Battery and manufacturing method of battery

Abstract

To provide a battery in which a gasket is hardly damaged.SOLUTION: A battery 1 of an embodiment comprises: a positive electrode can 2 having a cylinder part 15 and a bottom part to which a positive electrode terminal is formed; a negative electrode terminal plate 12 which is provided to an open 18 of the positive electrode can 2 and in which a negative electrode terminal 13 is formed; a gasket 14 that is provided to the positive electrode terminal side by the negative electrode terminal plate 12, and blocks the open 18; and a negative electrode mixture that is provided at an inner part of the positive electrode can 2. In an outer edge of the negative electrode terminal 13, an opposite part 20 that is extended to a separation direction and is opposite to the cylinder part 15 in the case where a direction separated from the bottom part along a center shaft of the cylinder part 15 is a separation direction is formed. In an outer edge of the gasket 14, a nipping part 44 that is nipped to between the cylinder part 15 and the opposite part 20 so as to be extended to the separation direction, and a first annular part 45 that is extended toward the center shaft of the cylinder part 15 from an end part of the nipping part 44, and covers the end part of the opposite part 20 to the separation direction side are formed, and a hard resin layer 8 that is provided to between the opposite part 20 and the nipping part 44 is further included.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to a battery and a method for manufacturing the battery.

Background Art

[0002] As shown in Patent Document 1, some batteries include a positive electrode can, a negative electrode terminal plate, and a gasket. The positive electrode can has a cylindrical portion having a cylindrical shape and a bottom portion closing one end side of the cylindrical portion. The negative electrode terminal plate is provided at the opening of the positive electrode can. An opposing portion extending in a direction away from the bottom portion and facing the cylindrical portion of the positive electrode can is formed at the outer edge of the negative electrode terminal plate. The gasket is provided at the opening of the positive electrode can. A sandwiching portion extending in a direction away from the bottom portion and sandwiched between the opposing portion of the negative electrode terminal plate and the positive electrode can is formed at the outer edge of the gasket. By sandwiching the sandwiching portion between the opposing portion and the positive electrode can, the opening of the positive electrode can is closed by the gasket. The tip of the sandwiching portion is formed with an annular portion bent so as to extend toward the central axis of the cylindrical portion of the positive electrode can, and the annular portion covers the tip of the opposing portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The negative electrode terminal plate is made of metal. Also, the gasket is made of resin. The annular portion of the gasket covers the tip of the opposing portion provided at the outer edge of the negative electrode terminal plate. When an impact is applied to the battery due to dropping or the like, the tip of the opposing portion of the negative electrode terminal plate made of metal buffers, and the annular portion of the gasket made of resin may be damaged, cracked, or have holes. If the gasket is cracked or has holes, there is a risk that the negative electrode mixture and the electrolyte provided inside the positive electrode can will leak through the cracks or holes.

[0005] The disclosed technology aims to provide a battery in which the gasket is less likely to be damaged.

Means for Solving the Problem

[0006] A battery according to one aspect of the present disclosure includes a positive electrode can having a cylindrical tubular portion and a bottom portion that closes one end side of the tubular portion and on which a positive electrode terminal is formed, a negative electrode terminal plate provided at an opening of the positive electrode can and on which a negative electrode terminal is formed, a gasket provided on the positive electrode terminal side of the negative electrode terminal plate and closing the opening, and a negative electrode mixture provided inside the positive electrode can. An outer edge of the negative electrode terminal has a facing portion that extends in a separation direction, which is a direction away from the bottom portion along the central axis of the tubular portion, and faces the tubular portion. An outer edge of the gasket has a clamping portion that extends in the separation direction and is clamped between the tubular portion and the facing portion, and a first annular portion that extends from an end of the clamping portion toward the central axis of the tubular portion and covers an end of the facing portion from the separation direction side. The battery further includes a hard resin layer provided between the facing portion and the clamping portion.

Effect of the Invention

[0007] According to one aspect of the battery disclosed in the present application, a battery in which the gasket is less likely to be damaged can be provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

[0009] Hereinafter, embodiments of the battery disclosed in the present application will be described in detail with reference to the drawings. Note that the battery disclosed in the present application is not limited by the following embodiments.

