Perovskite-type Nd0.5Sr0.5Co0.5Fe0.5O3-δ as a novel cathode material for intermediate-temperate solid oxide fuel cell

Suitable cathode materials were crucial to develop intermediate-temperature solid oxide fuel cells (IT-SOFCs). Herein, perovskite-type Nd0.5Sr0.5Co0.5Fe0.5O3-delta (NSCF) was synthesized as a novel cathode material using EDTA-citric acid-nitrate combustion. X-ray diffraction (XRD) analysis shows that a structure composed using a single perovskite is obtained upon sintering in air at 1000 degrees C. Brunauer-Emmett -Teller (BET) and high-resolution-transmission electron microscopy (HRTEM) were applied to analyze the physical characteristics of cathode materials. In addition, the performances of NSCF-SDC as a cathode and complete cell (NiO-SDC/SDC/NSCF-SDC) at 450-650 degrees C were also tested when 100% H-2 and ambient air were fed into anode and cathode, respectively. The maximum power density obtained at 650 degrees C was 1560 mWcm(-2), and the maximum voltage was 0.89 V under operating conditions at 500 degrees C. Electrochemical impedance spectroscopy (EIS) of symmetrical cell demonstrated that the polarization resistance was the main loss, and the area-specific resistance was 0.034 Omega cm(-2) at 700 degrees C. The EIS of single cell indicated that the main loss of the fuel cell was due to the Ohmic polarization when the single cell was operated at lower than 500 degrees C, when the temperature is higher than 500 degrees C, the main loss is polarization resistance. This conclusion can help to improve the performance of single cell according to the loss reason. (C) 2019 Elsevier B.V. All rights reserved.