Energy storage device and method for manufacturing the same

Abstract

The objective is to provide energy storage devices and their manufacturing methods that can be manufactured efficiently and stably by further improving the manufacturing process of energy storage devices. [Solution] The electrode body comprises an electrode body manufacturing step of manufacturing an electrode body having a negative electrode tab group 220 and a negative electrode tab group 270; an arrangement step of arranging the negative electrode tab group 220 and the negative electrode tab group 270 in the tab housing space 670 through the open region 680 after the electrode body manufacturing step, with the second connecting wall 660 not placed in the open region 680; a sealing step of arranging the second connecting wall 660 in the open region 680 after the arrangement step; and a bending step of bending the negative electrode tab group 220 and the negative electrode tab group 270 with the surrounding wall facing the main outer surface of the negative electrode tab group 220 and the second connecting wall 660 facing the main outer surface of the negative electrode tab group 270 after the sealing step.

Description

Technical Field

[0001] The present technology relates to a power storage device and a method for manufacturing the same.

Background Art

[0002] Japanese Patent No. 4537353 (Patent Document 1) discloses a rectangular power storage device in which a positive electrode terminal is provided on one side surface of a battery case of a secondary battery and a negative electrode terminal is provided on the other end.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, by using a rectangular power storage device in which a positive electrode terminal is provided on one side surface of a battery case and a negative electrode terminal is provided on the other end, a secondary battery with a low height can be obtained. However, in order to obtain a secondary battery that can be manufactured efficiently and stably, there is room for further improvement. For example, inside the battery case, a spacer is provided between the electrode body and the sealing plate.

[0005] When connecting a tab electrode (tab electrode group) provided on the electrode body to the electrode terminal of the sealing plate, a step of passing the tab electrode through an opening provided in the spacer is required, and a working space for this purpose is required, and improvement of this step is demanded. This problem is not limited to secondary batteries and is the same in power storage devices capable of charge and discharge.

[0006] The present technology has been made to solve the above problems, and an object thereof is to provide a power storage device that can be manufactured efficiently and stably and a method for manufacturing the same by further improving the manufacturing process of the power storage device. ​

[0007] This technology provides a method for manufacturing the following energy storage devices. [1] An electrode body comprising a first electrode and a second electrode having a different polarity from the first electrode, and a case housing the electrode body, the case comprising a case body having a first opening at one end and a first sealing plate sealing the first opening, the electrode body comprising a first tab and a second tab at the end on the side of the first sealing plate, respectively electrically connected to the first electrode, a first spacer disposed between the first sealing plate and the electrode body, the first tab and the second tab being arranged in a curved state in a tab housing space provided in the first spacer, the first spacer comprising a surrounding wall located around the tab housing space, the surrounding wall comprising a tab housing space in a part of the surrounding wall A method for manufacturing an energy storage device, comprising: an electrode body manufacturing step of manufacturing an electrode body having the first tab and the second tab; an arrangement step of arranging the first tab and the second tab in the tab housing space through the open region, after the electrode body manufacturing step, with the sealing wall not arranged in the open region; a sealing step of arranging the sealing wall in the open region after the arrangement step; and a bending step of bending the first tab and the second tab, with the enclosing wall facing the main outer surface of the first tab and the sealing wall facing the main outer surface of the second tab, after the sealing step.

[0008] [2] A method for manufacturing an energy storage device according to [1], comprising the step of joining at least one of the first tab and the second tab to the first conductive member (first current collector) before the arrangement step.

[0009] [3] The method for manufacturing an energy storage device according to [1] or [2], wherein the first tab has a first recess that is recessed on the side of the second tab when curved, the second tab has a second recess that is recessed on the side of the first tab when curved, the enclosure wall has a first protrusion, the sealing wall has a second protrusion, the first protrusion is located within the first recess, and the second protrusion is located within the second recess.

[0010] [4] The method for manufacturing an energy storage device according to any one of [1] to [3], wherein the enclosure wall has a first concave curved surface portion on the side of the first sealing plate of the first protrusion, and the sealing wall has a second concave curved surface portion on the side of the first sealing plate of the second protrusion.

[0011] [5] A method for manufacturing an energy storage device according to any one of [1] to [4], comprising: an insertion step of inserting the electrode body and the first spacer into the case body after the arrangement step; and, after the insertion step, a bending step of bending the first tab and the second tab while bringing the enclosure wall into contact with the first tab and the sealing wall into contact with the sealing wall.

[0012] [6] The method for manufacturing an energy storage device according to any one of [1] to [5], wherein the case body has a second opening at the other end, and the second opening is sealed with a second sealing plate.

[0013] [7] A method for manufacturing an energy storage device according to any one of [1] to [6], wherein the first spacer is placed on one end of the electrode body, and the electrode body and the first spacer are covered with an insulating sheet.

[0014] [8] The method for manufacturing an energy storage device according to any one of items [1] to [7], wherein the sealing wall is a separate component from the enclosure wall.

[0015] [9] The method for manufacturing an energy storage device according to any one of [1] to [8], wherein the sealing wall is integral with the enclosure wall and the sealing wall is movable relative to the enclosure wall.

[0016]

[10] The method for manufacturing an energy storage device according to [8] or [9], wherein the sealing wall has an engaging projection, and the first spacer has an engaging recess into which the engaging projection engages.

[0017]

[11] The method for manufacturing an energy storage device according to

[10] , wherein the engagement projection has a snap-fit ​​structure.

[0018] This technology provides the following energy storage devices.

[12] An electrode body comprising a first electrode and a second electrode having a different polarity from the first electrode, and a case housing the electrode body, the case comprising a case body having a first opening at one end and a first sealing plate sealing the first opening, the electrode body comprising a first tab and a second tab at the end on the side of the first sealing plate, respectively electrically connected to the first electrode, a first spacer disposed between the first sealing plate and the electrode body, the first tab and the second tab being curved and electrically connected to the first electrode An energy storage device connected to a first spacer, wherein the first tab and the second tab are arranged in a curved state within a tab housing space provided in the first spacer, the first spacer includes an enclosure wall located around the tab housing space, the enclosure wall having an open area in a part of the enclosure wall that opens the tab housing space and a sealing wall that closes the open area, the first tab and the second tab are curved with the enclosure wall facing the main outer surface of the first tab and the sealing wall facing the main outer surface of the second tab.

[0019]

[13] The sealing wall is a separate component from the enclosure wall, as described in

[12] .

[14] The sealing wall is integral with the enclosure wall, and the sealing wall is movable relative to the enclosure wall, as described in

[12] . [Effects of the Invention]

[0020] This technology makes it possible to provide energy storage devices and their manufacturing methods that can be manufactured efficiently and stably by further improving the manufacturing process of energy storage devices.

Brief Description of the Drawings

[0021] [Figure 1] It is a front view showing the configuration of the secondary battery of Embodiment 1. [Figure 2] It is a view showing the state of the secondary battery shown in FIG. 1 as seen from the direction of arrow II. [Figure 3] It is a view showing the state of the secondary battery shown in FIG. 1 as seen from the direction of arrow III. [Figure 4] It is a view showing the state of the secondary battery shown in FIG. 1 as seen from the direction of arrow IV. [Figure 5] It is a view showing the state of the secondary battery shown in FIG. 1 as seen from the direction of arrow V. [Figure 6] It is a front cross-sectional view of the secondary battery shown in FIG. 1. [Figure 7] It is a cross-sectional view of the negative electrode plate. [Figure 8] It is a front view showing the negative electrode plate. [Figure 9] It is a cross-sectional view of the positive electrode plate. [Figure 10] It is a front view showing the positive electrode plate. [Figure 11] It is a XI-XI cross-sectional view of the secondary battery shown in FIG. 1. [Figure 12] It is a XII-XII cross-sectional view of the secondary battery shown in FIG. 1. [Figure 13] It is a first perspective view showing the form of the spacer. [Figure 14] It is a second perspective view showing the form of the spacer. [Figure 15] It is a XV-XV end view of the spacer shown in FIG. 13. [Figure 16] It is a flowchart showing the manufacturing method of the secondary battery according to Embodiment 1. [Figure 17] It is a perspective view showing the state in which the current collectors are joined to the two electrode bodies included in the secondary battery according to Embodiment 1. [Figure 18] It is an XVIII-XVIII cross-sectional view of the electrode body and the current collector shown in FIG. 17. [Figure 19] It is a perspective view showing the state in which the spacer is attached to the electrode body. [Figure 20] This is a perspective view showing the electrode body and spacer before they are covered with an insulating sheet. [Figure 21] This is a perspective view showing the state after the electrode body and spacer have been covered with an insulating sheet. [Figure 22] This is a perspective view showing the positive electrode current collector with a sealing plate attached. [Figure 23] This is a cross-sectional view showing the negative electrode tab on the negative electrode side before it was bent. [Figure 24] This is a cross-sectional view showing the state after the negative electrode tab on the negative electrode side has been bent. [Figure 25] This is a perspective view showing the configuration of a secondary battery. [Figure 26] This is a first front view showing the configuration of the spacer according to Embodiment 1. [Figure 27] This is a second front view showing the configuration of the spacer according to Embodiment 1. [Figure 28] This is a partially enlarged cross-sectional view showing the detailed configuration of the spacer in Embodiment 1. [Figure 29] This is a partially enlarged cross-sectional view showing a modified example of the spacer according to Embodiment 1. [Figure 30] This is a partially enlarged view showing another variation of the spacer of Embodiment 1. [Figure 31] This is a cross-sectional view taken from XXXXI-XXXI in Figure 30. [Figure 32] This is a partially enlarged cross-sectional view showing another variation of the spacer of Embodiment 1. [Figure 33] This is a partially enlarged cross-sectional view showing another variation of the spacer of Embodiment 1. [Figure 34] This is a partially enlarged cross-sectional view showing another variation of the spacer of Embodiment 1. [Figure 35] This is a partially enlarged cross-sectional view showing another variation of the spacer of Embodiment 1. [Figure 36] This is a partially enlarged view showing another variation of the spacer of Embodiment 1. [Figure 37] This is a cross-sectional view of XXXVII-XXXVII in Figure 36. [Figure 38] This is a first front view showing the configuration of the spacer according to Embodiment 2. [Figure 39] This is a second front view showing the configuration of the spacer in Embodiment 2. [Figure 40] This is a first front view showing the configuration of the spacer according to Embodiment 3. [Figure 41] This is a second front view showing the configuration of the spacer according to Embodiment 3. [Figure 42] This is a first front view showing the configuration of the spacer according to Embodiment 4. [Figure 43] This is a second front view showing the configuration of the spacer according to Embodiment 4. [Figure 44] This is a first front view showing the configuration of the spacer according to Embodiment 5. [Figure 45] This is a second front view showing the configuration of the spacer according to Embodiment 5. [Figure 46] This is a first front view showing the configuration of the spacer according to Embodiment 6. [Figure 47] This is a second front view showing the configuration of the spacer according to Embodiment 6. [Modes for carrying out the invention]

[0022] Embodiments of this technology are described below. Note that the same or corresponding parts may be denoted by the same reference numerals, and their descriptions may not be repeated.

