Direct kinetic loss analysis with hierarchy configuration of catalyst coated membrane in proton exchange membrane water electrolysis cell

The electrode kinetics and degradation originations are key factors for proton exchange membrane water electrolyzer (PEMWE). However, it is hard to directly characterize these factors in an operating PEMWE, which is because of the coupled components. In this study, we fabricate a hierarchy configured catalyst coated membrane by implementing voltage sensing wires, which enables the in-situ characterization on each part in a PEMWE. Specially, using the integrated configuration, the voltages on anode and cathode electrode can be measured, which provides a chance for determining the kinetics of the electrode. The exchange current density and charge transfer coefficient could be easily obtained. This integrated hierarchy configuration provides a reliable pathway for developing usable catalyst materials and optimizing catalyst layers. The impedance on an inner component can also be measured, and we find that the kinetics are the main losses for both anode and cathode electrode, which contribute to more than 96.6% to electrode voltage loss in low current density range. Additionally, the technique can monitor the internal voltages in an operating PEMWE, which provides valuable data for performance change diagnostic and analysis. The hierarchy configuration enriches the PEMWE characterization methods, and has great promise for industrial applications due to its easy setup and high feasibility.