JP2011119153A - Alkaline battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent leakage of an alkaline electrolyte under high temperature and high humidity by preventing movement of the alkaline electrolyte to the opening side of a battery case through between a negative current collector and a gasket under high temperature and high humidity and delaying the time of the movement. <P>SOLUTION: An opening 1a of a battery case 1 is sealed with a negative terminal plate 7 to which a negative current collector 6 is connected and a gasket 5. The negative current collector 6 has a shaft part 61 and a flange part 62, one end of the shaft part 61 is placed inside a negative electrode 3, and the flange part is formed at the other end of the shaft part. The gasket 5 is made of polyamide resin, and has a cylindrical part into which the shaft part 61 of the negative current collector 6 is pressure-inserted. The negative terminal plate 7 is arranged on the opposite side to the cylindrical part 51 in the flange part 62. The cylindrical part 51 of the gasket 5 and the flange part 62 of the negative current collector 6 are arranged at some intervals. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an alkaline battery.

  Alkaline batteries are widely used as a power source for various devices because they are versatile and inexpensive. In an alkaline battery, a positive electrode, a negative electrode, a separator, and an alkaline electrolyte are accommodated in a battery case (positive electrode terminal), and the opening of the battery case is sealed with a nail-shaped negative electrode current collector, a negative electrode terminal plate, and a gasket. ing. Specifically, one end of the negative electrode current collector is press-fitted into a gasket and inserted into the negative electrode, and the other end of the negative electrode current collector is welded to the inner surface of the negative electrode terminal plate. The negative electrode terminal plate is caulked to the opening of the battery case via a gasket.

By the way, the malfunction that alkaline electrolyte solution leaks under high temperature and humidity is known. The reason for this failure is that the operating potential of the negative electrode changes due to the preferential generation of OH ⁻ on the meniscus, so that the alkaline electrolyte passes between the negative electrode current collector and the gasket and opens the battery case. It is thought that it is because it moves to.

  The alkaline electrolyte is a strong alkali. In Patent Document 1, the boundary between the inner surface of the negative electrode terminal plate and the end surface of the negative electrode current collector rod is covered with a sealing agent containing polybutene, so that the welding point between the inner surface of the negative electrode terminal plate and the end surface of the negative electrode current collector rod becomes alkaline electrolytic. Prevents being corroded by liquid.

  Moreover, in patent document 2, the neutralizing agent layer for neutralizing alkaline electrolyte in the outer peripheral part of the part to which the head part (saddle part) of the negative electrode collector is welded among the inner surface sides of a negative electrode terminal board. Is provided. Thereby, since the alkaline electrolyte which moved to the opening side of the battery case is neutralized, leakage of the alkaline electrolyte under high temperature and high humidity is prevented or the timing of leakage is delayed.

JP 2007-157585 A Japanese Patent Application Laid-Open No. 07-122248

  However, even if each technique disclosed in Patent Documents 1 and 2 is used, the alkaline electrolyte is prevented from moving to the opening side of the battery case through the gap between the negative electrode current collector and the gasket under high temperature and high humidity. It is difficult to delay the movement time.

  This invention is made | formed in view of this point, The place made into the objective is that alkaline electrolyte moves to the opening side of a battery case through between a negative electrode collector and a gasket under high temperature and humidity. This is to prevent this or to delay the moving time, thereby preventing leakage of the alkaline electrolyte under high temperature and high humidity.

  In the alkaline battery according to the present invention, the positive electrode, the negative electrode, the separator, and the electrolytic solution are accommodated in the battery case, and the opening of the battery case is sealed by the negative electrode terminal plate to which the negative electrode current collector is connected and the gasket. Yes. The negative electrode current collector has a shaft portion and a flange portion, one end side of the shaft portion is provided in the negative electrode, and a flange portion is provided at the other end of the shaft portion. The gasket is made of polyamide resin and has a cylindrical portion into which the shaft portion of the negative electrode current collector is press-fitted. The negative electrode terminal plate is disposed on the opposite side of the cylindrical portion with respect to the flange portion. The cylindrical portion of the gasket and the flange portion of the negative electrode current collector are disposed with a gap therebetween.

Under high temperature and high humidity, moisture in the air enters the battery case. Moisture in the air that has entered the battery case adheres to the surface of the collar portion of the negative electrode current collector or enters the gasket. In the alkaline battery according to the present invention, it is possible to avoid contact between the flange portion of the negative electrode current collector on which moisture in the air adheres to the surface and the cylindrical portion of the gasket in which moisture in the air has entered, so the local battery in the battery Formation can be prevented. Therefore, since it is possible to prevent OH ^{− from} being excessively present in the vicinity of the ridge portion of the negative electrode current collector, the alkaline electrolyte moves between the negative electrode current collector and the gasket and moves toward the opening side of the battery case. Can be prevented.

  It is preferable that the space | interval of the collar part of a negative electrode collector and the cylinder part of a gasket is 0.1 mm or more. If this distance is less than 0.1 mm, formation of a local battery under high temperature and high humidity may not be prevented.

  It is preferable that the space | interval of the collar part of a negative electrode collector and the cylinder part of a gasket is 0.5 mm or less. Thereby, formation of a local battery under high temperature and humidity can be prevented without causing capacity reduction.

It is preferable that a sealant is provided between the cylindrical portion of the gasket and the flange portion of the negative electrode current collector. Thereby, it is possible to prevent OH ⁻ generated in the vicinity of the collar portion of the negative electrode current collector from entering between the negative electrode current collector and the gasket. More preferably, the sealing agent is filled between the cylindrical portion of the gasket and the collar portion of the negative electrode current collector, or the sealing agent covers the collar portion of the negative electrode current collector. That is. The sealant may be chlorosulfonated polyethylene resin or asphalt.

  According to the present invention, it is possible to prevent the alkaline electrolyte from moving to the opening side of the battery case through between the negative electrode current collector and the gasket under high temperature and high humidity. Alternatively, the movement time can be delayed. Therefore, leakage of the alkaline electrolyte under high temperature and high humidity can be prevented.

It is a half sectional view near the opening side of a conventional alkaline battery. (A)-(f) is sectional drawing explaining the reason for alkaline electrolyte solution leaking under high temperature and humidity. It is the electrochemical circuit diagram of the area | region III shown in FIG.2 (d). It is a half sectional view of an alkaline battery concerning one embodiment of the present invention. FIG. 5 is an enlarged view of a region V shown in FIG. 4. It is the figure which described area | region VI shown in FIG. 5 electrochemically. It is a half sectional view near the opening side of an alkaline battery according to a first modification of one embodiment of the present invention. It is the figure which described field VIII shown in Drawing 7 electrochemically. It is a half sectional view near the opening side of an alkaline battery according to a second modification of one embodiment of the present invention. It is a half sectional view near the opening side of an alkaline battery according to a third modification of one embodiment of the present invention. It is the table | surface which put together the result of having investigated leakage resistance with respect to the battery of an Example. It is the table | surface which put together the result of having investigated the liquid-proof property using another method with respect to the battery of an Example.