[0010] (Embodiment 1) <Schematic Configuration of Battery> FIG. 1 is a cross-sectional view of the battery according to Embodiment 1. The battery 1 according to Embodiment 1 includes a positive electrode can 2, a positive electrode mixture 3, a negative electrode mixture 5, a current collector rod 6, a separator 7, a gasket 14, a negative electrode terminal plate 12, a hard resin layer 8, a washer 9, and a label 10. The battery 1 is, for example, an alkaline battery.

[0011] The positive electrode can 2 is formed of a conductor exemplified by metal. The positive electrode can 2 includes a cylindrical portion 15 and a bottom portion 16. The cylindrical portion 15 is formed in a cylindrical shape. The bottom portion 16 is formed integrally with the cylindrical portion 15 so as to close one end side of the cylindrical portion 15. A positive electrode terminal 17 is formed at the center of the bottom portion 16. The positive electrode terminal 17 is formed so as to protrude from the inside to the outside of the positive electrode can 2. The other end side of the positive electrode can 2 is an opening 18. An annular second annular portion 19 extending toward the central axis of the cylindrical portion 15 is formed at the edge of the opening 18 of the positive electrode can 2.

[0012] The positive electrode mixture 3 contains manganese dioxide MnO₂, graphite C, an aqueous potassium hydroxide solution, and a binder. The binder contains, for example, a polymer compound and adheres the powder formed from manganese dioxide MnO₂ and graphite C to each other to form a solid. The positive electrode mixture 3 is formed in a cylindrical shape. The positive electrode mixture 3 is disposed inside the positive electrode can 2 such that the outer surface faces the inner peripheral surface of the cylindrical portion 15 of the positive electrode can 2. The positive electrode mixture 3 is in close contact with the positive electrode can 2 so that manganese dioxide MnO₂ and graphite C are electrically connected to the positive electrode can 2.

[0013] The negative electrode mixture 5 contains zinc powder, an aqueous potassium hydroxide solution, and a gelling agent and is in a gel state. The negative electrode mixture 5 is disposed inside the positive electrode mixture 3. Note that the zinc powder contained in the negative electrode active material may be replaced with zinc alloy powder formed from a zinc alloy containing zinc.

[0014] The current collector rod 6 is formed of a conductor and is formed in a rod shape. The current collector rod 6 is inserted into the negative electrode mixture 5 from the opening 18 side along the central axis of the cylindrical portion 15.

[0015] The separator 7 is formed of an insulator exemplified by vinylon, pulp, etc. The separator 7 is formed in a bottomed cylindrical shape and includes a cylindrical portion 21 and a bottom portion 22. The cylindrical portion 21 is formed in a cylindrical shape. The bottom portion 22 closes one end side of the cylindrical portion 21.

[0016] The separator 7 is disposed inside the positive electrode can 2 such that the cylindrical portion 21 having a cylindrical shape is coaxial with the positive electrode can 2. Further, the bottom portion 22 of the separator 7 is in contact with the bottom portion 16 of the positive electrode can 2. The cylindrical portion 21 of the separator 7 is provided between the positive electrode mixture 3 and the negative electrode mixture 5. That is, inside the positive electrode can 2, the positive electrode mixture 3 is provided outside the separator 7, and the negative electrode mixture 5 is provided inside the separator 7. The negative electrode mixture 5 is insulated from the positive electrode mixture 3 and the positive electrode can 2 by the separator 7.

[0017] Inside the positive electrode can 2, an electrolytic solution is injected. The electrolytic solution is formed from an aqueous solution containing potassium hydroxide KOH. The electrolytic solution has penetrated into the positive electrode mixture 3, the negative electrode mixture 5, and the separator 7.

[0018] The gasket 14 is formed of a resin, which is an insulator for example. Nylon is exemplified as the resin used for the gasket 14. The gasket 14 closes the opening 18 of the positive electrode can 2. The gasket 14 has a support portion 41, a valve portion 42, an outer peripheral portion 43, a clamping portion 44, and a first annular portion 45.

[0019] FIG. 2 is a partially enlarged cross-sectional view of the A portion shown in FIG. 1. The support portion 41 is provided at the center of the gasket 14. A hole 41a formed coaxially with the cylindrical portion 15 is formed in the support portion 41. The current collector rod 6 is inserted into the hole 41a. By being inserted into the hole 41a, the current collector rod 6 is supported by the gasket 14.

[0020] The valve portion 42 is formed in an annular shape so as to surround the support portion 41. As shown in FIG. 2, the valve portion 42 is formed thinner than other portions of the gasket 14. The valve portion 42 is a portion that functions as a safety valve that breaks when the internal pressure of the battery 1 rises.

