The physical properties and effects of sintering conditions on rSOFC fuel electrodes evaluated by molecular dynamics simulation

Reversible solid oxide fuel cell (rSOFC) can produce and store energy through dual-mode operating, which is promising for balancing the conflicts between power supply and requirements. One crucial issue is to develop high performance of fuel electrode materials, in terms of materials costs, mechanical strength, mass production in commercialization. The reversible performance of the materials may be enhanced by electrode microstructure optimization in the preparation procedures. It is beneficial to understand the mechanisms of sintering process, in terms of the electrode particle interactions and sintered structure in the molecular/nanoparticle level. Accordingly, a molecular dynamics method is developed to simulate the sintering process for the LST/GDC nanoparticle systems. It is found that a high sintering temperature is beneficial for increasing triple-phase-boundary (TPB) length, but not for the effective surface area of catalyst particles. A mass fraction of 0.5–0.6 is predicted as the optimal LST composition for the TPB length, active surface area, and compatible thermal expansion coefficient. The heat capacity and thermal conductivity increase in the high sintering temperature and high mass fraction of LST conditions. The methodology and findings can provide a guideline on optimization of the sintering conditions for LST/GDC electrodes, which may promote the commercialization of rSOFC technology.