Structure-property relationship in Mg-doped La_0.75Sr_0.25Mn_0.5Cr_0.5O₃ anode for solid oxide fuel cell

Lanthanum strontium chromium manganite (LSCM) has been found to be a potential candidate for SOFC anode to use in hydrocarbon fuels. Mg-doped LSCM has been synthesized by solid state reaction and tested for its sulphur tolerance when used as anode of solid oxide fuel cells. This material shows redox stability, compatibility with other cell components, acceptable level of cocking and sulphur tolerance. Structural studies using X-ray and neutron powder diffraction shows that the materials crystallize in the rhombohedral symmetry in the R-3C space group. Thermogravimetric analysis shows stable redox behaviour similar to LSCM. Microstructural analysis shows porous structure which is essential for an anode material. Performance of this material as an anode of SOFC has been tested in H2, CH4 and H₂S/H₂/CH₄ atmosphere at different temperatures. Impedance analysis show that best performance can be achieved at about 870 °C corresponding to the polarization resistance of 0.5 ohm/cm² in pure H₂ and 1.0 ohm/cm² in CH₄. Microstructural analysis after cell preparations shows a good lamination between the electrolyte and anode.