Investigation on the phase stability of cubic perovskite BaCo0.7Fe0.2Nb0.1O3-δ oxygen-permeable membrane

The phase stability of the cubic perovskite-type oxide BaCo_0.7Fe_0.2Nb_0.1O_3?δ (BCFNO) has been examined by means of X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). And, the timescale on the second phases has been established by using the TOPAS 4.2. Compared with Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3?δ (BSCFO), for samples annealed at T?=?1023?K for t?=?64 d, the rhombohedral and hexagonal phases formed on the surface of cubic perovskite BCFNO surface simultaneously and the amount of them is smaller. As for the rhombohedral phase, it comes out firstly along the grain boundary, and whose amount in equilibrium is about 5％. In contrast to the rhombohedral phase, the hexagonal phase is more likely to form at lower temperature which lead to the microcracks. In brief, obtaining the eligible phase stability is crucial for the industrial application of the oxygen permeation membrane.     

Insight of BaCe0.5Fe0.5O3−δ twin perovskite oxide composite for solid oxide electrochemical cells

One-pot synthesized twin perovskite oxide composite of BaCe_0.5Fe_0.5O_3−δ (BCF), comprising cubic and orthorhombic perovskite phases, shows triple-conducting properties for promising solid oxide electrochemical cells. Phase composition evolution of BCF under various conditions was systematically investigated, revealing that the cubic perovskite phase could be fully/partially reduced into the orthorhombic phase under certain conditions. The reduction happened between the two phases at the interface, leading to the microstructure change. As a result, the corresponding apparent conducting properties also changed due to the difference between predominant conduction properties for each phase. Based on the revealed phase composition, microstructure, and electrochemical properties changes, a deep understanding of BCF's application in different conditions (oxidizing atmospheres, reducing/oxidizing gradients, cathodic conditions, and anodic conditions) was achieved. Triple-conducting property (H⁺/O²⁻/e⁻), fast open-circuit voltage response (∼16–∼470 mV) for gradients change, and improved single-cell performance (∼31% lower polarization resistance at 600°C) were comprehensively demonstrated. Besides, the performance was analyzed under anodic conditions, which showed that the microstructure and phase change significantly affected the anodic behavior.     

Novel Sr1.95Fe1.4Co0.1Mo0.5O6-δ anode heterostructure for efficient electrochemical oxidative dehydrogenation of ethane to ethylene by solid oxide electrolysis cells

The electrocatalytic conversion of ethane to ethylene is an important industrial process since ethylene is useful for the production of various chemical intermediates and polymers. However, this process often requires high temperatures. Metal-oxide heterogeneous interfaces constructed by in-situ exsolved process under reducing conditions would be favorable for promoting the catalyst activity, selectivity, and stability of ethane conversion to ethylene. Herein, Sr_1.95Fe_1.4Co_0.1Mo_0.5O_6-δ (abbreviated as SFCoM) was prepared as a novel anode material of solid oxide electrolysis cells (SOECs) for green ethylene production by electrochemical oxidative dehydrogenation of ethane. After reduction, nano CoFe particles were in-situ exsolved on SFCoM oxides to form a nano alloy-oxide heterostructure (CoFe@SFCoM) with large numbers of reactive sites, relevant for improving the conversion rate of ethane and the yield of ethylene. At 800 °C, the single cell based on CoFe@SFCoM anode exhibited a current density of 1.89 A cm⁻² at 1.6 V with an ethane conversion rate of 36.4% and corresponding ethylene selectivity of 94.5%. After 50 h of testing, the electrolysis current density(∼0.5 A cm⁻²) and ethylene yield(∼18.43%) of the single cell did not change significantly, showing good stability. In sum, CoFe@SFCoM looks very promising for future use as a SOECs anode for the electro-catalytic conversion of ethane to ethylene.     

Electro-spinning Pr0.4Sr0.6Co0.2Fe0.7Nb0.1O3−δ nanofibers infiltrated with Gd0.2Ce0.8O1.9 nanoparticles as cathode for intermediate temperature solid oxide fuel cell

