Intermediate Temperature Solid Oxide Research Articles

Structural and Electrochemical Characterisation of NBZFO Cobalt-Free Cathode Material for Intermediate-Temperature Solid Oxide Fuel Cells: An Experimental Investigation

Compared to other energy-generating technologies and energy conversion devices, intermediate-temperature solid oxide fuel cells (IT-SOFCs) have gained significant attention from energy experts due to its high energy density, moderate operating temperature (600–800°C), low emissions and reliability. Enhancing the performance of IT-SOFCs requires suitable and excellent cathode materials. Thus, a perovskite-type Nd0.5Ba0.5Zr0.8Fe0.2O3+δ (NBZFO) material was synthesised via traditional solid-state reaction technique and analysed as a potential cathode material for IT-SOFCs. Analysis of X-ray diffraction data (XRD) revealed a single-phase perovskite material that crystallises in cubic space group (pm-3m). The thermal and electrochemical properties were analysed with the aid of thermogravimetric analysis (TGA) and electrochemical impedance spectroscopy (EIS). NBZFO has an electrical conductivity in air of 80 S cm−1 at 400°C and a polarisation resistance (Rp) of 0.106 Ω cm2 at 800°C. TGA reveals a slight loss in weight of about 0.58%, thereby suggesting a highly stable cathode material for IT-SOFC. Electrochemical investigation shows that NBZFO has good electronic and ionic conductivity and excellent oxygen stichometry. Further studies are required to understand the effects of varying B-site composition of the cathode material.

Solution Infiltrated Lanthanum nickelate–GDC Composite Cathode via Flash-Light Sintering for Intermediate Temperature Solid Oxide Fuel Cells

Solution Infiltrated Lanthanum nickelate–GDC Composite Cathode via Flash-Light Sintering for Intermediate Temperature Solid Oxide Fuel Cells

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.

High-speed laser cladding (Fe,Cu)-dopped Ni-Co protective coatings for SOFC MICs: From long-term oxidation behavior to mechanical stability

The long-term operation of intermediate temperature-solid oxide fuel cells (IT-SOFCs) could be significantly influenced by the stability of the interconnect itself, especially, its oxidation resistance under the cathode environment. To effectively prevent Cr-volatilization and improve the interconnector performance, application of highly dense and stable protective coatings over the interconnector is indispensable. In this work, Ni-Co-based alloy protective coatings doped with Fe and Cu were applied onto the 441 interconnector via a novel high-speed laser cladding technology. The microstructure evolution, phase composition, oxidation resistance, electrical conductivity and mechanical properties of the coated steels were investigated at different oxidation stages at 800 °C. It was found that the Ni33.8Co34Fe32.2-coated steel shows the best oxidation resistance and electrical properties. The oxidation rate (kp) and ASR of Ni33.8Co34Fe32.2-coated steel is respectively 4.44 × 10−13 g2 cm−4 s−1 and 25.55 mΩ cm2, significantly lower than the uncoated steel and Ni44.6Co44.7Cu10.7-coated steel at the end of 1000-h test cycle. The resultant conductivity of the Ni44.6Co44.7Cu10.7 and Ni33.8Co34Fe32.2-coated steels is approximately 7.8 and 4.1 S cm−1, respectively, which could meet the requirement for SOFC stacks. In addition, the nano-hardness of the Ni33.8Co34Fe32.2 and Ni44.6Co44.7Cu10.7-coated steels was found to be 8.3 GPa and 8.8 GPa, respectively, through nanoindentation testing. The improved surface hardness is attributed to grain refinement and increased oxide content on the coating surface. The results indicated that the Ni-Co-based alloy coatings effectively improved the long-term stability and mechanical property of the 441 interconnector under the SOFC cathode environment.

