Solid Oxide Fuel Cell Cathode Research Articles

High-entropy perovskite (Pr1/6Nd1/6Sm1/6Ba1/6Sr1/6)6/7(Mn1/6Co)6/7O3-δ as a highly active and CO2 durable cathode for solid oxide fuel cells

Solid oxide fuel cells (SOFCs) are environmentally friendly energy conversion devices that convert the chemical energy in fuels directly into electrical power. The development of high-catalytic activity and durability cathode materials is crucial for the commercialization of SOFCs. Herein, a novel A-site deficient high-entropy perovskite oxide (Pr1/6Nd1/6Sm1/6Ba1/6Sr1/6)6/7(Mn1/6Co)6/7O3-δ (PNSBSMC) was designed. The strong disorder effect associated with entropy increase in high-entropy perovskite oxide is anticipated to accelerate oxygen reduction reaction (ORR) kinetics. PNSBSMC demonstrates excellent catalytic activity for oxygen reduction, primarily due to the entropy-driven enhancement that promotes oxygen adsorption, dissociation, and charge transfer dynamics. The increase in entropy not only significantly mitigates the thermal expansion of PNSBSMC but also provides additional pathways for ionic/electronic transport. At 800 °C, the PNSBSMC-based single cell achieved a remarkable peak power density of 1.41 W cm−2, representing an 88.0 % improvement over the single-phase PBC. Additionally, PNSBSMC demonstrates superior performance stability and CO2 tolerance. These findings suggest that high-entropy PNSBSMC perovskite holds significant potential as an effective cathode for SOFCs. This study offers new insights for the future development of high-stability, high-activity SOFC cathode materials.

An active and Cr-tolerant high-entropy La0.7Sr0.3FeO3-δ based cathode for solid oxide fuel cells

The development of high active and stable cathode materials is one of the main challenges of intermediate temperature solid oxide fuel cells (SOFCs). Herein, a high-entropy Fe-based perovskite oxide La0.7Sr0.3Fe0.3Ni0.3Co0.3Mo0.1O3-δ (LSFNCM) is synthesized by self-propagation combustion based on La0.7Sr0.3FeO3-δ (LSF) and the electrochemical properties are systematically tested. The symmetric half-cell with the LSFNCM cathode has a high catalytic activity with a polarization impedance of 0.12 Ω·cm2 at 800 °C, and also shows outstanding CO2 resistance and chromium resistance owing to the entropy stabilization strategy. After 50h of treatment in a 10% CO2 environment, the polarization impedance of the LSF electrode increases by 8.89 Ω·cm2, while that of the LSFNCM electrode only increases by 1.81 Ω·cm2. Additionally, after being treated for 24h in a chromium vapor environment, the polarization impedance of the LSF electrode increases by 5.95 Ω·cm2, whereas that of the LSFNCM electrode only increases by 0.44 Ω·cm2. Moreover, the single cell with LSFNCM cathode exhibits the maximum power density of 932.82 mW/cm2 and the polarization impedance of 0.34 Ω·cm2 at 800 °C with humidify hydrogen as fuel. Our results indicate that high-entropy perovskite oxide LSFNCM is an active and Cr-tolerant promising cathode for SOFCs.

Tailoring the catalytic activity of PrBaFe2O5+δ cathode material with non-transition metal In-doping for solid oxide fuel cells

