Area Specific Resistance Research Articles

Low Area Specific Resistance La-Doped Bi2O3 Nanocomposite Thin Film Cathodes for Solid Oxide Fuel Cell Applications.

In the context of solid oxide fuel cells (SOFCs), vertically aligned nanocomposite (VAN) thin films have emerged as a leading material type to overcome performance limitations in cathodes. Such VAN films combine conventional cathodes like LaxSr1-xCoyFe1-yO3 (LSCF) and La1-xSrxMnO3 (LSM) together with highly O2- ionic conducting materials including yttria-stabilized zirconia (YSZ) or doped CeO2. Next-generation SOFCs will benefit from the exceptionally high ionic conductivity (1 S cm-1 at 730 °C) of Bi2O3-based materials. Therefore, an opportunity exists to develop Bi2O3-based VAN cathodes. Herein, we present the first growth and characterization of a Bi2O3-based VAN cathode, containing epitaxial La-doped Bi2O3 (LDBO) columns embedded in a LSM matrix. Our novel VANs exhibit low area specific resistance (ASR) (8.3 Ω cm2 at 625 °C), representing ∼3 orders of magnitude reduction compared to planar LSM. Therefore, by demonstrating a high-performance Bi2O3-based cathode, this work provides an important foundation for future Bi2O3-based VAN SOFCs.

Self-assembled composite cathode material Pr0.5In0.5BaCo3ZnO7+δ for solid oxide fuel cells

In this study, Pr0.5In0.5BaCo3ZnO7+δ (PIBCZ) is synthesised by the high-temperature solid state reactions method as a cathode material for solid oxide fuel cells (SOFCs). Interestingly, a self-assembled composite cathode with three phases of Pr0.5-xIn0.5+xBaCo3ZnO7+δ (P0.5-xI0.5+xBCZ), PrBaCo2O5+δ and CoO is formed by one pot methode. The average thermal expansion coefficient (TEC) of PIBCZ in air is 14.0 × 10−6 K−1 in the temperature range of 20–900 °C, and its electrical conductivity reaches 20.8 S cm−1 at 800 °C. The area specific resistance (ASR) and maximum power density (MPD) reach 0.02 Ω cm2 and 435 mW cm−2 at 800 °C, respectively.

An advanced bifunctional single-element-incorporated ternary perovskite cathode for next-generation fuel cells

Bifunctional perovskite oxides are widely considered to be promising cathode materials for the commercialization of fuel cells, with cobalt-rich variants traditionally preferred. However, challenges such as instability at elevated temperatures and high cost hinder their commercial viability. To address these issues, this study successfully develops a high-performance, cobalt-free ternary cathode material, Ba0.95Pr0.05FeO3-δ (BP5F), by substituting a small amount of Pr into the A-site of the perovskite parent BaFeO3-δ (BF), tailored for bifunctional applications in both solid oxide fuel cells (SOFCs) and protonic ceramic fuel cells (PCFCs). The incorporation of Pr not only optimizes the crystal phase structure but also enhances the oxygen vacancy concentration and triple-conducting capabilities of BP5F. Consequently, this cathode material exhibits remarkable electrocatalytic activity at intermediate-to-low temperatures (ILT, 400–700 °C), with ultra-low area specific resistances of just 0.028 and 0.134 Ω cm2 at 600 °C in symmetrical cells with oxygen ion- and proton-conducting electrolytes, respectively. Correspondingly, in single cells, the peak power densities reach up to 1.528 and 1.135 W cm−2. Furthermore, BP5F demonstrates exceptional long-term durability, operating stably for over 100 h at 600 °C in both SOFC and PCFC single cells. These performance metrics position BP5F among the best-performing ternary perovskite oxides to date. Experimental results combined with theoretical calculations validate the critical role of Pr, establishing BP5F as a highly promising and economically viable bifunctional candidate perovskite cathode, thus providing a significant step towards the commercial development of fuel cell technologies.

Oxidation kinetics and electrical properties of oxide scales formed under exposure to air and Ar–H2-H2O atmospheres on the Crofer 22 H ferritic steel for high-temperature applications such as interconnects in solid oxide cell stacks

A 100 h isothermal oxidation kinetics study for Crofer 22H was conducted in air and the Ar–H2-H2O gas mixture (p(H2)/p(H2O) = 94/6) in the range of 973–1123 K. The parabolic rate constant was independent of oxygen partial pressure in the range from 6.2 × 10−24 to 0.21 atm at 1023 and 1073 K, while at 973 and 1123 K it was higher in air than in Ar–H2-H2O. The scales consisted of Cr2O3 and manganese chromium spinel with an Mn:Cr ratio dependent on the oxidation conditions. Cross-scale resistance was evaluated with regards to the application of the steel in solid oxide fuel cells using a number of methods, including X-ray diffraction, scanning electron microscopy, confocal Raman imaging and area-specific resistance measurements.

