Carbon-based and metal hydride materials for advanced hydrogen storage: progress, challenges and future directions

Abstract

Hydrogen storage remains a crucial challenge for realising a sustainable hydrogen economy. This review critically examines recent advancements in hydrogen storage technologies, focusing on metal hydrides, rare-earth metal hydrides, and carbon-based materials. The study highlights the mechanism, advantages and limitations of these technologies, emphasizing their potential to address global energy challenges. Metal hydrides, particularly magnesium-based systems, offer high volumetric and gravimetric storage capacities but face kinetic and cyclic stability issues. Rare-earth metal hydrides exhibit excellent reversibility and catalytic activity, yet their high cost and supply constraints limit their widespread adoption. Carbon-based materials, including nanotubes, graphene, and activated carbon, stand out for their high surface area, porosity, and tunable properties, achieving a storage capacity of 7–10 wt%. This review explores advanced material designs such as transition metals and nanostructured composites that enhance performance. Practical challenges such as cycling stability, cost, and environmental impact are discussed, alongside policy and infrastructure needs for commercialization. The article concludes with future research directions, encouraging the development of hybrid systems and sustainable material solutions to meet global energy demands by synthesizing existing research and identifying critical gaps to guide the development of efficient, scalable, and eco-friendly hydrogen storage technologies.