Noble‐Metal‐Free High‐Entropy Alloys for Energy Storage Applications

High-entropy alloys (HEAs), an emerging class of materials, have attracted significant interest in recent years for their use in energy-storing electrochemical devices, including batteries and supercapacitors (SCs). Their distinct structural characteristics, modifiable elemental compositions, and adjustable properties give them extraordinary potential. High-entropy, sluggish diffusion, considerable lattice distortion, and the cocktail effect are four main drivers of these remarkable properties, which make HEAs extremely adaptable for energy storage applications. The unique features of HEAs include exceptional electrocatalytic performance, enhanced cycling stability, and remarkable resilience. Noble metal-based HEAs having platinum (Pt), ruthenium (Ru), and iridium (Ir) in their moiety show remarkable performance in energy storage applications. However, the limited availability and elevated expense for such noble metals have impeded their extensive industrial utilization. This chapter examines the advancements in research concerning energy storage applications of noble-metal-free HEAs (NMF-HEAs). Following an overview of the background and synthesis of NMF-HEAs, we examine their applications for SCs and batteries, with the objective of elucidating the link between their morphology and electrochemical performances.