JP6160049B2 - Power storage device manufacturing method and power storage device - Google Patents

Description

The present invention relates to a method for manufacturing a power storage device using a sealing plug that includes a shaft portion and a flange portion that extends from the shaft portion in a direction that intersects the axis of the shaft portion, and a power storage device. Relates to the device.

Such a sealing plug is used for, for example, a power storage device of a type in which an electrolytic solution is injected from a liquid injection hole formed on a side surface of the device housing with respect to the device housing containing the power storage element.
This liquid injection hole needs to be sealed with a sealing plug, and as a structure of the sealing plug, for example, as described in Patent Document 1 below, the shaft portion and the shaft core of the shaft portion are orthogonal to each other. As a structure having a flange portion extending from the shaft portion in the direction to be sealed, the shaft portion is fitted into the liquid injection hole, and the periphery of the flange portion is sealed by welding to the apparatus housing by a welding technique such as laser welding. Technology to stop is considered.

JP 2000-106156 A

However, in the above-described conventional configuration, when welding the flange portion of the sealing plug and the apparatus housing, a welding failure may occur, and sealing of the liquid injection hole may be incomplete.
The present invention has been made in view of such circumstances, and an object thereof is to enable accurate sealing with a sealing plug.

According to a first aspect of the present application, a sealing plug including a shaft portion and a flange portion extending from the shaft portion in a direction intersecting the axis of the shaft portion is formed on a side surface of the apparatus housing. In the method of manufacturing a power storage device, the shaft portion is attached to the liquid injection hole in a state where the shaft portion is fitted into the liquid injection hole, and an end portion on the extending side of the flange portion is welded to the device housing. The collar portion of the stopper is configured such that, on the surface on the distal end side of the shaft portion, the end portion on the extending side is positioned closer to the distal end side of the shaft portion than the portion on the shaft portion side, In the fitting operation of the stopper plug into the liquid injection hole, the operation is performed in the direction from the distal end side to the proximal end side of the shaft portion while maintaining the state in which the end portion on the extension side and the device housing are in contact with each other. With the pressing force, the end portion on the extending side is displaced in the direction from the distal end side to the proximal end side of the shaft portion, and the flange portion is deformed. In a state where the end portion of the extending side and the device housing is in contact, to weld the said device housing and the extension-side end.

That is, when the sealing plug is inserted into the liquid injection hole of the power storage device, first, the end portion on the extension side of the collar portion (the edge side portion of the collar portion) is inserted along with the insertion of the shaft portion into the liquid injection hole. Contacts the surface of the device housing.
In this state, the shaft portion side portion of the flange portion is floating from the surface of the apparatus housing.
After that, when the sealing plug is further pushed into the liquid injection hole, the shaft side portion of the collar part is also attached to the apparatus housing while maintaining the state where the end part of the collar part on the extension side is in contact with the surface of the apparatus housing. Approach the body surface.
Therefore, when the sealing plug is inserted into the liquid injection hole, the difference in the distance between the end portion on the extending side and the portion on the shaft portion side with respect to the surface of the apparatus housing on the surface on the distal end side of the shaft portion of the collar portion. Accordingly, the contact state between the end portion of the flange extending side and the surface of the device housing can be maintained with a certain width, so that the welding operation between the sealing plug and the device housing is performed in the manufacturing process of the power storage device. Can be performed accurately.

In addition, when the sealing plug is inserted into the liquid injection hole of the power storage device, the end of the flange extending side (the edge side of the flange) precedes as the shaft is inserted into the liquid injection hole. When the sealing plug is further pushed into the liquid injection hole after contacting the surface of the device casing, the flange portion is maintained while the end of the flange portion on the extension side is in contact with the surface of the device casing. Is deformed, and the shaft side portion of the collar portion also approaches the surface of the apparatus housing.
Thus, when inserting the sealing plug into the liquid injection hole, by utilizing the deformation of the flange, the extension side end of the flange of the sealing plug and the surface of the device casing are fixed with a certain width. Can be maintained in contact with each other, so that the welding operation of the sealing plug and the device housing can be performed accurately in the manufacturing process of the power storage device.

