Storage element

Abstract

To provide: a power storage element which allows improvement in energy density; and a manufacturing method of the power storage element.SOLUTION: A power storage element comprises: a positive electrode terminal; an electrode body; and a positive electrode collector 600 which connects the positive electrode terminal to the electrode body. The positive electrode collector 600 has: a terminal connection part 602 which is connected to the positive electrode terminal; an electrode connection part 603 which is connected to the electrode body in a first direction; and an intermediate part 604 which connects the terminal connection part 602 to the electrode connection part 603. The intermediate part 604 is disposed at a position overlapping the terminal connection part 602 when viewed from the first direction Z. The electrode connection part 603 and the terminal connection part 602 are disposed on one side of the intermediate part 604 in the first direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a power storage element including an electrode terminal, an electrode body, and a current collector connecting the electrode terminal and the electrode body, and a method for manufacturing the same.

Background Art

[0002] Conventionally, a power storage element including an electrode terminal, an electrode body, and a current collector connecting the electrode terminal and the electrode body has been widely known. In Patent Document 1, there are disclosed a secondary battery (power storage element) including an electrode terminal, a plurality of electrode plates (electrode bodies), and a plurality of laminated connection plates (current collectors) whose both ends are joined to the electrode terminal and the plurality of electrode plates and which electrically connect the electrode terminal and the plurality of electrode plates, and the plurality of laminated connection plates are folded in a meandering shape between the electrode terminal and the plurality of electrode plates.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described conventional power storage element, there is a risk of a decrease in energy density.

[0005] An object of the present invention is to provide a power storage element capable of improving energy density and a method for manufacturing the same.

Means for Solving the Problems

[0006] The power storage element according to one aspect of the present invention is a power storage element including an electrode terminal, an electrode body, and a current collector connecting the electrode terminal and the electrode body, wherein the current collector has a terminal connection portion connected to the electrode terminal, an electrode connection portion connected to the electrode body in a first direction, and an intermediate portion connecting the terminal connection portion and the electrode connection portion, the intermediate portion is disposed at a position overlapping the terminal connection portion when viewed from the first direction, and the electrode connection portion and the terminal connection portion are disposed on one side of the intermediate portion in the first direction.

[0007] The present invention can be realized not only as such a power storage element, but also as a current collector provided in the power storage element, a current collector and a regulating unit, or a manufacturing method thereof.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a power storage element or the like capable of improving the energy density.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Best Mode for Carrying Out the Invention

[0010] In the above conventional energy storage element, there is a risk of a decrease in energy density. That is, in the above conventional energy storage element, since the current collector is folded in a meandering shape and is configured to connect the electrode terminal and the electrode body, the electrode body is arranged at a position away from the electrode terminal. As a result, the size of the electrode body is restricted, leading to a decrease in energy density.

[0011] An energy storage element according to one aspect of the present invention is an energy storage element including an electrode terminal, an electrode body, and a current collector connecting the electrode terminal and the electrode body, wherein the current collector has a terminal connection portion connected to the electrode terminal, an electrode connection portion connected to the electrode body in a first direction, and an intermediate portion connecting the terminal connection portion and the electrode connection portion, the intermediate portion is arranged at a position overlapping the terminal connection portion when viewed from the first direction, and the electrode connection portion and the terminal connection portion are arranged on one side of the intermediate portion in the first direction.

[0012] According to this, in the energy storage element, the current collector has a terminal connection portion, an electrode connection portion, and an intermediate portion. The intermediate portion is arranged at a position overlapping the terminal connection portion when viewed from the first direction, and the electrode connection portion and the terminal connection portion are arranged on one side of the intermediate portion in the first direction. When the intermediate portion is arranged to overlap the terminal connection portion when viewed from the first direction, the electrode connection portion may be arranged away from the terminal connection portion in the first direction. If the electrode connection portion is arranged away from the terminal connection portion in the first direction, the electrode body will be arranged at a position away from the electrode terminal in the first direction, and the size of the electrode body will be restricted. Therefore, the electrode connection portion and the terminal connection portion are arranged on one side of the intermediate portion in the first direction. Thereby, the electrode body can be brought closer to the electrode terminal in the first direction, so that a larger electrode body can be arranged, and an improvement in energy density can be achieved.

[0013] The electrode connection portion may be arranged at a position not overlapping the terminal connection portion when viewed from the first direction.

[0014] According to this, in the current collector, the electrode connection portion is disposed at a position that does not overlap the terminal connection portion when viewed from the first direction. In this way, by disposing the electrode connection portion at a position that does not overlap the terminal connection portion when viewed from the first direction, the electrode connection portion can be brought closer to the terminal connection portion in the first direction. For this reason, since the electrode body can be brought closer to the electrode terminal in the first direction, a larger electrode body can be disposed, and the energy density can be improved.

[0015] The electrode connection portion is disposed in a second direction intersecting the first direction in the middle portion, and the middle portion may be connected to an end portion of the terminal connection portion in a third direction intersecting the first direction and the second direction.

[0016] According to this, in the current collector, the electrode connection portion is disposed in the second direction of the middle portion, and the middle portion is connected to the end portion of the terminal connection portion in the third direction. In this way, by disposing the electrode connection portion in the second direction of the middle portion, a portion of the electrode connection portion that does not overlap the middle portion when viewed from the first direction can be brought closer to the terminal connection portion in the first direction. For this reason, since the electrode body can be brought closer to the electrode terminal in the first direction, a larger electrode body can be disposed. By connecting the middle portion to the end portion of the terminal connection portion in the third direction, it may be easy to connect the electrode connection portion to the electrode body. Thereby, while facilitating the connection between the current collector and the electrode body, the energy density can be improved.

[0017] The middle portion has a bent portion bent or curved toward the electrode connection portion at a connection portion with the electrode connection portion, and the bent portion may be disposed at a position overlapping the terminal connection portion when viewed from the first direction.

[0018] According to this, in the current collector, the intermediate portion has a bent portion at the connection portion with the electrode connection portion, and the bent portion is disposed at a position overlapping the terminal connection portion. In this way, by overlapping the bent portion of the intermediate portion with the terminal connection portion, the intermediate portion is shaped to bend from the position of the terminal connection portion, so that the size of the electrode connection portion can be increased. Thereby, since the electrode body can be connected to a larger electrode connection portion, the electrode body and the current collector can be connected more stably.

