JP3443209B2 - Active material powder for non-sintered nickel electrode of alkaline storage battery and method for producing the same, and non-sintered nickel electrode for alkaline storage battery and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a non-sintered nickel electrode active material powder for alkaline storage batteries such as nickel-hydrogen storage batteries and nickel-cadmium storage batteries, a method for producing the same, and a non-sintered type for alkaline storage batteries. The present invention relates to a nickel electrode and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
As a nickel electrode for an alkaline storage battery, a so-called sintered nickel electrode is known in which a substrate (sintered substrate) obtained by sintering nickel powder on a perforated steel plate or the like is impregnated with an active material. In this sintered nickel electrode, the bonds between the particles of the nickel powder are weak, and if the porosity of the substrate is increased, the nickel powder will fall off from the substrate. Met. Since the porosity of the substrate cannot be increased in this way and a substrate such as a perforated steel plate is required, the sintered nickel electrode has a problem that the packing density of the active material is low.

Further, since the pores of the sintered body formed by sintering are as small as 10 μm or less, complicated steps must be repeated for several cycles in order to fill the sintered substrate with the active material. There are also problems such as having to rely on the law.

As a solution to these problems, for example, an alkali resistant metal fiber sintered body or a carbon fiber nonwoven fabric plated with an alkali resistant metal is used.
There is known a so-called paste type nickel electrode (a type of non-sintered nickel electrode) in which a nickel hydroxide (active material) powder is made into a slurry or paste with a binder and a solvent and applied or filled. However, in this paste nickel electrode, because of the presence of a binder, and because it is difficult to form a conductive network,
There is a problem that the utilization rate of the active material is significantly poorer than that of the sintered nickel electrode.

In order to increase the utilization rate of the active material of the paste type nickel electrode, the surface of the nickel hydroxide particles may be coated with cobalt hydroxide to enhance the conductivity of the surface of the active material particles. Cobalt hydroxide dissolves in alkaline electrolyte,
HCoO ₂ ⁻ having an ionic valence of 1 is generated, and this HCoO _{2 −}
^This is because-becomes highly conductive CoOOH (cobalt oxyhydroxide) at a noble potential and deposits on the surface of the nickel hydroxide particles. A method of coating the surface of such nickel hydroxide particles with cobalt hydroxide is disclosed in Japanese Patent Laid-Open No. 62-
It is disclosed in Japanese Patent No. 234867 and Japanese Patent Laid-Open No. 62-237667. In addition, JP-A-3-62457 proposes a method of coating the surface of nickel hydroxide particles with a solid solution coating of nickel hydroxide and cobalt hydroxide.

However, in each of the above conventional methods,
The cobalt hydroxide coating the surface of the nickel hydroxide particles diffuses inside the nickel hydroxide particles as the charge and discharge cycles are repeated, so that the original conductivity of the cobalt hydroxide is to increase the conductivity of the electrode surface. The action cannot be maintained for a long period of the charging / discharging cycle, and thus there is a problem that it is difficult to obtain a paste-type nickel electrode that gives a battery in which the decrease in discharge capacity with the progress of the charging / discharging cycle is small.

The present invention has been made in view of the above circumstances, and an object thereof is to suppress the diffusion of cobalt hydroxide coating the surface of nickel hydroxide particles into the inside of the nickel hydroxide particles. Therefore, it is possible to maintain the effect of increasing the conductivity of the electrode plate by cobalt hydroxide over a long-term charge / discharge cycle, and a non-sintered nickel electrode active material powder for alkaline storage batteries and a method for producing the same. The present invention also provides a non-sintered nickel electrode for alkaline storage batteries and a method for producing the same.

[0008]

The non-sintered nickel electrode active material powder (invention) of the alkaline storage battery according to the present invention for achieving the above object is mainly composed of nickel hydroxide particles or nickel hydroxide. Composite particles obtained by coating the surface of solid solution particles as a component with a mixed crystal composed of a hydroxide of at least one metal (M) selected from the group consisting of aluminum, magnesium, indium and zinc and cobalt hydroxide. Consists of.

