Electricity storage unit

Abstract

The utility model relates to an electric power storage unit, comprising an electrode body comprising a winding body and a tab lead, the winding body is formed by winding a positive electrode plate and a negative electrode plate through a separator plate, and the tab lead protrudes from the end face of the winding body; a unit case that accommodates the electrode body; the electrolyte is filled in the unit shell; and an insulating plate which is made of an insulating material and is adhered to the end surface of the winding body. The cell case includes a cylindrical portion surrounding the electrode body, and a cover connected to the cylindrical portion so as to close an opening of the cylindrical portion. A plurality of holes are formed in the insulating plate, and the plurality of holes comprise holes for the tab lead wires, and the tab lead wires can be inserted into the holes for the tab lead wires. As a result, the stress generated in the electrode body when the electrode body expands can be reduced.

Description

Technical Field

[0001] The utility model relates to an electricity storage unit. Background Art

[0002] Japanese Patent Application Laid-Open No. 2007-200755 discloses a battery including a battery element formed of a wound body, a battery container for housing the battery element, and an insulating plate disposed on the battery element. The insulating plate has a plurality of openings.

[0003] In the battery disclosed in Japanese Patent Application Laid-Open No. 2007-200755, a connecting member such as a tape is used to fix the terminal end of the battery element formed of a wound body. The connecting member generates stress in the battery element when the battery cell expands. Utility Model Content

[0004] In view of the above circumstances, an object of the present invention is to provide a power storage unit capable of reducing stress generated in an electrode body when the electrode body expands.

[0005] One aspect of the utility model relates to a storage unit comprising: an electrode body, including a winding body and a tab lead, wherein the winding body is formed by winding a positive electrode sheet and a negative electrode sheet with a separator in between, and the tab lead protrudes from the end face of the winding body; a unit shell, which accommodates the electrode body; an electrolyte filled in the unit shell; and an insulating plate, which is made of insulating material and bonded to the end face of the winding body, the unit shell comprising a cylindrical portion and a cover, the cylindrical portion surrounding the electrode body, the cover being connected to the cylindrical portion in a manner of closing an opening of the cylindrical portion, and a plurality of holes being formed on the insulating plate, the plurality of holes including a tab lead hole for inserting the tab lead.

[0006] In the above power storage unit, a groove extending in a direction intersecting the circumferential direction of the winding body may be formed on the inner circumferential surface of the cylindrical portion, and the plurality of holes may include a groove hole for guiding the electrolyte solution to flow into the groove.

[0007] In the above power storage unit, the plurality of holes may include adjacent holes formed at positions overlapping with portions of the wound body adjacent to the tab lead in a circumferential direction of the wound body in an axial direction of the wound body.

[0008] According to the utility model, there is provided a power storage unit capable of reducing stress generated in an electrode body when the electrode body expands. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a cross-sectional view schematically showing a power storage unit in one embodiment of the present invention.

[0010] Figure 2 for Figure 1 Cross-sectional view at line II-II in FIG. DETAILED DESCRIPTION

[0011] The embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings referred to below, the same or corresponding components are denoted by the same reference numerals.

[0012] Figure 1 This is a partial cross-sectional view schematically showing an electric storage unit in one embodiment of the present invention. This electric storage unit 1 is preferably mounted on a vehicle.

[0013] like Figure 1 As shown, the power storage cell 1 includes an electrode body 10, a cell case 20, a sealing member 30, a positive electrode side insulating plate 40, and a negative electrode side insulating plate 50. The positive electrode side insulating plate 40 and the negative electrode side insulating plate 50 correspond to "insulating plates" in the present invention.

[0014] The electrode body 10 includes a positive electrode sheet 11, a negative electrode sheet 12, a separator 13, a positive tab lead 15, and a negative tab lead 16. The positive tab lead 15 and the negative tab lead 16 are equivalent to the "tab lead" in the present invention.

