Anodic Performance of BaO-Added Ni/SDC for Solid Oxide Fuel Cell Fed With Dry CH4

SOFCs fed with dry H2 and CH4 fuels were examined using 20 wt% Ni/SDC and 0.2 wt% BaO-added 20 wt% Ni/SDC [Ni(BaO)/SDC] anodes. The i–v characteristics of the cells in H2 and CH4 resulted in a higher output produced by CH4 fuel compared to that produced by H2 fuel in both anodes. In both fuels, better anode characteristics were obtained for Ni(BaO)/SDC. Consequently, the anodic performance was in the order of Ni(BaO)/SDC in CH4 > Ni/SDC in CH4 > Ni(BaO)/SDC in H2 > Ni/SDC in H2. A significant carbon deposition was observed in the Ni/SDC anode in CH4, but the carbon deposition observed in Ni(BaO)/SDC was less. From the DC electrical resistance measurement of the anode films, a remarkable decrease in resistance was observed in Ni/SDC due to the carbon deposition after CH4 exposure. The resistance of Ni(BaO)/SDC was higher than that of Ni/SDC and did not change even after CH4 exposure because of the less carbon deposit. The high dispersibility of Ni particles was confirmed in both anodes and was particularly remarkable in Ni(BaO)/SDC. The highest anodic performance in Ni(BaO)/SDC was attributed to the high Ni dispersibility which might promote CH4 decomposition by producing less carbon deposit. It was speculated that the higher cell output in CH4 than that in H2 is due to the locally high concentration of H2 and/or CO gas on the anode surface by the promotion of CH4 decomposition.

Morphology of ZnO Films Fabricated by Electrochemical Oxidation of Metallic Zn

Anodic oxide films of zinc oxide in an aqueous solution of K Cl (0.1 M; 0.5 M and 1 M) were obtained by electrochemical oxidation of zinc metal. Zinc electrode was used as anode and platinum plate as cathode. The study discusses the influence of the concentrations of K Cl solution and the voltage applied to the electrochemical cell on the morphology of the obtained anode films, as well as their thermodynamic stability. The analysis of volt-ampere curves of linear potential sweep and chronoamperometric dependences showed that oxidation in 0.1 M K Cl solution at a voltage of 7.5 V allows to obtain continuous stable defect-free Zn O films on metal zinc.

Влияние диффузионных барьеров на емкостные свойства композитных анодов состава Si-CuSi-Cu

As an anode material for liquid lithium-ion batteries, film structures consisting of several identical modules [Co(x)/a-Si(100)/Cu(70)], where the value of x varied from 2 to 10 nm, have been studied. It is shown that relatively thick cobalt layers are effective diffusion barriers for silicon and copper atoms, as well as lithium ions. This leads to a decrease in the capacitive properties of the studied films. Thin cobalt layers (less than 3 nm) with a network structure, on the contrary, contribute to an increase in the capacitive properties of anode films. This is due to a more uniform distribution in their volume of drift channels of lithium ions, which are formed at the initial stage of electrode cycling.