JP6726622B2 - Flat battery and its assembly member - Google Patents

Description

The present invention relates to a flat battery and a member for assembling the flat battery.

Conventionally, an outer can is provided with a bottomed cylindrical outer can and a sealing can arranged inside the outer can to maintain the airtightness inside the battery and to ensure electrical insulation between the outer can and the sealing can. As a flat battery in which a resin gasket is arranged between the sealing can and the sealing can, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 2012-190758.

Japanese Unexamined Patent Application Publication No. 2012-190758 includes an outer can, a sealing can, and a gasket integrally formed on the peripheral wall of the sealing can, and the gasket has a gasket tip portion that functions as a seal between the sealing can and the outer can. And a gasket outer portion that presses the gasket tip against the bottom of the outer can when the outer can is fitted in the sealing can, and the opening end of the peripheral wall of the outer can is fitted in the outer gasket. There is disclosed a flat battery in which a protrusion is provided at a certain position.

In the flat battery of JP2012-190758A, the protrusion is formed such that the side surface located on the base end side of the sealing can is located inside the sealing can rather than the outer surface of the expanded portion of the sealing can. Has been done. Therefore, when the opening end of the peripheral wall of the outer can is caulked against the step of the sealing can, the force pressing the protrusion is transmitted to the gasket tip through the gasket outer side, and the gasket tip is moved to the outer can. It can be pressed harder against the bottom of the.

By the way, in the flat battery of JP 2012-190758 A, a part of the gasket outer part formed so as to cover the outer surface of the step part of the sealing can at a position facing the protruding part of the gasket outer part (hereinafter, referred to as X part) exists. When the opening end portion of the peripheral wall portion of the outer can is caulked to the step portion of the sealing can, the X portion comes into contact with the protrusion portion of the gasket outer portion and directly applies the pressing force applied to the protrusion portion of the gasket outer portion. It is the part to receive.

That is, the flat battery disclosed in JP 2012-190758 A has a structure in which, due to the presence of the X portion, the protruding portion of the gasket outer portion does not directly contact the outer surface of the step portion of the sealing can. Therefore, a part of the pressing force applied to the protruding portion on the outer side of the gasket is absorbed and dispersed in the X portion, and all of the pressing force cannot be sufficiently transmitted to the stepped portion of the sealing can. As a result, the pressing force of the gasket tip portion against the bottom portion of the outer can is reduced, and there is a problem that the airtightness inside the battery is reduced.

An object of the present invention is to provide a flat battery in which the airtightness inside the battery is further improved by enhancing the sealing performance of the gasket.

Another object of the present invention is to provide a member for assembling a flat battery in which the airtightness inside the battery is further improved by enhancing the sealing performance of the gasket.

According to the embodiment of the present invention, a flat battery is a flat battery that includes an outer can, a sealing can, and a gasket, and has an open end of a peripheral wall of the outer can crimped and sealed. The outer can has a cylindrical peripheral wall. The sealing can is disposed inside the peripheral wall of the outer can and has a cylindrical peripheral wall smaller than the outer diameter of the outer can. The gasket is arranged between the peripheral wall of the outer can and the peripheral wall of the sealing can. The peripheral wall of the sealing can has a base end portion on the bottom side, an enlarged diameter portion on the opening end side formed larger than the outer diameter of the base end portion, and a step portion between the base end portion and the enlarged diameter portion. Have and. The gasket covers the outer surface of the expanded diameter portion of the sealing can and is arranged between the outer cylindrical portion in contact with the stepped portion of the sealing can, the expanded diameter portion of the sealing can and the bottom portion of the outer can, and the outer can. And a protrusion that contacts the bottom of the. On the outer can side of the portion of the outer tube portion that is in contact with the stepped part of the sealing can, a rising portion that protrudes in the radial direction of the sealing can from the sealing can side is formed. With the open end of the peripheral wall of the outer can being crimped, the rising portion of the gasket contacts at least a part of the base end of the peripheral wall of the sealing can.

According to the embodiment of the present invention, a member for assembling the flat battery is the member for assembling the flat battery, and includes a sealing can and a gasket. The sealing can has a cylindrical peripheral wall. The gasket has a substantially cylindrical shape integrated with the sealing can. The peripheral wall of the sealing can has a base end portion on the bottom side, an enlarged diameter portion on the opening end side formed larger than the outer diameter of the base end portion, and a step portion between the base end portion and the enlarged diameter portion. Have. The gasket includes an outer cylindrical portion that covers the outer surface of the expanded diameter portion of the sealing can, is in contact with the stepped portion of the sealing can, and a protrusion that is connected to the outer cylindrical portion and covers the open end of the expanded diameter portion. On the outer surface side of the portion of the outer tubular portion that contacts the stepped portion of the sealing can, a rising portion that projects in the axial direction of the sealing can from the side of the sealing can is formed. The width A of the rising portion is smaller than the width B of the outer cylindrical portion that covers the outer surface of the expanded diameter portion. The height h of the rising portion and the width t of the outer tubular portion on the inner side of the rising portion satisfy h>t.

