Multi-material additive manufacturing of conductor-insulator compounds for battery cell cap fabrication

This study aims to simplify and accelerate the production of battery cell housings through additive manufacturing, emphasizing reduced tooling requirements and flexible design possibilities—especially advantageous for early-stage prototyping. The research focuses on fabricating conductor-insulator compounds through multi-material powder bed fusion with a laser beam (PBF-LB). An additional nozzle-based powder deposition method allows for the processing of three materials within a single build job: electrically insulating alumina-toughened zirconia, along with highly conductive pure aluminum and pure copper. Initial results from mono-material ceramic manufacturing were followed by a detailed analysis of the multi-material process between the metals and ceramics. Various strategies for optimizing the material transition zone were explored, with the most effective approach incorporating a stepped interface design combined with overlapping laser vectors to compensate for thermal shrinkage. The aluminum–ceramic samples produced with this strategy successfully met the helium leak tightness criterion, exhibiting a maximum leak rate below 1x10^(-5) mbarL/s. This confirms that both the material transition and the ceramic region itself can be processed to be helium-tight. Furthermore, the investigations on ceramic processing revealed a maximum Archimedean density of 97.30%, and the ceramic specimens demonstrated a mean dielectric breakdown strength of 7.92 kV mm^(-1), underlining their suitability for insulation applications. These results demonstrate the robustness and potential of the proposed multi-material PBF-LB method for creating conductor-insulator compounds, particularly when compared to the current state of the art. The insights gained have led to the creation of guidelines that provide scientific support for future applications in multi-material manufacturing.