Oxide cathodes for electrochemical devices made with the use of a nanostructured composition material

Abstract

The possibility of using the LnO x mischmetal (Ln = Ce, La, Nd, Pr, Sm) for preparation of cath- odes for solid-oxide fuel cells with the supported YSZ electrolyte is studied. The electrical and electrochem- ical characteristics of Ln-Mn-O electrodes with the ratio of all lanthanides contained in the mischmetal except for cerium to manganese Ln : Mn = 1 : 1 and also of a material comprised of Ln-Mn-O and La 0.8Sr 0.2MnO 3 are studied. The latter electrode material that contains 35-40 wt % of Ln-Mn-O and was sintered at 1200°C has the specific ohmic resistance of 0.1 O cm at 800°C. The polarization conductivity is compared for electrodes made of 100% Ln-Mn-O, 40 wt % Ln-Mn-O + 60 wt % La0.8Sr0.2MnO3, and 100% La 0.8Sr 0.2MnO 3 in the initial state and after their modification through the introduction of an electro- catalyst (PrO 2 - x). The highest polarization conductivity is typical of Ln-Mn-O + (La, Sr)MnO3 electrodes containing 40 wt % Ln-Mn-O and PrO 2 - x. The polarization conductivity of these electrodes is found to be 25 S/cm2 at 800°C. © Pleiades Publishing, Ltd., 2012.