JP2019053863A - Power storage element - Google Patents

Abstract

To provide a highly reliable power storage element including a conductive member connected to a tab of an electrode body, and an insulating member for insulating the conductive member from a container.SOLUTION: A power storage element 10 includes: an electrode body 400; a container 100 accommodating the electrode body 400; a conductive member 120 connected to a negative electrode tab 420 of the electrode body 400; and a lower insulating member 260 insulating the conductive member 120 from the container 100. The conductive member 120 has a shaft portion 125 which passes a side of the negative electrode tab 420 and penetrates the lower insulating member 260. A connection portion 420a of the negative electrode tab 420 with the conductive member 120 is sandwiched between the conductive member 120 and the lower insulating member 260.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a power storage element including a conductive member connected to a tab of an electrode body, and an insulating member that insulates the conductive member and a container.

  2. Description of the Related Art Conventionally, an energy storage device including a container that accommodates an electrode body, a conductive member connected to the electrode body, and an insulating member that insulates the conductive member and the container is widely known. For example, Patent Document 1 discloses a battery including an electrode terminal provided with a fastening member, an insulating resin that insulates the electrode terminal from a battery lid, and a laminated electrode body formed by laminating electrode plates. . In this battery, a through hole is formed in the electrode tab of the electrode plate, and the electrode terminal and the electrode plate are electrically connected by a fastening member through the through hole.

JP 2012-104226 A

  In the conventional battery, since a through hole is provided in the tab of the electrode plate, for example, a problem that the strength of the tab is lowered may occur. In addition, the presence of the through hole in the tab may lead to a reduction in the contact area between the tab and the conductive member (for example, electrode terminal). These events cause problems such as a decrease in battery performance or a shortened life.

  The present invention has been made by the inventor of the present application newly paying attention to the above problems, and includes a conductive member connected to a tab of an electrode body, and an electric storage element including an insulating member that insulates the conductive member and the container Then, it aims at providing a highly reliable electrical storage element.

  In order to achieve the above object, an electricity storage device according to one aspect of the present invention is an electricity storage device including an electrode body and a container that accommodates the electrode body, and a conductive member connected to a tab of the electrode body; An insulating member that insulates the conductive member and the container, the conductive member having a shaft portion that passes through the side of the tab and penetrates the insulating member, and the conductive member of the tab The connecting portion is a power storage element sandwiched between the conductive member and the insulating member.

  According to this configuration, since the shaft portion of the conductive member is disposed so as to pass through the side of the tab, there is no need to provide a through hole in the tab. Therefore, for example, the conductive member and the tab are connected without reducing the contact area between the tab and the conductive member and without reducing the strength of the tab. As a result, for example, an increase in electrical resistance in the conduction path between the electrode body and the electrode terminal is suppressed, and the maintenance of the conduction path (long life) is achieved. Thereby, a highly reliable power storage element can be obtained.

  Moreover, the connection part (part connected with the conductive member) of the tab is sandwiched between the conductive member and the insulating member. Therefore, for example, the conductive member and the tab are electrically and mechanically connected by the clamping force between the conductive member and the insulating member without welding, caulking, or screwing the conductive member and the tab. It is possible. Therefore, for example, an operation for joining the tab to the conductive member is completed by an assembly operation for incorporating the conductive member and the insulating member into the container. Moreover, relative movement of the electrode body housed in the container and the conductive member fixed to the container is regulated by the container. Therefore, for example, even when the tab is not fixed to the conductive member by welding or the like, a problem or the like hardly occurs in the electrical and mechanical connection between the conductive member and the tab. As described above, the power storage element according to this embodiment can ensure high reliability with a simple structure.

  In the power storage element according to one embodiment of the present invention, a first uneven portion may be formed on a surface of the conductive member that is in contact with the tab.

  According to this structure, since the connection part of a tab is formed in the state in which the 1st uneven | corrugated | grooved part of the electrically-conductive member digged into the tab, the position shift with respect to the electrically-conductive member of a tab is suppressed, for example. Further, the contact area between the negative electrode tab and the conductive member can be increased. As a result, the reliability of the electrical and mechanical connection between the tab and the conductive member is improved.

  Moreover, in the electrical storage element which concerns on 1 aspect of this invention, the 2nd uneven | corrugated | grooved part may be formed in the surface which contacts the said connection part of the said tab in the said insulating member.

