Secondary battery manufacturing method and secondary battery

Abstract

To improve the energy density of a secondary battery, and stably manufacture a secondary battery.SOLUTION: In this secondary battery, a spacer 600 (first spacer) is disposed between a first sealing plate and an electrode body in a first opening of a case main body. This spacer 600 (first spacer) includes a convex part 616 (first convex part) facing a first electrode tab 220, and the first electrode tab 220 is bent and curved so that a bent part 221a (first concave part) that is bent at a position facing the convex part 616 is formed. With this structure, the energy density of the secondary battery can be improved and the secondary battery can be stably manufactured.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present technology relates to a method for manufacturing a secondary battery and a secondary battery. [Background technology]

[0002] Japanese Patent No. 4537353 (Patent Document 1) shows a rectangular secondary battery in which an electrode group (25) is housed in a case (14) having openings (14a, 14b) at both ends, and electrode terminals (21, 23) are attached to cap plates (33, 33') that seal the openings (14a, 14b). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4537353 Summary of the Invention [Problem to be solved by the invention]

[0004] In the secondary battery described in Patent Document 1, there is room for improvement in the energy density and for stable production of secondary batteries.

[0005] The present technology has been made to solve the above-mentioned problems, and aims to provide a method for manufacturing a secondary battery that can improve energy density and be stably manufactured, and a secondary battery. [Means for solving the problem]

[0006] The present technology provides the following secondary battery.

[0007] [1] A secondary battery comprising: an electrode assembly, each including a first electrode and a second electrode having a polarity opposite to that of the first electrode; and a case that accommodates the electrode assembly, wherein the case includes a case main body having a first opening at one end and a first sealing plate that seals the first opening, the electrode assembly including, at an end facing the first sealing plate, a first electrode tab and a third electrode tab, each electrically connected to the first electrode, the first electrode tab and the third electrode tab being electrically connected to the first electrode in a curved state, the first electrode tab having a first recess that is recessed in the curved state, and the third electrode tab having a third recess that is recessed in the curved state, a first spacer being disposed in the first opening of the case main body between the first sealing plate and the electrode assembly, the first spacer having a first protrusion that faces the first electrode tab, the first protrusion being positioned so as to face the first recess.

[0008] [2] The secondary battery described in [1], wherein the first recess is provided on the outer surface of the first electrode tab facing the case body, the third recess is provided on the outer surface of the third electrode tab facing the case body, the first spacer is positioned between the case body and the first electrode tab, and the first spacer is not positioned between the case body and the third electrode tab.

[0009] [3] The secondary battery according to [1] or [2], wherein the first electrode tab and the third tab are electrically connected to the first electrode while being curved in opposite directions.

[0010] [4] The secondary battery according to any one of [1] to [3], wherein the first spacer has a second convex portion facing the third electrode tab, and the second convex portion is positioned so as to face the second concave portion.

[0011] [5] The secondary battery described in [4], wherein the first recess is provided on the outer surface of the first electrode tab facing the case body, the third recess is provided on the outer surface of the third electrode tab facing the case body, and the first spacer is positioned between the case body and the first electrode tab, and between the case body and the third electrode tab.

[0012] [6] The secondary battery according to any one of [1] to [5], wherein the first recess is provided on an outer surface of the first electrode tab facing the third electrode tab, the third recess is provided on an outer surface of the third electrode tab facing the first electrode tab, and the first spacer is disposed between the first electrode tab and the third electrode tab.

[0013] [7] The secondary battery according to any one of [1] to [6], wherein the first electrode tab has a first curved portion on the outer surface on which the first recess is formed, closer to the first sealing plate than the first recess, and the third electrode tab has a second curved portion on the outer surface on which the third recess is formed, closer to the first sealing plate than the third recess.

[0014] [8] The secondary battery according to any one of [1] to [7], wherein the electrode body and the first spacer are wrapped in an insulating sheet, and the insulating sheet is connected to the first spacer.

[0015] [9] The secondary battery according to any one of [1] to [8], wherein the case includes a second sealing plate, the case body has a second opening at an end opposite to the first opening, the second opening is sealed by the second sealing plate, the electrode body has a second electrode tab and a fourth electrode tab at an end on the second sealing plate side, the second electrode tab and the fourth electrode tab being electrically connected to the second electrode, and the second electrode tab and the fourth electrode tab are each electrically connected to the second electrode in a curved state.

[0016]

[10] The secondary battery described in [9], wherein the second electrode tab has a second recess that is recessed when curved, and the fourth electrode tab has a fourth recess that is recessed when curved, and a second spacer is disposed in the second opening of the case body between the second sealing plate and the electrode body, and the second spacer has a second convex portion facing the second electrode tab and a fourth convex portion facing the fourth electrode tab, and the second convex portion is positioned so as to face the second recess and the fourth convex portion is positioned so as to face the fourth recess.

[0017] The present technology provides the following method for manufacturing a secondary battery.

[0018]

[11] An electrode assembly including a first electrode and a second electrode having a polarity different from that of the first electrode, and a case accommodating the electrode assembly, wherein the case includes a case main body having a first opening at one end and a first sealing plate sealing the first opening, and the first electrode assembly includes, at an end on the first sealing plate side, a first electrode tab and a third electrode tab, each electrically connected to the first electrode, and the first electrode tab and the third electrode tab are each electrically connected to the first electrode in a curved state, the first electrode tab having a first recess that is recessed in the curved state, and the third electrode tab having a second recess that is recessed in the curved state. a first spacer is disposed in the first opening of the case body between the first sealing plate and the electrode body, the first spacer having a first convex portion facing the first electrode tab, the first convex portion being positioned so as to face the first concave portion, the method comprising: a first connecting step of connecting the first electrode tab and the third electrode tab to the first sealing plate; and an electrode tab bending step of, after the first connecting step, bringing the first sealing plate and a main body of the electrode body closer to each other to bend the first electrode tab to form the first concave portion and to bend the third electrode tab to form the third concave portion.

[0019]

[12] The method for manufacturing a secondary battery according to

[11] , wherein in the electrode tab bending step, the first recess is formed while the first convex portion of the first spacer is brought into contact with the first electrode tab.

[0020]

[13] The method for manufacturing a secondary battery described in

[11] or

[12] , wherein the first spacer has a second convex portion facing the third electrode tab, and in the electrode tab bending process, the second concave portion is formed while contacting the second convex portion of the first spacer with the third electrode tab.

[0021]

[14] The method for manufacturing a secondary battery according to any one of

[11] to

[13] , wherein in the electrode tab bending step, the second recess is formed while a jig is brought into contact with the third electrode tab.

[0022]

[15] A method for manufacturing a secondary battery according to any one of

[11] to

[14] , comprising the steps of: arranging the first spacer on an end face of the electrode body on which the first electrode tab and the third electrode tab are provided; and covering the electrode body and the first spacer with an insulating sheet.

[0023]

[16] In the secondary battery, the case includes a second sealing plate, the case body has a second opening at an end opposite to the first opening, the second opening is sealed by the second sealing plate, the electrode body has a second electrode tab and a fourth electrode tab at an end on the second sealing plate side, the second electrode tab and the fourth electrode tab are each electrically connected to the second electrode in a curved state, the second electrode tab has a second recess that is recessed in the curved state,

[15] . The method for manufacturing a secondary battery according to any one of

[11] to

[15] , wherein a fourth electrode tab has a fourth recess that is recessed when bent, a second spacer is disposed in the second opening of the case body between the second sealing plate and the electrode body, the second spacer having a second protrusion that faces the second electrode tab, and the second protrusion is positioned so as to face the second recess, and the method further comprises a step of bringing the second protrusion of the second spacer into contact with the second electrode tab to bend the second electrode tab.

[0024]

[17] A method for manufacturing a secondary battery according to

[16] , comprising: a second connecting step of connecting the second electrode tab and the fourth electrode tab to the second sealing plate; and an inserting step of inserting the electrode body into the case body from the second opening of the case body, starting with the first electrode tab and the third electrode tab, after the second connecting step, in a state in which the first sealing plate is not connected to the first electrode tab and the third electrode tab. [Effects of the Invention]

