JP2007073242A - Alkaline battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alkaline battery enhancing high rate discharge characteristics and low rate discharge characteristics and suppressing drop in discharge capacity caused by self discharge during storage. <P>SOLUTION: The alkaline battery includes a positive electrode mix 4 containing a positive active material comprising nickel oxyhydroxide particles containing 2×10<SP>-3</SP>to 6×10<SP>-3</SP>mol of Zn and 2×10<SP>-3</SP>to 2×10<SP>-2</SP>mol to 1 mol nickel oxyhydroxide in the form of a solid solution, and 40-60 mass% of manganese dioxide, and a gel-like negative electrode 6 containing zinc. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an alkaline battery such as a zinc alkaline battery.

  For example, sealed manganese alkaline zinc primary batteries are used as power sources for portable electronic devices such as portable radios and cassette recorders. It is also known that in the configuration of this type of sealed alkaline primary battery, for example, an alkaline zinc primary battery, the battery element (electromotive part) has an inside-out type structure to reduce the cost.

  That is, adopting an inside-out type structure in which a positive electrode mixture molded into a hollow cylinder is used as a positive electrode, a bottomed cylindrical separator is disposed in the hollow, and a negative electrode is disposed in the bottomed cylindrical separator. As a result, productivity can be improved as compared with the case of adopting a spiral structure in which a laminate of a sheet-like positive electrode, separator and negative electrode is wound. As a result, low-cost, high-capacity alkaline zinc primary Battery can be provided.

  A primary battery having an inside-out structure as described above is advantageous in terms of productivity and cost reduction, but it is generally used because the facing area between the positive electrode and the negative electrode is small compared to a spiral structure. In addition, there is a problem that the high rate discharge characteristics are inferior.

  Therefore, as a positive electrode active material of an alkaline zinc primary battery having an inside-out structure, a high-rate discharge capacity (heavy load) is obtained by using a positive electrode active material in which a cobalt compound or the like is added to nickel oxyhydroxide particles or a surface coating is applied. Attempts have been made to improve the discharge characteristics. However, this nickel oxyhydroxide compound is more reducible than the manganese oxide that is the positive electrode active material of the alkaline manganese primary battery, and causes a self-discharge during storage, resulting in a decrease in discharge capacity. It was.

Patent Document 1 discloses that self-discharge of an alkaline zinc primary battery can be suppressed by dissolving 0.7 × 10 ^{−2 to} 7.4 × 10 ⁻² mol of zinc per mol of nickel oxyhydroxide. It is disclosed. Patent Document 1 also describes that when the amount of zinc solid solution per mole of nickel oxyhydroxide is less than 0.7 × 10 ⁻² mole, the effect of suppressing self-discharge cannot be obtained.

However, if the amount of zinc solid solution per mole of nickel oxyhydroxide is increased to 0.7 × 10 ^{−2 to} 7.4 × 10 ⁻² mole as in Patent Document 1, heavy load discharge characteristics will occur due to insufficient theoretical capacity. And discharge characteristics such as light load discharge characteristics are not sufficient.
JP 2002-75354 A

  An object of the present invention is to provide an alkaline battery that is excellent in both heavy load discharge characteristics and light load discharge characteristics and in which a decrease in discharge capacity due to self-discharge during storage is suppressed.

In the alkaline battery according to the present invention, Zn and Co are dissolved in 2 × 10 ^{−3 to} 6 × 10 ⁻³ mol, 2 × 10 ⁻³ to 2 × 10 ⁻² mol, respectively, with respect to 1 mol of nickel oxyhydroxide. A positive electrode mixture comprising a positive electrode active material composed of nickel oxyhydroxide particles that are present and 40 to 60% by mass of manganese dioxide;
And a gelled negative electrode containing zinc.

  ADVANTAGE OF THE INVENTION According to this invention, the alkaline battery which was excellent in both the heavy load discharge characteristic and the light load discharge characteristic, and the fall of the discharge capacity by the self discharge at the time of storage was suppressed can be provided.

