JP6221383B2 - Electric storage element, core material, and method of manufacturing electric storage element - Google Patents

Description

  The present invention relates to a power storage element including an electrode body formed by winding a positive electrode, a negative electrode, and a separator, a core material disposed on the innermost periphery of the electrode body, and a method for manufacturing the power storage element.

  The shift from gasoline cars to electric cars has become important as a global environmental problem. For this reason, development of an electric vehicle using a power storage element such as a lithium ion secondary battery as a power source is being promoted.

  Here, in a conventional power storage element, a wound type power storage element including an electrode body formed by winding a positive electrode, a negative electrode, and a separator is widely known (see, for example, Patent Document 1). Such a winding type power storage device is manufactured by winding a positive electrode, a negative electrode, and a separator to form an electrode body, and inserting the electrode body into a container.

JP 2013-16440 A

  However, the conventional winding type power storage element has a problem that sagging or wrinkles may occur in the electrode body in which the positive electrode, the negative electrode, and the separator are wound, and the performance of the power storage element may be deteriorated.

  That is, when the electrode body is formed, a gap is generated between the positive electrode, the negative electrode, and the separator, so that sagging or wrinkles may occur in the electrode body. In this case, the distance between the positive electrode and the negative electrode is increased to increase the resistance, the electrolyte is partially drained, or the film growth on the electrode is partially accelerated. The performance of the device is degraded.

  The present invention has been made in order to solve the above-mentioned problem, and is arranged in the innermost circumference of the power storage element that can reduce the occurrence of sagging and wrinkles in the electrode body and suppress the deterioration in performance. It is an object of the present invention to provide a core material to be manufactured and a method for manufacturing a power storage element.

  In order to achieve the above object, a power storage device according to one embodiment of the present invention is a power storage device including an electrode body formed by winding a positive electrode, a negative electrode, and a separator around a winding axis, the electrode The body includes a core material disposed at an innermost inner periphery of the wound positive electrode, the negative electrode, and the separator, and the core material includes the positive electrode, the negative electrode, and the separator as the winding shaft. A winding portion for attaching a winding shaft to be wound around to form the electrode body, and a connecting portion having elasticity and connecting the two winding shaft attachment portions. The part is formed so that the width of the core member in the direction intersecting the winding axis can be reduced by elastic deformation by changing the positional relationship between the two winding axis attachment parts.

  According to this, the electrical storage element includes a core member disposed on the innermost periphery of the electrode body, and the core member includes two winding shaft mounting portions to which the winding shaft is mounted and an elastic connecting portion. The connecting portion is formed so as to be capable of reducing the width of the core material by elastic deformation by changing the positional relationship between the two winding shaft attachment portions. That is, since the connecting portion can be elastically deformed by changing the positional relationship between the two winding shaft attachment portions, the positional relationship between the two members of the winding shaft attached to the two winding shaft attachment portions is changed. Thus, the connecting portion can be elastically deformed to reduce the width of the core material. And the force which tries to spread to an outer side arises in a core material by making a connecting part elastically deform and changing the width | variety of a core material small. As a result, outward force is applied to the positive electrode, the negative electrode, and the separator wound around the core material, so that sagging and wrinkles are reduced in the electrode body, and deterioration in the performance of the storage element is suppressed. be able to.

  Further, the connecting portion is in a state in which the positive electrode, the negative electrode, and the separator are wound around the core material, and in a state where the positive electrode, the negative electrode, and the separator are not wound around the core material. You may decide to be elastically deformed so that the said width | variety of the said core material may become small.

  According to this, the connecting portion is elastically deformed so that the width of the core material is smaller than the state where the electrode is wound around the core material in a state where the electrode is wound around the core material. In the state where the core member is disposed on the innermost periphery of the electrode body, a force for spreading outward is generated. Thereby, since an outward force is applied to the electrode wound around the core material, it is possible to reduce the occurrence of sagging and wrinkles in the electrode body, and to suppress the deterioration of the performance of the storage element.

  In addition, the connecting portion may be formed so that the width of the core member can be reduced and deformed by reducing a distance between the two winding shaft attaching portions by elastic deformation.

  According to this, by reducing the distance between the two winding shaft attachment portions, the connecting portion is elastically deformed, and the width of the core material can be reduced. In other words, since the distance between the two winding shaft attachment portions can be reduced by bringing the two members of the winding shaft attached to the two winding shaft attachment portions close to each other, the connecting portion can be easily elastically deformed. The width of the core material can be reduced.

  Further, the two winding shaft attachment portions may be arranged in a direction intersecting the longitudinal direction and the short direction of the core material when the core material is viewed from the winding axis direction. .

  According to this, since the two winding shaft attachment portions are arranged in a direction intersecting the longitudinal direction and the short direction of the core material, the distance between the two winding shaft attachment portions is reduced to reduce the width of the core material. Is deformed to a small size, a force directed in the intersecting direction is applied to the electrodes wound around the core material. For this reason, not only the longitudinal direction or the short direction of the core material but also the force directed to both the longitudinal direction and the short direction is applied to the electrode, so that sagging and wrinkles are further reduced in the electrode body, The performance degradation can be suppressed.

  The connecting portion is connected to an intermediate portion arranged at a position sandwiched between the two winding shaft attachment portions, each of both end portions of the intermediate portion, and each of the two winding shaft attachment portions. And the intermediate portion may be formed to be thicker than the two connection portions when the core member is viewed from the winding axis direction. .

  According to this, the connecting portion is formed so that the intermediate portion is thicker than the two connecting portions on both sides of the intermediate portion. Here, when the connecting portion is elastically deformed, not the intermediate portion but the two connecting portions are elastically deformed, whereby the width of the core material is deformed to be small. For this reason, the unnecessary deformation | transformation of a connection part is suppressed by thickening the thickness of the intermediate part which is not required to elastically deform a connection part rather than two connection parts required to elastically deform a connection part. And the joint portion can be effectively elastically deformed.

  Further, at least one of the two winding shaft mounting portions has a non-circular opening into which the winding shaft is inserted when the core material is viewed from the winding shaft direction. May be formed.

  According to this, since the winding shaft is inserted into the non-circular opening formed in the winding shaft mounting portion of the core material, when winding the electrode around the core material by rotating the winding shaft, the winding shaft It is possible to fix the core material. For this reason, when forming an electrode body, it can further reduce that a sagging and a wrinkle arise in an electrode body, and can suppress the fall of the performance of an electrical storage element.

