Chemische Stabilität von Perowskitstrukturen auf der Basis von LaFeO$_{3}$ an der Grenzfläche zum Festelektrolyten einer Hochtemperatur-Brennstoffzelle
Chemische Stabilität von Perowskitstrukturen auf der Basis von LaFeO$_{3}$ an der Grenzfläche zum Festelektrolyten einer Hochtemperatur-Brennstoffzelle
For reducing the operation temperature of a solid oxide fuel cell from 1000°C to 850°C the developement of a new and advanced cathode material is a necessary demand. The investigation of the chemical stability and compatibility of a new material based on LaFeO$_{3}$ was of main interest in this work...
Saved in:
Personal Name(s): | Kindermann, L. (Corresponding author) |
---|---|
Hilpert, K. / Nickel, Hubertus | |
Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
1997
|
Physical Description: |
129 p. |
Document Type: |
Report Book |
Research Program: |
Addenda |
Series Title: |
Berichte des Forschungszentrums Jülich
3382 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
For reducing the operation temperature of a solid oxide fuel cell from 1000°C to 850°C the developement of a new and advanced cathode material is a necessary demand. The investigation of the chemical stability and compatibility of a new material based on LaFeO$_{3}$ was of main interest in this work. In addition the electrical properties and the thermal expansion coefficient of some selected compositions were investigated. Also experiments to determine the oxygen vacancy formation were carried out. Physicochemical compatibilities of different compositions, (La$_{0.6}$A$_{0.4}$)zFe$_{0.8}$M$_{0.2}$O$_{3.6}$ (A = Sr, Ca; M = Cr, Mn, Co, Ni; z = 0.9, 1.0) and (La$_{1-x}$Sr$_{x})_{z}$Fe$_{1-y}$Mn$_{y}$O$_{3-6}$ (x = 0 - 0.4; y = 0 - 1; z = 0.9, 0.95, 1.0), with the solid electrolyte zirconia - yttria (8 mol % Y$_{2}$O$_{3}$) were investigated. Powder mixtures of these perovskites were annealed at 1000°C, 1100°C and 1400°C for time periods up to 3600h in a high temperature furnace. After quenching, the samples were analyzed by XRD, SEM/EDX and TEM/EDX for identification of the reaction products. Interdiffusion processes between the perovskite material and the electrolyte lead to the formation of new phases. High Sr content on A site lead to the formation of SrZrO$_{3}$ whereas La$_{2}$Zr$_{2}$O$_{7}$ was detected in powder mixtures with high La concentration. Samples with Ca on A site and Co or Ni on B site showed the formation of a CaZrO$_{3}$ phase while a garnet phase was observed with M = Cr or Mn. In some cases also monoclinic zirconia was found. Some compositions showed no reaction products. Based on these results it was possible to work out different stability criteria for LaFeO$_{3}$ based perovskites. Some suggestions were made concerning an electrolyte with a modified composition as well as different dopants namely Co, Zr or Ir. |