Performance Prediction of High-Entropy Perovskites La0.8Sr0.2MnxCoyFezO3 with Automated High-Throughput Characterization of Combinatorial Libraries and Machine Learning.

Perovskite oxides form a large family of materials with applications across various fields, owing to their structural and chemical flexibility. Efficient exploration of this extensive compositional space is now achievable through automated high-throughput experimentation combined with machine learning. In this study, we investigate the composition-structure-performance relationships of high-entropy La0.8Sr0.2MnxCoyFezO3±𝞭 perovskite oxides (0 < x, y, z <1; x+y+z≈1) for application as oxygen electrodes in Solid Oxide Cells. Following the deposition of a continuous compositional map using thin-film combinatorial pulsed laser deposition, compositional, structural, and performance properties are characterized using six different techniques with mapping capabilities. Random forests effectively model electrochemical performance, consistently identifying Fe-rich oxides as optimal compounds with the lowest area-specific resistance values for oxygen electrodes at 700 °C. Additionally, the models identify a statistical correlation between oxygen sublattice distortion-derived from spectral analysis of Raman-active modes-and enhanced performance.

Electrochemical characterization of Bi3Ru3O11 – 40 wt% Bi1.6Er0.4O3 as an EOG electrode material

This paper reports on the study of the electrochemical behavior of porous Bi3Ru3O11 – 40 wt% Bi1.6Er0.4O3 electrodes on a Bi2O3 – 10 wt% Bi24B2O39 electrolyte in a symmetric cell configuration by impedance spectroscopy. The dependence of the area specific resistance (ASR) for electrode polarization on the partial pressure of oxygen replaced from PO2−1/2 to PO2−3/4 with decreasing thickness of the layer, which inhibited wetting. This indicates a change in the rate-limiting oxidation-reduction reactions of oxygen. It is assumed that the dissociation of adsorbed oxygen molecules on the active catalytic centers of the triple phase boundary (TPB) is the limiting stage of a surface oxygen exchange, and with a decrease in the layer thickness, additional difficulty in the transfer of gaseous oxygen molecules from the gas phase to these active catalytic centers is observed.

Communication—Prediction of Area Specific Resistance of Solid Oxide Cell Stacks from Electrochemical Impedance Spectra

A support vector regression model was trained to predict the area specific resistance of solid oxide cell stacks from electrochemical impedance spectroscopy measurements. In particular, the minimum necessary frequency range required for accurate predictions was investigated. Therefore, 711 pairs of DC polarization and electrochemical impedance spectroscopy measurements, conducted at the same stage of stack degradation and under similar measurement conditions, were evaluated. Prediction accuracies of less than 8% mean absolute percentage error and coefficients of determination greater than 93% were achieved. The 101–102 Hz range is sufficient for accurate predictions, allowing an efficient and non-destructive etimation of DC polarization measurements.

Characterization of Oxygen Diffusion and Catalytic Behavior of Composite Materials in Solid Oxide Fuel Cells Using the Non-destructive Adler-Lane-Steele Method

Solid oxide fuel cells (SOFCs) are technologically interesting because they provide high-efficiency energy conversion via an electrochemical reaction within the cells. To bring SOFC to market, researchers must develop highly electroactive, low-cost devices that are chemically stable in both high (800 – 1000 °C) and low (600 – 800 °C) temperatures, as well as optimize oxygen reduction in electrodes. The electrochemical performance of SOFC is highly dependent on the catalytic activity (or catalyst behaviours) of the electrode materials involved in the oxygen reduction reaction due to the slower oxygen reduction kinetics at lower temperatures. Understanding the fundamental properties of oxygen self-diffusion in solid-state ionic systems is critical for developing nextgeneration electrolyte and electrode material compositions and microstructures that enable SOFCs to operate at lower temperatures more effectively, durably, and affordably. To date, the most common method for evaluating electrocatalytic performance is electrochemical impedance spectroscopy (EIS), which causes sample damage due to its set-up procedure. As a result, modelling approaches have been used to better understand the reaction mechanism, oxygen diffusion coefficient, and kinetics of SOFC electrode reactions, including the mixed ionic electronic conductor (MIEC)-based electrode. Several models have recently been developed to represent the reaction mechanisms of SOFCs, with Adler-Lane-Steele (ASL) mathematical theory believed to be suitable for predicting oxygen gas diffusion through the pores of the MIEC-based materials. Hence, the aim of this paper is to validate the area-specific resistance of composite electrodes using the ASL modeling technique rather than the standard EIS analysis. The findings are significant in contributing to the development of a new non-destructive method for analyzing the catalytic behavior of SOFC components.