[0015] The positive electrode sheet 11 has a positive electrode foil and a positive electrode active material layer provided on the positive electrode foil. The negative electrode sheet 12 has a negative electrode foil and a negative electrode active material layer provided on the negative electrode foil. The separator 13 is arranged between the positive electrode sheet 11 and the negative electrode sheet 12. The separator 13 is made of an insulating material and allows ions to pass through. The positive electrode sheet 11, the negative electrode sheet 12 and the separator 13 constitute a winding body in which the positive electrode sheet 11 and the negative electrode sheet 12 are wound with the separator 13 interposed therebetween.

[0016] The positive electrode tab lead 15 is connected to the positive electrode sheet 11 of the wound body. The positive electrode tab lead 15 protrudes upward from the upper end surface of the wound body.

[0017] The negative electrode tab lead 16 is connected to the negative electrode sheet 12 of the wound body. The negative electrode tab lead 16 protrudes downward from the lower end surface of the wound body.

[0018] The cell case 20 accommodates the electrode assembly 10 . The cell case 20 also accommodates an electrolyte solution (not shown). The cell case 20 is sealed. The cell case 20 includes a case body 21 and a lid 22 .

[0019] The housing body 21 is opened upward. The housing body 21 is made of metal such as aluminum. The housing body 21 has a cylindrical portion 21a and a bottom portion 21b.

[0020] The cylindrical portion 21a surrounds the electrode body 10. Figure 2As shown in FIG. 1 , a groove a1 extending in a direction intersecting the circumferential direction of the winding body is formed on the inner circumferential surface of the cylindrical portion 21a. The groove a1 may extend parallel to the axial direction of the winding body or may be formed in a spiral shape on the inner circumferential surface of the cylindrical portion 21a. Figure 1 The groove a1 is omitted in the figure.

[0021] The bottom portion 21b is formed in a disk shape. The bottom portion 21b is connected to the lower end portion of the cylindrical portion 21a. The negative electrode tab lead 16 is connected to the bottom portion 21b. Therefore, the case body 21 is charged with the same polarity as the negative electrode.

[0022] The cover 22 is connected to the cylindrical portion 21a in a manner to close the opening of the cylindrical portion 21a. Figure 1 As shown, the cover 22 is connected to the upper end of the cylindrical portion 21a via the sealing member 30. The positive electrode tab lead 15 is connected to the lower surface of the cover 22. Therefore, the cover 22 is charged with the same polarity as the positive electrode.

[0023] The positive electrode side insulating plate 40 is made of an insulating material. The positive electrode side insulating plate 40 is formed in a disk shape. The positive electrode side insulating plate 40 is bonded to the upper end surface of the winding body by a bonding member or the like. Figure 2 As shown, a plurality of holes h are formed in the positive electrode side insulating plate 40. The plurality of holes h include a tab lead hole h1, an adjacent hole h2, and a slot hole h3.

[0024] The tab lead hole h1 is a through hole for inserting the positive electrode tab lead 15 .

[0025] The adjacent hole h2 is formed at a position overlapping with a portion of the wound body adjacent to the positive electrode tab lead 15 in the circumferential direction in the axial direction of the wound body. That is, the adjacent hole h2 is formed at a position adjacent to the tab lead hole h1 in the circumferential direction. The adjacent hole h2 may be connected to the tab lead hole h1 or may be separated from the tab lead hole h1.

[0026] The groove hole h3 is a through hole for guiding the electrolyte to flow into the groove a1 of the cylindrical portion 21a. The groove hole h3 is formed at a position facing the groove a1. In the present embodiment, the groove hole h3 is formed by a notch opening toward the groove a1.

[0027] The negative electrode side insulating plate 50 is made of an insulating material. The negative electrode side insulating plate 50 is formed in a disk shape. The negative electrode side insulating plate 50 is bonded to the lower end surface of the winding body by a bonding member or the like. Figure 1 As shown, a through hole 50 h for inserting the negative electrode tab lead 16 is formed in the negative electrode side insulating plate 50 .