  The present inventors have studied the reason why the alkaline electrolyte moves to the opening side of the battery case through the gap between the negative electrode current collector and the gasket under high temperature and high humidity, and completed the present invention. Below, after explaining the content which the present inventors considered, embodiment of this invention is described. First, the structure of a conventional alkaline battery (especially the structure of a sealing unit) will be briefly described.

  FIG. 1 is a half sectional view of the vicinity of the opening side of a conventional alkaline battery.

  A battery case 1 of a conventional alkaline battery contains a positive electrode 2, a negative electrode 3, a separator 4 and an alkaline electrolyte (not shown). The alkaline electrolyte is contained in the positive electrode 2, the negative electrode 3 and the separator 4. Yes. An opening 1 a is formed in the battery case 1, and the opening 1 a is sealed by a sealing unit including a gasket 5, a nail-shaped negative electrode current collector 6, and a negative electrode terminal plate 7. One end side of the shaft portion 61 of the negative electrode current collector 6 (the lower end side of the shaft portion 61 in FIG. 1) is press-fitted into the through hole 51 a of the cylindrical portion 51 of the gasket 5 and inserted into the negative electrode 3. A flange portion 62 is provided at the other end of the shaft portion 61 of the current collector 6 (the upper end of the shaft portion 61 in FIG. 1). The flange portion 62 is located between the cylindrical portion 51 of the gasket 5 and the negative electrode terminal plate 7, and the opening side end surface of the cylindrical portion 51 of the gasket 5 (the end surface positioned on the opening 1 a side of the battery case 1, FIG. 1). And is welded to the negative electrode terminal plate 7. Further, the sealing side end surface of the cylindrical portion 51 of the gasket 5 (the end surface located on the bottom side of the battery case 1, the lower surface of the cylindrical portion 51 in FIG. 1) is immersed in the negative electrode 3. Here, the gasket 5 is made of a polyamide resin (for example, 6,6 nylon). The negative electrode current collector 6 is formed by plating tin on the surface of a rod made of, for example, brass. The negative electrode terminal plate 7 is, for example, a press-molded nickel-plated steel plate, and the negative electrode terminal plate 7 has a gas vent hole 7a.

  Then, it shows what the present inventors considered as the said reason using FIG. 2 (a)-(f) and FIG. 2A to 2F are cross-sectional views for explaining the reason why the alkaline electrolyte leaks under high temperature and high humidity. FIG. 3 is an electrochemical circuit diagram of region III shown in FIG.

In the negative electrode 3, zinc (negative electrode active material) and the alkaline electrolyte are in contact. Therefore, even in a non-discharge state (for example, during storage), zinc is oxidized by the alkaline electrolyte in the negative electrode 3 (Zn → Zn ²⁺ + 2e ⁻ ). Electrons generated by this oxidation flow through the shaft portion 61 of the negative electrode current collector 6 and reach the flange portion 62 as shown in FIG.

When such an alkaline battery is left under high temperature and high humidity, as shown in FIG. 2 (b), moisture in the air enters the inside of the battery case 1 from the vent hole 7a of the negative electrode terminal plate 7, and the negative electrode terminal It adheres on the inner surface of the plate 7 or on the surface of the flange 62 of the negative electrode current collector 6. Thus, since the moisture in the air and the electrons flowing through the shaft portion 61 of the negative electrode current collector 6 coexist in the flange portion 62 of the negative electrode current collector 6, the reaction shown in Formula 1 occurs and OH ⁻ is generated. (FIG. 2 (c)).

2H ₂ O + 2e ⁻ → H ₂ + 2OH ⁻ Formula 1
A part of the generated OH ⁻ is between the outer surface of the shaft portion 61 of the negative electrode current collector 6 and the inner surface of the through hole 51a formed in the cylindrical portion 51 of the gasket 5 as shown in FIG. Hereinafter, it is simply referred to as “between the shaft portion 61 of the negative electrode current collector 6 and the cylindrical portion 51 of the gasket 5”) and enters the negative electrode 3. Further, since the cylindrical portion 51 of the gasket 5 is in contact with both the flange portion 62 and the negative electrode 3 of the negative electrode current collector 6 and the cylindrical portion 51 of the gasket 5 is excellent in water content, the generated OH ⁻ A part thereof penetrates into the negative electrode 3 through the cylindrical portion 51 of the gasket 5 as shown in FIG. In this way, the generated OH ⁻ enters the negative electrode 3. Since zinc is present in the negative electrode 3, the reaction shown in Formula 2 occurs in the negative electrode 3.

_{^{Zn + 4OH - → Zn (OH}} ) 4 2- + 2e - ··· Formula 2
The generated electrons move from the negative electrode 3 through the shaft portion 61 of the negative electrode current collector 6 to the flange portion 62. Since moisture in the air exists on the surface of the flange portion 62 of the negative electrode current collector 6, the reaction represented by the above formula 1 occurs in the flange portion 62. The OH ⁻ generated by this reaction enters the negative electrode 3 between the shaft portion 61 of the negative electrode current collector 6 and the cylindrical portion 51 of the gasket 5 or through the cylindrical portion 51 of the gasket 5. The reaction shown in FIG. In this way, the generation of OH ^{− in} the vicinity of the flange 62 → the penetration of OH ⁻ into the negative electrode 3 → the generation of electrons in the negative electrode 3 → the movement of electrons into the flange 62 → the generation of OH ^{− in} the vicinity of the flange 62. → ... is repeated. That is, the local battery shown in FIG. 3 is formed in region III.

  In the local battery shown in FIG. 3, the positive electrode P is obtained by immersing tin in an aqueous solution, and corresponds to the flange portion 62 of the negative electrode current collector 6 having moisture attached to the surface. The negative electrode N is obtained by immersing zinc in an alkaline aqueous solution, and corresponds to the negative electrode 3. The separator S is made of a material excellent in water content, and corresponds to the space between the shaft portion 61 of the negative electrode current collector 6 and the cylindrical portion 51 of the gasket 5 or the cylindrical portion 51 of the gasket 5. The conducting wire L corresponds to the shaft portion 61 of the negative electrode current collector 6.

