Oxide Cathodes for Electrochemical Devices Made with the Use of a Nanostructured Composition Material
Russian Journal of Electrochemistry
, E-ISSN: 1608-3342
||(La,Sr)MnO 3, Electrocatalytic additive PrO2 - x, Electrochemical activity, Mischmetal, Nanostructured composite, Ohmic resistance
Institute of High Temperature Electrochemistry, Ural Branch, Russian Academy of Sciences, ul. S. Kovalevckoi 22, Yekaterinburg, 620990 Russia
Ural Federal University, ul. Mira 19, Yekaterinburg, 620002 Russia
Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, pr. ak. Lavrent’eva 5, Novosibirsk, 630090 Russia
The possibility of using the LnO x mischmetal (Ln = Ce, La, Nd, Pr, Sm) for preparation of cathodes for solid-oxide fuel cells with the supported YSZ electrolyte is studied. The electrical and electrochemical 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 La0.8Sr0.2MnO3 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 Ω 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% La0.8Sr0.2MnO3 in the initial state and after their modification through the introduction of an electrocatalyst (PrO2 − x ). The highest polarization conductivity is typical of Ln-Mn-O + (La, Sr)MnO3 electrodes containing 40 wt % Ln-Mn-O and PrO2 − x . The polarization conductivity of these electrodes is found to be 25 S/cm2 at 800°C.