[0025] According to the present technology, the energy density of a secondary battery can be improved and secondary batteries can be stably manufactured. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a front view showing a configuration of a secondary battery according to a first embodiment of the present technology. [Figure 2] 2 is a diagram showing the secondary battery shown in FIG. 1 as viewed from the direction of arrow II. [Figure 3] 3 is a diagram showing the secondary battery shown in FIG. 1 as viewed from the direction of arrow III. [Figure 4] 4 is a diagram showing the secondary battery shown in FIG. 1 as viewed from the direction of arrow IV. FIG. [Figure 5] 2 is a diagram showing the secondary battery shown in FIG. 1 as viewed from the direction of arrow V. FIG. [Figure 6] FIG. 2 is a front cross-sectional view of the secondary battery shown in FIG. [Figure 7] FIG. 2 is a front view showing a negative electrode blank before being formed into a negative electrode plate. [Figure 8] 8 is a cross-sectional view taken along the line VIII-VIII of the negative electrode plate shown in FIG. 7. [Figure 9] FIG. 2 is a front view showing a negative electrode plate formed from a negative electrode original plate. [Figure 10] FIG. 2 is a front view showing a positive electrode plate before it is formed into a positive electrode plate. [Figure 11] 11 is a cross-sectional view of the positive electrode plate taken along the line XI-XI in FIG. 10. [Figure 12] FIG. 2 is a front view showing a positive electrode plate formed from a positive electrode original plate. [Figure 13] 1. FIG. 2 is a cross-sectional view of the secondary battery shown in FIG. [Figure 14] 1. FIG. 2 is a cross-sectional view of the secondary battery shown in FIG. [Figure 15] FIG. 1 is a first perspective view showing the overall configuration of a spacer. [Figure 16] FIG. 2 is a second perspective view showing the overall configuration of the spacer. [Figure 17] 3 is a flowchart showing a method for manufacturing a secondary battery according to the first embodiment. [Figure 18] 1 is a perspective view showing a state before two electrode bodies included in the secondary battery according to Embodiment 1 are overlapped. [Figure 19] 19 is a cross-sectional view of the electrode body and current collector shown in FIG. 18 taken along the line XIX-XIX. [Figure 20] FIG. 2 is a perspective view showing a state in which an insulating sheet and a spacer are attached to an electrode body. [Figure 21] FIG. 10 is a diagram showing the insulating sheet in an unfolded state. [Figure 22] FIG. 10 is a diagram showing another insulating sheet in an unfolded state. [Figure 23] 23 is a cross-sectional view taken along the line XXIII-XXIII in FIG. 20. [Figure 24] FIG. 2 is a perspective view showing a state in which a holder and a spacer are attached to an electrode body. [Figure 25] FIG. 2 is a perspective view showing a state in which a first sealing plate is attached to a first current collector. [Figure 26] 26 is a cross-sectional view taken along the line XXVI-XXVI of the electrode body and current collector shown in FIG. 25. [Figure 27] FIG. 2 is a perspective view showing a state in which an electrode body is being inserted into a case main body. [Figure 28] FIG. 10 is a perspective view showing a state in which a second sealing plate is attached to a second current collector. [Figure 29] 29 is a cross-sectional view of the electrode body and current collector shown in FIG. 28 taken along the line XXIX-XXIX. [Figure 30] 1 is a perspective view showing the configuration of a secondary battery according to Embodiment 1. FIG. [Figure 31] 26 is a cross-sectional view of the electrode body and current collector of the secondary battery according to Embodiment 2, taken along line XXVI-XXVI of FIG. 25. FIG. [Figure 32] FIG. 10 is a cross-sectional view showing a state in which the electrode tab is bent. [Figure 33] FIG. 10 is a first perspective view showing the overall configuration of a spacer according to a second embodiment. [Figure 34] FIG. 10 is a second perspective view showing the overall configuration of the spacer according to the second embodiment. [Figure 35]FIG. 11 is a perspective view showing the overall configuration of a spacer according to a third embodiment. [Figure 36] 1 according to the fourth embodiment. FIG. [Figure 37] FIG. 10 is a first perspective view showing the overall configuration of a spacer according to a fourth embodiment. [Figure 38] FIG. 11 is a second perspective view showing the overall configuration of the spacer according to the fourth embodiment. [Figure 39] FIG. 11 is a first perspective view showing the overall configuration of a spacer according to a fifth embodiment. [Figure 40] FIG. 13 is a second perspective view showing the overall configuration of the spacer according to the fifth embodiment. [Figure 41] 26 is a cross-sectional view of the electrode body and current collector shown in FIG. 25, taken along line XXVI-XXVI. [Figure 42] 2 is a cross-sectional view corresponding to the XIII-XIII cross section of the secondary battery shown in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present technology will be described. Note that the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0028] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiments.

[0029] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0030] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0031] In this specification, the term "secondary battery" is not limited to lithium ion batteries, but may include other secondary batteries such as nickel-metal hydride batteries and sodium ion batteries. In this specification, the term "electrode" may collectively refer to a positive electrode and a negative electrode.

[0032] In the drawings, the direction along the winding axis of the electrode body provided in the secondary battery is the X direction, the shorter side direction of the electrode body as viewed from the X direction is the Y direction, and the longer side direction of the electrode body as viewed from the X direction is the Z direction. Also, to make the invention easier to understand, the dimensions of each component in the drawings may be shown differently from the actual dimensions.

[0033] In this specification, the first direction (X direction) may be referred to as the "width direction" of the secondary battery or the case body, the second direction (Y direction) may be referred to as the "thickness direction" of the secondary battery or the case body, and the third direction (Z direction) may be referred to as the "height direction" of the secondary battery or the case body.

[0034] (Embodiment 1) (Overall battery configuration) Fig. 1 is a front view of a secondary battery 1 according to this embodiment. Figs. 2 to 5 are views showing the secondary battery 1 shown in Fig. 1 as viewed from the directions of arrows II, III, IV, and V, respectively. Fig. 6 is a front cross-sectional view of the secondary battery 1 shown in Fig. 1. For convenience of explanation, a spacer 600, which will be described later, is not shown in the cross-sectional view shown in Fig. 6.

[0035] The secondary battery 1 can be mounted in an electric vehicle (BEV: Battery Electric Vehicle), a plug-in hybrid electric vehicle (PHEV: Plug-in Hybrid Electric Vehicle), a hybrid electric vehicle (HEV: Hybrid Electric Vehicle), etc. However, the use of the secondary battery 1 is not limited to being mounted in a vehicle.

[0036] 1 to 6, the secondary battery 1 includes a case 100, an electrode assembly 200, an electrode terminal 300, and a current collector 400. The case 100 includes a case body 110, a first sealing plate 120, and a second sealing plate 130.

[0037] When configuring a battery pack including secondary batteries 1, multiple secondary batteries 1 are stacked in their thickness direction. The stacked secondary batteries 1 may be constrained in the stacking direction (Y direction) by a constraining member to form a battery module, or the battery pack may be directly supported on the side surface of a battery pack case without using a constraining member.

[0038] The case body 110 is made 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, an aluminum alloy, iron, an iron alloy, or the like.

[0039] As shown in Figures 1 and 2, a first sealing plate 120 and a second sealing plate 130 are provided at both ends of the case body. The case body 110 can be formed into a rectangular tube shape, for example, by abutting the edges of bent plate-like members (at joint 115 shown in Figure 2) and joining them together (by laser welding, for example). The corners of the "rectangular tube" may be rounded.

[0040] In this embodiment, the case body 110 is formed so that it is 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 allows for the construction of 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 allows for the construction of a relatively low-height secondary battery 1, which improves, for example, the mountability in a vehicle.

[0041] The case main body 110 includes a pair of first side surface portions 111 and a pair of second side surface portions 112. The pair of first side surface portions 111 constitute part of the side surfaces of the case 100. The pair of second side surface portions 112 constitute the bottom surface portion and the top surface portion of the case 100. The pair of first side surface portions 111 and the pair of second side surface portions 112 are arranged to intersect with each other. The pair of first side surface portions 111 and the pair of second side surface portions 112 are connected at their respective ends. It is desirable that each of the pair of first side surface portions 111 has a larger area than each of the pair of second side surface portions 112.

[0042] 5, a gas release valve 150 is provided on one second side surface portion 112A of the pair of second side surface portions 112. The gas release valve 150 extends in the width direction (X direction) of the secondary battery 1. The gas release valve 150 extends in the X direction from the center of the case body 110 in the X direction but does not reach both ends. The gas release valve 150 can be modified as appropriate.

[0043] The thickness of the plate-like member in the gas release valve 150 is thinner than the thickness of the plate-like members of the case body 110 other than the gas release valve 150. As a result, when the pressure inside the case 100 reaches or exceeds a predetermined value, the gas release valve 150 breaks preferentially compared to other parts of the case body 110, and releases gas inside the case 100 to the outside.

[0044] 2, a joint 115 is formed on the other second side surface portion 112B of the pair of second side surface portions 112. The joint 115 extends in the width direction (X direction) of the secondary battery 1. At the joint 115, the edges of the plate-like members that make up the case body 110 are joined together.

[0045] 3, a first opening 113 is provided at an end of a first side in a first direction (X direction) of case body 110. First opening 113 is sealed by first sealing plate 120. A joint portion 115 is formed in first opening 113 to seal first opening 113. First opening 113 and first sealing plate 120 have a substantially rectangular shape with the Y direction as the short side direction and the Z direction as the long side direction.

[0046] A negative electrode terminal 301 (first electrode terminal) is provided on the first sealing plate 120. The position of the negative electrode terminal 301 can be changed as appropriate.

[0047] 4, a second opening 114 is provided at the end of a second side of case body 110 opposite the first side in the first direction (X direction). That is, second opening 114 is located at the end opposite to first opening 113. Second opening 114 is sealed by second sealing plate 130. A joint 115 is formed in second opening 114 to seal second opening 114. Second opening 114 and second sealing plate 130 have a substantially rectangular shape with the Y direction as the short side direction and the Z direction as the long side direction.

[0048] A positive electrode terminal 302 (second electrode terminal) and a liquid injection hole 134 are provided on the second sealing plate 130. The positions of the positive electrode terminal 302 and the liquid injection hole 134 can be changed as appropriate.

[0049] The first sealing plate 120 and the second sealing plate 130 are made of metal. Specifically, the first sealing plate 120 and the second sealing plate 130 are made of aluminum, an aluminum alloy, iron, an iron alloy, or the like.

[0050] The negative electrode terminal 301 is electrically connected to the negative electrode (first electrode) of the electrode body 200. The negative electrode terminal 301 is attached to the first sealing plate 120, that is, the case 100.

[0051] The positive electrode terminal 302 is electrically connected to the positive electrode (second electrode) of the electrode body 200. The positive electrode terminal 302 is attached to the second sealing plate 130, that is, the case 100.

[0052] The negative electrode terminal 301 is made of a conductive material (more specifically, a metal), and may be made of, for example, copper or a copper alloy. The outer surface of the negative electrode terminal 301 may be provided with a portion or layer made of aluminum or an aluminum alloy.

[0053] The positive terminal 302 is made of a conductive material (more specifically, a metal), and may be made of, for example, aluminum or an aluminum alloy.

[0054] The liquid inlet hole 134 is sealed with a sealing member (not shown), which may be, for example, a blind rivet or other metal member.

[0055] The electrode assembly 200 is a flat-shaped electrode assembly having positive and negative electrode plates, as described below. Specifically, the electrode assembly 200 is a wound-type electrode assembly in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound together via a strip-shaped separator (not shown). However, in this specification, the term "electrode assembly" is not limited to a wound-type electrode assembly and may also be a stacked-type electrode assembly in which multiple positive electrode plates and multiple negative electrode plates are alternately stacked. The strip-shaped separator may be formed, for example, of a polyolefin microporous membrane. The electrode assembly may include multiple positive electrode plates and multiple negative electrode plates, and the positive electrode tabs provided on each positive electrode plate may be stacked to form a positive electrode tab group, or the negative electrode tabs provided on each negative electrode plate may be stacked to form a negative electrode tab group. The electrode assembly 200 may include multiple wound-type electrode bodies or multiple stacked-type electrode bodies.

[0056] As shown in Fig. 6, case 100 houses electrode assembly 200. Fig. 6 illustrates a first electrode assembly 201, which will be described later. First electrode assembly 201 is housed in case 100 so that its winding axis is parallel to the X direction.

