Extending the 3D-battery concept: large areal ultrashort pulsed laser structuring of multilayered electrode coatings

In the presented study, the use of an ultrashort pulsed laser system with high average laser power up to 300 W and repetition rate in the MHz regime in combination with multilayer coating was evaluated regarding the processing of multidimensional structured silicon/graphite anodes. Line patterned composite graphite anodes with grooves of different aspect ratios were generated by variation of laser and process parameters like laser fluence, pulse overlap, and repetition rate. The perspective of laser process upscaling is discussed, and it was shown that an increasing number of scans almost linearly increases the ablation depth, while the ablation width stays constant. The structured graphite anodes were handed over to a second coating step, in which a silicon containing slurry was coated to create an electrode architecture with spatial separation of graphite and silicon in the plane of the electrode. The quality of the multiple coated electrodes was studied to define a structure geometry in which defect-free filling is achieved in the second coating process. The filling of the electrode in the multilayer coating showed a dependence in blade gap during coating and laser-generated structure aspect ratio.