As described above, OH ⁻ generated due to the formation of the local battery exists in the vicinity of the flange portion 62 of the negative electrode current collector 6. Some of the OH ⁻ present in the vicinity of the flange 62 of the negative electrode current collector 6 may enter the negative electrode 3, but remain in the vicinity of the flange 62 of the negative electrode current collector 6 without entering the negative electrode 3. There are also things. Therefore, as the battery reaction in the local battery proceeds, the amount of OH ⁻ present in the vicinity of the flange 62 of the negative electrode current collector 6 increases. That is, OH ⁻ is excessively present in the vicinity of the flange portion 62 of the negative electrode current collector 6. Since the electrically neutral state is more electrically stable than the electrically negative state, a cation is required in the vicinity of the collar portion 62 of the negative electrode current collector 6. Therefore, a cation (for example, K ⁺ ) in the alkaline electrolytic solution passes between the shaft portion 61 of the negative electrode current collector 6 and the cylindrical portion 51 of the gasket 5 from within the negative electrode 3 as shown in FIG. It passes through and moves to the vicinity of the flange 62 of the negative electrode current collector 6.

  The cations in the alkaline electrolyte that have moved to the vicinity of the flange 62 of the negative electrode current collector 6 move on the inner surface of the negative electrode terminal plate 7 and degas the negative electrode terminal plate 7 as shown in FIG. It leaks out of the battery case 1 from the hole 7a. That is, leakage occurs.

  In view of the above, the present inventors considered that leakage of the alkaline electrolyte under high temperature and high humidity can be prevented if the local battery can be prevented from being formed in region III under high temperature and high humidity. The reason why the local battery is formed in the region III under high temperature and high humidity is that metals having different oxidation-reduction potentials are electrically connected to each other, and these metals are arranged across an insulating film containing moisture. Because. The present inventors have completed the present invention based on the above consideration. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to embodiment shown below. Moreover, below, the same code | symbol is attached | subjected with respect to the same member.

<< Embodiment of the Invention >>
FIG. 4 is a half sectional view of an alkaline battery according to an embodiment of the present invention. FIG. 5 is an enlarged view of a region V shown in FIG.

  In the alkaline battery according to this embodiment, as shown in FIGS. 4 and 5, the positive electrode 2, the negative electrode 3, the separator 4, and an alkaline electrolyte (not shown) are accommodated in the battery case 1.

  The battery case 1 serves as both a positive electrode terminal and a positive electrode current collector. For example, a nickel-plated steel sheet is press-molded into a predetermined size and a predetermined shape (specifically, a cylindrical shape with one end sealed). It is. The outer peripheral surface of the battery case 1 is covered with a label 8.

  The positive electrode 2 is formed in a cylindrical shape, and is in close contact with the inner peripheral surface of the battery case 1 via, for example, a graphite film (not shown). The positive electrode 2 includes a positive electrode active material (for example, electrolytic manganese dioxide powder), a conductive agent (for example, graphite powder) and an alkaline electrolyte, and further includes a binder (for example, polyethylene powder) or a lubricant (for example, (Stearate) may be included.

  The negative electrode 3 is provided on the inner peripheral side with respect to the positive electrode 2 through a bottomed cylindrical separator 4, and the negative electrode active material (for example, zinc alloy powder) is a gel material (for example, gel such as sodium polyacrylate) In which the agent is added to the alkaline electrolyte). A metal having a hydrogen overvoltage higher than that of zinc, such as indium or bismuth, or a compound thereof may be added to the negative electrode 3, whereby the corrosion resistance of the negative electrode 3 can be improved. Further, a small amount of silicon compound such as silicic acid or a salt thereof may be added to the negative electrode 3, whereby generation of zinc dendrite can be suppressed.

  It is preferable that the zinc alloy is excellent in corrosion resistance, and it is more preferable to use mercury, cadmium, lead, or an additive-free material in consideration of the environment. The zinc alloy may contain, for example, at least one of 0.01 to 0.1 mass% indium, 0.005 to 0.02 mass% bismuth, and 0.001 to 0.005 mass% aluminum. .

  The separator 4 is formed into a bottomed cylindrical shape, and is, for example, a non-woven fabric obtained by blending mainly polyvinyl alcohol fiber and rayon fiber.

  Such positive electrode 2, negative electrode 3 and separator 4 contain an alkaline electrolyte, and the alkaline electrolyte contains, for example, 30 to 40% by mass of potassium hydroxide, for example, 1 to 3% by mass of zinc oxide. is doing.

  An opening 1 a is formed in the battery case 1, and the opening 1 a is sealed by a sealing unit 9. The sealing unit 9 is obtained by integrating the gasket 5, the negative electrode current collector 6, and the negative electrode terminal plate 7. The configuration of the sealing unit 9 will be described while explaining the configurations of the gasket 5, the negative electrode current collector 6, and the negative electrode terminal plate 7.

  The gasket 5 has a cylindrical portion 51 in the center of the opening 1a. The cylindrical portion 51 extends in parallel with the axial direction of the battery case 1, and the sealing side end surface of the cylindrical portion 51 is immersed in the negative electrode 3. A through hole 51 a is formed in the longitudinal direction of the cylinder portion 51. A peripheral edge 52 is provided at the periphery of the opening 1 a rather than the cylindrical part 51, and the cylindrical part 51 and the peripheral part 52 are connected via a connecting part 53. The connecting portion 53 extends in the radial direction of the opening 1a, and a thin portion 53A is provided in a part of the connecting portion 53. Thereby, when the internal pressure of the battery rises, the thin wall portion 53A breaks, and further increase of the internal pressure can be prevented. Such a gasket 5 is made of polyamide resin such as 6,6 nylon, 6,10 nylon, or 6,12 nylon. Thereby, the gasket 5 can be produced in large quantities at low cost by injection molding. Among 6,6 nylon, 6,10 nylon and 6,12 nylon, 6,12 nylon has the lowest water content. Therefore, if the gasket 5 is made of 6,12 nylon, the water content of the separator S in the local battery shown in FIG. 3 can be reduced, so that the reaction in the local battery can be inhibited. Therefore, the gasket 5 is preferably made of 6,12 nylon.

  The negative electrode terminal plate 7 has a terminal portion 71 in the center of the opening 1 a, and the terminal portion 71 faces the opening side end surface of the cylindrical portion 51 of the gasket 5. A peripheral edge 72 is provided at the periphery of the opening 1 a rather than the terminal portion 71, and the peripheral edge 72 is caulked to the opening 1 a via the peripheral edge 52 of the gasket 5. A gas vent hole 7a is formed between the terminal portion 71 and the peripheral edge portion 72 with a gap in the circumferential direction of the negative electrode terminal plate 7, so that when the thin portion 53A of the gasket 5 is broken, the battery case 1 The internal gas (for example, hydrogen gas) can be released from the gas vent hole 7a. Such a negative electrode terminal plate 7 is formed by press-forming, for example, a nickel-plated steel plate or a tin-plated steel plate into a predetermined size and a predetermined shape.

