Stainless steel bipolar plate fuel cell with different flow field structures prepared by laser additive manufacturing

The bipolar plate is a key component of the proton exchange membrane fuel cell (PEMFC), as it connects each cell electrically, supplies reactant gases to both the anode and the cathode, and removes reaction products from the cell. In this work, stainless steel bipolar plates with different flow field structures were prepared by the selective laser melting (SLM) technique, and assembled into a single PEMFC to implement the polarization test. Finally, the operating parameters of CFD multiphase flow numerical simulation were set. The differences of current density distribution, gas diffusion characteristics and water distribution characteristics of different flow field structures and their influences on the performance of PEMFC were analyzed. Results show that the bipolar plates prepared by the SLM technology show high forming quality. The square mesh flow field (SMFF) is superior to the obstruction mesh flow field (OMFF). The power density of SMFF reaches 387.9 mW cm−2 at 0.3 V, which is ∼30% higher than OMFF. The gas and water distribution of SMFF is more uniform, and the electrical conductivity is higher, reducing its ohmic loss, and improving the output performance of PEMFC.