[0057] Specifically, one or more wound electrode bodies are housed together with an electrolytic solution (electrolyte), not shown, inside an insulating sheet 700 (described below) placed inside the case 100. The electrolytic solution (nonaqueous electrolytic solution) can be, for example, a nonaqueous solvent made by mixing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) in a volume ratio (25°C) of 30:30:40, in which LiPF is dissolved at a concentration of 1.2 mol / L. Note that a solid electrolyte may be used instead of the electrolytic solution.

[0058] The first electrode body 201 includes a main body portion (a portion where positive electrode plates and negative electrode plates are stacked with a separator interposed therebetween), a first electrode tab 220 (a negative electrode tab group), and a second electrode tab 250 (a positive electrode tab group).

[0059] The main body is composed of a negative electrode plate 210 and a positive electrode plate 240, which will be described later. The first electrode tab 220 is located at the end of a first side of the first electrode body 201 in a first direction (X direction) relative to the main body. The first side in this embodiment is the first sealing plate 120 side. The second electrode tab 250 is located at the end of a second side of the first electrode body 201 in the first direction (X direction) relative to the main body. The second side in this embodiment is the second sealing plate 130 side.

[0060] The first electrode tab 220 and the second electrode tab 250 are formed to protrude from the center portion of the electrode body 200 toward the first sealing plate 120 or the second sealing plate 130, respectively.

[0061] The current collectors 400 include 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 a plate-shaped member. The electrode assembly 200 is electrically connected to a negative electrode terminal 301 and a positive electrode terminal 302 via the current collectors 400.

[0062] The negative electrode current collector 400A is disposed on the first sealing plate 120 via a resin insulating member. The negative electrode current collector 400A is electrically connected to the first electrode tab 220 and the negative electrode terminal 301. The negative electrode current collector 400A is made of a conductive material (more specifically, a metal), and may be made of, for example, copper or a copper alloy. Details of the negative electrode current collector 400A will be described later.

[0063] The positive electrode current collector 400B is disposed on the second sealing plate 130 via a resin insulating member. The positive electrode current collector 400B is electrically connected to the second electrode tab 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 second electrode tab 250 may be electrically connected to the second sealing plate 130 directly or via the positive electrode current collector 400B. In this case, the second sealing plate 130 may serve as the positive electrode terminal 302. The positive electrode current collector 400B will be described in detail later.

[0064] (Configuration of electrode body 200) FIG. 7 is a front view showing a negative electrode blank 210S before the negative electrode plate 210 (first electrode) is formed, FIG. 8 is a cross-sectional view taken along line VIII-VIII of the negative electrode blank 210S shown in FIG. 7, and FIG. 9 is a front view showing the negative electrode plate 210 formed from the negative electrode blank 210S.

[0065] The negative electrode plate 210 is manufactured by processing a negative electrode original plate 210S. As shown in Figures 7 and 8, the negative electrode original plate 210S includes a negative electrode core 211 and a negative electrode active material layer 212. The negative electrode core 211 is a copper foil or a copper alloy foil.

[0066] A negative electrode active material layer 212 is formed on both surfaces of the negative electrode substrate 211 except for one end portion. The negative electrode active material layer 212 is formed by applying a negative electrode active material layer slurry using a die coater.

[0067] The negative electrode active material layer slurry is prepared by kneading graphite as the negative electrode active material, styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC) as binders, and water as a dispersion medium so that the mass ratio of graphite:SBR:CMC is approximately 98:1:1.

[0068] The negative electrode substrate 211 coated with the negative electrode active material layer slurry is dried to remove water contained in the negative electrode active material layer slurry, thereby forming the negative electrode active material layer 212. The negative electrode active material layer 212 is then compressed to form a negative electrode base plate 210S including the negative electrode substrate 211 and the negative electrode active material layer 212. The negative electrode base plate 210S is cut into a predetermined shape to form the negative electrode plate 210. The negative electrode base plate 210S can be cut by laser processing using energy beam irradiation, mold processing, cutter processing, or the like.

[0069] As shown in FIG. 9, a plurality of negative electrode tabs 230 each made of a negative electrode core 211 are provided at one end in the width direction of a negative electrode plate 210 formed from a negative electrode original plate 210S. When the negative electrode plate 210 is wound, the plurality of negative electrode tabs 230 are stacked to form a first electrode tab 220. As a result, the first electrode tab 220 is connected to the negative electrode plate 210 (first electrode). The position and length in the protruding direction of each of the plurality of negative electrode tabs 230 are appropriately adjusted taking into consideration the state in which the first electrode tab 220 is connected to the negative electrode current collector 400A. The shape of the negative electrode tab 230 is not limited to that exemplified in FIG. 8.

[0070] FIG. 10 is a front view showing a positive electrode plate 240S before the positive electrode plate 240 (second electrode) is formed, FIG. 11 is a cross-sectional view of the positive electrode plate 240S shown in FIG. 10 taken along line XI-XI, and FIG. 12 is a front view showing the positive electrode plate 240 formed from the positive electrode plate 240S.

[0071] The positive electrode plate 240, which is the second electrode, has a polarity different from that of the negative electrode plate 210, which is the first electrode. The positive electrode plate 240 is manufactured by processing a positive electrode base plate 240S. As shown in FIGS. 10 and 11, the positive electrode base plate 240S includes a positive electrode core 241, a positive electrode active material layer 242, and a positive electrode protective layer 243. The positive electrode core 241 is an aluminum foil or an aluminum alloy foil.

[0072] A positive electrode active material layer 242 is formed on both surfaces of the positive electrode core 241 except for one end portion. The positive electrode active material layer 242 is formed on the positive electrode core 241 by applying a positive electrode active material layer slurry using a die coater.

[0073] The positive electrode active material layer slurry is prepared by kneading lithium nickel cobalt manganese composite oxide as the positive electrode active material, polyvinylidene fluoride (PVdF) as a binder, a carbon material as a conductive material, and N-methyl-2-pyrrolidone (NMP) as a dispersion medium so that the mass ratio of lithium nickel cobalt manganese composite oxide:PVdF:carbon material is approximately 97.5:1:1.5.

[0074] The positive electrode protective layer 243 is in contact with the positive electrode core 241 and is formed on one end of the positive electrode active material layer 242 in the width direction. The positive electrode protective layer 243 is formed on the positive electrode core 241 by applying a positive electrode protective layer slurry using a die coater. The positive electrode protective layer 243 has a larger electrical resistance than the positive electrode active material layer 242.

[0075] The positive electrode protective layer slurry is prepared by kneading alumina powder, a carbon material as a conductive material, PVdF as a binder, and NMP as a dispersion medium so that the mass ratio of alumina powder:carbon material:PVdF is approximately 83:3:14.

[0076] The positive electrode substrate 241 coated with the positive electrode active material layer slurry and the positive electrode protective layer slurry is dried, and the NMP contained in the positive electrode active material layer slurry and the positive electrode protective layer slurry is removed, thereby forming the positive electrode active material layer 242 and the positive electrode protective layer 243. The positive electrode active material layer 242 is then compressed to form a positive electrode base plate 240S including the positive electrode substrate 241, the positive electrode active material layer 242, and the positive electrode protective layer 243. The positive electrode base plate 240S is cut into a predetermined shape to form the positive electrode plate 240. The positive electrode base plate 240S can be cut by laser processing using energy beam irradiation, mold processing, cutter processing, or the like.

[0077] As shown in FIG. 12, a plurality of positive electrode tabs 260 each made of a positive electrode core 241 are provided at one end in the width direction of a positive electrode plate 240 formed from a positive electrode original plate 240S. When the positive electrode plate 240 is wound, the plurality of positive electrode tabs 260 are stacked to form a second electrode tab 250. As a result, the second electrode tab 250 is connected to the positive electrode plate 240 (second electrode). The position and length in the protruding direction of each of the plurality of positive electrode tabs 260 are appropriately adjusted taking into consideration the state in which the second electrode tab 250 is connected to the positive electrode current collector 400B. The shape of the positive electrode tab 260 is not limited to that exemplified in FIG. 12.

[0078] A positive electrode protective layer 243 is provided at the base of each of the positive electrode tabs 260. The positive electrode protective layer 243 does not necessarily have to be provided at the base of the positive electrode tab 260.

[0079] In a typical example, the thickness of the negative electrode tab 230 (one piece) is smaller than the thickness of the positive electrode tab 260 (one piece). In this case, the thickness of the first electrode tab 220 is smaller than the thickness of the second electrode tab 250.

[0080] (Connection structure between electrode body 200 and current collector 400) Fig. 13 is a cross-sectional view taken along line XIII-XIII of the secondary battery shown in Fig. 1. As shown in Fig. 13, 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 first electrode (negative electrode) and a second electrode (positive electrode). Note that the electrode body 200 may be composed of three or more electrode bodies.

[0081] 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.

[0082] The first electrode body 201 includes a first electrode tab 220. The first electrode tab 220 is electrically connected to the first electrode at a first end 205 in the X direction. The second electrode body 202 includes a third electrode tab 270. The third electrode tab 270 is electrically connected to the first electrode at a third end 207 in the X direction.

[0083] The first electrode tab 220 has a curved portion 221 (first curved portion) and a tip portion 222. The curved portion 221 (first curved portion) is a portion of the first electrode tab 220 that is curved relative to the tip portion 222 on the side to which the first electrode is connected. The first electrode tab 220 includes a recessed portion 221a (first recessed portion) in which an area facing a protruding portion 616 (first protruding portion) provided on a spacer 600, the configuration of which will be described in detail later, is recessed. The tip portion 222 is a portion of the first electrode tab 220 that is located at the end opposite the side to which the first electrode is connected.

[0084] The third electrode tab 270 has a curved portion 271 (third curved portion) and a tip portion 272. The curved portion 271 (third curved portion) is a portion of the third electrode tab 270 that is curved relative to the tip portion 272 on the side to which the first electrode is connected. The third electrode tab 270 includes a recess 271a (third recess) in which an area facing a protrusion 626 (second protrusion) provided on the spacer 600, the configuration of which will be described in detail later, is recessed. The tip portion 272 is a portion of the third electrode tab 270 that is located at the end opposite the side to which the first electrode is connected.

[0085] The first electrode tab 220 and the third electrode tab 270 are curved in opposite directions so that the tip ends 222, 272 approach each other. In the present embodiment, the tip ends 222, 272 are spaced apart, but this configuration is not limiting, and the tip ends 222, 272 may be in contact with each other.

