Structural and Conductivity of NiO-BCZY Anode Functional Layer for Proton Conducting Fuel Cell

Abstract

The main objective of this study is to perform a structural analysis of NiO-BCZY anode functional layer (AFL) with different weight ratio (NiO:BCZY = 20:80 and 40:60). NiO commercial powder and in-house developed BCZY synthesized by a sol-gel method are mixed and ground and then sintered at 1450° C for 5 hours to produce AFL powder. The single-cell (anode | CG-AFL| electrolyte | cathode) is fabricated with the anode substrates firstly die-pressed, then compositionally gradient anode functional layer (CG-AFL) and spin-coated with electrolyte thin film, accordingly. Structural characterization of AFL powder and conductivity of the single cell is performed using room temperature X-ray diffraction (XRD) and in-house developed electrochemical impedance spectroscopy (EIS) test station, respectively. Rietveld refinement analysis of the XRD data confirms the high purity single phase of NiO and BCZY. Both NiO and BCZY show a cubic crystal structure and each belongs to space group Fm-3m and Pm-3m, respectively. The lattice parameter (a = b = c) of NiO and BCZY are about 4.1818 Å3 and 4.3433 Å3 for 20NiO-80BCZY and 4.1825 Å3 and 4.3439 Å3 for 40NiO-60BCZY. EIS results show ohmic resistance (RS) and polarization resistance (RP) of the single cell are 14.8 and 16.23 Ωcm2 at 800 °C, respectively.