Power storage module

Abstract

To provide a power storage module capable of sufficiently reducing resistance of a current path.SOLUTION: A power storage module comprises a power storage device. The power storage device comprises an outer jacket that has a lid plate provided with an external terminal, a polar plate that has a tab and is stored in the outer jacket, a conductive shaft part that penetrates the lid plate and has one end connected to the external terminal, and a conductive plate part that is stored in the outer jacket, has a first face to which the other end of the conductive shaft part is connected and a second face to which the tab is connected. The dimension of the conductive shaft part in a surface direction of the lid plate is greater than the dimension of the external terminal in the surface direction of the lid plate. The tab is integrally formed with the polar plate. The tab is arranged apart from a side face of the outer jacket in the surface direction. The polar plate has a positive electrode plate and a negative electrode plate. The tab has a positive electrode tab which extends from a portion of an edge of the positive electrode plate toward the lid plate, and a negative electrode tab which extends from an edge of the negative electrode plate toward the lid plate.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an electricity storage module. [Background technology]

[0002] Chargeable and dischargeable energy storage elements are used in various devices such as mobile phones and automobiles. Vehicles that use electrical energy as their power source, such as electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs), require large amounts of energy and are therefore equipped with large-capacity energy storage modules that include multiple energy storage elements.

[0003] The energy storage element includes an outer casing and an electrode assembly having a plurality of positive and negative electrode plates housed in the outer casing and stacked with separators interposed therebetween. The positive and negative electrode plates each have a tab. The outer casing is provided with two external terminals corresponding to the positive and negative electrode plates.

[0004] Patent Document 1 discloses a lithium ion secondary battery having a rectangular case. The lid of the case has a through hole. A rod-shaped body is inserted into the through hole, one end of the body is connected to a first flange inside the case, and the other end of the body is connected to a terminal plate (external terminal). A tab of an electrode body is connected to the first flange. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-91659 A Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, there has been a demand for a storage element capable of rapid charging and rapid discharging. During rapid charging or rapid discharging, a relatively large current flows through the current path. There has been a demand for a high-performance storage element in which the resistance loss in the current path is small even when a large current flows. There has also been a demand for the current path not to melt even when a large current flows.

[0007] The present invention has been made in view of the above circumstances, and has an object to provide an electricity storage module capable of sufficiently reducing the resistance of a current path. [Means for solving the problem]

[0008] The energy storage module of the present invention comprises an outer casing having an external terminal provided on a cover plate, an electrode plate having a tab and housed in the outer casing, a conductive shaft portion penetrating the cover plate and having one end connected to the external terminal, and a conductive plate portion housed in the outer casing and having the other end of the conductive shaft portion connected to a first surface and the tab connected to a second surface, wherein the dimension of the conductive plate portion in the surface direction of the cover plate is larger than the dimension of the external terminal in the surface direction of the cover plate, the tab is formed integrally with the electrode plate and is positioned away from a side surface of the outer casing in the surface direction, the electrode plate has a positive electrode plate and a negative electrode plate, and the tab comprises an energy storage element having a positive electrode tab extending from a part of an edge of the positive electrode plate toward the cover plate, and a negative electrode tab extending from a part of an edge of the negative electrode plate toward the cover plate. Effect of the Invention

[0009] In the present invention, the dimension of the conductive plate portion in the surface direction of the cover plate is larger than the dimension of the external terminal in the surface direction, which increases the contact area between the tab and the conductive plate portion and reduces the resistance of the current path compared to when the dimension of the conductive plate portion in the surface direction is smaller than the dimension of the external terminal in the surface direction. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic perspective view of an energy storage element. [Diagram 2] FIG. 2 is a schematic front view of the energy storage element. [Diagram 3] 3 is a schematic cross-sectional view of the energy storage element taken along line III-III shown in FIG. 2. [Figure 4] 4 is a partially enlarged cross-sectional view of the vicinity of the cover plate taken along line IV-IV shown in FIG. 2. [Diagram 5] FIG. 2 is a schematic diagram of a storage module having a plurality of storage elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described below with reference to the drawings showing an energy storage device according to an embodiment. Fig. 1 is a schematic perspective view of the energy storage device, and Fig. 2 is a schematic front view of the energy storage device. Energy storage device 1 may be a lithium ion secondary battery.