[0086] The negative electrode current collector 400A electrically connects the negative electrode terminal 301 to the first electrode tab 220 and the third electrode tab 270. The negative electrode current collector 400A in this embodiment is connected to the negative electrode terminal 301 between the electrode body 200 and the first sealing plate 120.

[0087] The negative electrode current collector 400A includes a first current collector 410, a third current collector 430, and a first electrode terminal side current collector 440.

[0088] The first current collector 410 is a plate-like member. The first current collector 410 has a longitudinal direction in the Z direction and a lateral direction in the Y direction. The third current collector 430 is a plate-like member. The third current collector 430 has a longitudinal direction in the Z direction and a lateral direction in the Y direction. The first current collector 410 and the third current collector 430 are arranged in parallel in the X direction. In this way, the first current collector 410 and the third current collector 430 are formed from separate parts.

[0089] The first electrode tab 220 is joined to the first current collector 410 at a joining point 411, which will be described later. The third electrode tab 270 is joined to the third current collector 430 at a joining point 431, which will be described later. The joining points 411, 431 may be formed by, for example, ultrasonic welding, resistance welding, laser welding, caulking, or the like. In this embodiment, the first electrode tab 220 and the first current collector 410, and the third electrode tab 270 and the third current collector 430 are joined by, for example, ultrasonic welding.

[0090] The first electrode terminal side current collector 440 is joined to the first current collector 410 and the third current collector 430 at joints (not shown) located at the ends in the Z direction. The first electrode terminal side current collector 440 is connected to the negative electrode terminal 301. The connection between the first electrode terminal side current collector 440 and the negative electrode terminal 301 can be formed by, for example, crimping and / or welding.

[0091] Negative electrode terminal 301 is exposed to the outside of first sealing plate 120 and is provided so as to reach first electrode terminal side current collector 440 of negative electrode current collector 400A provided on the inside surface of first sealing plate 120. Negative electrode terminal 301 is connected to first plate portion 303.

[0092] The first plate portion 303 is located on the outside of the first sealing plate 120. The first plate portion 303 is arranged so as to fit along the first sealing plate 120. The first plate portion 303 is conductive. The first plate portion 303 is arranged to ensure a connection area with a bus bar or the like that electrically connects the secondary battery 1 to another adjacent secondary battery. The connection between the negative electrode terminal 301 and the first plate portion 303 can be formed by, for example, laser welding.

[0093] A first insulating member 510 is disposed between the first plate portion 303 and the first sealing plate 120. A second insulating member 520 is disposed between the negative electrode terminal 301 and the first sealing plate 120. A third insulating member 530 is disposed between the first electrode terminal side current collector 440 and the first sealing plate 120.

[0094] However, negative electrode terminal 301 may be electrically connected to first sealing plate 120. Also, first sealing plate 120 may serve as negative electrode terminal 301.

[0095] A spacer 600 (first spacer) is disposed between the first sealing plate 120 and the electrode assembly 200. This spacer 600 suppresses large movements of the electrode assembly 200 within the case 100. The spacer 600 is made of an insulating resin material. The spacer 600 includes a first component 610 and a second component 620. The first component 610 and the second component 620 engage with each other at engaging portions (not shown) at both ends in the Z direction.

[0096] The first component 610 has a protrusion 616 (first protrusion) that protrudes in the Y direction toward the second component 620 at its end on the electrode body 200 side in the X direction. The second component 620 has a protrusion 626 (second protrusion) that protrudes in the Y direction toward the first component 610 at its end on the electrode body 200 side in the X direction. By providing the protrusion 616 (first protrusion) and the protrusion 626 (second protrusion), the spacer 600 serves as a guide to facilitate bending of the bending portion 221 (first bending portion) and the bending portion 271 (third bending portion) when bending the bending portion 221 (first bending portion) and the bending portion 271 (third bending portion). The detailed structure of the spacer 600 will be described later.

[0097] A resin insulating sheet 700 is disposed between the electrode body 200 and the case body 110. More specifically, the insulating sheet 700 covers the electrode body 200, and the spacer 600 is also covered by the insulating sheet 700 so as to surround the side wall of the spacer 600 on the case body 110 side. Furthermore, the insulating sheet 700 is connected to the spacer 600 by a method described below.

[0098] Insulating sheet 700 may be made of, for example, resin. More specifically, insulating sheet 700 may be made of, for example, polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), or polyolefin (PO).

[0099] Furthermore, the third insulating member 530 is positioned between the spacer 600 (first spacer) and the first sealing plate 120. As a result, movement of the spacer 600 (first spacer) toward the first sealing plate 120 can be restricted.

[0100] Fig. 14 is a cross-sectional view taken along line XIV-XIV of the secondary battery shown in Fig. 1. The connection structure between the electrode body 200 and the current collector 400 on the second electrode (positive electrode) side of the secondary battery 1 in this embodiment differs from the structure on the first electrode (negative electrode) side in that the portions corresponding to the first current collector 410 and the third current collector 430 on the first electrode (negative electrode) side are configured as a single part.

[0101] The first electrode body 201 includes a second electrode tab 250. The second electrode tab 250 is electrically connected to the second electrode at a second end 206 in the X direction. The second electrode body 202 includes a fourth electrode tab 280. The fourth electrode tab 280 is electrically connected to the second electrode at a fourth end 208 in the X direction.

[0102] The second electrode tab 250 has a curved portion 251 (second curved portion) and a tip portion 252. The curved portion 251 (second curved portion) is a portion of the second electrode tab 250 that is curved relative to the tip portion 252 on the side where the second electrode is connected. The second electrode tab 250 includes a recess 251a (second recess) in which an area facing a protrusion 616 (second protrusion) provided on a spacer 600 (second spacer), the configuration of which will be described in detail later, is recessed. The tip portion 252 is a portion of the second electrode tab 250 that is located at the end opposite the side where the second electrode is connected.

[0103] The fourth electrode tab 280 has a curved portion 281 (fourth curved portion) and a tip portion 282. The curved portion 281 (fourth curved portion) is a portion of the fourth electrode tab 280 that is curved relative to the tip portion 282 on the side to which the second electrode is connected. The fourth electrode tab 280 includes a recess 281a (fourth recess) in which an area facing a protrusion 626 (fourth protrusion) provided on the spacer 600, the configuration of which will be described in detail later, is recessed. The tip portion 282 is a portion of the fourth electrode tab 280 that is located at the end opposite the side to which the second electrode is connected.

[0104] The second electrode tab 250 and the fourth electrode tab 280 are curved in opposite directions so that the tip portions 252, 282 approach each other. 282 However, the present invention is not limited to this configuration, and the tip portions 252 and 282 may be in contact with each other.

[0105] The positive electrode current collector 400B electrically connects the positive electrode terminal 302 to the second electrode tab 250 and the fourth electrode tab 280. The positive electrode current collector 400B in this embodiment is connected to the positive electrode terminal 302 between the electrode body 200 and the second sealing plate 130.

[0106] The positive electrode current collector 400B includes a second current collector 420 and a second electrode terminal side current collector 450.

[0107] The second current collector 420 is a plate-like member. The second current collector 420 has a longitudinal direction in the Z direction and a lateral direction in the Y direction. The second current collector 420 is configured as a single, integrated part.

[0108] The second electrode tab 250 and the fourth electrode tab 280 are joined to the second current collector 420, which is configured as a single component, at a joining point 421, which will be described later. The joining point 421 may be formed by, for example, ultrasonic welding, resistance welding, laser welding, crimping, or the like. In the present embodiment, the second electrode tab 250 and the fourth electrode tab 280 are joined to the second current collector 420 by, for example, ultrasonic welding.

[0109] The second electrode terminal side current collector 450 is joined to the second current collector 420 at a joint (not shown) located at an end in the Z direction. The second electrode terminal side current collector 450 is connected to the positive electrode terminal 302. The connection between the second electrode terminal side current collector 450 and the positive electrode terminal 302 can be formed by, for example, crimping and / or welding.

[0110] Positive electrode terminal 302 is exposed to the outside of second sealing plate 130 and is provided so as to reach second electrode terminal side current collector 450 of positive electrode current collector 400B provided on the inside surface of second sealing plate 130. Positive electrode terminal 302 is connected to second plate portion 304.

[0111] The second plate portion 304 is located outside the second sealing plate 130. The second plate portion 304 is arranged so as to fit along the second sealing plate 130. The second plate portion 304 is conductive. The second plate portion 304 is arranged to ensure a connection area with a bus bar or the like that electrically connects the secondary battery 1 to another adjacent secondary battery. The connection between the positive electrode terminal 302 and the second plate portion 304 can be formed by, for example, laser welding.

[0112] A first insulating member 510 is disposed between the second plate portion 304 and the second sealing plate 130. A second insulating member 520 is disposed between the positive electrode terminal 302 and the second sealing plate 130. A third insulating member 530 is disposed between the second electrode terminal side current collector 450 and the second sealing plate 130.

[0113] However, the positive electrode terminal 302 may be electrically connected to the second sealing plate 130. Also, the second sealing plate 130 may serve as the positive electrode terminal 302.

[0114] A spacer 600 (second spacer) is disposed between the second sealing plate 130 and the electrode body 200. This spacer 600 (second spacer) suppresses large movements of the electrode body 200 within the case 100. The spacer 600 is made of an insulating resin material. The spacer 600 includes a first component 610 and a second component 620. The first component 610 and the second component 620 engage with each other at engaging portions (not shown) at both ends in the Z direction.

[0115] Between the electrode body 200 and the case body 110, an insulating sheet 700 (electrode body holder) made of resin is arranged.

[0116] On the second electrode (positive electrode) side of the secondary battery 1, a resin insulating sheet 700 (electrode body holder) is also disposed between the electrode body 200 and the case body 110. More specifically, the insulating sheet 700 covers the electrode body 200, and the spacer 600 (second spacer) is covered by the insulating sheet 700 so as to surround the side of the spacer 600 (second spacer) facing the case body 110. Furthermore, the insulating sheet 700 is connected to the spacer 600 by a method described below.

[0117] Furthermore, the third insulating member 530 is positioned between the spacer 600 (second spacer) and the second sealing plate 130. The spacer 600 may be in contact with the third insulating member 530. The spacer 600 (second spacer) may be in contact with the second sealing plate 130.

