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A micro-nano porous oxide hybrid for efficient oxygen reduction in reduced-temperature solid oxide fuel cells.

- Sci Rep (2012)

Bottom Line: Tremendous efforts to develop high-efficiency reduced-temperature (≤ 600°C) solid oxide fuel cells are motivated by their potentials for reduced materials cost, less engineering challenge, and better performance durability.A key obstacle to such fuel cells arises from sluggish oxygen reduction reaction kinetics on the cathodes.Here we reported that an oxide hybrid, featuring a nanoporous Sm(0.5)Sr(0.5)CoO(3-δ) (SSC) catalyst coating bonded onto the internal surface of a high-porosity La(0.9)Sr(0.1)Ga(0.8)Mg(0.2)O(3-δ) (LSGM) backbone, exhibited superior catalytic activity for oxygen reduction reactions and thereby yielded low interfacial resistances in air, e.g., 0.021 Ω cm(2) at 650°C and 0.043 Ω cm(2) at 600°C.

View Article: PubMed Central - PubMed

Affiliation: CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics , Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050, P. R. China.

ABSTRACT
Tremendous efforts to develop high-efficiency reduced-temperature (≤ 600°C) solid oxide fuel cells are motivated by their potentials for reduced materials cost, less engineering challenge, and better performance durability. A key obstacle to such fuel cells arises from sluggish oxygen reduction reaction kinetics on the cathodes. Here we reported that an oxide hybrid, featuring a nanoporous Sm(0.5)Sr(0.5)CoO(3-δ) (SSC) catalyst coating bonded onto the internal surface of a high-porosity La(0.9)Sr(0.1)Ga(0.8)Mg(0.2)O(3-δ) (LSGM) backbone, exhibited superior catalytic activity for oxygen reduction reactions and thereby yielded low interfacial resistances in air, e.g., 0.021 Ω cm(2) at 650°C and 0.043 Ω cm(2) at 600°C. We further demonstrated that such a micro-nano porous hybrid, adopted as the cathode in a thin LSGM electrolyte fuel cell, produced impressive power densities of 2.02 W cm(-2) at 650°C and 1.46 W cm(-2) at 600°C when operated on humidified hydrogen fuel and air oxidant.

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Impedance measurements on symmetric cathode fuel cells in ambient air.(a) Representative impedance spectra measured at 600°C for the SSC/LSGM hybrid at VSSC = 12.9%. (b) The cathode polarization resistance (Rp) and the ohmic resistance (Ro), derived from the impedance data, plotted versus the SSC loading.
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f2: Impedance measurements on symmetric cathode fuel cells in ambient air.(a) Representative impedance spectra measured at 600°C for the SSC/LSGM hybrid at VSSC = 12.9%. (b) The cathode polarization resistance (Rp) and the ohmic resistance (Ro), derived from the impedance data, plotted versus the SSC loading.

Mentions: Fig. 2a shows a representative Nyquist plot of the EIS data in air at 600°C from a symmetric fuel cell at VSSC = 12.9%, where the high frequency real-axis intercept is primarily associated with the cell ohmic loss (Ro) and the difference between the high and low frequency real-axis intercept corresponds to the RP value. Notably, the polarization resistance at 600°C was 0.043 Ω cm2 for the micro-nano porous SSC/LSGM hybrid at VSSC = 12.9%. For comparison, the state-of-the-art micron-scale SOFC cathodes have larger Rp values at comparable temperatures, e.g., > 2 Ω cm2 for LSM-YSZ14, 0.5 Ω cm2 for random Sm0.5Sr0.5CoO3−δ-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3-δ (SSC-LSGMC) composites18, 0.12 Ω cm2 for Pd-promoted SSC-LSGMC composites18, 0.055-0.071 Ω cm2 for BSCF reported by Shao and Haile8 or 0.06 Ω cm2 for heterostructured BSCF by Zhou et al15.