Double perovskite PrBaFe2O5+δ (PBF) is a promising cathode material for solid oxide fuel cell (SOFCs) due to the favorable catalytic activity and superior electrochemical stability. Herein, to further tailor the oxygen-ion transport kinetics and electrochemical performance, unlike the typical approach through using higher valence, non-transition metal In3+ ion doping is initially investigated to partially replace Fe3+/Fe4+ site, forming the compositions of PrBaFe2−xInxO5+δ (PBFInx, x = 0, 0.05, 0.1, and 0.15). Xray diffraction (XRD) analysis indicates that PBFInx exhibit satisfactory chemical and thermal compatibility with the gadolinia-doped ceria (GDC) electrolyte. Expectedly, the polarization resistance (Rp) of PBFIn0.1 cathode is decreased by approximately 40 % and an anode-supported single cell with PBFIn0.1 cathode yields a 36 % higher peak power density (PPD) at 800 °C compared to that of PBF. Moreover, the single cell using PBFIn0.1 as the cathode can be operated stably at 0.4 A cm−2 for more than 50 h without obvious performance degradation. In addition, the X-ray photoelectron spectroscopy (XPS) results confirm that the low-valence state In3+ introduced into PBF have a positive impact on the oxygen vacancy concentration and boost the oxygen reduction reaction (ORR) activity, thus significantly enhancing the electrochemical performance of the PBF cathode. The results show that the non-transition metal In3+ ion doping is an effective method to improve the performance of the PBF cathode for SOFCs.

Temperature-controlled in-situ construction of composition-tunable nanoparticle-decorated SOFC cathodes with enhanced oxygen reduction kinetics and CO2 tolerance

High oxygen reduction reaction (ORR) catalytic activity and CO2 resistance of the cathode are fundamental to the commercial application of solid oxide fuel cells (SOFCs). Therefore, we develop a temperature-driven reduction-reoxidation strategy to in-situ construct heterostructured perovskite cathodes decorated with different nanoparticles by controlling the reduction temperature. For (Pr0.4Sr0.6)0.95Co0.2Fe0.8-xNixO3-δ (PSCFN, x = 0.05, 0.1), reduction (@700 °C)-reoxidation results in the exsolution of a ComFenNi3-m-nO4 spinel phase on the perovskite scaffold surface, while reduction (@750 °C)-reoxidation leads to the formation of both ComFenNi3-m-nO4 spinel phase and NiO nanoparticles. The exsolution of these highly active species increases the quantity of oxygen reduction active sites and effectively suppresses Sr segregation. The simultaneous formation of ComFenNi3-m-nO4 spinel phase and NiO nanoparticles induces B-site ion vacancies in the main phase, therefore facilitates the formation of oxygen vacancies. Additionally, the presence of ComFenNi3-m-nO4/NiO/PSCFN heterointerfaces promotes oxygen adsorption and transfer. The strong interactions among ComFenNi3-m-nO4, NiO, and PSCFN significantly enhance the structural stability. At 800 °C, Reo2-PSCFN0.1 achieves an output performance of 1.12 W cm−2, representing a 36.6 % enhancement compared to PSCFN0.1. Moreover, the Rp of Reo2-PSCFN0.1 is merely 0.0186 Ω cm2, marking a 40.4 % decrease relative to PSCFN0.1. This temperature-driven reduction-reoxidation strategy shows great promise as a novel approach for creating high-performance IT-SOFC cathodes.

Recent Advances in Barium Cobaltite-Based Perovskite Oxides as Cathodes for Intermediate-Temperature Solid Oxide Fuel Cells.

Solid oxide fuel cells (SOFCs) are considered as advanced energy conversion technologies due to the high efficiency, fuel flexibility, and all-solid structure. Nevertheless, their widespread applications are strongly hindered by the high operational temperatures, limited material selection choices, inferior long-term stability, and relatively high costs. Therefore, reducing operational temperatures of SOFCs to intermediate-temperature (IT, 500-800°C) range can remarkably promote the practical applications by enabling the use of low-cost materials and enhancing the cell stability. Nevertheless, the conventional cathodes for high-temperature SOFCs display inferior electrocatalytic activity for oxygen reduction reaction (ORR) at reduced temperatures. Barium cobaltite (BaCoO3-δ)-based perovskite oxides are regarded as promising cathodes for IT-SOFCs because of the high free lattice volume and large oxygen vacancy content. However, BaCoO3-δ-based perovskite oxides suffer from poor structural stability, inferior thermal compatibility, and insufficient ionic conductivity. Herein, an in-time review about the recent advances in BaCoO3-δ-based cathodes for IT-SOFCs is presented by emphasizing the material design strategies including functional/selectively doping, deficiency control, and (nano)composite construction to enhance the ORR activity/durability and thermal compatibility. Finally, the currently existed challenges and future research trends are presented. This review will provide valuable insights for the development of BaCoO3-δ-based electrocatalysts for various energy conversion/storage technologies.

