Electrochemical evaluation of La2NiO4+δ as a cathode material for intermediate temperature solid oxide fuel cells

La₂NiO_4+δ powders were synthesized using a polyaminocarboxylate complex precursor method. La₂NiO_4+δ electrodes were prepared on Ce_0.8Sm_0.2O_1.9 (SDC) substrates using a screen-printing technique. The microstructure feature and electrocatalytic activity of the electrodes were investigated with respect to the calcination temperature of the starting powders and sintering temperature of the electrodes. The effects of microstructure features on the electrochemical properties of La₂NiO_4+δ electrodes have been inspected. Moreover, the electrochemical performance of the La₂NiO_4+δ cathode has been evaluated based on a Ni-SDC anode supported single cell. The single cell showed a modified electrochemical performance compared with the literature results, attaining a maximum power density of 295 mW cm⁻² at 800 °C. For the single cell, applying an Au layer onto the La₂NiO_4+δ cathode led to an evident reduction of ohmic resistance and a substantial enhancement of the maximum power density to 464 mW cm⁻².     

Pr2NiO4–Ag composite cathode for low temperature solid oxide fuel cells with ceria-carbonate composite electrolyte

Pr₂NiO₄–Ag composite was synthesized and evaluated as cathode component for low temperature solid oxide fuel cells based on ceria-carbonate composite electrolyte. X-ray diffraction analysis reveals that the formation of a single phase K₂NiF₄–type structure occurs at 1000 °C and Pr₂NiO₄–Ag composite shows chemically compatible with the composite electrolyte. Symmetrical cells impedance measurements prove that Ag displays acceptable electrocatalytic activity toward oxygen reduction reaction at the temperature range of 500–600 °C. Single cells with Ag active component electrodes present better electrochemical performances than those of Ag-free cells. An improved maximum power density of 695 mW cm⁻² was achieved at 600 °C using Pr₂NiO₄–Ag composite cathode, with humidified hydrogen as fuel and air as the oxidant. Preliminary results suggest that Pr₂NiO₄–Ag composite could be adopted as an alternative cathode for low temperature solid oxide fuel cells.     

Electrochemical properties of composite cathodes for La0.995Ca0.005NbO4−δ-based proton conducting fuel cells

The electrochemical properties of mixed-conducting ceramic-ceramic (cer-cer) composites for proton-conducting solid oxide fuel cells (PC-SOFCs) based on La_0.995Ca_0.005NbO_4−δ (LCN) have been investigated. Different ratios of La_0.8Sr_0.2MnO_3−δ/La_0.995Ca_0.005NbO_4−δ (LSM/LCN) composites have been tested as cathodes in symmetrical cells based on La_0.995Ca_0.005NbO_4−δ dense electrolytes while two different electrode sintering temperatures (1050 and 1150 °C) have been studied. Additionally, different LCN doped materials (Pr, Ce and Mn), which present a different conduction behavior, have been used as components in composite cathodes (mixtures of LSM/doped-LCN 50/50 vol.%). Electrochemical impedance spectroscopy analysis has been carried out in the temperature range 700-900 °C under moist (2.5%) atmospheres. Different oxygen partial pressures (pO₂) have been employed in order to characterize the processes (surface reaction and charge transport) occurring at the composite electrode under oxidizing conditions. The main outcome of the present study is that the mixture of LSM (electronic phase) and LCN (protonic phase) enables to decrease substantially the electrode polarization resistance. This is ascribed to the increase in the three-phase-boundary length and therefore it allows electrochemical reactions to occur in a larger region (thickness) of the electrode.     

Durability study of an intermediate temperature fuel cell based on an oxide–carbonate composite electrolyte

It was reported that ceria–carbonate composites are promising electrolyte materials for intermediate temperature fuel cells. The conductivity stability of composite electrolyte with co-doped ceria and binary carbonate was measured by AC impedance spectroscopy. At 550 °C, the conductivity dropped from 0.26 to 0.21 S cm⁻¹ in air during the measured 135 h. At a constant current density of 1 A cm⁻², the cell performance keeps decreasing at 550 °C, with a maximum power density change from 520 to 300 mW cm⁻². This is due to the increase of both series and electrode polarisation resistances. Obvious morphology change of the electrolyte nearby the cathode/electrolyte interface was observed by SEM. Both XRD and FT-IR investigations indicate that there are some interactions between the doped ceria and carbonates. Thermal analysis indicates that the oxide–carbonate composite is quite stable at 550 °C. The durability of this kind of fuel cell is not good during our experiments. A complete solid oxide-carbonate composite would be better choice for a stable fuel cell performance.     

