Complex Effect of Sm3+/W6+ Codoping on α‐β Phase Transformation and Phonon Scattering of Oxygen‐Deficient La2Mo2O9

Lanthanum molybdate, La₂Mo₂O₉, has been attracted considerable attention owing to its high concentration of intrinsic oxygen vacancies, which could be reflected by enhanced phonon scattering and low thermal conductivity. A new series of La₂Mo₂O₉‐based oxides of the general formula La_2?xSm_xMo_2?xW_xO₉, where x ≤ 0.2, were synthesized by citric acid sol–gel process. The variation in thermal conductivity with Sm³⁺and W⁶⁺ fractions was analyzed based on structure information provided by X‐ray diffraction and Raman spectroscopy. The fully dense La_2?xSm_xMo_2?xW_xO₉ ceramics showed a minimum thermal conductivity value [κ = 0.84 W·(m·K)^?1,T = 1073 K] at the composition of La_1.8Sm_0.2Mo_1.8W_0.2O₉, which stems from the multiple enhanced phonon scatterings due to mass and strain fluctuations at the La³⁺ and Mo⁶⁺ sites as well as the high concentration of intrinsic oxygen vacancies embedded in the crystal lattice. The thermal conductivities present an abrupt decrease at the structural transition, which is due to the phase transformation from a low‐temperature ordered form (monoclinic α‐La₂Mo₂O₉) to a high‐temperature disordered form (cubic β‐La₂Mo₂O₉₎.     

Effects of La content on the densification,microstructure, and conductivity of doped La10−xGe6O26±δ electrolytes

In this study, the influence of La content on the characteristics of Nb‐, Mo‐, and W‐doped La_xGe₆O_26±δ electrolytes was investigated through sintering study, X‐ray diffraction, scanning electron microscopy, and conductivity measurement. The densification of La_xGe_5.5Nb_0.5O_26±δ and La_xGe_5.5W_0.5O_26±δ was retarded as the x reached 9.75, while that of La_xGe_5.5Mo_0.5O_26±δ improved with increasing La content. The average grain size slightly increased and weight loss due to evaporation of GeO₂ significantly reduced with increasing La content, ranging from 1.39% to 0.26%. Among the systems studied, La_9.33Ge_5.5Nb_0.5O_26.245, La_9.33Ge_5.5Mo_0.5O_26.045, and La_9.50Ge_5.5W_0.5O_26.75 electrolytes revealed great potential for use in SOFC applications.     

Ionic and electronic transport in stabilized β-La2Mo2O9 electrolytes

Increasing temperature from 973 to 1173 K leads to a substantial increase of the electronic contribution to the total conductivity of undoped lanthanum molybdate and La₂Mo₂O₉-based solid electrolytes, including La₂Mo_1.7W_0.3O₉, La₂Mo_1.95V_0.05O₉ and La_1.7Bi_0.3Mo₂O₉, where the stabilization of β-La₂Mo₂O₉ down to room temperature was confirmed by high-resolution X-ray diffraction (XRD) and differential scanning calorimetry (DSC) data. In air, the ion transference numbers determined by the modified Faradaic efficiency (FE) technique, decrease from 0.991-0.997 at 973-1023 K down to 0.977-0.984 at 1173 K. Reducing oxygen partial pressure also increases electronic conduction evaluated by the emf and oxygen permeability (OP) measurements, which indicates that the electronic transport is n-type, resulting from decreasing oxygen content in the molybdate lattice. The level of n-type electronic conductivity in air is quite similar for all La₂Mo₂O₉-based ceramics. The results show that these materials can be used as solid electrolytes only under oxidizing conditions and only at temperatures below 1073 K. Their practical applications may also be complicated due to relatively high thermal expansion coefficients (CTEs), (14.1-14.8)×10⁻⁶ K⁻¹ at 300-700 K and (16.4-22.5)×10⁻⁶ K⁻¹ at 850-1070 K, which are close to those of stabilized δ-Bi₂O₃ and γ-Bi₂VO_5.5 electrolytes.     