[0019] Furthermore, at least one of the electrode connection portion and the intermediate portion may be provided with a restricting portion that restricts movement in a direction away from the terminal connection portion in the first direction.

[0020] According to this, the energy storage element includes a restricting portion that restricts at least one of the electrode connection portion and the intermediate portion of the current collector from moving away from the terminal connection portion in the first direction. In this way, by restricting at least one of the electrode connection portion and the intermediate portion from moving away from the terminal connection portion in the first direction, it is possible to suppress the electrode body from moving away from the electrode terminal in the first direction. Thereby, since the electrode body can be brought closer to the electrode terminal in the first direction, a larger electrode body can be arranged, and the energy density can be improved.

[0021] A method for manufacturing an energy storage element according to an aspect of the present invention is a method for manufacturing an energy storage element including an electrode terminal, an electrode body, and a current collector that connects the electrode terminal and the electrode body, wherein the current collector has a terminal connection portion connected to the electrode terminal, an electrode connection portion connected to the electrode body in a first direction, and an intermediate portion connecting the terminal connection portion and the electrode connection portion, and the method for manufacturing the energy storage element includes a bending step of bending the current collector so that the intermediate portion is disposed at a position overlapping the terminal connection portion when viewed from the first direction, and the electrode connection portion and the terminal connection portion are disposed on one side of the intermediate portion in the first direction.

[0022] According to this, in the method for manufacturing an energy storage element, in the bending step, the middle part of the current collector is arranged at a position overlapping the terminal connection part of the current collector, and the electrode connection part and the terminal connection part of the current collector are arranged on one side of the middle part in the first direction, and the current collector is bent. By arranging the electrode connection part on the one side of the middle part, the electrode body can be brought closer to the electrode terminal, so that a larger electrode body can be arranged and the energy density can be improved.

[0023] In the bending step, the current collector is bent in two steps in the order of the first bending step and the second bending step. In the first bending step, while supporting at least one of the electrode connection part and the middle part from both sides in the first direction, the terminal connection part is brought closer to the middle part. In the second bending step, while supporting at least one of the electrode connection part and the middle part from the side opposite to the terminal connection part in the first direction, the terminal connection part may be further brought closer to the middle part.

[0024] According to this, in the bending step, by bending the current collector in two steps in the order of the first bending step and the second bending step, the bending operation of the current collector can be efficiently performed. Thereby, it is possible to easily manufacture an energy storage element capable of improving the energy density.

[0025] Hereinafter, with reference to the drawings, an energy storage element according to an embodiment (and its modification) of the present invention will be described. Each of the embodiments described below shows comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are examples and are not intended to limit the present invention. In each figure, the dimensions and the like are not strictly illustrated.

[0026] In the following description and drawings, the arrangement direction of a pair of electrode terminals (positive electrode side and negative electrode side) of the energy storage element, the arrangement direction of a pair of current collectors, the arrangement direction of a pair of tab bundles of the electrode body, or the opposing direction of the short side surface of the container is defined as the X-axis direction. The opposing direction of the long side surface of the container, the short-side direction of the short side surface of the container, the thickness direction of the container, or the stacking direction of the electrode plates of the electrode body is defined as the Y-axis direction. The arrangement direction of the electrode terminal, the current collector, and the electrode body, the arrangement direction of the container body and the lid of the energy storage element, the longitudinal direction of the short side surface of the container, or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect (orthogonal in this embodiment) with each other. Depending on the usage mode, the Z-axis direction may not be the vertical direction, but hereinafter, for convenience of explanation, the Z-axis direction will be described as the vertical direction. In the following description, the plus side in the X-axis direction indicates the arrow direction side of the X-axis, and the minus side in the X-axis direction indicates the side opposite to the plus side in the X-axis direction. The same applies to the Y-axis direction and the Z-axis direction.

[0027] (Embodiment) [1 General description of the energy storage element] First, a general description of the energy storage element 10 in this embodiment will be given. FIG. 1 is a perspective view showing the appearance of the energy storage element 10 according to this embodiment. FIG. 2 is an exploded perspective view showing the energy storage element 10 according to this embodiment disassembled into its respective components.

[0028] The energy storage element 10 is a secondary battery that can charge and discharge electricity, and specifically, is a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. The energy storage element 10 is used as a battery for driving or starting an engine of a moving body such as an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), a motorcycle, a watercraft, a snowmobile, an agricultural machine, a construction machine, etc.

[0029] The energy storage element 10 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The energy storage element 10 may be a primary battery that is not a secondary battery and in which the electricity stored can be used without the user charging it. Further, the energy storage element 10 may be a battery using a solid electrolyte. In the present embodiment, a rectangular parallelepiped (square) energy storage element 10 is illustrated, but the shape of the energy storage element 10 is not limited to a rectangular parallelepiped shape, and may be a polygonal prism shape, a cylindrical shape, an elliptical cylindrical shape, etc. other than a rectangular parallelepiped shape, or may be a laminated energy storage element.

[0030] As shown in FIG. 1, the energy storage element 10 includes a container 100, a positive electrode terminal 200, a negative electrode terminal 210, a positive electrode upper gasket 300, and a negative electrode upper gasket 310. As shown in FIG. 2, inside the container 100, a positive electrode lower gasket 400, a negative electrode lower gasket 500, a positive electrode current collector 600, a negative electrode current collector 610, and an electrode body 700 are accommodated. Although an electrolytic solution (non-aqueous electrolyte) is enclosed inside the container 100, it is omitted from the illustration. The type of the electrolytic solution is not particularly limited as long as it does not impair the performance of the energy storage element 10, and various types can be selected. In addition to the above components, a spacer disposed on the side or above of the electrode body 700, or an insulating film that wraps the electrode body 700 or the like may be disposed.

[0031] The container 100 is a rectangular parallelepiped (box-shaped) case composed of a container body 110 having a rectangular cylindrical shape with a bottom and a lid body 120 which is a plate-like member that closes the opening of the container body 110. The container 100 has a configuration in which the inside can be sealed by welding or the like the container body 110 and the lid body 120 after accommodating the electrode body 700 and the like inside. The material of the container 100 is not particularly limited, but is preferably a weldable metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet.

[0032] The lid body 120 is provided with a gas discharge valve 121 for discharging the gas inside the container 100 when the internal pressure of the container 100 rises. The container 100 may be formed with a liquid injection part for injecting an electrolytic solution therein.

