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Flowerlike CeO2 microspheres coated with Sr2Fe1.5Mo0.5Ox nanoparticles for an advanced fuel cell.

Liu Y, Tang Y, Ma Z, Singh M, He Y, Dong W, Sun C, Zhu B - Sci Rep (2015)

Bottom Line: Advanced single layer fuel cell was constructed using the flowerlike CeO2/Sr-Fe-Mo-oxide layer attached to a Ni-foam layer coated with the conducting transition metal oxide.Such fuel cell has yielded a peak power density of 802 mWcm(-2) at 550 °C.These results provide a promising strategy for developing advanced low-temperature SOFCs.

View Article: PubMed Central - PubMed

Affiliation: 1] Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Physics and Electronic Science, Hubei University, Wuhan, Hubei 430062 [2] Hebei Key Laboratory of Applied Chemistry, College of Environmental and Chemical Engineering, Yanshan University, 438 Hebei Street, Qinhuangdao, 066004, P.R. China.

ABSTRACT
Flowerlike CeO2 coated with Sr2Fe1.5Mo0.5Ox (Sr-Fe-Mo-oxide) nanoparticles exhibits enhanced conductivity at low temperatures (300-600 °C), e.g. 0.12 S cm(-1) at 600 °C, this is comparable to pure ceria (0.1 S cm(-1) at 800 °C). Advanced single layer fuel cell was constructed using the flowerlike CeO2/Sr-Fe-Mo-oxide layer attached to a Ni-foam layer coated with the conducting transition metal oxide. Such fuel cell has yielded a peak power density of 802 mWcm(-2) at 550 °C. The mechanism of enhanced conductivity and cell performance were analyzed. These results provide a promising strategy for developing advanced low-temperature SOFCs.

No MeSH data available.


(a) The operation stability test result of SLFC at a current densityof 312.5 mA/cm2 at530 oC; b) XRD patterns ofF-CeO2/Sr-Fe-Mo-oxide layer after long-term stability test.
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f6: (a) The operation stability test result of SLFC at a current densityof 312.5 mA/cm2 at530 oC; b) XRD patterns ofF-CeO2/Sr-Fe-Mo-oxide layer after long-term stability test.

Mentions: Figure 5 shows I-V and I-P characteristics forF-CeO2/Sr-Fe-Mo-oxide fuel cells, measured at the operatingtemperature of 500 oC,550 oC and 600 oC,respectively. It shows that all obtained open circuit voltage (OCV) of the fuelcells above 1.0 V at various temperatures, as a prerequisite forobtaining excellent performance, indicating that these as-prepared materialshave superior catalytic activity as a single layer material. It can be seen thatthe maximum current densities were approximately 1718, 2389, and2574 mA cm−2 at500 oC, 550 oC and600 oC, respectively. The peak output powerdensity is 610 mW cm−2 at500 oC, and increases to 802 mWcm−2 at 550 oC. At600 oC, a peak power density reaches about848 mW cm−2, which is consistent with theresults of electrical conductivity measured with AC impedance spectrum. Theseresults demonstrate that the conductivity of F-CeO2/Sr-Fe-Mo-oxidecomposite is sufficiently high. We further evaluated the operation stability ofthe F-CeO2/Sr-Fe-Mo-oxide fuel cell. The device was operated at acurrent density of 312.5 mA cm−2 at530 oC for over 16 h. The voltagechange was recorded over time during operation. It can be seen from Fig. 6a that the device has a relatively good durabilitywith the minimal voltage degradation. Generally, the main factor for degradationcan be attributed to the increased polarization resistance25. Thecell voltage slightly degrades at around 5 h. This could be resultedfrom the change of cerium valence state in the F-CeO2/Sr-Fe-Mo-oxidecomposite in the initial stage2627. Some Ce4+ions were reduced to Ce3+ ions at H2 input side282930 leading to the coexistence of bothcerium ions valence states. The phase analysis of theF-CeO2/Sr-Fe-Mo-oxide layer after long-term stability test wasdisplayed in Fig. 6b. The same peak positions to theF-CeO2/Sr-Fe-Mo-oxide composite can be clearly identified in theXRD patterns. This suggests that the material structure has no changes. Someadditional peaks were identified because the NCAL layer was mixed into thematerial when the sample was scraped from the tested device pellet. Furtherlonger life test is limited by our testing device. After the durability test, wefound some rusting surface on the steel chamber of the testing device used,which caused a slight degradation due to the testing device resistance growingwith the measurement.