Ruddlesden-Popper Perovskite Materials for Solid Oxide Fuel Cell Cathode: A Review

This review paper summarizes the recent findings on Ruddlesden-Popper (RP) phase materials for solid oxide fuel cell (SOFC) cathodes. These materials, known for their unique layered structure, show excellent performance in intermediate-temperature SOFCs due to their outstanding catalytic activity for the oxygen reduction reaction (ORR) and relatively high durability. RP perovskites are notable for their fast oxygen surface exchange rates and stability under operating conditions, making them suitable for both oxide ion and proton-conducting SOFCs. The paper examines the relationship between their crystal structure, physical properties, and the transport mechanisms of oxygen ions. Key strategies to enhance the properties of RP perovskites in SOFCs are discussed, including doping to optimize conductivity and thermal expansion coefficients, and creating composite cathodes to improve stability and performance. The paper also briefly covers the long-term stability of these materials with some examples. Finally, the review highlights the need for further research on the ORR kinetics of RP perovskites, especially in proton-conducting SOFCs, to fully realize their potential for efficient and durable energy conversion technologies.

Construction of more oxygen vacancies of BaCo0.4Fe0.4Zr0.2O3-δ for high-performance proton-conducting solid oxide fuel cell cathodes

The cathodic catalytic activity for the oxygen reduction reaction (ORR) plays a critical role in determining the performance of proton-conducting solid oxide fuel cells (P-SOFCs). BaCo0.4Fe0.4Zr0.2O3-δ (BCFZ) has emerged as a promising cathode for P-SOFCs due to its triple-phase conductivity. Nevertheless, its suboptimal proton conductivity and hydration ability at intermediate temperatures prevent it from achieving the anticipated ORR catalytic activity. To address these limitations, this study explores the enhancement of electrocatalytic activity in BCFZ through alkali metal doping and A-site defect construction. The effects of such modifications on oxygen surface exchange kinetics and ORR catalytic activity are systematically investigated. The findings reveal that BCFZ exhibits relatively low parameters in terms of electronic conductivity, oxygen ion conductivity, oxygen vacancy concentration, kchem, and Dchem. Conversely, these parameters are markedly improved in A-site deficient BCFZ (D-BCFZ) and Na/K-doped BCFZ. Consequently, the enhancement of these properties yields a significant increase in ORR catalytic activity, with D-BCFZ demonstrating the best electrochemical performance. Specifically, P-SOFC with D-BCFZ cathode achieves an Rp value of just 0.073 Ω cm2 and a Pmax value of 0.928 W cm-2 at 650 °C. This study provides theoretical insight into the mechanisms by how alkali metal doping and defect construction enhance the ORR catalytic activity of BCFZ. These findings offer valuable guidance for the development and optimization of high-performance P-SOFC cathodes.

Sr and Mn co-doping PrBaFe2O5+δ optimizes the electrochemical performance and stability of solid oxide fuel cell cathode

Developing cobalt-free cathode with high stability and high electrochemical activity is very important for constructing low-cost, high-performance solid oxide fuel cells. Layered perovskite PrBaFe2O5+δ (PBF) is known to ave important magnetic, oxygen exchange kinetic and electrochemical properties. In this study, Sr and Mn co-doping A-site and B-site of PrBa0.5Sr0.5Fe1.6Mn0.4O5+δ (PBSFM) electrode was synthesized and characterized its properties. The first-principles calculation shows that Sr and Mn co-doped PBSFM decreases the oxygen vacancy energy, improves the overlap of oxygen-metal bond hybridization and structural stability. The polarization resistance (Rp) of PBSFM decreases from 0.22 to 0.077 Ω cm2 at 700 °C. At 800 °C, the power density of fuel cell reaches 674 mW cm−2 using hydrogen as fuel. In addition, Sr and Mn co-doped PBSFM significantly improves impedance and single cell stability under operating conditions.

