TY - CONF A1 - Tichter, Tim T1 - Analytical solutions for the impedance of symmetrically distributed relaxation processes N2 - Distribution of relaxation times (DRT) analysis of impedance data is a powerful tool for unravelling entangled relaxation processes. However, reconstructing the DRT function from experimental data is an ill-posed inversion problem which suffers from noisy input and, hence, assigns a pseudo-signal to any kind of noise. To circumvent the resulting overfitting, different methods have been proposed, which are usually based on regularization. Alternatively, carefully selected distributed basis functions (e.g. Gauss-type, Cauchy-type, Matern-type) can be included in the algorithm of DRT reconstruction. This concept originates from the work of Cuicci and coworkers and has been implemented in their great software package DRT-tools. While this works exceptionally well for minimizing the demand on regularization, it must be kept in mind that the impedance of real-world relaxation processes of the constant phase element type is not represented by any of the resulting DRT functions. Bridging this gap was therefore the motivation for the present study. We derived analytical solutions for the impedance of several different types of distribution functions. The resulting impedances are compared with classical relaxation models and special features are pinpointed. The choice of an optimized basis function for reconstructing the DRT from experimentally acquired impedance data will improve electrochemical analysis in future work. Additionally, analytical solutions may be used for assigning a physical origin to the distributed behaviour in the impedance of certain types of electrodes. T2 - Bunsentagung CY - Leipzig, Germany DA - 17.03.2025 KW - Electrochemical Impedance Spectroscopy KW - Distribution of Relaxation Times KW - Cauchy Distribution KW - Gaussian Distribution KW - Cole-Cole Relaxation PY - 2025 AN - OPUS4-62894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scharpmann, Philippa T1 - Tracing overdischarge-induced degradation in lithium-ion cells using cyclic voltammetry and differential voltage analysis N2 - Differential voltage analysis (DVA) and cyclic voltammetry (CV) are powerful electroanalytical techniques. While CV can be used to study the kinetics of electron transfer reactions [1], DVA can visualise phase transitions by correlating the opencircuit voltage and exchanged charge [2]. Recently, DVA receives an increasing attention in the battery community for characterising full-cell setups. In contrast, CV is less prominent for batteries, yet the prevalently used technique for ex-situ characterisations of novel electrode materials in half-cell configuration. In this study, we have investigated the overdischarge process of LiFePO4 pouch cells – which is usually presumed to result in a decomposition of the solid electrolyte interphase (SEI) and a corrosion of the copper current collector – in a complementary electrochemical analysis which uses both, CV and DVA in full-cell mode. For this purpose, CV consisting of three low sweep-rate scans and DVA of three low current rate cycles was performed. Degradation was traced by successive CV/DVA sequences during, pre- and post-overdischarge which allowed to pinpoint the features, the limitations, and similarities of both techniques. In this manner, we demonstrate that CV can successfully identify the dynamics of degradation processes, indicating that an irreversible side reaction starts at cell voltages below 0.55 V. For this reason, this study underlines that CV can be effectively used for spotting dynamic degradation mechanisms which are hardy seen in DVA. This may pave the way for further analysis which can be used for fingerprinting characteristic degradation. T2 - 124. Bunsentagung 2025 CY - Leipzig, Germany DA - 17.03.2025 KW - Differential Voltage Analysis KW - Cyclic Voltammetry KW - Batteries PY - 2025 AN - OPUS4-65055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tichter, Tim A1 - Tichter, Alex A1 - Andrae, Dirk A1 - Roth, Christina T1 - Simulating cyclic voltammetry at rough electrodes by the digital-simulation–deconvolution–convolution algorithm N2 - The influence of electrode roughness on diffusional cyclic voltammetry (CV) is investigated from a theoretical perspective. For this purpose, the digital-simulation–deconvolution–convolution (DSDC) algorithm, initially developed for the simulation of CV at porous electrodes, is subjected to three substantial modifications. First, by employing adaptive numerical resolution and sample volumina, the computational demand of the digital simulation (DS) step is reduced significantly. Second, by modifying the Douglas–Gunn algorithm of the DS-step to operate on an arbitrarily incremented spatial grid perpendicular to the macroscopically planar electrode surface, the bulk of the fluid can be treated with an exponentially increasing spatial discretization which uses computational power even more efficiently. The third modification is an optimization of the computationally demanding deconvolution step which is used to extract the mass-transfer function from the data computed in the DS-step. This, initially recursive procedure, is replaced by a three-step sequence consisting of (I) a numerical Laplace transformation (NLT) on an exponentially expanding time-grid, (II) a Laplace-domain integration (LDI) and finally (III) a numerical inversion of Laplace transformation (NILT) using the Gaver–Stehfest (GS) inversion formula. Based on this novel strategy for CV simulation, the effects of electrode roughness are thoroughly investigated. It is demonstrated that for an ideally reversible reaction the effects of electrode roughness on the CV response are insignificant at common experimental timescales. In contrast, for scenarios with electrochemically quasi-reversible (or irreversible) kinetics, the apparent rate constants are allegedly upscaled by the area ratio 𝜓 = 𝐴rough∕𝐴planar . This manifests in a lower peak-to-peak separation without a distortion of the shape of the voltammetric profile. This behavior is finally explained in a quantitative manner in terms of convolution-sums and mass-transfer functions which ultimately puts the parameter electrode roughness into the semianalytical framework of convolutive modeling. KW - Rough electrodes KW - Electrode kinetics and Peak-to-Peak separation KW - Vanadium redox-flow batteries KW - Convolutive modeling KW - Digital-simulation KW - Numerical inversion of Laplace transformation KW - Gaver–Stehfest inversion formula PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614620 DO - https://doi.org/10.1016/j.electacta.2024.145175 VL - 508 SP - 1 EP - 17 PB - Elsevier B.V. AN - OPUS4-61462 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scharpmann, Philippa T1 - Exploring the effects of accelerated ageing on lithium- and sodium-ion cells N2 - Lithium-iron-phosphate (LFP) and sodium-ion batteries (SIBs) offer safe and cost-effective options for energy storage. In this study, the effects of continuous electrical stress, including high current loads and overdischarge, during cyclic ageing are investigated by tracing capacity loss and Coulombic efficiency during cycling of both cell types. Additionally, differential voltage analysis of pseudo open-circuit voltage discharges is utilised for degradation mode analysis. The results show that electrical stress accelerates degradation in both LFPs and SIBs, with high current rates potentially triggering plating or even cell failure in SIBs. Overdischarging primarily intensifies ageing by promoting accelerated solid electrolyte interphase growth. T2 - Doktorandenseminar der Technischen Universität Berlin CY - Berlin, Germany DA - 29.09.2025 KW - Lithium-ion -batteries KW - Sodium-ion-batteries KW - Electrical stress KW - Differential voltage analysis KW - Plating PY - 2025 AN - OPUS4-65057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scharpmann, Philippa T1 - Electrochemical characterisation of degradation mechanisms in lithium- and sodium-ion batteries during overdischarge N2 - Lithium-iron-phosphate (LFP) and sodium-ion batteries (SIBs) are promising technologies for energy storage systems due to their safe handling and cost-effectiveness. SIBs can be discharged to 0V without the safety concerns associated with lithium-ion batteries' copper current collector oxidation. However, overdischarging both types of batteries may decompose and subsequently rebuild the solid electrolyte interphase (SEI), leading to irreversible capacity loss and degradation. This study performs an in-situ analysis of the overdischarge process of LiFePO4 pouch and Na-ion cylindrical cells. Therefore, the cells are characterised for three low C-rate constant current or three slow-scan voltage cycles. While the voltage range of the manufacturer’s specifications is chosen for the first and third cycle, for the second cycle the minimum voltage is modified to 0.5V (LFP) and 0V (SIB), respectively. This