Solid Oxide Fuel Cell Cathode Research Articles

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 ℃.

Advantages of ionic conductors over electronic conductors as infiltrates in solid oxide fuel cell cathodes

To investigate the difference between ionic and electronic conductors as infiltrates in solid oxide fuel cells (SOFCs), high-throughput and high-performance finite element simulations were carried out on 51 different cathode microstructures. Five cathode backbones, reconstructed from a commercial SOFC, were infiltrated computationally with varying number densities of nanoscale electronically or ionically conducting particles. Local electrochemical quantities were computed within the volumetric meshes that represent the complex 3D microstructural morphologies that include the infiltrated particles. As infiltrates, ionic conductors improve the performance more than electronic conductors. By differentiating transport and reaction pathways originating from backbone phases and infiltrates, we show that new ionic transport pathways opened by the ionically conducting infiltrates are the origin of this difference. These new transport paths redistribute current throughout the cathode, thereby increasing (decreasing) the available local activation (Ohmic) overpotential at triple phase boundaries and rendering them more active than for the case of electronic conductors as infiltrates. These results give us insight to engineering improved electrodes for SOFCs via infiltration with surface active nano-particles.

Lithium doping enhanced ORR kinetics and CO2 tolerance of iron-based double perovskite cathode for solid oxide fuel cells

Fe-based double perovskites exhibit significant potential as cathode materials for solid oxide fuel cells (SOFCs) owing to their affordability, moderate thermal expansion, and impressive stability. Nevertheless, their practical utility has been constrained by their comparatively lower oxygen reduction reaction (ORR) catalytic activity. In this study, for the first time, lithium (Li) was employed as a dopant to improve the ORR activity of the Fe-based double perovskite PrBaFe2O5+δ (PBFO). The results indicated that the ratios of Fe3+/Fe2+ and Oads/Olat were effectively tuned by incorporating Li at Ba-sites of PBFO. Consequently, the adsorption and dissociation of oxygen, along with the charge transfer processes were regulated significantly, resulting in an increase in ORR kinetics and improved CO2 resistance. At 800 °C, PrBa0.9Li0.1Fe2O5+δ (PBLFO) demonstrated an Rp of 0.072 Ω cm², which was decreased by 43.3% compared to PBFO. Simultaneously, the maximum power density of PBLFO-based full cell was improved by 23.3%, reaching 670 mW cm−2. These findings suggest that Li-doping holds great potential for improving the performance of Fe-based SOFC cathodes, thereby contributing to the advancement of clean and sustainable energy technologies.

Ta/Nb doping motivating cubic phase stability and CO2 tolerance of Sr2Co1.6Fe0.4O6-δ double perovskite for high-performing SOFC cathode

Developing cathodes that are both phase-stable and tolerant to carbon dioxide (CO2) is a crucial and challenging task for solid-oxide fuel cells (SOFCs) operating at reduced temperatures. The activity of oxygen reduction reaction (ORR) in SOFC cathodes is typically influenced by factors such as geometric features and oxygen vacancies. In this study, new and robust cathodes for SOFCs, Sr2Co1.5Fe0.4Ta0.1O5+δ (SCFT) and Sr2Co1.5Fe0.4Nb0.1O5+δ (SCFN) are developed by doping a small amount of niobium (Nb) and tantalum (Ta) into Sr2Co1.6Fe0.4O5+δ (SCF) using a simple solid-state reaction technique. The effects of Nb/Ta doping on the crystal structure, oxygen vacancies, electrical conductivity, and electrochemical properties of SCFT and SCFN are investigated. The results reveal that these materials possess a fully cubic structure in the Fm-3m space group, with improved oxygen vacancy and electrical conductivity. They also exhibit good chemical compatibility with electrolytes at 1100 °C for 8 h and remain thermally stable when exposed to air and CO2 at 700 °C, without any additional phase formation. The area-specific resistance (ASR) of the SCFT cathode is found to be only 0.06 Ω cm2, whereas the SCFN cathode has an ASR of 0.10 Ω cm2. The superior performance of SCFT can be attributed to the higher oxygen vacancy, which enhances oxygen surface exchange kinetics and diffusivity compared to SCFN. When tested in a single cell using humidified H2 as the fuel and ambient air as the oxidant, the SCFT cathode achieves a power density of 656 mW cm−2 at 700 °C, while the SCFN cathode reaches 559 mW cm−2, indicating the potential of SCFT as a promising cathode material for SOFCs. The excellent performance of these materials can be attributed to their mixed electronic-ionic conduction properties, unique structural features, and high observed oxygen vacancy, which contribute to their remarkable electronic conductivity and significant ionic mobility.