Nanostructured thin film SrCo0.8Nb0.1Ta0.1O3-δ cathode for low-temperature solid oxide fuel cells

Nanostructured perovskite-type cathodes are considered essential for the realization of high-performance solid oxide fuel cell (SOFC). However, perovskite-type cathode materials demonstrating high electrochemical performance in the low-temperature operating region below 600° are limited. SrCo0.8Nb0.1Ta0.1O3-δ (SCNT) has been identified as a material that exhibits exceptional performance even in the low-temperature region of 500 °C. This paper investigates the growth behavior and electrochemical properties of SCNT thin films for SOFC cathode applications. Pulsed laser deposition (PLD) was employed to fabricate SCNT films under varying chamber pressures: 5 mTorr, 75 mTorr, and 150 mTorr. Systematic analysis through X-ray diffraction and X-ray photoelectron spectroscopy indicates that the structural factors of PLD perovskite oxide nanostructures, such as grain size, porosity, and in-plane connectivity, are intricately influenced by deposition pressure without affecting crystallinity and chemical composition. The findings demonstrate that achieving desired electrochemical properties of the nanostructured PLD perovskite oxide necessitates specific optimal deposition conditions for these structural parameters. Electrochemical assessments revealed an optimal nanostructure achieved with 1200 nm at 75mTorr, demonstrating enhanced power density due to increased active reaction surface area, which significantly reduced resistances in ohmic and polarization. Excessive thickness, however, led to performance decline due to film delamination. Integration of optimized SCNT films into an anodic aluminum oxide supported thin film SOFC exhibited 907 mW/cm2 of peak power density at 550 °C.

Redox Stability Optimization in Anode-Supported Solid Oxide Fuel Cells.

For Ni-YSZ anode-supported solid oxide fuel cells (SOFCs), the main drawback is that they are susceptible to reducing and oxidizing atmosphere changes because of the Ni/NiO volume variation. The anode expansion upon oxidation can cause significant stresses in the cell, eventually leading to failure. In order to improve the redox stability, an analytical model is developed to study the effect of anode structure on redox stability. Compared with the SOFC without AFL, the tensile stresses in the electrolyte and cathode of SOFC with an anode functional layer (AFL) after anode oxidation are increased by 27.07% and 20.77%, respectively. The thickness of the anode structure has a great influence on the structure's stability. Therefore, the influence of anode thickness and AFL thickness on the stress in these two structures after oxidation is also discussed. The thickness of the anode substrate plays a more important role in the SOFC without AFL than in the SOFC with AFL. By increasing the thickness of the anode substrate, the stresses in the electrolyte and cathode decrease. This method provides a theoretical basis for the design of a reliable SOFC in the redox condition and will be more reliable with more experimental proofs in the future.

Effective suppression of surface cation segregations on double perovskite oxides through entropy engineering

Cation segregation on cathode surfaces plays a key role in determining the activity and operational stability of solid oxide fuel cells (SOFCs). The double perovskite oxide PrBa0.8Ca0.2Co2O5+δ (PBCC) has been widely studied as an active cathode but still suffer from serious detrimental segregations. To enhance the cathode stability, a PBCC derived A-site medium-entropy Pr0.6La0.1Nd0.1Sm0.1Gd0.1Ba0.8Ca0.2Co2O5+δ (ME-PBCC) oxide was prepared and its segregation behaviors were investigated under different conditions. Compared with initial PBCC oxide, the segregations of BaO and Co3O4 on the surface of ME-PBCC material are significantly suppressed, especially for Co3O4, which is attributed to its higher configuration entropy. Our results also confirm the improved electrochemical performance and structural stability of ME-PBCC material, enabling it as a promising cathode for SOFCs.