Also, a method for producing a non-sintered nickel electrode active material powder for an alkaline storage battery according to the present invention (method of the present invention)
Contains nickel hydroxide particles or solid solution particles containing nickel hydroxide as a main component, and a salt of at least one metal (M) selected from the group consisting of aluminum, magnesium, indium and zinc, and a cobalt salt. It is dipped in a solution, alkali is added to cause the hydroxide of the metal (M) and cobalt hydroxide to co-deposit, and the surface of the nickel hydroxide particles or the solid solution particles is treated with the metal (M). This is a method of coating with a mixed crystal of hydroxide and cobalt hydroxide.

The non-sintered nickel electrode for an alkaline storage battery according to the present invention (the present invention) has a surface of nickel hydroxide particles or solid solution particles containing nickel hydroxide as a main component, which is made of aluminum, magnesium, indium and zinc. The active material powder is composed of composite particles coated with a mixed crystal of at least one metal (M) hydroxide selected from the group consisting of and a cobalt hydroxide.

Further, in the method for producing a non-sintered nickel electrode for an alkaline storage battery according to the present invention (the method of the present invention), nickel hydroxide particles or solid solution particles containing nickel hydroxide as a main component are treated with aluminum, magnesium or indium. And at least one metal (M) selected from the group consisting of zinc and
Of the nickel hydroxide particles or the solid solution particles by immersing in a solution containing a salt of cobalt and a cobalt salt and adding an alkali to co-deposit the hydroxide of the metal (M) and cobalt hydroxide. Step 1 of producing an active material powder composed of composite particles by coating the surface with a mixed crystal of the metal (M) hydroxide and cobalt hydroxide, and applying the active material powder to a core or Step 2 of filling and drying to produce a nickel electrode.

In the present invention, the active material particles (nickel hydroxide) are prepared by mixing cobalt hydroxide with a hydroxide of at least one metal (M) selected from the group consisting of aluminum, magnesium, indium and zinc. Since the surfaces of the particles or solid solution particles are coated, it is difficult for the active material particles to diffuse inside. Therefore, in the alkaline storage battery using the electrode of the present invention as the positive electrode, the action of increasing the conductivity of the electrode of cobalt hydroxide is maintained for a long period of the charge / discharge cycle, and the decrease of the discharge capacity with the progress of the charge / discharge cycle is effective. Suppressed to. According to the method of the present invention, the present invention having such excellent specification can be easily obtained.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION As the composite particles in the present invention, the surface of nickel hydroxide particles or solid solution particles is a mixed crystal of magnesium hydroxide and cobalt hydroxide, zinc hydroxide and cobalt hydroxide. A mixed crystal composed of or a mixed crystal composed of magnesium hydroxide, zinc hydroxide and cobalt hydroxide is preferred, and a mixed crystal composed of magnesium hydroxide and cobalt hydroxide is most preferred. .

The composite particles according to the present invention include magnesium hydroxide and / or zinc hydroxide based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal in terms of metal in the mixed crystal. Therefore, those containing 0.5 to 50% by weight are preferable.

If the content is less than 0.5% by weight, it becomes difficult to effectively suppress the diffusion of cobalt hydroxide into the active material particles (nickel hydroxide particles or solid solution particles), and the charge-discharge cycle is difficult. It is difficult to obtain an electrode for a battery, which has a small decrease in discharge capacity with the progress of the above. on the other hand,
If the content exceeds 50% by weight, the conductivity will decrease, and it will be difficult to obtain an electrode for a battery with a large capacity. Further, as the composite particles in the present invention,
Those containing 3 to 25% by weight of the above mixed crystal (solid solution) are preferable. When the content of the mixed crystal is less than 3% by weight, the amount of cobalt hydroxide becomes insufficient, it becomes difficult to sufficiently increase the conductivity of the electrode, and it is difficult to obtain an electrode that gives a battery having a large capacity. Becomes On the other hand, the mixed crystal content is 25
When the content exceeds the weight%, the amount of nickel hydroxide as an active material becomes small, and it becomes difficult to obtain an electrode for a battery having a large capacity. After all, the most preferable composite particles are magnesium hydroxide and / or zinc hydroxide in the mixed crystal, in terms of metal, based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal. 5
˜50% by weight and 3 to 25% by weight of the above mixed crystal.

