▎ 摘　　要

NOVELTY - A hydrogen storage material comprises covalent-bonded graphenes and alkaline earth metal ions. The covalent-bonded graphenes have three-dimensional structure by forming a junction point with a carbon atom on an end portion of a graphene monolayer and another carbon atom on the other end portion of the graphene monolayer by covalent bond. The alkaline earth metal ion is adsorbed and dispersed on the junction point. USE - Hydrogen storage material is used for hydrogen storage device (claimed). ADVANTAGE - The hydrogen storage material has high hydrogen storage modulus even at normal temperature. DETAILED DESCRIPTION - A hydrogen storage material comprises covalent-bonded graphenes and alkaline earth metal ions. The covalent-bonded graphenes have three-dimensional structure by forming a junction point with a carbon atom on an end portion of a graphene monolayer and another carbon atom on the other end portion of the graphene monolayer by sp3 covalent bond. The alkaline earth metal ion is adsorbed and dispersed on the junction point. An INDEPENDENT CLAIM is included for hydrogen storage device.