System simulation and parametric analysis of low-concentration coal mine gas fed SOFC-CHP with deoxygenation and enrichment pretreatment

Solid oxide fuel cell (SOFC) combined heat and power (CHP) can efficiently convert low-concentration coal mine gas (LC-CMG) into clean energy, avoiding the greenhouse effect of LC-CMG. Deoxygenation and methane enrichment pretreatment of LC-CMG can prevent explosion and anode oxidation risk. Herein, a chemical process model of LC-CMG fed SOFC-CHP system with the pretreatment was established to predict the performances under different operating conditions. Performance evaluation and exergy analysis were performed considering the use of oxygen-rich gas from the pretreatment at SOFC cathode. The effects of key operation parameters on system performances were investigated in terms of residual oxygen concentration, inlet methane concentration, fuel flow and fuel utilization. The results indicated that net electrical efficiency and heat supply efficiency can respectively reach 49.13 % and 23.90 % using LC-CMG of 15 % CH4 with enhancing effect of oxygen-rich gas at cathode. The decrease of methane concentration and the increase of residual oxygen concentration and flow rate caused the decreased electrical efficiency but the increased heat supply efficiency due to the enlargement of concentration polarization and heat supply. The optimal operation parameters were recognized by comprehensively considering diverse performance indicators. This work can guide system integration and operation optimization of LC-CMG fed SOFC-CHP.

Turning bad into good: A medium-entropy double perovskite oxide with beneficial surface reconstruction for active and robust cathode of solid oxide fuel cells

The cathodes of solid oxide fuel cells (SOFCs) often suffer from detrimental cation segregations and associated impurities poisoning, leading to insufficient electroactivity and poor stability. Here we developed a medium-entropy double perovskite GdBa(Co1.2Mn0.2Fe0.2Ni0.2Cu0.2)O5-δ (ME-GBCO) for promising SOFC cathode. The increased configuration entropy can effectively tailor the surface composition with in situ formed active BaCoO3-δ (BCO) species, rather than inert and deleterious BaOx segregation on parent GdBaCo2O5-δ (GBCO) surface. Accordingly, the layered ME-GBCO cathode with beneficial surface reconstruction exhibited not only high oxygen reduction activity but excellent durability against CO2 impurity, enabling it a very attractive cathode for intermediate temperature SOFCs (IT-SOFCs). Our study provides a new idea for development of efficient and durable cathodes via configurational entropy induced rational surface reconstruction.

Synergistic effects and electrocatalytic insight of single-phase hexagonal structure as low-temperature solid oxide fuel cell cathode

Enhancing the electrocatalytic activity of the electrode materials, specifically oxygen reduction reaction (ORR), at lower operating temperatures (<600 °C) is the prime rank to realize the commercialization of solid oxide fuel cells (SOFCs) research. Herein, a new hexagonal structure-based cathode material was developed with the co-doping of Gd2O3 and Cr2O3 of parent SrFe12O19 oxide, respectively. At 550‒475 °C, Sr0.90Gd0.10Fe11.90Cr0.10O19 (SFO-10) cathode sample leading to the large peak power density (PPD) of 395 mW/cm2, has appropriate surface oxygen defects (Oβ) up to 17%, as verified by X-ray photoelectron microscopy (XPS). Theoretical calculations reveal that the co-doping of Gd and Cr oxides creates lattice disorder at the hexagonal lattice, which decreases the energy barrier for ion transport and enhances the electrocatalytic characteristics of ORR. Consequently, the SFO-10 cathode shows a favorable ORR activity with the least lower polarization resistance (ASR) at 550 °C with gadolinium-doped ceria (GDC) electrolyte. This work provides a self-assembled single-phase hexagonal cathode to accelerate the low-temperature hindrance of SOFC technology.

