JP2017134987A - Power storage device and method of manufacturing power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device capable of sealing a liquid injection port with higher reliability, and also to provide a method of manufacturing the power storage device.SOLUTION: A sealing plug 19 includes an elastic member 40 and a pin member 50, and the elastic member 40 has a shank 41 and a first flange part 42. A pin member 50 includes: a bar part 51 which is inserted into a recess 41a of the shank 41 and expands the diameter of the shank 41 to seal a liquid injection port inner surface with the outer peripheral surface of the shank 41; and a second flange part 52 which is provided at the bar part 51 in the outside of a case 11 and covers the periphery of a liquid injection port 18 more widely than in the first flange part 42, and a portion 53 on the outer peripheral side than the first flange 42 in the second flange part 52 serves as a sealing part with a case. The sealing plug has a first seal part S1 which is formed of the elastic member 40 and located between the outer peripheral surface of the shank 41 and the liquid injection port inner surface, and a second seal part S2 which is formed by sealing of the pin member 50 at the portion 53 on the outer peripheral side of the second flange part 52.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power storage device in which an electrode assembly and an electrolytic solution are housed in a case having a liquid injection port, and a method for manufacturing the power storage device.

  In a power storage device such as a lithium ion battery, an electrode assembly and an electrolytic solution are accommodated in a case having a liquid injection port. In manufacturing this power storage device, after the electrode assembly is housed in the case, an electrolyte is injected from the liquid inlet into the case, and the liquid inlet is temporarily sealed. And after performing initial charge, aging, etc., the gas generated in the case is discharged from the liquid inlet to the outside of the case, and then the liquid inlet is fully sealed. A technique is known in which the shaft portion of the elastic member is inserted into the liquid injection port during temporary sealing, and the liquid injection port is temporarily sealed by inserting a pin into the concave portion of the shaft portion (for example, Patent Document 1). .

JP2015-204134A

By the way, there is a demand to improve the sealing performance of the liquid injection port.
An object of the present invention is to provide a power storage device capable of sealing a liquid injection port with higher reliability and a method for manufacturing the power storage device.

  The invention according to claim 1 is a power storage device in which the electrode assembly and the electrolytic solution are housed in a case having a liquid injection port, and includes a sealing plug that seals the liquid injection port. The sealing plug includes an elastic member and a pin member, and the elastic member is inserted into the liquid injection port and has a shaft portion having a recess opening outside the case, and outside the case The shaft portion has a first flange portion that extends radially outward of the shaft portion and contacts around the liquid injection port, and the pin member is inserted into a concave portion of the shaft portion so that the shaft portion is A rod portion that expands the diameter and seals the inner surface of the liquid injection port with the outer peripheral surface of the shaft portion, and covers the periphery of the liquid injection port wider than the first flange portion provided on the rod portion outside the case. It has a 2nd flange part and the perimeter than the 1st flange part in the 2nd flange part Is a sealing portion with the case, the first seal portion between the outer peripheral surface of the shaft portion and the inner surface of the liquid injection port by the elastic member, and the outer periphery of the second flange portion by the pin member The gist is to have a second seal portion by sealing at the side portion.

  According to invention of Claim 1, a seal | sticker is a 1st seal part of the outer peripheral surface of the axial part and elastic liquid inlet inner surface by an elastic member, and the site | part of the outer peripheral side of the 2nd flange part by a pin member. By performing the sealing at the second seal portion, it is possible to seal the liquid injection port with higher reliability.

  According to a second aspect of the present invention, there is provided a method of manufacturing a power storage device in which an electrode assembly and an electrolytic solution are housed in a case having an electrolyte solution injection port, the shaft portion having a recess and the shaft portion Using the elastic member having the first flange portion extending outward in the radial direction and the pin member having the rod portion and the second flange portion, outside the case in the shaft portion inserted into the liquid injection port A temporary sealing step of temporarily sealing the liquid injection port by inserting the rod portion into the opening recess and expanding the diameter of the shaft portion and sealing the inner surface of the liquid injection port with the outer peripheral surface of the shaft portion; After the temporary sealing step, at least the pin member of the pin member and the elastic member is removed, and a gas venting step for discharging the gas in the case to the outside of the case; after the gas venting step, the temporary sealing step Reuse the elastic member and pin member used in The rod portion is inserted into the concave portion of the shaft portion inserted into the liquid injection port, and the outer peripheral side of the first flange portion in the second flange portion that covers the periphery of the liquid injection port wider than the first flange portion. And a main sealing step of sealing the liquid injection port by sealing the part to the case.