  Moreover, the present invention can be realized not only as such a power storage element, but also as an electrode body provided in the power storage element or a core material disposed on the innermost periphery of the electrode body.

  In order to achieve the above object, a method for manufacturing a power storage element according to one embodiment of the present invention includes a power storage element including an electrode body formed by winding a positive electrode, a negative electrode, and a separator around a winding axis. A core material deforming step for elastically deforming a core material to be disposed on the innermost circumference of the electrode body, and deforming the width of the core material in a direction intersecting the winding axis; A winding step of forming the electrode body by winding the positive electrode, the negative electrode, and the separator around the core material in a state where the width of the core material is reduced.

  According to this, in the method for manufacturing the energy storage device, the core material is elastically deformed to reduce the width of the core material, and the electrode is wound around the core material in a state where the width of the core material is reduced to be small. Form the body. That is, the core material is elastically deformed in advance so that the width of the core material is reduced, and the electrode is wound while maintaining the elastically deformed state. Thereby, it can wind in the state in which the force which spreads to the outer side is not produced in the core material, and can produce the force which tries to spread outward on the core material after winding. For this reason, since the outward force is applied to the positive electrode, the negative electrode, and the separator wound around the core material after winding, the occurrence of sagging and wrinkles in the electrode body is reduced, and the performance of the storage element is reduced. The decrease can be suppressed.

  Further, before the core material deforming step, a winding shaft for winding the positive electrode, the negative electrode, and the separator around the winding shaft to form the electrode body is attached to the core material. You may decide to include a shaft attachment process.

  According to this, in the manufacturing method of an electrical storage element, a winding axis is attached to a core material before a core material deformation | transformation process. That is, after attaching a winding axis to a core material, an electrode body can be formed by performing a winding process by deforming the core material and rotating the winding axis.

  Further, in the winding shaft attaching step, the winding shaft is attached to two winding shaft attaching portions of the core material, and in the core material deforming step, the positional relationship between the two winding shaft attaching portions is changed. The connecting portion that connects the two winding shaft attachment portions may be elastically deformed so that the width of the core member is reduced.

  According to this, in the method of manufacturing the electricity storage device, after attaching the winding shaft to the two winding shaft attachment portions, the connecting portion is elastically deformed by changing the positional relationship between the two winding shaft attachment portions, and the core Deform the width of the material small. That is, since the positional relationship between the two winding shaft attachment portions can be changed by changing the positional relationship between the two shafts of the winding shafts attached to the two winding shaft attachment portions, the connecting portion can be easily obtained. Can be elastically deformed to reduce the width of the core material.

  According to the present invention, it is possible to reduce the occurrence of sagging and wrinkles in the electrode body and to suppress the deterioration of the performance of the power storage element.

It is an external appearance perspective view of the electrical storage element which concerns on embodiment of this invention. It is a perspective view which shows the structure of the electrode body which concerns on embodiment of this invention. It is a front view which shows the detailed structure of the electrode body which concerns on embodiment of this invention. It is a perspective view which shows the structure of the core material which concerns on embodiment of this invention. It is a flowchart which shows the manufacturing process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the winding shaft attachment process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the core material deformation | transformation process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the winding process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is sectional drawing which shows the state in which the electrode body which concerns on embodiment of this invention was accommodated inside the container. It is a figure which shows the structure of the core material which concerns on the modification 1 of embodiment of this invention. It is a figure which shows the structure of the core material which concerns on the modification 2 of embodiment of this invention. It is a figure which shows the structure of the core material which concerns on the modification 3 of embodiment of this invention. It is a figure which shows the structure of the core material which concerns on the modification 4 of embodiment of this invention.

  Hereinafter, an electrical storage element, an electrode body, a core material disposed on the innermost periphery of the electrode body, and a method for manufacturing the electrical storage element 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 of the present invention are described as optional constituent elements that constitute a more preferable embodiment. Moreover, in each figure, a dimension etc. do not correspond exactly | strictly.

(Embodiment)
First, the configuration of the power storage element 10 will be described.

  FIG. 1 is an external perspective view of a power storage device 10 according to an embodiment of the present invention. In addition, the figure is a figure which saw through the container inside. FIG. 2 is a perspective view showing the configuration of the electrode assembly 400 according to the embodiment of the present invention. FIG. 3 is a front view showing a detailed configuration of the electrode body 400 according to the embodiment of the present invention. Specifically, this figure is a view when the electrode body 400 shown in FIG. 2 is viewed from the X axis plus side.

  The power storage element 10 is a secondary battery that can charge electricity and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. In addition, the electrical storage element 10 is not limited to a nonaqueous electrolyte secondary battery, A secondary battery other than a nonaqueous electrolyte secondary battery may be sufficient, and a capacitor may be sufficient as it.

  First, as shown in FIG. 1, the electric storage element 10 includes a container 100, a positive electrode terminal 200, and a negative electrode terminal 300, and the container 100 includes a lid plate 110 that is an upper wall. In addition, an electrode body 400, a positive electrode current collector 120, and a negative electrode current collector 130 are disposed inside the container 100. In addition, although liquids, such as electrolyte solution, are enclosed in the inside of the container 100, illustration of the said liquid is abbreviate | omitted.

  The container 100 includes a casing body having a rectangular cylindrical shape made of metal and having a bottom, and a metal lid plate 110 that closes an opening of the casing body. In addition, the container 100 can be hermetically sealed by welding the lid plate 110 and the housing body after the electrode body 400 and the like are accommodated therein.

  As shown in FIG. 2, the electrode body 400 includes a positive electrode 410, a negative electrode 420, and a separator 430, and is a member that can store electricity. Specifically, the electrode body 400 is formed by winding a layered arrangement so that the separator 430 is sandwiched between the positive electrode 410 and the negative electrode 420 so that the whole becomes an oval shape. .

  That is, the electrode body 400 is a wound electrode body formed by winding the positive electrode 410, the negative electrode 420, and the separator 430 around the winding axis. Here, the winding axis is a central axis when the positive electrode 410, the negative electrode 420, and the separator 430 are wound, and is an axis A in the X-axis direction (hereinafter referred to as a winding axis A) in FIG. . In the present embodiment, the electrode body 400 has an elliptical shape (a cross-sectional shape when cut along the YZ plane in the figure), but the shape may be a circular shape or an elliptical shape.

