A brief review of high-entropy oxides in solid oxide fuel cell applications

TL;DR

This review discusses the potential of high-entropy oxides to address key material challenges in solid oxide fuel cells, highlighting their unique properties and recent progress in applications as electrodes and electrolytes.

Contribution

It provides a comprehensive overview of high-entropy oxides, including their fundamentals, design principles, and recent advancements in SOFC applications, which is a novel synthesis of current research.

Findings

High-entropy oxides exhibit enhanced stability and electrochemical performance.

Recent studies show promising results for SOFC cathodes and electrolytes.

Challenges include optimizing material composition and understanding degradation mechanisms.

Abstract

Solid oxide fuel cells are efficient energy conversion devices essential to clean energy development, yet their broad application is limited by material challenges, including sluggish oxygen reduction kinetics at intermediate temperatures, electrode instability and vulnerability to contaminants. High-entropy oxides, a novel class of materials characterized by multiple principal elements and high configurational entropy, present a promising approach to overcome these issues via their distinctive "four core effects". This review begins with the fundamentals of high-entropy materials, covering their definition, phase stabilization mechanisms, and relevant descriptors, then systematically reviews their progress as SOFC cathodes, electrolytes, and anodes. Key advances are summarized, and current challenges are analyzed, offering guidance for the design of high-performance and stable high-entropy oxides for solid oxide fuel cells.