Theoretical Analysis of Cation Diffusion Pathway in SOFC Interlayer

Cation diffusions in solid oxide fuel cell (SOFC) interface can cause some degradations. For instance, the effect that gadolinium-doped ceria (GDC) interlayer on the cathode prevent degradation of the SOFC cathode, and its degradation during current load cycling was investigated (1). Additionally, when  (LSCF) is used as cathode, Sr diffuses from the cathode to electrolyte through GDC interlayer and then insulating materials precipitates on the electrolyte. It is necessary to raise the temperature immediately or use large-scale experimental devices such as neutron diffraction device or accelerator (2) to trace cation diffusion pathway. By using molecular dynamics simulation (MD), diffusion pathway of oxygen ion is elucidated. However, in the time scale of MD simulation the structural and chemical transformations involving the breaking and formation of bonds are rare events (3). It is caused by the difference of jump probabilities. Thus, to accelerate the diffusion of cation, metadynamics method which adds history-dependent bias potential constructed by summing Gaussian-shaped is used (4). In this work, LSCF cathode, GDC interlayer and yttria stabilized zirconia (YSZ) electrolyte are modeled to simulate to trace cation diffusion pathway in SOFC interface.

References

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3. J. Kiss, T. Gruhn, G. Roma, C. Felser, J. Phys. Chem. C, 117, 25933 (2013)
4. U. Aschauer, P. Bowen, S. C. Parker, Acta Materialia, 57, 4765 (2009)