Novel doped barium cerate–carbonate composite electrolyte material for low temperature solid oxide fuel cells

A composite of a perovskite oxide proton conductor (BaCe_0.7Zr_0.1Y_0.2O_3−δ, BCZ10Y20) and alkali carbonates (2Li₂CO₃:1Na₂CO₃, LNC) is investigated with respect to its morphology, conductivity and fuel cell performance. The morphology shows that the presence of carbonate phase improves the densification of oxide matrix. The conductivity is measured by AC impedance in air, nitrogen, wet nitrogen, hydrogen, and wet hydrogen, respectively. A sharp increase of the conductivity at certain temperature is seen, which relates to the superionic phase transition at the interface phases between oxide and carbonates. Single cell with the composite electrolyte is fabricated by dry-pressing technique, using nickel oxide as anode and lithiated nickel oxide as cathode, respectively. The cell shows a maximum power density of 957 mW cm⁻² at 600 °C with hydrogen as the fuel and oxygen as the oxidant. The remarkable proton conductivity and excellent cell performance make this kind of composite material a good candidate electrolyte for low temperature solid oxide fuel cells (SOFCs).     

Electrical properties of SDC–BCY composite electrolytes for intermediate temperature solid oxide fuel cell

The electrolyte material Ce_0.85Sm_0.15O_1.92 (SDC) powders are synthesized by glycine–nitrate processes and BaCe_0.83Y_0.17O_3−δ (BCY) powders are synthesized by sol–gel processes, respectively. Then SDC–BCY composite electrolytes are prepared by mixing SDC and BCY. The SDC and BCY powders are mixed in the weight ratio of 95:5, 90:10 and 85:15 and named as SB95, SB90 and SB85, respectively. The electrical properties of SDC and SDC–BCY composites are investigated. The experimental results show that SDC–BCY composites exhibit the excellent conductivity and could significantly enhance the fuel cell performances. The behavior that SDC–BCY composites display hybrid proton and oxygen ion conduction is substantiated. Among these electrolytes, the maximum power density reaches as high as 159 mW cm⁻² for the fuel cell based on SB90 composite electrolyte at 600 °C.     

La2NiO4+δ potential cathode material on La0.9Sr0.1Ga0.8Mg0.2O2.85 electrolyte for intermediate temperature solid oxide fuel cell

La₂NiO_4+δ, a mixed ionic-electronic conducting oxide with K₂NiF₄ type structure, has been studied as cathode material with La_0.9Sr_0.1Ga_0.8Mg_0.2O_2.85 (LSGM) electrolyte for intermediate solid oxide fuel cells (IT-SOFCs). XRD results reveal excellent chemical compatibility between the La₂NiO_4+δ sample and LSGM electrolyte.A single cell (0.22 cm² active area) was fabricated with La₂NiO_4+δ as cathode, Ni-Sm_0.2Ce_0.8O_1.9 (2:1; w/w) as anode and LSGM as electrolyte. A thin buffer layer of Sm_0.2Ce_0.8O_1.9 (SDC) between anode and electrolyte was used to avoid possible interfacial reactions. The cell was tested under humidified H₂ and stationary air as fuel and oxidant, respectively. The electrochemical behaviour was evaluated by means of current-voltage curves and impedance spectroscopy. Microstructure and morphology of the cell components were analysed by SEM-EDX after testing.The maximum power densities were 160, 226, and 322 mW cm⁻² at 750, 800 and 850 °C, respectively with total polarisation resistances of 0.77, 0.48 and 0.31 Ω cm² at these temperatures. Cell performance remained stable when a current density of 448 mA cm⁻² was demanded for 144 h at 800 °C, causing no apparent degradation in the cell. The performance of this material may be further improved by reducing the electrolyte thickness and optimisation of the electrode microstructure.     

