Optimization of blocked flow field performance of proton exchange membrane fuel cell with auxiliary channels

The flow field optimization design is one of the important methods to improve the performance of proton exchange membrane fuel cell (PEMFC). In this study, a new structure with staggered blocks on the parallel flow channels of PEMFC and auxiliary flow channels under the ribs is proposed. Through numerical calculation method, the effect of blocks auxiliary flow field (BAFF) on pressure drop, reactant distribution and liquid water removal in the fuel cells are investigated. The results show that when the operating voltage is 0.5 V, the current density of BAFF is 21.74% higher than that of the straight parallel flow field (SPFF), and the power density reaches 0.65 W cm⁻². BAFF improves performance by equalizing the pressure drop across sub-channels, promoting the uniform distribution of reactant, and enhancing transport across the ribs. In addition, through parameter analysis, it is found that BAFF can discharge liquid water in time at the conditions of high humidification, high current density and low temperature, which ensures the output performance of the fuel cell and improves the durability of the fuel cell. This paper provides new ideas for the improvement of PEMFC flow field design, which is beneficial to the development of PEMFC with high current density.