storage element

Abstract

The power storage element includes an electrode body, a first conductive member, and a second conductive member. The electrode body includes an electrode body main body and a tab portion. The tab portion is provided at an end portion on one side in a first direction of the electrode body main body. The tab portion includes a tab connection portion bent in a second direction intersecting the first direction. The first conductive member includes a first connection portion connected to the tab connection portion and a second connection portion connected to the second conductive member. The first connection portion and the second connection portion are arranged in a third direction intersecting the first direction and the second direction when viewed from the one side in the first direction. The second connection portion is disposed on the one side in the first direction more than the first connection portion.

Description

Technical Field

[0001] This invention relates to energy storage components. Background Technology

[0002] Patent Document 1 discloses a battery comprising: a battery casing, an electrode body, a positive terminal, a first positive current collector, and a second positive current collector. In this battery, the positive electrode tabs of the electrode body and the positive terminal are electrically connected via the first and second positive current collectors. Specifically, the positive electrode tabs are joined to the second positive current collector. Further, the first positive current collector, fixed to a sealing plate of the battery casing, is joined to the second positive current collector. As a method for joining the first and second positive current collectors, welding by irradiation with high-energy rays such as lasers is employed, for example.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-15681 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the aforementioned existing batteries, the junction between the first positive current collector and the second positive current collector is located closer to the main body of the electrode body (the portion other than the positive and negative electrode tabs) than the junction between the second positive current collector and the positive electrode tab group. Therefore, the heat generated during the formation of this junction may adversely affect the electrode body, potentially damaging the battery's quality.

[0008] This invention was made by the inventors of this application with regard to the above-mentioned problems, and its purpose is to provide an energy storage element with improved quality.

[0009] Technical means to solve the problem

[0010] One aspect of the present invention relates to an energy storage element having an electrode body, a first conductive member, and a second conductive member. The electrode body has an electrode body main body and a tab portion. The tab portion is disposed at one end of the electrode body main body in a first direction. The tab portion has a tab connecting portion that bends in a second direction intersecting the first direction. The first conductive member has a first connecting portion connected to the tab connecting portion and a second connecting portion connected to the second conductive member. When viewed from the side in the first direction, the first connecting portion and the second connecting portion are arranged in a third direction intersecting the first and second directions. The second connecting portion is disposed on the side in the first direction that is closer to the first connecting portion than the first connecting portion.

[0011] Invention Effects

[0012] According to the present invention, it is possible to provide an energy storage element with improved quality. Attached Figure Description

[0013] Figure 1 This is a perspective view showing the appearance of the energy storage element involved in the embodiment.

[0014] Figure 2 This is an exploded perspective view of the energy storage element involved in the implementation method.

[0015] Figure 3 This is a perspective view showing the current collector and its surrounding structure involved in the implementation method.

[0016] Figure 4 It is a cross-sectional view showing the current collector and its surrounding structure involved in the embodiment.

[0017] Figure 5 This is a cross-sectional view showing the current collector and its surrounding structure according to Modified Example 1 of the embodiment.

[0018] Figure 6 This is a cross-sectional view showing the current collector and its surrounding structure in Modified Example 2 of the embodiment.

[0019] Figure 7 This is a top view schematically illustrating the structure of an energy storage device having the energy storage element involved in the embodiment. Detailed Implementation

[0020] (1) One aspect of the present invention relates to an energy storage element having an electrode body, a first conductive member and a second conductive member, the electrode body having an electrode body main body and an electrode tab, the electrode tab being disposed at an end of one side of the electrode body in a first direction, the electrode tab having an electrode tab connecting portion that bends in a second direction intersecting the first direction, the first conductive member having a first connecting portion connected to the electrode tab connecting portion and a second connecting portion connected to the second conductive member, wherein when viewed from the side of the first direction, the first connecting portion and the second connecting portion are arranged in a third direction intersecting the first direction and the second direction, and the second connecting portion is disposed on the side of the first direction further away than the first connecting portion.

[0021] According to one aspect of the present invention, in an energy storage element, the second connecting portion is disposed on a side further in the first direction than the first connecting portion. That is, the second connecting portion is disposed in the first direction at a position further away from the electrode body than the first connecting portion. Therefore, it is possible to suppress the adverse effects of heat generated during the connection operation (e.g., welding) between the second connecting portion and the second conductive member on the electrode body. Thus, the energy storage element according to one aspect of the present invention is an energy storage element with improved quality.

[0022] (2) In the energy storage element described in (1) above, the first conductive member may have a bent portion between the first connecting portion and the second connecting portion.

[0023] According to the energy storage element described in (2) above, a first conductive member with a shape in which the second connecting portion is disposed on the side further in the first direction than the first connecting portion can be manufactured, for example, by bending a plate-shaped metal material. Therefore, the first conductive member is easy to manufacture. Furthermore, the positions of the first connecting portion and the second connecting portion can be arbitrarily changed or appropriately modified. That is, the design freedom of the first conductive member is increased.

[0024] (3) In the energy storage element described in (1) or (2) above, the thickness of at least a portion of the second connection portion in the first direction may be less than the thickness of the first connection portion in the first direction.

[0025] According to the energy storage element described in (3) above, at least a portion of the second connecting part is provided as a thin-walled part on the first conductive member. This reduces the energy required for connecting the second connecting part to the second conductive member. In other words, the connection operation becomes easier, and adverse effects on the electrode body can be further suppressed.