First principles calculation and experimental study of Ln0.125Sr0.875Co0.875Ta0.125O3-δ(Ln = La, Sm, and Nd) as potential cathode materials for intermediate-temperature solid oxide fuel cells

Solid oxide fuel cells (SOFCs), as important energy equipment, have excellent characteristics, including low pollution and high catalytic activity. The cathode, which is the key component of an SOFC, plays a vital role in practical applications. Herein, we study the properties of Ln0.125Sr0.875Co0.875Ta0.125O3-δ (Ln = La, Sm, and Nd, abbreviated as LSCT, SSCT, and NSCT, respectively) cathode materials both theoretically and experimentally. The conductivity of LnSCT gradually decreased with decreasing Ln3+ ionic radius. Density of states (DOS) analysis indicated that LSCT has the highest conductivity owing to the band center of Co 3d being closer to O 1s. Density functional theory (DFT) calculations showed that the SSCT sample has the lowest oxygen vacancy formation energy, which facilitated the formation of oxygen vacancies. The binding energy results show that SSCT and NSCT have relatively good structural stability compared to LSCT. The polarization impedance values of LSCT, SSCT, and NSCT at 700 °C are 0.105, 0.069, and 0.304 Ω cm2, respectively. The CO2 sensitivity of LSCT, SSCT, and NSCT was evaluated by calculating the CO2 adsorption energy and performing impedance tests under different CO2 concentrations. These results indicate that LSCT and SSCT have better CO2 tolerance than NSCT. At 700 °C, for Ln = La, Sm, and Nd, the maximum power of NiCu-SDC/SDC/LSGM/LnSCT electrolyte-supported fuel cell reached 430, 462, and 382 mW cm−2, respectively. These findings provide a reference for the future design and development of SOFCs cathode material.

High performance of SrCo1-xZrxO3-δ perovskite cathodes for IT-SOFCs

Stabilization of a tetragonal perovskite structure in the SrCoO3-δ system at room temperature has been achieved through wet chemical techniques, and it has been successfully tested in Solid Oxide Fuel Cells (SOFCs). Chemical substitutions at the Co position were carried out by introducing different amounts of zirconium (SrCo1-xZrxO3−δ; x = 0.05, 0.08 and 0.11) to destabilize the columns of CoO6 octahedra sharing faces in the competitive 2H-hexagonal phase. The crystal structure was studied by X-ray diffraction (XRD) and neutron powder diffraction (NPD) at 25 °C and correlated with mechanical and electrical properties. Chemical compatibility studies between the samples and the La0.8Sr0.2Ga0.83Mg0.17O3-δ (LSGM) electrolyte revealed not interaction at high temperatures. Dilatometric analysis measurements showed a compatible thermal expansion with the LSGM electrolyte over the entire temperature range, demonstrating good mechanical compatibility. Furthermore, the relatively high conductivity values (∼83 S cm-1 at 850 °C) indicated their suitability as cathodes in SOFCs. Finally, test cells prepared with an electrolyte (LSGM) supported configuration provided a maximum output power exceeding 600 mW/cm2 using pure H2 as fuel at 850 °C. Importantly, the performance of the cathode materials did not degrade after extended operation at this temperature.

Fabrication and performance investigation of high entropy perovskite (Sr0.2Ba0.2Bi0.2La0.2Pr0.2)FeO3 IT-SOFC cathode material

The high-entropy oxide (HEO) concept expands the design space of solid oxide fuel cell (SOFC) cathode materials. There is great potential for the development of HEO cathode materials that has not been fully explored, and the relationship between their chemical composition, grain size, and electrochemical performance is not yet fully understood. This experimental design involved the preparation of single-phase perovskite (Sr0.2Ba0.2Bi0.2La0.2Pr0.2)FeO3 HEO SOFC cathode materials, and we systematically studied the effects of synthesis temperature and microstructure on their electrochemical performance. The results show that as the synthesis temperature increases, structural transformations from multiphase to single-phase perovskite HEO can be observed. It exhibits excellent conductivity and electrochemical performance (the minimum polarization resistance reaches 0.033 Ω∙cm2, and the maximum power density is 664 mW∙cm−2). The single-phase perovskite HEO sample exhibits higher electrochemical performances compared to those of multiphase perovskite. Furthermore, it exhibits outstanding ability to suppress Sr segregation, chemical compatibility with Ce0.8Sm0.2O1.9(SDC), and CO2 tolerance performance. The Distribution of relaxation time(DRT) analysis shows that as the synthesis temperature (1000–1150 ℃) increase, HEO single-phase formed and the oxygen atom reduction ability of the SBBLP samples was improved; and the adsorption of gas oxygen on the electrode surface is limited with porosity decreases. The work shows it is interesting and valuable to optimize the performance of SOFC cathode materials using a high entropy design.

