JP7024286B2 - Power storage element - Google Patents

Description

The present invention relates to a power storage element including an electrode body and a current collector.

Conventionally, a power storage element having an electrode body and a current collector and having a current collector connected to the electrode body is widely known. For example, Patent Document 1 includes an electrode body and a current collector bar (current collector), and the current collector bar has a second flat plate portion and a second flat plate portion arranged in the internal space of the electrode sheet of the electrode body. Disclosed is a power storage element having a wing portion that is projected outward from the surface and joined to an electrode sheet.

Japanese Patent Application Laid-Open No. 2003-249423

However, in a configuration in which the current collector has a second flat plate portion inside the wing portion joined to the electrode body as in the conventional power storage element, the electrode body moves due to external vibration, impact, or the like. In this case, the second flat plate portion may enter the inside of the electrode body, and the corner portion of the second flat plate portion may damage the electrode body.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a power storage element capable of suppressing damage to an electrode body.

In order to achieve the above object, the power storage element according to one aspect of the present invention is a power storage element including an electrode body and a current collector, and the electrode body is connected to a main body and the current collector. The current collector is arranged closer to the main body than the end, and has a facing surface facing the main body and a side opposite to the main body from the facing surface. It has a curved surface that is curved in a dome shape toward the surface.

According to this, in the power storage element, the current collector is arranged on the main body side of the electrode body rather than the end portion of the electrode body and faces the main body portion, and the main body portion of the electrode body from the facing surface. It has a curved surface curved in a dome shape toward the opposite side. Here, when the current collector has a facing surface on the main body side of the end portion of the electrode body, if the facing surface enters the inside of the electrode body due to vibration or impact from the outside, the facing surface There is a risk that the corners of the electrode will damage the electrode body. Therefore, the corners of the facing surface of the current collector are formed on a curved surface curved in a dome shape toward the side opposite to the main body of the electrode body. As a result, even if the facing surface enters the inside of the electrode body due to vibration or impact from the outside, the dome-shaped curved surface abuts on the electrode body, thereby suppressing damage to the electrode body. Can be done.

Further, the curved surface is a curved surface formed at the position of a vertex formed by the facing surface and two adjacent surfaces extending from two adjacent sides of the facing surface to the opposite side of the main body portion. You may do it.

According to this, in the current collector, the curved surface is a curved surface formed at the position of the apex formed by the facing surface and the two adjacent surfaces. That is, if the vertices of the three surfaces including the facing surface are sharp, the sharp vertices may damage the electrode body when the facing surface gets inside the electrode body. A curved surface is formed at the position of the apex. As a result, even if the facing surface enters the inside of the electrode body due to vibration or impact from the outside, the curved surface formed at the position of the apex abuts on the electrode body, so that the electrode body is damaged. Can be suppressed.

Further, a space may be formed at the boundary portion between the two adjacent surfaces.

According to this, in the current collector, a space is formed at the boundary portion between the two adjacent surfaces adjacent to the facing surfaces. Since the space is formed at the boundary between the two adjacent surfaces in this way, the current collector is more flexible than when the space is not formed at the boundary (the two adjacent surfaces are connected). The sex is high. Therefore, when the electrode body moves due to external vibration, impact, or the like, the current collector can absorb the movement of the electrode body, and it is possible to suppress damage to the electrode body.

Further, the curved surface may have a first curved surface that is curved in a dome shape from the surface of the facing surface on the electrode terminal side toward the side opposite to the main body portion.

According to this, the current collector has a first curved surface curved in a dome shape from the surface of the facing surface on the electrode terminal side toward the side opposite to the main body of the electrode body. Here, since the facing surface of the current collector is arranged closer to the main body than the end of the electrode body, the facing surface of the current collector faces the main body of the electrode body from the portion on the electrode terminal side. It has a protruding shape. Therefore, since the corner portion on the electrode terminal side of the facing surface may damage the electrode body, the corner portion is curved in a dome shape to form the first curved surface. As a result, even if the facing surface enters the inside of the electrode body due to vibration or impact from the outside, the dome-shaped first curved surface abuts on the electrode body, thereby suppressing damage to the electrode body. can do.

Further, the curved surface may have a second curved surface curved in a dome shape from a surface opposite to the electrode terminal on the facing surface toward the side opposite to the main body portion.

According to this, the current collector has a second curved surface curved in a dome shape from the surface opposite to the electrode terminal on the facing surface toward the side opposite to the main body portion of the electrode body. Here, since the facing surface of the current collector is arranged closer to the main body than the end of the electrode body, the corner portion on the opposite side to the electrode terminal on the facing surface may damage the electrode body. .. Therefore, the corner portion on the opposite side to the electrode terminal on the facing surface is curved in a dome shape to form a second curved surface. As a result, even if the facing surface enters the inside of the electrode body due to vibration or impact from the outside, the dome-shaped second curved surface abuts on the electrode body, thereby suppressing damage to the electrode body. can do.

It should be noted that the present invention can be realized not only as such a power storage element but also as a current collector included in the power storage element.

According to the power storage element in the present invention, it is possible to suppress damage to the electrode body.

It is a perspective view which shows the structure of the power storage element which concerns on embodiment with the container body separated. It is a perspective view which shows the structure arranged in the container main body of the power storage element which concerns on embodiment with separated spacers. It is a perspective view which shows by disassembling each component arranged in the container of the power storage element which concerns on embodiment. It is a perspective view which shows the structure of the positive electrode current collector which concerns on embodiment. It is a perspective view which shows the structure of the spacer which concerns on embodiment. It is sectional drawing which shows the arrangement position of the electrode body, the positive electrode current collector and the spacer which concerns on embodiment. It is sectional drawing which shows the arrangement position of the electrode body, the positive electrode current collector and the spacer which concerns on embodiment.

Hereinafter, the power storage element according to the embodiment of the present invention (and its modification) will be described with reference to the drawings. It should be noted that all of the embodiments described below are 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. Further, among the components in the following embodiments, the components not described in the independent claim indicating the highest level concept are described as arbitrary components. Further, in each figure, the dimensions and the like are not exactly shown.