[0023] In the embodiments described below, when referring to the number, quantity, etc., unless otherwise specified, the scope of this technology is not necessarily limited to that number, quantity, etc. In the embodiments described below, each component is not necessarily essential to this technology unless otherwise specified. This technology is not necessarily limited to achieving all of the effects and advantages mentioned in these embodiments.

[0024] In this specification, the terms “comprise,” “include,” and “have” are in open-ended form. That is, if a configuration includes one configuration, it may also include other configurations, or it may not.

[0025] Where geometric terms and terms describing positional and directional relationships are used herein, such as "parallel," "orthogonal," "45° oblique," "coaxial," and "alongside," these terms allow for manufacturing tolerances or slight variations. Where terms describing relative positional relationships, such as "upper" and "lower," are used herein, these terms are used to indicate the relative positional relationship in a single state, and the relative positional relationship may be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by inverting the entire mechanism upside down).

[0026] In this specification, secondary batteries are described as an example of "energy storage devices," but the term is not limited to secondary batteries. "Energy storage device" is a term that refers to all energy storage devices that can be repeatedly charged and discharged, and is a concept that encompasses secondary batteries (chemical batteries) such as lithium-ion secondary batteries and nickel-metal hydride batteries, and capacitors (physical batteries) such as lithium-ion capacitors and electric double-layer capacitors.

[0027] In this specification, "electrode" may refer collectively to both the positive electrode and the negative electrode. In this specification, the first direction (X direction) is sometimes referred to as the "width direction" of the secondary battery, electrode body, and case body; the second direction (Z direction) is sometimes referred to as the "height direction" of the secondary battery or case body; and the third direction (Y direction) is sometimes referred to as the "thickness direction" of the secondary battery or case body. To facilitate understanding of this technology, detailed shapes of each component are sometimes omitted in the drawings.

[0028] [Embodiment 1] (Overall configuration of a secondary battery) Referring to Figures 1 to 6, the overall configuration of the secondary battery 1 of Embodiment 1 will be described.

[0029] In this specification, "secondary battery" is not necessarily limited to prismatic cells, but may also include cells of other shapes such as cylindrical, pouch-type, and blade-type. Furthermore, "secondary batteries" can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). However, the use of "secondary batteries" is not limited to automotive applications.

[0030] The secondary battery 1 includes a case 100, an electrode body 200, electrode terminals 300, and a current collector 400. The case 100 includes a case body 110, a sealing plate 120 (first sealing plate), and a sealing plate 130 (second sealing plate).

[0031] When a battery pack including a secondary battery 1 is constructed, multiple secondary batteries 1 are stacked in the thickness direction. The stacked secondary batteries 1 may be constrained in the stacking direction (Y direction) by a restraining member to form a battery module, or the battery pack may be directly supported on the side of the battery pack case without using a restraining member.

[0032] The case body 110 consists of a cylindrical, preferably rectangular, member. This results in a rectangular secondary battery 1. The case body 110 is made of metal. Specifically, the case body 110 is made of aluminum, aluminum alloy, iron, or iron alloy.

[0033] As shown in Figures 1 and 2, sealing plates 120 and 130 are provided at both ends of the case body, respectively. The case body 110 can be formed into a rectangular tube shape by, for example, bringing together the ends of bent plate-shaped members (joint portion 115 as illustrated in Figure 2) and joining them together (for example, by energy ray irradiation such as laser welding). The corners of the "rectangular tube" may have a rounded shape. The secondary battery in this technology is not necessarily limited to a rectangular secondary battery.

[0034] In this embodiment, the case body 110 is formed to be longer in the width direction (X direction) of the secondary battery 1 than in the thickness direction (Y direction) and height direction (Z direction) of the secondary battery 1. The dimension (width) of the case body 110 in the X direction is preferably about 30 cm or more. This makes it possible to construct a relatively large (high capacity) secondary battery 1. The dimension (height) of the case body 110 in the Z direction is preferably about 20 cm or less, more preferably about 15 cm or less, and even more preferably about 10 cm or less. This makes it possible to construct a relatively low-height secondary battery 1, which improves, for example, its mountability in a vehicle.

[0035] The case body 110 includes a pair of first side sections 111 and a pair of second side sections 112. The pair of first side sections 111 constitute a part of the side surface of the case 100. The pair of second side sections 112 constitute the bottom and top surfaces of the case 100. Each of the pair of first side sections 111 and the pair of second side sections 112 is provided so as to intersect each other. The pair of first side sections 111 and the pair of second side sections 112 are connected at their respective ends. It is desirable that each of the pair of first side sections 111 has a larger area than each of the pair of second side sections 112.

[0036] As shown in Figure 5, a gas exhaust valve 150 is provided on one of the pair of second side portions 112A. The gas exhaust valve 150 extends in the width direction (X direction) of the secondary battery 1. The gas exhaust valve 150 extends in the X direction to the extent that it does not reach the ends of the case body 110 from the center in the X direction. The shape of the gas exhaust valve 150 can be changed as appropriate.

[0037] The thickness of the plate-shaped member in the gas discharge valve 150 is thinner than the thickness of the other plate-shaped members in the case body 110. As a result, when the pressure inside the case 100 exceeds a predetermined value, the gas discharge valve 150 preferentially ruptures compared to other parts of the case body 110, and discharges the gas inside the case 100 to the outside.

[0038] As shown in Figure 2, a joint portion 115 is formed on the other second side portion 112B of the pair of second side portions 112. The joint portion 115 extends in the width direction (X direction) of the secondary battery 1. At the joint portion 115, the ends of the plate-shaped members constituting the case body 110 are joined together.

[0039] As shown in Figure 3, an opening 113 (first opening) is provided at the first side end of the case body 110 in the first direction (X direction). The opening 113 is sealed by a sealing plate 120. A joint 115 is formed in the opening 113 to seal it. The opening 113 and the sealing plate 120 have a substantially rectangular shape with the Y direction being the short side and the Z direction being the long side. The substantially rectangular shape includes a rectangular shape, or a rectangular shape with rounded corners, etc.

[0040] A negative terminal 301 is provided on the sealing plate 120 (first sealing plate). The position of the negative terminal 301 can be changed as appropriate.

[0041] As shown in Figure 4, an opening 114 (second opening) is provided at the end of the second side of the case body 110, opposite to the first side in the first direction (X direction). That is, the opening 114 is located at the end opposite to the opening 113, and the openings 113 and 114 face each other. The opening 114 is sealed by a sealing plate 130. A joint 115 is formed in the opening 114 to seal it. The opening 114 and the sealing plate 130 have a substantially rectangular shape, with the Y direction being the shorter side and the Z direction being the longer side.

[0042] A positive electrode terminal 302 and an electrolyte injection hole 134 are provided on the sealing plate 130 (second sealing plate). The electrolyte injection hole 134 only needs to be large enough to inject electrolyte into the case 100, and is preferably smaller than the insertion hole for the positive electrode terminal 302 provided on the sealing plate 130. It is preferable that the electrolyte injection hole 134 is offset from the center of the sealing plate 130 in the Z direction. The positions of the positive electrode terminal 302 and the electrolyte injection hole 134 can be changed as appropriate.

[0043] The sealing plates 120 and 130 are made of metal. Specifically, the sealing plates 120 and 130 are made of aluminum, aluminum alloy, iron, or iron alloy, etc.

[0044] The negative electrode terminal 301 (first electrode terminal) is electrically connected to the negative electrode of the electrode body 200. The negative electrode terminal 301 is attached to the sealing plate 120, i.e., the case 100.

[0045] The positive electrode terminal 302 (second electrode terminal) is electrically connected to the positive electrode of the electrode body 200. The positive electrode terminal 302 is attached to the sealing plate 130, i.e., the case 100.

[0046] The negative electrode terminal 301 is made of a conductive material (more specifically, a metal), such as copper or a copper alloy. A portion or layer made of aluminum or an aluminum alloy may be provided on the outer surface of the negative electrode terminal 301.

[0047] The positive terminal 302 is made of a conductive material (more specifically, a metal), which may be made of aluminum or an aluminum alloy, for example.

[0048] The injection hole 134 is sealed by a sealing member (not shown). For example, a blind rivet or other metal member can be used as the sealing member.