  The present inventors have obtained the following knowledge in an alkaline battery provided with a gelled negative electrode containing zinc.

That is, oxyhydroxide in which Zn and Co are in a solid solution of 2 × 10 ^{−3 to} 6 × 10 ⁻³ mol and 2 × 10 ⁻³ to 2 × 10 ⁻² mol, respectively, with respect to 1 mol of nickel oxyhydroxide. It has been found that by forming a positive electrode active material from nickel particles and 40 to 60% by mass of manganese dioxide, self-discharge can be suppressed without impairing heavy load discharge characteristics. In addition, according to the above configuration, the amount of zinc and cobalt solid solution is as small as the above range, and the formation of cobalt high-order oxide on the surface of the nickel oxyhydroxide particles is unnecessary, so that the theoretical capacity can be improved. , Light load discharge characteristics can be improved.

  Self-discharge is suppressed by the above-described configuration because the amount of the electrolyte consumed by the self-discharge of the positive electrode and the amount of the electrolyte that moves from the negative electrode to the positive electrode can be reduced. This is because a decrease in the discharge capacity due to storage is prevented and an improvement in the discharge capacity retention rate is achieved.

  Nickel oxyhydroxide is a compound represented by NiOOH, and an average particle size of 8 to 12 μm is preferable because it has the most excellent battery characteristics. The discharge reaction of nickel oxyhydroxide is represented by the following reaction formula.

NiOOH + H ₂ O + e ⁻ → Ni (OH) ₂ + OH ⁻
The amount of zinc solid solution will be described. When the amount is less than 2 × 10 ⁻³ mol with respect to 1 mol of nickel oxyhydroxide, self-discharge increases or friction during molding of the mixture increases. On the other hand, when it exceeds 6 × 10 ⁻³ mol, the self-discharge suppressing effect is reduced, and the discharge capacity is decreased. A preferable zinc solid solution amount is 3 × 10 ⁻³ mol or more and 5 × 10 ⁻³ mol or less with respect to 1 mol of nickel oxyhydroxide.

The cobalt solid solution amount will be described. If it is less than 2 × 10 ⁻³ mol relative to 1 mol of nickel oxyhydroxide, it is not desirable because self-discharge increases or the particle size and shape of nickel oxyhydroxide changes. Moreover, when it exceeds 2 × 10 ⁻² mol, there is a problem that the discharge capacity decreases. The preferable amount of cobalt solid solution is 4 × 10 ⁻³ mol or more and 1.5 × 10 ⁻² mol or less with respect to 1 mol of nickel oxyhydroxide.

  A method for determining zinc and cobalt will be described. The positive electrode mixture is taken out from the alkaline battery, and water is added and boiled for 30 minutes to remove the electrolytic solution. Thereafter, it is dissolved in an acid, nickel, cobalt and zinc are quantified by ICP emission spectroscopy, and each of the cobalt amount and the zinc amount is converted into a mole ratio per 1 mol of nickel oxyhydroxide.

  The addition ratio of manganese dioxide is preferably 40 to 60% by mass with respect to the positive electrode active material. This is because when the addition ratio is less than 40% by mass, the capacity reduction due to self-discharge of nickel oxyhydroxide is large, and when it exceeds 60% by mass, the heavy load characteristics are greatly degraded. A more preferable addition ratio is 45 to 55% by mass. Thereby, self-discharge can be suppressed without impairing heavy load characteristics.

  Manganese dioxide is preferably electrolytic manganese dioxide, and those generally used for alkaline manganese batteries having an average particle size of 20 to 40 μm can be used.

  By setting the solid solution amount of zinc and cobalt and the addition ratio of manganese dioxide within the above ranges, self-discharge can be suppressed without coating the surface of the nickel oxyhydroxide particles with a cobalt high-order oxide. Since the theoretical capacity can be increased by not covering the cobalt high-order oxide and it can contribute to the improvement of the light load characteristics, an alkaline battery suitable for general-purpose use can be provided.

