Research on the structures and discharge capacities of Mg-Ni alloy with different Ni contents synthesized by high-energy ball milling

摘要

The effects of different Ni contents and milling durations on the discharge capacities of Mg-Ni alloys were investigated. The samples were prepared by high-energy ball milling. Their structures were determined with X-ray diffraction and their discharge capacities were tested. The results showed that the nanocrystalline Mg_2Ni, amorphous MgNi and nanocrystalline Mg-Ni alloy could be obtained respectively when the Mg_2Ni, Mg_(1.5)Ni and MgNi powders were milled under different conditions. The discharge capacities of milled Mg-Ni alloy powder depend on their structures. The discharge capacity of the mixed structure of nanocrystalline Mg_2Ni and Mg is higher than that of nanocrystalline Mg_2Ni phase, but the capacity of amorphous MgNi phase is not as good as that of nanocrystalline Mg-Ni alloy. The milled MgNi powder showed the best discharge capacity, 500 mAh/g, when its structure is comprised of nanocrystalline Mg-Ni alloy and nanocystalline Ni.