JP2014022095A - Sealed battery, and method for manufacturing sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed battery and a method for manufacturing the sealed battery, capable of improving positioning accuracy in a height direction of a sealing member by which a liquid injection hole is sealed.SOLUTION: In a battery 1, a seal member 20 includes a stopper 38 which is formed by protruding from a surface 40 on a liquid injection hole 26 side of a metal seal plate 36 and arranged adjacent to a periphery of a seal part 32. A surface 46 on the protrusion direction side of the stopper 38 is abutted on a cover plate 18.

Description

  The present invention relates to a sealed battery such as a lithium ion battery and a method for producing the sealed battery.

  In recent years, a chargeable / dischargeable battery has been used as a driving power source for vehicles such as hybrid vehicles and electric vehicles, and portable electronic devices such as notebook computers and video camcorders. In the manufacture of such a battery, when sealing the injection hole formed in the cover plate for injecting the electrolyte into the battery, a metal made under reduced pressure is used to keep the inside of the battery in a reduced pressure state. There is a method of sealing a liquid injection hole by welding a sealing plug to a lid plate. And when welding the metal sealing plug to the lid plate in this way, the welding device is housed in the decompression device, or the laser or electron beam is transmitted from the outside of the decompression device to the beam transmission member for welding. It is possible to do. However, there is a possibility that the apparatus becomes large or the welding becomes unstable due to contamination or distortion of the beam transmitting member.

  Therefore, there is a method in which an elastic body part of a sealing plug composed of a metal part and an elastic body part is inserted into the liquid injection hole under reduced pressure, and then the metal part is welded to the lid plate having the liquid injection hole in the atmosphere. Conceivable. As an example of this method, in Patent Document 1, a resin protrusion is inserted into the liquid injection hole, and the liquid injection hole is formed by welding the outer peripheral edge of the flat holding member made of aluminum alloy and the sealing plate. A sealed battery for sealing is disclosed. In the sealed battery of Patent Document 1, the resin-made protruding portion is composed of a root portion and a tip portion, the root portion is in contact with the concave portion of the sealing plate, and the tip portion is inserted into the liquid injection hole.

JP 2009-085659 A

  However, in the sealed battery of Patent Document 1, there is no positioning function in the height direction (center axis direction) of the sealing plug, and the compression ratio of the projecting portion varies, making it difficult to position the sealing plug in the height direction. It is. And if the compression rate of the protruding portion is low, the sealing performance of the protruding portion is lowered and the inside of the battery cannot be sealed. Moreover, when the compression ratio of the projecting portion is high, deformation of the projecting portion and the sealing plate occurs, and similarly, the sealing performance is lowered and the inside of the battery cannot be sealed. In addition, when the welding beam penetrates the flat plate holding part when welding the flat plate holding part of the sealing plug and the sealing plate, the reflected light of the welding beam is irradiated to the protruding part and the sealing performance of the protruding part is lowered. There is a fear.

  Accordingly, the present invention has been made to solve the above-described problems, and a sealed battery and a sealed battery that can improve the positioning accuracy in the height direction of the sealing member that seals the liquid injection hole. It is an object of the present invention to provide a manufacturing method.

  One aspect of the present invention made to solve the above-described problems is that a cover plate including a liquid injection hole for closing an opening of a case main body member and injecting an electrolyte into the case main body member, and a flat plate And a resin sealing plug that is disposed on the surface of the metal sealing plate on the side of the liquid injection hole and is inserted into the liquid injection hole. In the sealed battery in which the lid plate and the metal sealing plate are joined by butt welding, the sealing member is formed to protrude from the surface on the liquid injection hole side of the metal sealing plate. And an annular convex portion disposed adjacent to the periphery of the resin sealing plug, and a surface of the annular convex portion on the protruding direction side is in contact with the lid plate.

