Densification of Plasma-Sprayed ScSZ Enables High Performance of Intermediate Temperature Solid Oxide Fuel Cells With EWSB/ScSZ Bilayer Electrolyte

The stabilized Bi₂O₃ electrolyte bilayer solid oxide fuel cells (SOFCs) are known as promising intermediate temperature SOFCs. However, it is necessary to develop a cost-effective method for manufacturing electrolyte bilayer SOFCs. In this study, atmospheric plasma spraying (APS) is employed to develop a facile method to deposit EWSB ((Bi₂O₃)_0.705(Er₂O₃)_0.245(WO₃)_0.05) and ScSZ ((Sc₂O₃)_0.1(Zr₂O₃)_0.9) electrolytes for assembling SOFCs with an EWSB/ScSZ bilayer structure. Results show that the maximum power density (MPD) of the electrolyte bilayer cell with 20 µm EWSB is increased by 52% compared with the monolayer ScSZ electrolyte cell at 750°C. The cell of electrolyte bilayer with a densified ScSZ presents open circuit voltage of ∼1 V and a remarkable performance enhancement with the MPDs of 1110 mW cm⁻² at 750°C and 581 mW cm⁻² at 650°C, being increased by 57% at 650°C compared with electrolyte bilayer cell with the as-sprayed ScSZ electrolyte. The dense ScSZ electrolyte effectively ensures the superior electrochemical performance and stability of EWSB at the interface between electrolytes of EWSB/ScSZ bilayer cell.