JPH11260360A - Positive electrode for alkaline storage battery and alkaline storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate formation of a conductive matrix and to improve availability and charging efficiency under a high temperature environment by including Yb in a layer formed on the surface and formed of a Co compound principally. SOLUTION: A layer principally consisting of a Co compound is formed at least in a part of a positive electrode, while grain principally consisting of nickel hydroxide is contained and the layer contains Yb. The grain consisting principally of nickel desirably contains one or more kind of element selected from Zn, Co, Yb, and elements forming an eutectic mixture with nickel hydroxide are preferable as these elements. In nickel hydroxide, a full width at half maximum(FWFM) of a peak in the (101) face in powder X-ray diffraction (Cu-Kx, 2θ) is preferably 0.8 degree or. In the layer consisting principally of a cobalt compound, the preferred content of Yb is 0.1-10.0 wt.% to the grain principally consisting of nickel hydroxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a positive electrode for an alkaline storage battery containing nickel hydroxide as an active material and an alkaline storage battery provided with the positive electrode.

[0002]

2. Description of the Related Art At present, a paste is prepared by adding and mixing a conductive agent, a binder and water to nickel hydroxide particles mainly for a positive electrode of a high-capacity type alkaline storage battery. A paste-type positive electrode manufactured by filling a conductive core having a three-dimensional structure such as a porous metal body or a metal fiber mat is used. This paste-type positive electrode has an advantage that the porosity and the average particle diameter of the conductive core are larger than that of the sintered-type positive electrode, so that the active material can be easily filled, and the filling amount can be increased. .

[0003] In recent years, the speed of CPUs used in portable computers has been increasing, and the amount of heat generated by the CPUs has increased accordingly. Therefore, alkaline storage batteries near the CPUs are considerably higher than room temperature. It will be exposed to the temperature environment.

In order to sufficiently bring out the performance of an alkaline storage battery in a high-temperature environment, it is necessary to secure a good conductive matrix in the paste-type positive electrode and to improve charge / discharge efficiency in a high-temperature environment.

[0005] The conductive matrix is usually formed by using cobalt or a cobalt compound as the conductive agent and converting the cobalt or the cobalt compound to a higher cobalt oxide such as cobalt oxyhydroxide by, for example, initial charging. You. However, if the method is to add the conductive agent separately from the active material, a problem remains in the dispersibility of the conductive agent.

[0006]

On the other hand, JP-A-56-5
No. 9460 discloses nickel hydroxide particles whose surface is coated with a cobalt compound. When such nickel hydroxide particles are used, it is easy to form a conductive matrix uniformly. However, it has been insufficient to improve the characteristics in a high temperature environment.

An object of the present invention is to provide a positive electrode for an alkaline storage battery in which a conductive matrix can be easily formed and the utilization efficiency and the charging efficiency in a high-temperature environment are improved.

Another object of the present invention is to provide an alkaline storage battery which has a positive electrode with an improved utilization factor and a high charging efficiency in a high-temperature environment and has a long cycle life. It is.

[0009]

According to the present invention, there is provided a positive electrode for an alkaline storage battery, wherein a layer mainly composed of a cobalt compound is formed on at least a part of the surface, and the alkaline storage battery contains particles mainly composed of nickel hydroxide. Positive electrode, wherein the layer contains ytterbium.

Further, the alkaline storage battery according to the present invention is an alkaline storage battery provided with a layer mainly composed of a cobalt compound on at least a part of its surface and having a positive electrode containing particles mainly composed of nickel hydroxide. The above-mentioned layer contains ytterbium.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a positive electrode for an alkaline storage battery according to the present invention will be described in detail.

This positive electrode has a layer mainly composed of a cobalt compound formed on at least a part of its surface and contains particles mainly composed of nickel hydroxide. The layer contains ytterbium (Yb).

Examples of the particles mainly containing nickel hydroxide include non-eutectic nickel hydroxide particles and nickel hydroxide particles containing at least one element selected from zinc, cobalt and ytterbium. . By containing such an element, the charging efficiency and the cycle life of the positive electrode at a high temperature can be further improved. In the particles, at least one selected from zinc, cobalt and ytterbium is preferably eutectic with nickel hydroxide. The nickel hydroxide particles in which zinc and cobalt are eutectic can be produced, for example, by the method described below. After dissolving nickel metal, cobalt and zinc in an aqueous sulfuric acid solution to produce nickel complex ions and cobalt and zinc complex ions, ammonia is added. By dropping the obtained solution into an aqueous sodium hydroxide solution, nickel hydroxide particles in which cobalt and zinc are eutectic are grown to obtain the particles.

