Comparative study of perovskites as cathode contact materials between an La0.8Sr0.2FeO3 cathode and a Crofer22APU interconnect in solid oxide fuel cells

Perovskites of different compositions were tested as cathode contact material between an La_0.8Sr_0.2FeO₃ cathode and a Crofer22APU interconnect by resistance measurements at 800 °C. The materials tested were LaNi_0.6Fe_0.4O₃ and La_0.8Sr_0.2FeO₃ which are also used as cathodes; La_0.8Sr_0.2Mn_0.5Co_0.5O₃ and La_0.8Sr_0.2Mn_0.1Co_0.3Fe_0.6O₃, selected for comparing perovskites with different Mn contents; and La_0.8Sr_0.2Co_0.75Fe_0.25O₃ and La_0.8Sr_0.2Co_0.75Cu_0.25O₃ for comparing perovskites with high Co content and two possible partial substitutions of the Co. The initial area-specific contact resistance (ASR) was found to depend on the electrical conductivity of the measured perovskites. Time evolution of the ASR depended on the interactions between the contact material and the interconnect, showing the highest degradation rates for LaNi_0.6Fe_0.4O₃ and La_0.8Sr_0.2FeO₃. Chromium from the interconnect reacted with the Sr-containing perovskites forming SrCrO₄. With the contact material without strontium chromium-containing perovskites were formed. A reduced interfacial reaction was achieved by application of a MnCo_1.9Fe_0.1O₄ spinel protection layer on Crofer22APU in terms resulting in low and stable ASR.     

La0.8Sr0.2MnO3 and (Mn1.5Co1.5)O4 double layer coated by electrophoretic deposition on Crofer22 APU for SOEC interconnect applications

Electrophoretic deposition (EPD) was employed to coat (Mn_1.5Co_1.5)O₄ spinel layer and La_0.8Sr_0.2MnO₃ layer on Crofer22 APU to improve its corrosion resistance for SOEC interconnect applications. Coatings were obtained by following five steps: (1) charging of the individual particles in suspension in a suitable organic liquid, (2) deposition of (Mn_1.5Co_1.5)O₄ onto Crofer22 APU, (3) heat treatment of the (Mn_1.5Co_1.5)O₄ spinel layer, (4) deposition of La_0.8Sr_0.2MnO₃ layer on (Mn_1.5Co_1.5)O₄ spinel layer and (5) sintering the double coated layers. The coated double layers on Crofer22 APU were sintered at 1200 °C for 2 h in argon atmosphere to form a dense film. Microstructural evaluation indicated that the double layers inhibited outward diffusion of chromium. ASR of the La_0.8Sr_0.2MnO₃ layer coated Crofer22 APU with the (Mn_1.5Co_1.5)O₄ spinel protection layers showed excellent long-term stability and electrical performance.     

Interface reactivity study between La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) cathode material and metallic interconnect for fuel cell

Interface reactivity between La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ (LSCF) cathode material and metallic interconnect (Crofer22APU) was investigated in laboratory air at 700 °C. Due to the interconnect geometry, two interfaces have been analysed: (i) interconnect rib/cathode interface (physically in contact); (ii) the interface under the channel of interconnect. In both cases, formation of a parasite phase was observed after various ageing treatments (20 h, 100 h and 200 h). However, the growth of the determined SrCrO₄ parasite phase depends on interface type and on ageing time. Two different mechanisms have been established in function of interface type: (i) SrCrO₄ phase was formed after solid state diffusion of Cr from metallic interconnect to the cathode; (ii) gas phase reaction induced formation of SrCrO₄ under the channel of interconnect. Finally, the influence of a chemical etching on cathode/interconnect reactivity was evaluated.     

Seal glass compatibility with bare and (Mn,Co)3O4 coated Crofer 22 APU alloy in different atmospheres

