JP2007026716A - Alkaline dry cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alkaline dry cell in which fall-off of a sealing body is prevented when a short circuit or a trouble in charge or the like occurs and which is superior in high-rate characteristics. <P>SOLUTION: The alkaline dry cell is equipped with a bottomed and cylindrical positive electrode can 1 with a thickness of its trunk part 6 of 0.185 mm or more and 0.215 mm or less and with a thickness of its opening part 5 of 1.1 times or more and 1.85 times or less of the thickness of the trunk part 6, a bag-shaped separator 11 arranged in the positive electrode can 1, a gelatinous negative electrode 15 filled into the separator 11, a positive electrode mixture 10 which is arranged between the inner peripheral face of the positive electrode can 1 and the separator 11 and which contains nickel oxyhydroxide, and the sealing body arranged at the opening part 5 of the positive electrode can 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an alkaline battery.

  The use of ultra-heavy loads or heavy loads such as notebook personal computers, CD players, MD players, portable AV equipment such as liquid crystal televisions, and mobile phones has been required for recent alkaline batteries. For this reason, a capacity increase has been attempted as compared with the former battery. For example, in an alkaline battery, an increase in the content of a positive electrode active substance in the positive electrode mixture, an increase in the amount of the negative electrode active substance in the negative electrode gel, and a reduction in the thickness of the positive electrode can base material have been attempted. For this reason, in the unlikely event that a failure such as a short circuit occurs in the battery (for example, heat generation and gas generation), the capacity increases, and the conventional positive electrode can with a uniform thickness causes such a failure. When this happens, it is becoming difficult to maintain the sealing properties.

  In the alkaline battery, when gas is generated due to a short circuit, a safety valve attached to the resin sealing body is activated to ensure safety. However, in recent years, batteries for heavy load characteristics, for which demand is increasing, have a high gas generation rate when a malfunction occurs, and the sealing body may occasionally come off before valve operation.

  In Patent Document 1, in order to increase the internal volume of a battery and prevent leakage due to expansion and contraction of the sealing body resin due to a rapid temperature change, the thickness of the body portion is less than 0.18 mm, and the sealing It is described that the outer can made of a killed steel plate whose thickness is 1.4 times or more of the thickness of the body portion is described.

  However, the outer can of Patent Document 1 cannot solve the problem that the sealing body comes off when gas is generated.

In Patent Document 2, the base material of the metal case is plated with nickel or nickel alloy (Ni—Co, Ni—Ag), and the thickness of the opening of the metal case exceeds the thickness of the base material. The thickness of the base of the metal case is 120% or less, the thickness of the body of the metal case is 60% to 100% of the thickness of the base, and the Vickers hardness of the metal case is specified within a specific range. Describes improving the sealing strength.
JP 2002-151017 A JP-A-9-312150

  An object of the present invention is to provide an alkaline dry battery that prevents the sealing body from coming off when a malfunction such as a short circuit or charging occurs and is excellent in heavy load characteristics.

The alkaline dry battery according to the present invention has a body thickness of 0.185 mm or more and 0.215 mm or less, and an opening thickness of 1.1 times or more and 1.85 times or less of the thickness of the body part. A bottomed cylindrical positive electrode can,
A bag-shaped separator disposed in the positive electrode can;
A gelled negative electrode filled in the separator;
A positive electrode mixture that is disposed between the inner peripheral surface of the positive electrode can and the separator, and contains nickel oxyhydroxide,
And a sealing body disposed in the opening of the positive electrode can.

  ADVANTAGE OF THE INVENTION According to this invention, the alkaline dry battery which is prevented from detaching | sealing of the sealing body at the time of malfunctions, such as a short circuit and charge, and is excellent in a heavy load characteristic can be provided.

  The alkaline dry battery according to the present invention has a body thickness of 0.185 mm or more and 0.215 mm or less, and an opening thickness of 1.1 times or more and 1.85 times or less of the thickness of the body part. A certain bottomed cylindrical positive electrode can is provided.

  Alkaline batteries equipped with a positive electrode using nickel oxyhydroxide as the positive electrode active substance have excellent heavy load characteristics, but on the other hand, the amount of heat generated and the amount of gas generated by a large current flowing due to short circuit or charging increase. Is easily deformed, and the sealing body is easily removed.

  According to the positive electrode can, it is possible to improve the pressure strength of the opening while suppressing buckling deformation at the time of manufacturing the positive electrode can. As a result, it is possible to suppress the deformation of the opening even during a sudden gas generation caused by nickel oxyhydroxide, and to prevent the sealing body from coming off. Therefore, it is possible to realize an alkaline battery excellent in heavy load characteristics and sealing properties.

