Structure and electrochemical performance of hydrogen storage alloy La0.7Mg0.3Ni2.875Co0.525Mn0.1-boron composite

The structure and electrochemical characteristics of La0.7Mg0.3Ni2.875Co0.525Mn0.1-boronLa composite was studied systematically. The AB3 type hydrogen storage alloys La0.7Mg0.3Ni2.875Co0.525Mn0.1-boron were successfully synthesized by means of inter-media alloy La2Mg17. The alloys were composited with boron at different weight rate. From the XRD analyses, each alloy of this series is mainly composed of (La, Mg)Ni3 phase and the LaNi5 phase, and the phase abundance of each phase varies with the boron weight rate, moreover, after composition, the c and cell volumes of (La, Mg)Ni3 phase increase, and the LaNi5 phase keep the same, which indicate that the boron may enter (La, Mg)Ni3 phase. The electrochemical studies show that the maximum discharge capacity of the composites decreases, but the cycling life improved. And the high rate discharge ability and exchange impendence spectroscopy (EIS) of the AB3 alloys and its composite were also studied.