Abstract
<jats:p>High-entropy materials (HEMs) are gaining significant attention due to their exceptional mechanical strength, thermal stability, and chemical durability, making them promising for advanced energy storage and conversion systems. This review critically examines recent developments in HEM architectures tailored for electrochemical applications. It first outlines the thermodynamic principles governing HEM stabilization, lattice structures, and the four core entropy-driven effects. The structure–property relationships influencing their performance are then systematically analyzed. The review further evaluates HEM applications in solid-state hydrogen storage, alkali-ion batteries, electrocatalytic water splitting, fuel cells, and supercapacitors. Key mechanisms, including d-band center modulation and site-energy distribution, are discussed to explain their electrochemical behavior. Emphasis is placed on how compositional disorder enhances ion/electron transport, synergistic interactions, and reaction pathways. Finally, critical challenges such as the kinetic paradox, lack of standardized benchmarking, and scalability limitations are addressed. By providing an integrated and mechanistic perspective, this work establishes a coherent framework to guide future research and accelerate the development of HEM-based energy technologies.</jats:p>