Hydrogen storage alloy for nickel-metal hydride battery and manufacturing method of hydrogen storage alloy

Abstract

The invention relates to hydrogen storage alloy for a nickel-metal hydride battery and a manufacturing method of the hydrogen storage alloy. The chemical formula of the hydrogen storage alloy is La1-x-yCexReyNi4.83-a-b-cCoaMnbAlcMd, x, y, a, b and c in the formula are atomic ratios, and the ranges of x, y, a, b and c satisfy the conditions that x=(0.175, 0.20, 0.30 and 0.35), y=(0.015, 0.02, 0.03 and 0.05), a=(0.15, 0.18, 0.20 and 0.25), b=(0.36, 0.42, 0.54 and 0.85), c=(0.15, 0.18 and 0.21), d=(0.25, 0.45 and 0.56), 0.19<=x+y<=0.4, and 0.9<=a+b+c+d<=1.4, wherein Re is one of Y, Zr and Gd, and M is at least one of Fe, Cr and Si. In the manufacturing process, gas and impurities in the alloy are removed in a film forming manner, raw materials are fully alloyed, annealing treatment is used as assistance, the composition segregation of the alloy can be remarkably reduced, and lattice imperfection and lattice stress are eliminated. The hydrogen storage alloy manufactured through the method has the beneficial effects of being high in discharge capacity and anti-pulverization capacity, low in production cost and the like, and the requirements of the Ni-MH battery for production cost and the performance can be met.

Description

technical field [0001] The invention belongs to the field of nickel-hydrogen batteries. Background technique [0002] In recent years, the skyrocketing market price of rare earth raw materials has brought great cost pressure to China's downstream deep processing enterprises of rare earth, and downstream industries such as rare earth permanent magnet materials, rare earth luminescent materials and rare earth hydrogen storage materials are facing severe tests. Conventional hydrogen storage alloy products have caused unprecedented pressure on the nickel-metal hydride battery industry due to the rise in rare earth raw materials, and have also caused nickel-metal hydride batteries to lose their cost advantage over lithium batteries. Since lithium-ion batteries have higher energy density than Ni-MH batteries, and the production cost of lead-acid batteries is lower, the development of Ni-MH batteries has been greatly impacted and challenged. With the enhancement of domestic enviro...

AI Technical Summary

Problems solved by technology

In the current research results, the patent CN201310035757 of the Guangzhou Institute of Nonferrous Metals announced a samarium-containing hydrogen storage alloy for nickel-hydrogen power batteries. The alloy has high discharge capacity and cycle stability, but the alloy contains High rare earth Sm and Co elements lead to higher production costs of the alloy

In addition, the patent CN201210260102.8 of Anshan Xinpu New Material Co., Ltd. also announced a low-cost AB5 type hydrogen storage alloy without cobalt, praseodymium and neodymium. The alloy has low cost and good cycle stability, but its discharge capacity is still low needs to be further improved

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