Advances in High-Entropy Alloys

High-entropy alloys (HEAs), which consist of five or more major elements in nearly equiatomic or non-equiatomic ratios, have established themselves as a transformative class of materials that challenge conventional principles of alloy development. Unlike conventional alloys, which are based on a dominant element, HEAs can exhibit a unique stabilization mechanism driven by configurational entropy, leading to exceptional combinations of mechanical strength, corrosion resistance, thermal stability, and tunable electronic structures. In recent years, HEAs have attracted increasing attention not only in construction but also in electrochemical and functional material applications due to the diversity of their composition and their synergistic surface chemistry. Their ability to provide abundant active sites, tunable phase structures, and improved stability makes them extremely promising for catalysis, energy storage, hydrogen production, sensor technology, and protective coatings. These developments position HEAs at the intersection of advanced materials and electrochemical technology.Although there's been remarkable development in alloys design, the rational design of HEAs for electrochemical and environmental applications remains a major scientific and industrial challenge. Critical questions remain regarding phase stability under electrochemical conditions, surface reconstruction, catalytic activity, and long-term stability. Although the original HEA concept emphasized entropy-stabilized single-phase solid solutions, the majority of reported HEAs are multiphase rather than truly single-phase equilibrium alloys, which indeed makes a proper structure-activity correlation difficult. An important issue is the lack of robust correlations between composition, structure, and properties. At the same time, the urgent need for robust materials for sustainable energy conversion, corrosion-resistant systems, and multifunctional devices has accelerated research on HEAs as next-generation solutions. Recent advances in computational thermodynamics, materials libraries, machine-learning-aided composition screening, nanoscale synthesis, and in situ electrochemical characterization have opened new avenues for the tailored development of HEAs with targeted performance characteristics. This research topic aims to gather current studies addressing both the fundamental understanding and practical application of HEAs and high-entropy oxides (HEOs), with a particular focus on their electrochemical behavior, functional mechanisms, and integration into real-world technologies in the fields of materials science and applied chemistry.This Research Topic welcomes original research articles, reviews, and perspectives focusing on, but not limited to, the following areas:• Design principles and thermodynamic modeling of HEAs for electrochemical applications • Novel synthesis routes for bulk, thin-film, nanoporous, and nanostructured HEAs • Surface chemistry, passivation behavior, and corrosion resistance mechanisms of HEAs • High-entropy alloy electrocatalysts for hydrogen evolution, oxygen evolution, oxygen reduction, ammonia reaction, and CO₂ reduction reactions • HEAs in batteries, supercapacitors, fuel cells, and other energy storage/conversion systems • Composition–microstructure–performance relationships • Wear-resistant, anti-corrosion, and HEA coatings • Industrial, environmental, and biomedical applications of HEAs• In situ/operando characterization of HEAs under electrochemical or reactive environments • Machine learning and computational approaches for HEA discovery and optimization Topic editors: Hatem Amin, Ana Sofia Fajardo Source: https://www.frontiersin.org/research-topics/82050/advances-in-high-entropy-alloys