[0012] The energy storage element 1 includes a rectangular parallelepiped exterior body 2. The exterior body 2 houses a laminated electrode body 3, which will be described later, together with an electrolyte solution. In this embodiment, a metal case is used as the exterior body 2. The material of the metal case may be, for example, aluminum, an aluminum alloy, or stainless steel. The exterior body 2 includes a rectangular bottom wall 7 and a top wall 8 that are arranged opposite each other and have approximately the same size, a rectangular cover plate 9 and a rear wall 10 that connect the short sides of the bottom wall 7 and the top wall 8 and have a smaller area than the bottom wall 7 and the top wall 8, and two rectangular side walls 11, 11 that connect the long sides of the bottom wall 7 and the top wall 8 and have a larger area than the bottom wall 7 and the top wall 8. In this embodiment, the cover plate 9 extends perpendicularly to the bottom wall 7 that is installed on the installation surface (not shown) of the energy storage element 1, and the cover plate 9 forms a part of the side surface of the energy storage element 1. Alternatively, the cover plate may be located at the position of the top wall 8 opposite the bottom wall 7 of the energy storage element 1.

[0013] 2, a positive electrode external terminal 4 is provided at one end of the outer surface of the cover plate 9 via an outer gasket 19, and a negative electrode external terminal 5 is provided at the other end of the outer surface of the cover plate 9 via an outer gasket 19. The positive electrode external terminal 4 and the negative electrode external terminal 5 have their flat outer surfaces exposed, and are adapted to be welded to a conductive member (not shown) such as a bus bar. A rupture valve 6 is provided on the cover plate 9 between the positive electrode external terminal 4 and the negative electrode external terminal 5.

[0014] FIG. 3 is a schematic cross-sectional view of the energy storage element 1 taken along line III-III in FIG. 2. As shown in FIG. 3, the laminated electrode body 3 includes a plurality of positive electrode plates 12, a plurality of negative electrode plates 13, and a plurality of separators 14. The positive electrode plates 12, the negative electrode plates 13, and the separators 14 are each rectangular when viewed in a direction penetrating the side walls 11, 11 in FIG. 3. The plurality of positive electrode plates 12 and negative electrode plates 13 are alternately laminated with the separators 14 interposed therebetween. FIG. 3 shows a state in which negative electrode tabs 16 (described later) extending from each negative electrode plate 13 are bundled at their tip ends and joined to the conductive plate portion 18a. The negative electrode tabs 16 are accommodated in a curved state in the exterior body 2 so as to improve the energy density of the energy storage element 1 (so as to reduce the space occupied by the current path between the negative electrode external terminal 5 and the negative electrode plate 13). Although not shown, a positive electrode tab 15 (described later) extending from the positive electrode plate 12 is configured similarly to the negative electrode tab 16.

[0015] The positive electrode plate 12 has a conductive foil- or sheet-like positive electrode substrate and a positive electrode active material layer laminated on both sides of the positive electrode substrate. The negative electrode plate 13 has a conductive foil- or sheet-like negative electrode substrate and a negative electrode active material layer laminated on both sides of the negative electrode substrate.

[0016] The separator 14 is made of a sheet-like or film-like material that is permeated with the electrolyte. Examples of materials for the separator 14 include woven fabric, nonwoven fabric, and porous sheet-like or film-like resin. The separator 14 separates the positive electrode plate 12 and the negative electrode plate 13, and holds the electrolyte between the positive electrode plate 12 and the negative electrode plate 13.