Effect of Tm3+ Ions on the White Light Emission of Dy3+–Tm3+ Codoped SrMg2La2W2O12 Phosphors

Dy³⁺–Tm³⁺ ions codoped SrMg₂La₂W₂O₁₂ (strontium magnesium lanthanum tungstate) phosphors were synthesized by conventional high‐temperature solid‐state reaction method. X‐ray analysis of the end products revealed the well‐crystallized phases with orthorhombic structure. The functional groups present in the phosphors were studied by the Fourier transform infrared measurements. To know the potential applicability of these phosphors for white light emission, the excitation and emission spectra were recorded. The excitation spectra exhibited an intense broad band at 313 nm, pertaining to the O → W ligand‐to‐metal charge‐transfer state (LMCT) of the host. With the excitation of LMCT band (313 nm), the decay curves of singly doped SrMg₂La₂W₂O₁₂:Dy phosphors exhibited single exponential, where as the codoped SrMg₂La₂W₂O₁₂:DyTm phosphors exhibited double exponential nature. The luminescence colors of these phosphors were estimated from Commission Internationale de L'Eclairage (CIE) coordinates using the photoluminescence data. The color of singly doped SrMg₂La₂W₂O₁₂:Dy phosphor has been tuned by codoping with Tm³⁺ ions. It has been noticed that the CIE chromaticity coordinates (x,y) determined from the luminescence spectrum of singly Dy³⁺ doped SrMg₂La₂W₂O₁₂ phosphor shifted toward the white light region, when codoped with Tm³⁺ ions. The increase in correlated color temperatures (T_cct) has been noticed with the increase of Tm³⁺ ions concentration in SrMg₂La₂W₂O₁₂:DyTm phosphors.     

Development of Mn and Mo double-substituted La5.5WO11.25-δ based membranes with enhanced hydrogen permeation flux

Mixed protonic-electronic ceramic lanthanum tungstate membranes of La_5.5W_1-xMn_xO_11.25-δ (LWMn_x, x = 0.1, 0.15 and 0.2) and La_5.5W_0.8-yMn_0.2Mo_yO_11.25-δ (LWMn_0.2Mo_y, y = 0.1, 0.2, 0.3 and 0.4) were developed in present work. The H₂ permeation flux through lanthanum tungstate membrane was increased by substitution of Mn ions into W sites. However, the impurity of La₂O₃ formed in LWMn_0.15 and LWMn_0.2 membranes. Introduction of a moderate amount of Mo ions in LWMn_0.2 was beneficial to single phase formation and H₂ permeation. LWMn_0.2Mo_0.2 exhibited a pure cubic phase structure without any impurities. LWMn_0.2Mo_0.2 membrane had a H₂ permeation flux about 0.12 mL/min?cm² at 1000 °C, which was 1.7 times higher than that through LWMn_0.2 membranes.     

Ionic conductivities and phase transitions of lanthanide rare-earth substituted La2Mo2O9

The ion conductivities and phase transitions of lanthanum molybdate (La₂Mo₂O₉) substituted with lanthanide rare-earths are investigated using impedance spectroscopy, dilatometry, and X-ray powder diffraction. Among the substituted La₂Mo₂O₉ of 10 mol% Ce, Nd, Sm, Gd, Dy, Er, Yb, the specimens containing Er, and Dy exhibit depressed α–β phase transformation and high conductivities. Their 700 °C conductivities are approximately five to seven times that of La₂Mo₂O₉, around 0.26 S cm⁻¹, comparable with those of (LaSr)(GaMg)O₃ and Gd-substituted CeO₂. Among the three compositions of 10 mol% Gd, Dy, Er showing depressed phase transition, Er- and Dy-substituted La₂Mo₂O₉ possess relatively low thermal expansion coefficient 11×10⁻⁶ K⁻¹, compared with that of the Gd-substituted La₂Mo₂O₉, 18×10⁻⁶ K⁻¹, which is near that of La₂Mo₂O₉. Hence, Dy and Er are valuable dopants in improving the La₂Mo₂O₉ properties. Across the lanthanide series, 10 mol%-substituted La₂Mo₂O₉ demonstrates systematic variations in the conductivity–temperature relation. Hysteresis phenomena in both of conductivity and thermal expansion are also observed in those compositions which display phase transition.     

Electrical properties of La2Mo2O9/Al2O3 nanocomposites fabricated by microwave sintering method

High density La₂Mo₂O₉/Al₂O₃ nanocomposite electrolytes were successfully fabricated by microwave sintering method from the nano-scaled La₂Mo₂O₉/Al₂O₃ powders. Phase formation, microstructure, grain size and electrical properties of the specimens were examined using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and AC impedance spectroscopy. It was confirmed that the composite electrolytes consist of nanocrystalline La₂Mo₂O₉ phase with an average grain size of 70–150 nm and a small amount of crystalline α-Al₂O₃ phase at grain boundary. With increasing alumina content, the total conductivity at 600 °C of the composite specimens increases at first and then decreases with a maximum value of about 0.024 S/cm appearing at 2.25 mol% alumina. It was suggested that the enhancement of total conductivity of the composites may be ascribed to the improvement of both grain and grain-boundary conduction introduced by the addition of appropriate amount of alumina.     