In the method of the present invention, the salt of the metal (M) is preferably sulfate and nitrate, and the cobalt salt is preferably cobalt sulfate and cobalt nitrate. When each of these metal salts is used, impurities that deteriorate the electrode characteristics are less mixed into the active material particles (nickel hydroxide particles or solid solution particles containing nickel hydroxide as a main component), and the active material particles have no adverse effect. Hard to receive. Sulfate and nitrate may be used in combination, and cobalt sulfate and cobalt nitrate may be used in combination. In addition, sulfates and nitrates
One or both of them may be used in combination.

In the method of the present invention, a solution containing a magnesium salt and a cobalt salt, a solution containing a zinc salt and a cobalt salt, or a solution containing a magnesium salt, a zinc salt and a cobalt salt is used as the solution. In this case, the composite particles contain magnesium hydroxide and / or zinc hydroxide in the mixed crystal in an amount of 0.5 to 50 based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal in terms of metal. weight%
It is preferred to adjust the composition of the solution to include. Usually, the metal conversion ratio of the magnesium salt and / or zinc salt and the cobalt salt in the solution is the ratio of magnesium and / or zinc and cobalt in the mixed crystal. In addition, the composite particles,
It is preferable to adjust the amount (coating amount) of the mixed crystal deposited on the surface of the active material particles so that the mixed crystal is contained in an amount of 3 to 25% by weight. The amount of the mixed crystal (coating amount) can be adjusted by adjusting the respective concentrations of the metal (M) salt and the cobalt salt in the solution. After all, the most preferable preparation method when using a solution containing a magnesium salt and a cobalt salt, a solution containing a zinc salt and a cobalt salt, or a solution containing a magnesium salt, a zinc salt and a cobalt salt as the solution is The above is a production method in which the above-mentioned two types of adjustment are performed together. Examples of the alkali used in the method of the present invention include sodium hydroxide, potassium hydroxide and lithium hydroxide.

Examples of the solid solution particles in the present invention and the method of the present invention include particles of nickel hydroxide in which at least one element selected from zinc, cobalt, calcium and cadmium is dissolved. It Specific examples of the core body include a foamed metal porous body, a metal fiber, a carbon fiber,
Examples include metal mesh and punching metal.

[0019]

EXAMPLES The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to the following examples, and various modifications may be made without departing from the scope of the invention. Is possible.

(Example 1) [Preparation of active material] 1000 m of an aqueous solution prepared by dissolving 14.3 g of cobalt sulfate and 10.7 g of magnesium sulfate in water.
100 g of nickel hydroxide powder was added to 1, and a 1M sodium hydroxide aqueous solution was added dropwise to the solution until the pH reached 12, and the mixture was maintained for 1 hour. To measure the pH at this time,
A glass electrode pH meter with automatic temperature compensation was used. Then, the mixture was filtered, the filter cake was washed with water, and vacuum dried to prepare an active material powder composed of composite particles in which the surfaces of nickel hydroxide particles were coated with a mixed crystal of magnesium hydroxide and cobalt hydroxide. . The ratio of cobalt hydroxide and magnesium hydroxide in the mixed crystal was adjusted by adjusting the amount ratio of cobalt salt (cobalt sulfate) and magnesium salt (magnesium sulfate) dissolved in water. The mixed crystal content of the composite particles was adjusted by adjusting the amounts of cobalt salt and magnesium salt used. The ratio of magnesium hydroxide in the mixed crystal was 1 wt% [Mg / (Mg + Co) × 100] in terms of metal, based on the total amount of cobalt and magnesium in the mixed crystal. The mixed crystal content of the composite particles was 5% by weight. Both are obtained from the values measured by atomic absorption spectrometry.

In the same manner as described above, cobalt hydroxide-zinc hydroxide, cobalt hydroxide-indium hydroxide, cobalt hydroxide-aluminum hydroxide, cobalt hydroxide-magnesium hydroxide-zinc hydroxide, cobalt hydroxide-water. Magnesium oxide-aluminum hydroxide or cobalt hydroxide-
An active material powder composed of composite particles in which the surface of nickel hydroxide particles was coated with each mixed crystal composed of zinc hydroxide-indium hydroxide was prepared. Sulfate was used as the cobalt raw material, zinc raw material, indium raw material, aluminum raw material, and magnesium raw material. In each case, the ratio of the metal (M) hydroxide in the mixed crystal was 1 wt% in terms of metal, based on the total amount of cobalt and metal (M) in the mixed crystal. . The mixed crystal content of the composite particles was 5% by weight.