  According to this configuration, the second uneven portion of the insulating member bites into the connection portion of the tab, for example, so that the displacement of the tab with respect to the insulating member is suppressed, and thereby the displacement of the tab with respect to the conductive member is also suppressed. . As a result, the reliability of the electrical and mechanical connection between the tab and the conductive member is improved.

  Further, in the energy storage device according to one aspect of the present invention, the conductive member is a plate-like portion that forms a surface that contacts the tab, and has a plate-like portion integrated with the shaft portion, The shaft portion may penetrate the insulating member and be caulked on the outside of the container.

  According to this configuration, since the connecting portion of the tab is sandwiched between the insulating member and the plate-like portion integrated with the shaft portion that is caulked outside the container, the caulking force on the shaft portion is reduced. It is efficiently used as a fixing force for fixing the connecting portion. As a result, for example, the reliability of electrical and mechanical connection between the tab and the conductive member is improved.

  ADVANTAGE OF THE INVENTION According to this invention, it is an electrical storage element provided with the electrically-conductive member connected with the tab of the electrode body, and the insulating member which insulates a conductive member and a container, Comprising: An electrical storage element with high reliability can be provided.

It is a perspective view which shows the external appearance of the electrical storage element which concerns on embodiment. It is a disassembled perspective view which shows the component of the electrical storage element which concerns on embodiment. It is the 1st sectional view showing the structure around the electrode terminal of the electrical storage element concerning an embodiment. It is a 2nd sectional view showing the structure around the electrode terminal of the electrical storage element concerning an embodiment. It is a perspective view which shows the structure outline | summary of the electrically-conductive member which concerns on the modification 1 of embodiment. It is a perspective view which shows the structure outline | summary of the lower insulating member which concerns on the modification 2 of embodiment.

  Hereinafter, an electricity storage device according to embodiments and modifications of the present invention will be described with reference to the drawings. Each figure is a schematic diagram and is not necessarily illustrated exactly.

  In addition, each of the embodiments and modifications described below is a specific example of the present invention. The shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, order of manufacturing steps, and the like shown in the following embodiments and modifications are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments and modifications, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

  Further, in the description and drawings in the following embodiments and modifications, the arrangement direction of a pair of electrode terminals included in the storage element, the arrangement direction of a pair of conductive members, the arrangement direction of the negative electrode tab and the positive electrode tab of the electrode body, or The opposing direction of the short side surface of the container is defined as the X-axis direction. Moreover, the opposing direction of the long side surface of the container, the short side direction of the short side surface of the container, or the thickness direction of the container is defined as the Y-axis direction. Further, the direction in which the container body and the cover plate of the electricity storage element are arranged, the longitudinal direction of the short side surface of the container, the extending direction of the shaft portion of the conductive member, or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect (orthogonal in this embodiment). Although the case where the Z-axis direction does not become the vertical direction may be considered depending on the usage mode, the Z-axis direction will be described below as the vertical direction for convenience of explanation. In the following description, for example, the X axis direction plus side indicates the arrow direction side of the X axis, and the X axis direction minus side indicates the opposite side to the X axis direction plus side. The same applies to the Y-axis direction and the Z-axis direction.

(Embodiment)
[1. General description of storage element]
First, with reference to FIG. 1 and FIG. 2, a general description of the energy storage device 10 according to the embodiment will be given. FIG. 1 is a perspective view showing an external appearance of a power storage element 10 according to the embodiment. FIG. 2 is an exploded perspective view showing components of the energy storage device 10 according to the embodiment.

  In FIG. 2, the container main body 101 is not shown, and the shaft portion 125 of the conductive member 120 and the shaft portion 135 of the conductive member 130 are shown in a state where the tips are caulked. These matters are the same in FIGS. 3 to 6 described later.

  The power storage element 10 is a secondary battery that can charge electricity and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. For example, the electric storage element 10 is applied to various vehicles such as an electric vehicle (EV), a plug-in hybrid electric vehicle (PHEV), and a hybrid electric vehicle (HEV). In addition, the electrical storage element 10 is not limited to a nonaqueous electrolyte secondary battery, A secondary battery other than a nonaqueous electrolyte secondary battery may be sufficient, and a capacitor may be sufficient as it. Moreover, the electrical storage element 10 may be a primary battery that can use the stored electricity without being charged by the user.