[0017] Fig. 4 is a partially enlarged cross-sectional view of the vicinity of the cover plate 9 taken along line IV-IV shown in Fig. 2. Two through holes 9a, 9b are provided in the cover plate 9 at an interval in the longitudinal direction of the cover plate 9. The burst valve 6 is disposed between the two through holes 9a, 9b. Alternatively, the burst valve 6 may be disposed in a rear wall 10 (see Fig. 3) facing the cover plate 9.

[0018] As shown in FIG. 4, an electrically insulating inner gasket 20 is provided on the inner surface of the cover plate 9 near the through hole 9a. The inner gasket 20 has a rectangular plate-shaped gasket body with long sides parallel to the longitudinal direction of the cover plate 9, and the gasket body extends in contact with the inner surface of the cover plate 9. A through hole is provided in the gasket body of the inner gasket 20, and a cylindrical boss 20b is provided to surround the through hole. A recess 20a extending in the longitudinal direction of the cover plate 9 is formed on the surface of the gasket body of the inner gasket 20 facing the laminated electrode assembly 3. The inner gasket 20 has a ring-shaped compressed convex portion on both sides of the gasket body on the outer periphery side of the boss 20b. The compressed convex portion is not limited to a ring shape, and may be provided in a plurality of portions spaced apart from each other in the circumferential direction. The compressed convex portion may be provided on only one side (the outer surface or the inner surface) of the gasket body. The compressed convex portion is crushed to ensure the airtightness of the exterior body 2.

[0019] An electrically insulating outer gasket 19 is provided on the outer surface of the cover plate 9 near the through hole 9a. The outer gasket 19 is a rectangular plate like the inner gasket 20, and has a through hole 19a formed in its center. The diameter of the through hole 19a is larger than the outer diameter of the boss 20b of the inner gasket 20. A recess 19b is formed on one surface of the outer gasket 19. The other surface of the outer gasket 19 faces the outer surface of the cover plate 9. The boss 20b of the inner gasket 20 is inserted into the through hole 9a of the cover plate 9 and the through hole 19a of the outer gasket 19. The tip surface of the boss 20b is approximately flush with the bottom surface of the recess 19b of the outer gasket 19.

[0020] The positive electrode external terminal 4 is plate-shaped, and has a through hole 4a formed near its center. The diameter of the through hole 4a is approximately the same as the inner diameter of the boss 20b. A countersunk 4b is formed around the through hole 4a on one surface of the positive electrode external terminal 4. The positive electrode external terminal 4 is disposed in the recess 19b such that the other surface of the positive electrode external terminal 4 faces the bottom surface of the recess 19b of the outer gasket 19. The through hole 4a and the boss 20b are disposed coaxially, and the countersunk 4b is exposed to the outside.

[0021] The positive electrode external terminal 4 and an outer gasket 19 are disposed on the outer surface of the cover plate 9, and the inner gasket 20 and the positive electrode current collector 17 are disposed on the inner surface of the cover plate 9. When a bus bar or the like is welded to the positive electrode external terminal 4, heat generated by the welding is easily transferred to the outer gasket 19. The compressed convex portion for ensuring the airtightness of the exterior body 2 is provided on the inner gasket 20 as described above, and since heat is not easily transferred thereto, the compressed convex portion can maintain the airtightness of the exterior body 2.

[0022] The positive electrode current collector 17 is attached to the positive electrode external terminal 4. The positive electrode current collector 17 includes a rectangular positive electrode conductive plate portion 17a having long sides parallel to the longitudinal direction of the cover plate 9, and a cylindrical positive electrode conductive shaft portion 17b protruding from one surface of the positive electrode conductive plate portion 17a. The outer diameter of the positive electrode conductive shaft portion 17b is smaller than the diameter of the through hole 4a of the positive electrode external terminal 4 and the inner diameter of the boss 20b of the inner gasket 20. In this embodiment, the positive electrode conductive shaft portion 17b is hollow (hollow rivet), but alternatively, the positive electrode conductive shaft portion may be solid (solid rivet). The other surface of the positive electrode conductive plate portion 17a is formed flat. The other surface of the positive electrode conductive plate portion 17a is preferably a flat surface, but may have some recesses as long as the tab connection is not lost. The positive electrode conductive plate portion 17a and the positive electrode conductive shaft portion 17b are integrally molded. In this embodiment, the positive electrode conductive plate portion 17a and the positive electrode conductive shaft portion 17b are formed as a single component made of the same material.