Further, in the following description and drawings of the embodiment, the arrangement direction of the pair of electrode terminals of the power storage element, the arrangement direction of the pair of current collectors, the arrangement direction of the pair of spacers, and both ends of the electrode body (a pair). The arrangement direction of the active material layer non-forming portion), the winding axis direction of the electrode body, or the facing direction of the short side surface of the container is defined as the X-axis direction. Further, the arranging direction of a plurality of electrode bodies, the arranging direction of the connection portion with the electrode body in one current collector, the facing direction of the long side surface of the container, the short side direction of the short side surface of the container, or the thickness direction of the container. Is defined as the Y-axis direction. Further, the alignment direction between the container body and the lid of the power storage element, the longitudinal direction of the short side surface of the container, the extension direction of the connection portion with the electrode body of the current collector, or the vertical direction is defined as the Z-axis direction. These X-axis directions, Y-axis directions, and Z-axis directions intersect each other (orthogonally in the present embodiment). Depending on the usage mode, the Z-axis direction may not be the vertical direction, but for convenience of explanation, the Z-axis direction will be described below as the vertical direction. Further, in the following description, for example, 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.

(Embodiment)
[1 General description of the power storage element 10]
First, with reference to FIGS. 1 to 3, a general description of the power storage element 10 according to the present embodiment will be given. FIG. 1 is a perspective view showing the configuration of the power storage element 10 according to the present embodiment by separating the container main body 110. Further, FIG. 2 is a perspective view showing the configuration of the power storage element 10 according to the present embodiment arranged inside the container body 110 with the spacers 500 and 600 separated. That is, the figure shows a state after the positive electrode current collector 700 and the negative electrode current collector 800 are connected to the electrode body 400. Further, FIG. 3 is a perspective view showing each component arranged inside the container 100 of the power storage element 10 according to the present embodiment in an exploded manner. That is, the figure shows a state before connecting the positive electrode current collector 700 and the negative electrode current collector 800 to the electrode body 400.

The power storage element 10 is a secondary battery capable of charging electricity and discharging electricity, and specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 10 is used, for example, as a power source for automobiles such as an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), a power source for electronic devices, a power source for power storage, and the like. The power storage element 10 is not limited to the non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery, or may be a capacitor. Further, the power storage element 10 may be a primary battery that can use the stored electricity without being charged by the user, instead of the secondary battery. Further, in the present embodiment, the rectangular parallelepiped (square) power storage element 10 is shown, but the shape of the power storage element 10 is not particularly limited and may be a cylindrical shape, a long cylindrical shape, or the like. , It can also be a laminated type power storage element.

As shown in FIG. 1, the power storage element 10 includes a container 100 having a container body 110 and a lid 120, a positive electrode terminal 200, a positive electrode gasket 210, a negative electrode terminal 300, a negative electrode gasket 310, and an electrode body 400. It includes spacers 500 and 600. Further, as shown in FIGS. 2 and 3, the power storage element 10 further includes a positive electrode current collector 700, a negative electrode current collector 800, and a clip 900.

An electrolytic solution (non-aqueous electrolyte) is sealed inside the container 100, but the illustration is omitted. The type of the electrolytic solution is not particularly limited as long as it does not impair the performance of the power storage element 10, and various types can be selected. In addition to the above components, a gas discharge valve for releasing the pressure when the pressure in the container 100 rises, a liquid injection unit for injecting an electrolytic solution into the container 100, or an electrode body 400. An insulating film or the like that wraps the or the like may be arranged.

[1.1 Description of container 100, positive electrode terminal 200 and negative electrode terminal 300]
The container 100 is a rectangular parallelepiped (box-shaped) case composed of a container body 110 having a rectangular tubular shape and a bottom, and a lid body 120 which is a plate-shaped member that closes the opening of the container body 110. Specifically, the lid 120 is a flat plate-shaped and rectangular wall portion extending in the X-axis direction, and is arranged on the positive side in the Z-axis direction of the container body 110. The container body 110 has a flat plate-shaped and rectangular bottom wall portion on the minus side in the Z-axis direction, a flat plate-shaped and rectangular long side wall portion on both side surfaces in the Y-axis direction, and a flat plate-shaped and rectangular bottom wall portion on both side surfaces in the X-axis direction. It has five wall portions of a rectangular short side wall portion.

Further, in the container 100, after the electrode body 400, spacers 500, 600, positive electrode current collector 700, negative electrode current collector 800 and the like are housed inside the container body 110, the container body 110 and the lid 120 are welded or the like. As a result, the inside can be sealed. The material of the container body 110 and the lid 120 is not particularly limited, and for example, stainless steel, aluminum, aluminum alloy, iron, plated steel plate and the like can be weldable metals, but resins can also be used.

The positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode plate of the electrode body 400, and the negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode plate 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 the electricity is stored in the internal space of the power storage element 10 in order to store electricity in the electrode body 400. It is a metal electrode terminal for introducing. Further, the positive electrode terminal 200 and the negative electrode terminal 300 are attached to a lid 120 arranged above the electrode body 400.

Specifically, the positive electrode terminal 200 is crimped by inserting the protruding portion 201 (see FIG. 7) into the through hole of the lid 120, the through hole of the positive electrode gasket 210, and the through hole 711 of the positive electrode current collector 700. As a result, it is fixed to the lid 120 together with the positive electrode gasket 210 and the positive electrode current collector 700. Similarly, the negative electrode terminal 300 is also fixed to the lid 120 together with the negative electrode gasket 310 and the negative electrode current collector 800. As described above, the positive electrode terminal 200 and the negative electrode terminal 300 are arranged on the positive side in the Z-axis direction of the positive electrode current collector 700 and the negative electrode current collector 800.

The positive electrode gasket 210 is an insulating sealing member arranged between the lid 120, the positive electrode terminal 200, and the positive electrode current collector 700. The positive electrode gasket 210 is formed of, for example, a resin such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), or polyphenylene sulfide resin (PPS). Since the negative electrode gasket 310 has the same configuration as the positive electrode gasket 210, detailed description thereof will be omitted.

[1.2 Description of electrode body 400]
The electrode body 400 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 is an electrode plate in which a positive electrode active material layer is formed on a positive electrode base material layer which is a long strip-shaped current collecting foil made of aluminum, an aluminum alloy, or the like. The negative electrode plate is an electrode plate in which a negative electrode active material layer is formed on a negative electrode base material layer which is a long strip-shaped current collector foil made of copper, a copper alloy, or the like. As the current collector foil, known materials such as nickel, iron, stainless steel, titanium, calcined carbon, conductive polymer, conductive glass, and Al—Cd alloy can also be used as appropriate. Further, 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, known materials can be appropriately used as long as they are active materials that can occlude and release lithium ions. Further, as the separator, for example, a microporous sheet made of resin or a non-woven fabric can be used.

The electrode body 400 is formed by arranging a separator between the positive electrode plate and the negative electrode plate and winding (stacking) the separator body 400. Specifically, in the electrode body 400, the positive electrode plate and the negative electrode plate are wound so as to be displaced from each other in the direction of the winding axis (virtual axis parallel to the X-axis direction in the present embodiment) via the separator. ing. Then, in the positive electrode plate and the negative electrode plate, a portion where the active material is not applied (the active material layer is not formed) and the base material layer is exposed (active material layer non-formed portion) at the end portions in the shifted directions. )have.

