TY - GEN A1 - Langner, Thomas A1 - Sieber, Tim A1 - Rietig, Anja A1 - Merk, Virginia A1 - Pfeiffer, Lutz A1 - Acker, Jörg T1 - A Phenomenological and Quantitative View on the Degradation of Positive Electrodes from Spent Lithium-ion Batteries in Humid Atmosphere T2 - Scientific Reports N2 - The present study deals with the phenomenological observation of the corrosion of the positive electrode foil of lithium-ion batteries containing LiNi0.6Co0.2Mn0.2O2 (NMC) as cathode material. Due to the presence of moisture, localized water accumulation is formed on the NMC surface. The water absorbed by the electrolyte reacts with the NMC under Li+/H+ exchange and the resulting pH increase leads to dissolution of the carrier foil and characteristic salt-like blooms on the NMC surface. With the increase in the relative area occupied by the holes in the aluminum foil per time, a sufficiently suitable parameter was found with which to quantitatively determine the extent of corrosion. The degree of degradation depends on time and ambient humidity. It was shown that functional recycling with the water jet method is no longer applicable for degraded foils, since the mechanical stability of the foils decreases as corrosion progresses. Lithium, aluminum, sulfur and oxygen were detected in the blooms using SEM–EDX and Laser-Induced-Breakdown-Spectroscopy (LIBS). The underlying NMC layer was found to contain mainly aluminum and significantly lower lithium content than the non-degraded material. SEM and Raman microscopy analyses also showed that the active material is also locally degraded and therefore no longer suitable for functional recycling. KW - Analytical chemistry KW - lithium KW - cathode KW - materials KW - LIBS KW - Raman KW - SEM-EDX KW - degradation Y1 - 2023 U6 - https://doi.org/10.1038/s41598-023-32688-0 SN - 2045-2322 VL - 13 ER - TY - GEN A1 - Rietig, Anja A1 - Langner, Thomas A1 - Acker, Jörg T1 - About determining reliable etching rates and the role of temperature in kinetic experiments on acidic wet chemical etching of silicon T2 - Physical Chemistry Chemical Physics Y1 - 2023 UR - https://pubs.rsc.org/en/content/articlelanding/2023/cp/d2cp05837e U6 - https://doi.org/10.1039/D2CP05837E SN - 1463-9084 VL - 25 IS - 16 SP - 11387 EP - 11397 ER - TY - GEN A1 - Rietig, Anja A1 - Acker, Jörg T1 - Kinetic studies on acidic wet chemical etching of silicon in binary and ternary mixtures of HF, HNO3 and H2SiF6 T2 - Physical Chemistry Chemical Physics Y1 - 2023 U6 - https://doi.org/10.1039/d3cp03188h SN - 1463-9084 SN - 1463-9076 VL - 25 IS - 38 SP - 26245 EP - 26257 ER - TY - GEN A1 - Markowski, Jens A1 - Arellano-García, Harvey A1 - Meißner, André A1 - Acker, Jörg T1 - Comparative studies on the quality of recovered secondary graphites from the recycling of lithium-ion traction batteries T2 - Sustainable Minerals N2 - Automotive technology is increasingly determined by drives based on electric motors in combination with batteries. The lithium-ion traction battery is a storage medium that combines high electrical efficiency with compact dimensions and relatively low weight. For the recycling of the cathode coatings (esp. Ni, Mn, Co) and peripheral battery components a variety of recycling options already exist. The graphite coating of the anodes has hardly been the focus of research activities to date. State of the art is currently the melting of the complete Copper-anode foils including graphite coating, whereby the graphite contributes only as a carbon carrier to the recycling of the copper. Separation and reuse of the very high-quality graphite on an industrial scale has not yet taken place. At the BTU, a methodology has been developed, with which recovered anode graphites from traction batteries can be comprehensively characterised chemically and mechanically-physically. On this basis, targeted preparation for secondary applications is possible. The secondary graphites achieve a quality that allows them to be reused as second-use anode material and for other applications. KW - Graphitrecycling KW - Li-Ionen-Traction Batteries Y1 - 2023 UR - https://www.ceecthefuture.org/resource-center/comparative-studies-on-the-quality-of-recovered-secondary-graphites-from-the-recycling-of-lithium-ion-traction-batteries PB - Mining Engineering CY - Falmouth (UK) ER -