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

A BaZr _0.4Ce _0.4Y _0.2O _{3 - 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 BaZr _0.4Ce _0.4Y _0.2O _{3 - δ} (BZCY) as the electrolyte and composite BZCY-Ba _0.5Sr _0.5(Co _0.8Fe _0.2) _0.9Ti _0.1O _{3 - 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.