기계적 합금화법으로 제조한 Mg2NiHx-Graphene 복합재료의 수소화 특성 평가

Abstract

Mg hydride has a high hydrogen capacity (7.6%), at high temperature, and is a lightweight and low cost material, thus it a promising hydrogen storage material. However, its high operation temperature and very slow reaction kinetics are obstacles to practical application. In order to overcome these disadvantages of Mg hydride, graphene powder was added to it. The addition of graphene has been shown to reduce the operating temperature of dehydrogenation. Moreover, in this report the environmental aspects of MgHx-Graphene composites are investigated by means of the environmental life cycle assessment (LCA) method. MgHx-Graphene mixture was prepared by hydrogen induced mechanical alloy (HIMA). The synthesized powder was characterized by XRD(X-ray Diffraction). The hydro- genation behaviors were evaluated by using a Sievert's type automatic PCT apparatus. Such evaluation of Materials also conducted in the LCA. From the result of P-C-T(Pressure-Composition-Temperature) curves, the MgHx-3wt.% graphene composite was evaluated as having a 5.86wt.% maximum hydrogen storage capacity, at 523K. From absorption kinetic testing, the MgHx-7wt.%graphene composite was evaluated as having a maximum 6.94wt.%/ms hydrogen absorption rate, at 573K. Environment evaluation results for the MgHx-graphene composites and other materials indicated environmental impact from the electric power used and from the materials themselves.