According to a second aspect of the present application, a liquid injection hole is formed on a side surface of an apparatus housing, the liquid injection hole is sealed with a sealing plug, and the sealing plug is a shaft that fits into the liquid injection hole. And a flange portion extending from the shaft portion in a direction intersecting the axis of the shaft portion, and an end portion on the extending side of the flange portion is welded to the device casing. In the power storage device, the flange portion of the sealing plug is located on the distal end side of the shaft portion in the surface on the distal end side of the shaft portion, with the end portion on the extending side being located on the distal end side of the shaft portion side. In addition, with the operation of fitting the sealing plug into the liquid injection hole, the base end from the distal end side of the shaft portion is maintained while maintaining a state in which the end portion on the extension side and the apparatus housing are in contact with each other. The extended end portion is deformed in a state of being displaced in a direction from the distal end side to the proximal end side of the shaft portion by a pressing force acting in a direction toward the side. It is, in a state where said extending side end and the device housing is in contact, with the extending side of the end portion and the device housing are welded.

That is, when the sealing plug is inserted into the liquid injection hole of the power storage device, the end of the flange portion on the extension side (the edge side portion of the flange portion) is first inserted into the liquid injection hole of the shaft portion. ) Contacts the surface of the device housing.
In this state, the shaft portion side portion of the flange portion is floating from the surface of the apparatus housing.
After this, when the sealing plug is further pushed into the liquid injection hole, the collar part is deformed while the end part of the collar part on the extension side is kept in contact with the apparatus housing surface, and the shaft of the collar part is deformed. The part side part also approaches the surface of the device casing.
Therefore, when the sealing plug is inserted into the liquid injection hole, the difference in the distance between the end portion on the extending side and the portion on the shaft portion side with respect to the surface of the apparatus housing on the surface on the distal end side of the shaft portion of the collar portion. Accordingly, it is possible to maintain the contact state between the end of the extending portion of the flange portion and the surface of the apparatus housing with a certain width.
As described above, as a sealing structure for the liquid injection hole of the power storage device, a sealed state that can easily create a state in which the extended side end of the flange portion of the sealing plug and the surface of the device housing are in proper contact with each other. Since it has a stop structure, it is possible to provide a power storage device that can accurately perform welding work between the device casing and the sealing plug.

  According to the invention of the present application, it is possible to easily create a state where the extending side end portion of the flange portion and the welding counterpart side surface are in proper contact with each other, and the sealing with the sealing plug can be accurately performed. became.

1 is an external perspective view of a power storage device according to an embodiment of the present invention. The perspective view which shows the internal structure of the electrical storage apparatus concerning embodiment of this invention The external perspective view of the electrical storage apparatus before the sealing plug attachment concerning embodiment of this invention The expanded sectional view of the sealing stopper concerning an embodiment of the invention The perspective view of the sealing stopper from the upper side concerning embodiment of this invention The perspective view of the sealing stopper from the downward side concerning embodiment of this invention Sectional drawing which shows the insertion state of the sealing plug concerning embodiment of this invention Sectional drawing which shows the insertion state of the sealing plug concerning embodiment of this invention The perspective view which shows the welding operation of the sealing stopper and apparatus housing | casing concerning embodiment of this invention. Sectional drawing of the sealing stopper concerning another embodiment of this invention.

Hereinafter, an embodiment in which a sealing plug of the present invention and a power storage device using the sealing plug are configured as a battery, particularly a secondary battery, as an example of the power storage device will be described with reference to the drawings.
In the present embodiment, a nonaqueous electrolyte secondary battery (more specifically, a lithium ion battery) will be described as an example of the secondary battery.

As shown in the perspective view of FIG. 1, the non-aqueous electrolyte secondary battery RB includes a device casing BC (hereinafter referred to simply as “casing”) that is configured by welding a cover 2 on an open surface of a can body 1. BC ”). The lid portion 2 is formed of a strip-shaped rectangular plate material, and a terminal bolt 5 that is a positive electrode terminal and a terminal bolt 7 that is a negative electrode terminal are attached to a surface on the outer side of the casing BC. It has been.
The can 1 is a flat rectangular parallelepiped in accordance with the shape of the lid portion 2, and thus has a flat and substantially rectangular parallelepiped shape as a whole of the casing BC, and the internal space of the casing BC is also flat and substantially rectangular. It has become.
Both the can 1 and the lid 2 are made of a metal material mainly composed of aluminum.