enables tracing the degradation during the overdischarge, as well as through a comparison of the results pre- and post-overdischarging. For this purpose, the study employs two electrochemical characterisation techniques: differential voltage analysis (DVA) and cyclic voltammetry (CV). While cyclic voltammetry allows for the study of the kinetics of electron transfers [1], DVA enables the assessment of lithium distribution homogeneity and capacity degradation [2]. In both cells, the characterisation shows significant differences before and after overdischarging, indicating lasting changes through the decomposition and rebuilding of the SEI. This comparative study elucidates the overdischarge-induced degradation in sodium- and lithium-ion batteries, highlighting the utility of CV and DVA in analysing degradation mechanisms. T2 - Advanced Battery Power CY - Aachen, Germany DA - 02.04.2025 KW - Battery degradation KW - Overdischarge KW - Solid electrolyte interphase PY - 2025 AN - OPUS4-65056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita T1 - Lithiumbatterien - Transport und Sicherheit N2 - Regularien und Anforderungen (zum Transport) von Lithiumbatterien. T2 - 6. Photovoltaik-Betriebs- und Sicherheitstagung CY - Berlin, Germany DA - 24.11.2022 KW - Lithiumbatterien KW - Regularien KW - Energiespeicher KW - Transport PY - 2022 AN - OPUS4-56744 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita T1 - Neue Regeln - Klassifizierungsregeln: Was tut sich auf UN-Ebene? - TRGS 520: Es tut sich etwas auf nationaler Ebene N2 - Die Entwicklungen der Regelwerke auf nationaler und internationaler Ebene werden vorgestellt. Die BAM ist hier beteiligt und trägt mit zahlreichen Versuchsergebnissen bei, die hier erläutert werden. T2 - Fachkonferenz Lithiumbatterien CY - Göttingen, Germany DA - 23.01.2023 KW - Lithiumbatterien KW - Prüfung KW - Regelwerksentwicklung PY - 2023 AN - OPUS4-59275 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita T1 - Safety in transport of Li-ion batteries N2 - Safety in transport is the pre-requisite for bringing Lithium-ion batteries on the market. In order to consider the different types and degree of hazards, UN has set out to define a new classification system based on testing. BAM has participated in the test rounds and presents here the results. T2 - Technical Workshop on Advanced Materials Challenges and Standardisation Needs for Net Zero Technologies (AMCSNZT-2023) CY - New Delhi, India DA - 09.10.2023 KW - Lithium-ion batteries KW - Propagation testing KW - Safety PY - 2023 AN - OPUS4-59274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita T1 - Lithiumbatterien im Seeschiffsverkehr: lassen sich zukünftig Brände verhindern? N2 - Ausgehend von der Vielzahl an Bränden im Seeverkehr, die Lithiumbatteriebränden zugeschrieben werden, wird betrachtet, wie ein sichererer Transport von Lithiumbatterien im Seeverkehr erfolgen kann und inwiefern die BAM durch Ihre Mitarbeit in der Regelwerksentwicklung und Forschung dazu beiträgt. T2 - KLIB Mitgliederforum CY - Frankfurt am Main, Germany DA - 19.03.2024 KW - Lithiumbatterien KW - Gefahrguttransport KW - Seeverkehr KW - Sicherheit PY - 2024 AN - OPUS4-62324 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tichter, Tim T1 - Simulating diffusional cyclic voltammetry at rough electrodes by means of the DSDC algorithm N2 - Electrode roughness is an exceptionally important, yet oftentimes overlooked factor in electrokinetic analysis and catalyst research. Essentially any electroanalytical experiment involving an electrode with a surface which is not perfectly smooth will be subjected to more or less severe effects of roughness. This includes any circumstance where electrodes are decorated with micro- or nanoparticles and is therefore relevant for a plethora of experimental scenarios. Since the roughness-related gain in surface area scales the reaction rate – and thus the current – it is an inherently non-straightforward task to assess intrinsic electrode kinetics from experimental data of rough structures. In other words, a significant overestimation of kinetic constants may arise when rough electrodes are employed and kinetics are analyzed under the assumption of perfectly planar surfaces. For this reason, it is fundamentally interesting to approach electrode roughness from a purely theoretical point of view, since surface roughness and kinetics can be tuned in a deliberate manner for separating their individual contributions. In this study, we propose a strategy for the simulation of the most common electroanalytical technique – cyclic voltammetry – at mesoscopically rough surfaces. For this purpose, our previously introduced digital simulation - deconvolution - convolution (DSDC) algorithm [1] is employed. By modifying, the Douglas--Gunn algorithm, which is used in the digital simulation step to operate on an arbitrarily incremented spatial grid, a high numerical resolution near the electrode/electrolyte boundary and a larger spatial discretization in the bulk of the electrolyte can be used. This provides a fine resolution of artifacts of surface roughness and efficiently utilizes computational power. As a consequence, simulations can be performed on real-space data of rough electrodes which is obtained from atomic force microscopy (AFM). It is demonstrated that for an ideally reversible reaction the effects of electrode roughness on the CV response are insignificant. In contrast, for practically relevant scenarios with electrochemically irreversible or quasi-reversible kinetics, the apparent rate constants are allegedly upscaled by the area-ratio Arough/Aplanar up to a certain threshold. Qualitatively, this manifests in a lower peak-to-peak separation without a distortion of the shape of the voltammetric profile. As soon as the surface profile becomes much deeper than wide, a distortion of the CV response occurs which is associated with an increasingly finite diffusion domain. This behavior is finally explained in terms of convolution-sums and mass-transfer functions and provides a quantitative interpretation of roughness effects. T2 - Electrochemistry 2024 CY - Braunschweig, Germany DA - 16.09.2024 KW - Rough electrodes KW - Convolutive Modeling KW - Digital Simulation KW - Cyclic voltammetry KW - Redox-Flow Batteries PY - 2024 AN - OPUS4-62308 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tichter, Tim T1 - Frühwarnsystem für EV-Batterien: Prädiktion des Thermischen Durchgehens von Lithium-Ionen-Speichern N2 - Kritisch defekte Lithium-Ionen Batterien bergen ein signifikantes Gefährdungspotenzial, da die Möglichkeit eines so genannten thermischen Durchgehens (TD) besteht. Dabei handelt es sich um eine autoamplifizierende Reaktion, welche zu einer unkontrollierten Erwärmung mit Rauch- und Flammenerscheinung oder gar einer Explosion führt. Insbesondere bei großen Batterien mit einer Kapazität von über 100 kWh, stellt ein TD ein sehr großes Schadensereignis dar. Folglich gilt es, dieses Ereignis strikt zu vermeiden. Im Rahmen der Präsentation werden aktuelle Arbeiten der BAM im Bereich der TD-Früherkennung vorgestellt. T2 - Gefahrguttag 2024 CY - Hannover, Germany DA - 19.09.2024 KW - Thermisches Durchgehen KW - Lithium-Ionen Batterien KW - Automotive Anwendungen PY - 2024 AN - OPUS4-62309 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita T1 - Natrium-Ionen Batterien N2 - Der Bedarf an Forschung der Bundesoberbehörden zu Natrium-Batterien als neues Thema wurde identifiziert. Hier kann die BAM jedoch bereits zahlreiche Untersuchungen im Rahmen des BAM-internen Projekts "SIB-Links" vorweisen. T2 - BoB Bundes-Oberbehörden CY - Online meeting DA - 10.06.2024 KW - Natrium-Ionen Batterien PY - 2024 AN - OPUS4-62325 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita T1 - Lithiumbatterien - Transport und Sicherheit N2 - Fachwissen zum Transport und sicherem Umgang mit Lithiumbatterien ist eine essentielle für die Arbeit der Gefahrgutbeauftragten der Polizei. Dabei geht e nicht nur um selbstgenutzte Geräte sondern häufig auch um sichergestellte und möglicherweise beschädigte Geräte / Akkus. Diese müssen bestmöglich vor Datenverlust bewahrt werden, gleichzeitig ist die Sicherheit für die zuständigen Mitarbeiter unabdingbar. Der Vortrag dient dazu, die Zuhörer in die Lage zu versetzen, fallbezogene Entscheidungen für Maßnahmen für den sicheren Umgang und den Transport zu treffen. T2 - Polizeiakademie Niedersachsen Gefahrgutbeauftragte CY - Dannenberg, Germany DA - 10.12.2024 KW - Lithiumbatterien KW - Gefahrguttransport KW - Lagerung PY - 2024 AN - OPUS4-62331 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita A1 - Moench, Lars A1 - Rausch, Talea T1 - Vorstellung des Berichtes Batteriezellenherstellung des Arbeitskreises Elektrische Energiespeichersysteme der Kommission für Anlagensicherheit N2 - In der Kommission Anlagensicherheit (KAS) Arbeitsgruppe Elektrische Energiespeicher wurde ein Bericht erstellt, der den Stand der Technik für die Batteriezellproduktion in Deutschland widerspiegelt