[0118] (Spacer 600) The detailed structure of spacer 600 will be described with reference to Figures 15 and 16. Figure 15 is a first perspective view showing the overall configuration of spacer 600, and Figure 16 is a second perspective view as viewed from the opposite side to the first perspective view. The first perspective view is a view as viewed from the first sealing plate 120 (second sealing plate 130) side when spacer 600 is placed between first sealing plate 120 (second sealing plate 130) and electrode body 200.

[0119] The spacer 600 is made of an insulating resin material. The spacer 600 includes a first component 610 and a second component 620. When the first component 610 and the second component 620 are joined together, the spacer 600 has an annular shape and can be separated into two components along the Y direction. Since the spacer 600 is thus made up of two components, it is arranged so as to sandwich the electrode tab. Note that the spacer 600 is not limited to being made up of two components, and may be made up of one component as shown in FIG. 35 (described later), or may be made up of two or more components.

[0120] The first component 610 has a long side wall 611 extending in the Z direction, and short side wall 612 and short side wall 614 extending from both ends of the long side wall 611 toward the second component 620. A plate 617 is provided at a corner of the joint between the long side wall 611 and the short side wall 612. A slit-shaped through hole 617s is provided in the plate 617. Similarly, a plate 618 is provided at a corner of the joint between the long side wall 611 and the short side wall 614. A slit-shaped through hole 618s is provided in the plate 618. A protrusion 616 protruding toward the second component 620 in the Y direction is provided at an end of the long side wall 611 in the X direction.

[0121] The plate portions 617 and 618 are located on the end face side of the electrode assembly. These plate portions may abut against the end face of the electrode assembly. Even if they do not abut against the end face, the shortest distance between them is preferably within 2 mm, more preferably within 1 mm. Furthermore, by providing the through-holes 618s, when the secondary battery 1 shown in FIG. 1 is placed with the Z direction facing upward (the first opening 113 and the second opening 114 at both ends of the case body 110 are arranged on the left and right), even if the electrolyte is forced out of the electrode assembly during charging (when the electrode plates generally expand) and flows out of these portions, it is easier for the electrolyte to return to the electrode assembly during discharging (when the electrode plates generally contract).

[0122] The convex portion 616 constitutes a first convex portion in the spacer 600 (first spacer) arranged between the first sealing plate 120 and the electrode body 200, and constitutes a third convex portion in the spacer 600 (second spacer) arranged between the second sealing plate 130 and the electrode body 200.

[0123] The second component 620 has a long side wall 621 extending in the Z direction, and short side wall 622 and short side wall 624 extending from both ends of the long side wall 621 toward the first component 610. A plate 627 is provided at a corner of the joint between the long side wall 621 and the short side wall 622. A slit-shaped through hole 627s is provided in the plate 627. Similarly, a plate 628 is provided at a corner of the joint between the long side wall 621 and the short side wall 624. A slit-shaped through hole 628s is provided in the plate 628. A protrusion 626 protruding toward the first component 610 in the Y direction is provided at an end of the long side wall 621 in the X direction.

[0124] The plate portions 627 and 628 are located on the end face side of the electrode assembly. These plate portions may abut against the end face of the electrode assembly. Even if they do not abut against the end face, the shortest distance between them is preferably within 2 mm, more preferably within 1 mm. Furthermore, by providing the through-holes 628s, when the secondary battery 1 shown in FIG. 1 is placed with the Z direction facing upward (the first opening 113 and the second opening 114 at both ends of the case body 110 are arranged on the left and right), even if the electrolyte is forced out of the electrode assembly during charging (when the electrode plates generally expand) and flows out of these portions, it is easier for the electrolyte to return to the electrode assembly during discharging (when the electrode plates generally contract).

[0125] The convex portion 626 constitutes a second convex portion in the spacer 600 (first spacer) arranged between the first sealing plate 120 and the electrode body 200, and constitutes a fourth convex portion in the spacer 600 (second spacer) arranged between the second sealing plate 130 and the electrode body 200.

[0126] An engagement claw 613 and an engagement groove 623 are provided between short side wall portion 612 and short side wall portion 622 so as to be detachable from each other. Similarly, an engagement claw 615 and an engagement groove 625 are provided between short side wall portion 614 and short side wall portion 624 so as to be detachable from each other.

[0127] When comparing the thickness in the X direction (thickness on the negative electrode side) of the spacer 600 arranged on the first electrode tab 220 and the third electrode tab 270 side with the thickness in the X direction (thickness on the positive electrode side) of the spacer 600 arranged on the second electrode tab 250 and the fourth electrode tab 280, the thickness on the positive electrode side can be made larger than the thickness on the negative electrode side. This is because, on the negative electrode side, the foil used for the first electrode tab 220 and the third electrode tab 270 is thinner, so the space between the electrode body and the sealing body is smaller on the negative electrode side than on the positive electrode side, and the mounting efficiency of the electrode body can be improved.

[0128] (Manufacturing process of secondary battery 1) A method for manufacturing a secondary battery according to the present embodiment will be described below. Fig. 17 is a flowchart showing a method for manufacturing a secondary battery according to embodiment 1. Fig. 18 is a perspective view showing a state before two electrode bodies included in the secondary battery according to embodiment 1 are overlapped. Fig. 19 is a cross-sectional view taken along the line XIX-XIX of the electrode body and current collector shown in Fig. 18.

[0129] 17, in the method for manufacturing a secondary battery according to the present embodiment, first, a first electrode body 201 and a second electrode body 202 are fabricated (step S1). A portion of the tip of each of the first electrode tab 220, the second electrode tab 250, the third electrode tab 270, and the fourth electrode tab 280 is cut off so that the tip lengths are the same when bundled.

[0130] As shown in FIGS. 17 to 19, after the first electrode body 201 and the second electrode body 202 are fabricated, the first electrode tab 220 is joined to the first current collector 410 (step S2). The first electrode tab 220 is joined to the first current collector 410 at a joining location 411. Next, the third electrode tab 270 is joined to the third current collector 430 (step S3). The third electrode tab 270 is joined to the third current collector 430 at a joining location 431.

[0131] Next, the first electrode body 201, the second current collector 420, and the second electrode body 202 are arranged in this order in the first direction (DR1 direction). The second electrode tab 250 is arranged on one side of the second current collector 420 in the first direction (DR1 direction). With the fourth electrode tab 280 arranged on the other side of the second current collector 420 in the first direction (DR1 direction), the second electrode tab 250 and the fourth electrode tab 280 are joined to the second current collector 420 (step S4). The second electrode tab 250 and the fourth electrode tab 280 are joined to the second current collector 420 at joining points 421.

[0132] In the height direction of the first electrode body 201 and the second electrode body 202, the first current collector 410, the second current collector 420, and the third current collector 430 are arranged biased to one side from the center of the first electrode body 201 and the second electrode body 202. This allows the current collectors to be configured to be short, and therefore the current collectors can be made compact.

[0133] Note that the first current collector 410, the second current collector 420, and the third current collector 430 are not limited to this configuration. The first current collector 410, the second current collector 420, and the third current collector 430 may be disposed at 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. In this case, the first electrode tab 220, the second electrode tab 250, the third electrode tab 270, and the fourth electrode tab 280 are each disposed at the center of the first electrode body 201 and the second electrode body 202 in accordance with the first current collector 410, the second current collector 420, and the third current collector 430 in the height direction of the first electrode body 201 and the second electrode body 202.

[0134] Furthermore, the order of the steps of joining the first current collector 410, the second current collector 420, and the third current collector 430 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 steps of joining the first current collector 410 and the third current collector 430 to the first electrode body 201 and the second electrode body 202, respectively, are preferably performed before the step of overlapping the first electrode body 201 and the second electrode body 202, which will be described later, and are preferably performed before the step of joining the second current collector 420 to the first electrode body 201 and the second electrode body 202.

[0135] Next, after joining the second electrode tab 250 and the fourth electrode tab 280 to the second current collector 420, the second electrode tab 250 and the fourth electrode tab 280 are bent in the thickness direction of the first electrode body 201 and the second electrode body 202 (a direction perpendicular to the DR1 direction in FIGS. 16 and 17) to overlap the first electrode body 201 and the second electrode body 202 (step S5). In other words, the first electrode body 201 and the second electrode body 202 are gathered together.

[0136] "Overlapping the first electrode body and the second electrode body" means that the first electrode body and the second electrode body may be directly overlapped, or another member may be disposed between the first electrode body and the second electrode body. The first electrode body and the second electrode body may or may not be fixed with tape or the like. Furthermore, the first electrode body, the second current collector, and the second electrode body do not have to be arranged on a straight line in the first direction (DR1 direction), and the first electrode body or the second electrode body may be inclined with respect to the first direction (DR1 direction) with respect to the second current collector.

[0137] By overlapping the first electrode body 201 and the second electrode body 202, the second electrode tab 250 and the fourth electrode tab 280 are bent so as to approach each other relative to the second current collector 420. The first electrode tab 220 and the third electrode tab 270 are also bent so that their tip ends face each other.

[0138] 17 and 20 to 24 are perspective views showing a state in which the holder and spacer are attached to the electrode assembly. As shown in Fig. 24, next, the spacer 600 and the insulating sheet 700 are assembled to the electrode assembly 200 (step S6).

[0139] 20, the insulating sheet 700 covers the entire outer periphery of the electrode body 200, and also surrounds the side of the spacer 600 (first spacer and second spacer) facing the case body 110. Furthermore, the insulating sheet 700 is connected to the spacer 600 by fixing means 710.

[0140] In this way, the entire periphery of the spacer 600 is covered with the insulating sheet 700, so that the electrode tabs are also covered with the insulating sheet 700. As a result, when the electrode body 200 covered with the insulating sheet 700 is inserted into the case body 110, the electrode tabs are protected and unintentional breakage of the electrode tabs can be suppressed.

[0141] Here, when comparing the thickness direction length W1 of the spacer 600 (first spacer and second spacer) and the electrode body 200 with the height direction length W2 of the spacer 600 and the electrode body 200, it is preferable that either the thickness or the height of the spacer is set smaller than the thickness or the height of the electrode body 200. In this way, the electrode body 200 is fixed by the insulating sheet 700, and therefore the insertability of the electrode body 200 into the case 110 can be improved.