Here, the electrode body 400 may be composed of one or more electrode bodies, but in the present embodiment, it is assumed that the electrode body 400 is composed of a plurality of electrode bodies. Specifically, it is assumed that the electrode body 400 has two separate electrode bodies, a first electrode body 410 and a second electrode body 420.

That is, in the first electrode body 410, the active material layer non-forming portion at the end portion of the positive electrode plate is laminated on one end portion in the winding axis direction (the end portion on the plus side in the X-axis direction) and bundled into one. It has a first positive electrode side end portion 412. Further, in the first electrode body 410, the active material layer non-forming portion at the end portion of the negative electrode plate is laminated on the other end portion in the winding axis direction (the end portion on the minus side in the X-axis direction) and bundled into one. It also has a first negative electrode side end portion 413. For example, the thickness of the active material layer non-forming portion (current collector foil) of the positive electrode plate and the negative electrode plate is about 5 μm to 20 μm, and when these are bundled, for example, about 50 to 70 sheets, the first positive electrode side end portion 412 And the first negative electrode side end portion 413 is formed. The portion of the first electrode body 410 other than the first positive electrode side end portion 412 and the first negative electrode side end portion 413 is referred to as the first electrode body main body portion 411. That is, the first electrode body main body portion 411 is a portion of the first electrode body 410 in which the active material layer is formed on the base material layer. Similarly, the second electrode body 420 is on the second positive electrode side in which the second electrode body main body portion 421 on which the active material layer is formed and the active material layer non-forming portion at the end of the positive electrode plate are bundled together. It has an end portion 422 and a second negative electrode side end portion 423 in which the active material layer non-forming portion at the end portion of the negative electrode plate is bundled into one.

In the present embodiment, the cross-sectional shape of the electrode body 400 (first electrode body 410 and second electrode body 420) is shown as an oval shape, but an elliptical shape, a circular shape, a polygonal shape, or the like may be used. Further, the shape of the electrode body 400 (first electrode body 410 and second electrode body 420) is not limited to the winding type, but may be a laminated type (stack type) in which flat plate-shaped electrode plates are laminated, or an electrode body. May be folded in a bellows shape (spin-folded shape).

[1.3 Explanation of positive electrode current collector 700 and negative electrode current collector 800]
The positive electrode current collector 700 is a current collector on the positive electrode side arranged on the positive side in the X-axis direction, which is the side of the electrode body 400. Specifically, the positive electrode current collector 700 is arranged between the positive electrode side end portion of the electrode body 400 and the short side wall portion of the container body 110, and electricity is applied to the positive electrode terminal 200 and the positive electrode side end portion of the electrode body 400. It is a member having conductivity and rigidity which are connected to each other. Similarly, the negative electrode current collector 800 is a current collector on the negative electrode side arranged on the negative side in the X-axis direction, which is the side of the electrode body 400. That is, the negative electrode current collector 800 is arranged between the negative electrode side end portion of the electrode body 400 and the short side wall portion of the container body 110, and is electrically connected to the negative electrode terminal 300 and the negative electrode side end portion of the electrode body 400. It is a member having conductivity and rigidity.

Specifically, the positive electrode current collector 700 is fixedly connected (bonded) to the first positive electrode side end portion 412 of the first electrode body 410 and the second positive electrode side end portion 422 of the second electrode body 420. .. More specifically, the first positive electrode side end portion 412 and the second positive electrode side end portion 422 are sandwiched between the positive electrode current collector 700 and the two clips 900 and joined by welding or the like. The clip 900 is a plate-shaped metal member. The method of joining the positive electrode current collector 700 to the first positive electrode side end portion 412 and the second positive electrode side end portion 422 may be any welding such as laser welding, ultrasonic welding, and resistance welding. , Other than welding, for example, mechanical joining such as caulking may be performed.

Similarly, the negative electrode current collector 800 is fixedly connected (bonded) to the first negative electrode side end portion 413 of the first electrode body 410 and the second negative electrode side end portion 423 of the second electrode body 420. That is, the first negative electrode side end portion 413 and the second negative electrode side end portion 423 are sandwiched between the negative electrode current collector 800 and the two clips 900, and are joined by welding or the like.

Further, the positive electrode current collector 700 and the negative electrode current collector 800 are fixedly connected (bonded) to the lid 120. With this configuration, the first electrode body 410 and the second electrode body 420 are held (supported) in a state of being suspended from the lid 120 by the positive electrode current collector 700 and the negative electrode current collector 800, and are subjected to external vibration and vibration. Shaking due to impact etc. is suppressed.

The material of the positive electrode current collector 700 is not limited, but is made of aluminum or an aluminum alloy, for example, like the positive electrode base material layer of the electrode body 400. Further, the material of the negative electrode current collector 800 is not limited, but is, for example, formed of copper or a copper alloy like the negative electrode base material layer of the electrode body 400. A detailed description of the configurations of the positive electrode current collector 700 and the negative electrode current collector 800 will be described later.

Here, when explaining the positional relationship of the members on the positive electrode side such as the positive electrode current collector 700, the direction facing the plus side in the X-axis direction is also referred to as the first direction. For example, it can be said that the positive electrode current collector 700 is arranged on the first direction side of the electrode body 400. Since the members on the negative electrode side such as the negative electrode current collector 800 are arranged in the opposite directions in the X-axis direction from the members on the positive electrode side, when applied to the positional relationship of the members on the negative electrode side, the X-axis direction. The direction facing the minus side is the first direction. For example, it can be said that the negative electrode current collector 800 is also arranged on the first direction side of the electrode body 400 like the positive electrode current collector 700. Further, the direction intersecting the first direction (in the present embodiment, the direction facing the plus side in the Z-axis direction) is also referred to as the second direction. For example, it can be said that the positive electrode terminal 200 and the negative electrode terminal 300 are arranged on the second direction side of the positive electrode current collector 700 and the negative electrode current collector 800.

[1.4 Description of spacers 500 and 600]
The spacer 500 is a spacer arranged on the positive side (first direction side) in the X-axis direction, which is the side of the positive electrode current collector 700, and is between the positive electrode current collector 700 and the short side wall portion of the container body 110. , Are arranged so as to extend in the Z-axis direction (second direction) along the short side wall portion. The spacer 600 is a spacer arranged on the negative side in the X-axis direction, which is the side of the negative electrode current collector 800, and is located on the short side wall portion between the negative electrode current collector 800 and the short side wall portion of the container body 110. It is arranged so as to extend in the Z-axis direction along the line. That is, the spacer 500 and the spacer 600 are arranged between both ends of the electrode body 400 and both side walls of the container 100 so as to sandwich the electrode body 400 from both ends in the X-axis direction.

