A novel manufacturing method for thin-walled battery cell cans made of pure aluminum with reduced geometrical distortion using PBF-LB/M

The early development of prismatic battery cells requires a rapid and flexible supply of housings in small quantities. Conventional manufacturing methods such as deep drawing or impact extrusion are time- and cost-intensive due to the need for specialized tooling with fixed geometry. Bending with welding or machining also has limitations for thin-walled designs. Additive Manufacturing (AM) via powder bed fusion of metals using a laser beam (PBF-LB/M) enables tool-free and geometrically flexible production, making it suitable for the time-efficient manufacturing of small batches, such as for iterative design adjustments. This study investigates the PBF-LB/M fabrication of thin-walled battery cell cans made of pure aluminum. To address the main challenge of process-induced distortion, several strategies were evaluated and assessed for suitability in two standardized formats for prismatic battery cells defined in DIN 91252:2016-11. These strategies include simulation-based pre-deformation, contactless support, a varied scan strategy, build plate heating, and stress-relief heat treatment. A novel direct support strategy was developed, enabling reproducible manufacturing with maximum out-of-plane distortion below 0.25 mm, measured via structured-light 3D scanning, in the BEV4 format. Post-processing by two-stage vibratory finishing achieved a surface roughness under 3 μm, meeting functional requirements. Helium leak testing confirmed hermetic sealing with leak rates below 2.57 x 10-1 mbar L s-1.