CO2/Cr-tolerance and oxygen reduction reaction of novel high-entropy perovskite cathode for intermediate temperature solid oxide fuel cell

The development and exploration of cathode oxides with outstanding electrocatalytic activity are critical processes aimed at achieving a decrease in the operation temperature of solid oxide fuel cells (SOFC). Herein, a novel high-entropy oxide, La0.2Pr0.2Nd0.2Sm0.2Gd0.2BaCoFeO5+δ (HEP), which incorporates five lanthanide species (La, Pr, Nd, Sm, and Gd) in the A-site of perovskite, has been specifically developed and assessed as selected cathode for intermediate-temperature SOFC. Investigations of phase structure, chemical compatibility, oxygen transport characteristics, oxygen reaction kinetic, thermal expansion, surface chemical state, conductivity, as well as CO2/Cr-durability are thoroughly performed to assess the basic physicochemical properties of the HEP cathodes. The HEP cathode possesses good operational stability, moderate thermal expansion behavior, fast oxygen transport dynamics, and superior chemical compatibility with the electrolyte. At 700 °C, the polarization resistance low to 0.072 Ω cm2 and output power density high to 332.2 mW cm−2 were obtained for the symmetrical and electrolyte-supported single cells. Furthermore, a stable current density is obtained for the single cell operating at 600 °C and 0.5 V for 100 h. Analysis of electrochemical impedance spectra (EIS) and distribution of relaxation time (DRT) data at different oxygen partial pressures reveal that the charge-transfer and oxygen ions ionization processes at intermediate frequencies present a significant limiting step in the rate of the oxygen reduction reaction. However, under realistic utilization conditions, cathodes of cells often endure irreversible performance degradation owing to the Cr deposition from interconnects or CO2 poisoning in air. Hence, the behavior of Cr and CO2 poisoning is also systematically investigated in symmetrical cell measurements; the results confirm that the HEP cathode displays good resistance to Cr and CO2 poisoning. Overall, our findings indicate that the HEP material is regarded as a favored ceramic cathode for SOFC.

Optimisation of the electrochemical performance of (Nd,Gd)1/3Sr2/3CoO3−δ cathode for solid oxide fuel cells via spray-pyrolysis deposition and decoration with Ag nanoparticles

Improved electrochemical performance of (Nd,Gd)1/3Sr2/3CoO3−δ:Ce0.9(Gd,Nd)0.1O1.95 air electrode for SOFCs employing spray pyrolysis deposition and simultaneous decoration with Ag nanoparticles.

INVESTIGATION OF THE SOLID OXIDE FUEL CELL (SOFC) BY MEANS OF CFD SIMULATION

In this research, computational fluid dynamics simulations are employed to investigate the behavior of the flow and electrochemistry of planer-type solid oxide fuel cells (SOFCs). The flow distributions in the cathode and anode of an original SOFC are simulated, and the results well agree with the experiments. To reduce non-flow areas in the cathode and anode and hence increase the operating life of the cell, a number of improved flow channel layouts are proposed and simulated. The most effective layout shows a significant reduction of non-flow areas improving flow and temperature distributions throughout the cell. However, as compared to the original SOFC, the electrical power density of the most effective channel SOFC is 12.5% lower. Further investigations are required to improve the flow and temperature distributions and increase the output power.

