Manipulating the grain boundary properties of BaCeO₃-based ceramic materials through sintering additives introduction

Abstract

BaCeO 3 -based materials represent a well-known family of proton-conducting electrolytes, which can be used in different solid oxide electrochemical devices. An effective operation of the latter across an intermediate-temperature range requires improved transport of PCEs, including their grain (G) and grain boundary (GB) components. In the present work, some 3d-elements in a small amount were used as sintering additives to verify the possibility of improving the GB conductivity of BaCe 0.9 Gd 0.1 O 3-δ . It is shown that copper oxide (CuO) can be considered as one of the most effective sintering agents, since its use enables decreasing the GB density of the BCG ceramic material at the reduced sintering temperatures. The obtained results form a new tactic for designing new protonic electrolytes, whose conductivity might be prevail over ones containing Ni-based modifiers.

Densification and Proton Conductivity of La1-xBaxScO3-δ Electrolyte Membranes

“…As well, the effective activation energy of GB conductivity for La0.95Ba0.05ScO3-δ (0.98 eV) is higher than for La0.95Ba0.05ScO3-δ + 0.5 wt.\% Co3O4 (0.95 eV). The positive effect of the introduction of sintering additives was previously also mentioned by the authors [62][63][64] for Ba(Ce,Zr)O3-based materials with NiO, CuO, ZnO, Co3O4 sintering additives and is associated simply with an improvement in the contact between grains. Some authors [65,66] explained the decrease in the GB resistance by pointing to an increase in the concentration of charge carriers in the space charge layers and with lower potential transfer barrier.…”

A review on recent advances and trends in symmetrical electrodes for solid oxide cells

“…Alternative mixed ionic-electronic conductors (MIECs) have also been investigated for intermediate temperature applications (500-800 ºC), such as La0.6Sr0.4Co0.2Fe0.8O3-, Ba0.5Sr0.5Co0.8Fe0.2O3-, Sm0.5Sr0.5CoO3- and (Gd,Pr)BaCo2O5+ [15][16][17][18]. Among the electrolytes, Zr0.84Y0.16O2- (YSZ), La0.8Sr0.2Ga0.8Mg0.2O3- (LSGM) and Ce0.8Gd0.2O1.9 (GDC) are the standard oxide ion conductors, while doped-Ba(Ce,Zr)O3- are the most widely used proton conductors [9,[19][20][21].…”

Direct Electrophoretic Deposition and Characterization of Thin-Film Membranes Based on Doped BaCeO3 and CeO2 for Anode-Supported Solid Oxide Fuel Cells

“…Cu-doping significantly increases the sinterability of protonconducting ceramics [37]. Moreover, added in a small amount as a sintering additive, CuO can improve not only sinterability but also the grain boundary (GB) conductivity of doped BaCeO 3 , lowering the GB density [38]. Recently, we demonstrated good compatibility of electrophoretically deposited Cu-doped BaCe 0.8 Sm 0.2 O 3 barrier layers (~20 µm) with a dense SDC substrate (550 µm) [39].…”