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 -