Performance of ceramic cathode current collector with novel microstructure for solid oxide fuel cells

A ceramic material, Sm_0.5Sr_0.5CoO₃, is used for both cathode and current collector, aiming to lower the interface barrier. The current collector is prepared by phase inversion combined with laser scanning technique to obtain a novel microstructure featured by highly oriented finger-like pores inside and an array of hump-like tips on surface. The pores and surface two-dimensional trench network serve as micro-channels for gas transport, while the hump-like micro-points function as current collecting tips. The mean distance between the adjacent tips is about 50 μm, which significantly decreases the migration distance of electrons. The polarization resistance of symmetrical cell with the as-prepared current collector is only 20% of that with Ag collector, and the corresponding value in single cell decreases about 40% at 800 °C. The underlying mechanism for the impact of the ceramic current collector is discussed by revealing the correlation between the unique microstructure and the electrochemical performance.