“…Many cobalt-containing perovskite oxides (like Sm0.5Sr0.5CoO3-δ [6][7][8], La1-xSrxCoO3-δ [9][10][11][12][13][14], La1-xSrxCo1-yFeyO3-δ [15,16], Ba1-xSrxCo1-yFeyO3-δ [17][18][19]) have been developed as cathode materials for intermediate temperature range (500-700 ℃), which demonstrate that excellent ionic and electronic conductivities extend the triple-phase boundary (TPB) region from the cathodeelectrolyte interface into the bulk of the cathode. The powders of these cathode materials are made typically by sol-gel [20][21][22], solid state [23][24][25], combustion [26][27][28], acetic-acrylic [5,29,30], citric acid-EDTA [4,9,10,16,31], solid-liquid [32][33][34][35] etc.…”