[0049] The electrode body 200 is a flat-shaped electrode body in which positive electrode plates and negative electrode plates, described later, are stacked. Specifically, the electrode body 200 is a laminated electrode body in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately stacked via a separator 800, described later. However, in this specification, "electrode body" is not limited to a laminated electrode body, and may also be a wound electrode body in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound together via a strip-shaped separator. The separator can be made of, for example, a polyolefin microporous film. When the electrode body is a laminated electrode body including a plurality of positive electrode plates and a plurality of negative electrode plates, the positive electrode tabs provided on each positive electrode plate can be stacked to form a group of positive electrode tabs, and the negative electrode tabs provided on each negative electrode plate can be stacked to form a group of negative electrode tabs.

[0050] As shown in Figure 6, the case 100 houses the electrode body 200. In Figure 6, the first electrode body 201, which will be described later, is shown as an example. The first electrode body 201 is housed in the case 100 so that its longitudinal direction is parallel to the X direction.

[0051] Specifically, one or more laminated electrode bodies are housed inside the insulating sheet 700 (described later) placed within the case 100, together with an electrolyte (not shown). As the electrolyte (non-aqueous electrolyte), for example, a non-aqueous solvent prepared by mixing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) in a volume ratio (25°C) of 30:30:40, in which LiPF6 is dissolved at a concentration of 1.2 mol / L can be used. A solid electrolyte may be used instead of an electrolyte.

[0052] The electrode body 200 includes a first electrode body 201. The first electrode body 201 includes a substantially rectangular main body, a negative electrode tab group 220, and a positive electrode tab group 250.

[0053] The main body is composed of a negative electrode plate 210 and a positive electrode plate 240, which will be described later. The negative electrode tab group 220 is located at the first side end of the first electrode body 201 in the first direction (X direction) relative to the main body. In this embodiment, the first side is the sealing plate 120 side. The positive electrode tab group 250 is located at the second side end of the first electrode body 201 in the first direction (X direction) relative to the main body. In this embodiment, the second side is the sealing plate 130 side.

[0054] The negative electrode tab group 220 and the positive electrode tab group 250 are formed to protrude from the central portion of the electrode body 200 toward the sealing plate 120 or the sealing plate 130, respectively.

[0055] The current collector 400 includes a negative electrode current collector 400A and a positive electrode current collector 400B. The negative electrode current collector 400A and the positive electrode current collector 400B are each made of plate-shaped members. The electrode body 200 is electrically connected to the negative electrode terminal 301 and the positive electrode terminal 302 via the current collector 400.

[0056] The negative electrode current collector 400A is positioned on the sealing plate 120 via a resin insulating member. The negative electrode current collector 400A is electrically connected to the negative electrode tab group 220 and the negative electrode terminal 301. The negative electrode current collector 400A is made of a conductive material (more specifically, a metal), which may be made of copper or a copper alloy, for example. Details of the negative electrode current collector 400A will be described later.

[0057] The positive electrode current collector 400B is positioned on the sealing plate 130 via a resin insulating member. The positive electrode current collector 400B is electrically connected to the positive electrode tab group 250 and the positive electrode terminal 302. The positive electrode current collector 400B is made of a conductive material (more specifically, a metal), such as aluminum or an aluminum alloy. The positive electrode tab group 250 may be electrically connected to the sealing plate 130 directly or via the positive electrode current collector 400B. In this case, the sealing plate 130 may also function as the positive electrode terminal 302. Details of the positive electrode current collector 400B will be described later.

[0058] (Configuration of electrode body 200) As shown in Figures 7 and 8, the first electrode, the negative electrode plate 210, has a different polarity from the second electrode, the positive electrode plate 240. A negative electrode tab 230 (first electrode tab) made of a negative electrode core 211 is provided at one end of the negative electrode plate 210 in the width direction. When the negative electrode plates 210 are stacked, multiple negative electrode tabs 230 are stacked to form a negative electrode tab group 220. The negative electrode tab group 220 is electrically connected to the first electrode. The length of the protruding direction of each negative electrode tab 230 in the multiple negative electrode plates 210 is appropriately adjusted considering the state in which the negative electrode tab group 220 is connected to the negative electrode current collector 400A. The shape of the negative electrode tab 230 is not limited to that illustrated in Figure 7.

[0059] As shown in Figures 9 and 10, a positive electrode tab 260 (second electrode tab) made of a positive electrode core 241 is provided at one end in the width direction of the molded positive electrode plate 240. When the positive electrode plates 240 are stacked, multiple positive electrode tabs 260 are stacked to form a positive electrode tab group 250. The positive electrode tab group 250 is electrically connected to the second electrode. The length of the protruding direction of each positive electrode tab 260 on the multiple positive electrode plates 240 is appropriately adjusted considering the state in which the positive electrode tab group 250 is connected to the positive electrode current collector 400B. The shape of the positive electrode tab 260 is not limited to that illustrated in Figure 10.

[0060] A positive electrode protective layer 243 is provided at the base of the positive electrode tab 260. However, the positive electrode protective layer 243 is not necessarily provided at the base of the positive electrode tab 260.

[0061] In a typical example, the thickness of one negative electrode tab 230 is less than the thickness of one positive electrode tab 260. In this case, the thickness of the negative electrode tab group 220 is less than the thickness of the positive electrode tab group 250.

[0062] (Connection structure between electrode body 200 and current collector 400) The connection structure between the electrode body 200 and the current collector 400 will be described with reference to Figures 11 and 12.

[0063] <Negative side> Figure 11 shows the connection structure on the negative electrode side. The electrode body 200 includes a first electrode body 201 and a second electrode body 202. Each of the first electrode body 201 and the second electrode body 202 includes a positive electrode (second electrode) and a negative electrode (first electrode). The electrode body 200 may be composed of three or more electrode bodies.

[0064] The electrode body 200 is formed by stacking a first electrode body 201 and a second electrode body 202. The first electrode body 201 and the second electrode body 202 are aligned in the thickness direction (Y direction) of the first electrode body 201 and the second electrode body 202.

[0065] The first electrode body 201 includes a negative electrode tab group 220 (first tab). The negative electrode tab group 220 is electrically connected to the current collector 410 (negative electrode current collector) at a first end 205 in the X direction. The second electrode body 202 includes a negative electrode tab group 270 (second tab). The negative electrode tab group 270 is electrically connected to the current collector 410 (negative electrode current collector) at a third end 207 in the X direction.

[0066] The negative electrode tab group 220 has a curved portion 221 and a tip portion 222. The curved portion 221 is the part of the negative electrode tab group 220 that is curved on the side to which the first electrode is connected relative to the tip portion 222. The tip portion 222 is the part of the negative electrode tab group 220 that is located at the end opposite to the side to which the first electrode is connected.

[0067] The negative electrode tab group 220 has a first recess 220r that recesses towards the negative electrode tab group 270 when it is curved. The negative electrode tab group 270 has a second recess 270r that recesses towards the negative electrode tab group 220 when it is curved.

[0068] The first protrusion 652, which will be described later, is provided on the surrounding wall of the spacer 600, and is located within the first recess 220r. Similarly, the second protrusion 662, which will be described later, is provided on the surrounding wall of the spacer 600, and is located within the second recess 270r.

[0069] The negative electrode tab group 270 has a curved portion 271 and a tip portion 272. The curved portion 271 is the part of the negative electrode tab group 270 that is curved on the side to which the first electrode is connected relative to the tip portion 272. The tip portion 272 is the part of the negative electrode tab group 270 that is located at the end opposite to the side to which the first electrode is connected.

[0070] Each of the negative electrode tab group 220 and negative electrode tab group 270 is curved in opposite directions such that their tips 222 and 272 are closer together. In this embodiment, the tips 222 and 272 are spaced apart, but the configuration is not limited to this, and the tips 222 and 272 may be in contact with each other.

[0071] Here, the negative electrode tab group 220 is referred to as the first tab, and the negative electrode tab group 270 is referred to as the second tab. The first tab means that one of the negative electrode tab group 220 includes at least a negative electrode tab that is electrically in contact with the current collector 410, which will be described later, and the second tab means that the other negative electrode tab group 270 includes at least a negative electrode tab that is electrically in contact with the current collector 410. Therefore, the first tab and the second tab may be the negative electrode tabs located closest to the current collector 410, or they may be part of the core (metal foil) that constitutes the negative electrode plate, or they may be separate parts.

[0072] The negative electrode current collector 400A electrically connects the negative electrode terminal 301 to the negative electrode tab group 220 and the negative electrode tab group 270. In this embodiment, the negative electrode current collector 400A is connected to the negative electrode terminal 301 between the electrode body 200 and the sealing plate 120.

[0073] The negative electrode current collector 400A includes current collectors 410 and 430. The current collector 410 is a plate-shaped member. The current collector 410 has a longitudinal direction in the Z direction and a short direction in the Y direction. The current collector 410 is made up of a single, integrated part. The current collector 430 is a plate-shaped member. The current collector 430 has a longitudinal direction in the Z direction and a short direction in the Y direction. The current collectors 410 and 430 are arranged in parallel in the X direction. Thus, the current collectors 410 and 430 are made up of separate parts.

[0074] The negative electrode tab groups 220 and 270 are joined to the current collector 410 at a joint 411, which will be described later (see Figure 17). The joint 411 can be formed by, for example, ultrasonic welding, resistance welding, laser welding, crimping, etc. In this embodiment, the negative electrode tab groups 220 and 270 and the current collector 410 are joined by, for example, ultrasonic welding.

[0075] The current collector 430 is joined to the current collector 410 at a joint (not shown) located at its Z-direction end. The current collector 430 is connected to the negative terminal 301. The connection between the current collector 430 and the negative terminal 301 can be formed, for example, by crimping and / or welding.

[0076] The negative electrode terminal 301 is exposed to the outside of the sealing plate 120. The negative electrode terminal 301 is connected to the plate-shaped member 303. The negative electrode terminal 301 includes a region 301a made of copper or a copper alloy and a region 301b made of aluminum or an aluminum alloy, and it is preferable that the region 301a made of copper or a copper alloy is connected to the current collector 430.