  According to this aspect, the surface on the projecting direction side of the annular convex portion is brought into contact with the cover plate, and the deformation of the resin sealing plug is suppressed by the annular convex portion so that the compression rate of the resin sealing plug is increased. Since it is stabilized, the positioning accuracy of the sealing member in the height direction can be improved.

  Moreover, in the said aspect, the said cover plate is provided with the recessed part provided with the inlet_port | entrance of the said liquid injection hole in a bottom face, the surface by the side of the protrusion of the said cyclic | annular convex part is contact | abutted to the said bottom face, and the said sealing member is said It is preferable that the cover plate and the metal sealing plate are arranged flush with each other while being inserted into the recess.

  According to this aspect, the lid plate and the metal sealing plate can be easily welded. Therefore, the welding quality in the welded portion between the lid plate and the metal sealing plate can be improved. Therefore, it is possible to improve the quality of the sealed battery by improving the sealing performance in the sealed battery.

  Moreover, in the said aspect, it is preferable that the welding part of the said cover plate and the said metal sealing plate has penetrated the said metal sealing plate about the plate | board thickness direction of the said metal sealing plate.

  According to this aspect, when the lid plate and the metal sealing plate are welded, gas easily escapes to the outside of the welded portion, and a gap is hardly generated in the welded portion between the lid plate and the metal sealing plate. Become. Therefore, the welding quality in the welding part of a cover plate and a metal sealing plate can be improved reliably. Therefore, it is possible to reliably improve the sealing property in the sealed battery and to improve the quality of the sealed battery without fail.

  Another aspect of the present invention made in order to solve the above problems is a lid plate that closes an opening of a case body member and includes a liquid injection hole for injecting an electrolyte into the case body member; A sealing member comprising: a flat metal sealing plate; and a resin sealing plug that is disposed on the surface of the metal sealing plate on the liquid injection hole side and is inserted into the liquid injection hole. In the manufacturing method of a sealed battery in which the lid plate and the metal sealing plate are joined by butt welding, the sealing member is a surface on the liquid injection hole side of the metal sealing plate An annular convex portion that is formed to protrude from the resin sealing plug and is disposed adjacent to the periphery of the resin sealing plug, the projecting side surface of the annular convex portion is brought into contact with the lid plate, and the lid plate The metal sealing plate is joined by butt welding.

  According to this aspect, the surface on the projecting direction side of the annular convex portion is brought into contact with the cover plate, and the deformation of the resin sealing plug is suppressed by the annular convex portion so that the compression rate of the resin sealing plug is increased. Since it is stabilized, the positioning accuracy of the sealing member in the height direction can be improved.

  In addition, when laser welding welds the lid plate and metal sealing plate together, laser light is blocked by the annular projection, so that the resin sealing plug is irradiated with laser light. Can be suppressed. Therefore, the sealing performance of the resin sealing plug can be maintained. Therefore, the sealing property in the sealed battery can be maintained and the quality of the sealed battery can be maintained.

  According to the sealed battery and the manufacturing method of the sealed battery according to the present invention, the positioning accuracy in the height direction of the sealing member for sealing the liquid injection hole can be improved.

It is a perspective view of the sealed battery of a present Example. It is an enlarged view (top view) of the periphery of the sealing member. It is AA sectional drawing of FIG. It is drawing corresponding to FIG. 3, and has shown the state before joining a sealing member to a cover board. It is a figure which shows a modification.

[Overall description of sealed battery]
First, the sealed battery (hereinafter mainly referred to as “battery”) of the present embodiment will be generally described. As shown in FIG. 1, the battery 1 of this example is a sealed lithium ion secondary battery having a battery case 10 containing an electrode body (not shown) and an electrolyte solution (not shown). The battery 1 also includes a negative electrode terminal structure 12 that is bonded to a negative electrode plate (not shown) of the electrode body, and a positive electrode terminal structure 14 that is bonded to a positive electrode plate (not shown) of the electrode body.