[0028] As described above, in the storage cell 1 of the present embodiment, the positive electrode side insulating plate 40 is bonded to the upper end surface of the winding body, and the negative electrode side insulating plate 50 is bonded to the lower end surface of the winding body, so that the connecting member (belt, etc.) for fixing the terminal portion of the winding body can be omitted. Therefore, the stress generated in the electrode body 10 when the electrode body 10 expands is reduced.

[0029] Furthermore, since a plurality of holes h are formed in the positive electrode side insulating plate 40 , the flow of electrolyte or gas is allowed while avoiding a short circuit caused by contact between the upper end surface of the wound body and the lid 22 .

[0030] Those skilled in the art should understand that the above exemplary embodiments are specific examples of the following aspects.

[0031] The first method is a storage unit, which comprises: an electrode body, including a winding body and a tab lead, wherein the winding body is formed by winding a positive electrode sheet and a negative electrode sheet with a separator in between, and the tab lead protrudes from the end face of the winding body; a unit case, which accommodates the electrode body; an electrolyte filled in the unit case; and an insulating plate, which is made of insulating material and bonded to the end face of the winding body, the unit case includes a cylindrical portion surrounding the electrode body and a cover connected to the cylindrical portion in a manner to close the opening of the cylindrical portion, and a plurality of holes are formed on the insulating plate, and the plurality of holes include a tab lead hole for inserting the tab lead.

[0032] In this storage unit, since an insulating plate is bonded to the end face of the winding body, a connecting member (belt, etc.) for fixing the terminal end of the winding body can be omitted. Therefore, the stress generated in the electrode body when the electrode body expands is reduced. In addition, since a plurality of holes are formed in the insulating plate, a short circuit caused by contact between the end face of the winding body and the cover can be avoided while allowing the circulation of electrolyte or gas.

[0033] According to a second aspect, in the power storage unit of the first aspect, a groove extending in a direction intersecting the circumferential direction of the winding body is formed on the inner circumferential surface of the cylindrical portion, and the plurality of holes include a groove hole for guiding the electrolyte solution to flow into the groove.

[0034] In this embodiment, when the electrolyte is supplied, the electrolyte flows into the grooves of the cylindrical portion through the groove holes of the insulating plate, so that the electrolyte can be smoothly injected into the wound body.

[0035] According to a third aspect, in the power storage unit of the first aspect or the second aspect, the plurality of holes include adjacent holes formed at positions overlapping with portions of the winding body adjacent to the tab lead in the circumferential direction of the winding body in the axial direction of the winding body.

[0036] In this embodiment, since the electrolyte flows into the portion of the wound body adjacent to the tab lead in the circumferential direction through the adjacent holes, the injection of the electrolyte into the wound body becomes smoother.

[0037] The embodiments disclosed this time are illustrative in all aspects and should not be considered restrictive. The scope of the present invention is indicated by the technical claims rather than the description of the embodiments above, and includes all modifications within the meaning and scope equivalent to the technical claims.

Claims

1. A power storage unit, characterized in that: have: The electrode body comprises a winding body and a tab lead, wherein the winding body is formed by winding a positive electrode sheet and a negative electrode sheet with a separator interposed therebetween, and the tab lead protrudes from an end surface of the winding body; A unit housing for housing the electrode body; An electrolyte is filled in the unit shell; and an insulating plate, made of an insulating material and bonded to the end surface of the winding body, The unit case includes a cylindrical portion and a cover, wherein the cylindrical portion surrounds the electrode body, and the cover is connected to the cylindrical portion in a manner of closing an opening of the cylindrical portion. A plurality of holes are formed on the insulating plate, The plurality of holes include a tab lead hole through which the tab lead is inserted.

2. The power storage unit according to claim 1, characterized in that: A groove extending in a direction intersecting the circumferential direction of the wound body is formed on the inner circumferential surface of the cylindrical portion. The plurality of holes include a channel hole for guiding the electrolyte to flow into the channel.

3. The power storage unit according to claim 1, characterized in that: The plurality of holes include adjacent holes formed at positions overlapping with portions of the wound body adjacent to the tab lead in the circumferential direction of the wound body in the axial direction of the wound body.

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