1 is a sectional view showing a schematic configuration of a flat battery according to an embodiment of the present invention. It is a partial expanded sectional view which expands and shows the structure of the electrode body in a flat type battery in a cross section. It is a partial expanded sectional view which expands and shows the step part vicinity of a sealing can. It is a figure which shows a mode at the time of mold-molding a gasket to a sealing can. It is an expanded sectional view which expands and shows a gasket. It is sectional drawing in the state before and after crimping the peripheral wall of a sealing can on the peripheral wall of an exterior can.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and description thereof will not be repeated. In addition, in order to make the description easy to understand, in the drawings referred to below, the configuration is shown in a simplified or schematic manner, or some of the constituent members are omitted. Further, the dimensional ratios between the constituent members shown in the respective drawings do not necessarily indicate the actual dimensional ratios.

[overall structure]
Referring to FIG. 1, flat battery 1 according to the embodiment of the present invention mainly includes an outer can 10, a sealing can 20, a gasket 30, and an electrode body 40.

More specifically, as shown in FIG. 1, the flat battery 1 includes an outer can 10 having a cylindrical peripheral wall, an outer can 10 disposed inside the outer can, and an outer diameter of the outer can 10. A sealing can 20 having a small cylindrical peripheral wall, a gasket 30 arranged between the outer can 10 and the sealing can 20, and a space formed between the outer can 10 and the sealing can 20. And an electrode body 40. Note that FIG. 1 shows a state in which the open end of the peripheral wall 12 of the outer can 10 is caulked to the peripheral wall 22 of the sealing can 20.

The flat battery 1 becomes a flat coin shape as a whole by combining the outer can 10 and the sealing can 20. In the space formed between the outer can 10 and the sealing can 20 of the flat battery 1, a non-aqueous electrolytic solution (not shown) is sealed in addition to the electrode body 40.

In the flat battery 1 according to the embodiment of the present invention, the outer can 10 is a positive can and the sealing can 20 is a negative can.

The outer can 10 is made of a metal material such as stainless steel, and is formed into a cylindrical shape with a bottom by press molding. The outer can 10 includes a circular bottom portion 11 and a cylindrical peripheral wall 12 formed on the outer periphery of the bottom portion 11 so as to be continuous with the bottom portion 11. Further, as shown in FIG. 1, the bottom portion 11 includes a circular bottom portion 11a on which the electrode body 40 is arranged, and a cylindrical bottom portion 11b in a step portion formed on the outer peripheral side of the bottom portion 11a.

As shown in FIG. 1, the peripheral wall 12 extends in the vertical direction (the same direction as the alternate long and short dash line P in FIG. 1) from the outer peripheral end of the bottom portion 11b in a vertical sectional view. Here, the symbol P in FIG. 1 indicates a cylinder axis of the outer can 10 and the sealing can 20. That is, the peripheral wall 12 extends in the upward direction of the cylinder axis P of the outer can 10.

Like the outer can 10, the sealing can 20 is made of a metal material such as stainless steel and is formed into a cylindrical shape with a bottom by press molding. The sealing can 20 has a substantially cylindrical peripheral wall 22 having an outer shape smaller than that of the peripheral wall 12 of the outer can 10, and a circular flat portion 21 that closes one opening of the peripheral wall 22.

As shown in FIG. 1, the peripheral wall 22 extends downward from the outer peripheral end of the flat surface portion 21 in the direction of the cylinder axis P, and is formed as a straight can without a folded-back portion at the tip of the peripheral wall 22.

The peripheral wall 22 of the sealing can 20 has a base end portion 22a, an enlarged diameter portion 22b, and a step portion 22c. As shown in FIG. 1, the base end portion 22a extends downward from the outer peripheral end of the flat portion 21 in the cylinder axis P. As shown in FIG. 1, the enlarged diameter portion 22b is formed larger than the outer diameter of the base end portion 22a, and has a shape that expands the opening end of the peripheral wall 22 in a stepwise manner. The step portion 22c has a shape in which the opening end of the peripheral wall 22 is expanded in a step shape. In other words, the base end portion 22a extends from the step portion 22c and extends on the side opposite to the bottom portion 11b of the outer can 10. The step portion 22c is arranged between the base end portion 22a and the enlarged diameter portion 22b, and is connected to the base end portion 22a and the enlarged diameter portion 22b.

As shown in FIG. 1, the gasket 30 has a substantially cylindrical shape, is arranged between the peripheral wall 12 of the outer can 10 and the peripheral wall 22 of the sealing can 20, and electrically connects the outer can 10 and the sealing can 20. Ensure insulation. The gasket 30 covers the inner surface and the outer surface of the peripheral wall 22 of the sealing can 20, is in contact with the inner surface of the peripheral wall 12 of the outer can 10, and protrudes downward from the opening end of the peripheral wall 22 along the cylinder axis P of the sealing can 20. Contacts the bottom portion 11b of the outer can 10.

The gasket 30 is made of polypropylene (PP). However, the material of the gasket 30 is not limited to polypropylene, and may be a resin composition containing polyphenylene sulfide (PPS) containing an olefin elastomer, polytetrafluoroethylene (PFA), a polyamide resin, or the like.

As shown in FIG. 2, the electrode body 40 includes a plurality of positive electrodes 41 and a plurality of negative electrodes 46.

The electrode body 40 is formed by alternately stacking a plurality of positive electrodes 41 and a plurality of negative electrodes 46 in a space formed between the bottom portion 11 a of the outer can 10 and the flat portion 21 of the sealing can 20. The electrode body 40 has a substantially columnar shape as a whole as such a laminated structure.

Further, the electrode body 40 has a plurality of positive electrodes 41 and a plurality of negative electrodes 46 arranged such that both polarities located at both ends in the direction of the cylinder axis P are negative. That is, the negative electrodes 46 are arranged at both ends of the electrode body 40.