  About the opening part and trunk | drum of a positive electrode can, the part from an opening end to a bead part is an opening part, and a part from a bead part to a bottom face is a trunk | drum. When the thickness of the body portion is less than 0.185 mm, buckling deformation is likely to occur when producing the positive electrode can, and the omission of the sealing body at the time of gas generation increases. On the other hand, when the thickness of the body exceeds 0.215 mm, a high capacity cannot be obtained.

  When the thickness of the opening is less than 1.1 times the thickness of the body, the buckling deformation at the time of producing the positive electrode can increases, and the omission of the sealing body at the time of gas generation also increases. On the other hand, when it exceeds 1.85 times, buckling deformation at the time of producing a positive electrode can increases. A more preferable range is 1.1 times or more and 1.4 times or less.

  As for the thickness of the trunk and the thickness of the opening, the thicknesses of three arbitrary positions are measured in the trunk and the opening, respectively, and the average values are obtained.

  The base material constituting the positive electrode can is a steel plate, and it is desirable that a Ni layer or a Ni alloy layer be formed on the surface of the base material. From the viewpoint of reducing the amount of gas generated, a NiFe-containing alloy layer is preferable. The NiFe-containing alloy layer may be formed before drawing or after drawing, but it is desirable to perform the drawing before drawing in order to uniformly form the alloy layer. As a preferred method for producing a positive electrode can, after nickel plating on both surfaces of a steel plate, a heat treatment is performed to react the Fe component of the steel plate with a nickel plating layer to form a Ni-Fe alloy plating layer, followed by drawing. Is mentioned.

  The NiFe-containing alloy layer may be formed of an alloy composed of two components of Ni and Fe, or may be formed of an alloy of three or more components containing elements other than Ni and Fe (for example, Co, Ag, etc.). good. In order to improve the adhesion to the substrate, an alloy layer composed of two components of Ni and Fe is desirable.

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

1) Positive electrode mixture The positive electrode mixture contains nickel oxyhydroxide as a positive electrode active substance, and can contain a conductive agent and a binder as necessary. As the positive electrode active substance, only nickel oxyhydroxide may be used, but in order to obtain a high capacity, it is desirable to use manganese dioxide in combination. When a mixture of nickel oxyhydroxide and manganese dioxide is used, the content of nickel oxyhydroxide in the positive electrode active material is preferably 40% by weight or more and 100% by weight or less. On the other hand, examples of the conductive agent include carbon materials such as graphite. In order to increase the capacity, the carbon material content in the positive electrode mixture is preferably 3 to 10% by weight.

2) Gelled negative electrode For the gelled negative electrode, for example, a gelled zinc negative electrode containing a non-catalyzed zinc alloy powder, an alkaline electrolyte and a gelling agent (for example, polyacrylic acid) can be used.

3) Separator Examples of the separator include an insulating porous sheet such as a nonwoven fabric. The separator is preferably formed from a hydrophilic material.

  An embodiment of the alkaline dry battery of the present invention will be described with reference to FIG.

  The positive electrode can (positive electrode container) 1 has a bottomed cylindrical shape, and the bottom surface protrudes 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. In the positive electrode can 1, the opening 5 is from the opening end 4 to the bead portion 3, and the body 6 is from the bead 3 to the positive electrode terminal 2 on the bottom surface. As shown in FIG. 2, the plate material 7 forming the positive electrode can 1 is formed on the base material 8 made of a steel plate, the plating layer 9 a formed on the inner surface side of the base material 8, and the surface side of the base material 8. A plated layer 9b. The thickness of the body 6 of the positive electrode can 1 is 0.185 mm or more and 0.215 mm or less, and the thickness of the opening 5 is 1.1 times or more and 1.85 times or less of the thickness of the body 6. is there.

  A conductive film (not shown) mainly composed of graphite powder is formed on the plating layer 9 a of the body 6 of the positive electrode can 1.

  The cylindrical positive electrode mixture 10 is accommodated in the positive electrode can 1, and the outer peripheral surface thereof is in contact with the conductive coating on the inner surface of the positive electrode can 1. The positive electrode mixture 10 can be obtained, for example, by mixing a positive electrode active substance containing nickel oxyhydroxide and a conductive agent, and pressing the mixture into a hollow cylinder with a predetermined pressure using a molding die. The bottomed cylindrical separator 11 is in contact with the inner peripheral surface of the positive electrode mixture 10.

  A sealing body is disposed in the opening 5 of the positive electrode can 1. The sealing body includes a double annular insulating gasket 12 and a negative terminal plate 13. The insulating gasket 12 is disposed in the positive electrode can 1 so as to close the opening of the separator 11. The outer peripheral surface of the insulating gasket 12 is in contact with the opening 5 of the positive electrode can 1 and the inner surface of the bead portion 3. The insulating gasket 12 is made of a polyamide resin such as nylon 6 or 6, for example. The negative terminal plate 13 is caulked and fixed to the opening of the positive electrode can 1 via an insulating gasket 12. The negative electrode terminal plate 13 can be formed of a metal such as a cold rolled steel plate material on which a nickel plating or nickel alloy plating layer is formed. The metal washer 14 is interposed between the double annular portions of the insulating gasket 12.