  The positive electrode 410 is an electrode plate in which a positive electrode active material layer is formed on the surface of a long belt-shaped conductive positive electrode current collector foil made of aluminum or an aluminum alloy. In addition, the positive electrode 410 used for the electrical storage element 10 according to the present invention is not particularly different from those conventionally used, and those normally used can be used.

That is, as the positive electrode active material used for the positive electrode active material layer of the positive electrode 410, a known material can be appropriately used as long as it is a positive electrode active material capable of occluding and releasing lithium ions. For example, as a positive electrode active material, a polyanion compound such as LiMPO ₄ , LiMSiO ₄ , LiMBO ₃ (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), lithium titanate, Spinel compounds such as lithium manganate, lithium transition metal oxides such as LiMO ₂ (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, and the like) can be used.

  The negative electrode 420 is an electrode plate in which a negative electrode active material layer is formed on the surface of a long strip-like conductive negative electrode current collector foil made of copper or a copper alloy. The negative electrode active material layer is arrange | positioned in the position which opposes the positive electrode active material layer of a positive electrode on both sides of a separator. In addition, the negative electrode 420 used for the electrical storage element 10 according to the present invention is not particularly different from that conventionally used, and a commonly used one can be used.

That is, as the negative electrode active material used for the negative electrode active material layer of the negative electrode 420, any known material can be used as long as it is a negative electrode active material capable of occluding and releasing lithium ions. For example, as the negative electrode active material, lithium metal, lithium alloy (lithium metal-containing alloys such as lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and wood alloy), and lithium can be used. Alloys that can be occluded / released, carbon materials (eg, graphite, non-graphitizable carbon, graphitizable carbon, low-temperature calcined carbon, amorphous carbon, etc.), metal oxides, lithium metal oxides (Li ₄ Ti ₅ O _12, etc.) ) And polyphosphoric acid compounds.

  Note that, when graphite or graphitizable carbon is used as the negative electrode active material, the expansion and contraction of the electrode body 400 increase, and the electrode body 400 is likely to sag and wrinkle. large.

  The separator 430 is a long strip-shaped separator disposed between the positive electrode 410 and the negative electrode 420, and is specifically a microporous sheet. In addition, the material of the separator 430 is not specifically limited, A well-known material can be used suitably.

  Further, as shown in FIG. 3, the electrode body 400 further includes a core member 500 disposed on the innermost inner periphery of the wound positive electrode 410, negative electrode 420, and separator 430. That is, the electrode body 400 is formed by winding the positive electrode 410, the negative electrode 420, and the separator 430 around the core material 500 (around the winding axis A).

  The core material 500 is an insulating member disposed on the innermost periphery of the electrode body 400. Specifically, the core material 500 is a core made of resin such as polypropylene or polyethylene. In addition, the material of the core material 500 is not limited to resin. For example, in the electrode body 400, when a separator is disposed at a position closest to the core material 500 or the core material 500 is covered with an insulating member, the potential of either the positive electrode 410 or the negative electrode 420 is set as the core material. When dropping to 500, a conductive material such as metal may be used. The detailed configuration of the core material 500 will be described later.

  Returning to FIG. 1, the positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode 410 of the electrode body 400 via the positive electrode current collector 120, and the negative electrode terminal 300 is connected to the positive electrode current collector 130 via the negative electrode current collector 130. , An electrode terminal electrically connected to the negative electrode 420 of the electrode body 400.

  That is, the positive electrode terminal 200 and the negative electrode terminal 300 lead the electricity stored in the electrode body 400 to the external space of the power storage element 10, and in order to store the electricity in the electrode body 400, It is an electrode terminal made of metal for introducing. The positive electrode terminal 200 and the negative electrode terminal 300 are attached to a lid plate 110 disposed above the electrode body 400.

  The positive electrode current collector 120 is a member that is disposed between the positive electrode 410 of the electrode body 400 and the side wall of the container 100 and has electrical conductivity and rigidity that are electrically connected to the positive electrode terminal 200 and the positive electrode 410. . The positive electrode current collector 120 is formed of a metal containing aluminum as a main component, like the positive electrode current collector foil of the positive electrode 410.

  The negative electrode current collector 130 is disposed between the negative electrode 420 of the electrode body 400 and the side wall of the container 100, and has conductivity and rigidity that are electrically connected to the negative electrode terminal 300 and the negative electrode 420 of the electrode body 400. It is a member. The negative electrode current collector 130 is formed of a metal containing copper as a main component, like the negative electrode current collector foil of the negative electrode 420.

  Next, a detailed configuration of the core material 500 will be described.

  FIG. 4 is a perspective view showing a configuration of core material 500 according to the embodiment of the present invention. Specifically, this figure is a perspective view showing the configuration of the core member 500 in a state where the positive electrode 410, the negative electrode 420, and the separator 430 are not wound.

  In addition, the core material 500 of the figure has an outer shape (width in the Y-axis direction and the Z-axis direction) than the core material 500 in the state where the positive electrode 410, the negative electrode 420, and the separator 430 illustrated in FIG. 3 are wound. It has spread. That is, the outer shape of the core member 500 is smaller when the positive electrode 410, the negative electrode 420, and the separator 430 are wound than when the positive electrode 410, the negative electrode 420, and the separator 430 are not wound. Is formed. The explanation about the small deformation of the outer shape will be described later.

  As shown in the figure, the core material 500 is a member extending in the X-axis direction, and the cross-sectional shape in the YZ plane, which is a flat plate-like member bent into an S shape, has an S shape. Yes. Here, the core member 500 includes two winding shaft attachment portions 510 and a connecting portion 520 that connects the two winding shaft attachment portions 510.

  The winding shaft attachment portion 510 is a portion to which a later-described winding shaft 600 is attached, and is a rod-shaped portion that extends in the X-axis direction. Further, the winding shaft attaching portion 510 is formed with a non-circular opening 511 into which the winding shaft 600 is inserted when the core member 500 is viewed from the winding shaft direction. Specifically, the opening 511 is a through-hole extending in the X-axis direction having a rectangular cross section. Note that the winding axis direction is a direction in which the winding axis A shown in FIG. 3 extends, and specifically, the X-axis direction in the drawing.