Neodymium-deficient nickelate oxide Nd1.95NiO4+δ as cathode material for anode-supported intermediate temperature solid oxide fuel cells

The neodymium-deficient nickelate Nd_1.95NiO_4+δ, mixed conducting K₂NiF₄-type oxide, was evaluated as cathode for solid oxide fuel cells. The electrochemical properties were investigated on planar Ni–YSZ anode-supported SOFC based on co-tape casted and co-fired HTceramix^® cells. Using a layer of strontium doped lanthanum cobaltite as current collector, a current density of 1.31 A cm⁻² (at 0.70 V) was obtained at 800 °C using hydrogen fuel with small single cells, after optimizing the cathode sintering temperature. Impedance spectroscopy measurements were performed; the different resistive contributions and the values of the corresponding equivalent capacities are discussed.     

Effects of bi-layer La0.6Sr0.4Co0.2Fe0.8O3−δ-based cathodes on characteristics of intermediate temperature solid oxide fuel cells

In this study, anode-supported planar IT-SOFCs, with a thin Sm_0.2Ce_0.8O_2−δ (SDC) electrolyte film and a bi-layer cathode, are fabricated using tape-casting and screen-printing processes. The bi-layer cathode consists of a current collector La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ (LSCF) layer and a functional LSCF-SDC composite layer in various thicknesses. Microstructure studies reveal that the interfaces among various layers show good adhesion, except for Cell A equipped with a cathode of pure LSCF. Cell A reports the lowest ohmic (R₀) and polarization (R_P) resistances. R_P, which increases with the thickness of the LSCF-SDC composite layer in the cathode, rises rapidly as the temperature drops, particularly at temperatures ≤550 °C. This indicates the high electrical conductivity of the cathode as a major contribution to the decrease of R_P at 500 °C. The best cell performances are observed at 650 °C for all cases, in which Cell A shows a maximum power density of 1.51 W cm⁻² and an open circuit voltage of 0.80 V. Considering both of the electrical and the mechanical integrity of the single cell, insertion of the composite layer is required to guarantee a good adhesion of cathode layer to electrolyte layer. However, the thickness of the composite layer should be retained as thin as possible to minimize the R₀ and R_P and maximize the cell performance.     

Optimization on the electrochemical properties of La2NiO4+δ cathodes by tuning the cathode thickness

The electrochemical properties of La₂NiO_4+δ electrodes were investigated as a function of the electrode thickness based on three-electrode half cells. The electrocatalytic activity of the electrodes with the varied thicknesses ranging from 5 to 30 μm was surveyed by electrochemical impedance spectroscopy technique under open-current voltage conditions. The cathodic polarization curves of these electrodes were also inspected. The results indicated that the electrochemical properties of these electrodes were highly dependent on their thickness. The polarizations of involved electrode reaction processes displayed different variations with changing the electrode thickness. Tuning the electrode thickness was confirmed to be effective for optimizing the electrochemical properties. Among the investigated electrodes, the electrode with a thickness of ～20 μm achieved the optimal properties. At 800 °C in air, this electrode exhibited a polarization resistance of 0.24 Ω cm², an exchange current density of 201 mA cm^?2 and an overpotential of 40 mV at 200 mA cm^?2. On this ground, an anode-supported single cell with ～20 μm thick La₂NiO_4+δ cathode was fabricated. At 800 °C and using hydrogen fuel, this single cell attained a maximum powder density of 500 mW cm^?2.     

Study on BaCo0.7Fe0.2Nb0.1O3−δ—SDC composite cathodes for intermediate temperature solid oxide fuel cell

BaCo_0.7Fe_0.2Nb_0.1O_3−δ(BCFN)/Ce_0.8Sm_0.2O_1.9(SDC) composite material was prepared and characterized as cathode for intermediate temperature solid oxide fuel cells. The X-ray diffraction result proved that there was no obvious reaction between the BCFN and SDC after calcination at 1000 °C for 10 h. AC impedance spectra based on La_0.9Sr_0.1Ga_0.8Mg_0.2O_3−δ(LSGM) electrolyte measured at intermediate temperatures showed that a cathode with 30 wt% SDC exhibited the best electrochemical performance among the electrodes studied. The interfacial resistance value for BCFN/30SDC was as low as 0.0104, 0.017, 0.029, and 0.062 Ω cm² at 800, 750, 700 and 650 °C, respectively. The maximum power density of a single cell with BCFN/30SDC cathode, Ni_0.9Cu_0.1-SDC anode, and LSGM/SDC electrolyte was 209.7, 298.2, 407.1, 543.4 and 697.9 mW cm⁻² at 600, 650, 700, 750 and 800 °C.     

