High-entropy alloys in energy storage systems: From electrochemical and hydrogen storage to thermal energy applications

High-entropy alloys (HEAs) have emerged as a transformative class of multicomponent materials. The alloys are capable of overcoming many limitations associated with conventional alloys in energy storage technologies. This review provides a comprehensive assessment of HEAs across three major energy storage platforms: electrochemical energy storage, hydrogen storage, and thermal energy storage. The article integrates a systematic bibliometric analysis of literature published between 2018 and 2026 to identify research trends and knowledge gaps across different applications such as batteries, supercapacitors, electrocatalysts, hydrogen-storage materials, and high-temperature thermal energy systems. The findings from over 262 publications highlight key synthesis strategies, phase-structure relationships, nanoscale engineering approaches, and predictive tools such as density functional theory (DFT), CALPHAD, and machine-learning-assisted design. The study consolidates recent advances and highlights unresolved challenges. This review highlights the roles of HEAs as a unifying materials platform for next-generation, high-performance, and durable energy storage technologies.