Investigation and optimization of high-valent Ta-doped SrFeO3−δ as air electrode for intermediate-temperature solid oxide fuel cells

Investigation and optimization of high-valent Ta-doped SrFeO3−δ as air electrode for intermediate-temperature solid oxide fuel cells

Improved ionic conductivity of Ca-doped and Ca-La co-doped ceria electrolytes for intermediate temperature solid oxide fuel cells

Improved ionic conductivity of electrolytes is necessary for solid oxide fuel cells, meant for the development of efficient and clean energy devices. This study is focused on the enhancement of ionic conductivity in Ca-doped and Ca-La co-doped cerium oxide (ceria) electrolytes for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The co-doped ceria electrolytes, LCDC20 (Ce0.8La0.1Ca0.1O2−δ), exhibited enhanced ionic conductivity of 1.06 ×10−1 S cm−1 at 1073 K, when compared to conventional yttria-stabilized zirconia (YSZ) electrolytes, and has lower activation energy of 1.02 eV. Also, these co-doped electrolytes showed decreased sintering temperatures, which amounts to cost-effective electrolyte materials for IT-SOFCs.

Reduction behaviour in neodymium doped ceria

Doped cerium oxides are technologically relevant materials and used as electrolytes in intermediate temperature solid oxide fuel cells. An important issue for these materials is the reduction of ceria at low oxygen partial pressures which leads to mixed ionic electronic conduction. In the present work, reduction behaviour in Ce0.8Nd0.2O1.9-δ is examined under inert and strongly reducing conditions. Even under inert conditions, ca. 3.5 % of the Ce is redox active up to around 800 °C, which appears to be correlated with non-linear behaviour in the Arrhenius plot of conductivity and thermal expansion of the lattice. Under more strongly reducing conditions, a secondary partial reduced phase is formed related to triclinic Ce11O20, which introduces significant electronic conductivity into the system. The dynamics of the re-oxidation process are examined using X-ray powder diffraction and electrochemical impedance spectroscopy.

Enhancement of redox cycling stability of Ni/GDC cermets for intermediate-temperature SOFC anodes through Ge incorporation in the ceramic phase

In this study, Ge4+ was incorporated into the ceramic matrix of nickel-based anode materials, synthesizing anode materials NiO-Gd0.1Ce0.9-xGexO1.95 (x = 0.01, 0.04, 0.07) and NiO-Ce0.9Gd0.1O2–δ. Corresponding anode support samples were also prepared, designated as A-CGDC, A-C1Ge, A-C4Ge, and A-C7Ge. Additionally, single cell samples using the newly co-doped anode materials were prepared, identified as C-CGDC, C-C1Ge, C-C4Ge, and C-C7Ge. The research indicates that after doping the ceramic phase framework with Ge4+, these composite anode materials exhibit the potential to withstand more redox cycles than C-CGDC without catastrophic mechanical structural damage or degradation in electrochemical performance. Particularly, after incorporating 7mol% Ge4+ into the ceramic backbone, the issue of 86 % strain accumulation in the anode support was mitigated. Additionally, the ion doping ratio is closely linked to the stability of the single cell samples, with the A-C7Ge sample able to withstand up to 11 extreme recycling sessions at 700 °C without complete structural failure, improving structural stability by approximately 57 % compared to A-C1Ge. In terms of electrochemical output performance, the impedance of C-C1Ge prior to complete failure was nearly double that before oxidation-reduction, with a maximum power density reduction of about 26.47 %. As the co-doping concentration in the ceramic phase reached 7mol%, the impedance increase during single cell cycle testing was about four times smaller, with C-C7Ge 's impedance before mechanical failure only 37 % higher than before cycling, and a reduction in maximum power density of just 11.11 %. Moreover, during consecutive cycling tests, the average damage to the open-circuit voltage was only 0.02V, showing almost no negative impact from the cycling operations, and it maintained efficient output performance after multiple cycles. Therefore, the newly synthesized nickel-based anode materials, modified via co-doping methods within the ceramic phase, can be considered as potential composite anode materials for intermediate-temperature solid oxide fuel cells.

Sr0.90Ba0.10Co0.95Ti0.05O3-δ cathode as an improved electrode for IT-SOFCs

The novel perovskite Sr0.90Ba0.10Co0.95Ti0.05O3-δ has been designed as cathode material to be used in intermediate-temperature solid oxide fuel cells (IT-SOFC). To enlarge the unit-cell size and enhance oxygen diffusion, Sr atoms have been partially substituted by a 10 % of Ba. This new compound was characterized through X Ray Diffraction (XRD) unveiling a tetragonal phase at RT. An in situ Neutron Powder Diffraction (NPD) study between RT and 800 °C showed a transition to a cubic perovskite at 400 °C, which was also noticeable in the thermogravimetric analysis (TGA) and dilatometric analysis. Adequate chemical and mechanical compatibility were achieved with the components of the cell. Electrical conductivity peaked at 400 °C, with values over 200 S cm−1, where it changed its behavior from semiconductor-like to insulator. Finally, polarization resistances as low as 0.062 Ω cm−2 were obtained for the working temperature of the cell in a symmetric cell, associated with the excellent power densities of 564 and 752 mW cm−2 obtained at 850 °C using pure H2 as fuel for the conventional test fuel cell and in a Pd-infiltrated one.

