Metallic composite phase-change materials and methods of using are disclosed. In some embodiments, a thermal energy storage module is provide that included one or more phase change alloys having a variable phase transition temperature between about 400.degree. C. and about 1200.degree. C. and having a latent heat of more than about 200 kJ/kg.
STATEMENT OF GOVERNMENT SUPPORT
 This invention was made with Government Support under Contract Number DE-AR0000181 awarded by the Advanced Research Projects Agency--Energy, Department of Energy. The Government has certain rights in the invention.