An active and durable ammonia cracking layer for direct ammonia protonic ceramic fuel cells

Ammonia protonic ceramic fuel cells (NH3-PCFCs) are highly appealing energy conversion technologies due to their high efficiency, environmental responsibility, and benign safety features. Nonetheless, progress in NH3-PCFCs is notably impeded by the restricted performance and insufficient lifespan of standard Ni-cermet anodes for ammonia cracking, especially at 550 °C or below. Herein, we report an efficient ammonia cracking layer with a formula of xCo3O4/100-xBaZr0.8Y0.2O3-δ (Co/BZY) (x=10, 20, 30), which is deposited onto the Ni-BaZr0.1Ce0.7Y0.1Yb0.1O3−δ (BZCYYb) anode to significantly enhance the NH3 decomposition catalytic activity, thereby improving the performance and durability of NH3-PCFCs at low temperatures. The cells with the addition of a 20Co/80BZY anode catalytic layer (ACL) exhibit low area-specific resistance (ASR) and promising operational longevity under NH3 conditions. At 550°C, the NH3-PCFCs with a 20Co/80BZY ACL exhibit a high peak power density of 0.626 W cm−2 and promising operation durability. This study provides important guidance for constructing high-performance and durable NH3-PCFCs.

An active and durable perovskite electrode with reversibly phase transition-induced exsolution for protonic ceramic cells

Protonic ceramic cells (PCCs) possess great application potential, attributed to their cleanliness and high energy conversion efficiency. However, designing active air electrodes with both high stability is challenging. Herein, we report a nanospinel-modified perovskite oxide, Nd0.5Ba0.5Mn0.7Co0.15Ni0.15O3−δ-(CoxNiy)3O4 (CNO@NBMCN), obtained by a reversibly phase transition-induced exsolution process, as a highly active and durable air electrode for PCCs. Phase-field simulations reveal the intrinsic mechanism of nanoparticles strongly pinning to the substrate in a high-temperature oxidizing environment. The CNO@NBMCN electrode exhibits remarkable low area specific resistance (0.38 Ω cm2 at 600 °C) and exceptional stability (degradation rate 0.01 % h−1). It is confirmed by soft X-ray absorption spectroscopy that the construction of the heterostructure leads to more distortion in Mn–O octahedra and weaker metal–oxygen bonds, thereby contributing to the formation of oxygen vacancies. And the exceptionally high durability supported by both fast ion surface exchange and charge transfer at triple-phase boundaries. A single cell with the CNO@NBMCN air electrode achieves outstanding performances in the fuel cell (peak power density of 1.28 W cm−2) and electrolysis modes (current density of −2.14 A cm−2 at 1.3 V), recorded at 700 °C. This work inspires innovative design concepts for robust heterogeneous electrocatalysts.

Design and preparation of composite bipolar plates with synergistic conductive networks of graphite and metal foam