Effect of Mg-doping on electrochemical performance of PrBaFe2O5+δ cathode materials for solid oxide fuel cells

PrBaFe2O5+δ (PBF) is one of the promising cathode materials for intermediate-temperature solid oxide fuel cell (IT-SOFC) technology. However, as the operating temperature decreases, the electrochemical performance of this material deteriorates rapidly. To counter this, various doping strategies have been tested and reported in order to improve the electrochemical properties of this material at intermediate-temperatures. In this study, Mg-doping to partially substitute Fe of PBF was investigated. PrBaFe2–xMgxO5+δ (PBFMgx, x=0.1, 0.15, 0.2, 0.3) materials were successfully synthesized, and their electrochemical performance as IT-SOFC cathode was evaluated. It is shown that Mg-doping enhances the conductivity of PBF between 650–800 °C, impacts little on the area-specific resistance of oxygen reduction reaction at and above 700 °C, and, most significantly, improves the power density of the Ni-SDC/SDC/PBFMg0.15 single cell by 52% compared to the un-doped PBF. This enhanced electrochemical performance is attributed to the improvement in PBF conductivity by Mg-doping.

Improved electrochemical performance of high-entropy La0.8Sr0.2FeO3-based IT-SOFC cathode

It is widely accepted that solid oxide fuel cells (SOFCs) have the potential to be the most efficient and cost-effective system for the direct conversion of various fuels into electricity with low environmental pollution and high efficiency. Herein, we demonstrate a novel Fe-based high-entropy perovskite oxide as a cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The high-entropy perovskite La0.2Pr0.2Sm0.2Nd0.2Sr0.2FeO3-δ (HE-LSF), composed of La, Pr, Nd, Sm, and Sr is prepared by incorporating five components into the A-site of La0.8Sr0.2FeO3-δ (LSF). Doping of Pr, Nd, Sm, and Sr into the A-site significantly enhances the redox stability of LSF and restrains the surface Sr-segregation in both oxidizing and reducing conditions. The electrode polarization resistance of the anode-supported single cell with HE-LSF cathode is significantly low at intermediate temperature. Meanwhile, at 800 °C, the power density is 1029.2 mW/cm2, and the polarization resistance (Rp) is 0.101 Ω cm2, while at 700 °C, the power density is 581.52 mW/cm2 with an Rp of 0.21 Ω cm2 in humidified H2. Further, the HE-LSF cathode presents good and long-term stability at a constant voltage of 0.7 V for 100 h at 700 °C. The excellent electrochemical performance and stability results exhibit that Fe-based high-entropy perovskite oxide is a new promising candidate and cathode material for SOFCs at intermediate temperatures.

Prevention of morphological change for (Ba,Sr)(Co,Fe)O3 cathodes by incorporating (Ce,Gd)O2 for intermediate-temperature solid oxide fuel cells

Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) generally exhibits superior cathode activity compared to La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) for intermediate-temperature solid oxide fuel cells (IT-SOFCs). However, the chemical stability of BSCF is inferior to that of LSCF. When BSCF cathodes are sintered at a high temperature of 1050 °C, performance was compromised due to the formation of (Ba,Sr)ZrO3 between the scandia-stabilized zirconia (ScSZ) electrolyte and gadolinia-doped ceria (GDC) interlayer. The oxide ionic conductivity of (Ba,Sr)ZrO3 was low, decreasing the cathode performance. Furthermore, the BSCF grains enlarged, and cobalt oxide formed due to BSCF decomposition, decreasing the active specific surface area. However, by incorporating GDC into the BSCF cathode, the morphology remained unchanged and cobalt oxide formation was prevented, despite (Ba,Sr)ZrO3 still forming. The performance of the cell with the BSCF-GDC composite cathode surpassed that with the BSCF cathode due to decreased polarization resistance attributed to the oxygen surface exchange and diffusion processes in the cathode.