[0077] The plate-shaped member 303 is located on the outside of the sealing plate 120. The plate-shaped member 303 is arranged along the sealing plate 120. The plate-shaped member 303 is electrically conductive. The plate-shaped member 303 is arranged to secure connection area with busbars, etc., that electrically connect the secondary battery 1 to other adjacent secondary batteries. The connection between the negative electrode terminal 301 and the plate-shaped member 303 can be formed, for example, by laser welding.

[0078] An insulating member 510 is placed between the plate-shaped member 303 and the sealing plate 120. An insulating member 520 is placed between the negative terminal 301 and the sealing plate 120. An insulating member 530 is placed between the current collector 430 and the sealing plate 120.

[0079] However, the negative terminal 301 may be electrically connected to the sealing plate 120. The sealing plate 120 may also serve as the negative terminal 301.

[0080] A spacer 600 (first spacer) is positioned between the sealing plate 120 (first sealing plate) and the main body of the electrode body 200 (excluding the negative electrode tab groups 220 and 270). The spacer 600 is made of an insulating resin material. The spacer 600 suppresses the movement of the electrode body 200 within the case 100 in the X direction, and suppresses damage to the negative electrode tab groups 220, 270 and the electrode body 200. The negative electrode tab groups 220 and 270 pass through the tab housing space 670 provided in the spacer 600, thereby protecting the negative electrode tab groups 220 and 270 and preventing them from deforming into unintended shapes. Furthermore, unintended short circuits of the negative electrode tab groups 220 and 270 (such as contact with conductive members of different polarity) can be suppressed.

[0081] A resin insulating sheet 700 (electrode holder) is placed between the electrode body 200 and the case body 110. The insulating sheet 700 may be made of resin, for example. More specifically, the material of the insulating sheet 700 may be polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), or polyolefin (PO).

[0082] <Positive side> Figure 12 shows the connection structure on the positive electrode side. In this embodiment, the connection structure between the electrode body 200 and the current collector 400 on the positive electrode side of the secondary battery 1 differs from the configuration on the negative electrode side in that the part corresponding to the current collector 410 on the negative electrode side is composed of two parts.

[0083] The first electrode body 201 includes a group of positive electrode tabs 250 (second tab). The group of positive electrode tabs 250 is electrically connected to the current collector 420 (positive electrode current collector) at a second end 206 in the X direction. The second electrode body 202 includes a group of positive electrode tabs 280 (first tab). The group of positive electrode tabs 280 is electrically connected to the current collector 420 (positive electrode current collector) at a fourth end 208 in the X direction.

[0084] The positive electrode tab group 250 has a curved portion 251 and a tip portion 252. The curved portion 251 is the part of the positive electrode tab group 250 that is curved on the side to which the second electrode is connected relative to the tip portion 252. The tip portion 252 is the end of the positive electrode tab group 250 that is located on the side opposite to which the second electrode is connected.

[0085] The positive electrode tab group 250 has a first recess 250r that recesses towards the positive electrode tab group 280 when it is curved. The positive electrode tab group 280 has a second recess 280r that recesses towards the positive electrode tab group 250 when it is curved.

[0086] The second protrusion 662, which will be described later, is provided on the surrounding wall of the spacer 600, and is located within the first recess 250r. Similarly, the first protrusion 652, which will be described later, is provided on the surrounding wall of the spacer 600, and is located within the second recess 280r.

[0087] The positive electrode tab group 280 has a curved portion 281 and a tip portion 282. The curved portion 281 is the part of the positive electrode tab group 280 that is curved on the side to which the second electrode is connected relative to the tip portion 282. The tip portion 282 is the part of the positive electrode tab group 280 that is located at the end opposite to the side to which the second electrode is connected.

[0088] Each of the positive electrode tab group 250 and the positive electrode tab group 280 is curved in opposite directions such that their tips 252 and 282 are closer together. In this embodiment, the tips 252 and 272 are spaced apart, but the configuration is not limited to this, and the tips 252 and 282 may be in contact with each other.

[0089] Here, the positive electrode tab group 250 is referred to as the second tab, and the positive electrode tab group 280 is referred to as the first tab. The second tab means that the positive electrode tab group 250 includes at least one positive electrode tab that is electrically in contact with the current collector 420, which will be described later, and the first tab means that the other positive electrode tab group 280 includes at least one positive electrode tab that is electrically in contact with the current collector 420. Therefore, the first tab and the second tab may be the positive electrode tabs located closest to the current collector 420, or they may be part of the core (metal foil) that constitutes the positive electrode plate, or they may be separate parts.

[0090] The positive electrode current collector 400B electrically connects the positive electrode terminal 302 to the positive electrode tab group 250 and the positive electrode tab group 280. In this embodiment, the positive electrode current collector 400B is connected to the positive electrode terminal 302 between the electrode body 200 and the sealing plate 130.

[0091] The positive electrode current collector 400B includes a current collector 420 (first current collector) and a current collector 450 (second current collector). A plate 460 is interposed between the current collector 420 (first current collector) and the current collector 450 (second current collector) as an insulating member, but the two are electrically joined at a position different from the cross-section shown in the figure.

[0092] The current collector 420 is a plate-shaped member. The current collector 420 has a longitudinal direction in the Z direction and a short direction in the Y direction. The current collector 420 is composed of one current collector and another current collector. That is, the current collector 420 is composed of two parts.

[0093] The positive electrode tab group 250 and the positive electrode tab group 280 are joined to the current collector 420, which is composed of two parts, at a joint 421 (see Figure 17), which will be described later. The joint 421 can be formed by, for example, ultrasonic welding, resistance welding, laser welding, crimping, etc. In this embodiment, the positive electrode tab group 250 and the positive electrode tab group 280 and the current collector 420 are joined by, for example, ultrasonic welding.

[0094] The current collector 440 is joined to the current collector 420 at a joint (not shown) located at its Z-direction end. The current collector 440 is connected to the positive terminal 302. The connection between the current collector 440 and the positive terminal 302 can be formed, for example, by crimping and / or welding.

[0095] The positive terminal 302 is exposed on the outside of the sealing plate 130 and is positioned to reach the current collector 440 of the positive current collector 400B, which is located on the inner surface side of the sealing plate 130. The positive terminal 302 is connected to the plate-shaped member 304.

[0096] The plate-shaped member 304 is located on the outside of the sealing plate 130. The plate-shaped member 304 is arranged along the sealing plate 130. The plate-shaped member 304 is electrically conductive. The plate-shaped member 304 is positioned to secure connection area with busbars, etc., that electrically connect the secondary battery 1 to other adjacent secondary batteries. The connection between the positive electrode terminal 302 and the plate-shaped member 304 can be formed, for example, by laser welding.

[0097] An insulating member 510 is placed between the plate-shaped member 304 and the sealing plate 130. An insulating member 520 is placed between the positive terminal 302 and the sealing plate 130. An insulating member 470 is placed between the current collector 440 and the sealing plate 130.

[0098] However, the positive terminal 302 may be electrically connected to the sealing plate 130. The sealing plate 130 may also serve the role of the positive terminal 302.

[0099] A spacer 600 (second spacer) is positioned between the sealing plate 130 (second sealing plate) and the main body of the electrode body 200 (excluding the positive electrode tab groups 250 and 280). The spacer 600 is made of an insulating resin material. The spacer 600 suppresses the movement of the electrode body 200 within the case 100 in the X direction, thereby suppressing damage to the positive electrode tab groups 250 and 280 and the electrode body 200. The positive electrode tab groups 250 and 280 pass through the tab housing space 670 provided in the spacer 600, thereby protecting the positive electrode tab groups 250 and 280 and preventing them from deforming into unintended shapes. Furthermore, unintended short circuits of the positive electrode tab groups 250 and 280 (such as contact with conductive members of different polarity) can be suppressed.

[0100] The spacers 600, which are positioned on the negative and positive electrode sides, are made of, for example, resin. The material of the spacers 600 may be, for example, polypropylene (PP), polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), or ethylene propylene diene rubber (EPDM).

[0101] The aforementioned resin insulating sheet 700 (electrode holder) is placed between the electrode body 200 and the case body 110.

[0102] (Spacer 600) The shape of the spacer 600 will be described with reference to Figures 13 to 15. In this embodiment, the spacer 600 positioned on the side of the negative electrode tab group 220 and the negative electrode tab group 270 and the spacer 600 positioned on the side of the positive electrode tab group 250 and the positive electrode tab group are identical in shape.

[0103] The outer shape of the spacer 600 is rectangular, following the inner circumferential surface of the case body 110, and, like the case body 110, is longer in the height direction (Z direction) than in the thickness direction (Y direction) of the secondary battery 1.

[0104] The spacer 600 includes a first base portion 610 and a second base portion 620. The first base portion 610 is surrounded by a first circumferential wall 621, a second circumferential wall 622, a third circumferential wall 623, and a fourth circumferential wall 624. The fourth circumferential wall 624 is located on the inside and is therefore set lower than the other circumferential walls. On the end of the first circumferential wall 621 opposite to the first base portion 610, protrusions 627 and 628 are provided at a predetermined distance apart.

[0105] In the region where the third perimeter wall 623 and the fourth perimeter wall 624 intersect, one of the first support walls 625 is provided for fixing the second connecting wall 660, which will be described later as a sealing wall. The first support wall 625 is provided with a first engagement hole 626 (engagement recess).

[0106] The second base portion 620 is surrounded by the fifth circumferential wall 641, the sixth circumferential wall 642, the seventh circumferential wall 643, and the eighth circumferential wall 644. The eighth circumferential wall 644 is located on the inside and is therefore set lower than the other circumferential walls. On the end of the fifth circumferential wall 641 opposite to the second base portion 620, protrusions 647 and 648 are provided at a predetermined distance apart.

