Baln(0.3)Ti(0.7)O(2.85) (BIT07) is a new electrolyte material for solid oxide fuel cells (SOFC). Its use with the cathode material La0.58Sr0.4Co0.2Fe0.8O3-delta (LSCF) is advantageous due to their reaction (above 1000 degrees C) that leads to the formation of perovskite compounds called BLSITCFx (Ba(x)L(0.58(1-x))Sr(0.4(1-x))In(0.3)Ti(0.7)xCo(0.2(1-x))Fe(0.8(1-x))O(3-delta), with 0 <= x <= 1) at the cathode/electrolyte interface. In this study, the influence of the cathode microstructure on its performance has been investigated, by varying the cathode parameters. An area specific resistance (ASR) value of 0.07 Omega cm(2) at 700 degrees C has been reached and more generally the cathodes exhibit good performance (below 0.2 Omega cm(2)) for a large range of thermal treatments, cathode grain sizes and thicknesses. An ageing study realised at 700 degrees C for 320 h showed an ageing rate of 0.125%h(-1). (C) 2012 Elsevier B.V. All rights reserved.