Graphite composite bipolar plate (BP) have limited conductivity, which makes them less than ideal for extensive application in proton exchange membrane fuel cell (PEMFC). In traditional graphite composite BP, the construction process of the conductive network is entirely random. To enhance conductivity, it is typically necessary to increase the content of conductive fillers or incorporate high aspect ratio carbon nanomaterials to optimize the density of the conductive network. In this work, we manufactured a highly conductive composite bipolar plate with synergistic conductive networks of graphite and metal foam (MF). With a synergistic conductive network, the ASR of CuG80-20ppi decreased to 7.7 mΩ cm2. Additionally, thermal conductivity increased to 24.76 W/(m·K), and in-plane conductivity reached 294.1 S/cm at 80 wt% mass fractions of conductive filler, using 20 ppi copper foam as the metallic conductive network. CuG80-20ppi exhibited a flexural strength of 52.2 MPa. G80 and CuG80-20ppi have the 80 wt% conductive filler and are molded into BP with parallel flow fields. CuG80-20ppi enhances the current density of PEMFC by 0.132 W/cm2 and reduces the ohmic impedance by 5.25%. Therefore, the findings of this study offer valuable insights for the enhancement of composite BP conductivity, while simultaneously ensuring the stability and continuity of the synergistic conductive network. A novel approach is presented to enhance the electrical conductivity of graphite composite bipolar plate (BP) for proton exchange membrane fuel cells (PEMFCs). By embedding metal foam as a supplementary conductive network within the graphite matrix, a synergistic conductive architecture is achieved. This innovation significantly reduces the area specific resistance (ASR) to 7.7 mΩ cm2 and boosts thermal conductivity to 24.76 W/(m·K). The resulting CuG80-20ppi BP, with 80 wt% conductive filler, exhibits improved mechanical strength and conductivity, contributing to a 0.132 W/cm2 increase in PEMFC current density and a 5.25% reduction in ohmic impedance. This work highlights the potential of metal foam integration to enhance BP conductivity and PEMFC performance.

Electrophoretic Deposition and Physicochemical Properties of Ni- and Fe-Doped Cu–Mn Spinel Coatings Enhanced with Ce0.9Y0.1O2 Nanoparticles on Fe16Cr Ferritic Stainless Steel Interconnects for SOEC Applications

Cu- and Mn-based spinel coatings are currently among the most promising materials for solid oxide electrolyzer cell (SOEC) interconnects due to their high electrical conductivity and ability to eliminate environmentally hazardous cobalt, which is included in the most widely used coatings. However, their properties are affected by the presence of the Cr2O3 scale and high-temperature corrosion, and to mitigate this they could be doped with elements such as Ni and Fe. In addition, the electrical properties of such steel/shell layered systems can be further improved using rare-earth element nanoparticles (Ce0.9Y0.1O2). In this work, low-chromium steel was modified using nanoparticles and/or spinel coatings and oxidized in air atmosphere at 800 °C for 2000 hours. The oxidized systems were then characterized using diffraction studies, microstructural observations and electrical measurements. Electrical studies in particular showed a significant reduction in area-specific resistance for steels modified using a combination of both nanoparticles and spinel coatings.

A novel Co-free and efficient Pr0.5Ba0.5Fe0.8Cu0.2O3-δ nanofiber cathode material for intermediate temperature solid oxide fuel cells

Fe-based perovskite without Co has a low thermal expansion coefficient and can be used as a solid oxide fuel cell (SOFC) cathode to ensure the thermal compatibility with the electrolyte; however, its further advancement is impeded by sluggish oxygen reduction reaction (ORR) dynamics. In this work, the electrospinning method and Cu doping strategy are employed to improve the microstructure and oxygen reduction kinetics of Pr0.5Ba0.5FeO3-δ cathodes. The results show that Pr0.5Ba0.5Fe0.8Cu0.2O3-δ has a unique fiber structure and high specific surface area, and the introduction of Cu facilitates the release of lattice oxygen, effectively increasing the oxygen vacancy content. The relaxation time distribution analysis and oxygen reduction reaction dynamics indicate that the oxygen adsorption-dissociation process is the main rate-limiting step in the oxygen reduction reaction of Pr0.5Ba0.5Fe0.8Cu0.2O3-δ electrode materials. At 700 °C, the area-specific resistance (ASR) of the symmetric cell of Pr0.5Ba0.5Fe0.8Cu0.2O3-δ fiber material is 0.071 Ω cm2, and the power density of the single cell reaches 988 mW cm−2, which shows good electrochemical output performance and long-term operational stability. The preparation of nanofiber cathodes with high specific surface area and porosity by electrospinning provides an effective strategy to enhance the electrocatalytic activity of the IT-SOFC cathode.

A new Co‐based cathode with high performance for intermediate‐temperature solid oxide fuel cells

AbstractSolid oxide fuel cells (SOFCs) as highly effective energy conversation devices have gained substantial recognition and research interest. The electrochemical properties of the traditional SOFCs are restricted by the sluggish reaction kinetics for the cathode material when lowering the operation temperature to below 600°C. In addition, the stability of the cathode at reduced temperatures is also a big challenge for the widely popularization of SOFC technology. Achieving high activities and stable ORR in the cathode is crucial for the development of SOFCs. The doping active metal method has been demonstrated as an effective approach to optimize the phase structure and improve the ORR activity of the cathode. Herein, we successfully develop an Ir‐doped SrCoO3 − δ (SrCo0.98Ir0.02O3 − δ, SCI) cathode for SOFCs. SCI exhibits a low area‐specific resistance (ASR) of 0.057 Ω cm2 at 650°C, ~ 44% lower than 0.102 Ω cm2 of Ir‐free SrCoO3 − δ. The Ni–Sm0.2Ce0.8O1.90 (SDC) anode‐supported fuel cell with SDC electrolyte and SCI cathode obtains an excellent output performance (e.g., 1,128 mW cm−2 at 650°C). The desired results underscore the feasibility of the Ir‐doping strategy as an optimized method for the exploitation of advancing cathode in SOFCs.