To prevent gas mixing and leakage during solid oxide fuel/electrolyzer cell operation, the interconnect/seal glass interface should bond well and remain stable. A SrO-La₂O₃-Al₂O₃-SiO₂ (SABS-0) seal glass has been bonded to bare Crofer 22 APU alloy and (Mn,Co)₃O₄ coated Crofer 22 APU alloy. The stability of the interconnect/SABS-0 interface has been studied in air and H₂/H₂O atmospheres at 800 °C for 1000 h. The interconnect/seal glass interaction involves the oxidation of the bare and (Mn,Co)₃O₄ coated Crofer 22 APU alloy surfaces, inter-diffusion of elements, chemical reaction, and the devitrification of the SABS-0 glass. The study shows that the thermal treatment atmosphere greatly affects the interfacial stability of both bare Crofer 22 APU/SABS-0 and (Mn,Co)₃O₄ coated Crofer 22 APU/SABS-0 samples. The interfacial stability is better in the H₂/H₂O atmosphere for both samples. The instability of the (Mn,Co)₃O₄ coating under the thermal treatment conditions degrades the interfacial compatibility of the (Mn,Co)₃O₄ coated Crofer 22 APU/SABS-0 sample.     

Effects of La0.67Sr0.33MnO3 protective coating on SOFC interconnect by plasma-sputtering

Two metallic alloys, namely, Crofer22 APU and equivalent ZMG23 were investigated as possible interconnect materials in SOFC fuel cells. A _{La0.67Sr0.33MnO3}${\mathrm{La}}_{0.67}{\mathrm{Sr}}_{0.33}{\mathrm{MnO}}_3$ (LSM) thin film is coated on these materials using pulsed DC magnetron sputtering. The as-deposited film is amorphous but is transformed into perovskite structure after annealing at different temperatures and times. The coating and uncoated structures and surface morphologies are analyzed using X-ray diffraction (XRD), electron Probe Micro Analyzer (EPMA), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The result shows that the LSM thin film on Crofer22 APU is good for compaction and adhesion, but there are some stresses between the equivalent ZMG232 and the coating and then create some cracks on the coating. Thereby, the coefficients of thermal expansion (CTE) of the equivalent ZMG232 may be higher than the CTE of the LSM. The cross-section of equivalent ZMG232 did not allow diffusion of Cr element. Thus, coating by plasma-sputtering could prevent the growth of oxide and the diffusion of Cr element to avoid cathode poisoning and the decline of conductivity in SOFC at high temperature.     

Optimization of La2O3-containing diopside based glass-ceramic sealants for fuel cell applications

We report on the optimization of La₂O₃-containing diopside based glass-ceramics (GCs) for sealant applications in solid oxide fuel cells (SOFC). Seven glass compositions were prepared by modifying the parent glass composition, Ca_0.8Ba_0.1MgAl_0.1La_0.1Si_1.9O₆. First five glasses were prepared by the addition of different amounts of B₂O₃ in a systematic manner (i.e. 2, 5, 10, 15, 20 wt.%) to the parent glass composition while the remaining two glasses were derived by substituting SrO for BaO in the glasses containing 2 wt.% and 5 wt.% B₂O₃. Structural and thermal behavior of the glasses was investigated by infrared spectroscopy (FTIR), density measurements, dilatometry and differential thermal analysis (DTA). Liquid–liquid amorphous phase separation was observed in B₂O₃-containing glasses. Sintering and crystallization behavior, microstructure, and properties of the GCs were investigated under different heat treatment conditions (800 and 850 °C; 1–300 h). The GCs with ≥5 wt.% B₂O₃ showed an abnormal thermal expansion behavior above 600 °C. The chemical interaction behavior of the glasses with SOFC electrolyte and metallic interconnects, has been investigated in air atmosphere at SOFC operating temperature. Thermal shock resistance and gas-tightness of GC sealants in contact with 8YSZ was evaluated in air and water. The total electrical resistance of a model cell comprising Crofer 22 APU and 8YSZ plates joined by a GC sealant has been examined by the impedance spectroscopy. Good matching of thermal expansion coefficients (CTE) and strong, but not reactive, adhesion to electrolyte and interconnect, in conjunction with a low level of electrical conductivity, indicate that the investigated GCs are suitable candidates for further experimentation as SOFC sealants.     