Here, the spacers 500 and 600 are made of an insulating material such as polypropylene (PP), polyphenylene sulfide (PPS), polyethylene terephthalate (PET), ceramics, and composite materials thereof. That is, the spacers 500 and 600 insulate the electrode body 400, the positive electrode current collector 700, the negative electrode current collector 800, and the container 100. Further, the spacers 500 and 600 fill the space between the electrode body 400, the positive electrode current collector 700, the negative electrode current collector 800, and the container 100, whereby the electrode body 400, the positive electrode current collector 700, and the negative electrode current collector are filled. The 800 is supported so as not to vibrate with respect to the container 100. A detailed description of the configurations of the spacers 500 and 600 will be described later.

[2 Detailed description of the positive electrode current collector 700]
Next, the configuration of the positive electrode current collector 700 will be described in detail. Although the configuration of the positive electrode current collector 700 will be described below, the configuration of the negative electrode current collector 800 is the same as the configuration of the positive electrode current collector 700. FIG. 4 is a perspective view showing the configuration of the positive electrode current collector 700 according to the present embodiment. Specifically, FIG. 4 (a) is an enlarged perspective view of the positive electrode current collector 700 shown in FIG. 3, and FIG. 4 (b) is a positive electrode current collector of FIG. 4 (a). It is a perspective view when the electric body 700 is seen from the opposite side (back side).

As shown in FIG. 4, the positive electrode current collector 700 includes a terminal connection portion 710, a first electrode body connection portion 720, a second electrode body connection portion 730, a connection portion 740, an intermediate portion 750, and an extension portion. It is equipped with 760.

The terminal connection portion 710 is the base of the positive electrode current collector 700 connected to the positive electrode terminal 200. That is, the terminal connection portion 710 is a rectangular and flat plate-shaped portion arranged on the positive electrode terminal 200 side (upper side, positive side in the Z-axis direction) of the positive electrode current collector 700, and is electrically and mechanically connected to the positive electrode terminal 200. It is connected (joined) to. In the terminal connection portion 710, a circular through hole 711 into which the above-mentioned protrusion 201 of the positive electrode terminal 200 is inserted and a penetration for preventing rotation into which the protrusion 211 of the positive electrode gasket 210 (see FIG. 7) is inserted. A hole 712 and a reinforcing bead portion 713 are formed.

The first electrode body connecting portion 720 and the second electrode body connecting portion 730 are portions connected to the electrode body 400. That is, the first electrode body connecting portion 720 and the second electrode body connecting portion 730 are portions arranged on the electrode body 400 side (lower side, negative side in the Z-axis direction) of the positive electrode body 700, and the electrode body 400. Is electrically and mechanically connected (joined) to. Specifically, the first electrode body connecting portion 720 is a long and flat plate-shaped portion extending in the Z-axis direction (second direction), and is arranged on the first electrode body 410 side (minus side in the Y-axis direction). Then, it is connected to the first positive electrode side end portion 412 of the first electrode body 410. Further, the second electrode body connecting portion 730 is a long and flat plate-shaped portion extending in the Z-axis direction (second direction), and is arranged on the second electrode body 420 side (Y-axis direction plus side). It is connected to the second positive electrode side end portion 422 of the second electrode body 420.

The connecting portion 740 is the end edge of the first electrode body connecting portion 720 on the electrode body 400 side (minus side in the X-axis direction or the side opposite to the first direction), and the electrode body of the second electrode body connecting portion 730. It is a part that connects the edges on the 400 side. That is, the connecting portion 740 is a long and flat wall extending in the Z-axis direction connecting the end edges of the two connecting portions connected to the electrode body 400 of the positive electrode current collector 700 on the electrode body 400 side. It is a department. As a result, the connecting portion 740 is arranged at a position facing the electrode body 400 in the X-axis direction (first direction). A through hole may be formed in the connecting portion 740 in order to ensure the injectability of the electrolytic solution.

The intermediate portion 750 is a portion between the connecting portion 740 and the terminal connecting portion 710 and is arranged outside the connecting portion 740 (on the plus side in the X-axis direction or on the first direction side). Here, the intermediate portion 750 has a first intermediate portion 751 and a second intermediate portion 752.

The first intermediate portion 751 is a rectangular and flat plate-shaped portion extending from the upper end portion (end portion on the plus side in the Z-axis direction) of the connecting portion 740 to the plus side in the X-axis direction. That is, the first intermediate portion 751 is a wall portion parallel to the XY plane arranged on the positive side (second direction side) in the Z-axis direction with respect to the first electrode body connecting portion 720 and the second electrode body connecting portion 730. .. Further, the second intermediate portion 752 is a rectangular and flat plate-shaped portion extending downward (minus side in the Z-axis direction) from the end on the plus side in the X-axis direction of the terminal connection portion 710. That is, the second intermediate portion 752 is a wall portion parallel to the YZ plane arranged along the end portion at a position facing the end portion of the electrode body 400 in the X-axis direction (first direction).

The extension portion 760 is a portion extending from the connection portion 740 to the side opposite to the terminal connection portion 710 (minus side in the Z-axis direction) from the first electrode body connection portion 720 and the second electrode body connection portion 730. Is. Specifically, the extension portion 760 is located on the outer side (X-axis direction plus side or first direction side) of the connecting portion 740 on the first electrode body connecting portion 720 side and the second electrode body connecting portion 730 side. ), And is arranged on the negative side in the Z-axis direction (opposite to the second direction) from the connecting portion 740. Here, the extension portion 760 has a first extension portion 761 and a second extension portion 762.

The first extending portion 761 is a rectangular and flat plate-shaped portion extending from the lower end portion (end portion on the minus side in the Z-axis direction) of the connecting portion 740 to the plus side in the X-axis direction. That is, the first extension portion 761 is parallel to the XY plane arranged on the negative side in the Z-axis direction (the side opposite to the second direction) with respect to the first electrode body connection portion 720 and the second electrode body connection portion 730. It is a wall part. Further, the second extension portion 762 is a rectangular and flat plate-shaped portion extending downward (minus side in the Z-axis direction) from the end portion on the plus side in the X-axis direction of the first extension portion 761. That is, the second extending portion 762 is a wall portion parallel to the YZ plane arranged along the end portion of the electrode body 400 at a position facing the end portion in the X-axis direction (first direction). .. As described above, the first extending portion 761 and the second extending portion 762 are the first intermediate portion 751 and the second intermediate portion 752 in the Z-axis direction (second direction), and the first electrode body connecting portion 720. And is arranged at a position sandwiching the second electrode body connecting portion 730.

