alkaline batteries

Abstract

An alkaline dry battery according to the present invention is provided with: a cylindrical case having a bottom; a hollow cylindrical positive electrode that is in contact with the interior of the case; a negative electrode that fills the hollow section of the positive electrode and that contains a negative-electrode active material containing zinc; a separator disposed between the positive electrode and the negative electrode; an alkaline electrolytic solution contained in the positive electrode, the negative electrode, and the separator; and a sealing unit that covers an opening of the case. A gap between the negative electrode and the sealing unit and / or a gap between the negative electrode and the bottom of the case is filled with an additive agent. The additive agent contains an organic acid with a melting point of 90°C or more.

Description

[Technical Field]

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

[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 proposes that in an inside-out alkaline battery, a resin swollen with an electrolyte is placed on top of the positive electrode mixture and gelled zinc on the opening side of the positive electrode can. Patent Document 2 proposes incorporating terephthalic acid of a specific particle size into the gelled negative electrode. This prevents internal short circuits when the battery is subjected to a strong impact. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-275624 [Patent Document 2] International Publication No. 2018 / 066204 Brochure Summary of the Invention

[0005] There is a demand for further improvements in safety of alkaline batteries by suppressing temperature rise during an external short circuit.

[0006] One aspect of the present disclosure provides a battery comprising: a cylindrical case with a bottom; a hollow cylindrical positive electrode inscribed in the case; a negative electrode filled in a hollow portion of the positive electrode and including a negative electrode active material containing zinc; a separator disposed between the positive electrode and the negative electrode; an alkaline electrolyte contained in the positive electrode, the negative electrode, and the separator; and a sealing unit that covers an opening of the case; The alkaline dry battery has an additive filled in the gap between the negative electrode and the sealing unit and / or the gap between the negative electrode and the bottom of the case, and the additive contains an organic acid having a melting point of 90°C or higher.

[0007] According to the present disclosure, it is possible to suppress a temperature rise in an alkaline dry battery when an external short circuit occurs. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a partially cross-sectional front view of an alkaline dry battery according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a partially cross-sectional front view of an alkaline dry battery according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] An alkaline dry battery according to an embodiment of the present disclosure includes a cylindrical case with a bottom, a hollow cylindrical positive electrode inscribed within the case, a negative electrode filled in the hollow portion of the positive electrode, a separator disposed between the positive electrode and the negative electrode, an alkaline electrolyte, and a sealing unit that covers the opening of the case. The negative electrode includes a negative electrode active material containing zinc. The alkaline electrolyte is contained in the positive electrode, the negative electrode, and the separator. An additive is filled in the gap between the negative electrode and the sealing unit and / or the gap between the negative electrode and the bottom of the case, and the additive includes an organic acid with a melting point of 90°C or higher. The melting point is a value measured by a general method described, for example, in Japanese Industrial Standards (JIS K0064) or the like.

[0010] When the temperature inside the battery rises due to an external short circuit, the organic acid filled adjacent to the negative electrode begins to melt and diffuses into the negative electrode, efficiently supplying protons to the electrolyte in the negative electrode, which reduces the hydroxide ion concentration in the electrolyte in the negative electrode. This causes the tetrahydroxide zincate ion ([Zn(OH)4] 2-) decreases, zinc oxide (ZnO) precipitates and coats the surface of the negative electrode active material, inhibiting the zinc elution reaction, which is the discharge reaction of the negative electrode, and suppressing the generation of short-circuit current and the accompanying temperature rise. In this way, by reducing the hydroxide ion concentration in the negative electrode during an external short circuit, the temperature rise of the battery (surface) during an external short circuit is effectively suppressed.

[0011] On the other hand, during normal use (storage) of the battery, the organic acid exists as a solid, which suppresses the diffusion of the organic acid into the negative electrode (reduction in the hydroxide ion concentration in the negative electrode), thereby achieving the desired discharge performance.

[0012] By filling the gaps, the additive is less likely to absorb the electrolyte (or swell as a result). It is desirable that the additive filled in a predetermined gap in the battery does not substantially contain the electrolyte. Most of the organic acids do not form salts with the alkali metals derived from the electrolyte, and are filled in a state that allows them to effectively supply protons to the negative electrode during an external short circuit. The molar ratio of the alkali metals present in the additive to the acidic groups derived from the organic acids present in the additive is, for example, 1 / 10 or less (or 1 / 15 or less).

