JPH09161788A - Hydrogen storage alloy electrode and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the high-rate discharge characteristic and cycle characteristic by using the hydrogen storage alloy powder having a small grain size as an active material so that the total quantity of the hydrogen storage alloy powder accumulated from the small grain size side to the large grain size side after crushing becomes a specific quantity. SOLUTION: Hydrogen storage alloy lumps manufactured by quench solidification are crushed to obtain hydrogen storage alloy powder, and the hydrogen storage alloy powder satisfying the equation I within this hydrogen storage alloy powder is used as the active material of a hydrogen storage alloy electrode. Nearly all the hydrogen storage alloy used for the electrode is uniformly charged and discharged, and the hydrogen storage alloy can be prevented from being set to the inactive state or from being pulverized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogen storage alloy electrode used as a negative electrode of a metal hydride storage battery, and more specifically, it is an electrode material for the purpose of improving cycle characteristics and high rate discharge characteristics. The present invention relates to improvement of hydrogen storage alloys.

[0002]

2. Description of the Related Art In recent years, the progress of electronics technology has been remarkable and tends to continue to accelerate. Along with this, portable and cordless electronic devices have been developed, and at the same time, there has been a strong demand for the development of small, lightweight, high-energy-density, high-performance secondary batteries as power supplies for these devices. Therefore, a metal hydride storage battery using a hydrogen storage alloy for the negative electrode has recently attracted particular attention as a clean power source having a higher capacity, higher density, and a higher capacity than nickel cadmium storage batteries, lead storage batteries, and the like.

By the way, a hydrogen storage alloy for alkaline storage batteries must be capable of reversibly storing and releasing hydrogen near room temperature. The following method has been proposed as a method for producing an electrode using a hydrogen storage alloy.

First, a metal element is weighed, the metal element is melted in a melting furnace, and then this molten metal is cooled by a rapid solidification method such as a roll method to prepare a hydrogen storage alloy ingot. Next, this hydrogen storage alloy ingot is pulverized by a mechanical pulverization method or a hydrogenation pulverization method to prepare a hydrogen storage alloy powder, and then this hydrogen storage alloy powder and a binder are kneaded to form an active material paste. To make. Then, the active material paste was pressure-bonded to both sides of the current collector and pressed to produce the active material paste.

[0005]

However, in the above-mentioned conventional metal hydride storage battery using the hydrogen storage alloy electrode, when the hydrogen atoms are stored and released during charge and discharge, the crystal lattice of the alloy expands and contracts. Is applied. For this reason, when repeatedly charged and discharged, the hydrogen storage alloy gradually becomes finer,
A new surface is formed, and the element of the alloy exposed on the new surface is oxidized to form an inactive film on the surface of the alloy, or the element of the alloy is dissolved in the electrolytic solution to change the alloy composition.

In particular, a hydrogen storage alloy produced by a rapid solidification method such as a roll method has a higher cooling rate than a usual casting method (a method of pouring a molten hydrogen storage alloy into a water-cooled mold for cooling and solidification). , For example, in the case of the roll method, the roll surface side (the side in contact with the roll, where the molten metal of the hydrogen storage alloy is rapidly cooled)
Alloy and the alloy on the side opposite to the roll surface (on the side in contact with the gas, where cooling of the molten hydrogen storage alloy is slightly slower), the alloy structure and hydrogen after crushing the hydrogen storage alloy The particle size of the occlusion alloy powder is different. Specifically, the alloy of the quenching portion has a chilled crystal with a uniform structure, and the hardness is high, while the particle size of the hydrogen storage alloy powder after crushing is large,
The alloy of the slow cooling part has a slightly nonuniform structure, and the hardness is low, and the particle size of the hydrogen storage alloy powder after pulverization is small.

When an electrode and a battery are manufactured by using hydrogen storage alloy powders of all sizes, large and small, and the charging / discharging cycle is repeated, the hydrogen storage alloy powders of small size are selectively charged / discharged. As a result, the atomization of the alloy is promoted, and the elements of the alloy exposed on the new surface are oxidized, while the hydrogen-absorbing alloy powder having a large particle size is not charged / discharged and becomes inactive. For these reasons, there is a problem that the high rate discharge characteristics and the cycle characteristics are deteriorated.

The present invention has been made in view of the above problems, and provides a hydrogen storage alloy electrode and a method for manufacturing the same, which makes it possible to obtain a metal hydride storage battery excellent in high rate discharge characteristics and cycle characteristics. It is an object of the present invention to provide.

