| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1293430 | Solid State Ionics | 2015 | 6 Pages |
•On Sr and Fe doping the diffusivity of PBCO was estimated to increase.•Higher diffusivity in PBSCO and PBCFO can be correlated to the reduction in ASR.•The diffusivity was estimated to be maximum in co-doped PBSCFO.•High diffusivity in PBSCFO explains the measured high peak power density.•The diffusivity follows the trend PBSCFO > NBSCFO > GBSCFO for co-doped structures.
Molecular dynamics simulations were utilized to calculate self-diffusion coefficients in double perovskite LnBa1 − ySryCo2 − xFexO5 + δ (Ln = Pr, Nd, Gd) electrodes. Anisotropic oxygen diffusion was observed in the a–b plane for all the studied structures. In order to assess the role of A-site and B-site dopants such as Sr and Fe, the diffusion coefficient of oxygen ion in PrBaCo2O5.5 was estimated and compared to PrBa0.5Sr0.5Co2O5.5 and PrBaCo1.5Fe0.5O5.5. On doping with 50% Sr at A′-site, a 2.77 fold increase in diffusivity value was predicted at 873 K as compared to the undoped structure. Similar levels of increase in diffusivity values were observed with 25% Fe doping relative to PrBaCo2O5.5. On co-doping Sr and Fe, oxygen diffusion coefficient was observed to be of the highest value (1.18 × 10− 7 cm2 s− 1) at 873 K for PrBa0.5Sr0.5Co1.5Fe0.5O5.5. Changing the A-site lanthanide cation from Pr to Gd and Nd, led to the reduction in diffusivity value in the order of Pr3 + > Nd3 + > Gd3 +. The calculated diffusivity was observed to be higher, wherever an improved electrochemical performance is reported, highlighting the important role of oxygen anion transport.
