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

Abstract The structure and electrochemical characteristics of La 0.7 Mg 0.3 Ni 2.875 Co 0.525 Mn 0.1 -boronLa composite was studied systematically. The AB 3 type hydrogen storage alloys La 0.7 Mg 0.3 Ni 2.875 Co 0.525 Mn 0.1 -boron were successfully synthesized by means of inter-media alloy La 2 Mg 17 . 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)Ni 3 phase and the LaNi 5 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)Ni 3 phase increase, and the LaNi 5 phase keep the same, which indicate that the boron may enter (La, Mg)Ni 3 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 AB 3 alloys and its composite were also studied.