An Efficient High-Entropy Perovskite-Type Air Electrode for Reversible Oxygen Reduction and Water Splitting in...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Reversible protonic ceramic electrochemical cells (R-PCECs) offer efficient energy conversion and storage.
• Commercialization of R-PCECs is limited by the need for effective air electrodes for oxygen reduction and water-splitting reactions.

Purpose of the Study:

• To design and investigate a highly active and durable air electrode for R-PCECs.
• To evaluate the performance of the new air electrode in both fuel cell and electrolysis modes.

Main Methods:

• Synthesis and characterization of a novel high-entropy material: Pr$_{0.2}$ Ba$_{0.2}$ Sr$_{0.2}$ La$_{0.2}$ Ca$_{0.2}$ CoO$_{3-δ}$ (HE-PBSLCC).
• Electrochemical performance testing in fuel cell (FC) and electrolysis cell (EC) modes at 650 °C.
• Durability and stability assessments under operational conditions.

Main Results:

• The HE-PBSLCC electrode demonstrated high activity and stability for oxygen reduction and water-splitting reactions.
• In FC mode, a maximum power density of 1.51 W cm$^{-2}$ was achieved.
• In EC mode, a current density of -2.68 A cm$^{-2}$ at 1.3 V was recorded.
• Excellent operational durability exceeding 270 h (FC mode) and 500 h (EC mode), with good cycling stability.

Conclusions:

• The developed HE-PBSLCC is a promising air electrode material for R-PCECs.
• This work provides an effective strategy for designing advanced air electrodes for efficient energy applications.
• The material shows potential for both electricity generation and hydrogen production via water splitting.