und die Einstufung nach Störfallverordnung mittels einer Liste aller enthaltenen Stoffe ermöglicht. Dieser wird vorgestellt und die Anwendung der maßgeblich durch die BAM erstellte Liste erläutert. T2 - UBA Fachbereichgespräch CY - Online meeting DA - 24.10.2024 KW - Störfallverordnung KW - Batterie-Zellproduktion KW - LIthiumbatterien KW - Anlagensicherheit PY - 2024 AN - OPUS4-62327 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dayani, Shahabeddin A1 - Markötter, Henning A1 - Krug von Nidda, Jonas A1 - Schmidt, Anita A1 - Bruno, Giovanni T1 - Quantification of the Deep Discharge Induced Asymmetric Copper Deposition in Lithium‐Ion Cells by Operando Synchrotron X‐Ray Tomography N2 - AbstractLithium‐ion cells connected in series are prone to an electrical safety risk called overdischarge. This paper presents a comprehensive investigation of the overdischarge phenomenon in lithium‐ion cells using operando nondestructive imaging. The study focuses on understanding the behavior of copper dissolution and deposition during overdischarge, which can lead to irreversible capacity loss and internal short‐circuits. By utilizing synchrotron X‐ray computed tomography (SXCT), the concentration of dissolved and deposited copper per surface area is quantified as a function of depth of discharge, confirming previous findings. The results also highlight for the first time a nonuniform distribution pattern for copper deposition on the cathode. This research provides insights for safer battery cell design. KW - Lithium Ion Batteries KW - Deep Discharge KW - Computer Tomography KW - Copper Deposition KW - Litium Ion Cells PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-592717 DO - https://doi.org/10.1002/admt.202301246 SP - 1 EP - 7 PB - Wiley AN - OPUS4-59271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Böttcher, Nils A1 - Dayani, Shahabeddin A1 - Markötter, Henning A1 - Bau, Alexander A1 - Setzchen, Max A1 - Schmidt, Anita A1 - Kowal, Julia A1 - Krug von Nidda, Jonas T1 - High Precision Nail‐Penetration Setup for the Controlled Thermal Runaway Initiation of Lithium‐Ion Cells at Very Low Temperatures N2 - A high precision nail‐penetration (NP) tool for characterizing the mechanically induced thermal‐runaway (TR) of lithium‐ion battery (LIB) cells in a defined range of temperatures down to −140 °C was developed. To understand the cell specific behavior at low temperatures aiming at the determination of safe handling conditions, different scenarios are analyzed. First, accuracy tests of the NP‐tool regarding motion and penetration depth are conducted with cylindrical cells at different temperatures. Thus, postmortem computer tomographic (CT) images are compared to the data measured with the newly integrated 3‐axis force sensor which is further combined with a high‐resolution position sensor. The herein developed setup allows evaluation of the NP‐metrics at an accuracy of ±1 pierced electrode layer without CT‐scans. Further NP examinations at 20 °C of fully charged cylindrical lithium nickel manganese cobalt oxide cells reveal a reproducible minimum damage as a reliable TR‐trigger. Moreover, NP‐tests at low temperature disclose a relation of the short circuit conductivity and TR‐reactions during subsequent rethermalization to room temperature. Finally, the implementation of a novel fixture for a controlled very fast cooling of LIB‐cells during critical damage opens the way to investigate the individual steps during a TR and, thus, to gain important information of the specific TR‐mechanism of different LIB‐cells. KW - Battery Safety KW - High-precision nail penetration KW - Lithium-ion batteries KW - Abuse testing KW - Thermal runaway PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598127 DO - https://doi.org/10.1002/ente.202301379 SN - 2194-4288 SP - 1 EP - 13 PB - Wiley VHC-Verlag AN - OPUS4-59812 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Leonhardt, Robert A1 - Böttcher, Nils A1 - Dayani, Shahabeddin A1 - Rieck, Arielle A1 - Markötter, Henning A1 - Schmidt, Anita A1 - Kowal, Julia A1 - Tichter, Tim A1 - Krug von Nidda, Jonas T1 - Exploring the electrochemical and physical stability of lithium-ion cells exposed to liquid nitrogen N2 - The transport and storage of lithium-ion (Li-ion) batteries — damaged or in an undefined state — is a major safety concern for regulatory institutions, transportation companies, and manufacturers. Since (electro)chemical reactivity is exponentially temperature-dependent, cooling such batteries is an obvious measure for increasing their safety. The present study explores the effect of cryogenic freezing on the electrochemical and physical stability of Li-ion cells. For this purpose, three different types of cells were repeatedly exposed to liquid nitrogen (LN2). Before and after each cooling cycle, electrical and electrochemical measurements were conducted to assess the impact of the individual freezing steps. While the electrochemical behavior of the cells did not change significantly upon exposure to LN2 , it became apparent that a non-negligible number of cells suffered from physical changes (swelling) and functional failures. The latter defect was found to be caused by the current interrupt device of the cylindrical cells. This safety mechanism is triggered by the overpressure of expanding nitrogen which enters the cells at cryogenic temperatures. This study underlines that the widely accepted reversibility of LN2 -cooling on a material scale does not allow for a direct extrapolation toward the physical integrity of full cells. Since nitrogen enters the cell at cryogenic temperatures and expands upon rethermalization, it can cause an internal overpressure. This can, in turn, lead to mechanical damage to the cell. Consequently, a more appropriate temperature condition — less extreme than direct LN2 exposure — needs to be found KW - Lithium-ion battery KW - LN2 cooling KW - Battery characterization PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599248 DO - https://doi.org/10.1016/j.est.2024.111650 VL - 89 SP - 1 EP - 7 PB - Elsevier B.V. AN - OPUS4-59924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Böttcher, Nils A1 - Dayani, Shahabeddin A1 - Markötter, Henning A1 - Schmidt, Anita A1 - Kowal, J. A1 - Lu, Y. A1 - Krug von Nidda, Jonas A1 - Bruno, Giovanni T1 - Visualization of stepwise electrode decomposition in a nail penetrated commercial lithium-ion cell using low-temperature synchrotron X-ray computed tomography N2 - The transition towards zero carbon emissions in power generation hinges on the integration of efficient electrical energy storage systems, with lithium-ion batteries (LIBs) positioned as a pivotal technology. While generally safe, deviations in their operational guidelines due to manufacturing defects or misuse can lead to critical safety concerns, notably thermal runaway (TR) events. Internal short circuits (ISCs) are primary initiators of TR within LIBs. For abuse testing, ISCs are often triggered by nail penetration. This study explores the morphological changes and mechanisms underlying ISC-induced TR in LIBs using operando synchrotron X-ray computed tomography (SXCT) at subzero temperatures. A novel cryogenic setup was developed to control a stepwise temperature increase in the damaged sample while monitoring electrochemical characteristics and simultaneously enabling acquisition of high-resolution SXCT images. The findings reveal that conducting nail penetration at minus 80°C prevents immediate TR, enabling detailed analysis of subsequent structural and electrochemical behavior during controlled thawing. Thus, the initiation of TR processes at localized ISC sites has been observed, evidenced by voltage fluctuations and morphological changes, such as cathode material cracking and decomposition. These results underscore the importance of temperature control in mitigating TR risks and provide critical insights into the internal dynamics of LIBs under abusive conditions. The developed cryogenic SXCT methodology offers a powerful tool for non-destructive, high-resolution investigation of battery failure mechanisms, contributing to the enhancement of LIB safety. KW - Tomography KW - X-ray imaging KW - Lithium-ion battery PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611327 DO - https://doi.org/10.1016/j.jpowsour.2024.235472 VL - 623 SP - 1 EP - 10 PB - Elsevier CY - New York, NY AN - OPUS4-61132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krug von Nidda, Jonas T1 - Hazard-Based Classification of Lithium-Ion Cells and Batteries N2 - Next to performance features, safety aspects of lithium-ion batteries (LIBs) are a crucial research field. The abuse/misuse of a LIB can trigger a chain of exothermic reactions on cell level. Hence, the cell temperature increases dramatically, causing the so-called thermal runaway (TR). Moreover, the TR of one cell can initiate the TR of adjacent cells leading to a TR-propagation. Due to the risk of a TR, special measures need to be applied while handling, storing, and