  The negative electrode current collector 6 has a nail shape having a shaft portion 61 and a flange portion 62. The shaft portion 61 extends in the axial direction of the battery case 1, and one end thereof is press-fitted into the through hole 51 a of the gasket 5 and inserted into the negative electrode 3. The flange portion 62 is provided at the other end of the shaft portion 61 and has a larger diameter than the shaft portion 61. The flange portion 62 is disposed between the cylindrical portion 51 of the gasket 5 and the terminal portion 71 of the negative electrode terminal plate 7. Specifically, the flange portion 62 is disposed with a gap G in advance from the cylindrical portion 51. In addition, the terminal portion 71 is electrically connected (for example, welded). Such a negative electrode current collector 6 is obtained by pressing a wire such as silver, copper, or brass into a nail shape having a predetermined size. The surface of the negative electrode current collector 6 is preferably plated with tin or indium, so that impurities generated during processing of the negative electrode current collector 6 can be eliminated or concealed.

  Such an alkaline battery is manufactured according to the following method. First, after putting the pellet-shaped positive electrode 2 in the bottomed cylindrical battery case 1, the positive electrode 2 is pressurized and brought into close contact with the inner peripheral surface of the battery case 1. Next, a bottomed cylindrical separator 4 is disposed in the hollow portion of the positive electrode 2, and the negative electrode 3 is filled in the hollow portion of the separator 4. In addition, an alkaline electrolyte is injected into the battery case 1. Then, one end side of the negative electrode current collector 6 connected to the negative electrode terminal plate 7 is inserted into the negative electrode 3, and the peripheral edge of the negative electrode terminal plate 7 is connected to the edge of the opening 1 a of the battery case 1 via the peripheral edge portion 52 of the gasket 5. The part 72 is caulked. Thereafter, the outer peripheral surface of the battery case 1 is covered with a label 8.

Hereinafter, when the alkaline battery of this embodiment was placed under high temperature and high humidity, the electronic and OH within the cell ^- shows the behavior. FIG. 6 is an electrochemical description of the region VI shown in FIG. FIG. 6 shows the case where the surface of the negative electrode current collector 6 is plated with tin.

Under high temperature and high humidity, moisture in the air enters the battery case 1 through the gas vent hole 7a of the negative electrode terminal plate 7, and the surface of the flange portion 62 of the negative electrode current collector 6 or the terminal portion 71 of the negative electrode terminal plate 7 is obtained. It adheres to the inner surface or enters into the gasket 5. Since the electrons generated in the negative electrode 3 are present in the flange portion 62 of the negative electrode current collector 6 (FIG. 2A), the reaction shown in Formula 1 occurs. As a result, OH ⁻ is generated in the vicinity of the flange portion 62 of the negative electrode current collector 6.

However, in the present embodiment, as shown in FIG. 5, the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 are disposed with a gap G therebetween. That is, it is possible to avoid contact between the flange portion 62 where moisture in the air adheres to the surface and the cylinder portion 51 containing moisture in the air. Therefore, OH generated near the flange portion 62 ^- so hard to penetrate into the tubular portion 51 of the gasket 5, OH infiltrating into the negative electrode 3 ^- can reduce the amount of. Thereby, compared with the case where the cylinder part 51 of the gasket 5 and the collar part 62 of the negative electrode collector 6 are mutually contacting, progress of Formula 2 can be delayed. That is, generation of electrons in the negative electrode 3 can be suppressed as compared with the case shown in FIG. Therefore, since it can suppress that an electron is supplied to the collar part 62 through the axial part 61 of the negative electrode collector 6 from the negative electrode 3, progress of Formula 1 can be delayed. As described above, in this embodiment, OH ⁻ is generated near the flange 62 → OH ⁻ is penetrated into the negative electrode 3 → electrons are generated at the negative electrode 3 → electrons are transferred to the flange 62 → near the flange 62. It is possible to delay the time when the repetition of the generation of OH ⁻ of. Therefore, the formation time of the local battery in the region VI can be delayed.

In other words, in this embodiment, as shown in FIG. 6, as shown in FIG. 6, a nylon film 51 ′ containing moisture (simply described as “nylon film 51 ′”) and an aqueous solution 62 ′ in which tin is immersed (simply referred to as “aqueous solution 62”). There is a region G ′ (simply referred to as “region G ′”) that is not excellent in water content. Therefore, OH ⁻ generated in the aqueous solution 62 ′ is difficult to enter the nylon film 51 ′ through the region G ′, so that the amount of OH ⁻ that enters the alkaline aqueous solution 3 ′ can be reduced. Thereby, compared with the case where nylon membrane 51 'and aqueous solution 62' are contacting, the production | generation time of the electron in alkaline aqueous solution 3 'can be delayed. Therefore, since it can suppress that an electron passes through the inside of conducting wire 61 'from aqueous alkaline solution 3' and is supplied to aqueous solution 62 ', progress of Formula 1 can be delayed. Therefore, the formation time of the local battery in the region VI can be delayed or the formation thereof can be suppressed.

From the above, in the present embodiment, it is possible to delay the time when OH ⁻ is excessively present in the vicinity of the flange portion 62 of the negative electrode current collector 6, so that the cation in the alkaline electrolyte is the cylindrical portion 51 of the gasket 5. It is possible to delay the timing of moving to the opening 1a side of the battery case 1 through the space between the electrode portion 61 and the shaft portion 61 of the negative electrode current collector 6. Thereby, in this embodiment, compared with the alkaline battery shown in FIG. 1, the leakage of the alkaline electrolyte under high temperature and high humidity can be prevented or the liquid leakage timing can be delayed. For example, when the storage time under high temperature and high humidity is relatively short, leakage of the alkaline electrolyte can be prevented.

If the gap between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 (described as “the size of the gap G”) is too small, for example, the size of the gap G is less than 0.1 mm. In some cases, OH ⁻ generated in the vicinity of the flange portion 62 of the negative electrode current collector 6 may enter the cylindrical portion 51 of the gasket 5 through the gap G. Therefore, the size of the gap G is preferably 0.1 mm or more, and is preferably as large as possible. However, if the size of the gap G is too large, for example, if the size of the gap G exceeds 0.5 mm, the space in the battery case that can be filled with the active material may be narrowed, thus causing a decrease in capacity. There is. Therefore, the size of the gap G is preferably 0.5 mm or less. From the above, the size of the gap G is preferably 0.1 mm or more, and more preferably 0.1 mm or more and 0.5 mm or less. The size of the gap G is preferably within the above range regardless of the length of the battery case 1.

  As described above, in the present embodiment, the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 are arranged with a gap G therebetween, so that the formation time of the local battery in the region VI is illustrated. Compared to the case shown in FIG. Thereby, the leakage of the alkaline electrolyte under high temperature and high humidity can be prevented, or the liquid leakage timing can be delayed.