On the inner side of the casing BC, the power generation element 3 and current collectors 4 and 6 indicated by a two-dot chain line in FIG. 2 are housed and arranged in a state of being partially immersed in the electrolyte. FIG. 2 shows the inner side of the casing BC as a perspective view looking up from the lower side with the can 1 removed.
The current collectors 4 and 6 are members for electrically connecting the power generating element 3 and the terminal bolts 5 and 7, both of which are formed of a metal material.
The current collector 4 and the current collector 6 have a relationship in which substantially the same shape is arranged symmetrically, but the materials are different, and the current collector 4 on the positive electrode side is mainly composed of aluminum. The current collector 6 on the negative electrode side is formed of a material mainly composed of copper.

  The schematic shape of the current collectors 4 and 6 is such that the above-described metal material plate-like member is bent and formed in a posture along the side surface on the short side of the casing BC to have a substantially L shape. A portion extending along the surface of the lid portion 2 that is an arrangement surface of the lid portion, and a vertical posture portion that is bent 90 degrees downward near the longitudinal end portion of the lid portion 2 and extends in the normal direction of the lid portion 2. It has a continuous shape. Bifurcated connecting portions 4a and 6a for connecting to the power generation element 3 are formed by bending the current collectors 4 and 6 to the power generation element 3 side.

The power generating element 3 is formed by applying an active material layer to both the front and back surfaces of each of a pair of electrode plates including a foil-like positive electrode plate formed in a long belt shape and a foil-like negative electrode plate formed in a long belt shape. It is configured as a so-called winding type power generation element that is formed and stacked in a state of being wound around a separator that is formed into a long belt-like sheet.
The formation state of the active material layer in the foil-like positive electrode plate and the foil-like negative electrode plate is set to a narrow band-like region where the active material layer is not applied and formed at each lateral width direction end, and these regions are used as current collectors. 4 and 6 are uncoated portions 3a and 3b.
The uncoated portion 3a of the foil-shaped positive electrode plate and the uncoated portion 3b of the foil-shaped negative electrode plate are positioned at opposite ends (reverse sides) in the lateral width direction, as schematically shown in FIG. The uncoated portion 3a of the foil-shaped positive electrode plate protrudes in the lateral width direction from the edges of the foil-shaped negative electrode plate and the separator, and the uncoated portion 3b of the foil-shaped negative electrode plate includes the foil-shaped positive electrode plate and It protrudes in the lateral width direction from the edge of the separator.

In the power generation element 3 having the above-described configuration, the uncoated portions 3a and 3b are welded and electrically connected to the connection portions 4a and 6a of the current collectors 4 and 6 by ultrasonic welding.
The current collectors 4 and 6 are fixed to the lid portion 2 together with the terminal bolts 5 and 7, the positive terminal bolt 5 is electrically connected to the positive current collector 4, and the negative terminal bolt 7. Is electrically connected to the current collector 6 on the negative electrode side.
The current collector 4 on the positive electrode side is electrically connected to the terminal bolt 5 via a rivet 8 integrally formed on the head side of the terminal bolt 5, and the rivet 8 includes the current collector 4, the current collector 4, and the current collector 4. Lower gasket 12 for electrical insulation between rivet 8 and lid 2, upper gasket 11 for electrical insulation between lid 2 and terminal bolt 5 including lid 2 and rivet 8 and lid 2 In this state, the current collector 4 is caulked at the inner end portion of the casing BC, thereby fixing the current collector 4 to the lid portion 2.
The negative electrode side has the same configuration, and the negative electrode side current collector 6 is electrically connected to the terminal bolt 7 via a rivet 15 integrally formed on the head side of the terminal bolt 7. The electrical current between the terminal 6 including the electrical current 6, the current collector 6 and the lower gasket 18 for electrical insulation between the rivet 15 and the lid 2, the lid 2 and the rivet 15 and the lid 2 The current collector 6 is fixed to the lid portion 2 by being caulked at the inner end of the casing BC in a state of passing through the upper gasket 17 for insulation.

