In this study, Nd_1.6Ca_0.4Ni_1−yCu_yO_4+δ-based electrode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs) are investigated. Materials of the series (y = 0–0.4) are obtained by pyrolysis of glycerol-nitrate compositions. The study of crystal structure and high-temperature stability in air and under low oxygen partial pressure atmospheres are performed using high-resolution neutron and in situ X-ray powder diffraction. All the samples under the study assume a structure with Bmab sp.gr. below 350 °C and with I4/mmm sp.gr. above 500 °C. A transition in the volume thermal expansion coefficient values from 7.8–9.3 to 9.1–12.0 × 10⁻⁶, K⁻¹ is observed at approximately 400 °C in air and 500 °C in helium.The oxygen self-diffusion coefficient values, obtained using isotope exchange, monotonically decrease with the Cu content increasing, while concentration dependence of the charge carriers goes through the maximum at x = 0.2. The Nd_1.6Ca_0.4Ni_0.8Cu_0.2O_4+δ electrode materialdemonstrates chemical compatibility and superior electrochemical performance in the symmetrical cells with Ce_0.8Sm_0.2O_1.9, BaCe_0.8Sm_0.2O_3−δ, BaCe_0.8Gd_0.19Cu_0.1O_3−δ and BaCe_0.5Zr_0.3Y_0.1Yb_0.1O_3−δ solid electrolytes, potentially for application in IT-SOFCs.

The ¹⁶ O/ ¹⁸ O oxygen exchange kinetics between the gas phase and the oriented single crystal and polycrystalline specimen has been studied; the rates of individual stages of oxygen exchange have been calculated and discussed.