Improved oxidation resistance of a nanocrystalline chromite-coated ferritic stainless steel

An economical dip coating process was developed to synthesize uniform, crack-free, and adherent thin nanocrystalline LaCrO₃ films on a ferritic stainless steel substrate for the solid oxide fuel cell interconnect applications. LaCrO₃ perovskite phase was formed after annealing in air at 800 °C for 1 h for both the LaCrO₃ and La₂O₃ precursors. The effectiveness of the coating in improving the oxidation resistance of the alloy was demonstrated by both isothermal and cyclic oxidation tests. The LaCrO₃ coatings were found to cause a pronounced reduction in oxidation rate of the alloy, especially with low La-content precursors. The area-specific resistance of the oxide scales formed on the bare and coated alloy substrates was also evaluated and discussed.     

LaCrO3-based coatings deposited by high-energy micro-arc alloying process on a ferritic stainless steel interconnect material

Currently used ferritic stainless steel interconnects are unsuitable for practical applications in solid oxide fuel cells operated at intermediate temperatures due to chromium volatility, poisoning of the cathode material, rapidly decreasing electrical conductivity and a low oxidation resistance. To overcome these problems, a novel, simple and cost-effective high-energy micro-arc alloying (HEMAA) process is proposed to prepare LaCrO₃-based coatings for the type 430 stainless steel interconnects. However, it is much difficult to deposit an oxide coating by HEMAA than a metallic coating due to the high brittleness of oxide electrodes for deposition. Therefore, a Cr-alloying layer is firstly obtained on the alloy surface by HEMAA using a Cr electrode rod, followed by a LaCrO₃-based coating using an electrode rod of LaCrO₃-20 wt.%Ni, with a metallurgical bonding between the coating and the substrate. The preliminary oxidation tests at 850 °C in air indicate that the LaCrO₃-based coatings showed a three-layered microstructure with a NiFe₂O₄ outer layer, a thick LaCrO₃ sub-layer and a thin Cr₂O₃-rich inner layer, which thereby possesses an excellent protectiveness to the substrate alloy and a low electrical contact resistance.     

Oxidation behavior and electrical property of ferritic stainless steel interconnects with a Cr-La alloying layer by high-energy micro-arc alloying process

Chromium volatility, poisoning of the cathode material and rapidly decreasing electrical conductivity are the major problems associated with the application of ferritic stainless steel interconnects of solid oxide fuel cells operated at intermediate temperatures. Recently, a novel and simple high-energy micro-arc alloying (HEMAA) process is proposed to prepare LaCrO₃-based coatings for the type 430 stainless steel interconnects using a LaCrO₃-Ni rod as deposition electrode. In this work, a Cr-La alloying layer is firstly obtained on the alloy surface by HEMAA using Cr and La as deposition electrode, respectively, followed by oxidation treatment at 850 °C in air to form a thermally grown LaCrO₃ coating. With the formation of a protective scale composed of a thick LaCrO₃ outer layer incorporated with small amounts of Cr-rich oxides and a thin Cr₂O₃-rich sub-layer, the oxidation rate of the coated steel is reduced remarkably. A low and stable electrical contact resistance is achieved with the application of LaCrO₃-based coatings, with a value less than 40 mΩ cm² during exposure at 850 °C in air for up to 500 h.     

Electrical conductivity and performance of doped LaCrO3 perovskite oxides for solid oxide fuel cells

The crystalline structure, redox stability and electrical conductivity of LaCrO₃, (La_1−xM_x)CrO₃ (M = Mg, Ca, Ba for x = 0.3 and M = Sr for x = 0.25), and (La_0.75Sr_0.25)(Cr_0.5Mn_0.5)O₃ (LSCM) perovskites are studied from 500 to 800 °C in both oxidizing and reducing atmospheres. Dopability, redox stability and electrical conductivity are compared and examined. A-site doping with alkaline elements is found to improve significantly the electrical conductivity, particularly if properly doped. The highest conductivity is obtained with Ca- and Sr-doped LaCrO₃. A-site doping also reduces the activation energy of the electrical conductivity, particularly under a reducing environment. Preliminary electrochemical results indicate that Ca-doped LaCrO₃ shows promise as a cathode for solid oxide fuel cells.     