[0033] The electrode body 700 includes a positive electrode plate, a negative electrode plate, and a separator, and is a power storage element (power generation element) capable of storing electricity. The positive electrode plate has a flat and rectangular positive electrode current collector foil made of aluminum or an aluminum alloy, etc., and a positive electrode active material layer formed on the surface of the positive electrode current collector foil. The negative electrode plate has a flat and rectangular negative electrode current collector foil made of copper or a copper alloy, etc., and a negative electrode active material layer formed on the surface of the negative electrode current collector foil. As the positive electrode active material and the negative electrode active material used for the positive electrode active material layer and the negative electrode active material layer, any known material can be appropriately used as long as it is an active material capable of occluding and releasing lithium ions.

[0034] Both the positive electrode current collector foil and the negative electrode current collector foil have rectangular tabs protruding upward (the positive Z-axis direction side). By laminating a plurality of positive electrode plates and a plurality of negative electrode plates with a separator interposed therebetween, a plurality of tabs of both the positive electrode plate and the negative electrode plate are laminated. As a result, a positive electrode side tab bundle 710 and a negative electrode side tab bundle 720 are formed in the electrode body 700.

[0035] Although the positive electrode plate and the negative electrode plate are assumed to have a rectangular shape, the shapes of the positive electrode plate and the negative electrode plate are not limited to a rectangular shape, and may be a polygon other than a rectangular shape, an oblong shape, an oval shape, etc. The tabs of the positive electrode plate and the negative electrode plate are also not limited to a rectangular shape, and may be any shape such as a polygon other than a rectangular shape, a semi-circular shape, a semi-oval shape, a semi-elliptical shape, etc. The laminated positive electrode plate and negative electrode plate may be fixed by arranging insulating tapes around the electrode body 700 or on both sides in the X-axis direction and being sandwiched in the lamination direction (Y-axis direction). Or, the positive electrode plate and the negative electrode plate may be fixed in the lamination direction by heat pressing or the like.

[0036] The positive electrode terminal 200 is an electrode terminal that is electrically connected to the positive electrode plate of the electrode body 700 via the positive electrode current collector 600. The negative electrode terminal 210 is an electrode terminal that is electrically connected to the negative electrode plate of the electrode body 700 via the negative electrode current collector 610. That is, the positive electrode terminal 200 and the negative electrode terminal 210 are metal electrode terminals for leading out the electricity stored in the electrode body 700 to the external space of the energy storage element 10 and introducing electricity into the internal space of the energy storage element 10 to store electricity in the electrode body 700. The positive electrode terminal 200 and the negative electrode terminal 210 are connected to the positive electrode current collector 600 and the negative electrode current collector 610 by caulking or the like and are attached to the lid body 120.

[0037] Specifically, the positive electrode terminal 200 has a cylindrical shaft portion 201 (rivet portion) extending downward (negative side in the Z-axis direction). The shaft portion 201 is inserted into the circular through-hole 301 of the positive electrode upper gasket 300, the circular through-hole 123 of the lid body 120, the circular through-hole 401 of the positive electrode lower gasket 400, and the circular through-hole 601 of the positive electrode current collector 600 and is caulked. Thereby, the positive electrode terminal 200 is fixed to the lid body 120 together with the positive electrode upper gasket 300, the positive electrode lower gasket 400, and the positive electrode current collector 600. The same applies to the negative electrode side. The positive electrode terminal 200 and the negative electrode terminal 210 are formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0038] The positive electrode current collector 600 is a flat conductive member that electrically connects the positive electrode plate of the electrode body 700 and the positive electrode terminal 200. The negative electrode current collector 610 is a flat conductive member that electrically connects the negative electrode plate of the electrode body 700 and the negative electrode terminal 210. Specifically, the positive electrode current collector 600 is joined to the tab bundle 710 on the positive electrode side of the electrode body 700 by welding or the like and is joined to the positive electrode terminal 200 by caulking or the like as described above. The negative electrode current collector 610 is joined to the tab bundle 720 on the negative electrode side of the electrode body 700 by welding or the like and is joined to the negative electrode terminal 210 by caulking or the like as described above. The positive electrode current collector 600 is formed of aluminum or an aluminum alloy, etc., and the negative electrode current collector 610 is formed of copper or a copper alloy, etc.

[0039] The positive current collector 600 and the negative current collector 610 are disposed between the electrode body 700 and the lid 120 of the container 100. Specifically, the positive current collector 600 is disposed between the tab bundle 710 on the positive electrode side of the electrode body 700 and the positive lower gasket 400, and the negative current collector 610 is disposed between the tab bundle 720 on the negative electrode side of the electrode body 700 and the negative lower gasket 500. That is, the positive current collector 600 is disposed at a position sandwiching the positive lower gasket 400 with the lid 120, and the negative current collector 610 is disposed at a position sandwiching the negative lower gasket 500 with the lid 120. Details of the configurations of the positive current collector 600 and the negative current collector 610 will be described later.

[0040] The positive upper gasket 300 is a flat plate-shaped electrical insulating sealing member disposed between the lid 120 of the container 100 and the positive electrode terminal 200. The negative upper gasket 310 is a flat plate-shaped electrical insulating sealing member disposed between the lid 120 of the container 100 and the negative electrode terminal 210. Specifically, the positive upper gasket 300 is formed to cover the lower part and the side part of the positive electrode terminal 200, and the negative upper gasket 310 is formed to cover the lower part and the side part of the negative electrode terminal 210.

[0041] The positive lower gasket 400 is a flat plate-shaped electrical insulating sealing member disposed between the lid 120 and the positive current collector 600. The negative lower gasket 500 is a flat plate-shaped electrical insulating sealing member disposed between the lid 120 and the negative current collector 610.

[0042] The positive upper gasket 300, the negative upper gasket 310, the positive lower gasket 400, and the negative lower gasket 500 are formed of resins such as polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), polyethylene terephthalate (PET), polyether ether ketone (PEEK), tetrafluoroethylene·perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polybutylene terephthalate (PBT), polyethersulfone (PES), and composite materials thereof.

[0043] [Description of the Structures of the Positive Current Collector and the Negative Current Collector] Next, the structures of the positive current collector 600 and the negative current collector 610 will be described in detail. Since the positive current collector 600 and the negative current collector 610 have the same structure (a shape symmetric with respect to the YZ plane), hereinafter, the positive current collector 600 will be described in detail, and the description of the negative current collector 610 will be simplified or omitted.