  According to invention of Claim 2, a seal | sticker is by the seal | sticker in the site | part of the outer peripheral side of the 2nd flange part by the pin member between the outer peripheral surface of the axial part and elastic liquid inlet inner surface by an elastic member. By doing so, the injection port can be sealed with higher reliability. In addition, the temporary sealing is performed by sealing (shaft sealing) the outer peripheral surface of the shaft portion and the inner surface of the liquid injection port using the rod portion of the pin member, and the main sealing is performed in the first flange portion. Since the outer peripheral portion of the flange portion is sealed with the case, temporary sealing and main sealing can be easily performed using a member that serves as both temporary sealing and main sealing.

According to a third aspect of the present invention, in the power storage device manufacturing method according to the second aspect, the pin member may be made of metal.
According to a fourth aspect of the present invention, in the method for manufacturing the power storage device according to the second or third aspect, the pin member is made of the same material as the case and is sealed to the case by welding.

  According to the present invention, it is possible to seal the liquid injection port with higher reliability.

The perspective view which shows the secondary battery in embodiment. The manufacturing process figure of a secondary battery. (A) is a fragmentary sectional view of a secondary battery, (b) is sectional drawing in the AA of (a). The partial cross section figure of the secondary battery for demonstrating the temporary sealing process in the manufacturing process of a secondary battery. The partial cross section figure of the secondary battery for demonstrating a temporary sealing process. The partial cross section figure of the secondary battery for demonstrating a degassing process. The partial cross section figure of the secondary battery for demonstrating this sealing process. The partial cross section figure of the secondary battery for demonstrating this sealing process. (A), (b) is a partial cross section figure of the secondary battery for demonstrating another example. (A), (b) is a partial cross section figure of the secondary battery for demonstrating another example. The partial cross section figure of the secondary battery for demonstrating another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, a secondary battery 10 as a power storage device includes a case 11 made of metal (aluminum in the present embodiment), and an electrode assembly 12 and an electrolytic solution (not shown) are accommodated in the case 11. Has been. The case 11 includes a bottomed square cylindrical case body 13 and a rectangular flat plate-like lid body 14 that closes an opening for inserting the electrode assembly 12 into the case body 13. Therefore, the secondary battery 10 of the present embodiment is a prismatic battery whose appearance is square. Further, the secondary battery 10 of the present embodiment is a lithium ion battery.

  The electrode assembly 12 includes a positive electrode, a negative electrode, and a separator that insulates the positive electrode and the negative electrode. The positive electrode is configured by applying a positive electrode active material to both surfaces of a positive metal foil (aluminum foil). The negative electrode is configured by applying a negative electrode active material to both surfaces of a negative electrode metal foil (copper foil). The electrode assembly 12 has a laminated structure in which a plurality of positive electrodes and a plurality of negative electrodes are alternately laminated, and a separator is interposed between the positive electrode and the negative electrode.

  A positive electrode terminal 15 and a negative electrode terminal 16 are electrically connected to the electrode assembly 12. Each part of the positive electrode terminal 15 and the negative electrode terminal 16 is exposed to the outside of the case 11 from the lid body 14. Further, ring-shaped insulating members 17 for insulating from the case 11 are attached to the positive electrode terminal 15 and the negative electrode terminal 16, respectively.

  The lid 14 of the case 11 is provided with a liquid injection port 18 for injecting an electrolyte into the case 11 (case body 13). The liquid injection port 18 is closed by a sealing plug 19. Yes. The liquid injection port 18 has a circular shape.

Next, the manufacturing process of the secondary battery 10 will be described.
As shown in FIG. 2, after the process of housing the electrode assembly 12 in the case 11 is completed, an electrolytic solution is injected into the case 11 from the liquid injection port 18 (liquid injection process). Thereafter, the liquid injection port 18 is temporarily sealed with a temporary sealing member (temporary sealing step). And after electrolyte solution osmose | permeates the active material of each electrode, case 11 is restrained and initial charge is performed (initial charge process). Subsequently, the secondary battery 10 is left for a predetermined time in a state where the temperature is raised to the aging temperature (aging process). Thereafter, the gas generated in the case 11 in the aging process is discharged from the liquid injection port 18 to the outside of the case 11 (gas venting process). And the liquid injection port 18 is sealed with this sealing member (main sealing process). Further, the secondary battery 10 is self-discharged (self-discharge process). Thereby, the secondary battery 10 is completed.

A sealing plug 19 provided in the secondary battery 10 is shown in FIG. 3, and the liquid injection port 18 is sealed by the sealing plug 19.
The sealing plug 19 includes an elastic member 40 and a pin member 50. The elastic member 40 is made of a rubber material. The pin member 50 is made of a metal, specifically, an aluminum material.

