Thermodynamics and kinetics of hydriding and dehydriding reactions in Mg-based hydrogen storage materials

TLDR

Mg‑based materials are promising hydrogen storage candidates because of their high capacity, environmental benignity, and high Clarke number, yet their limited thermodynamic and kinetic properties hinder engineering applications. This review aims to assess recent advances that improve the thermodynamics and kinetics of Mg‑based hydrogen storage. The authors examine how alloying, composites, and nano‑crystallization affect thermodynamics and kinetics, correlate modification strategies with hydrogen capacity, dehydrogenation enthalpy, temperature, and rates, and analyze storage mechanisms through classical kinetic theories and microscopic hydrogen transfer. The review concludes by outlining remaining challenges and future prospects for Mg‑based hydrogen storage.

Abstract

Mg-based materials are one of the most promising hydrogen storage candidates due to their high hydrogen storage capacity, environmental benignity, and high Clarke number characteristics. However, the limited thermodynamics and kinetic properties pose major challenges for their engineering applications. Herein, we review the recent progress in improving their thermodynamics and kinetics, with an emphasis on the models and the influence of various parameters in the calculated models. Subsequently, the impact of alloying, composite, and nano-crystallization on both thermodynamics and dynamics are discussed in detail. In particular, the correlation between various modification strategies and the hydrogen capacity, dehydrogenation enthalpy and temperature, hydriding/dehydriding rates are summarized. In addition, the mechanism of hydrogen storage processes of Mg-based materials is discussed from the aspect of classical kinetic theories and microscope hydrogen transferring behavior. This review concludes with an outlook on the remaining challenge issues and prospects.