Ynthesis and Characterization of Nonstructural MG2NI with Replacement Diffusion Method

Abstract

Nonstructural Mg₂Ni powder was prepared by replacement-diffusion method. The structure of the Mg₂Ni powder was investigated by X-ray diffraction and transmission electron microscopy. Crystallographic structure analysis showed that the synthesized sample powder was constituted with Mg₂Ni and a small fraction of MgO. The TEM image in low-resolution indicated that the diameter of the synthesized Mg₂Ni powder was in the range of 20~80 nm, and the high-resolution transmission electron microscope (HRTEM) image suggested that the interlinear spacing of (113) lattice planes was 0.229 nm, and the specific surface area examined was 50 m² /g. The electrochemical hydrogen storage capacity of the Mg₂Ni power was also measured in this work. It was 82.5 mAh g^-1. The reasons of the low capacity hydrogen storage and decrepitating were analyzed, and the mainly cause were the grievous oxidation of the powder and the pulverization.