Long term behaviors of La0.8Sr0.2MnO3 and La0.6Sr0.4Co0.2Fe0.8O3 as cathodes for solid oxide fuel cells

This work studies the electrochemical performance and stability of La_0.8Sr_0.2MnO₃ (LSM) and La_0.6Sr_0.4Co_0.2Fe_0.8O₃ (LSCF) cathodes in a AISI441 interconnect/cathode/YSZ electrolyte half-cell configuration at 800 °C for 500 h. Ohmic resistance and polarization resistance of the cathodes are analyzed by deconvoluting the electrochemical impedance spectroscopy (EIS) results. The LSM cathode has much higher resistance than the LSCF electrode even though the respective cathode resistance either decreases or stays stable over the long term thermal treatment. During the 500 h thermal treatment, dramatic elemental distribution changes influence the electrochemical behaviors of the cathodes. Chromium diffusion from the interconnect into the LSM electrode at triple phase boundaries (TPBs) leads to segregation of Sr away from La and Mn. For the LSCF cathode, Sr and Co segregation is dominant. The fundamental processes at the TPBs are proposed. Overall, LSCF is a much preferred cathode material because of its much smaller resistance for the 500 h thermal treatment time.     

Electrochemical study of La0.6Sr0.4Co0.8Fe0.2O3 during oxygen evolution reaction

In this paper, oxygen evolution reaction (OER) mechanism in La_0.6Sr_0.4Co_0.8Fe_0.2O₃ was investigated in KOH solution by electrochemical impedance spectroscopy (EIS) and voltammetric measurements. The Tafel slopes and reaction orders evaluated in this paper are consistent with the B. O’Grady’s Path for oxygen evolution on oxides. The activation energy for OER in La_0.6Sr_0.4Co_0.8Fe_0.2O₃ was 28.3 kJ mol⁻¹. The obtained apparent porosity of La_0.6Sr_0.4Co_0.8Fe_0.2O₃ electrode is 48% and the roughness factor is around 1.6 × 10⁴. The polarization resistance of La_0.6Sr_0.4Co_0.8Fe_0.2O₃ is much low compared with other similar oxides. This can be due the high roughness and high porosity in addition to the low active energy for the process.     

Electrical contacts between cathodes and metallic interconnects in solid oxide fuel cells

In this work, simulated cathode/interconnect structures were used to investigate the effects of different contact materials on the contact resistance between a strontium doped lanthanum ferrite cathode and a Crofer22 APU interconnect. Among the materials studied, Pt, which has a prohibitive cost for the application, demonstrated the best performance as a contact paste. For the relatively cost-effective perovskites, the contact ASR was found to depend on their electrical conductivity, scale growth on the metallic interconnect, and interactions between the contact material and the metallic interconnect or particularly the scale grown on the interconnect. Manganites appeared to promote manganese-containing spinel interlayer formation that helped minimize the increase of contact ASR. Chromium from the interconnects reacted with strontium in the perovskites to form SrCrO₄. An improved performance was achieved by application of a thermally grown (Mn,Co)₃O₄ spinel protection layer on Crofer22 APU that dramatically minimized the contact resistance between the cathodes and interconnects.     

Area specific resistance of oxide scales grown on ferritic alloys for solid oxide fuel cell interconnects

Planar solid oxide fuel cells (SOFC) are considered to be power generators with high efficiency and low emission at small power units (1-200 kW_el). Many prototype systems are already successfully realized. For mass production the costs have to be reduced and the long-term stability has to be enhanced. Power losses <0.5%/1000 h is the target value for stacks in stationary SOFC-based power systems. To reach this goal, the factors influencing degradation have to be found and reduced. In this work the interaction between interconnect and different ceramic materials such as perovskites (La_0.8Sr_0.2(Mn_,Co)O₃, La_0.65Sr_0.3MnO₃, La_0.65Sr_0.3(Mn,Co)O₃) and spinels (Mn(Co,Fe)O₄, (Cu,Ni)Mn₂O₄) was investigated on the cathode (air) side of conventional ferritic interconnect materials (CroFer22APU, ITMLC, ZMG232L). The method to determine the value of the area specific resistance between interconnect and contact layer (R_#ICC) within a tolerance of 10% has been developed to provide reliable data for ASR values and their degradation.The R_#ICC-value increases with annealing time. The degree of this increase depends on used materials and their combination. The spinel contact layers form a thin dense ceramic layer at the beginning of the annealing process. This layer reduces the oxidation rate of the alloy. Because of this protection layer a thinner oxide scale grows and the ASR aging rate is much lower (0.4-0.9 mΩ cm²/1000 h). The comparison of the aging rates of different alloys with La_0.8Sr_0.2(Mn,Co)O₃ contact layer reveals remarkable differences: 3.1 mΩ cm²/1000 h for CroFer22APU, 10.9 mΩ cm²/1000 h for ITMLC and 21.2 mΩ cm²/1000 h for ZMG232L.The degradation in a stack has been determined from the R_#ICC-values and geometric factors. The impact of oxidation at the cathode side of interconnect is about one third of the total stack degradation. The method opens the possibility for comparing area specific resistances of special material combinations with high accuracy. By optimized material combinations the degradation in stacks can be reduced to <0.5%/1000 h.     