BSCF/GDC as a refined cathode to the single-chamber solid oxide fuel cell based on a LAMOX electrolyte

In an effort to build the solid oxide fuel cell for intermediate temperature operations, the oxide ion conductor member of LAMOX family appears to be an ideal candidate for electrolyte since its parent crystal La₂Mo₂O₉ shows a monoclinic-cubic phase transition around 580 °C. Nonetheless, members of the LAMOX family are much less refractory than the conventional electrode compositions which are targeted to coordinate with the electrolyte of yttrium stabilized zirconia. In this work, we study the viability of a cathode composite of Ba_0.5Sr₀₅Co_0.8Fe_0.2O₃ (BSCF) and gadolinium doped ceria (GDC) to match the electrolyte La_1.8Dy_0.2Mo₂O₉ (LDM). Severe interfacial reactions between BSCF and LDM require a ceria-based diffusion barrier between them. The iron-doped GDC barrier of high sinterability is a convenient choice to block the unwanted reactions, allowing us to devise a BSCF/GDC composite cathode of gradient GDC content to relieve thermal stresses. The cell, operated in a mixed reactant chamber with flowing methane/air, functions properly at operation temperature 625–700 °C. Its maximum power output is recorded at 675 °C, since the BSCF crystal begins to degrade at 700 °C under the methane/air atmosphere.     

Electrical conductivity and redox stability of La2Mo2−xWxO9 materials

A series of compounds La₂Mo_2−xW_xO₉ (x = 0-2) were synthesized using a freeze-dried precursor method at relatively low temperatures (673-823 K). These materials were characterised by thermogravimetric and differential thermal analysis (TG/DTA), differential scanning calorimetric (DSC), X-ray diffraction (XRD), and transmission electron microscopy (TEM) and dilatometric measurements. Oxygen stoichiometry was evaluated by coulometric titration and thermogravimetric analysis at 873-1273 K. The ionic and electronic conductivities of these materials were analysed by impedance spectroscopy and a Hebb-Wagner ion-blocking method under moderately reducing conditions. The presence of W⁶⁺ leads to an increase of the stability range (about 10⁻¹⁶ Pa for La₂Mo_0.5W_1.5O₉ at 1073 K) and prevents oxygen loss and amorphisation. Within the stability range, the electronic conductivity increases gradually as the temperature increases and as the oxygen partial pressure reduces. This indicates that the electronic transport is mainly n-type as a result of the oxygen-content decreasing in the molybdate lattice. Further reduction of the oxygen partial pressure gave rise to the decomposition of La₂Mo_2−xW_xO₉, leading to the formation of new phases with molybdenum in lower oxidation states, which further enhances the electronic conductivity. The results of the coulometric titration and the thermogravimetric studies under a dry 5% H₂/Ar flow suggest that tungsten doped lanthanum molybdate materials can be used as electrolyte only at low temperature and under moderate reducing conditions.     

Effect of Ba concentration on phase stability and mechanical and thermal properties of La2Mo2O9

Ba-substituted La₂Mo₂O₉ ((La_1−xBa_x)₂Mo₂O_9−δ, x = 0–0.12) was prepared and the thermal and mechanical properties were evaluated. The thermal expansion coefficients (TECs) were determined from high-temperature X-ray diffraction (XRD) analysis. Phase transition in La₂Mo₂O₉ was suppressed via substitution of Ba for La, as demonstrated by differential scanning calorimetry (DSC) analysis. The mechanical properties, such as the bulk modulus, shear modulus, Young’s modulus, compressibility, and Debye temperature were evaluated from the measured sound velocities. The thermal conductivity was evaluated from the thermal diffusivity, heat capacity, and density in the temperature range from room temperature to 1073 K. The thermal conductivity decreased with increasing Ba content. Theoretical calculations based on the Klemens–Callaway model were performed to analyze the thermal conductivity, and the results suggest that the reduction of the thermal conductivity was mainly attributed to oxygen defects in the anion sublattice of La₂Mo₂O₉.     