Effects of Pr substitution in Y1-xPrxBaCo3ZnO7+δ (0 ≤ x ≤ 0.5) cathodes for intermediate temperature solid oxide fuel cells

In this investigation, we successfully synthesized a series of Swedenborgite-type Y1-xPrxBaCo3ZnO7+δ (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5, abbreviated as YPxBCZ) oxides by a solid-state reaction method. The results show that YPxBCZ (x = 0.0, 0.1, 0.2, and 0.3) are single-phase structures, but YP0.4BCZ and YP0.5BCZ show interesting self-assembled composite phases. After long-term phase stability testing, YP0.3BCZ showed the best thermal stability. All samples show good chemical and thermal compatibility with La0.9Sr0.1Ga0.8Mg0.2O3-δ electrolyte. The thermal expansion coefficients in the temperature range from 30 °C to 1000 °C are equal to 9.8-13.1 × 10−6 K−1, close to that of the LSGM electrolyte. It is also found that Pr doping improves high temperature conductivity of YPxBCZ. The conductivity of YP0.3BCZ, YP0.4BCZ, and YP0.5BCZ reach 15.1, 18.5, and 22.5 S cm−1 at 800 °C. In addition, the area specific resistance (ASR) value decreases as the Pr content increases (0.038, 0.033, and 0.027 Ω cm2 at 800 °C for YP0.3BCZ, YP0.4BCZ, and YP0.5BCZ), improving the catalytic activity of the material. Another interesting finding was that the ASR of samples subjected to high temperature thermal decomposition was not adversely affected by the presence of decomposition products. The maximum power densities of YP0.3BCZ, YP0.4BCZ, and YP0.5BCZ in the single cells at 800 °C were 845, 930, and 1044 mW cm2, respectively. These results indicate that YP0.3BCZ, YP0.4BCZ, and YP0.5BCZ are promising cathode materials for intermediate-temperature solid oxide fuel cell.

Electrospinning of Sm0.5Sr0.5CoO3-δ nanofiber cathode for solid oxide fuel cells

Sm0.5Sr0.5CoO3-δ (SSC) fiber-electrode materials were prepared via electrospinning in this work. The characteristics of SSC fibers are influenced by the parameters of electrospinning, specifically the nitrate concentration of the spinning solution, applied voltage, and the gap between the spinneret and collector. The as-prepared SSC fibers exhibited average diameters ranging from 240 nm to 6.49 μm, which contracted to 50 nm–2.53 μm after calcination at 800 °C. Symmetric cells with SSC fiber-electrodes demonstrated an area-specific resistance (ASR) ranging from 0.212 to 0.508 Ω cm2 at 700 °C in air. In addition to the morphology of SSC fibers, the average grain size of the SSC fibers also exhibited potential influence on their ASR performance.

An Analytical Model for Electrochemical Tubular Flow Reactors

This paper introduces the first analytical model designed for tubular electrochemical flow reactor, enabling a detailed examination of how reactor geometry and material selection impact performance. The model revealed that certain conditions, such as high electrode resistance relative to charge transfer, electrolyte, and separator resistance, can lead to uneven current distributions and reduced electrode utilization. The model highlights a critical electrode radius, dependent on reactor geometry and material properties, that minimizes the Area Specific Resistance (ASR) while minimizing reactor size. Additionally, it was found that the ASR increases with reactor length, but this effect can be mitigated by using highly conductive electrodes, thus allowing for enhanced power output. These insights provide a foundation for future research and the development of more efficient tubular reactor designs.

