Electrochemical performance and stability of nano-particulate and bi-continuous La1−X Sr X CoO3 and Ce0.9Gd0.1O1.95 composite electrodes

Abstract

A bi-continuous porous cathode consisting of nano-particles of strontium substituted lanthanum cobaltite (LSC) covering the surface of a Ce 0.9 Gd 0.1 O 1.95 (CGO10) backbone has been produced. The polarization resistance (R P ) of this cathode was measured to ∼35 mΩ cm 2 at 650°C. The area-specific resistance at 650°C (ASR) when applied onto an anode supported cell (ASC) was found to increase from 540 to 730 mΩ cm 2 when subjected to a thermal cycle to 850°C. This effect was attributed to particles coarsening but also to a reaction with the electrolyte. The results imply that a CGO10 barrier is required for this type of nano-structured cathode.

Development of Fuel Electrode Supported Solid Oxide Cell with Ni/CGO Active Layer

“…However, comparing Rair* to ΔRp caused by changing from air to oxygen the relative change is 0.07/0.27=26%. This relative change is comparable to literature values for the pO2 dependence of LSC-CGO air electrode resistance which is reported to be Rp ∝ (pO2) −n with n=0.21±0.02 (8) Ongoing Activities to Improve Cell Performance…”

Durability and Performance of High Performance Infiltration Cathodes

“…However, the series resistance was this time found to decrease with increasing maximum temperature, in contrast to the case of six infiltrations. Combined with the XRD it seems plausible that the increasing maximum temperature the infiltrate has been subjected to results in an increased formation of LSC thus increasing the electronic conductivity, in agreement with what has been observed in another study [30]. In addition, the electrode contains more infiltrate material wherefore percolation is not so easily lost.…”

Surface recrystallization – an underestimated phenomenon affecting oxygen exchange activity

“…24 A fruitful approach to fabrication commercially relevant electrodes with rapid ORR/OER kinetics has been to manufacture composites where perovskites are combined with fast ionic conductors like Gd-doped ceria or even zirconia. 5,[25][26][27][28][29][30][31] In such an approach, one utilizes the best properties of the constituting materials -the fluorite serves as the primary path for oxygen ions, while the perovskite provides catalytic activity for oxygen exchange and a path for electrons. Sometimes, besides providing their separate functions for charge transport more elaborate forms of synergy between the two materials have been reported, where a beneficial effect on one material emerges only when the other one is present.…”