Alkaline battery

Abstract

This alkaline battery comprises: a positive electrode; a negative electrode; a separator positioned between the positive electrode and the negative electrode; and a liquid electrolyte included in the positive electrode, the negative electrode, and the separator. The negative electrode contains a zinc-containing negative electrode active material, a phthalic acid compound, and a gallium compound.

Description

alkaline batteries

[0001] The present disclosure relates to alkaline dry batteries.

[0002] Alkaline batteries (alkaline manganese batteries) are widely used because they have a larger capacity and can extract a larger current than manganese batteries.

[0003] Patent Document 1 discloses an alkaline dry battery including a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte solution contained in the positive electrode, the negative electrode, and the separator, wherein the electrolyte solution contains an alkaline aqueous solution, the negative electrode contains a negative electrode active material containing zinc, and an additive, the additive containing at least one selected from the group consisting of benzoic acid, phthalic acid, isophthalic acid, and salts thereof, the amount of the negative electrode active material contained in the negative electrode is 176 to 221 parts by mass per 100 parts by mass of water contained in the electrolyte solution, and the amount of the additive contained in the negative electrode is 0.1 to 1.0 part by mass per 100 parts by mass of the negative electrode active material.

[0004] International Publication No. 2018 / 163485

[0005] After assembly, alkaline batteries are aged by storing them at high temperatures to promote circulation of the electrolyte in the positive electrode, detect defects due to impurities, etc. However, negative electrodes are usually gel-like, and the inside of the negative electrode (the surface of the negative electrode active material) is difficult to homogenize during high-temperature storage, which can lead to increased variations in internal resistance.

[0006] One aspect of the present disclosure relates to an alkaline dry battery including a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte solution contained in the positive electrode, the negative electrode, and the separator, wherein the negative electrode includes a negative electrode active material containing zinc, a phthalic acid compound, and a gallium compound.

[0007] According to the present disclosure, it is possible to reduce the variation in internal resistance of alkaline dry batteries.

[0008] The novel features of the present invention are set forth in the appended claims, but the present invention, both in terms of structure and content, together with other objects and features of the present invention, will be better understood from the following detailed description taken in conjunction with the drawings.

[0009] 1 is a partially cross-sectional front view of an alkaline dry battery according to an embodiment of the present disclosure.

[0010] The following describes embodiments of the present disclosure using examples, but the present disclosure is not limited to the examples described below. In the following description, specific numerical values ​​and materials may be exemplified, but other numerical values ​​and materials may be applied as long as the effects of the present disclosure are obtained. In this specification, the term "numerical value A to numerical value B" includes numerical value A and numerical value B and can be read as "numerical value A or more and numerical value B or less." In the following description, when lower and upper limits for specific physical properties or conditions are exemplified, any of the exemplified lower limits and any of the exemplified upper limits can be arbitrarily combined, as long as the lower limit is not equal to or greater than the upper limit. When multiple materials are exemplified, one of the materials may be selected and used alone, or two or more materials may be used in combination.

[0011] An alkaline dry battery according to an embodiment of the present disclosure includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte. The electrolyte is contained in the positive electrode, the negative electrode, and the separator. The negative electrode includes a negative electrode active material containing zinc, as well as a gallium compound and a phthalate compound as additives. The additives contained in the negative electrode are dispersed (or dissolved) in the electrolyte in the negative electrode. In the electrolyte in the negative electrode, the gallium compound and the phthalate compound may exist as Ga ions and phthalate ions.

[0012] When a gallium compound and a phthalate compound are used in combination as additives in the negative electrode, the increase in the variation in the internal resistance of the battery during high-temperature storage (aging treatment) after battery assembly is significantly suppressed. Although the detailed reason for this is unknown, it is speculated that Ga ions and phthalate ions present in the electrolyte in the negative electrode interact with each other on the surface of the negative electrode active material, resulting in homogenization of the surface of the negative electrode active material during aging treatment. It is speculated that the deposition potential of Ga is close to the potential of the negative electrode (negative electrode active material containing Zn), which also contributes to this homogenization.

