Enhanced oxygen discharge with structured mesh channel in proton exchange membrane electrolysis cell

The oxygen discharge in the proton exchange membrane electrolysis cell (PEMEC) has a great influence on the performance because it hinders the liquid water supply from channel to the catalyst layer (CL). In this study, a novel structured mesh channel is proposed to enhance the oxygen discharge capacity in PEMEC, in which the solid skeleton structure facilitates oxygen bubble splitting, and the structural capillary force effect promotes the oxygen detach the liquid/gas diffusion layer (L/GDL) surface. The gas and liquid two-phase flow characteristics in structured mesh channel and conventional straight hollow channel are compared in detail using the volume of fluid (VOF) model, which is subsequently integrated with a three-dimensional (3D) multiphase full-cell model through data exchange to simulate the influence of oxygen in channel on the PEMEC performance. Note that the reliability of this integration method is validated against the experimental oxygen distribution in parallel and serpentine flow fields and the electrochemical performance simultaneously. It is also found that reducing the skeleton surface hydrophobicity (i.e. contact angle) gradually from the channel top to L/GDL surface helps improve the oxygen discharge capacity and hence the PEMEC performance.