With such a configuration, the positive electrode current collector 700 is formed with a current collector recess 741 which is a recess having a connecting portion 740 as a bottom. That is, the current collector recess 741 has the first electrode body connection portion 720 and the second electrode body connection portion 730, which are two connection portions with the electrode body 400, the connection portion 740, the first intermediate portion 751, and the first. It is a recess formed on the negative side in the X-axis direction formed by the extending portion 761.

Further, the positive electrode current collector 700 has a curved surface 770 curved in a dome shape from the facing surface 742, which is the surface on the negative side in the X-axis direction of the connecting portion 740, toward the positive side in the X-axis direction. Here, the facing surface 742 is arranged on the main body portion side of the electrode body 400 with respect to the end portion of the electrode body 400, and is a surface facing the main body portion of the electrode body 400 (see FIGS. 6 and 7). The end of the electrode body 400 is the positive side in the X-axis direction of the first positive electrode side end portion 412 and the second positive electrode side end portion 422, or the first positive electrode side end portion 412 and the second positive electrode side end portion 422. It is the end of. The main body of the electrode body 400 is the first electrode body main body 411 and the second electrode body main body 421.

The curved surface 770 is a surface curved in a dome shape from the facing surface 742 toward the side opposite to the main body of the electrode body 400. That is, the curved surface 770 is four curved surfaces curved in a dome shape from the corners of the four corners of the facing surface 742 toward the plus side in the X-axis direction. Specifically, the curved surface 770 has two adjacent surfaces (for example, a first electrode body connecting portion 720) extending from two adjacent sides of the facing surface 742 and the facing surface 742 to the opposite side of the main body portion of the electrode body 400. It is a curved surface formed at the position of the apex formed by the outer surface of the first intermediate portion 751). As described above, the curved surface 770 is not a planar (two-dimensional) curved surface formed by bending a plane in one direction, but a three-dimensional surface formed by bending the plane in two or more directions. It is a (three-dimensional) curved surface.

Here, the curved surface 770 has two first curved surfaces 771 and 772 and two second curved surfaces 773 and 774. The first curved surfaces 771 and 772 are curved surfaces curved in a dome shape from the surface of the facing surface 742 on the positive electrode terminal 200 side toward the side opposite to the main body of the electrode body 400. That is, the first curved surface 771 is formed at the position of the apex formed by the three surfaces of the facing surface 742, the outer surface of the first electrode body connecting portion 720, and the outer surface (two adjacent surfaces) of the first intermediate portion 751. It is a curved surface. Further, the first curved surface 772 is formed at the position of the apex formed by three surfaces of the facing surface 742, the outer surface of the second electrode body connecting portion 730, and the outer surface (two adjacent surfaces) of the first intermediate portion 751. It is a curved surface. As described above, the first curved surfaces 771 and 772 are curved surfaces formed at the corners (apex portions) of the three adjacent surfaces.

The second curved surfaces 773 and 774 are curved surfaces curved in a dome shape from the surface of the facing surface 742 opposite to the positive electrode terminal 200 toward the side opposite to the main body of the electrode body 400. That is, the second curved surface 773 is located at the position of the apex formed by the three surfaces of the facing surface 742, the outer surface of the first electrode body connecting portion 720, and the outer surface (two adjacent surfaces) of the first extending portion 761. It is a formed curved surface. Further, the second curved surface 774 is located at the position of the apex formed by the three surfaces of the facing surface 742, the outer surface of the second electrode body connecting portion 730, and the outer surface (two adjacent surfaces) of the first extending portion 761. It is a formed curved surface. As described above, the second curved surfaces 773 and 774 are also curved surfaces formed at the corners (apex portions) of the three adjacent surfaces, like the first curved surfaces 771 and 772.

In addition, a space is formed at the boundary between the two adjacent surfaces. For example, when the two adjacent surfaces are the outer surface of the first electrode body connecting portion 720 and the outer surface of the first intermediate portion 751, a space 775 is provided at the boundary portion between the first electrode body connecting portion 720 and the first intermediate portion 751. Is formed. The same applies to the other two adjacent surfaces. The space at the boundary between the curved surface 770 and the two adjacent surfaces such as the space 775 can be formed by drawing a plate-shaped member or the like.

[Detailed description of 3 spacer 500]
Next, the configuration of the spacer 500 will be described in detail. Although the configuration of the spacer 500 will be described below, the configuration of the spacer 600 is the same as the configuration of the spacer 500. FIG. 5 is a perspective view showing the configuration of the spacer 500 according to the present embodiment. Specifically, FIG. 5A is an enlarged perspective view showing the spacer 500 shown in FIGS. 2 and 3, and FIG. 5B is an enlarged perspective view of the spacer 500 shown in FIG. 5A. It is a perspective view when viewed from the opposite side (back side).

As shown in FIG. 5, the spacer 500 includes a spacer main body portion 510 and spacer side wall portions 520 and 530. The spacer main body 510 is a plate-shaped portion parallel to the YZ plane extending in the Z-axis direction constituting the main body of the spacer 500, and a plurality of protrusions protruding in the negative side in the X-axis direction are formed. Further, the spacer side wall portions 520 and 530 are plate-shaped portions parallel to the XZ plane extending in the Z-axis direction constituting the side wall portion of the spacer 500, and a protruding portion protruding inward in the Y-axis direction is formed. ..

Specifically, the spacer main body 510 has a spacer first convex portion 511 and a spacer second convex portion 512. The spacer first convex portion 511 is a substantially rectangular parallelepiped protruding portion (convex portion) that protrudes on the minus side in the X-axis direction (the side opposite to the first direction) and extends in the Z-axis direction. Further, on the back side (plus side in the X-axis direction) of the spacer first convex portion 511, a spacer first recess 511a recessed toward the minus side in the X-axis direction is formed. The spacer second convex portion 512 is a protruding portion (convex portion) that protrudes to the minus side in the X-axis direction and extends in the Y-axis direction, and the back side (plus side in the X-axis direction) of the spacer second convex portion 512 has a protrusion. A spacer second recess 512a recessed toward the minus side in the X-axis direction is formed.