Systematic and predictive trends to chromium poisoning in solid oxide fuel cell cathodes

High performance computing simulations of Cr-poisoning are used to develop systematic trends for overpotential driven degradation modes in microstructurally resolved fuel cell cathodes. Oxygen reduction and chromium oxide deposition at triple phase boundaries (tpbs), and species transport, are numerically computed within 19 microstructures (103 µm3 domains) over a range of operating conditions. Three primary input parameters drive degradation: tpb density of the microstructure ρtpb, normalized charge-transfer current density for Cr-poisoning i∗, and galvanostatic current density j. Simulations converged over large fractions of the potential operating time, ranging from thousands to over a hundred thousand hours. For all simulations, normalized overpotential η∗ versus time t curves can be modeled using a progressive, asymptotic function η∗=ma(ta−t) with two fitting parameters: the initial slope m and the asymptote a. A third output parameter tl was defined as the time when a specific fraction of overpotential range was lost. Several methods to determine each output parameter are presented. More importantly, using the large amount of data generated from over 95 time-dependent simulation series (over 29,000 individual simulations), simple correlations are made between the input and output parameters that provide predictive capability of operational lifetime tl (and m and a), without needing further high-performance computing.

Enhancing Oxygen Reduction Activity and CO2 Tolerance by a Bismuth Doping Strategy for Solid Oxide Fuel Cell Cathodes

AbstractLayered perovskite related oxides, LnBaCo2O5+δ (Ln = rare‐earth element) are potential ceramic cathodes for intermediate temperature solid oxide fuel cells. Herein, a simple way to tune the performance of NdBaCo2O5+δ (NBC) perovskite as a cathode by doping the Co‐site with bismuth cation is reported. Compared with the parent oxide, the obtained stabilized double perovskites NdBaCo2−xBixO5+δ (x = 0.1 and 0.2) show a much improved electrocatalytic activity, achieving area‐specific resistance of 0.268, 0.107 and 0.152 Ω cm2 at 700 °C in air for NBC, x = 0.1, and 0.2, respectively. Density functional theory results demonstrate that bismuth doping effectively reduces the formation energy of oxygen vacancies. Moreover, the bismuth doping of NdBaCo2−xBixO5+δ cathode is much more robust against CO2 than that of NBC cathode. This work indicates that bismuth doping in the B‐site of LnBaCo2O5+δ may be a highly attractive strategy for the future development of cathode materials.

Electrochemical performance of Pr0.6Sr0.4Fe0.8Co0.2O3−δ as potential cathode material for IT-SOFC

Solid oxide fuel cells (SOFCs) are renowned for being effective energy sources that have potential to influence how energy is developed in future. SOFCs operate at low temperatures provides different benefits for widespread commercialization. In the present study a perovskite material Pr0.6Sr0.4Fe0.8Co0.2O3−δ (PSFCo) was investigated as cathode for SOFC in intermediate temperature range. Glycine nitrate process was used for the preparation of the samples. PSFCo exhibited cubic structure having small particle size (100–200 nm). The electrical conductivity of the PSFCo was measured as function of temperature up to 850 ℃. The sample displayed maximum electrical conductivity of 370 Scm−1 at around 550–600 ℃. The polarization behavior of PSFCo was calculated by means of AC impedance with Sm0.8Ce0.2O2 (SDC) as electrolyte. The value of area specific resistance (ASR) was calculated as 0.146 Ωcm2 at 800 ℃ and 0.248 Ωcm2 at 700 ℃.