The plurality of positive electrodes 41 have a substantially disc shape. As shown in FIG. 2, each of the plurality of positive electrodes 41 has a positive electrode active material layer 42 containing a positive electrode active material such as lithium cobalt oxide on both sides of a positive electrode current collector 43 made of a metal foil such as aluminum. It is a thing. As shown in FIG. 2, the plurality of positive electrodes 41 are respectively housed in a plurality of separators 44 having a bag shape.

The separator 44 is a bag-shaped member formed in a circular shape in a plan view, and has a size capable of accommodating the substantially disk-shaped positive electrode 41. The separator 44 is made of a polyethylene material having an excellent insulating property.

The separator 44 is made of a microporous thin film. Thereby, lithium ions can pass through the separator 44. The separator 44 is formed by wrapping the positive electrode 41 with a sheet material of a rectangular microporous thin film and adhering it to a portion where the sheet materials overlap by heat welding or the like.

As shown in FIGS. 1 and 2, the positive electrode collector 43 of the positive electrode 41 is integrally connected to a conductive positive electrode lead 51 extending rightward with respect to the cylinder axis P. The positive electrode lead 51 is partially covered with the separator 44 at a portion near the positive electrode current collector 43.

As shown in FIG. 1, each of the plurality of positive electrode leads 51 is exposed to the outside of the separator 44 from a position where it is connected to the positive electrode current collector 43, and converges at a position on the right side with respect to the cylinder axis P.

A positive electrode current collector 43 having no positive electrode active material layer 42 is arranged between the insulating sheet 49 and the bottom 11 a of the outer can 10. That is, the positive electrode current collector 43 is in electrical contact with the bottom portion 11 a of the outer can 10.

The plurality of negative electrodes 46 have a substantially disc shape. As shown in FIG. 2, each of the negative electrodes 46 has a negative electrode active material layer 47 containing a negative electrode active material such as graphite on both sides of a negative electrode current collector 48 made of a metal foil such as copper.

However, the negative electrode active material layer 47 is arranged only on one surface of the negative electrode current collector 48, which is the position facing the positive electrode 41, in the negative electrode 46 arranged on the outer can 10 side and the sealing can 20 side.

More specifically, in the negative electrode 46 arranged on the side of the outer can 10, the negative electrode active material layer 47 is arranged only on one surface of the negative electrode current collector 48. That is, the negative electrode 46 arranged on the side of the outer can 10 is, as shown in FIG. 2, the upper surface of the insulating sheet 49 located above the positive electrode 41 (positive electrode current collector 43) arranged on the bottom 11 a of the outer can 10. On the other hand, the negative electrode active material layer 47 is not arranged, and the negative electrode current collector 48 is arranged in direct contact with the negative electrode current collector 48.

Further, also with respect to the negative electrode 46 arranged on the side of the sealing can 20, the negative electrode active material layer 47 is arranged only on one surface of the negative electrode current collector 48. That is, as shown in FIG. 1, the negative electrode 46 arranged on the sealing can 20 side is arranged so that the negative electrode current collector 48 directly contacts the flat surface portion 21 of the sealing can 20.

As shown in FIGS. 1 and 2, the negative electrode current collector 48 is integrally connected to a conductive negative electrode lead 52 extending leftward with respect to the cylinder axis P.

As shown in FIG. 1, each of the negative electrode leads 52 converges at a position on the left side of the cylinder axis P from a position where the negative electrode 46 is connected to the negative electrode current collector 48.

The tip ends of the plurality of positive electrode leads 51 are overlapped in the thickness direction and are connected by ultrasonic welding or the like. As a result, the plurality of positive electrodes 41 are electrically connected to each other via the plurality of positive electrode leads 51, and each positive electrode 41 and the outer can 10 are electrically connected.

With respect to the plurality of negative electrode leads 52 as well, in the state where the plurality of positive electrodes 41 and the negative electrodes 46 are stacked, the tip ends are overlapped in the thickness direction and are connected to each other by ultrasonic welding or the like. As a result, the plurality of negative electrodes 46 are electrically connected to each other via the plurality of negative electrode leads 52, and each negative electrode 46 and the sealing can 20 are electrically connected.

[Composition of gasket]
The configuration of the gasket 30 will be described in detail.

As shown in FIG. 1, the gasket 30 is arranged between the outer tubular portion 31 and the inner tubular portion 32 that cover the peripheral wall 22 of the sealing can 20, the peripheral wall 22 of the sealing can 20 and the bottom portion 11b of the outer can 10, The projecting portion 33 is in contact with the bottom portion 11 b of the outer can 10.

The outer cylinder portion 31 covers the outer surface of the peripheral wall 22 of the sealing can 20, contacts the base end portion 22 a and the step portion 22 c of the sealing can 22, and protrudes outward from the open end of the peripheral wall 12 of the outer can 10. The outer cylinder portion 31 is connected to the protruding portion 33 near the opening end of the peripheral wall 22 of the sealing can 20.

As shown in FIG. 1, the outer cylinder part 31 covers the outer surface from the base end part 22a which constitutes the peripheral wall 22 of the sealing can 20 to the opening end of the enlarged diameter part 22b, and the peripheral wall 12 of the exterior can 10 and the sealing can. The space between the peripheral wall 22 and the peripheral wall 22 is maintained in a sealed state.