  Moreover, when erbium oxide is added to the positive electrode mixture, the oxygen overvoltage of the positive electrode is increased, and the reducing ability of nickel oxyhydroxide is weakened, that is, the oxygen gas generation reaction, which is decomposition of water in the electrolyte, is reduced. This has the effect of suppressing self-discharge and maintaining the discharge capacity. The amount of erbium oxide added is desirably 0.3 to 1% by mass with respect to the positive electrode active material. If the amount of erbium oxide added is less than 0.3% by mass, the effect of maintaining the discharge capacity during storage may not be sufficiently obtained. Moreover, when the addition amount of erbium oxide exceeds 1 mass%, there exists a possibility that the electrical resistance of a positive electrode mixture may rise and initial discharge capacity may fall.

  The form of the alkaline battery is not particularly limited. However, in the present invention, the heavy load discharge characteristic and the light load discharge characteristic of the alkaline battery having the inside-out structure can be drastically improved. An alkaline battery having a shape structure is particularly preferred. Moreover, the productivity of alkaline batteries can be improved by adopting the inside-out type structure.

  As an alkaline battery having an inside-out type structure, for example, an outer can, a cylindrical positive electrode mixture housed in the outer can, and a space surrounded by the inner peripheral surface of the positive electrode mixture (a hollow cylinder) And a separator disposed between the positive electrode mixture and the negative electrode, and a gelled negative electrode containing zinc.

  An example of this alkaline battery is shown in FIG.

  The positive electrode can (exterior can) 1 has a bottomed cylindrical shape, and the bottom surface projects outwardly, and this convex portion functions as the positive electrode terminal 2. Further, a step 3 (bead portion) protruding inward is provided near the open end of the positive electrode can 1. The positive electrode can 1 is made of, for example, a steel plate having a surface plated with nickel or nickel alloy.

  The cylindrical positive electrode mixture 4 is accommodated in the positive electrode can 1, and the outer peripheral surface thereof is in electrical contact with the inner peripheral surface of the positive electrode can 1. The bottomed cylindrical separator 5 is disposed in a space surrounded by the inner peripheral surface of the positive electrode mixture 4 and is in contact with the inner peripheral surface of the positive electrode mixture 4. The separator 5 can be a nonwoven fabric formed from hydrophilic fibers such as polyvinyl alcohol fibers. A gelled negative electrode 6 containing a negative electrode active material containing zinc and an electrolytic solution is filled in the separator 5.

  A packing 7 made of a polyamide resin having a double ring structure is disposed in the opening of the positive electrode can 1. For example, the negative electrode current collector rod 8 made of brass is inserted into the inner annular portion of the packing 7, and the tip portion is in contact with the gelled negative electrode 6. The metal washer 9 is disposed between the inner annular portion and the outer annular portion of the packing 7 so as to press the packing 7 against the inner peripheral surface of the positive electrode can 1. The negative electrode terminal plate 10 made of metal and having a hat shape is disposed on the metal washer 9 so as to be in electrical contact with the head of the negative electrode current collector rod 8, and the upper end of the opening of the positive electrode can 1 is bent inward. Thus, the positive electrode can 1 is caulked and fixed.

  Hereinafter, the positive electrode mixture, the gelled negative electrode, and the electrolytic solution will be described.

1) Positive electrode mixture The positive electrode mixture has the shape retention of the above-mentioned positive electrode active material, a conductive material such as carbon particles for improving the electrical conductivity of the positive electrode active material, and a molded body obtained by molding these components. A binder for improvement and an electrolytic solution are included.

  The positive electrode mixture is produced, for example, by the method described below.

(First Step) Mixing of Positive Electrode Mixture Components A positive electrode active material and a conductive material that is a positive electrode mixture additive, a binder, a lubricant, an electrolytic solution, and the like are mixed. The conductive material that is a component of the positive electrode mixture is used to reduce the internal electrical resistance in the positive electrode mixture, and graphite is generally used. In addition, the binder is used to enhance shape retention during molding of the positive electrode mixture and to maintain shape retention during the molding operation and in the battery. Examples of the binder include polyolefin resins. Further, the lubricant is used to improve the manufacturing yield by improving the slip between the mold used when the positive electrode mixture is molded and the positive electrode mixture molded body. As this lubricant, zinc stearate, calcium stearate, ethylene bisstearamide, or the like is used. Moreover, electrolyte solution is used in order to improve the ionic conductivity in a positive mix, and to improve a moldability. It is preferable to use the same electrolytic solution as the electrolytic solution used for maintaining ionic conduction between the positive electrode and the negative electrode of the battery. A preferred electrolyte is a 40% aqueous KOH solution.