  The gelled negative electrode 15 is filled in the separator 11. For example, the negative electrode current collector rod 16 made of brass is fixed to the inner surface of the negative electrode terminal plate 13, penetrates through the insulating gasket 12, and the tip is inserted into the gelled negative electrode 15.

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

Example 1
After performing nickel plating on both surfaces of the cold rolled steel sheet material, a Ni—Fe alloy plating layer was formed by heat treatment. By subjecting the obtained plate material to a drawing process, a bottomed cylindrical positive electrode can having a body thickness of 0.185 mm and an opening thickness of 1.25 times the body thickness was produced.

  A conductive film mainly composed of graphite powder was formed on the inner surface of the positive electrode can except for the portion in contact with the gasket of the opening. The conductive coating is applied by diluting a conductive paint mainly composed of graphite powder with a low-boiling organic solvent such as methyl ethyl ketone, and spraying it on the inner surface of the positive electrode can with a spray gun. It was made not to apply to the part which touches the gasket of the part. After applying the conductive paint with a spray gun, the solvent was evaporated with a dryer. The thickness of the remaining conductive film is preferably about 1 to 10 μm.

  Graphite powder is mixed with a positive electrode active material composed of 40% by weight of manganese dioxide powder and 60% by weight of nickel oxyhydroxide powder so that the content in the positive electrode mixture is 7% by weight, and this is mixed with a mold. A positive electrode mixture was obtained by pressure forming into a hollow cylindrical shape at a predetermined pressure.

  A bottomed cylindrical separator made of a nonwoven fabric of vinylon and polyvinyl alcohol (PVA) fibers was prepared.

  A non-glazed zinc alloy powder, an alkaline electrolyte, and polyacrylic acid as a gelling agent were mixed to obtain a gelled zinc negative electrode.

  A JIS standard LR6 type (AA) alkaline dry battery shown in FIG. 1 was assembled using a positive electrode can, a positive electrode mixture, a separator, and a gelled zinc negative electrode on which a conductive film was formed.

(Examples 2-3 and Comparative Examples 1-4)
An alkaline dry battery having the same configuration as that described in Example 1 was assembled except that the barrel thickness and the ratio of the opening thickness to the barrel thickness were set as shown in Table 1 below.

1000 pieces were prepared for each of the above alkaline batteries, and the presence or absence of buckling deformation was examined by appearance inspection. Moreover, 1000 pieces were newly prepared for each type, and the number of omissions of the sealing body when charged at 600 mA was investigated. Furthermore, 20 pieces were newly prepared for each type, and the capacity (mAh) when discharged with a load of 1200 mAP (pulse) was measured. The results are shown in Table 1 below.

  As is apparent from Table 1, in Examples 1 to 3 having a body thickness of 0.185 mm or more and 0.215 mm or less, there are few buckling deformations and omissions of the sealing body, and high capacity is obtained in heavy load discharge. It was.

  On the other hand, in Comparative Examples 1 and 2 having a body thickness of less than 0.185 mm, buckling deformation and omission of the sealing body were more than in Examples 1 to 3. Further, in Comparative Examples 3 and 4 where the body thickness exceeded 0.215 mm, there was no problem in appearance and sealing, but there was a disadvantage in capacity.

  From the results of Table 1, it is considered that the thickness of the body portion of the positive electrode can is 0.185 mm or more and 0.215 mm or less.

  Subsequently, the body thickness was kept constant at 0.200 mm, and the same examination was performed with respect to the magnification (0.8 to 2.15 times) of the opening thickness with respect to the body thickness.

(Examples 4-9 and Comparative Examples 5-8)
An alkaline dry battery having the same configuration as described in Example 1 was assembled except that the ratio of the opening thickness to the opening thickness and the trunk thickness was set as shown in Table 2 below.

About the obtained alkaline dry battery, the presence or absence of buckling deformation by visual inspection, the number of seals removed, and the capacity when discharged with a load of 1200 mAP were measured under the conditions described above, and the results are shown in Table 2 below.

  As is clear from Table 2, according to Examples 4 to 9 in which the magnification of the opening thickness with respect to the body thickness is 1.1 times or more and 1.85 times or less, buckling deformation and omission of the sealing body are small. In addition, a high capacity was obtained in heavy load discharge.

  On the other hand, in Comparative Examples 5 and 6 having a magnification of less than 1.1 times, buckling deformation and omission of the sealing body were more than in Examples 4 to 9. Moreover, in Comparative Examples 7 and 8 in which the magnification exceeded 1.85 times, the sealing body did not come off, but the buckling deformation was greater than in Examples 4 to 9.

