AC impedance characteristics for anode-supported microtubular solid oxide fuel cells

作者：Sumi Hirofumi^*; Yamaguchi Toshiaki; Hamamoto Koichi; Suzuki Toshio; Fujishiro Yoshinobu; Matsui Toshiaki; Eguchi Koichi

来源：Electrochimica Acta, 2012, 67: 159-165.

DOI：10.1016/j.electacta.2012.02.021

• Solid oxide fuel cell (SOFC)
• Anode microstructure
• AC impedance
• Distribution of relaxation times

The DRT method was applied to analyze the AC impedance spectra for anode-supported microtubular solid oxide fuel cells (SOFCs). The anode microstructure has a more severe effect on the electrochemical properties of the anode-supported microtubular SOFCs because of the small inside diameter and thickness of the anode. For example, the maximum current density and fuel utilization for the cells sintered at 1400 degrees C were lower than that at 1350 degrees C due to the low porosity of the anode. However, it is difficult to separate the anode and cathode impedances by the general method of complex non-linear least squares (CNLS) with equivalent circuit models, because several components overlap for the impedance spectra measured between the anode and cathode without a reference electrode. The DRT method can easily separate the impedance spectra into five polarization components for the anode-supported microtubular SOFCs. The activation energy of the anode diffusion resistance was only 24-33 kJ/mol. The walls of the pores in the anode were relatively well-packed with the nickel and YSZ particles for the cells made by the use of acrylic resin as a pore former. The anode diffusion resistance decreased by only a small amount with a rise of operating temperature for the anode-supported microtubular SOFCs.

• 出版日期2012-4-15