Evaluation of BaCo0.4Fe0.4Zr0.2−xNixO3−δ perovskite cathode using nickel as a sintering aid for IT-SOFC

Abstract

In this research work, BaCo₀.₄Fe₀.₄Zr_0.2−xNi_xO_3−δ (x = 0, 0.01, 0.02, 0.03, 0.04) perovskite cathode material for IT-SOFC is synthesized successfully using a combustion method and sintered at low temperature. The effects of nickel as a sintering aid on the properties of BaCo₀.₄Fe₀.₄Zr₀.₂O_3−δ are investigated through different characterization methods. The addition of nickel increased the densification and grain growth at a lower sintering temperature 1200 °C. XRD analysis confirms a single phase of BaCo₀.₄Fe₀.₄Zr₀.₂O_3−δ, and an increase in crystalline size is observed. SEM micrographs show formation of dense microstructure with increased nickel concentration. TGA analysis revealed that BaCo₀.₄Fe₀.₄Zr_0.2−xNi_x cathode materials are thermally stable within the SOFC temperature range, and negligible weight loss of 2.3% is observed. The bonds of hydroxyl groups and metal oxides are confirmed for all samples through FTIR analysis. The highest electrical properties are observed for BaCo₀.₄Fe₀.₄Zr_0.2−xNi_x (x = 0.04) due to increased densification and electronic defects compared to other compositions. The maximum power density of 0.47 W cm⁻² is obtained for a cell having cathode material BaCo₀.₄Fe₀.₄Zr_0.2−xNi_x (x = 0.02) owing to its permeable and well-connected structure compared to others.