Novel methods were applied in this work to elucidate the structure evolution of Ln2-xCaxNiO4+δ oxides (Ln = La, Pr, Nd; x = 0, 0.3) and study their oxygen mobility. Relationship between cations state, structural, electrical, electrochemical and kinetic properties was revealed. In all doped materials the overall oxygen mobility characterized by Do declined by more than an order of magnitude due to decreasing the interstitial oxygen content and hampering cooperative mechanism of oxygen migration. For La nikelate additional slow diffusion channel appears with DO 5.4·10−14 cm2/s at 700 K. Correlation of electrochemical and oxygen transport properties was demonstrated. A high electrical conductivity (up to 120 S/cm at 700 K) in Ln1.7Ca0.3NiO4+δ (Ln = Pr, Nd) along with satisfactory oxygen mobility and electrochemical properties makes these materials promising for a wide row of electrochemical applications.