[0044] FIG. 3 is a perspective view and a front view showing the structure of the positive current collector 600 according to the present embodiment. Specifically, FIG. 3(a) is a perspective view of the positive current collector 600 as viewed obliquely from above, that is, an enlarged perspective view showing the positive current collector 600 shown in FIG. 2 in an enlarged manner. FIG. 3(b) is a front view of the positive current collector 600 in FIG. 3(a) as viewed from the minus side in the Y-axis direction. FIG. 4 is a perspective view showing the connection structure of the positive current collector 600, the positive terminal 200, and the electrode body 700 according to the present embodiment. Specifically, FIG. 4(a) is a perspective view of the structure when the terminal connection portion 602 of the positive current collector 600 and the positive terminal 200 are connected, as viewed obliquely from below. FIG. 4(b) is a perspective view of the structure when the electrode connection portion 603 of the positive current collector 600 and the tab bundle 710 of the electrode body 700 are connected, as viewed obliquely from below. In FIG. 4(b), for convenience of explanation, the electrode body 700 is shown with omission.

[0045] The positive current collector 600 is a member having one end connected to the positive terminal 200 and the other end connected to the electrode body 700. Specifically, as shown in FIG. 3, the positive current collector 600 has a terminal connection portion 602 connected to the positive terminal 200, an electrode connection portion 603 connected to the electrode body 700, and an intermediate portion 604 disposed between the terminal connection portion 602 and the electrode connection portion 603. That is, a single L-shaped flat plate member is bent to form the positive current collector 600 having the terminal connection portion 602, the intermediate portion 604, and the electrode connection portion 603.

[0046] The terminal connection portion 602 is a rectangular and flat portion that is connected (joined) to the positive terminal 200 by caulking or the like, and is arranged parallel to the XY plane. That is, as described above, the terminal connection portion 602 has a through hole 601, and in a state facing in the Z-axis direction (hereinafter also referred to as the first direction), the shaft portion 201 of the positive terminal 200 is inserted into the through hole 601. As shown in Fig. 4(a), by caulking the end portion on the minus side in the Z-axis direction of the shaft portion 201, a caulked portion 201a is formed, and the positive terminal 200 and the terminal connection portion 602 are joined in the Z-axis direction. The method of connecting (joining) the terminal connection portion 602 and the positive terminal 200 is not limited to caulking, and welding such as ultrasonic welding, laser welding, resistance welding, or mechanical joining other than caulking such as screw fastening may be used.

[0047] Returning to Fig. 3, the electrode connection portion 603 is a rectangular and flat portion that is connected (joined) to the tab bundle 710 of the electrode body 700 by welding or the like, and is arranged parallel to the XY plane. Specifically, in a state where the intermediate portion 604 and the electrode connection portion 603 shown in Fig. 4(a) face in the Y-axis direction, the tab bundle 710 (not shown) of the electrode body 700 is joined by welding to the first electrode connection surface 603a, which is the surface on the plus side in the Y-axis direction of the electrode connection portion 603. Welding is performed with the tab bundle 710 sandwiched between the first electrode connection surface 603a and a backing plate (not shown). As shown in Fig. 4(b), the intermediate portion 604 and the electrode connection portion 603 are bent toward the minus side in the Y-axis direction. As a result, the first electrode connection surface 603a becomes the surface on the minus side in the Z-axis direction, and the electrode connection portion 603 is configured to be joined to the tab bundle 710 of the electrode body 700 in the Z-axis direction (the first direction) in a state facing in the Z-axis direction.

[0048] In other words, the tab bundle 710 of the electrode body 700 is joined to the first surface 603a of the electrode connection portion in a state of extending in the Z-axis direction, and after joining, it is bent in the Y-axis direction and extends in the Y-axis direction. As a method of connecting (joining) the electrode connection portion 603 and the tab bundle 710 of the electrode body 700, any welding such as ultrasonic welding, laser welding, resistance welding, etc. may be used, or mechanical joining such as caulking or screw fastening may be used.

[0049] Returning to FIG. 3, the intermediate portion 604 is a substantially rectangular and substantially flat portion that connects the terminal connection portion 602 and the electrode connection portion 603, and is arranged parallel to the XY plane. Specifically, the intermediate portion 604 is arranged on the minus side in the Z-axis direction of the terminal connection portion 602 and on the minus side in the X-axis direction of the electrode connection portion 603. That is, the intermediate portion 604 is arranged at a position overlapping the terminal connection portion 602 when viewed from the Z-axis direction (the first direction), and is arranged side by side with the electrode connection portion 603 in the X-axis direction. The intermediate portion 604 has a connection portion 605 with the terminal connection portion 602 and a connection portion 606 with the electrode connection portion 603.

[0050] The connection portion 605 is connected to the end portion on the plus side in the Y-axis direction of the terminal connection portion 602, and is curved so as to be convex on the plus side in the Y-axis direction, and is a portion having a U-shaped cross-sectional shape in the YZ plane. That is, as described above, the connection portion 605 is a bent portion formed by bending the intermediate portion 604 with respect to the terminal connection portion 602, and is formed to be thinner than other portions of the intermediate portion 604 and the terminal connection portion 602 so as to be easily bent. Specifically, the connection portion 605 is formed by bending the intermediate portion 604 with respect to the terminal connection portion 602 in the minus side in the Z-axis direction and the minus side in the Y-axis direction. As a result, the intermediate portion 604 is connected to the end portion on the plus side in the Y-axis direction (hereinafter, also referred to as the third direction) of the terminal connection portion 602 and is arranged on the minus side in the Z-axis direction of the terminal connection portion 602. The connection portion 605 may be a portion that is bent rather than curved.

[0051] The connection part 606 is connected to the minus-side end of the electrode connection part 603 in the X-axis direction, and is a part whose cross-sectional shape in the XZ plane is substantially S-shaped, inclined toward the minus side in the Z-axis direction toward the minus side in the X-axis direction. That is, the connection part 606 is an inclined part formed by bending the intermediate part 604 twice with respect to the electrode connection part 603 toward the minus side in the Z-axis direction and the minus side in the X-axis direction. As a result, the intermediate part 604 is arranged on the minus side in the X-axis direction and the minus side in the Z-axis direction of the electrode connection part 603.