In the manufacturing process of the secondary battery RB, as described above, the terminal bolts 5 and 7 and the current collectors 4 and 6 are assembled to the lid portion 2 by caulking the rivets 8 and 15, and then the current collector 4 , 6 and the uncoated portions 3a, 3b of the power generating element 3 are welded.
An assembly in which the lid 2 and the power generation element 3 are assembled together is inserted into the can 1 and the edge of the lid 2 and the open end of the can 1 are welded by laser welding.
FIG. 3 shows an external perspective view of the secondary battery RB in a state completed up to this step.
Thereafter, an electrolytic solution is injected into the casing BC of the secondary battery RB.
The electrolytic solution is injected from the injection hole 21 shown in FIGS.
The liquid injection hole 21 is formed as a through hole in the lid portion 2 and has a circular shape when viewed in the through direction.

After injecting a predetermined amount of electrolyte, the injection hole 21 of the lid 2 is sealed with a sealing plug 22.
The sealing plug 22 is a metal member formed of a metal material mainly composed of aluminum similar to the lid 2, and is a cross-sectional view of FIG. 4, a perspective view from the upper side of FIG. 5, and FIG. 6. As shown in the perspective view from below, the shaft portion 23 is fitted into the liquid injection hole 21 without a gap, and the flange portion 24 is disposed on one end side of the shaft portion 23.
The shaft portion 23 is formed in a cylindrical shape that matches the shape of the liquid injection hole 21.
The flange portion 24 extends in a plate shape from the shaft portion 23 in a direction intersecting (substantially orthogonal) with the axis of the shaft portion 23, and has a flat portion 24 a continuously provided at the end portion of the shaft portion 23, and the flat portion thereof. It comprises a bent portion 24b that is bent to the other end side (tip side) of the shaft portion 23 in a state of extending in the radial direction of the shaft portion 23 from the portion 24a. The flat portion 24a and the bent portion 24b are arranged concentrically around the axis of the shaft portion 23, and as a whole, the flat portion 24a and the bent portion 24b have an umbrella shape that is circular when viewed in the axial direction of the shaft portion 23.

After the electrolyte injection is completed, the shaft portion 23 of the sealing plug 22 is inserted into the injection hole 21.
When the tip of the shaft part 23 is fitted into the liquid injection hole 21 and the sealing plug 22 is pushed into the deep part of the liquid injection hole 21, as shown in the enlarged sectional view of FIG. The front end of the collar portion 24 (the front end of the bent portion 24 b) is in contact with the surface of the lid portion 2.
Since the contact portion between the tip of the flange 24 and the surface of the lid 2 is a position to be welded by laser welding, good laser welding is possible by the contact of the welding object.
As described above, the collar portion 24 has an umbrella shape, and the end-side end portion (outer periphery) of the collar portion 24 on the tip-side surface of the shaft portion 23 (the surface facing the surface of the lid portion 2). Since the end portion on the side is located closer to the distal end side (surface side of the lid portion 2) of the shaft portion 23 than the portion on the shaft portion 23 side, at this time, the vicinity of the base end portion of the shaft portion 23 is the lid. It floats from the surface of the part 2.

When the sealing plug 22 is further pushed in from the state shown in FIG. 7, the state shown in the enlarged sectional view of FIG. 8 is obtained.
With the insertion of the sealing plug 22, a pressing force acts in the direction from the distal end side of the shaft portion 23 toward the proximal end side with respect to the extension side end portion (outer end portion) of the flange portion 24. However, since the collar portion 24 is a metal plate, it is easily deformed with respect to the pressing force, and the umbrella shape of the collar portion 24 is crushed and deformed into a flat plate shape as shown in FIG.
Even if the flange portion 24 is deformed in this way, the tip end of the flange portion 24 in the radial direction of the shaft portion 23 maintains contact with the lid portion 2 and maintains a state where good laser welding is possible. Yes.
That is, when the sealing plug 22 is inserted into the liquid injection hole 21, the tip of the flange portion 24 in the radial direction of the shaft portion 23 maintains contact with the surface of the lid portion 2 with a certain width. It is possible to easily create a state in which the flange 24 of the sealing plug 22 and the surface of the lid 2 are in proper contact.
With the sealing plug 22 fitted in the liquid injection hole 21 as shown in FIG. 7 or FIG. 8, the laser beam LB is collected at the end on the extending side of the flange 24 as shown in the perspective view of FIG. As shown by arrow A in FIG. 9, welding is performed over the entire circumference of the flange 24.
By this welding, sealing of the casing BC is completed, and the secondary battery RB is completed through preliminary charging or the like.