[0021] The outer peripheral portion 43 is formed in an annular shape so as to surround the valve portion 42. The outer peripheral portion 43 is formed thicker than the valve portion 42. An annular groove 46 extending coaxially with the cylindrical portion 15 is formed in the outer peripheral portion 43. The portion where the groove 46 is formed functions as a buffer portion that bends when a load is applied to the gasket 14 during the manufacture of the battery 1 or the like, preventing the valve portion 42 from breaking.

[0022] The direction away from the bottom portion 16 along the central axis of the cylindrical portion 15 is defined as the separation direction. The separation direction is indicated by an arrow X in FIG. 2 and the like. The clamping portion 44 is formed so as to extend in the separation direction from the outer edge of the outer peripheral portion 43. The clamping portion 44 is formed in an annular shape so as to surround the outer peripheral portion 43. An annular first annular portion 45 extending from the end of the clamping portion 44 toward the central axis of the cylindrical portion 15 is formed in the gasket 14.

[0023] The negative electrode terminal plate 12 is formed of a conductor exemplified by metal. The negative electrode terminal plate 12 is provided at the opening 18 portion of the positive electrode can 2. More specifically, the negative electrode terminal plate 12 is provided on the opposite side of the separator 7 with the gasket 14 interposed therebetween. A certain region from the portion overlapping the central axis of the cylindrical portion 15 of the positive electrode can 2 toward the outer periphery of the negative electrode terminal plate 12 serves as the negative electrode terminal 13. One end of the current collector rod 6 is joined to the negative electrode terminal plate 12.

[0024] An opposing portion 20 extending in the separating direction and facing the cylindrical portion 15 of the positive electrode can 2 is formed on the outer edge of the negative electrode terminal 13. As shown in FIG. 2, the sandwiching portion 44 formed in the gasket 14 is sandwiched and held between the cylindrical portion 15 of the positive electrode can 2 and the opposing portion 20 of the negative electrode terminal plate 12. By sandwiching the sandwiching portion 44 between the cylindrical portion 15 and the opposing portion 20, the positive electrode can 2 and the negative electrode terminal plate 12 are electrically insulated.

[0025] Also, the end portion of the opposing portion 20 on the separating direction side is covered from the separating direction side by the first annular portion 45 formed in the gasket 14.

[0026] The hard resin layer 8 is provided between the opposing portion 20 and the sandwiching portion 44. The hard resin layer 8 is a resin layer that is applied to the inner peripheral side of the sandwiching portion 44 and then cured. For the hard resin layer 8, for example, an ultraviolet curable resin is used. The hard resin layer 8 is bonded to the opposing portion 20 and the sandwiching portion 44 to prevent the opposing portion 20 from moving in the separating direction. Thereby, it is prevented that the end portion of the opposing portion 20 collides with the first annular portion 45 and the first annular portion 45 is damaged. Thereby, it is prevented that the negative electrode mixture 5 and the electrolytic solution leak from the crack or hole of the first annular portion 45.

[0027] The washer 9 is formed of an insulator such as resin. The washer 9 has a first portion 51 and a second portion 52. The first portion 51 is inserted between the negative electrode terminal 13 and the second annular portion 19. The first portion 51 is formed in an annular shape. The second portion 52 is formed to extend outward from an end portion on the separation direction side of the first portion 51. The second portion 52 is formed in an annular shape. The second portion 52 is provided on the opposite side of the first annular portion 45 of the gasket 14 with the second annular portion 19 of the positive electrode can 2 interposed therebetween, and covers the second annular portion 19. By covering the second annular portion 19 with the second portion 52, it is possible to prevent a short circuit from occurring due to the conductor coming into contact with both the positive electrode can 2 and the negative electrode terminal plate 12.

[0028] The label 10 is formed from a sheet made of an insulator. The label 10 covers a region of the outer surface of the positive electrode can 2 excluding the positive electrode terminal 17.

[0029] <Process of assembling the positive electrode can, the gasket, and the negative electrode terminal plate> Figures 3 to 6 are diagrams for explaining the process of assembling the positive electrode can, the gasket, and the negative electrode terminal plate in the manufacturing process of the battery according to Embodiment 1. Here, a process of fitting the negative electrode terminal plate 12 into the gasket 14 and attaching the gasket 14 and the negative electrode terminal plate 12 to the opening 18 of the positive electrode can 2 in the manufacturing process of the battery 1 will be described.

