Oxygen electrode degradation in solid oxide cells operating in electrolysis and fuel cell modes: LSCF destabilization and interdiffusion at the electrode/electrolyte interface

A multiscale model validated on local current measurements for understanding the solid oxide cells performances

“…In this context, High-Temperature Steam Electrolysis (HTSE) based on Solid Oxide Cells (SOCs) technology presents a great potential to produce H 2 at a low cost and high efficiency [2]. SOCs are electrochemical devices that can operate in fuel cell mode (SOFC) and electrolysis mode (SOEC) with a large range of fuels and no utilization of expensive catalysts [3]. Due to its reversibility, this technology can also be used to match the fluctuations between electricity demand and production, mainly during the consumption peaks [4]- [6].…”

“…A porous Nickel and Yttria-Stabilized Zirconia (Ni-YSZ) cermet is typically used for the fuel electrode, while the air electrode is composed of a Mixed Ionic and Electronic Conductor (MIEC). Nowadays the most common material for the air electrode is a composite of Lanthanum Strontium Cobalt Ferrite (La x Sr 1-x Co y Fe 1-y O 3-δ -LSCF) and Gadolinium-doped Ceria (Gd x Ce 1-x O 2-δ -CGO) [3], [7], [8]. The electrolyte is a pure ionic conductor, which allows the migration of oxygen vacancies , and it is usually made of Yttria-Stabilized Zirconia with 8.mol% of yttria (8YSZ) [9].…”

“…These models can be useful to identify microstructural corrections that control the electrode efficiency [26]. In terms of electrochemical response, some microscale electrochemical models have been proposed to describe precisely the electrode reaction mechanism including mass and charge transfer within the active functional layer [3],…”

Multiscale modelling potentialities for solid oxide fuel cell performance and degradation analysis

“…For instance, LSCF demixing consists of a heavy accumulation of strontium and cobalt, in less amount, near the electrolyte interface creating insulating zirconate deposits. 16 Moreover, secondary phase formation also derives from the interactions with ferritic stainless-steel based interconnects, which release Cr volatile species covering the catalytically active sites. 17 In addition to the release of Cr, interconnects provoke fracture development and electrical resistance increase due to the thickening of the oxide scale used to prevent steel corrosion.…”

Precursor‐driven facile densification of Gd 0. 1 Ce 0 . 9 O 2− δ interlayer for high‐performance solid oxide fuel cells

“…Solid oxide fuel cells (SOFCs) are promising energy conversion systems because of their high conversion efficiency without any harmful emissions 1‐3 . However, their performance 4 and durability 5‐7 over the long‐term operation, which are directly associated with system costs, remain a challenge for wider commercial applications. Among the various candidates of electrolyte for SOFCs, yttria‐stabilized zirconia (YSZ) is the most commonly used electrolyte material that demonstrates reasonable ionic conductivity and structural robustness 8,9 .…”