Triangular baffle design for proton exchange membrane fuel cell bipolar-plate channels evaluated by decoupled multi-physics analysis

Flow-channel design in bipolar plates of proton exchange membrane fuel cells (PEMFCs) is critical to mass transfer and water management, and incorporating baffles into channels is an effective strategy for improving cell performance. In this study, a three-dimensional multi-physics model of a PEMFC flow channel with triangular baffles was established and validated against experimental data, and the effects of baffle count, baffle height and tooth count on performance were examined independently. On this basis, the results were analyzed comprehensively using power density and polarization curves, together with velocity and concentration fields. The findings indicate that the multi-physics coupling model can accurately capture the operational behavior of PEMFC, achieving a maximum relative error of only 3.7 %. Increasing baffle count elevates the average oxygen velocity and substantially enhances PEMFC performance, whereas increasing tooth count provides a discernible yet modest benefit. In parallel, moderate increases in baffle height strengthen oxygen convection, while excessive height markedly raises the pressure drop and can induce recirculation between adjacent baffles, thereby impeding oxygen transport. Overall performance is maximized when baffle count is 5, baffle height is 0.5 mm and tooth count is 4, yielding power-density gains of 11.4 % at 0.6 V and 9.2 % at 0.4 V relative to the conventional channel. These findings provide robust modeling evidence and identify a practical baffle configuration for enhancing PEMFC performance.