  The elastic member 40 includes a shaft portion 41 that is erected and a first flange portion 42 that protrudes from the upper end of the shaft portion 41 to the outer diameter side. The shaft portion 41 has a bottomed cylindrical shape and has a recess 41a that opens on the upper surface. The recess 41 a opens to the outside of the case 11. The shaft portion 41 is inserted into the liquid injection port 18. The first flange portion 42 has a disk shape, and the diameter thereof is larger than the diameter of the liquid injection port 18. The first flange portion 42 extends outward in the radial direction of the shaft portion 41 outside the case 11 and contacts around the liquid injection port 18.

  The pin member 50 includes a rod portion (pin) 51 and a second flange portion 52 that protrudes to the outer diameter side at the end of the rod portion 51. The rod part 51 has a cylindrical shape. The rod portion 51 is inserted into the concave portion 41 a of the shaft portion 41 to expand the diameter of the shaft portion 41 and seal the inner surface of the liquid injection port with the outer peripheral surface of the shaft portion 41. The second flange portion 52 has a disk shape, and the diameter thereof is larger than the diameter of the first flange portion 42. The second flange portion 52 is provided on the rod portion 51 outside the case 11 and covers the periphery of the liquid injection port 18 wider than the first flange portion 42. That is, the second flange portion 52 is larger on the outer peripheral side than the first flange portion 42. In a state where the second flange portion 52 is placed on the first flange portion 42, the outer peripheral side portion 53 of the second flange portion 52 protrudes over the entire circumference on the outer peripheral side of the first flange portion 42. This protruding part 53 becomes a welded part in the main sealing. That is, a portion 53 on the outer peripheral side of the first flange portion 42 in the second flange portion 52 is a sealing portion with the case 11. This part 53 is a protrusion protruding downward.

  The first seal portion S1 between the outer peripheral surface of the shaft portion 41 and the inner surface of the liquid injection port by the elastic member 40, and the second seal portion S2 by sealing at the portion 53 on the outer peripheral side of the second flange portion 52 by the pin member 50. Have

Next, the effect | action of this embodiment is demonstrated, explaining a temporary sealing process, a degassing process, and a main sealing process in detail.
As shown in FIGS. 4 and 5, in the temporary sealing step, the elastic member 40 having the shaft portion 41 formed with the recess 41 a and the first flange portion 42 extending radially outward of the shaft portion 41, and A pin member 50 having a rod portion 51 and a second flange portion 52 is used. Then, as shown in FIG. 4, the shaft portion 41 is inserted into the liquid injection port 18, and as shown in FIG. 5, the rod portion 51 is inserted into the recess 41 a that opens outside the case 11 in the shaft portion 41. The injection port 18 is temporarily sealed by expanding the diameter of the portion 41 and sealing the inner surface of the injection port with the outer peripheral surface of the shaft portion 41. Thereby, the inside of the case 11 is hermetically sealed.

  As shown in FIG. 6, in the gas venting process, the rod 51 is removed from the recess 41 a, the pin member 50 is removed, and the gas in the case 11 is discharged out of the case 11. In the degassing step, the elastic member 40 may be removed in addition to the pin member 50 to discharge the gas in the case 11 to the outside of the case 11.

  As shown in FIGS. 7 and 8, in the main sealing step, the elastic member 40 and the pin member 50 used in the temporary sealing step are used again. Then, as shown in FIG. 7, the rod portion 51 is inserted into the concave portion 41 a of the shaft portion 41 inserted into the liquid injection port 18. At this time, the second flange portion 52 covers the periphery of the liquid injection port 18 wider than the first flange portion 42. Then, as shown in FIG. 8, a portion 53 on the outer peripheral side of the first flange portion 42 in the second flange portion 52 is welded by laser beam irradiation and sealed to the case 11. Thus, the liquid injection port 18 is fully sealed.

  A comparative example will be described. As a comparative example, the liquid injection port is temporarily sealed by inserting a rod portion (pin) into the recess of the shaft portion of the elastic member and expanding the shaft portion. After degassing, these parts are removed and finally sealed with a blind rivet (BR) which is a separate part. Therefore, in the comparative example, it is necessary to prepare an elastic member, a pin member, and a blind rivet (BR). Moreover, in the comparative example, it becomes difficult to manage the reuse of the elastic member and the pin member. In addition, the pin member needs to be made of stainless steel (SUS) in consideration of durability.