A Novel Cell‐Array Design for Single Chamber SOFC Microstack

A novel design of single chamber solid oxide fuel cell (SC‐SOFC) microstack with cell‐array arrangement is fabricated and operated successfully in a methane–oxygen–nitrogen mixture. The small stack, consisting of five anode‐supported single cells connected in series, exhibits an open circuit voltage (OCV) of 4.74 V at the furnace temperature of 600 °C and a maximum power output of 420 mW (total active electrode area is 1.4 cm²) at the furnace temperature of 700 °C. A gas mixture of CH₄/O₂ = 1 leads to best performance and stability.     

Catalytic and Heating Behavior of Nanoscaled Perovskites under Microwave Radiation

Perovskite powders of the types La_0.5Ca_0.5Al_yM_1–yO_3–δ (y = 0–0.8), M = Fe, Cr, Mn, Co and La_xSr_1–xMn_yCo_1–y (x = 0.5–1, y = 0–1) were prepared via a sol‐gel route according to the modified Pechini method. Incineration of the resins was performed before final sintering at 1000 °C for 6 h. The phase composition of the samples was established by X‐ray powder diffraction analysis, and the lattice parameters were calculated using Rietveld analysis. The shape and size of the particles were determined via scanning electron microscopy and the specific surface area of the powder perovskites was established by the BET method. The principal particles were ca. 100 nm in size and formed agglomerates larger than 1.0 μm. The composition of the perovskites was established by EDX analysis. Following this, the catalytic behavior was tested by means of total oxidation of propane. The catalytic performance was measured at atmospheric pressure with 3 g of catalyst in a fixed‐bed quartz reactor (i.d. = 18 mm) under thermal‐assisted and microwave‐assisted conditions. Initial results show a strong dependence of the catalytic and heating behavior on the nature of the M‐atom and its number of unpaired d‐electrons as well as on the particle size and its specific surface area. No significant difference in the results could be detected from comparison of the two heating methods.     

Crystallographic Structure and Ferroelectricity of (AxLa1−x)2Ti2O7 (A = Sm and Eu) Solid Solutions with High Tc

The solubility and ferroelectric properties of (A_xLa_1?x)₂Ti₂O₇ (A = Sm and Eu) solid solutions were investigated. The crystallographic structure of the solid solutions was studied using X‐ray diffraction and Raman spectroscopy. The solubility limits of Eu and Sm in (A_xLa_1?x) ₂Ti₂O₇ were found to be greater than x = 0.5 and 0.8, respectively. The solid solutions had a monoclinic perovskite‐like layered structure (PLS), similar to that of the pure La₂Ti₂O₇, when x was less than the solubility limit. When x was above the solubility limit the materials were biphase. The biphases of (Sm_xLa_1?x)Ti₂O₇ (x = 0.9) consisted of (Sm_xLa_1?x)₂Ti₂O₇ with PLS and pure Sm₂Ti₂O₇ with pyrochlore structure, and the biphases of (Eu_xLa_1?x)Ti₂O₇ (x = 0.6, 0.7, and 0.8) consisted of (Eu_xLa_1?x)₂Ti₂O₇ with PLS structure and La³⁺ doped Eu₂Ti₂O₇ with pyrochlore structure. The effect of A‐site substitution on the properties of La₂Ti₂O₇ was investigated by measuring the dielectric permittivity and loss at different frequencies and temperatures. The highest piezoelectric constant d₃₃ was 2.8 pC/N for (Sm_0.1La_0.9)Ti₂O₇.     

High lithium ionic conductivity in the garnet‐type oxide Li7−2xLa3Zr2−xMoxO12 (x=0‐0.3) ceramics by sol‐gel method

Lithium garnet‐type oxides Li_7?2xLa₃Zr_2?xMo_xO₁₂ (x=0, 0.1, 0.2, 0.3) ceramics were prepared by a sol‐gel method. The influence of molybdenum on the structure, microstructure and conductivity of Li₇La₃Zr₂O₁₂ were investigated by X‐ray diffraction, scanning electron microscopy, and impedance spectroscopy. The cubic phase Li₇La₃Zr₂O₁₂ has been stabilized by partial substitution of Mo for Zr at low temperature. The introduction of Mo (x≥0.1) can accelerate densification. Li_6.6La₃Zr_1.8Mo_0.2O₁₂ sintered at lower temperature 1100°C for 3 hours exhibits highest total ionic conductivity of 5.09 × 10^?4 S/cm. Results indicate that the Mo doping LLZO synthesized by sol‐gel method effectively lowers its sintering temperature and improves the ionic conductivity.     