  As shown in FIG. 1, the power storage element 10 includes a container 100 and electrode terminals 200 and 300. Further, as shown in FIG. 2, a negative electrode side conductive member 120, a positive electrode side conductive member 130, and an electrode body 400 are accommodated in the container 100.

  The power storage element 10 may include a spacer disposed on the side of the conductive members 120 and 130, an insulating film that wraps the electrode body 400, and the like in addition to the above-described components. In addition, an electrolytic solution (nonaqueous electrolyte) or the like is sealed in the container 100 of the power storage element 10, but the illustration thereof is omitted. In addition, as long as the electrolyte solution enclosed with the container 100 does not impair the performance of the electrical storage element 10, there is no restriction | limiting in particular in the kind, Various things can be selected.

  The container 100 includes a container body 101 having a rectangular cylindrical shape and a bottom, and a lid plate 110 that is a plate-like member that closes the opening of the container body 101. The container 100 has a structure that seals the inside by welding the lid plate 110 and the container body 101 after the electrode body 400 and the like are accommodated therein. The material of the lid plate 110 and the container body 101 is not particularly limited, but is preferably a weldable metal such as stainless steel, aluminum, or aluminum alloy.

  The electrode body 400 is a power storage element (power generation element) that includes a positive electrode plate, a negative electrode plate, and a separator and can store electricity. In the present embodiment, a laminated (stacked) electrode body 400 formed by laminating a plurality of flat plate-like positive electrode plates and negative electrode plates with a separator interposed therebetween is used as an electricity storage element ( Power generation element).

  Specifically, the positive electrode plate is an electrode plate in which a composite material layer containing a positive electrode active material is formed on a positive electrode base material layer which is a flat current collector foil made of aluminum or an aluminum alloy. The negative electrode plate is an electrode plate in which a composite material layer containing a negative electrode active material is formed on a negative electrode base material layer that is a flat current collector foil made of copper or a copper alloy. The separator is a microporous sheet made of resin or the like. The electrode body 400 is formed by laminating a plurality of these positive electrode plates and negative electrode plates with a separator interposed therebetween.

  In addition, each of the plurality of negative electrode plates has a protruding portion in which a base material layer on which a composite material layer is not formed is exposed at an end portion in a predetermined direction (in the present embodiment, the Z-axis direction plus side). The negative electrode tab 420 of the electrode body 400 is formed by stacking the protruding portions of the negative electrode plate. Each of the plurality of positive plates has a protruding portion in which a base material layer on which a composite material layer is not formed is exposed at an end in a predetermined direction (in the present embodiment, on the positive side in the Z-axis direction). The positive electrode tab 430 of the electrode body 400 is formed by stacking the protruding portions of the positive electrode plate. In other words, the electrode body 400 according to the present embodiment includes a main body portion 410 that is a substantial part for power storage (power generation), and a negative electrode tab 420 and a positive electrode tab 430 that protrude from the main body portion 410. doing.

  In FIG. 2, the main body 410 is simply illustrated as a rectangular parallelepiped object, and each of the negative electrode tab 420 and the positive electrode tab 430 includes only a part of the plurality of protrusions constituting the main body. It is shown in the figure. These matters are the same in FIGS. 3 to 6 described later.

  The electrode terminal fixed to the container 100 is electrically connected to the electrode body 400 having the above configuration via a conductive member. Specifically, the electrode terminal 200 that is a negative electrode terminal is electrically connected to the negative electrode of the electrode body 400 via the conductive member 120. The electrode terminal 300, which is a positive electrode terminal, is electrically connected to the positive electrode of the electrode body 400 through the conductive member 130. The electrode terminals 200 and 300 are attached to the cover plate 110 disposed above the electrode body 400 via upper insulating members 250 and 350.

  As shown in FIG. 2, the conductive member 120 includes a plate-like portion 122 connected to the negative electrode tab 420 of the electrode body 400 and a shaft portion 125 connected to the electrode terminal 200. A lower insulating member 260 is disposed between the plate-like portion 122 and the lid plate 110 of the container 100. The conductive member 120 is formed of, for example, copper or a copper alloy similarly to the negative electrode base material layer of the electrode body 400.

  As shown in FIG. 2, the conductive member 130 has a plate-like portion 132 connected to the positive electrode tab 430 of the electrode body 400 and a shaft portion 135 connected to the electrode terminal 300. A lower insulating member 360 is disposed between the plate-like portion 132 and the lid plate 110 of the container 100. The conductive member 130 is made of aluminum or an aluminum alloy, for example, similarly to the positive electrode base material layer of the electrode body 400.

