Ionic conductivity of oxygen in BaTiO 3 , Ba 0.9 A 0.1 TiO 3-δ (A: Li + , Na + , Ca 2+ ), and BaTi 0.9 B 0.1 O 3-δ (B: V 3+ , Cr 3+, Si 4+ ) crystals with cubic perovskite structure as cathode in fuel cell: A molecular dynamics study

Abstract Oxygen ions diffusion in the perfect barium titanate ( BaTi O 3 ), Ba 0.9 A 0.1 TiO 3- δ (A : Li + , Na + , Ca 2+ ), and BaTi 0.9 B 0.1 O 3- δ (B: V 3+ , Cr 3 + , Si 4+ ) crystals using molecular dynamics, in order to improve the ionic conductivity of BaTi O 3 as a cathode in fuel cells have been investigated. In this study, the interactions between the ions are modeled by the Buckingham and electrostatic potentials. The results of investigations into BaTi O 3 structures including Li + , Na + , Ca 2 + , V 3 + , Cr 3 + and Si 4 + , indicated that Li + cation improves oxygen ions diffusion and thus the ionic conductivity of BaTi O 3 is better than the others. In addition, it found that suitable site for doped external cations ( Li + , Na + , Ca 2 + , V 3 + , Cr 3 + and Si 4 + ) to improve ionic conductivity of oxygen in AB O 3 Perovskite, is A-site. Also, investigation into migration and distribution of doped external cations showed that these cations refrain from the formation of cation clusters with a good approximation.