The content of the element in the particles is preferably in the range of 0.1 to 10.0% by weight based on the particles mainly composed of nickel hydroxide. This is due to the following reasons. If the content is less than 0.1% by weight, the effect of further increasing the charging efficiency and cycle life of the positive electrode at high temperatures may not be obtained.
On the other hand, when the content exceeds 10.0% by weight, the capacity may be reduced because the amount of nickel hydroxide is reduced. A more preferable range of the content is 0.5 to 8.0.
% By weight.

The nickel hydroxide is prepared by powder X-ray diffraction (C
It is desirable that the full width at half maximum (FWHM) of the (101) plane of (u-Kα, 2θ) be 0.8 deg or more. When the nickel hydroxide has such a half-value width, the utilization rate of the positive electrode, the charging efficiency at a high temperature of the positive electrode, and the cycle life can be further improved.
A more preferred range of the half width is 0.9 to 1.1 deg.
It is.

The particles containing nickel hydroxide as a main component preferably have a spherical shape or a shape similar thereto.

The particles mainly composed of nickel hydroxide have an average particle diameter of 5 to 30 μm and a tap density of 1.8 g / g.
cm ³ or more.

The particles mainly composed of nickel hydroxide preferably have a specific surface area of 25 m ² / g or less.

As the cobalt compound contained in the layer, for example, cobalt hydroxide, cobalt monoxide and the like can be mentioned.

The layer mainly composed of the cobalt compound is formed on the surface of the particles so that the conversion amount of the cobalt element to the particles mainly composed of nickel hydroxide is in the range of 0.5 to 10% by weight. Is preferred. This is due to the following reasons. If the amount is less than 0.5% by weight, the utilization efficiency of the positive electrode may decrease due to the non-uniformity of the conductive matrix in the positive electrode. On the other hand, when the amount exceeds 10% by weight, the discharge capacity may be reduced due to a decrease in the amount of nickel hydroxide in the positive electrode. A more preferable range of the formation amount of the layer is 2.0
-5.0% by weight.

The ytterbium content of the layer is 0.1 to 10.0 with respect to the particles mainly composed of nickel hydroxide.
It is preferred to be in the range of weight%. This is due to the following reasons. When the content is less than 0.1% by weight, the utilization rate of the positive electrode, particularly, the utilization rate of the positive electrode in a high-temperature environment may decrease. On the other hand, if the content exceeds 10% by weight, the discharge capacity may be reduced due to a decrease in the amount of nickel hydroxide in the positive electrode. A more preferable range of the content is 0.2 to 5.0% by weight.

The particles can be produced, for example, by the method described below. First, particles mainly composed of nickel hydroxide are immersed in an alkaline aqueous solution whose pH is controlled (for example, pH is 12) in a weak base region.
On the other hand, cobalt and ytterbium are dissolved in sulfuric acid to prepare an aqueous solution containing complex ions. In the nickel hydroxide-containing alkaline solution, the cobalt and ytterbium mixed solution is gradually dropped, and while being convected, deposited on the nickel hydroxide particle surface, at least a part of the surface is a mixed crystal of cobalt hydroxide and ytterbium. Can be produced. The crystal structure of the mixed crystal present in the particles obtained by such a method is presumed to be in a form in which the cobalt atoms in the cobalt hydroxide have been replaced by ytterbium atoms.

The positive electrode is prepared, for example, by kneading the particles and the binder in the presence of water to prepare a paste, filling the conductive substrate with the paste, drying, and rolling. Manufactured.

Examples of the binder include fluororesin (eg, polytetrafluoroethylene), carboxymethylcellulose, methylcellulose, polyacrylate (eg, sodium polyacrylate), hydroxymethylcellulose, and polyvinyl alcohol. .

Examples of the conductive substrate include a sponge-like porous body, a metal fiber mat, a punched metal, and a metal flat plate.

Hereinafter, an alkaline storage battery incorporating the positive electrode according to the present invention will be described in detail with reference to FIG.