[0107] In the region where the seventh perimeter wall 643 and the eighth perimeter wall 644 intersect, a second support wall 645 is provided for fixing the second connecting wall 660, which will be described later as a sealing wall. The second support wall 645 is provided with a second engagement hole 646 (engagement recess).

[0108] Between the first base portion 610 and the second base portion 620, a first connecting wall 650 is provided that connects the second circumferential wall 622 and the sixth circumferential wall 642. This first connecting wall 650 includes a first connecting circumferential wall 651 that connects the second circumferential wall 622 and the sixth circumferential wall 642, and a first protrusion 652 that projects inward from the first connecting circumferential wall 651 and extends from the second circumferential wall 622 to the sixth circumferential wall 642.

[0109] Between the first base portion 610 and the second base portion 620, and between the third peripheral wall 623 and the seventh peripheral wall 643, a second connecting wall 660 is provided, which constitutes a sealing wall that is detachably (movably) attached to the spacer 600. In the spacer 600 of this embodiment, all parts except the second connecting wall 660 are integrally molded from resin, and the second connecting wall 660 is a separate part.

[0110] The second connecting wall 660 includes a second connecting circumferential wall 661 that extends from the third circumferential wall 623 to the seventh circumferential wall 643, and a second protrusion 662 that projects inward from the second connecting circumferential wall 661 and extends from the third circumferential wall 623 to the seventh circumferential wall 643. Engaging projections 664 and 665 (engaging protrusions) that project inward are provided at both ends of the second connecting circumferential wall 661. The shapes of the second connecting circumferential wall 661 and the second protrusion 662 may be identical to those of the first connecting circumferential wall 651 and the first protrusion 652.

[0111] In the spacer 600 having the above configuration, the second connecting peripheral wall 661 is fixed to the first support wall 625 and the second support wall 645 by engaging the engaging projections 664 and 665 of the second connecting peripheral wall 661 with the first engaging hole 626 and the second engaging hole 646, thereby forming an integrated structure.

[0112] In the spacer 600 with the above configuration, the inner surfaces of the fourth peripheral wall 624, the first connecting wall 650, the eighth peripheral wall 644, and the second connecting wall 660 form an enclosure wall, defining the tab accommodation space 670. The sixth peripheral wall 642, the first connecting wall 650, and the eighth peripheral wall 644 constitute the enclosure wall, and the second connecting wall 660 constitutes a sealing wall that is part of the enclosure wall and is located in an open area 680 that opens up the tab accommodation space 670.

[0113] Furthermore, it is preferable that the second connecting wall 660, which is a sealing wall, be positioned to block the open area 680. However, it is not necessary for the open area 680 to be completely blocked by the second connecting wall 660. It is sufficient that the second connecting wall 660 is positioned to face the main outer surface of the second tab.

[0114] In the enclosure wall, the portion of the first tab facing the main outer surface can be a fixed wall that is attached to the enclosure wall. The sealing wall of the second tab facing the main outer surface can be a movable wall that is movable relative to the enclosure wall during the manufacturing process of the energy storage device.

[0115] In this embodiment, the spacer 600 is positioned such that the tab housing space 670 is located on the side of the first base portion 610, aligned with the position of the electrode tab protruding from the electrode body 200. Therefore, the position of the tab housing space 670 can be appropriately changed to match the position of the electrode tab protruding from the electrode body 200.

[0116] The spacer 600 (first spacer) includes an enclosure wall located around the tab storage space 670, and the enclosure wall has a sealing wall (second connecting wall 660) positioned in an open area 680 that opens up the tab storage space 670 to a part of the enclosure wall, and enclosure walls (fourth perimeter wall 624, first connecting wall 650, eighth perimeter wall 644) that together with the sealing wall constitute the enclosure wall, and the configuration can be provided so that a first state in which the tab storage space 670 is surrounded by the enclosure wall and a second state in which an open area 680 is formed without the sealing wall being positioned can be selected.

[0117] As shown in Figure 15, the first protrusion 652, which is provided on the inside of the first connecting peripheral wall 651 that constitutes the enclosure wall, is preferably provided with a curved outer surface because it comes into contact with the first tab during the secondary battery manufacturing process. Furthermore, it is preferable that a first concave curved surface portion 653 be provided on the side of the first protrusion 652 facing the sealing plate 120 (first sealing plate) (upper side in the figure).

[0118] By providing the outer surface of the first protrusion 652 in a curved shape, the first tab can be deformed into a predetermined shape more stably, and damage to the first tab when it comes into contact can be suppressed. Furthermore, by providing the first concave curved surface 653, the first tab can be deformed into a predetermined shape more stably, and damage to the first tab when it comes into contact can be further suppressed.

[0119] Similarly, the second protrusion 662, which is provided on the inside of the second connecting wall 660 that constitutes the sealing wall, should have a curved outer surface, similar to the first connecting peripheral wall 651 described above, because it comes into contact with the second tab during the secondary battery manufacturing process. Furthermore, it is preferable that a second concave curved portion 663 be provided on the side of the second protrusion 662 facing the sealing plate 120 (first sealing plate) (the upper side shown in the figure).

[0120] By providing the outer surface of the second protrusion 662 in a curved shape, the second tab can be deformed into a predetermined shape more stably, and damage to the second tab when it comes into contact can be suppressed. Furthermore, by providing the second concave curved surface 663, the second tab can be deformed into a predetermined shape more stably, and damage to the second tab when it comes into contact can be suppressed even further.

[0121] (Manufacturing process for secondary battery 1 (electrode fabrication process)) The method for manufacturing a secondary battery according to this embodiment will be described below.

[0122] As shown in Figure 16, in the method for manufacturing a secondary battery according to this embodiment, first, the first electrode body 201 and the second electrode body 202 are manufactured (step S1). It is preferable that a portion of the tip of each of the negative electrode tab group 220, positive electrode tab group 250, negative electrode tab group 270, and positive electrode tab group 280 is cut so that when the tips are bundled together they are the same length.

[0123] As shown in Figures 16 to 18, after the first electrode body 201 and the second electrode body 202 are manufactured, the positive electrode tab groups 250 and 280 are joined to the current collector 420 (step S2). The positive electrode tab groups 250 and 280 are joined to the current collector 420 at the joining point 421.

[0124] Next, the first electrode body 201, the current collector 410, and the second electrode body 202 are arranged in this order in the DR1 direction. The negative electrode tab group 220 is placed on one side of the current collector 410 in the DR1 direction. With the negative electrode tab group 270 placed on the other side of the current collector 410 in the DR1 direction, the negative electrode tab group 220 and the negative electrode tab group 270 are joined to the current collector 410 (step S3). The negative electrode tab group 220 and the negative electrode tab group 270 are joined to the current collector 410 at the joining point 411.

[0125] In the height direction of the first electrode body 201 and the second electrode body 202, the current collectors 410 and 420 are positioned off-center to one side of the center of the first electrode body 201 and the second electrode body 202. This allows the current collectors to be made shorter, thus enabling them to be made smaller. The current collectors 410 and 420 are not limited to this configuration. The current collectors 410 and 420 may be positioned in the center of the first electrode body 201 and the second electrode body 202 in the height direction of the first electrode body 201 and the second electrode body 202.

[0126] The order in which the current collectors 410 and 420 are joined to the first electrode body 201 and the second electrode body 202 is not limited to the above, and the order may be changed. The step of joining the current collectors 420 to the first electrode body 201 and the second electrode body 202 is preferably performed before the step of overlapping the first electrode body 201 and the second electrode body 202, which will be described later, and is preferably performed before the step of joining the current collector 410 to the first electrode body 201 and the second electrode body 202.

[0127] Next, after joining the negative electrode tab group 220 and the negative electrode tab group 270 to the current collector 410, the negative electrode tab group 220 and the negative electrode tab group 270 are bent in the thickness direction of the first electrode body 201 and the second electrode body 202 (in the direction perpendicular to the DR1 direction in Figures 17 and 18) to overlap the first electrode body 201 and the second electrode body 202 (step S4). In other words, the first electrode body 201 and the second electrode body 202 are brought together.

[0128] "Overlapping the first electrode and the second electrode" means that the first electrode and the second electrode may be directly overlapped, or other components may be placed between the first electrode and the second electrode. The first electrode and the second electrode may or may not be fixed with tape or the like. Furthermore, the first electrode, the current collector and the second electrode do not have to be arranged in a straight line in the DR1 direction, and the first electrode or the second electrode may be inclined with respect to the current collector in the DR1 direction.

[0129] The negative electrode tab group 220 and the negative electrode tab group 270 are bent so that their tips face each other. The positive electrode tab group 250 and the positive electrode tab group 280 are also bent so that their tips face each other.

[0130] As shown in Figures 16, 19, and 20, the spacer 600 and insulating sheet 700 are assembled to the electrode body 200 (step S5).

[0131] Figure 19 illustrates the procedure for assembling the spacer 600 to the electrode body 200 on the positive electrode tab group 250 and the positive electrode tab group 280 (positive electrode side). Although not illustrated, the procedure is similar for the negative electrode tab group 220 and the negative electrode tab group 270.

[0132] The spacer 600 has an open area 680 that opens the tab storage space 670 when the second connecting wall 660, which is a sealing wall, is not attached. In this embodiment, the open area 680 that opens the tab storage space 670 is formed on the longitudinal side of the spacer 600, but the configuration is not limited to this, and the open area 680 that opens the tab storage space 670 may be formed on the short side of the spacer 600.

[0133] The positive electrode tab group 250 and the positive electrode tab group 280 are placed in the tab storage space 670 from the open area 680 (placement step). If an open area 680 that opens up the tab storage space 670 is provided on the longitudinal side of the spacer 600, the positive electrode tab group 250 and the positive electrode tab group 280 are placed in the tab storage space 670 along the stacking direction of the positive electrode tabs 260 of the positive electrode tab group 250 (Y direction in the figure).

