title: Chromium deposition and poisoning of La(0.8)Sr(0.2)MnO3 oxygen electrodes of solid oxide electrolysis cells.
abstract: The effect of the presence of an Fe-Cr alloy metallic interconnect on the performance and stability of La(0.8)Sr(0.2)MnO3 (LSM) oxygen electrodes is studied for the first time under solid oxide electrolysis cell (SOEC) operating conditions at 800 °C. The presence of the Fe-Cr interconnect accelerates the degradation and delamination processes of the LSM oxygen electrodes. The disintegration of LSM particles and the formation of nanoparticles at the electrode/electrolyte interface are much faster as compared to that in the absence of the interconnect. Cr deposition occurs in the bulk of the LSM oxygen electrode with a high intensity on the YSZ electrolyte surface and on the LSM electrode inner surface close to the electrode/electrolyte interface. SIMS, GI-XRD, EDS and XPS analyses clearly identify the deposition and formation of chromium oxides and strontium chromate on both the electrolyte surface and electrode inner surface. The anodic polarization promotes the surface segregation of SrO and depresses the generation of manganese species such as Mn(2+). This is evidently supported by the observation of the deposition of SrCrO4, rather than (Cr,Mn)3O4 spinels as in the case under the operating conditions of solid oxide fuel cells. The present results demonstrate that the Cr deposition is essentially a chemical process, initiated by the nucleation and grain growth reaction between the gaseous Cr species and segregated SrO on LSM oxygen electrodes under SOEC operating conditions.
authors.affiliation: Fuels and Energy Technology Institute, Department of Chemical Engineering, Curtin University, Perth, WA 6102, Australia. s.jiang@curtin.edu.au.
authors.forename: Kongfa
authors.initials: K
authors.lastname: Chen
authors.affiliation: Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Motooka 744, Nishi-ku, Fukuoka, 819-0395, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Hyodo
authors.affiliation: Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, WA 6009, Australia.
authors.forename: Aaron
authors.initials: A
authors.lastname: Dodd
authors.affiliation: Fuels and Energy Technology Institute, Department of Chemical Engineering, Curtin University, Perth, WA 6102, Australia. s.jiang@curtin.edu.au.
authors.forename: Na
authors.initials: N
authors.lastname: Ai
authors.affiliation: Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Motooka 744, Nishi-ku, Fukuoka, 819-0395, Japan and International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Motooka 744, Nishi-ku, Fukuoka, 819-0395, Japan.
authors.forename: Tatsumi
authors.initials: T
authors.lastname: Ishihara
authors.affiliation: Center for Fuel Cell Innovation, School of Materials Science and Engineering, State Key Laboratory of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Li
authors.initials: L
authors.lastname: Jian
authors.affiliation: Fuels and Energy Technology Institute, Department of Chemical Engineering, Curtin University, Perth, WA 6102, Australia. s.jiang@curtin.edu.au.
authors.forename: San Ping
authors.initials: SP
authors.lastname: Jiang