[Preparation of Non-Sintered Nickel Electrode] 80 parts by weight of the above active material powder and 20 parts by weight of a 1% by weight aqueous solution of methylcellulose were kneaded to prepare a paste, and this paste was nickel-plated metal foam ( It was filled in a porous body having a porosity of 95 and an average particle size of 200 μm). Then
This porous body was dried and molded to prepare a non-sintered nickel electrode.

[Production of Battery] The non-sintered nickel electrode is used as a positive electrode, and a known paste type cadmium electrode is used as a negative electrode.
These and nylon non-woven separator, alkaline electrolyte,
AA size nickel-cadmium batteries A1 to A7 are combined with a battery member such as a metal battery container and a metal lid.
(Battery capacity: 1100 mAh) was produced. As the alkaline electrolyte, an aqueous solution (specific gravity: 1.285) of a mixture of potassium hydroxide, sodium hydroxide and lithium hydroxide in a weight ratio of 8: 1: 1 was used.

Battery A1 is a mixed crystal of cobalt-magnesium, battery A2 is a mixed crystal of cobalt hydroxide-zinc hydroxide, and battery A3 is a mixed crystal of cobalt hydroxide-indium hydroxide. Battery A4 is a mixed crystal of cobalt hydroxide-aluminum hydroxide, battery A5 is a mixed crystal of cobalt hydroxide-magnesium hydroxide-zinc hydroxide, and battery A6 is cobalt hydroxide-magnesium hydroxide-water. Battery A with a mixed crystal of aluminum oxide
Reference numeral 7 is a battery using mixed crystal of cobalt hydroxide-zinc hydroxide-indium hydroxide, each of which used active material powder composed of composite particles obtained by coating the surface of nickel hydroxide particles.

(Comparative Example 1) 100 g of the same nickel hydroxide powder as used in Example 1 was added to 1000 ml of an aqueous solution in which 14.3 g of cobalt sulfate was dissolved in water with stirring, and 1 M sodium hydroxide was added with stirring. Aqueous solution p
The solution was dropped until H became 12, and kept for 1 hour. Then
The mixture was filtered, the filter cake was washed with water, and dried in vacuum to prepare an active material powder composed of composite particles in which the surface of nickel hydroxide particles was coated with cobalt hydroxide. The cobalt hydroxide content of the composite particles was 5% by weight. Comparative battery X was prepared in the same manner as in Example 1 except that this active material powder was used for the positive electrode.
Was produced. Incidentally, this comparative battery X is disclosed in JP-A-62-2
This battery was manufactured according to the method disclosed in Japanese Patent No. 34867.

Comparative Example 2 Aqueous solution 1000 in which 14.3 g of cobalt sulfate and 4.52 g of nickel sulfate were dissolved in water.
100 ml of the same nickel hydroxide powder as that used in Example 1 was added to ml with stirring, and 1M with stirring.
An aqueous sodium hydroxide solution was added dropwise until the pH reached 12, and the mixture was kept for 1 hour. Then, it is filtered, the filter cake is washed with water,
Vacuum drying was performed to prepare an active material powder composed of composite particles in which the surface of nickel hydroxide particles was coated with a mixed crystal of cobalt hydroxide and nickel hydroxide. The proportion of nickel hydroxide in the mixed crystal was 20% by weight in terms of metal, based on the total amount of cobalt and nickel in the mixed crystal. The mixed crystal content of the composite particles was 5% by weight. Comparative battery Y was produced in the same manner as in Example 1 except that this active material powder was used for the positive electrode. Incidentally, this comparative battery Y
Is a battery manufactured according to the method disclosed in Japanese Patent Application Laid-Open No. 3-62457.

<Charge / Discharge Cycle Characteristics of Each Battery> Battery A1
~ A7 and comparative battery X, Y, charging current 0.1C
After 160% charge with a discharge current of 1C, the final voltage is 1.0
A charging / discharging cycle test in which the process of discharging to V was defined as one cycle was performed to examine the charging / discharging cycle characteristics of each battery.