  The mixing ratio of these positive electrode mixture components is 72 to 48:48 to 72: 4 to 8: 0 as nickel oxyhydroxide: manganese dioxide: conductive agent: binder: lubricant: electrolytic solution: erbium oxide. A blending ratio of 0.05 to 0.5: 0.05 to 0.30: 4 to 7: 0.36 to 1.2 is preferable. However, it mix | blends so that the sum total of the nickel oxyhydroxide which is a positive electrode active material, and manganese dioxide may be set to 120.

  In addition, these components are mixed with stirring apparatuses, such as a rotary mixer and a Henschel mixer.

(Second Step) Roller Compaction Treatment The positive electrode mixture blended in the above step is then compressed and pressurized by a roller compactor to increase the packing density for granulation. This roller compactor supplies a positive electrode mixture between twin rolls and pressurizes it to increase the packing density. The compressive stress is 0.5 × 10 ^{4 to} 5 × 10 ⁴ obtained by dividing the applied force by the roller width. but is preferably in the range of from N / cm, more preferably in the range of ^{1.5 × 10 4 ~3.5 × 10 4} N / cm. This roller compactor can improve the throughput in proportion to the square of the radius and the roll width.

(Third Step) Granulation Treatment The positive electrode mixture that has been subjected to the roller compaction treatment is in the form of a compressed mass. In order to produce a molded body using this, it is necessary to granulate once into a granule. For this purpose, granulation is performed by a granulator using twin rolls having protrusions fitted to the roll surface. The positive electrode mixture formed into a compacted mass is crushed into granules by passing through this granulator. The diameter of the obtained particles is about a few tens of μm to 1 mm.

(4th process) Classification process The positive mix particle obtained at the said process is classified by the size. By setting it as the particle | grains of the range of 200-850 micrometers, it can be set as the positive electrode mixture molded object with a high packing density. When the granulated powder of less than 200 μm is molded, it takes time to measure the granulated powder and is not suitable. Further, granulated powder exceeding 850 μm is not suitable because the weight of the molded product varies when the mold is formed. A granulation system in which particles having a large diameter sieved by this classification treatment are supplied again to the granulator treatment and reused, and particles having a small shape are supplied to the roller compactor treatment process and reused. It can be built in mass production facilities.

(Fifth Step) Molding The positive electrode mixture particles granulated in the above step are then molded into a positive electrode molded body using a mold. Since the inside-out type positive electrode mixture has a hollow cylindrical shape, a male mold is formed by filling the positive electrode mixture particles in a cylindrical mold having a mandrel at the center and having a required volume. Molding is performed by press-fitting. The molding pressure at this time is preferably a pressure of 0.5 × 10 ^{8 to} 9.8 × 10 ⁸ Pa. When the molding pressure falls below the above range, the required filling density of the positive electrode mixture cannot be obtained, and it becomes difficult to ensure the contact between the particles. Therefore, when the battery is used, a predetermined discharge capacity cannot be obtained. On the other hand, when the molding pressure exceeds the above range, the electrolytic solution hardly penetrates into the positive electrode mixture, and the utilization rate is lowered.

2) Gelled negative electrode The gelled negative electrode contains a negative electrode active material containing zinc as a main component, and a zinc alloy can be used for the negative electrode active material containing zinc. For the gelled negative electrode, zinc gel used in known manganese dioxide-zinc primary batteries can be used. Since this negative electrode material is in a gel form, it is easy to handle. In order to make the negative electrode into a gel, it can be easily made into a gel by dispersing a zinc alloy as a negative electrode active substance in a gel electrolyte prepared from the electrolyte and a thickener.

