Characterisation and optimisation of the cathode/electrolyte couple for SOFC LSCF/BIT07

BaIn0.3Ti0.7O2.85 (BIT07) is a new electrolyte material for solid oxide fuel cells (SOFC). Its use with the cathode material La0.58Sr0.4Co0.2Fe0.8O3−δ (LSCF) is advantageous due to their reaction (above 1000 °C) that leads to the formation of perovskite compounds called BLSITCFx (BaxLa0.58(1−x)Sr0.4(1−x)In0.3xTi0.7xCo0.2(1−x)Fe0.8(1−x)O3−δ, 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 Ω cm2 at 700 °C has been reached and more generally the cathodes exhibit good performance (below 0.2 Ω cm2) for a large range of thermal treatments, cathode grain sizes and thicknesses. An ageing study realised at 700 °C for 320 h showed an ageing rate of 0.125% h−1.

► Mechanical and chemical characterisations of an LSCF/BIT07 assembly. ► Optimisation of the half cell performance by a design of experiments. ► Study of the half cell ageing behaviour