[0026] (4) In any one of (1) to (3) above, the first connecting portion has a first facing surface facing the electrode body, and the second connecting portion has a second facing surface facing the electrode body, wherein the second facing surface is disposed on the side further in the first direction than the first facing surface.

[0027] According to the energy storage element described in (4) above, the second facing surface of the second connection portion is positioned further away from the electrode body body in the first direction than the first facing surface of the first connection portion. In particular, the second facing surface is the surface facing the electrode body body, which may cause adverse heat-related effects on a certain area of ​​the electrode body body. Therefore, it is possible to more reliably suppress the adverse effects of heat generated during the connection operation between the second connection portion and the second conductive member on the electrode body body.

[0028] (5) In any one of (1) to (4) above, the energy storage element may be configured such that the second connection portion has an outer side facing the first direction, the first connection portion is disposed between the tab connection portion and the electrode body, the tab connection portion has a tab side facing the first direction, and the outer side is disposed in the first direction at the same position as the tab side or on the other side of the first direction.

[0029] According to the energy storage element described in (5) above, the outer side of the second connection portion is positioned in the first direction at the same position as the tab side of the tab connection portion or closer to the electrode body than the tab side of the tab connection portion. Therefore, it is possible to suppress the second connection portion from protruding excessively to the side in the first direction compared to the first connection portion, thereby enabling the energy storage element to be miniaturized.

[0030] Hereinafter, the energy storage element according to embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the embodiments described below are general or specific examples. The numerical values, shapes, materials, structural elements, arrangement and connection methods of structural elements, manufacturing processes, and order of manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present invention. Additionally, dimensions in the figures are not strictly illustrated. Furthermore, the same reference numerals are used to label the same or identical structural elements in the figures.

[0031] In the following description and accompanying drawings, the X-axis direction is defined as the arrangement direction of a pair of terminals (positive and negative, the same below) of the energy storage element, the arrangement direction of a pair of current collectors, or the facing direction of a pair of short sides of the container. The Y-axis direction is defined as the facing direction of a pair of long sides of the container, the stacking direction of the electrode plates of the electrode body, or the thickness direction of the container. The Z-axis direction is defined as the arrangement direction of the container body and the cover of the energy storage element, or the direction of the long side of the short side of the container. These X-axis, Y-axis, and Z-axis directions are intersecting (orthogonal in this embodiment). Depending on the usage, the Z-axis direction may not be vertical, but for ease of explanation, the Z-axis direction will be described as vertical below.

[0032] In the following explanations, for example, the positive X-axis direction refers to the direction of the arrow pointing to the X-axis, and the negative X-axis direction refers to the direction opposite to the positive X-axis direction. The same applies to the Y-axis and Z-axis directions. When simply referred to as the "X-axis direction," it means either direction parallel to the X-axis. The terminology for the Y-axis and Z-axis follows the same pattern.

[0033] Furthermore, expressions indicating relative directions or orientations such as parallel and orthogonal also include cases where the direction or orientation is not strictly defined. For example, two orthogonal directions not only mean that the two directions are completely orthogonal, but also that they are substantially orthogonal, i.e., including differences of, for example, several percentage points. In the following description, "insulating" refers to "electrical insulation." Materials with insulating properties are preferably those with a volume resistivity of 1 × 10⁻⁶. 10 Materials with an Ωm or greater are formed.

[0034] (Implementation Method)

[0035] [1. Overall description of the energy storage components]

[0036] First, use Figure 1 and Figure 2 The overall description of the energy storage element 10 in this embodiment will be provided. Figure 1 This is a perspective view showing the appearance of the energy storage element 10 according to the embodiment. Figure 2 This is an exploded perspective view of the energy storage element 10 involved in the embodiment.

[0037] The energy storage element 10 is a secondary battery, more specifically, a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. The energy storage element 10 can be used, for example, as a battery for driving or starting the engine of mobile vehicles such as automobiles, motorized two-wheelers, watercraft, ships, powered snowmobiles, agricultural machinery, construction machinery, automated guided vehicles (AGVs), or railway vehicles for electric railways. Examples of automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, light oil, liquefied natural gas, etc.) vehicles. Examples of railway vehicles for electric railways include trams, monorails, linear electric locomotives, and hybrid trams with both diesel and electric motors. Furthermore, the energy storage element 10 can also be used as a stationary battery for household or commercial use.

[0038] The energy storage element 10 is not limited to a non-aqueous electrolyte secondary battery; it can also be a secondary battery other than a non-aqueous electrolyte secondary battery, or it can be a capacitor. The energy storage element 10 can also be a primary battery.

[0039] like Figure 1 The energy storage element 10 has a container 100, a pair of terminals 200, and a pair of external insulating members 300. For example... Figure 2The container 100 contains an electrode body 700, a pair of current collectors 500, and a pair of internal insulating members 400. An electrolyte (non-aqueous electrolyte) is sealed inside the container 100, but is not shown in the diagram. As for the electrolyte, there are no particular restrictions on its type, as long as it does not impair the performance of the energy storage element 10; various electrolytes can be selected. Furthermore, spacers and insulating films (not shown) may also be arranged inside the container 100.

[0040] Container 100 is a rectangular parallelepiped (box-shaped) shell. Here, a rectangular parallelepiped refers to a hexahedron whose faces are all composed of rectangles or squares. Container 100 has a container body 110 and a lid 120 that closes the opening of the container body 110. After the electrode body 700 is housed inside the container body 110, the interior of container 100 is sealed by welding or other methods. The materials of the container body 110 and the lid 120 are not particularly limited; for example, weldable metals such as stainless steel, aluminum, aluminum alloy, iron, and plated steel are preferred.