transporting batteries. According to current transport regulations, all different types of lithium-ion and lithium metal cells/batteries (by means of cell format, cathode chemistry, etc.) require the same transport conditions regardless of the intensity of their reaction during abuse tests. To allow more differentiated transport requirements, the United Nations (UN) Subcommittee Transport of Dangerous Goods created an Informal Working Group (IWG) on the topic of a hazard-based classification of LIBs. BAM is one of nine laboratories working on the development of a respective classification scheme including appendant test protocols. Herein, we discuss the latest results of our safety tests on commercial LIB-cells employing the test protocols developed in the UN-IWG. Single cell tests are analysed regarding different hazardous features during the TR, e.g., cell temperature, flame occurrence, and gas amount. Next to the general occurrence of a propagation, the propagation speed is analysed by propagation tests. In total, the presented results are gathered from over 200 tests. Next to the classification of the tested cells, the data set obtained is analysed in respect to the cells’ key features, such as cell energy, state of charge and cathode type. Generally, the presented results can increase the overall understanding of the TR-mechanism supporting the design of advanced safety measures on cell level in the future. T2 - International Battery Safety Workshop CY - Ulm, Germany DA - 28.09.2023 KW - Battery Classification KW - Safe Transport KW - Thermal Runaway KW - Lithium Ion Batteries PY - 2023 AN - OPUS4-59269 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 - JOUR A1 - Scharpmann, Philippa A1 - Leonhardt, Robert A1 - Schmidt, Anita A1 - Kowal, Julia A1 - Tichter, Tim A1 - Krug von Nidda, Jonas T1 - Exploring restrictive overdischarge cycling as a method to accelerate characteristic ageing in lithium-ion cells N2 - This study presents a test protocol that greatly accelerates the ageing process of lithium-ion battery cells comprising a positive electrode of nickel manganese cobalt oxide while preserving their characteristic degradation upon cyclic ageing. Applying a repetitive restricted overdischarge, resulting in a depth of discharge larger than 100%, a capacity loss of 20% is achieved over five times faster compared to conventional cycling. The well-known overdischarge degradation phenomenon of copper current collector dissolution is deliberately prevented by setting a discharge cutoff voltage above the theoretical threshold of copper oxidation. Hence, the accelerated degradation can be primarily connected to solid electrolyte interphase growth. A comparative assessment of the ageing dynamics using electrochemical impedance spectroscopy and differential voltage analysis hints towards similar, characteristic degradation processes during accelerated and conventional ageing. A post-ageing examination of the electrical behaviour (i.e., coulombic and energy efficiency, capacity fade) under reference conditions reveals very little to no lasting damages caused by overdischarging. Additionally, post-mortem analysis discloses no increased copper dissolution when comparing cells subjected to accelerated and conventional ageing. Generally, the developed ageing method appears suitable for providing cells with a defined state of health at a reasonable timescale without altering the main degradation mechanisms significantly. KW - Lithium-ion cell KW - Accelerated ageing KW - Overdischarge KW - Degradation processes KW - Differential voltage analysis KW - Electrochemical impedance spectroscopy PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650917 DO - https://doi.org/10.1016/j.jpowsour.2025.239072 SN - 0378-7753 VL - 665 SP - 1 EP - 9 PB - Elsevier B.V. AN - OPUS4-65091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leonhardt, Robert T1 - Characterization of overdischarge-related degradation in commercial sodium-ion cells N2 - Sodium-ion batteries (SIBs) have recently gained significant attention as a cost-effective and sustainable alternative to lithium-ion batteries for large-scale energy storage applications and battery-electric vehicles. With their ability to be fully discharged to 0 V, they allow much safer handling and transport. The reversibility of such a complete discharge is, however, debated as the solid electrolyte interphase (SEI) formed by commonly used electrolytes in SIBs becomes unstable at low full-cell voltages. In the present study, the effects of overdischarging SIBs and the implications on their long-term impedance degradation are investigated for commercial SIB-cells, comprising sodium nickel manganese iron oxide (NaNi0.33Mn0.33Fe0.33O2) as cathode active material. During the study, extensive characterization measurements (e.g., electrochemical impedance spectroscopy, open-circuit voltage analysis, etc.) were performed at various stages of degradation. This allows the monitoring of the electrochemical characteristics of the tested SIBs. Notably, the long-term degradation behavior of the cells was significantly affected, indicating lasting changes in the passivating properties of the altered SEI. Finally, the results show that overdischarging can indeed cause irreversible changes in sodium-ion batteries, emphasizing the need to enhance their stability at low full-cell voltages to make the best possible use of their potential safety features. T2 - SBS6 – International Sodium Battery Symposium CY - Dresden, Germany DA - 03.09.2025 KW - Overdischarge of sodium ion batteries KW - Solid electrolyte interphase KW - Impedance spectroscopy KW - Battery degradation and aging PY - 2025 AN - OPUS4-65066 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 - Leonhardt, Robert T1 - Deconvoluting the impact of early-life abuse conditions on the degradation of lithium-ion cells N2 - The successful repurposing of degraded lithium-ion (Li-ion) batteries in second-life applications is a vital step towards achieving a circular economy. While reusing aged Li-cells is a promising way of mitigating their overall environmental footprint, it is crucial to anticipate their future safety and performance characteristics . Unfortunately, predicting these properties is a cumbersome task, essentially caused by limited knowledge of the interference of different degradation modes in the cells’ first life. To still enable estimating of these parameters from a current state, the present study systematically investigates the impacts of abusive conditions in an early phase of the cells’ life on their subsequent degradation behavior. For this purpose, individual Li-cells are initially stressed by different measures such as overcharging, deep-discharging, plating, and deliberate combinations of the aforementioned methods. Electrochemical performance indicators are monitored during subsequent cycling of the cells which provides insights into the interdependencies of different degradation modes induced by specific stress conditions. In this manner, it is clarified whether or not the total degradation can be determined by a convolution or a superposition of individual deterioration effects and, thus, be described as a multidimensional state function. This knowledge will finally contribute to a better understanding of the performance and safety behavior of degraded Li-ion batteries which can help to successfully implement them into second-life applications. T2 - ECS Gothenburg CY - Gothenburg, Sweden DA - 08.10.2023 KW - Li-ion batteries KW - Early-life overstress KW - Ageing PY - 2023 AN - OPUS4-59221 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leonhardt, Robert T1 - Exploring the safety behavior of lithium-ion cells aged at elevated temperatures N2 - Understanding the safety characteristics of aged Lithiumion (Li-ion) batteries is essential for their effective integration into second-life applications. The SafeLiBatt project is a research initiative focused on evaluating safety-related parameters of these batteries. The presented study elucidates the impact of a cells’ state of health (SOH) on its safety behavior. Four highpower pouch cells (Li-NMC622) were exposed to elevated temperatures to achieve accelerated ageing. Subsequent thermal abuse tests were utilized to assess crucial parameters related to the thermal runaway (TR). When compared to their non-aged (begin of life, BOL) analogs, the aged cells implicated a TR-onset lowered by about 10 – 20 K. T2 - Advanced Battery Power 2023 CY - Aachen, Germany DA - 26.04.2023 KW - li-ion batteries KW - ageing KW - battery ageing PY - 2023 AN - OPUS4-59220 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 - Böttcher, Nils T1 - Determination of safe handling and transport conditions of critically damaged lithium battery cells at low temperatures N2 - Lithium batteries are the key technology for the successful implementation of the energy transition. Nevertheless, the consequences of thermal runaway of lithium batteries pose the greatest safety risk. In particular, the transport of damaged lithium batteries poses special challenges in order to minimize the effects of thermal runaway. By developing a precision nail test rig, the positive effects of cooling damaged lithium batteries can be investigated and safe transport temperatures identified. T2 - Advanced Battery konference CY - Aachen, Germany DA - 26.04.2023 KW - Lithium-Ion Battery Safety and Testing PY - 2023 AN - OPUS4-59207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Menga, D. A1 - Low, J. L. A1 - Li, Y.