Long-term  Cell  Testing  of  Interlayer-free  Lanthanum  Strontium  Cobalt Ferrite Cathodes for Solid Oxide Fuel Cells

Ammonia produced using renewable hydrogen is being viewed as a promising media for the export of energy from locations rich in renewable energy sources. Solid oxide fuel cells (SOFCs) are efficient devices for converting such exported ammonia back into electricity at the point of use, however investigations on materials and operating regime for direct ammonia fuelled SOFCs are limited. The studies on fuel electrodes tailored specifically for ammonia fuel are limited. In this work, we evaluated the direct ammonia SOFC performance with Silver-Lanthanum Strontium Cobalt Ferrite (Ag-LSCF) composite anode and a novel Palladium (Pd) nanoparticle decorated Silver-Lanthanum Strontium Cobalt Ferrite (Pd-Ag-LSCF) composite anode in the temperature range of 500 °C to 800 °C. It is hypothesized that Palladium nanoparticles in the anode provide hydrogen dissolution and shift the ammonia decomposition reaction towards the right. The cell performance was evaluated with both hydrogen and ammonia as fuels and a clear-cut improvement in the performance was observed with the addition of Pd for both the fuels. The results showed a performance enhancement by 20% and 43% with hydrogen and ammonia fuels respectively from the Pd addition of Ag-LSCF anode. Open circuit voltage (OCV) values of the cells with hydrogen and ammonia fuel recorded over the temperature range of 500 °C to 800 °C indicated the possibility of direct electro-oxidation of ammonia in SOFCs.

Download Full-text

Computational engineering of the oxygen electrode-electrolyte interface in solid oxide fuel cells

npj Computational Materials ◽

10.1038/s41524-021-00584-8 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Kaiming Cheng ◽

Huixia Xu ◽

Lijun Zhang ◽

Jixue Zhou ◽

Xitao Wang ◽

...

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Microstructure Evolution ◽

Oxygen Electrode ◽

Solid Oxide ◽

Ohmic Loss ◽

Oxide Fuel ◽

Computational Engineering ◽

Electrolyte Interface

AbstractThe Ce0.8Gd0.2O2−δ (CGO) interlayer is commonly applied in solid oxide fuel cells (SOFCs) to prevent chemical reactions between the (La1−xSrx)(Co1−yFey)O3−δ (LSCF) oxygen electrode and the Y2O3-stabilized ZrO2 (YSZ) electrolyte. However, formation of the YSZ–CGO solid solution with low ionic conductivity and the SrZrO3 (SZO) insulating phase still happens during cell production and long-term operation, causing poor performance and degradation. Unlike many experimental investigations exploring these phenomena, consistent and quantitative computational modeling of the microstructure evolution at the oxygen electrode–electrolyte interface is scarce. We combine thermodynamic, 1D kinetic, and 3D phase-field modeling to computationally reproduce the element redistribution, microstructure evolution, and corresponding ohmic loss of this interface. The influences of different ceramic processing techniques for the CGO interlayer, i.e., screen printing and physical laser deposition (PLD), and of different processing and long-term operating parameters are explored, representing a successful case of quantitative computational engineering of the oxygen electrode–electrolyte interface in SOFCs.

Download Full-text