[0030] First, as shown in FIG. 3, the uncured resin 8a is applied to the inner peripheral surface of the sandwiching portion 44 of the gasket 14. Next, as shown in FIG. 4, the negative electrode terminal plate 12 is inserted inside the sandwiching portion 44. In this process, the resin 8a is provided between and around the sandwiching portion 44 and the opposing portion 20.

[0031] Next, as shown in FIG. 5, the gasket 14 and the negative electrode terminal plate 12 are inserted into the cylindrical portion 15 of the positive electrode can 2. Next, as shown in FIG. 6, the resin 8a is cured by irradiating ultraviolet rays, thereby forming the hard resin layer 8.

[0032] Next, the end portion of the cylindrical portion 15 of the positive electrode can 2 on the separation direction side and the end portion of the clamping portion 44 of the gasket 14 on the separation direction side are bent inward to form a second annular portion 19 and a first annular portion 45. In this step, a part of the hard resin layer 8 is also bent. Considering the crack resistance of the hard resin layer when bent, for example, an epoxy resin may be used as the ultraviolet curable resin.

[0033] As shown in FIG. 4, the negative electrode terminal plate 12 is inserted inside the clamping portion 44 of the gasket 14. When the hard resin layer 8 is not provided, the gasket 14 and the negative electrode terminal plate 12 need to be fixed by fitting the clamping portion 44 and the opposing portion 20. Therefore, the negative electrode terminal plate 12 is formed such that the outer shape of the opposing portion 20 is slightly larger than the inner diameter of the clamping portion 44, and the negative electrode terminal plate 12 is press-fitted inside the clamping portion 44 to fix the gasket 14 and the negative electrode terminal plate 12.

[0034] On the other hand, in the first embodiment 1, the clamping portion 44 and the opposing portion 20 are joined by the hard resin layer 8, and the gasket 14 and the negative electrode terminal plate 12 are fixed. Therefore, even if there is a gap between the clamping portion 44 and the opposing portion 20, the gasket 14 and the negative electrode terminal plate 12 are fixed. Therefore, in the battery 1 of the first embodiment 1, it is not always necessary to press-fit the negative electrode terminal plate 12 inside the clamping portion 44. Note that this description does not exclude the configuration in which the negative electrode terminal plate 12 is press-fitted inside the clamping portion 44 from the configuration of the battery 1 of the first embodiment 1.

[0035] The step of irradiating ultraviolet rays to cure the ultraviolet curable resin 8a may be performed before inserting the gasket 14 and the negative electrode terminal plate 12 into the positive electrode can 2, that is, in the state shown in FIG. 4. Also, when irradiating ultraviolet rays in the state shown in FIG. 4, it may be irradiated from the outside of the clamping portion 44, and the resin 8a may be cured by the ultraviolet rays that have passed through the gasket 14 and reached the resin 8a.

[0036] Note that the step of assembling the positive electrode can, the gasket, and the negative electrode terminal plate also includes a step of inserting the current collector rod 6 into the hole 41a of the gasket 14 and a step of joining the negative electrode terminal 13 and the current collector rod 6.

[0037] <Regarding a modified example of the battery> FIG. 7 is a partially enlarged cross-sectional view of the battery of the modified example of Embodiment 1. The portion enlarged in FIG. 7 corresponds to the portion A in FIG. 1. In the battery 1 of the modified example, the second portion 52 of the washer 9 extends outward from the end portion on the side opposite to the separation direction of the first portion 51. The second portion 52 is inserted between the opposing portion 20 of the negative electrode terminal 13 and the first annular portion 45 of the gasket 14. Further, the tip of the second portion 52 is inserted into the hard resin layer 8, and the washer 9 is fixed by the hard resin layer 8.

[0038] The tip of the first portion 51 protrudes toward the separation direction side from the virtual plane connecting the negative electrode terminal 13 and the second annular portion 19. Since the tip of the first portion 51 protrudes toward the separation direction side from the virtual plane connecting the negative electrode terminal 13 and the second annular portion 19, it becomes difficult for the conductor to come into contact with the negative electrode terminal 13 and the positive electrode can 2 on the negative electrode terminal plate 12 side of the battery 1, and the occurrence of a short circuit is prevented.