Here, as shown in FIG. 1, the outer cylinder portion 31 extends in the radial direction of the sealing can 20 from the base end portion 22a to a portion from the peripheral wall 22 of the sealing can 20 to the peripheral wall 12 side of the outer can 10. Has a boundary portion L. More specifically, as shown in FIG. 3, the boundary portion L represents a contact portion between the curved portion 31a and a portion of the outer cylindrical portion 31 that covers the outer surface of the expanded diameter portion 22b.

Further, the outer cylinder portion 31 includes a curved portion 31a. As shown in FIGS. 1 and 3, the curved portion 31a is in contact with the outer surface of the base end portion 22a that forms the peripheral wall 22 of the sealing can 20, and is connected to the base end portion 22a and the step portion 22c of the sealing can 20. The space formed between the peripheral wall 12 of the outer can 10 and the curved portion on the open end side is sealed.

As described above, in the flat battery 1, the space between the peripheral wall 12 of the outer can 10 and the peripheral wall 22 of the sealing can 20 is maintained in a totally sealed state, so that the sealing performance of the gasket 30 is enhanced, The airtightness inside the battery is further improved.

Further, the end portion of the curved portion 31a of the outer tubular portion 31 projects outside the open end of the peripheral wall 12 of the outer can 10. More specifically, as shown in FIG. 3, the curved portion 31 a is sandwiched between the base end portion 22 a of the sealing can 20 and the open end of the peripheral wall 12 of the outer can 10. In particular, the end portion of the curved portion 31a is in a state of protruding to the outside from between the open end of the peripheral wall 12 of the outer can 10 and the base end 22a of the sealing can 20.

That is, since the gasket 30 seals between the base end 22 a of the sealing can 20 and the opening end of the peripheral wall 12 of the outer can 10, the gasket 30 is sealed between the peripheral wall 12 of the outer can 10 and the peripheral wall 22 of the sealing can 20. It is possible to further improve the airtightness in the space. Furthermore, since the curved portion 31a is sandwiched between the base end portion 22a of the sealing can 20 and the opening end of the peripheral wall 12 of the outer can 10, and the end portion of the curved portion 31a projects to the outside, the sealing can It is possible to prevent contact between the base end portion 22a of 20 and the open end of the peripheral wall 12 of the outer can 10 and maintain the electrically insulated state between the outer can 10 and the sealing can 20.

The inner cylindrical portion 32 covers the inner surface of the peripheral wall 22 of the sealing can 20. More specifically, as shown in FIG. 1, the inner cylindrical portion 32 extends from the inner surface of the step portion 22 c of the peripheral wall 22 to the open end of the peripheral wall 22 of the sealing can 20 and extends to the inner surface of the peripheral wall 22 of the sealing can 20. Is formed in a substantially cylindrical shape so as to cover the. The inner peripheral surface of the inner cylindrical portion 32 is formed to be substantially flush with the inner peripheral surface of the base end portion 22 a of the peripheral wall 22. The inner cylindrical portion 32 is connected to the protruding portion 33 near the opening end of the peripheral wall 22 of the sealing can 20.

The protruding portion 33 contacts the bottom portion 11b of the outer can 10. When the peripheral wall 12 of the outer can 10 is caulked to the peripheral wall 22 of the sealing can 20, the tip portion of the protruding portion 33 is pressed against the bottom portion 11b of the outer can 10, and the peripheral wall 12 of the outer can 10 and the peripheral wall 22 of the sealing can 20 are The space between is sealed.

The inner cylindrical portion 32 and the protruding portion 33 are sandwiched between the step portion 22c of the sealing can 20 and the bottom portion 11b of the outer can 10 by the pressing force applied to the peripheral wall 12 of the outer can 10 when caulking. Then, as shown in FIG. 1, the inner cylindrical portion 32 and the protruding portion 33 are pressed against the bottom portion 11 b of the outer can 10 more strongly, so that the inner surface is concave toward the peripheral wall 12 of the outer can 10. ing. Therefore, the protruding portion 33 and the bottom portion 11b of the outer can 10 are more hermetically sealed.

[Production method]
The flat battery 1 according to the embodiment of the present invention is obtained through the following manufacturing steps.

First, the outer can 10 and the sealing can 20 are manufactured by press molding.

The electrode body 40 is formed by alternately stacking a plurality of plate-shaped positive electrodes 41 covered with a separator 44 and a plurality of plate-shaped negative electrodes 46 in the thickness direction. Since the electrode body 40 is manufactured by the same method as the conventional method, the detailed description of the manufacturing method is omitted.

The step of molding the gasket 30 on the sealing can 20 will be described with reference to FIG.

As shown in FIG. 4, the fixed molding die 61, the movable molding die 62, and the piston movable molding die 63 having a ring-shaped cross section are arranged outside the sealing can 20, and the pin 64 is arranged inside the sealing can 20. Deploy. A molding die for molding the gasket 30, that is, a space 60 for forming the gasket 30 is formed around the peripheral wall 22 of the sealing can 20 by the molding dies 61, 62, 63 and the pin 64.

The fixed molding die 61 has an injection port (not shown) for injecting a resin material into the space 60 from the outside. The molten resin material is injected into the space 60 from this injection port, and the space 60 is filled with the resin material.

