LAUSR

The design of new electrode materials with high redox stability has great potential for the fabrication of solid oxide fuel and electrolysis cells having a symmetrical configuration; such a configuration is particularly promising in terms of economic and technological factors due to involving a reduced number of functional materials and technological steps. Under the framework of the present study, we developed new Nd1–xBaxFe0.9M0.1O3–δ materials (where M = Cu or Ni, x = 0.4 or 0.6), characterizing their functional properties (oxygen non-stoichiometry, thermomechanical and electrical properties) under both oxidizing and reducing conditions, as well as demonstrating the principal capability of their application as symmetrical electrodes in proton-conducting electrochemical cells. The obtained results demonstrate the desirability of a low barium content due to decreased thermal expansion coefficients and chemical strain contribution and Cu-doping due to the formation of an electrochemically active scaffold having nano-sized sediments. The Nd0.6Ba0.4Fe0.9Cu0.1O3–δ electrodes fabricated onto the BaCe0.5Zr0.3Y0.1Yb0.1O3–δ proton-conducting electrolytes exhibit polarization resistances of 1.1 and 15.1 Ω cm2 at 600 °C in wet air and wet hydrogen measuring atmospheres, respectively. These reported results are among the first concerning the effective operation of symmetrical electrodes in systems with proton-conducting electrolytes. Graphical abstract Graphical abstract