[0013] By filling a predetermined gap adjacent to the gelled negative electrode in the battery with an additive containing an organic acid, the hydroxide ion concentration in the negative electrode can be reduced during an external short circuit. When an organic acid is added to the inside of the gelled negative electrode during production, it is not possible to control the hydroxide ion concentration to a low level only during a short circuit as described above.

[0014] When the melting point of the organic acid is 90°C or higher, the diffusion of the organic acid into the negative electrode during normal use of the battery is suppressed, and the organic acid can diffuse into the negative electrode during an external short circuit. From the viewpoint of battery safety and reliability, the melting point of the organic acid may be 100°C or higher, or may be 100°C or higher and 500°C or lower.

[0015] If the melting point of the organic acid is below 90°C, the organic acid may begin to melt and diffuse into the gel-like negative electrode during normal use, making it impossible to control the hydroxide ion concentration low only during short circuiting. In addition, in this case, the hydroxide ion concentration decreases during normal use, and discharge performance is likely to deteriorate.

[0016] Examples of organic acids include organic compounds having an acidic group such as a carboxy group or a sulfonic acid group. The organic acid molecule may have an aromatic group or an aliphatic group. The aromatic group may contain, for example, one benzene ring. The aliphatic group may contain a linear or branched hydrocarbon group. The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. Some of the hydrogen atoms bonded to the carbon atoms of the hydrocarbon group and some of the hydrogen atoms bonded to the aromatic ring may be substituted with a substituent such as a halogen atom. One organic acid may be used alone, or two or more organic acids may be used in combination.

[0017] The organic acid preferably contains a carboxylic acid. The carboxylic acid has, for example, four or less carboxy groups per molecule. From the viewpoint of efficiently supplying protons to the negative electrode during an external short circuit, a carboxylic acid having multiple (e.g., 2 to 4) carboxy groups per molecule is preferred. The carboxylic acid preferably contains at least one of a dicarboxylic acid (e.g., succinic acid, adipic acid, isophthalic acid, terephthalic acid) and a tricarboxylic acid (e.g., trimesic acid).

[0018] The carboxylic acid may be an aliphatic carboxylic acid or an aromatic carboxylic acid. Examples of aliphatic carboxylic acids include compounds in which a carboxy group is bonded to each end of a linear saturated hydrocarbon group (e.g., an alkylene group having 2 to 4 carbon atoms). Examples of such compounds include succinic acid, glutaric acid, adipic acid, oxalic acid, maleic acid, fumaric acid, tartaric acid, and citric acid.

[0019] Examples of aromatic carboxylic acids include compounds in which one to three carboxy groups are bonded to one benzene ring, such as phthalic acid (ortho-, meta-, and para-isomers), benzoic acid, benzenetricarboxylic acids (trimesic acid and trimellitic acid), and salicylic acid.

[0020] Preferred examples of the carboxylic acid include succinic acid, adipic acid, benzoic acid, isophthalic acid, terephthalic acid, trimesic acid, etc. One type of carboxylic acid may be used alone, or two or more types may be used in combination.

[0021] The amount of organic acid filled into a predetermined gap in the battery may be 20 mg or more and 2000 mg or less, or 40 mg or more and 2000 mg or less, per gram of zinc derived from the negative electrode active material. When the amount of organic acid is within the above range, it is easy to fill the predetermined gap in the battery with the organic acid, and it is easy to obtain the effect of suppressing temperature rise during an external short circuit by the organic acid.

[0022] The additive contains at least an organic acid, and may contain other components in addition to the organic acid. The other components may be components (e.g., polytetrafluoroethylene) that enhance the binding strength of the solid organic acid, and may be used in combination with the powdered organic acid. The additive filled into a predetermined gap in the battery may be in powder or pellet form. The pellets may be obtained, for example, by pressure molding a powdered organic acid or a mixture of a powdered organic acid and other components.

[0023] In addition, from the viewpoint of suppressing side reactions during normal use (at room temperature) and suppressing the electrolyte from permeating into the additive, a thin film for partial shielding (for example, cellophane) may be placed between the negative electrode and the additive.

[0024] The alkaline dry battery according to this embodiment will be described in detail below with reference to the drawings. Note that the present invention is not limited to the following embodiment. Furthermore, appropriate modifications are possible within the scope of the effects of the present invention. Furthermore, the present embodiment can be combined with other embodiments.