[0009]

The hydrogen storage alloy electrode according to the present invention is a hydrogen storage alloy powder obtained by crushing a hydrogen storage alloy ingot produced by a rapid solidification method, which satisfies the following formula 3. It is characterized in that a storage alloy powder is used as an active material.

[0010]

(Equation 3)

The method for producing a hydrogen storage alloy electrode according to the present invention comprises a first step of producing a hydrogen storage alloy ingot by a rapid solidification method and a crushing of the hydrogen storage alloy ingot to obtain a hydrogen storage alloy powder. A second step, a third step of selecting a hydrogen storage alloy powder satisfying the above expression 3 among the hydrogen storage alloy powders, and a fourth step of producing an electrode using the hydrogen storage alloy powder obtained in the third step as an active material. It is characterized by comprising steps.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In a rapid solidification method such as a roll method or a gas atomizing method, since the cooling rate is high, a portion having a different cooling rate, that is, a quenching portion and a slow cooling portion are formed. The quenching part (roll surface side of the roll method, surface part of the atomizing method) has a more uniform alloy structure than the slow cooling part, and the hardness is high, and the particle size of the hydrogen-absorbing alloy powder after crushing is large. Become.

The hydrogen storage alloy in the quenched portion, that is, the alloy on the large particle side, is less activated than the alloy on the small particle side because it has a more uniform structure, and the high rate discharge characteristics are deteriorated.
Also, during the charge / discharge cycle, the alloy part on the small particle side is selectively charged / discharged, pulverized and oxidized, and the large particle side becomes inactive because it is not charged / discharged, the alloy capacity decreases, and eventually the cycle Service life is reduced.

Therefore, in the hydrogen storage alloy electrode of the present invention, among the hydrogen storage alloy powder obtained by crushing the hydrogen storage alloy ingot produced by the rapid solidification method, the value of the following expression 4 is 80 wt% or less. By using the storage alloy powder as the active material, almost all hydrogen storage alloys used in the electrodes are uniformly charged and discharged, and it is possible to suppress the hydrogen storage alloy from becoming an inactive state or being pulverized. it can.

[0015]

(Equation 4)

Details will be described with reference to FIG. In FIG. 1, the vertical axis represents% by weight, the horizontal axis represents particle size, the total amount of hydrogen storage alloy powder after pulverization is indicated by A + B, and the total amount of hydrogen storage alloy powder from the small particle size side is indicated by A. An unused hydrogen storage alloy powder is indicated by B. Then, only the hydrogen-storing alloy powder on the small particle size side is separated so that the value represented by the above mathematical expression 4 becomes 80 wt% or less, and only the separated hydrogen-storing alloy powder on the small particle size side is used as the active material for hydrogen storage. It is used for alloy electrodes.

Examples of the rapid solidification method include a roll method, an atomizing method, a centrifugal atomizing method, and an underwater casting method (unlike the ordinary casting method, the molten hydrogen storage alloy is cooled in water so that it is rapidly cooled). However, the method is not limited to these methods. When the roll method is used, the roll method has a particularly high cooling rate among the rapid solidification methods, so that the effects of preventing the inactive state of the alloy and preventing pulverization are further exhibited.

As the method for crushing the above hydrogen storage alloy ingot, a hydrogenation crushing method or a mechanical crushing method can be used.
In particular, when the hydro-crushing method is used, the hydrogen-crushing method is for crushing the hydrogen storage alloy by taking in and out of hydrogen similarly to charging / discharging of the battery, so that activation of the alloy is promoted and mechanical crushing is performed. The high-rate discharge characteristics are improved compared to, and a high capacity battery can be obtained from the beginning of the cycle.

Further, as a hydrogen storage alloy, Mm _1.0 Ni
Examples include _3.4 Co _0.8 Al _0.2 Mn _0.6 , LaNi ₅ , MmNi _{5 and the} like, but it goes without saying that the hydrogen storage alloy is not limited to these.

If the value of the above equation 4 is set too small, the amount of unused hydrogen storage alloy powder increases and the manufacturing cost rises. Therefore, the value of the above equation 4 is 60 to 80 wt%
It is desirable to be between.

Further, in order to make the charge-discharge reaction of the hydrogen storage alloy powder as the active material more uniform, 20% by weight or more of the rapidly cooled alloy part, that is, the alloy on the large particle size side after crushing is removed and then crushed. After that, the hydrogen storage alloy powder around the minimum particle size may be removed. In this case, the small particle size side after pulverization of the above Equation 4 means the minimum particle size of the remaining hydrogen storage alloy powder after removing the hydrogen storage alloy powder near the minimum particle size after pulverization. .

