Pore-Scale Study of Liquid Water Management in Proton Exchange Membrane Fuel Cell with Alaterally Graded Porous Microporous Layer

A 2D multi-component polyphase model pseudopotential LB model was developed and verified in the present study. This model is applied to the electrodes of MPL with the laterally graded porous distribution.The porous structure with the gradient direction parallel (PLCG) and perpendicular to the bipolar plate gas channel (PRCG) was reconstructed. Based on the above model, the transport and distribution of liquid water and reactive gas under different working conditions were studied. In the PRCG model, the gas saturation increases with the gradient, resulting in an increase in liquid water removal efficiency. In the models with gradients of 4 and 6, the saturation of gas and liquid showed uniform changes, and the distribution of gas and liquid was also relatively uniform. In addition, the multi-stage model is conducive to the removal of liquid water for the same gradient. In the PLCG model, pores with large gradient distribution in MPL are favorable for liquid water removal and gas retention. Inlet air velocity increases will only affect gas-liquid saturation in models with gradients 4 and 6. Therefore, the transport and distribution of liquid water in the electrode can be effectively improved by optimizing the laterally ordered distribution of pores in MPL.