Synthesis and characteristics of densified GDC-LSO composite as a new apatite-based electrolyte for intermediate-temperature solid oxide fuel cells (IT-SOFC)

Developing solid-state ionic conductors with desirable charge-transport efficiency and reasonable durability is a fundamental and long-lasting challenge for solid-oxide fuel cells (SOFCs). Ceria-based electrolytes, as one of the most common types of electrolytes for intermediate-temperature solid-oxide fuel cells (IT-SOFCs), offer a high surface-exchange coefficient and faster kinetics in the triple phase boundaries (TPBs); however, they suffer to some extent of electronic conductivity in the reducing atmosphere and gradual phase transitions. Here in this work, we have reported a novel co-doped IT-SOFC electrolyte composite combining the apatite structure of Lanthanum Silicate (LSO) with the fluorite structure of Gadolinium-doped Ceria (GDC), which showed a high ionic conductivity and a minimal electronic leak. The resulting GDC-LSO composite electrolyte also achieved an OCV (open-circuit voltage) of 1 V at 800 °C, implying a significant improvement in the OCV values reported for the typical ceria-based electrolytes (∼0.75 V). The sample was prepared using 40 wt% GDC and 60 wt% LSO (40GDC-60LSO) showed a maximum electrical conductivity of 25 mS cm−1 at 800 °C with good densification properties (>95 % relative density). The cell electrochemical performance measurement was conducted using a 3.0 vol% humified H2 stream at the anode side while the cathode side was exposed to the air at 800 °C. The interdiffusion of cations between La3+ in the LSO phase and Ce4+ and Gd3+ in the GDC phase was detected by XRD and EDX results after sintering samples at 1500 °C for 4 h using 0.5 wt% PVA or 0.5 wt% Ethyl cellulose (EC) as the binder. The proposed GDC-LSO composite could help better understand the influence of compositional constituents and processing variables on the densification and electrical properties of the electrolyte materials for the IT-SOFCs.

Reconstituting the microstructural properties and ionic conductivity of copper - doped yttria-stabilized zirconia via mechanochemical synthesis for intermediate-temperature solid oxide fuel cell applications

The development of highly conductive and thermally stable solid electrolytes is crucial for the next generation of intermediate temperature solid oxide fuel cells (IT-SOFCs). This study investigates the influence of copper (Cu) doping on the microstructure and ionic conductivity of 8 mol. % yttria-stabilized zirconia (8YSZ) when sintered at lower temperatures. The mechanochemical synthesized 1, 3, and 5 wt. % Cu-doped 8YSZ compacts were extensively characterized their properties through a suite of analytical techniques like X-ray diffraction, Raman, X-ray photoelectron, UV–Vis diffused reflectance, particle size analyzer, BET surface area, Emission Scanning Electron Microscopy-Energy Dispersive X-Ray, and AC impedance. The results revealed enhanced ionic conductivity and sinterability, at reduced temperature of 1373 K, with the 5 wt. % Cu-doped 8YSZ demonstrating the highest ionic conductivity of 4.18 × 10−3 S cm−1 at 1023 K, alongside reduced activation energy of 1.14 eV. The lower sintering temperatures and consequential benefits in performance metrics suggest Cu-doping as an effective strategy for optimizing 8YSZ-based electrolytes lowering SOFC manufacturing costs without compromising performance for IT-SOFCs.

Ca-Doping Cobalt-Free Double Perovskite Oxide as a Cathode Material for Intermediate-Temperature Solid Oxide Fuel Cell.

Mixed oxygen ion and electron-conducting materials are viable cathodes for solid oxide fuel cells due to their excellent oxygen transport kinetics and mixed electrical conductivity, which ensure highly efficient operation at low and medium temperatures. However, iron-based double perovskite oxides usually exhibit poor electrocatalytic activity due to low electron and oxygen ion conductivity. In this paper, Ca is doped in PrBaFe2O5+δ A-site to improve the electrochemical performance of PrBaFe2O5+δ. Results show that replacing Pr with Ca does not change the crystal structure, and the Ca doping effectively increases the adsorbed oxygen content and accelerates the migration and diffusion rate of O2- to the electrolyte|cathode interface. The polarization resistance of the symmetric cell PC0.15BF|CGO|PC0.15BF is 0.033 Ω·cm2 at 800 °C, which is about 56% lower than that of PBF, confirming the enhancement of the mixed conduction of oxygen ions and electrons. In addition, the anode-supported single cell has a peak power density of 512 mW·cm-2 at 800 °C.