Co/LaCrO3 composite coatings for AISI 430 stainless steel solid oxide fuel cell interconnects

Rapidly decreasing electronic conductivity, chromium volatility and poisoning of the cathode material are the major problems associated with inevitable growth of chromia on ferritic stainless steel interconnects of solid oxide fuel cells (SOFC). This work evaluates the performance of a novel, electrodeposited composite Co/LaCrO₃ coating for AISI 430 stainless steel. The oxidation behaviour of the Co/LaCrO₃-coated AISI 430 substrates is studied in terms of scale microstructure and growth kinetics. Area-specific resistance (ASR) of the coated substrates has also been tested. The results showed that the Co/LaCrO₃ coating forms a triple-layer scale consisting of a chromia-rich subscale, a Co–Fe spinel mid-layer and a Co₃O₄ spinel top layer at 800 °C in air. This scale is protective, acts as an effective barrier against chromium migration into the outer oxide layer and exhibits a low, stable ASR of ∼0.02 Ω cm² after 900 h at 800 °C in air.     

NiMn2O4 spinel as an alternative coating material for metallic interconnects of intermediate temperature solid oxide fuel cells

In an effort to improve the performance of SUS 430 alloy as a metallic interconnect material, a low cost and Cr-free spinel coating of NiMn₂O₄ is prepared on SUS 430 alloy substrate by the sol-gel method and evaluated in terms of the microstructure, oxidation resistance and electrical conductivity. A oxide scale of 3-4 μm thick is formed during cyclic oxidation at 750 °C in air for 1000 h, consisting of an inner layer of doped Cr₂O₃ and an outer layer of doped NiMn₂O₄ and Mn₂O₃; and the growth of Cr₂O₃ and formation of MnCr₂O₄ are depressed. The oxidation kinetics obeys the parabolic law with a rate constant as low as 4.59 × 10⁻¹⁵ g² cm⁻⁴ s⁻¹. The area specific resistance at temperatures between 600 and 800 °C is in the range of 6 and 17 mΩ cm². The above results indicate that NiMn₂O₄ is a promising coating material for metallic interconnects of the intermediate temperature solid oxide fuel cells.     

The effect of coating crystallization and substrate impurities on magnetron sputtered doped LaCrO3 coatings for metallic solid oxide fuel cell interconnects

For IT-SOFC metallic interconnects, surface coating is effective for reducing Cr poisoning of the cathode and controlling scale growth. In this work, LaCrO₃ and doped LaCrO₃ coatings were deposited by magnetron sputtering on SS446 and Crofer 22 APU substrates. The crystallization process was studied by means of X-ray Diffraction (XRD) during the annealing of the sputter coated samples in ambient and reducing environments. The formation of intermediate phases when annealed in air, LaCrO₄ and La₂CrO₆, results in vacancy formation upon subsequent transformation to the LaCrO₃ phase and thus a decreased oxidation resistance. While the avoidance of an intermediate phase change when the coatings are initially annealed in a reducing environment leads to dense and compact coatings. This confirmed both by XRD and by scanning electron microscopy (SEM) of coating cross-sections. Crofer 22 APU alloys with various silicon and aluminum levels are deposited with doped LaCrO₃ coating to study substrate impurity effects on coating properties. It was found that silicon content in the substrates leads to increased ASR of the coatings. In addition, long term annealing in air shows that aluminum impurities in the substrate can lead to the formation of alumina at substrate grain boundaries, which in turn leads to enhanced Mn migration at the grain boundaries. Increased manganese concentrations at the film/grain boundary interface in coated samples produces larger than normal amounts of (Mn,Cr)₃O₄ spinel in these regions, which cracks the coating and reduces the ASR value due to extra electronic conduction path. A similar mechanism is not observed in a low Al/Si alloy.     