[0052] In other words, the electrode connection part 603 is arranged on the plus side in the X-axis direction of the intermediate part 604 (hereinafter, also referred to as the second direction). Specifically, the electrode connection part 603 is arranged on the plus side in the X-axis direction with respect to the intermediate part 604 and the terminal connection part 602. That is, the electrode connection part 603 is arranged at a position that does not overlap the intermediate part 604 and the terminal connection part 602 when viewed from the Z-axis direction (the first direction). The electrode connection part 603 and the terminal connection part 602 are arranged on one side (the plus side in the Z-axis direction) of the intermediate part 604 in the Z-axis direction (the first direction). It can also be said that the electrode connection part 603 is arranged closer to the terminal connection part 602 side than the intermediate part 604 in the Z-axis direction (the first direction). That is, the electrode connection part 603 is arranged at a position closer to the terminal connection part 602 or the lid body 120 (or closer to the positive electrode lower gasket 400) than the intermediate part 604 in the Z-axis direction (the first direction). In the present embodiment, the electrode connection part 603 is arranged at the same position as the terminal connection part 602 in the Z-axis direction.

[0053] Specifically, the first electrode connection surface 603a, which is the surface on the minus side in the Z-axis direction of the electrode connection portion 603, is arranged on the plus side in the Z-axis direction rather than the first intermediate surface 604a, which is the surface on the minus side in the Z-axis direction of the intermediate portion 604. That is, the first electrode connection surface 603a is arranged on the same plane (at the same position in the Z-axis direction) as the first terminal connection surface 602a, which is the surface on the minus side in the Z-axis direction of the terminal connection portion 602. The second electrode connection surface 603b, which is the surface on the plus side in the Z-axis direction of the electrode connection portion 603, is arranged on the same plane (at the same position in the Z-axis direction) as the second terminal connection surface 602b, which is the surface on the plus side in the Z-axis direction of the terminal connection portion 602.

[0054] By arranging the electrode connection portion 603 on the minus side or the plus side in the Z-axis direction relative to the terminal connection portion 602, the first electrode connection surface 603a may be arranged on the minus side or the plus side in the Z-axis direction rather than the first terminal connection surface 602a. Alternatively, by having a different thickness for the electrode connection portion 603 compared to the terminal connection portion 602, the first electrode connection surface 603a may be arranged on the minus side or the plus side in the Z-axis direction rather than the first terminal connection surface 602a. Similarly, for the second electrode connection surface 603b, it may be arranged on the minus side or the plus side in the Z-axis direction rather than the second terminal connection surface 602b.

[0055] Next, the manufacturing method of the power storage element 10 (the bending process of the positive electrode current collector 600) will be described. FIG. 5 is a diagram for explaining the manufacturing method of the power storage element 10 (the bending process of the positive electrode current collector 600) according to the present embodiment. Specifically, FIG. 5(a) is a side view showing the state before bending the positive electrode current collector 600, FIG. 5(b) is a side view showing the state during the bending of the positive electrode current collector 600, and FIG. 5(c) is a side view showing the state after bending the positive electrode current collector 600. In the above, the Z-axis direction was also referred to as the first direction, but in the bending process of the positive electrode current collector 600 shown in FIG. 5, the Y-axis direction will also be referred to as the first direction. In FIG. 5, for convenience of explanation, the illustration of the positive electrode terminal 200, the positive electrode upper gasket 300, and the positive electrode lower gasket 400 is omitted, and the lid body 120, the positive electrode current collector 600, and the electrode body 700 are schematically shown.

[0056] As shown in FIG. 5(a), with the terminal connection portion 602, the electrode connection portion 603, and the intermediate portion 604 of the positive electrode current collector 600 being orthogonal to each other, the terminal connection portion 602 is joined to the lid body 120, and the electrode connection portion 603 is joined to the tab bundle 710 of the electrode body 700. In this state, as the first bending process, while supporting at least one of the electrode connection portion 603 and the intermediate portion 604 from both sides in the Y-axis direction (the first direction), the terminal connection portion 602 is brought closer to the intermediate portion 604. In the present embodiment, the intermediate portion 604 is pressed and supported by a jig or the like with a force F1 from both sides in the Y-axis direction. The terminal connection portion 602 is pushed in the negative Z-axis direction with a force F2, and by bending the connection portion 605, the terminal connection portion 602 is rotated around the connection portion 605 and brought closer to the intermediate portion 604. Instead of the intermediate portion 604, or in addition to the intermediate portion 604, the electrode connection portion 603 may be supported from both sides in the Y-axis direction.

[0057] In this way, as shown in Fig. 5(b), the connection portion 605 is bent so that the terminal connection portion 602 rotates about 50° to 70° until the springback amount caused by the connection portion 605 exceeds the peak, and the terminal connection portion 602 is brought closer to the intermediate portion 604. Then, as a second bending step, while at least one of the electrode connection portion 603 and the intermediate portion 604 is supported from the side opposite to the terminal connection portion 602 in the Y-axis direction (the first direction), the terminal connection portion 602 is further brought closer to the intermediate portion 604. In the present embodiment, the intermediate portion 604 is pressed and supported by a jig or the like with a force F3 from the plus side in the Y-axis direction. By pressing the terminal connection portion 602 toward the plus side in the Y-axis direction with a force F4 and further bending the connection portion 605, the terminal connection portion 602 is rotated about the connection portion 605 and further brought closer to the intermediate portion 604. Instead of the intermediate portion 604, or in addition to the intermediate portion 604, the electrode connection portion 603 may be supported from the plus side in the Y-axis direction.

[0058] As a result, as shown in Fig. 5(c), the terminal connection portion 602 is in a state facing in the Y-axis direction (facing the Y-axis direction), in other words, in a state parallel to the electrode connection portion 603 and the intermediate portion 604. In this state, the intermediate portion 604 is arranged at a position overlapping the terminal connection portion 602 when viewed from the Y-axis direction, and the electrode connection portion 603 and the terminal connection portion 602 are arranged on one side (the minus side in the Y-axis direction) of the intermediate portion 604 in the Y-axis direction. That is, in the bending step, the positive current collector 600 is bent in two steps in the order of the first bending step and the second bending step. In this bending step, the positive current collector 600 is bent so that the intermediate portion 604 is arranged at a position overlapping the terminal connection portion 602 when viewed from the Y-axis direction (the first direction), and the electrode connection portion 603 and the terminal connection portion 602 are arranged on one side (the minus side in the Y-axis direction) of the intermediate portion 604 in the Y-axis direction (the first direction). It can also be said that the positive current collector 600 is bent so that the electrode connection portion 603 is arranged on the terminal connection portion 602 side rather than the intermediate portion 604 side in the Y-axis direction (the first direction).

