Realising an ideal lithium-ion battery (LIB) cell characterised by entirely homogeneous physical properties poses a significant, if not an impossible, challenge in LIB production. Even the slightest deviation in a process parameter in its production leads to inhomogeneities and causes a deviation in performance parameters of LIBs within the same batch. The greater the number and/or intensity of inhomogeneities, the more they need to be avoided. Severe inhomogeneities (defects), such as metal particle contamination, significantly impact the cell’s performance. Besides electrical measurements, image-based measurement methods can be used to identify defects and, thus, ensure the production quality and safety of LIBs. While the applicability of computed tomography (CT) as an image-based measurement method for detecting defects has been proven, the limitations of this method still need to be determined. In this study, a systematic analysis of the capabilities of CT imaging was conducted. A multilayer pouch cell without an electrolyte was reassembled with several defects on one of the middle anodes. To investigate the boundaries of CT, defects such as a partial and complete removal of the coating, a cut, or a kink, as well as particle contaminations of various sizes and materials (aluminium, copper, iron) were chosen. By comparing the CT images of the cell using laser scanning microscope images of the defective anode, it could be proven that all selected defects except the kink were detectable.
Advanced driver assistance systems (ADASs) rely heavily on the resilient spatial perception of the surrounding environment of vehicles enabled by sensor systems, such as radio detection and ranging (RADAR), light detection and ranging (LIDAR), and cameras. The electric/electronic (E/E) architecture of the vehicle must ensure that the sensor systems and data gathering and processing for the perception operate under all circumstances. However, certain factors can affect the resilience of the sensor system and the supporting E/E architecture, such as internal software failures and external weather conditions. This paper provides a comprehensive review of the latest developments in automotive sensor systems and architectures, highlighting potential disturbances and presenting corresponding countermeasures for hardware and software failures. We also identify challenging applications and assess the requirements for resilience to make these applications feasible under all circumstances. Based on this review, we propose a comprehensive framework for developing resilient sensor systems and architectures that can serve as a basis for further research towards fully automated driving.
Sodium-ion batteries (SIBs) are gaining attention in research and industry as a sustainable alternative to lithium-ion batteries (LIBs). However, the advantages of sodium over lithium in terms of accessibility, price, and environmental impact are currently not fully exploited because of inexperience in production, leading to inhomogeneities in their behavior. Using electrical (e.g., open-circuit voltage curve (OCV), electrochemical impedance spectroscopy) and non-electrical measurement methods (e.g., laser scanning microscopy, computed tomography), three widely used LIB technologies and one SIB technology, all with the same rated capacity (1500 mAh) and format (18650), are compared in this article. The study reveals significant differences, such as a 12% lower cell weight at the same rated capacity of the SIB using less windings in the jelly roll, as well as a high energy density cell configuration and a much more severe dependency of the discharge capacity on temperature, exceeding the LIBs by at least a factor of 5. Additionally, the impedance of the SIB differs due to slower ion kinetics on the electrodes, showing relevant differences in both the frequency behavior and the pulse relaxation to the LIBs. An OCV reconstruction indicates the sparsity in the available literature data and the necessity to further investigate the characteristics of the SIB to validate it as a drop-in technology on the market.
To provide storage capacities for the emerging markets of electromobility and stationary applications, the increase of productivity within the production of lithium‐ion batteries is crucial. A special focus lies on the assembly of the electrode–separator–compound as a bottleneck process within battery cell production. Consequently, novel process technologies arise for high‐throughput assembly technologies. However, complex process–product interactions drive complexity within the design of new processes. Process models, experiments, and simulations support the process design but must depict nonlinear material behavior. This increases the expanse in time and resources for the process design. Herein, an approach to reduce the effort of process design using the example of the assembly of the electrode–separator–compound is shown. The approach aims to identify and select solutions within the process design. Analytical, simulative, and experimental methods and tools are applied within the approach to investigate the design solutions at different levels of detail. The practical application of the approach is demonstrated in two case studies within the assembly of the electrode–separator–compound. The results of the case studies show a profound choice of the process design and a gain in knowledge on process–product–interactions of the novel processes.