To cover the growing demand of lithium ion batteries, an increase in the productivity for cell assembly processes is necessary. The process steps of cutting, packaging and contacting are a bottleneck in the process chain and limit the output of the cell assembly process significantly. The project “HoLiB – High throughput processes for the production of lithium ion batteries” aims to increase the productivity of these process steps by the development of new technologies and the reduction of non-value-adding times within the process chain.
Regarding the cutting, a laser die cutter is developed which is able to cut electrodes within milliseconds while the electrode material is supplied continuously from a coil. A newly developed rotating stacking wheel places the electrode sheets for the packaging process. This technology replaces the pick-and-place process of a robot, as a further increase in productivity is limited for pick-and-place-processes. Laser welding is used for contacting of the electrode stack. Process quality and process speed are optimisation parameters for the welding process.
The project aims to link the different process steps as mentioned above. Therefore, the supply of the rotating stacking wheel by the laser die cutter and the electrode feed is very flexible. This leads to the reduction of buffers and waiting times and connects the process steps efficiently.
The developed technologies are realised in a prototype. An inline quality assurance is implemented in the prototype to evaluate the processes. An electrochemical analysis of fully assembled cells completes the assessment of the process.
The results of the project highly influence the productivity increase the cell assembly process of lithium ion batteries.