An excellent bismuth-doped perovskite cathode with high activity and CO2 resistance for solid-oxide fuel cells operating below 700 °C

Lowering the operating temperatures of solid-oxide fuel cells (SOFCs) is critical, although achieving success in this endeavor has proven challenging. Herein, Bi0.15Sr0.85Co0.8Fe0.2O3−δ (BiSCF) is systematically evaluated as a carbon dioxide (CO2)-tolerant and highly active cathode for SOFCs. BiSCF, which features Bi3+ with an ionic radius similar to Ba2+, exhibits activity (e.g., 0.062 Ω cm2 at 700 °C) comparable to that of Ba0.5Sr0.5Co0.8Fe0.2O3−δ and PrBaCo2O5+δ, while demonstrating a considerable advantage over Bi-doped cathodes. Moreover, BiSCF exhibits long-term stability over a period of 500 h, and an anode-supported cell with BiSCF achieves a power density of 912 mW cm−2 at 650 °C. The CO2-poisoned BiSCF exhibits quick reversibility or slight activation after returning to normal conditions. The exceptional CO2 tolerance of BiSCF can be attributed to its reduced basicity and high electronegativity, which effectively restrict surface Sr diffusion and hinder subsequent carbonate formation. These findings highlight the substantial potential of BiSCF for SOFCs operating below 700 °C.

Enhancing ORR activity and CO2 tolerance of Pr0.4Sr0.6Co0.2Fe0.8O3-δ-based SOFC cathode through synergistic doping and surface modification

The development of cathodes with high catalytic activity and stability remains a critical challenge for the commercialization of solid oxide fuel cells (SOFCs). In this study, a novel approach combining doping and surface modification was employed to enhance the catalytic activity and CO2 resistance of Pr0.4Sr0.6Co0.2Fe0.8O3-δ (PSCF) cathode. Initially, Ni was partially substituted for Fe in PSCF, resulting in the reduction of the average bond energy of metal–oxygen, thereby increasing oxygen vacancy concentration and electrochemical activity. The polarization resistance of PSCFN0.1 at 800 °C was found to be 0.025 Ω·cm2, representing a 32.4 % reduction compared to PSCF. Subsequently, Pr(NO3)3 solution was impregnated on the surface of the PSCFN0.1 using a spin-coating technique, resulting in the formation of a PrO2/PSCFN0.1 heterostructure that significantly improved the oxygen reduction reaction (ORR) kinetics. At 800 °C, the polarization resistance of PrO2-PSCFN0.1 was only 0.016 Ω·cm2, a 56.8 % reduction compared to PSCF. Moreover, the peak power density of PrO2-PSCFN0.1 reached 1190 mW·cm−2 at 800 °C, representing a substantial increase of 207.4 % compared to PSCF. Furthermore, PrO2-PSCFN0.1-based full cell exhibited excellent performance stability and CO2 resistance. This work provides an effective strategy to explore novel cathodes for SOFCs.

A way to limit the long-term degradation of solid oxide fuel cell cathode by decorating the surface with K2NiF4-Structure Pr4Ni3O10+δ phase

Prolonged annealing of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) at 700 °C for 1000 h resulted in phase segregation on the surface in the form of submicron-sized SrO on the grains and micron-sized CoFe2O4 particles near the grain boundaries during electrical conductivity relaxation (ECR) measurements. The presence of segregated particles results in a substantial decrease in the surface exchange coefficient, kchem. To mitigate this issue, the LSCF electrodes underwent a systematic coating process with the K2NiF4-structure Pr4Ni3O10+δ (PNO), while varying the loading content, thickness, and porosity. This is achieved by adjusting the gap between the nozzle exit and LSCF surface, ranging from 2 cm to 9 cm, coupled with the application of ultrasonic vibration of the nozzle chamber operating between 40 kHz and 180 kHz. Optimal surface coverage with a loading content of 0.28 mg cm−2 referred to as PNO5 results in a significant increase in kchem by up to one and a half order of magnitude compared to bare LSCF. The PNO coating effectively suppresses phase segregation during prolonged exposure, resulting in a substantial decrease in degradation. The improved performance is attributed to the optimal surface coverage of coated particulates, which enhances the active sites for oxygen reduction reaction (ORR) and the triple phase boundary (TPB) area. These exceptional characteristics position PNO coated LSCF as a highly promising cathode option for low temperature solid oxide fuel cells (SOFCs).