[0025] Fig. 1 is a front view of an alkaline dry battery according to one embodiment of the present disclosure, with half of the battery in cross section. Fig. 2 is a front view of an alkaline dry battery according to another embodiment of the present disclosure, with half of the battery in cross section. Figs. 1 and 2 show an example of a cylindrical battery having an inside-out structure. In Fig. 2, the same components as in Fig. 1 are designated by the same reference numerals.

[0026] As shown in FIG. 1, an alkaline dry battery includes a power generating element including a hollow cylindrical positive electrode 2, a gelled negative electrode 3 disposed within the hollow portion of the positive electrode 2, a separator 4 disposed between them, and an alkaline electrolyte. The power generating element is housed in a cylindrical metal case 1 with a bottom that also serves as the positive electrode terminal. For example, a nickel-plated steel plate is used for the case 1. The positive electrode 2 is disposed in contact with the inner wall of the case 1. To improve adhesion between the positive electrode 2 and the case 1, the inner surface of the case 1 is preferably coated with a carbon film.

[0027] The cylindrical separator 4 with a bottom 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, separating 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, separating the negative electrode 3 from the case 1.

[0028] The opening of the case 1 is sealed with a sealing unit 9. The sealing unit 9 includes a resin gasket 5, a negative electrode terminal plate 7 that also serves as a negative electrode terminal, and a negative electrode current collector 6. The negative electrode current collector 6 is inserted into the negative electrode 3. The negative electrode current collector 6 is made of a material such as an alloy containing copper and zinc, such as brass. The negative electrode current collector 6 may be plated with tin or other plating, as necessary. The negative electrode current collector 6 has a nail-like shape having a head and a body. The body is inserted into a through-hole provided in a 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.

[0029] The open end of the case 1 is crimped onto the flange on the periphery of the negative electrode terminal plate 7 via the outer peripheral end of the gasket 5. The outer surface of the case 1 is covered with an exterior label 8.

[0030] In the alkaline dry battery according to this embodiment, the gap between the gelled negative electrode 3 and the sealing unit 9 (the gap formed by the negative electrode 3, the negative electrode current collector 6 (the portion exposed from the negative electrode 3), and the gasket 5) is filled with an additive 10 containing an organic acid with a melting point of 90°C or higher. The additive 10 may be filled as a ring-shaped pellet containing the organic acid. In this case, the body of the negative electrode current collector 6 is disposed in the hollow portion of the pellet. By filling the additive 10 adjacent to the negative electrode 3, the organic acid contained in the additive 10 can quickly diffuse into the negative electrode 3 in the event of an external short circuit. From the viewpoint of preventing the electrolyte in the negative electrode from permeating into the additive during normal use, it is preferable to fill the additive 10 as a pellet. Because the separator 4a adjacent to the additive 10 holds the electrolyte, the electrolyte in the separator 4a is less likely to permeate into the additive 10.

[0031] As shown in FIG. 2, the gap between the gelled negative electrode 3 and the bottom of the case 1 (the gap formed by the protruding portion of the positive electrode terminal at the bottom) may be filled with an additive 20 containing an organic acid with a melting point of 90°C or higher. By filling the additive 20 adjacent to the negative electrode 3 via the bottom paper 4b, the organic acid contained in the additive 20 can quickly diffuse into the negative electrode 3 in the event of an external short circuit. The additive 20 may be in powder or pellet form. The bottom paper 4 adjacent to the additive 20 holds the electrolyte, making it difficult for the electrolyte to penetrate the additive 20.

[0032] The additive 20 of Fig. 2 may be filled together with the additive 10 of Fig. 1. From the viewpoint of suppressing side reactions during normal use (at room temperature) and suppressing penetration of the electrolyte into the additive, a thin film for partial shielding (e.g., cellophane) may be disposed between the gelled negative electrode 3 and the additive 10 and / or between the gelled negative electrode 3 and the additive 20 (at the position of the bottom paper 4b).

[0033] The positive electrode 2 contains manganese dioxide, which is a positive electrode active material, and an electrolyte. As the manganese dioxide, electrolytic manganese dioxide is preferred. The manganese dioxide is used in the form of powder. From the viewpoint of easily ensuring the filling property of the positive electrode and the diffusibility of the electrolyte within the positive electrode, the average particle size (D50) of the manganese dioxide is, for example, 20 μm or more and 60 μm or less. From the viewpoint of moldability and suppression of expansion of the positive electrode, the BET specific surface area of ​​the manganese dioxide is, for example, 20 m 2 / g or more, 50m 2 / g or less.