[0039] In the battery 1 of Modified Example 1, since the second portion 52 of the washer 9 is inserted into the hard resin layer 8, it is necessary to assemble the washer 9 in the state of the resin 8a before the hard resin layer 8 is cured. For example, if ultraviolet rays are irradiated after the gasket 14 and the negative electrode terminal plate 12 are inserted into the positive electrode can 2, it is necessary to assemble the washer 9 in the state shown in FIG. 4 or FIG. 5. If ultraviolet rays are irradiated before the gasket 14 and the negative electrode terminal plate 12 are inserted into the positive electrode can 2, it is necessary to assemble the washer 9 in the state of FIG. 4.

[0040] <Evaluation test of the battery> The evaluation test of the above-described battery 1 was conducted. FIG. 8 is a diagram showing the results of the evaluation test. In the evaluation test, as the batteries having the configuration of the battery 1, batteries of Examples 1 to 4 having the configuration of the battery 1 were prepared in both the battery size LR20 of the single-type battery and the battery size LR6 of the AA-type battery. Further, batteries of Comparative Examples 1 and 2 were prepared for comparison in both the battery size LR20 of the single-type battery and the battery size LR6 of the AA-type battery. For each of the batteries of Examples 1 to 4 and Comparative Examples 1 and 2, a drop test, a charging test, and a leakage resistance test were conducted.

[0041] First, the batteries of Examples 1 to 4 will be described.

[0042] In the batteries of Examples 1 to 4, a hard resin layer 8 is provided. In FIG. 8, it is shown as "Yes" in the column of "Hard layer".

[0043] In the batteries of Example 1 and Example 2, the negative electrode terminal plate 12 is press-fitted inside the clamping portion 44 of the gasket 14. In FIG. 8, it is shown as "Press-fitting" in the column of "Current collector assembly".

[0044] In the batteries of Example 3 and Example 4, the negative electrode terminal plate 12 is not press-fitted inside the clamping portion 44 of the gasket 14. In FIG. 8, it is shown as "Non-press-fitting" in the column of "Current collector assembly".

[0045] In the batteries of Example 1 and Example 3, the second portion 52 of the washer 9 is provided on the separation direction side of the second annular portion 19 of the positive electrode can 2. That is, in Example 1 and Example 3, the washer 9 shown in FIG. 2 is provided. In FIG. 8, it is shown as "Placed on" in the column of "Washer".

[0046] In the batteries of Example 2 and Example 4, the second portion 52 of the washer 9 is inserted between the first annular portion 45 of the gasket 14 and the opposing portion 20 of the negative electrode terminal plate 12, and the washer 9 is fixed to the hard resin layer 8. That is, in Example 2 and Example 4, the washer 9 shown in FIG. 7 is provided. In FIG. 8, it is shown as "Incorporated" in the column of "Washer".

[0047] Next, the batteries of Comparative Example 1 and Comparative Example 2 will be described.

[0048] In the batteries of Comparative Example 1 and Comparative Example 2, the hard resin layer 8 is not provided. In FIG. 8, "none" is indicated in the column of "hard layer". The batteries of Examples 1 to 4 and the batteries of Comparative Examples 1 and 2 differ in the presence or absence of the hard resin layer 8.

[0049] In the battery of Comparative Example 1, the negative electrode terminal plate 12 is press-fitted between the clamping portions 44 of the gasket 14 ("press-fitting"), and the second portion 52 of the washer 9 is provided on the separation direction side of the second annular portion 19 of the positive electrode can 2 ("placed on").

[0050] In the battery of Comparative Example 2, the negative electrode terminal plate 12 is not press-fitted between the clamping portions 44 of the gasket 14 ("non-press-fitting"), and the second portion 52 of the washer 9 is inserted between the first annular portion 45 of the gasket 14 and the opposing portion 20 of the negative electrode terminal plate 12 ("incorporated").

[0051] Next, the test conditions and the like of various tests will be described. In each of the various tests, the number of samples n is 10.

[0052] <Drop Test> The drop test was performed using the test apparatus shown in FIG. 9. FIG. 9 is a diagram showing the schematic configuration of the apparatus used for the drop test. FIG. 10 is a cross-sectional view taken along the C-C line shown in FIG. 9. As shown in FIGS. 9 and 10, the corner of the L-shaped iron angle 61 was installed upward, and a vinyl chloride pipe 62 with an opening facing upward was installed on the corner.