Mechanistic Study on the Corrosion of (La,Sr)(Co,Fe)O3-δ Cathodes Induced by CO2.

Solid Oxide Fuel Cell (SOFC) cathodes operating in ambient atmospheric conditions inevitably encounter CO2 contamination, leading to sustained performance deterioration. In this investigation, we examined the impact of CO2 on three variants of (La,Sr)(Co,Fe)O3-δ cathodes and employed the distribution of relaxation times method to distinguish distinct electrochemical processes based on impedance spectra analysis. We meticulously analyzed and discussed the corrosion resistance of these (La,Sr)(Co,Fe)O3-δ cathodes under high CO2 concentrations, relying on the experimental data. Electrochemical impedance spectroscopy results revealed that La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF-6428), La0.4Sr0.6Co0.2Fe0.8O3-δ (LSCF-4628), and La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ (LSCFN-46271) cathodes exhibited persistent degradation when exposed to CO2 at temperatures of 650 °C or 800 °C during the durability-testing period. An increase in electrode polarization resistance was observed upon CO2 introduction to the electrode, but electrode performance recovered upon returning to a pure air environment. Furthermore, X-ray diffraction and scanning electron microscopy analyses confirmed that CO2 did not cause permanent damage to the (La,Sr)(Co,Fe)O3-δ cathodes. These findings indicate that the (La,Sr)(Co,Fe)O3-δ cathodes exhibit excellent resistance to CO2-induced corrosion.

Design and sensitivity analysis of a multistage solid oxide fuel cell hybrid system with an inter-cooled-recuperated gas turbine and organic Rankine cycle

A solid oxide fuel cell (SOFC) hybrid system with an inter-cooled-recuperated gas turbine(ICRGT) and organic Rankine cycle (ORC) was designed to address exergy destruction in the burner of a conventional SOFC and gas turbine (GT) system. In unfired mode of this system, SOFC acts as the GT heater and reheater instead of burners; burners are used only to aid load regulation in fired mode. In unfired mode, the system electrical efficiency is 69.86 % and the overall efficiency is 82.22 %. The total exergy destruction of the system is 21.93 % lower than that in fired mode by exergy analysis, which indicates the effectiveness of reducing afterburner exergy destruction, and the superior energy efficiency of this mode. For the design analysis, we analyzed the influence of different factors on the system, including the number of SOFC modules, turbine outlet temperature, burner exhaust into the turbine, oxidant utilization of SOFC cathode(OUC), and fuel utilization of SOFC anode(FUA) on the system. For the sensitivity analysis, we determined the variation rules of the components and system parameters for fuel proportions of 70–105 %. This work provides a reference for optimizing the design and operation of SOFC-GT and other SOFC hybrid systems.

Advancements in Perovskite-Based Cathode Materials for Solid Oxide Fuel Cells: A Comprehensive Review.

The high-temperature solid oxide fuel cells (SOFCs) are the most efficient and green conversion technology for electricity generation from hydrogen-based fuel as compared to conventional thermal power plants. Many efforts have been made to reduce the high operating temperature (>800 °C) to intermediate/low operating temperature (400 °C<T<800 °C) in SOFCs in order to extend their life span, thermal compatibility, cost-effectiveness, and ease of fabrication. However, the major challenges in developing cathode materials for low/intermediate temperature SOFCs include structural stability, catalytic activity for oxygen adsorption and reduction, and tolerance against contaminants such as chromium, boron, and sulfur. This research aims to provide an updated review of the perovskite-based state-of-the-art cathode materials LaSrMnO3 (LSM) and LaSrCOFeO3 (LSCF), as well as the recent trending Ruddlesden-Popper phase (RP) and double perovskite-structured materials SOFCs technology. Our review highlights various strategies such as surface modification, codoping, infiltration/impregnation, and composites with fluorite phases to address the challenges related to LSM/LSCF-based electrode materials and improve their electrocatalytic activity. Moreover, this study also offers insight into the electrochemical performance of the double perovskite oxides and Ruddlesden-Popper phase materials as cathodes for SOFCs.