[0034] In this specification, the average particle size (D50) refers to the median diameter in a volume-based particle size distribution. The average particle size can be determined, for example, using a laser diffraction and / or scattering particle size distribution analyzer. The BET specific surface area is the 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 analyzer based on the nitrogen adsorption method.

[0035] The positive electrode 2 may contain a conductive agent in addition to manganese dioxide and an electrolyte. Examples of the conductive agent include carbon black such as acetylene black and conductive carbon materials such as graphite. Graphite can be natural graphite, artificial graphite, or the like. The conductive agent may be fibrous or the like, but is preferably powdered. The average particle size (D50) of the conductive agent can be selected, for example, from 5 nm to 50 μm. When the conductive agent is carbon black, the average particle size (D50) of the conductive agent is preferably 5 nm to 40 nm, and when the conductive agent is graphite, the average particle size (D50) of the conductive agent is preferably 3 μm to 50 μm. The content of the conductive agent in the positive electrode mixture is, for example, 3 parts by mass to 10 parts by mass, preferably 4 parts by mass to 8 parts by mass, per 100 parts by mass of manganese dioxide.

[0036] The positive electrode 2 can be obtained, for example, by press-molding a positive electrode mixture containing a positive electrode active material, a conductive agent, and an alkaline electrolyte into a pellet shape. The positive electrode mixture may be first formed into flakes or granules, classified as necessary, and then press-molded into a pellet shape. After being placed in a case, the pellets may be secondarily pressed using a predetermined tool so as to adhere to the inner wall of the case. The average density of manganese dioxide in the positive electrode pellets is, for example, 2.78 g / cm 3 More than 3.08g / cm 3 The positive electrode (positive electrode mixture) may further contain other components (for example, polytetrafluoroethylene) as necessary.

[0037] The negative electrode 3 has a gel-like form. That is, the negative electrode 3 typically contains a gelling agent in addition to a negative electrode active material and an electrolyte. The negative electrode active material contains zinc or a zinc alloy. From the viewpoint of corrosion resistance, the zinc alloy preferably contains at least one selected from the group consisting of indium, bismuth, and aluminum. The electrolyte can be the same as the electrolyte contained in the positive electrode pellet.

[0038] The negative electrode active material is usually used in powder form. From the viewpoint of the packing property of the negative electrode and the diffusibility of the alkaline electrolyte in the negative electrode, the average particle size (D50) of the negative electrode active material powder is, for example, 80 μm or more and 200 μm or less, preferably 100 μm or more and 150 μm or less. The content of the negative electrode active material powder in the negative electrode is, for example, 170 parts by mass or more and 220 parts by mass or less per 100 parts by mass of the electrolyte.

[0039] The gelling agent may be any known gelling agent used in the field of alkaline batteries, 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 parts by mass or less per 100 parts by mass of the negative electrode active material.

[0040] The separator 4 may be made of, for example, a nonwoven fabric or a microporous membrane. Examples of separator materials include cellulose and polyvinyl alcohol. The nonwoven fabric may be made primarily of fibers of these materials. The microporous membrane may be made of, for example, cellophane. The thickness of the separator is, for example, 80 μm or more and 300 μm or less. The separator may be made by stacking multiple sheets (such as nonwoven fabrics) so that the thickness falls within the above range.

[0041] 1, the bottomed cylindrical separator 4 is composed of a cylindrical separator 4a and a bottom paper 4b, but is not limited to this.A bottomed cylindrical one-piece separator may also be used, and separators of known shapes used in the field of alkaline batteries can be used.

[0042] The electrolyte may be, for example, an alkaline aqueous solution containing potassium hydroxide. 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. The content of the electrolyte in the positive electrode mixture is, for example, 4 parts by mass or more and 15 parts by mass or less per 100 parts by mass of manganese dioxide.

[0043] <Example> The present disclosure will be specifically described below based on examples and comparative examples, but the present invention is not limited to the following examples.

[0044] Example 1 An AA cylindrical alkaline battery (LR6) shown in Figure 1 was fabricated according to the following procedure.

[0045] [Preparation of positive electrode] A mixture was obtained by adding graphite powder (average particle size (D50) 8 μm) as a conductive agent to electrolytic manganese dioxide powder (average particle size (D50) 35 μm) as a positive electrode active material. 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).

