Electrodeposited Medium- and High-Entropy Alloys: A Review of Recent Advances in Electrochemical Energy-Related Applications

Medium-entropy alloys (MEAs) and high-entropy alloys (HEAs) have emerged as promising materials for advanced electrocatalytic applications, offering a unique balance between compositional complexity and structural tunability. This review highlights the fundamental design principles of MEAs and HEAs, focusing on their configurational entropy, mechanical strength, corrosion resistance, and magnetic properties. It also covers different synthesis approaches used to produce entropy alloys, including additive manufacturing, powder metallurgy, magnetron sputtering, high-pressure torsion, and electrodeposition. In comparison, this review specifically emphasizes the advantages and detailed types of electrodeposition methods for synthesizing MEA and HEA. The electrodeposition method is highlighted as a flexible, scalable approach for synthesis, enabling precise control of film thickness, surface features, and elemental distribution in ambient conditions. Various electrodeposition methods, including chronopotentiometry (constant current), chronoamperometry (constant potential), and pulse electrodeposition, are critically examined for their role in fabricating nanostructured MEA and HEA electrocatalysts. The multifunctional capabilities of these alloys are explored across key electrochemical applications, including water splitting, alcohol oxidation, oxygen reduction, and carbon dioxide reduction. By integrating the intrinsic compositional complexity of MEAs and HEAs with the synthesis flexibility of electrodeposition, these materials offer a powerful platform for designing tailored catalytic interfaces and enhancing performance in diverse electrochemical energy conversion systems.