An Overview on the Novel Core-Shell Electrodes for Solid Oxide Fuel Cell (SOFC) Using Polymeric Methodology

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Intermediate temperature solid oxide fuel cells (ITSOFCs) require minimized interface charge transfer, ohmic, and diffusion impedances for efficiency.
• Achieving low impedance relies on careful selection of electrode materials and microstructure control.
• Current methods like impregnation and infiltration face challenges with particle agglomeration, reducing electrocatalysis and gas pathways.

Purpose of the Study:

• To develop a novel core-shell electrode structure for ITSOFCs to overcome limitations of conventional methods.
• To enhance electrode performance by improving charge transport, ionic/electronic conductivity, and triple-phase boundary (TPB) area.
• To improve the thermal stability of electrodes and their compatibility with electrolytes.

Main Methods:

• Fabrication of electrode particles with a pre-formed core-shell structure.
• Utilizing a simple chelating solution for a cost-effective, one-step preparation process.
• Characterization of electrode properties, including charge transfer, conductivity, and TPB utilization.
• Testing half-cell performance with thin electrolytes and pseudo-core-shell anodes.

Main Results:

• The core-shell structure effectively prevented particle agglomeration, maintaining electrocatalytic activity and fuel gas pathways.
• A small amount of shell nanoparticles created continuous charge transport pathways, increasing electronic and ionic conductivity.
• The core-shell anode (SLTN-LSBC) and cathode (BSF-LC) configuration demonstrated improved thermal stability due to matched thermal expansion coefficients.
• A half-cell with a thin electrolyte (iLSBC) and pseudo-core-shell anode (LST) achieved a peak power density of 325 mW/cm² at 700 °C.

Conclusions:

• The core-shell electrode preparation method offers a significant enhancement in full-cell electrochemical performance.
• This approach provides improved thermal stability and potential for application in double ion conducting cells at lower temperatures.
• The cost-effective and simple fabrication process makes this method highly promising for advanced fuel cell technologies.