Dimensional tolerance analysis of proton exchange membrane fuel cells with metallic bipolar plates

Abstract Metallic bipolar plates (BPPs) are promising candidates for replacing conventional carbon-based BPPs. However, manufacturing errors are unavoidable on metallic BPPs due to the characteristics of fabrication processes. This study is conducted to further develop tolerance design method for dimensional error and assembly error based on the contact behavior model proposed in our previous work. Contact pressure distribution, contact resistance and gas diffusion layer (GDL) porosity are used as the evaluation indexes combined by desirability function method. Based on the contact behavior model, effect of dimensional error is substituted into the model by Monte Carlo Simulation, and misalignment between the upper plate and lower plate is included in the model to obtain the effect of assembly error. It is found that dimensional error and assembly error contribute to uneven pressure distribution, larger contact resistance and higher GDL porosity. The acceptable maximum dimensional error of 0.007, 0.012, 0.010 mm and assembly error of 0.080, 0.10, and 0.060 mm are recommended for the fuel cells with the channel widths of 1.0, 2.0 and 4.0 mm, respectively. This methodology developed is beneficial to the understanding of the effect of dimensional error and assembly error, and effective supplement to fabrication management of metallic BPPs.