Pr_0.4Sr_0.6Co_0.2Fe_0.7Nb_0.1O_3−δ (PSCFN) nanofibers and their corresponding Pr_0.4Sr_0.6Co_0.2Fe_0.7Nb_0.1O_3−δ–Gd_0.2Ce_0.8O_1.9 (PSCFN–GDC) composites have been synthesized and applied as cathodes for intermediate temperature solid oxide fuel cells (IT-SOFCs). In this paper, PSCFN nanofibers were obtained through electro-spinning and the following pyrolysis process. The resultant PSCFN nanofibers were infiltrated with GDC precursor to prepare nanofiber-structured PSCFN–GDC composite cathodes. The optimal PSCFN: GDC mass ratio of 1: 0.10 was identified to possess the lowest interfacial polarization resistances of 0.264, 0.155, 0.039 and 0.018 Ω cm² at 650, 700, 750 and 800 °C, respectively, lower than those of the PSCFN–GDC nanoparticle-structured composite cathode. The PSCFN–GDC (1: 0.10) shows an excellent stability of electrochemical activity under a current density of 200 mA cm⁻² for 100 h at 800 °C. All results proved that the nanofiber-structured PSCFN–GDC composite could act as a highly efficient cathode candidate for the IT-SOFCs.     

Ba0.95La0.05Fe0.8Ni0.2O3−δ perovskite as efficient cathode electrocatalysts for proton-conducting solid oxide fuel cells

The key issue that limits the electrochemical performance of proton-conducting solid oxide fuel cells (H⁺-SOFCs) is the sluggish kinetics of the oxygen reduction reaction (ORR) of cathode at intermediate and low temperatures. Herein, oxygen vacancy engineering is conducted on cobalt-free Ba_0.95La_0.05FeO_3?δ (BLF) by nickel substitution, which is confirmed by density functional theory computations. Nickel-substituted BLF material (Ba_0.95La_0.05Fe_1?xNi_xO_3?δ (x = 0, 0.1, 0.2, 0.3)) can promote the generation of oxygen vacancies and improve catalytic activity, which is found to be in line with the experimental results of XPS. The phase structure, microstructure, and electrochemical performance of Ba_0.95La_0.05Fe_0.8Ni_0.2O_3?δ (BLFNi0.2) are well-investigated. The single cells with the BLFNi0.2-BaCe_0.7Zr_0.1Y_0.1Yb_0.1O_3?δ (BCZYYb) composite cathode achieve low polarization resistance (R_p) of 0.099 Ω cm² and a peak power density of 631 mW cm^?2 at 700 °C while maintaining good durability for 120 h with no observable degradation. The results demonstrate that Ni-doped BLF is a promising cobalt-free cathode material for H⁺-SOFCs.     

Ce0.9Gd0.1O1.95 supported La0.6Sr0.4Co0.2Fe0.8O3−δ cathodes for solid oxide fuel cells

Lanthanum-based iron- and cobalt-containing perovskite has a high potential as a cathode material because of its high electro-catalytic activity at a relatively low operating temperature in solid oxide fuel cells (SOFCs) (600–800). To enhance the electro-catalytic reduction of oxidants on La_0.6Sr_0.4Co_0.2Fe_0.8O_3?δ (LSCF), Ga doped ceria (Ce_0.9Gd_0.1O_1.95, GDC) supported LSCF (15LSCF/GDC) is successfully fabricated using an impregnation method with a ratio of 15 wt% LSCF and 85 wt% GDC. The cathodic polarization resistances of 15LSCF/GDC are 0.015 Ω cm², 0.03 Ω cm², 0.11 Ω cm², and 0.37 Ω cm² at 800 °C, 750 °C, 700 °C, and 650 °C, respectively. The simply mixed composite cathode with LSCF and GDC of the same compositions shows 0.05 Ω cm², 0.2 Ω cm², 0.56 Ω cm², and 1.20 Ω cm² at 800 °C, 750 °C, 700 °C, and 650 °C, respectively. The fuel cell performance of the SOFC with 15LSCF/GDC shows maximum power densities of 1.45 W cm^?2, 1.2 W cm^?2, and 0.8 W cm^?2 at 780 °C, 730 °C, and 680 °C, respectively. GDC supported LSCF (15LSCF/GDC) shows a higher fuel cell performance with small compositions of LSCF due to the extension of triple phase boundaries and effective building of an electronic path.     