  As the zinc alloy, a mercury and lead-free zinc alloy known as a non-freeze zinc alloy can be used. Specifically, a zinc alloy containing 0.06% by mass of indium, 0.014% by mass of bismuth, and 0.0035% by mass of aluminum is preferable because it has an effect of suppressing generation of hydrogen gas. In particular, indium and bismuth are desirable for improving the discharge performance. By using a zinc alloy instead of pure zinc as the negative electrode active substance, the self-dissolution rate in the alkaline electrolyte is slowed down, and hydrogen gas generation inside the battery in the case of a sealed battery product is suppressed, thereby preventing leakage. Accidents caused by liquids can be prevented.

  Moreover, it is desirable that the shape of the zinc alloy is powdery so that the surface area can be increased to cope with a large current discharge. In the present invention, the preferred average particle diameter of the zinc alloy is preferably in the range of 75 to 150 μm. When the average particle diameter of the zinc alloy exceeds the above range, the surface area becomes relatively small, and it may be difficult to cope with a large current discharge. Also, if the average particle size is below the above range, handling during battery assembly is difficult, and it becomes difficult not only to mix uniformly with the electrolyte and gelling agent, but also because the surface is active, it is oxidized. Easy and lacks stability.

  As the thickener, polyvinyl alcohol, polyacrylate, CMC, alginic acid, or the like can be used. In particular, sodium polyacrylate is preferable because of its excellent water absorption ratio with respect to a strong alkaline aqueous solution.

3) Electrolytic Solution The alkaline electrolytic solution is preferably an aqueous solution using an alkali salt such as potassium hydroxide, sodium hydroxide, or lithium hydroxide as a solute, and potassium hydroxide is particularly preferable. In addition, it is desirable to add a zinc compound to the electrolytic solution. Such zinc compounds include compounds such as zinc oxide and zinc hydroxide, with zinc oxide being particularly preferred.

  When an alkaline aqueous solution containing at least a zinc compound is used as the electrolytic solution, the self-dissolution of the zinc alloy in the alkaline aqueous solution is significantly less than that of the acidic electrolytic solution, and further in the alkaline electrolytic solution of the zinc alloy. This self-dissolution is further suppressed by dissolving zinc compounds such as zinc oxide and pre-existing zinc ions.

[Example]
Examples of the present invention will be described in detail below.

Example 1
Nickel oxyhydroxide particles in which 2 × 10 ⁻³ mol of Zn and Co were dissolved in 1 mol of nickel oxyhydroxide were prepared. 48 parts by mass of electrolytic manganese dioxide and 7 parts by mass of graphite as a conductive agent are added to 72 parts by mass of nickel oxyhydroxide particles having an average particle diameter of 10 μm thus obtained, and polyethylene having an average particle diameter of 5 μm is used as a positive electrode active material. After adding 1000 ppm to the mixture, dry stirring was performed for 10 minutes at a rotation speed of 300 rpm, and then 6.2 parts by weight of a 40% by weight potassium hydroxide aqueous solution as a kneading liquid was added, and wet stirring was performed at a rotation speed of 600 rpm for 10 minutes. The mixture was stirred. Subsequently, the stirring mixture was compacted at a compressive strength of 200 kg / mm ² to prepare a thin piece. Furthermore, the granule mixture was manufactured by crushing the thing of a thin piece state using a classifier.

  Thereafter, a positive electrode mixture having a constant weight and a predetermined size was formed and inserted into the positive electrode can. Subsequently, re-pressurization was performed in order to achieve close contact between the positive electrode mixture and the positive electrode can. The addition ratio (mass%) of manganese dioxide in the positive electrode active material (nickel oxyhydroxide + manganese dioxide) is shown in Table 1 below. In addition, the manganese dioxide addition ratio was calculated by the following formula.

Manganese dioxide addition ratio = {W _Mn / (W _Ni + W _Mn )} × 100
W _Mn is the mass of manganese dioxide, W _Ni is the mass of nickel oxyhydroxide, and the value of (W _Ni + W _Mn ) was calculated as 120 parts by mass.