CoFe2O4 spinel protection coating thermally converted from the electroplated Co-Fe alloy for solid oxide fuel cell interconnect application

CoFe₂O₄ has been demonstrated as a potential spinel coating for protecting the Cr-containing ferritic interconnects. This spinel had an electrical conductivity of 0.85 S cm⁻¹ at 800 °C in air and an average coefficient of thermal expansion (CTE) of 11.80 × 10⁻⁶ K⁻¹ from room temperature to 800 °C. A series of Co-Fe alloys were co-deposited onto the Crofer 22 APU ferritic steel via electroplating with an acidic chloride solution. After thermal oxidation in air at 800 °C, a CoFe₂O₄ spinel layer was attained from the plated Co_0.40Fe_0.60 film. Furthermore, a channeled Crofer 22 APU interconnect electrodeposited with a 40-μm Co_0.40Fe_0.60 alloy film as a protective coating was evaluated in a single-cell configuration. The presence of the dense, Cr-free CoFe₂O₄ spinel layer was effective in blocking the Cr migration/transport and thus contributed to the improvement in cell performance stability.     

A new anode material for intermediate solid oxide fuel cells

A new anode material for intermediate temperature solid oxide fuel cells (IT-SOFCs) with a composite of La_0.7Sr_0.3Cr_1−xNi_xO₃ (LSCN), CeO₂ and Ni has been synthesized. EDX analysis showed that 1.19 at% Ni was doped into the perovskite-type La_0.7Sr_0.3CrO₃ and Ce could not be detected in the perovskite phases. Results showed that the fine CeO₂ and Ni were highly dispersed on the La_0.7Sr_0.3Cr_1−xNi_xO₃ substrates after calcining at 1450 °C and reducing at 900 °C. The thermal expansion coefficient (TEC) of the as-prepared anode material is 11.8 × 10⁻⁶ K⁻¹ in the range of 30–800 °C. At 800 °C, the electrical conductivity of the as-prepared anode material calcined at 1450 °C for 5 h is 1.84 S cm⁻¹ in air and 5.03 S cm⁻¹ in an H₂ + 3% H₂O atmosphere. A single cell with yttria-stabilized zirconia (YSZ, 8 mol% Y₂O₃) electrolyte and the new materials as anodes and La_0.8Sr_0.2MnO₃ (LSM)/YSZ as cathodes was assembled and tested. At 800 °C, the peak power densities of the single cell was 135 mW cm⁻² in an H₂ + 3% H₂O atmosphere.     

Al-doped Li7La3Zr2O12 synthesized by a polymerized complex method

Li₇La₃Zr₂O₁₂ electrolytes doped with different amounts of Al (0, 0.2, 0.7, 1.2, and 2.5 wt.%) were prepared by a polymerized complex (Pechini) method. The influence of aluminum on the structure and conductivity of Li₇La₃Zr₂O₁₂ were investigated by X-ray diffraction (XRD), impedance spectroscopy, scanning electron microscopy (SEM), and thermal dilatometry. It was found that even a small amount of Al (e.g. 0.2 wt.%) added to Li₇La₃Zr₂O₁₂ can greatly accelerate densification during the sintering process. SEM micrographs showed the existence of a liquid phase introduced by Al additions which led to the enhanced sintering rate. The addition of Al also stabilized the higher conductivity cubic form of Li₇La₃Zr₂O₁₂ rather than the less conductive tetragonal form. The combination of these two beneficial effects of Al enabled greatly reduced sintering times for preparation of highly conductive Li₇La₃Zr₂O₁₂ electrolyte. With optimal additions of Al (e.g. 1.2 wt.%), Li₇La₃Zr₂O₁₂ electrolyte sintered at 1200 °C for only 6 h showed an ionic conductivity of 2.0 × 10⁻⁴ S cm⁻¹ at room temperature.     

Improved electrical performance and sintering ability of the composite interconnect La0.7Ca0.3CrO3−δ/Ce0.8Nd0.2O1.9 for solid oxide fuel cells