  The conductive members 120 and 130 having the above configuration play a role of electrical connection between the electrode body 400 and the electrode terminals 200 and 300, and the negative electrode tab 420, the positive electrode tab 430, the electrode terminals 200 and 300, and the like of the electrode body 400. It also functions as a member for fixing the element.

  Specifically, the shaft portion 125 of the conductive member 120 is inserted into the opening 262 of the lower insulating member 260, the opening 112 of the cover plate 110, the opening 252 of the upper insulating member 250, and the through hole 202 of the electrode terminal 200. The tip is caulked. Thereby, the electrode terminal 200 is fixed to the cover plate 110 together with the upper insulating member 250, the lower insulating member 260, and the conductive member 120.

  The shaft portion 135 of the conductive member 130 is inserted into the opening 362 of the lower insulating member 360, the opening 113 of the cover plate 110, the opening 352 of the upper insulating member 350, and the through hole 302 of the electrode terminal 300. The part is caulked. Accordingly, the electrode terminal 300 is fixed to the lid plate 110 together with the upper insulating member 350, the lower insulating member 360, and the conductive member 130.

  Further, in the present embodiment, the positive electrode tab 430 of the electrode body 400 is sandwiched and fixed between the conductive member 130 and the lower insulating member 360, and the negative electrode tab 420 of the electrode body 400 is fixed to the conductive member 120 and the lower insulating member 260. It is sandwiched between and fixed. This fixing structure will be described below with reference to FIGS.

[2. Electrode tab fixing structure]
Next, a tab fixing structure of electrode body 400 in power storage element 10 according to the present embodiment will be described with reference to FIGS. 3 and 4. In the present embodiment, the fixing structures of the negative electrode tab 420 and the positive electrode tab 430 of the electrode body 400 are common. Therefore, hereinafter, the fixing structure of the negative electrode tab 420 will be described, and illustration and description of the fixing structure of the positive electrode tab 430 will be omitted.

  3 is a first cross-sectional view showing a structure around electrode terminal 200 of power storage element 10 according to the embodiment, and FIG. 4 shows a structure around electrode terminal 200 of power storage element 10 according to the embodiment. It is 2nd sectional drawing. 3 shows a part of the cross section of the power storage element 10 in the XZ plane passing through the line III-III in FIG. 1, and FIG. 4 shows the power storage element in the YZ plane passing through the line IV-IV in FIG. A portion of 10 cross-sections are shown.

  As shown in FIGS. 3 and 4, in the present embodiment, power storage element 10 includes conductive member 120 connected to negative electrode tab 420 of electrode body 400, and lower insulating member that insulates conductive member 120 from container 100. 260. The conductive member 120 has a shaft portion 125 that passes through the side of the negative electrode tab 420 and penetrates the lower insulating member 260. A portion (connecting portion 420 a) of the negative electrode tab 420 connected to the conductive member 120 is sandwiched between the conductive member 120 and the lower insulating member 260.

  As described above, in the present embodiment, the shaft portion 125 of the conductive member 120 is disposed so as to pass through the side of the negative electrode tab 420, so there is no need to provide a through hole in the negative electrode tab 420. Therefore, for example, the conductive member 120 and the negative electrode tab 420 can be connected without reducing the contact area of the negative electrode tab 420 with the conductive member 120 and without reducing the strength of the negative electrode tab 420. As a result, for example, an increase in electrical resistance in the conduction path between the electrode body 400 and the electrode terminal 200 is suppressed, and the conduction path is maintained (long life). Thereby, the highly reliable electrical storage element 10 can be obtained.

  Further, the connecting portion 420 a of the negative electrode tab 420 is sandwiched between the conductive member 120 and the lower insulating member 260. Therefore, for example, without conducting welding, caulking, or screwing the conductive member 120 and the negative electrode tab 420, the conductive member 120 and the negative electrode tab 420 can be connected to each other by the clamping force between the conductive member 120 and the lower insulating member 260. Can be electrically and mechanically connected. Therefore, for example, the work for joining the negative electrode tab 420 to the conductive member 120 is completed by the assembly work for incorporating the conductive member 120 and the lower insulating member 260 into the container 100. Further, relative movement of the electrode body 400 housed in the container 100 and the conductive member 120 fixed to the container 100 is restricted by the container 100. That is, for example, during normal use of the electricity storage element 10, the conductive member 120 does not move significantly with respect to the main body portion 410 of the electrode body 400. Therefore, even when the negative electrode tab 420 is not fixed to the conductive member 120 by welding or the like, a problem or the like hardly occurs in the electrical and mechanical connection between the conductive member 120 and the negative electrode tab 420. As described above, the power storage element according to this embodiment can ensure high reliability with a simple structure.

