Improvement of La0.8Sr0.2MnO3−δ Cathode Material for Solid Oxide Fuel Cells by Addition of YFe0.5Co0.5O3

The high efficiency of solid oxide fuel cells with La0.8Sr0.2MnO3−δ (LSM) cathodes working in the range of 800–1000 °C, rapidly decreases below 800 °C. The goal of this study is to improve the properties of LSM cathodes working in the range of 500–800 °C by the addition of YFe0.5Co0.5O3 (YFC). Monophasic YFC is synthesized and sintered at 950 °C. Composite cathodes are prepared on Ce0.8Sm0.2O1.9 electrolyte disks using pastes containing YFC and LSM powders mixed in 0:1, 1:19, and 1:1 weight ratios denoted LSM, LSM1, and LSM1, respectively. X-ray diffraction patterns of tested composites reveal the presence of pure perovskite phases in samples sintered at 950 °C and the presence of Sr4Fe4O11, YMnO3, and La0.775Sr0.225MnO3.047 phases in samples sintered at 1100 °C. Electrochemical impedance spectroscopy reveals that polarization resistance increases from LSM1, by LSM, to LSM2. Differences in polarization resistance increase with decreasing operating temperatures because activation energy rises in the same order and equals to 1.33, 1.34, and 1.58 eV for LSM1, LSM, and LSM2, respectively. The lower polarization resistance of LSM1 electrodes is caused by the lower resistance associated with the charge transfer process.

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Fabrication and Electrochemical Performance of Zn-Doped La0.2Sr0.25Ca0.45TiO3 Infiltrated with Nickel-CGO, Iron, and Cobalt as an Alternative Anode Material for Solid Oxide Fuel Cells

Catalysts ◽

10.3390/catal9030269 ◽

2019 ◽

Vol 9 (3) ◽

pp. 269 ◽

Cited By ~ 1

Author(s):

Nazan Muzaffar ◽

Nasima Arshad ◽

Daniel Drasbæk ◽

Bhaskar Sudireddy ◽

Peter Holtappels

Keyword(s):

Fuel Cells ◽

Electrochemical Performance ◽

Solid Oxide Fuel Cells ◽

Polarization Resistance ◽

Electrochemical Impedance ◽

Open Circuit ◽

Solid Oxide ◽

Oxide Fuel ◽

Sulphur Poisoning ◽

Operating Temperatures

In solid oxide fuel cells, doped strontium titinates have been widely studied as anode materials due to their high n-type conductivity. They are used as current conducting backbones as an alternative to nickel-cermets, which suffer degradation due to coking, sulphur poisoning, and low tolerance to redox cycling. In this work, anode backbone materials were synthesized from La0.2Sr0.25Ca0.45TiO3−δ (LSCTA-), modified with 5 wt.% Zn, and infiltrated with nickel (Ni)/ceria gadolinium-doped cerium oxide (CGO), Fe, and Co. The electrodes were further studied for their electrochemical performance using electrochemical impedance spectroscopy (EIS) at open circuit voltage (OCV) in different hydrogen to steam ratios and at various operating temperatures (850–650 °C). Infiltration of electrocatalysts significantly reduced the polarization resistance and among the studied infiltrates, at all operating temperatures, Ni-CGO showed excellent electrode performance. The polarization resistances in 3% and 50% H2O/H2 atmosphere were found to be 0.072 and 0.025 Ω cm2, respectively, at 850 °C, and 0.091 and 0.076 Ω cm2, respectively, at 750 °C, with Ni-CGO. These values are approximately three orders of magnitude smaller than the polarization resistance (25 Ω cm2) of back bone material measured at 750 °C.

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Inkjet Printing Functionalization of SOFC LSCF Cathodes

Nanomaterials ◽

10.3390/nano9040654 ◽

2019 ◽

Vol 9 (4) ◽

pp. 654 ◽

Cited By ~ 6

Author(s):

Eleonora Venezia ◽

Massimo Viviani ◽

Sabrina Presto ◽

Vasant Kumar ◽

Rumen I. Tomov

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Inkjet Printing ◽

High Efficiency ◽

Electrochemical Impedance ◽

Electrical Energy ◽

Reduction Reaction ◽

Solid Oxide ◽

Oxide Fuel ◽

Ion Conductor

An important segment of the future renewable energy economy is the implementation of novel energy generation systems. Such electrochemical systems are solid oxide fuel cells, which have the advantage of direct conversion of the chemical energy stored in the fuel to electrical energy with high efficiency. Improving the performance and lowering the cost of solid oxide fuel cells (SOFCs) are strongly dependent on finding commercially viable methods for nano-functionalization of their electrodes via infiltration. Inkjet printing technology was proven to be a feasible method providing scalability and high-resolution ink delivery. LaxSr1−xCoyFe1−yO3−δ cathodes were modified using inkjet printing for infiltration with two different materials: Gd-doped ceria (CGO) commonly used as ion-conductor and La0.6Sr0.4CoO3–δ (LCO) commonly used as a mixed ionic electronic conductor. As-modified surface structures promoted the extension of the three-phase boundary (TPB) and enhanced the mechanisms of the oxygen reduction reaction. Electrochemical impedance measurements revealed significantly lowered polarization resistances (between 2.7 and 3.7 times) and maximum power output enhancement of 24% for CGO infiltrated electrodes and 40% for LCO infiltrated electrodes.

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