  Two plate-like members of the winding shaft 600 are inserted into the openings 511 of the two winding shaft attachment portions 510, and the winding shaft 600 rotates, whereby the positive electrode 410, the negative electrode 420, and the separator 430 are wound around the core material 500. Turned. Note that the cross-sectional shape of the opening 511 may be a non-circular shape, and may be an oval shape or a triangular shape.

  Further, the two winding shaft attachment portions 510 are arranged in a direction intersecting with the longitudinal direction and the short direction of the core material 500 when the core material 500 is viewed from the winding axis direction (X-axis direction in the figure). ing. In addition, the said longitudinal direction is a longitudinal direction of the cross-sectional shape at the time of cut | disconnecting the core material 500 in a YZ plane, and points out the Z-axis direction of the figure. The short direction is the short direction of the cross-sectional shape when the core member 500 is cut along the YZ plane, and indicates the Y-axis direction in FIG. In other words, the two winding shaft attachment portions 510 are arranged in an oblique direction that is neither the Y-axis direction nor the Z-axis direction (on the diagonal line of the cross-sectional shape when the core member 500 is cut along the YZ plane).

  The connecting portion 520 is an S-shaped portion extending in the X-axis direction that has elasticity and connects the two winding shaft attachment portions 510. The connecting portion 520 can be deformed to have a small width in the direction intersecting the winding axis of the core member 500 (direction intersecting the X axis in the figure) by elastic deformation by changing the positional relationship between the two winding shaft attachment portions 510. Is formed. A detailed description of the elastic deformation of the connecting portion 520 will be described later. Here, the connecting portion 520 includes an intermediate portion 521 and two connecting portions 522.

  The intermediate portion 521 is a rod-shaped portion that is disposed at a position between the two winding shaft attachment portions 510 and extends in the X-axis direction. That is, the intermediate portion 521 is disposed at a position where it intersects with a line segment connecting the two winding shaft attachment portions 510.

  Further, the intermediate portion 521 is formed so as to be thicker than the two connecting portions 522 when the core member 500 is viewed from the winding axis direction (X-axis direction in the figure). That is, in the cross-sectional shape when the core member 500 is cut along the YZ plane, the intermediate portion 521 is thicker than the two connection portions 522.

  The connection part 522 is a part connected to each of both ends of the intermediate part 521 and each of the two winding shaft attachment parts 510. That is, each connection portion 522 is a curved plate-like portion extending in the X-axis direction, one end of which is connected to the end of the intermediate portion 521 and the other end is connected to one winding shaft attachment portion 510. Specifically, each connection part 522 has a U-shaped cross section in the YZ plane, and the two connection parts 522 are point-symmetric with respect to the winding axis (winding axis A shown in FIG. 3). It has a related shape.

  Next, the manufacturing method of the electrical storage element 10 is demonstrated.

  FIG. 5 is a flowchart showing a manufacturing process in the method for manufacturing power storage device 10 according to the embodiment of the present invention. Specifically, the figure is a flowchart showing a process of manufacturing electrode body 400 constituting power storage element 10 according to the embodiment of the present invention.

  Moreover, FIG. 6 is a figure for demonstrating the winding shaft attachment process in the process of manufacturing the electrode body 400 which is 1 process of the manufacturing method of the electrical storage element 10 which concerns on embodiment of this invention. Moreover, FIG. 7 is a figure for demonstrating the core material deformation | transformation process in the process in which the said electrode body 400 is manufactured with the manufacturing method of the electrical storage element 10 which concerns on embodiment of this invention. Moreover, FIG. 8 is a figure for demonstrating the winding process in the process in which the said electrode body 400 is manufactured with the manufacturing method of the electrical storage element 10 which concerns on embodiment of this invention.

  First, as shown in FIG. 5, as a winding shaft attaching step, the winding shaft 600 is attached to the two winding shaft attaching portions 510 included in the core member 500 (S <b> 102). Here, the winding shaft 600 is a shaft body for forming the electrode body 400 by winding the positive electrode 410, the negative electrode 420, and the separator 430 around a winding shaft (winding shaft A shown in FIG. 3).

  Specifically, as shown in FIG. 6, two plate members 610 of the winding shaft 600 are inserted into the openings 511 of the two winding shaft mounting portions 510, so that the winding shaft 600 is attached to the two winding shafts. Attach to part 510. The material of the winding shaft 600 is not particularly limited, and may be made of resin or metal.

  Here, the two plate-like members 610 are rod-like members that protrude in the X-axis direction toward the openings 511 of the two winding shaft attachment portions 510 provided on the winding shaft 600. Further, the two plate-like members 610 are arranged corresponding to the arrangement positions of the two openings 511 so as to be fitted to the two openings 511, and also correspond to the shapes of the two openings 511. It has a shape.

  Returning to FIG. 5, next, as a core material deformation step, the core material 500 to be disposed on the innermost periphery of the electrode body 400 is elastically deformed before the positive electrode 410, the negative electrode 420, and the separator 430 are wound. Thus, the width in the direction intersecting the winding axis of the core material 500 is reduced (S104). That is, in the core material deforming step, by changing the positional relationship between the two winding shaft attachment portions 510, the connecting portion 520 that connects the two winding shaft attachment portions 510 is elastically deformed, and the width of the core material 500 is reduced. To do.

  Specifically, as shown in FIG. 7, the positional relationship between the two plate-like members 610 is determined in a state where the two plate-like members 610 of the reel 600 are inserted into the openings 511 of the two reel attachment portions 510. By changing, the positional relationship between the two winding shaft attachment portions 510 is changed. Thereby, the connecting portion 520 is elastically deformed, and the width in the direction intersecting with the winding axis of the core member 500 (in the present embodiment, the Y-axis direction and the Z-axis direction) is deformed to be small.

  That is, by moving the two plate-like members 610 inward from the state of FIG. 7A, the two plate-like members 610 are moved inward to reduce the distance between the two plate-like members 610. To do. As a result, as shown in FIG. 7B, the connecting portion 520 is elastically deformed, the distance between the two winding shaft attachment portions 510 is reduced, and the core material 500 in the Y-axis direction and the Z-axis direction is reduced. The width is deformed small.

