Development of new anodes compatible with the solid oxide fuel cell electrolyte BaIn0.3Ti0.7O2.85

A new family of MIEC compounds resulting from the electrolyte BaIn0.3Ti0.7O2.85 (BIT07) was developed by coupled substitution of titanium by iron and barium by lanthanum. Total conductivity increases significantly with iron and lanthanum content. BaIn0.3Ti0.7O2.85 yields a total conductivity in air of 10−2 S cm−1 at 700 °C whereas that of Ba0.7La0.3In0.3Ti0.1Fe0.6O3−δ (BLITFe06) is 3 S cm−1. Doped compounds are p-type conductors. In reducing atmosphere the electrical conductivity decreases drastically to σ = 2 × 10−2 S cm−1 for the best value, which is not sufficient for a use as MIEC anode. Nevertheless, Ni/BLITFe06 cermets seem to be good candidates as SOFC anodes. The total conductivity of Ni/BLITFe cermets is higher than that of 18.7 vol.% Ni/BIT07 (σ700 °C ≈ 102 S cm−1), even for a lower Ni content (16.1 vol.% Ni/BLITFe σ700 °C ≈ 200 S cm−1). The percolation threshold moves towards the small quantities of nickel (from 15.7 vol.% to 10 vol.%). Ni/BLITFe06 cermets, compared with Ni/BIT07, show a better electrochemical behaviour towards fuel oxidation.

► New Ni–MIEC cermet anodes compatible with BaIn0.3Ti0.7O2.85 (BIT07) were developed.
► MIEC compounds BLITFe based on BIT07 were developed by coupled substitution.
► Ni/BLITFe cermets exhibit a better electrochemical behaviour towards fuel oxidation.