[0053] The batteries of Examples 1 to 4 and the batteries of Comparative Examples 1 and 2 were dropped along the inner peripheral surface of the pipe 62 with the negative electrode terminal side facing downward. The heights from the corners of the iron angle 61 when dropping the batteries were 0.5 m, 1.0 m, 1.5 m, and 2.0 m. The drop from a height of 0.5 m assumes, for example, the drop of a battery from a low platform. The drop from a height of 1.0 m assumes the JIS drop test and the drop from waist level. The drop from a height of 1.5 m assumes, for example, the drop from face height. The drop from a height of 2.0 m assumes, for example, the drop from the height of a wall-mounted clock.

[0054] In the drop test, the deformation, heat generation, and presence of liquid leakage of the batteries were confirmed. In Fig. 8, when there is no deformation in the battery, or even if there is deformation in the battery but there is no high-temperature heat generation or liquid leakage, it is indicated as "〇". When there is deformation in the battery and there is either high-temperature heat generation or liquid leakage, it is indicated as "×". Note that liquid leakage means that the electrolyte or negative electrode mixture (mixture) provided inside the positive electrode can 2 leaks to the outside of the positive electrode can 2.

[0055] <Charge test> The battery was continuously charged with a current of 150 mA, and the jump of the washer when the valve part operated was confirmed. In Fig. 8, when there is no dropout of the washer, it is indicated as "〇". When the washer dropped but did not scatter to a distance of more than 25 cm, it is indicated as "△". There was no sample in which the washer scattered to a distance of more than 25 cm.

[0056] <Liquid leakage resistance test> The battery was subjected to a liquid leakage resistance test in a high-temperature and high-humidity environment. In Fig. 8, when there is no occurrence of liquid leakage during the specified number of days, it is indicated as "〇". When there is an occurrence of liquid leakage during the specified number of days, it is indicated as "×".

[0057] <Evaluation> As a result of the evaluation tests, in Comparative Examples 1 and 2, when dropped from a height of 1.5 m or more in the drop test, high-temperature heat generation and liquid leakage occurred. On the other hand, in Examples 1 to 4, high-temperature heat generation and liquid leakage did not occur regardless of the height from which the battery was dropped in the drop test. From this, it can be seen that by providing the hard resin layer 8, it becomes difficult for high-temperature heat generation and liquid leakage to occur when the battery drops. This is presumably because the hard resin layer 8 prevents the tip of the opposing portion 20 of the negative terminal plate 12 from colliding with the first annular portion 45 due to the impact during dropping or the like, thereby damaging the first annular portion 45, and the negative terminal plate 12 is fixed.

[0058] Also, the dropping and flying of the washer in the charging test are less likely to occur when the second portion 52 is inserted between the first annular portion 45 and the opposing portion 20.

[0059] Also, in the liquid leakage resistance test, liquid leakage has occurred in the battery of Comparative Example 2. The battery of Comparative Example 2 is not provided with the hard resin layer 8, and the negative terminal plate 12 is not press-fitted between the clamping portions 44.

[0060] Since the negative terminal plate 12 is not press-fitted, the gap between the opposing portion 20 and the clamping portion 44 is wider than when it is press-fitted, and there is room for the clamping portion 44 to move toward the opposing portion 20. Therefore, it is considered that liquid leakage has occurred from between the clamping portion 44 and the cylindrical portion 15 of the positive can 2. Here, in Examples 3 and 4 as well, since the negative terminal plate 12 is not press-fitted, the gap between the opposing portion 20 and the clamping portion 44 is wide, but the hard resin layer 8 is provided, so that the clamping portion 44 cannot move toward the opposing portion 20. Therefore, it is considered that it is difficult for liquid leakage to occur from between the clamping portion 44 and the cylindrical portion 15 of the positive can 2.

[0061] Therefore, by providing the hard resin layer 8, it becomes possible to prevent the occurrence of liquid leakage without press-fitting the negative electrode terminal plate 12 inside the clamping portion 44. If it is not necessary to press-fit the negative electrode terminal plate 12, the operation of assembling the negative electrode terminal plate 12 to the gasket 14 becomes easier. Also, it is possible to prevent the gasket 14 and the negative electrode terminal plate 12 from being damaged by the load applied during press-fitting.