[0022]

【Example】

(First Example) (Example I) [Preparation of hydrogen storage alloy] Mm (mixture of rare earth elements):
Each metal element of Ni: Co: Al: Mn was added in the ratio of 1.0: 3.
Commercially available metal elements were weighed so as to have a ratio of 4: 0.8: 0.2: 0.6, melted in a high-frequency melting furnace to prepare a molten metal, and then the peripheral surface of a roll rotating at a high speed. It was solidified by a so-called roll method in which it was jetted to the. At this time, the peripheral speed of the roll was adjusted so that the cooling rate of the molten metal was 10 × 10 ³ ° C./sec or more. Through the above steps, the composition formula MmN
A hydrogen storage alloy ingot represented by i _3.4 Co _0.8 Al _0.2 Mn _0.6 was obtained.

[Preparation of Hydrogen Storage Alloy Electrode] The above hydrogen storage alloy ingot was mechanically pulverized by a ball mill in an inert gas to prepare hydrogen storage alloy powder. At this time, the grinding time was 8.4 minutes. Next, the hydrogen-absorbing alloy powder was classified according to particle size, and then the hydrogen-absorbing alloy powder was separated by meshing so that the value represented by the formula 4 was 50 wt%. The hydrogen storage alloy produced in this manner is referred to as alloy a1 of the invention. The average particle diameter of the hydrogen storage alloy powder thus separated is 50 μm.

Next, 5 wt% of the polytetrafluoroethylene powder as a binder was added to the above-mentioned hydrogen-absorbing alloy powder a1 on the small particle size side as an active material to prepare an active material paste. After that, this active material paste was pressure-bonded to both sides of a current collector made of punching metal, and further pressed to produce a negative electrode.

The electrode thus manufactured is hereinafter referred to as an electrode A1 of the invention.

(Embodiment II) The value shown by the above equation 4 is 60.
An electrode and a battery were produced in the same manner as in Example I except that the alloy a2 of the present invention was produced by adjusting the content to be wt%. However, the grinding time of the hydrogen storage alloy in this Example II was 8.5 minutes so that the average particle size of the hydrogen storage alloy powder was 50 μm as in the above Example I.

The electrode thus manufactured is hereinafter referred to as an electrode A2 of the invention.

(Embodiment III) The value represented by the above-mentioned equation 4 is 7
An electrode and a battery were produced in the same manner as in Example I except that the alloy a3 of the invention was produced by adjusting the content to be 0 wt%. However, the grinding time of the hydrogen storage alloy in this Example III was set to 8.7 minutes so that the average particle size of the hydrogen storage alloy powder was set to 50 μm as in the above Example I.

The electrode thus manufactured is hereinafter referred to as an electrode A3 of the invention.

(Embodiment IV) The value shown by the above equation 4 is 80.
An electrode and a battery were produced in the same manner as in Example I except that the alloy a4 of the invention was produced by adjusting the content to be wt%. However, the grinding time of the hydrogen storage alloy in the present Example IV was set to 9 minutes so that the average particle size of the hydrogen storage alloy powder was 50 μm as in the above Example I.

The electrode thus manufactured is hereinafter referred to as an electrode A4 of the invention.

(Example V) The above-mentioned Example 1 was repeated except that a negative electrode was prepared using a hydrogen storage alloy powder having an average particle size of 40 μm.
Electrodes and batteries were prepared in the same manner as in. The above embodiment
As with IV, the crushing time of the hydrogen storage alloy in Example 5 was set to 10 so that the value represented by the above mathematical expression 4 was 80 wt%.
Minutes. The alloy and the electrode thus produced are referred to as the present invention alloy a5 and the present invention electrode A5, respectively.

(Comparative Examples I and II) Comparative Examples I and II were prepared in the same manner as in Example I, except that the comparative alloys x1 and x2 were prepared by adjusting the values shown in the equation 4 to be 90 wt% and 100 wt%, respectively. To produce electrodes and batteries. However, the grinding time of the hydrogen storage alloy was set to 9.5 minutes and 10 minutes, respectively, so that the average particle diameter of the hydrogen storage alloy powder was set to 50 μm as in Example I.

The electrodes thus manufactured are hereinafter referred to as a reference electrode X1 and a reference electrode X2, respectively.