Nanofiber-structured Pr0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ-Gd0.2Ce0.8O1.9 symmetrical composite electrode for solid oxide fuel cells

In this research, nanofiber-structured Pr_0.4Sr_0.6Co_0.2Fe_0.7Nb_0.1O_3-δ (PSCFN) electrode scaffolds were impregnated with Gd_0.2Ce_0.8O_1.9 (GDC) nanoparticles to prepare PSCFN-GDC nanofiber-structured composite electrodes, which could function well as a novel electrode material for symmetrical solid oxide fuel cells (SSOFCs). The polarization resistances of PSCFN-GDC (1:0.56) composite electrodes as cathode and anode were 0.044 and 0.309 Ω cm² at 800 °C, respectively, indicating that the composite electrodes demonstrated excellent electrochemical performances for both oxygen reductions and fuel oxidation reactions. La_0.8Sr_0.2Ga_0.8Mg_0.2O_3-δ (LSGM) electrolyte-supported single cells with the PSCFN-GDC symmetrical composite electrodes showed excellent long-term stability in wet H₂ (97% H₂-3% H₂O) and wet CH₄ (97% CH₄-3% H₂O) for 100 h with constant current density at 800 °C. A conversion electrode method was applied by interchanging the atmosphere of cathode and anode to solve the problem of PSCFN-GDC symmetrical single cell's carbon deposition in wet CH₄. After working three cycles for 384 h, carbon deposition was not found in the symmetrical electrode scaffold. Taken together, the results described above demonstrated that the PSCFN-GDC composite material acted as a promising symmetrical electrode for SSOFCs, and the conversion electrode method would make for a good application to process carbon deposition generated by hydrocarbon fuels.     

Improved oxygen reduction reaction activity by in-situ synthesizing Sr3Fe1.8Nb0.2O7-δ coating on SrFe0.9Nb0.1O3-δ cathode via the microwave water bath heating method

The sluggish oxygen reduction kinetics remains to be the main obstacle to the development of low temperature proton ceramic fuel cells which limits its commercial application. This phenomenon has driven the exploration of the oxide electrode materials which both possess high oxygen reduction reaction activity and heterogeneous structure. In this work, mixed ionic and electronic conductor SrFe_0.9Nb_0.1O_3-δ (SFN113) is partially transformed into the triple-phase conductor Sr₃Fe_1.8Nb_0.2O_7-δ (SFN327) by in-situ reaction with uniformly coated SrO layer using a microwave water bath heating method. The introduction of the second phase SFN327 significantly improves the oxygen surface exchange kinetics of SFN113 investigated by the electrical conductivity relaxation method. The present work not only remarkably improves the electrocatalytic reduction activity of SFN113 by the introduction of the second phase SFN327 and the construction of the heterogeneous interface, but also provides a valuable route for the further optimization of the exiting electrode materials.     

Effects of mass fraction of La0.9Sr0.1Cr0.5Mn0.5O3-δ and Gd0.1Ce0.9O2-δ composite anodes for nickel free solid oxide fuel cells

The optimal anode mass fraction of La_0.9Sr_0.1Cr_0.5Mn_0.5O_3-δ (LSCM) and Gd_0.1Ce_0.9O_2-δ (GDC) is evaluated in this study. The anodes with GDC share of 30–100 wt.% are investigated. Initial polarization resistance decreased as the GDC share increased. However, anodes with GDC share over 80 wt.% significantly deteriorated in the degradation tests. Nano-scale cracks were observed in the GDC phase at the grain boundaries after the test. These nano-cracks were not observed in composite anodes, from which it is implied that LSCM has stabilization effect on GDC structure. The mass fraction of LSCM : GDC = 30 : 70 wt.% is found to be optimal in terms of initial electrochemical performance and stability. The optimal LSCM-GDC shows lower polarization resistance than conventional Ni-YSZ at low temperatures, which is comparable to Ni-GDC anode.     

Structure and electrical conductivity of BaCe0.7In0.1A0.2O3−δ (A = Gd,Y) ceramics

BaCe_0.7In_0.1A_0.2O_3?δ (A = Gd, Y) ceramics were synthesized by solid state reaction method. The microstructure and electrical properties of BaCe_0.7In_0.1A_0.2O_3?δ ceramics were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and complex impedance analysis at intermediate temperatures of 773–1073 K in different atmospheres. All BaCe_0.7In_0.1A_0.2O_3?δ ceramics exhibit a cubic perovskite structure. Relative densities of BaCe_0.7In_0.1A_0.2O_3?δ ceramics are above 92%. BaCe_0.7In_0.1Gd_0.2O_3?δ and BaCe_0.7In_0.1Y_0.2O_3?δ ceramics exhibit an excellent chemical stability against boiling water. The conductivity values of BaCe_0.7In_0.1Gd_0.2O_3?δ are higher than those of BaCe_0.7In_0.1Y_0.2O_3?δ in both air and dry hydrogen atmospheres. The highest conductivity is 4.6 × 10^?2 S cm^?1 for BaCe_0.7In_0.1Gd_0.2O_3?δ ceramic in air at 1073 K. BaCe_0.7In_0.1Gd_0.2O_3?δ ceramic with a conductivity value of 1.0 × 10^?2 S cm^?1 at 823 K in both air and dry hydrogen atmospheres is considered as a promising alternative for electrolytes of SOFC in view of decreasing the operating temperature and keeping both high conductivity and good chemical stability.     

