The proton-exchange membrane fuel cell is a highly attractive clean energy technology for the future. However

differences in the consistency and uniformity of commercial-size fuel cell stacks significantly impact their health status and lifespan. This study is based on a commercial-size 10-cell stack. First

the characteristic frequency was determined by multipoint voltage and impedance sweeping experiments. Subsequently

the consistency and uniformity of the output characteristics of the stack at various loads under standard operating conditions were comprehensively analyzed using fixed-frequency multipoint impedance. Finally

a sensitivity analysis was conducted to quantitatively assess the effects of key parameters

including the air stoichiometry ratio and operating temperature

on the consistency and uniformity of voltage and high-frequency resistance. The inconsistency is more pronounced at high current densities

especially at the cathode inlet side compared to the outlet side. At low-current-density operation

the high-frequency resistance is greater at the cathode inlet side compared to the outlet side due to uneven gas distribution and more severe membrane drying at the inlet side. Increasing the air stoichiometry ratio enhances the consistency and uniformity of the stack. The effect of temperature on stack consistency is not significant in the appropriate temperature interval

but higher temperatures can reduce cell uniformity differences. The analytical approach in this study can provide guidance for stack consistency and uniformity studies.