[0142] The configuration of insulating sheet 700 will be described with reference to Fig. 21 to Fig. 23. Fig. 21 is a diagram showing insulating sheet 700 in an unfolded state, Fig. 22 is a diagram showing insulating sheet 700 of another configuration in an unfolded state, and Fig. 23 is a cross-sectional view taken along line XXIII-XXIII in Fig. 20.

[0143] The insulating sheet 700 has a rectangular shape when unfolded, and it is preferable that fold lines L1 be provided in advance at positions corresponding to the corners of the electrode body 200 when the insulating sheet 700 is wrapped around the outer surface of the electrode body 200.

[0144] When the insulating sheet 700 is wrapped around the outer surface of the electrode body 200, the insulating sheet 700 is arranged so that one side end region T1 and the other side end region T2 of the insulating sheet 700 overlap on the side of the electrode body 200, which is the second electrode body side 200S2 side facing the pair of second side portions 112 of the case body 110, which has a smaller area than the first electrode body side 200S1 facing the pair of first side portions 111 of the case body 110 shown in Figures 3 and 4.

[0145] Furthermore, the side edge region T1 is provided with an opening 700h for fixing the side edge region T1 to the side edge region T2 when the side edge region T1 and the side edge region T2 overlap. Although the opening 700h is rectangular in the drawing, it is not limited to a rectangular shape and may be any other opening shape, such as a circular shape. Furthermore, as shown in FIG. 22, the opening 700h may be a notch shape.

[0146] Referring to FIG. 23 , the opening 700h is used to secure the side edge regions T1 and T2 to the spacer 600 using a securing method 710 such as welding, ultrasonic bonding, taping, adhesive bonding, fitting, or hooking. Welding and ultrasonic bonding are particularly preferred as securing methods 710. The insulating sheet 700 is preferably secured to the spacer 600 only around the opening 700h, with gaps preferably provided in the overlapping areas between the other side edge regions T1 and T2. Furthermore, gaps preferably also exist between the insulating sheet 700 and the spacer 600. This is because these gaps provide a path for gas within the case 100 to be released to the outside when the pressure inside the case 100 exceeds a predetermined value. Therefore, it is preferable to secure the insulating sheet 700 to the spacer 600 by overlapping one side edge region T1 and the other side edge region T2 at the second side surface portion 112B where the joint 115 is provided.

[0147] It should be noted that the insulating sheet 700 does not necessarily have to cover the entire surface of the electrode body 200. The insulating sheet 700 preferably covers approximately 50% or more, and more preferably approximately 70% or more, of the area of ​​the outer surface of the electrode body. Of the six faces of the substantially rectangular parallelepiped (flat) electrode body 200, the insulating sheet 700 preferably covers the entire four faces other than at least the two faces on which the first electrode tab 220 and the second electrode tab 250 are formed.

[0148] Fig. 25 is a perspective view showing a state in which a first sealing plate is attached to a first current collector, and Fig. 26 is a cross-sectional view taken along line XXVI-XXVI of the electrode assembly and current collector shown in Fig. 25.

[0149] The negative electrode terminal 301 and the first electrode terminal side current collector 440 are attached to the first sealing plate 120 via the second insulating member 520 and the third insulating member 530. Note that the first plate portion 303 may be connected to the negative electrode terminal 301 at any time.

[0150] 17, 25, and 26, after joining the first electrode tab 220 to the first current collector 410, joining the third electrode tab 270 to the third current collector 430, and overlapping the first electrode body 201 and the second electrode body 202, the first current collector 410 and the third current collector 430 are electrically connected to the negative electrode terminal 301 via the first electrode terminal side current collector 440 (step S7 / connection step). Because the negative electrode terminal 301 is fixed to the first sealing plate 120 via the second insulating member 520, the first electrode tab 220 and the third electrode tab 270 are connected to the first sealing plate 120.

[0151] It should be noted that step S7 can also be performed before step S6. Performing step S7 before step S6 facilitates a more stable electrical connection between the negative electrode terminal 301 and the first electrode tab 220 and the third electrode tab 270. It also facilitates a configuration in which the space between the first sealing plate 120 and the main body of the electrode assembly 200 is smaller.

[0152] The first electrode terminal side current collector 440 attached to the first sealing plate 120 is brought into contact with the first current collector 410 and the third current collector 430 from the X direction. The first electrode terminal side current collector 440 is joined to the first current collector 410 and the third current collector 430 by laser welding between the first sealing plate 120 and the insulating sheet 700.

[0153] At this time, the outer side of the bottom of the first electrode tab 220 should be positioned so as to abut against the protrusion 616 provided on the spacer 600. Similarly, the outer side of the bottom of the third electrode tab 270 should be positioned so as to abut against the protrusion 626 provided on the spacer 600.

[0154] 27 is a perspective view showing the state in which the electrode bodies are being inserted into the case body. Next, as shown in Fig. 17 and Fig. 27, after the first electrode body 201 and the second electrode body 202 are overlapped, the first electrode body 201 and the second electrode body 202 are inserted into the case body 110 from the first opening 113, with the second current collector 420 side first (step S8).

[0155] The first electrode tab 220 and the third electrode tab 270 are curved by bringing the first sealing plate 120 and the main body of the electrode body 200 (the first electrode body 201 and the second electrode body 202) closer to each other. Preferably, the first sealing plate 120 and the main body of the electrode body 200 arranged in the case body 110 are brought closer to each other. As shown in FIG. 13 , the curved state of the first electrode tab 220 starts from a protrusion 616 (first recess) that abuts the bottom of the first electrode tab 220, and the first electrode tab 220 that faces the protrusion 616 starts to curve inward, and the curved portion 221 (first curved portion) is formed by bending the first electrode tab 220. Similarly, the curved state of the third electrode tab 270 starts from a protrusion 626 (second protrusion) that abuts against the bottom of the third electrode tab 270, and the third electrode tab 270 that faces the protrusion 626 starts curving inward, and a curved portion 271 (second curved portion) is formed by folding the third electrode tab 270. As shown in Fig. 13, it is preferable that the first electrode tab 220 and the third electrode tab 270 are curved in a substantially symmetrical manner.

[0156] After first sealing plate 120 is brought into contact with case body 110, first sealing plate 120 is temporarily joined to case body 110. By temporary joining, first sealing plate 120 is partially joined to first opening 113 of case body 110. In this way, first sealing plate 120 is positioned relative to case body 110.

[0157] When inserting the electrode body 200 into the case body 110, the electrode body 200 may be pulled from the second current collector 420 side, or may be pushed from the first current collector 410 and third current collector 430 sides. When the electrode body 200 is pushed from the first current collector 410 and third current collector 430 sides, the first electrode tab 220 and the third electrode tab 270 can be bent at the same time.

[0158] Fig. 28 is a perspective view showing a state in which a second sealing plate is attached to the second current collector. Fig. 29 is a cross-sectional view taken along line XXIX-XXIX of the electrode assembly and current collector shown in Fig. 28. Note that in Fig. 29, case body 110 is omitted.

[0159] As shown in Figures 17, 28 and 29, next, after the first electrode body 201 and the second electrode body 202 are inserted into the case body 110, the second current collector 420 is electrically connected to the positive electrode terminal 302 (step S9).

[0160] Specifically, the positive electrode terminal 302 and the second electrode terminal side current collector 450 are attached to the second sealing plate 130 via an insulating member. The second electrode terminal side current collector 450 is brought into contact with the second current collector 420 from the X direction. The second electrode terminal side current collector 450 and the second current collector 420 are joined by laser welding between the second sealing plate 130 and the insulating sheet 700. Note that the second plate portion 304 may be connected to the positive electrode terminal 302 at any time.

[0161] 29, the second electrode tab 250 and the fourth electrode tab 280 are each bent from an extended state to a curved state in opposite directions so that the tip portions 252, 282 located at the ends opposite to the side to which the second electrode is connected approach each other. As a result, the same bending shape becomes a symmetrical state. Specifically, the second electrode tab 250 starts from a protrusion 616 (third protrusion) provided on the spacer 600 (second spacer) and comes into contact with the protrusion 616, so that the second electrode tab 250 is gradually bent from an extended state to a curved state, whereby the second electrode tab 250 is bent in a curved state so that a recess is formed at a position facing the protrusion 616. Similarly, the fourth electrode tab 280 starts from the protrusion 626 (fourth protrusion) provided on the spacer 600 (first spacer) as a starting point, comes into contact with the protrusion 626, and is gradually bent so that the fourth electrode tab 280 changes from an extended state to a curved state, whereby the fourth electrode tab 280 is bent so as to have a recessed portion at a position facing the protrusion 626. As a result, the same bending shape becomes symmetrical.

[0162] The second electrode tab 250 and the fourth electrode tab 280 are curved by bringing the second sealing plate 130 and the main body of the electrode assembly 200 closer together. At this time, the second sealing plate 130 and the case main body 110 are brought closer together. As shown in Fig. 14, the curved state of the second electrode tab 250 starts from a protrusion 616 (third protrusion) that abuts the bottom of the second electrode tab 250, and the second electrode tab 250 that faces the protrusion 616 starts to curve inward, and a curved portion 251 (first curved portion) is formed as the second electrode tab 250 is bent. Similarly, the curved state of the fourth electrode tab 280 starts from the convex portion 626 (fourth convex portion) that abuts the bottom of the fourth electrode tab 280, and the fourth electrode tab 280 facing the convex portion 626 begins to curve inward, and the curved portion 281 (second curved portion) is formed by folding the fourth electrode tab 280.

[0163] After first sealing plate 120 is brought into contact with case body 110, second sealing plate 130 is temporarily welded to case body 110. By temporary joining, second sealing plate 130 is partially joined to second opening 114 of case body 110. As a result, second sealing plate 130 is positioned relative to case body 110.

[0164] 26 and 29, the distance D1 from the end face of the case body to the portion of the sealing plate that is to abut against the end face of the case body is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 10 mm or less. When the electrode tab is extended, the distance D2 from the current collector to the end of the electrode body (the base of the electrode tab) is preferably 40 mm or less, more preferably 30 mm or less, and even more preferably 20 mm or less.

[0165] 13 and 14, when the sealing plate and the case body are in contact, the distance D3 from the current collector to the end of the electrode assembly (the base of the electrode tab) is preferably 15 mm or less, more preferably 10 mm or less, and even more preferably 5 mm or less. With this configuration, the battery will have a higher volumetric energy density.