[0041] The container body 110 is a rectangular cylindrical component with a bottom and an opening at the top. The container body 110 has a pair of short side surfaces 112 on both sides in the X-axis direction, a pair of long side surfaces 113 on both sides in the Y-axis direction, and a bottom surface 114 in the negative Z-axis direction. The cover 120 is a rectangular plate-like component used to seal the opening of the container body 110. An exhaust valve 122 is disposed on the cover 120, which discharges gas from inside the container 100 when the internal pressure of the container 100 rises excessively. The cover 120 also has an injection port for injecting electrolyte into the container 100.

[0042] The electrode body 700 has a positive electrode plate, a negative electrode plate, and a spacer 711, and is an energy storage element (power generation element) capable of storing electricity. The electrode body 700 has an electrode body main body 710 and a pair of tabs 720 disposed at both ends in the X-axis direction of the electrode body main body 710. Hereinafter, when distinguishing between the positive and negative tabs 720, the positive tab 720 will be referred to as tab 720A, and the negative tab 720 will be referred to as tab 720B.

[0043] More specifically, the electrode body 700 is a wound electrode body formed by stacking and winding a positive electrode plate and a negative electrode plate separated by a spacer 711. Figure 2 In the attached drawing, the double-dotted line marked with reference numeral W indicates the winding axis W of the electrode body 700. The winding axis W is a virtual axis that serves as the central axis when winding the positive electrode plate, etc. In this embodiment, the winding axis W is parallel to the X-axis direction. The X-axis direction is an example of a first direction. The electrode body 700 is formed into a flat shape in a direction orthogonal to the winding axis W. That is, the electrode body 700 is a wound and flat electrode body. In this embodiment, as... Figure 2 As shown, the electrode body 700 has a flat shape in the Y-axis direction. The Y-axis direction is an example of the second direction.

[0044] More specifically, the electrode body 700 has curved portions at both ends in the Z-axis direction and a middle portion located between these curved portions. The middle portion is formed by stacking the flat portions (parts approximately parallel to the XZ plane) of the electrode plates (positive and negative electrode plates) along the Y-axis direction. That is, in this embodiment, the main stacking direction of the electrode plates of the electrode body 700 is the Y-axis direction. The stacking direction referred to below as "the stacking direction of the electrode plates of the electrode body 700" refers to the Y-axis direction.

[0045] The positive electrode plate has a strip-shaped metal foil, i.e., a positive electrode current collector foil, and a positive electrode active material layer formed on the surface of the positive electrode current collector foil. The negative electrode plate has a strip-shaped metal foil, i.e., a negative electrode current collector foil, and a negative electrode active material layer formed on the surface of the negative electrode current collector foil. In the electrode body 700, the positive electrode active material layer of the positive electrode plate and the negative electrode active material layer of the negative electrode plate are stacked with a spacer 711 in between, thereby forming the electrode body body 710. A spacer 711 is wound around the outermost periphery of the electrode body body 710 more than once. The tabs of the positive electrode current collector foil are stacked in the Y-axis direction to form a tab portion 720A. The tabs of the negative electrode current collector foil are stacked in the Y-axis direction to form a tab portion 720B. For both the positive and negative current collector foils, any material stable to the redox reaction during charging and discharging can be used, and known materials can be appropriately employed, such as nickel, iron, stainless steel, titanium, sintered carbon, conductive polymers, conductive glass, Al-Cd alloys, etc. For the positive active material used in the positive electrode active material layer and the negative active material used in the negative electrode active material layer, any material capable of absorbing and releasing charges and transporting ions can be used, and known materials can be appropriately employed.

[0046] In this embodiment, such as Figure 2 As shown, a first conductive member 510 of a current collector 500 is joined to each of the pair of tabs 720. Further, each of the pair of tabs 720 is aligned with the stacking direction of the electrode plates of the electrode body 700. Figure 2 The section is folded along the negative Y-axis. The connection method between the tab 720 and the current collector 500 will be discussed later. Figure 4 and Figure 5 Please provide an explanation.

[0047] Terminal 200 is a component electrically connected to electrode body 700 via current collector 500. Specifically, one side of a pair of terminals 200 is electrically connected to the positive plate of electrode body 700, and the other side of a pair of terminals 200 is electrically connected to the negative plate of electrode body 700. Terminal 200 is mounted on cover 120 disposed above electrode body 700. Specifically, terminal 200 has a shaft portion 201 penetrating cover 120. The shaft portion 201 of terminal 200 is inserted into and riveted to the through hole 301 of external insulating member 300, through hole 123 of cover 120, through hole 401 of internal insulating member 400, and through hole 523 of current collector 500. Thus, terminal 200, together with external insulating member 300, internal insulating member 400, and current collector 500, is fixed to cover 120. Terminal 200 is formed of aluminum, aluminum alloy, copper, or copper alloy, etc.

[0048] The external insulating member 300 is a member that insulates the cover 120 and the terminal 200. In this embodiment, the external insulating member 300 also functions as a sealing gasket that seals the space between the cover 120 and the shaft portion 201 of the terminal 200. The internal insulating member 400 is a member that insulates the cover 120 and the current collector 500. Both the external insulating member 300 and the internal insulating member 400 are formed of an electrically insulating resin material.