[0134] Next, the second connecting wall 660 is fixed to the first support wall 625 and the second support wall 645, sealing the tab housing space 670 (sealing step). At this time, the second protrusion 662 of the second connecting wall 660 is positioned to face the main outer surface of the positive electrode tab group 250 (second tab), and the first protrusion 652 of the first connecting wall 650 is positioned to face the main outer surface of the positive electrode tab group 280 (first tab). Here, the main outer surface refers to the surface with the larger area, not the side end surface of the tab. Note that in the sealing step, the open area 680 does not need to be completely closed by the second connecting wall 660. It is sufficient that the second connecting wall 660 is positioned to face the main outer surface of the second tab.

[0135] Although a diagrammatic explanation of the negative electrode side is omitted, after the spacer 600 is assembled to the negative electrode tab group 220 and the negative electrode tab group 270, the first protrusion 652 of the first connecting wall 650 is positioned to face the main outer surface of the negative electrode tab group 220 (first tab), and the second protrusion 662 of the second connecting wall 660 is positioned to face the main outer surface of the negative electrode tab group 270 (second tab).

[0136] In the above process, the spacer 600 can utilize the open region 680 to arrange the negative electrode tab group 220, negative electrode tab group 270, positive electrode tab group 250, and positive electrode tab group 280, which serve as the first and second tabs, in the tab housing space 670. Therefore, compared to the case where holes are provided in the spacer for inserting the electrode tabs and the electrode tabs are inserted through these holes, the spacer 600 can be easily assembled to the electrode body 200.

[0137] As shown in Figure 20, after assembling the spacers 600 to the negative and positive sides of the electrode body 200, the electrode body 200 and the spacers 600 on both sides are covered with an insulating sheet 700. In this way, with the spacers 600 positioned on both sides of the electrode body 200, the electrode body 200 and the spacers 600 on both sides are covered with an insulating sheet 700.

[0138] By covering the spacer 600 with the insulating sheet 700, the negative electrode tab group and positive electrode tab group located inside the spacer 600 can be more securely protected.

[0139] The insulating sheet 700 is fixed to the spacers 600 on both sides. The insulating sheet 700 is fixed to the spacers 600 by heat welding it to region R1 on the spacers 600.

[0140] As shown in Figure 21, the insulating sheet in this embodiment covers the entire circumference of the electrode body 200 and spacer 600 in the axial direction in the X direction. The insulating sheet 700 does not necessarily need to cover the entire surface of the electrode body 200. Preferably, the insulating sheet 700 covers an area of ​​50% or more, more preferably 70% or more, of the outer surface of the electrode body. Preferably, the insulating sheet 700 covers the entirety of four of the six surfaces of the substantially rectangular parallelepiped (flat-shaped) electrode body 200, excluding the two surfaces on which the negative electrode tab group 220 and the positive electrode tab group 250 are formed, respectively. Preferably, the protrusions 627, 628, 647, and 648 provided on the spacer 600 are exposed from the insulating sheet 700.

[0141] As shown in Figure 21, the current collector 410 is then electrically connected to the negative terminal 301 via the current collector 430 (step S6). Step S6 can also be performed before step S5.

[0142] Specifically, as shown in Figure 21, the negative electrode tab group 220 and the negative electrode tab group 270 are bent so that their tips 222 and 272 face each other.

[0143] The negative electrode terminal 301 and the current collector 430 are attached to the sealing plate 120 via an insulating member. The current collector 430 is brought into contact with the current collector 410 in the X direction. The connection of the plate-shaped member 303 to the negative electrode terminal 301 can be done at any time. The current collector 430 and the current collector 410 are joined by laser welding from between the sealing plate 120 and the insulating sheet 700.

[0144] Next, as shown in Figure 22, the spacer 600 and electrode body 200 are inserted into the case body 110 through the opening 113, with the current collector 420 side leading (step S7).

[0145] Next, as shown in Figure 23, the negative electrode tab groups 220 and 270 are bent by bringing the sealing plate 120 and the main body of the electrode body 200 (first electrode body 201 and second electrode body 202) closer together from their extended state (as shown in Figure 24). The negative electrode tab groups 220 and 270 are bent along the shape of the spacer 600 so that the folded portions of the bent parts 221 and 271 are closer to the case body 110 in the Y direction.

[0146] After the sealing plate 120 is brought into contact with the case body 110, the sealing plate 120 is temporarily joined to the case body 110. This temporary joining partially joins the sealing plate 120 to the opening 113 of the case body 110. This positions the sealing plate 120 relative to the case body 110.

[0147] When inserting the electrode body 200 into the case body 110, the electrode body 200 may be pulled from the current collector 420 side or pushed from the current collector 410 side. When the electrode body 200 is pushed from the current collector 410 side, the negative electrode tab group 220 and the negative electrode tab group 270 can be bent at the same time.

[0148] In the process of bending the negative electrode tab group 220 and the negative electrode tab group 270 (bending process), the first connecting wall 650 faces the main outer surface of the negative electrode tab group 220 (first tab), and the second connecting wall 660 faces the main outer surface of the negative electrode tab group 270 (second tab), while the negative electrode tab group 220 and the negative electrode tab group 270 are bent. This effectively prevents the negative electrode tab group 220 and the negative electrode tab group 270 from deforming into unintended shapes, such as deforming significantly outward and having a portion come into contact with the inner surface of the case body 110.

[0149] Furthermore, it is more preferable to bend the negative electrode tab group 220 and the negative electrode tab group 270 with the first connecting wall 650 in contact with the main outer surface of the negative electrode tab group 220 and the second connecting wall 660 in contact with the main outer surface of the negative electrode tab group 270. This makes it easier to bend the negative electrode tab group 220 and the negative electrode tab group 270 into a predetermined shape.

[0150] Furthermore, it is even more preferable to bend the negative electrode tab group 220 and the negative electrode tab group 270 while the first protrusion 652 provided on the first connecting wall 650 is in contact with the main outer surface of the negative electrode tab group 220, and the second protrusion 662 provided on the second connecting wall 660 is in contact with the main outer surface of the negative electrode tab group 270.

[0151] As a result, as shown in Figure 24, after the sealing plate 120 is positioned relative to the case body 110, the negative electrode tab group 220 (first tab) has a first recess 220r that recesses toward the negative electrode tab group 270 (second tab) when curved, and the negative electrode tab group 270 (second tab) has a second recess 270r that recesses toward the negative electrode tab group 220 (first tab) when curved.

[0152] Furthermore, the first protrusion 652 of the first connecting wall 650 is positioned within the first recess 220r, and the second protrusion 662 of the second connecting wall 660 is positioned within the second recess 270r.

[0153] By providing a first protrusion 652 on the negative electrode tab group 220 (first tab) at a position facing the main outer surface, and a second protrusion 662 on the negative electrode tab group 270 (second tab) at a position facing the main outer surface, the negative electrode tab group 220 and the negative electrode tab group 270 can be easily bent into a predetermined shape, thereby improving the ease of assembly of the secondary battery.

[0154] Next, after inserting the electrode body 200 into the case body 110, the current collector 420 is electrically connected to the positive terminal 302 (step S8).

[0155] Specifically, the positive electrode terminal 302 is attached to the sealing plate 130 via an insulating member. After inserting the first electrode body 201 and the second electrode body 202 into the case body 110, the current collector 450 is brought into contact with the current collector 420 protruding from the opening 114 in the X direction. The connection of the plate-shaped member 304 to the positive electrode terminal 302 can be done at any time.

[0156] The positive electrode tab groups 250 and 280 connected to the current collector 420 are bent so that their tips 252 and 282 face each other. As shown in Figure 12, the positive electrode tab groups 250 and 280 are curved to conform to the shape of the spacer 600 so that the folded portions of the curved sections 251 and 281 approach the case body 110 in the Y direction.

[0157] In the bending process for the positive electrode tab group 250 and positive electrode tab group 280 on the positive electrode side, a first protrusion 652 is provided at a position facing the main outer surface of the positive electrode tab group 280 (first tab), and a second protrusion 662 is provided at a position facing the main outer surface of the positive electrode tab group 250 (second tab), based on the same process as for the negative electrode tab group 220 and negative electrode tab group 270 on the negative electrode side. This makes it possible to easily deform the positive electrode tab group 250 and positive electrode tab group 280 into a predetermined curved shape, thereby improving the ease of assembly of the secondary battery.

[0158] As shown in Figure 25, after inserting the spacer 600 and electrode body 200 into the case body 110, the sealing plate 130 (first sealing plate) and sealing plate 120 (second sealing plate) are joined to the case body 110 (step S9).

[0159] Specifically, after the sealing plate 130 is brought into contact with the case body 110, the sealing plate 130 is tack-welded to the case body 110. Through this tack-welding, the sealing plate 130 is partially joined to the opening 114 of the case body 110. This positions the sealing plate 130 relative to the case body 110.

[0160] Next, the sealing plates 120 and 130 are joined to the case body 110. Sealing plate 120 seals the opening 113 of the case body 110, and sealing plate 130 seals the opening 114 of the case body 110. As a result, the first electrode body 201 and the second electrode body 202 are housed in the case 100.

[0161] After the above process, inspections such as leak testing are performed (S10 process). After the leak testing, the secondary battery 1 is dried to remove moisture from inside the case 100.

[0162] Next, in the vertical direction, the sealing plate 130 (second sealing plate) is positioned above the sealing plate 120 (first sealing plate), and the spacer 600 (first spacer) is positioned below the electrode body 200. With this position, the electrolyte is injected into the case 100 through the injection hole provided in the sealing plate 130 (second sealing plate) (Step S11). Because the spacer 600 is provided around where the electrolyte is injected, damage to the electrode body 200 and other components is suppressed even if the electrolyte is injected forcefully into the case 100. As a result, the secondary battery 1 of this embodiment can inject the electrolyte in a shorter time compared to the case without the spacer 600.