[0013] It is presumed that when a gallium compound is dispersed (or dissolved) in the electrolyte in the negative electrode, Ga ions are likely to be present on the surface of the negative electrode active material and are likely to interact with phthalate ions. If the negative electrode active material is zinc alloy particles containing gallium, it is presumed that the increase in internal resistance variation is difficult to suppress. In this case, gallium is contained within the zinc alloy particles, and since gallium is not exposed to the particle surface much, it is presumed that the interaction with phthalate ions is small, making it difficult to homogenize the surface of the negative electrode active material.

[0014] The aging treatment is carried out, for example, by storing the assembled battery in an environment of 40° C. or higher and 60° C. or lower for 24 hours or longer and 100 hours or shorter.

[0015] (Gallium Compound) The gallium compound preferably contains at least one of gallium oxide and gallium hydroxide. The gallium oxide is gallium oxide (Ga ２ O ３ Gallium hydroxide includes gallium hydroxide (Ga(OH) ３ ), gallium oxyhydroxide (GaOOH), etc. Among these, gallium hydroxide is more preferable, and GaOOH is particularly preferable. Gallium hydroxide has a higher affinity for alkaline electrolytes (potassium hydroxide aqueous solution) than gallium oxide. Gallium oxyhydroxide has a high Ga content per unit mass of the compound and has high doping efficiency.

[0016] From the viewpoint of easily suppressing an increase in internal resistance variation while ensuring a sufficient filling amount of the negative electrode active material, the content of the gallium compound in the negative electrode may be 0.005 parts by mass or more and 0.15 parts by mass or less (or 0.1 parts by mass or less) per 100 parts by mass of the negative electrode active material, or may be 0.01 parts by mass or more and 0.06 parts by mass or less. When the negative electrode is produced (immediately after the battery is assembled), the content of the gallium compound is preferably within the above range. Furthermore, the gallium compound in the negative electrode is easily dissolved in the electrolyte in the negative electrode, and after the battery is assembled (after aging), a portion of the gallium compound in the negative electrode may diffuse to the positive electrode and separator. Therefore, after the battery is assembled, the content of the gallium compound in the negative electrode tends to be smaller than the above range. After the battery is assembled, the content of the gallium compound in the negative electrode may be 0.003 parts by mass or more and 0.1 parts by mass or less per 100 parts by mass of the negative electrode active material.

[0017] From a similar viewpoint, in the negative electrode, the molar ratio of Ga derived from the gallium compound to Zn derived from the negative electrode active material: Ga / Zn may be 0.00002 or more and 0.0007 or less, or may be 0.00007 or more and 0.0004 or less.

[0018] The molar ratio Ga / Zn is determined as follows. First, the battery after aging is disassembled, a portion of the negative electrode is collected, and nitric acid is added and heated to dissolve. The mixture is then allowed to cool, and insoluble matter is removed by filtration to obtain a sample solution. The amounts of Ga and Zn in the sample solution are determined by inductively coupled plasma (ICP) atomic emission spectroscopy, and the molar ratio of Ga / Zn is calculated based on the analytical values. Note that, during analysis, the sample solution is diluted with pure water to a constant volume and used. Furthermore, since the amount of Zn derived from ZnO in the electrolyte in the negative electrode is much smaller than the amount of Zn derived from the negative electrode active material, the amount of Zn determined by analysis can be considered to be the amount of Zn derived from the negative electrode active material.

[0019] (Phthalic Acid Compound) Phthalic acid compounds include phthalic acid (salts) and derivatives thereof. In this specification, phthalic acid refers to at least one selected from the group consisting of o-phthalic acid, p-phthalic acid (terephthalic acid), and m-phthalic acid (isophthalic acid). Derivatives of phthalic acid include, for example, those in which the hydrogen atom bonded to the benzene ring of phthalic acid is substituted with a substituent such as a halogen atom or an alkyl group such as a methyl group. Among these, terephthalic acid is preferred. Terephthalic acid has a low solubility in the electrolyte solution, and therefore interacts relatively slowly with the gallium compound, making it easy to homogenize the surface of the negative electrode active material.