  Further, in order to sandwich the negative electrode tab 420 between the lower insulating member 260 arranged along the inner surface of the container 100 and the conductive member 120, the main body portion 410 of the electrode body 400 is disposed to a position close to the inner surface of the container 100. be able to. As a result, the ratio (energy density) occupied by the main body 410 of the electrode body 400 in the volume of the container 100 can be improved.

  In the present embodiment, the shaft portion 125 of the conductive member 120 is disposed away from the negative electrode tab 420. However, for example, the peripheral surface of the shaft portion 125 and the negative electrode tab 420 may be in contact with each other.

  In the present embodiment, the upper insulating member 250 and the lower insulating member 260 disposed between the cover plate 110 and the electrode terminal 200 include the shaft portion 125 and the opening 112 of the cover plate 110 (see FIG. 2). It has a role to maintain airtightness between. That is, the upper insulating member 250 and the lower insulating member 260 also have a role as a so-called gasket. Each of the upper insulating member 250 and the lower insulating member 260 having such a function is made of an insulating material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), or polyphenylene sulfide resin (PPS). Is formed.

  Further, in the present embodiment, the upper insulating member 250 and the lower insulating member 260 are separate components from each other. For example, the storage element is integrated as one insulating member with the cover plate 110 by insert molding or the like. 10 may be provided.

  In the present embodiment, the conductive member 120 is a plate-like portion 122 that forms a surface that contacts the negative electrode tab 420, and has a plate-like portion 122 that is integrated with the shaft portion 125. The shaft portion 125 penetrates the lower insulating member 260 and is caulked outside the container 100.

  In the present embodiment, for example, the conductive member 120 including the shaft portion 125 and the plate-like portion 122 integrally is manufactured by performing a pressing process or the like on a copper bar. The shaft portion 125 is caulked at the tip end (the end opposite to the plate-like portion 122) in a state of penetrating the lower insulating member 260, the lid plate 110, the upper insulating member 250 and the electrode terminal 200. As a result, a large-diameter portion 125 a having an outer diameter larger than that of other portions of the shaft portion 125 is formed at the tip portion of the shaft portion 125.

  Thus, in the present embodiment, the connecting portion 420 a of the negative electrode tab 420 is sandwiched between the plate-like portion 122 and the lower insulating member 260 that are integrated with the shaft portion 125 that is caulked outside the container 100. Therefore, the caulking force with respect to the shaft portion 125 is efficiently used as a fixing force for fixing the connecting portion 420 a of the negative electrode tab 420. As a result, for example, the reliability of the electrical and mechanical connection between the negative electrode tab 420 and the conductive member 120 is improved.

  Here, unlike the present embodiment, for example, the shaft portion extending from the electrode terminal 200 toward the inside of the container 100 penetrates the through hole provided in the plate-like portion 122, and the shaft portion Assume that the end is caulked inside the container 100. Even in this case, the negative electrode tab 420 is sandwiched between the plate-like portion 122 and the lower insulating member 260, whereby the plate-like portion 122 and the negative electrode tab 420 are electrically and mechanically connected. However, in this case, since the caulking operation is performed in a state where the shaft portion and the plate-like portion 122 are not fixed, for example, the axial pressing force applied to the shaft portion in the caulking operation is lateral to the shaft portion. There is a possibility that the negative electrode tab 420 positioned may not be used sufficiently. On the other hand, in the present embodiment, the tip end portion of the shaft portion 125 is caulked with the shaft portion 125 fixed to the plate-like portion 122. For this reason, the pressing force applied to the shaft portion 125 when the shaft portion 125 is caulked is efficiently used as a force for sandwiching the negative electrode tab 420. As a result, the negative electrode tab 420 is insulated from the plate-shaped portion 122 by lower insulation. It is firmly sandwiched between the member 260. Therefore, the reliability of electrical and mechanical connection between the negative electrode tab 420 and the plate-like portion 122 is further improved.