Impact of the electrospinning synthesis route on the structural and electrocatalytic features of the LSCF (La0.6Sr0.4Co0.2Fe0.8O3–δ) perovskite for application in solid oxide fuel cells

In-house electrospun La0.6Sr0.4Co0.2Fe0.8O3–δ (LSCF) nanofibers have been tested through synchrotron x-ray diffraction and electrochemical impedance spectroscopy (EIS) in the 823–1173 K range, namely in the operating window of intermediate-temperature solid oxide fuel cells. Identical tests have been carried out on commercial LSCF powders, as a control sample. The results demonstrate that the electrospinning manufacturing procedure influences the crystalline properties of the perovskite. The rhombohedral structure (R), stable at room temperature, is retained by nanofibers throughout the whole temperature range, while a rhombohedral to cubic transition (R→C) is detected in powders at ⁓1023 K as a discontinuity in the rhombohedral angle α, accompanied by an abrupt change in oxygen occupation and microstrain. EIS data have a single trend in the nanofibers Arrhenius plot, and two different ones in powders, separated by a discontinuity at the structural transition temperature. Thus, a striking parallel is demonstrated between the variation with temperature of crystallographic features and electrochemical performance. Interestingly, this parallel is found for both nanofiber and granular electrodes. This opens up questions and new perspectives in attributing activation energies derived from EIS tests of LSCF materials to electrochemical processes and/or crystal structure variations.

Investigation of the properties of layered perovskite materials with varying constituent elements as SOFC cathodes

Layered perovskite materials are gaining attention as electrode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). This study explores the incorporation of various elements into the lanthanide, alkaline earth, and transition metal sites within the layered perovskite crystal structure to create diverse compositions. Structural stability and O-ion conduction performance were evaluated through simulations employing a deep learning-assisted approach. Results indicate that at the simulation temperature of 1000 K, the Sm–Sr–Co composition displays structural instability, while the La–Sr–Fe and Sm/Gd–Ba–Fe compositions exhibit decreased O-ion conductivity attributed to phase transitions, rendering them unsuitable for SOFC cathodes. Conversely, the Pr–Ba–Co and La–Sr–Co compositions demonstrate structural stability along with the highest O-ion conductivity, suggesting further exploration of these materials. Additionally, compositions such as Sm/Gd–Ba–Co, Gd–Sr–Co, La–Ba–Fe, and Sm–Sr–Fe, which exhibit structural stability and reasonable O-ion conductivity, may also merit consideration as potential candidates.

Bi1.8Gd0.1Er0.05M0.05O3 (M = Pr, Sm, Dy and Y) electrolytes for intermediate temperature solid oxide fuel cells

In this study, a novel solid electrolyte system consisting of co-doped cubic phase stabilised bismuth oxide was successfully synthesized via the sol-gel method. X-ray diffraction (XRD) analysis revealed that all synthesized samples exhibited stable cubic fluorite-type structures. Notably, as the dopant ion radius decreased, a trend of increasing full width half maximum (FWHM) of the main (111) peak and crystal microstrain, along with a decrease in the average crystallite size and lattice constant, was observed. Interestingly, the sample Bi1.8Gd0.1Er0.05Pr0.05O3, possessing a dopant ion radius closest to Bi3+ (1.17 Å), exhibited exceptional electrical properties, achieving a high conductivity of 0.347 S cm−1 at 800 °C and a low activation energy of 0.20 eV for the high-temperature regions (HTR). This superior performance was attributed to the significant role played by the grain boundary volume and conductivity in facilitating ionic conduction, thus explaining the variations in conductivity among the different samples.