[0020] The content of the phthalic acid compound in the negative electrode may be 0.05 parts by mass or more and 0.3 parts by mass or less, or 0.05 parts by mass or more and 0.15 parts by mass or less, per 100 parts by mass of the negative electrode active material. When the content of the phthalic acid compound in the negative electrode is 0.05 parts by mass or more per 100 parts by mass of the negative electrode active material, interaction with the gallium compound is easily exhibited. When the content of the phthalic acid compound in the negative electrode is 0.3 parts by mass or less per 100 parts by mass of the negative electrode active material, the electrolyte in the negative electrode is easily able to achieve a good viscosity. Note that the phthalic acid compound has low solubility in the electrolyte, and therefore, after assembly of the battery, the phthalic acid compound in the negative electrode hardly migrates to the positive electrode or separator.

[0021] In the negative electrode, the molar ratio of Ga derived from the gallium compound to the phthalic acid compound: (Ga / phthalic acid compound) may be 0.06 or more (or 0.12 or more) and 2.9 or less (or 2.4 or less), or may be 0.06 or more (or 0.12 or more) and 1.5 or less, or may be 0.18 or more and 0.8 or less.

[0022] The content of the phthalic acid compound in the negative electrode is determined as follows: (i) The aged battery is disassembled, and the gelled negative electrode is removed. A mixture of the negative electrode active material, the phthalic acid compound, the gelling agent, and the electrolyte is separated from the gelled negative electrode by centrifugation. (ii) The mixture obtained in (i) is diluted with pure water to obtain Liquid A. (iii) The phthalic acid compound obtained in (i) is washed with pure water, and then the water in which the phthalic acid compound is dispersed is filtered to obtain the phthalic acid compound and filtrate B. (iv) The negative electrode active material obtained in (i) is washed with pure water, and then the water in which the negative electrode active material is dispersed is filtered to obtain filtrate C. (v) Liquid A obtained in (ii), filtrate B obtained in (iii), and filtrate C obtained in (iv) are analyzed by ion chromatography to determine the total amount W1 of the phthalic acid compound (soluble content) contained in Liquid A, filtrate B, and filtrate C. (vi) The phthalic acid compound obtained in (iii) above is dried, and the amount of the phthalic acid compound (insoluble matter) W2 is determined. (vii) The sum of W1 determined in (v) above and W2 determined in (vi) above is determined as the content of the phthalic acid compound in the negative electrode.

[0023] The alkaline battery will be described in detail below.

[0024] (Negative electrode) The negative electrode usually contains a negative electrode active material, an additive (a gallium compound and a phthalate compound), an electrolyte solution, and a gelling agent. The negative electrode is obtained, for example, by mixing the negative electrode active material, the additive, the gelling agent, and the electrolyte solution. The negative electrode may further contain other components in addition to those described above.

[0025] Examples of negative electrode active materials include zinc and zinc alloys. From the viewpoint of corrosion resistance, the zinc alloy may contain at least one element selected from the group consisting of indium, bismuth, and aluminum. The indium content in the zinc alloy is, for example, 0.01 to 0.1 mass%, and the bismuth content is, for example, 0.003 to 0.02 mass%. The aluminum content in the zinc alloy is, for example, 0.001 to 0.03 mass%. From the viewpoint of corrosion resistance, the proportion of elements other than zinc in the zinc alloy is preferably 0.025 to 0.08 mass%.

[0026] The negative electrode active material is usually used in a particulate form. From the viewpoint of the filling property of the negative electrode and the diffusibility of the electrolyte in the negative electrode, the average particle size of the negative electrode active material particles may be, for example, 100 μm or more and 200 μm or less, or 110 μm or more and 160 μm or less.

[0027] In this specification, the average particle size refers to the median diameter (D50) in a volume-based particle size distribution. The average particle size can be determined, for example, using a laser diffraction / scattering particle distribution analyzer.