  Further, for example, when the shaft portion is caulked inside the container 100, a large diameter portion caused by caulking is present inside the container 100, and the large diameter portion causes the electrode body 400 in the container 100 to be inside. The space above the main body 410 is consumed. This is not preferable from the viewpoint of improving the energy density, for example. However, in the present embodiment, since the shaft portion 125 is caulked outside the container 100, the caulked portion (large diameter portion 125a) is disposed in a manner that does not consume the internal space of the container 100. In this case, the large-diameter portion 125a is exposed on the surface of the electrode terminal 200. However, in addition to the large-diameter portion 125a on the surface of the electrode terminal 200, a sufficient region for joining the bus bar by laser welding or the like is secured. be able to. Therefore, there is no substantial problem with the large diameter portion 125a being exposed on the surface of the electrode terminal 200.

  In the present embodiment, the cover plate 110 is formed with a protruding portion 115 formed so as to bulge into a box shape, and as shown in FIGS. 3 and 4, the space inside the protruding portion 115 is formed. In addition, the plate-like portion 122 of the conductive member 120 is accommodated. In addition, the space inside the protruding portion 115 also accommodates a surplus portion of the negative electrode tab 420 (a portion other than the connection portion 420a). As described above, by providing the protruding portion 115 at the position where the electrode terminal 200 is disposed on the lid plate 110, at least a part of the conductive member 120 and the negative electrode tab 420 connected to the electrode terminal 200 is disposed inside the protruding portion 115. Can be accommodated in any space. Further, in the present embodiment, the cover plate 110 is also provided with a protrusion 116 at a position where the positive electrode terminal 300 is disposed, and the conductive member 130 and the positive electrode tab 430 connected to the electrode terminal 300 are provided. At least a part is accommodated in the space inside the protrusion 116. Thus, by providing the protrusions 115 and 116 on the lid plate 110, for example, the internal space of the container 100 can be effectively used while improving the strength of the lid plate 110.

  The power storage element 10 according to the embodiment has been described above. However, the power storage element 10 may include the conductive member 120 and the upper insulating member 250 that are different from the modes illustrated in FIGS. Therefore, hereinafter, a modified example of the conductive member 120 and the upper insulating member 250 in the power storage element 10 will be described focusing on differences from the above embodiment.

(Modification 1)
FIG. 5 is a perspective view illustrating a schematic configuration of the conductive member 120a according to the first modification of the embodiment. A conductive member 120a illustrated in FIG. 5 is a member provided in the power storage element 10 in place of the conductive member 120 according to the above embodiment. That is, the conductive member 120a is a member that sandwiches the negative electrode tab 420 of the electrode body 400 together with the lower insulating member 260 (see FIG. 2). Specifically, the conductive member 120a includes a plate-like portion 122 that forms a surface in contact with the negative electrode tab 420, and a shaft portion 125 that is integrated with the plate-like portion 122. The shaft portion 125 has a lower insulation. It penetrates the member 260 and is caulked outside the container 100 (see FIG. 1).

  These configurations are common to the conductive member 120 according to the above embodiment. However, in the conductive member 120a according to the present modification, the first uneven portion 126 is formed on the surface in contact with the negative electrode tab 420. That is, the first uneven portion 126 is formed on the upper surface of the plate-like portion 122 (the surface on the negative electrode tab 420 side). Thereby, since the connection part 420a is formed in the state in which the 1st uneven | corrugated | grooved part 126 bites into the negative electrode tab 420, the position shift with respect to the electrically-conductive member 120a of the negative electrode tab 420 is suppressed, for example. Further, the contact area between the negative electrode tab 420 and the conductive member 120a can be increased. As a result, the reliability of electrical and mechanical connection between the negative electrode tab 420 and the conductive member 120a is improved.

  In addition, there is no limitation in particular in the method of formation of the 1st uneven | corrugated | grooved part 126 in the electrically-conductive member 120a. For example, the first concavo-convex portion 126 may be formed on the plate-like portion 122 by press working when forming the plate-like portion 122 and the shaft portion 125. Further, for example, the first uneven portion 126 may be formed in the plate-like portion 122 by performing processing such as cutting or grinding on the plate-like portion 122 where the first uneven portion 126 is not formed.