  Specifically, the two connecting portions 522 of the connecting portion 520 are elastically deformed so that the inner spaces of the connecting portions 520 become smaller, so that the inner space of the core material 500 becomes smaller and the core material 500 has the Y-axis direction. And the width in the Z-axis direction is small and deformed. That is, when the core member 500 is viewed from the X-axis direction, a region surrounded by the outer edge by connecting the outer edges of the core member 500 (in the present embodiment, a region having a substantially elliptical shape or an oval shape). The connecting portion 520 is elastically deformed so that the area of the connecting member 520 becomes smaller (so that the outer shape of the core member 500 becomes smaller).

  In the present embodiment, the two winding shaft mounting portions 510 are moved in the direction intersecting the Y-axis direction and the Z-axis direction so that the distance between the two winding shaft mounting portions 510 is reduced. Therefore, the core material 500 is deformed with a small width in both the Y-axis direction and the Z-axis direction.

  As described above, the connecting portion 520 is formed so that the width in the direction intersecting the winding axis of the core member 500 can be reduced by elastic deformation by changing the positional relationship between the two winding shaft attachment portions 510. That is, the connecting portion 520 is formed so that the width of the core member 500 can be reduced and deformed by reducing the distance between the two winding shaft attachment portions 510 by elastic deformation.

  Returning to FIG. 5, next, as a winding step, the electrode body 400 is formed by winding the positive electrode 410, the negative electrode 420, and the separator 430 around the core material 500 in a state where the width of the core material 500 is reduced. (S106).

  Specifically, as shown in FIG. 8A, the distance between the two plate-like members 610 of the winding shaft 600 is reduced, and the distance between the two winding shaft attachment portions 510 is kept small. Then, the winding shaft 600 is rotated around the winding shaft A. Thereby, the positive electrode 410, the negative electrode 420, and the separator 430 are wound around the core material 500, and the electrode body 400 is formed. Then, as shown in FIG. 8B, after the electrode body 400 is formed, the winding shaft 600 is pulled out.

  As described above, the connecting portion 520 is in a state where the positive electrode 410, the negative electrode 420, and the separator 430 are wound around the core material 500, and the positive electrode 410, the negative electrode 420, and the separator 430 are not wound around the core material 500. The core material 500 is elastically deformed so as to have a smaller width.

  And the electrode body 400 formed in this way is accommodated inside the container 100. That is, the electrode body 400 formed in this way is welded to the positive electrode current collector 120 and the negative electrode current collector 130 and inserted into the housing body of the container 100. And after the said housing body and the cover board 110 are welded and electrolyte solution is injected from a liquid injection hole (not shown), the said liquid injection hole is sealed and the electrical storage element 10 is completed.

  FIG. 9 is a cross-sectional view showing a state in which the electrode body 400 according to the embodiment of the present invention is housed inside the container 100. That is, this figure is a diagram showing a cross section of the electricity storage device 10 when the electricity storage device 10 shown in FIG. 1 is cut along the YZ plane.

  As shown in the drawing, since the winding shaft 600 is pulled out from the two winding shaft attachment portions 510 in a state where the connecting portion 520 is elastically deformed so that the width of the core material 500 is reduced, Stresses F1 to F6 directed outward are generated. That is, since the width of the core material 500 is deformed to be small in the Y-axis direction and the Z-axis direction so that the distance between the two winding shaft attachment portions 510 becomes small, the core material 500 is directed in the Y-axis direction. Stresses F1 and F4, stresses F2 and F5 in the direction intersecting the Y axis and the Z axis, and stresses F3 and F6 in the Z axis direction are generated.

  As described above, according to the electric storage element 10 according to the embodiment of the present invention, the core member 500 is provided on the innermost periphery of the electrode body 400, and the core member 500 is attached to the core member 500. It has two winding shaft attachment portions 510 and a connecting portion 520 having elasticity, and the connecting portion 520 deforms the width of the core material 500 to be small by elastic deformation by changing the positional relationship between the two winding shaft attachment portions 510. It is made possible. That is, since the connecting portion 520 can be elastically deformed by changing the positional relationship between the two winding shaft attachment portions 510, the positions of the two shafts of the winding shaft 600 attached to the two winding shaft attachment portions 510. By changing the relationship, the connecting portion 520 can be easily elastically deformed and the width of the core material 500 can be reduced. And the force which tries to spread to the outer side arises in the core material 500 by elastically deforming the connection part 520 and changing the width | variety of the core material 500 small. As a result, outward force is applied to the positive electrode 410, the negative electrode 420, and the separator 430 wound around the core member 500, so that sagging and wrinkles are reduced in the electrode body 400. A decrease in performance can be suppressed.

  In addition, the connecting portion 520 has a width of the core material 500 in a state where the electrodes (the positive electrode 410, the negative electrode 420, and the separator 430) are wound around the core material 500, as compared with a state where no electrode is wound around the core material 500. Since the core member 500 is elastically deformed so as to be smaller, a force is generated in the core member 500 to spread outward in a state where the core member 500 is disposed on the innermost periphery of the electrode body 400. Thereby, since an outward force is applied to the electrode wound around the core member 500, the occurrence of sagging and wrinkles in the electrode body 400 is reduced, and the deterioration of the performance of the storage element 10 is suppressed. it can.

  Further, by reducing the distance between the two winding shaft attachment portions 510, the connecting portion 520 is elastically deformed, and the width of the core member 500 can be reduced. That is, since the distance between the two winding shaft attachment portions 510 can be reduced by bringing the two plate-like members 610 of the winding shaft 600 attached to the two winding shaft attachment portions 510 closer, The connecting portion 520 can be elastically deformed to reduce the width of the core material 500.

  Further, since the two winding shaft attachment portions 510 are arranged in a direction intersecting the longitudinal direction and the short direction of the core member 500, the distance between the two winding shaft attachment portions 510 is reduced to reduce the length of the core member 500. When the width is deformed to be small, a force directed in the intersecting direction is applied to the electrode wound around the core member 500. For this reason, since not only the longitudinal direction or the lateral direction of the core material 500 but also the force directed to both the longitudinal direction and the lateral direction is applied to the electrode, the occurrence of sagging and wrinkles in the electrode body 400 is further reduced. A decrease in the performance of the power storage element 10 can be suppressed.

