Comprehensive analysis and optimization of Y-doped and Ni-added BaZrO3 proton conductor

Abstract

Proton-conducting materials have been proposed as the electrolytes for the medium to low-temperature Solid Oxide Cells (SOC). It is challenging to be widely applied as these materials suffer issues associated with cost, durability, and high energy consumption for preparation. Among all the proton conductors, the Y-doped and Ni-added BaZrO3-based conductors possess sufficient conductivity and stability under humid and/or carbon dioxide atmospheres. Here, we prepared a series of Y and NiO-co-doped BaZr1 − xYxO3−δ (x = 0.1, 0.15, 0.2, 0.25, y = 0, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%) using the classical solid phase synthesis and liquid phase sintering. The optimum amount of Y doping and Ni addition for BaZrO3-based conductors is proposed after analyzing and reviewing phases, structures, relative densities, microstructures, and hybrid conductivity properties under different atmospheres. BaZr0.8Y0.2O3−δ (BZY20) with 2 wt% NiO achieves a high relative density (~ 96%) at 1400 ℃ for 5 h. It exhibits a best conductivity value of 8.32, 1.12 and 3.15 mS cm− 1 at 600°C in air, dry and humidified 5%H2-Ar, respectively. Y and NiO-co-doped BaZr1 − xYxO3−δ is an excellent candidate as an electrolyte material for low-temperature SOC.