Significant improvements on sintering characteristic and electrical performance of traditional interconnect La_0.7Ca_0.3CrO_3−δ were presented in this paper. For a composite interconnecting ceramic La_0.7Ca_0.3CrO_3−δ/Ce_0.8Nd_0.2O_1.9, it was found that the addition of Ce_0.8Nd_0.2O_1.9 significantly increased the electrical conductivity of La_0.7Ca_0.3CrO_3−δ both in air and in hydrogen. Among all the investigated specimens, La_0.7Ca_0.3CrO_3−δ with 5 wt% Ce_0.8Nd_0.2O_1.9 possessed the maximal electrical conductivity. In air and hydrogen, the maximal electrical conductivity at 800 °C were 55.4 S cm⁻¹ and 5.0 S cm⁻¹, respectively, which increased significantly as compared with La_0.7Ca_0.3CrO_3−δ under the same conditions. With the increase of Ce_0.8Nd_0.2O_1.9 content the relative density increased, reaching 97.1% from 93.9% of La_0.7Ca_0.3CrO_3−δ. This indicated that Ce_0.8Nd_0.2O_1.9 functioned as an effective sintering aid in enhancing the sinterability of the powders. The average coefficient of thermal expansion at 30-1000 °C in air increased with Ce_0.8Nd_0.2O_1.9 content. Most coefficients of thermal expansion of specimens are compatible with other cell components. The oxygen permeation measurement illustrated a negligible oxygen ionic conduction, indicating it is still an electronically conducting ceramic. Results indicate that this composite is suitable to be used as a high-performance interconnect for intermediate temperature solid oxide fuel cells.     

Degradation of LaSr2Fe2CrO9−δ solid oxide fuel cell anodes in phosphine-containing fuels

The performance and stability of La_0.9Sr_0.1Ga_0.8Mg_0.2O_3-δ-electrolyte supported solid oxide fuel cells with composite LaSr₂Fe₂CrO_9-δ-Gd_0.1Ce_0.9O₂ anodes were studied in wet H₂ and coal syngas containing phosphine impurity. Introduction of 5-20 ppm PH₃ into the fuels caused an initial slow cell performance degradation followed by a very rapid complete cell degradation that initiated within 11-24 h - earlier at higher PH₃ concentration. There was no recovery after removing PH₃ impurity from the fuels. Electrochemical impedance analysis suggested that the initial gradual performance degradation was due to conductivity loss of the oxide anode due to chemisorption and reaction of phosphine. X-ray diffraction analysis showed the formation of FeP_x and LaPO₄ compounds. The rapid degradation presumably occurred when most or all of the Fe initially present in the LaSr₂Fe₂CrO_9−δ was consumed. Thermodynamic calculations confirmed that Fe is highly reactive with PH₃ at 800 °C, even at concentrations below 1 ppm.     

Metallic interconnects for solid oxide fuel cell: Effect of water vapour on oxidation resistance of differently coated alloys

The need of interconnect to separate fuel and oxidant gasses and connect individual cells into electrical series in a SOFC stack appears as one of the most important point in fuel cell technology. Due to their high electrical and thermal conductivities, thermal expansion compatibility with the other cell components and low cost, ferritic stainless steels (FSS) are now considered to be among the most promising candidate materials as interconnects in SOFC stacks. Despite the formation at 800 °C of a protective chromia Cr₂O₃ scale, it can transform in volatile chromium species, leading to the lost of its protectiveness and then the degradation of the fuel cell. A previous study demonstrated that in air, the application by metal organic chemical vapour deposition (MOCVD) of a nanometric layer of reactive element oxides (La₂O₃, Y₂O₃, Nd₂O₃) on FSS improved both the electrical conductivity and the oxidation resistance. The beneficial effect of this type of coating on FSS on oxidation resistance in H₂/H₂O (anode side) is not yet completely understood. So, the goal of this study is to apply reactive element oxide coating (La₂O₃, Y₂O₃, Nd₂O₃) on two FSS (a commercial, Crofer22APU, and a model, Fe30Cr) and to perform oxidation tests in H₂/10%H₂O. Kinetics was registered for 100 h at 800 °C and the corrosion products were characterized by SEM, EDX, TEM, SIMS and XRD.     

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.     

Synthesis and properties of La0.6Sr0.4CoO3−δ nanopowder

Uniform nanopowders of La_0.6Sr_0.4CoO_3−δ (LSC) were synthesized by the combined citrate–EDTA method. The precursor solution was prepared from nitrates of the constituent metal ion, citric acid and EDTA with a pH value controlled by ammonia. The obtained product was characterized by TG/DTA, XRD, SEM, and BET measurements. The single perovskite phase could form completely after sintering at the temperature of 900 °C. There was no significant effect of the precursor solution pH value on the perovskite phase formation temperature; however, LSC powders prepared from the precursors with different pH values showed specific shapes. The morphology of La_0.6Sr_0.4CoO_3−δ powder was also optimized with proper surfactant addition. The sintered La_0.6Sr_0.4CoO_3−δ bulk samples exhibited an electrical conductivity of 1867 S cm⁻¹ in air at 800 °C. The impedance spectra of a symmetric LSC cathode on a GDC electrolyte substrate were measured and polarization resistance (R_p) values of 0.17 Ω cm² at 700 °C and 0.07 Ω cm² at 750 °C in air were obtained.     