[0046] The flake-like positive electrode mixture was crushed into granules, which were then classified using a 10 to 100 mesh sieve. 11 g of the resulting granules were then pressure-molded into a predetermined hollow cylindrical shape with an outer diameter of 13.65 mm to produce two positive electrode pellets.

[0047] [Preparation of negative electrode] A negative electrode active material, an electrolyte, and a gelling agent were mixed to obtain a gelled negative electrode 3. The negative electrode active material was a zinc alloy powder (particle size (D50) 130 μm) containing 0.02 mass% indium, 0.01 mass% bismuth, and 0.005 mass% aluminum. The electrolyte was the same as that used in the preparation of the positive electrode. The gelling agent was a mixture of cross-linked branched polyacrylic acid and highly cross-linked chain sodium polyacrylate. The mass ratio of the negative electrode active material, electrolyte, and gelling agent was 100:50:1.

[0048] [Assembling alkaline batteries] A bottomed cylindrical case (outer diameter 13.80 mm, cylindrical wall thickness 0.15 mm, height 50.3 mm) made of nickel-plated steel sheet was coated on its inner surface with Bunny Height (manufactured by Nippon Graphite Co., Ltd.) to form a carbon coating approximately 10 μm thick, yielding case 1. Two positive electrode pellets were inserted vertically into case 1, and then pressure was applied to form positive electrode 2 in close contact with the inner wall of case 1. A bottomed cylindrical separator 4 was placed inside positive electrode 2, and then an electrolyte was injected to impregnate separator 4. The electrolyte used was the same as that used to prepare the positive electrode. The case was left in this state for a predetermined time, allowing the electrolyte to permeate through separator 4 into positive electrode 2.

[0049] Thereafter, 6 g of the gelled negative electrode 3 was filled inside the separator 4. An additive 10 was placed on the negative electrode 3. The additive 10 was a ring-shaped pellet obtained by pressure molding a powdered organic acid listed in Table 1. The amount of organic acid filled was 40 mg per 1 g of zinc derived from the negative electrode active material.

[0050] 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 a nonwoven fabric sheet (basis weight 28 g / m) mainly composed of rayon fiber and polyvinyl alcohol fiber in a mass ratio of 1:1. 2 The thickness of the nonwoven fabric sheet used for the bottom paper 4b was 0.27 mm. The separator 4a was formed by rolling a nonwoven fabric sheet having a thickness of 0.09 mm three times.

[0051] The negative electrode current collector 6 was obtained by pressing ordinary brass (Cu content: approximately 65% ​​by mass, Zn content: approximately 35% by mass) into a nail shape and then tin-plating the surface. The diameter of the body of the negative electrode current collector 6 was 1.15 mm. The head of the negative electrode current collector 6 was electrically welded to a negative electrode terminal plate 7 made of nickel-plated steel plate. The body of the negative electrode current collector 6 was then press-fitted into the central through-hole of a gasket 5 made of polyamide resin. In this way, a sealing unit 9 consisting of the gasket 5, negative electrode terminal plate 7, and negative electrode current collector 6 was produced.

[0052] Next, a sealing unit 9 was placed in the opening of the case 1. At this time, the body of the negative electrode current collector 6 was passed through the hollow portion of the ring-shaped pellet (additive 10) and inserted into the negative electrode 3. The open end of the case 1 was crimped to the periphery of the negative electrode terminal plate 7 via a gasket 5, sealing the opening of the case 1. The outer surface of the case 1 was covered with an exterior label 8. In this way, an alkaline dry battery A1 was produced in which the gap between the negative electrode and the sealing unit was filled with additive.

[0053] Examples 2 to 6 Batteries A2 to A6 of Examples 2 to 6 were produced in the same manner as for battery A1 of Example 1, except that the compounds shown in Table 1 were used as organic acids.

[0054] Examples 7 and 8 Batteries A7 and A8 of Examples 7 and 8 were fabricated in the same manner as battery A1 of Example 1 and battery A4 of Example 4, respectively, except that the amount of organic acid filled was set to the value shown in Table 1.

[0055] Examples 9 and 10 Instead of filling with additive 10, a powdered organic acid was filled in the recess in the bottom of the case as additive 20. Except for the above, batteries A9 to A10 of Examples 9 and 10 (batteries shown in FIG. 2) in which an additive was filled in the gap between the negative electrode and the bottom of the case were fabricated in the same manner as batteries A7 to A8 of Examples 7 and 8.