[0059] After that, the positive electrode current collector 600 is tilted together with the lid body 120 to the plus side in the Y-axis direction (the tab bundle 710 is bent), and assumes a state facing in the Z-axis direction (facing the Z-axis direction) as shown in FIG. 4(b). Thus, since the positive electrode current collector 600 changes from the state facing in the Y-axis direction to the state facing in the Z-axis direction, the definition of the first direction also changes from the Y-axis direction to the Z-axis direction. The above-described forces F1 to F4 may be any values as long as the positive electrode current collector 600 can be bent as described above, and are appropriately determined according to the material of the positive electrode current collector 600 and the like.

[0060] [Explanation of Effects] As described above, according to the power storage element 10 according to the embodiment of the present invention, the positive electrode current collector 600 has a terminal connection portion 602, an electrode connection portion 603, and an intermediate portion 604. The intermediate portion 604 is disposed at a position overlapping the terminal connection portion 602 when viewed from the first direction (Z-axis direction), and the electrode connection portion 603 and the terminal connection portion 602 are disposed on one side of the intermediate portion 604 in the first direction. When the intermediate portion 604 is disposed so as to overlap the terminal connection portion 602 when viewed from the first direction, the electrode connection portion 603 may be disposed away from the terminal connection portion 602 in the first direction. If the electrode connection portion 603 is disposed away from the terminal connection portion 602 in the first direction, the electrode body 700 will be disposed at a position away from the positive electrode terminal 200 in the first direction, and the size of the electrode body 700 will be limited. Therefore, the electrode connection portion 603 and the terminal connection portion 602 are disposed on one side of the intermediate portion 604 in the first direction. Thereby, since the electrode body 700 can be brought closer to the positive electrode terminal 200 in the first direction, a larger electrode body 700 can be disposed, and the energy density can be improved.

[0061] In the positive current collector 600, the electrode connection portion 603 is disposed at a position that does not overlap with the terminal connection portion 602 when viewed from the first direction. By disposing the electrode connection portion 603 at a position that does not overlap with the terminal connection portion 602 when viewed from the first direction, the electrode connection portion 603 can be brought closer to the terminal connection portion 602 in the first direction. For this reason, since the electrode body 700 can be brought closer to the positive electrode terminal 200 in the first direction, a larger electrode body 700 can be disposed, and the energy density can be improved.

[0062] In the positive current collector 600, the electrode connection portion 603 is disposed in the second direction (the positive X-axis direction) of the intermediate portion 604, and the intermediate portion 604 is connected to the end portion of the terminal connection portion 602 in the third direction (the positive Y-axis direction). By disposing the electrode connection portion 603 in the second direction of the intermediate portion 604 in this way, the portion of the electrode connection portion 603 that does not overlap with the intermediate portion 604 when viewed from the first direction can be brought closer to the terminal connection portion 602 in the first direction. For this reason, the electrode body 700 can be brought closer to the positive electrode terminal 200 in the first direction.

[0063] By connecting the intermediate portion 604 to the end portion of the terminal connection portion 602 in the third direction, the electrode connection portion 603 can be easily connected to the electrode body 700. That is, when the intermediate portion 604 is connected to the end portion on the minus side in the X-axis direction of the terminal connection portion 602, when connecting the tab bundle 710 of the electrode body 700 to the electrode connection portion 603 in a state where the intermediate portion 604 is opened at 90° in an L shape with respect to the terminal connection portion 602, it is necessary to twist the tab bundle 710 by 90°. On the other hand, by connecting the intermediate portion 604 to the end portion of the terminal connection portion 602 in the third direction, it is not necessary to twist the tab bundle 710 by 90° even when the intermediate portion 604 is opened with respect to the terminal connection portion 602, so the tab bundle 710 can be easily connected to the electrode connection portion 603. Thereby, while facilitating the connection between the current collector 600 and the electrode body 700, a larger electrode body 700 can be disposed, and the energy density can be improved.

[0064] The positive current collector 600 has a structure in which a plate-shaped member is bent, and the position of the electrode connection portion 603 with respect to the terminal connection portion 602 can be moved somewhat arbitrarily via the intermediate portion 604. For this reason, since the degree of freedom in the position of the electrode connection portion 603 is high, the connection between the electrode connection portion 603 and the electrode body 700 can be easily made. Further, since the electrode connection portion 603 can be brought closer to the electrode body 700, the protruding length of the tab bundle 710 can be shortened. When the protruding length of the tab bundle 710 can be shortened, the space occupied by the tab bundle 710 in the container 100 is reduced, so that a larger electrode body 700 can be arranged and the energy density can be improved.

[0065] In the manufacturing method of the energy storage element 10, in the bending step, the intermediate portion 604 of the positive current collector 600 is arranged at a position overlapping the terminal connection portion 602 of the positive current collector 600, and the electrode connection portion 603 and the terminal connection portion 602 of the positive current collector 600 are arranged on one side of the intermediate portion 604 in the first direction, and the positive current collector 600 is bent. By arranging the electrode connection portion 603 on the one side of the intermediate portion 604, the electrode body 700 can be brought closer to the positive terminal 200, so that a larger electrode body 700 can be arranged and the energy density can be improved.

[0066] In the bending step, by bending the positive current collector 600 in two steps in the order of the first bending step and the second bending step, the bending operation of the positive current collector 600 can be efficiently performed. Thereby, it is possible to easily manufacture the energy storage element 10 capable of improving the energy density.

[0067] In the above, the effects of the configuration on the positive electrode side (positive current collector 600 side) have been described, but the same effects are exhibited for the configuration on the negative electrode side (negative current collector 610 side). The same applies hereinafter.

[0068] [Description of Modification Example 4] (Modification Example 1) Next, a modification example 1 of the above embodiment will be described. FIG. 6 is a perspective view showing a connection configuration of the positive electrode current collector 600, the positive electrode terminal 200, and the electrode body 700 according to the modification example 1 of the present embodiment. Specifically, FIG. 6(a) corresponds to FIG. 4(a), and FIG. 6(b) corresponds to FIG. 4(b).

[0069] As shown in FIG. 6, in this modification example, instead of the positive electrode lower gasket 400 in the above embodiment, a positive electrode lower gasket 400a is arranged. Specifically, the positive electrode lower gasket 400a in this modification example has a restricting portion 403 in addition to the configuration of the positive electrode lower gasket 400 in the above embodiment. Other configurations are the same as those in the above embodiment.