-S. A1 - Arcon, I. A1 - Koyutürk, B. A1 - Wagner, F. A1 - Ruiz-Zepeda, F. A1 - Gaberscek, M. A1 - Paulus, B. A1 - Fellinger, Tim-Patrick T1 - Resolving the Dilemma of Fe-N-C Catalysts by the Selective Synthesis of Tetrapyrrolic Active Sites via an Imprinting Strategy N2 - Combining the abundance and inexpensiveness of their constituent elements with their atomic dispersion, atomically dispersed Fe−N−C catalysts represent the most promising alternative to precious-metal-based materials in proton Exchange membrane (PEM) fuel cells. Due to the high temperatures involved in their synthesis and the sensitivity of Fe ions toward carbothermal reduction, current synthetic methods are intrinsically limited in type and amount of the desired, catalytically active Fe−N4 sites, and high active site densities have been out of reach (dilemma of Fe−N−C catalysts). We herein identify a paradigm change in the synthesis of Fe−N−C catalysts arising from the developments of other M−N−C single-atom catalysts. Supported by DFT calculations we propose fundamental principles for the synthesis of M−N−C materials. We further exploit the proposed principles in a novel synthetic strategy to surpass the dilemma of Fe−N−C catalysts. The selective formation of tetrapyrrolic Zn−N4 sites in a tailor-made Zn−N−C material is utilized as an active-site imprint for the preparation of a corresponding Fe−N−C catalyst. By successive low- and high-temperature ion exchange reactions, we obtain a phase-pure Fe−N−C catalyst, with a high loading of atomically dispersed Fe (>3 wt %). Moreover, the catalyst is entirely composed of tetrapyrrolic Fe−N4 sites. The density of tetrapyrrolic Fe−N4 sites is more than six times as high as for previously reported tetrapyrrolic single-site Fe−N−C fuel cell catalysts. KW - Fe-N-C catalyst KW - Precious-group metal-free catalyst KW - Tetrapyrrolic active-site KW - Single-site catalyst KW - Fuel cell KW - Carbon materials PY - 2021 DO - https://doi.org/10.1021/jacs.1c04884 SN - 1520-5126 VL - 143 IS - 43 SP - 18010 EP - 18019 PB - American Chemical Society AN - OPUS4-53657 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koyutürk, B. A1 - Farber, E. A1 - Wagner, F. A1 - Fellinger, Tim-Patrick A1 - Eisenberg, D. T1 - A simple decagram-scale synthesis of an atomically dispersed, hierarchically porous Fe–N–C catalyst for acidic ORR N2 - Carbons doped with iron and nitrogen (Fe–N–Cs) are highly promising electrocatalysts for energy conversion reactions in the oxygen, nitrogen and carbon cycles. Containing no platinum group metals, they nevertheless compete with platinum-based catalysts in crucial fuel cell reactions, such as oxygen reduction in acid. Yet deployment of Fe–N–Cs in fuel cells requires also a flow-enhancing pore structure, and a scalable synthesis procedure – a rarely-met combination of requirements. We now report such a simple synthesis of over 10 g of an Fe–N–C catalyst with high activity towards oxygen reduction in acid. Atomically-dispersed Fe–N4 active sites were designed orthogonally and simultaneously with hierarchical micro-, meso- and macroporosity, by exploiting a dual role of magnesium ions during pyrolysis. Combining the “active site imprinting” and “self-templating” strategies in a single novel magnesium iminodiacetate precursor yielded a catalyst with high specific surface area (SSA > 1600 m2 g−1), a flow-enhancing hierarchical porosity, and high relative abundance of the most desirable D1-type Fe–N4 sites (43%, by Mössbauer spectroscopy at 4.2 K). Despite the relatively low iron contents, the catalysts feature halfwave potentials up to 0.70 V vs. RHE at pH 1 and a mass activity of 1.22 A g−1 at 0.8 V vs. RHE in RDE experiments. Thanks to the simple and scalable synthesis, this active and stable catalyst may serve as a workhorse in academic and industrial research into atomically-dispersed ORR electrocatalysis. KW - Catalysis KW - Fe-N-C catalysts KW - Fuel Cells KW - Electrochemistry PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550113 DO - https://doi.org/10.1039/d2ta00925k SN - 2050-7488 SP - 1 EP - 10 PB - Royal Society of Chemistry AN - OPUS4-55011 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Titirici, M. A1 - Baird, S. G. A1 - Sparks, T. D. A1 - Yang, S. M. A1 - Brandt-Talbot, A. A1 - Hosseinaei, O. A1 - Harper, D. P. A1 - Parker, R. M. A1 - Vignolini, S. A1 - Berglund, L. A. A1 - Li, Y. A1 - Gao, H.-L. A1 - Mao, L.-B. A1 - Yu, S.-H. A1 - Díez, N. A1 - Ferrero, G. A. A1 - Sevilla, M. A1 - Szilágyi, P. Á. A1 - Stubbs, C. J. A1 - Worch, J. C. A1 - Huang, Y. A1 - Luscombe, C. K. A1 - Lee, K.-Y. A1 - Luo, H. A1 - Platts, M. J. A1 - Tiwari, D. A1 - Kovalevskiy, D. A1 - Fermin, D. J. A1 - Au, H. A1 - Alptekin, H. A1 - Crespo-Ribadeneyra, M. A1 - Ting, V. P. A1 - Fellinger, Tim-Patrick A1 - Barrio, J. A1 - Westhead, O. A1 - Roy, C. A1 - Stephens, I. E. L. A1 - Nicolae, S. A. A1 - Sarma, S. C. A1 - Oates, R. P. A1 - Wang, C.-G. A1 - Li, Z. A1 - Loh, X. J. A1 - Myers, R. J. A1 - Heeren, N. A1 - Grégoire, A. A1 - Périssé, C. A1 - Zhao, X. A1 - Vodovotz, Y. A1 - Earley, B. A1 - Finnveden, G. A1 - Björklund, A. A1 - Harper, G. D. J. A1 - Walton, A. A1 - Anderson, P. A. T1 - The sustainable materials roadmap N2 - Our ability to produce and transform engineered materials over the past 150 years is responsible for our high standards of living today, especially in the developed economies. Yet, we must carefully think of the effects our addiction to creating and using materials at this fast rate will have on the future generations. The way we currently make and use materials detrimentally affects the planet Earth, creating many severe environmental problems. It affects the next generations by putting in danger the future of economy, energy, and climate. We are at the point where something must drastically change, and it must change NOW. We must create more sustainable materials alternatives using natural raw materials and inspiration from Nature while making sure not to deplete important resources, i.e. in competition with the food chain supply. We must use less materials, eliminate the use of toxic materials and create a circular materials economy where reuse and recycle are priorities. We must develop sustainable methods for materials recycling and encourage design for disassembly. We must look across the whole materials life cycle from raw resources till end of life and apply thorough life cycle assessments based on reliable and relevant data to quantify sustainability. KW - Electrochemistry KW - Fe-N-C catalysts KW - Fuel cells KW - Catalysis PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550126 DO - https://doi.org/10.1088/2515-7639/ac4ee5 SN - 2515-7639 VL - 5 IS - 3 SP - 1 EP - 98 PB - IOP Publishing CY - Bristol AN - OPUS4-55012 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rappsilber, Tim A1 - Yusfi, Nawar A1 - Krüger, Simone A1 - Hahn, S.-K. A1 - Fellinger, Tim-Patrick A1 - Krug von Nidda, Jonas A1 - Tschirschwitz, Rico T1 - Meta-analysis of heat release and smoke gas emission during thermal runaway of lithium-ion batteries N2 - Herein a meta-analysis of 76 experimental research papers from 2000 to 2021 is given about possible effects on the thermal runaway of lithium-ion battery cells. Data on the hazards of gas emissions and released heat are related to each other and differentiated by cell properties such as, cell geometry, cathode type or state of charge. Quantitative information on the total heat release in the range of 2.0–112.0 kJ Wh−1, the peak heat release rate in the range of 0.006–2.8 kW Wh−1and the smoke gas emission were extracted, normalized in terms of cell energy (Wh), combined in a data library and compared graphically. The total amount of gas emitted (3–48 mmol Wh−1) as well as the released amount of carbon monoxide (1–161 mg Wh−1) and hydrogen fluoride (2–197 mg Wh−1) were investigated as a function of the state of charge and cell geometry. The analysis reveals that the measured values are significantly influenced by the types of calorimeters and smoke gas analyzers used as well as by the type of thermal runaway trigger. This meta-analysis can serve as an important basis for any risk assessment of lithium-ion batteries. KW - Lithium-ion battery KW - Thermal runaway KW - Cathode active material KW - Heat release KW - Smoke gas emission PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568071 DO - https://doi.org/10.1016/j.est.2022.106579 SN - 2352-152X VL - 60 SP - 1 EP - 15 PB - Elsevier CY - Amsterdam AN - OPUS4-56807 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pampel, Jonas T1 - Investigating the thermal runaway behaviour of commercial lithium ion batteries: Influence of initiation mode and state of charge N2 - Lithium ion batteries (LIBs) are omnipresent in our daily lives. LIBs power our laptops and mobile phones, are the energy storage of choice for the electrification of vehicles, and play a vital role in the layout of the storage devices needed for the balancing of the grid. Research groups all over the world work on the improvement of LIBs, e.g., an increase in energy density and cycle-life as well as a decrease in costs. In recent years, investigations concerning the LIB’s safety continuously gain importance, especially, pushed by incidents with electric vehicles. They are multiple levels at which safety measures can be implemented, i.e., material, cell, battery and system level. Accordingly, the behaviour of LIBs under abuse/misuse conditions are often investigated on those levels. Here, we focus on the safety on cell level. Generally, the abuse/misuse leads to an increase in heat in the cell at worst triggering a chain of exothermic reactions. Hence, the cell’s temperature rapidly increases leading to the so-called thermal runaway (TR) possibly accompanied by flames and/or explosion of the cell. Herein, different hazardous features during the TR of different commercial cells are analysed such as temperature, flames, projectiles and toxic gases. In order to gain further insights on the parameters influencing the TR, different type of initiation modes, e.g., external heating, overcharging, nail penetration and external short circuiting are utilized. Moreover, the state of charges (SOCs) are varied to differ the amount of electrical energy present in the cells. Next to the characteristic of the TR of a single cell, the investigation of the propagation of the TR from one cell to another is an important parameter, as a battery is usually composed of multiple cells. Due to the close packaging of the single cells, the TR of one cell is often able to initiate the TR of the surrounding cells, finally, causing the TR of the whole battery. Herein, the propagation ability is studied depending on the cell type and SOC. Finally, the results will be used to formulate (cell specific) conditions for a safe transport of LIBs. Moreover, the gained knowledge can support the development of advanced measures to increase the safety on cell level in the future. T2 - Advanced Battery Power Conference CY - Online meeting DA - 28.01.2021 KW - Abuse Tests KW - Lithium-Batteries KW - Thermal Runaway PY - 2021 AN - OPUS4-54060 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 - Krug von Nidda, Jonas T1 - Löschwasseruntersuchungen bei Bränden von Energiespeichern mit Lithium-Ionen-Zellen (LöwE) N2 - Die Untersuchung der Zusammensetzung des Löschwassers bei Bränden von Lithium-Ionen-Batterien ist von hohem Interesse. Bisher sind nur wenige bzw. unzureichende Studien in diesem Themenfeld vorhanden. T2 - BAM-UBA-Behördenerfahrungsaustausch 2023 CY - Berlin, Germany DA - 12.06.2023 KW - Lithium-Ionen-Batterien KW - Löschwasser KW - Sicherheit PY - 2023 AN - OPUS4-59273 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krug von Nidda, Jonas T1 - Linking Key Features of Commercial Lithium-Ion Cells to Thermal Runaway Effects and Propagation Behavior N2 - Lithium-ion batteries (LIBs) are essential for the electrification of vehicles and play an important role for stationary storage units needed for grid-balancing. Research groups all over the world work on the improvement of LIBs regarding an increase in energy density as well as cycle-life and a decrease in costs. Next to these research topics, a continuously uprising and crucial field is safety features of LIBs, which can be implemented at different levels, such as material, cell, battery and system level. The abuse/misuse of a LIB can cause an internal release of heat which can trigger a chain of exothermic reactions on cell level. Hence, the cell temperature increases dramatically, causing the so-called thermal runaway (TR), possibly leading to flames and/or explosion of the cell. Moreover, the TR of one cell can initiate the TR of adjacent cells leading to a so-called propagation, possibly, causing the TR of the whole battery. Ideally, easily obtainable key features of a certain cell – such as cathode type, cell format, cell energy and state of charge (SOC) - could allow the prediction of its behaviour under abuse conditions. In the present study, we will discuss the latest result of our safety tests on cell level employing an external heater as TR-trigger. Single cell tests will be analysed regarding different hazardous features during the TR, e.g., cell temperature, occurrence of flames, peak pressure, gas amount and gas composition. Moreover, the possibility of a TR-propagation and the respective propagation speed will be gained from propagation tests utilizing six cells with identical SOC. In total, the study comprises over 200 tests on cell level. The gained data set is analysed in respect to the cell parameters, such as cell format, cell energy, SOC and the cathode type as well as the atmosphere (air vs. N2) present during the test. A special focus is put on the discussion of general conclusions linking cell parameters to TR-effects and propagation behaviour. The findings regarding common conclusions between key features and TR-effects can enable a rather facile selection process of cells/batteries for certain applications according to specific safety targets. Moreover, it allows to choose cell-specific safety measures, suitable during operation. In further works, the study will be extended to end-of-first life cells yielding important conclusions regarding crucial safety aspects for the implementation of those cells in 2nd-life application. Generally, the presented results can increase the overall understanding of the TR mechanism supporting the design of advanced measures to enhance the safety on cell level in the future. T2 - 224th ECS Meeting CY - Gothenburg, Sweden DA - 08.10.2023 KW - Lithium Ion Batteries KW - Thermal Runaway KW - Propagation KW - Safety PY - 2023 AN - OPUS4-59268 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scharpmann, Philippa T1 - In-situ Quantification of the Ageing Dynamics in Lithium-Ion Cells up to Failure-Near Conditions N2 - Implementing end-of-life (EOL) lithium-ion batteries from automotive applications in stationary energy storages is of utmost relevance for a sustainable handling of scarce resources. Beneficial from an economic and ecological perspective, such second-life applications urgently require a guarantee for safe operation. Unlike the state of health (SOH), defined by classical performance indicators such as capacity and voltage, the state of safety (SOS) of an aged battery cannot be assessed straightforward. Its determination requires a plethora of cells to be tested which is a particular challenge for new technologies with limited access to EOL batteries. For providing cells with a defined SOH at a reasonable timescale, we herein propose a novel method of greatly accelerating the ageing process of lithium-ion batteries. In a preliminary test series, lithium-ion NMC pouch cells are exposed to incrementally increasing temperatures, current rates and/or states of charge (SOC), until thermal runaway is induced. In this manner, the critical state in proximity to cell failure is spotted for individual and combined stress parameters. Based on this knowledge, cell-specific test parameters for heavily accelerated ageing are developed. In this protocol, electrical abuse conditions are defined by over/under charging and high current rates. Typically, the cells are cycled utilizing a depth of discharge above 100 %. The accelerated aging dynamics under these critical conditions are monitored by systematic capacity, open circuit voltage and electrochemical impedance spectroscopy (EIS) measurements. This enables a comparative assessment of the electrical behaviour, following conventional vs. heavily accelerated ageing. Such knowledge will in turn help to define the threshold to which cyclic ageing can be accelerated without changing the characteristic degradation mechanisms of lithium-ion batteries. T2 - 244th ECS Meeting CY - Gothenburg, Sweden DA - 08.10.2023 KW - Lithium-Ion Battery KW - Safety KW - Ageing PY - 2023 AN - OPUS4-61490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Böttcher, Nils T1 - Low Temperature Tomographic In-Situ and Operando Studies in Energy Research N2 - Using low temperatures empowers in-depth investigations of abuse processes in Li-ion cells. A thermal runaway (TR) can be suppressed also on material level at low temperatures.The rethermalization of a critical damaged cell not always leads to a TR. Using the snyergies at BAM enables now In-depth investigation of low temperature inertisation mechanisms in commercial Lithium-Ion-Batteries. In