[Another embodiment]
Hereinafter, other embodiments of the present invention will be listed.
(1) In the above embodiment, the shape of the flange portion 24 of the sealing plug 22 is exemplified by the shape of the flat portion 24a and the bent portion 24b that are connected to one end of the shaft portion 23. The specific shape of 24 can be variously changed. For example, as shown in the cross-sectional view of FIG. 10 (a), the substantially entire shape of the collar portion 24 is curved in a dish shape, or the cross-sectional view of FIG. 10 (b). A bent portion 24d that is bent toward the distal end side of the shaft portion 23 extends from the edge of the flat portion 24c continuously provided at one end of the shaft portion 23 to the existing side of the lid portion 2 at an angle of approximately 90 degrees. It is good also as a shape to do.
In any case, on the surface on the distal end side of the shaft portion 23 in the flange portion 24, the extending end portion is positioned closer to the distal end side of the shaft portion 23 than the portion on the shaft portion 23 side, and is sealed. As the stop plug 22 is inserted into the liquid injection hole 21, the flange portion 24 is deformed by the pressing force from the lid portion 2 side, and the tip of the flange portion 24 contacts the surface of the lid portion 2 in the process of the deformation. Any shape can be used as long as the shape is maintained.

(2) In the above embodiment, the case where the liquid injection hole 21 is formed as a through-hole having a circular cross section and the shape of the shaft portion 23 of the sealing plug 22 is made to be a columnar shape in correspondence therewith is illustrated. These specific shapes can also be changed as appropriate, for example, the liquid injection hole 21 is a through hole having a rectangular cross section, and the shaft portion 23 of the sealing plug 22 is a quadrangular prism.
(3) In the above embodiment, the non-aqueous electrolyte secondary battery RB is described as an example of the power storage element. However, the present invention can be applied to various power storage elements such as capacitors.
(4) In the above embodiment, the case where the liquid injection hole 21 is formed in the lid portion 2 forming the side surface on the upper side of the apparatus housing BC is exemplified. You may form in a wall surface or a bottom face, and the present invention is applicable also in that case.

21 Injection hole 22 Sealing plug 23 Shaft part 24 Hook part BC device housing RB Power storage device

Claims (2)

A sealing plug having a shaft portion and a flange portion extending from the shaft portion in a direction intersecting the axis of the shaft portion is formed in a liquid injection hole formed on a side surface of the apparatus housing. Installed in a state of fitting into the liquid injection hole,
  A method of manufacturing a power storage device in which an end portion on the extending side of the flange portion is welded to the device housing,
  The flange portion of the sealing plug is configured such that, on the tip side surface of the shaft portion, the end portion on the extension side is located closer to the tip side of the shaft portion than the portion on the shaft portion side,
  In the operation of fitting the sealing plug into the liquid injection hole, the direction from the distal end side to the proximal end side of the shaft portion is maintained while maintaining the state in which the end portion on the extension side and the device housing are in contact with each other. With the pressing force acting at, the end portion on the extending side is deformed in a state of being displaced in a direction from the distal end side to the proximal end side of the shaft portion,
  A method of manufacturing a power storage device, wherein the extension-side end portion and the device casing are welded in a state where the extension-side end portion and the device casing are in contact with each other. A liquid injection hole is formed on the side surface of the apparatus housing, and the liquid injection hole is sealed with a sealing plug,
  The sealing plug is configured to include a shaft portion that fits into the liquid injection hole, and a flange portion that extends from the shaft portion in a direction intersecting the axis of the shaft portion,
  An end of the extending side of the flange is a power storage device welded to the device housing,
  The flange portion of the sealing plug has an end portion on the extending side located on a distal end side of the shaft portion with respect to a portion on the shaft portion side on a surface on a distal end side of the shaft portion, and the sealing portion. A direction from the distal end side to the proximal end side of the shaft portion while maintaining a state in which the end portion on the extension side and the device housing are in contact with the operation of fitting the stopper into the liquid injection hole The extending side end portion is deformed in a state of being displaced in a direction from the distal end side to the proximal end side of the shaft portion by the pressing force acting at
  A power storage device in which the extension-side end and the device casing are welded in a state where the extension-side end and the device casing are in contact with each other.

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