Solid State Hydrogen Storage: Hybrid Materials Exploring the Fundamentals, Challenges, and Integration of Renewable Energy for Sustainability

In the age of Industry 4.0, fossil fuels account for 75% of global greenhouse gas emissions and 90% of carbon dioxide output. Hydrogen, with a high heating value of 143 MJ/kg and zero carbon emissions, offers a sustainable alternative energy carrier. However, its widespread adoption is hindered by challenges in storage—particularly safety, kinetics, and capacity. This chapter reviews recent progress in hybrid materials for hydrogen storage, targeting international benchmarks (USDOE: 6.5 wt%, FCH JU: 6 wt%). It emphasizes the synergy between the hydrogen and circular economies, highlighting electrolysis—currently contributing just 2% to global hydrogen production—as a key link between the two systems. The chapter explores various hydrogen storage methods, focusing on material-based approaches: physisorption and chemisorption, their classifications, and associated limitations. It also presents three industrial case studies: the HYDRAGE metal hydride tank by Japan Steel Works, the HYDROSTIK Pro Cartridge by Horizon Educational, and Toshiba’s H2One system, which integrates electrolysis and hydrogen storage.