Ceramic Electrodes for SOFC's
The current trend in Solid Oxide Fuel Cell (SOFC) development is for a lowering of the operation temperature from ~ 1000°C to temperatures as low as 600°C. This lowering of temperature is beneficial in a number of ways. It relaxes the stringent materials requirements for cell components, particularl...
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 1998 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/51154 |
| Acceso en línea: | http://hdl.handle.net/10261/51154 |
| Access Level: | acceso abierto |
| Palabra clave: | Ceramic electrodes Solid Oxide Fuell |
| Sumario: | The current trend in Solid Oxide Fuel Cell (SOFC) development is for a lowering of the operation temperature from ~ 1000°C to temperatures as low as 600°C. This lowering of temperature is beneficial in a number of ways. It relaxes the stringent materials requirements for cell components, particularly, the interconnect, and for the balance of plant. One adverse consequence of the lower temperatures is a slowing. Of the electrode kinetics, particularly, at the cathode (air electrode). It is thus necessary to have a thorough understanding of the processes occuring at the cathode to aid material selection and optimisation for low operating temperatures. The majority of the cathode materials use at present, are based on mixed conducting, acceptor (A) doped, rare-earth (Ln) transition metal (T) perovskite oxides with the general formula. Ln-^^A^TOg +5. Examples of these materials include Laj_^Sr^Mn03_^g La-^_^Sr^Co03 +g etc. The performance of these electrodes can be linked to their microsturcture, and to the kinetics of oxygen exchange and diffusion. In order to model the behaviour of such materials as cathodes. We have undertaken a systematic study of the kinetics of the oxygen exchange process using the isotope exchange depth profiling method (lEDP) employing Secondary Ion Mass Spectrometry (SIMS). Oxygen self diffusion and surface exchange data are presented for a number of perovskite cathode compositions, in particular the effect of increasing the acceptor dopant level are explored together with the effect of changing the rare earth and transition metal cations. |
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