(Comparative Example III) The above Comparative Example except that a negative electrode was prepared using a hydrogen storage alloy powder having an average particle size of 40 μm.
As in II, the crushing time of the hydrogen storage alloy was set to 11 minutes so that the value expressed by the above equation 4 was 100 wt%. The alloy and the electrode thus manufactured are referred to as a comparative alloy x3 and a comparative electrode X3, respectively.

[Positive Electrode] As a positive electrode, a known sintered nickel positive electrode was prepared.

[Electrolytic Solution] A 30% by weight KOH aqueous solution was prepared.

[Production of Battery] A cylindrical battery of the present invention was produced using the positive and negative electrodes and the alkaline electrolyte described above. A non-woven fabric was used as the separator, which was impregnated with the electrolytic solution.

FIG. 2 is a sectional view schematically showing a battery using the electrode A1 of the present invention. The battery of the present invention shown in FIG.
The negative electrode 2, a separator 3 separating these two electrodes, a positive electrode lead 4, a negative electrode lead 5, a positive electrode external terminal 6, a negative electrode can 7 and the like. The positive electrode 1 and the negative electrode 2 were inserted into the negative electrode can 7 while being wound in a spiral shape via the separator 3, and then a 30 wt% KOH aqueous solution was injected. Further, the positive electrode 1 is connected to the positive electrode external terminal 6 via the positive electrode lead 4, and the negative electrode 2 is connected to the negative electrode can 7 via the negative electrode lead 5, so that chemical energy generated inside the battery can be taken out as electric energy to the outside. It has become.

The theoretical capacity of the battery thus manufactured is 1000 mAh.

[Preparation of Test Cell] The alloys a1 to a1 of the present invention
1.2 g of carbonyl nickel powder as a conductive agent and 0.2 g of polytetrafluoroethylene (PTFE) powder as a binder were mixed with 1 g of each of the a5 powder and the comparative alloy powders x1 to x3 and kneaded to obtain an alloy paste. The alloy paste is wrapped with nickel mesh and pressed, a sintered nickel positive electrode having a capacity sufficiently larger than that of the electrode is placed in a closed container, and K as an electrolytic solution is further added.
A test cell was prepared by adding an excess amount of OH.

[Characteristic Test 1] High Rate Discharge Characteristics Using the test cell prepared as described above, charging and discharging were performed under the following conditions, and the activity was measured. First, the alloy was charged with a current value of 50 mA per gram for 8 hours, and was left for 1 hour, and then discharged with a current value of 200 mA per gram of alloy until the discharge end voltage reached 1.0 V. It was designated as C _H. Then, after a pause of 1 hour, that is, the voltage was restored, and discharge was performed at a current value of 50 mA per 1 g of the alloy until the discharge end voltage reached 1.0 V, and the discharge capacity at this time was taken as C _L.

The evaluation of the high rate discharge characteristic is as follows: Activity (%) = C
_{Performed using H} / (C _H + C _L ) × 100. The results are shown in Table 1 below.

Alloy Capacity Measurement Test Using the test cell prepared as described above, charging and discharging were performed under the following conditions to measure the alloy capacity. 5 per 1g alloy
Charge for 4 hours at 0mA current, rest for 1 hour, and discharge end voltage is 1.0V at 50mA current per 1g of alloy.
It was discharged until it reached. After repeating this for 3 cycles, the alloy was charged with a current of 50 mA / g for 8 hours, and
After a lapse of time, the alloy was discharged at a current of 50 mA per 1 g of the alloy until the discharge end voltage reached 1.0 V, and the capacity at this time was measured. The results are shown in Table 1 below.

Charge / Discharge Cycle Characteristics First, with respect to the batteries using the electrodes A1 to A5 of the present invention and the reference electrodes X1 to X3, 100 mA at room temperature (25 ° C.)
After 16 hours of charging, the battery was activated for 1 hour and then discharged at 200 mA to a discharge end voltage of 1.0 V and stopped for 1 hour.

Then, after charging each battery at room temperature (25 ° C.) at 1500 mA for 48 minutes and resting for 1 hour,
A charging / discharging cycle test in which one cycle includes a step of discharging at 1500 mA to a discharge end voltage of 1.0 V and resting for 1 hour was performed, and the time when the battery capacity reached 500 mAh (half the initial capacity) was defined as the life. The results are shown in Table 1 below.