In the bottomed cylindrical container 1, an electrode group 5 produced by stacking the positive electrode 2, the separator 3, and the negative electrode 4 having the above-described configuration and winding them spirally is accommodated. . The negative electrode 4 is arranged at the outermost periphery of the electrode group 5 and is in electrical contact with the container 1. The alkaline electrolyte is contained in the container 1. A circular first sealing plate 7 having a hole 6 in the center is arranged at the upper opening of the container 1. Ring-shaped insulating gasket 8
Is disposed between the peripheral edge of the sealing plate 7 and the inner surface of the upper opening of the container 1, and the sealing plate 7 is connected to the container 1 through the gasket 8 by caulking to reduce the diameter of the upper opening inward. And airtightly fixed. One end of the positive electrode lead 9 is connected to the positive electrode 2, and the other end is connected to the lower surface of the sealing plate 7. The positive electrode terminal 10 having a hat shape is attached on the sealing plate 7 so as to cover the hole 6.
The safety valve 11 made of rubber includes the sealing plate 7 and the positive electrode terminal 1.
It is arranged so as to close the hole 6 in a space surrounded by 0. A circular holding plate 12 made of an insulating material having a hole in the center is arranged on the positive electrode terminal 10 such that a protrusion of the positive electrode terminal 10 projects from the hole of the holding plate 12. The outer tube 13 covers the periphery of the holding plate 12, the side surface of the container 1, and the periphery of the bottom of the container 1.

Hereinafter, the negative electrode 4, the separator 3, and the alkaline electrolyte will be described in detail.

1) Negative electrode 4 This negative electrode 4 is kneaded with a negative electrode active material, a conductive material, a binder and water to prepare a paste, and the paste is filled in a conductive substrate and dried.
It is manufactured by molding.

Examples of the negative electrode active material include cadmium compounds such as metal cadmium and cadmium hydroxide, and hydrogen. Examples of the host matrix of hydrogen include a hydrogen storage alloy.

Above all, the hydrogen storage alloy is preferable because the capacity of the storage battery can be improved as compared with the case where the cadmium compound is used. The hydrogen storage alloy is not particularly limited, and may be any as long as it can store hydrogen electrochemically generated in an electrolytic solution and can easily release the stored hydrogen during discharge. For example, LaNi ₅ , MmN
i ₅ (Mm is misch metal), LmNi ₅ (Lm is L
at least one selected from rare earth elements including a), and a part of Ni of these alloys is Al, Mn, Co, Ti, C
Examples thereof include a multi-element-based material substituted with an element such as u, Zn, Zr, Cr, and B, or a TiNi-based or TiFe-based material. In particular, the general formula LmNi _w Co _x Mn
_y Al _z (the total value of atomic ratios w, x, y, and z is 5.00 ≦
(W + x + y + z ≦ 5.50) The hydrogen storage alloy having the composition represented by the formula (1) is suitable because it can suppress the pulverization accompanying the progress of the charge / discharge cycle and improve the charge / discharge cycle life.

Examples of the conductive material include carbon black and graphite.

Examples of the binder include polyacrylates such as sodium polyacrylate and potassium polyacrylate, fluororesins such as polytetrafluoroethylene (PTFE), and carboxymethyl cellulose (C).
MC) and the like.

Examples of the conductive substrate include a two-dimensional substrate such as a punched metal, an expanded metal, a perforated rigid plate, and a nickel net; a felt-like porous metal;
Examples include a three-dimensional substrate such as a sponge-like porous metal body.

The theoretical capacity of the negative electrode is preferably 1.1 to 1.6 times the theoretical capacity of the positive electrode.

3) Separator 3 Examples of the separator 3 include a nonwoven fabric made of a polyamide fiber and a nonwoven fabric made of a polyolefin fiber such as polyethylene or polypropylene provided with a hydrophilic functional group.

4) Alkaline Electrolyte Examples of the alkaline electrolyte include sodium hydroxide (NaOH), lithium hydroxide (LiOH), potassium hydroxide (KOH),
Cesium hydroxide (CsOH) and rubidium hydroxide (R
bOH).

The ratio between the amount of the alkaline electrolyte and the theoretical capacity of the positive electrode is preferably in the range of 0.6 to 2.0 cm ³ / Ah.