Here, the spacer second convex portion 512 has a U-shape in which the central portion on the spacer first convex portion 511 side (plus side in the Z-axis direction) is recessed. As a result, between the spacer first convex portion 511 and the spacer second convex portion 512, it extends in the Y-axis direction surrounded by the spacer first convex portion 511 and the concave portion of the spacer second convex portion 512. A rectangular spacer recess 513 is formed. The spacer first convex portion 511 is arranged so as to project into the current collector recess 741 of the positive electrode current collector 700, and the extended portion 760 of the positive electrode current collector 700 is arranged in the spacer recess 513. , A detailed description of these configurations will be given later.

Further, the spacer side wall portion 520 has a spacer third convex portion 521, and the spacer side wall portion 530 has a spacer fourth convex portion 531. The spacer third convex portion 521 is a substantially rectangular parallelepiped protruding portion (convex portion) that projects to the plus side in the Y-axis direction and extends in the Z-axis direction. Further, on the back side (minus side in the Y-axis direction) of the third convex portion 521 of the spacer, a spacer third concave portion 521a recessed toward the positive side in the Y-axis direction is formed. The spacer fourth convex portion 531 is a substantially rectangular parallelepiped protruding portion (convex portion) that protrudes on the negative side in the Y-axis direction and extends in the Z-axis direction. Further, on the back side (plus side in the Y-axis direction) of the fourth convex portion 531 of the spacer, a spacer fourth concave portion 531a recessed toward the minus side in the Y-axis direction is formed.

[4 Explanation of the arrangement positions of the electrode body 400, the positive electrode current collector 700, and the spacer 500]
Next, the arrangement positions of the electrode body 400, the positive electrode current collector 700, and the spacer 500 will be described in detail. In the following, the arrangement position of the positive electrode side (electrode body 400, positive electrode current collector 700 and spacer 500) will be described, but the arrangement position of the negative electrode side (electrode body 400, negative electrode current collector 800 and spacer 600) will also be the positive electrode side. It is the same as the placement position on the side. 6 and 7 are cross-sectional views showing the arrangement positions of the electrode body 400, the positive electrode current collector 700, and the spacer 500 according to the present embodiment. Specifically, FIG. 6 is a cross-sectional view showing the configuration on the positive electrode side when the configuration shown in FIG. 1 is cut along a VI-VI cross section (a plane parallel to the XY plane). Further, FIG. 7 is a cross-sectional view showing the configuration on the positive electrode side when the configuration shown in FIG. 1 is cut along a VII-VII cross section (a plane parallel to the XZ plane).

As shown in FIG. 6, in the positive electrode current collector 700, the first electrode body connecting portion 720 is in contact with the surface on the positive side in the Y-axis direction of the first positive electrode side end portion 412 of the first electrode body 410. , Is joined to the first positive electrode side end portion 412. Specifically, the first electrode body connecting portion 720 is joined to the first positive electrode side end portion 412 in a state where the first positive electrode side end portion 412 is sandwiched between the clip 900 and the first positive electrode body connecting portion 720. Further, the second electrode body connecting portion 730 is joined to the second positive electrode side end portion 422 in a state of being in contact with the surface on the negative side in the Y-axis direction of the second positive electrode side end portion 422 of the second electrode body 420. There is. Specifically, the second electrode body connecting portion 730 is joined to the second positive electrode side end portion 422 in a state where the second positive electrode side end portion 422 is sandwiched between the clip 900 and the second positive electrode side end portion 422. With this configuration, the connecting portion 740 is between the first electrode body 410 and the second electrode body 420, that is, the first positive electrode side end portion 412 of the first electrode body 410 and the second positive electrode side of the second electrode body 420. It is placed between the end 422 and the end.

Further, the spacer first convex portion 511 projects toward the connecting portion 740 in the X-axis direction (first direction) and is arranged in the current collector recess 741. That is, the spacer first convex portion 511 is located between the first electrode body connecting portion 720 and the second electrode body connecting portion 730 and facing the first electrode body connecting portion 720 and the second electrode body connecting portion 730. Is placed in. With this configuration, the spacer first convex portion 511 is located between the first electrode body 410 and the second electrode body 420, that is, the first positive electrode side end portion 412 of the first electrode body 410 and the second electrode body 420. It is arranged between the two positive electrode side ends 422 (between the ends of the two electrode bodies 400).

Further, the spacer third convex portion 521 and the spacer fourth convex portion 531 are arranged between the container 100 and the end portion of the electrode body 400, and are arranged so as to project toward the end portion of the electrode body 400. Further, the spacer third convex portion 521 and the spacer fourth convex portion 531 are arranged on the side opposite to the positive electrode current collector 700 with respect to the end portion of the electrode body 400, and on the side opposite to the end portion of the electrode body 400. Has a recess in. Specifically, the spacer third convex portion 521 is arranged between the long side wall portion on the negative side in the Y-axis direction of the container body 110 and the first positive electrode side end portion 412 of the first electrode body 410, and is the first positive electrode. It is arranged so as to project toward the positive side in the Y-axis direction toward the side end portion 412. Further, the spacer third convex portion 521 is arranged on the side opposite to the first electrode body connecting portion 720 with respect to the first positive electrode side end portion 412, and the spacer first is on the side opposite to the first positive electrode side end portion 412. It has three recesses 521a. The same applies to the spacer fourth convex portion 531.

Further, the spacer third convex portion 521 and the spacer fourth convex portion 531 are arranged so as to project along the end edges of the first electrode body main body portion 411 and the second electrode body main body portion 421 on the plus side in the X-axis direction. There is. As a result, the movement of the electrode body 400 (first electrode body 410 and second electrode body 420) can be suppressed, so that the electrode body 400 can be suppressed from being damaged by external vibration, impact, or the like. Can be done.

Further, as shown in FIG. 7, in the positive electrode current collector 700, the first intermediate portion 751 is located on the positive side (second direction side) of the spacer first convex portion 511 in the Z-axis direction and on the spacer first convex portion 511. They are placed facing each other. Further, the first extending portion 761 is arranged on the negative side in the Z-axis direction (the side opposite to the second direction side) of the spacer first convex portion 511, facing the spacer first convex portion 511. That is, the spacer first convex portion 511 is arranged between the first intermediate portion 751 and the first extension portion 761. Specifically, the spacer first convex portion 511 is arranged in the current collector recess 741 formed by the connecting portion 740, the first intermediate portion 751, and the first extending portion 761.

Further, the second positive electrode side end portion 422 has a second positive electrode side upper end portion 422a at the upper portion and a second positive electrode side lower end portion 422b at the lower portion (see FIG. 3), and the second electrode body connecting portion 730 has a second electrode body connecting portion 730. It is joined to a portion between the upper end portion 422a on the second positive electrode side and the lower end portion 422b on the second positive electrode side (the central portion in the Z-axis direction of the end portion 422 on the second positive electrode side). Similarly, for the first positive electrode side end portion 412, the second electrode body connecting portion 720 is located between the first positive electrode side upper end portion 412a (see FIG. 3) and the first positive electrode side lower end portion 412b (see FIG. 3). It is joined to the site.