Flexural strength and flaw distributions of SrFe0.2Co0.4Mo0.4O3−δ ceramic-supports for SOFCs at operating conditions

Solid-oxide fuel cells (SOFCs) have the potential to increase electricity generation efficiency, but traditional SOFCs supported by nickel cermets suffer from reliability challenges due to weaker mechanical strength caused by cracking after redox cycling. To solve this problem, a new ceramic anode material, SrFe_0.2Co_0.4Mo_0.4O_3−δ (SFCM) combined with Ce_0.9Gd_0.1O₂ (GDC), was evaluated for conductivity and mechanical strength at SOFC operating conditions and after redox cycling. Fracture toughness of SFCM was determined to be (0.124 ± 0.023) MPa√m at room temperature in air, increasing to (0.286 ± 0.038) MPa√m at 600°C. A mixture of SFCM:GDC showed fracture toughness between the two materials, following SFCM's trend with temperature. The SFCM-GDC anode supported half-cell strength increases by 31% from room temperature to 600°C as intrinsic stresses remaining from sintering are relaxed and thermal expansion pushes existing cracks closed. Exposure to reducing gasses decreases strength by 29% compared to ambient, due to oxygen vacancy formation and microstructural flaw changes. It is found that SFCM-GDC based cells tolerate cycling well because of phase stability but weaken from 34.3 to 22.4 MPa due to uniform growth of critical microstructural flaws.     

Highly CO2RR activity and electrochemical performance of A-site deficient symmetrical electrode materials (La0.6Sr0.4)1−xFe0.8Ni0.2O3-δ for CO2 electrolysis

A-site deficient (La_0.6Sr_0.4)_1−xFe_0.8Ni_0.2O_3-δ (x = 0, 0.05, 0.1) perovskite oxide materials (LSFN100, LSFN95, and LSFN90) are evaluated as symmetrical electrode materials for CO₂ electrolysis. All three perovskite oxides display pure cubic perovskite structure. The introduction of A-site deficiency results in greater tendency of in-situ exsolution and stronger CO₂ adsorption capacity, which are verified by temperature-programmed reduction of H₂ and temperature-programmed desorption of CO₂. Furthermore, the current densities with LSNF90 symmetrical cell are 1.72, 1.18 and 0.72 A·cm⁻² under the applied voltage of 1.8 V at 850, 800 and 750 °C to electrolysis CO₂, respectively. Low polarization resistance of 0.186, 0.267 and 0.454 Ω·cm² is also observed under open circuit conditions at 850, 800 and 750 °C, respectively. A-site deficiency of perovskite materials reduces the activation energy of oxygen evolution reaction (OER) and carbon dioxide reduction reaction (CO₂RR). Symmetrical cell with LSFN90 electrode shows good electrochemical performance and long-term stability for CO₂ electrolysis.     

A-site deficient Sr0.9Ti0.3Fe0.7O3−δ perovskite：A high stable cobalt-free oxygen electrode material for solid oxide electrochemical cells with excellent electrocatalytic activity and CO2 tolerance

Recently, SrTi_0.3Fe_0.7O_3?δ (STF) has been investigated as a highly stable oxygen electrode material for solid oxide electrochemical cells (SOCs) with a sufficiently low resistance for cell operation at temperatures of > 700 °C. However, in general, the STF electrode performance is limited at temperatures of ≤ 700 °C due to the low oxygen surface exchange coefficient, which is mainly caused by high Sr surface segregation. To improve the electrode performance, Sr_0.9(Ti_0.3Fe_0.7)O_3?δ (A-STF) with an A-site-deficient design is developed to reduce the Sr content and thus reduce the Sr surface segregation, thereby providing a unique combination of excellent oxygen electrode performance and long-term stability. The A-site deficiency reduces the electrode polarization resistance by > 3 times at 600 °C and clearly improves the oxygen diffusion and surface exchange coefficients due to the decrease of Sr surface segregation. The A-STF electrode exhibits stable performance in the fuel cell and electrolysis modes at 1 A cm^?2 > 1200 h. The stability of STF-based oxygen electrodes in a CO₂-enriched atmosphere is investigated, and the results indicate that A-STF exhibits excellent CO₂ tolerance.     

