Influence of non-uniform assembly contact pressure on multiphysics characteristics and performance loss of large-area PEMFC using 2D partitioned model

Large-area proton exchange membrane fuel cells (PEMFCs) are prone to multiphysics inhomogeneity and performance degradation under non-uniform assembly forces. However, conventional single-channel or small-scale models cannot capture contact pressure variations across large active areas and their coupled transport-electrochemical behaviors. In this study, a novel two-dimensional (2D) partitioned model is developed to predict the distributions of water, gas, and current density under non-uniform contact pressure. Local contact resistance, gas diffusion layer porosity, and permeability are coupled with contact pressure to reflect compression-induced structural heterogeneity. The results show that non-uniform contact pressure mainly affects ohmic loss, followed by concentration loss, while activation loss is marginally influenced. Based on the pressure-distribution characterization method, reducing the radius of the central low-pressure region improves current density uniformity by 4.5%, whereas increasing the gradient scaling factor improves it by 13.5%. The model provides an efficient approach for evaluating non-uniform contact pressure effects on large-area PEMFC performance.