Article

Applied Physics A

, Volume 96, Issue 2, pp 349-352

Open Access This content is freely available online to anyone, anywhere at any time.

Hydrogen storage characteristics of nanograined free-standing magnesium–nickel films

  • Matthew RogersAffiliated withAdvanced Energy Technologies Department, Lawrence Berkeley National LaboratoryDepartment of Mechanical Engineering, University of California at Berkeley
  • , Steven BarceloAffiliated withAdvanced Energy Technologies Department, Lawrence Berkeley National LaboratoryDepartment of Mechanical Engineering, University of California at Berkeley
  • , Xiaobo ChenAffiliated withAdvanced Energy Technologies Department, Lawrence Berkeley National LaboratoryDepartment of Mechanical Engineering, University of California at Berkeley
  • , Thomas J. RichardsonAffiliated withAdvanced Energy Technologies Department, Lawrence Berkeley National Laboratory
  • , Vincent BerubeAffiliated withDepartment of Physics, Massachusetts Institute of Technology
  • , Gang ChenAffiliated withDepartment of Mechanical Engineering, Massachusetts Institute of Technology
  • , Mildred S. DresselhausAffiliated withDepartment of Physics, Massachusetts Institute of Technology
  • , Costas P. GrigoropoulosAffiliated withAdvanced Energy Technologies Department, Lawrence Berkeley National LaboratoryDepartment of Mechanical Engineering, University of California at Berkeley
  • , Samuel S. MaoAffiliated withAdvanced Energy Technologies Department, Lawrence Berkeley National LaboratoryDepartment of Mechanical Engineering, University of California at Berkeley Email author 

Abstract

Free-standing magnesium–nickel (Mg–Ni) films with extensive nanoscale grain structures were fabricated using a combination of pulsed laser deposition and film delaminating processes. Hydrogen sorption and desorption properties of the films, free from the influence of substrates, were investigated. Oxidation of the material was reduced through the use of a sandwiched free-standing film structure in which the top and bottom layers consist of nanometer-thick Pd layers, which also acted as a catalyst to promote hydrogen uptake and release. Hydrogen storage characteristics were studied at three temperatures, 296, 232, and 180°C, where multiple sorption/desorption cycles were measured gravimetrically. An improvement in hydrogen storage capacity over the bulk Mg–Ni target material was found for the free-standing films. As shown from a Van’t Hoff plot, the thermodynamic stability of the nanograined films is similar to that of Mg2Ni. These results suggest that free-standing films, of which better control of material compositions and microstructures can be realized than is possible for conventional ball-milled powders, represent a useful materials platform for solid-state hydrogen storage research.

PACS

68.43.Mn 68.43.Nr 68.55.-a