[0023] The dimension of the positive conductive plate portion 17a in the longitudinal direction of the cover plate 9, in other words, in the planar direction, is larger than that of the positive external terminal 4. As shown in Fig. 4, in cross-sectional view, one end 17d and the other end 17e of the positive conductive plate portion 17a protrude in the planar direction of the cover plate 9 from one end 4c and the other end 4d of the positive external terminal 4, respectively.

[0024] The positive electrode conductive shaft portion 17b is inserted into the boss 20b from the recess 20a of the inner gasket 20, and its tip portion 17c is disposed outside the through hole 4a of the positive electrode external terminal 4 and is crimped (expanded). The crimped tip portion 17c is disposed in the counterbore 4b. The positive electrode conductive plate portion 17a is disposed inside the recess 20a. By crimping the tip portion 17c, the positive electrode external terminal 4, the outer gasket 19, the cover plate 9, and the inner gasket 20 are sandwiched between the tip portion 17c and the positive electrode conductive plate portion 17a.

[0025] As shown in Fig. 4, each of the positive electrode plates 12 has a strip-shaped positive electrode tab 15. The dimension of the positive electrode tab 15 in the longitudinal direction of the cover plate 9, in other words, in the planar direction, is larger than that of the positive electrode external terminal 4. The positive electrode tab 15 is formed on the other surface of the positive electrode conductive plate portion 17a, i.e., the positive electrode conductive shaft portion 17b protrudes. The positive electrode tab 15 is connected to the surface opposite to the surface where the positive electrode tab 15 is provided, for example, by ultrasonic welding, laser welding or crimping. The positive electrode tab 15 is connected to the positive electrode conductive plate portion 17a from a portion of the positive electrode conductive plate portion 17a that protrudes from one end 4c of the positive electrode external terminal 4 to a portion of the positive electrode conductive plate portion 17a that protrudes from the other end 4d of the positive electrode external terminal 4. The positive electrode tab 15 is connected to at least a portion of the other surface of the positive electrode conductive plate portion 17a that faces the positive electrode conductive shaft portion 17b.

[0026] An inner gasket 20, an outer gasket 19, a negative electrode external terminal 5, and a negative electrode current collector 18 are provided in the vicinity of the through hole 9b of the cover plate 9. These inner gasket 20, outer gasket 19, negative electrode external terminal 5, and negative electrode current collector 18 have the same configuration as the inner gasket 20, outer gasket 19, positive electrode external terminal 4, and positive electrode current collector 17 provided in the vicinity of the through hole 9a, and therefore detailed description thereof will be omitted below as appropriate.

[0027] The negative external terminal 5 has a through hole 5a and a countersink 5b. The negative current collector 18 has a negative conductive plate portion 18a and a negative conductive shaft portion 18b protruding from one surface of the negative conductive plate portion 18a, and a tip portion 18c of the negative conductive shaft portion 18b is crimped. The dimension of the negative conductive plate portion 18a in the longitudinal direction of the cover plate 9, in other words, in the surface direction, is larger than that of the negative external terminal 5.