  The battery case 10 includes a case body member 16 including an opening and a lid plate 18. Among these, the cover plate 18 is a rectangular plate shape, closes the opening of the case body member 16, and is welded to the case body member 16.

  The battery case 10 also includes a sealing member 20 that seals the liquid injection hole 26 (see FIGS. 3 and 4) of the lid plate 18. As shown in FIG. 2, the sealing member 20 has a circular outer periphery in the present embodiment, and a welded portion 22 that is a portion welded to the cover plate 18 at the outer peripheral edge. ing.

[Description of lid plate and sealing member]
Next, the cover plate 18 and the sealing member 20 will be described. As shown in FIG. 3, the lid plate 18 includes a recess 24 and a liquid injection hole 26 for injecting an electrolyte into the case main body member 16. The recess 24 includes a side surface 28 and a seal surface 30 (bottom surface), and the seal surface 30 includes an inlet for the liquid injection hole 26. Specifically, a seal surface 30 is provided around the outer periphery in the radial direction of the inlet of the circular liquid injection hole 26, and the side surface 28 rises perpendicularly to the seal surface 30 from the circular outer periphery of the seal surface 30. Is provided.

  The sealing member 20 includes a seal part 32 and a metal part 34. The metal part 34 further includes a metal sealing plate 36 and a stopper 38. The seal part 32 is an elastic body and is made of resin. The seal portion 32 is disposed on the surface 40 on the liquid injection hole 26 side (the lower side in FIG. 3) of the metal sealing plate 36 and is inserted into the liquid injection hole 26. In this embodiment, the seal portion 32 includes a cylindrical portion 42 on the base side and a conical portion 44 on the distal end side. And the cylindrical part 42 is arrange | positioned inside the inner peripheral surface of the stopper 38 (refer FIG. 3), and the conical part 44 is a part inside the inner peripheral surface of the liquid injection hole 26, and the case main body member 16 (refer FIG. 1). Inserted inside and out. The seal portion 32 is an example of the “resin sealing plug” in the present invention.

  In addition, as resin which comprises the seal | sticker part 32, what does not have the reactivity with a nonaqueous electrolyte and has moderate elasticity is good. Examples of the resin material constituting the seal portion 32 include ethylene propylene rubber, silicone rubber, nitrile rubber, fluorine rubber, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, polypropylene, tetrafluoroethylene / ethylene. It is conceivable to use a copolymer, polytetrafluoroethylene or the like.

  The metal sealing plate 36 is a metal flat plate, and is formed in a disk shape as an example in the present embodiment. The metal sealing plate 36 and the lid plate 18 are joined by butt welding. The stopper 38 is formed so as to protrude from the surface 40 on the liquid injection hole 26 side of the metal sealing plate 36, and is formed so as to be adjacent to the periphery of the seal portion 32. That is, the stopper 38 is formed in a circular shape, whereby the sealing portion 32 is surrounded by the metal sealing plate 36 and the stopper 38, and deformation when the sealing portion 32 is compressed is suppressed.

  Furthermore, in this embodiment, the surface 46 of the stopper 38 in the protruding direction (the lower side in FIG. 3) is brought into contact with the seal surface 30 of the lid plate 18. Specifically, the sealing member 20 is inserted into the recess 24 with the surface 46 on the protruding direction side of the stopper 38 in contact with the seal surface 30 of the recess 24, and the upper surface 48 of the lid plate 18 and the metal The upper surface 50 of the sealing plate 36 is arranged flush (on the same surface). In this way, the stopper 38 prevents the seal portion 32 from being excessively compressed from the lid plate 18. In addition, it is desirable for the compression rate of the seal part 32 to be 10% to 30%. The stopper 38 is an example of the “annular protrusion” in the present invention.

  In addition, as a metal material which comprises the metal part 34, it is desirable to use the same metal material as the cover plate 18, for example, using aluminum and aluminum alloy is considered.

