Coupling cation migration with segregation for versatile air electrode in proton-conducting ceramic cells

Area of Science:

• Materials Science
• Electrochemistry
• Ceramic Engineering

Background:

• Proton conducting ceramic cells require versatile perovskite air electrodes with high proton uptake, conductivity, and oxygen kinetics for efficient H2-to-power conversion.
• Conventional single-phase perovskites often struggle to achieve these properties simultaneously, limiting cell performance and stability.

Purpose of the Study:

• To develop a novel perovskite air electrode with enhanced versatility by coupling bulk cation migration and surface segregation.
• To improve the performance and stability of proton conducting ceramic cells for electrocatalytic applications.

Main Methods:

• Synthesized a coupled bulk-surface perovskite electrode (cm-BCFN@NiO) utilizing Ba0.9Ce0.1-α)(CeαFe0.8Ni0.2-β)O3-δ-βNiO.
• Investigated the synergistic effects of NiO nanoparticles and Ce migration on surface oxygen kinetics, bulk proton conductivity, and electronic transport.

Main Results:

• The optimized cm-BCFN@NiO electrode demonstrated a significantly reduced area-specific resistance (0.3 Ω cm² at 550°C), a 75% decrease from the NiO-free counterpart.
• Achieved a 77.1% increase in maximum power density and over 1200 hours of stable single-cell operation.
• Ce migration from A-sites to B-sites and NiO nanoparticles synergistically optimized electrode properties.

Conclusions:

• The coupled bulk-surface architecture strategy effectively enhances perovskite air electrode versatility for proton conducting ceramic cells.
• This approach offers a pathway for designing advanced perovskites through atomic-scale cation migration and surface segregation for diverse electrocatalytic applications.