Thermoelectric properties of La7Mo7O30 sintered by reactive spark plasma sintering

In this work, spark plasma sintering of La₂Mo₂O₉ powder was used to achieve dense ceramics of La₇Mo₇O₃₀ and explore their thermoelectric properties. SPS sintering of La₂Mo₂O₉ powder at 973 K for 10 min under 90 MPa leads to a bicoloured sample with white and black faces. XRD patterns of white and black faces are attributed to La₂Mo₂O₉ and La₇Mo₇O₃₀ phases, respectively. These experimental conditions allow observing the in-situ reduction of La₂Mo₂O₉ during the SPS process. With a longer sintering time of 30 min, a ceramic of La₇Mo₇O₃₀ is obtained. Its electrical conductivity exhibits a semiconducting behaviour and reaches a value of 1000 Sm^-1 at 1000 K. The negative Seebeck coefficient show a n-type conduction in this phase. La₇Mo₇O₃₀ exhibits a very low thermal conductivity, less than 1 Wm⁻¹K⁻¹ from room temperature up to 1000 K, similar to the values reported for La₂Mo₂O₉. A figure of merit of 0.04 is reached at 1000 K.     

Wet Atomisation of Gd‐doped CeO2 Electrolyte Slurries for Intermediate Temperatures' Microtubular SOFC Applications

A wet atomising system has been employed as a novel method to prepare ultrafine Gd‐doped CeO₂ (GDC) electrolyte slurries. By changing the fluid flow pressure and repeating the atomisation process several times for the same atomised slurries, we have obtained optimised ultrafine GDC slurry with high‐dispersed and homogeneous distribution. The sizes of the particles of GDC were in the range of tens of nanometres. A highly dense electrolyte layer (membrane) was prepared using the ultrafine GDC slurries for intermediate temperatures microtubular solid oxide fuel cell (SOFC) applications. The SOFC was fabricated by using supporting porous anode tubes of NiO and GDC, and the cathode consisted of La_0.6Sr_0.4Co_0.2Fe_0.8O_3–y and GDC. A dense 10 μm GDC electrolyte layer was obtained at a lower sintering temperature of 1,250 °C for 1 h. The SOFC was tested with humidified (3% H₂O) hydrogen as a fuel and the static air as an oxidant, and the tubular cell maintained its high performance even at 500 °C.     

Improvement of the Electrochemical Performance of Ln0.58Sr0.4Fe0.8Co0.2O3 – δ IT‐SOFC Cathodes by Ternary Lanthanide Combinations (La‐Pr‐Sm)

Active perovskite‐based SOFC cathodes have been developed through lanthanide combination in the (La_{1 – x – y}Pr_xSm_y)_0.58Sr_0.4Fe_0.8Co_0.2O_{3 – δ} system following a ternary mixture experimental design. These compositions were prepared through a sol–gel method and characterised by electrochemical impedance spectroscopy (EIS) as symmetrical cells on GDC‐electrolyte samples in the 450–650 °C temperature range. The electrochemical properties of the single lanthanide‐based Ln_0.58Sr_0.4Fe_0.8Co_0.2O_{3 – δ} compounds were enhanced when different lanthanides were combined together in the same crystalline structure. The observed improvement does not follow a mere additional effect of the performance from the parent Ln_0.58Sr_0.4Fe_0.8Co_0.2O_{3 – δ} compounds, i.e. it does not follow a linear behaviour, and the better performance is ascribed to synergetic catalytic effects among lanthanide cations. A reduction in electrode polarisation resistance with respect to non‐substituted compositions is stated for most Ln_0.58Sr_0.4Fe_0.8Co_0.2O_{3 – δ} electrode compositions combining two or three lanthanides. Samarium addition to the electrode material involves a substantial reduction in the activation energy and the reduction degree is directly dependant on the samarium amount incorporated in the lattice. The best performing composition comprises a praseodymium‐rich lanthanum‐based electrode material. The experimental data derived from the ternary mixture design were modelled using nonlinear functions and this modelling allowed finding an electrode composition minimising the polarisation resistance while maintaining the activation energy at reduced values. Selected cathode compositions were tested in fully assembled anode‐supported cells and electrochemical characterisation supports the cooperative effect of lanthanide combination.     