(Modification 2)
FIG. 6 is a perspective view illustrating a configuration outline of a lower insulating member 260a according to the second modification of the embodiment. A lower insulating member 260a shown in FIG. 6 is a member provided in the power storage element 10 in place of the lower insulating member 260 according to the above embodiment. That is, the lower insulating member 260 a is a member that sandwiches the negative electrode tab 420 of the electrode body 400 together with the conductive member 120. Specifically, the lower insulating member 260a is a member that insulates the conductive member 120 and the container 100, and is disposed between the plate-like portion 122 of the conductive member 120 and the cover plate 110 (see FIG. 2) of the container 100. Is done. Moreover, it has the opening part 262 which the axial part 125 of the electrically-conductive member 120 penetrates.

  These configurations are common to the lower insulating member 260 according to the above embodiment. However, in the lower insulating member 260a according to this modification, the second uneven portion 265 is formed on the surface that contacts the connecting portion of the negative electrode tab 420. That is, the second uneven portion 265 is formed on the inner surface (the surface on the negative electrode tab 420 side) of the lower insulating member 260a. According to this configuration, the second uneven portion 265 bites into the connection portion 420 a of the negative electrode tab 420, for example, so that displacement of the negative electrode tab 420 with respect to the lower insulating member 260 a is suppressed. Misalignment with respect to 120 is also suppressed. As a result, the reliability of the electrical and mechanical connection between the negative electrode tab 420 and the conductive member 120 is improved.

  In addition, there is no limitation in particular in the method of formation of the 2nd uneven | corrugated | grooved part 265 in the lower insulating member 260a. For example, the second uneven portion 265 may be formed by a mold used for forming the lower insulating member 260a. Further, for example, the second uneven portion 265 may be formed in the lower insulating member 260a by performing processing such as cutting, grinding, melting, etc. on the lower insulating member 260a in which the second uneven portion 265 is not formed. .

(Other embodiments)
As described above, the power storage device according to the present invention has been described based on the embodiment and the modifications thereof. However, the present invention is not limited to the above-described embodiments and modifications. Without departing from the gist of the present invention, various modifications conceived by those skilled in the art may be applied to the above-described embodiment or modification, or a form constructed by combining a plurality of the constituent elements described above. It is included in the range.

  For example, the negative electrode tab 420 is electrically and mechanically connected to the conductive member 120 by being sandwiched between the conductive member 120 and the lower insulating member 260. However, the negative electrode tab 420 may be further joined to the conductive member 120 by welding, for example.

  Even in this case, it is possible to caulk the shaft portion 125 of the conductive member 120 joined to the negative electrode tab 420 on the outside of the container 100 (above the electrode terminal 200). Further, in this case, a portion of the negative electrode tab 420 other than the welded portion with the conductive member 120 is pressed against the conductive member 120 by the lower insulating member 260. Thereby, for example, the contact area between the negative electrode tab 420 and the conductive member 120 is increased, and as a result, an increase in electrical resistance in the conduction path between the electrode terminal 200 and the electrode body 400 is suppressed.

  In addition, before the negative electrode tab 420 is sandwiched between the conductive member 120 and the lower insulating member 260, a plurality of base material layers (a mixture layer non-forming portion) constituting the negative electrode tab 420 are bundled by welding. Also good. In this case, for example, when the power storage element 10 is manufactured, the negative electrode tab 420 is connected to the conductive member 120 in a state where one or more base material layers included in the negative electrode tab 420 are shifted in the X-axis direction (see, for example, FIG. 2). A situation of being pinched by the lower insulating member 260 is prevented. This contributes to improving the reliability of the electrical and mechanical connection between the negative electrode tab 420 and the conductive member 120.

  Further, in this embodiment, the negative electrode tab 420 and the positive electrode tab 430 are substantially rectangular when viewed from the thickness direction (the stacking direction of the base material layer (a mixture layer non-forming portion)). The shape of the positive electrode tab 430 is not particularly limited. For example, the shape when the negative electrode tab 420 is viewed from the thickness direction may be a polygonal shape other than a rectangle or a shape including a curve. Further, for example, when the negative electrode tab 420 is viewed from the thickness direction, there may be a concave portion, and in this case, the shaft portion 125 is arranged such that at least a part of the shaft portion 125 is located inside the concave shape. It may be arranged. In any case, the negative electrode tab 420 may be formed in a shape and size that can be sandwiched between the conductive member 120 and the lower insulating member 260.