[0028] Each of the negative electrode plates 13 has a strip-shaped negative electrode tab 16. The dimension of the negative electrode tab 16 in the longitudinal direction of the cover plate 9, in other words, in the surface direction, is larger than that of the negative electrode external terminal 5. One end 18d and the other end 18e of the negative electrode conductive plate portion 18a protrude from one end 5c and the other end 5d of the negative electrode external terminal 5, respectively, in the surface direction of the cover plate 9. The negative electrode tab 16 is connected to the other surface of the negative electrode conductive plate portion 18a by, for example, ultrasonic welding, laser welding or crimping, from the part of the negative electrode conductive plate portion 18a protruding from the one end 5c of the negative electrode external terminal 5 to the part protruding from the other end 5d of the negative electrode external terminal 5.

[0029] In the above-described energy storage element 1, a laminated electrode body is used in which a plurality of positive electrode plates 12 and negative electrode plates 13 are laminated, but alternatively, a wound electrode body in which one positive electrode plate and one negative electrode plate are wound with a separator interposed therebetween may be used. The positive electrode external terminal 4 and the negative electrode external terminal 5 are arranged on the cover plate 9, but the positive electrode external terminal 4 and the negative electrode external terminal 5 may be provided on two surfaces of the exterior body 2, respectively.

[0030] In the energy storage element 1 described above, the dimensions of each of the conductive plate portions 17a, 18a and the tabs 15, 16 in the surface direction of the cover plate 9 are larger than the dimensions of the external terminals 4, 5. This increases the contact area between the tabs 15, 16 and the conductive plate portions 17a, 18a, and reduces the resistance of the current path, compared to when the dimensions of each of the conductive plate portions 17a, 18a and the tabs 15, 16 in the surface direction are smaller than the dimensions of the external terminals 4, 5. Because the width dimensions of the tabs 15, 16 are large, the tabs 15, 16 are less likely to melt even when a large current flows.

[0031] Since the tabs 15, 16 are connected at least to the portions of the conductive plate portions 17a, 18a that face the conductive shaft portions 17b, 18b, the current path from the tabs 15, 16 to the external terminals 4, 5 is shortest, and the resistance value of the current path can be reduced.

[0032] One end 17d, 18d and the other end 17e, 18e of the conductive plate portions 17a, 18a protrude from one end 4c, 5c and the other end 4d, 5d of the external terminals 4, 5, respectively, in the surface direction of the cover plate 9, and the tabs 15, 16 are connected from the part of the conductive plate portions 17a, 18a protruding from the one end 4c, 5c of the external terminals 4, 5 to the part protruding from the other end 4d, 5d of the external terminals 4, 5. Therefore, a sufficiently large contact area between the tabs 15, 16 and the conductive plate portions 17a, 18a is ensured, and the resistance value of the current path can be reduced.

[0033] The conductive plate portions 17a, 18a and the conductive shaft portions 17b, 18b are integrally formed, which reduces the resistance of the current path and improves the strength of the current collectors 17, 18 compared to when the two are formed as separate parts.

[0034] One end of the conductive shaft portions 17b, 18b is inserted into the through holes 4a, 5a of the external terminals 4, 5 and crimped to the external terminals 4, 5. For example, the conductive shaft portions 17b, 18b can be attached to the external terminals 4, 5 easily and in a short time by spin crimping. By locating the crimping portion on the outside of the cover plate 9, no crimping portion exists on the inside of the cover plate 9. Therefore, the surface of the conductive plate portions 17a, 18a facing the laminated electrode body 3 can be made flat without any irregularities, and the tabs 15, 16 can be easily and reliably joined to that flat surface.

[0035] A storage module can be fabricated using a plurality of storage elements 1. FIG. 5 is a schematic diagram of a storage module 26 having a plurality of storage elements 1. The storage module 26 includes a holding member 24 such as a box or an end plate, and a plurality of storage elements 1 held by the holding member 24. The plurality of storage elements 1 are arranged so that the walls (cover plates) on which the external terminals are provided face the same direction. In this embodiment, the cover plates of the plurality of storage elements 1 rise from the installation surface, and the external terminals provided on the cover plates face the side of the storage element module. In the plurality of storage elements 1, adjacent storage elements are arranged so that the positive electrode external terminal 4 and the negative electrode external terminal 5 are upside down. The positive electrode external terminal 4 and the negative electrode external terminal 5 of adjacent storage elements 1 are connected by a bus bar 25, so that the plurality of storage elements 1 can be connected in series. The plurality of storage elements 1 may be connected in parallel by connecting the same poles.