After the resin material in the space 60 is cured and the gasket 30 is molded, the movable mold 62 is removed. Then, by moving the piston movable molding die 63 in the axial direction of the pin 64 (the direction of the white arrow in FIG. 4), the sealing can 20 molded with the gasket 30 is detached from the pin 64 and the fixed molding die 61. Let

The fixed molding die 61 is formed in a tapered shape such that the inner diameter thereof gradually increases toward the step portion 22c of the peripheral wall 22 of the sealing can 20 in a portion for molding the outer peripheral surface of the cylindrical gasket 30. Due to this shape, when the gasket 30 is pushed by the movable piston mold 63, the sealing can 20 can be easily detached from the fixed mold 61.

As shown in FIG. 4, the movable mold 62 includes a convex portion 62a and a concave portion 62b. The convex portion 62a is in contact with the base end portion 22a and the step portion 22c of the sealing can 20 during molding. The concave portion 62b is formed at a position adjacent to the outside of the convex portion 62a, and is a portion where the resin material melted from the injection port is filled as a part of the space 60.

As shown in FIG. 5, at least part of the outer surface of the step portion 22c and the outer surface of the base end portion 22a are not covered with the gasket 30 and are exposed to the outside by the protrusions 62a after molding. Has become. The outer surface of the step portion 22c may not be covered by the gasket 30 at all.

In addition, as shown in FIG. 5, the gasket 30 after molding rises above the step portion 22c of the sealing can 20 as a part of the outer cylinder portion 31 at the position of the concave portion 62b of the movable molding die 62. A rising portion Z is formed. The outer surface of the rising portion Z is connected to the outer surface of the outer tubular portion 31 other than the rising portion Z. Further, as shown in FIG. 5, the rising portion Z is formed such that its lateral width (dimension A) is smaller than the lateral width (dimension B) of the portion covering the expanded diameter portion 22b of the sealing can 20.

Further, when the height of the rising portion Z is h and the width of the outer tubular portion 31 on the inner side of the rising portion Z is t, the height h and the width t satisfy h>t. Further, the height h and the dimension A satisfy h>A.

When the height h and the width t satisfy h>t, when the peripheral wall 12 of the outer can 10 is caulked, the rising portion Z of the gasket 30 easily comes into contact with the base end 22a of the sealing can 20, and the sealing can 20 The peripheral wall 22 is pushed toward the bottom 11 of the outer can 10. As a result, the protruding portion 33 of the gasket 30 is strongly pressed against the bottom portion 11b of the outer can 10.

Therefore, the sealing performance of the gasket is enhanced, and the airtightness inside the battery can be improved.

Further, when the height h and the dimension A satisfy h>A, when the peripheral wall 12 of the outer can 10 is caulked, the rising portion Z of the gasket 30 easily bends toward the base end 22a side of the sealing can 20 to cause the sealing. It becomes easy to contact the base end portion 22a of the can 20. As a result, as described above, the sealing performance of the gasket is improved, and the airtightness inside the battery can be improved.

In the embodiment of the present invention, if the rising portion Z of the gasket 30 is in contact with at least a part of the base end portion 22a of the peripheral wall 22 of the sealing can 20, with the peripheral wall 12 of the outer can 10 being caulked. Good. With such a configuration, the space between the peripheral wall 12 of the outer can 10 and the peripheral wall 22 of the sealing can 20 is sealed, and the airtightness inside the battery can be improved.

Next, a process of combining the outer can 10 and the sealing can 20 will be described.

First, the electrode body 40 is placed in the outer can 10 together with the insulating sheet 49 and the like, and the nonaqueous electrolytic solution is injected. Here, the non-aqueous electrolytic solution is obtained, for example, by dissolving LiPF ₆ in a solvent in which ethylene carbonate and methyl ethyl carbonate are mixed.

Then, the outer can 10 and the sealing can 20 in which the gasket 30 is molded are put together to obtain the state shown in the upper diagram of FIG. From this state, as shown in the lower diagram of FIG. 6, the open end of the peripheral wall 12 of the outer can 10 is crimped in the direction toward the peripheral wall 22 of the sealing can 20.

Here, as shown in the upper diagram of FIG. 6, the outer cylinder portion 31 of the gasket 30 has a rising portion Z before the peripheral wall 12 of the outer can 10 is caulked to the peripheral wall 22 of the sealing can 20. The rising portion Z is formed so that the width dimension (dimension A shown in FIG. 5) is smaller than the width dimension (dimension B shown in FIG. 5) of the portion covering the outer surface of the expanded diameter portion 22b of the sealing can 20, and the outer can. 10 is extended on the opposite side to the bottom 11b.

In addition, at a stage before caulking the peripheral wall 12 of the outer can 10 to the peripheral wall 22 of the sealing can 20, at least a part of the outer surface of the step portion 22c and the outer surface of the base end portion 22a are not covered with the gasket 30, It is exposed to.

When caulking the peripheral wall 12 of the outer can 10 to the peripheral wall 22 of the sealing can 20, the rising portion Z is bent toward the peripheral wall 22 of the sealing can 20 while the peripheral wall 12 of the outer can 10 is bent. After caulking the peripheral wall 12 of the outer can 10, as shown in the lower diagram of FIG. 6, the rising portion Z serves as a curved portion 31a and is exposed to the outside without being covered by the gasket 30, and thus the base end 22a of the sealing can 20 is exposed . It comes into contact with the outer surface.

In this way, the pressing force applied to the peripheral wall 12 of the outer can 10 is not absorbed by the other parts of the gasket 30 but is directly transmitted to the step portion 22c of the sealing can 20 through the rising portion Z, and the sealing can 20 Push down. Finally, the peripheral wall 22 of the sealing can 20 is pushed down toward the bottom portion 11b of the outer can 10 so that the protruding portion 33 of the gasket 30 is pressed against the bottom portion 11b of the outer can 10.