  Further, the connecting portion 520 is formed so that the intermediate portion 521 is thicker than the two connecting portions 522 on both sides of the intermediate portion 521. Here, when the connecting portion 520 is elastically deformed, not the intermediate portion 521 but the two connecting portions 522 are elastically deformed, so that the width of the core member 500 is reduced. For this reason, the intermediate portion 521 that is not necessary for elastically deforming the connecting portion 520 is made thicker than the two connecting portions 522 necessary for elastically deforming the connecting portion 520, thereby eliminating the need for the connecting portion 520. Therefore, the connecting portion 520 can be effectively elastically deformed.

  Further, since the winding shaft 600 is inserted into the non-circular opening 511 formed in the winding shaft attachment portion 510 of the core material 500, when winding the electrode around the core material 500 by rotating the winding shaft 600. The core material 500 can be fixed to the winding shaft 600. For this reason, when the electrode body 400 is formed, it is possible to further reduce the occurrence of sagging and wrinkles in the electrode body 400, and to suppress the deterioration of the performance of the power storage element 10.

  In addition, according to the method for manufacturing power storage element 10 according to the embodiment of the present invention, before winding the electrode, core material 500 is elastically deformed to reduce the width of core material 500, thereby reducing the width of core material 500. The electrode body 400 is formed by winding an electrode around the core material 500 in a state of being deformed to a small extent. That is, the core material 500 is elastically deformed in advance so that the width of the core material 500 is reduced, and the electrode is wound while maintaining the elastically deformed state. Thus, the core member 500 can be wound in a state where no force to spread outward is generated, and after the winding, the core member 500 can be caused to generate force to spread outward. For this reason, since the outward force is applied to the positive electrode 410, the negative electrode 420, and the separator 430 wound around the core material 500 after winding, the occurrence of sagging and wrinkles in the electrode body 400 is reduced, A decrease in the performance of the power storage element 10 can be suppressed.

  Further, in the method for manufacturing the electricity storage device 10, after the winding shaft 600 is attached to the two winding shaft attachment portions 510, the connecting portion 520 is elastically deformed by changing the positional relationship between the two winding shaft attachment portions 510. The core material 500 is deformed to have a small width. In other words, the positional relationship between the two winding shaft attachment portions 510 can be changed by changing the positional relationship between the two plate-like members 610 of the winding shaft 600 attached to the two winding shaft attachment portions 510. The connecting portion 520 can be elastically deformed and the width of the core material 500 can be changed small.

(Modification 1)
Next, Modification 1 of the present embodiment will be described. In the above embodiment, the core material 500 has an S-shape, but in this modification, the core material has an O-shape.

  FIG. 10 is a diagram showing a configuration of a core material 500a according to the first modification of the embodiment of the present invention. Specifically, this figure is a plan view when the core member 500a is viewed from the X axis plus side.

  As shown in the figure, the core member 500a has two winding shaft attachment portions 510a and a connecting portion 520a that connects the two winding shaft attachment portions 510a. The two winding shaft attachment portions 510a are arranged in a direction intersecting with the longitudinal direction and the short direction of the core material 500a, and the opening portion into which the plate-like member 610 of the winding shaft 600 is inserted, as in the above embodiment. 511a is formed.

  Further, the connecting portion 520a has two connecting portions 522a, but does not have an intermediate portion between the two connecting portions 522a as in the above embodiment. That is, each of the two connection portions 522a has one end connected to one winding shaft attachment portion 510a and the other end connected to another winding shaft attachment portion 510a. Thereby, the core material 500a forms an O-shaped shape as a whole.

  As in the above embodiment, the connecting portion 520a can be deformed to have a small width in the direction intersecting the winding axis of the core member 500a by elastic deformation by changing the positional relationship between the two winding shaft attachment portions 510a. Is formed. Specifically, the connecting portion 520a is formed such that the width in the Y-axis direction of the core member 500a can be reduced and reduced by reducing the distance between the two winding shaft attachment portions 510a by elastic deformation. That is, the connecting portion 520a is in a state where the positive electrode 410, the negative electrode 420, and the separator 430 are wound around the core material 500a, and more than in a state where the positive electrode 410, the negative electrode 420, and the separator 430 are not wound around the core material 500a. The core material 500a is elastically deformed so that the width in the Y-axis direction becomes small.

  Specifically, from the state of (a) in the figure, the two connecting parts 522a of the connecting part 520a are elastically deformed so that the respective inner spaces become smaller, so that in (b) of the figure. As in the state, the inner space of the core member 500a is reduced, and the width of the core member 500a in the Y-axis direction is reduced.

  Since other configurations are the same as the configurations in the above-described embodiment, the description thereof is omitted. As mentioned above, according to the electrical storage element which concerns on the modification 1 of embodiment of this invention, there exists an effect similar to the said embodiment.

(Modification 2)
Next, a second modification of the present embodiment will be described. In the first modification of the above embodiment, the core material 500 has an O-shape, but in this modification, the core material has a C-shape.

  FIG. 11 is a diagram illustrating a configuration of a core material 500b according to the second modification of the embodiment of the present invention. Specifically, this figure is a plan view when the core member 500b is viewed from the X axis plus side.

  As shown in the figure, the core member 500b has two winding shaft attachment portions 510b, a connecting portion 520b that connects the two winding shaft attachment portions 510b, and a connection portion 523b. Here, the connecting portion 520b has a connecting portion 522b.

  That is, the connecting portion 522b is a connecting portion that connects the two winding shaft attachment portions 510b, and one end is connected to one winding shaft attachment portion 510b and the other end is connected to another winding shaft attachment portion 510b. For this reason, the connection part 522b is made so that the width (width in the Y-axis direction) of the core material 500b is reduced by the process of deforming the core material 500b (core material deformation process) from (a) to (b) in FIG. Transformed into Further, only one end of the connecting portion 523b is connected to one winding shaft attaching portion 510b, and the connecting portion 523b has a shape spreading outward (Y-axis direction plus side) even after the core material deforming step.

  As described above, the core member 500b has a shape such that one connection portion 522a of the O-shaped core member 500a in the first modification is separated from one winding shaft attachment portion 510a. Thereby, the core material 500b forms a C-shape as a whole. Other configurations are the same as those in the above-described embodiment or modification 1, and detailed description thereof is omitted.