Electrical stability of a novel sealing glass with (Mn,Co)-spinel coated Crofer22APU in a simulated SOFC dual environment

A novel alkaline-earth silicate (Sr-Ca-Y-B-Si-Zn) sealing glass was developed for solid oxide fuel cell (SOFC) applications. The glass was sandwiched between two metallic interconnect plates and tested for electrical stability in a dual environment at elevated temperatures of 800-850 °C. A ferritic stainless steel (Crofer22APU) was used as the metallic interconnect material in the as-received state and coated with (Mn,Co)₃O₄ spinel. The isothermal aging results showed stable electrical resistivity at 800-850 °C for ∼500-1000 h. The electrical resistivities at 800 or 850 °C of the spinel coated samples were lower than the as-received ones; however, they were still several orders of magnitude higher than typical SOFC functional parts. Interfacial microstructure was characterized and possible reactions are discussed.     

Oxidation behavior of metallic interconnect coated with La–Sr–Mn film by screen painting and plasma sputtering

Two Fe-based alloys, specific company developed and designated as Crofer22APU and ZMG232, have been extensively evaluated and considered as outstanding metallic interconnect materials. Both these alloys contain significant and minute amounts of elemental Cr and La, respectively. In this study, they are coated with films of La–Sr–Mn (LSM) using two methods, screen painting and plasma sputtering, to determine the effect of LSM on corrosion resistance and electrical resistivity of Crofer22APU and ZMG232. They were then treated in a simulated oxidizing environment at 800 °C for 200 h. Analytical results indicate that the LSM film changed the oxidation behavior of the base alloys, Crofer22 APU and ZMG232. The bare alloys formed Cr₂O₃, while the coated alloys produced (Mn, Fe) Cr ₂O₄. The electrical resistance of the former oxide at high temperature is several thousand times higher than that of the latter oxide. This remarkable effect of the LSM film on the electrical characteristics warrants further in-depth research.     

Effect of reactive elements on oxidation behaviour of Fe–22Cr–0.5Mn ferritic stainless steel for a solid oxide fuel cell interconnect

Ferritic stainless steel has become a promising material for metallic interconnects for solid oxide fuel cells (SOFCs) operating in an intermediate temperature range (650–800 °C). Ferritic stainless steels containing reactive elements (REs) such as Crofer22APU and ZMG232 have been developed for SOFC interconnects. Nevertheless, the effectiveness of REs on the growth kinetics of the chromia-rich scale that forms on the ferritic stainless steels is not yet well understood. The current study focuses on the investigation of the effect of REs such as Y, Ce and La on the oxidation behaviour and scale properties of Fe–22Cr–0.5Mn stainless steel. The results show that Y is the most effective reactive element for reducing the scale growth kinetics and area-specific resistance of the chromia scale which forms on this stainless steel. The growth kinetics of the chromia-rich scale can be effectively reduced by the dominant segregation of Y at the interface between the oxide scale and alloy substrate, and by the formation of a thin SiO₂ and MnO layer underneath the Cr₂O₃-rich oxide.     

Electrical behavior of aluminosilicate glass-ceramic sealants and their interaction with metallic solid oxide fuel cell interconnects

A series of alkaline-earth aluminosilicate glass-ceramics (GCs) were appraised with respect to their suitability as sealants for solid oxide fuel cells (SOFCs). The parent composition with general formula Ca_0.9MgAl_0.1La_0.1Si_1.9O₆ was modified with Cr₂O₃ and BaO. The addition of BaO led to a substantial decrease in the total electrical conductivity of the GCs, thus improving their insulating properties. BaO-containing GCs exhibited higher coefficient of thermal expansion (CTE) in comparison to BaO-free GCs. An extensive segregation of oxides of Ti and Mn, components of the Crofer22 APU interconnect alloy, along with negligible formation of BaCrO₄ was observed at the interface between GC/interconnects diffusion couples. Thermal shock resistance and gas-tightness of GC sealants in contact with yttria-stabilized zirconia electrolyte (8YSZ) was evaluated in air and water. Good matching of CTE and strong, but not reactive, adhesion to the solid electrolyte and interconnect, in conjunction with a high level of electrical resistivity, are all advantageous for potential SOFC applications.     

