Laser systems to catalyze productive manufacturing, says ILT

07 Feb 2023

EU project NextGenBat to boost energy storage with new materials and laser-based manufacturing.

The EU infrastructure project NextGenBat has ambitious goals: to significantly increase the performance of mobile energy storage devices such as batteries by employing new materials and laser-based manufacturing processes.

To achieve these goals, the partners are using an approach that will run laser-machining processes in parallel. With special optics, up to several hundred partial beams can be generated, which can then be used to significantly increase productivity through parallel processing. However, only a handful of specialist companies such as Pulsar Photonics have mastered this technology.

It all started with a very large project: For two years, six institutes from Aachen, Jülich and Münster used a budget of 10 million euros to create forward-looking infrastructure for new production technologies and production concepts. By expanding the research infrastructure already in place in Nord Rhein Westfalia, they have created optimum conditions for regional companies to research and develop batteries of the next generation.

Laser micromachining

One of the NextGenBat participants, Pulsar Photonics (Herzogenrath, Germany), is now putting the preliminary work of the European Regional Development Fund (ERDF) project into practice.

The laser source, optics, sensor technology and software can be optimally combined in a customized system to process any material and component . Optical components and systems for beam shaping and multi-beam processing are developed in-house, thereby significantly boosting the processing speed.

In terms of battery technology, Pulsar has received support from Patrick Gretzki since summer 2020; from the beginning, the physicist has been involved in the NextGenBat project at Fraunhofer ILT as a team leader for Thin Film Structuring.

The institute developed a roll-to-roll system that dries and structures electrodes for lithium-ion cells in order to achieve new properties, such as higher capacity to increase fast-charging.

Gretzki, Department Manager for System Components and Optical Systems, commented, “We now benefit from the experience gained in customer inquiries for large-area structuring of components.”

He added, “The MultiBeamMultiScanner optics developed by Pulsar can divide the power of the laser system into a large number of partial beams. The method has proven particularly useful for ultrashort pulse lasers, whose output can otherwise only be increased to a limited extent in single-beam processes, partly because the thermal load on the workpiece is too high.”

The parallel operation of several laser beams allows each individual partial beam to operate at maximum efficiency and thus to process the workpiece in a highly productive manner with practically no thermal stress.

Infrared and green

The optics from Herzogenrath split the infrared, pulsed laser radiation into 24 partial beams that structure an approximately 300mm-wide band of a battery anode. The optics module can then be used in a second process step with a green laser to cut out the individual battery cells with a single beam.

The system developed at Fraunhofer ILT (ILT) offers a variety of possibilities for laser-based microstructuring for battery production.

But what do potential users want? “On the one hand, customers want easily adjustable optics that need little calibration, are optimized for high laser power and operate with long-term stability in production environments,” said Gretzki.He added, “There is a demand for scanners that can be synchronized with appropriate software and control support to coordinate the processing of multiple scan fields with each other. Or even, as in this case, synchronized with the movement of a belt. The demand for such sophisticated solutions is growing.”

2023 target: series production

Few technologies are truly technologies of the future. Multi-beam processing, on the other hand, holds enormous potential for optimizing production steps in terms of flexibility, digitalization and cost efficiency. The fields of application lie in the entire area of laser microstructuring, parallel processing of multiple components or the general parallelization of laser processes.

Next up for the company is thus further advancing combined multi-beam processing for a production-ready application in industry. Gretzki added, “We are still looking for partners and applications to adapt the concept and validate it in continuous production operation. We imagine that a large number of processes can be economically scaled with this in the future.”