Hydrogen storage properties of Mg/Cu and Mg/Pd laminate composites and metallographic structure

Abstract

The Mg-based laminate composites, Mg/Cu and Mg/Pd, were prepared by repetitive-rolling, which is considered to suit for mass production. Mg/Cu laminate composites (Mg/Cu = 2) absorb and desorb hydrogen reversibly at 473 K, and the laminate composites have a better reaction kinetics than melting-casting alloys. TEM observations revealed that the as-rolled Mg-based laminate composite had the sub-micrometer-ordered layered structure with dense dislocations and vacancies. After initial activation and dehydrogenation process, the samples have kept the sub-micrometer-ordered laminate structure with dense dislocations and vacancies. The nano-structure of Mg-based laminate composites leads to lower hydrogen desorption temperature and better kinetics, which would contribute to achieve high capacity hydrogen storage materials. In Mg/Pd laminate composites (Mg/Pd = 6), Mg 6Pd is formed during initial activation process. This Mg 6Pd also can store hydrogen reversibly through the disproportionation and recombination process.