Intermediate temperature fuel cells based on doped ceria–LiCl–SrCl2 composite electrolyte

A new type of oxide-salt composite electrolyte, gadolinium-doped ceria (GDC)–LiCl–SrCl₂, was developed and demonstrated its promising use for intermediate temperature (400–700 °C) fuel cells (ITFCs). The dc electrical conductivity of this composite electrolyte (0.09–0.13 S cm⁻¹ at 500–650 °C) was 3–10 times higher than that of the pure GDC electrolyte, indicating remarkable proton or oxygen ion conduction existing in the LiCl–SrCl₂ chloride salts or at the interface between GDC and the chloride salts. Using this composite electrolyte, peak power densities of 260 and 510 mW cm⁻², with current densities of 650 and 1250 mA cm⁻² were achieved at 550 and 625 °C, respectively. This makes the new material a good candidate electrolyte for future low-cost ITFCs.     

Effect of DC current polarization on the electrochemical behaviour of La2NiO4+δ and La3Ni2O7+δ-based systems

The electrode performance of La₂NiO₄ and La₃Ni₂O₇ as cathode materials for solid oxide fuel cells (SOFC) was analyzed. The study was focused on the electrode polarization resistance of the interfaces formed by the cathodes with Ce_0.8Sm_0.2O_2−δ + 2%Co electrolyte. The study was extended to cathodes based on La₂NiO₄-Ce_0.8Sm_0.2O_2−δ composite and Pt to analyze the effect of changing the electronic and/or ionic transport properties on the electrode interface resistance. The electrode performance was studied in open circuit conditions and with DC current polarization. Important differences in the performance of the pure cathode materials were obtained as function of DC current flux. However, in La₂NiO₄-Ce_0.8Sm_0.2O_2−δ composite the DC current flux produces minor changes in the electrode polarization resistance. The aging process also affects the OCV electrode performance of cathodes based on Pt and pure ceramics, whereas the effect is practically invaluable in La₂NiO₄-Ce_0.8Sm_0.2O_2−δ composite. The electrode performance is higher for the composite cathode compared to pure ceramic electrodes for OCV or for low values of DC polarization. However, the important decrease in the interface resistance obtained for high values of DC current flux for La₂NiO₄ and La₃Ni₂O₇ cathodes increases their electrode performances to values close to those obtained in La₂NiO₄-Ce_0.8Sm_0.2O_2−δ composite. This retains the cathode overpotential with values as low as 140 mV at 750 °C for values of current load of 530 mA cm⁻² for both pure and composite La₂NiO₄-based cathodes. The low cathode overpotential allows to estimate values of power density between 300 and 350 mW cm⁻² at 750 °C for La₂NiO₄, La₃Ni₂O₇ and La₂NiO₄-Ce_0.8Sm_0.2O_2−δ composite, operating with Ce_0.8Sm_0.2O_2−δ + 2%Co electrolyte, with 300 μm in thickness, and a Ni-Ce_0.8Sm_0.2O_2−δ cermet anode with H₂ as fuel.     

High-performance PrBaCo2O5+δ-Ce0.8Sm0.2O1.9 composite cathodes for intermediate temperature solid oxide fuel cell

PrBaCo₂O_5+δ-Ce_0.8Sm_0.2O_1.9 (PBCO-SDC) composite material are prepared and characterized as cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). The powder X-ray diffraction result proves that there are no obvious reaction between the PBCO and SDC after calcination at 1100 °C for 3 h. AC impedance spectra based on SDC electrolyte measured at intermediate temperatures shows that the addition of SDC to PBCO improved remarkably the electrochemical performance of a PBCO cathode, and that a PBCO-30SDC cathode exhibits the best electrochemical performance in the PBCO-xSDC system. The total interfacial resistances R_p is the smallest when the content of SDC is 30 wt%, where the value is 0.035 Ω cm² at 750 °C, 0.072 Ω cm² at 700 °C, and 0.148 Ω cm² at 650 °C, much lower than the corresponding interfacial resistance for pure PBCO. The maximum power density of an anode-supported single cell with PBCO-30SDC cathode, Ni-SDC anode, and dense thin SDC/LSGM (La_0.9Sr_0.1Ga_0.8Mg_0.2O_3−δ)/SDC tri-layer electrolyte are 364, 521 and 741 mW cm⁻² at 700, 750 and 800 °C, respectively.     

