Simulations of REBaCo2O5.5 (REGd, La, Y) cathode materials through energy minimisation and molecular dynamics

► REBaCo2O5.5 materials were simulated by energy minimisation and molecular dynamics. ► Oxygen vacancies are always located preferentially in the RE plane. ► The oxygen diffusion coefficient increases as RE radius increases. ► The stability of the A-site ordered phase tends to diminish as RE radius increases.