High-Entropy Materials: Controllable Synthesis, Deep Characterization, Electrochemical Energy Application, and Outlook

High-entropy materials (HEM) are expected to make new advances in electrocatalysis and energy storage by virtue of their broad compositional tunabilities, high-temperature stabilities, and high chemical stabilities. In recent years, HEM have been investigated extensively in these fields, prompting researchers to investigate the relationships among structure, composition, and electrochemical performance. This paper systematically reviews the recent advances of HEM, focusing on the controlled syntheses, atomic-scale structural analyses, progresses in electronic properties, and quantum calculations. The electrochemical performances of HEM in several representative reactions and batteries are then further discussed to demonstrate their structure–composition–property relationships. Finally, the development prospects of HEM in terms of controllable syntheses, deep characterizations and analyses, and applications are discussed and foreseen.