Preparation method of high capacity rare earth magnesium base hydrogen storage alloy

Abstract

The invention relates to high volume rare earth magnesium group hydrogen storage alloy manufacturing method. It features are adding raw material and its 0.1-20% protective cover into intermediate frequency furnace; pumping vacuum degree to less than 10-1pa; inputting argon or nitrogen to 0.03-0.1MPa; melting; keeping for 3-30 minutes after full melting; cooling alloy solution to gain alloy pig or alloy piece with thickness 0.05-1mm; doing heat preservation heat treatment for 2-24h at 700-1150 centigrade degree; cooling to room temperature; crushing to 100-300 order rare earth magnesium group hydrogen storage alloy. The AB3 type rare earth magnesium group hydrogen storage alloy has high volume, good cycle performance, and good sucking-discharging hydrogen performance. The cost is low. The technique is simple; process is easy to control; and it is adapted to large-scale industrial production.

Description

technical field [0001] The invention relates to a preparation method of a rare-earth magnesium-based hydrogen storage alloy for a new nickel-metal hydride battery negative electrode material. Background technique [0002] In recent years, with the continuous development of nickel-metal hydride batteries in the direction of high capacity and high power, higher requirements have been put forward for hydrogen storage alloys, the key anode materials of nickel-hydrogen batteries, which need to have high capacity, good cycle performance and high-current discharge performance. High-performance anode materials with the characteristics of low cost and low cost. The current commercialized rare earth-based AB 5 The specific capacity of the type hydrogen storage alloy is about 300-340mAh / g, and there is not much room for improvement, so it cannot better meet the development requirements of high-capacity and high-power nickel-metal hydride batteries. [0003] AB 2 Alloys with high dis...

AI Technical Summary

Problems solved by technology

[0009] in AB 3 In the production of rare-earth magnesium-based hydrogen storage alloys, because the melting point of metal magnesium is too different from that of nickel and cobalt, the melting temperature of the alloy is much higher than the boiling point of magnesium, so the conventional process of melting hydrogen storage alloys in a vacuum intermediate frequency induction furnace: pumping Vacuum, filled with argon or nitrogen to less than 0.1MPa negative pressure melting, it is difficult to produce a hydrogen storage alloy with stable composition

Because at the melting temperature of the alloy, a large amount of metal magnesium will volatilize in the furnace. On the one hand, because the volatilization amount of magnesium cannot be predicted and controlled, it is impossible to ensure uniform and stable alloy composition; on the other hand, because the volatilized magnesium vapor is extremely active, It will burn and explode when it meets air, so if the equipment is abnormal, it is easy to cause safety accidents