The review addresses and highlights the main results of research on the physicohemical properties of single-phase and composite materials based on transition metal oxides in relation to their practical application as electrode materials for symmetrical solid oxide fuel cells. The electronic structures and thermodynamic stability of transition metal oxides with the perovskite structure are discussed. A detailed consideration is given to the thermal behaviour, chemical stability, electrical conductivity and electrochemical properties of a broad range of electrode materials based on iron-, chromium- and manganese-containing perovskite-like oxides and oxides that crystallize in other structure types. The analysis revealed the most promising compositions of electrode materials for symmetrical solid oxide fuel cells and effective approaches to the improvement of their functional characteristics. The bibliography includes 202 references.

Oxygen diffusion in ${\text{Sr}}_{0.75}{\text{Y}}_{0.25}{\text{CoO}}_{2.625}$ is investigated using molecular dynamics simulations in conjunction with an established set of Born model potentials. We predict an activation energy of diffusion for 1.56 eV in the temperature range of 1000–1400 K. We observe extensive disordering of the oxygen ions over a subset of lattice sites. Furthermore, oxygen ion diffusion both in the $a\text{−}b$ plane and along the $c$ axis requires the same set of rate-limiting ion hops. It is predicted that oxygen transport in ${\text{Sr}}_{0.75}{\text{Y}}_{0.25}{\text{CoO}}_{2.625}$ is therefore isotropic.

High-spin ground state of Co³⁺ was found in brownmillerite-like Sr₂Co_1.2Ga_0.8O₅ by low-temperature NPD and XAS study.