Effect of anode functional layer on the performance of proton-conducting solid oxide fuel cells (SOFCs)

A BaZr0.4Ce0.4Y0.2O3 − δ (BZCY)-NiO anode functional layer was added between the BZCY electrolyte and the BZCY-NiO anode substrate to investigate its effect on the performance of single cells. With BaZr0.4Ce0.4Y0.2O3 − δ (BZCY) as the electrolyte and composite BZCY-Ba0.5Sr0.5(Co0.8Fe0.2)0.9Ti0.1O3 − δ as the cathode material, anode-supported electrolyte fuel cells were fabricated and tested. The single cell without an anode functional layer generated maximum power densities of 181, 138, 116, 77, and 49 mW cm− 2 at 700, 650, 600, 550, and 500 °C, respectively, whereas those for the single cell with an anode functional layer significantly improved up to 281, 243, 194, 145, and 95 mW cm− 2 at the same temperatures, almost doubling the power output. Electrochemical impedance spectroscopy (EIS) measurements for these two cells revealed that the addition of the anode functional layer reduced the contact resistance as well as the polarization resistance for the cell, resulting thus in the improved cell performance.

► The importance of the anode microstructure on the cell performance was demonstrated.
► The addition of anode functional layer can dramatically improve the cell performance.
► The anode functional layer reduced both contact and polarization resistances.