High energy ball milling composite modification of Mg2Ni hydrogen storage alloy by graphene and MWCNTs

Abstract

This study focuses on the preparation of a Mg2Ni hydrogen storage alloy through high-energy ball milling, further enhanced by composite graphene and multi-walled carbon nanotubes (MWCNTs) modification. It is evident that high-energy ball milling successfully incorporates graphene and MWCNTs onto the surface of Mg2Ni particles. This process not only creates surface defects but also establishes hydrogen pathways, facilitating the absorption and desorption of hydrogen. This improvement enhances the performance of hydrogen storage. With an increase in the composite quantity of graphene and MWCNTs, a more noticeable lubrication and grinding aid effect become evident during the ball milling process. This effect promotes more efficient grain refinement and minimizes agglomeration and welding phenomena. A comparative analysis with the Mg2Ni alloy reveals that the activation duration for the composite hydrogen storage alloy material significantly decreases. Concurrently, the kinetic performance sees substantial enhancement, and the temperature needed for hydrogen absorption and discharge is correspondingly reduced.