[0028] The gelling agent may be any known gelling agent used in the field of alkaline batteries, without any particular limitation, such as a water-absorbent polymer. Examples of such gelling agents include polyacrylic acid and sodium polyacrylate. The amount of gelling agent added is, for example, 0.5 parts by mass or more and 2.5 parts by mass or less per 100 parts by mass of the negative electrode active material.

[0029] (Positive Electrode) The positive electrode typically contains manganese dioxide as a positive electrode active material, a conductive agent, and an electrolyte. The positive electrode may further contain a binder, if necessary. As the manganese dioxide, electrolytic manganese dioxide is preferred. Manganese dioxide is used in the form of powder. From the viewpoint of easily ensuring the filling of the positive electrode and the diffusibility of the electrolyte within the positive electrode, the average particle size of the manganese dioxide is, for example, 25 μm or more and 60 μm or less.

[0030] From the viewpoint of moldability and suppression of expansion of the positive electrode, the BET specific surface area of ​​manganese dioxide is, for example, 20 m 2 / g or more, 50m 2 / g or less. The BET specific surface area is a surface area measured and calculated using the BET equation, which is a theoretical equation for multilayer adsorption. The BET specific surface area can be measured, for example, using a specific surface area measuring device based on the nitrogen adsorption method.

[0031] Examples of conductive agents include carbon black such as acetylene black and conductive carbon materials such as graphite. Examples of graphite that can be used include natural graphite and artificial graphite. The conductive agent may be in a fibrous form, but is preferably in a powder form. The average particle size of the conductive agent is, for example, 3 μm or more and 20 μm or less.

[0032] The content of the conductive agent in the positive electrode is, for example, 3 parts by mass or more and 10 parts by mass or less, and preferably 5 parts by mass or more and 9 parts by mass or less, relative to 100 parts by mass of manganese dioxide.

[0033] The positive electrode can be obtained, for example, by press-molding a positive electrode mixture containing a positive electrode active material, a conductive agent, an electrolyte, and, if necessary, a binder, into pellets. The positive electrode mixture may be first formed into flakes or granules, classified as necessary, and then press-molded into pellets. The pellets may be placed in a battery case and secondary-pressurized using a predetermined tool so as to adhere to the inner wall of the battery case.

[0034] (Separator) Examples of separator materials include cellulose and polyvinyl alcohol. The separator may be a nonwoven fabric made primarily of fibers of the above materials, or a microporous film such as cellophane or polyolefin. A nonwoven fabric and a microporous film may be used in combination. Examples of nonwoven fabrics include a nonwoven fabric made primarily of cellulose fibers and polyvinyl alcohol fibers, and a nonwoven fabric made primarily of rayon fibers and polyvinyl alcohol fibers.

[0035] The thickness of the separator is, for example, 200 μm or more and 300 μm or less. The separator as a whole preferably has the above thickness, and if the sheets constituting the separator are thin, multiple sheets may be stacked to achieve the above thickness.

[0036] (Electrolyte) As the electrolyte, for example, an alkaline aqueous solution containing potassium hydroxide is used. The concentration of potassium hydroxide in the electrolyte is, for example, 30% by mass or more and 50% by mass or less. The electrolyte may further contain zinc oxide. The concentration of zinc oxide in the electrolyte is, for example, 1% by mass or more and 5% by mass or less.

[0037] Examples of alkaline dry batteries according to an embodiment of the present disclosure include cylindrical batteries and coin batteries.

[0038] The alkaline dry battery according to this embodiment will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to the following embodiment. Furthermore, appropriate modifications are possible within the scope of the effects of the present disclosure. Furthermore, the present disclosure can be combined with other embodiments.

[0039] Fig. 1 is a front view of a horizontal half cross section of an alkaline dry battery according to an embodiment of the present disclosure, showing an example of a cylindrical battery having an inside-out structure.

[0040] 1, an alkaline dry battery includes a hollow cylindrical positive electrode 2, a gelled negative electrode 3 disposed in the hollow portion of the positive electrode 2, a separator 4 disposed therebetween, and an electrolyte (not shown), all of which are housed in a cylindrical battery case 1 with a bottom that also serves as the positive electrode terminal. An alkaline aqueous solution is used as the electrolyte.

