Multi-technique experimental characterization of a PEM electrolyzer cell with interdigitated-jet hole flow field

In this study, an interdigitated-jet hole flow field (IJFF) was fabricated and experimentally investigated. Following the concept of multi-technique characterization, the characteristics of IJFF with serpentine flow field (SFF) and interdigitated flow field (IFF) were compared in a PEM electrolyzer cell (PEMEC). Specifically, through polarization curves, electrochemical impedance spectroscopy (EIS), and distribution of relaxation time (DRT), the polarization losses in the electrochemical processes of different flow fields were thoroughly analyzed. The results confirmed the advantages of IJFF in reducing Ohmic impedance and promoting mass transfer. In addition, the in-plane temperature distribution and current density distribution were measured within the flow field area, revealing better temperature stability and current distribution uniformity in the IJFF. Furthermore, two-phase flow visualization and numerical simulations demonstrated the capability of IJFF to enhance bubble movement and improve under-rib convection. The outcomes indicated that multi-technique characterization was a comprehensive performance evaluation method, and the experimental results robustly affirmed the advantages of IJFF in electrochemical performance, electro-thermal-fluid field uniformity, and efficient mass transfer.