Flowerlike CeO2 microspheres coated with Sr2Fe1.5Mo0.5Ox nanoparticles for an advanced fuel cell.

Liu Y, Tang Y, Ma Z, Singh M, He Y, Dong W, Sun C, Zhu B - Sci Rep (2015)

(a) The operation stability test result of SLFC at a current densityof 312.5 mA/cm2 at530 oC; b) XRD patterns ofF-CeO2/Sr-Fe-Mo-oxide layer after long-term stability test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495617&req=5

f6: (a) The operation stability test result of SLFC at a current densityof 312.5 mA/cm2 at530 oC; b) XRD patterns ofF-CeO2/Sr-Fe-Mo-oxide layer after long-term stability test.
Mentions: Figure 5 shows I-V and I-P characteristics forF-CeO2/Sr-Fe-Mo-oxide fuel cells, measured at the operatingtemperature of 500 oC,550 oC and 600 oC,respectively. It shows that all obtained open circuit voltage (OCV) of the fuelcells above 1.0 V at various temperatures, as a prerequisite forobtaining excellent performance, indicating that these as-prepared materialshave superior catalytic activity as a single layer material. It can be seen thatthe maximum current densities were approximately 1718, 2389, and2574 mA cm−2 at500 oC, 550 oC and600 oC, respectively. The peak output powerdensity is 610 mW cm−2 at500 oC, and increases to 802 mWcm−2 at 550 oC. At600 oC, a peak power density reaches about848 mW cm−2, which is consistent with theresults of electrical conductivity measured with AC impedance spectrum. Theseresults demonstrate that the conductivity of F-CeO2/Sr-Fe-Mo-oxidecomposite is sufficiently high. We further evaluated the operation stability ofthe F-CeO2/Sr-Fe-Mo-oxide fuel cell. The device was operated at acurrent density of 312.5 mA cm−2 at530 oC for over 16 h. The voltagechange was recorded over time during operation. It can be seen from Fig. 6a that the device has a relatively good durabilitywith the minimal voltage degradation. Generally, the main factor for degradationcan be attributed to the increased polarization resistance25. Thecell voltage slightly degrades at around 5 h. This could be resultedfrom the change of cerium valence state in the F-CeO2/Sr-Fe-Mo-oxidecomposite in the initial stage2627. Some Ce4+ions were reduced to Ce3+ ions at H2 input side282930 leading to the coexistence of bothcerium ions valence states. The phase analysis of theF-CeO2/Sr-Fe-Mo-oxide layer after long-term stability test wasdisplayed in Fig. 6b. The same peak positions to theF-CeO2/Sr-Fe-Mo-oxide composite can be clearly identified in theXRD patterns. This suggests that the material structure has no changes. Someadditional peaks were identified because the NCAL layer was mixed into thematerial when the sample was scraped from the tested device pellet. Furtherlonger life test is limited by our testing device. After the durability test, wefound some rusting surface on the steel chamber of the testing device used,which caused a slight degradation due to the testing device resistance growingwith the measurement.

Bottom Line: Advanced single layer fuel cell was constructed using the flowerlike CeO2/Sr-Fe-Mo-oxide layer attached to a Ni-foam layer coated with the conducting transition metal oxide.Such fuel cell has yielded a peak power density of 802 mWcm(-2) at 550 °C.These results provide a promising strategy for developing advanced low-temperature SOFCs.

View Article: PubMed Central - PubMed

Affiliation: 1] Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Physics and Electronic Science, Hubei University, Wuhan, Hubei 430062 [2] Hebei Key Laboratory of Applied Chemistry, College of Environmental and Chemical Engineering, Yanshan University, 438 Hebei Street, Qinhuangdao, 066004, P.R. China.

ABSTRACT
Flowerlike CeO2 coated with Sr2Fe1.5Mo0.5Ox (Sr-Fe-Mo-oxide) nanoparticles exhibits enhanced conductivity at low temperatures (300-600 °C), e.g. 0.12 S cm(-1) at 600 °C, this is comparable to pure ceria (0.1 S cm(-1) at 800 °C). Advanced single layer fuel cell was constructed using the flowerlike CeO2/Sr-Fe-Mo-oxide layer attached to a Ni-foam layer coated with the conducting transition metal oxide. Such fuel cell has yielded a peak power density of 802 mWcm(-2) at 550 °C. The mechanism of enhanced conductivity and cell performance were analyzed. These results provide a promising strategy for developing advanced low-temperature SOFCs.

No MeSH data available.