[0163] When injecting the liquid, the angle of the main surface of the sealing plate with respect to the vertical direction is preferably about 90 ± 45° from the vertical direction. When injecting the liquid, it is more preferable that the main surface of the sealing plate is perpendicular to the vertical direction.

[0164] The weight of the electrode body 200 placed inside the case 100 is preferably 500g or more, and more preferably 1kg or more. This weight of the electrode body 200 does not include the electrolyte. If there are multiple electrode bodies 200, this weight is the total weight. Even if the electrode body 200 is heavy, it can be supported by the spacer 600 (first spacer).

[0165] Subsequently, degassing and charging are performed. During degassing and charging, the electrolyte injection port 134 may be temporarily sealed. After that, the electrolyte injection port 134 is sealed, and the secondary battery 1 is completed.

[0166] In the secondary battery 1 and its manufacturing method according to Embodiment 1 of this technology, the spacer 600 allows the first tab and the second tab to be placed in the tab housing space 670 through the open region 680.

[0167] As a result, compared to the case where a hole is provided in the spacer for inserting the electrode tab and the electrode tab is inserted through that hole, the spacer 600 can be easily assembled to the electrode body 200. Consequently, the ease of assembly of the secondary battery can be improved, and ultimately, a highly reliable secondary battery can be provided.

[0168] Furthermore, by blocking the open area 680 with the second connecting wall 660 that constitutes the sealing wall, and by having the second connecting wall 660 and the negative electrode tab group 270 face each other, it is possible to effectively suppress the deformation of the negative electrode tab group 270 into an unintended shape when the negative electrode tab group 270 is bent.

[0169] Furthermore, after placing the electrode tabs in the tab housing space 670, fixing the second connecting wall 660 to the spacer 600 to seal the tab housing space 670 makes it possible to improve the strength of the spacer 600 compared to the case where the second connecting wall 660 is not provided.

[0170] Furthermore, in the spacer 600, the placement of the electrode tab between the first base portion 610 and the second base portion 620 allows the force applied from the spacer 600 to the electrode body 200 to be distributed, thereby suppressing damage to the ends of the electrode body 200.

[0171] Furthermore, since spacers 600 are provided between the sealing plates on both sides and the electrode body 200, the electrode body 200 can be sandwiched between the spacers 600 on both sides, thereby suppressing movement of the electrode body 200 within the case 100.

[0172] Furthermore, in the electrolyte injection process, by injecting the electrolyte into the case 100 from the injection hole 134 with the spacer 600 positioned below the electrode body 200, deformation of the spacer 600 is suppressed, thereby stably supporting the electrode body 200. This suppresses damage to the electrode tab and the electrode body 200. Moreover, because the electrode body 200 can be stably supported, even if the electrolyte injection speed is high, the electrode body 200 does not move unnecessarily inside the case 100, allowing the electrolyte to be injected in a short time and improving the efficiency of electrolyte injection.

[0173] In the manufacturing method of the secondary battery 1 according to Embodiment 1 of this technology, by covering the electrode body 200 and spacer 600 with an insulating sheet 700, the insulating sheet 700 is positioned on the outer periphery, making it easier to insert the electrode body 200 and spacer 600 into the case body 110. The insulating sheet 700 can effectively suppress damage to the electrode tab and electrode body 200.

[0174] (Fixing structure of the second connecting wall 660 to the spacer 600) Referring to Figures 26 and 37, the fixing structure of the second connecting wall 660, which is a sealing wall, to the spacer 600 will be described. The area enclosed by C1 in Figure 26 is where the fixing structure C1 of the second connecting wall 660 to the spacer 600 is employed. Although only the negative side is shown as an example in the illustration, the positive side is similar.

[0175] As shown in Figure 27, in the spacer 600, the negative electrode tab group 220 and the negative electrode tab group 270 are placed into the tab accommodation space 670 from the open region 680 that opens up the tab accommodation space 670. Then, the second connecting wall 660 is attached to the spacer 600, and the open region 680 is closed by the second connecting wall 660.

[0176] As shown in Figure 28, the specific fixing structure C1 is a structure in which the second connecting peripheral wall 661 is fixed to the first support wall 625 and the second support wall 645 by engaging the engaging projections 664 and 665 provided on the second connecting peripheral wall 661 of the second connecting wall 660 with the first engaging hole 626 and the second engaging hole 646. Since gaps are unlikely to occur between both sides of the second connecting wall 660 and the spacer 600, the ingress of foreign matter can also be suppressed. The engaging projections 664 and 665 are not limited to a cylindrical shape and may take other forms, and the tips of the engaging projections 664 and 665 may have a chamfered shape.

[0177] In this fixed structure C1, since the second connecting wall 660 is smaller than the spacer 600, the supply process size and transportation costs can be reduced. Furthermore, because the shape of the second connecting wall 660 is significantly different from that of the spacer 600, identification is made easy and there is no risk of other parts being mixed in.

[0178] In the fixed structure C1, a structure is employed in which the engaging projection is fitted into the engaging hole, but the structure for connecting the second connecting peripheral wall 661 to the first support wall 625 and the second support wall 645 is not limited to this structure. For example, a fixed structure by adhesive or the like may be used. The molding and shape control of the connecting peripheral wall and support wall are easy, and the fit strength is easy to adjust.

[0179] As an alternative fixing structure, as shown in Figure 29, fixing structure C2 may be provided with engaging protrusions 664 on both sides of the second connecting peripheral wall 661, and the second connecting peripheral wall 661 may embrace both sides of the first support wall 625. Similar to the fixing structure described above, the molding and shape control of the connecting peripheral wall and support wall are easy, and the interlocking strength is easy to adjust.

[0180] As an alternative fixing structure, a fixing structure C3 shown in Figures 30 and 31 may be provided in which a mating groove 625s is provided in the first support wall 625 and a mating piece 660s that mates into the mating groove 620s is provided in the second connecting peripheral wall 661. Similar to the fixing structure described above, the molding and shape control of the connecting peripheral wall and support wall are easy, and the mating strength is easy to adjust. The dimensional tolerance between the mating groove 620s and the mating piece 660s should preferably be +0.1 mm or less.

[0181] As an alternative fixing structure, as shown in Figure 32, fixing structure C4, the shape of the engaging projection 664b provided on the second connecting peripheral wall 661 can be a pair of snap-fit ​​claws K1 provided on either side of the gap S10. With this fixing structure C4, the burrs of the claws K1 allow the engaging projection 664b to be easily engaged with the first engaging hole 626 with even a weak force, and the engaging projection 664b can be prevented from coming out of the first engaging hole 626.

[0182] As an alternative fixing structure, as shown in Figure 33, a burr 664c is provided at the end of the second connecting peripheral wall 661 and engaged with the first engagement hole 626, thereby preventing the burr 664c from coming out of the first engagement hole 626.

[0183] As an alternative fixing structure, as shown in Figure 34, the second connecting peripheral wall 661 may be directly welded to the first support wall 625, thereby creating a welded area M1. Known welding methods such as adhesives, heat welding, laser welding, and ultrasonic welding can be used to form the welded area M1. With this fixing structure, the external shape of the second connecting peripheral wall 661 is simple and easy to form, and there is little risk of the spacer 600 falling off or moving after being assembled to the electrode body 200.

[0184] As an alternative fixing structure, as shown in Figure 35, a thin-walled portion 660r is provided in the second connecting peripheral wall 661, making it possible to easily form a welded region M1 using thermal melting or the like.

[0185] As an alternative fixing structure, as shown in Figures 36 and 37, fixing structure C8, the shape of the interlocking groove 623r can be made to match the outer shape of the interlocking piece 661s that interlocks with the interlocking groove 623r.

[0186] (Spacer in another embodiment) Other forms of the spacer will be described with reference to Figures 38 to 47. Note that, including the configuration of the second connecting wall 660 as a sealing wall as described above, the second connecting wall 660 described below may be designed so as not to have a gap between it and the third circumferential wall 623 and the seventh circumferential wall 643, or it may be designed to have a slight gap between it and the third circumferential wall 623 and the seventh circumferential wall 643. In the figures, only the negative side is shown as an example, but the positive side is similar. In the figures below, the arrow indicated by R1 indicates the direction of rotation in the direction in which the second connecting wall 660 seals the open region 680.

[0187] (Spacer 600A in Embodiment 2) In the second embodiment shown in Figures 38 and 39, the spacer 600A has a second connecting wall 660 rotatably fixed to the third peripheral wall 623 using a rotating bearing RH1. As a result, after placing the negative electrode tab group 220 and the negative electrode tab group 270 in the tab housing space 670, the tab housing space 670 can be easily closed by rotating the second connecting wall 660 in the direction of arrow R1 in the figure.

[0188] Since the second connecting wall 660 is integrated with the other components (enclosing wall, etc.) of the spacer 600A, the second connecting wall 660 is not separated from the other components (enclosing wall, etc.), thus suppressing an increase in transportation costs in the supply process. The second connecting wall 660 will not detach from the other components (enclosing wall, etc.).

[0189] For fixing the second connecting wall 660 to the seventh peripheral wall 643 on the opposite side of the rotating bearing RH1, the fixing structures C1 to C7 described above can be used. The same applies to the other forms of spacers shown below.

[0190] (Spacer 600B of Embodiment 3) In the third embodiment shown in Figures 40 and 41, the spacer 600B has the second connecting wall 660 rotatably fixed to the third peripheral wall 623 using a hinge RH2 made of a thinner material than the surrounding area. The thickness of the hinge RH2 is preferably 1 mm or less. As a result, it is possible to obtain the same effects as the spacer 600A described above, and the second connecting wall 660 can be easily opened and closed. Furthermore, even if the second connecting wall 660 is deformed, the shape of the hinge RH2 can be maintained.

