• Energy Research

Abstract The rising number of electric vehicles (EV) will eventually lead to a comparable number of EV batteries reaching their end-of-life (EOL). Efforts are therefore being made to develop technologies and processes for recycling, remanufacturing and reusing EV batteries. One important step of many such processes is the disassembly of EOL EV batteries, which poses a challenging task due to unpredictable lot sizes and volumes, as well as significant variations in battery design between different car models. In response to these challenges and the increasing demand, we present a concept for a battery disassembly workstation where a human is assisted by a robot. While the human performs the more complex tasks, the proposed robot performs simple, repetitive tasks such as removing screws and bolts. Such a robot requires 1) a suitable procedure for the unscrewing task, 2) a means of autonomously changing screwdriver bit in accordance with the variety of screws and bolts found in EV batteries, and 3) some means of acquiring information regarding the location of these fasteners. This paper summarises the results of our preliminary investigations.

Production technology for automotive lithium-ion battery (LIB) cells and packs has improved considerably in the past five years. However, the transfer of developments in materials, cell design and processes from lab scale to production scale remains a challenge due to the large number of consecutive process steps and the significant impact of material properties, electrode compositions and cell designs on processes. This requires an in-depth understanding of the individual production processes and their interactions, and pilot-scale investigations into process parameter selection and prototype cell production. Furthermore, emerging process concepts must be developed at lab and pilot scale that reduce production costs and improve cell performance. Here, we present an introductory summary of the state-of-the-art production technologies for automotive LIBs. We then discuss the key relationships between process, quality and performance, as well as explore the impact of materials and processes on scale and cost. Finally, future developments and innovations that aim to overcome the main challenges are presented. The battery manufacturing process significantly affects battery performance. This Review provides an introductory overview of production technologies for automotive batteries and discusses the importance of understanding relationships between the production process and battery performance.

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.

Electromobility is a new approach to the reduction of CO2 emissions and the deceleration of global warming. Its environmental impacts are often compared to traditional mobility solutions based on gasoline or diesel engines. The comparison pertains mostly to the single life cycle of a battery. The impact of multiple life cycles remains an important, and yet unanswered, question. The aim of this paper is to demonstrate advances of 2nd life applications for lithium ion batteries from electric vehicles based on their energy demand. Therefore, it highlights the limitations of a conventional life cycle analysis (LCA) and presents a supplementary method of analysis by providing the design and results of a meta study on the environmental impact of lithium ion batteries. The study focuses on energy demand, and investigates its total impact for different cases considering 2nd life applications such as (C1) material recycling, (C2) repurposing and (C3) reuse. Required reprocessing methods such as remanufacturing of batteries lie at the basis of these 2nd life applications. Batteries are used in their 2nd lives for stationary energy storage (C2, repurpose) and electric vehicles (C3, reuse). The study results confirm that both of these 2nd life applications require less energy than the recycling of batteries at the end of their first life and the production of new batteries. The paper concludes by identifying future research areas in order to generate precise forecasts for 2nd life applications and their industrial dissemination.

AbstractVacuum-based handling is widely used in industrial production systems, particularly for hand-ling of sheet metal parts. The process design for such handling tasks is mostly based on approximate calculations and best-practice experience. Due to the lack of detailed knowledge about the parameters that significantly influence the seal and force transmission behavior of vacuum grippers, these uncertainties are encountered by oversizing the gripping system by a defined safety margin. A model-based approach offers the potential to overcome this limitation and to dimension the gripping system based on a more exact prediction of the expected maximum loads and the resulting gripper deformation. In this work, we introduce an experiment-based modeling method that considers the dynamic deformation behavior of vacuum grippers in interaction with the specific gripper-object combination. In addition, we demonstrate that for these specific gripper-object combinations the gripper deformation is reversible up to a certain limit. This motivates to deliberately allow for a gripper deformation within this stability range. Finally, we demonstrate the validity of the proposed modeling method and give an outlook on how this method can be implemented for robot trajectory optimization and, based on that, enable an increase of the energy efficiency of vacuum-based handling of up to 85%.

AbstractThe industrialized winding of electrode–separator composites (ESCs; “jelly rolls”) applies bending stress to the winding mandrel. This affects the mechanical integrity of the substrate's coating and adhesion and may reduce the cycle stability and the battery life. Even though this motivates strong interest in the minimization of bending stress during production, there is no testing method available yet to characterize the composite such that process parameters can be derived. This article introduces a test method and apparatus for the effect of bending stress of electrodes. In this test method, electrodes are pulled over defined radii while the coating adhesion is observed continuously. This resembles the variation of the mandrel diameter and gives detailed insight into the limits of the allowed production parameter window. In a case study, a cathode material with Li(LiMnAl)2O4 (LMO) as active material is selected as an example to show the effectiveness of the method.

Electrode manufacturing requires multiple process steps, e.g., dispersing and coating. In‐between these steps, intermediate products have to be transferred, stored, and handled. Especially for the development of new active materials or electrode formulations, the variety of parameters that need to be screened is enormous. In addition, these materials are initially tested in small batches, and it is not always possible to upscale the used processes. To evaluate the performance of different materials or differently processed materials, test cells are assembled. This usually requires manual work procedures, which are inherently sensitive to variations and untraceable errors. If the stochastic flaws are large enough, the effects of process variations are covered by these. It is therefore important to increase reproducibility in all process steps. Herein, new concepts for electrode production and automated sample preparation for highly reproducible production and more effective electrode development and screening of parameters are presented. A combined grinding and dispersion process for the production of silicon‐based anodes and an automated assembly system for efficient testing is presented. The processes are supported by methods of data mining to collect process data, ensure high reproducibility, and support research on new active materials.