Optimization of the interface polarization of the La2NiO4-based cathode working with the Ce1–xSmxO2–δ electrolyte system

The performance of La₂NiO₄ cathode material and Ce_1–xSm_xO_2–δ (x = 0.1, 0.2, 0.3, 0.4) electrolyte system was analyzed. Ceria-based materials were prepared by the freeze-drying precursor route whereas La₂NiO₄ was prepared by the nitrate–citrate procedure. Electrolyte pellets were obtained after sintering the powders at 1600 °C for 10 h. Also dense ceria-based electrolytes samples were obtained by calcining the powders at 1150 °C after the addition of 2 mol%-Co. Interface polarization measurements were performed by impedance spectroscopy in air at open circuit voltage, using symmetrical cells prepared after the deposition of porous La₂NiO₄-electrodes on the Ce_1–xSm_xO_2–δ system. X-ray diffraction (XRD) of cathode materials after using in symmetrical cells confirmed no significant reaction between La₂NiO₄ and ceria-based electrolytes. The efficiency of the cathode material is highly dependent on the composition of the electrolyte, and low-content Sm-doped ceria samples revealed an important decrease in the performance of the system. Differences in electrochemical behaviour were attributed principally to the oxide ion transference between cathode and electrolyte, and were correlated to the conductivity of the electrolyte. In this way cobalt-doped electrolytes with a Sm-content ≤30% perform better than free-cobalt samples due to the increase in grain boundary conductivity. Finally, composites of the ceria-based materials and La₂NiO₄ to use as cathode were prepared and an important increase of the interface performance was observed compared to La₂NiO₄ pure cathode. Predictions of maximun power density were obtained by the mixed transport properties of the electrolytes and by the interface polarization results. The use of composite materials could allow to increase the performance of the cell from 170 mW cm⁻² for pure La₂NiO₄ cathode, to 370 mW cm⁻² for La₂NiO₄–Ce_0.8Sm_0.2O_2–δ cathode, both working with Ce_0.8Sm_0.2O_2–δ electrolyte 300 μm in thickness and Ni–Ce_0.8Sm_0.2O_2–δ as anode at 800 °C.     

Development of trimetallic Ni–Cu–Zn anode for low temperature solid oxide fuel cells with composite electrolyte

Trimetallic alloys of Ni_0.6Cu_0.4−xZn_x (x = 0, 0.1, 0.2, 0.3, 0.4) have been investigated as promising anode materials for low temperature solid oxide fuel cells (SOFCs) with composite electrolyte. The alloys have been obtained by reduction of Ni_0.6Cu_0.4−xZn_xO oxides, which are synthesized by using the glycine–nitrate process. Increasing the Zn content x decreases the particle sizes of the oxides at a given sintering temperature. Fuel cells have been constructed using lithiated NiO as cathode and as-prepared alloys as anodes based on the composite electrolyte. Peak power densities are observed to increase with the increasing Zn addition concentration into the anode. The maximum power density of 624 mW cm⁻² at 600 °C, 375 mW cm⁻² at 500 °C has been achieved for the fuel cell equipped with Ni_0.6Zn_0.4 anode. A.c. impedance results show that the resistances dramatically decrease with increasing temperatures under open circuit voltage state. Both cathodic and anodic interfacial polarization resistances increase with the amplitude of applied DC voltage. Possible reaction process for H₂ oxidation reaction at anode based on composite electrolyte has been proposed for the first time. The stability of the fuel cell with Ni_0.6Cu_0.2Zn_0.2 composite anode has been investigated. The results indicate that the trimetallic Ni_0.6Cu_0.4−xZn_x anodes are considerable for low temperature SOFCs.     

Nd1.8Sr0.2NiO4−δ:Ce0.9Gd0.1O2−δ composite cathode for intermediate temperature solid oxide fuel cells

