Properties and applications of perovskite proton conductors

Abstract

A brief overview is given of the main types and principles of solid-state proton conductors with perovskite structure. Their properties are summarized in terms of the defect chemistry, proton transport and chemical stability. A good understanding of these subjects allows the manufacturing of compounds with the desired electrical properties, for application in renewable and sustainable energy devices. A few trends and highlights of the scientific advances are given for some classes of protonic conductors. Recent results and future prospect about these compounds are also evaluated. The high proton conductivity of barium cerate and zirconate based electrolytes lately reported in the literature has taken these compounds to a highlight position among the most studied conductor ceramic materials.

96Zr Tracer Diffusion in AZrO3 (A = Ca, Sr, Ba)

“…The formation of A-site partly Schottky-type defects is significantly lower in energy than for the corresponding B-site. According to Table 3, the formation energies for full Schottky-type defects, reaction (1), are decreasing in the order SZ, BZ, and CZ [29,31], while the energies of formation for the AO partly Schottky-type defects decrease in the order BZ, SZ, and CZ. Higher energy of formation implies lower concentration of the frozen-in defects, and slower cation diffusivity is inferred.…”

“…AZrO 3 perovskite materials are attractive due to their high proton conductivity, with potential applications in protonic ceramic fuel cells (PCFC), electrolyzers, gas sensors, and hydrogen membrane technology [1][2][3][4][5][6][7]. The majority of studies on AZrO 3 proton conductors have focused on the transport properties, but a recent study has also addressed the mobility of cations in the BaZrO 3 (BZ)-materials, revealing the challenges with solid state sintering of the ceramics and chemical instability in CO 2 at elevated temperature [8].…”

Effect of synthesis atmosphere on the proton conductivity of Y-doped barium zirconate solid electrolytes

“…In addition, yttrium-doped barium zirconate (BYZ) has also been proposed as the best choice due to its high chemical stability under CO 2 -rich atmospheres and high mechanical resistance, and high proton conductivity at intermediate temperatures [12][13][14][15]. Indeed, the bulk conductivity at 500°C of barium zirconate containing 20 mol% Y 3 þ in solid solution (BZY20) is comparable to the conductivity of gadoliniumdoped ceria (Ce 0.9 Gd 0.1 O 2 À δ ), which is one of the best oxygen-ion conductors [12].…”

A Theoretical Study of Structural, Electronic and Elastic Properties of the Antiperovskite SnNCa3

“…These materials can be synthesised with a wide range of elements where large (ionic radius) cations sit in the A site and small cations sit on the B site. As a results of these features, they can be used in semiconductors, fuel cells, batteries, sensors, membrane reactors, hydrogen production and so on [1].…”