FIG. 1 shows charge / discharge cycle characteristics of each battery.
The vertical axis represents the discharge capacity (index when the discharge capacity in the first cycle is 100), and the horizontal axis represents the number of charge / discharge cycles (times).
It is the graph which took and showed. As shown in FIG. 1, in Comparative Batteries X and Y, the discharge capacity decreased with the progress of charge / discharge cycles, whereas in Batteries A1 to A7 using the electrodes of the present invention, a decrease in capacity was observed. I can't. This is because, in the batteries A1 to A7, nickel hydroxide particles were formed into a mixed crystal composed of a hydroxide of at least one metal (M) selected from the group consisting of aluminum, magnesium, indium and zinc and cobalt hydroxide. This is because the composite particles coated by the method are used as the active material, so that the diffusion of cobalt hydroxide into the nickel hydroxide particles does not easily occur.

The surface of solid solution particles containing nickel hydroxide as a main component, which is obtained by solid-solving at least one element selected from zinc, cobalt, calcium and cadmium inside the nickel hydroxide particles, is mixed with the above mixed crystal. It was confirmed that a non-sintered nickel electrode that gives a battery having the same excellent charge-discharge cycle characteristics as those of the batteries A1 to A7 can be obtained even when it is coated with.

Example 2 The proportion of magnesium hydroxide in the mixed crystal on the surface of nickel hydroxide particles was 0.10% by weight, 0.25% by weight, 0.5% by weight in terms of metal,
Different from 1% by weight, 5% by weight, 10% by weight, 25% by weight, 35% by weight, 50% by weight, 55% by weight, 60% by weight,
A non-sintered nickel electrode for an alkaline storage battery was prepared by using composite particles coated with a mixed crystal of cobalt hydroxide and magnesium hydroxide as an active material, and then Example 1
Similarly, using each of these electrodes as a positive electrode, nickel-cadmium storage batteries B1 to B11 were sequentially manufactured.
The mixed crystal content of the composite particles was 10% by weight.

The batteries B1 to B11 were subjected to a charge / discharge cycle test under the same conditions as in Example 1 to examine the charge / discharge cycle characteristics of each battery. The results are shown in FIG. 2 and Table 1 in the same coordinate system as in FIG. Table 1 shows the discharge capacity of each battery at the 300th cycle as an index with the discharge capacity of the battery B4 at the 300th cycle as 100.

[0032]

[Table 1]

As shown in FIG. 2, batteries B3 to B11 in which the ratio of magnesium hydroxide in the mixed crystal in terms of metal is 0.5% by weight or more, and the ratio is less than 0.5% by weight. It has excellent charge / discharge cycle characteristics as compared with B1 and B2. From this, it is understood that the same ratio is preferably 0.5% by weight or more.

On the other hand, as shown in Table 1, the batteries B10 and B11 in which the ratio of magnesium hydroxide in the mixed crystal in terms of metal exceeds 50% by weight are the batteries B3 to B9 in which the ratio is 50% by weight or less. The discharge capacity at the 300th cycle is smaller than that of. From this, it was found that the same ratio is preferably 50% by weight or less, and in consideration of the results shown in FIG. 2 above, the ratio of magnesium hydroxide in the mixed crystal in terms of metal is 0. It can be seen that the amount is preferably 5 to 50% by weight.

With respect to zinc, it is preferable that the proportion of these hydroxides in the mixed crystal in terms of metal is 0.5 to 50% by weight.

(Example 3) The surface of nickel hydroxide particles is coated with a mixed crystal of cobalt hydroxide and magnesium hydroxide, and the mixed crystal content is 0% by weight, 2% by weight and 3% by weight. %, 5% by weight, 10% by weight, 15% by weight, 2
0% by weight, 25% by weight, 26% by weight, 28% by weight, 30
A non-sintered nickel electrode for an alkaline storage battery was prepared by using composite particles different in weight% as an active material, and then, Example 1
Similarly, using each of these electrodes as a positive electrode, nickel-cadmium storage batteries C1 to C11 were sequentially manufactured.
The ratio of magnesium hydroxide in the mixed crystal in terms of metal was 10% by weight.

The batteries C1 to C11 were subjected to a charge / discharge cycle test under the same conditions as in Example 1, and 30 batteries of each battery were tested.
The discharge capacity at the 0th cycle was examined. The results are shown in Fig. 3.
In FIG. 3, the vertical axis represents the discharge capacity at the 300th cycle of each battery (index when the discharge capacity of the battery C4 at the 10th cycle is 100), and the horizontal axis represents the mixed crystal content of the composite particles (% by weight). ) Is shown.