Here, as shown in the upper diagram of FIG. 6, the lateral width of the rising portion Z (dimension A shown in FIG. 5) is the outer portion located between the peripheral wall 12 of the outer can 10 and the expanded diameter portion 22b of the sealing can 20. It is formed to be smaller than the lateral width of the tubular portion 31 (dimension B shown in FIG. 5). Therefore, as shown in the lower diagram of FIG. 6, the boundary portion L that represents the contact portion between the curved portion 31a and the portion that covers the outer surface of the enlarged diameter portion 22b in the outer tubular portion 31 is in the radial direction of the sealing can 20. The state extends from the base end portion 22a to a portion extending from the outer surface of the expanded diameter portion 22b of the sealing can 20 to the peripheral wall 12 side of the outer can 10.

That is, when the peripheral wall 12 of the outer can 10 is caulked to the peripheral wall 22 of the sealing can 20, the boundary portion L appears, so that the rising portion Z of the gasket 30 comes into contact with the base end 22a of the sealing can 20 and the sealing can 20 The stepped portion 22c is pushed toward the bottom portion 11b of the outer can 10. As a result, the protruding portion 33 of the gasket 30 is strongly pressed against the bottom portion 11b of the outer can 10, and the sealing performance of the gasket 30 is improved. Therefore, the airtightness inside the battery can be further improved.

Dimensions C1 and C2 shown in FIG. 6 indicate the distance between the bottom portion 11b of the outer can 10 and the opening end of the peripheral wall 22 of the sealing can 20. As shown in FIG. 6, the dimension C2 is smaller than the dimension C1 before and after caulking the peripheral wall 12 of the outer can 10 to the peripheral wall 22 of the sealing can 20. That is, by caulking the peripheral wall 12 of the outer can 10 to the peripheral wall 22 of the sealing can 20, the distance between the bottom portion 11b of the outer can 10 and the opening end of the peripheral wall 22 of the sealing can 20 is reduced, and the protruding portion of the gasket 30 is reduced. 33 is strongly pressed against the bottom portion 11b of the outer can 10.

Further, the pressing force applied to the peripheral wall 12 of the outer can 10 is also propagated to the inner cylindrical portion 32 in contact with the inner surface of the step portion 22c of the sealing can 20. As a result, the inner cylindrical portion 32 and the protruding portion 33 of the gasket 30 are concave toward the peripheral wall 12 of the outer can 10, as shown in the lower diagram of FIG. 6.

Further, as shown in the lower diagram of FIG. 6, the outer cylindrical portion 31 has a terminal end portion protruding more outward than the open end of the peripheral wall 12 of the outer can 10. The end portion of the curved portion 31a of the outer tubular portion 31 is sandwiched between the base end portion 22a of the sealing can 20 and the opening end of the peripheral wall 12 of the outer can 10, and the open end of the peripheral wall 12 of the outer can 10. And the base end 22a of the sealing can 20 project to the outside.

As described above, the open end of the peripheral wall 12 of the outer can 10 is caulked to the peripheral wall 22 of the sealing can 20, and the flat battery 1 including the outer can 10 and the sealing can 20 is completed as shown in the lower diagram of FIG. ..

As shown in the upper diagram of FIG. 6, the sealing can 20 in which the gasket 30 is molded on the peripheral wall 22 constitutes the “flat battery assembling member” according to the embodiment of the present invention.

[Effect]
The operational effects of the flat battery 1 according to the embodiment of the present invention will be described below.

The flat battery 1 according to the embodiment of the present invention has an outer can 10 having a cylindrical peripheral wall 12, a cylindrical outer wall of the outer can 10 and a smaller outer diameter of the outer can 10. A sealing can 20 having a peripheral wall 22 and a gasket 30 arranged between the peripheral wall 12 of the outer can 10 and the peripheral wall 22 of the sealing can 20 are provided. The peripheral wall 22 of the sealing can 20 includes a step portion 22c that expands the opening end thereof in a step shape. The gasket 30 covers the outer surface of the peripheral wall 22 of the sealing can 20, and is arranged between the outer cylindrical portion 31 that contacts the step portion 22c of the sealing can 20, the peripheral wall 22 of the sealing can 20 and the bottom 11b of the outer can 10. And a projecting portion 33 that contacts the bottom portion 11b of the outer can 10. The outer cylinder portion 31 includes a boundary portion L extending in the radial direction of the sealing can 20 from the base end portion 22 a to a portion extending from the peripheral wall 22 of the sealing can 20 to the peripheral wall 12 side of the outer can 10.

In such a flat battery 1, the boundary portion L appears in a state where the peripheral wall 12 of the outer can 10 is caulked to the peripheral wall 22 of the sealing can 20, so that the gasket 30 comes into contact with the base end 22a of the sealing can 20, The step 22c of the sealing can 20 is pushed toward the bottom 11b of the outer can 10. As a result, the protruding portion 33 of the gasket 30 is strongly pressed against the bottom portion 11b of the outer can 10, and the sealing performance of the gasket 30 is improved. Therefore, the airtightness inside the battery can be further improved.

Further, the gasket 30 includes an inner cylindrical portion 32 that covers the inner surface of the peripheral wall 22 of the sealing can 20. The inner cylindrical portion 32 extends from the protruding portion 33 and contacts the inner surface of the step portion 22c of the sealing can 20, and the inner cylindrical portion 32 and the protruding portion 33 face the peripheral wall 12 of the outer can 10. It is concave.

