Hydrogen production in a proton exchange membrane electrolysis cell (PEMEC) with titanium meshes as flow distributors

Abstract

The proton exchange membrane electrolysis cell (PEMEC) is a green and efficient method for producing hydrogen. The flow field structure is a critical factor affecting the performance of electrolysis. However, conventional processing of flow channels is complex and expensive, a novel PEMEC structure utilizing three-dimensional titanium meshes as flow distributors instead of flow channels is proposed. It is found to exhibit higher current density, pressure, hydrogen concentration, and lower temperature than the traditional parallel flow fields. The current density is improved by 88.2 mA/cm2 and the energy consumption is reduced by 0.15 kW h N−1·m−3 at 1.9 V. Based on the uniformity index, the new structure is found to improve the current and temperature uniformity by 20.6% and 13.4%, respectively, when compared to the parallel flow field structure. Additionally, the physical properties of the mesh layers are studied in terms of their influence on electrolysis performance. The increase in porosity and decrease in thickness can enhance the performance of the cell. The results show that a structure with titanium meshes is more beneficial for improving the heat and mass transfer performance and optimizing uniform distribution than the parallel channels, which provides a new direction for the design of electrolysis cell structures.