[0191] (Spacer 600C of Embodiment 4) The spacer 600C of Embodiment 4 shown in Figures 42 and 43 uses two second connecting walls 660A. One second connecting wall 660A is rotatably fixed to the third peripheral wall 623 using a hinge RH2 made of a thin material, and the other second connecting wall 660A is rotatably fixed to the seventh peripheral wall 643 using a hinge RH2 made of a thin material. In other words, the two second connecting walls 660A form the shape of a double door. As a result, it is possible to obtain the same effects as the spacer 600A described above. Furthermore, the tab housing space 670 can be made wider, and the assembly of the spacer to the electrode body 200 can be made easier.

[0192] (Spacer 600D of Embodiment 5) The spacer 600D of Embodiment 5, shown in Figures 44 and 45, is provided on the inner surface of the second connecting wall 660 and has multiple slits S1 in the second protrusion 662, compared to the spacer 600B of Embodiment 3. This allows the second connecting wall 660 to bend so that it becomes concave outward. As a result, it is possible to obtain the same effects as the spacer 600A described above. Furthermore, deformation and stress when the second connecting wall 660 is open can be distributed, and fracture and plastic deformation of the deformed part can be suppressed.

[0193] (Spacer 600E of Embodiment 6) In each of the spacers described above, under normal conditions, the open area 680 is sealed by the second connecting wall 660, and the tab storage space 670 is a closed space. When arranging the negative electrode tab group 220 and the negative electrode tab group 270, it was necessary to move (open) the second connecting wall 660, and then, afterwards, to seal the open area 680 again with the second connecting wall 660 and close the tab storage space 670.

[0194] On the other hand, in the spacer 600E of Embodiment 6, under normal conditions, the open area 680 is kept open by the second connecting wall 660, and after the negative electrode tab group 220 and the negative electrode tab group 270 are placed in the tab housing space 670, the open area 680 is sealed by the second connecting wall 660.

[0195] As a result, after assembling the spacer 600E to the electrode body 200, the second connecting wall 660 can be moved to seal the open area 680 with the second connecting wall 660. Therefore, it is not necessary to hold the second connecting wall 660 in order to open the tab housing space 670, and the assembly of the spacer to the electrode body 200 can be made easier.

[0196] In the embodiments described above, a second connecting wall 660 is provided on the longitudinal side of the spacer 600 to form an open area 680 that opens up the tab storage space 670. However, the configuration is not limited to this, and a configuration in which a second connecting wall 660 is provided on the short side of the spacer 600 to form an open area 680 that opens up the tab storage space 670 is also possible.

[0197] Furthermore, it is preferable that the size of the open area 680 provided in the spacer 600 is less than or equal to a certain amount compared to the overall size of the spacer 600. For example, in the Z direction in Figure 13, it is preferable that the length of the open area 680 is 80% or less, and more preferably 70% or less, of the total length of the spacer 600. Alternatively, in the spacer 600, the volume ratio occupied by the sealing wall (e.g., the second connecting wall 660) that closes the open area 680 (volume of the sealing wall / total volume of the spacer 600) is preferably 40% or less, and more preferably 30% or less.

[0198] While embodiments of the present technology have been described above, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present technology is defined by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0199] 1 Secondary battery, 100 Case, 110 Case body, 111 First side section, 112, 112A, 112B Second side section, 113, 114 Opening, 115 Joint section, 120, 130 Sealing plate, 134 Liquid hole, 150 Gas release valve, 200 Electrode body, 201 First electrode body, 202 Second electrode body, 205 First end, 206 Second end, 207 Third end, 208 Fourth end, 210 Negative electrode plate, 211 Negative electrode core, 220, 270 Negative electrode tab group, 220r, 250r First recess, 221, 251, 271, 281 Curved section, 222, 252, 272, 282 Tip section, 230 Negative electrode tab, 240 Positive electrode plate, 241 Positive electrode core, 243 Positive electrode protective layer, 250, 280 Positive electrode tab group, 260 Positive electrode tab, 270r, 280r Second recess, 300 Electrode terminal, 301 Negative electrode terminal, 301a, 301b, R1 region, 302 Positive electrode terminal, 303, 304 Plate-shaped member, 400, 410, 420, 430, 440, 450 Current collector, 400A Negative electrode current collector, 400B Positive electrode current collector, 411, 421 Joint point, 460 Plate, 470, 510, 520, 530 Insulating member, 600, 600A, 600B, 600C, 600D, 600E Spacer, 610 First base part, 620 Second base part, 620r, 620s, 623s Engagement groove, 621 1st peripheral wall, 622 2nd peripheral wall, 623 3rd peripheral wall, 624 4th peripheral wall, 625 1st support wall, 626 1st engagement hole, 627,628,647,648 Projection, 641 5th peripheral wall, 642 6th peripheral wall, 643 7th peripheral wall, 644 8th peripheral wall, 645 2nd support wall, 646 2nd engagement hole, 650 1st connecting wall, 651 1st connecting peripheral wall, 652 1st convex portion, 653 1st concave curved surface portion, 660,660A 2nd connecting wall, 660r Thin wall portion, 661s ferrule piece, 661 2nd connecting peripheral wall, 662 2nd convex portion, 663 2nd concave curved surface portion, 664,664b,665 Engagement protrusion, 664c burr, 670 Tab housing space, 680 open area, 700 insulating sheet, 800 separator.

Claims

1. An electrode body including a first electrode and a second electrode having a different polarity from the first electrode, The system comprises a case for housing the electrode body, The case includes a case body having a first opening at one end, and a first sealing plate that seals the first opening. The electrode body includes a first tab and a second tab at the end on the side of the first sealing plate, which are electrically connected to the first electrode, A first spacer is placed between the first sealing plate and the electrode body. The first tab and the second tab are arranged in a curved state in the tab housing space provided in the first spacer. The first spacer includes an enclosure wall located around the tab housing space, The enclosure wall has an open area in a part of the enclosure wall that opens up the tab storage space, and a sealing wall positioned in the open area. A method for manufacturing an energy storage device, An electrode body manufacturing step for manufacturing the electrode body having the first tab and the second tab, After the electrode body manufacturing step, with the sealing wall not placed in the open region, the arrangement step involves placing the first tab and the second tab through the open region into the tab housing space, After the arrangement step, a sealing step is performed in which the sealing wall is placed in the open area, Following the sealing step, a bending step is performed in which the first tab and the second tab are bent with the surrounding wall facing the main outer surface of the first tab and the sealing wall facing the main outer surface of the second tab. A method for manufacturing an energy storage device, comprising the following:

2. Before the aforementioned arrangement step, The process includes joining at least one of the first tab and the second tab to the first conductive member, A method for manufacturing an energy storage device according to claim 1.

3. The first tab has a first recess that, when curved, is recessed on the side of the second tab. The second tab has a second recess that is recessed on the side of the first tab when it is curved, The aforementioned enclosure wall has a first protrusion, The sealing wall has a second protrusion, The first protrusion is positioned within the first recess, The second protrusion is positioned within the second recess. A method for manufacturing an energy storage device according to claim 1.

4. The enclosure wall has a first concave curved surface portion on the side of the first sealing plate of the first protrusion, The sealing wall has a second concave curved portion on the side of the second protrusion that faces the first sealing plate. A method for manufacturing an energy storage device according to claim 3.

5. After the arrangement step, an insertion step is performed in which the electrode body and the first spacer are inserted into the case body, After the insertion step, in the bending step, the first tab and the second tab are bent while the enclosure wall is brought into contact with the first tab and the sealing wall is brought into contact with the second tab. A method for manufacturing an energy storage device according to claim 1.

6. The case body has a second opening at the other end, The second opening is sealed by the second sealing plate. A method for manufacturing an energy storage device according to claim 1.

7. The first spacer is placed at one end of the electrode body. The electrode body and the first spacer are covered with an insulating sheet. A method for manufacturing an energy storage device according to claim 1.

8. The aforementioned sealing wall is a separate component from the aforementioned enclosure wall. A method for manufacturing an energy storage device according to claim 1.

9. The aforementioned sealing wall is integrated with the aforementioned enclosure wall, The sealing wall is movable relative to the enclosure wall. A method for manufacturing an energy storage device according to claim 1.

10. The sealing wall has an engaging projection, The first spacer has an engaging recess into which the engaging projection engages, A method for manufacturing an energy storage device according to claim 8 or 9.

11. The aforementioned engaging projection has a snap-fit ​​structure. A method for manufacturing an energy storage device according to claim 10.

12. An electrode body including a first electrode and a second electrode having a different polarity from the first electrode, The system comprises a case for housing the electrode body, The case includes a case body having a first opening at one end, and a first sealing plate that seals the first opening. The electrode body includes a first tab and a second tab at the end on the side of the first sealing plate, which are electrically connected to the first electrode, A first spacer is placed between the first sealing plate and the electrode body. The first tab and the second tab are each electrically connected to the first electrode in a curved state. The first tab and the second tab are arranged in a curved state in the tab housing space provided in the first spacer. It is an energy storage device, The first spacer includes an enclosure wall located around the tab housing space, The enclosure wall has an open area in a part of the enclosure wall that opens up the tab storage space, and a sealing wall that closes the open area. With the enclosure wall facing the main outer surface of the first tab and the sealing wall facing the main outer surface of the second tab, the first tab and the second tab are curved. Energy storage device.

13. The aforementioned sealing wall is a separate component from the aforementioned enclosure wall. The energy storage device according to claim 12.

14. The aforementioned sealing wall is integrated with the aforementioned enclosure wall, The sealing wall is movable relative to the enclosure wall. The energy storage device according to claim 12.

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