Abstract
In recent years, solid oxide fuel cells (SOFCs) have been considered as desired devices for generating electricity by electrochemical combination of a fuel with an oxidant. Oxygen ion conductors are usually used as the electrolytes for SOFCs. Among several types of oxygen ion conductors such as CeO2, stabilized Bi2O3 and ZrO2, Bi2O3 with stabilizers exhibit the highest oxygen ion conductivity. Although Bi2O3 tends to be reduced to Bi metal, Bi2O3 incorporated with proper dopants will show enhanced stability against hydrogen. The highest OCV for SOFC using Bi2O3-based electrolyte is around 0.5V which is still too low to be practical. On the other hand, Bi2O3-based system may make a good ionic component for a composite cathode. In this study, we choose yttria-stabilized bismuth oxides (YSB) as ionic conductor and mixed with strontium-doped lanthanum manganite (LSM) for composite cathode. Size effect of LSM on the polarization resistance was investigated by using conventional solid-state reacted and nano-sized LSM. The electrochemical performances of composite cathodes with different LSM:YSB ratios have been investigated at temperature ranging from 500°C to 650°C using AC impedance spectroscopy. The polarization resistance measured from a symmetric cell consisting of nano-sized LSM-YSB electrodes on a YSB electrolyte is 50% lower than that of submicron-sized LSM-YSB cathodes by SSR (0.2 ohmcm2) at 650°C. The polarization of cathode is reduced because of the mixing of high surface area electric conducting materials and ionic conducting materials. The nanostructure of composite cathode is able to extend triple phase boundary (electronic conductor, ionic conductor, and oxygen gas) and provide numerous reaction sites for electrochemical reaction to occur.
| Original language | English |
|---|---|
| Title of host publication | Solid Oxide Fuel Cells 14, SOFC 2015 |
| Editors | S. C. Singhal, K. Eguchi |
| Publisher | Electrochemical Society Inc. |
| Pages | 867-874 |
| Number of pages | 8 |
| Edition | 1 |
| ISBN (Electronic) | 9781607685395 |
| DOIs | |
| Publication status | Published - 2015 Jan 1 |
| Event | 14th International Symposium on Solid Oxide Fuel Cells, SOFC 2015; held as part of the Electrochemical Society, ECS Conference on Electrochemical Energy Conversion and Storage - Glasgow, United Kingdom Duration: 2015 Jul 26 → 2015 Jul 31 |
Publication series
| Name | ECS Transactions |
|---|---|
| Number | 1 |
| Volume | 68 |
| ISSN (Print) | 1938-6737 |
| ISSN (Electronic) | 1938-5862 |
Other
| Other | 14th International Symposium on Solid Oxide Fuel Cells, SOFC 2015; held as part of the Electrochemical Society, ECS Conference on Electrochemical Energy Conversion and Storage |
|---|---|
| Country | United Kingdom |
| City | Glasgow |
| Period | 15-07-26 → 15-07-31 |
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All Science Journal Classification (ASJC) codes
- Engineering(all)
Cite this
}
Stability of Bi2O3-based ionic conductor and its application on composite cathode. / Tsai, Shu Yi; Fung, Kuan Zong; Ni, Chung Ta; Chang, Yu Fan.
Solid Oxide Fuel Cells 14, SOFC 2015. ed. / S. C. Singhal; K. Eguchi. 1. ed. Electrochemical Society Inc., 2015. p. 867-874 (ECS Transactions; Vol. 68, No. 1).Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
TY - GEN
T1 - Stability of Bi2O3-based ionic conductor and its application on composite cathode
AU - Tsai, Shu Yi
AU - Fung, Kuan Zong
AU - Ni, Chung Ta
AU - Chang, Yu Fan
PY - 2015/1/1
Y1 - 2015/1/1
N2 - In recent years, solid oxide fuel cells (SOFCs) have been considered as desired devices for generating electricity by electrochemical combination of a fuel with an oxidant. Oxygen ion conductors are usually used as the electrolytes for SOFCs. Among several types of oxygen ion conductors such as CeO2, stabilized Bi2O3 and ZrO2, Bi2O3 with stabilizers exhibit the highest oxygen ion conductivity. Although Bi2O3 tends to be reduced to Bi metal, Bi2O3 incorporated with proper dopants will show enhanced stability against hydrogen. The highest OCV for SOFC using Bi2O3-based electrolyte is around 0.5V which is still too low to be practical. On the other hand, Bi2O3-based system may make a good ionic component for a composite cathode. In this study, we choose yttria-stabilized bismuth oxides (YSB) as ionic conductor and mixed with strontium-doped lanthanum manganite (LSM) for composite cathode. Size effect of LSM on the polarization resistance was investigated by using conventional solid-state reacted and nano-sized LSM. The electrochemical performances of composite cathodes with different LSM:YSB ratios have been investigated at temperature ranging from 500°C to 650°C using AC impedance spectroscopy. The polarization resistance measured from a symmetric cell consisting of nano-sized LSM-YSB electrodes on a YSB electrolyte is 50% lower than that of submicron-sized LSM-YSB cathodes by SSR (0.2 ohmcm2) at 650°C. The polarization of cathode is reduced because of the mixing of high surface area electric conducting materials and ionic conducting materials. The nanostructure of composite cathode is able to extend triple phase boundary (electronic conductor, ionic conductor, and oxygen gas) and provide numerous reaction sites for electrochemical reaction to occur.
AB - In recent years, solid oxide fuel cells (SOFCs) have been considered as desired devices for generating electricity by electrochemical combination of a fuel with an oxidant. Oxygen ion conductors are usually used as the electrolytes for SOFCs. Among several types of oxygen ion conductors such as CeO2, stabilized Bi2O3 and ZrO2, Bi2O3 with stabilizers exhibit the highest oxygen ion conductivity. Although Bi2O3 tends to be reduced to Bi metal, Bi2O3 incorporated with proper dopants will show enhanced stability against hydrogen. The highest OCV for SOFC using Bi2O3-based electrolyte is around 0.5V which is still too low to be practical. On the other hand, Bi2O3-based system may make a good ionic component for a composite cathode. In this study, we choose yttria-stabilized bismuth oxides (YSB) as ionic conductor and mixed with strontium-doped lanthanum manganite (LSM) for composite cathode. Size effect of LSM on the polarization resistance was investigated by using conventional solid-state reacted and nano-sized LSM. The electrochemical performances of composite cathodes with different LSM:YSB ratios have been investigated at temperature ranging from 500°C to 650°C using AC impedance spectroscopy. The polarization resistance measured from a symmetric cell consisting of nano-sized LSM-YSB electrodes on a YSB electrolyte is 50% lower than that of submicron-sized LSM-YSB cathodes by SSR (0.2 ohmcm2) at 650°C. The polarization of cathode is reduced because of the mixing of high surface area electric conducting materials and ionic conducting materials. The nanostructure of composite cathode is able to extend triple phase boundary (electronic conductor, ionic conductor, and oxygen gas) and provide numerous reaction sites for electrochemical reaction to occur.
UR - http://www.scopus.com/inward/record.url?scp=84938770223&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84938770223&partnerID=8YFLogxK
U2 - 10.1149/06801.0867ecst
DO - 10.1149/06801.0867ecst
M3 - Conference contribution
AN - SCOPUS:84938770223
T3 - ECS Transactions
SP - 867
EP - 874
BT - Solid Oxide Fuel Cells 14, SOFC 2015
A2 - Singhal, S. C.
A2 - Eguchi, K.
PB - Electrochemical Society Inc.
ER -