Performance of 3D-Printed Fuel Cells and Stacks

Abstract

Additive manufacturing (AM) is being touted as a possible tool for rapid prototyping fuel cell bipolar plate (BPP) designs. We use the AM method of direct metal laser sintering (DMLS) to make 21 cm2 titanium-alloy BPPs with embedded flow channels. The surface of the BPPs is then polished to the appropriate roughness and coated with a conductive corrosion barrier. The coated BPPs are assembled with the appropriate seals, catalyst coated membranes and gas diffusion layers into a 40-cell stack and tested. The resulting 400 W fuel cell stack power is 20% less than expected because of inadequate flatness of several of the DMLS BPPs as determined by white light profilometry, leading to high contact resistance. While DMLS clearly shows the benefit of being able to make complex flow fields and hollow parts with no welds, more work is needed toward reducing the weight and increasing the flatness of BPPs made by AM.