The (100 − x)Nd_1.8Sr_0.2NiO_4−δ:(x)Ce_0.9Gd_0.1O_2−δ (x = 00, 10, 20, 30, 40 and 50 vol%) composites are obtained by ball milling requisite mixture at 200 rotations per minute for 2 h under acetone followed by sintering at 1000 °C for 4 h. The increase in concentration of Ce_0.9Gd_0.1O_2−δ in composite reduces the crystallite size of host Nd_1.8Sr_0.2NiO_4−δ from 378 ± 0.7 to 210 ± 0.8 nm. The dc (electronic) conductivity of composite decreases moderately with an increase in Ce_0.9Gd_0.1O_2−δ content in composite up to 30 vol%, and it decreases abruptly, thereafter at x > 30. A minimum polarization resistance value of 0.24 Ω cm² (at 700 °C) is obtained for a (70)Nd_1.8Sr_0.2NiO_4−δ:(30)Ce_0.9Gd_0.1O_2−δ composite cathode, and this value is attributed to the optimal dispersion of Ce_0.9Gd_0.1O_2−δ into Nd_1.8Sr_0.2CuO_4−δ matrix. The oxygen partial pressure dependent polarization resistance study suggests that the charge transfer and the non-charge transfer oxygen adsorption–desorption along with diffusion are the major rate limiting steps of overall oxygen reduction reaction process.     

Novel layered perovskite SmBaCu2O5+δ as a potential cathode for intermediate temperature solid oxide fuel cells

A novel layered perovskite SmBaCu₂O_5+δ (SBCO) as a potential cathode for intermediate temperature solid oxide fuel cells (IT-SOFC) has been investigated in this paper. The SmBaCu₂O_5+δ oxide was synthesized by EDTA- Citrate complexing sol-gel process. The crystal structure, the thermal expansion, the electrical conductivity and electrochemical properties have been characterized by X-ray diffraction (XRD), dilatometer, four-probe dc method, electrochemical impedance spectroscopy (EIS) and cathodic polarization examinations. The average thermal expansion coefficient (TEC) of SBCO was 14.6 × 10⁻⁶/ °C in the temperature range of 50-800 °C, which matched Sm-doped ceria (SDC) electrolytes. The electrode polarization resistance was 0.469 Ωcm². Considering low thermal expansions and good electrochemical properties, layered perovskite SBCO shows promising performance as cathode material for IT-SOFCs.     

ZrO2–SiO2/Nafion composite membrane for polymer electrolyte membrane fuel cells operation at high temperature and low humidity

Recast Nafion^® composite membranes containing ZrO₂–SiO₂ binary oxides with different Zr/Si ratios are investigated for polymer electrolyte membrane fuel cells (PEMFCs) at temperatures above 100 °C. Fine particles of the ZrO₂–SiO₂ binary oxides, same as an inorganic filter, are synthesized from a sodium silicate and a carbonate complex of zirconium by a sol–gel technique. The composite membranes are prepared by blending a 10% (w/w) Nafion^®-water dispersion with the inorganic compound. All composite membranes show higher water uptake than unmodified membranes, and the proton conductivity increases with increasing zirconia content at 80 °C. By contrast, the proton conductivity decreases with zirconia content for the composite membranes containing binary oxides at 120 °C. The composite membranes are tested in a 9-cm² commercial single cell at both 80 °C and 120 °C in humidified H₂/air under different relative humidity (RH) conditions. Composite membrane containing the ZrO₂–SiO₂ binary oxide (Zr/Si = 0.5) give the best performance of 610 mW cm⁻¹ under conditions of 0.6 V, 120 °C, 50% RH and 2 atm.     

Performances of SmBaCoCuO5+δ–Ce0.9Gd0.1O1.95 composite cathodes for intermediate-temperature solid oxide fuel cells

SmBaCoCuO_5+δ–xCe_0.9Gd_0.1O_1.95 (SBCCO–xGDC, x = 10, 30, 50, 60, wt%) composite cathodes have been investigated for their potential utilization in intermediate temperature solid oxide fuel cells (IT-SOFCs). The thermal expansion behavior shows that the thermal expansion coefficient (TEC) values of SBCCO cathode decrease with GDC addition. The TEC of SBCCO–50GDC cathode is 13.1 × 10⁻⁶ K⁻¹ from 30 to 850 °C in air. By means of DC polarization and AC impedance spectroscopy, the electrochemical performance of SBCCO–xGDC composite cathodes on GDC electrolyte is examined. Results indicate that the proper addition of GDC could improve the performance of SBCCO cathode. The optimum content of GDC in the composite cathodes is 50 wt% with the polarization resistance (R_p) of 0.040 Ω cm² at 800 °C. An electrolyte-supported single-cell configuration of SBCCO–50GDC/GDC/Ni–GDC attains a maximum power density of 628 mW cm⁻² at 800 °C. Preliminary results indicate that SBCCO–50GDC is especially promising as a cathode for IT-SOFCs.