  As shown in FIG. 3, the welded portion 22 between the lid plate 18 and the metal sealing plate 36 is formed so as to penetrate the metal sealing plate 36 in the plate thickness direction.

[Battery Manufacturing Method]
In the manufacturing method of the battery 1 having such a structure, first, an electrode body or the like is accommodated in the case body member 16, and the opening of the case body member 16 is closed by the lid plate 18. Next, an electrolytic solution is injected into the case body member 16 from the liquid injection hole 26. Next, the liquid injection hole 26 is sealed with the sealing member 20.

  Here, when sealing the liquid injection hole 26 with the sealing member 20, specifically, from the state shown in FIG. 4, while inserting the conical part 44 of the seal part 32 into the liquid injection hole 26, the stopper The surface 46 of 38 is brought into contact with the sealing surface 30. In this way, the surface 46 on the protruding direction side of the stopper 38 is brought into contact with the seal surface 30, the sealing member 20 is inserted into the recess 24, and the upper surface 48 of the lid plate 18 and the metal sealing plate 36 are inserted. The upper surface 50 is arranged flush.

  Next, while the surface 46 of the stopper 38 is brought into contact with the seal surface 30 as shown in FIG. 3, the side surface 28 of the recess 24 of the lid plate 18 and the outer peripheral edge 52 of the metal sealing plate 36 (see FIG. 4). Are joined by butt welding. At this time, by performing through welding so that the metal sealing plate 36 is melted to a thickness equal to or greater than the plate thickness, gas easily escapes to the outside of the welded portion 22 and voids (voids or blowholes) are formed inside the welded portion 22. It becomes difficult to occur. Thereby, the sealing member 20 can be reliably joined to the cover plate 18 by welding.

  In this way, when performing the laser welding, when the laser welding is performed, the laser beam is irradiated to the stopper 38, and thus the seal portion 32 is not irradiated. Therefore, the sealing performance of the seal part 32 can be maintained. As described above, the liquid injection hole 26 is sealed by the sealing member 20.

  As shown in FIG. 4, as an example of the dimensions of the cover plate 18, the thickness A = 1.0 mm, the depth B of the recess 24 = 0.7 mm, the diameter C of the recess 24 = φ5.0 mm, the injection hole It can be considered that the diameter D of 26 is φ1.6 mm. Further, as an example of the dimensions of the sealing member 20, the diameter E = φ5.0 mm of the metal sealing plate 36, the plate thickness F = 0.3 mm of the metal sealing plate 36, and the upper surface 50 of the metal sealing plate 36. It is considered that the width G from the surface 38 of the stopper 38 to 0.7 mm, the inner diameter H of the stopper 38 = 2.0 mm, and the outer diameter I of the stopper 38 = 2.0 mm.

[Effect of this embodiment]
According to the battery 1 of the present embodiment, the surface 46 on the protruding direction side of the stopper 38 is brought into contact with the lid plate 18, and the deformation of the seal portion 32 is suppressed by the stopper 38 to reduce the compression rate of the seal portion 32. Since it is stabilized, the positioning accuracy of the sealing member 20 in the height direction (center axis direction, vertical direction in FIG. 3) can be improved.

  In addition, when the lid plate 18 and the metal sealing plate 36 are brought into contact with each other and through welding is performed by laser welding, the laser beam is blocked by the stopper 38, so that the laser beam is not irradiated on the seal portion 32. it can. Therefore, the sealing performance of the seal part 32 can be maintained. Therefore, the airtightness in the battery 1 can be maintained and the quality of the battery 1 can be maintained.

  The lid plate 18 includes a recess 24 having an inlet for the liquid injection hole 26 on the seal surface 30, and the sealing member 20 is placed inside the recess 24 by bringing the surface 46 of the stopper 38 into contact with the seal surface 30 of the recess 24. The upper surface 48 of the lid plate 18 and the upper surface 50 of the metal sealing plate 36 are arranged flush with each other. Thereby, it becomes easy to weld the cover plate 18 and the metal sealing plate 36. Therefore, the welding quality at the welded portion 22 between the lid plate 18 and the metal sealing plate 36 can be improved. Therefore, the airtightness in the battery 1 can be improved and the quality of the battery 1 can be improved.

