Fabrication of PEM fuel cell bipolar plate by indirect selective laser sintering
A new manufacturing technique utilizing Selective Laser Sintering (SLS) has been developed for fabrication of proton exchange membrane fuel cell (PEMFC) bipolar plates. The layer-based nature of SLS offers several advantages for bipolar plate development and manufacturing. This additive process provides the ability to manufacture complex geometries that are otherwise difficult to obtain using conventional manufacturing techniques. SLS fabrication of bipolar plates will significantly benefit bipolar plate design research because prototypes can be produced and tested in a much shorter period of time and at a lower cost. In addition, fuel cell performance with plates having single serpentine, triple serpentine and interdigitated flow field designs were simulated using commercial Computational Fluid Dynamics (CFD) software package, FLUENT, which has a special PEMFC toolbox implemented for performance simulation. The PEMFC model in FLUENT is a multi-phase mixture model that is capable of predicting local current density distribution, temperature distribution and species vii concentration, etc. To verify the simulation results and demonstrate the value of the SLS technique, real plates with abovementioned flow field configurations were constructed based on the established SLS fabrication routes. Experiments were then conducted using a newly assembled PEMFC test unit with a bubble humidifier installed. Improved design and prompt experimental validation of fuel cell bipolar plates became possible through the combination of CFD simulation and the established indirect SLS process. Other novel bipolar plate designs were also proposed.