turn a proposed calculation to rank the contributions of surface adsorption and pore filling capacity can be confirmed. The materials also create the opportunity to conduct a range of operando experiments (e.g., SAXS) that can shed further light on the sodium storage mechanism. T2 - ECS Montreal 2025 CY - Montreal, Canada DA - 18.05.2025 KW - Electrochemical Energy Materials KW - Negative Electrodes KW - Sodium Ion Batteries PY - 2025 AN - OPUS4-65115 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fellinger, Tim-Patrick T1 - Sicherheit von NIB und das Potenzial synthetischer Kohlenstoff-Anoden N2 - Nach einer kurzen Einleitung zu kommerziellen Natrium-Ionen-Batterien, deren Zusammensetzung und Sicherheitstest die auch an der BAM untersucht wurden, folgt eine Vorstellung der Forschungsarbeiten des Fachbereich 3.6 im Rahmen des Verbundprojekts Dialysorb. Die Forschungsergebnisse stellen u.a. das Potenzial von synthetischen Anodenmaterialien dar. T2 - Deutsches Batterieforum 2025 CY - Berlin, Germany DA - 21.01.2025 KW - Natrium-Ionen-Batterien KW - Zusammensetzung KW - Potenzial KW - Sicherheit KW - Synthetische Anoden PY - 2025 AN - OPUS4-64904 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Paul T1 - Designing Core-Shell Carbon Structures as High- Capacity Negative Electrodes for Sodium Ion Batteries N2 - Due to abundant raw materials, low costs and promising high reversible specific capacities, hard carbons (HCs) are a common choice for commercially manufactured anodes in sodium-ion batteries (SIBs). Despite their potential and extensive use, the storage mechanism is still under debate. The non-stoichiometric adsorption mechanism also means that the search for an upper limit for the reversible capacity is ongoing. There is a strong requirement for synthetic anodes that enable a better understanding of the theoretical capacity associated with HC-anodes. We have developed core-shell carbon anodes consisting of a highly porous carbon core and (almost) non-porous shell. Thus, the reversible capacity can be deconvoluted from irreversible capacity losses, arising from the formation of the solid electrolyte interphase (SEI). Moreover, the porosity of the carbon-core can be linked to the reversible capacities gained. A range of microporous activated carbons were coated via an optimized chemical vapour deposition technique.[1][2] These materials were characterised using a range of techniques including powder x-ray diffraction, small angle x-ray diffraction (SAXS), gas physisorption (N2, CO2) measurements and electrochemical characterisation at coin cell level. After coating, the material showed a significant reduction in detectable surface area (up to a factor of 192x) by N2-physisorption. The tailor-made shell allows the stable cycling of a carbon anode vs metallic Na-electrode in coin cells at room temperature. For the best performing material, the reversible capacity increased from 139 ± 2 mAhg-1 to 396 ± 2 mAhg-1 while irreversible capacity is decreased from 636 ± 3 mAhg-1 to 89 ± 3 mAhg-1 (see Figure 1). After initial stabilization, a CE of 99% was achieved. The coating technique was usefully applied to a range of materials. [3] The successful formation of core-shell structures with high capacities enables separation of the storage mechanism from SEI-formation. In turn a proposed calculation to rank the contributions of surface adsorption and pore filling capacity can be confirmed. The materials also create the opportunity to conduct a range of operando experiments (e.g., SAXS) that can shed further light on the sodium storage mechanism. T2 - MatSUS Conference Sevilla CY - Sevilla, Spain DA - 03.03.2025 KW - Electrochemical Energy Materials KW - Negative Electrodes KW - Sodium Ion Batteries PY - 2025 AN - OPUS4-65113 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Low, Jian Liang T1 - Elucidating the Intrinsic CO2RR performance at MN4 sites using Morphologically Comparable M-N-Cs N2 - Metal- and nitrogen-doped carbons (M-N-Cs) are a promising class of low-cost electrocatalysts derived from earth-abundant elements for various electrochemical applications including ORR and CO2RR [1,2]. Traditionally, M-N-Cs containing active metals (M = Fe, Co, and Ni) are synthesized through direct pyrolysis of inorganic and organic precursors. However, this process often leads to the undesired formation of inorganic side phases via carbothermal