Preparation of Porous LSM/YSZ Composite with Varying Grain Size of YSZ Precursor Using Solid State Reaction Method

Abstract

Lanthanum strontium manganite (LSM) and yttria-stabilized zirconia (YSZ) composite is a promising material as an anode for solid oxide electrolysis cell (SOEC) applications. In this study, LSM/YSZ with a 1:1 LSM to YSZ weight ratio was synthesized via solid state reaction method using oxide precursors of commercial micrograined size LSM with varying YSZ precursor grain size. For the YSZ precursor, both nanograined (nanoYSZ) and micrograined YSZ (microYSZ) precursors were studied. Graphite was added at 10% weight ratio as a pore former. Density measurements using Archimedes principle revealed that LSM/nanoYSZ had the highest relative density of 97.8%, whereas LSM/nanoYSZ with graphite had the lowest density of 89.1%. The addition of graphite to LSM/nanoYSZ reduced the density by 8.7% compared to the decrease of 5.5% for LSM/microYSZ. Scanning electron microscopy confirms that the addition of graphite has a greater effect on the microstructure of LSM/nanoYSZ as compared to LSM/microYSZ. The electrochemical impedance spectroscopy results show that the samples with nanoYSZ had a higher total conductivity than the samples with microYSZ. LSM/nanoYSZ and LSM/nanoYSZ with graphite revealed a total conductivity values of 0.0470 Scm-1and 0.0440 Scm-1at 700 °C with activation energies of 0.0178 eV and 0.0234 eV, respectively.