  Further, in the present embodiment, it is possible to prevent liquid leakage under a high temperature and high humidity or delay the liquid leakage timing without changing the size and material of the members constituting the alkaline battery. Therefore, it is not necessary to change the manufacturing conditions of the constituent members, and it is not necessary to newly examine the resistance to zinc and alkaline electrolyte. Therefore, it is possible to prevent liquid leakage under a high temperature and high humidity or delay the liquid leakage timing without causing an increase in cost.

  Furthermore, in this embodiment, when the capacity of the alkaline battery is increased, a great effect can be obtained. The following is a brief description.

  Recently, it has been studied to use alkaline batteries even in a large current region (a region where the current is 0.5 A or more), and accordingly, higher capacity of alkaline batteries is required. If the filling amount of the active material is increased, the capacity of the alkaline battery can be increased. However, when the filling amount of the active material is increased, the cylindrical portion 51 of the gasket 5 may be immersed in the negative electrode 3 as compared with the case shown in FIG. Even in such a case, since the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 are provided with a gap G therebetween, the formation time of the local battery in the region VI can be delayed. it can. Therefore, the leakage of the alkaline electrolyte under high temperature and high humidity can be prevented, or the time of the liquid leakage can be delayed. Therefore, in this embodiment, a high-capacity alkaline battery in which safety is ensured can be provided.

  In addition, as means for delaying the formation time of the local battery in the region VI, the solving means described in the present embodiment (the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 are arranged with a space therebetween). In addition, contact between the cylindrical portion 51 of the gasket 5 and the negative electrode 3 is avoided, the water content of the gasket 5 is reduced, or the oxidation-reduction potential of the flange portion 62 of the negative electrode current collector 6 is less than or equal to the oxidation-reduction potential of zinc. And so on. When the present inventors examined the feasibility of these three solutions, the following problems were confirmed in any of the solutions. Therefore, the present inventors consider that it is preferable to delay the formation time of the local battery in the region VI by using the solution described in the present embodiment instead of these three solutions.

In order to realize the first solution, the length of the cylindrical portion 51 of the gasket 5 is shortened or the filling height of the negative electrode 3 (the length of the negative electrode 3 in the axial direction of the battery) is reduced. good. However, if the length of the cylindrical part 51 of the gasket 5 is shortened, the transmission distance of moisture or OH ⁻ in the cylindrical part 51 of the gasket 5 is shortened. Therefore, an adverse effect is caused, that is, the local battery is formed earlier in the region VI. Moreover, if the filling height of the negative electrode 3 is lowered, the filling amount of the negative electrode active material is lowered, and the capacity of the alkaline battery is lowered.

  In order to realize the second solution, the gasket 5 may be manufactured using a material having low water content. However, the gasket 5 has a crimped portion (peripheral portion 52) that is excellent in compressibility, that the safety valve (thin wall portion 53A) is excellent in terms of an increase in the internal pressure of the battery, and that it is electrically insulating. It is required to be excellent and to be manufactured in large quantities at low cost by injection molding or the like. The material satisfying all these requirements is the polyamide resin listed in this embodiment.

  In order to realize the third solution, at least the surface of the negative electrode current collector 6 (particularly, the flange portion 62) is a metal whose oxidation-reduction potential is lower than that of zinc (for example, alkali metal, alkaline earth metal, or aluminum). Alternatively, it may be formed of a metal (for example, zinc) having the same oxidation-reduction potential as that of zinc. However, the negative electrode current collector 6 is required to have low resistivity, excellent strength, low reactivity with an alkaline electrolyte, zinc, and the like. In addition, the material of the surface of the negative electrode current collector 6 is required to eliminate or conceal impurities generated during processing of the negative electrode current collector 6. It is difficult to satisfy all these requirements with a material having a redox potential lower than that of zinc or the same material as zinc.

  The alkaline battery according to this embodiment may have the following configuration.

  Each material of the battery case, the positive electrode, the negative electrode, the separator, the gasket, the negative electrode current collector, and the negative electrode terminal plate listed in the present embodiment is merely an example. Moreover, content of the metal which comprises a zinc alloy, and content of the compound which comprises an alkaline electrolyte are each an example.

  The sealing side end surface of the cylindrical portion of the gasket may be immersed in the negative electrode or may not be immersed in the negative electrode.

  The alkaline battery according to the present embodiment may have a structure shown in the following first to third modifications.

(First modification)
FIG. 7 is a cross-sectional view of the vicinity of the opening in the alkaline battery according to the first modification. In the following, portions different from the above embodiment will be mainly described.

  In the alkaline battery according to this modification, as shown in FIG. 7, the sealant 10 is provided between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 (corresponding to the gap G in the above embodiment). Is provided. The sealant 10 may be any material that has insulating properties and is inferior in water content to the gasket 5, and among them, a chlorosulfonated polyethylene resin or asphalt is preferably used.

When a chlorosulfonated polyethylene resin is used as the sealant 10, the following effects can be obtained. Since the chlorosulfonated polyethylene is excellent in thermal stability, it is suppressed from softening and flowing at a high temperature, and thus the stable water repellency of the sealant 10 can be secured. Moreover, since the chlorosulfonated polyethylene is bonded to the polyamide resin (material of the gasket 5) through intermolecular force, the sealant 10 can be adhered to the gasket 5. Further, since the chlorosulfonated polyethylene resin is excellent in water repellency, it is possible to prevent moisture or OH ⁻ from adhering to the surface of the sealant 10, and thus OH ⁻ is connected to the cylindrical portion 51 of the gasket 5 and the negative electrode current collector. Intrusion into the negative electrode 3 through the space between the shaft portion 61 of the body 6 can be prevented.

When asphalt is used as the sealant 10, the following effects can be obtained. Since asphalt is excellent in heat resistance, the heat resistance of the sealant 10 can be improved. Further, asphalt is bonded to the polyamide resin (material of the gasket 5) through intermolecular force, so that the sealant 10 can be adhered to the gasket 5. Furthermore, since asphalt is excellent in water repellency, it is possible to prevent moisture or OH ⁻ from adhering to the surface of the sealant 10. Accordingly, OH ⁻ is the axis of the cylindrical portion 51 of the gasket 5 and the negative electrode current collector 6. Intrusion into the negative electrode 3 through the space between the portions 61 can be prevented.