Fabrication and characterization of a co-fired La0.6Sr0.4Co0.2Fe0.8O3−δ cathode-supported Ce0.9Gd0.1O1.95 thin-film for IT-SOFCs

A dense membrane of Ce_0.9Gd_0.1O_1.95 on a porous cathode based on a mixed conducting La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ was fabricated via a slurry coating/co-firing process. With the purpose of matching of shrinkage between the support cathode and the supported membrane, nano-Ce_0.9Gd_0.1O_1.95 powder with specific surface area of 30 m² g⁻¹ was synthesized by a newly devised coprecipitation to make the low-temperature sinterable electrolyte, whereas 39 m² g⁻¹ nano-Ce_0.9Gd_0.1O_1.95 prepared from citrate method was added to the cathode to favor the shrinkage for the La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ. Bi-layers consisting of <20 μm dense ceria film on 2 mm thick porous cathode were successfully fabricated at 1200 °C. This was followed by co-firing with NiO–Ce_0.9Gd_0.1O_1.95 at 1100 °C to form a thin, porous, and well-adherent anode. The laboratory-sized cathode-supported cell was shown to operate below 600 °C, and the maximum power density obtained was 35 mW cm⁻² at 550 °C, 60 mW cm⁻² at 600 °C.     

Preparation and characterization of La0.9Sr0.1Ga0.8Mg0.2O3 − δ thin film on the porous cathode for SOFC

A dense and crack-free La_0.9Sr_0.1Ga_0.8Mg_0.2O_3 − δ thin film has been prepared by RF magnetron sputtering. The XRD, FESEM, XPS and four-probe technique are employed to characterize the La_0.9Sr_0.1Ga_0.8Mg_0.2O_3 − δ film. Results show that after annealing at 1000 °C, the La_0.9Sr_0.1Ga_0.8Mg_0.2O_3 − δ film presents a polycrystalline perovskite structure with grain size of 100–300 nm. XPS data show that both La and Ga are in their +3 state. Sr element has two chemical states which are related to Sr²⁺ in the perovskite lattice and SrO_1 − δ suboxide. The O 1s spectrum also shows two chemical states which can be assigned to molecularly adsorbed O₂ species and O²⁻ in the lattice. The electrical conductivity reaches to 0.093 S cm⁻¹ at 800 °C. The microstructure and conductivity analysis indicates that the La_0.9Sr_0.1Ga_0.8Mg_0.2O_3 − δ thin film prepared by RF magnetron sputtering is suitable for intermediate temperature Solid oxide fuel cell.     

Ionic conductivity of apatite-type solid electrolyte material, La10−XBaXSi6O27−X/2 (X = 0-1), and its fuel cell performance

We prepared Ba substituted lanthanum silicate (La_10−XBa_XSi₆O_27−X/2) and examined the effect of Ba substitution on the crystal structure and conductivity. The X-ray diffraction (XRD) results for a series of compositions showed that Ba ion can occupy the La site of an apatite structure with the composition La_10−XBa_XSi₆O_27−X/2 (X = 0-1). Rietveld analysis of the synchrotron XRD profiles revealed Ba occupation in the La 4f site rather than the La 6 h site and a decrease in the occupation factors of the oxide ions of the SiO₄ tetrahedra.The conductivity of La_10−XBa_XSi₆O_27−X/2 exhibited a maximum at X = 0.6 and the value was the same as that of YSZ (8 mol% Y₂O₃ doped ZrO₂) at 750 °C. On the other hand, the activation energy of about 50 kJ mol⁻¹ for La_9.4Ba_0.6Si₆O_26.7 was smaller than that of YSZ. Thus the conductivity of La_9.4Ba_0.6Si₆O_26.7 was a higher than those of YSZ below 750 °C. The conductivity parallel to the c-axis which is attributed to the 2a site oxide ions migration is known to be dominant in La₁₀Si₆O₂₇. However, Ba substitution seems to produce oxygen vacancies and create another pathway for oxide ions perpendicular to the c-axis. The increase in the pathways leads to an increase in the conductivity. We also reported the solid oxide fuel cell (SOFC) performance of La_10−XBa_XSi₆O_27−X/2 with a maximum power density of 65 mW cm⁻² using La_0.9Sr_0.1CoO_3−δ as a cathode and NiO-SDC (Sm doped CeO₂) as an anode.     