[0070] The restricting portion 403 is a portion that restricts at least one of the electrode connection portion 603 and the intermediate portion 604 of the positive electrode current collector 600 from moving in the Z-axis direction (first direction) away from the terminal connection portion 602 (the minus side of the Z-axis direction).

[0071] Specifically, as shown in FIG. 6(a), the restricting portion 403 is provided on the minus-side surface in the Z-axis direction of the plus-side portion in the X-axis direction of the positive electrode lower gasket 400a, and is a protrusion (claw) protruding toward the minus side in the X-axis direction. As shown in FIG. 6(b), when the electrode connection portion 603 and the intermediate portion 604 are bent with respect to the terminal connection portion 602, the restricting portion 403 is arranged on the minus side in the Z-axis direction of the plus-side end portion of the electrode connection portion 603 in the X-axis direction. Thereby, the restricting portion 403 engages with the plus-side end portion of the electrode connection portion 603 in the X-axis direction, and restricts the electrode connection portion 603 from moving in the Z-axis direction (first direction) away from the terminal connection portion 602 (the minus side of the Z-axis direction).

[0072] The restricting portion 403 may be arranged at the plus-side or minus-side end portion of the electrode connection portion 603 in the Y-axis direction, or may be arranged at the minus-side end portion of the intermediate portion 604 in the X-axis direction or Y-axis direction. Alternatively, the positive electrode lower gasket 400a may have a plurality of restricting portions 403 arranged at any of these end portions.

[0073] From the perspective of effectively restricting the movement of the electrode connection portion 603, etc., the restricting portion 403 is preferably disposed at the end portion on the plus side in the X-axis direction or the minus side in the Y-axis direction of the electrode connection portion 603. From the perspective of suppressing damage to the tab bundle 710 joined to the electrode connection portion 603, etc., the restricting portion 403 is preferably disposed at the end portion on the minus side in the X-axis direction or the minus side in the Y-axis direction of the intermediate portion 604. From the perspective of effectively suppressing the opening of the electrode connection portion 603 and the intermediate portion 604 with respect to the terminal connection portion 602, etc., the restricting portion 403 is preferably disposed at the end portion on the minus side in the Y-axis direction of the electrode connection portion 603 or the end portion on the minus side in the Y-axis direction of the intermediate portion 604.

[0074] As described above, according to the energy storage element according to this modification example, the same effects as those of the above-described embodiment can be achieved. In particular, the positive electrode lower gasket 400a includes a restricting portion 403 that restricts at least one of the electrode connection portion 603 and the intermediate portion 604 of the positive electrode current collector 600 from moving away from the terminal connection portion 602 in the first direction (Z-axis direction). In this way, by restricting at least one of the electrode connection portion 603 and the intermediate portion 604 from moving away from the terminal connection portion 602 in the first direction, it is possible to suppress the electrode body 700 from moving away from the positive electrode terminal 200 in the first direction. In particular, since the positive electrode current collector 600 has a structure in which the plate-like member is bent at the connection portion 605, due to the springback caused by the connection portion 605, the electrode connection portion 603 and the intermediate portion 604 are likely to move in a direction away from the terminal connection portion 602. For this reason, the significance of restricting at least one of the electrode connection portion 603 and the intermediate portion 604 from moving away from the terminal connection portion 602 by the restricting portion 403 is particularly great. Thereby, since the electrode body 700 can be brought closer to the positive electrode terminal 200 in the first direction, a larger electrode body 700 can be arranged, and the energy density can be improved.

[0075] The restricting part 403 does not have to be a protrusion that engages with at least one of the electrode connection part 603 and the intermediate part 604, and may be a fitting part that fits with at least one of the electrode connection part 603 and the intermediate part 604. The restricting part 403 may be provided not on the lower positive electrode gasket 400a but on the terminal connection part 602, the lid body 120, or the caulking part 201a or the like. The restricting part 403 may be an adhesive or double-sided tape that adheres at least one of the electrode connection part 603 and the intermediate part 604 to the terminal connection part 602 or the lower positive electrode gasket 400a or the like, a joining part that caulks and joins, a fastening part that screws and fastens, a welding part that welds and joins, a welding part that welds and adheres, or the like.

[0076] (Modification Example 2) Next, Modification Example 2 of the above-described embodiment will be described. FIG. 7 is a perspective view and a front view showing the configuration of the positive electrode current collector 600a according to Modification Example 2 of the present embodiment. Specifically, FIG. 7(a) is a perspective view when the positive electrode current collector 600a is in an open state, that is, when viewed obliquely downward from the state shown in FIG. 4(a). FIG. 7(b) is a front view when the positive electrode current collector 600a is in a closed state, that is, when viewed from the front in the state shown in FIG. 4(b), and corresponds to FIG. 3(b).

[0077] As shown in FIG. 7(a), unlike the positive electrode current collector 600 in the above-described embodiment, the positive electrode current collector 600a in this modification has a recess 607 that is recessed toward the negative side in the X-axis direction at the connection location with the terminal connection part 602 of the intermediate part 604. As a result, the connection portion 605a in this modification is shorter in length in the X-axis direction than the connection portion 605 in the above-described embodiment. That is, in this modification, the connection portion 606 and the electrode connection part 603 are arranged on the negative side in the X-axis direction more than in the above-described embodiment.

[0078] With such a configuration, the bent portions 606a and 606b of the connection portion 606 are also arranged on the minus side in the X-axis direction. As shown in Fig. 7(b), the bent portion 606a is arranged at a position overlapping the terminal connection portion 602 when viewed from the Z-axis direction (the first direction). The bent portions 606a and 606b are portions bent or curved from the intermediate portion 604 toward the electrode connection portion 603 in the connection portion 606. That is, the bent portion 606a is the curved portion on the minus side in the X-axis direction of the connection portion 606, and the bent portion 606b is the curved portion on the plus side in the X-axis direction of the connection portion 606. Other configurations are the same as those in the above embodiment.

[0079] As described above, according to the energy storage element according to this modification, the same effects as those in the above embodiment can be achieved. In particular, in the positive electrode current collector 600a, the intermediate portion 604 has a bent portion 606a at the connection portion 606 with the electrode connection portion 603, and the bent portion 606a is arranged at a position overlapping the terminal connection portion 602. In this way, by overlapping the bent portion 606a of the intermediate portion 604 with the terminal connection portion 602, the intermediate portion 604 has a shape bent from the position of the terminal connection portion 602, so that the size of the electrode connection portion 603 can be increased. As a result, the electrode body 700 can be connected to a larger electrode connection portion 603, so that the electrode body 700 and the positive electrode current collector 600 can be connected more stably. In this modification, when the electrode connection portion 603 is made the same size as in the above embodiment, the positive electrode current collector 600a can be miniaturized, so that space can be saved.

