First-principle insight on the electronics and structural properties of lanthanide metal doped BaZrO3

Abstract

An oxide of the perovskite type, barium zirconate (BaZrO3), has attracted a lot of interest for use as a potential candidate for electrolyte of solid oxide fuel cells (SOFCs) that conduct protons. The perovskite crystal structure of BaZrO3 is well-known for its adaptability in accepting various dopants and preserving stability in a range of circumstances. BaZrO3 is appropriate for the severe operating conditions of SOFCs because it is chemically stable in both reducing and oxidizing environments. When doped, BaZrO3 acts as an electrolyte that conducts protons. Protons (H+), which travel through the crystal structure to complete the fuel cell circuit, are the main charge carriers in these materials. BaZrO3 can function at lower temperatures, which lessens thermal stress and lengthens the life of fuel cells. Additionally, a greater variety of fuels, including ones with higher hydrogen contents, are permitted. The examination of the mechanism underlying the enhanced performance requires the atomic knowledge. We have used the ab-initio DFT computation for that. Band-gap and electrochemical stability assessments have been made more accurate by using Grimme d3 dispersion correction and PBE. A distinct metric, the global instability index (GII), was employed to evaluate the thermodynamic stability of BaZrO3 and the doped structures. It bases its calculation on the bond valence sum technique utilized in SoftBV. All DFT calculations were carried out using Quantum ESPRESSO pwscf codes. XCrySDen and VESTA, two open-source programs, were used to create all of the visuals.