[0047]

[Table 1]

As is apparent from Table 1, in the test cell using the alloys a1 to a5 of the present invention whose value shown by the above-mentioned formula 4 is 80 wt% or less, the comparative alloy whose value shown by the above-mentioned formula 4 exceeds 80 wt%. Compared to the test cell using x1 to x3,
It is recognized that high rate discharge characteristics, alloy capacity per 1 g of alloy and cycle life characteristics are excellent. This is because in the test cells using the alloys a1 to a5 of the present invention, almost all the hydrogen storage alloys are uniformly charged and discharged, so that the activation of the entire electrode is achieved and the proportion of alloys in the inactive state is small. Against
In the test cells using the comparative alloys x1 to x3, since the large-diameter hydrogen storage alloy is not charged / discharged, activation of the entire electrode cannot be achieved, and the proportion of alloys in the inactive state increases, and It is considered that the cycle life was shortened because the alloy capacity of was reduced.

(Examples VI to IX) Alloys, electrodes, batteries and test cells were produced in the same manner as in Examples I to IV except that the alloy was produced by using the atomizing method as the method for casting the hydrogen storage alloy. did.

The atomizing method is a method of spraying the molten hydrogen-absorbing alloy produced in the same manner as in Example 1 through the pores by the argon gas pressure and quenching it.
The average particle size of the hydrogen storage alloy powder after the spraying is 100.
μm, which was then mechanically ground.

The alloys and electrodes produced in this manner are respectively referred to as alloys a6 to a9 of the present invention and electrodes A6 to A9 of the present invention.
Called.

(Comparative Examples IV and V) Alloys, electrodes, batteries and test cells were produced in the same manner as in Comparative Examples I and II except that the alloy was produced by using the atomizing method as the method for casting the hydrogen storage alloy. did.

The alloys and electrodes prepared in this manner are hereinafter referred to as comparative alloys x4 to x5 and comparative electrodes X4 to X5.

[Characteristics Test 2] Regarding the batteries and test cells using the alloys a6 to a9 of the present invention and the comparative alloys x4 to x5, the high rate discharge characteristics, according to the above [Characteristics Test 1],
The alloy capacity measurement test and the charge / discharge cycle characteristics were measured, and the results are also shown in Table 1 above.

As shown in Table 1, in the battery and the test cell using the alloys a6 to a9 of the present invention, the value of which is 80 wt% or less, the value of which 4 is 80 w.
It is recognized that the activity of the alloy, the alloy capacity per 1 g of the alloy, and the cycle characteristics are superior to the battery and the test cell using the comparative alloys x4 to x5 exceeding t%. It is considered that this is due to the same reason as that shown in [Characteristic test 1].

(Comparative Examples VI to IX) Alloys were prepared in the same manner as in Examples III to IV and Comparative Examples I to II, except that an ordinary casting method was used as a method for casting hydrogen storage alloys.
Electrodes, batteries and test cells were made.

The casting method is a method in which the molten hydrogen storage alloy prepared in the same manner as in Example I is poured into a water-cooled steel mold and cooled.

The alloys and electrodes prepared in this manner are hereinafter referred to as comparative alloys x6 to x9 and comparative electrodes X6 to X9, respectively.

[Characteristic test 3] With respect to the batteries and test cells using the comparative alloys x6 to x9, the high rate discharge characteristic, the alloy capacity measurement test, and the charge / discharge cycle characteristic were measured according to the above [Characteristic test 1]. The results are also shown in Table 1 above.

As shown in Table 1, the battery and the test cell using the comparative alloys x6 to x7 having the value shown by the formula 4 of 80 wt% or less and the value shown by the formula 4 are 80 wt%.
No difference is observed in the activity of the alloy, the alloy capacity per 1 g of the alloy, and the cycle characteristics of the battery and the test cell using the comparative alloys x8 to x9 exceeding the above range. It is considered that this is because in the casting method in which the molten hydrogen-absorbing alloy is not rapidly cooled, the pulverization is performed uniformly, so that the difference in the structure due to the grain size is small. Therefore, the present invention is useful when the rapid solidification method for quenching the molten hydrogen storage alloy is used.

(Second Embodiment) (Examples I to IX) The first embodiment except that the hydrogen storage alloy is pulverized by hydrogenation and pulverization in which hydrogen is absorbed and released in the hydrogen storage alloy. Alloys, electrodes, batteries and test cells were prepared in the same manner as in Examples I to IX.