Therefore, the bottom 11b of the outer can 10 is more strongly pressed, and the protrusion 33 and the bottom 11b of the outer can 10 can be more hermetically sealed.

Further, the outer cylinder portion 31 has a terminal end portion protruding outward from the opening end of the peripheral wall 12 of the outer can 10.

Therefore, the space between the base end portion 22a of the sealing can 20 and the opening end of the peripheral wall 12 of the outer can 10 is hermetically sealed, and the hermeticity in the space between the peripheral wall 12 of the outer can 10 and the peripheral wall 22 of the sealing can 20 is improved. It can be further improved.

In the flat battery 1 according to the embodiment of the present invention, the sealing can 20 has a base end portion 22a extending from the step portion 22c and extending to the opposite side of the bottom portion 11b of the outer can 10. Further, before the caulking of the peripheral wall 12 of the outer can 10 to the peripheral wall 22 of the sealing can 20, the outer cylinder portion 31 is formed so that the width dimension thereof is smaller than the width dimension of the portion covering the outer surface of the peripheral wall 22 of the sealing can 20. In addition, at least a part of the outer surface of the step portion 22c and the outer surface of the base end portion 22a are exposed by having a rising portion Z extending on the side opposite to the bottom portion 11b of the outer can 10.

According to this embodiment, caulking when the peripheral wall 12 of the case 10 on the peripheral wall 22 of the sealing can 20, the rising portion Z is a proximal end 22a of the sealing can 20 exposed to the outside without being covered by the gasket 30 Touches the outer surface of. Therefore, the pressing force applied to the peripheral wall 12 of the outer can 10 is not absorbed by the other part of the gasket 30 and is directly transmitted to the step portion 22c of the sealing can 20 via the rising portion Z, so that the sealing can 20 can be removed. Push down. Thereby, the sealing performance of the gasket 30 is improved, and the airtightness inside the battery can be further improved.

[Other Embodiments]
In the above-described embodiment, the electrode body 40 has a configuration in which a plurality of positive electrodes 41 and negative electrodes 46 are alternately laminated, but the configuration of the electrode body may be other than this.

In the above embodiment, the outer can 10 is a positive electrode can and the sealing can 20 is a negative electrode can. However, conversely, the sealing can 20 may be a positive electrode can and the outer can 10 may be a negative electrode can.

In the above-described embodiment, the bottom portion 11 is configured to include the bottom portion 11a on which the electrode body 40 is arranged, and the bottom portion 11b on which the protruding portion 33 of the gasket 30 is pressed against the step portion formed on the outer peripheral side of the bottom portion 11a. However, the circular bottom 11 having no stepped portion may be provided, and the electrode body 40 and the gasket 30 may be arranged on the same surface of the bottom 11.

In the above-described embodiment, the outer can 10 and the sealing can 20 are each formed in a cylindrical shape having a bottom, and the flat battery 1 is formed in a coin shape. It may be formed in a shape other than the cylindrical shape.

According to the embodiment of the present invention, a flat battery is a flat battery that includes an outer can, a sealing can, and a gasket, and has an open end of a peripheral wall of the outer can crimped and sealed. The outer can has a cylindrical peripheral wall. The sealing can is disposed inside the peripheral wall of the outer can and has a cylindrical peripheral wall smaller than the outer diameter of the outer can. The gasket is arranged between the peripheral wall of the outer can and the peripheral wall of the sealing can. The peripheral wall of the sealing can has a base end portion on the bottom side, an enlarged diameter portion on the opening end side formed larger than the outer diameter of the base end portion, and a step portion between the base end portion and the enlarged diameter portion. Have and. The gasket covers the outer surface of the expanded diameter portion of the sealing can and is arranged between the outer cylindrical portion in contact with the stepped portion of the sealing can, the expanded diameter portion of the sealing can and the bottom portion of the outer can, and the outer can. And a protrusion that contacts the bottom of the. On the outer can side of the portion of the outer tube portion that is in contact with the stepped part of the sealing can, a rising portion that protrudes in the radial direction of the sealing can from the sealing can side is formed. With the open end of the peripheral wall of the outer can being crimped, the rising portion of the gasket contacts at least a part of the base end of the peripheral wall of the sealing can.

According to this embodiment, the gasket contacts the step portion of the sealing can and pushes the step portion of the sealing can toward the bottom of the outer can in a state where the peripheral wall of the outer can is caulked to the peripheral wall of the sealing can. As a result, the protruding portion of the gasket is strongly pressed against the bottom of the outer can, and the gasket sealing performance is improved. Therefore, the airtightness inside the battery can be further improved.

According to the embodiment of the present invention, the gasket further includes an inner cylindrical portion that covers the inner surface of the expanded diameter portion of the sealing can. The inner cylindrical portion extends from the protruding portion and contacts the inner surface of the stepped portion of the sealing can. The inner tube portion and the protruding portion are crimped at the open end of the peripheral wall of the outer can so as to be concave toward the peripheral wall of the outer can.

With such a gasket structure, the space between the outer can and the sealing can can be more tightly sealed by being pressed against the bottom of the outer can more strongly.

According to the embodiment of the present invention, the end portion of the rising portion of the outer tubular portion projects more outward than the open end of the peripheral wall of the outer can.

