JP2018022596A - Power storage element and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage element, etc. which are arranged so as to be able to suppress the occurrence of short circuit in an electrode body when an external force is applied thereto.SOLUTION: A power storage element 100 comprises; a container 10; and an electrode body 20 in which a positive electrode plate 21 and a negative electrode plate 22 are laminated, and which is encased in the container 10. The electrode body 20 is supported by supported parts 20ia, 20ib, 20ja and 20jb at end portions 20a and 20b in a direction crossing a lamination direction. In the supported parts, edges 21a and 21b of the positive electrode plate 21 have notched edge portions 21ea1, 21eb1, 21fa1 and 21fb1; and edges 22a and 22b of the negative electrode plate 22 have non-notched edge portions 22ea, 22eb, 22fa and 22fb. A distance between the notched edge portions 21ea1, 21eb1, 21fa1 and 21fb1, and the non-notched edge portions 22ea, 22eb, 22fa and 22fb is larger than a distance between an edge 21a or 21b of the positive electrode plate 21 except the supported parts, and an edge 22a or 22b of the negative electrode plate 22.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a power storage device including an electrode body and a method for manufacturing the power storage device.

  Some power storage elements such as lithium ion secondary batteries include an electrode body formed by stacking a positive electrode plate, a negative electrode plate, and a sheet-like separator having electrical insulation. For example, Patent Document 1 describes a secondary battery including a flat wound electrode body. In this secondary battery, a spacer made of an insulating material is disposed in an outer can in which the electrode body is accommodated.

JP 2011-159389 A

  In the secondary battery described in Patent Document 1, both ends are buffered between the lid and the electrode body in order to prevent the electrode body from being deformed and causing an internal short circuit when subjected to a drop impact. Spacers made of a material are arranged. The cushioning material is disposed in order to reduce the impact applied to both ends of the flat electrode body. However, even if the buffer material is arranged, the electrode body may be deformed, and this deformation may cause a short circuit in the electrode body.

  The present invention has been made to solve the above-described problems, and provides a storage element and a method for manufacturing the storage element that suppress the occurrence of a short circuit in the electrode body when an external force is applied.

  An energy storage device according to one embodiment of the present invention includes a container and an electrode body that is housed in the container and includes a stacked positive electrode plate and a negative electrode plate, and the electrode body has a stacking direction of the positive electrode plate and the negative electrode plate. The edge of the positive electrode plate at the end in the crossing direction has a first edge portion at the supported part, and the edge of the negative electrode plate at the end is The supporting portion has a second edge portion, and the distance in the direction from the end portion toward the inside of the electrode body between the first edge portion and the second edge portion is a supported portion at the end portion. It is larger than the distance between the edge of the positive electrode plate and the edge of the negative electrode plate in the direction from the end to the inside of the electrode body.

  The edge of the positive electrode plate at the end may be in a position that is recessed from the edge of the negative electrode plate at the end in the direction from the end toward the inside of the electrode body.

  A power storage element according to one embodiment of the present invention includes an electrode body including a positive electrode plate and a negative electrode plate that are wound in an overlapping manner, and the electrode body includes a supported portion at an end in a winding axis direction. The positive electrode plate has a first edge portion that is recessed in the supported portion so as to partially narrow the width of the positive electrode plate in the winding axis direction, and the first edge portion is the end portion From the edge of the negative electrode plate at the supported portion in the direction from the top to the inside of the electrode body.

The positive electrode plate and the negative electrode plate are wound together, and the first edge portion may be located at a curved portion of the electrode body along the winding direction of the positive electrode plate and the negative electrode plate.
The positive electrode plate may include a plurality of first edge portions over a plurality of turns of the positive electrode plate.
The region where the plurality of first edge portions in the end portion are formed may include the entire supported portion.
The electrode body may have a 1st edge part in the two said edge part in the position which mutually opposes in an electrode body.
The power storage element may include a spacer that supports the supported portion of the electrode body, and the spacer may separate the electrode body from the wall portion of the container.
The positive electrode plate and the negative electrode plate are wound together, the container has a container body having an opening and a lid that closes the opening, and the electrode body has a lid and a winding shaft of the electrode body. You may arrange | position in a container in the direction which cross | intersects.

  A method for manufacturing a power storage device according to one embodiment of the present invention includes a positive electrode plate and a negative electrode plate that are wound in a stacked manner, and is supported by a supported portion at an end in the winding axis direction of the positive electrode plate and the negative electrode plate. A method of manufacturing an electricity storage device including an electrode body, the step of forming a cutout portion having a shape recessed from the edge at a position corresponding to the supported portion of the edge along the winding direction in the positive electrode plate; A step of stacking and winding the positive electrode plate and the negative electrode plate and arranging the cutout portion at a position corresponding to the supported portion.

  The cutout portion may be formed by cutting using a laser in a curved portion along the winding direction of the positive electrode plate.

  According to the electricity storage element or the like in the present invention, it is possible to suppress occurrence of a short circuit in the electrode body when an external force is applied.

It is a perspective view which shows typically the external appearance of the electrical storage element which concerns on embodiment of this invention. It is a disassembled perspective view of the electrical storage element of FIG. It is a disassembled perspective view of the cover body of FIG. 2, and its peripheral component. It is a perspective view of the electrode body which expands and shows a part of electrode body of Drawing 2. It is the figure which expanded the expansion | deployment part of the positive electrode plate and negative electrode plate in the electrode body of FIG. It is the typical perspective view which expanded the edge part of the curved part of the electrode body of FIG. FIG. 7 is a cross-sectional side view of the energy storage device as viewed in a direction VII along a cross section along the longitudinal direction of the container of the energy storage device of FIG. It is sectional drawing along the VIII-VIII line of the electrical storage element of FIG. 7, and is a figure which shows sectional drawing of an electrode body and its periphery.

  Hereinafter, a power storage element and the like according to an embodiment of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, manufacturing steps, order of manufacturing steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

  Each figure in the accompanying drawings is a schematic diagram and is not necessarily illustrated strictly. Furthermore, in each figure, the same code | symbol is attached | subjected about the same or similar component. In the following description of the embodiments, expressions with “substantially” such as substantially parallel and substantially orthogonal may be used. For example, “substantially parallel” not only means completely parallel, but also means substantially parallel, that is, including a difference of, for example, several percent. The same applies to expressions involving other “abbreviations”.

[Embodiment]
The structure of the electrical storage element 100 which concerns on embodiment is demonstrated. FIG. 1 is a perspective view schematically showing an external appearance of a power storage device 100 according to the embodiment. As shown in FIG. 1, the power storage element 100 has a flat rectangular parallelepiped outer shape. The storage element 100 is a chargeable / dischargeable secondary battery. For example, the electrical storage element 100 is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. However, the storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery or a capacitor.

  Referring to FIGS. 1 and 2, the storage element 100 includes a flat rectangular parallelepiped container 10, an electrode body 20 accommodated in the container 10, a positive electrode terminal 30 and a negative electrode terminal 40, and electrodes in the container 10. Spacers 70 and 80 for holding the body 20 are provided. 2 is an exploded perspective view of the storage element 100 of FIG. Here, the positive electrode terminal 30 and the negative electrode terminal 40 are examples of electrode terminals.

  The container 10 has a bottomed rectangular tube-shaped container body 11 and an elongated rectangular plate-like lid body 12 that can close the elongated rectangular opening 11 a of the container body 11. The container body 11 has an elongated rectangular bottom wall 11b and four rectangular side walls 11c, 11d, 11e, and 11f that stand upright from four edges of the bottom wall 11b. The side walls 11c and 11e are located opposite to each other to form narrow short side walls (hereinafter, the side walls 11c and 11e are also referred to as short side walls 11c and 11e). The side walls 11d and 11f are opposed to each other and form wide long side walls (hereinafter, the side walls 11d and 11f are also referred to as long side walls 11d and 11f). Here, the lid body 12 is an example of a wall portion of the container.

  The container body 11 and the lid body 12 are fixed with their joints in an airtight state by a joining method such as welding. Although it does not limit, the container main body 11 and the cover body 12 may be produced from weldable metals, such as stainless steel, aluminum, aluminum alloy, for example.