future the synergies will be used for in-depth investigation of other abuse processes in commercial cells e.g., plating or aeging. T2 - HZB Usermeeting CY - Berlin, Germany DA - 11.12.2024 KW - Lithiumbatteries KW - Thermal Runaway KW - Sychrotron computer tomopgrahy KW - Low temperature PY - 2024 AN - OPUS4-62300 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krug von Nidda, Jonas T1 - Investigating thermal runaway effects and propagation behaviour of various types of commercial lithium-ion cells N2 - Lithium-ion battery (LIB) powered devices, such as laptops, mobile phones and power tools are ubiquitous in our daily lives. Moreover, LIBs are essential for the electrification of vehicles, and play an important role for stationary storage units needed for grid-balancing. The improvement of LIBs, in terms of increasing energy density as well as cycle-life and decreasing costs, is tackled by numerous research groups all over the world. In the last years, research regarding safety aspects has steadily gained more interest. The safety of LIBs can be implemented at different levels, such as material, cell, battery and system level. The abuse/misuse of an LIB can lead to an internal increase in heat which can trigger a chain of exothermic reactions on cell level. Thus, the cell temperature increases dramatically causing the so-called thermal runaway (TR). This process can lead to flames and/or explosion of the cell. Furthermore, the TR of one cell can initiate the TR of adjacent cells causing the so-called propagation, possibly, leading to the TR of the whole battery. Herein, we will show the latest result of our safety tests on cell level employing an external heater as TR-trigger. Regarding single cell tests, we will compare different hazardous features during the TR, e.g., cell temperature, occurrence of flames, peak pressure, and toxic gases, depending on the cell format, cell energy and the cathode type. The same cell parameters will be used to discuss the results of the propagation tests. Moreover, the influence of the state of charge (SOC) and the present atmosphere (air vs. N2) as well as the repeatability will be discussed. Overall, the study comprises over 180 tests on cell level. The findings regarding the TR behaviour can be used to create a hazard-classification scheme of LIBs, e.g., allowing the definition of (cell type specific) conditions for a safe transport. Furthermore, the results can increase the general understanding of the TR mechanism promoting the development of advanced measures to enhance the safety on cell level in the future. T2 - Advanced Battery Power 2023 CY - Aachen, Germany DA - 27.04.2023 KW - Thermal Runaway KW - Lithium Ion Batteries KW - Safety PY - 2023 AN - OPUS4-59267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tichter, Tim A1 - Böttcher, Nils A1 - Schmidt, Anita A1 - Krug von Nidda, Jonas T1 - Exploring the Low-Temperature Threshold for Reactions in Commercial Lithium-Ion Cells N2 - Low-temperature passivation of lithium-ion batteries (LIBs) can reduce the probability of thermal runaway events [1]. In this context, we explore the thermal threshold at which reactions in commercial Li-cells become feasible. It is found that electrochemical reactions take place even below the first phase transition of the electrolyte. Finally, it is concluded that the passivation temperature for all samples in our study does not require cryogenic conditions which is of great relevance for defining the conditions for a safe transportation. T2 - Advanced Battery Power Konferenz CY - Münster, Germany DA - 10.04.2024 KW - Batteries KW - Thermal passivation KW - Arrhenius-law KW - Cyclic voltammetry KW - Chronoamperometry PY - 2024 AN - OPUS4-62307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Böttcher, Nils T1 - Visualizing the progression of the thermal runaway in lithium-ion-cells by controlled abuse tests at low temperatures N2 - Due to their increasing energy density, lithium-ion-batteries (LIBs) play a key role in the traffic energy transition. Regarding their safety behavior, the main challenge of LIB-cells remains the thermal runaway (TR) process. In situ/operando investigations of the TR on commercial cells is possible with radiographic and computer tomographic measurements. Nonetheless, high resolution visualization of the TR persists as a challenge due to the high progression speed of the TR-process itself. Generally, performing abuse tests at cryogenic temperatures allows to slow down or even prevent the TR. Nevertheless, not all abuse methods are suitable for TR investigations at low temperatures. Nail penetration is an appropriate option, however, contains numerous unknown parameters and therefore suffers regarding reproducibility. Herein, a self-developed high precision nail-penetration-setup is introduced, approaching the necessary mechanically reproducibility with controlled temperatures down to -190°C. The setup allows the preparation of critically abused, however, at cryogenic temperatures stable LIB-cells. These cells were controlled rethermalized to room temperature during synchrotron x-ray computer tomography (SXCT) with a pixel size up to 0.7 μm. During this measurement, the temperature and voltage of the cell is monitored allowing the visualization of the initial internal cell reactions. This study reveals the relation between internal reactions and cell voltage. Finally, the developed set-up enables in-depth analysis of thermal runaway behavior down to material level for various commercial battery cells in the future. T2 - International Battery Safety Workshop CY - Ulm, Germany DA - 28.09.2023 KW - Thermal Runaway KW - Lithium Ion Batteries KW - Computer Tomography PY - 2023 AN - OPUS4-59270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Markötter, Henning T1 - In situ tomographic imaging with hard x rays at Bamline (BESSY II) N2 - The BAMline at the synchrotron X-ray source BESSY II (Berlin, Germany) is supporting researchers especially in materials science [1]. As a non-destructive characterization method, synchrotron X-ray imaging, especially tomography (SXCT) with hard X-Rays, plays an important role in structural 3D characterization. The imaging capabilities allow for in-situ and operando experiments. In this presentation the equipment, data handling pipeline as well as various examples from material science are presented. In series-connected lithium-ion cells are susceptible to an electrical safety hazard called over-discharge. Here the behavior of copper dissolution and deposition during over-discharge is presented, which leads to irreversible loss of capacity and internal short circuits. The concentration of dissolved and deposited copper is quantified. Also, a non-uniform distribution pattern of copper deposition on the cathode is shown. The second example deals with an Al alloy 7017 customized for a 3d-printing process by means of laser-based powder bed fusion (PBF-LB) technique. These advanced alloys have a significantly higher modulus of elasticity than conventional Al alloys, making them attractive for applications requiring high stiffness. SXCT during In-situ tensile tests confirmed that fracture initiation strongly depends on defects created during printing. However, the cracks are deflected from decohesion around inclusions/precipitates embedded in the Al matrix, increasing ductility. Low temperature cofired ceramic (LTCC) multilayer housings offer 3D-circuits for a wide range of applications in telecommunications, microsystems and sensor technology. Such housings are produced by combining structured and metallized ceramic layers using tape-casting and multilayer technology. The characterization of the integrity, deformation, defects, and positioning of the internal metal features was carried out using in-situ SXCT at up to 950°C. A high-precision nail penetration tool was developed to characterize the mechanically induced thermal runaway (TR) of lithium-ion battery (LIB) cells in a dynamic temperature range down to -190 °C. To investigate safety-specific low-temperature transport conditions, the damaged cells were tomographically imaged during thawing. T2 - ICTMS - International Conference on Materials and Structures 2024 CY - Cape Town, South Africa DA - 01.07.2024 KW - Synchrotron radiation KW - X-ray tomography KW - Li-ion battery PY - 2024 AN - OPUS4-60658 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scharpmann, Philippa T1 - Segregating the Degradation Mechanisms in Lithium-Ion Cells during Strongly Accelerated Ageing with Critically Extended Voltage Ranges N2 - Repurposing end-of-life (EOL) lithium-ion batteries from mobile applications, such as electric vehicles, is of utmost importance for a sustainable handling of scarce resources. For an economically and ecologically desirable reuse of aged batteries in second-life applications, a guarantee for safe and reliable operation is urgently required. However, the assessment of the state of safety (SOS) is not straightforward, as multiple abuse