Further, the second intermediate portion 752 is located at a position facing the first positive electrode side end portion 412 and the second positive electrode side end portion 422 in the X-axis direction (first direction), and the first positive electrode side end portion 412 and the second. It is arranged along the positive electrode side end portion 422. Specifically, the second intermediate portion 752 is located at a position facing the first positive electrode side upper end portion 412a and the second positive electrode side upper end portion 422a in the X-axis direction, and the first positive electrode side upper end portion 412a and the second positive electrode side. It is arranged along the upper end portion 422a.

Similarly, the second extending portion 762 and the spacer second convex portion 512 are located at positions facing the first positive electrode side end portion 412 and the second positive electrode side end portion 422 in the X-axis direction (first direction). It is arranged along the one positive electrode side end portion 412 and the second positive electrode side end portion 422. Specifically, the second extending portion 762 and the spacer second convex portion 512 are located on the first positive electrode side at positions facing the first positive electrode side lower end portion 412b and the second positive electrode side lower end portion 422b in the X-axis direction. It is arranged along the lower end portion 412b and the second positive electrode side lower end portion 422b.

As described above, the second extending portion 762 and the spacer second convex portion 512 are connected to the first electrode body connecting portion 720 and the second electrode body with the second intermediate portion 752 in the Z-axis direction (second direction). It is arranged at a position sandwiching the portion 730. Specifically, the spacer second convex portion 512 is on the negative side in the Z-axis direction (opposite to the second direction) and the first extension of the first electrode body connection portion 720 and the second electrode body connection portion 730. It is arranged on the minus side in the Z-axis direction with respect to the installation portion 761 and the second extension portion 762.

Further, by arranging the second extending portion 762 in the spacer recess 513 facing the extending portion 760, the inside of the second intermediate portion 752 (minus side in the X-axis direction, opposite to the first direction). The surface and the inner surface of the second extending portion 762 and the spacer second convex portion 512 are arranged on the same plane (on the plane P1 in FIG. 7). Further, the outer surface of the second intermediate portion 752 (plus side in the X-axis direction, the first direction side) and the outer surface of the second extending portion 762 are on the same plane (on the plane P2 in FIG. 7). Have been placed. As a result, the second intermediate portion 752 and the second extension portion 762 are arranged in contact with the inner surface of the spacer main body portion 510 on the same plane. In addition, the arrangement on the same plane is not limited to the arrangement on the completely same plane, and some deviation due to processing error and selection of the optimum plate thickness for the material is allowed. Will be done.

[5 Explanation of effect]
As described above, according to the power storage element 10 according to the embodiment of the present invention, the positive electrode current collector 700 is arranged on the main body side of the electrode body 400 with respect to the end portion of the electrode body 400 and is located on the main body portion. It has a facing surface 742 and a curved surface 770 curved in a dome shape from the facing surface 742 toward the side opposite to the main body of the electrode body 400. Here, when the positive electrode current collector 700 has the facing surface 742 on the main body side of the end of the electrode body 400, the facing surface 742 gets into the inside of the electrode body 400 due to vibration or impact from the outside. Then, the corner portion of the facing surface 742 may damage the electrode body 400. Therefore, the corner portion of the facing surface 742 of the positive electrode current collector 700 is formed on the curved surface 770 curved in a dome shape toward the side opposite to the main body portion of the electrode body 400. As a result, even if the facing surface 742 enters the inside of the electrode body 400 due to vibration or impact from the outside, the dome-shaped curved surface 770 abuts on the electrode body 400, so that the electrode body 400 is damaged. Can be suppressed.

Further, in the positive electrode current collector 700, the curved surface 770 is a curved surface formed at the position of the apex formed by the facing surface 742 and the two adjacent surfaces. That is, if the vertices of the three surfaces including the facing surface 742 are sharp, if the facing surface 742 gets inside the electrode body 400, the sharp vertices may damage the electrode body 400. Therefore, a curved surface 770 is formed at the position of the apex. As a result, even if the facing surface 742 enters the inside of the electrode body 400 due to vibration or impact from the outside, the curved surface 770 formed at the position of the apex abuts on the electrode body 400, so that the electrode body 400 Can be prevented from being damaged.

Further, in the positive electrode current collector 700, a space is formed at the boundary portion between the two adjacent surfaces adjacent to the facing surface 742. As described above, since the space is formed at the boundary portion between the two adjacent surfaces, the positive electrode current collector 700 is more than the case where the space is not formed at the boundary portion (the two adjacent surfaces are connected). Is more flexible. Therefore, when the electrode body 400 moves due to external vibration, impact, or the like, the positive electrode current collector 700 can absorb the movement of the electrode body 400, and damage to the electrode body 400 can be suppressed. Further, when the plate-shaped member is bent, the curved surface 770 can be easily formed by forming the curved surface 770 at the positions of the vertices of the facing surface 742 and the three adjacent surfaces. In this case, the curved surface 770 can be easily formed. A space will be formed at the boundary between the two adjacent surfaces. That is, rather than forming a curved surface 770 at the apex position when two adjacent surfaces are connected, a method of forming a curved surface 770 at the apex position when a space is formed at the boundary between the two adjacent surfaces. However, the positive electrode current collector 700 can be easily manufactured.

Further, the positive electrode current collector 700 has first curved surfaces 771 and 772 curved in a dome shape from the surface of the facing surface 742 on the positive electrode terminal 200 side toward the side opposite to the main body of the electrode body 400. ing. Here, since the facing surface 742 of the positive electrode current collector 700 is arranged closer to the main body than the end of the electrode body 400, the positive electrode current collector 700 is a portion (second intermediate portion) on the positive electrode terminal 200 side. The facing surface 742 protrudes from 752) toward the main body of the electrode body 400. Therefore, since the corner portion of the facing surface 742 on the positive electrode terminal 200 side may damage the electrode body 400, the corner portion is curved in a dome shape to form the first curved surfaces 771 and 772. As a result, even if the facing surface 742 enters the inside of the electrode body 400 due to vibration or impact from the outside, the dome-shaped first curved surfaces 771 and 772 come into contact with the electrode body 400, so that the electrode body 400 Can be prevented from being damaged.

