**2. Building Blocks of an Automated Disassembly Station**

An automated disassembly station for EVBs can be reduced to two building blocks: (1) a mechanical system that directly interacts with the EoL products, and (2) a disassembly planner that adaptively calculates and updates the disassembly strategies (see Figure 2). The subcomponents are described in the following sections to show the big picture of our work. Thereby, publications in the context of battery disassembly are assigned to the respective subcomponent.

#### *2.1. Mechanical System*

#### 2.1.1. Manipulators

Manipulators are responsible for moving several components during the disassembly process. These components can either be part of the battery or the disassembly station, such as tools and sensors. Robot arms are typical manipulators. The disassembly process can be carried out using a single manipulator resulting in a sequential disassembly, in which the parts are removed one by one. However, multiple manipulators have a great potential to reduce the disassembly time if parallel disassembly activities are possible. This is known as corporative disassembly. The disassembly sequence planning is more complicated if more than one manipulator is used [15].

**Figure 2.** Building blocks of disassembly stations.

## 2.1.2. Disassembly Tools

EVBs are complex products whose disassembly is associated with multiple difficulties. Screw connections are frequently found in batteries. This allows the application of non-destructive disassembly. However, different screw types are often used, which are not accessible from the same direction [16]. This means that disassembly involves frequent tool and direction changes, which have to be considered while planning the disassembly process. Furthermore, many non-detachable connections are used in EVBs, such as welded joints. This is especially the case at the module level when connecting the cells [17], where welding processes have become established because they increase the electrical performance and improve the joints' thermal properties and long-term stability [18]. However, these joints are difficult to disassemble, especially when alternative circular economy strategies are targeted.

Moreover, various other joining techniques are used in the battery, such as adhesive bonding and riveting. In addition, there are several connector systems and flexible components that have to be disconnected or cut. That is why an automated disassembly of EVBs can only be achieved with a wide range of disassembly tools. In the literature, various tools have been presented that can be used in automating individual steps of battery disassembly. Tan et al. [9] presented a pneumatically actuated separation tool suitable for removing covers and stack holders and an unscrewing device with integrated torque sensors. Kay et al. [19] proposed a cost-effective cutting instrument based on a high-speed rotary cut-off wheel, which can be integrated into a disassembly station for battery modules. However, according to their evaluation, laser cutting is more suitable to achieve lower heat

generation and vibration amplitudes and higher cutting accuracy. Li et al. [20] proposed an automated disassembly system for Z-folded pouch cells consisting of three modules for the pouch trimming, housing removal, and electrode sorting. Thereby, they presented a pouch trimming module consisting of a trimming blade set, a trimming base set, and a conveyor roller set. In this context, the main challenge in designing disassembly tools will be to develop universal tools that are, first, suitable for different battery variants and, second, capable of performing more than one disassembly task to reduce the number of tool changes during disassembly.