[0036] Since the conductive plate portions 17a, 18a of the energy storage element 1 are disposed directly below the conductive shaft portions 17b, 18b, the dimensions of the current collectors 17, 18 in the longitudinal direction of the cover plate 9 can be made smaller than when the conductive plate portions 17a, 18a are not disposed directly below the conductive shaft portions 17b, 18b. As a result, the height dimension of the energy storage module 26 can also be made smaller, making it applicable to cases where it is necessary to place the energy storage module in a space with limited height.

[0037] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical features described can be combined with each other, and the scope of the present invention is intended to include all modifications within the scope of the claims and the scope equivalent to the claims.

[0038] As long as the resistance of the current path can be sufficiently suppressed, the dimensions of the tabs 15, 16 may be equal to or slightly smaller than the dimensions of the external terminals 4, 5. By joining the tabs 15, 16 to the portions of the conductive plate portions 17a, 18a that face the laminated electrode body 3, facing the conductive shaft portions 17b, 18b, and to both side portions thereof, it is possible to ensure the contact area between the tabs 15, 16 and the conductive plate portions 17a, 18a.

[0039] Although the case where the energy storage element 1 is a lithium ion secondary battery has been described, the energy storage element 1 is not limited to a lithium ion secondary battery. The energy storage element 1 may be another secondary battery such as a nickel-metal hydride battery, a primary battery, or an electrochemical cell such as a capacitor. [Explanation of symbols]

[0040] 1 Energy storage element 2 Exterior body 4 Positive external terminal 5 Negative external terminal 9 Lid plate 12 Positive plate 13 Negative plate 17 Positive electrode current collector 17a Positive electrode conductive plate part 17b Positive conductive shaft 18 Negative electrode current collector 18a Negative conductive plate part 18b Negative conductive shaft part 26 Energy Storage Module

Claims

1. an exterior body having an external terminal provided on a cover plate; An electrode plate having a tab and housed in the exterior body; a conductive shaft portion that passes through the cover plate and has one end connected to the external terminal; a conductive plate portion that is housed in the exterior body, the other end of the conductive shaft portion being connected to a first surface thereof and the tab being connected to a second surface thereof; Equipped with a dimension of the conductive plate portion in a surface direction of the cover plate is larger than a dimension of the external terminal in the surface direction of the cover plate, the tab is integrally formed with the plate; The tab is disposed apart from a side surface of the exterior body in the planar direction, The electrode plate includes a positive electrode plate and a negative electrode plate, The tabs include a positive electrode tab extending from a portion of an edge of the positive electrode plate toward the cover plate, and a negative electrode tab extending from a portion of an edge of the negative electrode plate toward the cover plate. Equipped with a storage element, Energy storage module.

2. The dimension of the tab in the surface direction of the cover plate is larger than the dimension of the external terminal in the surface direction of the cover plate. The energy storage module according to claim 1 .

3. The external terminal has a through hole formed therein, One end of the conductive shaft portion is inserted into the through hole and is crimped to the external terminal. The energy storage module according to claim 1 or 2.

4. the second surface of the conductive plate portion is formed flat; The tab is connected to at least a portion of the conductive plate portion that faces the conductive shaft portion. The energy storage module according to claim 1 .

5. one end and the other end of the conductive plate portion protrude from one side end and the other side end of the external terminal in a surface direction of the cover plate, The tab is connected to the conductive plate portion from a portion of the conductive plate portion protruding from one side end of the external terminal to a portion of the conductive plate portion protruding from the other side end of the external terminal. The energy storage module according to claim 1 .