[0049] The current collector 500 is a component that electrically connects the tab 720 of the electrode body 700 and the terminal 200. More specifically, the current collector 500 has a first conductive member 510 and a second conductive member 520. The first conductive member 510 is connected to the tab 720. The second conductive member 520 is connected to the first conductive member 510. The second conductive member 520 is also connected to the terminal 200. That is, the second conductive member 520 electrically connects the first conductive member 510 and the terminal 200. Thus, the tab 720 of the electrode body 700 is electrically connected to the terminal 200 via the first conductive member 510 and the second conductive member 520. The structures of the first conductive member 510 and the second conductive member 520 will be discussed later. Figure 4 and Figure 5 illustrate.

[0050] When manufacturing the energy storage element 10 configured in this way, the first conductive member 510 connected to the tab portion 720 of the electrode body 700 and the second conductive member 520 fixed to the cover 120 are connected, for example, by laser welding. In this embodiment, the current collector 500 is configured in a way that suppresses the adverse effects of heat generated by this connection operation on the electrode body 710. Hereinafter, further reference will be made to... Figure 3 and Figure 4 Describe the structure of current collector 500 and its surrounding area.

[0051] [2. Regarding the structure of current collector 500 and its surroundings]

[0052] Figure 3 This is a perspective view showing the current collector 500 and its surrounding structure according to the embodiment. Figure 3 The diagrams of components of the energy storage element 10, other than the current collector 500 and the electrode body 700, are omitted. Figure 4 This is a cross-sectional view showing the current collector 500 and its surrounding structure according to the embodiment. Figure 4 The diagram schematically shows a portion of the cross-section of the energy storage element 10, which is through... Figure 1 A section of line IV-IV that is parallel to the XZ plane.

[0053] The energy storage element 10 involved in this embodiment can be located between the electrode body 710 and the current collector 500, and on the inner surface 111 of the current collector 500 and the container 100 (see reference). Figure 4 The electrode body 710 and the container 100 have insulating sheets or spacers between them, but these are not shown in the illustration. The inner side 111 of the container 100 is the inner side of the short side 112 of the container body 110. In this embodiment, the connecting piece 525 of the first conductive member 510 and the second conductive member 520 is disposed between the electrode body 710 and the inner side 111 of the container 100.

[0054] In the energy storage element 10 according to this embodiment, the connection method between the positive electrode tab 720A and the current collector 500 is the same as the connection method between the negative electrode tab 720B and the current collector 500. Therefore, the following description focuses on the connection method between the positive electrode tab 720A and the current collector 500.

[0055] like Figures 2-4 As shown, in this embodiment, the current collector 500 connecting the tab 720 and the terminal 200 is composed of a first conductive member 510 and a second conductive member 520. The tab 720 has a current collector in the Y-axis direction (in... Figures 2-4 The electrode connection portion 721 is bent in the negative Y-axis direction. The first conductive member 510 has a first connecting portion 511 connected to the electrode connection portion 721 and a second connecting portion 515 connected to the second conductive member 520. The second conductive member 520 has a connecting plate portion 521 and a connecting piece portion 525. The connecting plate portion 521 is connected to the shaft portion 201 of the terminal 200, and the connecting piece portion 525 extends from the connecting plate portion 521 and is connected to the second connecting portion 515 of the first conductive member 510.

[0056] Thus, in the energy storage element 10 according to this embodiment, the current collector 500 is composed of mutually independent components, namely the first conductive member 510 and the second conductive member 520. Therefore, the tab 720 can be ultrasonically bonded to the first conductive member 510, which is not connected to the second conductive member 520 fixed to the cover 120.

[0057] Specifically, in a state where the tab portion 720 is parallel to the X-axis direction (refer to...) Figure 2 The electrode tab 720 can be connected to the first conductive member 510. Therefore, the electrode tab 720 and the first connecting portion 511, which overlap in the Y-axis direction, can be easily clamped, for example, using an ultrasonic welding head and an anvil. Thus, the electrode tab 720 and the first connecting portion 511 can be efficiently and / or precisely connected using ultrasonic bonding. Figure 4 In this example, the approximate configuration range of the connection portion between the electrode portion 720 and the first connection portion 511, which utilizes ultrasonic bonding, is schematically shown as the first connection range 550.

[0058] The connection method between the tab 720 and the first conductive member 510 is not limited to ultrasonic bonding. Various methods such as riveting, laser welding, or resistance welding can be used as connection methods between the tab 720 and the first conductive member 510.

[0059] Furthermore, the tab 720 connected to the first conductive member 510 is bent so that the first conductive member 510 is located between the tab 720 and the electrode body 710 in the X-axis direction. As a result, a tab connecting portion 721 bent in the Y-axis direction is formed on the tab 720. In this state, the second connecting portion 515 of the first conductive member 510 is connected to the connecting piece portion 52 of the second conductive member 520. Therefore, when the electrode body 700 connected to the current collector 500 is housed in the container body 110, the distance between the electrode body 710 and the inner surface 111 of the container 100 facing the electrode body 710 in the X-axis direction can be shortened (see reference). Figure 4 ).

[0060] When connecting the second connecting portion 515 and the connecting piece portion 525, for example, Figure 4As shown, the space between the overlapping portion of the second connecting portion 515 and the connecting piece portion 525 and the electrode body 710 is relatively narrow. Therefore, it is difficult to perform ultrasonic bonding by clamping this overlapping portion using, for example, an ultrasonic welding head and anvil. Therefore, laser welding is used, for example, in the connection of the second connecting portion 515 and the connecting piece portion 525. Specifically, the connecting piece portion 525 of the second conductive member 520 is overlapped on the second opposing surface 516 of the second connecting portion 515 facing the electrode body 710, and a laser is irradiated onto the outer surface 517 of the second connecting portion 515. This allows the second connecting portion 515 and the connecting piece portion 525 to be connected. Figure 4 In this example, the approximate configuration range of the connection portion (the portion that solidifies after melting) between the second connection portion 515 and the connection piece portion 525, which is achieved by laser welding, is schematically shown as the second connection range 540.