In FIG. 1 described above, the separator 3 is interposed between the negative electrode 4 and the positive electrode 2 and spirally wound and housed in the cylindrical container 1 having a bottom. The separator may be interposed therebetween to form a laminate, and the laminate may be stored in a bottomed rectangular cylindrical container.

As described in detail above, the positive electrode for an alkaline storage battery according to the present invention has a layer mainly composed of a cobalt compound formed on at least a part of its surface and contains particles mainly composed of nickel hydroxide. The layer is characterized by containing ytterbium. Such a positive electrode,
Since a conductive matrix having a preferable form can be formed, the utilization factor, particularly the utilization factor in a high-temperature environment, can be improved, and the charging efficiency at a high temperature can be improved.

The alkaline storage battery according to the present invention has a positive electrode having a layer mainly composed of a cobalt compound formed on at least a part of its surface and containing particles mainly composed of nickel hydroxide, wherein the layer contains ytterbium. It is characterized by doing. Since such a storage battery can form a conductive matrix having a preferable form in the positive electrode, the positive electrode utilization rate, particularly the positive electrode utilization rate in a high-temperature environment, can be improved, and the charging efficiency of the positive electrode at high temperatures can be improved. Can be improved. As a result, the storage battery can achieve a long life even in a high temperature environment.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail.

<Preparation of Nickel Hydroxide Particles> First, metallic nickel (Ni) and zinc (Zn) were dissolved in a sulfuric acid aqueous solution to prepare a solution in which nickel and zinc complex ions were generated. Subsequently, the resulting solution was dropped into an aqueous sodium hydroxide solution to prepare nickel hydroxide particles in which zinc was eutectic. In the neutralization process, convection is caused in the aqueous sodium hydroxide solution to gradually grow nickel hydroxide crystals, and three types of particles having different half widths are obtained by controlling the temperature and pH of the reaction system. Was.

The powder X of nickel hydroxide in the obtained particles
The half-value width of the peak of the (101) plane in the line diffraction (Cu-Kα, 2θ) is 0.5 deg (particle A),
0.8 deg (particle B) and 1.1 deg (particle C). The content of zinc in each of the particles A to C is 5
% By weight. Each of the particles A to C is spherical in shape,
There were few pores. Further, the average particle size was 10 μm, and the tap density was 2.2 g / cm ³ .

The half width was measured using a powder X-ray diffraction analyzer (trade name: Cu.K, manufactured by Shimadzu Corporation) under the trade name of XD-3A.
α) was used to obtain a diffraction pattern (for example, shown in FIG. 2) in powder X-ray diffraction (2θ), and the half width of a peak near 38.7 deg corresponding to the (101) plane of the diffraction pattern was measured Was calculated. The average particle size is obtained by measuring the particle size distribution of the obtained nickel hydroxide particles by a laser method,
It was determined from 50% of the total. The tap density is SEIS
Using a trade name of HIN CO, LTD; SEISHIN TAPDENSER KYT3000, filling the obtained nickel hydroxide particles in the container (capacity: 20 cm ³ ), and performing measurement by performing tapping 200 times. .

(Example) <Preparation of positive electrode> Cobalt and ytterbium were dissolved in sulfuric acid to prepare an aqueous solution containing complex ions. On the other hand, the particles C were immersed in an aqueous solution whose pH was controlled at 12. Into the particle C-containing alkaline aqueous solution, the mixed solution of cobalt and ytterbium is gradually dropped, and while being convected, deposited on the surface of the particle C, the surface is coated with a layer made of cobalt hydroxide and ytterbium, and Nickel hydroxide particles with eutectic zinc were produced. The layer was formed on the surface of the particles C such that the amount of cobalt element conversion to the particles C was 5% by weight. Further, the amount of ytterbium in the layer is determined by the particle C
3% by weight.

Next, 1.0 part by weight of a binder (carboxymethylcellulose, PTFE (polytetrafluoroethylene)) is added to 100 parts by weight of the surface-forming nickel hydroxide particles, and the paste is kneaded with pure water. Was prepared. This paste was filled into a nickel-plated metal porous body having a porosity of 96% and an average pore diameter of 200 μm, dried, and pressed to a predetermined thickness to produce a paste-type nickel positive electrode.