  Such a sealant 10 may be provided between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 according to any of the following methods. The sealing agent 10 may be provided between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 after the sealing unit 9 is manufactured. The sealant 10 may be provided on the opening-side end surface of the cylindrical portion 51 of the gasket 5, and the shaft portion 61 of the negative electrode current collector 6 may be press-fitted into the through hole 51 a of the cylindrical portion 51 of the gasket 5. Alternatively, after the sealing agent 10 is provided on the sealing side end face of the flange portion 62 of the negative electrode current collector 6, the shaft portion 61 of the negative electrode current collector 6 is press-fitted into the through hole 51 a of the cylindrical portion 51 of the gasket 5. May be.

Hereinafter, when the alkaline battery according to this modification was placed under high temperature and high humidity, the electronic and OH within the cell ^- shows the behavior. FIG. 8 is an electrochemical description of region VIII shown in FIG. FIG. 8 shows a case where the surface of the negative electrode current collector 6 is tin-plated.

Under high temperature and high humidity, moisture in the air enters the battery case 1 through the gas vent hole 7 a of the negative electrode terminal plate 7. In this modification, the sealing side end surface of the flange portion 62 of the negative electrode current collector 6 is covered with the sealing agent 10. Therefore, it is possible to prevent moisture that has entered the battery case 1 from adhering to the sealing side end face of the flange 62. Therefore, the amount of OH ⁻ generated in the vicinity of the flange portion 62 of the negative electrode current collector 6 can be suppressed as compared with the above embodiment.

Moreover, in this modification, as shown in FIG. 7, the sealant 10 is provided between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6. The sealant 10 is inferior in water content than the gasket 5. Therefore, OH ⁻ generated in the vicinity of the flange portion 62 of the negative electrode current collector 6 is less likely to enter the cylindrical portion 51 of the gasket 5 as compared with the above embodiment. In other words, in this modification, as shown in FIG. 8, a sealing film 10 ′ (the sealing film 10 ′ is inferior in water content to the nylon film 51 ′) is provided in the region G ′. Therefore, OH ⁻ generated in the aqueous solution 62 ′ is more difficult to enter the nylon membrane 51 ′ than in the case shown in FIG.

In addition, in this modified example, since the sealant 10 is provided between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6, the vicinity of the flange portion 62 of the negative electrode current collector 6. It is difficult for OH ⁻ generated in step 1 to enter the negative electrode 3 through the space between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6. As described above, in this modified example, OH ^- is not only prevented from intruding into the negative electrode 3 through the cylindrical portion 51 of the gasket 5, OH ^- it is the tubular portion 51 of the gasket 5 and the negative electrode current collector 6 Intrusion into the negative electrode 3 through the gap 62 can also be prevented. Therefore, the amount of OH ⁻ entering the negative electrode 3 can be suppressed as compared with the above embodiment.

  From the above, in this modification, the formation time of the local battery in the region VIII can be further delayed or suppressed from being formed as compared with the above embodiment. Therefore, leakage of the alkaline electrolyte under high temperature and high humidity can be further prevented than in the above embodiment, or the liquid leakage timing can be further delayed than in the above embodiment.

  Note that this modification may have the following configuration.

The sealant 10 may not be filled in the gap G (see FIG. 5), and may be provided only in a part of the gap G in the radial direction. For example, the sealant 10 may be provided only on the radially outer side in the gap G, or may be provided only on the radially inner side in the gap G. However, if the sealant 10 is provided only on the radially inner side in the gap G, the portion of the flange 62 of the negative electrode current collector 6 where the sealant is not provided (the radially outer side in the gap G). ) May be adhering to moisture in the air, and OH ⁻ may be generated in that portion. On the other hand, if the sealing agent 10 is provided on the radially outer side in the gap G, the portion of the flange 62 of the negative electrode current collector 6 where the sealing agent is not provided (the radially inner side in the gap G). Since it is possible to prevent moisture in the air from adhering to the surface, generation of OH ^{− at} that portion can be suppressed. Therefore, the sealant 10 is preferably provided at least on the radially outer side in the gap G.

(Second modification)
FIG. 9 is a cross-sectional view of the vicinity of the opening in the alkaline battery according to the second modification. Hereinafter, portions different from the first modification will be mainly described.

In the present modification, the sealant 10 covers not only between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 but also covers the entire surface of the flange portion 62 of the negative electrode current collector 6. Yes. Therefore, it is possible to prevent moisture that has entered the inside of the battery case 1 from the gas vent hole 7 a of the negative electrode terminal plate 7 from adhering to the surface of the flange portion 62 of the negative electrode current collector 6. Therefore, the amount of OH ⁻ generated in the vicinity of the flange portion 62 of the negative electrode current collector 6 can be further suppressed as compared with the first modification. Thereby, in this modification, the formation time of the local battery in a battery can be further delayed rather than the said 1st modification, or the formation can be suppressed further than the said 1st modification. Therefore, the leakage of the alkaline electrolyte under high temperature and high humidity can be further prevented than in the first modification.

  Such a sealant 10 may be coated on the surface of the flange portion 62 of the negative electrode current collector 6 after the sealing unit 9 is manufactured, or before the negative electrode current collector 6 is manufactured before the sealing unit 9 is manufactured. The surface of the collar part 62 may be covered.

  In the present modification, the sealant 10 is filled between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 for the same reason as described in the first modification. It is not necessary.

(Third Modification)
FIG. 10 is a cross-sectional view of the vicinity of the opening in an alkaline battery according to a third modification. Hereinafter, portions different from the first modification will be mainly described.

  In the present modification, the sealant 10 is not only between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 but also the cylindrical portion 51 of the gasket 5 and the shaft portion 61 of the negative electrode current collector 6. It is also provided between.

  In this modification, the sealant 10 is applied to both the other end side of the shaft portion 61 of the negative electrode current collector 6 and the lower surface of the flange portion 62 of the negative electrode current collector 6, One end side of the shaft portion 61 of the negative electrode current collector 6 of the shaft portion 61 may be press-fitted into the cylindrical portion 51 of the gasket 5. However, if a large amount of the sealing agent 10 is applied to the other end side of the shaft portion 61 of the negative electrode current collector 6, for example, the sealing applied to the other end side of the shaft portion 61 of the negative electrode current collector 6 by the above-described method. If the sealing agent 10 is applied to the other end side of the shaft portion 61 of the negative electrode current collector 6, the sealing agent 10 is applied in an amount of about 1.5 to 3 times the amount of the sealing agent 10. The sealing unit in this modification can be produced without being provided on the lower surface of 62. Specifically, when the shaft portion 61 of the negative electrode current collector 6 is press-fitted into the tube portion 51 of the gasket 5, a part of the sealant 10 is separated from the tube portion 51 of the gasket 5 and the shaft portion 61 of the negative electrode current collector 6. Protruding from between. The protruding sealant 10 moves between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 according to the press-fitting direction of the shaft portion 61 of the negative electrode current collector 6. Therefore, the sealant 10 can be provided between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6. Thus, the amount of the sealant 10 provided between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 is applied to the other end side of the shaft portion 61 of the negative electrode current collector 6. Depends on the amount of sealant 10.