Supersonic spray derived Cu–Co oxide coating on SUS441 to protect the metallic interconnect and to increase stability of SOFC cathode

The interconnects for solid oxide fuel cells (SOFCs) are usually ferritic stainless steels such as SUS441. These steels have issues of oxidation and Cr diffusion under the operational high temperatures, which can cause serious deterioration of the cathode performance. In order to improve the electrode stability and the oxidation resistivity, this work deposits Cu–Co oxide coating on SUS441 interconnects via room-temperature supersonic spray using fine CuCo2O4 spinel-based oxide powders synthesized via a combustion process. The coating can significantly inhibit the growth of chromium oxide scale on the steel surface and increase the interconnect conductivity by a factor of 4.4 in 200-hr oxidation test in air. The coating effectively prevents Cr diffusion to the cell composed of La0·6Sr0·4FeO3-δ electrode and La0·8Sr0.2Ga0.8Mg0·2O3-δ electrolyte. As a result, the coating substantially increases the cathode performance by reducing the interfacial polarization resistance and improving the stability in 100-hr test at 800 °C. This study demonstrates that this high-performance protective Cu–Co oxide coating has a promising application prospect for SOFC interconnects.

In situ self-assembled NdBa0.5Sr0.5Co2O5+δ/Gd0.1Ce0.9O2-δ hetero-interfaces enable enhanced electrochemical activity and CO2 durability for solid oxide fuel cells

The development of solid oxide fuel cells (SOFCs) faces impediments in terms of challenges associated with oxygen reduction activity and CO2 durability. Therefore, a series of novel composite cathode materials, consisting of NdBa0.5Sr0.5Co2O5+δ (NBSC) and Gd0.1Ce0.9O2-δ (GDC), were designed and synthesized using a one-pot strategy through a self-assembly process. The incorporation of GDC leads to a significant increase in the number of active sites. Furthermore, it alters the anisotropic transport properties of oxygen ions within layered double perovskite materials, consequently creating a three-dimensional conduit for O2– transportation. Simultaneously, the in-situ formation of closely intertwined heterogeneous interfaces between NBSC and GDC particles can facilitate the charge transfer processes and oxygen ion transport, thereby improving the kinetics of the oxygen reduction reaction (ORR). The NBSC-10GDC cathode, prepared through the one-pot method, exhibits reduced polarization resistances and enhanced CO2 tolerance in comparison to the mechanically mixed cathode. At 750 °C, the one-pot NBSC-10GDC exhibits a low area-specific resistance (ASR) of 0.029 Ω cm2, which is 69.8% lower than the ASR of single-phase NBSC and 42.0% lower than mechanically mixed NBSC-10GDC. Additionally, the one-pot NBSC-10GDC demonstrates a remarkable maximum power density (MPD) of 1.36 W cm−2 at 750 °C. These findings highlight the considerable potential of the one-pot NBSC-10GDC as a promising material for SOFC cathode.

Surface electron modulation of metal oxide‐based electrochemical devices by surface additives—linking sensors and fuel cells

AbstractThe interaction between ambient oxygen and the metal oxide surface is central to various electrochemical devices. Solid oxide fuel cell cathodes and semiconducting metal oxide gas sensors are two prominent examples. Parallels between these two systems are highlighted in this perspective. In both cases, the presence of foreign surface species has been found to significantly alter the interactions of the metal oxides’ surfaces with oxygen. On the one hand, interactions are hindered due to the presence of certain impurities, such as the degradation of fuel cell cathode by Si‐species that originate from processing or from operating environments. On the other hand, electrochemically active noble metal additives have been intentionally used to tune the sensor response of metal oxides. In the case of electrochemically active additives, the need for operando spectroscopies to elucidate the mechanism is discussed. Electronic coupling of the surface additive with the metal oxide is found to play a central role in both cases. We use these results to demonstrate that insights gained from either field can be effectively applied to the other.