Processing and performance of solid oxide fuel cell with Gd-doped ceria electrolyte

Abstract

Fuel Cell performance was measured at 792–1095 K for Ni-GDC (Gd-doped ceria) anode-supported GDC film (60 μm thickness) with a (La 0.8Sr 0.2)(Co 0.8Fe 0.2)O 3 cathode using H 2 fuel containing 3 vol% H 2O. A maximum power density, 436 mW/cm 2, was obtained at 1095 K. The electrical conductivity of GDC electrolyte in N 2 atmosphere of 10 −15–10 0 Pa oxygen partial pressures ( Po 2) at 773–1073 K was independent of Po 2, which indicated the diffusion of oxide ions. The conductivity of GDC in H 2O/H 2 atmosphere increased because of the further formation of electrons due to the dissociation of hydrogen in GDC (H 2 → 2H + + 2e −). The hole conductivity was observed at 873 K in Po 2 = 10 0–10 4 Pa. The key factors in increasing power density are the increase of open circuit voltage and the suppression of H 2 fuel dissolution in GDC electrolyte. These are controlled by the cathode material and Gd-dopant composition.