Electrochemical properties of Mg-based alloys containing carbon nanotubes

Abstract

In this work, effects of partial substitution of Mg, Ni with AB 2 in Mg-based alloy and subsequent surface modification by further ball-milling with carbon nanotubes (CNTs) on electrochemical properties were investigated. Mg 1.9(AB 2) 0.1Ni 0.8 (AB 2=LaNi 2, LaNiCo and LaNiMn) alloys were prepared by solid-state diffusion method, the nanocrystalline Mg-based alloys were prepared by ball-milling the mixture of obtained Mg 1.9(AB 2) 0.1Ni 0.8 alloys and nickel powder. It was found that the electrochemical capacities of nanocrystalline Mg 1.9(AB 2) 0.1Ni 1.8 alloys were measured to be 460–490 mAh/g. The nanocrystalline Mg-based alloys containing carbon nanotubes (10 wt.%) obtained by ball-milling after 60 min were demonstrated to show improved electrochemical properties with respect to the original nanocrystalline Mg-based alloys. The electrochemical reaction activity was detected by electrochemical impedance spectra (EIS). Raman and X-ray photoelectron spectroscopy (XPS) proved the interaction between Mg 1.9(AB 2) 0.1Ni 1.8 alloys and carbon nanotubes after ball-milling, which resulted in an increase in the surface Ni/Mg ratio.