Integration of laser structuring into the electrode manufacturing process chain for lithium-ion batteries

Despite the electrochemical benefits of laser electrode structuring, the process is not yet implemented in state-of-the-art industrial battery production due to a limited knowledge regarding its implementation into the manufacturing process chain. In this study, three process integration positions for laser structuring of graphite anodes, which are either after coating, after drying or after calendering, were experimentally evaluated. The obtained electrodes were analyzed regarding geometrical, mechanical and electrochemical characteristics. The results indicate that the material ablation process is governed by the evaporation of solvent and binder for wet and dry electrodes, respectively. As a consequence, electrodes structured in wet condition exhibited fewer particle residues on the electrode surfaces and a high coating adhesion strength. In contrast, laser structuring of dry electrodes significantly reduced the pull-off strengths of the electrode coatings. A tortuosity reduction and an increased discharge capacity at high C-rates by laser structuring were observed for all structured electrodes, but with higher performance improvements for electrodes structured in dry state. Although a partial clogging of the structures was observed in electrodes structured before calendering, laser structuring yielded a comparable electrochemical performance of electrodes which were structured in dry condition before and after calendering.

Automated summary

Despite the advantages of laser electrode structuring, its implementation in industrial battery production is limited due to a lack of knowledge regarding its integration into the manufacturing process chain. This study experimentally evaluated three process integration positions for laser structuring of graphite anodes. The results showed that the material ablation process is influenced by the evaporation of solvent and binder for wet and dry electrodes, respectively. Laser structuring improved the discharge capacity and reduced tortuosity for all structured electrodes, with better performance for dry electrodes.