E-Mobility Engineering 016 l Aurora Powertrains eSled dossier l In Conversation: Thomas de Lange l Automated manufacturing focus l Torque sensing insight l Battery Show Europe 2022 report l Sodium batteries insight l User interfaces focus

Cutting-edge research and prototype factories are helping to advance the automation of EV component manufacturing, writes Nick Flaherty Just push the button S ome car makers have had fully automated assembly of vehicles for many years, and EV makers are looking to achieve this ‘lights out’ approach, but face added issues with the assembly of lithium-ion cells, battery packs and wiring harnesses. An automated assembly approach for e-mobility uses a wide range of industrial automation processes, from roll printing to industrial robots, with techniques such as additive manufacturing (AM) and digital twin software being added to improve the process. A new production process and a larger lithium-ion cylindrical cell size are aiming to drive the automated manufacturing of battery cells; the cell’s design is key to scaling up production. Its form factor measures 46 mm in diameter and 80 mm long, or 4680 format. That compares with the previous 1865 and 2170 cells that are 18 mm and 21 mm in diameter respectively. It uses a tabless construction with a dry electrode process, a simple silicon anode and a cobalt-free high-nickel cathode. All this is built on a high- speed continuous line similar to that in a bottling plant, and produces 20 GWh worth of batteries a year – seven times the capacity of existing lines. The high speed is a result of the tabless construction. Rather than using tabs top and bottom, the substrate of the ‘jelly roll’ that holds the anode, electrolyte and cathode has copper edges that are laser-patterned that fold over to produce the connections top and bottom. That avoids having to stop and start the line to insert the tabs. The cell also has no intermediate structure, so there’s more space for the materials to boost its energy capacity. Instead of a flame-retardant filler in the pack, the filler is a structural adhesive that is also flame retardant. That allows shear transfer between the top and bottom sheets, which gives stiffness. Traceability A key advantage of automating the assembly process, other than throughput, is the traceability. Being able to monitor the data from each stage of the process feeds into the digital twin that is used to optimise the process further, and to track the performance of the cells. If there is a problem further down the line, in the battery pack or a vehicle, the traceability can determine the exact cause, the batch affected and the issues for a supplier. That can reduce the size and impact of any recall. In Germany, the DigiBattPro 4.0 project aims to completely digitise a cell production facility, to improve and stabilise the quality of lithium-ion batteries. Starting with coin cells, the process will be developed and tested during the first phase of the project and then transferred to 21700 lithium-ion Automated assembly of battery packs uses a range of processes, including industrial robots (Courtesy of KUKA) 34 Winter 2022 | E-Mobility Engineering