As shown in FIG. 3, the mixed crystal content is 3 to 25.
The batteries C3 to C8 in the range of weight% have a larger discharge capacity at the 300th cycle than the batteries C1 to C2 and C9 to C11 in which the mixed crystal content ratio is outside this range. From this, it is understood that the mixed crystal content of the composite particles is preferably 3 to 25% by weight.

With respect to aluminum, indium and zinc other than magnesium, the mixed crystal content of the composite particles is 3%.
It is preferably about 25% by weight.

(Example 4) In the same manner as in Example 1, each of cobalt hydroxide-magnesium hydroxide, cobalt hydroxide-zinc hydroxide, cobalt hydroxide-indium hydroxide or cobalt hydroxide-aluminum hydroxide. Alkaline storage battery using composite particles having different contents of magnesium hydroxide, zinc hydroxide, indium hydroxide or aluminum hydroxide in the coprecipitate, which are obtained by coating the surface of nickel hydroxide particles with a mixed crystal. A non-sintered nickel electrode was prepared and then, similarly to Example 1, each of these electrodes was used as a positive electrode to prepare a nickel-cadmium storage battery. In any case, the coprecipitate content (not the mixed crystal content) of the composite particles was set to 10% by weight.

The following tests were conducted in order to investigate the influence of coprecipitates in each of the above batteries. For each battery, after charging 160% at a charging current of 0.1 C, 10 cycles of charging / discharging with one cycle of discharging at a discharging current of 1 C to a final voltage of 1.0 V were performed, and then at a charging current of 0.1 C, 160 %
Charged A resistance of 5Ω was connected to each battery in this charged state, and the battery was left at a temperature of 70 ° C for 7 days. After that, the battery was charged at a charging current of 0.1 C by 160% and then discharged at a discharging current of 1 C to a final voltage of 1.0 V, and the discharge capacity D1 was measured. The ratio (%) of the discharge capacity D1 at this time to the discharge capacity D2 at the 10th cycle was determined. The results are shown in Table 2. The larger the ratio, the smaller the decrease in discharge capacity in the load connected state.

[0042]

[Table 2]

As shown in Table 2, composite particles obtained by coating the surface of nickel hydroxide particles with a cobalt hydroxide-magnesium hydroxide coprecipitate or a cobalt hydroxide-zinc hydroxide coprecipitate were used as the active material. It can be seen that the sintered nickel electrode gives a battery in which the decrease in discharge capacity in the load connected state is small. This is presumably because the cobalt hydroxide-magnesium hydroxide coprecipitate and the cobalt hydroxide-zinc hydroxide coprecipitate exist as mixed crystals in a wide composition range. Among them, a cobalt hydroxide-magnesium hydroxide coprecipitate gives a battery having the smallest decrease in discharge capacity under load connection. As shown in Table 2, for indium and aluminum, when the amount of indium hydroxide and aluminum hydroxide in the coprecipitate was large, mixed crystal was not obtained because indium hydroxide or aluminum hydroxide was isolated. .

In the above examples, nickel hydroxide particles were used as the active material particles, but even when solid solution particles are used, the same excellent effects as above can be obtained by applying the present invention.

Further, in the above embodiment, the nickel-cadmium storage battery was described as an example, but the present invention is widely applicable to alkaline storage batteries such as nickel-hydrogen storage batteries.

[0046]

In the alkaline storage battery using the electrode of the present invention as the positive electrode, the action of increasing the conductivity of the cobalt hydroxide electrode is maintained for a long period of the charging / discharging cycle. The drop is effectively suppressed.

[Brief description of drawings]

FIG. 1 is a graph showing charge / discharge cycle characteristics of nickel-cadmium storage batteries prepared in Examples.

FIG. 2 is a graph showing charge / discharge cycle characteristics of nickel-cadmium storage batteries manufactured in Examples.

