Improvement in Power Density of Protonic Ceramic Fuel Cells with Yb Doped BaZrO3 Electrolyte

Abstract

This paper reports our development of protonic ceramic fuel cells (PCFCs) with BaZr0.8Yb0.2O3−δ (BZYb) electrolyte. Although PCFCs can theoretically achieve ultra-high energy-conversion efficiency for power generation, higher power density even at lower temperatures below 600°C is required to widespread application. Here, a zirconate-based oxide of BZYb was selected as electrolyte material of PCFCs because of its high chemical stability against CO2. Also, cost-effective conventional wet processes were used to fabricate the PCFCs. High-temperature co-sintering successfully produced a dense and thin BZYb electrolyte. The PCFC showed a stable operation for 400 h without significant degradation. Investigation into changing parameters of large-size PCFCs (50 × 50 mm) such as anode porosity, interlayer function, electrolyte thickness, and cathode material improved the power density of the PCFCs with BZYb electrolyte. At 600°C, the power density reached 0.38 and 0.48 W cm−2 at 0.85 and 0.75 V, respectively.