[0166] Fig. 30 is a perspective view showing the configuration of the secondary battery according to embodiment 1. As shown in Figs. 17 and 30, next, a first sealing plate 120 and a second sealing plate 130 are joined to the case body 110 (step S10). The first sealing plate 120 seals the first opening 113 of the case body 110, and the second sealing plate 130 seals the second opening 114 of the case body 110. This allows the first electrode body 201 and the second electrode body 202 to be housed in the case 100.

[0167] After the above steps are completed, inspections such as a leak inspection are performed (step S11). After the leak inspection, the secondary battery 1 is dried to remove moisture from inside the case 100. Then, electrolyte is injected into the inside of the case 100 through the liquid injection hole 134. When injecting the electrolyte, the case 100 is tilted with the second sealing plate 130 facing up and the first sealing plate 120 facing down, and the electrolyte is injected into the inside of the case 100 through the liquid injection hole 134 of the second sealing plate 130. Then, degassing charging is performed. The liquid injection hole 134 may be temporarily sealed during degassing charging. The liquid injection hole is then sealed, and the secondary battery 1 is completed.

[0168] In the manufacturing method of the secondary battery 1 and the secondary battery 1 according to the first embodiment of the present technology, the first electrode body 201, the second current collector 420 configured from one component, and the second electrode body 202 are arranged in this order in a first direction (DR1 direction), the second electrode tab 250 and the fourth electrode tab 280 formed on the first electrode body 201 and the second electrode body 202 are joined to the second current collector 420, and then the first electrode body 201 and the second electrode body 202 are overlapped in the thickness direction. As a result, separate electrode tabs are formed on the first electrode body 201 and the second electrode body 202, and the second electrode tab 250 and the fourth electrode tab 280 are each folded to form the first electrode body 201 and the second electrode body 202. With this configuration, the first electrode body 201 and the second electrode body 202 form a single electrode tab, which can be made shorter than when this electrode tab is folded. Furthermore, with this configuration, the first electrode body 201 and the second electrode body 202 after being stacked together can be 2 The electrode tab 250 and the fourth electrode tab 280 are respectively current collector420, the length of each tab can be shortened. As a result, the volume occupied by the electrode tabs can be reduced, thereby improving the energy density of the secondary battery 1. Furthermore, forming separate electrode tabs for the first electrode body 201 and the second electrode body 202 and bending each of these electrode tabs to form the first electrode body 201 and the second electrode body 202 makes it easier to bend the electrode tabs compared to forming a single electrode tab from the first electrode body 201 and the second electrode body 202, which makes it easier to join the electrode tabs to the current collector, allowing for stable production of the secondary battery. In particular, stable production of the secondary battery 1 can increase the reliability of the connection between the electrode tabs and the current collector.

[0169] In the manufacturing method of the secondary battery 1 according to embodiment 1 of the present technology, after the second electrode tab 250 and the fourth electrode tab 280 are joined by the second current collector 420, the first electrode body 201 and the second electrode body 202 are inserted into the case body 110 from the side of the second current collector 420 that has been joined together, thereby making it easier to insert the electrode body 200 into the case body 110.

[0170] Furthermore, by providing the spacer 600 with a convex portion 616 that abuts against the bottom of the first electrode tab 220 and the bottom of the second electrode tab 250, and a convex portion 626 that abuts against the bottom of the third electrode tab 270 and the bottom of the fourth electrode tab 280, the electrode tab facing the convex portion starts to curve inward from the convex portion abutting the bottom, making it possible to easily guide the folding of the electrode tab in an appropriate direction.

[0171] Furthermore, since the entire periphery of the spacer 600 is covered with the insulating sheet 700, the electrode tabs are also covered with the insulating sheet 700. As a result, when the electrode body 200 covered with the insulating sheet 700 is inserted into the case body 110, the electrode tabs are protected and unintentional breakage of the electrode tabs is suppressed, making it possible to provide a highly reliable secondary battery.

[0172] In the manufacturing method of the secondary battery 1 and the secondary battery 1 according to the first embodiment of the present technology, separate electrode tabs are formed in the first electrode body 201 and the second electrode body 202, and the electrode body 200, in which the first electrode body 201 and the second electrode body 202 are formed by bending each of these electrode tabs, can be applied to a case body 110 having a first opening 113 and a second opening 114 located at an end opposite to the first opening 113. This allows the secondary battery 1 to be made low-profile when the first opening 113 and the second opening 114 of the case body 110 are arranged side by side in the horizontal direction.

[0173] In the manufacturing method of the secondary battery 1 and the secondary battery 1 according to the first embodiment of the present technology, the first electrode tab 220 and the third electrode tab 270 are each curved in opposite directions so that the tip portions 222, 272 located at the end opposite to the side to which the first electrode is connected approach each other, thereby making it possible to form the electrode tab easily from the outside in the thickness direction of the electrode body.

[0174] In the manufacturing method of the secondary battery 1 and the secondary battery 1 according to the first embodiment of the present technology, compared to connecting separate current collectors to the electrode tabs of the first electrode body 201 and the second electrode body 202, the electrode tabs can be connected by the second current collector 420 which is formed from a single integrated part, thereby reducing the number of connection points of the constituent parts and increasing the reliability of the connection between the electrode tabs and the current collectors.

[0175] Secondary batteries according to embodiments 2 to 5 will be described below. The secondary batteries according to these embodiments have different spacer configurations from secondary battery 1 according to embodiment 1, and therefore, the description of the configurations that are similar to secondary battery 1 according to embodiment 1 of the present technology will not be repeated.

[0176] (Embodiment 2) The configuration of a secondary battery according to embodiment 2 is shown with reference to Fig. 31 to Fig. 34. Fig. 31 is a cross-sectional view corresponding to the XXVI-XXVI cross section of the electrode body and current collector shown in Fig. 25, Fig. 32 is a cross-sectional view showing a state in which the electrode tab is bent, Fig. 33 is a first perspective view showing the overall configuration of the spacer, and Fig. 34 is a second perspective view showing the overall configuration of the spacer.

[0177] Referring to FIG. 31, in the secondary battery according to the second embodiment, each of first electrode tab 220A and third electrode tab 270A has tip portions 222A and 272A bent in the same direction in the Y direction.

[0178] Thereafter, the first electrode body 201A and the second electrode body 202A are inserted into the case body, and the first sealing plate 120 is brought into contact with the case body. As the first sealing plate 120 and the case body approach each other, the first electrode tab 220A and the third electrode tab 270A are bent from their extended state to a state in which they are curved in the same direction. As a result, the tip portions 222A, 272A face the same direction, and are bent into a state in which the same bent shapes are lined up. Specifically, the first electrode tab 220 A The first electrode tab 220 A The third electrode tab 270 is gradually bent from the protrusion 616 (first protrusion) provided on the spacer 600 (first spacer) as a starting point so that the third electrode tab 270 changes from an extended state to a curved state, and is thereby bent so that a recess is formed at a position facing the protrusion 616. A is the third electrode tab 270 A The protrusions provided on the spacer 600 (first spacer) are used to change the state from the extended state to the curved state. 619 By gradually bending the first convex part (second convex part), 619 As a result, the same folded shapes are bent side by side.

[0179] To make it easier to bend tip portions 222A, 272A in the same direction, spacer 600A has an intermediate side wall 650 extending in the Z direction between long side wall portion 611 and long side wall portion 621 between first electrode tab 220A and third electrode tab 270A. A protrusion 619 (third protrusion) protruding toward second component 620 in the Y direction is provided on the end side of intermediate side wall 650 in the X direction. On the other hand, no protrusion is provided on long side wall portion 621 on the second component 620 side.

[0180] When the tip portions 222A, 272A of the first electrode tab 220A and the third electrode tab 270A are curved in the same direction in the Y direction, the first electrode body 201A in which the first current collector 410 is joined to the first electrode tab 220A and the second electrode body 202 in which the third current collector 430 is joined to the third electrode tab 270A can be configured as one type of electrode body 200A.

[0181] 32, in a state in which the first electrode tab 220A and the third electrode tab 270A are bent, the first electrode tab 220A has a curved portion 221 (first curved portion) and a tip portion 222. The first electrode tab 220A includes a recess 221a (first recess) in which an area facing the protrusion 616 provided on the spacer 600A is recessed.

[0182] The third electrode tab 270A has a curved portion 271 (second curved portion) and a tip portion 272. The third electrode tab 270A includes a recess 271a (third recess) in which the area facing the protrusion 619 provided on the spacer 600A is recessed.

[0183] Although not shown, the same applies to the connection structure between the electrode body and the current collector on the second electrode (positive electrode) side of the secondary battery as shown in Figures 14 and 29. Therefore, the second electrode tab 250 A and fourth electrode tab 280 AEach of the second electrode tabs 250 is bent from its extended state to a curved state in the same direction so that the tip ends located at the end opposite to the side where the second electrode is connected face the same direction. As a result, the tip ends 222A, 272A are bent into a state in which the same bent shapes are lined up so that they face the same direction. Specifically, the second electrode tabs 250 A The second electrode tab 250 A The fourth electrode tab 280 is gradually bent from the protrusion 616 (third protrusion) provided on the spacer 600 (second spacer) as a starting point so that the fourth electrode tab 280 changes from an extended state to a curved state, and is thereby bent so that a recess is formed at a position opposite the protrusion 616. A is the fourth electrode tab 280 A The protrusions provided on the spacer 600 (first spacer) are used to change the state from the extended state to the curved state. 616 By gradually bending the part starting from the fourth convex part, 616 As a result, the tip portions 222A and 272A are bent in the same shape so that the tip portions 222A and 272A face in the same direction and are arranged side by side.

[0184] (Spacer 600A) The detailed structure of spacer 600A will be described with reference to Figures 33 and 34. Note that the same parts as those of spacer 600 in the first embodiment are given the same reference numerals, and overlapping descriptions will not be repeated.

[0185] The basic configuration of spacer 600A is the same as that of spacer 600 in the first embodiment, but first component 610 is provided with intermediate side wall 650 extending in the Z direction at a position between long side wall 611 and long side wall 621. An X-direction end of intermediate side wall 650 is provided with protrusion 651 (third protrusion) that protrudes toward second component 620 in the Y direction. On the other hand, long side wall 621 on the second component 620 side is not provided with a protrusion.