[0061] Thus, as Figure 4 As shown, the second connection portion 515, which is connected to the second conductive member 520 by laser welding, is positioned further away from the electrode body 710 than the first connection portion 511. Therefore, the heat generated by laser welding is less likely to adversely affect the electrode body 710. For example, in the electrode body 710, spacers 711 located at the outermost periphery and between the positive and negative electrodes are less likely to shrink or deform due to the heat generated by laser welding. On the other hand, as... Figure 4 As shown, the first connecting portion 511, which connects to the tab portion 720 of the electrode body 700, is disposed inside the tab connecting portion 721 of the tab portion 720. Figure 4 (in the negative X-axis direction). Therefore, in the arrangement direction of the electrode body 710 and the first connecting part 511 (in the X-axis direction in this embodiment), the distance between the electrode body 710 and the inner side surface 111 of the container 100 can be relatively shortened.

[0062] As described above, the energy storage element 10 according to this embodiment includes: an electrode body 700, a first conductive member 510, a second conductive member 520, and a container 100 for accommodating the electrode body 700, the first conductive member 510, and the second conductive member 520. The electrode body 700 has an electrode body main body 710 and a tab portion 720, wherein the tab portion 720 is disposed on one side of the electrode body main body 710 in the X-axis direction ( Figure 4The end of the electrode portion 720 (in the positive X-axis direction). The electrode tab portion 720 has an electrode tab connecting portion 721 that is bent in the Y-axis direction, which intersects the X-axis direction. The first conductive member 510 has: a first connecting portion 511 connected to the electrode tab connecting portion 721; and a second connecting portion 515 connected to the second conductive member 520. When viewed from the positive X-axis direction, the first connecting portion 511 and the second connecting portion 515 are arranged in the Z-axis direction, which intersects the X-axis and Y-axis directions. The second connecting portion 515 is positioned further in the positive X-axis direction than the first connecting portion 511.

[0063] Thus, according to the energy storage element 10 of this embodiment, the second connecting portion 515 is positioned further along the positive X-axis than the first connecting portion 511. That is, the second connecting portion 515 is positioned further away from the electrode body 710 in the X-axis direction than the first connecting portion 511. Therefore, it is possible to suppress the adverse effects of heat generated during the connection operation (laser welding in this embodiment, hereinafter the same) between the second connecting portion 515 and the second conductive member 520 on the electrode body 710. Thus, the energy storage element 10 according to one aspect of the present invention is an energy storage element with improved quality.

[0064] In this embodiment, the first conductive member 510 has a bent portion 519 between the first connecting portion 511 and the second connecting portion 515. Specifically, as Figures 2-4 As shown, the first conductive member 510 has a plate-shaped portion as a bent portion 519, which connects the first connecting portion 511 and the second connecting portion 515, and has bent portions at both ends in the Z-axis direction. That is, the first connecting portion 511 and the second connecting portion 515, both parallel to the YZ plane and plate-shaped, are connected by the bent portion 519, which has a portion parallel to the X-axis direction and inclined relative to the Z-axis direction. Thus, the second connecting portion 515 is positioned further in the positive X-axis direction than the first connecting portion 511. The bent portion 519 can be described as bending away from the electrode body 710 as it moves closer to the second connecting portion 515 from the first connecting portion 511. Such a shape of the first conductive member 510 is, for example, referred to as a crank shape.

[0065] According to this structure, a first conductive member 510 with a shape in which the second connecting portion 515 is positioned further along the X-axis direction than the first connecting portion 511 can be manufactured by bending a plate-shaped metal material, for example. Therefore, the first conductive member 510 can be easily manufactured. Furthermore, the positions of the first connecting portion 511 and the second connecting portion 515 can be arbitrarily changed and appropriately modified. That is, the design freedom of the first conductive member 510 is increased.

[0066] The positional relationship between the first connecting portion 511 and the second connecting portion 515 in this embodiment is described more specifically as follows. The first connecting portion 511 has a first facing surface 512 facing the electrode body 710. The second connecting portion 515 has a second facing surface 516 facing the electrode body 710. The second facing surface 516 is disposed on a side further along the X-axis than the first facing surface 512. Figure 4 The position of the positive X-axis in the graph.

[0067] Thus, in this embodiment, the second facing surface 516 of the second connecting portion 515 is positioned further away from the electrode body 710 in the X-axis direction than the first facing surface 512 of the first connecting portion 511. In particular, the second facing surface 516 is the surface facing the electrode body 710, which may cause adverse heat effects on a certain area of ​​the electrode body 710. Therefore, the adverse effects of heat generated during the connection operation between the second connecting portion 515 and the second conductive member 520 on the electrode body 710 can be more reliably suppressed.

