Hydrogen-absorbing alloy, fabrication method thereof and alkaline storage battery

一种贮氢合金、制造方法的技术，应用在碱性蓄电池、碱性蓄电池电极、镍蓄电池等方向，能够解决贮氢合金开裂、碱性蓄电池循环寿命降低等问题，达到抑制体积变化之差、抑制龟裂、高容量的效果

CN102104145AInactive Publication Date: 2011-06-22SANYO ELECTRIC CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2011-06-22
Estimated Expiration
Not applicable · inactive patent

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Abstract

An alkaline storage battery has a negative electrode using a hydrogen-absorbing alloy represented by a general formula Ln1-xMgxNiyAz wherein Ln is at least one element selected from rare-earth elements including Y, Ca, Zr, and Ti, A is at least one element selected from Co, Fe, Mn, V, Cr, Nb, Al, Ga, Zn, Sn, Cu, Si, P and B, and 0.15<=x<=0.30, 0<z<=1.5, and 2.8<=y+z<=4.0 are satisfied. The hydrogen-absorbing alloy has a hexagonal system crystal structure or a rhombohedral system crystal structure as its main phase and has a subphase of line which average number of not less than 50 nm in thickness existing in the range of 10 [mu]m10 [mu]m in the cross section of the main phase is 3 or less.
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Description

technical field

[0001] The invention relates to a hydrogen storage alloy, a method for producing the hydrogen storage alloy and an alkaline storage battery using the hydrogen storage alloy in the negative electrode. In particular, it has the characteristics of improving the durability of the hydrogen storage alloy used in the negative electrode of the alkaline storage battery while maintaining its high hydrogen storage capacity, and improving the cycle life of the alkaline storage battery. Background technique

[0002] Conventionally, nickel-cadmium storage batteries have been widely used as alkaline storage batteries, but in recent years, from the viewpoint of higher capacity than nickel-cadmium storage batteries and excellent environmental safety because cadmium is not used, hydrogen-absorbing alloys have been used for negative electrodes. Nickel-metal hydride storage batteries are attracting attention.

[0003] Further, in order to make alkaline storage batteries compose...

Examples

Embodiment 1

[0059] In the alkaline storage battery of Example 1, when producing the hydrogen storage alloy used in the negative electrode active material of the negative electrode, the rare earth elements La, Ce, and Nd were mixed with Mg, Ni, and Al according to the specified alloy composition, and the hydrogen storage alloy was mixed in an argon atmosphere. After melting in a high-frequency induction melting furnace, it was poured into a mold and cooled to room temperature to obtain an ingot of a hydrogen storage alloy. Here, the composition of the hydrogen storage alloy thus obtained was analyzed by high-frequency plasma emission spectrometry (ICP), and as a result, the composition was (La 0.3 Ce 0.4 Nd 0.3 ) 0.85 Mg 0.15 Ni 3.3 Al 0.2 . In addition, the melting point of the hydrogen storage alloy was measured with a differential scanning calorimeter (DSC), and the melting point was 1015°C.

[0060] Then, heat-treat the ingot of the hydrogen storage alloy in a furnace in an argo...

Embodiment 2

[0085] In the alkaline storage battery of Example 2, when manufacturing the hydrogen storage alloy used for the negative electrode active material, the rare earth elements La and Sm are mixed with Mg, Ni, and Al according to the specified alloy composition, and they are melted in a high-frequency induction melting furnace. After melting in an argon atmosphere, it was poured into a mold and cooled to room temperature to obtain an ingot of a hydrogen storage alloy. Here, the composition of the hydrogen storage alloy thus obtained was analyzed by high-frequency plasma emission spectrometry (ICP), and as a result, the composition was La 0.65 SM 0.15 Mg 0.20 Ni 3.40 Al 0.20 . In addition, the melting point of the hydrogen storage alloy was measured with a differential scanning calorimeter (DSC), and the melting point was 980°C.

[0086] Next, the ingot of the hydrogen storage alloy was heat-treated in a furnace in an argon atmosphere at a temperature of 50°C lower than the mel...