Abstract
To increase the performance of solid oxide fuel cells operated at intermediate temperatures (<700 °C), we used the electronic conductor La0.8Sr0.2MnO3 (LSM) and the mixed conductor La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) to modify the cathode in the electrode microstructure. For both cathode materials, we employed a Sm0.2Ce0.8O2 (SDC) buffer layer as a diffusion barrier on the yttria-stabilized zirconia (YSZ) electrolyte to prevent the interlayer formation of SrZrO3 and La2Zr2O7, which have a poor ionic conductivity. These interfacial reaction products were formed only minimally at the electrolyte-cathode interlayer after sintering the SDC layer at high temperature; in addition, the degree of cathode polarization also decreased. Moreover to extend the triple phase boundary and improve cell performance at intermediate temperatures, we used sol-gel methods to coat an SDC layer on the cathode pore walls. The cathode resistance of the LSCF cathode cell featuring SDC modification reached as low as 0.11 Ω cm2 in air when measured at 700 °C. The maximum power densities of the cells featuring the modified LSCF and LSM cathodes were 369 and 271 mW/cm2, respectively, when using O2 as the oxidant and H2 as the fuel.
Original language | English |
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Pages (from-to) | 9213-9219 |
Number of pages | 7 |
Journal | International Journal of Hydrogen Energy |
Volume | 34 |
Issue number | 22 |
DOIs | |
Publication status | Published - 2009 Nov |
Keywords
- Ceria coating
- Diffusion barrier layer
- Intermediate-temperature solid oxide fuel cell
- LaSrCoFeO
- LaSrMnO
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology