Sm0.5Sr0.5CoO3–Ce1.8Sm0.2O1.9 electrodes enhanced by Sm0.5Sr0.5CoO3 impregnation for proton conductor based solid oxide fuel cells

Sm_0.5Sr_0.5CoO_3−δ–Ce_0.8Sm_0.2O_2−δ (SSC–SDC) composites, which are often used as the cathodes for solid oxide fuel cells (SOFCs) with oxygen-ion conducting electrolytes, have been recently shown to be also applicable in SOFCs based on proton conductors such as BaZr_0.1Ce_0.7Y_0.2O_3−δ (BZCY). The electrochemical performances of blank SSC–SDC electrodes on BZCY electrolytes are substantially improved in this work by impregnating SSC nanoparticles additionally. When the loading increases, the interfacial polarization resistance of the symmetric cell decreases gradually at first, notably when it exceeds 14 wt.%, and to the lowest value at about 22 wt.%. Furthermore, impregnating SSC reduces the low-frequency-arc resistance that corresponds to the surface exchange step. In addition, impregnating SSC reduces the activation energy for oxygen reduction from 1.14 to 0.70 eV, thus resulting in significantly improvement on electrode performance at the reduced temperatures for SOFCs based on proton conductors.     

Cathode reaction mechanism of porous-structured Sm0.5Sr0.5CoO3−δ and Sm0.5Sr0.5CoO3−δ/Sm0.2Ce0.8O1.9 for solid oxide fuel cells

The cathode reaction mechanism of porous Sm_0.5Sr_0.5CoO_3−δ, a mixed ionic and electronic conductor (MIEC), is studied through a comparison with the composite cathode Sm_0.5Sr_0.5CoO_3−δ/Sm_0.2Ce_0.8O_1.9. First, the cathodic behaviour of porous Sm_0.5Sr_0.5CoO_3−δ and Sm_0.5Sr_0.5CoO_3−δ/Sm_0.2Ce_0.8O_1.9 are observed for micro-structure and impedance spectra according to Sm_0.2Ce_0.8O_1.9 addition, thermal cycling and long-term properties. The cathode reaction mechanism is discussed in terms of frequency response, activation energy, reaction order and electrode resistance for different oxygen partial pressures p(O₂) at various temperatures. Three elementary steps are considered to be involved in the cathodic reaction: (i) oxygen ion transfer at the cathode-electrolyte interface; (ii) oxygen ion conduction in the bulk cathode; (iii) gas phase diffusion of oxygen. A reaction model based on the empirical equivalent circuit is introduced and analyzed using the impedance spectra. The electrode resistance at high frequency (R_c,HF) in the impedance spectra represents reaction steps (i), due to its fast reaction rate. The electrode resistance at high frequency is independent of p(O₂) at a constant temperature because the semicircle of R_c,HF in the complex plane of the impedance spectra is held constant for different values of p(O₂). Reaction steps (ii) and (iii) are the dominant processes for a MIEC cathode, according to the analysis results. The proposed cathode reaction model and results for a solid oxide fuel cell (SOFC) well describe a MIEC cathode with high ionic conductivity, and assist the understanding of the MIEC cathode reaction mechanism.     

Characterization of La0.5Sr0.5Co0.5Ti0.5O3−δ as symmetrical electrode material for intermediate-temperature solid-oxide fuel cells

La_0.5Sr_0.5Co_0.5Ti_0.5O_3−δ perovskite oxide has been prepared as polycrystalline powder, characterized and tested as cathode and anode material for solid-oxide fuel cells. The oxidized material is suggested to present mixed ionic-electronic conductivity (MIEC) from “in-situ” neutron powder diffraction (NPD) experiments, complemented with transport measurements; the presence of a sufficiently high oxygen deficiency, with large displacement factors for oxygen atoms suggest a large lability and mobility combined with a semiconductor-like behaviour with a maximum conductivity of 29 S cm⁻¹ at T = 850 °C. A complete reversibility towards reduction–oxidation processes has been observed, where the reduced Pm-3m perovskite with La_0.5Sr_0.5Co_0.5Ti_0.5O_2.64 composition has been obtained by topotactical oxygen removal without abrupt changes in the thermal expansion. The oxidized material shows good performance working as a cathode with LSGM electrolyte, yielding output power densities close to 500 mW/cm² at 850 °C. At intermediate temperatures (800 °C) it may be used as a cathode or as an anode, yielding power densities of 220 and 170 mW/cm², respectively. When used simultaneously as cathode and anode a maximum power density of 110 mW/cm² was obtained. Therefore, we propose the La_0.5Sr_0.5Co_0.5Ti_0.5O_3−δ composition as a promising candidate for symmetrical electrode in intermediate-temperature SOFC.     

Nanostructured palladium–La0.75Sr0.25Cr0.5Mn0.5O3/Y2O3–ZrO2 composite anodes for direct methane and ethanol solid oxide fuel cells

A palladium-impregnated La_0.75Sr_0.25Cr_0.5Mn_0.5O_3−δ/yttria-stabilized zirconia (LSCM/YSZ) composite anode is investigated for the direct utilization of methane and ethanol fuels in solid oxide fuel cells (SOFCs). Impregnation of Pd nanoparticles significantly enhances the electrocatalytic activity of LSCM/YSZ composite anodes for the methane and ethanol electrooxidation reaction. At 800 °C, the maximum power density is increased by two and eight times with methane and ethanol fuels, respectively, for a cell with the Pd-impregnated LSCM/YSZ composite anode, as compared with that using a pure LSCM/YSZ anode. No carbon deposition is observed during the reaction of methane and ethanol fuels on the Pd-impregnated LSCM/YSZ composite anode. The results show the promises of nanostructured Pd-impregnated LSCM/YSZ composites as effective anodes for direct methane and ethanol SOFCs.     

Intermediate-to-low temperature protonic ceramic membrane fuel cells with Ba0.5Sr0.5Co0.8Fe0.2O3-δ–BaZr0.1Ce0.7Y0.2O3-δ composite cathode

The perovskite-type Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ–BaZr_0.1Ce_0.7Y_0.2O_3-δ (BSCF–BZCY) composite oxides were synthesized by a modified Pechini method and examined as a novel composite cathode for intermediate-to-low temperature protonic ceramic membrane fuel cells (ILT-PCMFCs). Thin proton-conducting BaZr_0.1Ce_0.7Y_0.2O_3-δ (BZCY) electrolyte and NiO–BaZr_0.1Ce_0.7Y_0.2O_3-δ (NiO–BZCY) anode functional layer were prepared over porous anode substrates composed of NiO–BaZr_0.1Ce_0.7Y_0.2O_3-δ by a one-step dry-pressing/co-firing process. A laboratory-sized quad-layer cell of NiO–BZCY/NiO–BZCY(∼50 μm)/BZCY(∼20 μm)/BSCF–BZCY(∼50 μm) was operated from 550 to 700 °C with humidified hydrogen (∼3% H₂O) as fuel and the static air as oxidant. A high open-circuit potential of 1.009 V, a maximum power density of 418 mW cm⁻², and a low polarization resistance of the electrodes of 0.10 Ω cm² was achieved at 700 °C. These investigations have indicated that proton-conducting BZCY electrolyte with BSCF perovskite cathode is a promising material system for the next generation solid oxide fuel cells (SOFCs).     

Interaction of La0.8Sr0.2MnO3 interlayer with Gd0.1Ce0.9O1.95 electrolyte membrane and Ba0.5Sr0.5Co0.8Fe0.2O3−δ cathode in low-temperature solid oxide fuel cells

Low-temperature solid oxide fuel cells with a La_0.8Sr_0.2MnO₃ (LSM) interlayer between the Ce_0.9Gd_0.1O_1.95 (GDC) electrolyte membrane (20 μm) and the Ba_0.5Sr_0.5Co_0.8Fe_0.2O₃ (BSCF)–GDC composite cathode are fabricated by sintering the BSCF–GDC composite cathodes at 900, 950 and 1000 °C. The results of scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX) for a model LSM/BSCF bi-layer pellet suggest that Ba, Co and Fe in BSCF as well as La and Mn in LSM have diffused into their counter sides. The X-ray diffraction (XRD) results on the simulated cells also indicate the incorporation of La into the GDC electrolyte membrane and the mutual diffusion of elements between the LSM layer and the BSCF layer. Analysis of the impedance spectra and interfacial reaction activation energies shows that LSM interlayer accelerates the oxygen reduction. Considering a good cell performance and the highest open-circuit voltages (OCVs) at 600–500 °C, the optimum sintering temperature of BSCF–GDC composite cathode onto LSM interlayer is 900 °C.     

