Towards robotizing the processes of testing lithium-ion batteries

Abstract

To boost the circular economy of the electric vehicle battery industry, an accurate assessment of the state of health of retired batteries is essential to assign them an appropriate value in the post automotive market and material degradation before recycling. In practice, the advanced battery testing techniques are usually limited to laboratory benches at the battery cell level and hardly used in the industrial environment at the battery module or pack level. This necessitates developing battery recycling facilities that can handle the assessment and testing undertakings for many batteries with different form factors. Towards this goal, for the first time, this article proposes proof of concept to automate the process of collecting the impedance data from a retired 24kWh Nissan LEAF battery module. The procedure entails the development of robot end-of-arm tooling that was connected to a Potentiostat. In this study, the robot was guided towards a fixed battery module using visual servoing technique, and then impedance control system was applied to create compliance between the end-of-arm tooling and the battery terminals. Moreover, an alarm system was designed and mounted on the robot’s wrist to check the connectivity between a Potentiostat and the battery terminals. Subsequently, the electrochemical impedance spectroscopy test was run over a wide range of frequencies at a 5% state of charge. The electrochemical impedance spectroscopy data obtained from the automated test is validated by means of the three criteria (linearity, causality and stability) and compared with manually collected measurements under the same conditions. Results suggested the proposed automated configuration can accurately accomplish the electrochemical impedance spectroscopy test at the battery module level with no human intervention, which ensures safety and allows this advanced testing technique to be adopted in grading retired battery modules.

Roadmap for a sustainable circular economy in lithium-ion and future battery technologies

“…In order to improve the economics of sorting batteries for reuse or recycle, the removal of manual operations could potentially speed the throughput of battery processing. To this end, robotisation of the testing process could lead to significant efficiency and economic gains [31].…”

“…Once the connection created, the Potentiostat starts collecting the LIB data. Reproduced from [31]. CC BY 4.0. challenge for automation.…”

“…In this technique, a custom-designed connector was attached to the end-effector of a collaborative robot (i.e. Franka robot arm) in order to make a firm connection with the battery terminals and to the Potentiostat [31]. The experiment proposed a framework to minimise the human interaction during LIB testing.…”

Semi-Autonomous Behaviour Tree-Based Framework for Sorting Electric Vehicle Batteries Components

“…Handling and recycling this type of material represents a high risk to the human health if not properly managed. This risk can be minimised if robots takeover the task of testing [2] or dismantling of EV batteries (EVB) in high demand situations [1,3]. However, a significant amount of research has to be carried out in order to ensure high reliability.…”

Improving the Manipulability of a Redundant Arm Using Decoupled Hybrid Visual Servoing

“…Controlling a robot using the image information has been the focus of a number of studies in the field of robotics and automation. There are a number of research studies that applied VS for solving industrial challenges and human-robot cooperation [4][5][6][7][8]. However, VS introduces new complexities in the image-space, joint space, and the intersection of these two; all of which must be considered [9].…”