A New Durable Surface Nanoparticles-Modified Perovskite Cathode for Protonic Ceramic Fuel Cells from Selective Cation...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• High-performance protonic ceramic fuel cell (PCFC) cathodes require excellent oxygen reduction reactivity, high ionic/electronic conductivity, and stability.
• Surface modification via nanoparticle exsolution is effective but faces challenges with nanoparticle re-incorporation.

Purpose of the Study:

• To develop a durable perovskite-based nanocomposite cathode for PCFCs.
• To investigate nanoparticle exsolution in an oxidizing atmosphere for cathode fabrication.
• To enhance both bulk proton conduction and surface oxygen exchange kinetics.

Main Methods:

• Designed and synthesized a perovskite precursor (Ba$_{0.95}$ (Co$_{0.4}$ Fe$_{0.4}$ Zr$_{0.1}$ Y$_{0.1}$ )$_{0.95}$ Ni$_{0.05}$ O$_{3-δ}$, BCFZYN-095) with controlled cation nonstoichiometry.
• Fabricated the nanocomposite cathode via nanoparticle exsolution in an oxidizing atmosphere.
• Investigated the resulting perovskite/NiO nanocomposite structure and its electrochemical performance.

Main Results:

• The calcination yielded a nanocomposite with a major perovskite phase and surface-enriched NiO nanoparticles.
• The perovskite phase facilitated bulk proton conduction, while NiO nanoparticles enhanced surface oxygen exchange.
• Achieved a peak power density of 1040 mW cm$^{-2}$ at 650 °C and 400 h stability at 550 °C.

Conclusions:

• The facile exsolution of NiO nanoparticles in an oxidizing atmosphere creates a stable and high-performance PCFC cathode.
• This approach overcomes nanoparticle re-incorporation issues, offering a promising strategy for durable PCFC electrode design.
• The developed nanocomposite cathode demonstrates significant potential for efficient and stable energy conversion in PCFCs.