Cobalt-impregnated La0.75Sr0.25Cr0.5Mn0.5O3−δ anodes for solid oxide fuel cells

In this study, we will report our investigation for La_0.75Sr_0.25Cr_0.5Mn_0.5O_3−δ (LSCrM) based anodes impregnated with solutions of cobalt (Co) nitrate. A YSZ supported SOFC with pure LSCrM anode and La_0.7Sr_0.3MnO₃ (LSM) cathode exhibits the maximum power density (P_max) of 58.7 and 5.2 mW cm⁻² at 850 °C in dry H₂ and dry CH₄. After the modification of anode with Co nitrate, the P_max reaches 196.2 mW cm⁻² in dry H₂ and 28.5 mW cm⁻² in dry CH₄, about 3.34 times and 5.48 times increase, respectively. These results indicate that Co is also a potential catalyst for LSCrM anode. Moreover, the effect of impregnation amount of catalyst on the cell performance is also evaluated in this study.     

Electrochemical properties of ceramic membranes based on SrTi0.5Fe0.5O3−δ in reduced atmosphere

The present work aims at the investigation of the electrochemical properties of SrTi_0.5Fe_0.5O_3−δ as a membrane material for hydrogen production via electrochemical reforming. The dependence of the electrical conductivity on the oxygen partial pressure, as well as the oxygen permeability in the range of 10⁻²⁰ atm ≤ pO₂$p_{{\text{O}}_2}$ ≤ 10⁻¹⁴ atm is examined. The oxygen permeability is measured by an electrochemical method. The dependences of ion current as a function of the electromotive force (EMF) at various temperatures, oxygen partial pressures and the membrane surface conditions (rough and activated by PrO_x) are studied. Finally, the values of hydrogen flux at different temperatures are calculated and a long term investigation during 600 h at pO₂$p_{{\text{O}}_2}$ = 10⁻¹⁹ atm, T = 1173 K is carried out. According to the present results, the permeation current increases with the increase of temperature, oxygen partial pressure gradient and activation by PrO_x. The long term investigation shows that the electrical resistance of the SrTi_0.5Fe_0.5O_3−δ ceramic membrane increases by 10%, possibly due to the formation of micro-domains into the material's volume and the decrease in the grain boundary conductivity, because of the segregation of dopant-rich layers near the grain boundaries.     

Ca/Cu共掺杂的O3-NaFe0.5Mn0.5O2钠离子电池正极材料的电化学性能研究

层状过渡金属氧化物由于其较高的理论比容量和较低的经济成本,被视为一种具有良好应用前景的钠离子电池正极材料。采用溶胶-凝胶法和热处理的方式,制备Ca/Cu共掺杂的铁锰基层状氧化物(O3-Na_0.9Ca_0.05Fe_0.45Mn_0.45Cu_0.1O₂)。采用X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)等对该O3型铁锰基层状氧化物正极材料进行表征分析。结果表明,在32 mA/g电流密度下该材料具有205.2 m A·h/g的高比容量,循环50圈之后仍具有67.64%的容量保持率,在160 m A/g下循环100圈后依然具有81.4 m A·h/g的放电比容量。由于Ca的掺入,引起Na⁺空位的增加,并且Cu的掺入提高了Mn的价态,从而提高了Na⁺的扩散速率,抑制了Mn³⁺的Jahn-Teller效应,缓解了晶格应力,有效提高了材料的结构稳...     

Silver-modified Ba0.5Sr0.5Co0.8Fe0.2O3−δ as cathodes for a proton conducting solid-oxide fuel cell

Electrochemical performance of silver-modified Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ (BSCF-Ag) as oxygen reduction electrodes for a protonic intermediate-temperature solid-oxide fuel cell (SOFC-H⁺) with BaZr_0.1Ce_0.8Y_0.1O₃ (BZCY) electrolyte was investigated. The BSCF-Ag electrodes were prepared by impregnating the porous BSCF electrode with AgNO₃ solution followed by reducing with hydrazine and then firing at 850 °C for 1 h. The 3 wt.% silver-modified BSCF (BSCF-3Ag) electrode showed an area specific resistance of 0.25 Ω cm² at 650 °C in dry air, compared to around 0.55 Ω cm² for a pure BSCF electrode. The activation energy was also reduced from 119 kJ mol⁻¹ for BSCF to only 84 kJ mol⁻¹ for BSCF-3Ag. Anode-supported SOFC-H⁺ with a BZCY electrolyte and a BSCF-3Ag cathode was fabricated. Peak power density up to 595 mW cm⁻² was achieved at 750 °C for a cell with 35 μm thick electrolyte operating on hydrogen fuel, higher than around 485 mW cm⁻² for a similar cell with BSCF cathode. However, at reduced temperatures, water had a negative effect on the oxygen reduction over BSCF-Ag electrode, as a result, a worse cell performance was observed for the cell with BSCF-3Ag electrode than that with pure BSCF electrode at 600 °C.     

