To provide a hydrogen storage alloy combining lightweight with a small size, and to provide a hydrogen storage tank, a multilayer structure, and a method for producing a composite hydrogen storage alloy.

The hydrogen storage member is characterized in that a hydrogen storage layer and a hydrogen permeation layer are alternately layered, one or more layers for each, the thickness of the hydrogen storage layer is 10 nm to 10 μm, and the thickness of the hydrogen permeation layer is ≥10 nm and is ≤35.2% of the thickness of the hydrogen storage layer. By controlling the thickness of the hydrogen storage layer to ≥10 nm, the occurrence of the unstable or imperfect structure of the hydrogen storage layer can be suppressed. By controlling the thickness of the hydrogen storage layer to ≤10 μm, the surface area per unit volume is increased, then, hydrogen storage capability can be increased. By controlling the thickness of the hydrogen permeation layer to ≥10 nm, hydrogen stored/discharged by the hydrogen storage layer is made easy to permeate the inside of the stacked face. By controlling the thickness of the hydrogen permeation layer to ≤35.2% of the thickness of the hydrogen storage layer, the ratio of the hydrogen storage layer per unit volume can be controlled to ≥74 vol.%.

COPYRIGHT: (C)2008,JPO&INPIT