Heterogeneous metal hydride (MH) compositions comprising a main region comprising a first metal hydride and a secondary region comprising one or more additional components selected from the group consisting of second metal hydrides, metals, metal alloys and further metal compounds are suitable as anode materials for lithium ion cells. The first metal hydride is for example MgH.sub.2. Methods for preparing the composition include coating, mechanical grinding, sintering, heat treatment and quenching techniques.
GOVERNMENT SUPPORT STATEMENT
 This invention was made with government support under DE-AR0000386 awarded by Advanced Research Projects Agency-Energy under the Robust Affordable Next Generation EV Storage Program (RANGE). The government has certain rights in the invention.