Structure and conductivity of yttria and scandia‐doped zirconia crystals grown by skull melting

In this paper a detailed study of the (ZrO₂)_1‐x(Y₂O₃)_x (x=0.025–0.15), (ZrO₂)_1‐x(Sc₂O₃)_x (x = 0.06 – 0.11) and (ZrO₂)_1‐x‐y(Sc₂O₃)_x(Y₂O₃)_y (x=0.07 – 0.11; y=0.01 – 0.04) solid solution crystals grown by skull melting technique is presented. The structure, phase composition, and ion conductivity of the obtained crystals were investigated by X‐ray diffraction, transmission electron microscopy, Raman scattering spectroscopy, and impedance spectroscopy. Maximum conductivity as (ZrO₂)_1‐x(Y₂O₃)_x and (ZrO₂)_1‐x(Sc₂O₃)_x solid solution crystals is observed for the compositions containing 10 mol% stabilizing oxide, and the conductivity of 10ScSZ is ~3 times higher than for 10YSZ. Experiments on crystal growth (ZrO₂)_1‐x‐y(Sc₂O₃)_x(Y₂O₃)_y solid solutions showed that uniform, transparent crystals 7Sc3YSZ, 7Sc4YSZ, 8Sc2YSZ, 8Sc3YSZ, 9Sc2YSZ, 9Sc3YSZ, 10Sc1YSZ, and 10Sc2YSZ are single phase crystal containing t″ phase. It is established that a necessary condition of melt growth of (ZrO₂)_1‐x‐y(Sc₂O₃)_x(Y₂O₃)_y single‐phase crystals is the total concentration of the stabilizing oxides from 10 to 12 mol%. The addition of Y₂O₃ affects the (ZrO₂)_1‐x‐y(Sc₂O₃)_x(Y₂O₃)_y solid solution conductivity different ways and depends on the Sc₂O₃ content in the starting composition. The effects of structure, phase composition, concentration, and type of stabilizing oxides on the electrical characteristics of obtained crystals are discussed.     

Catalytic performance of La0.66Sr0.34Co0.2Fe0.8O3 perovskite in propane combustion: Effect of preparation and specific surface area

Several compositions in a system of La_1-x SrxCo_1-y FeyO_3-δ perovskites are known as very good electronic and ionic conductors, as well as excellent catalysts for hydrocarbon oxidation. In this study La_0.66Sr_0.34Co_0.2Fe_0.8O₃ was selected as possibly the optimum composition. To assess the effect of preparation and calcination conditions on the activity in propane combustion, a series of different samples was prepared by a method based on slurry of reactive component precursors processed by freeze-drying. Three different materials were used as source of iron and the samples were aged at successively higher temperatures (1,153–1,343 K). The specific surface areas varied between 5.9 and 1 m²/g, depending on iron precursor and/or aging. The activity was determined in an integral U-shape reactor, typically for 1 and 2 vol% propane in air, with 1 g catalyst and 200 or 100 ml/min flowrate. Kinetics determined on the basis of a wider range of concentrations (1–4.3 vol% propane; 10 vol%-pure oxygen) for a selected, the least aged sample indicated that the propane catalytic combustion is best represented by a Mars van Krevelen model with 0.5 order in oxygen and the two kinetic constants having E _app of 83 and 81 kJ/mol, respectively. For the aged samples, the pseudofirst order E _app varied from 85 to 98 kJ/mol.     

A novel cobalt–free La0.5Ba0.5Fe0.95Mo0.05O3–δ electrode for symmetric solid oxide fuel cell

Cobalt − free perovskite oxide La_0.5Ba_0.5Fe_0.95Mo_0.05O_3−δ (LBFMo) was investigated as the electrode of symmetric solid oxide fuel cell (S − SOFC) based on 300−um − thick La_0.9Sr_0.1Ga_0.8Mg_0.2O_3−δ (LSGM) electrolyte. The electrochemical performance of the S − SOFC with LBFMo|LSGM|LBFMo configuration was evaluated using ambient air as oxidant and H₂ as fuel. The maximum power density (P_max) of the S − SOFC achieves as high as 0.96 W cm⁻² at 800 °C; meanwhile, the total polarization resistance (R_pt) of the S − SOFC (including the contributions of both cathode and anode) is only ∼0.12 Ω cm². Impedance spectra analysis indicates the polarization associated with anode plays a more rate − limiting role in the whole electrochemical reaction process of the S − SOFC. In addition, using LBFMo as symmetric electrode, the S − SOFC also exhibits good cell stability. All results indicate that the LBFMo is a very potential candidate for S − SOFC electrode.