Preparation and Electrochemical Characteristics of MgNi-TiNi0.56M0.44￡¨M=Al,Fe￡ Alloys

MgNi and MgNi-TiNi0.56M0.44￡¨M=Al,Fe￡ alloys were successfully synthesized by mechanical alloying (MA) approach. The structure and the electrochemical characteristics of these Mg-based electrodes were studied. The results of X-ray diffraction and scanning electron microscope show that the alloys have amorphous structures. The chargea2discharge cycle tests indicate that the cycle performance of these alloys are better than those of MgNi alloys, although the first discharge capacities are lower than that of the MgNi alloys. Among these alloys, the discharge capacity of MgNi-TiNi0.56Al0.44 is the highest, up to 380.64mAh/g￡ and the capacity maintaining rate is 48.97￡￥ after 50 cycles. Potentiodynamic polarization curves prove that anti-corrosion performance of the electrodes become better. Cyclic voltammetry (CV) and electrochemical impedance spectroscope (EIS) tests show that the introduction of the TiNi0.56M0.44￡¨M=Al,Fe￡ alloys decrease the charge-transfer reaction resistance and the H atom diffusion impedance, and improve the electrode catalytic activity significantly.