Characteristic of (La0.8Sr0.2)0.98MnO3 coating on Crofer22APU used as metallic interconnects for solid oxide fuel cell

This study reports the high temperature oxidation kinetics, area specific resistance (ASR), and interfacial microstructure of metallic interconnects coated by (La_0.8Sr_0.2)_0.98MnO₃ (LSM) in air atmosphere at 800 °C. An efficient LSM conductive layer was fabricated on metallic interconnects for solid oxide fuel cells (SOFCs) by using a wet spray coating method. The optimum conditions for slurries used in the wet spray coating were determined by the measurement of slurry viscosity and coated surface morphology. The surface roughnesses of the substrates were increased through sandblast treatment. The adhesive strength of the interface between the coated layer and the metal substrate increased with increased surface roughness of the metallic interconnects. The electrical conductivities of the coated substrates were measured by using a DC two-point and four-wire method under air atmosphere at 800 °C. Of note, the Crofer22APU treated at 1100 °C in N₂ with 10 vol.% H₂ showed long-term stability and a lower ASR value than other samples(heat-treated at 800 °C and 900 °C). After an 8000-h oxidation experiment the coated Crofer22APU substrate, the ASR showed a low value of 23 mΩ cm². The thickness of the coated conductive oxide layer was about 10-20 μm. These results show that a coated oxide layer prevents the formation and the growth of scale (Cr₂O₃ and (Mn, Cr, Fe)₃O₄ layer) and enhances the long-term stability and electrical performance of metallic interconnects for SOFCs.     

(Mn,Co)3O4 spinel coatings on ferritic stainless steels for SOFC interconnect applications

(Mn,Co)₃O₄ spinel with a nominal composition of Mn_1.5Co_1.5O₄ demonstrates excellent electrical conductivity, satisfactory thermal and structural stability, as well as good thermal expansion match to ferritic stainless steel interconnects. A slurry-coating technique was developed for fabricating the spinel coatings onto the steel interconnects. Thermally grown layers of Mn_1.5Co_1.5O₄ not only significantly decreased the contact resistance between a LSF cathode and stainless steel interconnect, but also acted as a mass barrier to inhibit scale growth on the stainless steel and to prevent Cr outward migration through the coating. The level of improvement in electrical performance and oxidation resistance (i.e. the scale growth rate) was dependent on the ferritic substrate composition. For E-brite and Crofer22 APU, with a relatively high Cr concentration (27 wt% and 23%, respectively) and negligible Si, the reduction of contact ASR and scale growth on the ferritic substrates was significant. In comparison, limited improvement was achieved by application of the Mn_1.5Co_1.5O₄ spinel coating on AISI430, which contains only 17%Cr and a higher amount of residual Si.     

Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

Oxidation-resistant alloys find use as interconnect materials, heat exchangers, and gas supply tubing in solid oxide fuel cell (SOFC) systems, especially when operated at temperatures below ∼800 °C. If fueled with synthesis gas derived from coal or biomass, such metallic components could be exposed to impurities contained in those fuel sources. In this study, coupons of ferritic stainless steels Crofer 22 APU and SS 441, austenitic nickel-chromium superalloy Inconel 600, and an alumina-forming high nickel alloy alumel were exposed to synthesis gas containing ≤2 ppm phosphorus, arsenic and antimony, and reaction products were tested. Crofer 22 APU coupons coated with a (Mn,Co)₃O₄ protective layer were also evaluated. Phosphorus was found to be the most reactive. On Crofer 22 APU, the (Mn,Cr)₃O₄ passivation layer reacted to form an Mn-P-O product, predicted to be manganese phosphate from thermochemical calculations, and Cr₂O₃. On SS 441, reaction of phosphorus with (Mn,Cr)₃O₄ led to the formation of manganese phosphate as well as an Fe-P product, predicted from thermochemical calculations to be Fe₃P. Minimal interactions with antimony or arsenic in synthesis gas were limited to Fe-Sb and Fe-As solid solution formation. Though not intended for use on the anode side, a (Mn,Co)₃O₄ spinel coating on Crofer 22 APU reacted with phosphorus in synthesis gas to produce products consistent with Mn₃(PO₄)₂ and Co₂P. A thin Cr₂O₃ passivation layer on Inconel 600 did not prevent the formation of nickel phosphides and arsenides and of iron phosphides and arsenides, though no reaction with Cr₂O₃ was apparent. On alumel, an Al₂O₃ passivation layer rich in Ni did not prevent the formation of nickel phosphides, arsenides, and antimonides, though no reaction with Al₂O₃ occurred. This work shows that unprotected metallic components of an SOFC stack and system can provide a sink for P, As and Sb impurities that may be present in fuel gases, and thus complicate experimental studies of impurity interactions with the anode.     