Further, the positive electrode current collector 700 has second curved surfaces 773 and 774 curved in a dome shape from the surface of the facing surface 742 opposite to the positive electrode terminal 200 toward the side opposite to the main body of the electrode body 400. Have. Here, since the facing surface 742 of the positive electrode current collector 700 is arranged closer to the main body than the end of the electrode body 400, the corner portion of the facing surface 742 opposite to the positive electrode terminal 200 forms the electrode body 400. It may be damaged. Therefore, the corner portion of the facing surface 742 opposite to the positive electrode terminal 200 is curved in a dome shape to form the second curved surfaces 773 and 774. As a result, even if the facing surface 742 enters the inside of the electrode body 400 due to vibration or impact from the outside, the dome-shaped second curved surfaces 773 and 774 come into contact with the electrode body 400, so that the electrode body 400 Can be prevented from being damaged.

Since the negative electrode side has the same configuration as the positive electrode side, the same effect can be obtained.

[6 Explanation of modified example]
Although the power storage element according to the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. That is, it should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

For example, in the above embodiment, the curved surface 770 is a curved surface formed at the position of the apex formed by the three surfaces of the facing surface 742 and the two adjacent surfaces adjacent to the facing surface 742. Here, the three surfaces are not limited to a flat surface, and any surface may be a curved surface, for example, the facing surface 742 is a curved surface. Alternatively, the first electrode body connecting portion 720, the second electrode body connecting portion 730, the connecting portion 740, the first intermediate portion 751 and the first extending portion 761 are all curved surfaces, and are spherical or long spherical as a whole. The curved surface 770 may be formed by having the shape of the portion. The same applies to the negative electrode side.

Further, in the above embodiment, it is assumed that a space is formed at the boundary portion between the two adjacent surfaces adjacent to the facing surface 742. However, the space may be configured such that the two adjacent surfaces are connected to each other and the space is not formed. The same applies to the negative electrode side.

Further, in the above embodiment, the positive electrode current collector 700 is provided with an extension portion 760 having a first extension portion 761 and a second extension portion 762. However, the positive electrode current collector 700 may not have the second extension portion 762, or may have the first extension portion 761 and the second extension portion 762 (that is, the extension portion 760). You may not do it. When the positive electrode current collector 700 does not have the extending portion 760, the curved surface 770 may not have the two second curved surfaces 773 and 774. Similarly, the curved surface 770 may not have two first curved surfaces 771,772. That is, even if the curved surface 770 does not have any of the four curved surfaces of the two first curved surfaces 771 and 772 and the two second curved surfaces 773 and 774. good. The same applies to the negative electrode side.

Further, in the above embodiment, the positive electrode current collector 700 is joined to the end portion of the electrode body 400 with the end portion of the electrode body 400 sandwiched between the clip 900 and the positive electrode body 400. However, the positive electrode current collector 700 may be joined to the end of the electrode body 400 without arranging the clip 900. The same applies to the negative electrode side.

Further, in the above embodiment, the connecting portion 740 connects the end edges of the first electrode body connecting portion 720 and the second electrode body connecting portion 730 on the electrode body 400 side (minus side in the X-axis direction). did. However, the connecting portion 740 is located at the end edge of the first electrode body connecting portion 720 and the second electrode body connecting portion 730 on the opposite side (plus side in the X-axis direction) from the electrode body 400, or at the center position in the X-axis direction. Any position may be connected, such as connecting each other. That is, the connecting portion 740 connects the first electrode body connecting portion 720 and the second electrode body connecting portion 730, and the first positive electrode side end portion 412 of the first electrode body connecting portion 720 and the second electrode body connecting portion 730. And a portion arranged along the connection portion with the second positive electrode side end portion 422. The connection portion is a joint portion formed by long welding or the like extending in the Z-axis direction. The same applies to the negative electrode side.

Further, in the above embodiment, the spacer 500 is arranged on the side of the positive electrode current collector 700, and the spacer 500 has a plurality of convex portions and concave portions. However, the spacer 500 may not have some or all of these protrusions and recesses. For example, the spacer 500 may not be formed with the spacer recess 513 in which the second extending portion 762 is arranged. Further, the spacer 500 may not be provided on the side of the positive electrode current collector 700. The same applies to the negative electrode side.

Further, in the above embodiment, both the positive electrode current collector 700 and the negative electrode current collector 800 have the above-mentioned configuration, but the positive electrode current collector 700 or the negative electrode current collector 800 has the above-mentioned configuration. It may not have a configuration.

Further, a form constructed by arbitrarily combining the components included in the above-described embodiment and its modifications is also included in the scope of the present invention.

Further, the present invention can be realized not only as such a power storage element but also as a current collector (positive electrode current collector 700, negative electrode current collector 800) included in the power storage element.

The present invention can be applied to a power storage element such as a lithium ion secondary battery.

10 Power storage element 200 Positive electrode terminal 400 Electrode body 410 First electrode body 411 First electrode body main body 412 First positive electrode side end 420 Second electrode body 421 Second electrode body main body 422 Second positive electrode side end 700 Positive electrode collection Electrical body 720 First electrode body connection part 730 Second electrode body connection part 740 Connection part 742 Opposing surface 750 Intermediate part 751 First intermediate part 760 Extension part 761 First extension part 770 Curved surface 771, 772 First curved surface 773, 774 Second curved surface 775 Space

Claims (4)

A power storage element including an electrode body and a current collector.
The electrode body has a main body portion and an end portion to which the current collector is connected.
The current collector
With a surface facing the main body, which is arranged closer to the main body than the end,
It has a curved surface curved from the facing surface toward the side opposite to the main body portion.
The curved surface has a portion where the portion arranged at the apex position formed by the facing surface and two adjacent surfaces extending from two adjacent sides of the facing surface to the opposite side of the main body portion is the facing surface. It is a curved surface curved from the above two adjacent surfaces.
Power storage element. The power storage element according to claim 1 , wherein a space is formed at the boundary between the two adjacent surfaces. The curved surface has a first curved surface that is curved from the first surface of the facing surface on the electrode terminal side toward the side opposite to the main body portion.
The first curved surface is arranged at the position of a vertex formed by the first surface and two first adjacent surfaces extending from two adjacent sides of the first surface to the side opposite to the main body portion. The portion is a curved surface curved from the first surface toward the two first adjacent surfaces.
The power storage element according to claim 1 or 2 . The curved surface has a second curved surface that is curved from a second surface opposite to the electrode terminal on the facing surface toward the side opposite to the main body portion.
The second curved surface is arranged at the position of a vertex formed by the second surface and two second adjacent surfaces extending from two adjacent sides of the second surface to the side opposite to the main body portion. The portion is a curved surface curved from the second surface toward the two second adjacent surfaces.
The power storage element according to any one of claims 1 to 3 .

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