Rare-earth elements doped Nd2CuO4 as Cu-based cathode for intermediate-temperature solid oxide fuel cells

The design of cobalt-free cathode substance with unexceptionable electrochemical property and high thermochemical stability is an important target for IT-SOFC. In this work, the impact of some rare earth elements doping on the construction, TEC, DC conductivity and electrochemical properties of Nd(1.9)Ln(0.1)CuO(4) (Ln=La, Nd, Sm and Ce) are investigated. Nd(1.9)Ln(0.1)CuO(4) forms single tetragonal structure. The doped rare earth elements are found to have major influences to the cell parameter c, and the cell volumes decrease steadily when the doped elements change from lanthanum to cerium. XPS measurement certifies that Ce4+-doping facilitates the oxygen adsorption capacity on material surface. Among the studied Nd(1.9)Ln(0.1)CuO(4) materials, Nd1.9Ce0.1CuO4 shows the highest surface oxygen adsorption capacity, the largest DC conductivity, and the compatible TEC values with that of Ce0.9Gd0.1O1.95 (CGO) electrolyte. Meanwhile, the electrochemical impedance spectrum (EIS) result shows that Nd1.9Ce0.1CuO4 has the highest electrocatalytic activity. The polarization resistance is 0.66 Omega cm(2) at 700 degrees C in air. And the CGO electrolyte supported single cell delivers a peak power density (PPD) of 283 mW.cm(-2) at 700 degrees C. The oxygen partial pressure depending EIS measurements prove that the oxygen reduction reaction limiting step is oxygen dissociation process on Nd1.9Ce0.1CuO4. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Doped rare earth elements significantly influence the properties of Nd(1.9)Ln(0.1)CuO(4), with Nd1.9Ce0.1CuO4 showing the highest performance in terms of surface oxygen adsorption, DC conductivity, and electrocatalytic activity.