A cobalt-free Sm0.5Sr0.5FeO3−δ–BaZr0.1Ce0.7Y0.2O3−δ composite cathode for proton-conducting solid oxide fuel cells

A cobalt-free Sm_0.5Sr_0.5FeO_3−δ–BaZr_0.1Ce_0.7Y_0.2O_3−δ (SSF–BZCY) was developed as a composite cathode material for proton-conducting solid oxide fuel cells (H-SOFC) based on proton-conducting electrolyte of stable BZCY. The button cells of Ni-BZCY/BZCY/SSF–BZCY were fabricated and tested from 550 to 700 °C with humidified H₂ (～3% H₂O) as a fuel and ambient oxygen as oxidant. An open-circuit potential of 1.024 V, maximum power density of 341 mW cm⁻², and a low electrode polarization resistance of 0.1 Ω cm² were achieved at 700 °C. The experimental results indicated that the SSF–BZCY composite cathode is a good candidate for cathode material.     

Sm0.5Sr0.5Co0.4Ni0.6O3−δ–Sm0.2Ce0.8O1.9 as a potential cathode for intermediate-temperature solid oxide fuel cells

The mixed ionic and electronic conductors (MIECs) of Sm_0.5Sr_0.5Co_0.4Ni_0.6O_3−δ (SSCN)–Sm_0.2Ce_0.8O_1.9 (SDC) were investigated for potential application as a cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs) based on an SDC electrolyte. Electrochemical impedance spectroscopy (EIS) technique was performed over the temperature range of 600–850 °C to determine the cathode polarization resistance which is represented by area specific resistance (ASR). To investigate the ORR mechanism, the impedance diagram for 70SSCN–30SDC was measured under applied cathodic voltage from E = 0.0 to E = −0.3 V. It indicated that the charge transfer dominated the rate-determining step at the temperature of 600 °C; whereas the diffusion or dissociative adsorption of oxygen dominated the rate-determining step at the temperature of 800 °C. In this study, the exchange current density (i₀) for oxygen reduction reaction (ORR) was determined from the EIS data. The i₀ value of 70SSCN–30SDC/SDC was 187.6 mA cm⁻² which is larger than the i₀ value of 160 mA cm⁻² for traditional cathode/electrolyte, i.e. LSM/YSZ at 800 °C, indicating that the 70SSCN–30SDC composite cathode with a high catalytically active surface area could provide the oxygen reduction reaction areas not only at the triple-phase boundaries but also in the whole composite cathode.     

Stable and easily sintered (Pr0.5Nd0.5)0.7Ca0.3CrO3−δ/Sm0.2Ce0.8O1.9 composite interconnect materials for IT-solid oxide fuel cells

(Pr_0.5Nd_0.5)_0.7Ca_0.3CrO_3−δ (PNCC) interconnect materials are stable in SOFC operating conditions. To improve the sintering ability and electrical conductivity of PNCC, a composite of PNCC/SDC interconnect materials was synthesized by a sol-gel auto-ignition process. The XRD results indicate that PNCC is chemically stable against reaction with SDC at high temperatures. Additionally, SDC-doped PNCC has enhanced sintering activity and electrical conductivity compared to PNCC alone. For 5 wt.% SDC, the relative density of the sample was 95.8% after sintering at 1400 °C, and the electrical conductivity of the sample reached 59.6 S cm⁻¹ in air and 4.48 S cm⁻¹ in H₂ at 650 °C. Both of these values are higher than those of pure PNCC. The average thermal expansion coefficient of the samples is close to that of other components of SOFCs. Our results indicate that PNCC/SDC composites are promising intermediate materials for IT-SOFCs.     