[0041] The positive electrode 2 is disposed in contact with the inner wall of the battery case 1. The positive electrode 2 contains manganese dioxide and an electrolyte. A gelled negative electrode 3 is filled in the hollow portion of the positive electrode 2 with a separator 4 interposed therebetween. The negative electrode 3 contains a negative electrode active material, additives (a gallium compound and a phthalate compound), the electrolyte, and a gelling agent.

[0042] The separator 4 is cylindrical with a bottom and contains an electrolyte. The separator 4 is composed of a cylindrical separator 4a and a bottom paper 4b. The separator 4a is arranged along the inner surface of the hollow portion of the positive electrode 2 and separates the positive electrode 2 from the negative electrode 3. Therefore, the separator arranged between the positive electrode and the negative electrode refers to the cylindrical separator 4a. The bottom paper 4b is arranged at the bottom of the hollow portion of the positive electrode 2 and separates the negative electrode 3 from the battery case 1.

[0043] For example, a cylindrical metal case with a bottom is used as the battery case 1. For example, a nickel-plated steel plate is used as the metal case. In order to improve the adhesion between the positive electrode and the battery case, it is preferable to use a battery case in which the inner surface of the metal case is coated with a carbon film.

[0044] The opening of the battery case 1 is sealed by a sealing unit 9. The sealing unit 9 includes a resin gasket 5, a negative electrode current collector 6, and a negative electrode terminal plate 7 that also serves as a negative electrode terminal. The gasket 5 has an annular thin-walled portion 5a. When the internal pressure of the battery exceeds a predetermined value, the thin-walled portion 5a breaks, releasing gas to the outside of the battery. The negative electrode current collector 6 contains, for example, copper, and may be made of an alloy containing copper and zinc, such as brass, and may have a surface that is plated, for example, with tin, if necessary.

[0045] The negative electrode current collector 6 is inserted into the negative electrode 3. The negative electrode current collector 6 has a nail-like shape with a head and a body, and the body is inserted into a through-hole provided in the central cylindrical portion of the gasket 5, and the head of the negative electrode current collector 6 is welded to the flat portion in the center of the negative electrode terminal plate 7. The open end of the battery case 1 is crimped to a flange portion on the periphery of the negative electrode terminal plate 7 via the outer peripheral end of the gasket 5. The outer surface of the battery case 1 is covered with an exterior label 8.

[0046] In Fig. 1, the cylindrical separator 4 with a bottom is formed using a cylindrical separator 4a and a bottom paper 4b, but the cylindrical separator with a bottom is not limited to this, and any separator with a known shape used in the field of alkaline batteries may be used. The separator may be formed from a single sheet, or, if the sheets constituting the separator are thin, it may be formed by overlapping multiple sheets. The cylindrical separator may also be formed by winding a thin sheet multiple times.

[0047] [Examples] Hereinafter, the present disclosure will be specifically described based on examples and comparative examples, but the present disclosure is not limited to the following examples.

[0048] Example 1 An AA-size cylindrical alkaline battery (LR6) shown in FIG. 1 was fabricated according to the following procedure. (Fabrication of Positive Electrode) Graphite powder (average particle size 8 μm), a conductive agent, was added to electrolytic manganese dioxide powder (average particle size 35 μm), a positive electrode active material, to obtain a mixture. The mass ratio of electrolytic manganese dioxide powder to graphite powder was 92.4:7.6. 1.5 parts by mass of electrolyte was added to 100 parts by mass of the mixture, thoroughly stirred, and then compression-molded into flakes to obtain a positive electrode mixture. The electrolyte was an alkaline aqueous solution containing potassium hydroxide (concentration 35% by mass) and zinc oxide (concentration 2% by mass).

[0049] The flake-like positive electrode mixture was crushed into granules, which were then classified using a 10 to 100 mesh sieve. The granules were then pressure-molded into a predetermined hollow cylindrical shape to produce two positive electrode pellets.