According to the embodiment of the present invention, a member for assembling the flat battery is the member for assembling the flat battery, and includes a sealing can and a gasket. The sealing can has a cylindrical peripheral wall. The gasket has a substantially cylindrical shape integrated with the sealing can. The peripheral wall of the sealing can has a base end portion on the bottom side, an enlarged diameter portion on the opening end side formed larger than the outer diameter of the base end portion, and a step portion between the base end portion and the enlarged diameter portion. Have. The gasket includes an outer cylindrical portion that covers the outer surface of the expanded diameter portion of the sealing can, is in contact with the stepped portion of the sealing can, and a protrusion that is connected to the outer cylindrical portion and covers the open end of the expanded diameter portion. On the outer surface side of the portion of the outer tubular portion that contacts the stepped portion of the sealing can, a rising portion that projects in the axial direction of the sealing can from the side of the sealing can is formed. The width A of the rising portion is smaller than the width B of the outer cylindrical portion that covers the outer surface of the expanded diameter portion. The height h of the rising portion and the width t of the outer tubular portion on the inner side of the rising portion satisfy h>t.

When manufacturing a flat battery using such a flat battery assembling member, by caulking the open end of the peripheral wall of the outer can, the rising portion of the gasket contacts the base end of the peripheral wall of the sealing can, Press the peripheral wall of the sealing can against the bottom of the outer can.

Therefore, the sealing performance of the gasket is enhanced, and the airtightness inside the battery can be further improved.

According to the embodiment of the present invention, the gasket further includes an inner cylindrical portion that covers the inner surface of the expanded diameter portion of the sealing can. The inner tubular portion extends from the protruding portion and contacts the inner surface of the stepped portion of the sealing can.

When a flat battery is manufactured using such a flat battery assembling member, the peripheral wall of the sealing can is pressed against the bottom of the external can so that the inner cylinder of the gasket is recessed in the direction of the peripheral wall of the external can. ..

Therefore, the space between the outer can and the sealing can can be made more sealed.

According to the embodiment of the present invention, h>A at the rising portion of the gasket.

When a flat battery is manufactured using such a flat battery assembling member, when the open end of the peripheral wall of the outer can is caulked, the rising portion of the gasket causes the base end and the step of the peripheral wall of the sealing can. It becomes easy to fill the space between the outer can and the peripheral wall of the outer can. As a result, the peripheral wall of the sealing can is pressed against the bottom of the outer can.

Therefore, the sealing performance of the gasket is enhanced, and the airtightness inside the battery can be further improved.

According to the embodiment of the present invention, it is possible to provide a flat battery in which the airtightness inside the battery is further improved by improving the sealing performance of the gasket.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the invention.

INDUSTRIAL APPLICABILITY The present invention can be industrially used as a flat battery in which the airtightness inside the battery is further improved by improving the sealing performance of the gasket, and a member for assembling the flat battery.

Claims (3)

An outer can having a cylindrical peripheral wall, a sealing can arranged inside the peripheral wall of the outer can and having a cylindrical peripheral wall smaller than the outer diameter of the outer can, a peripheral wall of the outer can and the sealing can. A gasket arranged between the peripheral wall and the peripheral wall of the outer can, the open end of the peripheral wall of the outer can is caulked, a member for assembling a flat battery used for assembling a flat battery,
A sealing can having a cylindrical peripheral wall,
A substantially cylindrical gasket integrated with the sealing can,
The peripheral wall of the sealing can has a base end portion on the bottom side, an enlarged diameter portion on the opening end side formed to be larger than the outer diameter of the base end portion, and between the base end portion and the enlarged diameter portion. Has a step and
The gasket is
While covering the outer surface of the expanded diameter portion of the sealing can, an outer cylindrical portion that contacts the stepped portion of the sealing can,
A protruding portion that is connected to the outer tubular portion and covers an opening end of the expanded diameter portion,
On the outer surface side of the portion of the outer tube portion that is in contact with the stepped portion of the sealing can, a rising portion is formed that projects in the cylinder axial direction of the sealing can from the side of the sealing can in the radial direction of the sealing can. And
At least a part of the outer surface of the stepped portion and the outer surface of the base end portion are not covered by the gasket,
A width A of the rising portion is smaller than a width B of the outer tubular portion that covers the outer surface of the expanded diameter portion,
The height h of the rising portion and the width t of the outer tubular portion on the inner side of the rising portion satisfy h>t,
A member for assembling a flat battery, wherein h>A at the rising portion of the gasket. A member for assembling the flat battery according to claim 1,
The gasket further includes an inner cylindrical portion that covers the inner surface of the expanded diameter portion of the sealing can,
The inner cylindrical portion is a member for assembling a flat battery, which extends from the protruding portion and contacts the inner surface of the step portion of the sealing can. An outer can having a cylindrical peripheral wall, a sealing can arranged inside the peripheral wall of the outer can and having a cylindrical peripheral wall smaller than the outer diameter of the outer can, a peripheral wall of the outer can and the sealing can. A method for producing a flat battery , comprising a gasket disposed between the peripheral wall and a peripheral wall of the outer can, the opening end of the peripheral wall being caulked, and being sealed .
A step of preparing an outer can having a cylindrical peripheral wall and the assembly member according to claim 1 or 2 ;
Placing said assembly member inside the peripheral wall of the outer can,
And a step of caulking an open end of a peripheral wall of the outer can so that a rising portion of the gasket contacts at least a part of a base end portion of a peripheral wall of the sealing can.

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