  In this modification, the sealant 10 is filled between the cylindrical portion 51 of the gasket 5 and the flange portion 62 of the negative electrode current collector 6 for the same reason as described in the first modification. It does not have to be.

  In this example, the leakage resistance of the alkaline battery was examined to confirm the effect of the present invention.

[Production method of alkaline battery]
(Battery 1)
1. Preparation Method of Alkaline Electrolyte Potassium hydroxide, zinc oxide and water were mixed at a mass ratio of 32: 2: 66. In this way, an alkaline electrolyte was prepared.

2. Production Method of Positive Electrode Electrolytic manganese dioxide (average particle size is 38 μm) and graphite (average particle size is 17 μm) were mixed at a predetermined mass ratio to obtain a mixture. The obtained mixture and the alkaline electrolyte were mixed at a mass ratio of 100: 2, sufficiently stirred, and compression molded into flakes.

  This flaky material was pulverized into granules and then classified using a sieve and selected to pass through 10 to 100 mesh. The selected granular material was pressed into a hollow cylinder. Thereby, a pellet-shaped positive electrode was obtained.

3. First, a zinc alloy powder containing 0.020 mass% indium, 0.010 mass% bismuth, and 0.004 mass% aluminum was prepared. This powder contained 35% of particles having a volume average particle size of 160 μm and a particle size of 75 μm or less.

  Next, the sodium polyacrylate powder (gelator), the alkaline electrolyte, and the zinc alloy powder were mixed at a mass ratio of 0.8: 33.6: 65.6. Thereby, the negative electrode was obtained.

4). Method for Producing Alkaline Battery First, a nickel-plated steel sheet was press-formed to produce a bottomed cylindrical battery case. The thickness of the side surface of the produced battery case was 0.18 mm, and the height of the battery case was 49.6 mm.

  Next, two of the pellet-shaped positive electrodes obtained above were inserted into the battery case, and the positive electrodes were pressed using a pressing jig to adhere to the inner wall of the battery case.

  Subsequently, a bottomed cylindrical separator was disposed in the hollow portion of the positive electrode. As the separator, a non-woven fabric mainly composed of polyvinyl alcohol fiber and rayon fiber was used.

  Then, 1.6 g of alkaline electrolyte was injected into the separator. After a while after the injection, the negative electrode obtained above was filled on the inner peripheral side of the separator until the height in the battery case reached 41 mm.

  Then, the sealing unit was produced. First, a negative electrode current collector in which tin is plated on a surface of a gasket made of 6,6-nylon, a nail-shaped brass wire (thickness: 1.425 mm, length: 33 mm), and a nickel-plated steel plate A negative electrode terminal plate press-molded into a predetermined shape was prepared. Next, the flange part of the negative electrode current collector and the terminal part of the negative electrode terminal plate were spot welded, and then one end side of the negative electrode current collector was press-fitted into the through hole of the cylindrical part of the gasket. At this time, the flange part of the negative electrode current collector and the cylindrical part of the gasket were arranged with a gap therebetween, and the size of the gap was set to 0.1 mm. Thus, a sealing unit was produced.

  And the opening of the battery case was sealed using the produced sealing unit. Specifically, the negative electrode current collector connected to the negative electrode terminal plate was inserted into the negative electrode, and the peripheral edge of the negative electrode terminal plate was caulked to the edge of the opening of the battery case via the peripheral edge of the gasket. Then, an exterior label was coated on the outer surface of the battery case. Thus, the battery 1 was produced.

(Battery 2)
A battery 2 was produced according to the same method as the battery 1 except that the distance between the flange of the negative electrode current collector and the cylindrical portion of the gasket was 0.3 mm.

(Battery 3)
A battery 3 was produced according to the same method as the battery 1 except that the distance between the flange of the negative electrode current collector and the cylindrical portion of the gasket was 0.5 mm.

(Battery 4)
A battery 4 was produced according to the same method as the battery 1 except that the distance between the flange of the negative electrode current collector and the cylindrical portion of the gasket was 0.7 mm.

  The filling height of the negative electrode was 1 mm lower than that of the battery 1 in order to smoothly perform the sealing with the sealing unit.

(Battery 5)
In accordance with the same method as the battery 1 except that the chlorosulfonated polyethylene resin (grade TB1194E manufactured by ThreeBond Co., Ltd.) was filled between the collar part of the negative electrode current collector and the cylindrical part of the gasket, the battery 5 was Produced.

(Battery 6)
A battery 6 was produced according to the same method as the battery 5 except that the distance between the flange portion of the negative electrode current collector and the cylindrical portion of the gasket was 0.3 mm.

(Battery 7)
A battery 7 was produced according to the same method as the battery 5 except that the distance between the flange of the negative electrode current collector and the cylindrical portion of the gasket was 0.5 mm.

(Battery 8)
A battery 8 was produced according to the same method as the battery 5 except that the distance between the flange of the negative electrode current collector and the cylindrical portion of the gasket was 0.7 mm.

  The filling height of the negative electrode was 1 mm lower than that of the battery 5 in order to smoothly perform the sealing with the sealing unit.

(Battery 9)
A battery 9 was produced according to the same method as that of the battery 1 except that the entire surface of the collar part of the negative electrode current collector was covered with the chlorosulfonated polyethylene resin.

(Battery 10)
A battery 10 was produced according to the same method as the battery 1 except that asphalt (manufactured by Naka-Carbon Chemical Co., Ltd.) was filled between the collar part of the negative electrode current collector and the cylindrical part of the gasket.

(Battery 11)
A battery 11 was produced in the same manner as the battery 1 except that a gasket made of 6,12 nylon was used.

(Battery 12)
A battery 12 was produced in the same manner as the battery 5 except that a gasket made of 6,12 nylon was used.

(Battery 13)
The battery 1 is the same as the battery 1 except that the flange portion of the negative electrode current collector and the cylindrical portion of the gasket are brought into contact with each other (the interval between the flange portion of the negative electrode current collector and the cylindrical portion of the gasket is 0 mm). A battery 13 was produced according to the method.

(Battery 14)
A battery 14 was produced according to the same method as that of the battery 1 except that the distance between the flange portion of the negative electrode current collector and the cylindrical portion of the gasket was 0.05 mm.

(Battery 15)
A battery 15 was produced in the same manner as the battery 14 except that the chlorosulfonated polyethylene resin was filled between the flange of the negative electrode current collector and the cylindrical part of the gasket.

