Improvement of Protonic Ceramic Fuel Cells with Thin Film BCZY Electrolyte

Fuel cell performance of protonic ceramic fuel cells (PCFCs) using thin film BaCe_0.6Zr_0.2Y_0.2O_3-δ (BCZY622) electrolyte have been studied. First reference cell with La_0.8Sr_0.2MnO_3-δcathode and Ni anode showed poor performance and short-term degradation. Overpotential of anode and Ohmic loss was major limiting factor, and solid solution of Ni into BCZY622 electrolyte has been observed. The electrical conductivity and the proton concentration of BCZY622 and BCZY622 doped with 5wt% NiO were measured by impedance analysis and thermogravimetric analysis. The electrical conductivity and the proton concentration of BCZY622 were decreased by introducing NiO.

To avoid short-term degradation, cell construction, manufacturing process, and firing temperatures were improved. As a result, carefully designed PCFC with thin film BCZY622 showed good power density of 200-300mW/cm² in wide temperature range at 873 - 1073K , and performed stable generation.