A micro-nano porous oxide hybrid for efficient oxygen reduction in reduced-temperature solid oxide fuel cells.

- Sci Rep (2012)

Impedance measurements on symmetric cathode fuel cells in ambient air.(a) Representative impedance spectra measured at 600°C for the SSC/LSGM hybrid at VSSC = 12.9%. (b) The cathode polarization resistance (Rp) and the ohmic resistance (Ro), derived from the impedance data, plotted versus the SSC loading.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3375499&req=5

f2: Impedance measurements on symmetric cathode fuel cells in ambient air.(a) Representative impedance spectra measured at 600°C for the SSC/LSGM hybrid at VSSC = 12.9%. (b) The cathode polarization resistance (Rp) and the ohmic resistance (Ro), derived from the impedance data, plotted versus the SSC loading.
Mentions: Fig. 2a shows a representative Nyquist plot of the EIS data in air at 600°C from a symmetric fuel cell at VSSC = 12.9%, where the high frequency real-axis intercept is primarily associated with the cell ohmic loss (Ro) and the difference between the high and low frequency real-axis intercept corresponds to the RP value. Notably, the polarization resistance at 600°C was 0.043 Ω cm2 for the micro-nano porous SSC/LSGM hybrid at VSSC = 12.9%. For comparison, the state-of-the-art micron-scale SOFC cathodes have larger Rp values at comparable temperatures, e.g., > 2 Ω cm2 for LSM-YSZ14, 0.5 Ω cm2 for random Sm0.5Sr0.5CoO3−δ-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3-δ (SSC-LSGMC) composites18, 0.12 Ω cm2 for Pd-promoted SSC-LSGMC composites18, 0.055-0.071 Ω cm2 for BSCF reported by Shao and Haile8 or 0.06 Ω cm2 for heterostructured BSCF by Zhou et al15.

Bottom Line: Tremendous efforts to develop high-efficiency reduced-temperature (≤ 600°C) solid oxide fuel cells are motivated by their potentials for reduced materials cost, less engineering challenge, and better performance durability.A key obstacle to such fuel cells arises from sluggish oxygen reduction reaction kinetics on the cathodes.Here we reported that an oxide hybrid, featuring a nanoporous Sm(0.5)Sr(0.5)CoO(3-δ) (SSC) catalyst coating bonded onto the internal surface of a high-porosity La(0.9)Sr(0.1)Ga(0.8)Mg(0.2)O(3-δ) (LSGM) backbone, exhibited superior catalytic activity for oxygen reduction reactions and thereby yielded low interfacial resistances in air, e.g., 0.021 Ω cm(2) at 650°C and 0.043 Ω cm(2) at 600°C.

View Article: PubMed Central - PubMed

Affiliation: CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics , Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050, P. R. China.

ABSTRACT
Tremendous efforts to develop high-efficiency reduced-temperature (≤ 600°C) solid oxide fuel cells are motivated by their potentials for reduced materials cost, less engineering challenge, and better performance durability. A key obstacle to such fuel cells arises from sluggish oxygen reduction reaction kinetics on the cathodes. Here we reported that an oxide hybrid, featuring a nanoporous Sm(0.5)Sr(0.5)CoO(3-δ) (SSC) catalyst coating bonded onto the internal surface of a high-porosity La(0.9)Sr(0.1)Ga(0.8)Mg(0.2)O(3-δ) (LSGM) backbone, exhibited superior catalytic activity for oxygen reduction reactions and thereby yielded low interfacial resistances in air, e.g., 0.021 Ω cm(2) at 650°C and 0.043 Ω cm(2) at 600°C. We further demonstrated that such a micro-nano porous hybrid, adopted as the cathode in a thin LSGM electrolyte fuel cell, produced impressive power densities of 2.02 W cm(-2) at 650°C and 1.46 W cm(-2) at 600°C when operated on humidified hydrogen fuel and air oxidant.

Show MeSH