  As mentioned above, according to the electrical storage element which concerns on the modification 2 of embodiment of this invention, the effect similar to the said embodiment is show | played. In this modification, the width of the core material 500b is deformed small in both the Y-axis direction and the Z-axis direction as in the above-described embodiment, so that the Y-axis and the Z-axis as shown in FIG. An outward force directed in both directions can be generated.

(Modification 3)
Next, a third modification of the present embodiment will be described. In the above embodiment, the core material 500 has a vertical S shape, but in this modification, the core material has a horizontal S shape.

  FIG. 12 is a diagram showing a configuration of a core material 500c according to the third modification of the embodiment of the present invention. Specifically, this figure is a plan view when the core member 500c is viewed from the X axis plus side.

  As shown in the figure, the core member 500c has two winding shaft attachment portions 510c and a connecting portion 520c that connects the two winding shaft attachment portions 510c. Here, the connecting portion 520c has an intermediate portion 521c extending in the Z-axis direction, and two connection portions 522c connected to both end portions of the intermediate portion 521c and the two winding shaft attachment portions 510c. The intermediate portion 521c is formed so as to be thicker than the two connecting portions 522c. Thereby, the core material 500c forms a laterally-shaped S shape as a whole.

  As in the above embodiment, the distance between the two plate-like members 610 of the winding shaft 600 inserted into the opening 511c formed in the winding shaft attachment portion 510c is reduced, and the elastic deformation of the connecting portion 520c is performed. Thus, by reducing the distance between the two winding shaft attachment portions 510c, the width (width in the Y-axis direction) in the direction intersecting the winding shaft of the core member 500c is reduced. Since other configurations are the same as the configurations in the above-described embodiment, detailed description is omitted.

  In the figure, the two openings 511c are arranged in the short direction (Y-axis direction) of the core member 500c, but are arranged in a direction intersecting the longitudinal direction and the short direction of the core member 500c. It doesn't matter. In this case, by reducing the distance between the two plate-like members 610 and reducing the distance between the two openings 511c, the width of the core member 500c in the Y-axis direction and the Z-axis direction can be reduced. Can do.

  As mentioned above, according to the electrical storage element which concerns on the modification 3 of embodiment of this invention, the effect similar to the said embodiment is show | played.

(Modification 4)
Next, Modification 4 of the present embodiment will be described. In the first modification of the above embodiment, the connecting portion 520a of the core member 500a has two connecting portions 522a. However, in the present modified example, the connecting portion has three connecting portions. ing.

  FIG. 13 is a diagram showing a configuration of a core material 500d according to Modification 4 of the embodiment of the present invention. Specifically, this figure is a plan view when the core material 500d is viewed from the X axis plus side.

  As shown in the figure, the core member 500d has two winding shaft attachment portions 510d and a connecting portion 520d that connects the two winding shaft attachment portions 510d. The connecting portion 520d includes two connecting portions 522d and one connecting portion 523d as three connecting portions. That is, the connecting portion 520d includes a connecting portion 523d in addition to the two connecting portions 522d similar to the connecting portion 522a included in the connecting portion 520a in the first modification.

  Here, the connecting portion 523d is disposed at a position sandwiched between two winding shaft attachment portions 510d, one end is connected to one winding shaft attachment portion 510d, and the other end is connected to the other winding shaft attachment portion 510d. It is a member having elasticity. The connecting portion 523d is a member that generates an outward force when contracted, such as a spring. The material of the connection portion 523d is not particularly limited, and may be made of resin or metal.

  As described above, the connecting portion 520d intersects the winding axis of the core member 500d by reducing the distance between the two winding shaft attachment portions 510d by elastic deformation of the two connection portions 522d and the one connection portion 523d. The width in the direction is small and can be deformed.

  Specifically, from the state of (a) in the figure, the two connecting portions 522d are elastically deformed so that the respective inner spaces become smaller, and the connecting portion 523d is elastically deformed so as to shrink. As a result, as shown in the state of (b) in the figure, the internal space of the core material 500d is reduced, and the width of the core material 500d in the Y-axis direction is reduced and deformed. Since other configurations are the same as the configurations in the above-described embodiment, the description thereof is omitted.

  As mentioned above, according to the electrical storage element which concerns on the modification 4 of embodiment of this invention, there exists an effect similar to the said embodiment. In particular, in this modified example, since the connecting portion 520d has the connecting portion 523d in addition to the two connecting portions 522d, a strong force can be generated in the electrode body toward the outside of the core material 500d. Further, it is possible to further reduce the occurrence of sagging and wrinkles in the electrode body.

  In addition, when the connection part 520d has the connection part 523d like this modification, the two connection parts 522d may be formed with the member which does not have elasticity.

  The power storage device according to the embodiment of the present invention and the modification thereof has been described above, but the present invention is not limited to this embodiment and the modification thereof. In other words, it should be considered that the embodiment and its modification disclosed this time are illustrative and not restrictive in all respects. 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.

  For example, in the above-described embodiment and the modification thereof, the connecting portion is formed so as to be deformable by reducing the width of the core material by reducing the distance between the two winding shaft attachment portions. However, if the position of the two winding shaft mounting portions can be changed without changing the distance between the two winding shaft mounting portions and the width of the core material can be reduced, the connecting portion can be mounted on two winding shafts. The configuration may not be such that the distance between the parts is reduced.

  Moreover, in the said embodiment and the modification 3, the intermediate part was formed so that thickness might become thicker than two connection parts. However, the intermediate portion may be formed so as to have the same thickness as the two connecting portions, or to be thinner than the two connecting portions.

  Moreover, in the said embodiment and its modification, it was supposed that the non-circular opening part was formed in the winding shaft attachment part. However, the cross-sectional shape of the opening of the winding shaft attachment portion may be a circular shape instead of a non-circular shape. However, in order to fix the core material to the winding shaft when the winding shaft is rotated and the electrode is wound around the core material, the opening of at least one winding shaft mounting portion is non-circular. preferable.

  Further, in the above-described embodiment and its modification, the opening of the winding shaft attachment portion is a through-hole, but the opening may not be a through-hole, such as a concave shape that is notched, Any shape can be used as long as the winding shaft can be inserted. Further, the winding shaft attachment portion may not have an opening as long as the winding shaft can be attached thereto.