Investigation of electrospun Ba0.5Sr0.5Co0.8Fe0.2O3−δ-Gd0.1Ce0.9O1.95 cathodes for enhanced interfacial adhesion

Fibrous Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3?δ-Gd_0.1Ce_0.9O_1.95 (BSCF-GDC) composite cathodes are fabricated by a facile electrospinning method. However, the electropun BSCF-GDC cathode shows poor adhesion to a GDC electrolyte because of the high shrinkage rate of the electrospun BSCF-GDC cathode during sintering. To solve this adhesion issue, mixed BSCF fiber-GDC powder cathode is investigated. As a result, mixed BSCF fiber-GDC powder cathode with an enhanced adhesion is successfully fabricated. This improvement can be attributed to the modified microstructure with the GDC powder that joins the BSCF fibers to the GDC electrolyte at the cathode and electrolyte interface. The polarization resistance of the mixed BSCF fiber-GDC powder cathode is 0.10 Ω cm², which is lower than 0.13 Ω cm² of conventional BSCF-GDC powder cathode at 700 °C. It is attributable to the improved oxygen gas and lattice oxygen diffusion, and the surface exchange of the mixed BSCF fiber-GDC powder cathode. The single cell with a mixed BSCF fiber-GDC powder cathode show 500 mW cm^?2 at 700 °C, which is 25% higher than conventional BSCF-GDC powder cathode.     

Preparation and characterization of new cobalt-free cathode Pr0.5Sr0.5Fe0.8Cu0.2O3−δ for IT-SOFC

A new cobalt-free perovskite oxide Pr_0.5Sr_0.5Fe_0.8Cu_0.2O_3−δ (PSFC) has been synthesized and evaluated as cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The chemical compatibility of PSFC with Sm_0.2Ce_0.8O_1.9 (SDC) electrolyte has be proven by XRD, and its electrical conductivity reaches the maximum value of 264.1 S cm⁻¹ at 475 °C. Symmetrical cells with the configuration of PSFC/SDC/PSFC are used for the impedance study and the polarization resistance (Rp) of PSFC cathode is as low as 0.050 Ω cm² at 700 °C. Single cells, consisting of Ni–YSZ/YSZ/SDC/PSFC structure, are assembled and tested from 550 °C to 800 °C with wet hydrogen (∼3% H₂O) as fuel and static air as oxidant. A maximum power density of 1077 mW cm⁻² is obtained at 800 °C. All the results suggest that the cobalt-free perovskite oxide PSFC is a very promising cathode material for application in IT-SOFC.     

Synthesis and characterization of Ba0.5Sr0.5Co0.8Fe0.1Ni0.1O3-δ cathode for intermediate-temperature solid oxide fuel cells

Perovskite Ba_0.5Sr_0.5Co_0.8Fe_0.1Ni_0.1O_3-δ (BSCFNi) oxide is synthesized and characterized as a cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The X-ray diffraction (XRD) spectra show that BSCFNi is chemical compatible with La_0.9Sr_0.1Ga_0.83Mg_0.17O_2.865(LSGM) electrolyte below 950 °C, but weak reaction is observed between BSCFNi cathode and Sm_0.2Ce_0.8O_1.9 (SDC) electrolyte after calcined at 950 °C for 10 h. The XPS results indicate that transition metal cations in BSCFNi sample exist two different valence states, i.e., Co^4+/3+, Fe^4+/3+ and Ni^3+/2+. The average thermal expansion coefficient (TEC) of BSCFNi is 18.7 × 10^?6 K^?1 between 200 °C and 850 °C in air. The maximum electrical conductivity reaches 35.3 Scm^?1 at 425 °C in air. The polarization resistance of BSCFNi cathode on LSGM and SDC electrolytes are 0.033 and 0.066 Ωcm² at 800 °C, respectively. The maximum power density of LSGM electrolyte-supported single cell with BSCFNi cathode reaches 690 mWcm^?2 at 800 °C. These primarily results indicate that BSCFNi is a candidate cathode material for IT-SOFCs.     

