Mass transport conversion to an electrified powertrain requires suitable strategies for processing electric vehicle (EV) batteries after their intended first service life. Due to aging mechanisms, EV batteries lose capacity over their period of use and become unsuitable for their initial application at some point. However, to expand their lifetime and to meet the sustainability demand for EVs, the usage of these batteries in so-called Re-X applications is under intense discussion. Until now, downstream processing has been subject to high uncertainty regarding the expected advances. While many issues on the technical and ecological side have been at least partially resolved, the economics are still under assessment. For this reason, this paper intends to give a well-based outlook on the costs and benefits of three chosen scenarios: reuse, repurpose, and recycle. It is expected that under the given national policies and global market conditions, growing quantities of retired EV batteries will return from the transportation markets. Consequently, the market potential for retired batteries in downstream applications will significantly increase, as well as calls for stable solutions.

Die Zustandsbewertung von Batterien vom Gesamtsystem bis hin zur Zellebene stellt vor allem außerhalb des Laborumfelds weiterhin eine Herausforderung dar. Die in der Zelle ablaufenden Alterungsmechanismen überlagern sich auf komplexe Weise, was eine eindeutige Ursachenanalyse erschwert. Neben den elektrischen Charakterisierungsmethoden bieten die mechanischen Ansätze vielversprechende Möglichkeiten, bislang ungenutztes Potenzial zur Verbesserung der Datenverfügbarkeit und Transparenz zu erschließen.

Lithium-ion batteries (LIBs) are considered a pivotal enabling technology for the advancement of transportation electrification, the development of stationary energy storage systems, and the integration of renewable energy sources. Despite continuous advances in energy density and cell design, the fast-charging capability of LIBs is still significantly constrained by temperature-dependent electrochemical and thermal processes, which are crucial to the overall performance of the battery. The objective is to quantify the temperature-dependent fast-charging potential and charging power capability. This is achieved by experimentally analyzing the internal resistance (IR) during the charging of three large-format prismatic state-of-the-art cells, in addition to extrapolating their charging power capability and constant-current constant-voltage charging behavior under varying thermal boundary conditions. Utilizing the IRs ascertained during the charging process, the fast-charging potential (FCP) is introduced as a dimensionless metric that expresses the temperature-induced increase in the maximum theoretically achievable charging current at a given SoC, relative to 25 °C. Elevated cell temperatures are found to reduce IR and thus increase the theoretically achievable charging power, with the FCP nearly independent of SoC but cell-specific, ranging from about 18% (CATL) to 40% (SVolt) for a temperature increase from 25 °C to 45 °C. This potential can be exploited in two ways: firstly, by increasing the C-rate while maintaining the same constant-current duration; and secondly, by extending the constant-current phase at a constant initial C-rate. The proposed methodology facilitates a systematic and comparative evaluation of the maximum theoretically attainable temperature-dependent fast-charging potential of LIBs. It provides a foundation for the development of thermally optimized fast-charging strategies.

Pressure-related quantities such as internal pressure, cell expansion, and housing deformation are promising mechanical indicators of lithium-ion battery ageing because they are directly linked to degradation processes such as gas formation, lithium plating, and interphase growth. However, existing studies are largely limited to single-cell experiments under controlled laboratory conditions and do not provide a systematic framework for larger battery systems. This work reviews pressure- and expansion-based diagnostic approaches and derives a structured methodology for their practical application. The framework includes representative operating conditions, format-dependent assignment of measurement principles, sensor placement, sensor selection, and cycle-wise data processing. The results show that pressure-based diagnostics must be understood as a format-dependent methodological family, with dilatometric or force-based approaches being most suitable for pouch cells and strain-based methods for rigid housings. Overall, the study provides a scalable basis for integrating mechanical ageing diagnostics into future battery monitoring systems. The framework further describes the mechanical coupling of cells within a module, which determines both the magnitude of the measurable signal and the extent to which the state of individual cells can be resolved.