6. The conductive plate portion and the conductive shaft portion are integrally formed. The energy storage module according to claim 1 .

7. The surface direction is the longitudinal direction of the cover plate. The energy storage module according to claim 1 .

8. The dimension of the tab in the surface direction of the cover plate is larger than the dimension of the external terminal and smaller than the dimension of an electrically insulating member disposed between the cover plate and the conductive plate portion. The energy storage module according to claim 1 .

9. The energy storage element has a laminated electrode body in which a plurality of the positive electrode plates and a plurality of the negative electrode plates are laminated. The energy storage module according to claim 1 .

10. Further comprising a bus bar, The size of the conductive plate portion in the longitudinal direction of the cover plate is larger than the size of the bus bar in the longitudinal direction of the cover plate. The energy storage module according to claim 1 .

11. Further comprising a bus bar, The dimension of the tab in the longitudinal direction of the cover plate is greater than the dimension of the bus bar in the longitudinal direction of the cover plate. The energy storage module according to claim 1 .

12. The conductive plate portion has a positive conductive plate portion and a negative conductive plate portion, A burst valve is provided between the positive electrode conductive plate portion and the negative electrode conductive plate portion in the surface direction of the cover plate. The energy storage module according to claim 1 .

13. Further comprising a plurality of the storage elements and a bus bar, The plurality of energy storage elements are arranged such that the external terminals face the same direction, and the external terminals of adjacent energy storage elements are connected by the bus bar. The energy storage module according to claim 1 .

14. An exterior body having an external terminal provided on a cover plate; An electrode plate having a tab and housed in the exterior body; a conductive shaft portion that passes through the cover plate and has one end connected to the external terminal; a conductive plate portion that is housed in the exterior body, the other end of the conductive shaft portion being connected to a first surface thereof and the tab being connected to a second surface thereof; Equipped with a dimension of the conductive plate portion in a surface direction of the cover plate is larger than a dimension of the external terminal in the surface direction of the cover plate, the tab is integrally formed with the plate; The tab is disposed apart from a side surface of the exterior body in the planar direction, The electrode plate includes a positive electrode plate and a negative electrode plate, The tabs include a positive electrode tab extending from a portion of an edge of the positive electrode plate toward the cover plate, and a negative electrode tab extending from a portion of an edge of the negative electrode plate toward the cover plate. Energy storage element.

15. A dimension of the tab in a surface direction of the cover plate is larger than a dimension of the external terminal in a surface direction of the cover plate. The energy storage element according to claim 14.

16. The external terminal has a through hole formed therein, One end of the conductive shaft portion is inserted into the through hole and is crimped to the external terminal. The energy storage element according to claim 14 or 15.

17. The conductive plate portion and the conductive shaft portion are integrally molded. The energy storage element according to any one of claims 14 to 16.

18. A dimension of the tab in a surface direction of the cover plate is smaller than a dimension of an electrically insulating member disposed between the cover plate and the conductive plate portion in the surface direction of the cover plate. The energy storage element according to any one of claims 14 to 17.

19. The surface direction is the longitudinal direction of the cover plate. The energy storage element according to any one of claims 14 to 18.

20. A laminated electrode body in which a plurality of the positive electrode plates and a plurality of the negative electrode plates are laminated.

20. The energy storage element according to claim 14.

21. The second surface of the conductive plate portion is formed flat. The energy storage element according to any one of claims 14 to 20.

22. The tab is connected to at least a portion of the conductive plate portion facing the conductive shaft portion.

22. The energy storage element according to claim 14.

23. In a cross-sectional view, one end and the other end of the conductive plate portion protrude from one side end and the other side end of the external terminal in a surface direction of the cover plate, The tab is connected to the conductive plate portion from a portion of the conductive plate portion protruding from one side end of the external terminal to a portion of the conductive plate portion protruding from the other side end of the external terminal.

23. The energy storage element according to claim 14.

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