Nd0.5Sr0.5Fe0.8Cu0.2O3−δ–xSm0.2Ce0.8O1.9 cobalt-free composite cathodes for intermediate temperature solid oxide fuel cells

Cobalt-free composites Nd_0.5Sr_0.5Fe_0.8Cu_0.2O_3−δ (NSFCu)–xSm_0.2Ce_0.8O_1.9 (SDC) (x = 0–60 wt%) are investigated as IT-SOFC cathodes. The characteristic properties of cobalt-free composite cathodes comparing to cobalt-based composites are revealed. The DC conductivity and thermal expansion coefficient of the composite cathodes decrease with the content of SDC x, while the polarization resistance R_p shows the least value with addition of 40 wt% of SDC. The power density of the single cell with NSFCu-40% SDC composite cathode improved significantly compared with that of undoped NSFCu cathode, with peak values of 488, 623, 849 and 1052 mW cm⁻² at 600, 650, 700, and 750 °C, respectively. Moreover, the performance of the composite cathode is stable within testing period of 370 h at 700 °C, indicating that the NSFCu-40% SDC is an excellent cobalt-free composite cathode applied in IT-SOFC.     

LaCoO3-δ-coated Ba0.5Sr0.5Co0.8Fe0.2O3-δ: A promising cathode material with remarkable performance and CO2 resistance for intermediate temperature solid oxide fuel cells

LaCoO_3-δ (LC)-coated Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF) cathode is fabricated by the solution impregnation method and promoted electrochemical performance is obtained. After being coated by LC shell, the polarization resistance can be as low as 0.197 Ω cm² and the peak power density is 0.243 W cm^?2 at the operating temperature of 600 °C. The excellent CO₂ resistance of LC-coated BSCF cathode is verified by the CO₂-poisoning test. Even in the operating atmosphere with high CO₂ concentration, the polarization resistance change of LC-coated BSCF cathode is much smaller than that of the blank BSCF cathode. By long-term test of single cells, the remarkable electrochemical performance stability of LC-coated BSCF cathode is shown. The promoted electrochemical performance, excellent CO₂ resistance and remarkable long-term stability make LC-coated BSCF cathode promising for intermediate temperature solid oxide fuel cells.     

Oxygen reduction mechanism at Ba0.5Sr0.5Co0.8Fe0.2O3−δ cathode for solid oxide fuel cell

Perovskite structure Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ (BSCF) and La_0.9Sr_0.1Ga_0.8Mg_0.2O_3−δ (LSGM) powders have been successfully synthesized by glycine–nitrate combustion process. A porous and crack-free BSCF cathode is obtained by spraying the slurry of BSCF powders and terpineol onto LSGM pellet. The oxygen reduction reaction mechanism has been investigated by AC impedance spectroscopy and cyclic voltammetry method. AC impedance spectroscopy analysis shows that there are two different processes in the cathode reaction which are related to oxygen dissociation/adsorption and bulk oxygen diffusion. And the molecular oxygen is involved in the rate-determining step. The polarization resistance decreases with an increase of temperature and the oxygen partial pressure. With an increase of the applied DC bias, the logarithm of the polarization resistance decreases linearly due to additional oxygen vacancies and the lowered chemical potential of oxygen at the BSCF/LSGM interface by the applied voltage. The exchange current density reaches to 182 mA cm⁻² at 700 °C, suggesting that the ORR kinetics at the BSCF/LSGM interface is high due to the excellent mixed ionic and electronic conductivity of BSCF.     

Palladium and ceria infiltrated La0.8Sr0.2Co0.5Fe0.5O3−δ cathodes of solid oxide fuel cells

La_0.8Sr_0.2Co_0.5Fe_0.5O_3−δ (LSCF) cathodes infiltrated with electrocatalytically active Pd and (Gd,Ce)O₂ (GDC) nanoparticles are investigated as high performance cathodes for the O₂ reduction reaction in intermediate temperature solid oxide fuel cells (IT-SOFCs). Incorporation of nano-sized Pd and GDC particles significantly reduces the electrode area specific resistance (ASR) as compared to the pure LSCF cathode; ASR is 0.1 Ω cm² for the reaction on a LSCF cathode infiltrated with 1.2 mg cm⁻² Pd and 0.06 Ω cm² on a LSCF cathode infiltrated with 1.5 mg cm⁻² GDC at 750 °C, which are all significantly smaller than 0.22 Ω cm² obtained for the reaction on a conventional LSCF cathode. The activation energy of GDC- and Pd-impregnated LSCF cathodes is 157 and 176 kJ mol⁻¹, respectively. The GDC-infiltrated LSCF cathode has a lower activation energy and higher electrocatalytic activity for the O₂ reduction reaction, showing promising potential for applications in IT-SOFCs.