FIG. 3 is a graph showing the relationship between the mixed crystal content of composite particles and the discharge capacity at the 300th cycle.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshito Konno 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Koji Nishio 2-5 Keihan-hondori, Moriguchi-shi, Osaka No. 5 Sanyo Denki Co., Ltd. (72) Inventor Toshihiko Saito 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Denki Co., Ltd. (56) Reference JP 5-101823 (JP, A) JP 62-234867 (JP, A) JP 3-274666 (JP, A) JP 6-13075 (JP, A) JP 5-21064 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) H01M 4/36-4/62 H01M 4/32

Claims (24)

(57) [Claims] 1. A hydroxide of at least one metal (M) selected from the group consisting of aluminum, magnesium, indium and zinc on the surface of nickel hydroxide particles or solid solution particles containing nickel hydroxide as a main component. An active material powder for a non-sintered nickel electrode of an alkaline storage battery, which is composed of composite particles coated with a mixed crystal composed of and cobalt hydroxide. 2. The alkaline storage battery according to claim 1, wherein the solid solution particles are nickel hydroxide particles in which at least one element selected from zinc, cobalt, calcium and cadmium is solid-solved. Sintered nickel electrode active material powder. 3. The non-sintered nickel electrode active material powder for an alkaline storage battery according to claim 1, wherein the composite particles contain 3 to 25% by weight of the mixed crystal. 4. The mixed particles, wherein the surface of nickel hydroxide particles or solid solution particles containing nickel hydroxide as a main component is mixed crystal of magnesium hydroxide and cobalt hydroxide, zinc hydroxide and cobalt hydroxide. The non-sintered nickel active material powder for an alkaline storage battery according to claim 1, which is coated with a mixed crystal consisting of or a mixed crystal consisting of magnesium hydroxide, zinc hydroxide and cobalt hydroxide. 5. The composite particles contain magnesium hydroxide and / or zinc hydroxide in the mixed crystal based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal in terms of metal. The non-sintered nickel electrode active material powder for an alkaline storage battery according to claim 4, which contains 0.5 to 50% by weight. 6. The composite particles contain magnesium hydroxide and / or zinc hydroxide in the mixed crystal in terms of metal, based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal, The non-sintered nickel electrode active material powder for an alkaline storage battery according to claim 4, wherein the content of the mixed crystal is 0.5 to 50% by weight and the mixed crystal is 3 to 25% by weight. 7. The composite particles are obtained by coating the surface of nickel hydroxide particles or solid solution particles containing nickel hydroxide as a main component with a mixed crystal of magnesium hydroxide and cobalt hydroxide. 2. The non-sintered nickel electrode active material powder for an alkaline storage battery according to 1. 8. A hydroxide of at least one metal (M) selected from the group consisting of aluminum, magnesium, indium and zinc on the surface of nickel hydroxide particles or solid solution particles containing nickel hydroxide as a main component. A non-sintered nickel electrode for an alkaline storage battery, which uses an active material powder composed of composite particles coated with a mixed crystal composed of and cobalt hydroxide. 9. The non-alkaline battery according to claim 8, wherein the solid solution particles are nickel hydroxide particles in which at least one element selected from zinc, cobalt, calcium and cadmium is dissolved. Sintered nickel electrode. 10. The non-sintered nickel electrode for an alkaline storage battery according to claim 8, wherein the composite particles contain the mixed crystal in an amount of 3 to 25% by weight. 11. The composite particle comprises, on the surface of the nickel hydroxide particle or the solid solution particle, a mixed crystal of magnesium hydroxide and cobalt hydroxide, a mixed crystal of zinc hydroxide and cobalt hydroxide, or water. The non-sintered nickel electrode for an alkaline storage battery according to claim 8, which is coated with a mixed crystal of magnesium oxide, zinc hydroxide and cobalt hydroxide. 12. The composite particles contain magnesium hydroxide and / or zinc hydroxide in the mixed crystal based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal in terms of metal. The non-sintered nickel electrode for an alkaline storage battery according to claim 11, which contains 0.5 to 50% by weight. 13. The composite particles contain magnesium hydroxide and / or zinc hydroxide in the mixed crystal, in terms of metal, based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal, The non-sintered nickel electrode for an alkaline storage battery according to claim 11, which contains 0.5 to 50% by weight and 3 to 25% by weight of the mixed crystal. 14. The alkaline storage battery according to claim 8, wherein the composite particles are obtained by coating the surfaces of the nickel hydroxide particles or the solid solution particles with a mixed crystal of magnesium hydroxide and cobalt hydroxide. Non-sintered nickel electrode. 15. Nickel hydroxide particles or solid solution particles containing nickel hydroxide as a main component, and a salt of at least one metal (M) selected from the group consisting of aluminum, magnesium, indium and zinc, and a cobalt salt. The metal (M) is dipped in a solution containing
