High-Entropy Alloy Hydrogen Storage Materials: Core Effects, Hydrogen Absorption/Desorption Behavior, and Application Prospects

Abstract:

As a critical clean energy, hydrogen energy development is restricted by backward hydrogen storage technologies. Traditional hydrogen storage materials still suffer from deficiencies in hydrogen storage capacity, hydrogen absorption/desorption rate and structural stability. In recent years, high-entropy alloys (HEAs) have demonstrated promising hydrogen storage performance, yet their hydrogen storage behavior is complex and requires in-depth investigation. This paper discusses the correlation between the four core effects of HEAs (high-entropy effect, lattice distortion effect, sluggish diffusion effect and cocktail effect) and hydrogen storage performance, focuses onreviewing hydrogen storage kinetics and thermodynamics, analyzes microscopic mechanisms and performance regulation strategies, and explores their potential applications. The results show that: ① The high-entropy effect promotes the formation of single-phase solid solutions; the lattice distortion effect expands interstitial space and enhances hydrogen storage capacity; the sluggish diffusion effect improves material stability; the cocktail effect optimizes comprehensive performance. ② Kinetic models such as JMAK and Chou systematically analyze key processes including hydrogen absorption/desorption, diffusion and phase transformation, reveal rate-controlling mechanisms, and quantify activation energy and diffusion coefficient. ③ Based on the Van''t Hoff equation, the enthalpy and entropy changes of hydrogen absorption/desorption are calculated to clarify hydrogen storage equilibrium behavior. With the advantages of high capacity, fast kinetics and long cycle stability, HEAs exhibit good prospects for engineering applications. Future research should focus on composition design, synthesis process improvement and theoretical model construction to promote the research and application of such materials.