A method of forming a material for reversible hydrogen storage within a storage tank includes charging a mixture of a metal amide and a metal hydride to the storage tank, and chemically reacting the mixture at a reaction condition within the storage tank to form a thermally conducting composite material situated in the storage tank and for reversibly storing hydrogen. The composite material includes a three-dimensional and interconnected framework including a conductive metal. A method for reversibly storing hydrogen includes providing a storage tank and in situ chemically forming a composite material by charging a mixture of a metal amide and a metal hydride to the storage tank and chemically reacting the mixture at a reaction condition to form a thermally conducting composite material including a metal hydride and a substantially unreactive elemental metal framework. Hydrogen is absorbed into the composite material and is desorbed from the composite material.