  From the results in Table 2, it is considered appropriate that the magnification of the opening thickness relative to the body thickness is 1.1 times or more and 1.85 times or less. Among them, the ratio of 1.1 times or more and 1.4 times or less is preferable because there is no probability of occurrence of buckling deformation.

(Example 10)
An alkaline dry battery having the same configuration as that described in Example 2 was assembled except that only nickel oxyhydroxide was used as the positive electrode active substance.

(Comparative Examples 9-13)
An alkaline dry battery having the same configuration as that described in Example 1 was assembled except that the barrel thickness and the ratio of the opening thickness to the barrel thickness were set as shown in Table 3 below.

(Comparative Example 14)
An alkaline dry battery having the same configuration as that described in Comparative Example 11 was assembled except that only manganese dioxide was used as the positive electrode active substance.

(Comparative Example 15)
An alkaline dry battery having the same configuration as that described in Example 2 was assembled except that only manganese dioxide was used as the positive electrode active substance.

With respect to the obtained alkaline dry battery, the presence or absence of buckling deformation by appearance inspection, the number of seals removed, and the capacity when discharged with a load of 1200 mAP were measured under the above-mentioned conditions, and the results are shown in Table 3 below.

  As is apparent from Table 3, the barrel thickness is 0.185 mm or more and 0.215 mm or less, the magnification of the opening thickness with respect to the barrel thickness is 1.1 times or more and 1.85 times or less, and oxywater According to Examples 1 to 11 using nickel oxide, the buckling deformation and the number of occlusions of the sealing body were small, and a high capacity was obtained in heavy load discharge.

  On the other hand, in Comparative Examples 9 and 10 in which the body thickness was less than 0.185 mm, the external body was buckled because the body was thin, and it was not possible to make a standard battery. Further, in Comparative Example 9 with a magnification of 1.1 times, the sealing body is also missing. As for Comparative Examples 11 and 12, even when the body thickness is optimal, if the aperture is thin with a magnification of less than 1.1 times, or the aperture is thick with a magnification exceeding 1.85 times, A problem has occurred, and the sealing body has also been removed for thin objects. In Comparative Example 13 in which the body thickness exceeded 0.215 mm, the capacity was inferior although there was no buckling deformation and no sealing body removal.

  On the other hand, in Comparative Examples 14 and 15 in which only manganese dioxide is used as the positive electrode active substance, since the amount of gas generated during charging is small, Comparative Example 15 using a positive electrode can having the same configuration as in Example 2 and Comparative Example 11 There was no difference in the number of occlusions of the sealing body in Comparative Example 14 using the positive electrode can having the same configuration as in FIG. Moreover, the heavy load discharge characteristics were inferior.

  As described above, the positive electrode can body thickness is 0.185 mm or more and 0.215 mm or less, and the positive electrode can opening portion thickness is 1.1 times or more and 1.85 times or less of the body thickness. Alkaline battery with excellent safety, heavy-load discharge characteristics and sealing performance, which can prevent the sealing body from falling out when nickel oxyhydroxide is used as the positive electrode active substance, despite the fact that the thickness of the opening is made thinner Can be provided.

  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.

1 is a schematic cross-sectional view showing an embodiment of an alkaline dry battery of the present invention. The typical sectional view about the board material which constitutes the positive electrode can of the alkaline dry battery of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Positive electrode can, 2 ... Positive electrode terminal, 3 ... Bead part, 4 ... Open end, 5 ... Opening part, 6 ... Trunk part, 7 ... Plate material, 8 ... Base material, 9a, 9b ... Plating layer, 10 ... Positive electrode combination Agent: 11 ... Separator, 12 ... Insulating gasket, 13 ... Negative electrode terminal plate, 14 ... Metal washer, 15 ... Gelled negative electrode, 16 ... Negative electrode current collector rod.

Claims (3)

Bottomed cylindrical positive electrode can having a body thickness of 0.185 mm or more and 0.215 mm or less and an opening thickness of 1.1 times or more and 1.85 times or less of the thickness of the body part When,
A bag-shaped separator disposed in the positive electrode can;
A gelled negative electrode filled in the separator;
A positive electrode mixture containing nickel oxyhydroxide, disposed between the inner peripheral surface of the positive electrode can and the separator;
An alkaline dry battery comprising: a sealing member disposed in the opening of the positive electrode can.   2. The alkaline dry battery according to claim 1, wherein a thickness of the opening is 1.1 times or more and 1.4 times or less of a thickness of the body part.   The alkaline dry battery according to claim 1 or 2, wherein the positive electrode mixture contains nickel oxyhydroxide and manganese dioxide.

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