Optimization of the interface polarization of the La2NiO4-based cathode working with the Ce1–xSmxO2–δ electrolyte system

The performance of La₂NiO₄ cathode material and Ce_1–xSm_xO_2–δ (x = 0.1, 0.2, 0.3, 0.4) electrolyte system was analyzed. Ceria-based materials were prepared by the freeze-drying precursor route whereas La₂NiO₄ was prepared by the nitrate–citrate procedure. Electrolyte pellets were obtained after sintering the powders at 1600 °C for 10 h. Also dense ceria-based electrolytes samples were obtained by calcining the powders at 1150 °C after the addition of 2 mol%-Co. Interface polarization measurements were performed by impedance spectroscopy in air at open circuit voltage, using symmetrical cells prepared after the deposition of porous La₂NiO₄-electrodes on the Ce_1–xSm_xO_2–δ system. X-ray diffraction (XRD) of cathode materials after using in symmetrical cells confirmed no significant reaction between La₂NiO₄ and ceria-based electrolytes. The efficiency of the cathode material is highly dependent on the composition of the electrolyte, and low-content Sm-doped ceria samples revealed an important decrease in the performance of the system. Differences in electrochemical behaviour were attributed principally to the oxide ion transference between cathode and electrolyte, and were correlated to the conductivity of the electrolyte. In this way cobalt-doped electrolytes with a Sm-content ≤30% perform better than free-cobalt samples due to the increase in grain boundary conductivity. Finally, composites of the ceria-based materials and La₂NiO₄ to use as cathode were prepared and an important increase of the interface performance was observed compared to La₂NiO₄ pure cathode. Predictions of maximun power density were obtained by the mixed transport properties of the electrolytes and by the interface polarization results. The use of composite materials could allow to increase the performance of the cell from 170 mW cm⁻² for pure La₂NiO₄ cathode, to 370 mW cm⁻² for La₂NiO₄–Ce_0.8Sm_0.2O_2–δ cathode, both working with Ce_0.8Sm_0.2O_2–δ electrolyte 300 μm in thickness and Ni–Ce_0.8Sm_0.2O_2–δ as anode at 800 °C.     

La2NiO4+δ potential cathode material on La0.9Sr0.1Ga0.8Mg0.2O2.85 electrolyte for intermediate temperature solid oxide fuel cell

La₂NiO_4+δ, a mixed ionic-electronic conducting oxide with K₂NiF₄ type structure, has been studied as cathode material with La_0.9Sr_0.1Ga_0.8Mg_0.2O_2.85 (LSGM) electrolyte for intermediate solid oxide fuel cells (IT-SOFCs). XRD results reveal excellent chemical compatibility between the La₂NiO_4+δ sample and LSGM electrolyte.A single cell (0.22 cm² active area) was fabricated with La₂NiO_4+δ as cathode, Ni-Sm_0.2Ce_0.8O_1.9 (2:1; w/w) as anode and LSGM as electrolyte. A thin buffer layer of Sm_0.2Ce_0.8O_1.9 (SDC) between anode and electrolyte was used to avoid possible interfacial reactions. The cell was tested under humidified H₂ and stationary air as fuel and oxidant, respectively. The electrochemical behaviour was evaluated by means of current-voltage curves and impedance spectroscopy. Microstructure and morphology of the cell components were analysed by SEM-EDX after testing.The maximum power densities were 160, 226, and 322 mW cm⁻² at 750, 800 and 850 °C, respectively with total polarisation resistances of 0.77, 0.48 and 0.31 Ω cm² at these temperatures. Cell performance remained stable when a current density of 448 mA cm⁻² was demanded for 144 h at 800 °C, causing no apparent degradation in the cell. The performance of this material may be further improved by reducing the electrolyte thickness and optimisation of the electrode microstructure.