[0068] More specifically, in this embodiment, the second opposing surface 516 of the second connecting portion 515 is positioned further along the positive X-axis direction than the connecting surface 513 of the first connecting portion 511. The connecting surface 513 is the surface on the back side of the first opposing surface 512 in the first connecting portion 511, and is the surface on which the tab connecting portion 721 is connected using ultrasonic bonding or the like. This allows the overlapping portion of the second connecting portion 515 and the second conductive member 520 to be further removed from the electrode body 710. As a result, the adverse effects of heat generated during the connection operation between the second connecting portion 515 and the second conductive member 520 on the electrode body 710 can be more reliably suppressed. The second opposing surface 516 of the second connecting portion 515 can be positioned further along the negative X-axis direction than the connecting surface 513 of the first connecting portion 511, or it can be positioned further along the positive X-axis direction. In either case, as long as the second facing surface 516 of the second connecting portion 515 is positioned in the X-axis direction further away from the positive X-axis direction (away from the electrode body 710) than the first facing surface 512 of the first connecting portion 511.

[0069] In this embodiment, the outer surface 517 (refer to the side opposite to the second facing surface 516) of the second connecting portion 515 is referred to as the outer surface 517. Figure 3 and Figure 4 The location of the first connecting part 511 is described below. The second connecting part 515 has an outer surface 517 facing the positive X-axis direction. The first connecting part 511 is disposed between the tab connecting part 721 and the electrode body 710. The tab connecting part 721 has a tab side 722 facing the positive X-axis direction. The outer surface 517 is disposed in the X-axis direction at the same position as the tab side 722 or on the opposite side further in the X-axis direction than the tab side 722. Figure 4 The position of the negative X-axis (in the image).

[0070] Thus, the first connecting portion 511 of the first conductive member 510 is disposed between the tab connecting portion 721 and the electrode body 710, i.e., inside the tab connecting portion 721. This relatively shortens the distance between the electrode body 710 and the inner surface 111 of the container 100, resulting in an increase in the occupancy of the electrode body 710 relative to the internal volume of the container 100. Furthermore, the outer surface 517 of the second connecting portion 515 is disposed in the X-axis direction at the same position as the tab surface 722 or closer to the electrode body 710 than the tab surface 722. That is, the second connecting portion 515 is disposed in the X-axis direction away from the electrode body 710 and is not more protruding than the tab surface 722. Therefore, it is possible to suppress the increase in the distance between the electrode body 710 and the inner surface 111 of the container 100 in the X-axis direction caused by the second connecting portion 515 protruding more in the positive X-axis direction than the tab surface 722. As a result, it is possible to suppress the reduction in the occupancy of the electrode body 710 relative to the internal volume of the container 100.

[0071] The energy storage element 10 according to the embodiment has been described above. However, the energy storage element 10 may also have the same characteristics as... Figures 1-4 The energy storage element 10 can be used as an energy storage element in an energy storage device, depending on the different structures shown. Therefore, the following description will focus on the differences between the modified examples of the energy storage element 10 and the embodiments described above.

[0072] [3-1. Variation Example 1]

[0073] Figure 5 This is a cross-sectional view showing the current collector 500a and its surrounding structure according to Modified Example 1 of the embodiment. Figure 5 The diagram schematically shows a portion of the cross-section of the energy storage element 10a involved in this variation. Figure 5 The cross-sectional position in the middle is according to Figure 4 The location of the cross section.

[0074] The energy storage element 10a involved in this modification includes an electrode body 700, a first conductive member 510a, a second conductive member 520, and a container 100. The first conductive member 510a has a first connecting portion 511 connected to the tab connecting portion 721, and a second connecting portion 515 connected to the second conductive member 520. When viewed from the positive X-axis direction, the first connecting portion 511 and the second connecting portion 515 are arranged in the Z-axis direction. The second connecting portion 515 is positioned further along the positive X-axis direction than the first connecting portion 511. These structures are the same as those of the energy storage element 10 involved in the embodiment.

[0075] In the energy storage element 10 according to the embodiment, the thickness of the second connecting portion 515 in the X-axis direction is the same as the thickness of the first connecting portion 511 in the X-axis direction. In this variation, at least a portion of the thickness of the second connecting portion 515 in the X-axis direction is less than the thickness of the first connecting portion 511 in the X-axis direction. Specifically, the second connecting portion 515 of the first conductive member 510a has a thin-walled portion 518 that is thinner than the first connecting portion 511, and the thin-walled portion 518 is connected to the second conductive member 520. In this respect, the energy storage element 10a according to this variation differs from the energy storage element 10 according to the embodiment.

[0076] In this way, at least a portion of the second connecting portion 515 is provided as a thin-walled portion 518 on the first conductive member 510a, thus facilitating the connection operation between the second connecting portion 515 and the second conductive member 520. Specifically, for example, the second connecting portion 515 and the second conductive member 520 can be connected by laser welding with a shorter time and / or a smaller laser output. That is, the connection operation becomes easier, and adverse effects on the electrode body can be further suppressed. Furthermore, since the thin-walled portion 518 is connected to the connecting piece portion 525 of the second conductive member 520, such as Figure 5 As shown, the distance D1 between the connecting piece 525 and the electrode body 710 in the X-axis direction can be further extended. This allows for more reliable suppression of the adverse effects of heat generated during laser welding on the electrode body 710.

[0077] [3-2. Variation Example 2]

[0078] Figure 6 This is a cross-sectional view showing the current collector 500b and its surrounding structure according to Modified Example 2 of the embodiment. Figure 6 A portion of the cross-section of the energy storage element 10b involved in this variation is schematically shown. Figure 6 The cross-sectional position in the middle is according to Figure 4 The location of the cross section.