[0050] (Preparation of Negative Electrode) A negative electrode active material, an electrolyte, a gelling agent, a phthalic acid compound, and a gallium compound were mixed to obtain a gelled negative electrode 3. The negative electrode active material was a zinc alloy powder (average particle size 130 μm) containing 0.02% by mass of indium, 0.01% by mass of bismuth, and 0.005% by mass of aluminum. The electrolyte was the same as that used in preparing the positive electrode. The gelling agent was a mixture of cross-linked branched polyacrylic acid and highly cross-linked chain sodium polyacrylate. Terephthalic acid was used as the phthalic acid compound, and gallium oxyhydroxide (GaOOH) was used as the gallium compound. The mass ratio of the negative electrode active material, electrolyte, and gelling agent was 100:50:1.

[0051] The content of GaOOH in the negative electrode was 0.025 parts by mass per 100 parts by mass of the negative electrode active material. The content of phthalic acid in the negative electrode was 0.14 parts by mass per 100 parts by mass of the negative electrode active material. The molar ratio of Ga derived from GaOOH to Zn derived from the negative electrode active material in the negative electrode (Ga / Zn) was 0.00016. The molar ratio of Ga derived from GaOOH to terephthalic acid (Ga / terephthalic acid) was 0.29.

[0052] (Assembly of alkaline dry battery) A battery case 1 was obtained by forming a carbon coating approximately 10 μm thick on the inner surface of a bottomed cylindrical case (outer diameter 13.80 mm, height 50.3 mm) made of nickel-plated steel sheet. Two positive electrode pellets were inserted vertically into the battery case 1, and then pressure was applied to form a positive electrode 2 in close contact with the inner wall of the battery case 1. A bottomed cylindrical separator 4 was placed inside the positive electrode 2, and then an electrolyte solution was injected to impregnate the separator 4. The electrolyte solution used was the same as that used to prepare the positive electrode. The battery was left in this state for a predetermined time, allowing the electrolyte solution to permeate through the separator 4 into the positive electrode 2. A predetermined amount of gelled negative electrode 3 was then filled inside the separator 4.

[0053] The separator 4 was constructed using a cylindrical separator 4a and a bottom paper 4b. The cylindrical separator 4a and the bottom paper 4b were made of nonwoven fabric sheets mainly composed of rayon fiber and polyvinyl alcohol fiber in a mass ratio of 1:1. The thickness of the nonwoven fabric sheet used for the bottom paper 4b was 0.27 mm. The separator 4a was constructed by rolling a nonwoven fabric sheet with a thickness of 0.09 mm three times.

[0054] The negative electrode current collector 6 was obtained by pressing a common brass piece into a nail shape and then tin-plating the surface. The head of the negative electrode current collector 6 was electrically welded to a negative electrode terminal plate 7 made of nickel-plated steel. The body of the negative electrode current collector 6 was then press-fitted into the central through-hole of a resin gasket 5. In this way, a sealing unit 9 consisting of the gasket 5, the negative electrode terminal plate 7, and the negative electrode current collector 6 was produced.

[0055] Next, a sealing unit 9 was placed in the opening of the battery case 1. At this time, the body of the negative electrode current collector 6 was inserted into the negative electrode 3. The open end of the battery case 1 was crimped to the peripheral edge of the negative electrode terminal plate 7 via a gasket 5, thereby sealing the opening of the battery case 1. The outer surface of the battery case 1 was covered with an exterior label 8. In this manner, an alkaline dry battery (Battery A1) was produced. Battery A1 was evaluated as follows.

[0056] [Evaluation] Ten assembled batteries A1 were prepared, and the AC resistance (mΩ) was measured at a frequency of 1 kHz in an environment of 25° C. The difference between the maximum and minimum measured values ​​was calculated as the variation in internal resistance after assembly.

[0057] Thereafter, the ten batteries A1 were stored at 45° C. for three days for aging. The AC resistance of the ten batteries A1 after aging was measured in the same manner, and the difference between the maximum and minimum measured values ​​was calculated as the variation in internal resistance after aging.

