Method to determine the oxygen reduction reaction kinetics via porous dual-phase composites based on electrical conductivity relaxation

Abstract

The kinetics for the oxygen reduction reaction (ORR) via porous dual-phase composites are critical for high-temperature electrochemical devices such as solid oxide fuel cells. Herein, a method is proposed to...

Overview of Approaches to Increase the Electrochemical Activity of Conventional Perovskite Air Electrodes

“…The interaction of LSM with Zr-containing electrolytes, as it was mentioned above, results in the formation of low conducting LZO and, at high strontium content, SZO phases at the electrode sintering stage at temperatures above 1000-1200 °C, depending on the material dispersity [85]. It has also been found that Mn readily dissolves in YSZ, leaving chemically active La2O3 at the LSM/YSZ interface, which reacts with ZrO2 to form LZO [114]. To reduce the interaction of LSM with Zr-containing electrolytes, the use of (LS)xM, a cation deficient in the A position, has been proposed [129].…”

“…Automated methods developed for the detection of Sr nucleation seeds on the electrode surface [109,110], for the identification of the interlayer width between the perovskite and YSZ layers [111,112], and for the computational design and numerical simulation of the perovskite-based composite electrodes [113][114][115][116] allowed for the suggestion of possible degradation mechanisms and an understanding of the electrode behavior at both the atomic and macroscopic scales. The deposition of protective and noncatalytic layers on the electrode surface has been proposed as a solution to the problems of segregation [117][118][119], contaminant poisoning [120][121][122][123], and sluggish oxygen kinetics [124][125][126][127][128].…”

“…LSM composite electrodes can be prepared by various techniques: by mechanically mixing the components in a mill [114,396], by forming composites with a core-shell structure (by depositing one material on top of another) [206], by infiltrating one component of the composite electrode into the pre-sintered porous matrix of the other component [198,377], and by preparing vertically oriented high-entropy nanocomposites [393].…”

“…For the preparation of the LSCF-based electrodes, compositions with ionic conductors were used, such as YSZ [411,412], YSZ with GDC10 [413], GDC10 [160,336,407,[414][415][416][417][418] GDC [110,120,171,[417][418][419][420][421], Nd x Gd 0.15 Ce 0.85 − x O 2 − δ (NGCOx) [166], SDC [114,127,162,184,185,416,[422][423][424][425][426], Ce 0.8 Zr 0.2 O 2 − δ [427], BZYb [177], BCZYYb [178,181], BCZY [185], BCZY15 [186], La 2 Ce 2 O 7 (LCO) [185], LSGM [428,429], as well as with the MIEC materials Bi 0.3 Sr 0.7 Co 0.3 Fe 0.7 O 3 − δ [172], La 0.94 Ni 0.6 Fe 0.4 O 3 (LNF94) [340], Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3 − δ [430], SrCo 0.2 Fe 0.6 Ni 0.2 O 3 − δ [431]. As in the case of the LSM-based composites, the LSCF-based composite electrodes can be prepared by conventional mixing…”

Perspective on high-temperature surface oxygen exchange in a porous mixed ionic-electronic conductor for solid oxide cells

“…Decreased Δ p must result in a reduced ORR rate and consequently prolonged t e . 69 It takes much longer for the porous material than the dense material to obtain an evenly distributed oxygen partial pressure while reaching the highest Δ p everywhere. The simulation assumption indicates that uniform oxygen partial pressure cannot be achieved in porous material as quickly as in dense material.…”