[0062] <Effect> In the battery 1 of Embodiment 1, a positive electrode can 2 having a cylindrical tube portion 15 and a bottom portion 16 that closes one end side of the tube portion 15 and on which a positive electrode terminal 17 is formed, a negative electrode terminal plate 12 provided at the opening 18 of the positive electrode can 2 and on which a negative electrode terminal 13 is formed, a gasket 14 provided on the positive electrode terminal 17 side of the negative electrode terminal plate 12 and closing the opening 18, and a negative electrode mixture 5 provided inside the positive electrode can 2. An opposing portion 20 extending in the separation direction and facing the tube portion 15 is formed on the outer edge of the negative electrode terminal 13 when the direction away from the bottom portion 22 along the central axis of the tube portion 15 is defined as the separation direction. On the outer edge of the gasket 14, a clamping portion 44 extending in the separation direction and clamped between the tube portion 15 and the opposing portion 20, and a first annular portion 45 extending from the end of the clamping portion 44 toward the central axis of the tube portion 15 and covering the end of the opposing portion 20 from the separation direction side are formed. The battery further includes a hard resin layer 8 provided between the opposing portion 20 and the clamping portion 44.

[0063] Due to the hard resin layer 8 provided between the opposing portion 20 and the clamping portion 44, the gasket 14 and the negative electrode terminal plate 12 are fixed. Therefore, when an impact is applied to the battery due to dropping or the like, it becomes difficult for the opposing portion 20 to collide with the first annular portion 45. Since it becomes difficult for the opposing portion 20 to collide with the first annular portion 45, it becomes difficult for the first annular portion 45 to be damaged by the opposing portion 20, and it becomes difficult for the negative electrode mixture 5 and the electrolytic solution to leak.

[0064] Since the gasket 14 and the negative terminal plate 12 are fixed by the hard resin layer 8, it is not necessary to press-fit the negative terminal plate 12 inside the clamping portion 44 when assembling the negative terminal plate 12 to the gasket 14. As a result, the working load when assembling the negative terminal plate 12 to the gasket 14 is reduced, and it is possible to prevent the gasket 14 and the negative terminal plate 12 from being damaged by the load applied during press-fitting.

[0065] Also, the hard resin layer 8 is formed of an ultraviolet curable resin. By using an ultraviolet curable resin, it becomes easier to control the timing at which the resin cures. By using an ultraviolet curable resin, it is possible to shorten the curing time.

[0066] Further, the battery 1 has a second annular portion 19 that extends toward the central axis of the cylindrical portion 15 and overlaps the first annular portion 45 at the edge of the opening 18, and a first portion 51 inserted between the negative terminal 13 and the second annular portion 19, and a washer 9 having a second portion 52 provided on the opposite side of the first annular portion 45 with the second annular portion 19 interposed therebetween and covering the second annular portion 19. By providing the washer 9 having the second portion 52 that covers the second annular portion 19, it becomes difficult for a conductor to come into contact with the negative terminal 13 and the positive can 2 on the negative terminal plate 12 side of the battery 1, and the occurrence of a short circuit is prevented.

[0067] Also, a second annular portion 19 that extends toward the central axis of the cylindrical portion 15 and overlaps the first annular portion 45 is formed at the edge of the opening 18, and the battery 1 further includes a washer 9 having a first portion 51 inserted between the negative terminal 13 and the second annular portion 19, and a second portion 52 inserted between the first annular portion 45 and the opposing portion 20. The tip of the first portion 51 protrudes toward the separation direction side from a virtual plane connecting the negative terminal 13 and the second annular portion 19, and the tip of the second portion 52 is inserted into the hard resin layer 8.

[0068] By providing the washer 9 having the first portion 51 that protrudes toward the separation direction side from the virtual plane, it becomes difficult for a conductor to come into contact with the negative terminal 13 and the positive can 2 on the negative terminal plate 12 side of the battery 1, and the occurrence of a short circuit is prevented.

[0069] When the second part 52 of the washer 9 is inserted into the hard resin layer 8, the washer 9 is coupled to the hard resin layer 8. Since the washer 9 is coupled to the hard resin layer 8, it is less likely that the washer 9 will fall off even when the internal pressure of the battery 1 increases and the valve portion 42 operates.

[0070] Further, the method for manufacturing the battery according to Embodiment 1 includes a step of applying an ultraviolet curable resin to the inner peripheral surface of the sandwiching portion 44, a step of inserting the opposing portion 20 inside the sandwiching portion 44, and a step of irradiating the ultraviolet curable resin with ultraviolet rays to cure it to form the hard resin layer 8.

[0071] Since the ultraviolet curable resin is applied to the inner peripheral surface of the sandwiching portion 44 before the opposing portion 20 is inserted, it is easy to apply the ultraviolet curable resin, and the working efficiency is improved.