<Preparation of Negative Electrode> Commercially available Mm (Misch metal; mixture of rare earth elements), Ni, Co, Mn, Al
Were weighed so as to have a weight ratio of 4.0: 0.4: 0.3: 0.3, respectively, and then melted in a high-frequency melting furnace.
By cooling the molten metal, MmNi _4.0 Co _0.4 M
An alloy ingot having a composition of n _0.3 Al _0.3 was produced. Subsequently, the alloy ingot was mechanically pulverized and sieved to obtain a hydrogen storage alloy powder having a particle size of 50 μm or less. 97% by weight of this hydrogen storage alloy powder
Binder (carboxymethylcellulose, carbon, P
A paste was prepared by adding 3% by weight of TFE) and water. Then, apply the paste to the punched metal,
After drying and molding, a negative electrode was produced.

A separator composed of a hydrophilic non-woven polypropylene nonwoven fabric was placed between the obtained positive electrode and negative electrode,
A spiral electrode group was produced. After storing the electrode group in a metal container, an alkaline electrolyte composed of sodium hydroxide, potassium hydroxide, and lithium hydroxide is stored in the container, and each member such as a metal cover is used to calculate the AA size. A cylindrical nickel-metal hydride storage battery having a capacity of 1300 mAh was assembled.

(Comparative Example 1) An alkaline storage battery similar to that of the example was assembled except that a positive electrode as described below was used.

First, cobalt was dissolved in sulfuric acid to prepare an aqueous solution containing complex ions. On the other hand, the particles A were immersed in an aqueous solution whose pH was controlled at 12. The sulfuric acid aqueous solution is gradually dropped into the particle A-containing alkaline aqueous solution, and while being subjected to convection, cobalt hydroxide is deposited on the surface of the particle A, and the surface is coated with a layer made of cobalt hydroxide. Crystallized nickel hydroxide particles were produced.

The layer was formed on the surface of the particles A so that the conversion amount of the cobalt element to the particles A was 5% by weight. A positive electrode was produced from the obtained particles in the same manner as in Example 1.

Comparative Example 2 An alkaline storage battery similar to that of the example was assembled except that a positive electrode as described below was used.

First, a layer made of cobalt hydroxide was formed on the surface of the particles B in the same manner as in Comparative Example 1 described above.
It was formed so that the conversion amount of cobalt element was 5% by weight. A positive electrode was produced from the obtained particles in the same manner as in Example 1.

(Comparative Example 3) An alkaline storage battery similar to the example was assembled except that a positive electrode as described below was used.

First, a layer made of cobalt hydroxide was formed on the surface of the particles C in the same manner as in Comparative Example 1 described above.
It was formed so that the conversion amount of cobalt element was 5% by weight. A positive electrode was produced from the obtained particles in the same manner as in Example 1.

(Comparative Example 4) An alkaline storage battery similar to that of the example was assembled except that a positive electrode as described below was used.

Yb ₂ O ₃ powder was added to the same nickel hydroxide particles forming a cobalt hydroxide layer as described in Comparative Example 3 so as to be 3% by weight of nickel hydroxide in terms of Yb element. Further, a paste was prepared by adding 1.0 part by weight of a binder (carboxymethyl cellulose, PTFE (polytetrafluoroethylene)) and kneading the mixture with pure water. This paste was filled into a nickel-plated metal porous body similar to that described in Example 1, dried, and pressed to a predetermined thickness to produce a paste-type nickel positive electrode.

The obtained storage batteries of Example and Comparative Examples 1 to 4 were aged at 25 ° C. for 15 hours.
The battery was charged for 15 hours with an amount of electricity of 0.1 CmA, and after a pause of 30 minutes, a 1.0 CmA / 1.0 V cut discharge was performed to perform initial charge and discharge.

Example and Comparative Example 1 First Charged and Discharged
To 4 storage batteries at a current of 0.5 CmA at 25 ° C. for 120
%, And discharged at a cut of 1.0 CmA / 1.0 V. The positive electrode utilization rate was determined from the discharge capacity at this time, and the result is shown in FIG.

Further, the discharge capacity is set to a reference capacity of 25 ° C. Thereafter, charging and discharging are performed at 60 ° C. under the same conditions as those at 25 ° C., and the ratio of the discharge capacity to the reference capacity is determined. At the charging efficiency. The actual charging efficiency was calculated from the product of the obtained charging efficiency and the positive electrode utilization rate, and the result is shown in FIG.