[0079] The energy storage element 10b in this modification has the same structure as the energy storage element 10 in the embodiment. Furthermore, similarly to the energy storage element 10a in Modification 1, at least a portion of the thickness of the second connecting portion 515 in the X-axis direction is less than the thickness of the first connecting portion 511 in the X-axis direction. Specifically, the current collector 500b in this modification has a first conductive member 510b, and the second connecting portion 515 of the first conductive member 510b has a thin-walled portion 518. The thin-walled portion 518 is connected to the second conductive member 520. In these respects, the energy storage element 10b in this modification is the same as the energy storage element 10a in Modification 1. Therefore, the connection operation between the second connecting portion 515 and the second conductive member 520 becomes easier.

[0080] In this modified example, the thin-walled portion 518 is connected to the second conductive member 520, thereby extending the distance D2 between the second connecting portion 515 and the inner surface 111 of the container 100 in the X-axis direction without shortening the distance between the connecting piece 525 and the electrode body 710 in the X-axis direction. In this respect, it is similar to the energy storage element 10a involved in Modified Example 1 (see...). Figure 5 The difference is that, in this modified example, since the distance D2 is longer, the second connection 515 and the inner surface 111 of the container 100 facing the second connection 515 in the X-axis direction can be insulated more reliably.

[0081] [3-3. Variation Example 3]

[0082] Figure 7 This is a top view schematically illustrating the structure of an energy storage device 900 having the energy storage element 10 according to the embodiment. For example... Figure 7 As shown, the energy storage element 10 can also be used in the energy storage device 900. In this case, the technology of the present invention can be applied to at least one energy storage element 10 of the energy storage device 900.

[0083] Figure 7 The illustrated energy storage device 900 has a plurality of energy storage units 800 disposed internally. Each energy storage unit 800 is composed of a plurality of energy storage elements 10 electrically connected. The energy storage device 900 may also have a busbar (not shown) electrically connecting the plurality of energy storage elements 10, and a busbar (not shown) electrically connecting the plurality of energy storage units 800, etc. The energy storage unit 800 or the energy storage device 900 may also have a status monitoring device (not shown) for monitoring the status of one or more energy storage elements 10. The energy storage device 900 may also have only one energy storage unit 800. In this case, the energy storage unit 800 may also be referred to as an "energy storage device".

[0084] In this variation, the energy storage device 900 has one or more energy storage elements 10 as described in the above embodiments. However, the energy storage device 900 may also replace one or more energy storage elements 10, or may be supplemented with energy storage elements 10a or 10b as described in the above variations 1 or 2.

[0085] [4. Other variations]

[0086] The above description illustrates the energy storage element and its modifications according to embodiments of the present invention, but the present invention is not limited to these embodiments and modifications. That is, it should be understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is intended to include the meaning equivalent to the claims and all modifications within that scope.

[0087] The electrode body 700 of the energy storage element 10 may also have only one of a pair of tabs 720. For example, the electrode body 700 may have a positive tab 720A at the end of the electrode body 710 in the positive X-axis direction, and a bundle of negative electrode current collector foil (negative electrode bundle) exposed over the entire area of ​​the electrode body 710 in the Z-axis direction at the end of the electrode body 710 in the negative X-axis direction. In this case, it is also possible to... Figures 2-4 The current collector 500 shown is connected to the tab 720A of the positive electrode, and a current collector having a pair of legs that clamp the negative electrode cluster in the Y-axis direction is connected to the negative electrode cluster.

[0088] The energy storage element 10 may also have only one of the pair of terminals 200. For example, consider the case where the positive plate of the electrode body 700 is electrically connected to the container 100, i.e., the container 100 is used as the positive terminal. In this case, only one of the pair of current collectors 500 connected to the tab 720B of the negative terminal may be present. Furthermore, in this case, the energy storage element 10 may also have only one external insulating member 300 and one internal insulating member 400, respectively.

[0089] The second conductive member 520 may not be directly connected to the terminal 200. For example, the second conductive member 520 may also be electrically connected to the terminal 200 via another conductive member connected to the shaft portion 201 of the terminal 200.

[0090] The first conductive member 510 does not necessarily have a bent portion 519. For example, the connecting surface 513 of the first connecting portion 511 and the outer surface 517 of the second connecting portion 515 can also form a series of planes parallel to the YZ plane. Even in this case, the second opposing surface 516 can be positioned further in the X-axis direction than the first opposing surface 512 (e.g., Figure 4The position is in the positive X-axis direction. Therefore, the adverse effects of heat generated during the connection operation between the second connecting portion 515 and the second conductive member 520 on the electrode body 710 can be suppressed. That is, the first conductive member 510 does not need to be a so-called crank-shaped member. The first conductive member 510 can be, for example, a flat plate member, where the portion corresponding to the second connecting portion 515 is thinner than the portion corresponding to the first connecting portion 511. Alternatively, a straight-line connecting portion extending along the Z-axis can be used as an alternative to the shape of the bent portion 519. For example, when viewed from the Z-axis direction, if a portion of the first connecting portion 511 and a portion of the second connecting portion 515 are positioned in an overlapping position, a straight-line connecting portion extending along the Z-axis can be used to connect the portion of the first connecting portion 511 and the portion of the second connecting portion 515. Even in this case, the second opposing surface 516 can be positioned further along the X-axis direction than the first opposing surface 512 (e.g., ...). Figure 4 The position of the positive X-axis in the graph.

