Rational design of air-stable hydrogen storage composites: from discrete encapsulation to synergistic hybrid architectures

Abstract

Hydrogen is widely regarded as a promising clean energy carrier; however, its large-scale deployment remains constrained by the absence of safe and efficient storage technologies. Solid-state hydrogen storage materials, particularly metal hydrides (MHs), have attracted considerable interest due to their high volumetric energy density. Nevertheless, their practical implementation faces significant challenges, primarily their susceptibility to oxidative deactivation in ambient air, coupled with typically high reaction energy barriers and sluggish kinetics. While conventional modification strategies have largely focused on improving reaction kinetics, systematic strategies to mitigate the environmental sensitivity of these materials remain underrepresented. This review bridges this gap by systematically assessing recent progress in constructing air-stable architectures via encapsulation strategies, while critically analyzing the impact of encapsulation on the trade-off between protection efficacy and reaction kinetics. Transcending a simple physical barrier perspective, the physicochemical nature of encapsulation layers and their interfacial interactions with MHs are identified as the governing factors determining the comprehensive efficacy of the resulting composite systems. Furthermore, a rational design paradigm for synergistic organic–inorganic hybrid architectures is proposed. Consequently, this review provides critical design references for developing multifunctional integrated systems combining selective permeability, interfacial stabilization, and kinetic acceleration, thereby facilitating the development of high-performance solid-state hydrogen storage materials featuring both long lifespan and high safety.