Lanthanum-Ferrite based cathode: Impedance data interpretation via complex nonlinear least-squares and distribution of relaxation times analyses

Lanthanum Strontium Cobalt Ferrite Oxide (LaSrCoFeO3) has been widely used as cathode material for intermediate-temperature solid oxide fuel cells at the temperature of 500–800 °C. At this temperature range, understanding the electrochemical behavior which is commonly analyzed by complex nonlinear least-squares (CNLS) analysis is very crucial in improving the cathode's performance. However, this analysis shows some limitations in interpreting the electrochemical processes in detail, particularly at the electrode-electrolyte interface. Hence, this study is conducted to compare the electrochemical impedance data analyses by CNLS and the distribution of relaxation times (DRT) of a fabricated LaSrCoFe|BCZY|LaSrCoFe (LaSrCoFeLa0.6Sr0.4Co0.2Fe0.8O3 and BCZY=BaCe0.54Zr0.36Y0.1O2.95) symmetrical cell. Impedance data of the cell is collected at T = 800 °C at two different stabilization times and to further enhance the analysis process, the impedance data of the cell at measurement temperatures of 700 °C and 750 °C are also included. In a Nyquist plot, the cell exhibits depressed semi-circles that represent a few processes occurring at the interface. The DRT analysis is more precise and easily reveals the semi-circles consisting of four different sub-processes (represented by four peaks) than CNLS (represented by four impedance arcs). The extracted responses from both analyses correspond to the oxygen reduction reactions that follow the Adler-Lane-Steele model. The stabilized symmetrical cells for respective 34 h and 17 h show an area-specific resistance (ASR) of (i) 0.22 Ωcm2 and 0.30 Ωcm2 (by CNLS) and (ii) 0.20 Ωcm2 and 0.26 Ωcm2 (by DRT). In addition, the ASR of the cell at T = 700 °C and T = 750 °C after being stabilized for 34 h is (iii) 0.71 Ωcm2 and 0.40 Ωcm2 (by CNLS) and (iv) 0.70 Ωcm2 and 0.44 Ωcm2 (by DRT), accordingly. Conversely, the cell's microstructure is not affected by the applied stabilization periods as observed by a scanning electron microscope.

Thermal and chemical expansion of layered oxygen-deficient double perovskites

Layered oxygen-deficient double perovskites (ODP) based on the rare-earth elements (REE), barium and 3d-metals (Fe, Co, Cu etc.) are characterized by high values of electrical conductivity and high electrochemical activity in oxygen reduction reaction, and are considered as prospective cathode materials for intermediate-temperature solid oxide fuel cells (SOFC) on the base of proton- and oxygen-ion conducting solid electrolytes (SE). Effective cathode materials should be thermomechanically compatible with materials of SE, which tаkes place when the values of their thermal expansion coefficients (TEC) are close to each other. Due to this the study of thermal expansion of ODP as well as the isotation of different contributions in it (thermal, chemical, spin etc.), is of considerable interest. In this work using dilatometric method the thermal expansion of NdBa1–xSrxFeCo0,5Cu0,5O6−δ (0.0 ≤ х ≤ 1.0) (NBSFCC) ODP was studied using dilatometric method. It was established that the values of average linear thermal expansion coefficient (LTEC) (α) of the samples sharply increased from (15.1–16.2) · 10–6 K–1 at Т < 630–920 K to (18.9–23.5) 10–6 K–1 at Т > 630–920 K due to the evolution of weaklybonded oxygen from the samples. Values of α in the low-temperature region increase with increasing of values of their oxygen nonstoichiometry index (δ), and in the high-temperature one increase with the x increasing due to the increment of chemical contribution in the samples expansion. Based of the results of dilatometry, thermogravimetry, and iodometry, the thermal and chemical contributions in the expansion оn NBSFCC were isolated, and the effect of crystal structure, cationic and anionic composition of NBSFCC ODP on the values of their thermal and linear chemical expansion coefficient (LCEC, αδ ) was investigated. It was found, that LCEC values of the samples sharply increased from (8.6–11.8) · 10–3 at (х < 0.5) to (12.6–15.8) · 10–3 at (х > 0.5) when transition from ordered tetragonal (х < 0.5) to disordered cubic (х > 0.5) phase took place. It was shown, that dependences of LTEC and LCEC of NBSFCC phases on their crystal structure and chemical compositions obtained in this work are in good accordance with the analogous dependences determined earlier for the ODP of other types.