[Test method for checking the leakage resistance of alkaline batteries]
The batteries 1 to 15 produced according to the above method were stored in a 60 ° C. 90% RH (Relative Humidity) test tank for a certain period of time and then taken out to check for leakage. The result is shown in FIG. In addition, “sulfonated PE” in FIG. 11 means chlorosulfonated polyethylene.

Moreover, about the battery 1, the battery 5, the battery 9, and the battery 13, after storing for a fixed period in the said test tank, it took out, and the presence or absence of OH ^{< - >} and K ^{<+> in} the vicinity of the collar part of a negative electrode collector was investigated. Specifically, the presence or absence of OH ⁻ was examined using a cresol red solution. When OH ⁻ was detected by the cresol red solution, the presence or absence of K ⁺ was examined by EDS (Energy Dispersed Spectroscopy). The result is shown in FIG. Note that “not detected” in FIG. 12 means that both OH ⁻ and K ⁺ were not detected.

  As shown in FIG. 11, for batteries 1 to 4 and battery 11, the alkaline electrolyte does not leak even if left for 2 months in an environment of 60 ° C. and 90% RH, and for batteries 5 to 10 and battery 12. The alkaline electrolyte did not leak even after being left for 3 months or longer in an environment of 60 ° C. and 90% RH. On the other hand, when the batteries 13 to 15 were left in an environment of 60 ° C. and 90% RH for one month, the alkaline electrolyte leaked. The reason for this is that, as described in the above embodiment and the like, in the batteries 1 to 12, the distance between the cylindrical portion of the gasket and the collar portion of the negative electrode current collector is 0.1 mm or more, so the formation of the local battery in the battery This is because, in the batteries 13 to 15, the interval is less than 0.1 mm, so that a local battery is formed in the battery.

  The liquid leakage time of the battery 14 was later than the liquid leakage time of the battery 13, but earlier than the liquid leakage time of the battery 1. Also from this fact, it was confirmed that the distance between the flange portion of the negative electrode current collector and the cylindrical portion of the gasket is preferably 0.1 mm or more. Further, when the results of the batteries 1 to 4 and the results of the batteries 5 to 8 are compared, or the results of the battery 1 and the results of the battery 10 are compared, the collar portion of the negative electrode current collector and the cylindrical portion of the gasket It was confirmed that it was preferable to fill chlorosulfonated polyethylene resin or asphalt between the two.

  From the result of the battery 1 and the result of the battery 11, it was confirmed that it is preferable to select 6,12 nylon as the gasket material. The reason is that 6,12 nylon is not superior in water content than 6,6 nylon, so that the formation of local batteries can be prevented or the formation time thereof can be delayed.

  When the discharge capacities of the batteries 1 to 8 were measured, the discharge capacity of the battery 4 was smaller than the discharge capacities of the batteries 1 to 3, and the discharge capacity of the battery 8 was smaller than the discharge capacities of the batteries 5 to 7. The reason is that the filling height of the negative electrode in the battery 4 and the battery 8 is made lower than the filling height of the negative electrode in the batteries 1 to 3 and the batteries 5 to 7 in order to smoothly perform the sealing by the sealing unit.

As shown in FIG. 12, even if the battery 1 is stored for 1 month in an environment of 60 ° C. and 90% RH, no leakage is confirmed, and the battery 5 is stored for 1 month in an environment of 60 ° C. and 90% RH. K ⁺ was not detected, and OH ⁻ and K ⁺ were not detected even when the battery 9 was stored in an environment of 60 ° C. and 90% RH for 1 month. Therefore, the battery 1 can suppress the leakage of the alkaline electrolyte under high temperature and high humidity, but the battery 5 can suppress the leakage of the alkaline electrolyte under the high temperature and high humidity compared to the battery 1, and the battery 9 is the battery. It was confirmed that leakage of alkaline electrolyte under higher temperature and humidity than 5 could be suppressed.

On the other hand, when the battery 12 was stored in an environment of 60 ° C. and 90% RH, OH ⁻ was detected on the next day, and K ⁺ was also detected after one week. From this, it was confirmed that K ⁺ moved from the negative electrode to the buttocks of the negative electrode current collector after OH ⁻ was generated in the buttocks of the negative electrode current collector. Further, since K ⁺ was not detected from the inside of the gasket, it was confirmed that K ⁺ moved to between the cylindrical portion of the gasket and the shaft portion of the negative electrode current collector and to the vicinity of the collar portion of the negative electrode current collector. .

  In this modification, the leakage resistance of the AA alkaline battery under high temperature and high humidity is shown. However, the present inventors have changed the size of the battery (for example, the AA alkaline battery). It is considered that the same tendency as the results shown in FIG. 11 and FIG. 12 can be obtained (even with single-type alkaline batteries and single-size alkaline batteries).

  As described above, the present invention is useful for alkaline batteries, and particularly useful for alkaline batteries used under high temperature and high humidity.

DESCRIPTION OF SYMBOLS 1 Battery case 2 Positive electrode 3 Negative electrode 4 Separator 5 Gasket 51 Cylindrical part 6 Negative electrode collector 61 Axis part 62 Gutter part 7 Negative electrode terminal board 9 Sealing unit 10 Sealant G Gap

Claims (7)

An alkaline battery in which a positive electrode, a negative electrode, a separator, and an electrolyte are housed in a battery case, and the opening of the battery case is sealed by a negative electrode terminal plate and a gasket to which a negative electrode current collector is connected,
The negative electrode current collector has a shaft portion and a flange portion, one end side of the shaft portion is provided in the negative electrode, and the flange portion is provided at the other end of the shaft portion. ,
The gasket is made of polyamide resin, and has a cylindrical portion into which the shaft portion of the negative electrode current collector is press-fitted,
The negative electrode terminal plate is disposed on the opposite side of the cylindrical portion of the gasket with respect to the flange portion of the negative electrode current collector,
The alkaline battery in which the flange portion of the negative electrode current collector and the cylindrical portion of the gasket are arranged with a space therebetween. The alkaline battery according to claim 1,
An alkaline battery in which a gap between the flange portion of the negative electrode current collector and the cylindrical portion of the gasket is 0.1 mm or more. The alkaline battery according to claim 2,
An alkaline battery in which a gap between the flange portion of the negative electrode current collector and the cylindrical portion of the gasket is 0.5 mm or less. The alkaline battery according to claim 1,
An alkaline battery in which a sealant is provided between the flange portion of the negative electrode current collector and the cylindrical portion of the gasket. The alkaline battery according to claim 4,
The said sealing agent is an alkaline battery with which it filled between the said collar part of the said negative electrode collector, and the said cylinder part of the said gasket. The alkaline battery according to claim 4,
The sealant is an alkaline battery that covers the flange of the negative electrode current collector. The alkaline battery according to claim 4,
The said sealing agent is an alkaline battery which is a chlorosulfonated polyethylene resin or asphalt.

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