  Moreover, in the said embodiment and its modification, it decided to provide two winding shaft attaching parts in a core material. However, the configuration is not limited to the configuration in which two winding shaft mounting portions are provided, and a configuration in which three or more winding shaft mounting portions are provided may be employed. In other words, the core material is attached to the winding shaft by three or more winding shaft mounting portions, and the core material has a connecting portion that connects two winding shaft mounting portions of the three or more winding shaft mounting portions. There may be at least one, and the connecting portion may have a configuration in which the width of the core member is reduced and deformable.

  Further, in the method of manufacturing the electricity storage device in the above embodiment, the winding shaft is attached to the two winding shaft attachment portions, the connecting portion is elastically deformed by changing the positional relationship between the two winding shaft attachment portions, and the core The width of the material was changed to be small. However, in the method for manufacturing the power storage element, the core material may be elastically deformed so that the width is reduced by using a member other than the winding shaft. For example, the width of the core material may be reduced by applying stress to the core material with an elastic member such as a clip.

  Moreover, in the manufacturing method of the electrical storage element in the above embodiment, two winding shafts can be obtained by changing the positional relationship between the two plate-like members of the winding shaft attached to the two winding shaft mounting portions of the core material. We decided to change the positional relationship of the mounting part. That is, the core material is attached to the winding shaft before the core material is deformed. However, the core material may be attached to the winding shaft in a state where the core material is deformed. For example, it is preferable to set the winding shaft in a predetermined position in advance and attach the winding shaft to the winding shaft in a state where the width of the core material is reduced.

  Moreover, in the manufacturing method of the electrical storage element in the said embodiment, the core material deformation | transformation process was performed before the winding process. However, the core material deformation process may be performed after a part of the winding process, and then the remaining winding process may be performed. That is, after partially winding the electrode around the core material, the winding shaft may be displaced to elastically deform the core material, and then the electrode may be further wound to form the electrode body.

  Moreover, the form constructed | assembled combining the said embodiment and the said modification arbitrarily is also contained in the scope of the present invention. For example, the modification 4 may be applied to the above-described embodiment, modification 2 or modification 3.

  In addition, the present invention can be realized not only as such a power storage element, but also as an electrode body included in the power storage element or a core material disposed on the innermost periphery of the electrode body.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a power storage element that can reduce sagging and wrinkles in an electrode body and suppress a decrease in performance.

DESCRIPTION OF SYMBOLS 10 Electric storage element 100 Container 110 Cover plate 120 Positive electrode collector 130 Negative electrode collector 200 Positive electrode terminal 300 Negative electrode terminal 400 Electrode body 410 Positive electrode 420 Negative electrode 430 Separator 500, 500a, 500b, 500c, 500d Core material 510, 510a, 510b, 510c, 510d Winding shaft mounting portion 511, 511a, 511c Opening portion 520, 520a, 520b, 520c, 520d Connecting portion 521, 521c Intermediate portion 522, 522a, 522b, 522c, 522d, 523b, 523d Connection portion 600 Winding shaft 610 Plate Shaped member

Claims (10)

A storage element comprising an electrode body formed by winding a positive electrode, a negative electrode, and a separator around a winding axis,
The electrode body includes a core material disposed on the innermost inner periphery of the wound positive electrode, the negative electrode, and the separator,
The core material is
Two winding shaft mounting portions to which a winding shaft for winding the positive electrode, the negative electrode, and the separator around the winding shaft to form the electrode body is mounted;
And having a connecting portion that has elasticity and connects the two winding shaft attachment portions,
The storage portion is formed so that a width in a direction intersecting the winding axis of the core material can be reduced and deformed by elastic deformation by changing a positional relationship between the two winding shaft attachment portions. In the state where the positive electrode, the negative electrode, and the separator are wound around the core material, the connecting portion has the core more than the state where the positive electrode, the negative electrode, and the separator are not wound around the core material. The power storage element according to claim 1, wherein the material is elastically deformed so that the width becomes small. The power storage device according to claim 1, wherein the connecting portion is formed so as to be deformable to reduce the width of the core member by reducing a distance between the two winding shaft attaching portions by elastic deformation. The two winding shaft attachment portions are arranged in a direction intersecting with a longitudinal direction and a short direction of the core material when the core material is viewed from a direction in which the winding shaft extends. The electrical storage element of any one of these. The connecting portion is
An intermediate portion disposed at a position sandwiched between the two winding shaft attachment portions;
Two connection portions connected to each of both end portions of the intermediate portion and each of the two winding shaft attachment portions;
The said intermediate part is formed so that thickness may become thicker than said two connection part, when the said core material is seen from the direction where the said winding axis extends. The electricity storage device described. At least one of the two winding shaft mounting portions has a non-circular opening into which the winding shaft is inserted when the core is viewed from the direction in which the winding shaft extends. The electricity storage device according to any one of claims 1 to 5. A core material disposed inside the innermost circumference of the wound positive electrode, negative electrode, and separator of an electrode body formed by winding a positive electrode, a negative electrode, and a separator around a winding axis. And
Two winding shaft mounting portions to which a winding shaft for winding the positive electrode, the negative electrode, and the separator around the winding shaft to form the electrode body is mounted;
A core member having elasticity and a connecting portion that connects the two winding shaft attachment portions, and that can be deformed to have a small width in a direction intersecting the winding shaft of the core material by elastic deformation. A method of manufacturing an electricity storage device comprising an electrode body formed by winding a positive electrode, a negative electrode, and a separator around a winding axis,
A core material deforming step of elastically deforming a core material to be disposed on the innermost periphery of the electrode body, and deforming the width of the core material in a direction intersecting the winding axis;
The electrode body is formed by winding the positive electrode, the negative electrode, and the separator around the core material in a state where the width of the core material is deformed to be small and no outward force is generated in the core material. and a winding step of,
And a step of generating an outward force on the core member after forming the electrode body . further,
Before the core material deforming step, a winding shaft attaching step for attaching a winding shaft for forming the electrode body by winding the positive electrode, the negative electrode and the separator around the winding shaft to the core material. The manufacturing method of the electrical storage element of Claim 8. In the winding shaft attaching step, the winding shaft is attached to two winding shaft attaching portions of the core material,
In the core material deformation step, by changing the positional relationship between the two winding shaft attachment portions, the connecting portion connecting the two winding shaft attachment portions is elastically deformed, and the width of the core material is deformed to be small. The manufacturing method of the electrical storage element of Claim 9.

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