  The container 10 is filled with an electrolyte such as an electrolytic solution (in this embodiment, a nonaqueous electrolytic solution) together with the electrode body 20 and the spacers 70 and 80, but the illustration of the electrolyte is omitted. As the electrolyte sealed in the container 10, there is no particular limitation on the type thereof as long as it does not impair the performance of the electricity storage device 100, and various types can be selected.

  On the outer surface 12 a of the lid body 12, the positive terminal 30 and the negative terminal 40 are disposed. The positive electrode terminal 30 and the negative electrode terminal 40 having conductivity pass through the lid body 12 and protrude from the inner surface 12b opposite to the outer surface 12a of the lid body 12, and on the opposite side, the positive electrode lead plate having conductivity. 51 and the negative electrode lead plate 61. The positive electrode lead plate 51 and the negative electrode lead plate 61 are further connected to the electrode body 20. The electrode body 20 is accommodated in the container body 11 together with the positive electrode lead plate 51 and the negative electrode lead plate 61.

  The spacers 70 and 80 are made from an electrically insulating material such as resin. The spacers 70 and 80 hold the electrode body 20 from the outside in the container 10, electrically insulate the electrode body 20 from the container 10, and function as a buffer material for the electrode body 20.

  Referring to FIG. 3, the positive electrode terminal 30 is connected to a positive electrode lead plate 51 via a plate-like positive electrode current collector 50, and the negative electrode terminal 40 is connected to a negative electrode lead plate 61 via a plate-like negative electrode current collector 60. Connected. FIG. 3 is an exploded perspective view of the lid 12 of FIG. 2 and its surrounding components. The positive electrode lead plate 51 and the negative electrode lead plate 61 constitute part of the components of the positive electrode current collector 50 and the negative electrode current collector 60, respectively. Each of the positive electrode current collector 50 and the negative electrode current collector 60 is a flat plate member having conductivity and rigidity, and is made of the same material as the constituent material of the positive electrode plate and the negative electrode plate of the electrode body 20 described later. ing. For example, the positive electrode current collector 50 is made of a metal such as aluminum or an aluminum alloy, and the negative electrode current collector 60 is made of a metal such as copper or a copper alloy.

  Further, a plate-like upper insulating member 31 is provided between the positive electrode terminal 30 and the lid body 12 to electrically insulate them from each other, and a plate-like lower insulating member 32 serves as the lid body 12 and the positive electrode current collector. It is provided between the body 50 and electrically insulates them from each other. A plate-like upper insulating member 41 is provided between the negative electrode terminal 40 and the lid body 12 to electrically insulate them from each other, and a plate-like lower insulating member 42 serves as the lid body 12 and the negative electrode current collector 60. And electrically insulate them from each other. Each of the upper insulating members 31 and 41 and the lower insulating members 32 and 42 is formed from a material having electrical insulation properties such as resin, and is, for example, a gasket.

  The positive terminal 30 and the negative terminal 40 have plate-like terminal bodies 30a and 40a and columnar or cylindrical shaft portions 30b and 40b extending from the terminal bodies 30a and 40a, respectively. The shaft portion 30b (40b) extends through the upper insulating member 31 (41), the lid body 12, the lower insulating member 32 (42), and the positive electrode current collector 50 (negative electrode current collector 60). To do. In the present embodiment, the shaft portion 30b (40b) is caulked by plastic deformation such that the tip protruding from the positive electrode current collector 50 (negative electrode current collector 60) receives a pressure and expands in diameter. Thus, the positive electrode current collector 50 (negative electrode current collector 60) is connected. As a result, the terminal body 30a (40a) and the positive electrode current collector 50 (negative electrode current collector 60) sandwich the upper insulating member 31 (41), the lid 12 and the lower insulating member 32 (42). Are physically and electrically connected to each other.

  The connection structure between the terminal main body 30a (40a) and the positive electrode current collector 50 (negative electrode current collector 60) is not limited to the joining by caulking of the shaft portion 30b (40b). The connection structure includes the terminal body 30a (40a), the positive electrode current collector 50 (the negative electrode current collector 60), with the upper insulating member 31 (41), the lid 12 and the lower insulating member 32 (42) interposed therebetween. Any structure may be used as long as they are connected. For example, bolts and nuts may be used instead of the shaft portion 30b (40b), and the shaft portion 30b (40b) may be welded to the positive electrode current collector 50 (negative electrode current collector 60).

  In the present embodiment, the positive electrode lead plate 51 and the negative electrode lead plate 61 are formed of a plate material bent into a U shape. The positive electrode lead plate 51 and the negative electrode lead plate 61 are made of the same material as the positive electrode current collector 50 and the negative electrode current collector 60, respectively. Each of the positive electrode lead plate 51 and the negative electrode lead plate 61 is connected to the electrode body 20 and the positive electrode current collector 50 or the negative electrode current collector 60 at two sides forming the U-shape. The positive electrode lead plate 51 and the negative electrode lead plate 61 relay the connection between the electrode body 20 and the positive electrode current collector 50 or the negative electrode current collector 60, respectively. For the connection, welding such as ultrasonic welding or resistance welding, joining by caulking, or the like can be used. In addition, the shape of the positive electrode lead plate 51 and the negative electrode lead plate 61 is not limited to a U-shape, and has a configuration in which the connection between the electrode body 20 and the positive electrode current collector 50 or the negative electrode current collector 60 is relayed. Anything is acceptable. Further, the electrode body 20 and the positive electrode current collector 50 or the negative electrode current collector 60 may be directly connected by the same connection method as the above connection without using the positive electrode lead plate 51 and the negative electrode lead plate 61.

  With reference to FIG.2 and FIG.4, the structure of the electrode body 20 is demonstrated. FIG. 4 is a perspective view of the electrode body 20 in which a part of the electrode body 20 of FIG. 2 is developed. The electrode body 20 is a power generation element capable of storing electricity. The electrode body 20 includes a sheet-like positive electrode plate 21 having a long rectangular belt-like planar shape, a sheet-like negative electrode plate 22 having a long rectangular belt-like planar shape, and a long rectangular belt-like planar shape. The two sheet-like separators 23 are included.

  In the electrode body 20, one separator 23, the negative electrode plate 22, the other separator 23, and the positive electrode plate 21 are layered in this order, and the winding axis B is in a winding direction B as shown in FIG. It is formed by being wound together in multiple spirals. The winding axis A is a virtual axis indicated by a one-dot chain line in FIGS. 2 and 4, and the electrode body 20 has a substantially symmetric configuration with respect to the winding axis A. Although not limited, in the present embodiment, the electrode body 20 has a flat outer shape having an oblong shape with a flat cross section perpendicular to the winding axis A. Such an electrode body 20 is positioned so as to be opposed to each other with the winding axis A sandwiched between two flat portions 20c and 20d that are wide and flat, and opposed to each other with the winding axis A interposed therebetween, and is semicircular. It is comprised from the two curved parts 20e and 20f curved in the shape. However, the cross-sectional shape of the electrode body 20 may be other than an oval shape, and may be a circle, an ellipse, a rectangle, or other polygons.

  The positive electrode plate 21 includes a positive electrode base material 24 that is a long rectangular belt-shaped metal foil made of a metal such as aluminum or an aluminum alloy, and a coating or the like substantially over the wide main surface on both sides of the positive electrode base material 24. And a positive electrode active material layer 25 (indicated by hatching in FIG. 4) formed by the method. The negative electrode plate 22 includes a negative electrode base material 26 that is a long rectangular belt-shaped metal foil made of a metal such as copper or a copper alloy, and a coating or the like applied to substantially the entire wide main surface on both sides of the negative electrode base material 26. And a negative electrode active material layer 27 (indicated by hatching in FIG. 4) formed by the method. As the positive electrode active material used for the positive electrode active material layer 25 or the negative electrode active material used for the negative electrode active material layer 27, a known material is appropriately used as long as it is a positive electrode active material or negative electrode active material capable of occluding and releasing lithium ions. it can. In the present embodiment, the positive electrode active material layer 25 and the negative electrode active material layer 27 are formed on the main surfaces on both sides of the positive electrode substrate 24 and the negative electrode substrate 26, respectively, but only on one main surface. May be formed. The separator 23 is a microporous sheet made of a material having electrical insulation properties such as a resin.

