Synthesis of Ce0.8Sm0.2O1.9 solid electrolyte by a proteic sol-gel green method

Abstract

The present study reports the synthesis of Ce0.8Sm0.2O1.9 solid electrolyte by a novel proteic sol-gel method which uses gelatin as polymerizing agent. The as-synthesized powder material was calcined at 700 degrees C for 2 h, with X-ray diffraction revealing a single cubic phase with lattice parameter a = 0.5435 nm and theoretical density of 7.144 gcm(-3). The average crystallite size is 12 nm, as determined by the Scherrer equation. Impedance spectroscopy revealed a larger resistive contribution of the grain boundaries than that from grain bulk, which, due to its lower activation energy, tends to dominate the total conductivity above 650 degrees C. The total conductivity is in line with literature data for ceramics of the same composition prepared by various methods, thus confirming the potential of the proteic sol-gel method as a green, low cost alternative synthetic route to prepare ceria-based solid electrolytes.