Performance improvement and numerical study on cathode channel for air-cooled open-cathode proton exchange membrane fuel cells

Bipolar plates perform multiple functions for the proton exchange membrane fuel cell (PEMFC). This study focuses on optimizing cathode channels to leverage a local loss mechanism to enhance gas transfer and diffusion efficiency. Through the investigation of 3D simulations, this research delves into the effects of curvature of cathode channels on both reactant transfer and diffusion. The results illustrated that compared with straight channels, the cell performance improves as the bending angle ( $ \theta $ theta) of 2.5 degrees and 5 degrees at different current densities. Specifically, at a bending angle of 5 degrees, a 5.5% higher current density than the channel of 0 degrees is obtained. This suggests that moderate curvature can effectively promote efficient mass transport and diffusion, ultimately contributing to enhanced cell performance. Furthermore, the analysis of local mass transfer and diffusion around the bends of channels underscores the importance of the balance between these factors. While bending angles within the range of 2.5 degrees to 5 degrees offer optimal performance gains, excessive curvature, such as a 10 degrees angle, may lead to diminished cell performance. By identifying the optimal bending angle range and elucidating the underlying mechanisms driving performance improvements, this study provides insights into the design and optimization of cathode flow fields in AO-PEMFC.