  On one edge 21a of the two edges 21a and 21b along the longitudinal direction which is the winding direction B of the positive electrode plate 21, a plurality of positive electrode tabs 21c are formed so as to protrude substantially perpendicular to the edge 21a. . The positive electrode tab 21 c continuously and integrally extends from the positive electrode base material 24 and constitutes a part of the positive electrode base material 24. The positive electrode tab 21c is made of the same material as the positive electrode base material 24, and the positive electrode active material layer 25 is not formed on the positive electrode tab 21c. In the present embodiment, one positive electrode tab 21 c is disposed per turn of the positive electrode plate 21 in the electrode body 20. In the electrode body 20, the plurality of positive electrode tabs 21c are gathered and positioned at one place to form a positive electrode tab bundle 21d. In the positive electrode tab bundle 21d, the positive electrode tabs 21c are arranged in a line in the stacking direction of multiple layers formed by the wound positive electrode plate 21, negative electrode plate 22, and separator 23.

  On one edge 22a of the two edges 22a and 22b along the longitudinal direction which is the winding direction B of the negative electrode plate 22, a plurality of negative electrode tabs 22c are formed so as to protrude substantially perpendicular to the edge 22a. . The negative electrode tab 22 c extends continuously and integrally from the negative electrode substrate 26 and constitutes a part of the negative electrode substrate 26. The negative electrode tab 22c is made of the same material as the negative electrode base material 26, and the negative electrode active material layer 27 is not formed on the negative electrode tab 22c. In the present embodiment, one negative electrode tab 22 c is disposed per turn of the negative electrode plate 22 in the electrode body 20. In the electrode body 20, the plurality of negative electrode tabs 22c are gathered and positioned at one place to form a negative electrode tab bundle 22d. In the negative electrode tab bundle 22d, the negative electrode tabs 22c are positioned in a line in the stacking direction of the wound positive electrode plate 21, negative electrode plate 22, and separator 23.

  The number of the positive electrode tabs 21c and the negative electrode tabs 22c arranged for each turn of the positive electrode plate 21 and the negative electrode plate 22 is not limited to one. The number of the positive electrode tab bundle 21d and the negative electrode tab bundle 22d is not limited to one. Further, in the present embodiment, the positive electrode tab 21c and the negative electrode tab 22c have a rectangular planar shape, but may have any shape.

  The positive electrode plate 21 and the negative electrode plate 22 are overlapped with each other in the same longitudinal direction for winding. At this time, the positive electrode tab 21 c and the negative electrode tab 22 c are located on the same side with respect to the overlapping portion of the positive electrode plate 21 and the negative electrode plate 22. That is, the edge 21a of the positive electrode plate 21 and the edge 22a of the negative electrode plate 22 are adjacent to each other, and the edge 21b of the positive electrode plate 21 and the edge 22b of the negative electrode plate 22 are adjacent to each other. Furthermore, the edge 23a (refer FIG. 5) of the two edges 23a and 23b along the longitudinal direction which is the winding direction B of the separator 23 adjoins the edges 21a and 22a, and the edge 23b (refer FIG. 5). Adjacent to edges 21b and 22b.

  4 and 5, a plurality of notches 21ea and 21fa are formed on the edge 21a of the positive electrode plate 21, and a plurality of notches 21eb and 21fb are formed on the edge 21b of the positive electrode plate 21. Is formed. 5 is an enlarged view of the developed portion of the positive electrode plate 21 and the negative electrode plate 22 in the electrode body 20 of FIG. The notches 21ea and 21fa can be formed by notching the positive electrode base material 24 at the edge 21a, and the notches 21eb and 21fb can be formed by notching the positive electrode base material 24 at the edge 21b. The positive electrode active material layer 25 is not formed in the notches 21ea, 21fa, 21eb, and 21fb. The notches 21ea and 21fa are recessed in a direction intersecting the edge 21a, for example, in a direction substantially perpendicular to the edge 21a, from the edge 21a toward the edge 21b, that is, from the edge 21a toward the inside of the electrode body 20. have. The notches 21eb and 21fb also have a shape that is recessed from the edge 21b toward the inside of the electrode body 20 in a direction intersecting the edge 21b, for example, in a direction substantially perpendicular to the edge 21b. Here, the cutout portions 21ea, 21fa, 21eb, and 21fb are examples of cutout portions.

  In the present embodiment, the notches 21ea, 21fa, 21eb, and 21fb are formed one by one for each turn of the positive electrode plate 21 in the electrode body 20, and are further formed for each turn of the positive electrode plate 21. Has been. The notch portion 21ea and the notch portion 21eb are provided at positions facing the short side direction of the positive electrode base material 24, and the notch portion 21fa and the notch portion 21fb are positions facing the short side direction of the positive electrode base material 24. Is provided. For example, the plurality of notches 21ea and the plurality of notches 21eb are arranged at symmetrical positions with respect to the longitudinal direction of the positive electrode base 24, and the plurality of notches 21fa and the plurality of notches 21fb are positive electrodes. The substrate 24 may be disposed at a symmetrical position with respect to the longitudinal direction of the substrate 24.

  In the present embodiment, the notches 21ea, 21fa, 21eb, and 21fb have a rectangular shape with rounded corners. The cutout portions 21ea and 21fa form cutout edge portions 21ea1 and 21fa1 that recede from the edge 21a toward the edge 21b from the edge 21a as the respective bottom portions. The cutout portions 21eb and 21fb form cutout edge portions 21eb1 and 21fb1 that recede from the edge 21b toward the edge 21a from the edge 21b as respective bottom portions. In the notches 21ea, 21fa, 21eb, and 21fb, the corners at both ends of the notch edge portions 21ea1, 21fa1, 21eb1, and 21fb1 are rounded to be chamfered. Thereby, the fracture | rupture of the positive electrode base material 24 in the corner | angular of the bottom part of notch part 21ea, 21fa, 21eb, and 21fb is suppressed. Further, the depths from the edge 21a to the notch edge portions 21ea1 and 21fa1 in the notches 21ea and 21fa are approximately the same. The depths from the edge 21b to the notch edge portions 21eb1 and 21fb1 in the notches 21eb and 21fb are approximately the same. All the notches 21ea, 21fa, 21eb and 21fb may have the same depth. The notch part 21ea and the notch part 21eb at the opposite positions have the same length in the direction along the edges 21a and 21b. The notch portion 21fa and the notch portion 21fb at the opposing positions have the same length in the direction along the edges 21a and 21b. Note that the shapes of the notches 21ea, 21fa, 21eb, and 21fb are not limited to the above shapes.

  On the other hand, the edge portions 22ea and 22fa adjacent to the notches 21ea and 21fa on the edge 22a of the negative electrode plate 22 (hereinafter also referred to as non-notched edge portions) 22ea and 22fa do not retreat or protrude from the edge 22a. It is aligned on a straight line and constitutes a part of the straight edge 22a. Further, the non-notched edge portions 22eb and 22fb adjacent to the notched portions 21eb and 21fb on the edge 22b of the negative electrode plate 22 are aligned with the edge 22b without receding or protruding from the edge 22b. A part of the edge 22b is formed.

  Therefore, in the winding axis A direction toward the inside of the electrode body 20, the distance d1 between the non-notched edge portion 22ea and the notched edge portion 21ea1, and the distance between the non-notched edge portion 22fa and the notched edge portion 21fa1. d2 is greater than the distance d3 between the edge 22a and the edge 21a. Similarly, the distance d4 between the non-notched edge portion 22eb and the notched edge portion 21eb1 and the distance d5 between the non-notched edge portion 22fb and the notched edge portion 21fb1 are both the distance between the edge 22b and the edge 21b. It is larger than d6. Such notched edge portions 21ea1, 21fa1, 21eb1 and 21fb1 partially narrow the width of the positive electrode plate 21 in the winding axis A direction. Here, the notched edge portions 21ea1, 21fa1, 21eb1 and 21fb1 are examples of the first edge portion of the positive electrode plate, and the non-notched edge portions 22ea, 22fa, 22eb and 22fb are the second edges of the negative electrode plate. It is an example of a part.

  In the electrode body 20, the notches 21 ea and 21 eb are located at the curved portion 20 e of the electrode body 20, and the notches 21 fa and 21 fb are located at the curved portion 20 f of the electrode body 20. In the positive electrode plate 21 wound as the electrode body 20, the lengths of the cutout portions 21ea, 21fa21eb and 21fb in the direction along the edges 21a and 21b from the inner peripheral side to the outer peripheral side of the electrode body 20 are as follows. growing.

  The two separators 23 are respectively disposed on flat main surfaces on both sides of one negative electrode plate 22. The entire negative electrode plate 22 excluding the negative electrode tab 22 c is covered with two separators 23, and the negative electrode tab 22 c protrudes beyond the edge 23 a of the separator 23. One positive electrode plate 21 is arranged on the separator 23 so as to be positioned further inside the separator 23 adjacent to the negative electrode plate 22 on the inner side during winding. The entire positive electrode plate 21 excluding the positive electrode tab 21 c is covered with the negative electrode plate 22 and the separator 23, and the positive electrode tab 21 c protrudes from the separator 23.

  In the electrode body 20 formed by winding the positive electrode plate 21, the negative electrode plate 22, and the separator 23 that are overlapped as described above, the edges 21 a and 22 a of the positive electrode plate 21 and the negative electrode plate 22 are wound around the electrode body 20. An end 20a in the rotational axis A direction is formed. Further, the edges 21 b and 22 b of the positive electrode plate 21 and the negative electrode plate 22 form an end portion 20 b of the electrode body 20 in the winding axis A direction. In the present embodiment, the positive electrode tab bundle 21d and the negative electrode tab bundle 22d are disposed on the flat portion 20d of the electrode body 20, but are not limited thereto.

  Referring to FIGS. 4, 6 and 7, in the electrode body 20, the notches 21ea and 21eb are located at the bending portion 20e, and the notches 21fa and 21fb are located at the bending portion 20f. 6 is a schematic perspective view in which the end 20a of the curved portion 20e of the electrode body 20 of FIG. 4 is enlarged. In FIG. 6, in order to make the shapes of the positive electrode plate 21 and the negative electrode plate 22 in the curved portion 20e easier to understand, the separator 23 is not shown and the number of turns of the positive electrode plate 21 and the negative electrode plate 22 is reduced. FIG. 7 is a cross-sectional view of the battery element 100 as viewed in a direction VII in the depth direction of FIG. 1 along a longitudinal direction of the container 10 of the battery element 100 of FIG. 1 and passing through the centers of the positive electrode terminal 30 and the negative electrode terminal 40. It is a cross-sectional side view.

  The plurality of notches 21ea are arranged in a line so as to be stacked in the radial direction of the curved portion 20e, which is the stacking direction of the positive electrode plate 21, the negative electrode plate 22, and the separator 23, at the end 20a of the curved portion 20e. In the present embodiment, the plurality of cutout portions 21ea arranged in a line extend over the entire end portion 20a of the bending portion 20e. Thus, a positive counterbore region 20ga that is a region where only the negative electrode plate 22 and the separator 23 are stacked without including the positive electrode plate 21 is formed in the vicinity of the end 20a of the curved portion 20e. The positive counterbore region 20ga includes an outer peripheral surface of the bending portion 20e, an end portion 20a of the bending portion 20e, a notch edge portion 21ea1 of the plurality of notches 21ea, and a boundary surface between the bending portion 20e and the flat portions 20c and 20d. It corresponds to a semi-cylindrical three-dimensional region surrounded by.

  Similarly, the plurality of notches 21eb are arranged in a line so as to be stacked in the radial direction of the bending portion 20e at the end 20b of the bending portion 20e. The plurality of notches 21fa and 21fb are arranged in a line so as to be stacked in the radial direction of the curved portion 20f at the end portions 20a and 20b of the curved portion 20f, respectively. The plurality of notches 21eb also extend over the entire end 20b of the curved portion 20e, and form a semi-columnar positive counterbore region 20gb in the vicinity of the end 20b where only the negative electrode plate 22 and the separator 23 are stacked. The plurality of notches 21fa and 21fb also extend over the entire ends 20a and 20b of the curved portion 20f, respectively, and end the semi-columnar positive counterbore regions 20ha and 20hb in which only the negative electrode plate 22 and the separator 23 are stacked. Formed near the portions 20a and 20b.

  Here, the manufacture of the electrode body 20 having the notches 21ea, 21eb, 21fa, and 21fb as described above on the positive electrode plate 21 can be performed, for example, as described below. The notches 21ea, 21eb, 21fa, and 21fb change the length in the direction along the edges 21a and 21b and change their shapes every time the positive electrode plate 21 is wound. Furthermore, the arrangement pitch of the notches 21ea, 21eb, 21fa, and 21fb changes with each winding. For this reason, in this Embodiment, the cutting | disconnection using a laser is applied for formation of notch part 21ea, 21eb, 21fa, and 21fb. In the cutting using a laser, it is easy to arbitrarily change the shape, size and position of the cut portion. Further, in the present embodiment, the positive electrode tab 21c of the positive electrode plate 21 and the negative electrode tab 22c of the negative electrode plate 22 are formed by cutting using a laser. The formation of the notches 21ea, 21eb, 21fa, and 21fb and the formation of the positive electrode tab 21c and the negative electrode tab 22c may be performed by any method that does not use a laser, such as punching.

  At the time of manufacturing the electrode body 20, the positive electrode active material layer 25 is formed on the positive electrode base material 24 and the positive electrode plate 21 wound around one roll, the negative electrode base material 26 is formed with the negative electrode active material layer 27 and one roll The negative electrode plate 22 wound around the two rolls and the separator 23 wound around the two rolls are pulled out from the respective rolls by a winding machine (not shown) and overlapped with each other, while rotating the winding shaft in the winding machine. Wound around. Before the positive electrode plate 21, the negative electrode plate 22, and the separator 23 are overlapped between each roll and the winding shaft, cutting with a laser is performed in parallel with the winding of the electrode body 20. At this time, formation of the positive electrode tab 21c and the notches 21ea, 21eb, 21fa, and 21fb on the positive electrode plate 21 and formation of the negative electrode tab 22c on the negative electrode plate 22 are performed in parallel. In addition, the positive electrode base material 24, the negative electrode base material 26, and the separator 23 wound around each roll are pulled out and wound around the winding shaft of the winding machine. The layer 25 and the negative electrode active material layer 27 may be formed. At this time, the order of cutting by laser and formation of the positive electrode active material layer 25 and the negative electrode active material layer 27 is not limited.

  Referring to FIGS. 2, 3, and 7, the positive electrode tab bundle 21 d of the electrode body 20 is connected to the positive electrode lead plate 51, and the negative electrode tab bundle 22 d is connected to the negative electrode lead plate 61. Thereby, the positive electrode terminal 30 is physically and electrically connected to the positive electrode plate 21 of the electrode body 20 via the positive electrode current collector 50 and the positive electrode lead plate 51. The negative electrode terminal 40 is physically and electrically connected to the negative electrode plate 22 of the electrode body 20 via the negative electrode current collector 60 and the negative electrode lead plate 61. Thereby, the electrode body 20 is attached to the lid body 12.

  The electrode body 20 attached to the lid body 12 is accommodated in the container body 11 together with the spacers 70 and 80. The spacers 70 and 80 having the same configuration are respectively side walls 70a and 80a having an arcuate cross section, end walls 70b and 80b at one end of the side walls 70a and 80a, and end walls 70c and 80c at the other end. And support walls 70d and 80d having a C-shaped cross section extending in the opposite direction from the side walls 70a and 80a from the end walls 70b and 80b, respectively. The end walls 70b and 70c are provided so as to close the open ends formed by the arc-shaped ends of the side wall 70a, and are positioned facing the winding axis A direction when assembled to the electrode body 20 as will be described later. . The end walls 80b and 80c are provided so as to close the open ends formed by the arc-shaped ends of the side wall 80a, and are positioned facing the winding axis A direction when assembled to the electrode body 20.

  The spacer 70 (80) is assembled to the electrode body 20 so that the curved portion 20e (20f) of the electrode body 20 is fitted inside the side wall 70a (80a), the end wall 70b (80b), and the end wall 70c (80c). It is done. At this time, the end wall 70b (80b) and the end wall 70c (80c) are positioned adjacent to the end portions 20a and 20b of the electrode body 20, respectively, so that the electrode body 20 is sandwiched in the winding axis A direction. Hold.

  In the present embodiment, the side wall 70a (80a), the end wall 70b (80b), and the end wall 70c (80c) of the spacer 70 (80) cover a part or the whole of the curved portion 20e (20f) of the electrode body 20. That is, only the curved portion 20e (20f) is covered. However, the spacer 70 (80) may cover a part of the flat portion 20c and / or 20d in addition to the curved portion 20e (20f) of the electrode body 20.

  After the electrode body 20 assembled with the spacers 70 and 80 is accommodated in the container main body 11 of the container 10, the lid body 12 is fixed to the container main body 11 so as to close the opening 11a. In the container 10, the spacer 70 (80) is separated from the lid body 12 by the lid body 12 that abuts against the support wall 70d (80d) and the bottom wall 11b of the container body 11 that abuts the end wall 70c (80c). It is supported and fixed in the direction toward the wall 11b. Further, the spacer 70 (80) is supported and laterally along the lid body 12 and the bottom wall 11b by the side walls 11c, 11d and 11f (11d, 11e and 11f) of the container body 11 in contact with the side wall 70a (80a). Fixed.

  The side walls 70 a and 80 a of the spacers 70 and 80 hold the electrode body 20 with the curved portions 20 e and 20 f, and hold and fix the electrode body 20 in a state of being separated from the short side walls 11 c and 11 e of the container body 11. The end wall 70b (80b) and the end wall 70c (80c) of the spacer 70 (80) are separated from the positive electrode terminal 30 (negative electrode terminal 40), the positive electrode current collector 50 (negative electrode current collector 60), the bottom wall 11b, and the like. In this state, the electrode body 20 is held and fixed in the winding axis A direction. At this time, the electrode body 20 includes an end wall 70b (80b), an end wall 70c (80c), and a supported portion 20ia (20ja) of the end portion 20a and a supported portion 20ib (20jb) of the end portion 20b. And is supported by the end wall 70b (80b) and the end wall 70c (80c).

  Referring to FIGS. 7 and 8, in the present embodiment, a region on the end 20b in the positive counterbore region 20gb (20hb) of the electrode body 20 (indicated by hatching in FIG. 8) is a semicircular shape of the electrode body 20. It has a shape and dimensions that include the entire region of the supported portion 20ib (20jb), and is positioned so as to include the entire region of the supported portion 20ib (20jb). FIG. 8 is a cross-sectional view taken along the line VIII-VIII of the electricity storage device 100 of FIG. 7, and is a view showing a cross-sectional view of the electrode body 20 and its periphery. As described above, the positive counterbore region 20gb (20hb) covers the supported portion 20ib (20jb), which is a contact portion of the end portion 20b with the end wall 70c (80c).

  Further, the region on the end 20a in the positive counterbore region 20ga (20ha) of the electrode body 20 has a shape and dimensions including the entire region of the semicircular supported portion 20ia (20ja) of the electrode body 20, It is located so as to include the entire region of the supported portion 20ia (20ja). Therefore, the positive counterbore region 20ga (20ha) covers the supported portion 20ia (20ja), which is a contact portion with the end wall 70b (80b) in the end portion 20a. The positive counterbore regions 20ga, 20gb, 20ha, and 20hb on the ends 20a and 20b are preferably larger than the regions of the supported portions 20ia, 20ib, 20ja, and 20jb.

  Referring to FIG. 7, the thickness of the positive counterbore region 20gb (20hb) in the direction from the end wall 70c (80c) of the spacer 70 (80) to the end wall 70b (80b), that is, in the winding axis A direction of the electrode body 20. The length tb (td) is greater than or equal to the thickness of the end wall 70c (80c) in the winding axis A direction. The thicknesses tb and td are obtained by adding the distance d8 between the edge 23b of the separator 23 and the edge 22b of the negative electrode plate 22 to the distance d4 related to the notch 21eb and the distance d5 related to the notch 21fb shown in FIG. Distance. In addition, the thickness ta (tc) of the positive counterbore region 20ga (20ha) in the winding axis A direction is larger than the thickness of the end wall 70b (80b) of the spacer 70 (80) in the winding axis A direction. Have. The thicknesses ta and tc are obtained by adding the distance d7 between the edge 23a of the separator 23 and the edge 22a of the negative electrode plate 22 to the distance d1 related to the notch 21ea and the distance d2 related to the notch 21fa shown in FIG. Distance.

  When the storage element 100 receives an external force such as vibration or impact, the external force is transmitted to the electrode body 20 via the spacers 70 and 80. At this time, the supported portions 20ia and 20ja of the end portion 20a of the electrode body 20 and the supported portions 20ib and 20jb of the end portion 20b are moved in the winding axis A direction by the end walls 70b, 70c, 80b and 80c of the spacers 70 and 80. Can be pressed. At this time, the edge of the negative electrode plate 22 and the edge of the separator 23 in the positive counterbore regions 20ga, 20gb, 20ha, and 20hb can be deformed so as to be crushed by receiving pressure from the end walls 70b, 70c, 80b, and 80c. . As a result, the electrode body 20 can be relatively displaced in the winding axis A direction with respect to the spacers 70 and 80, but the displacement range thereof is the bottom wall 11 b of the container body 11 and the attachment of the lid body 12. And are subject to restrictions. The accessories of the lid 12 are the positive electrode terminal 30, the negative electrode terminal 40, the positive electrode current collector 50, the negative electrode current collector 60, the lead plates 51 and 61, and the like.

  Specifically, when receiving an external force, the electrode body 20 is displaced until a portion of the end 20b not covered with the spacers 70 and 80 comes into contact with the bottom wall 11b. Further, the electrode body 20 is displaced until the portion of the end portion 20 a not covered with the spacers 70 and 80 comes into contact with the appendage of the lid body 12. Therefore, in the direction toward the bottom wall 11b, the entire electrode body 20 is displaced by the thickness of the end walls 70c and 80c of the spacers 70 and 80 in the direction of the winding axis A, whereby the positive counterbore regions 20gb and 20hb The electrode bodies 20 in each can be deformed over the depth in the winding axis A direction corresponding to the thickness of the end walls 70c and 80c. Since the thicknesses tb and td of the positive counterbore regions 20gb and 20hb are larger than the thicknesses of the end walls 70c and 80c, the negative electrode plate 22 and the separator 23 in the positive counterbore regions 20gb and 20hb are deformed. Further, deformations that occur in the positive electrode plate 21, the negative electrode plate 22, and the separator 23 in the region exceeding the positive counterbore regions 20gb and 20hb toward the end portion 20a are suppressed. Therefore, the occurrence of a short circuit between the positive electrode plate 21 and the negative electrode plate 22 due to deformation of the stacked positive electrode plate 21, negative electrode plate 22, and separator 23 together is suppressed. The positive electrode plate 21, the negative electrode plate 22, and the separator 23 of the curved portions 20e and 20f are deformed by being pressed in the winding axis A direction by the end walls 70c and 80c and the like without including the positive counterbore regions 20gb and 20hb. In this case, the positive electrode plate 21 and the negative electrode plate 22 are easily short-circuited because they are deformed so as to be intricately complicated.

  Further, since the positive counterbore regions 20gb and 20hb extend over the entire supported portions 20ib and 20jb of the end 20b of the electrode body 20, the end walls 70c and 80c are connected to the negative electrode plate 22 and the separator in the positive counterbore regions 20gb and 20hb. Press only 23. Therefore, the positive electrode plate 21, the negative electrode plate 22, and the separator 23 outside the positive counterbore regions 20gb and 20hb are suppressed from being deformed by the pressing of the end walls 70c and 80c.

  In addition, according to the magnitude of the external force assumed for the storage element 100, the relationship between the thicknesses tb and td of the positive counterbore regions 20gb and 20hb and the thicknesses of the end walls 70c and 80c, and the positive counterbore region at the end 20b The relationship between the regions of 20 gb and 20 hb and the regions of the supported portions 20 ib and 20 jb of the electrode body 20 can be changed. The thicknesses tb and td of the positive counterbore regions 20gb and 20hb, and the widths thereof are such that the electrode body 20 can be deformed by the supported portions 20ib and 20jb when the storage element 100 receives an external force. It may be determined accordingly. For example, when the external force assumed for the storage element 100 is small, or when the thickness of the end walls 70c and 80c is large, the thickness tb and td of the positive counterbore regions 20gb and 20hb is larger than the thickness of the end walls 70c and 80c. May be small.

  Further, in the direction toward the lid 12, the entire electrode body 20 is displaced until the electrode body 20 contacts the appendage of the lid body 12, whereby the electrode bodies 20 in each of the positive counterbore regions 20 ga and 20 ha are It can be deformed over a depth in the winding axis A direction corresponding to the displacement. By setting the thicknesses ta and tc of the positive counterbore regions 20ga and 20ha to be equal to or larger than the displacement, deformation in the winding axis A direction at the end 20a is suppressed in the positive counterbore regions 20ga and 20ha. It is done. Therefore, deformation of the stacked positive electrode plate 21, negative electrode plate 22, and separator 23 together is suppressed.

  Furthermore, since the positive counterbore regions 20ga and 20ha cover the entire supported portions 20ia and 20ja at the end 20a of the electrode body 20, the end walls 70b and 80b are connected to the negative plate 22 and the separator in the positive counterbore regions 20ga and 20ha. Press only 23. Therefore, the positive electrode plate 21, the negative electrode plate 22, and the separator 23 outside the positive counterbore regions 20ga and 20ha are suppressed from being deformed by the pressing of the end walls 70b and 80b.

  It should be noted that depending on the magnitude of the external force assumed for the storage element 100, the requirements for the thicknesses ta and tc of the positive counterbore regions 20ga and 20ha, the region of the positive counterbore regions 20ga and 20ha at the end 20a, and the electrode body 20 The relationship between the supported portions 20ia and 20ja can vary. The thicknesses ta and tc of the positive counterbore regions 20ga and 20ha, and the widths thereof are such that the electrode body 20 can be deformed by the supported portions 20ia and 20ja when the storage element 100 receives an external force. It may be determined accordingly.

  As described above, the energy storage device 100 according to the present embodiment includes the container 10 and the electrode body 20 that includes the stacked positive electrode plate 21 and negative electrode plate 22 and is accommodated in the container 10. The electrode body 20 is supported by supported portions 20ia, 20ib, 20ja, and 20jb at end portions 20a and 20b in a direction that intersects the direction in which the positive electrode plate 21 and the negative electrode plate 22 are stacked. The edges 21a and 21b of the positive electrode plate 21 at the ends 20a and 20b have notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 as first edge portions on the supported portions 20ia, 20ib, 20ja, and 20jb. The edges 22a and 22b of the negative electrode plate 22 at the ends 20a and 20b have non-notched edge portions 22ea, 22eb, 22fa and 22fb as second edge portions on the supported portions 20ia, 20ib, 20ja and 20jb. Distances d1, d4, d2 in the direction from the end 20a or 20b to the inside of the electrode body 20 between the notched edge portions 21ea1, 21eb1, 21fa1 and 21fb1 and the non-notched edge portions 22ea, 22eb, 22fa and 22fb, and d5 is the end 20a or 20b between the edge 21a or 21b of the positive electrode plate 21 and the edge 22a or 22b of the negative electrode plate 22 other than the supported portions 20ia, 20ib, 20ja and 20jb at the end 20a or 20b. Is greater than the distances d3 and d6 in the direction from the electrode body 20 toward the inside.

  In the above-described configuration, when the power storage element 100 receives an external force such as an impact, the electrode body 20 can receive and press the external force to be transmitted in the supported portions 20ia, 20ib, 20ja, and 20jb. In the supported portions 20ia, 20ib, 20ja, and 20jb, the non-notched edge portions 22ea, 22eb, 22fa, and 22fb of the negative electrode plate 22 can be deformed by the pressing force to absorb the pressing force. The distance between the non-notched edge portions 22ea, 22eb, 22fa and 22fb and the notched edge portions 21ea1, 21eb1, 21fa1 and 21fb1, and the deformation of the negative electrode plate 22 does not reach the notched edge portions 21ea1, 21eb1, 21fa1 and 21fb1, respectively. By setting it as such a distance, the short circuit of the positive electrode plate 21 and the negative electrode plate 22 resulting from a deformation | transformation is suppressed.

  In the energy storage device 100 according to the embodiment, the edges 21a and 21b of the positive electrode plate 21 at the end portions 20a and 20b of the electrode body 20 are in the direction from the end portion 20a or 20b toward the inside of the electrode body 20, respectively. The end portions 20a and 20b of the 20 are in positions retreated from the edges 22a and 22b of the negative electrode plate 22. In the above-described configuration, the positive plates 21 can be prevented from facing each other without the negative plate 22 interposed therebetween. For example, when the positive electrode plates 21 are opposed to each other without the negative electrode plate 22, the possibility that lithium dendrite will precipitate increases. Lithium dendrite may grow and short-circuit the positive electrode plate 21 and the negative electrode plate 22. Therefore, the configuration of the positive electrode plate 21 and the negative electrode plate 22 as described above can suppress a short circuit between the positive electrode plate 21 and the negative electrode plate 22.

  In addition, the power storage device 100 according to the embodiment includes an electrode body 20 including a positive electrode plate 21 and a negative electrode plate 22 that are stacked and wound. Further, the electrode body 20 has supported portions 20ia, 20ib, 20ja and 20jb at the ends 20a and 20b in the winding axis A direction, and the positive electrode plate 21 is supported by the supported portions 20ia, 20ib, 20ja and 20jb. It has notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 that are recessed so as to partially narrow the width of the positive electrode plate 21 in the winding axis A direction.

  In the above-described configuration, when the power storage element 100 receives an external force such as an impact and the external force is transmitted to a portion where the notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 of the electrode body 20 are present, the notch of the positive electrode plate 21 The edges 22a and 22b of the negative electrode plate 22 protruding from the edge portions 21ea1, 21eb1, 21fa1, and 21fb1 can be deformed by the pressing force to absorb the pressing force. Then, by setting the depth positions of the notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 in the recess direction so that the negative electrode plate 22 is not deformed, the positive electrode plate 21 and the negative electrode plate 22 resulting from the deformation The short circuit is suppressed.

  In the power storage device 100 according to the embodiment, in the electrode body 20, the positive electrode plate 21 and the negative electrode plate 22 are wound together, and the notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 are the positive electrode plate 21 and the negative electrode plate, respectively. It is located at the curved portion of the electrode body 20 along the winding direction of 22. In the above-described configuration, when a pressing force in the winding axis A direction acts, the curved portion of the electrode body 20 protrudes in the winding axis A direction from the notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 of the positive electrode plate 21. The negative electrode plate 22 to be deformed by the pressing force can absorb the pressing force. For this reason, the deformation | transformation which arises in the positive electrode plate 21 and the negative electrode plate 22 which are laminated | stacked inside the winding axis A direction rather than the notch edge part 21ea1, 21eb1, 21fa1, and 21fb1 is suppressed. Therefore, the notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 provided in the curved portion of the electrode body 20 effectively contribute to the suppression of short-circuiting of the positive electrode plate 21 and the negative electrode plate 22 during the pressing action.

  In electrode body 20 of power storage device 100 according to the embodiment, positive electrode plate 21 includes a plurality of notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 across a plurality of turns of positive electrode plate 21. In the above-described configuration, the portion of the negative electrode plate 22 adjacent to the separator 23 and the negative electrode plate 22 without the positive electrode plate 21 is formed across the negative electrode plates 22 having a plurality of layers. The portions of these negative electrode plates 22 can form positive counterbore regions 20ga, 20gb, 20ha and 20hb in which only the negative electrode plate 22 and the separator 23 are laminated without including the positive electrode plate 21. In the positive counterbore regions 20ga, 20gb, 20ha, and 20hb, even if the electrode body 20 is deformed, a short circuit between the positive electrode plate 21 and the negative electrode plate 22 is suppressed.

  In electrode body 20 of power storage device 100 according to the embodiment, positive counterbore regions 20ga, 20gb, 20ha, and 20hb as regions where a plurality of notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 are formed in end portions 20a and 20b. Includes the entire supported portions 20ia, 20ib, 20ja and 20jb, respectively. In the above-described configuration, all the pressing force that the electrode body 20 receives from the supported portions 20ia, 20ib, 20ja, and 20jb is transmitted to the negative plate 22 in the positive counterbore regions 20ga, 20gb, 20ha, and 20hb and absorbed by the negative plate 22. The Therefore, a short circuit between the positive electrode plate 21 and the negative electrode plate 22 is effectively suppressed.

  In the electricity storage device 100 according to the embodiment, the electrode body 20 includes notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 at two end portions 20a and 20b at positions facing each other in the electrode body 20. In the above-described configuration, the electrode body 20 may move when receiving a pressing force from the supported portions 20ia and 20ja of the one end portion 20a and cause a collision at the other end portion 20b. Similarly, the electrode body 20 may move when receiving a pressing force from the supported portions 20ib and 20jb of the other end portion 20b and cause a collision at the one end portion 20a. The notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1 are formed in the positive electrode plate 21 in the supported portions 20ia, 20ib, 20ja, and 20jb of the two end portions 20a and 20b, respectively, so that the electrode body 20 has the end portion 20a. Even if it moves to the direction which goes to the edge part 20b from one side and the opposite direction, the short circuit of the positive electrode plate 21 and the negative electrode plate 22 in the edge parts 20a and 20b is attained.

  The power storage device 100 according to the embodiment includes spacers 70 and 80 that support the supported portions 20ia, 20ib, 20ja, and 20jb of the electrode body 20, and the spacers 70 and 80 support the electrode body 20 from the wall portion of the container 10. Release. In the configuration described above, the electrode body 20 is supported by the spacers 70 and 80 in a state where contact with the container 10 is suppressed. Therefore, it is possible to limit the contact location of the electrode body 20 with the elements other than the electrode body 20 to a portion supported by the spacers 70 and 80. Therefore, it is possible to limit the formation positions of the notched edge portions 21ea1, 21eb1, 21fa1, and 21fb1.

  In the electrode body 20 of the energy storage device 100 according to the embodiment, the positive electrode plate 21 and the negative electrode plate 22 are wound together, and the container 10 includes a container body 11 having an opening 11a and a lid that closes the opening 11a. The electrode body 20 is disposed in the container 10 in such a direction that the lid body 12 and the winding axis A of the electrode body 20 intersect. The electrode body 20 having the above-described configuration can be supported by the spacers 70 and 80 at the supported portions 20ia, 20ib, 20ja, and 20jb of the end portions 20a and 20b in the winding axis A direction. Thereby, the notch edge portions 21ea1, 21eb1, 21fa1, and 21fb1 are formed along the edges 21a and 21b of the positive electrode plate 21 located at the end portions 20a and 20b. The positive electrode plate 21 notched along the edges 21a and 21b can suppress a decrease in electric capacity and a bias of electric charges due to the notch.

  In addition, the method for manufacturing the energy storage device 100 according to the embodiment includes the positive electrode plate 21 and the negative electrode plate 22 that are overlapped and wound, and the end 20a in the winding axis A direction of the positive electrode plate 21 and the negative electrode plate 22 and It is a manufacturing method of an electrical storage element provided with the electrode body 20 supported by the supported parts 20ia, 20ib, 20ja, and 20jb of 20b. In this manufacturing method, the notch portion having a shape recessed from the edges 21a and 21b at positions corresponding to the supported portions 20ia, 20ib, 20ja and 20jb of the edges 21a and 21b along the winding direction in the positive electrode plate 21. 21ea, 21eb, 21fa and 21fb are formed, and the positive electrode plate 21 and the negative electrode plate 22 are overlapped and wound so that the notches 21ea, 21eb, 21fa and 21fb correspond to the supported portions 20ia, 20ib, 20ja and 20jb. Arranging at a position.

  In the above description, the positions of the notches 21ea, 21eb, 21fa, and 21fb are at positions corresponding to the supported portions 20ia, 20ib, 20ja, and 20jb. Therefore, when the storage element 100 receives an external force, in the supported portions 20ia, 20ib, 20ja and 20jb, the negative electrode plate 22 adjacent to the notches 21ea, 21eb, 21fa and 21fb can be deformed to absorb the external force. . The positive plate 21 of the notches 21ea, 21eb, 21fa, and 21fb can reduce external force transmitted to itself and suppress deformation thereof.

  In the method for manufacturing power storage device 100 according to the embodiment, cutout portions 21ea, 21eb, 21fa, and 21fb are formed by cutting using a laser in a curved portion of positive electrode plate 21 along the winding direction. In the above description, the cutting using the laser can change the shape and size of the notches 21ea, 21eb, 21fa, and 21fb and the position, that is, the pitch for each winding. Furthermore, cutting using a laser can form notches having various shapes and dimensions at various positions. This makes it possible to form positive counterbore regions 20ga, 20gb, 20ha, and 20hb having an arbitrary shape by a plurality of notches 21ea, 21eb, 21fa, and 21fb.

[Other variations]
The power storage element and the like according to the embodiment of the present invention have been described above, but the present invention is not limited to the embodiment. That is, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  In positive electrode plate 21 of electrode body 20 of power storage element 100 according to the embodiment, notches 21ea, 21eb, 21fa, and 21fb have a rectangular shape with rounded corners, but are not limited thereto. Not a thing. The corners of the notch may be rounded or not rounded. The shape of the notch may be any shape such as an arc, a semicircle, a semi-ellipse, a semi-oval, a polygon, or a combination thereof.

  In the positive electrode plate 21 of the electrode body 20 of the energy storage device 100 according to the embodiment, the notches 21ea, 21eb, 21fa, and 21fb are formed with different dimensions and shapes for each winding of the positive electrode plate 21. However, the present invention is not limited to this. The notches 21ea, 21eb, 21fa, and 21fb may be configured not to change at least one of the size and the shape regardless of the progress of winding of the positive electrode plate 21.

  In the positive electrode plate 21 of the electrode body 20 of the energy storage device 100 according to the embodiment, the four notches 21ea, 21eb, 21fa, and 21fb are arranged for each winding of the positive electrode plate 21, but the present invention is not limited thereto. It is not something. For example, the notches 21ea, 21eb, 21fa, and 21fb may be arranged for each of a plurality of turns of the positive electrode plate 21. In this case, all of the four notches 21ea, 21eb, 21fa, and 21fb may be disposed on the one-turn positive electrode plate 21, and some of the four notches 21ea, 21eb, 21fa, and 21fb may be arranged. May be arranged.

  In the electrode body 20 of the energy storage device 100 according to the embodiment, the non-notched edge portions 22ea, 22fa, 22eb and 22fb of the negative electrode plate 22 are aligned with the edge 22a or 22b of the negative electrode plate 22, It is not limited to. For example, the non-notched edge portions 22ea and 22fa protrude from the edge 22b toward the edge 22a rather than the edge 22a, and the non-notched edge portions 22eb and 22fb protrude from the edge 22a toward the edge 22b rather than the edge 22b. May be. In this case, the distances between the non-notched edge portions 22ea, 22eb, 22fa and 22fb and the notched edge portions 21ea1, 21eb1, 21fa1 and 21fb1 need only be sufficiently secured. For example, when the external force is applied to the storage element 100, the distance is determined by the deformation of the negative electrode plate 22 at the non-notched edge portions 22ea, 22eb, 22fa, and 22fb contacting the end wall of the spacer 70 or 80. The distance may be such that 21 is not deformed to cause a short circuit with the negative electrode plate 22. The notched edge portions 21ea1 and 21fa1 of the positive electrode plate 21 may be recessed from the edge 21a of the positive electrode plate 21, may protrude from the edge 21b toward the edge 21a, and are aligned with the edge 21a. May be. Similarly, the notched edge portions 21eb1 and 21fb1 of the positive electrode plate 21 may be recessed from the edge 21b of the positive electrode plate 21, may protrude, or may be aligned with the edge 21b.

  The power storage device 100 according to the embodiment is a power storage device including the electrode body 20 that is disposed with the winding axis A in a direction substantially perpendicular to the lid 12 of the container 10. 12 may be an electric storage element including an electrode body arranged in a direction along the line 12. In this case, similarly to the power storage element 100 according to the embodiment, the notched portion of the positive electrode plate 21 may be disposed in the supported portion of the electrode body by the spacer.

  In the storage element 100 according to the embodiment, the notches 21ea, 21eb, 21fa, and 21fb of the positive electrode plate 21 are arranged on the supported portions 20ia, 20ib, 20ja, and 20jb by the spacers 70 and 80 in the electrode body 20. However, it is not limited to this. For example, a notch part may be arranged in a portion of the positive electrode plate 21 that can come into contact with an element other than the electrode body 20 at the end portions 20a and 20b of the electrode body 20, and elements other than the electrode body 20 in the electrode body 20 A notch portion may be arranged in the positive electrode plate 21 in a portion that can come into contact. For example, the power storage element may have a configuration in which the end 20 a or 20 b of the electrode body 20 faces a gas discharge valve provided in the container 10. In this case, a notch part may be arrange | positioned in the positive electrode plate 21 of the part which the spacer provided between the edge part 20a or 20b and a gas exhaust valve can contact. Examples of elements other than the electrode body 20 include positive and negative electrode terminals, current collectors, and lead plates.

  In the electricity storage device 100 according to the embodiment, one positive electrode tab bundle 21d and one negative electrode tab bundle 22d are arranged at the end 20a of the electrode body 20, but the present invention is not limited to this. Two or more positive electrode tab bundles may be disposed at the end portion 20a of the electrode body 20, or two or more negative electrode tab bundles may be disposed. A positive electrode tab bundle and / or a negative electrode tab bundle may be disposed at the end portions 20 a and 20 b of the electrode body 20. In this case, the positive electrode tab bundle may be disposed only on one or both of the end portions 20a and 20b of the electrode body 20, and the negative electrode tab bundle is disposed only on the other of the end portions 20a and 20b of the electrode body 20 or both. May be arranged.

  In the electricity storage device 100 according to the embodiment, the electrode body 20 includes the positive electrode tab bundle 21d and the negative electrode tab bundle 22d. For example, the electrode body 20 includes a positive electrode uncoated portion in which the positive electrode base material is exposed without forming the positive electrode active material layer on the edge 21 a of the positive electrode plate 21, and the negative electrode active material is formed on the edge 22 b of the negative electrode plate 22. A negative electrode uncoated portion in which the negative electrode base material is exposed without forming the material layer may be included. In this case, the positive electrode lead plate 51 or the positive electrode current collector 50 may be connected to the positive electrode uncoated portion, and the negative electrode lead plate 61 or the negative electrode current collector 60 may be connected to the negative electrode uncoated portion.

In the power storage device 100 according to the embodiment, the electrode body 20 is a wound electrode body formed by winding a stacked positive electrode plate, negative electrode plate, and separator, but is not limited thereto. . The electrode body may be a stack type electrode body formed by stacking a large number of positive plates, negative plates and separators, and a set of two or more stacked positive plates, negative plates and separators. It may be a Z-shaped electrode body formed by bending a plurality of wires.
The power storage element 100 according to the embodiment includes one electrode body 20. However, the power storage element may include two or more electrode bodies.

  In addition, embodiments constructed by arbitrarily combining the embodiment and the modified examples are also included in the scope of the present invention. In addition, the present invention can be realized not only as a power storage element as described above but also in a power storage device including one or more power storage elements. For example, the present invention can be realized as a power storage device including a plurality of power storage elements 100. The power storage device includes a plurality of power storage units arranged side by side, and each power storage unit includes, for example, a plurality of power storage elements 100 arranged in a line and electrically connected to each other. With the above-described configuration, the plurality of power storage elements 100 are used as one unit, and the quantity and arrangement of the power storage units can be selected in accordance with the electric capacity required for the power storage device, the shape and dimensions of the power storage device, and the like. A power storage device that includes a plurality of power storage elements 100 and has a high output can be mounted as a power source for a vehicle such as an electric vehicle (EV), a hybrid vehicle (HEV), and a plug-in hybrid vehicle (PHEV).

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

10 container 12 lid (wall of container)
20 Electrode body 20a, 20b End portion 20ia, 20ib, 20ja, 20jb Supported portion 21 Positive electrode plate 21a, 21b Edge (edge of positive electrode plate)
21ea, 21eb, 21fa, 21fb Notch (cutout)
21ea1,21eb1,21fa1,21fb1 Notched edge portion (first edge portion)
22 Negative electrode plate 22a, 22b Edge (edge of negative electrode plate)
22ea, 22eb, 22fa, 22fb Non-notched edge portion (second edge portion)
30 Positive terminal (electrode terminal)
40 Negative terminal (electrode terminal)
70, 80 Spacer 100 Storage element A Winding shaft

Claims (11)

A container,
An electrode body including a stacked positive electrode plate and negative electrode plate housed in the container;
The electrode body is supported by a supported portion at an end portion in a direction crossing the direction of lamination of the positive electrode plate and the negative electrode plate,
The edge of the positive electrode plate at the end has a first edge portion on the supported portion;
The edge of the negative electrode plate at the end has a second edge portion on the supported portion;
The distance in the direction from the end portion toward the inside of the electrode body between the first edge portion and the second edge portion is the edge of the positive electrode plate other than the supported portion at the end portion. A power storage element that is larger than a distance in a direction from the end to the inside of the electrode body between the edge of the negative electrode plate. The electrical storage according to claim 1, wherein an edge of the positive electrode plate at the end portion is in a position retreated from an edge of the negative electrode plate at the end portion in a direction from the end portion toward the inside of the electrode body. element. An electrode body including a positive electrode plate and a negative electrode plate wound in an overlapping manner,
The electrode body has a supported portion at an end in a winding axis direction,
The positive electrode plate has a first edge portion that is recessed in the supported portion so as to partially narrow the width of the positive electrode plate in the winding axis direction;
The first edge portion is recessed from an edge of the negative electrode plate at the supported portion in a direction from the end portion toward the inside of the electrode body. The positive electrode plate and the negative electrode plate are wound together,
The power storage element according to any one of claims 1 to 3, wherein the first edge portion is located in a curved portion of the electrode body along a winding direction of the positive electrode plate and the negative electrode plate. The power storage device according to claim 3, wherein the positive electrode plate includes a plurality of the first edge portions over a plurality of turns of the positive electrode plate. The electric storage element according to claim 5, wherein a region where the plurality of first edge portions are formed in the end portion includes the entire supported portion. The electric storage element according to any one of claims 1 to 6, wherein the electrode body has the first edge portion at two end portions of the electrode body facing each other. A spacer for supporting the supported portion of the electrode body;
The electricity storage device according to any one of claims 1 to 7, wherein the spacer separates the electrode body from a wall portion of the container. The positive electrode plate and the negative electrode plate are wound together,
The container has a container body having an opening and a lid for closing the opening,
The electric storage element according to any one of claims 1 to 8, wherein the electrode body is disposed in the container in a direction in which the lid body and a winding axis of the electrode body intersect. A method of manufacturing an electricity storage device comprising an electrode body that includes a positive electrode plate and a negative electrode plate that are stacked and wound, and that is supported by a supported portion at an end of the negative electrode plate in the winding axis direction. ,
Forming a cutout portion having a shape recessed from the edge at a position corresponding to the supported portion of the edge along the winding direction of the positive electrode plate;
A step of stacking and winding the positive electrode plate and the negative electrode plate, and disposing the cutout portion at a position corresponding to the supported portion. The manufacturing method according to claim 10, wherein the cut-out portion is formed by cutting using a laser in a curved portion of the positive electrode plate along a winding direction.

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