Enhancing the Electrochemical Performance in Symmetrical Solid Oxide Cells through Nanoengineered Redox-Stable...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Symmetrical solid oxide cells (SSOCs) offer simplified configurations and cost-effectiveness for energy conversion.
• Previous research focused on doping perovskite electrodes, often overlooking microstructural optimization.
• Developing high-performance electrodes is crucial for advancing SSOC technology.

Purpose of the Study:

• To explore nanostructural tailoring of (La0.8Sr0.2)0.95Fe1-xTixO3-δ (LSFTx) electrodes for enhanced SSOC performance.
• To investigate the impact of incorporating LSFTx into a Ce0.9Gd0.1O1.95 (CGO) backbone or using nanocomposite architectures.
• To implement Ni-doping and microstructural control to further improve fuel oxidation and overall cell efficiency.

Main Methods:

• Single-step spray-pyrolysis deposition for nanostructural tailoring of LSFTx electrodes (x = 0.2, 0.4).
• Fabrication of SSOCs using LSFTx electrodes integrated with a CGO porous backbone or nanocomposite architecture.
• Implementation of Ni-doping and controlled exsolution of Ni nanoparticles under reducing conditions.
• Electrochemical characterization including polarization resistance (Rp) measurements and power density determination.

Main Results:

• Nanostructural tailoring of LSFTx electrodes significantly reduced polarization resistance compared to traditional screen-printed electrodes.
• Ni-doping and microstructural optimization led to remarkable Rp values of 0.34 Ω cm² in air and 0.11 Ω cm² in wet H2 at 700 °C.
• Electrolyte-supported cells with symmetrical electrodes achieved a stable maximum power density of 617 mW cm⁻² at 800 °C.
• Demonstrated the effectiveness of combining compositional and microstructural optimization.

Conclusions:

• Nanostructural control is a critical factor for enhancing the performance of perovskite-based electrodes in SSOCs.
• The Ni-exsolution strategy coupled with microstructural optimization offers a promising route to highly efficient and durable SSOCs.
• This work provides a foundation for designing advanced electrode architectures for next-generation energy conversion devices.