[0058] Comparative Example 1 Battery B1 was fabricated and evaluated in the same manner as Battery A1, except that terephthalic acid was not added in the preparation of the negative electrode.

[0059] Comparative Example 2 Battery B2 of Comparative Example 2 was produced and evaluated in the same manner as Battery A1, except that gallium oxyhydroxide was not added in the production of the negative electrode.

[0060] Comparative Example 3 Battery B3 of Comparative Example 3 was produced and evaluated in the same manner as Battery A1, except that terephthalic acid and gallium oxyhydroxide were not added in the production of the negative electrode.

[0061] The evaluation results are shown in Table 1. In each table, the contents of GaOOH and terephthalic acid are shown as amounts (parts by mass) per 100 parts by mass of the negative electrode active material.

[0062]

[0063] For Battery A, the variation in internal resistance was kept small even after aging, just as it was after assembly (before aging), and the increase in variation in internal resistance after aging was significantly suppressed. For Batteries B1 and B2, the variation in internal resistance increased after aging. For Battery B3, the variation in internal resistance increased both after assembly and after aging.

[0064] In both the battery B1 using only a gallium compound and the battery B2 using only a phthalic acid compound, the variation in internal resistance after aging was shown to increase, similar to that in the case of battery B3 (B3 → B1, B3 → B2).

[0065] Examples 2 to 4 Batteries A2 to A4 of Examples 2 to 4 were fabricated and evaluated in the same manner as Battery A1, except that the GaOOH content in the negative electrode was set to the value shown in Table 2. In Batteries A1 to A4, the molar ratio of Ga derived from GaOOH to Zn derived from the negative electrode active material in the negative electrode (Ga / Zn) was in the range of 0.00003 to 0.00064. The molar ratio of Ga derived from GaOOH to terephthalic acid (Ga / terephthalic acid) was in the range of 0.06 to 1.16. The evaluation results are shown in Table 2, along with those of Battery A1.

[0066]

[0067] In all of the batteries A1 to A4, the variation in internal resistance after aging was significantly reduced and was kept at approximately the same level as the variation in internal resistance after assembly.

[0068] The alkaline dry battery according to the present disclosure is suitable for use as a power source for, for example, portable audio devices, electronic games, lights, and the like.

[0069] While the present invention has been described in terms of presently preferred embodiments, such disclosure is not to be interpreted as limiting. Various changes and modifications will no doubt become apparent to those skilled in the art to which the present invention pertains upon reading the above disclosure. It is therefore intended that the appended claims be interpreted to cover all changes and modifications that do not depart from the true spirit and scope of the invention.

[0070] 1: battery case, 2: positive electrode, 3: negative electrode, 4: cylindrical separator with bottom, 4a: cylindrical separator, 4b: bottom paper, 5: gasket, 5a: thin portion, 6: negative electrode current collector, 7: negative electrode terminal plate, 8: exterior label, 9: sealing unit

Claims

1. a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte solution contained in the positive electrode, the negative electrode, and the separator; The alkaline dry battery, wherein the negative electrode comprises a negative electrode active material containing zinc, a phthalic acid compound, and a gallium compound.

2. 2. The alkaline battery according to claim 1, wherein the gallium compound comprises at least one of gallium oxide and gallium hydroxide.

3. 3. The alkaline battery according to claim 2, wherein the gallium compound comprises gallium oxyhydroxide.

4. The alkaline dry battery according to any one of claims 1 to 3, wherein the content of the gallium compound in the negative electrode is 0.005 parts by mass or more and 0.1 parts by mass or less per 100 parts by mass of the negative electrode active material.

5. 4. The alkaline dry battery according to claim 1, wherein the phthalic acid compound includes at least one selected from the group consisting of o-phthalic acid, isophthalic acid, and terephthalic acid.

6. The alkaline dry battery according to claim 5 , wherein the phthalic acid compound comprises terephthalic acid.

7. 4. The alkaline dry battery according to claim 1, wherein the content of the phthalic acid compound in the negative electrode is 0.05 parts by mass or more and 0.3 parts by mass or less per 100 parts by mass of the negative electrode active material.