Electrochemical hydrogen storage, mechanical and thermal behaviors of novel Mg-based alloy

Abstract

In this study, Mg65Ni25Y5B5 metallic glass synthesized by using the melt-spinning technique was examined in terms of its electrochemical hydrogen-storage characteristics and mechanical and thermal behaviors. The X-ray diffraction and scanning electron microscopy results indicated that the alloy ribbon has a fully amorphous structure. The thermal behavior of the alloy ribbon was determined using flash differential scanning calorimetry (DSC). According to flash DSC results, the amorphous alloy ribbon exhibited a distinct glass transition temperature (T g) and a wide supercooled liquid region (ΔT x = T x − T g) before crystallization. Accordingly, T g and ΔT x are 195 and 63°C, respectively. The mechanical behavior of the magnesium (Mg)-based alloy at room temperature was determined by means of a Vickers microhardness (HV) tester. The microhardness value of the alloy ribbon was measured as 336.8 HV. The discharge capacity of the Mg65Ni25Y5B5 alloy reached 313 mAh/g. The cycle stability revealed that the alloy ribbon protected at least 76.7% of its initial discharge capacity at the 12th charge–discharge cycle.