Post-heat treatment pressure effect on performances of metal-supported solid oxide fuel cells fabricated by atmospheric plasma spraying

Abstract

The nickel metal-supported cells fabricated by atmospheric plasma spraying are post-heat treated in air at 960°C for 2h with different pressures. The current–voltage–power and AC impedance measurements show the prepared cell with an applied pressure of 450gcm−2 in the post-heat treatment has a better electrochemical performance at test temperatures≥650°C. For test temperatures<650°C, the maximum power densities at 450gcm−2 pressure are about the same as the maximum power densities at 1250gcm−2 pressure. The SEM micrograph indicates that the cathode including the cathode interlayer and the cathode collector is the most porous region in the cell. AC impedance results show this cathode is the most sensitive part to the applied pressure in the post-heat treatment and the cell with 450gcm−2 pressure has the smallest low frequency intercept R2 and the polarization resistance Rp at temperatures from 600 to 800°C. The performance durability test of the cell post-heat treated at 450gcm−2 pressure shows a degradation rate of 0.0087mVh−1 or 0.0026mWh−1 at 300mAcm−2 constant current density and 750°C test temperature.