  On the other hand, in this embodiment, an aluminum material is used as the pin member 50, and the elastic member 40 and the pin member 50 used in the temporary sealing process after degassing are returned and sealed with the elastic member 40 and the pin member 50. . Thereby, the sealing plug 19 can serve as both the temporary sealing member and the main sealing member.

According to the above embodiment, the following effects can be obtained.
(1) As a configuration of the secondary battery 10 as a power storage device in which the electrode assembly 12 and the electrolytic solution are accommodated in the case 11 having the electrolytic solution injection port 18, a sealing plug that seals the injection port 18 19 and the sealing plug 19 includes an elastic member 40 and a pin member 50. The elastic member 40 is inserted into the liquid injection port 18, has a shaft portion 41 having a recess 41 a that opens to the outside of the case 11, and extends radially outward of the shaft portion 41 outside the case 11, and It has the 1st flange part 42 which contacts the circumference | surroundings of the liquid injection port 18. FIG. The pin member 50 is inserted into the recess 41 a of the shaft portion 41, expands the diameter of the shaft portion 41, and seals the inner surface of the liquid injection port with the outer peripheral surface of the shaft portion 41, and the rod portion outside the case 11 The second flange portion 52 is provided at 51 and covers the periphery of the liquid injection port 18 wider than the first flange portion 42. Further, in the pin member 50, a portion 53 on the outer peripheral side of the first flange portion 42 in the second flange portion 52 is a sealing portion with the case 11. The first seal portion S1 between the outer peripheral surface of the shaft portion 41 and the inner surface of the liquid injection port by the elastic member 40, and the second seal portion S2 by sealing at the portion 53 on the outer peripheral side of the second flange portion 52 by the pin member 50. Have Accordingly, the seal is sealed at the first seal portion S1 between the outer peripheral surface of the shaft portion 41 and the inner surface of the liquid injection port by the elastic member 40 and at the outer peripheral side portion 53 of the second flange portion 52 by the pin member 50. As a result, the liquid injection port can be sealed with higher reliability.

  (2) As a manufacturing method of the secondary battery 10 as a power storage device in which the electrode assembly 12 and the electrolytic solution are accommodated in the case 11 having the electrolyte injection hole 18, a temporary sealing step, a degassing step, and a book And a sealing step. In the temporary sealing step, the shaft portion 41 in which the concave portion 41a is formed, the elastic member 40 having the first flange portion 42 extending outward in the radial direction of the shaft portion 41, and the rod portion 51 and the second flange portion 52 are provided. Using the pin member 50 having the shaft portion 41 inserted into the liquid injection port 18, the rod portion 51 is inserted into the recess 41 a that opens outside the case 11 to expand the diameter of the shaft portion 41, and the outer peripheral surface of the shaft portion 41. Then, the liquid injection port 18 is temporarily sealed by sealing the inner surface of the liquid injection port. In the degassing step, after the temporary sealing step, at least the pin member 50 is removed from the pin member 50 and the elastic member 40 to discharge the gas in the case 11 to the outside of the case 11. In the main sealing step, the elastic member 40 and the pin member 50 used in the temporary sealing step are used again after the degassing step. Then, the first flange portion 42 in the second flange portion 52 that covers the periphery of the liquid injection port 18 wider than the first flange portion 42 by inserting the rod portion 51 into the concave portion 41 a of the shaft portion 41 inserted into the liquid injection port 18. The liquid injection port 18 is finally sealed by sealing the outer peripheral side portion 53 to the case 11. Thus, the sealing is performed by sealing between the outer peripheral surface of the shaft portion 41 and the inner surface of the liquid injection port by the elastic member 40 and at the outer peripheral side portion 53 of the second flange portion 52 by the pin member 50. Thus, the injection port can be sealed with higher reliability. Further, the temporary sealing is performed by sealing (shaft sealing) the outer peripheral surface of the shaft portion 41 and the inner surface of the liquid injection port using the rod portion 51 of the pin member 50, and the main sealing is performed by the second flange portion. Since the portion 53 on the outer peripheral side of the first flange portion 42 in 52 is sealed with the case 11, temporary sealing and main sealing are easily performed using a member that serves as both temporary sealing and main sealing. be able to.

(3) Since the pin member 50 is made of metal, it is easily sealed to the case 11.
(4) Since the pin member 50 is made of the same material as the case 11 and is sealed to the case 11 by welding, the pin member 50 is more easily sealed to the case 11.