reduction, hindering both the efficient incorporation of active metal and the intrinsic activity comparison among active sites. To overcome these challenges, we developed an active-site imprinting strategy where active metals are introduced post-pyrolysis through ion-exchange [3-5]. In this work, we applied a Mg imprinting strategy to synthesize Co-N-Cs and Ni-N-Cs with comparable morphology and metal dopant concentrations, enabling a more direct comparison of their intrinsic activities. Notably, Ni-N-Cs produced via this method consistently demonstrated superior activity and selectivity compared to isomorphic Co-N-Cs, achieving CO Faraday efficiencies of up to 95% at relatively low overpotentials. Furthermore, the Ni-N-C catalyst exhibited excellent stability at -0.65 VRHE, retaining 92.5% of its current density and 97.6% of its CO selectivity after 100 hours of continuous operation. A distinct advantage of the imprinting strategy lies in the suppression of inorganic side phases, enabling an accurate local structure characterization of the porphyrin-like tetrapyrrolic MN4 coordination structure using Extended X-ray Absorption Fine Structure (EXAFS). The characterization of the tetrapyrrolic NiN4 site is especially puzzling, as density functional theory (DFT) simulations often predict these sites to be inert to both CO2RR and HER. Drawing on recent studies which highlight the crucial role of cations for CO2RR on noble metal catalysts like Cu, Ag and Au [6-7], we performed mechanistic investigations using DFT to extend the relevance of cations to the CO2RR/HER performance at the MN4 sites, and further illustrate the advantage of the pyrrolic N atoms in anchoring them near the active metals. T2 - 4th Conference of the GDCh Division of Chemistry and Energy CY - Duisburg, Germany DA - 09.04.2025 KW - Electrochemical CO2 reduction KW - Active-site imprinting KW - Metal- and Nitrogen-doped Carbon (M-N-C) KW - Single Atom Catalyst PY - 2025 AN - OPUS4-65145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Low, Jian Liang T1 - Mg-based Imprinting for Assessing Intrinsic Behavior of Co/Ni-N4 sites towards CO2RR N2 - Metal-and nitrogen-doped carbons (MN-Cs) represent a promising class of low cost electrocatalysts derived from nature-abundant elements for various electrochemical processes including CO 2 RR [1, 2]. Traditionally, MN-Cs containing active metals (M= Fe, Co, Ni) are synthesized by direct pyrolysis of inorganic and organic precursors, a process that often results in the undesired formation of inorganic side phases through carbothermal reduction, impeding the effective integration of active metals like Fe, Co and Ni. Furthermore, comparing the intrinsic activities of different MN-Cs can be complicated due to variations in catalyst morphology and active site concentration that arise during the pyrolysis. To address these challenges, we developed an active-site imprinting strategy in which active metals are introduced post-pyrolysis via ion-exchange [3-5]. In this work, we employed the Mg imprinting strategy to produce Co-N-Cs and Ni-N-Cs with comparable morphology and metal dopant concentration. Our approach allows for a more direct comparison of the intrinsic activities that arise from the metal dopant. The Ni-N-Cs derived this way are consistently higher in activity and selectivity than the corresponding Co-N-Cs, exhibiting a CO Faraday efficiency of up to 95% at potentials between-0.5 to-0.8 V RHE. The Ni-NC catalyst maintains high stability at-0.65 V RHE, with 92.5% retention of current density and 97.6% retention of CO selectivity after 100 hours of continuous operation. T2 - The Materials for Sustainable Development Conference (MATSUS) Spring Meeting 2025 CY - Seville, Spain DA - 03.03.2025 KW - Electrochemical CO2 reduction KW - Active-site imprinting KW - Metal- and Nitrogen-doped Carbon (M-N-C) KW - Single Atom Catalyst PY - 2025 AN - OPUS4-65144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Appel, Paul Alexander T1 - Developing Tailor-Made Core-Shell Carbon Negative Electrode Materials for Sodium Ion Batteries N2 - Hard carbons (HCs) are currently one of the most promising anode materials for sodium-ion batteries (SIBs). However, the Na storage mechanism remains controversial, leaving the theoretical limits of carbon anodes unclear. To deconvolute the specific capacity from irreversible capacity losses, resulting from the