Experimental study of key operating parameters effects on the characteristics of proton exchange membrane fuel cell with anode recirculation

• Effects of HCA mode on water management and cell performance are investigated. • Transparent fuel cell and PCB segmented fuel cell technologies are used. • Increased hydrogen circulation rate can alleviate the adverse effects of flooding. • Effects of hydrogen circulation rate on current density distribution are measured. • Higher hydrogen circulation rate leads to better overall and local stability. Water management is essential to ensure high performance and stable operation of the proton exchange membrane fuel cell (PEMFC). However, little is known about water management in the hydrogen circulation anode (HCA) mode which can achieve high hydrogen utilization. In this work, the effects of hydrogen circulation rate, a key parameter of HCA mode, on water management and cell performance are experimentally investigated. In particular, transparent fuel cell and printed circuit board segmented fuel cell technologies are used to study the water distribution and the local current density distribution, respectively. Furthermore, the electrochemical properties and PEMFC stability at different hydrogen circulation rates are discussed in detail. The experimental results indicate that increasing the hydrogen circulation rate reduces liquid water in the cathode and anode flow channels, which can effectively alleviate the adverse effects of flooding on overall performance and cell stability. However, subsequent drying of the membrane and catalyst layer results in an increase in ohmic resistance and a decline in cell performance, especially at low current densities. The current density distribution shows that severe local flooding is likely to occur in the hydrogen and air outlet regions at a low hydrogen circulation rate. For a high hydrogen circulation rate, membrane drying will occur in some areas, especially near the hydrogen inlet. To achieve uniform current density distribution and high fuel cell performance, the hydrogen circulation rate should be increased with the load current.