The embodiment is not limited to the above, and may be embodied as follows, for example.
In FIGS. 3A and 3B, the outer peripheral portion 53 of the second flange portion 52 is a protruding portion that protrudes downward. Instead of this, as shown in FIG. 9A, the outer peripheral side portion 53 of the second flange portion 52 may not be a protrusion protruding downward (may be a flat surface). As shown in (b), the first flange portion 42 may be compressed and the second flange portion 52 may be disposed close to the case 11 and welded. Or you may weld in the state which pressed the outer peripheral part 53 against the case 11. FIG.

  3 (a) and 3 (b), the outer peripheral side portion 53 of the second flange portion 52 is a protruding portion protruding downward, but instead shown in FIGS. 10 (a) and 10 (b). As described above, the projecting portion 60 may be formed on the case 11 side while the outer peripheral side portion 53 of the second flange portion 52 is a flat surface that is not a projecting portion projecting downward.

  As shown in FIG. 11, the recess 70 is formed on the tip surface of the rod portion 51 of the pin member 50, and the protrusion 80 that engages with the recess 70 is formed on the bottom surface of the recess 41 a of the elastic member 40. Good.

The pin member 50 may be made of a metal other than an aluminum material, for example, may be made of stainless steel.
The pin member 50 may be made of resin other than metal, and may be sealed (sealed and sealed) to the case 11 by heat welding.

The case 11 may be made of a metal other than aluminum, for example, stainless steel.
The positive electrode and the negative electrode may have a structure in which an active material is present on one side of the metal foil.

The electrode assembly 12 is not limited to the laminated type, and may be a wound type obtained by winding a belt-like positive electrode and a belt-like negative electrode to form a layer.
The secondary battery 10 may not be a square battery but may be a cylindrical battery.

The secondary battery 10 may be another secondary battery. In short, any ion may be used as long as ions move between the active material for the positive electrode and the active material for the negative electrode and charge is transferred.
-You may apply to the capacitor as an electrical storage apparatus.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery, 11 ... Case, 12 ... Electrode assembly, 18 ... Injection hole, 19 ... Seal plug, 40 ... Elastic member, 41 ... Shaft part, 41a ... Recessed part, 42 ... First flange part, 50 ... Pin member, 51 ... Bar part, 52 ... Second flange part, 53 ... Site, S1 ... First seal part, S2 ... Second seal part.

Claims (4)

A power storage device in which an electrode assembly and an electrolytic solution are housed in a case having an injection port for an electrolytic solution,
Comprising a sealing plug for sealing the liquid injection port, the sealing plug comprises an elastic member and a pin member;
The elastic member is inserted into the liquid injection port and has a shaft portion having a recess that opens to the outside of the case, and extends outward in the radial direction of the shaft portion outside the case. Having a first flange portion in contact with the periphery of the liquid port;
The pin member is inserted into the recess of the shaft portion to expand the diameter of the shaft portion and seal the inner surface of the liquid injection port with the outer peripheral surface of the shaft portion, and the rod portion outside the case A second flange portion that is provided wider than the first flange portion and covers the periphery of the liquid injection port, and a portion of the second flange portion on the outer peripheral side of the first flange portion is sealed to the case Part
A first seal portion between the outer peripheral surface of the shaft portion and the inner surface of the liquid injection port by the elastic member, and a second seal portion by sealing at a portion on the outer peripheral side of the second flange portion by the pin member. A power storage device characterized by the above. A method of manufacturing a power storage device in which an electrode assembly and an electrolytic solution are housed in a case having an injection port for an electrolytic solution,
An elastic member having a shaft portion in which a recess is formed, a first flange portion extending radially outward of the shaft portion, and a pin member having a rod portion and a second flange portion are used for the liquid injection port. The liquid injection port is formed by inserting the rod portion into a recessed portion opened outside the case in the inserted shaft portion, expanding the diameter of the shaft portion, and sealing the inner surface of the liquid injection port with the outer peripheral surface of the shaft portion. A temporary sealing step of temporarily sealing,
After the temporary sealing step, a degassing step of removing at least the pin member from the pin member and the elastic member and discharging the gas in the case out of the case;
After the degassing step, the elastic member and the pin member used in the temporary sealing step are reused, and the rod portion is inserted into the concave portion of the shaft portion inserted into the liquid injection port. A main sealing step of sealing the liquid injection port by sealing a portion of the second flange portion that covers the periphery of the liquid injection port wider than the first portion to the case. When,
A method for manufacturing a power storage device, comprising:   The method for manufacturing a power storage device according to claim 2, wherein the pin member is made of metal.   The method for manufacturing a power storage device according to claim 2, wherein the pin member is made of the same material as the case and is sealed to the case by welding.

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