Carbon‐Based Materials Enhancing Hydrogen Storage Performance of Magnesium Hydride: Mechanisms, Multidimensional Performance Regulation and Future Perspectives

ABSTRACT This review summarizes recent advances and challenges in enhancing the hydrogen storage performance of magnesium hydride (MgH 2 ) through carbon modification strategies. Although MgH 2 possesses high hydrogen capacity and favorable safety characteristics, its practical application is limited by thermodynamic stability, sluggish kinetics, and poor cycling durability. Carbon materials provide multifunctional regulation through structural confinement, improved transport properties, interfacial electronic modulation, and defect engineering, enabling simultaneous optimization of hydrogen sorption kinetics, thermodynamics, and cycling stability. Recent progress in carbon materials with different dimensional structures and their synergistic coupling with metal catalysts is discussed, with emphasis on the underlying mechanisms, performance regulation, and future development challenges. These carbon‐based coupling strategies provide promising opportunities for developing high‐performance MgH 2 ‐based hydrogen storage systems for fuel‐cell vehicles, renewable energy storage, and portable power applications.