  Two or more tabs may be sandwiched between a pair of conductive members and insulating members. For example, when the electrode body 400 has two negative electrode tabs 420 arranged in the X-axis direction (see, for example, FIG. 2), the two negative electrode tabs 420 may be sandwiched between the conductive member 120 and the lower insulating member 260. In this case, for example, the conductive member 120 or the like such that the shaft portion 125 is positioned between the two negative electrode tabs 420 and the portions on both sides of the shaft portion 125 in the plate-like portion 122 are in contact with the negative electrode tab 420. The elements may be designed and fabricated. Thereby, the two negative electrode tabs 420 are fixed with good balance by caulking one shaft portion 125.

  In addition, the conductive member 120 integrally including the shaft portion 125 and the plate-like portion 122 is formed by pressing or the like on one bar. However, for example, even if the conductive member 120 is manufactured by joining the shaft portion 125 separate from the plate portion 122 to the plate portion 122 by a technique such as welding, screwing, or press fitting. Good.

  Further, for example, the plate-like portion 122 may be inclined so that the axial direction of the shaft portion 125 and the normal direction of the plate-like portion 122 are not parallel before the shaft portion 125 is caulked. For example, in the conductive member 120, the plate-like portion 122 is inclined so that the end portion on the plus side in the X-axis direction of the plate-like portion 122 (see FIG. 2) is higher than the root position of the shaft portion 125. (Or may be modified). Thus, when the plate-like portion 122 is deformed or inclined, the caulking force acts to push back the plate-like portion 122 when the tip portion of the shaft portion 125 is caulked outside the container 100. Therefore, the clamping force of the plate-like portion 122 and the lower insulating member 260 with respect to the negative electrode tab 420 is improved.

  In the present embodiment, the electrode body 400 is a laminated electrode body formed by laminating a flat positive electrode plate and a negative electrode plate. However, the type of electrode body included in the electricity storage element 10 is not limited to the stacked type. For example, the storage element 10 may be provided with a wound electrode body formed by winding a long belt-like positive electrode plate and negative electrode plate. For example, in a wound electrode body, when a negative electrode tab and a positive electrode tab are provided at one end in the winding axis direction, the negative electrode tab is sandwiched between the conductive member 120 and the lower insulating member 260, and It is possible to sandwich the positive electrode tab between the conductive member 130 and the lower insulating member 360. That is, for example, in FIG. 2, the winding type electrode body is arranged in a posture in which the winding axis is parallel to the Z axis, the negative electrode tab on the positive side in the Z axis direction is connected to the conductive member 120, and The positive electrode tab at the end may be connected to the conductive member 130. That is, the type or the like of the electrode body included in the power storage element 10 may be appropriately determined according to specifications required for the power storage element 10, for example.

  In addition, embodiments constructed by arbitrarily combining the configurations described in the above embodiments and modifications are also included in the scope of the present invention.

  Further, the present invention can be realized not only as the above-described power storage element, but also as a power storage device including a plurality of the power storage elements.

  The present invention is applicable to power storage elements such as lithium ion secondary batteries.

DESCRIPTION OF SYMBOLS 10 Storage element 100 Container 101 Container main body 110 Cover plate 112,113,252,262,352,352,362 Opening part 115,116 Protruding part 120,120a, 130 Conductive member 122,132 Plate-like part 125,135 Shaft part 125a Large diameter Part 126 First uneven part 200, 300 Electrode terminal 202, 302 Through hole 250, 350 Upper insulating member 260, 260a, 360 Lower insulating member 265 Second uneven part 400 Electrode body 410 Main body part 420 Negative electrode tab 420a Connection part 430 Positive electrode tab

Claims (4)

An electrical storage element comprising an electrode body and a container for housing the electrode body,
A conductive member connected to the tab of the electrode body;
An insulating member for insulating the conductive member and the container;
The conductive member has a shaft portion that passes through the side of the tab and penetrates the insulating member
The connecting portion of the tab with the conductive member is sandwiched between the conductive member and the insulating member.
Power storage element. The electrical storage element according to claim 1, wherein in the conductive member, a first uneven portion is formed on a surface in contact with the tab. The electric storage element according to claim 1, wherein in the insulating member, a second uneven portion is formed on a surface of the tab that contacts the connection portion. The conductive member is a plate-like portion that forms a surface that contacts the tab, and has a plate-like portion that is integrated with the shaft portion,
The power storage element according to any one of claims 1 to 3, wherein the shaft portion penetrates the insulating member and is caulked on the outside of the container.

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