Micro/Nano-Structures and Hydrogen Absorption/Desorption Properties of Mg/Cu Super-Laminates

Super-laminates have been attracting attention since co-authors Ueda et al. reported that Mg/Cu super-laminates showed reversible hydrogenation and dehydrogenation at 473K. The Mg/Cu super-laminates were prepared by a repetitive fold and roll method. Initial activation at 573 K led the super-laminates to absorb hydrogen at 473K. TEM observations of micro/nano-structures in the Mg/Cu super-laminates and Mg2Cu powder were performed in order to clarify the process of hydrogenation and dehydrogenation at 473K. The as-rolled Mg/Cu super-laminates have laminated structures sub-micrometer thick composed of Mg and Cu layers with dense lattice defects. The super-laminates after initial activation keep laminated structure and have uniformly distributed pores sub-micrometer in diameter. It is considered that these micro/nano-structures of Mg/Cu super-laminates lead to lower dehydrogenation temperature and better kinetics.