formation of solid electrolyte interphase (SEI), core-shell carbon materials were synthesized. Based on these core-shell materials, an investigation of the storage mechanism of sodium is possible. T2 - Batterieforum 2025 CY - Berlin, Germany DA - 21.01.2025 KW - Electrochemical Energy Materials KW - Negative Electrodes KW - Sodium Ion Batteries PY - 2025 AN - OPUS4-65110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sterr, Andrea A1 - Schwarz, Irina T1 - Valorization of Carbon Dioxide by Electrocatalytic Reduction Coupled to Acetogens via Multiple Electron Carriers (Ecat-Acetogens II) N2 - A Bioelectrochemical approach for reducing CO2 to fuels or value-added chemicals allows overcoming the limitations of a pure biochemical or electrochemical approach. A Bioelectrochemical system (BES) for this application has been developed in cooperation with TUM in the first project phase. BAM's contribution to the research focuses on the electrochemical side of the setup, mainly on the development of a suitable CO2RR catalyst for reducing CO2 to CO, which is then consumed by actogenic bacteria to produce further products. Single-metal-atom catalysts in a nitrogen-doped carbon matrix (M-N-Cs) are a promising, sustainable alternative to expensive rare-metal catalysts like Ag and Au. In this work, the first-generation catalyst, a ZIF-8-based Co-N-C is compared to a Mg salt mix templated Ni-N-C. In the new catalysts, the activity for CO2RR as well as the stability during BES operation could be enhanced. T2 - E-Biocat Statusupdate 2025 CY - Karlsruhe, Germany DA - 01.04.2025 KW - CO2RR KW - M-N-Cs KW - Bioelectrochemical System PY - 2025 AN - OPUS4-65143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Castells-Gil, Javier A1 - Zhu, Jinjie A1 - Itskou, Ioanna A1 - Wolpert, Emma H. A1 - Hunter, Robert D. A1 - Tidey, Jeremiah P. A1 - Pedersen, Angus A1 - Solvay, Elisa A1 - Tyrrell, Helen A1 - Petit, Camille A1 - Barrio, Jesús T1 - Impact of N-heterocyclic amine modulators on the structure and thermal conversion of a zeolitic imidazole framework N2 - The zeolitic imidazole framework-8 (ZIF-8) is a crystalline porous material that has been widely employed as template to fabricate porous nitrogen-doped carbons with high microporosity via thermal treatment at high temperatures. The properties of the carbon scaffold are influenced by the pore structure and chemical composition of the parent ZIF. However, the narrow pore size distribution and microporous nature from ZIF-8 often results in low mesopore volume, which is crucial for applications such as energy storage and conversion. Here we show that insertion of N-heterocyclic amines can disrupt the structure of ZIF-8 and dramatically impact the chemical composition and pore structure of the nitrogen-doped carbon frameworks obtained after high-temperature pyrolysis. Melamine and 2,4,6-triaminopyrimidine were chosen to modify the ZIF-8 structure owing to their capability to both coordinate metal ions and establish supramolecular interactions. Employing a wide variety of physical characterization techniques we observed that melamine results in the formation of a mixed-phase material comprising ZIF-8, Zn(Ac)6(Mel)2 and crystallized melamine, while 2,4,6-triaminopyrimidine induces the formation of defects, altering the pore structure. Furthermore, the absence of heterocyclic amine in the ZIF-8 synthesis leads to a new crystalline phase, unreported to date. The thermal conversion of the modified ZIFs at 1000 °C leads to nitrogen-doped carbons bearing Zn moieties with increased surface area, mesopore volume and varying degree of defects compared to ZIF-8 derived carbon. This work therefore highlights both the versatility of heterocyclic amines to modify the structure of framework materials as well as their role in tuning pore structure in nitrogen-doped carbons, paving the way to targeted design of high-performance electrodes for energy storage and conversion. KW - Zeolitic imidazole framework KW - Heterocyclic amine KW - Triaminopyrimidine PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639177 DO - https://doi.org/10.1039/D5TA04831A SN - 2050-7488 SP - 1 EP - 13 PB - Royal Society of Chemistry (RSC) AN - OPUS4-63917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braga, Daniel S. A1 - Pedersen, Angus A1 - Riyaz, Mohd A1 - Barrio, Jesús A1 - Bagger, Alexander A1 - Neckel, Itamar T. A1 - Mariano, Thiago M. A1 - Winkler, Manuel E. G. A1 - Stephens, Ifan E. L. A1 - Titirici, Maria‐Magdalena A1 - Nagao, Raphael T1 - In situ structural evolution and activity descriptor of atomically dispersed catalysts during nitrate electroreduction N2 - Single‐Atom Catalysts (SAC) have emerged as a promising class of materials for various catalytic applications, including the electrochemical nitrate reduction reaction (eNO3RR) and consequently ammonia production. While the efficiency and selectivity of these materials have been extensively highlighted for the eNO3RR, the in situ evolution to their structure and composition during electrocatalysis is largely unexplored and lacks catalyst design principles. To solve this, we investigated a series of high utilization metal‐nitrogen‐carbon (MNC) SACs (M = Cr, Fe, Co, Ni, and Cu) for eNO3RR. Except for CuNC, which selectively produced nitrite, all catalysts exhibited Faradaic efficiencies (FE) for ammonia exceeding 50%. NiNC demonstrated the highest performance (FE of 78.0 ± 2.9% at −0.4 V versus reversible hydrogen electrode (RHE) at pH 13 and maximum ammonia production rate of 615.7 ± 176.5 µmol·h−1·, corresponding to an energy efficiency of 15.1 ± 1.4% at −0.6 VRHE), followed by CoNC. In situ Synchrotron X‐ray fluorescence (SXRF) mapping at various cathodic potentials (from open circuit potential to 0.0 VRHE and then −0.6 VRHE at 100 mV steps) revealed significant mobility of Ni within the carbon matrix, leading to the formation of metallic clusters from 0.0 VRHE. Similar in situ metal clustering is observed for CoNC. Structure‐activity plots are generated from both MNC literature and results obtained here, finding a clear trend between OH binding energy and turnover frequency, with the high activity of NiNC and CoNC in this work explained by their stronger OH binding in the metallic structure compared to their SAC coordination. This work therefore, reveals the structure‐activity‐stability of MNCs for eNO3RR and provides a simple descriptor for identifying highly active eNO3RR catalysts and their in situ structural evolution. KW - Single atom KW - Nitrate reduction KW - Structure-activity-selectivity KW - In situ PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-640353 DO - https://doi.org/10.1002/advs.202510282 SN - 2198-3844 VL - 12 IS - 39 SP - 1 EP - 14 PB - Wiley-VCH CY - Weinheim AN - OPUS4-64035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Holistic Experimentation in the HExX-Lab N2 - Through bottom-up, comprehensive digitalisation of all aspects of an experiment, the HEX-lab improves the trustworthiness (traceability, reproducibility, quality) of scientific findings. The five main parts that make up a materials science experiment, i.e. Sample preparation, Measurements, Processing, Analysis, and Interpretation, each have been addressed in thorough and unique ways in this lab, building up a foundation for a wide range of materials science collaborations. Improvements span the spectrum. Hardware developments include new sample environments and stages, such as grazing incidence motion towers, electrochemistry cells and flow-through holders, electronic components such as safety interlocks and multipurpose I/O controllers, and liquid handling systems such as coolant flow cross-over systems. Software developments include: 1) a new comprehensive control system operating on both the RoWaN as well as the MOUSE allowing for full Python control and sequencing of all experimentation, 2) Automated scripts for instrument optimization, sample alignments and measurements, 3) revamped data pipelines and analysis software, standalone or launched as part of operations sequencing dashboards on servers, and 4) meticulously structured archival datafiles, fully documenting sample preparation, measurements, processing and analyses. These allow for holistic databases and dashboards to be constructed to investigate the links between synthesis parameters and resulting morphology. This poster will highlight some of the tools and techniques developed and available in the HEX-lab over the years, from sample environments to overarching experiment and data organisation structures. T2 - Materials Science Core Facility Synergy Forum 2025 CY - Bremen, Germany DA - 26.02.2025 KW - Digitalization KW - Holistic experiments KW - Traceability KW - Data provenance PY - 2025 AN - OPUS4-62675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -