Fabrication and performance analysis of A-site metal-promoted La_0.595V_0.005Sr_0.4CoO_3−∂ perovskite oxides as cathodes for intermediate temperature solid oxide fuel cells

Reducing fabrication costs and increasing system performance are the primary objectives of contemporary SOFC developments and research. One of the efficient ways to address the design and durability difficulties is to lower the operating temperatures to the intermediate range (IT, 500–800 °C). La_0.595V_0.005Sr_0.4CoO_3−∂ (LV05SC) perovskite cathode is investigated as a novel cathode for intermediate temperature solid oxide fuel cells (IT-SOFC). Anode-supported YSZ ((Y₂O₃)_0.08(ZrO₂)_0.92) and GDC (Gd_0.1Ce_0.9O_1.95) electrolytes were prepared by a multilayer tape casting and co-firing method. The green bi-layer tapes were co-fired at various temperatures with optimized electrolyte and anode slurries. X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were used to analyze the microstructures and the phase characterizations of the cathode material and single cell. At 1250 °C of the co-firing temperature, as-prepared anode-supported cells showed no defects and excellent microstructural properties such as no gas permeability, porosity, and sintered structure. The electrolytes with a thickness of almost 20 µm were fairly dense. The power densities were evaluated and both anode-supported electrolytes showed good electrochemical performance at intermediate temperatures. The peak power density of the cell reached 89 mW/cm², and the total resistance was only 3.05 Ω.cm² under open circuit conditions at 800 °C. The diffusion processes of oxide ions (O²⁻) were found to be the limiting step for ORR by the EIS analysis. These findings suggest that the compound is a promising cathode material for IT-SOFCs.