An efficient electrode for reversible oxygen reduction/evolution and ethylene electro-production on protonic ceramic electrochemical cells

Protonic ceramic electrochemical cells (PCECs) have demonstrated great promise for applications in the generation of electricity, and the synthesis of chemicals (for example, ethylene). However, enhancing the electrochemical reactions kinetics and stability of PCECs electrodes is one grand challenge. Here, we present a novel electrode material via a co-doping of cesium (Cs) and niobium (Nb) on PrBaCo2O6−δ with the composition of PrBa0.9Cs0.1Co1.9Nb0.1O6−δ (PBCCN), which naturally decomposes into dual phases of a double-perovskite PBCCN (DP-PBCCN, ∼92.3 wt%) and a single-perovskite Ba0.9Cs0.1Co0.95Nb0.05O3−δ (SP-BCCN, ∼7.7 wt%) under typical powder processing conditions. PBCCN exhibits a low area-specific resistance (ASR) value of 0.107 Ω cm2, an outstanding performance of 2.04 W cm−2 in fuel cell (FC) mode, a current density of −2.84 A cm−2 at 1.3 V in electrolysis cell (EC) mode, and promising reversible operational durability of 53 cycles in ∼212 h at +/− 0.5 A cm−2 and 650 °C. Cs doping generates more oxygen vacancies and accelerates the oxygen exchange kinetics, while Nb doping effectively enhances the stability, as illustrated by the analyses of X-ray photoelectron spectroscopy, and electrical conductivity relaxations. When applied as the positrode for electrochemical non-oxidative dehydrogenation of ethane (C2H6) to ethylene (C2H4) on PCECs, it displays an encouraging C2H6 conversion of 12.75% and a C2H4 selectivity of 98.4% at 1.2 V.

Ultralong lifespan solid-state sodium battery with a supersodiophilic and fast ionic conductive composite sodium anode

Solid-state sodium batteries (SSNBs) are considered as a promising alternative to organic liquid-based batteries due to their excellent safety, high energy density and cost-effectiveness. However, SSNBs suffer from undesirable interfacial contact between Na and solid-state electrolytes such as NASICON-type Na3Zr2Si2PO12 (NZSP), dendritic growth and dramatic volume changes during cycling, which hinder their development towards actual applications. Herein, dendrite-free composite-type Na/NZSP module with ultrafast built-in ionic conductive framework is designed to promote the Na diffusion kinetics, partially restrict the volume effect, and simultaneously improve the wettability towards NZSP. Thanks to the unique module with supersodiophilic property, the thus-made all-solid-state Na-symmetric cells offer a reduced area specific resistance by more than two orders of magnitudes (from 1774.0 Ω cm2 for the pristine Na/NZSP to 14.1 Ω cm2 for the composite-type Na/NZSP module) and endow an ultralong lifespan of 7800 h at room temperature. Moreover, a full SSNB coupling with the Na/NZSP module and Na3V2(PO4)3 cathode achieves extremely long and stable cycling of more than 5760 cycles at 1.0 C with 87.9 % of capacity retention and high-rate capability at 3.0 C, being among the best achievements reported so far. The findings open a new window of composite-type Na/NZSP module design for high-performance SSNBs.

An Efficient Trifunctional Spinel-Based Electrode for Oxygen Reduction/Evolution Reactions and Nonoxidative Ethane Dehydrogenation on Protonic Ceramic Electrochemical Cells.

Protonic ceramic electrochemical cells (PCECs) have received considerable attention as they can directly generate electricity and/or produce chemicals. Development of the electrodes with the trifunctionalities of oxygen reduction/evolution and nonoxidative ethane dehydrogenation is yet challenging. Here these findings are reported in the design of trifunctional electrodes for PCECs with a detailed composition of Mn0.9Cs0.1Co2O4-δ (MCCO) and Co3O4 (CO) (MCCO-CO, 8:2 mass ratio). At 600°C, the MCCO-CO electrode exhibits a low area-specific resistance of 0.382 Ω cm2 and reasonable stability for ≈105h with no obvious degradation. The single cell with the MCCO-CO electrode shows an encouraging peak power density of 1.73W cm-2 in the fuel cell (FC) mode and a current density of -3.93 A cm-2 at 1.3V in the electrolysis cell (EC) mode at 700°C. Moreover, the MCCO-CO cell displays promising operational stability in FC mode (223h), EC mode (209h), and reversible cycling stability (52 cycles, 208h) at 650°C. The MCCO-CO single cell shows an encouraging ethaneconversion to ethylene (with a conversion of 40.3% and selectivity of 94%) and excellent H2 production rates of 4.65mL min-1 cm-2 at 1.5V and 700°C, respectively, with reasonable Faradaic efficiencies.