[0091] The energy storage element 10 does not necessarily have a wound electrode body 700. The energy storage element 10 may also have a stacked electrode body formed by stacking a plurality of flat plates or a corrugated electrode body formed by folding the plates into a corrugated shape. In either case, the electrode body of the energy storage element 10 may have an electrode body body and a tab provided at one end of the electrode body body in a first direction (in the embodiment, the positive X-axis direction).

[0092] The number of tabs 720 connected to the first connecting portion 511 of the first conductive member 510 can be two or more. For example, if the electrode body 710 has two tabs 720A arranged in the Z-axis direction at the end in the positive X-axis direction, the two tabs 720A can be connected to the first connecting portion 511 by a prescribed method such as ultrasonic bonding.

[0093] The second conductive member 520 of the current collector 500 is fixed to the container 100 by riveting the shaft portion 201 of the terminal 200 and is electrically connected to the terminal 200, but this is not mandatory. For example, the second conductive member 520 may also have a shaft portion protruding in the positive Z-axis direction, and this shaft portion passes through the terminal 200 which does not have a shaft portion 201, and is riveted to the Z-axis-facing surface of the terminal 200. Even in this case, the second conductive member 520 is fixed to the container 100 and electrically connected to the terminal 200. The method of joining the second conductive member 520 and the terminal 200 is not limited to riveting. The second conductive member 520 and the terminal 200 may also be joined by welding, press-fitting, or threaded engagement (engagement by the mating of external and internal threads).

[0094] The first connecting portion 511 that connects to the tab portion 720 of the electrode body 700 is not necessarily located inside the tab connecting portion 721 of the tab portion 720. Figure 4 (in the negative X-axis direction). That is, the first connecting part 511 can also be disposed on the outside of the tab connecting part 721 (in the negative X-axis direction). Figure 4 (positive X-axis direction).

[0095] The thickness of the second connecting portion 515 of the first conductive member 510 in the X-axis direction is set to be the same as the thickness of the first connecting portion 511 of the first conductive member 510 in the X-axis direction, but the thickness of the second connecting portion 515 in the X-axis direction may also be greater than the thickness of the first connecting portion 511 in the X-axis direction.

[0096] The second facing surface 516 of the second connecting portion 515 does not necessarily have to be positioned opposite to the electrode body 710. The second facing surface 516 can also be positioned opposite to the space located in the positive Z-axis direction relative to the electrode body 710. That is, the first conductive member 510 can also be configured such that the first connecting portion 511 faces the electrode body 710, while the second connecting portion 511 does not face the electrode body 710.

[0097] The outer surface 517 of the second connecting portion 515 does not necessarily have to be positioned in the X-axis direction at the same position as the tab side 722 or closer to the electrode body 710 than the tab side 722. That is, the outer surface 517 of the second connecting portion 515 can also be positioned in the X-axis direction further away from the electrode body 710 than the tab side 722.

[0098] The supplementary details regarding the energy storage element 10 involved in the above embodiments can also be applied to the energy storage elements 10a and 10b involved in variations 1 and 2, respectively. Any combination of the structural elements included in the above embodiments and their variations is also included within the scope of this invention.

[0099] Industrial availability

[0100] This invention can be applied to energy storage components such as lithium-ion secondary batteries.

[0101] Explanation of reference numerals in the attached figures

[0102] 10, 10a, 10b energy storage components

[0103] 100 containers

[0104] 200 terminals

[0105] 500, 500a, 500b collectors

[0106] 510, 510a, 510b First conductive components

[0107] 511 First Connecting Part

[0108] 512 First Facing Plane

[0109] 513 Connecting Surface

[0110] 515 Second Connecting Part

[0111] 516 Second Phase Surface

[0112] 517 outer side

[0113] 518 Thin-walled section

[0114] 519 Bend

[0115] 520 Second Conductive Component

[0116] 521 Connecting Plate

[0117] 525 connecting piece

[0118] 700 electrode body

[0119] 710 Electrode Body

[0120] 711 spacer

[0121] 720, 720A, 720B electrode tabs

[0122] 721 tab connection part

[0123] 722 electrode side

Claims

1. An energy storage element, wherein, The energy storage element has an electrode body, a first conductive component, and a second conductive component. The electrode body has an electrode body main body and an electrode tab, the electrode tab being disposed at one end of the electrode body main body in a first direction. The electrode lug has an electrode lug connection portion that bends in a second direction that intersects the first direction. The first conductive member has a first connecting portion connected to the electrode connecting portion and a second connecting portion connected to the second conductive member. When viewed from one side of the first direction, the first connecting portion and the second connecting portion are arranged upwards on a third direction intersecting the first and second directions. The second connecting portion is disposed on the side that is further away from the first connecting portion in the first direction.

2. The energy storage element according to claim 1, wherein, The first conductive member has a bent portion between the first connecting portion and the second connecting portion.

3. The energy storage element according to claim 1 or 2, wherein, The thickness of at least a portion of the second connecting portion in the first direction is less than the thickness of the first connecting portion in the first direction.

4. The energy storage element according to claim 1 or 2, wherein, The first connecting portion has a first facing surface that faces the electrode body. The second connecting portion has a second facing surface that faces the electrode body. The second opposing surface is disposed on the side that is further away from the first opposing surface in the first direction than the first opposing surface.

5. The energy storage element according to claim 1 or 2, wherein, The second connecting portion has an outer side facing the side in the first direction. The first connecting portion is disposed between the tab connecting portion and the electrode body body. The electrode connector has an electrode side facing the side in the first direction. The outer side is positioned in the first direction at the same location as the tab side or on the other side of the first direction, which is further away from the tab side.

Images