The electrochemical properties of LaxMg3−xNi9 (x=1.0–2.0) hydrogen storage alloys

LaxMg3−xNi9 (x=1.0–2.0) alloys were prepared by a powder sintering method and the influence of partial substitution of Mg by La on the crystal structure and electrochemical performance of the alloys was investigated. The ternary alloys with different La/Mg ratio are related to the hexagonal PuNi3-type structure. The increase of La/Mg ratio in the alloys leads to a linear increase of the unit cell volume. The La-rich alloys (x=1.8–2.0) show promising electrode properties including a large discharge capacity (∼400 mAh/g), easy activation and good high-rate dischargeability, although the cycling stability needs further improvement.