NOVELTY - Alkali metal-carbon composition is produced by reacting 1 part of alkali metal with more than 24 parts of carbon, to form an alkali metal intercalated carbon precursor product. The precursor product is further added with alkali metal to form a reaction product comprising layers of carbon atoms with intercalated alkali metal and characterized by absence of X-ray diffraction maxima for carbon and alkali metal.    USE - For use as temporary storage device for reversible storage of hydrogen gas/fuel used for engines and fuel cells.    ADVANTAGE - The alkali metal-carbon composition efficiently collects and stores high quantities of hydrogen, at relatively low pressure, and releases gaseous hydrogen on demand. The alkali metal-intercalated graphite material can be efficiently utilized to temporarily store hydrogen fuel for engines and fuel cells, and also in hydrogen storage/separation applications. Ternary material obtained by loading lithium, sodium and/or potassium-intercalated graphite with hydrogen, has favorable magnetic and electrical conductivity properties. The hydrogen-absorbing, carbon compound, is inexpensive, as it is prepared from cheap graphite flakes or powder, graphite fibers and non-graphitic carbons.    DETAILED DESCRIPTION - Producing an alkali metal-carbon composition, involves preparing the precursor mixture comprising carbon material having graphite carbon, and alkali metal(s) such as lithium, sodium or potassium, in an atomic proportion of 1 part of alkali metal to more than 24 parts of carbon under an atmosphere which is inert to alkali metal. Then, the precursor mixture is reacting under specific atmosphere, temperature and pressure, to form a precursor product comprising layer of carbon atoms with intercalated alkali metals atoms. The precursor product is treated with alcohol to remove any unreacted alkali metal. Further, the precursor product is added with additional alkali metals, under an atmosphere which is inert to alkali metal, to reduce the atomic proportion of carbon to alkali metal to 6-24 parts carbon, to obtain another mixture. The obtained mixture is reacted under specific atmosphere, to form a reaction product comprising layers of carbon atoms with intercalated alkali metal atoms and further characterized by absence of X-ray diffraction maxima for carbon and alkali metal.