Lithium borohydride (LiBH₄) has emerged as a promising hydrogen storage material due to its exceptional theoretical hydrogen capacity (18.5 wt.%). However, its practical application is hindered by high dehydrogenation temperature (>400 °C), sluggish kinetics, and limited reversibility due to stable intermediate formation. This review critically analyzes recent advances in LiBH₄ modification through three primary strategies: catalytic enhancement, nanostructure engineering, and reactive composite design. Advanced carbon architectures and metal oxide catalysts demonstrate significant improvements in reaction kinetics and cycling stability through interface engineering and electronic modification. Sophisticated nanostructuring approaches, including mechanochemical processing and infiltration techniques, enable precise control over material architecture and phase distribution, effectively modifying thermodynamic and kinetic properties. The development of reactive hydride composites, particularly LiBH₄-MgH₂ systems, provides promising pathways for thermodynamic destabilization while maintaining high capacity. Despite these advances, challenges persist in maintaining engineered structures and suppressing intermediate phases during cycling. Future developments require integrated approaches combining multiple modification strategies while addressing practical implementation requirements.

The advancement of solid-state hydrogen storage materials is critical for the realization of a sustainable hydrogen economy. This comprehensive review elucidates the state-of-the-art characterization techniques employed in solid-state hydrogen storage research, emphasizing their principles, advantages, limitations, and synergistic applications. We critically analyze conventional methods such as the Sieverts technique, gravimetric analysis, and secondary ion mass spectrometry (SIMS), alongside composite and structure approaches including Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). This review highlights the crucial role of in situ and operando characterization in unraveling the complex mechanisms of hydrogen sorption and desorption. We address the challenges associated with characterizing metal-based solid-state hydrogen storage materials discussing innovative strategies to overcome these obstacles. Furthermore, we explore the integration of advanced computational modeling and data-driven approaches with experimental techniques to enhance our understanding of hydrogen–material interactions at the atomic and molecular levels. This paper also provides a critical assessment of the practical considerations in characterization, including equipment accessibility, sample preparation protocols, and cost-effectiveness. By synthesizing recent advancements and identifying key research directions, this review aims to guide future efforts in the development and optimization of high-performance solid-state hydrogen storage materials, ultimately contributing to the broader goal of sustainable energy systems.