cases, variables and interactions need to be considered [1]. Therefore, defining safety parameters and test procedures, as well as determining the SOS requires a plethora of aged cells to be tested. In this study, a novel method of greatly accelerating the ageing process of lithium-ion batteries is proposed. Overcharging and overdischarging are embedded in cyclic ageing, continuously employing a depth of discharge larger than 100 %. Different electrical abuse conditions (overcharge, overdischarge, high current rates) are applied on lithium-ion NMC and LFP pouch cells in a preliminary test series. In this manner, the cells are stressed until a cell failure or a thermal runaway is induced. Thus, the critical state in proximity to a cell failure is spotted for individual and combined stress parameters. Based on this knowledge, a test protocol for strongly accelerated ageing with cell-specific, abusive electrical parameters is developed. The aging dynamics under these critical conditions are monitored by systematic capacity, open circuit voltage and electrochemical impedance spectroscopy (EIS) measurements. This enables an assessment of the degradation mechanisms induced by overdischarge and overcharge cycling. A special focus is set on the comparative assessment of the electrical behaviour, following conventional vs. greatly accelerated ageing. This novel method is suitable for providing cells with a defined SOH at a reasonable timescale. Furthermore, the results are of high relevance for the evaluation to which degree cyclic ageing can be accelerated without changing the characteristic degradation mechanisms of lithium-ion batteries. T2 - Advanced Battery Power Conference 2024 CY - Münster, Germany DA - 10.04.2024 KW - Lithium-Ion Battery KW - Safety KW - Ageing PY - 2024 AN - OPUS4-61492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krug von Nidda, Jonas T1 - Single Cell Exchange in Battery Packs – Sustainability vs. Safety Aspects N2 - Lithium-ion batteries usually consist of numerous individual cells. There is ongoing discussion about enhancing sustainability by considering the replacement of heavily aged or damaged cells. Nevertheless, the planned replacement of individual cells poses significant challenges in ensuring the required reliability and safety of the refurbished device. T2 - KLIB Gesprächsrunde Batteriesysteme CY - Online meeting DA - 16.05.2023 KW - Lithium Ion Batteries KW - Lithium Ion Cells KW - Cell Exchange KW - Safety KW - Sustainability PY - 2023 AN - OPUS4-59272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Leonhardt, Robert A1 - Krug von Nidda, Jonas A1 - Andrae, Dirk A1 - Schmidt, Anita A1 - Kowal, Julia A1 - Tichter, Tim T1 - Reconstructing the distribution of relaxation times with analytical basis functions N2 - The present work proposes the implementation of non-singular basis functions into the algorithm for reconstructing the distribution of relaxation times (DRT) function of impedance data. These functions reflect the dispersed and asymmetrical nature of non-ideal capacitive–resistive processes. Inclusion is achieved by combining the singular Debye distribution basis with distributed relaxation functions, such as those derived from the analytical models of Cole–Cole and Havriliak–Negami. The shapes of the introduced basis functions are described by constant parameters, for which an empirical optimization approach is provided alongside. Using synthetic impedance data of non-ideal capacitive–resistive processes subjected to white noise, it is shown that the demand for regularization can be reduced significantly by using distributed bases. To underline the practical relevance of non-singular basis functions in DRT reconstruction, an experimental study comprising 100 sodium-ion and 80 lithium-ion ommercial cells is presented. In this context, it is shown that auxiliary information from the non-ideal nature of real-world electrochemical processes is outsourced into the basis and, hence, easily filtered out of the resulting DRT. This facilitates the separation of single processes without post-DRT curve fitting and thus improves the interpretation and classification of impedance data significantly. KW - Electrochemical Impedance Spectroscopy; KW - Distribution of relaxation times KW - Basis function KW - Cole-Cole KW - Cole-Davidson KW - Havriliak-Negami PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635486 DO - https://doi.org/10.1016/j.jpowsour.2025.237403 SN - 0378-7753 VL - 652 SP - 1 EP - 11 PB - Elsevier B.V. AN - OPUS4-63548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Markötter, Henning T1 - Tomographic Imaging Capabilities with hard X-Rays at BAMline (Bessy II) N2 - The BAMline at the synchrotron X-ray source BESSY II (Berlin, Germany) is supporting researchers especially in materials science. As a non-destructive characterization method, synchrotron X-ray imaging, especially tomography with hard X-Rays, plays an important role in structural 3D characterization. The imaging capabilities allow for in-situ and operando experiments. In this presentation the equipment, data handling pipeline as well as various examples from material science are presented. T2 - Correlative Materials Characterization Workshop 2023 CY - Brno, Czech Republic DA - 09.11.2023 KW - Tomography KW - X-ray imaging KW - Li-ion battery PY - 2023 AN - OPUS4-58958 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dayani, Shahabeddin A1 - Markötter, Henning A1 - Schmidt, Anita A1 - Widjaja, Martinus Putra A1 - Bruno, Giovanni T1 - Multi-level X-ray computed tomography (XCT) investigations of commercial lithium-ion batteries from cell to particle level N2 - Adopting X-ray computed tomography (XCT) for ex-situ characterization of battery materials has gained interest in the past decade. The main goal of this paper is to demonstrate the effectiveness of several X-ray computer tomography techniques to study commercial batteries. General guidelines are provided to select the most suitable imaging equipment and parameters for investigations of lithium-ion batteries, spanning the length scales from cell to electrode, down to particle level. Relevantly, such parameters would also be suitable for operando experiments. Safety mechanisms and manufacturing inconsistencies at cell level as well as defects and inhomogeneity in cathode and anode is illustrated and quantified. Furthermore, relation of beam energy and sample-detector-distance on contrast retrieved from attenuation and phase shift is inspected using Synchrotron XCT. KW - Non-destructive testing KW - X-ray computed tomography KW - Synchrotron X-ray computed tomography KW - Lithium-ion battery PY - 2023 DO - https://doi.org/10.1016/j.est.2023.107453 SN - 2352-152X VL - 66 SP - 107453 PB - Elsevier Ltd. AN - OPUS4-57512 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfaff, Jonas A1 - Schopferer, Sebastian A1 - Markötter, Henning A1 - Rack, Alexander A1 - Bruno, Giovanni A1 - Schmidt, Anita A1 - Tichter, Tim A1 - Böttcher, Nils T1 - High-speed synchrotron radiography of nail penetration-induced thermal runaway: Understanding the explosive behavior of commercial sodium-ion batteries with NFM cathode N2 - The dynamics of mechanically initiated thermal runaway (TR) events in cylindrical 18650 cells with NFM (Na(Ni1/3Fe1/3Mn1/3)O2), LFP (LiFePO4), and NMC532 (LiNi1/2Mn1/3Co1/5O2) cathode chemistries were investigated using high-speed synchrotron X-ray imaging. Structural similarity index measures (SSIM) were employed to identify and track rapid structural changes. In this manner, thermal decompositions and internal propagation dynamics, influencing the safety mechanisms of the cells, were studied. This lead to two major findings: (I) Among NFM, LFP, and NMC532 cells, the TR-characteristics differ significantly in temperature and internal propagation speed. Internal safety mechanisms appear, however, visually similar. Among all samples, LFP cells exhibit higher safety performance concerning the initiation of TR by nail penetration and the progression of TR. (II) The NFM cells used in this study displayed an almost explosive TR. This finding appears counterintuitive on a first glance, since sodium-ion batteries are usually considered safe. High-speed imaging revealed that the explosive TR is not necessarily caused by the thermochemical decomposition reactions, but rather by a failure of the venting mechanism. This results in a significant pressure buildup within the cell upon TR initiation and eventually a severely violent TR. These results underline that battery safety depends on many factors and not solely on optimized cell chemistries or materials. KW - High-speed X-ray radiography KW - Synchrotron X-rays KW - 18650 KW - SIB KW - Na-NFM KW - Structure similarity index measure PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-642649 DO - https://doi.org/10.1016/j.powera.2025.100188 SN - 2666-2485 VL - 36 SP - 1 EP - 7 PB - Elsevier Ltd. AN - OPUS4-64264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -