JP2018055893A - Power storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage element in which a space between an electrode body and a wall facing a curved portion of the electrode body in a container is reduced.SOLUTION: A power storage element includes: an electrode body including a wound electrode plate; a container receiving the electrode body and having a first wall facing a curved portion of the electrode body; and a penetrating body penetrating through the first wall and having a protruding portion protruding toward the electrode body. The distance between the first wall and the electrode body is less than a protruding distance of the protruding portion from the first wall.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to a power storage device including an electrode body.

  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 discloses a nonaqueous electrolyte secondary battery as a power storage element, and the nonaqueous electrolyte secondary battery includes an external electrode terminal on a sealing plate of an outer can that houses an electrode body. The external electrode terminal is connected to the electrode body via the sealing body lead and the current collecting tab member. In the external electrode terminal, the cylindrical portion passes through the sealing plate and the sealing body lead, and is further subjected to caulking processing in which the tip of the cylindrical portion is expanded outward.

JP 2008-66254 A

  In the nonaqueous electrolyte secondary battery described in Patent Document 1, the electrode body is housed in a horizontal direction with respect to the can axis direction of the outer can. That is, the electrode body is disposed with its convex curved portion facing the sealing plate. And between the sealing plate and the curved portion of the electrode body, a sealing body lead, a connecting portion with the sealing body lead of the current collecting tab member, and the like are arranged side by side from the sealing plate toward the electrode body. . For this reason, in an exterior can, the space required from a sealing board to an electrode body becomes large.

  The present disclosure has been made in order to solve the above-described problem, and a power storage device that reduces a space between a wall portion and an electrode body facing a curved portion of an electrode body in a container such as an outer can. provide.

  An electricity storage device according to an aspect of the present disclosure includes an electrode body including a wound electrode plate, a container that houses the electrode body and includes a first wall portion facing the curved portion of the electrode body, A penetrating body that has a projecting portion that penetrates the first wall portion and projects toward the electrode body, and the distance between the first wall portion and the electrode body is the projection from the first wall portion. It is smaller than the protruding distance of the part.

  An electricity storage device according to another aspect of the present disclosure includes an electrode body including a wound electrode plate, a container having the first wall portion that accommodates the electrode body and faces the curved portion of the electrode body. A penetrating body penetrating the first wall portion and having a projecting portion projecting toward the electrode body, the projecting portion being perpendicular to the first wall portion and winding the electrode body A reference plane that is parallel to the axis and that passes through the portion of the electrode body that is closest to the first wall portion, and is displaced in a direction perpendicular to the reference plane, wherein at least a part of the protrusion is It is located in a region between the one wall portion and the electrode body.

  According to the electricity storage device according to the present disclosure, it is possible to reduce the space between the electrode body and the wall portion of the container facing the curved portion of the electrode body.

FIG. 1 is a perspective view schematically showing the external appearance of the energy storage device according to the embodiment. FIG. 2 is an exploded perspective view of the electricity storage device of FIG. FIG. 3 is a cross-sectional side view of a cross section of the electricity storage device of FIG. 1 cut along a plane positioned substantially parallel to the short side wall of the container and in the vicinity of the short side wall on the negative electrode terminal side, as viewed in the direction III. 4 is an enlarged cross-sectional side view of the negative electrode terminal of FIG. 3 and its periphery. FIG. 5 is a cross-sectional side view showing a power storage device according to a modification of the embodiment in the same manner as FIG.

  First, an electricity storage device according to one embodiment of the present disclosure includes an electrode body including a wound electrode plate, a container that houses the electrode body and includes a first wall portion facing the curved portion of the electrode body. A penetrating body penetrating the first wall portion and having a protruding portion projecting toward the electrode body, wherein a distance between the first wall portion and the electrode body is from the first wall portion. It is smaller than the protrusion distance of the protrusion.

  The protrusion is perpendicular to the first wall and parallel to the winding axis of the electrode body, and from the reference plane passing through a portion closest to the first wall in the electrode body, the reference plane And at least a part of the protruding portion may be located in a region between the first wall portion and the electrode body.

  An electricity storage device according to another aspect of the present disclosure includes an electrode body including a wound electrode plate, a container having the first wall portion that accommodates the electrode body and faces the curved portion of the electrode body. A penetrating body penetrating the first wall portion and having a projecting portion projecting toward the electrode body, the projecting portion being perpendicular to the first wall portion and winding the electrode body A reference plane that is parallel to the axis and that passes through the portion of the electrode body that is closest to the first wall portion, and is displaced in a direction perpendicular to the reference plane, wherein at least a part of the protrusion is It is located in a region between the one wall portion and the electrode body.

The entire protrusion may be disposed away from the reference surface in a direction perpendicular to the reference surface.
The power storage element may further include a current collecting member connected to the penetrating body and the electrode body, and the protruding portion may include a caulking portion at a tip portion protruding from the current collecting member.
The caulking portion is perpendicular to the first wall portion, parallel to the winding axis of the electrode body, and in a direction along a reference plane that passes through a portion of the electrode body that is closest to the first wall portion. The width in the direction perpendicular to the reference plane may be smaller than the width.
The power storage element may further include an electrode terminal disposed on the first wall, and the penetrating body may connect the electrode terminal and the current collecting member.
The container may include a container main body having an opening and a lid that closes the opening, and the first wall may be the lid.
The electrode body may have a flat outer shape.

  Next, a power storage device according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that each of the embodiments described below shows a preferred specific example of the present disclosure. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, and the like shown in the following embodiments are merely examples, and are not intended to limit the present disclosure. 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 electricity storage device 100 is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. However, the electricity storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, for example, stored without a user charging. A primary battery that can use electricity or a capacitor may be used.

  Referring to FIGS. 1 and 2, the electricity storage device 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. 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 includes 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 positioned to face each other, and form short side walls that are narrow in the direction along the edge of the bottom wall 11b (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 long side walls that are wide in the direction along the edge of the bottom wall 11b (hereinafter, the side walls 11d and 11f are also referred to as long side walls 11d and 11f). The long side walls 11d and 11f are wider in the direction along the edge of the bottom wall 11b than the short side walls 11c and 11e. The bottom wall 11 b is positioned to face the lid body 12. Here, the lid body 12 is an example of a first wall portion.

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

  On the flat outer surface 12 a of the lid body 12, the positive electrode terminal 30 and the negative electrode terminal 40 are disposed. The positive electrode terminal 30 and the negative electrode terminal 40 having conductivity pass through the lid body 12 and are physically connected to the positive electrode current collector 50 and the negative electrode current collector 60 having conductivity on the side opposite to the outer surface 12a of the lid body 12. And electrically connected. The positive electrode current collector 50 and the negative electrode current collector 60 are further physically and electrically connected to the electrode body 20. The positive electrode current collector 50 and the negative electrode current collector 60 are accommodated in the container body 11 together with the electrode body 20. Here, the positive electrode current collector 50 and the negative electrode current collector 60 are examples of current collecting members. The positive electrode current collector 50 and the negative electrode current collector 60 according to the present embodiment are members made of a rigid metal.

  The positive electrode terminal 30, the negative electrode terminal 40, the positive electrode current collector 50, and the negative electrode current collector 60 are electrically insulated from the lid body 12 by insulating members 31, 32, 41, and 42. 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 50. And electrically insulate 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. For example, the insulating members 31, 32, 41, and 42 are gaskets made of resin or the like.

  The electrode body 20 is a power storage element capable of storing electricity. The electrode body 20 includes a belt-like sheet-like positive electrode plate (not shown), a belt-like sheet-like negative electrode plate (not shown), and a belt-like sheet-like separator (not shown). It is formed by being wound together in the winding direction R around A. As a result, the positive electrode plate and the negative electrode plate are stacked in multiple layers around the winding axis A with the separator interposed therebetween. The winding axis A is a virtual axis indicated by a one-dot chain line in FIG. 2, and the electrode body 20 has a substantially symmetric configuration with respect to the winding axis A. The winding direction R is a rotation direction around the winding axis A. The winding direction R is not particularly limited. In addition, although not limited, in the present embodiment, the electrode body 20 has a flat outer shape having an elliptical shape with a flat cross section perpendicular to the winding axis A. That is, the electrode body 20 includes two curved portions 20c and 20d that face the winding axis A in a direction perpendicular to the winding axis A, and two flat portions that face in the direction perpendicular to the winding axis A. 20e and 20f. 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 another polygon.

  The positive electrode plate includes a positive electrode base material (not shown) that is a strip-shaped metal foil made of a metal such as aluminum or an aluminum alloy, and a positive electrode active material layer (not shown) formed on the positive electrode base material by a method such as coating. Z). The negative electrode plate includes a negative electrode base material (not shown) that is a strip-shaped metal foil made of a metal such as copper or a copper alloy, and a negative electrode active material layer (not shown) formed on the negative electrode base material by a method such as coating. Z). As the positive electrode active material used for the positive electrode active material layer or the negative electrode active material layer, any known material can be used as long as it is a positive electrode active material or negative electrode active material capable of occluding and releasing lithium ions. The separator is a microporous sheet made of an electrically insulating material such as a resin.

  A positive electrode active material non-formation portion 21 of the positive electrode plate and a negative electrode active material non-formation portion 22 of the negative electrode plate are formed at the end portions 20a and 20b in the winding axis A direction of the electrode body 20, respectively. In the positive electrode active material non-formation part 21 and the negative electrode active material non-formation part 22, the positive electrode active material layer and the negative electrode active material layer are not formed, and the positive electrode base material and the negative electrode base material are exposed in a strip shape along the edge. ing. And in the positive electrode active material non-formation part 21 and the negative electrode active material non-formation part 22, only the exposed positive electrode base material and negative electrode base material are wound, respectively. In the flat portions 20e and 20f of the positive electrode active material non-forming portion 21 and the negative electrode active material non-forming portion 22, respectively, the positive electrode base material and the negative electrode base material are converged in a direction perpendicular to the flat portions 20e and 20f. The positive electrode current collector 50 and the negative electrode current collector 60 are connected to the flat portions 20e and 20f of the positive electrode active material non-formation part 21 and the negative electrode active material non-formation part 22, respectively, by a joining method such as welding or caulking. In the caulking joining, the two members are joined together by plastic deformation. The electrode body 20 connected to the positive electrode current collector 50 and the negative electrode current collector 60 has the winding axis A oriented along the longitudinal direction of the lid body 12 and the long side walls 11d and 11f, and one curved portion 20c is covered. It is disposed in the container 10 so as to face the body 12. In the container body 11, the end 20a of the electrode body 20 faces the short side wall 11c, and the end 20b faces the short side wall 11e. Furthermore, the flat part 20e of the electrode body 20 faces the long side wall 11d, and the flat part 20f faces the long side wall 11f.

  The positive electrode current collector 50 integrally includes one rectangular plate-shaped first fixing portion 51 and two leg-shaped second fixing portions 52 extending in substantially the same direction. Furthermore, the positive electrode current collector 50 has two rectangular plate-like third fixing portions 53 that sandwich the flat portions 20e and 20f of the positive electrode active material non-forming portion 21 of the electrode body 20 together with the two second fixing portions 52. have. The first fixing portion 51, the second fixing portion 52, and the third fixing portion 53 are made of a metal such as aluminum or an aluminum alloy, like the positive electrode base material of the electrode body 20.

  The negative electrode current collector 60 integrally includes a rectangular plate-shaped first fixing portion 61 and two leg-shaped second fixing portions 62 that extend in substantially the same direction. Furthermore, the negative electrode current collector 60 has two rectangular plate-like third fixing portions 63 that sandwich the flat portions 20e and 20f of the negative electrode active material non-forming portion 22 of the electrode body 20 together with the two second fixing portions 62. have. The first fixing portion 61, the second fixing portion 62, and the third fixing portion 63 are made of a metal such as copper or a copper alloy, like the negative electrode base material of the electrode body 20. Each of the third fixing portions 53 and 63 may be a holding member such as a clip that holds the second fixing portion 52 or 62 and the flat portion 20e or 20f from both outer sides thereof.

  The second fixing portion 52 and the third fixing portion 53 of the positive electrode current collector 50 are caulked or joined by ultrasonic welding, resistance welding, or the like with the flat portions 20e and 20f of the positive electrode active material non-forming portion 21 sandwiched therebetween. Are joined to each other by welding or the like, thereby being connected to the positive electrode active material non-forming portion 21. Similarly, the second fixing portion 62 and the third fixing portion 63 of the negative electrode current collector 60 are connected to each other by caulking or welding, with the flat portions 20e and 20f of the negative electrode active material non-forming portion 22 being sandwiched. Thus, the negative electrode active material non-formation part 22 is connected.

  The positive electrode terminal 30 integrally includes a rectangular plate-shaped terminal body 30a and a cylindrical shaft portion 30b extending from the terminal body 30a. The negative electrode terminal 40 integrally includes a rectangular plate-like terminal body 40a and a cylindrical shaft portion 40b extending from the terminal body 40a. In the present embodiment, the terminal bodies 30a and 40a are integrally formed with the shaft portions 30b and 40b, respectively, but may be separate members. Here, the shaft portions 30b and 40b are examples of penetrating bodies.

  2 and 3, the terminal main body 40a of the negative electrode terminal 40, the upper insulating member 41, the lid body 12, the lower insulating member 42, and the first fixing portion 61 of the negative electrode current collector 60 are stacked in this order. Is done. 3 shows a cross section of the electricity storage device 100 of FIG. 1 taken along a plane that is substantially parallel to the short side walls 11c and 11e of the container 10 and is located near the short side wall 11e on the negative electrode terminal 40 side. FIG. 3 is a cross-sectional side view seen in a direction III from the electrode toward the positive electrode terminal 30. The shaft portion 40 b of the negative electrode terminal 40 penetrates the upper insulating member 41, the lid body 12, the lower insulating member 42, and the first fixing portion 61, and protrudes from the first fixing portion 61 to the side opposite to the lid body 12. The tip portion of the shaft portion 40 b that protrudes from the first fixing portion 61 is caulked to form a caulking protrusion portion 40 c that protrudes from the first fixing portion 61. Specifically, the cylindrical tip portion of the shaft portion 40b receives a pressing force toward the first fixed portion 61 when being caulked, and thereby plastically deforms so as to expand in a circular shape radially outward, and the shaft A caulking protrusion 40c having a diameter larger than that of the portion 40b is formed. The caulking protrusion 40c can be formed by, for example, a spin caulking method in which a tip portion of the shaft portion 40b is pressed by a rotating jig and deformed radially outward. The axis CA of the shaft portion 40b also serves as the axis of the caulking protrusion 40c. Thereby, the negative electrode terminal 40, the upper insulating member 41, the lid body 12, the lower insulating member 42, and the negative electrode current collector 60 are fixed together. The shaft portion 40b may be a solid cylinder. The caulking protrusion 40c may be formed by pressing and crushing the tip portion of the shaft portion 40b, that is, by press caulking. Here, the caulking protrusion 40c is an example of a protruding part and a caulking part. In the present embodiment, the entire caulking protrusion 40c, which is a protrusion, is disposed in a space (region F described later) between the lid body 12 and the curved portion 20c. It suffices that at least a part is disposed in the space between the lid body 12 and the bending portion 20c.

  In the present embodiment, the caulking protrusion 40c has a circular planar shape when viewed in a direction perpendicular to the lid 12 that is the axial direction of the shaft 40b. That is, the caulking protrusion 40c has the same width in a direction along a center reference plane RP described later and a direction perpendicular to this direction. The center reference plane RP is perpendicular to the lid body 12 and parallel to the winding axis A of the electrode body 20. However, the caulking protrusion 40c may be formed so that the width in the direction perpendicular to the center reference plane RP is smaller than the width in the direction along the center reference plane RP. Such caulking protrusions reduce the occupied space in the direction perpendicular to the center reference plane RP while ensuring the bonding strength.

  With reference to FIGS. 3 and 4, in the present embodiment, the protrusion distance D <b> 1 that is the protrusion amount of the caulking protrusion 40 c from the first fixing portion 61 is based on the distance D <b> 2 between the first fixing portion 61 and the electrode body 20. Is also big. A protrusion distance D1a that is a protrusion amount of the caulking protrusion 40c from the lid body 12 is also larger than a distance D2a between the lid body 12 and the electrode body 20. FIG. 4 is an enlarged cross-sectional side view of the negative electrode terminal 40 of FIG. 3 and its periphery. The protrusion distance D1 is the distance between the portion of the caulking protrusion 40c that protrudes most from the first fixing portion 61 and the surface 61b of the first fixing portion 61 opposite to the lid body 12. The protruding distance D1a is the distance between the first fixed portion 61 in the caulking protruding portion 40c, that is, the most protruding portion from the lid body 12, and the inner surface 12b of the lid body 12. The inner surface 12b of the lid body 12 is a flat surface of the lid body 12 on the side opposite to the outer surface 12a. The distance D <b> 2 is a distance between the top line P that is closest to the first fixing portion 61 and the lid body 12 in the curved portion 20 c of the electrode body 20 and the surface 61 b of the first fixing portion 61. The distance D <b> 2 a is a distance between the top line P of the curved portion 20 c of the electrode body 20 and the inner surface 12 b of the lid body 12. The top line P is a line extending linearly at the top of the curved portion 20c toward the lid 12, and is also an intersection of the center reference plane RP and the outer surface of the curved portion 20c. The central reference plane RP is a plane that is perpendicular to the lid body 12 and parallel to the winding axis A of the electrode body 20 and passes through a portion of the electrode body 20 that is closest to the first fixing portion 61, that is, the lid body 12. It is. Further, in the present embodiment, the center reference plane RP also passes through the winding axis A. Thus, the electrode body 20 is positioned with its curved portion 20c approaching the first fixing portion 61 and the lid body 12. Here, the center reference plane RP is an example of a reference plane.

  Referring to FIGS. 2 to 4, the through hole 12 d of the lid body 12 through which the shaft portion 40 b of the negative electrode terminal 40 passes and the through hole 61 a of the first fixing portion 61 of the negative electrode current collector 60 are the lid body 12 and the first On the fixed portion 61, the container body 11 is positioned closer to the long side wall 11d than the long side wall 11f. The axis CA of the shaft portion 40b of the negative electrode terminal 40 fixed to the lid body 12 is located between the center reference plane RP and the long side wall 11d. The axis CA is shifted, that is, shifted in the direction E away from the center reference plane RP toward the long side wall 11d and the flat portion 20e of the electrode body 20. The direction E is also a direction perpendicular to the center reference plane RP, and is also a direction facing the direction opposite to the winding direction R of the curved portion 20c of the electrode body 20 from the center reference plane RP. In the present embodiment, the entire caulking protrusion 40c is located away from the center reference plane RP in the direction E.

  Furthermore, at least a part of the caulking protrusion 40 c is located in a region F between the lid body 12 and the electrode body 20. The region F is a region between the inner surface 12b of the lid body 12 and the curved portion 20c of the electrode body 20, and is a region that becomes a shadow of the electrode body 20 when the electrode body 20 is projected onto the inner surface 12b of the lid body 12. is there. That is, the outer shape of the cross section of the region F parallel to the inner surface 12 b is equivalent to the outer shape of the projection image of the electrode body 20 on the inner surface 12 b of the lid body 12. In the present embodiment, the region F is formed by extending the outer surface of the flat portion 20e of the electrode body 20, the outer surface of the flat portion 20f, the end surface of the end portion 20a, and the end surface of the end portion 20b to the inner surface 12b. This is an area surrounded by four surfaces. The width B of the region F in the direction from the long side wall 11d to the long side wall 11f is equal to the width of the electrode body 20 that is the distance between the outer surface of the flat portion 20e and the outer surface of the flat portion 20f. In the present embodiment, the entire caulking protrusion 40 c is located in the region F. Due to the position of the caulking protrusion 40c shifted as described above, the bending portion 20c can be disposed close to the first fixing portion 61 and the lid body 12 in the electrode body 20.

  The positive terminal 30 also has the same arrangement configuration as the negative terminal 40. The terminal main body 30a of the positive electrode terminal 30, the upper insulating member 31, the lid 12, the lower insulating member 32, and the first fixing portion 51 of the positive electrode current collector 50 are arranged in this order. A tip portion protruding through the first fixing portion 51 in the shaft portion 30 b of the positive electrode terminal 30 forms a caulking protruding portion protruding from the first fixing portion 51 on the side opposite to the lid body 12. Thereby, the positive electrode terminal 30, the upper insulating member 31, the lid body 12, the lower insulating member 32, and the positive electrode current collector 50 are fixed together.

  Further, the protruding distance from the first fixing part 51 of the caulking protruding part of the shaft part 30 b is larger than the distance between the first fixing part 51 and the electrode body 20. Further, the protruding distance of the caulking protruding portion of the shaft portion 30 b from the lid body 12 is also larger than the distance between the lid body 12 and the electrode body 20. The through hole 12c of the lid body 12 through which the shaft portion 30b of the positive electrode terminal 30 passes and the through hole 51a of the first fixing portion 51 of the positive electrode current collector 50 are respectively formed on the container body 11 on the lid body 12 and the first fixing portion 51. It is located closer to the long side wall 11d than the long side wall 11f. The axial center CA of the shaft portion 30b is located between the center reference plane RP and the long side wall 11d and is shifted in the direction E from the center reference plane RP. In the present embodiment, the entire caulking protrusion of the shaft portion 30b is located away from the center reference plane RP in the direction E. Furthermore, at least a part of the caulking protrusion of the shaft portion 30b is located in the region F. In the present embodiment, the entire caulking protrusion portion of the shaft portion 30b is located in the region F. Thereby, the curved portion 20c of the electrode body 20 can be disposed close to the first fixing portion 51 and the lid body 12.

  As described above, power storage device 100 according to the present embodiment includes electrode body 20 including a wound electrode plate, and first wall that accommodates electrode body 20 and faces curved portion 20c of electrode body 20. A container 10 having a lid 12 as a part, and a shaft 40b as a penetrating body having a caulking projection 40c that penetrates the lid 12 and projects toward the electrode body 20. The distance D2a between the lid body 12 and the electrode body 20 is smaller than the projection distance D1a of the caulking projection 40c from the lid body 12.

  In the above configuration, the electrode body 20 approaches the lid body 12 until the distance D2a between the lid body 12 and the electrode body 20 is smaller than the projection distance D1a of the caulking projection 40c from the lid body 12. Arranged. This makes it possible to reduce the space between the curved portion 20c of the electrode body 20 and the lid body 12 in the container 10 in the direction from the lid body 12 toward the electrode body 20. As a result, the space that the electrode body 20 can occupy in the container 10 can be increased. For example, when the container dimensions are determined, the volume of the electrode body 20 that can be accommodated in the container 10 can be increased. When the electrode body dimensions are determined, the container 10 can be reduced in size. Further, the shaft portion 30b of the positive electrode terminal 30 and the caulking protrusion portion thereof have the same configuration and effect as the shaft portion 40b and the caulking protrusion portion 40c of the negative electrode terminal 40.

The power storage device 100 according to the embodiment may include a positive electrode terminal 30 and a negative electrode terminal 40 as electrode terminals arranged on the lid 12. The shaft portions 30b and 40b may connect the positive electrode terminal 30 and the negative electrode terminal 40 to the positive electrode current collector 50 and the negative electrode current collector 60, respectively.
The container 10 includes a container body 11 having an opening 11a and a lid body 12 that closes the opening 11a. The shaft portions 30b and 40b may penetrate the lid body 12. The electrode body 20 is flat. You may have the external shape which is. In the above configuration, it is easy to reduce the gap between the flat flat portions 20e and 20f of the electrode body 20 and the container body 11. Thereby, the electrical storage element 100 can be thinned, that is, downsized.

  In the electricity storage device 100 according to the embodiment, the caulking protrusion 40 c is a portion that is perpendicular to the lid body 12, is parallel to the winding axis A of the electrode body 20, and is closest to the lid body 12 in the electrode body 20. Are shifted (shifted) from the center reference plane RP passing through the top line P in the direction perpendicular to the center reference plane RP. Further, at least a part of the caulking protrusion 40 c is located in a region F between the lid body 12 and the electrode body 20. In the above-described configuration, the caulking protrusion 40c in the region F is positioned so as to be shifted from the center reference plane RP in a direction perpendicular to the center reference plane RP. Therefore, the caulking protrusion 40c that greatly deforms the electrode body 20 is provided. The electrode body 20 can be disposed close to the lid body 12 while avoiding contact with the electrode body 20. Further, the shaft portion 30b of the positive electrode terminal 30 and the caulking protrusion portion thereof have the same configuration and effect as the shaft portion 40b and the caulking protrusion portion 40c of the negative electrode terminal 40.

  In the electricity storage device 100 according to the embodiment, the entire caulking protrusion 40c is arranged away from the center reference plane RP in a direction perpendicular to the center reference plane RP. In the above-described configuration, the distance between the electrode body 20 and the lid body 12 can be effectively reduced while avoiding contact between the caulking protrusion 40c and the electrode body 20 that greatly deforms the electrode body 20. The shaft portion 30b of the positive electrode terminal 30 and the caulking protrusion portion thereof have the same configuration and effects as the shaft portion 40b and the caulking protrusion portion 40c of the negative electrode terminal 40.

  The power storage device 100 according to the embodiment includes a negative electrode current collector 60 as a current collecting member connected to the shaft portion 40 b and the electrode body 20, and the caulking protrusion 40 c is a shaft portion protruding from the negative electrode current collector 60. It is formed at the tip of 40b. In the above-described configuration, the negative electrode current collector 60 is sandwiched between the caulking protrusion 40 c and the lid body 12. Therefore, the caulking protrusion 40 c protrudes toward the electrode body 20 from the first fixing part 61 of the negative electrode current collector 60. By making such a caulking projection 40c as described above, the electrode body 20 can be effectively moved closer to the lid body 12 and disposed. The shaft portion 30b of the positive electrode terminal 30 and the caulking protrusion portion thereof have the same configuration and effects as the shaft portion 40b and the caulking protrusion portion 40c of the negative electrode terminal 40.

  In the electricity storage device 100 according to the embodiment, the caulking protrusion 40 c is a portion that is perpendicular to the lid body 12, is parallel to the winding axis A of the electrode body 20, and is closest to the lid body 12 in the electrode body 20. The width in the direction perpendicular to the center reference plane RP may be smaller than the width in the direction along the center reference plane RP passing through the top line P. In the above-described configuration, the caulking protrusion reduces the occupied space in the direction perpendicular to the center reference plane RP while ensuring the bonding strength. Therefore, the caulking protrusion widens the gap between the peripheral edge and the center reference plane RP. Thereby, the electrode body 20 can be disposed close to the lid body 12. Further, the shaft portion 30b of the positive electrode terminal 30 and the caulking protrusion portion thereof have the same configuration and effect as the shaft portion 40b and the caulking protrusion portion 40c of the negative electrode terminal 40.

[Modification]
Hereinafter, with reference to FIG. 5, the electrical storage element which concerns on the modification of embodiment is demonstrated. FIG. 5 is a cross-sectional side view showing a power storage device according to a modification of the embodiment in the same manner as FIG. In power storage element 100 according to the embodiment, curved portion 20c of electrode body 20 has an arcuate outer shape. However, in power storage element according to a modification, curved portion 20c of electrode body 20 has lid 12 thereof. And has a partially flattened outer shape at the top toward the surface.

  Specifically, the electrode body 20 of the energy storage device according to the modification has a flat portion 20ca that forms a flat outer surface at the top of the arcuate shape of the curved portion 20c. The flat portion 20ca is substantially parallel to the inner surface 12b of the lid body 12, the surface 61b of the first fixing portion 61 of the negative electrode current collector 60, and the inner surface of the first fixing portion 51 (see FIG. 2) of the positive electrode current collector 50. Forming the outer surface. The entire flat portion 20 ca is a portion of the electrode body 20 that is closest to the lid body 12, the negative electrode current collector 60, and the positive electrode current collector 50. In this modification, the center reference plane RP passes through the center of the flat portion 20ca. The flat portion 20ca extends from the boundary line P1 to the boundary line P2 in a direction perpendicular to the center reference plane RP. The boundary lines P1 and P2 are boundaries between the flat portion 20ca and the arc-shaped portion 20cb other than the flat portion 20ca in the curved portion 20c, and extend substantially parallel to the center reference plane RP.

  And the caulking junction part of the axial part 40b of the negative electrode terminal 40 and the axial part 30b of the positive electrode terminal 30 is positioned with respect to the reference plane RP1 passing through the boundary line P1 positioned closer thereto. The reference plane RP1 is a plane that passes through the boundary line P1, is perpendicular to the lid body 12, is parallel to the winding axis A of the electrode body 20, and is also substantially parallel to the center reference plane RP. In addition, when there are a plurality of portions closest to the lid body 12, the negative electrode current collector 60, and the positive electrode current collector 50, such as the flat portion 20ca, the reference plane is the electrode body 20 in the plurality of portions. It is set so as to pass through one part of the parts located at both ends in the circumferential direction which is the winding direction R. That is, the reference plane is a plane that passes through the one part and is perpendicular to the lid 12 and parallel to the winding axis A of the electrode body 20.

  The protrusion distance D1 of the caulking protrusion 40c of the shaft part 40b of the negative electrode terminal 40 from the first fixing part 61 is larger than the distance D2 between the first fixing part 61 and the flat part 20ca of the electrode body 20. Further, the protrusion distance D1a of the caulking protrusion 40c from the lid body 12 is also larger than the distance D2a between the lid body 12 and the flat portion 20ca of the electrode body 20. Further, in the shaft portion 40b of the negative electrode terminal 40, the axis CA is located between the reference plane RP1 and the long side wall 11d. The axis CA is shifted in the direction E away from the reference plane RP1 toward the long side wall 11d. The direction E is also a direction perpendicular to the reference plane RP1, and is also a direction facing the direction opposite to the winding direction R of the bending portion 20c of the electrode body 20 from the reference plane RP1. In the present embodiment, the entire caulking protrusion 40c is located away from the reference plane RP1 in the direction E. Furthermore, at least a part of the caulking protrusion 40 c is located in a region F between the lid body 12 and the electrode body 20. In the present embodiment, the entire caulking protrusion 40 c is located in the region F. Further, the shaft portion 30 b of the positive electrode terminal 30 and the caulking protrusion portion thereof have the same arrangement configuration as the shaft portion 40 b and the caulking protrusion portion 40 c of the negative electrode terminal 40.

  Moreover, since the other structure of the electrical storage element which concerns on a modification is the same as that of the electrical storage element 100 which concerns on embodiment, the description is abbreviate | omitted. Furthermore, according to the electricity storage device according to the modification, the same effect as in the embodiment can be obtained.

[Other variations]
The power storage device according to the embodiment and the modification of the present disclosure has been described above, but the present disclosure is not limited to the embodiment and the modification. That is, it should be considered that the embodiment and the modification disclosed this time are examples in all respects and are 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 the energy storage device according to the embodiment and the modification, the shaft portions 30b and 40b constitute the positive electrode terminal 30 and the negative electrode terminal 40, respectively, and are integrally formed with the terminal main body 30a of the positive electrode terminal 30 and the terminal main body 40a of the negative electrode terminal 40. However, the present invention is not limited to this and may be a separate part. For example, each of the shaft portions 30b and 40b may individually form individual members, or may form part of the positive electrode current collector 50 and the negative electrode current collector 60. The shaft portions 30b and 40b forming part of the positive electrode current collector 50 and the negative electrode current collector 60 may be integrally connected to the first fixing portions 51 and 61 by a method such as integral molding or welding, respectively. . In this case, the first fixing portions 51 and 61 may constitute a protruding portion from the lid body 12, and the portions of the shaft portions 30 b and 40 b that protrude from the first fixing portions 51 and 61 to the opposite side of the lid body 12. However, you may comprise the protrusion part from the cover body 12. FIG.

  In the electricity storage device according to the embodiment and the modification, the caulking protrusion formed by each of the shaft portions 30b and 40b constitutes the protruding portion from the lid body 12, but is not limited thereto. The shaft portions 30b and 40b may be joined to the first fixing portions 51 and 61 of the positive electrode current collector 50 and the negative electrode current collector 60, respectively, by a joining method such as welding, screw fastening, fitting, or pinning. In this case, the portions of the shaft portions 30 b and 40 b that protrude from the first fixing portions 51 and 61 to the opposite side of the lid body 12 may constitute the protrusion portion from the lid body 12.

  In the energy storage device according to the embodiment and the modification, the entire caulking protrusions of the shaft portions 30b and 40b are from the center reference plane RP of the electrode body 20 or the reference plane RP1 at the end of the flat portion 20ca of the electrode body 20, Although it was located away in the direction E, it is not limited to this. For example, the caulking protrusion may be positioned so as to overlap the center reference plane RP or the reference plane RP1. In this case, the portion of the caulking protrusion that protrudes most from the lid body 12 only needs to be located away from the center reference plane RP or the reference plane RP1. Also with this configuration, the electrode body 20 can be disposed close to the lid body 12.

  The power storage element according to the embodiment and the modification includes one electrode body 20 in the container 10, but may have a configuration including two or more electrode bodies 20. In this case, for example, the axial center CA of the caulking projecting portions of the shaft portions 30b and 40b is located between the center reference planes RP of the adjacent electrode bodies 20 among the two or more electrode bodies 20, and the adjacent ones. At least one of the distances D2a between the two electrode bodies 20 and the lid body 12 may be configured to be smaller than the protrusion distance D1a of the caulking protrusion.

  The power storage device according to the embodiment and the modification has a configuration including the electrode body 20 arranged with the winding axis A in the direction along the lid body 12 of the container 10, but the winding axis A is the lid body 12. The electrode body may be arranged in a substantially vertical orientation. In this case, the positive electrode terminal 30 and the negative electrode terminal 40 may be disposed on the side wall of the container 10 that faces the curved portion 20c or 20d of the electrode body 20 among the side walls 11c, 11d, 11e, and 11f.

  In the energy storage device according to the embodiment and the modification, the electrode body 20 is configured to include the positive electrode active material non-formation portion 21 and the negative electrode active material non-formation portion 22 at the end portions 20a and 20b, respectively. Not. The electrode body 20 has a positive electrode tab and a negative electrode tab which are protruding pieces protruding from the positive electrode plate and the negative electrode plate at the end portions 20a and / or 20b in the winding axis A direction. It may be connected to an electric current collector and a negative electrode current collector.

  In the electricity storage device according to the embodiment and the modification, the center of the terminal bodies 30a and 40a and the center of the upper insulating members 31 and 41 in the direction along the direction E in the direction of the winding axis A are the lid body 12. Is shifted from the center. However, for example, the center of the terminal body and / or the upper insulating member may be configured to substantially coincide with the center of the lid. By comprising in this way, when the magnitude | size of an upper insulating member is constant, the distance of an upper insulating member and the outer edge of a cover body is securable. Therefore, when joining the outer edge of a cover body and a container main body by welding, a heat | fever can be transmitted to an upper insulating member and a possibility of producing a deformation | transformation etc. can be reduced.

  In addition, forms constructed by arbitrarily combining the embodiments and the modified examples are also included in the scope of the present disclosure. In addition, the present disclosure may include not only the above-described power storage element but also a power storage device including one or more power storage elements. For example, the power storage device can be realized as a 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 including a plurality of power storage elements 100 and having a high output is used as a power source for vehicles such as an electric vehicle (EV), a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), and an automated guided vehicle (AGV). It can also be installed.

  The present disclosure can be applied to power storage elements such as lithium ion secondary batteries.

10 Container 11 Container Body 11a Opening 12 Lid (First Wall)
20 Electrode bodies 20c, 20d Bending portion 30 Positive terminal (electrode terminal)
30b, 40b Shaft (penetrating body)
40 Negative terminal (electrode terminal)
40c Caulking protrusion (protruding part, caulking part)
50 Positive current collector (current collecting member)
60 Negative electrode current collector (current collecting member)
100 Power storage element A Winding axis F Region P Top line P1, P2 Boundary line RP Center reference plane (reference plane)
RP1 reference plane

Claims (9)

An electrode body including a wound electrode plate;
A container containing the electrode body and having a first wall portion facing the curved portion of the electrode body;
A penetrating body penetrating the first wall and having a projecting portion projecting toward the electrode body,
The distance between the first wall portion and the electrode body is smaller than the protruding distance of the protruding portion from the first wall portion. The protrusion is perpendicular to the first wall and parallel to the winding axis of the electrode body, and from the reference plane passing through a portion closest to the first wall in the electrode body, the reference plane Shifted in the direction perpendicular to
The power storage element according to claim 1, wherein at least a part of the protruding portion is located in a region between the first wall portion and the electrode body. An electrode body including a wound electrode plate;
A container containing the electrode body and having a first wall portion facing the curved portion of the electrode body;
A penetrating body penetrating the first wall and having a projecting portion projecting toward the electrode body,
The protrusion is perpendicular to the first wall and parallel to the winding axis of the electrode body, and from the reference plane passing through a portion closest to the first wall in the electrode body, the reference plane Shifted in the direction perpendicular to
An electricity storage device, wherein at least a part of the protruding portion is located in a region between the first wall portion and the electrode body. The electric storage element according to claim 2 or 3, wherein the entire protrusion is disposed away from the reference plane in a direction perpendicular to the reference plane. A current collecting member connected to the penetrating body and the electrode body;
The power storage element according to claim 1, wherein the protruding portion has a caulking portion at a tip portion protruding from the current collecting member. The caulking portion is perpendicular to the first wall portion, parallel to the winding axis of the electrode body, and in a direction along a reference plane that passes through a portion of the electrode body that is closest to the first wall portion. The power storage device according to claim 5, wherein the power storage element is formed so that a width in a direction perpendicular to the reference plane is smaller than a width. An electrode terminal disposed on the first wall;
The power storage device according to claim 5, wherein the through body connects the electrode terminal and the current collecting member. The container includes a container body having an opening, and a lid for closing the opening,
The power storage device according to any one of claims 1 to 7, wherein the first wall portion is the lid. The electric storage element according to claim 1, wherein the electrode body has a flat outer shape.

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