Strategic atomic trapping at heterointerfaces for protonic ceramic cells.

Area of Science:

• Materials Science and Engineering
• Electrochemistry
• Sustainable Energy Technologies

Background:

• Reversible protonic ceramic electrochemical cells (PCECs) are crucial for sustainable energy conversion.
• Minimizing precious metal usage in composite electrodes is essential for cost-effective PCECs.
• Precisely engineered heterointerfaces are key to unlocking PCEC potential.

Purpose of the Study:

• To introduce an atomic trapping strategy for restructuring interfacial chemistry in perovskite/fluorite heteroelectrodes.
• To achieve catalytic synergy by manipulating the ruthenium (Ru) coordination environment.
• To develop a universal strategy for next-generation solid-state energy devices.

Main Methods:

• Atomic trapping strategy applied to Ba$_{0.5}$Sr$_{0.5}$Co$_{0.8}$Fe$_{0.2}$O$_{3-δ}$ (BSCF) perovskite and Ru@CeO$_{2-δ}$ fluorite heteroelectrodes.
• Scalable co-sintering protocol to induce thermodynamically driven Ru migration.
• Analysis of interfacial electron redistribution, oxygen vacancies, and triple conductivity.

Main Results:

• Coupled interfaces formed by Ru migration into the perovskite matrix.
• Optimized interfacial properties, including enhanced electron redistribution and oxygen vacancy generation.
• Low Ru loading electrode demonstrated bifunctionality: 1.51 W cm$^{-2}$ (peak power density) and -2.21 A cm$^{-2}$ (electrolysis current density) at 650 °C.
• Notable durability with minimal degradation (0.09 mV h$^{-1}$) over 400 h at 600 °C.

Conclusions:

• The atomic trapping strategy effectively engineers dynamic heterointerfaces with atomic precision.
• This approach optimizes interfacial chemistry, leading to improved catalytic synergy and PCEC performance.
• The developed method offers a promising universal strategy for advanced solid-state energy devices.