Performance evaluation of BaCo_(0.7)Nb_(0.2)Ta_(0.1)O_(3-δ) cathode for intermediate-temperature solid oxide fuel cells

摘要

The BaCo0.7Nb0.2Ta0.1O3-delta (BCNT) perovskite-type oxide was prepared by the conventional solid phase reaction method as a potential electrocatalyst for the oxygen reduction reaction. Its electrochemical properties were characterized. The results indicated that the BCNT oxide sintered at 1100 degrees C for 10 h had formed a single-phase cubic perovskite structure. And the BCNT-Sm0.2Ce0.8O1.9 (SDC) mixture co-sintered at the same conditions showed good chemical compatibility and stability between BCNT and SDC. The BCNT cathode sintered at 1000 degrees C for 4 h on SDC electrolyte exhibited the lowest the polarization resistance (about 0.0495 Omega.cm(2) at 800 degrees C). Moreover, with a 351 mu m-thick SDC as electrolyte and BCNT as the cathode, maximum power densities of the single cell reached 466.81 and 626.41 mW.cm(2) at 750 and 800 degrees C, respectively, and the corresponding total interface polarization resistance of the cell were 0.0913 Omega.cm(2) and 0.0552 Omega.cm(2). Short-term stability of the cell showed that the cell was quite stable at 750 degrees C for 15 h. This suggested that BCNT was a very promising cathode material for IT-SOFCs. (C) 2018 Elsevier B.V. All rights reserved.