B. L. Kuzin

Electroconductivity, Nature of Conduction, Thermodynamic Stability of the BaPr1 –xYxO3 – αCeramics

AbstractThe electroconductivity and the nature of conduction of vacuum-dense ceramics BaPr1 – xYxO3 – α(x= 0.05–0.15) is studied at temperatures of 373 to 985°C,

Effect of oxygen activity and water partial pressure to degradation rate of Ni cermet electrode contacting Zr0.84Y0.16O1.92 electrolyte

P_{0_2}

Cathodes based on (La, Sr)MnO3 modified with PrO2 − x

of 2.1 × 104to 10–11Pa, and

Electrochemical properties of cathodes made of (La,Sr)(Fe,Co)O3 containing admixtures of nanoparticles of cupric oxide and intended for fuel cells with a solid electrolyte based on ceric oxide

P_{{\text{H}}_2 0}

Nickel-cermet electrodes for high-temperature electrochemical devices made using nanomaterials

of 40 to 2400 Pa. The coefficient of linear thermal expansion is measured. The ceramics have a perovskite structure and are practically p-type semiconductors with a maximum conductivity of 0.26 S cm–1at x= 0.10 and 800°C, in air. The share of ionic (proton) conductivity of the ceramics does not exceed 0.2–0.4%. The conductivity is weakly dependent on the air humidity. In a hydrogen-containing atmosphere, the ceramics undergoes reduction with destruction. Boundaries of thermodynamic stability of BaPr0.9Y0.1O3 – αat 500–900°C are determined.

Effect of Bi0.75Y0.25O1.5 electrolyte additive in collector layer to properties of bilayer composite cathodes of solid oxide fuel cells based on La(Sr)MnO3 and La(Sr)Fe(Co)O3 compounds

The electrochemical behavior of Ni cermet electrode with CeO2 − x additive in contact with YSZ electrode was studied by means of impedance spectroscopy in H2, H2O, CO2, CO, He, and Ar gas media of various composition within the temperature range of 700 to 950°C. Near the equilibrium potential, the electrochemical impedance spectra of the studied electrodes indicate to three stages of electrode reaction. The polarization conductivity of the low-frequency stage of electrode reaction (σlf) is characterized with the following regularities: (a) temperature dependence of σlf has a positive slope in Arrhenius coordinates; (b) σlf increases upon replacement of gas mixture with lower mutual diffusion coefficient by mixture with higher mutual diffusion coefficient, while polarization conductivity values of other stages remain practically invariable; (c) concentration relationships of 1/σlfrecorded for constant activity of oxygen in the gas phase are linear in the 1/σlf vs. 1/PCO2 (PCO) coordinates; (d) no low-frequency stage of the electrode reaction is observed upon electrochemical inflow (outflow) of the gas reagents (reaction products) to (from) the test electrodes (current passing through closely pressed specimens and central specimen impedance measurement); and (e) no change in the gas flow rate affects σlf value. The observed regularities were explained by assuming the gas diffusion nature of the low-frequency stage of the electrode reaction. The gas diffusion layer thickness was estimated.