The alloy and electrode thus produced were
The invention alloys b1 to b9 and the invention electrodes B1 to B1
It is called B9.

(Comparative Examples I to IX) As a method for pulverizing a hydrogen storage alloy, a hydrogenation pulverization method in which hydrogen is occluded and released in a hydrogen storage alloy is used for pulverization, and Comparative Example I of the first embodiment is used.
-Alloys, electrodes, batteries and test cells were prepared in the same manner as in Comparative Example IX.

The alloy and electrode thus produced were
Hereinafter, comparative alloys y1 to y9 and comparative electrodes Y1 to Y9, respectively.
Called.

[Characteristic Test 4] Regarding the batteries and test cells using the alloys b1 to b9 of the present invention and the comparative alloys y1 to y9, according to the above [Characteristic Test 1], high rate discharge characteristics,
The alloy capacity measurement test and the charge / discharge cycle characteristics were measured, and the results are shown in Table 2 below.

[0066]

[Table 2]

As shown in Table 2, in the battery and the test cell using the alloys b1 to b9 of the present invention in which the value represented by the formula 4 is 80 wt% or less, the value represented by the formula 4 is 80w.
It can be seen that the alloy activity, alloy capacity per gram of alloy, and cycle characteristics are superior to batteries and test cells using comparative alloys y1 to y5 exceeding t%. It is considered that this is due to the same reason as that shown in [Characteristic test 1].

Here, compared with the alloy produced by the mechanical pulverization method, the cycle life is reduced, but the high rate discharge characteristics are improved. This is because in the hydrogenation pulverization method, the alloy is pulverized by taking in and out hydrogen in the same way as charging and discharging the battery, so the corrosion resistance is slightly inferior, but the activation of the alloy is promoted, so high rate discharge characteristics Is expected to improve. Further, in the case of hydrogenated pulverization, when the value represented by the above mathematical expression 4 exceeds 80 wt%, the high rate discharge characteristics and the cycle life are greatly reduced, and the cycle life is particularly significantly reduced, as compared with mechanical pulverization. From this, it can be seen that the effect of the present invention is more clear when using hydrogenation crushing as compared with mechanical crushing.

A battery and a test cell using the comparative alloys y6 to y7 whose value shown by the equation 4 is 80 wt% or less,
Comparative alloy y in which the value represented by the above mathematical formula 4 exceeds 80 wt%
No difference is observed in the activity of the alloy, the alloy capacity per 1 g of the alloy, and the cycle characteristics between the battery using 8 to y9 and the test cell. It is considered that this is due to the same reason as the above-mentioned [Characteristic test 3].

[0070]

As is apparent from the above, according to the present invention, in a battery using an alloy produced by a rapid solidification method, almost all hydrogen storage alloys are uniformly charged and discharged to be in an inactive state. Since the proportion of the alloy can be reduced, the high rate discharge characteristics and charge / discharge cycle life are excellent, and its industrial value is extremely high.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a particle size and a weight% after crushing a hydrogen storage alloy.

FIG. 2 is a sectional view schematically showing a battery using the electrode of the present invention.

[Explanation of symbols]

 1: Positive electrode 2: Negative electrode 3: Separator

Claims (6)

[Claims] 1. A hydrogen storage alloy powder obtained by crushing a hydrogen storage alloy ingot produced by a rapid solidification method, the hydrogen storage alloy powder satisfying the following formula 1 being used as an active material. Storage alloy electrode. [Equation 1] 2. The hydrogen storage alloy electrode according to claim 1, wherein the rapid solidification method is a roll method. 3. The hydrogen storage alloy electrode according to claim 1, wherein the method for pulverizing the hydrogen storage alloy is a mechanical pulverization method and / or a hydrogenation pulverization method. 4. A first step of producing a hydrogen storage alloy ingot by a rapid solidification method, a second step of crushing the hydrogen storage alloy ingot to obtain a hydrogen storage alloy powder, and the following steps: A method for producing a hydrogen storage alloy electrode, comprising: a third step of selecting a hydrogen storage alloy powder satisfying the following expression 2; and a fourth step of manufacturing an electrode using the hydrogen storage alloy powder obtained in the third step as an active material. (Equation 2) 5. The method for producing a hydrogen storage alloy electrode according to claim 4, wherein the rapid solidification method is a roll method. 6. The method for producing a hydrogen storage alloy electrode according to claim 4, wherein the method for pulverizing the hydrogen storage alloy is a mechanical pulverization method and / or a hydrogenation pulverization method.