Plasma-sprayed Y₂O₃-stabilized ZrO₂ electrolyte with improved interlamellar bonding for direct application to solid oxide fuel cells

Atmospheric plasma spraying was employed to prepare anode, cathode, and Y2O3-stabilized ZrO2 (YSZ) electrolyte to aim at reducing manufacturing cost. YSZ electrolytes were deposited on the anode at different deposition temperatures of 200 C, 400 C and 600 C to optimize the gas tightness of plasma-sprayed YSZ electrolyte. The influences of the deposition temperature on the microstructure and gas-tightness of plasma-sprayed YSZ electrolyte were investigated. The effect of microstructure and the gas-tightness of YSZ electrolyte on the open circuit voltage and the output performance of solid oxide fuel cells (SOFCs) were examined. The results showed with the increase of deposition temperature, the porosity of YSZ electrolytes almost decreased by about 80% and the microstructure of YSZ electrolytes changed from the typical lamellar structure to the continuous columnar crystal structure. At a deposition temperature of 600 C the gas permeability decreased to 1.5 × 10-7 cm4gf-1s-1, and the highest open circuit voltage can reach 1.026 V, indicating the applicability of the as-sprayed YSZ directly to the SOFC electrolyte.