[0080] In this modified example, by arranging the electrode connection part 603 to move slightly in the minus Z-axis direction and further move in the minus X-axis direction, the bending part 606b can also be arranged at a position overlapping the terminal connection part 602 when viewed from the Z-axis direction. Until the electrode connection part 603 is arranged at a position overlapping the terminal connection part 602 when viewed from the Z-axis direction, the electrode connection part 603 can be further moved in the minus X-axis direction. Further, by moving the intermediate part 604 slightly in the minus Z-axis direction, until the electrode connection part 603 is arranged at a position overlapping the intermediate part 604 when viewed from the Z-axis direction, the electrode connection part 603 can be further moved in the minus X-axis direction. In these cases, since the electrode connection part 603 or the intermediate part 604 moves slightly in the minus Z-axis direction, the size of the electrode body 700 may be somewhat limited, but the size of the electrode connection part 603 can be further increased or space saving in the X-axis direction can be further achieved.

[0081] (Other modified examples) As described above, the energy storage element according to the embodiment and its modified examples of the present invention has been described. However, the present invention is not limited to this embodiment and its modified examples. That is, the disclosed embodiment and its modified examples are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, and all changes within the meaning and scope equivalent to the claims are included. Hereinafter, the positive current collector will be described, but the same applies to the negative current collector 610.

[0082] In the above embodiment and its modified examples, the electrode connection parts 603 of the positive current collectors 600 and 600a are bent toward the terminal connection part 602 after being joined to the tab bundle 710 of the electrode body 700. However, the electrode connection part 603 may be joined to the tab bundle 710 in a bent state.

[0083] In the above-described embodiments and their modified examples, it was assumed that the connection portions 605 and 605a of the intermediate portions 604 of the positive electrode current collectors 600 and 600a are connected to the plus-side end portion in the Y-axis direction of the terminal connection portion 602. However, the connection portions 605 and 605a may be connected to the minus-side end portion in the Y-axis direction or the minus-side end portion in the X-axis direction of the terminal connection portion 602. However, when the intermediate portion 604 is connected to the minus-side end portion in the X-axis direction of the terminal connection portion 602, it may be difficult to connect the tab bundle 710 of the electrode body 700 to the electrode connection portion 603 as described above. Therefore, the connection portions 605 and 605a are preferably connected to the plus-side end portion or the minus-side end portion in the Y-axis direction of the terminal connection portion 602.

[0084] In the above-described embodiments and their modified examples, a recess or a through-hole in which the caulking portion 201a is disposed inward may be formed in the intermediate portion 604 of the positive electrode current collectors 600 and 600a. Thereby, since the intermediate portion 604 can be brought closer to the terminal connection portion 602, a larger electrode body 700 can be arranged, and the energy density can be improved.

[0085] In the above-described embodiments and their modified examples, it was assumed that the electrode body 700 is a stacked-type electrode body in which a plurality of flat plate-shaped electrode plates are stacked. However, the shape of the electrode body 700 is not particularly limited, and the electrode body 700 may be a wound-type electrode body formed by winding a layered structure in which a separator is sandwiched between a positive electrode plate and a negative electrode plate. The electrode body 700 may be a bellows-type electrode body in which the electrode plate is folded in a bellows shape. The number of electrode bodies 700 is not limited to one, and two or more may be provided.

[0086] In the above-described embodiments and their modified examples, it was assumed that both the positive electrode side (the positive electrode current collector 600, 600a side) and the negative electrode side (the negative electrode current collector 610 side) have the above-described configuration. However, it is not necessary for the positive electrode side or the negative electrode side to have the above-described configuration.

[0087] A form constructed by arbitrarily combining the above-described embodiments and the above-described modified examples is also included within the scope of the present invention.

[0088] The present invention can be realized not only as such a power storage element, but also as a current collector (positive electrode current collector, negative electrode current collector) provided in the power storage element, or as the current collector and the restricting portion 403.

Industrial Applicability

[0089] The present invention can be applied to power storage elements such as lithium ion secondary batteries.

Explanation of Signs

[0090] 10 Power storage element 200 Positive electrode terminal 201 Shaft portion 201a Caulked portion 210 Negative electrode terminal 400, 400a Positive electrode lower gasket 403 Restricting portion 500 Negative electrode lower gasket 600, 600a Positive electrode current collector 602 Terminal connection portion 602a First surface of terminal connection portion 602b Second surface of terminal connection portion 603 Electrode connection portion 603a First surface of electrode connection portion 603b Second surface of electrode connection portion 604 Intermediate portion 604a First surface of intermediate portion 605, 605a, 606 Connection portion 606a, 606b Bent portion 610 Negative electrode current collector 700 Electrode body 710, 720 Tab bundle

Claims

1. An electric storage element including an electrode terminal, an electrode body, and a current collector connecting the electrode terminal and the electrode body, The current collector is a terminal connection portion connected to the electrode terminal; an electrode connection portion connected to the electrode assembly in a first direction that is an arrangement direction of the current collector and the electrode assembly; an intermediate portion connecting the terminal connection portion and the electrode connection portion; the intermediate portion is disposed at a position overlapping the terminal connection portion when viewed from the first direction, the intermediate portion has a first intermediate portion surface on an opposite side to a surface of the intermediate portion facing the terminal connection portion, a connection position between the electrode body and the electrode connection portion is located on an opposite side of the electrode body in the first direction from the first surface of the intermediate portion; Energy storage element.

2. The terminal connection portion has a terminal connection portion second surface on an opposite side of a surface of the terminal connection portion facing the intermediate portion, the connection position is located between the first surface of the intermediate portion and the second surface of the terminal connection portion in the first direction; The energy storage element according to claim 1 .

3. The electrode body includes a tab, The tab is connected to the electrode connection portion. The energy storage element according to claim 1 or 2.

4. The tab is connected to a surface of the electrode connection portion facing the electrode body. The energy storage element according to claim 3 .

5. The tab is disposed at a position not overlapping with the intermediate portion when viewed from the first direction. The energy storage element according to claim 3 or 4.

Images