An overview of high-entropy materials for energy applications, including H₂ catalysis and storage, CO₂ conversion, O₂ catalysis and electrochemical energy storage, is given and the challenges and opportunities within this field are discussed.

In recent years, high-entropy methodologies have garnered significant attention in the field of energy-storage applications, particularly in rechargeable batteries. Specifically, they can impart materials with unique structures and customized properties, thereby showcasing new attributes and application potential. In this review, we describe the various influences that the high-entropy concept exert on electrochemical performance of materials. We begin by introducing the concept and the basic effects, namely structural stabilization, lattice distortion, high defect density, and cocktail effects. Then, we provide a comprehensive overview of the fundamental advantages of high entropy or compositional/occupational disorder in battery materials design, including anodes, cathodes, and electrolytes. The summary of these effects is crucial for understanding how entropy affects the electrochemical properties of materials (redox activity, cyclability, etc.). Additionally, we outline the challenges encountered in this area of research and discuss the critical factors for rationally designing novel electrode materials, as well as the potential future directions for high-entropy strategies in the field of electrochemical energy storage.