  Moreover, the gelled negative electrode was produced by the method described below.

  300 parts by mass of zinc alloy powder containing 0.06% by mass of indium, 0.014% by mass of bismuth and 0.0035% by mass of aluminum, and 190 parts by mass of an electrolyte obtained by saturatedly dissolving zinc oxide in a 40% KOH aqueous solution A gelled negative electrode was prepared by mixing 5 parts by mass of a thickener composed of sodium polyacrylate.

  By using the positive electrode mixture obtained and the gelled negative electrode, a JIS standard LR6 type (AA) alkaline battery having the structure shown in FIG. 1 was assembled.

(Examples 2 to 13 and Comparative Examples 1 to 20)
JIS standard LR6 type in the same manner as in Example 1 except that the Zn solid solution amount, Co solid solution amount, presence / absence of coating with higher cobalt oxide, and manganese dioxide addition ratio are as shown in Tables 1 to 3 below. An (AA) alkaline battery was assembled.

(Example 14)
Nickel oxyhydroxide particles in which 2 × 10 ⁻³ mol of Zn and Co were dissolved in 1 mol of nickel oxyhydroxide were prepared. 48 parts by mass of electrolytic manganese dioxide and 7 parts by mass of graphite as a conductive agent are added to 72 parts by mass of nickel oxyhydroxide particles having an average particle diameter of 10 μm thus obtained, and polyethylene having an average particle diameter of 5 μm is used as a positive electrode active material. After adding 1000 ppm with respect to erbium oxide and adding dry stirring for 10 minutes at a rotational speed of 300 rpm, 6.2 parts by mass of a 40% by mass potassium hydroxide aqueous solution as a kneading liquid was added. Wet stirring was performed at 600 rpm for 10 minutes to obtain a stirring mixture. Subsequently, the stirring mixture was compacted at a compressive strength of 200 kg / mm ² to prepare a thin piece. Furthermore, the granule mixture was manufactured by crushing the thing of a thin piece state using a classifier.

  Thereafter, a positive electrode mixture having a constant weight and a predetermined size was formed and inserted into the positive electrode can. Subsequently, re-pressurization was performed in order to achieve close contact between the positive electrode mixture and the positive electrode can. Table 4 below shows the addition ratio (mass%) of manganese dioxide in the positive electrode active material (nickel oxyhydroxide + manganese dioxide) and the erbium oxide addition ratio (mass%) relative to the positive electrode active material. The addition ratio of manganese dioxide was calculated by the formula described above. The erbium oxide addition ratio was calculated using the erbium oxide addition amount (for example, 0.36 parts by mass) when the total amount of the positive electrode active material was 120 parts by mass.

  A JIS standard LR6 type (AA) type alkaline battery was assembled in the same manner as in Example 1 described above except that the obtained positive electrode mixture was used.

(Examples 15 to 41)
The same as in Example 14 except that the Zn solid solution amount, Co solid solution amount, presence / absence of coating with higher cobalt oxide, manganese dioxide addition ratio, and erbium oxide addition ratio are as shown in Tables 4 to 5 below. A JIS standard LR6 type (AA size) alkaline battery was assembled.

With respect to the LR6 type alkaline battery assembled as described above, an initial 1000 mW / 1.0 Vcut discharge, storage at 60 ° C. for 20 days, a 1000 mW / 1.0 Vcut discharge, and an initial 150 mA / 0.8 Vcut discharge test were performed at n = 6. The results are shown in Tables 1-5.

As apparent from Tables 1 to ³ , the batteries of Comparative Examples 1 to 4 having a Co solid solution amount of less than 2 × 10 ⁻³ mol or more than 2 × 10 ⁻² mol relative to 1 mol of nickel oxyhydroxide are The load discharge characteristics and the discharge retention rate after high temperature storage were low compared to the batteries of Examples 1-13. From this result, it is desirable that the amount of Co solid solution with respect to 1 mol of nickel oxyhydroxide be in the range of 2 × 10 ⁻³ to 2 × 10 ⁻² mol.