[0072] Further, the ultraviolet irradiation is performed from the gap between the sandwiching portion 44 and the opposing portion 20. Since the ultraviolet rays are irradiated from the gap between the sandwiching portion 44 and the opposing portion 20, an ultraviolet irradiation step can be provided after the gasket 14 and the negative electrode terminal plate 12 are assembled to the positive electrode can 2.

[0073] Further, the ultraviolet irradiation is performed by transmitting the ultraviolet rays through the gasket 14 from the surface side facing the bottom portion 16. Since the ultraviolet irradiation is performed by transmitting the ultraviolet rays through the gasket 14 from the surface side facing the bottom portion 16, it becomes easy to irradiate the entire hard resin layer 8a with ultraviolet rays uniformly. Note that if the gasket 14 and the negative electrode terminal plate 12 are assembled to the positive electrode can 2, the surface of the gasket 14 facing the bottom portion 16 is covered by the positive electrode can 2, and thus the ultraviolet rays cannot be irradiated to the surface facing the bottom portion 16. Therefore, when performing the ultraviolet irradiation by transmitting the ultraviolet rays through the gasket 14 from the surface side facing the bottom portion 16, it is necessary to provide an ultraviolet irradiation step before assembling the gasket 14 and the negative electrode terminal plate 12 to the positive electrode can 2.

Description of Reference Numerals

[0074] 1 Battery 2 Positive electrode can 3 Positive electrode mixture 5 Negative electrode mixture 6 Current collector 7 Separator 8 Hard resin layer 8a Resin 9 Washer 10 Label 12 Negative electrode terminal plate 13 Negative electrode terminal 14 Gasket 15 Cylindrical part 16 Bottom part 17 Positive electrode terminal 18 Opening 19 Second annular part 20 Opposing part 21 Cylindrical part 22 Bottom part 41 Support part 41a Hole 42 Valve part 43 Outer peripheral part 44 Clamping part 45 First annular part 46 Groove 51 First part 52 Second part

Claims

1. A positive electrode can having a cylindrical tube portion and a bottom portion that closes one end side of the tube portion and on which a positive electrode terminal is formed, a negative electrode terminal plate provided at the opening of the positive electrode can and on which a negative electrode terminal is formed, a gasket provided on the positive electrode terminal side with respect to the negative electrode terminal plate and closing the opening, and a negative electrode mixture provided inside the positive electrode can, wherein on the outer edge of the negative electrode terminal, when the direction away from the bottom portion along the central axis of the tube portion is defined as the separation direction, an opposing portion is formed that extends in the separation direction and faces the tube portion, on the outer edge of the gasket, a clamping portion that extends in the separation direction and is clamped between the tube portion and the opposing portion, and a first annular portion that extends from the end of the clamping portion toward the central axis of the tube portion and covers the end of the opposing portion from the separation direction side are formed, A battery further comprising a hard resin layer provided between the opposing portion and the clamping portion.

2. The battery according to claim 1, wherein the hard resin layer is formed of an ultraviolet curable resin.

3. On the edge of the opening, a second annular portion is formed that extends toward the central axis of the tube portion and overlaps the first annular portion, The battery according to claim 1, further comprising a washer having a first portion inserted between the negative electrode terminal and the second annular portion and a second portion provided on the opposite side of the first annular portion with the second annular portion interposed therebetween and covering the second annular portion.

4. On the edge of the opening, a second annular portion is formed that extends toward the central axis of the tube portion and overlaps the first annular portion, The battery further comprises a washer having a first portion inserted between the negative electrode terminal and the second annular portion and a second portion inserted between the first annular portion and the opposing portion, the tip of the first portion protrudes to the separation direction side from a virtual plane connecting the negative electrode terminal and the second annular portion, The battery according to claim 1, wherein the tip of the second portion is inserted into the hard resin layer.

5. A method for manufacturing the battery according to claim 2, comprising: a step of applying an ultraviolet curable resin to the inner peripheral surface of the clamping portion; a step of inserting the opposing portion inside the clamping portion; a step of irradiating the ultraviolet curable resin with ultraviolet rays to cure it into the hard resin layer.

6. The method for manufacturing a battery according to claim 5, wherein the ultraviolet ray irradiation is performed from a gap between the clamping portion and the opposing portion.

7. The method for manufacturing a battery according to claim 5, wherein the ultraviolet irradiation is performed by transmitting through the gasket from the surface side facing the bottom portion.

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