The motivation of this paper is to identify possible directions for future developments in the battery system structure for BEVs to help choosing the right cell for a system. A standard battery system that powers electrified vehicles is composed of many individual battery cells, modules and forms a system. Each of these levels have a natural tendency to have a decreased energy density and specific energy compared to their predecessor. This however, is an important factor for the size of the battery system and ultimately, cost and range of the electric vehicle. This study investigated the trends of 25 commercially available BEVs of the years 2010 to 2019 regarding their change in energy density and specific energy of from cell to module to system. Systems are improving. However, specific energy is improving more than energy density. More room for improvements is thus to be gained in packaging optimization and could be a next step for further battery system development. Other aspects looked at are cell types and sizes. There, a trend to larger and prismatic cells could be identified.

The most cost‐intensive components of the battery system for electric vehicles are the lithium‐ion battery cells. Thus, to reduce the overall cost of a battery system, a clear objective is to reduce the production cost of lithium‐ion battery cells. Cost drivers are to be identified, which are essential to enable potentials for cost reduction. In particular, the formation and aging process represents a high potential for process cost reduction because of its enormous process time expenditure. The automotive industry requires up to 3 weeks for the formation and aging process of a single lithium‐ion battery cell. Due to the high relevance of these processes, the research project OptiZellForm as part of the ProZell Cluster examines those production steps in detail. Environmental conditions such as mechanical load and elevated temperature as well as the electrical and chemical properties influencing the formation and aging process are investigated. The focus of this study is the investigation of the mechanical exertion and elevated temperature with regard to the reduction of the formation process duration and thus the reduction of the production cost. For this reason, a specially designed device is used to investigate these parameters for lithium‐ion battery cells.

A large number of battery pack returns from electric vehicles (EV) is expected for the next years, which requires economically efficient disassembly capacities. This cannot be met through purely manual processing and, therefore, needs to be automated. The variance of different battery pack designs in terms of (non-) solvable fitting technology and superstructures complicate this. In order to realize an automated disassembly, a computer vision pipeline is proposed. The approach of instance segmentation and point cloud registration is applied and validated within a demonstrator grasping busbars from the battery pack. To improve the sorting of the battery pack components to achieve high-quality recycling after the disassembly, a labeling system containing the relevant data (e.g., cathode chemistry) about the battery pack is proposed. In addition, the use of sensor-based sorting technologies for peripheral components of the battery pack is evaluated. For this purpose, components such as battery pack and module housings of multiple manufacturers were investigated for their variation in material composition. At the current stage, these components are usually produced as composites, so that, for a high-quality recycling, a pre-treatment may be necessary.

The cell finishing process is the final stage in the production of a battery cell. Almost one third of the production costs of a battery cell are related to this part of the production. It includes a series of steps and technologies aimed at optimizing the battery cell’s performance, quality, and safety. The process is divided into three categories: pre-treatment, formation procedure, and quality testing. The order of the processes and the time required for each step can vary depending on the manufacturer and the cell format. Recent trends in optimizing the cell finishing process include the integration of a second filling process for larger prismatic cells and the optimization of the formation protocol or Electrochemical Impedance Spectroscopy (EIS) as possible methods for quality inspection. Efforts are also being made to reduce the pre-treatment time and improve the degassing process to ensure cell performance, quality, and safety. In this paper, all process steps of the cell finishing process are presented, and their function and technological implementation in the industry are explained. Future innovations are analyzed in terms of time to market and the potential to optimize the process in terms of quality, time, and cost.

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