A high performance solid oxide fuel cells operating at intermediate temperature with a modified interface between cathode and electrolyte

By adding 1% Bi2O3 (mol%) into LSCF (La0.54Sr0.44Co0.2Fe0.8O3−δ), a layer of dense LSCF film is introduced to the upside of yttria stabilized zirconia (YSZ) electrolyte. The dense film increases the interface contact area and reduces the interface ion transfer resistance between cathode and electrolyte remarkably. As a result, the cell performance is greatly elevated from 492 to 901 mW cm−2 at 650 °C. Besides, on the basis of careful observation of the cathode surface by FE-SEM, the function of Bi2O3 to promote the cathode sintering is speculated. The Bi2O3 and the LSCF come into being a kind of eutectic liquid. The eutectic liquid flows down from the cathode bulk to the interface between the cathode and the electrolyte where it accumulates to form a dense layer. This dense layer illuminates the function of adding Bi2O3 into LSCF cathode.