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A 2D isothermal axisymmetric model of an anode‐supported solid oxide fuel cell has been developed. The model, which is based on finite element approach, comprises electronic and ionic charge balance, Butler–Volmer charge transfer kinetic, flow distribution and gas phase mass balance in both channels and porous electrodes. The model has been validated using available experimental data coming from a single anode‐supported cell comprising Ni–YSZ/YSZ/LSM–YSZ as anode, electrolyte and cathode, respectively. Hydrogen and steam were used as fuel inlet and air as an oxidant. The validation has been carried out at 1 atm, 1,500 ml min–1 air flow rate and three different operating conditions of temperature and fuel flow rate: 1,073 K and 400 ml min–1, 1,073 K and 500 ml min–1, and 1,003 K and 400 ml min–1. The polarization and power density versus current density curves show a good agreement with the experimental data. A parametric analysis has been carried out to highlight which parameters have main effect on the overall cell performance as measured by polarization curve, especially focusing on the influence of two geometrical characteristics, temperature and some effective material properties.

This research consists of both theoretical and experimental sections presenting a novel scenario for the consumption of hydrogen in the polymer electrolyte membrane fuel cell (PEMFC). In the theory section, a new correction factor called parameter δ is used for the calculation of fuel utilization by introducing concepts of “useful water” and “non-useful water”. The term of “useful water” refers to the state that consumed hydrogen leads to the production of liquid water and external electric current. In the experimental section, the effect of the relative humidity of the cathode side on the performance and power density is investigated by calculating the parameter δ and the modified fuel utilization at 50% and 80% relative humidity. Based on the experimental results, the maximum power density obtained at 50% and 80% relative humidity of the cathode side is about 645 mW/cm2 and 700 mW/cm2, respectively. On the other hand, the maximum value of parameter δ for a value of 50% relative humidity in the cathode side is about 0.88, while for 80% relative humidity it is about 0.72. This means that the modified fuel utilization for 50% relative humidity has a higher value than that for 80%, which is not aligned with previous literature. Therefore, it is necessary to find an optimal range for the relative humidity of the cathode side to achieve the best cell performance in terms of the power generation and fuel consumption as increasing the relative humidity of the cathode itself cannot produce the best result.