[0056] Comparative Example 1 Battery X1 of Comparative Example 1 was produced in the same manner as Battery A1 of Example 1, except that no additive (organic acid) was filled in the gap between the negative electrode and the sealing unit.

[0057] Comparative Examples 2 to 6 Batteries X2 to X6 of Comparative Examples 2 to 6 were produced in the same manner as battery A1 of Example 1, except that instead of filling the gap between the negative electrode and the sealing unit with an additive (organic acid), a compound shown in Table 1 was contained in the negative electrode as an organic acid.

[0058] [evaluation] For each battery fabricated as described above, the surface temperature of the battery was measured when an external short circuit was applied, and the maximum temperature at that time was determined. The evaluation results are shown in Table 1. The loading amount in Table 1 is the amount (mg) of organic acid loaded per 1 g of zinc derived from the negative electrode active material contained in the negative electrode.

[0059] [Table 1]

[0060] In Batteries A1 to A10 of the examples, the temperature rise during external short - circuit was suppressed more than in Batteries X1 to X6 of the comparative examples. In Batteries A3 to A6 using aromatic carboxylic acids, the maximum temperature during external short - circuit was in the relationship of A6 < A4 and A5 < A3. In A3, benzoic acid (with 1 carboxy group per molecule) was used. In A4 and A5, terephthalic acid and isophthalic acid (with 2 carboxy groups per molecule) were used. In A6, trimesic acid (with 3 carboxy groups per molecule) was used. A tendency was observed that the greater the number of carboxy groups per molecule of the aromatic carboxylic acid, the greater the effect of suppressing the temperature rise during external short - circuit.

[0061] In Batteries X1 without filling additives and Batteries X2 to X6 with organic acids included in the negative electrode, the concentration of hydroxide ions in the negative electrode did not decrease during external short - circuit, so the battery temperature increased during external short - circuit.

Industrial Applicability

[0062] The alkaline dry battery according to the present disclosure is suitably used as a power source for, for example, portable audio devices, electronic games, lights, etc.

Explanation of Symbols

[0063] 1 case 2 positive electrode 3 negative electrode 4 bottomed cylindrical separator 4a cylindrical separator 4b bottom paper 5 gasket 6 negative electrode current collector 7 negative electrode terminal plate 8 exterior label 9 sealing unit 10, 20 additive

Claims

1. A cylindrical case with a bottom, a hollow cylindrical positive electrode inscribed in the case; a negative electrode containing a negative electrode active material containing zinc, the negative electrode being filled in a hollow portion of the positive electrode; a separator disposed between the positive electrode and the negative electrode; an alkaline electrolyte contained in the positive electrode, the negative electrode, and the separator; a sealing unit that covers the opening of the case; Equipped with an additive is filled inside the separator in the gap between the negative electrode and the sealing unit; the additive contains an organic acid having a melting point of 90°C or higher, the organic acid comprises a carboxylic acid; The alkaline dry battery, wherein the carboxylic acid includes at least one selected from the group consisting of succinic acid, adipic acid, benzoic acid, isophthalic acid, terephthalic acid, and trimesic acid.

2. 2. The alkaline dry battery according to claim 1, wherein the organic acid is contained in an amount of 20 mg or more and 2000 mg or less per 1 g of zinc derived from the negative electrode active material.

3. A cylindrical case with a bottom, a hollow cylindrical positive electrode inscribed in the case; a negative electrode containing a negative electrode active material containing zinc, the negative electrode being filled in a hollow portion of the positive electrode; a separator disposed between the positive electrode and the negative electrode; an alkaline electrolyte contained in the positive electrode, the negative electrode, and the separator; a sealing unit that covers the opening of the case; Equipped with an additive is filled in a gap between the negative electrode and the sealing unit and / or a gap between the negative electrode and a bottom of the case; the additive contains an organic acid having a melting point of 90°C or higher, the organic acid comprises a carboxylic acid; The alkaline dry battery, wherein the carboxylic acid includes at least one selected from the group consisting of succinic acid, adipic acid, benzoic acid, isophthalic acid, terephthalic acid, and trimesic acid.

4. An alkaline dry battery as described in Claim 3, wherein the organic acid is contained in an amount of 20 mg or more and 2000 mg or less per gram of zinc derived from the negative electrode active material.

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