Characteristics of Cu and Mo-doped Ca3Co4O9−δ cathode materials for use in solid oxide fuel cells

In this study, Cu and Mo ions were doped in Ca₃Co₄O_9−δ to improve the electrical conductivity and electrochemical behavior of Ca₃Co₄O_9−δ ceramic and the performance of a solid oxide fuel cell (SOFC) single cell based on NiO-SDC/SDC/doped Ca₃Co₄O_9−δ-SDC were examined. Cu substitution in the monoclinic Ca₃Co₄O_9−δ ceramic effectively enhanced the densification, slightly increased the grain size, and triggered the formation of some Ca₃Co₂O₆; however, no second phase was found in porous Mo-doped Ca₃Co₄O_9−δ ceramics even when the sintering temperature reached 1050 °C. Substitution of Cu ions caused slight increase in the Co³⁺ and Co⁴⁺ contents and decrease in the Co²⁺ content; however, doping with Mo ions showed the opposite trend. Doping the Ca₃Co₄O_9−δ ceramic with a small amount of Cu or Mo increased its electrical conductivity. The maximum electrical conductivity measured was 218.8 S cm⁻¹ for the Ca₃Co_3.9Cu_0.1O_9−δ ceramic at 800 °C. The Ca₃Co_3.9Cu_0.1O_9−δ ceramic with a coefficient of thermal expansion coefficient of 12.1×10⁻⁶ K⁻¹ was chosen as the cathode to build SOFC single cells consisting of a 20 μm SDC electrolyte layer. Without optimizing the microstructure of the cathode or hermetically sealing the cell against the gas, a power density of 0.367 Wcm⁻² at 750 °C was achieved, demonstrating that Cu-doped Ca₃Co₄O_9−δ can be used as a potential cathode material for IT-SOFCs.     

Mechanical behavior of Ce0.9Gd0.1O1.95-La0.6Sr0.4Co0.2Fe0.8O3−δ oxygen electrode with a coral microstructure for solid oxide fuel cell and solid oxide electrolyzer cell

The objective of this work is to investigate the mechanical behavior of CGO-LSCF composite developed by electrostatic spray deposition as an oxygen electrode for Solid Oxide Fuel Cell and Solid Oxide Electrolysis Cell. The coating is characterized by a highly porous morphology designated coral microstructure. Its mechanical behavior was studied by scratch and ultramicroindentation tests and a model of material degradation under progressive compressive loading has been proposed. The coral's damage mechanism involves three regimes: at very low loads stresses are concentrated at the tips of individual corals that fracture and fill the spaces between corals (regime I); as load increases, generalized fracture of the corals occurs and the material starts compacting into an increasingly dense layer (regime II); finally, at the highest loads, the material behaves like an almost fully dense (regime III). As load increases during testing porosity decreases from about 60 to about 5 vol% in the compacted material. The transitions between regimes are associated to increases in the contact stress and the same damage mechanism is found during scratching and indentation. Hardness increases from about 2–100 MPa, while the Young's modulus varies in the range 1–18 GPa, as the porosity decreases. Calculations of the real contact pressure during loading allowed estimating a yield stress of 83 MPa that can be considered as a low limit for the materials fracture strength.     

Evaluation of A-site deficient Sr1−xSc0.175Nb0.025Co0.8O3−δ (x=0, 0.02, 0.05 and 0.1) perovskite cathodes for intermediate-temperature solid oxide fuel cells

This work strives to improve the performance of SrSc_0.175Nb_0.025Co_0.8O_3−δ (SSNC) cathode by introducing A-site cation deficiency up to 10 mol%. Three different Sr-deficient compositions, i.e., Sr_1−xSc_0.175Nb_0.025Co_0.8O_3−δ (S_1−xSNC, x=0.02, 0.05 and 0.1) including the non-deficient analogue, SSNC are prepared. Powder X-ray diffraction patterns indicate that the original cubic perovskite structure is retained. The thermal expansion coefficient between 50 °C and 900 °C increases progressively with increasing Sr deficiency, consistent with the “β-oxygen” release profiles trend. The electrical conductivities for SSNC, S_0.98SNC, S_0.95SNC and S_0.9SNC show a maximum-type profile against increasing temperature, i.e., semiconducting behavior followed by metallic behavior. Despite the consistent increase in the oxygen non-stoichiometry with increasing Sr deficiency, the oxygen reduction reaction performance increases in the order of SSNC, S_0.9SNC, S_0.98SNC and S_0.95SNC. That the highest oxygen reduction reaction (ORR) performance is demonstrated by S_0.95SNC indicates the trade-off between the increase in the concentration of oxygen vacancies and the formation of the phase impurities. At 650 °C, S_0.95SNC shows an area specific resistance of 0.017 Ω cm² (from symmetric cell test) and a peak power density of 1263 mW cm⁻² (from single fuel cell test on a Ni-Sm_0.2Ce_0.8O_1.9 (SDC) anode supported SDC electrolyte).     