Alkali to co-deposit the hydroxide and cobalt hydroxide to coat the surface of the nickel hydroxide particles or the solid solution particles with a mixed crystal of the metal (M) hydroxide and cobalt hydroxide. A method for producing a non-sintered nickel electrode active material powder for a storage battery. 16. The non-sintered nickel of an alkaline storage battery according to claim 15, wherein the salt of the metal (M) is a sulfate and / or a nitrate, and the cobalt salt is a cobalt sulfate and / or a cobalt nitrate. A method for producing an active material powder for extraordinary use. 17. The alkali according to claim 15, wherein the concentration of the salt of the metal (M) and the cobalt salt in the solution is adjusted so that the composite particles contain 3 to 25% by weight of the mixed crystal. A method for producing a non-sintered nickel electrode active material powder for a storage battery. 18. A solution containing a magnesium salt and a cobalt salt, a solution containing a zinc salt and a cobalt salt, or a solution containing a magnesium salt, a zinc salt and a cobalt salt is used as the solution, and The mixed crystal contains magnesium hydroxide and / or zinc hydroxide in an amount of 0.5 to 50 wt% in terms of metal, based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal. The method for producing a non-sintered nickel electrode active material powder for an alkaline storage battery according to claim 15, wherein the composition of the solution is adjusted. 19. A solution containing a magnesium salt and a cobalt salt, a solution containing a zinc salt and a cobalt salt, or a solution containing a magnesium salt, a zinc salt and a cobalt salt is used as the solution, and The mixed crystal contains magnesium hydroxide and / or zinc hydroxide in an amount of 0.5 to 50 wt% in terms of metal, based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal. A concentration of the magnesium salt and / or the zinc salt and the cobalt salt in the solution so that the composite particles contain the mixed crystal in an amount of 3 to 25% by weight. 16. The method for producing a non-sintered nickel electrode active material powder for an alkaline storage battery according to claim 15. 20. Nickel hydroxide particles or solid solution particles containing nickel hydroxide as a main component, and a salt of at least one metal (M) selected from the group consisting of aluminum, magnesium, indium and zinc, and a cobalt salt. The metal (M) is dipped in a solution containing
Of nickel hydroxide particles and cobalt hydroxide are co-deposited to coat the surfaces of the nickel hydroxide particles or the solid solution particles with a mixed crystal of the metal (M) hydroxide and cobalt hydroxide. A non-sintered nickel electrode for an alkaline storage battery, comprising: a step 1 of producing an active material powder composed of composite particles; and a step 2 of applying or filling the active material powder to a core and drying it to produce a nickel electrode. Manufacturing method. 21. The non-sintered nickel for an alkaline storage battery according to claim 20, wherein the salt of the metal (M) is a sulfate and / or a nitrate, and the cobalt salt is a cobalt sulfate and / or a cobalt nitrate. How to make poles. 22. The concentration of the metal (M) salt and the cobalt salt in the solution is adjusted so that the composite particle contains 3 to 25% by weight of the mixed crystal. Item 21. A method for producing a non-sintered nickel electrode for an alkaline storage battery according to Item 20. 23. A solution containing a magnesium salt and a cobalt salt, a solution containing a zinc salt and a cobalt salt, or a solution containing a magnesium salt, a zinc salt and a cobalt salt is used as the solution, and The mixed crystal contains magnesium hydroxide and / or zinc hydroxide in an amount of 0.5 to 50 wt% in terms of metal, based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal. The method for producing a non-sintered nickel electrode for an alkaline storage battery according to claim 20, wherein the composition of the solution is adjusted. 24. A solution containing a magnesium salt and a cobalt salt, a solution containing a zinc salt and a cobalt salt, or a solution containing a magnesium salt, a zinc salt and a cobalt salt is used as the solution, and The mixed crystal contains magnesium hydroxide and / or zinc hydroxide in an amount of 0.5 to 50 wt% in terms of metal, based on the total amount of cobalt and magnesium and / or zinc in the mixed crystal. Adjusting the composition of the solution, and so that the composite particles contain the mixed crystal in an amount of 3 to 25% by weight, the concentration of the magnesium salt and / or the zinc salt and the cobalt salt in the solution. The method for producing a non-sintered nickel electrode for an alkaline storage battery according to claim 20, wherein