Further, the storage batteries of Examples and Comparative Examples 1 to 4 were charged at 1 C (−dV) and then subjected to a charge / discharge cycle of discharging at 1 C, and the discharge capacity was 60% of the discharge capacity at the first cycle. The number of cycles required to reach was measured, and the results are shown in FIG.

As is apparent from FIG. 3, in the secondary battery of the embodiment in which ytterbium is present in the cobalt hydroxide layer formed on the surface of the particles containing nickel hydroxide as the main component, the ytterbium is added to the layer. Comparative Example 1 in which no is present
It can be seen that the utilization factor is higher than that of the secondary batteries of Comparative Examples 4 to ₃ in which ytterbium does not exist in the layer and the secondary battery in which Yb ₂ O ₃ powder is added instead. This is presumed to be because the formation of the conductive matrix was easily performed in the positive electrode of the secondary battery of the example.

As is clear from FIG. 4, the secondary batteries of the examples have higher actual charging efficiencies at the high temperature of the positive electrode than the secondary batteries of Comparative Examples 1 to 4.

Further, as is apparent from FIG. 5, the secondary batteries of the examples have a longer cycle life than the secondary batteries of Comparative Examples 1 to 4.

Further, it can be seen from FIGS. 3 to 5 that the utilization factor, the actual charging efficiency and the cycle life increase as the half width of nickel hydroxide increases.

In the above embodiment, zinc was eutectic with the nickel hydroxide particles. However, the same effect can be obtained by eutectic cobalt, ytterbium, or both with nickel hydroxide particles. .

[0068]

As described above in detail, according to the present invention, it is possible to provide a positive electrode for an alkaline storage battery which can easily form a conductive matrix, has a high utilization factor, and is excellent in charge efficiency in a high temperature environment. Further, according to the present invention, it is possible to provide an alkaline storage battery which has a positive electrode which is easy to form a conductive matrix, has a high utilization factor, has excellent charge efficiency in a high temperature environment, and has a long cycle life even at a high temperature.

[Brief description of the drawings]

FIG. 1 shows an example of an alkaline storage battery according to the present invention (for example,
FIG. 2 is a partially cutaway perspective view showing a cylindrical alkaline storage battery).

FIG. 2 shows a powder X-ray diffraction (Cu-Kα,
FIG. 2 is a characteristic diagram showing an example of a diffraction diagram of (2θ).

FIG. 3 is a characteristic diagram showing positive electrode utilization rates in the alkaline storage batteries of Example 1 and Comparative Examples 1 to 4.

FIG. 4 is a characteristic diagram showing the charging efficiency of a positive electrode at 60 ° C. in the alkaline storage batteries of Example 1 and Comparative Examples 1 to 4.

FIG. 5 is a characteristic diagram showing the cycle life of the alkaline storage batteries of Example 1 and Comparative Examples 1 to 4.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Positive electrode, 4 ... Negative electrode, 5 ... Electrode group, 7 ... Sealing plate.

Claims (6)

[Claims] 1. A positive electrode for an alkaline storage battery, wherein a layer mainly composed of a cobalt compound is formed on at least a part of the surface, and the layer contains particles mainly composed of nickel hydroxide, and said layer contains ytterbium. A positive electrode for an alkaline storage battery. 2. The positive electrode for an alkaline storage battery according to claim 1, wherein the particles contain at least one element selected from zinc, cobalt, and ytterbium. 3. The nickel hydroxide has a peak half-width (FWHM) of at least 0.8 deg on a (101) plane in powder X-ray diffraction (Cu-Kα, 2θ). 2. The positive electrode for an alkaline storage battery according to 1. 4. An alkaline storage battery provided with a positive electrode including a layer mainly composed of a cobalt compound on at least a part of its surface and including particles mainly composed of nickel hydroxide, wherein the layer contains ytterbium. An alkaline storage battery characterized in that: 5. The alkaline storage battery according to claim 4, wherein the particles contain at least one element selected from zinc, cobalt, and ytterbium. 6. The nickel hydroxide has a peak half width (FWHM) of at least 0.8 deg on a (101) plane in powder X-ray diffraction (Cu-Kα, 2θ). 4. The alkaline storage battery according to 4.