Nickel-cermet anode for fuel cells with the LSGM electrolyte

The effect of some technological parameters (firing temperature, thickness of an interphase layer made of solid electrolyte Ce_0.82Gd_0.18O_1.91 (GDC), the GDC electrolyte amount in nickel-cermet) on the electrochemical and electric properties of a nickel-cermet (Ni-GDC) anode intended for fuel cells with the La_0.88Sr_0.12Ga_0.82Mg_0.18O_2.85 (LSGM) electrolyte is studied. The polarization resistance of such an electrode is shown to hardly depend on the thickness of the interphase layer (4.5–23.5 μm) and the GDC electrolyte amount in nickel-cermet and to increase with the anode firing temperature. It is established that the contact resistance is concentrated in cells with the developed nickel-cermet electrode at the GDC/LSGM interface. At a temperature of 700°C the developed anodes may ensure a current density of 1 A cm^?2 at an overvoltage of less than 100 mV when using both moist hydrogen and a methane-oxygen mixture as the fuel.     

Structure and Electric Conductivity of (La,Sr)(Ga,Mg)O3-α Solid Electrolyte

Electric conductivity, Raman spectra, and thermal expansion of La_0.88Sr_0.12Ga_0.82Mg_0.18O_2.85 solid solution (LSGM1218) based on lanthanum gallate were studied at various temperatures, and Xray phase analysis was performed at room temperature. Dilatometric measurements showed that secondorder phase transitions occur at 775±10$ and 880± 20 K. The transition around 880 K is confirmed by Raman spectra and by a change in the conductivity activation energy in this temperature range. This transition is associated with a symmetry change in the oxygen sublattice.     

Certain features of cooling process of protons and antiprotons in ultracold electron gas

In this study, the method of molecular dynamics is used for investigation of the processes of energy losses of solitary protons and antiprotons in an electron gas in dependence on the kinetic energy of the charged particles and the value of the magnetic-field induction.     

Collisional recombination coefficient in an ultracold plasma: Calculation by the molecular dynamics method

New results of the calculations of the distribution function and the electron diffusion coefficient in energy space are presented. We analyze all of the data obtained and calculate the temperature dependence of the recombination coefficient. This dependence coincides with the Gurevich-Pitaevsky analytical formula in the region of a weakly coupled plasma and begins to differ in the direction of a decline in the region of a strongly coupled plasma; the difference can reach several orders of magnitude.     

Electrode kinetics at the Pt,O2|La0.9Sr0.1ScO3-δ interface

Journal of Solid State Electrochemistry - Most of the ceramic proton conductors reveal considerable hole conductivity in an oxidizing ambient. This results in a necessity of taking into account the...     

Statistical characteristics of polarization of pulse signals in vertical probing of the ionosphere

Scientific-Research Institute of Physics at the Rostov State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 32, No. 11, pp. 1327–1334, November, 1989.     

On the theory of anomalous absorption of an ordinary wave

We obtain and analyze numerically exact formulas for anomalous absorption of a probing ordinary wave due to its transformation into plasma waves under vertical sounding of an ionospheric plasma layer with given spectrum of irregularities. The nature of possible approximations and their validity limits are analyzed. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 8, pp. 826–836, August 1999.     

Formation of Thin-Film Electrolyte by Electrophoretic Deposition onto Modified Multilayer Cathode

Russian Journal of Applied Chemistry - Possibility of forming a gas-tight thin-film solid electrolyte by the electrophoretic deposition method on a modified multilayer cathode was examined. The...     

Behaviour of a dense In2O3/ YSZ electrode in oxygen containing atmospheres

A study of electrical and electrochemical properties of a dense In₂O₃ electrode in contact with a single crystal YSZ electrolyte was carried out by d.c. and a.c. methods. As a result, it was found that dense In₂O₃ electrodes have high electrical conductivity but very low electrochemical activity. In a vicinity of the equilibrium potential and under the anodic polarisation, the rate of Faraday reaction at the In₂O₃ electrodes was as low as to consider the electrode a blocking one. The blocking properties of the In₂O₃ electrodes were used to measure the hole conductivity of the YSZ electrolyte in the temperature range between 795 to 1163 K and oxygen partial pressure from 1 to 10⁵ Pa. A comparison with the literature data confirmed that the dense In₂O₃ electrode blockes the ionic transfer through the YSZ. A set of experiments indicated that the oxygen exchange between the indium oxide surface presented to the oxygen containing gaseous phase and this phase is very poor. A route of the electrode process at O₂, In₂O₃ / YSZ electrode was proposed a limiting stage of which is the discharge of the oxygen ions to the atomic oxygen adsorbed on the electrode surface: $$O_0 ^x \left( {In_2 O_3 } \right)_s = V_0 ^{ \bullet \bullet } \left( {In_2 O_3 } \right)_s + O_{ad} \left( {In_2 O_3 } \right)_s + 2e'\left( {In_2 O_3 } \right).$$ The polarisation resistance decreases when platinum or the praseodymium oxide is deposited on the surface of the In₂O₃ electrodes. The cathodic polarisation also increases the electrochemical activity of the electrodes. Both the establishment of the steady state of the electrode under polarisation and the recovery of the equilibrium state by the electrode are very long processes, which are probably related to the diffusion mechanism by which the stoichiometry of the indium oxide is changed.     

On the behavior of a dense indium oxide/yttria-stabilized zirconia electrode

The electrical, structural and electrochemical properties of a dense In₂O₃ layer in contact with a single crystal YSZ electrolyte were studied. As a result of dc and ac investigations, it was found that under anodic polarization the rate of Faraday reaction at the surface of the In₂O₃ electrode is as low as in an ionically blocked electrode. Under cathodic polarization, however, the electrochemical activity of the electrode improves depending on the magnitude of the polarization voltage. Likewise, the electrode polarization resistance decreases after platinum or praseodymium oxide having been deposited on the surface of the In₂O₃ layer. The possible mechanism responsible for such a peculiar behaviour and the limiting step of the electrode reactions are discussed.