Electrochemical impedance spectra of solid-oxide fuel cells and polymer membrane fuel cells

Ceramic systems of template explains and demonstrates how to prepare your camera-ready Ceramic systems of Bi2O3 and La-doped SrTiO3 (LST) solid mixtures La0.2Sr0.8TiO3–x%Bi2O3 (x = 0, 20, 25, 30, 35) are prepared and explored as possible anode materials for solid oxide fuel cells. It is shown that the conductivity of La0.2Sr0.8TiO3–x%Bi2O3 composites increases from 0.15 to 1.4 S cm−1 in 97%H2 +3%H2O at 800°C with increasing the content of Bi2O3. Electrochemical impedance spectra indicated that the addition of Bi2O3 into LST can significantly reduce the fuel cell’s polarization and refine the grains and increase the triple phase boundary, leading to a better performance of the fuel cells. The results suggest potential applications of LST–x%Bi2O3 composite as SOFC anode materials.

Download Full-text

Comparison of electrochemical impedance spectra for electrolyte-supported solid oxide fuel cells (SOFCs) and protonic ceramic fuel cells (PCFCs)

Scientific Reports ◽

10.1038/s41598-021-90211-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hirofumi Sumi ◽

Hiroyuki Shimada ◽

Yuki Yamaguchi ◽

Yasunobu Mizutani ◽

Yuji Okuyama ◽

...

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Electrochemical Impedance ◽

Gas Diffusion ◽

Solid Oxide ◽

Oxide Fuel ◽

Impedance Spectra ◽

Cathode Polarization ◽

Ceramic Fuel ◽

Ceramic Fuel Cells

AbstractProtonic ceramic fuel cells (PCFCs) are expected to achieve high power generation efficiency at intermediate temperature around 400–600 °C. In the present work, the distribution of relaxation times (DRT) analysis was investigated in order to deconvolute the anode and cathode polarization resistances for PCFCs supported on yttria-doped barium cerate (BCY) electrolyte in comparison with solid oxide fuel cells (SOFCs) supported on scandia-stabilized zirconia (ScSZ) electrolyte. Four DRT peaks were detected from the impedance spectra measured at 700 °C excluding the gas diffusion process for ScSZ and BCY. The DRT peaks at 5 × 102–1 × 104 Hz and 1 × 100–2 × 102 Hz were related to the hydrogen oxidation reaction at the anode and the oxygen reduction reaction at the cathode, respectively, for both cells. The DRT peak at 2 × 101–1 × 103 Hz depended on the hydrogen concentration at the anode for ScSZ, while it was dependent on the oxygen concentration at the cathode for BCY. Compared to ScSZ, steam was produced at the opposite electrode in the case of BCY, which enhanced the cathode polarization resistance for PCFCs.

Download Full-text

Performance of Ba0.5Sr0.5Co0.8Fe0.2O3-δ-Ag Composite Cathode Materials for IT-SOFCs

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.311-313.2309 ◽

2011 ◽

Vol 311-313 ◽

pp. 2309-2314 ◽

Cited By ~ 2

Author(s):

Wen Xia Zhu ◽

Zhe Lü ◽

Le Xin Wang ◽

Xiao Yan Guan ◽

Xin Yan Zhang

Keyword(s):

Solid Oxide Fuel Cells ◽

Electrochemical Impedance ◽

Composite Cathode ◽

Solid Oxide ◽

Electrode Polarization ◽

Impedance Spectra ◽

Electrochemical Impedance Spectra ◽

Composite Cathodes ◽

Reduced Temperature ◽

Resistance Value

°Abstract. In order to develop new cathodes for reduced temperature SOFCs, Ba0.5Sr0.5Co0.8Fe0.2O3-δ-Ag composite cathode was investigated in intermediate-temperature Solid Oxide Fuel Cells (IT-SOFCs). The XRD results suggested that no chemical reactions between BSCF and Ag in the composite cathode were found. The resistance measurements showed that the addition of Ag into BSCF improved electrical conductivity of pure BSCF, and the improved conductivity resulted in attractive cathode performance. In addition, electrochemical impedance spectra exhibited the better performance of BSCF-Ag composite cathodes than pure BSCF, e.g., the polarization resistance value of BSCF-Ag was only 0.36Ω cm2 at 650°C, which was nearly 80% lower than that of BSCF electrode. Polarization curves showed the overpotential decreased with the addition of Ag. The current density value of BSCF-Ag was 0.88Acm-2 under –120mV, about five times of that BSCF measured at 650°C. As a summary, compared to a pure BSCF cathode, it was found that adding Ag in the cathode enhanced the BSCF performance significantly.

Download Full-text