Jan Schmitt

Assessment of Automation Potentials for the Disassembly of Automotive Lithium Ion Battery Systems

Lithium ion batteries from electric vehicles contain lots of valuable materials (e.g. lithium, cobalt, copper). To successfully recover these materials the recycling process becomes crucial. In the recycling process, a central aspect is the mechanical disassembly, which needs to be automated to make the recycling economically viable. In this paper an integrated methodology is presented that enables the assessment of automation potentials for disassembly operations for automotive traction batteries. Based on a product analysis and a criteria catalogue, disassembly steps that are worth being automated, can be identified. Thus, decision making regarding the automation of single disassembly steps is supported.

Scenario-Based Development of Disassembly Systems for Automotive Lithium Ion Battery Systems

The rising number of lithium ion batteries from electric vehicles makes an economically advantageous and technically mature disassembly system for the end-of-life batteries inevitable. The disassembly system needs to cope with the size, the design and the remaining state of charge of the respective battery system. The complex design resulting from the number and type of connection elements challenges an automated disassembly. The realisation of an automated disassembly presupposes the consideration of elements from Design for Disassembly throughout the battery system development. In this paper a scenario-based development of disassembly systems is presented with varying possible design aspects as well as different amounts of end of life battery systems. These scenarios point out the resulting implications on battery disassembly systems in short, medium and long term. Using a morphological box the best option for each disassembly scenario is identified and framed in a disassembly system design. The disassembly systems are explained and the core elements are introduced. Newly developed and innovative disassembly tools, such as a robot that allows a hybrid human-robot-working-space and an advanced battery cell gripper are introduced. The gripper system for the battery cells enables with an integrated sensor an instant monitoring of the battery cell condition. The proposed disassembly element is verified in an experimental test series with automotive pouch cell batteries.

Design of a hyper-flexible assembly robot using artificial muscles

The paper presents the design of a hyper flexible robot, actuated by artificial muscles, based on the requirements of industrial assembly. The design process is inspired by biological examples and leads to a high-segmented kinematic structure with redundant degrees of freedom in order to increase the maneuverability of the robot. The actuators are arranged according to the agonist-antagonist principle of biological muscles to ensure the symmetric double sided deflection of the joints at each segment. Another advantage of the structure is the modular design. The mechanism is extendable by a simple, uniform mechanical interface. This contribution focuses on the mechanical structure, the kinematic behavior and the benefits of the chosen actuation principle in order to show the functionality of the robot. The prototype has six segments with twelve degrees of freedom, qualified by the corresponding number of actuators and their arrangement according to the mechanical structure. The endeffector has four coupled degrees of freedom, three translational and one rotational.

Disassembly automation for lithium-ion battery systems using a flexible gripper

The integration of lithium ion battery technology in the automotive sector has increased enormously during the last years. Additionally, beside the production and operation of these battery systems the recycling has to be taken into account concerning the challenge of ecologic sustainability. An economical recycling depends on the possibility to mechanize or automate several disassembly steps in order to separate the valuable battery cells or active cell materials. Hence, this contribution presents the challenges of disassembly automation in the special context of lithium ion battery technology in general. Furthermore, a flexible gripper system is presented in detail to show how the disassembly process can be supported by automation. Next to the mechanical design of the gripper system, the control architecture and the integrated functionalities, such as voltage or resistance measurement, are described.

Dynamic Reconfiguration of Parallel Mechanisms

Shorter product life cycle as well as higher product complexity and diversity require more flexible manufacturing systems. Dynamic reconfiguration is a time efficient way to adapt system properties to rapidly changing process requirements. The potential to reconfigure parallel mechanisms depends on specific and optimized machine components, which enable modification of kinematic behaviour of the system. In this contribution influence of several component parameters on system properties and the needs to develop more suitable machine components are highlighted. Furthermore, a possibility to adapt kinematic properties of a planar RRRRR-mechanism, using an adaptive revolute joint, is introduced.

Disassembly Planning and Assessment of Automation Potentials for Lithium-Ion Batteries

Traction batteries are composed of various materials that are both economic valuable and environmentally relevant. Being able to recover these materials while preserving its quality is not only economically attractive, but it can also contribute to decrease the environmental impact of electric vehicles. Disassembly can play in this regard a key role. On the one hand it might allow to separate potential hazardous substances and avoid an uncontrolled distribution of these substances into other material flows. One the other hand disassembly might promote improving the rate of material recovered while preserving its quality and decreasing disassembly costs. In this chapter we present a methodology for the estimation of disassembly sequences and for the estimation of automation potentials for the disassembly of traction batteries. The methodology is illustrated with an experimental case study.

TRoBS — a biological inspired robot

This contribution presents a biological inspired robot, called Trunk Robot Braunschweig (TRoBS). The structural shape of the robot is motivated by a trunk mechanism, where the robot is actuated by NiTi shape memory alloy (SMA) wires, placed according to the agonist-antagonist principle of muscles. The robot has a modular structure, the single segments are connected by compliant joints, whose arrangement permit a variable degree of freedom (DoF) depending on the number of segments. The joints have a similar working principle as revolute joints. In order to show the functionality of the robot, the mechanical structure, the benefits of compliant joints as well as a method of kinematic modelling are presented. Another focus is placed on the actuation principle. The robot is actuated by SMA wires formed like springs, which provide advantages in design as well as in control aspects. Due to the high modularity of the mechanism, the robot is arbitrarily extendable and so adoptable for several applications.

Coupled mechanical and electrochemical characterization method for battery materials

A battery separator isolates anode and cathode electrically and contributes to the ionic conductivity on the one side. On the other side, it is a highly sensitive functional component concerning mechanical loads. During production as well as the operation of a battery this thin, polymer based film is stressed by compressive and tensile forces. This contribution presents an enhanced characterization method for the separator/electrolyte system under defined mechanical load. The method is based on electrochemical impedance spectroscopy (EIS). The test bench design, functionality and the sample preparation as well as the characterization procedures are shown, before experimental results are discussed. The paper aims to contribute to the refinement of EIS data interpretation and determine critical states regarding mechanical pressure of the battery separator for both, production and operation.

Failure Mode Based Design and Optimization of the Electrode Packaging Process for Large Scale Battery Cells

The increasing demand of electric vehicles and thus Lithium-Ion batteries results in a multitude of challenges in production technology. The cost-effectiveness, reproducibility, performance and safety requirements of large scale batteries for automotive applications are very high. At the same time the production processes are complex and have many uncertainties, namely how single parameters influence the specific values of the battery performance. Therefore, this article focuses on the design and optimization of production processes of large scale batteries using an established FMEA approach. This method is applied to the electrode packaging process, which constitutes a crucial production step, as the anode and cathode material is assembled to create a multi-layer cell. Based on a failure mode ranking, two categories of essential failure are considered in detail. First the positioning error of the electrode foils and following this the multi-layer handling during the process. Here, an algorithm to simulate the stacking error is presented and a sensor concept to detect multi gripped layers during the handling by a gripper integrated eddy current sensor is introduced.