  Further, the welded portion 22 between the lid plate 18 and the metal sealing plate 36 penetrates the metal sealing plate 36 in the thickness direction (vertical direction in FIG. 3) of the metal sealing plate 36. As a result, when the lid plate 18 and the metal sealing plate 36 are welded, gas easily escapes to the outside of the welded portion 22, and voids are less likely to occur in the welded portion 22. Therefore, the welding quality in the welding part 22 can be improved reliably. Therefore, the airtightness in the battery 1 can be reliably improved, and the quality of the battery 1 can be reliably improved.

  A modification as shown in FIG. 5 is also conceivable. In the modification shown in FIG. 5, the sealing surface 30 of the recess 24 of the lid plate 18 is formed in a tapered shape so as to be inclined downward toward the liquid injection hole 26. Thereby, when the electrolytic solution is injected from the liquid injection hole 26, the electrolytic solution does not easily accumulate on the seal surface 30. Further, the surface 46 of the stopper 38 is formed in a tapered shape so as to be inclined downward toward the inner peripheral side of the stopper 38 with substantially the same inclination as the seal surface 30. Thereby, the surface 46 of the stopper 38 can be reliably brought into contact with the seal surface 30. Therefore, the positioning accuracy of the sealing member 20 in the height direction can be reliably improved.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Battery 10 Battery case 16 Case main body member 18 Cover plate 20 Sealing member 22 Welding part 24 Recessed part 26 Injection hole 28 Side face 30 Sealing surface 32 Sealing part 34 Metal part 36 Metal sealing board 38 Stopper 40 Face 46 surface

Claims (4)

A lid plate that closes the opening of the case body member and includes a liquid injection hole for injecting an electrolyte into the case body member;
A sealing member comprising: a flat metal sealing plate; and a resin sealing plug disposed on the surface of the metal sealing plate on the liquid injection hole side and inserted into the liquid injection hole;
Have
In the sealed battery in which the lid plate and the metal sealing plate are joined by butt welding,
The sealing member includes an annular convex portion that is formed to protrude from the surface on the liquid injection hole side of the metal sealing plate and is disposed adjacent to the periphery of the resin sealing plug,
The surface on the protruding direction side of the annular convex portion is in contact with the lid plate,
A sealed battery characterized by. The sealed battery according to claim 1, wherein
The lid plate includes a recess provided on the bottom surface with the inlet of the liquid injection hole,
The sealing member is inserted into the recess with the surface on the protruding direction side of the annular convex portion in contact with the bottom surface, and the lid plate and the metal sealing plate are arranged flush with each other. That
A sealed battery characterized by. The sealed battery according to claim 1 or 2,
The welded portion between the lid plate and the metal sealing plate penetrates the metal sealing plate in the thickness direction of the metal sealing plate;
A sealed battery characterized by. A lid plate that closes the opening of the case body member and includes a liquid injection hole for injecting an electrolyte into the case body member;
A sealing member comprising: a flat metal sealing plate; and a resin sealing plug disposed on the surface of the metal sealing plate on the liquid injection hole side and inserted into the liquid injection hole;
Have
In the manufacturing method of the sealed battery in which the lid plate and the metal sealing plate are joined by butt welding,
The sealing member includes an annular convex portion that is formed to protrude from the surface on the liquid injection hole side of the metal sealing plate and is disposed adjacent to the periphery of the resin sealing plug,
Bringing the surface of the annular convex portion on the protruding direction side into contact with the lid plate, and joining the lid plate and the metal sealing plate by butt welding;
A manufacturing method of a sealed battery characterized by the above.

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