La0.6Sr0.4Co0.2Fe0.8O3-δ nanofiber cathode for intermediate-temperature solid oxide fuel cells by water-based sol-gel electrospinning: Synthesis and electrochemical behaviour

Water-based sol-gel electrospinning is employed to manufacture perovskite oxide La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) nanofiber cathodes for intermediate-temperature solid oxide fuel cells. LSCF fibrous scaffolds are synthesized through electrospinning of a sol-gel solution employing water as the only solvent. Morphological characterizations demonstrate that the LSCF fibers have highly crystalline structure with uniform elemental distribution. After heat treatment, the average fiber diameter is 250 nm and the porosity of the nanofiber tissue is 37.5 %. The heat treated LSCF nanofibers are applied directly onto a Ce_0.9Gd_0.1O_1.95 (CGO) electrolyte disk to form a symmetrical cell. Electrochemical characterization is carried out through electrochemical impedance spectroscopy (EIS) in the temperature range 550?°C–950?°C, and reproducibility of the electrochemical performance for a series of cells is demonstrated. At 650?°C, the average measured polarization resistance R_p is 1.0 Ω cm². Measured performance decay is 1 % during the first 33?h of operation at 750?°C, followed by an additional 0.7 % over the subsequent 70?h.     

Microstructural analysis of highly active cathode material La0.7Sr0.3Ti0.15Fe0.65Ni0.2O3-δ (LSTFN) by optimizing different processing parameters

The modified Pechini method was applied to prepare a highly active and novel cathode material La_0.7Sr_0.3Ti_0.15Fe_0.65Ni_0.2O_3-δ (LSTFN). This material was coated on the LGSM electrolyte through a screen-printing technique with variable thicknesses of 28 ± 8, 41 ± 8, and 62 ± 8 μm, respectively. Different fabrication parameters, including sintering temperature, time, coating thickness, and variations in ball-milling, which affect the electrochemical performance of the cathode material, were investigated. X-ray diffraction analysis of the cathode material suggested that it exhibits a cubic crystal structure with a LSTFN single phase. The morphological studies were conducted using scanning electron microscopy (SEM), which confirmed that the electrode material had a highly porous structure. Meanwhile, the electrochemical properties of the material were studied by electrochemical impedance spectroscopy (EIS), which revealed that by varying different parameters, the electrochemical performance of the electrode material was enhanced. The coated cathode materials with variable thicknesses were analyzed at different sintering temperatures and times. Experimental results suggest that the optimum sintering temperature and time were 950 °C and 3 h, respectively, at which LSTFN exhibits the minimum polarization resistance (R_P) of 0.046 Ωcm² when sintered at 800 °C for 3 h.     

Effective buffer layer thickness of La-doped CeO2 for high durability and performance on La0.9Sr0.1Ga0.8Mg0.2O3-δ electrolyte supported type solid oxide fuel cells

Solid oxide fuel cells (SOFCs) have been gaining increased attention in the energy sector. Commonly, yttria-stabilized zirconia is widely employed as commercial electrolyte, however, resulted in drawbacks such as high-temperature operating and low conductivity which negatively affect the durability and efficiency. Thus there are many efforts to find high-ionic conductors. From the point of manufacturing, the major difficulty of LaGaO₃-based electrolyte as a high-ionic conductor is its incompatibility with commercial Ni-based anodes during high-temperature processes as well as operating. Several interlayers have been introduced to prevent the reaction between LaGaO₃-based electrolyte and Ni-based anode. In this study, we investigate the optimal thickness of the La-doped CeO₂ (LDC) interlayer by the screen-printing method using La_0.9Sr_0.1Ga_0.8Mg_0.2O_3-δ for the commercial electrolyte supported SOFCs. As a result, the superior power performance of 2.2 W·cm^?2 at 1123 K is achieved through the optimized LDC thickness of 20 μm through not lab-scaled but commercial ceramic manufacturing processing.