The batteries of Comparative Examples 5 to 8 having a Zn solid solution amount with respect to 1 mol of nickel oxyhydroxide of less than 2 × 10 ⁻³ mol or more than 6 × 10 ⁻³ mol have the discharge maintenance ratios after Examples 1 to 13 after high-temperature storage. It was inferior to the battery. From this result, it is desirable that the Zn solid solution amount with respect to 1 mol of nickel oxyhydroxide be in the range of 2 × 10 ^{−3 to} 6 × 10 ⁻³ mol.

  The batteries of Comparative Examples 9 to 13 and 19 in which the addition ratio of manganese dioxide is less than 40% by mass have a smaller discharge retention ratio after high-temperature storage than those in Examples 1 to 13, while the addition ratio of manganese dioxide is 60% by mass. The batteries of Comparative Examples 14 to 18 exceeding% had inferior initial heavy load discharge characteristics as compared with Examples 1 to 13. Therefore, the addition ratio of manganese dioxide is desirably in the range of 40 to 60% by mass.

  The battery of Comparative Example 20 in which the surface of the cobalt oxyhydroxide particles whose Zn solid solution amount and Co solid solution amount are the same as in Example 13 is coated with a high-order cobalt oxide has the first light load discharge characteristics of Examples 1 to 1. Compared to 13, it was low.

From these results, the amount of Zn solid solution with respect to 1 mol of nickel oxyhydroxide is 2 × 10 ^{−3 to} 6 × 10 ⁻³ mol, the amount of Co solid solution is 2 × 10 ⁻³ to 2 × 10 ⁻² mol, cobalt By using nickel oxyhydroxide that is not coated with higher-order oxide and adding manganese dioxide to the positive electrode active material at a rate of 40 to 60% by mass, the initial heavy load discharge characteristics, discharge after high-temperature storage It can be understood that a versatile battery having good retention rate and initial light load discharge characteristics can be realized.

  From Tables 4 and 5, the batteries of Examples 14 to 39 in which erbium oxide was contained in the positive electrode mixture in an amount of 0.3 to 1% by mass with respect to the positive electrode active material had an erbium oxide addition amount of 1% by mass. Compared with the battery of Example 40, which has excellent initial heavy load discharge characteristics and initial light load discharge characteristics as compared with the battery of Example 40 exceeding, and the erbium oxide addition amount is less than 0.3% by mass. It was found that the discharge maintenance rate after storage was excellent.

  As described above, according to the present invention, it is possible to improve the discharge retention rate and light load discharge characteristics after high-temperature storage without impairing heavy load discharge characteristics, and to provide a highly reliable alkaline battery in terms of product quality. it can.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The typical sectional view showing one embodiment of the alkaline battery of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Positive electrode can, 2 ... Positive electrode terminal, 3 ... Bead part, 4 ... Positive electrode mixture, 5 ... Separator, 6 ... Gel-like negative electrode, 7 ... Packing, 8 ... Negative electrode collector rod, 9 ... Metal washer, 10 ... Negative electrode terminal Board.

Claims (4)

Nickel oxyhydroxide particles in which Zn and Co are dissolved in 2 × 10 ^{−3 to} 6 × 10 ⁻³ mol and 2 × 10 ⁻³ to 2 × 10 ⁻² mol, respectively, with respect to 1 mol of nickel oxyhydroxide. And a positive electrode mixture containing a positive electrode active material composed of 40 to 60% by mass of manganese dioxide,
An alkaline battery comprising a gelled negative electrode containing zinc.   The alkaline battery according to claim 1, wherein the positive electrode mixture further contains erbium oxide.   The alkaline battery according to claim 2, wherein the amount of erbium oxide is 0.3 to 1 mass% with respect to the positive electrode active material.   The said positive electrode mixture has a cylindrical shape, The said gelled negative electrode is arrange | positioned through the separator in the space enclosed by the internal peripheral surface. Alkaline battery.

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