Structural and electrical properties of selected La1−xSrxCo0.2Fe0.8O3 and La0.6Sr0.4Co0.2Fe0.6Ni0.2O3 perovskite type oxides

In this paper, the structural and transport properties of selected La_1−xSr_xCo_0.2Fe_0.8O₃ (LSCF) perovskites and La_0.6Sr_0.4Co_0.2Fe_0.6Ni_0.2O₃ (LSCFN64262) perovskite are presented. Crystal structure of the samples was characterized by means of X-ray studies with Rietveld method analysis. DC electrical conductivity and thermoelectric power were measured at a wide temperature range (80–1200 K) in air. For La_0.2Sr_0.8Co_0.2Fe_0.8O₃ (LSCF2828) and La_0.4Sr_0.6Co_0.2Fe_0.8O₃ (LSCF4628) perovskites a maximum observed on electrical conductivity dependence on temperature exists at about 750 K. It can be associated with an appearance of oxygen vacancies and implies a mixed ionic-electronic transport. A growing amount of oxygen vacancies at higher temperatures causes a decrease in the electrical conductivity due to a recombination mechanism associated with lowering of the average valence of 3d metals. A similar characteristic was found for LSCFN64262 perovskite, which also exhibits a relatively high electrical conductivity.     

Evaluation of several low thermal expansion Fe–Co–Ni alloys as interconnect for reduced-temperature solid oxide fuel cell

Several low thermal expansion Fe–Co–Ni alloys including HRA 929C, Thermo-Span, EXP 4005 and Three-Phase were evaluated as interconnect for reduced-temperature solid oxide fuel cell (SOFC). The isothermal oxidation behaviors of the four alloys were determined at 800 °C in air corresponding to the SOFC cathode environment. The results indicate that the mass gains of HRA 929C and Thermo-Span increased continuously with oxidation time, and were higher than those of EXP 4005 and Three-Phase, both of which exhibited low oxidation rate after the first-week exposure due to the formation of a semi-continuous Al₂O₃ inner layer. Compared to the ferritic alloy Crofer 22 APU, these low thermal expansion alloys exhibited inferior oxidation resistance; however, the area specific resistance (ASR) of the oxide scales thermally grown on these alloys was lower than that for Crofer 22 APU, as a result of the formation of a highly-conductive, Cr-free surface spinel layer. The promises and problems of these low thermal expansion alloys were discussed with regard to SOFC interconnect application.     

Surface and interface behaviors of (La0.8Sr0.2)xMnO3 air electrode for solid oxide cells

In solid oxide cell operation, the stoichiometry of the air electrode is an important factor for its interaction with electrolyte and interconnect and long-term cell performance. In this study, tri-layer samples of yttria stabilized zirconia (YSZ)/(La_0.8Sr_0.2)_xMnO₃ (LSM)/AISI 441 stainless steel are made and thermally treated in dry air atmosphere at 800 °C for 500 h. The air electrode composition is varied by changing the x value in (La_0.8Sr_0.2)_xMnO₃ from 0.95 to 1.05 (LSM95, LSM100, and LSM105). The LSM composition segregation, YSZ/LSM/AISI 441 interfacial interaction, and the reaction of volatile chromium species with the LSM surface are characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Surface segregation of Sr and La are detected for all the LSM samples. Cr deposition is found across the LSM surface. For the LSM95 sample, Sr-containing compound leads to a high Cr content at the YSZ/LSM interface. For the LSM105 sample, on the other hand, the enrichment of La at the YSZ/LSM interface hinders the Cr deposition, leading to a very low Cr content. The mechanisms of LSM elemental surface segregation and Cr deposition are discussed.