[0186] By employing spacer 600A having this configuration, it is possible to position intermediate sidewall 650 having convex portion 651 (third convex portion) between first electrode tab 220A and third electrode tab 270A.

[0187] (Embodiment 3) Another embodiment of spacer 600B will be described with reference to Fig. 35. Note that the same parts as those of spacer 600 in the first embodiment are given the same reference numerals, and overlapping descriptions will not be repeated.

[0188] While the spacer 600 described in the first embodiment has a two-part structure including a first part 610 and a second part 620, the spacer 600B shown in Fig. 35 has an annular shape composed of only one part. The annular shape connects both ends of the short side walls 632, 634 with the long side wall portion 611 and the long side wall portion 621. This annular shape can also be used for the spacer 600A of the second embodiment.

[0189] Even when the spacer 600B having this configuration is employed, it is possible to obtain the same effects as those of the first and second embodiments.

[0190] (Fourth embodiment) 36 to 38, a connection structure between the electrode body 200 and the current collector 400 when a spacer 600C of another form is used will be described. Fig. 36 is a cross-sectional view corresponding to line XIII-XIII of the secondary battery shown in Fig. 1, and Figs. 37 and 38 are first and second perspective views showing the overall configuration of the spacer 600C.

[0191] 36 shows the connection structure between the electrode body 200 and the current collector 400 on the first electrode (negative electrode) side of the secondary battery 1. The connection structure between the electrode body 200 and the current collector 400 on the second electrode (positive electrode) side of the secondary battery 1 has the same electrode tab configuration as shown in FIGS. 13 and 14, so a description thereof will be omitted here. Furthermore, in the name of the spacer 600C, the same reference numerals are used for parts equivalent to those of the spacer 600 shown in FIGS. 15 and 16, and redundant description will not be repeated.

[0192] In the spacer 600C of this embodiment, the first part 610 and the second part 620 are arranged back to back at the center, and as a result, the protrusions 616 and 626 are provided so as to extend outward from the center.

[0193] The first electrode tab 220 and the third electrode tab 270 each have tip portions 222, 272 located at the end opposite to the side to which the first electrode is connected, facing in opposite directions, and are bent so that the electrode tabs are curved in opposite directions from their extended state. Specifically, the first electrode tab 220 is gradually bent from a protrusion 616 (first protrusion) provided on the spacer 600 (first spacer) as a starting point so that the first electrode tab 220 is curved from its extended state to its curved state, thereby forming a recessed portion at a position facing the protrusion 616. Similarly, the third electrode tab 270 is gradually bent from a protrusion 626 (second protrusion) provided on the spacer 600 (first spacer) as a starting point so that the third electrode tab 270 is curved from its extended state to its curved state, thereby forming a recessed portion at a position facing the protrusion 626. This results in a symmetrical state of the same folding configuration (opposite to the folding configuration shown in FIG. 13).

[0194] Even when the spacer 600C having this configuration is employed, it is possible to obtain the same effects as those of the first and second embodiments.

[0195] In the above-described embodiments, as shown in FIGS. 18 and 19, the first electrode body 201, the second current collector 420 formed by a single component, and the second electrode body 202 are arranged in this order in the first direction (DR1 direction), and the second electrode tabs 250 and fourth electrode tabs 280 formed on the first electrode body 201 and the second electrode body 202 are joined to the second current collector 420, and then the first electrode body 201 and the second electrode body 202 are overlapped in the thickness direction. However, this configuration is not limited to this. Alternatively, the second electrode tabs 250 and the fourth electrode tabs 280 may be joined to separate current collectors, and the first electrode body 201 and the second electrode body 202, which are not connected to each other, may be overlapped in the thickness direction. In this case, both the negative electrode side and the positive electrode side have the structure shown in FIG. 13.

[0196] (Embodiment 5) 39 to 42 show the configuration of a secondary battery according to embodiment 5. Fig. 39 is a first perspective view showing the overall configuration of a spacer, Fig. 40 is a second perspective view showing the overall configuration of the spacer, Fig. 41 is a cross-sectional view corresponding to the XXIV-XXIV cross section of the electrode body and current collector shown in Fig. 25, and Fig. 42 is a cross-sectional view corresponding to the XIII-XIII cross section of the secondary battery shown in Fig. 1.

[0197] The fifth embodiment differs from the first embodiment in the shape of the spacer, the method of bending the third electrode tab 270, and the method of bending the fourth electrode tab 280. Note that other configurations and methods can be the same as those of the first embodiment. Hereinafter, the fifth embodiment will be described using the first electrode tab 220 and the third electrode tab 270 as an example, but the second electrode tab 250 and the fourth electrode tab 280 can also have the same configuration and method.

[0198] 39 and 40, spacer 600D of embodiment 5 has long side wall portion 611 with protrusion 616 only on the side facing first electrode tab 220. In spacer 600D, long side wall portion 611 and protrusion 616 are not formed on the side facing third electrode tab 270. The size of plate portions 617, 618 and the number of through holes 617s, 618s differ from those of spacer 600C described above, but the function is the same.

[0199] As shown in Figures 41 and 42, the long side wall portion 611 having the protrusion 616 provided on only one side of the spacer 600D is placed outside the first electrode tab 220. In this state, the first sealing plate 120 and the electrode body 200 are brought closer to each other, so that the first electrode tab 220 and the third electrode tab 270 are curved into a predetermined shape. At this time, the protrusion 616 It is preferable to abut the third electrode tab 270 with a jig (which will not remain in the battery case when the secondary battery is completed) to bend the third electrode tab 270 into a predetermined shape.

[0200] The configuration of the fifth embodiment makes it easy to assemble the spacer 600D to the electrode body 200, and also allows the first electrode tab 220 and the third electrode tab 270 to be curved in a desirable state.

[0201] In addition, when most or all of the first electrode tab 220 and the third electrode tab 270 are located outside the first opening of the case body 110, it is also possible to abut the above-mentioned jig against the third electrode tab 270 to bend the third electrode tab 270.

[0202] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0203] 1 secondary battery, 100 case, 110 case body, 111 first side portion, 112, 112A, 112B second side portion, 113 first opening, 114 second opening, 115 joint portion, 120 first sealing plate, 130 second sealing plate, 134 liquid inlet, 150 gas release valve, 200, 200A electrode body, 201, 201A first electrode body, 202, 202A second electrode body, 205 first end, 206 second end, 207 third end, 208 fourth end, 210 negative electrode plate, 210S negative electrode base plate, 211 negative electrode core, 212 negative electrode active material layer, 220, 220A first electrode tab, 221, 251, 271, 281 Curved portion, 221a, 251a, 271a, 281a Recess, 222, 222A, 252, 272, 272A, 282 Tip portion, 230 Negative electrode tab, 240 Positive electrode plate, 240S Positive electrode base plate, 241 Positive electrode core, 242 Positive electrode active material layer, 243 Positive electrode protective layer, 250 Second electrode tab, 260 Positive electrode tab, 270, 270A Third electrode tab, 280 Fourth electrode tab, 300 Electrode terminal, 301 Negative electrode terminal, 302 Positive electrode terminal, 303 First plate portion, 304 Second plate portion, 400 Current collector, 400A Negative electrode current collector, 400B Positive electrode current collector, 410 First current collector, 411, 421, 431 Joint portion, 420 Second current collector, 430 Third current collector, 440 First electrode terminal side current collector, 450 Second electrode terminal side current collector, 510 First insulating member, 520 Second insulating member, 530 Third insulating member, 600, 600A, 600B, 600C Spacer, 610 First part, 611, 621 Long side wall portion, 612, 614, 622, 624 Short side wall portion, 613, 615 Engaging claws, 616, 619, 626, 651 Convex portion, 617, 618, 627, 628 Plate portion, 617s, 618s, 627s, 628s Through hole, 620 Second part, 623, 625 Engaging groove, 632, 634 Short side wall, 650 Middle side wall, 700 Insulating sheet.

Claims

1. an electrode assembly including a first electrode and a second electrode having a polarity different from that of the first electrode; a case for accommodating the electrode assembly; Equipped with the case includes a case body having a first opening at one end thereof and a first sealing plate that seals the first opening; the electrode body includes, at an end on the first sealing plate side, a first electrode tab and a third electrode tab, each electrically connected to the first electrode; the first electrode tab and the third electrode tab are each electrically connected to the first electrode in a curved state; the first electrode tab and the third electrode tab are electrically connected to a current collector disposed between the first sealing plate and the electrode body; an insulating member is disposed between the first sealing plate and the current collector; the first electrode tab has a first recess that is recessed in a curved state; the third electrode tab has a third recess that is recessed in a curved state; a first spacer is disposed in the first opening of the case body between the first sealing plate and the electrode body; the first spacer is a separate part from the insulating member, the first spacer has a first protrusion facing the first electrode tab; the first protrusion is positioned to face the first recess, the electrode body and the first spacer are wrapped in an insulating sheet, the insulating sheet is connected to the first spacer; Secondary battery.

2. the first recess is provided on an outer surface of the first electrode tab on the case body side, the third recess is provided on an outer surface of the third electrode tab on the case body side, the first spacer is located between the case body and the first electrode tab; the first spacer is not positioned between the case body and the third electrode tab; The secondary battery according to claim 1 .

3. The first electrode tab and the third electrode tab are electrically connected to the first electrode while being curved in opposite directions. The secondary battery according to claim 1 .

4. the first spacer has a second protrusion facing the third electrode tab; the second protrusion is positioned so as to face the third recess; The secondary battery according to claim 1 .

5. the first recess is provided on an outer surface of the first electrode tab on the case body side, the third recess is provided on an outer surface of the third electrode tab on the case body side, the first spacer is located between the case body and the first electrode tab and between the case body and the third electrode tab; The secondary battery according to claim 4 .

6. the first recess is provided on an outer surface of the first electrode tab on the side of the third electrode tab; the third recess is provided on an outer surface of the third electrode tab on the first electrode tab side, the first spacer is disposed between the first electrode tab and the third electrode tab; The secondary battery according to claim 1 .

7. the first electrode tab has a first curved portion on an outer surface on which the first recess is formed, the first curved portion being closer to the first sealing plate than the first recess; the third electrode tab has a second curved portion on the outer surface on which the third recess is formed, closer to the first sealing plate than the third recess; The secondary battery according to claim 1 .

8. the case includes a second sealing plate, the case body has a second opening at an end opposite to the first opening, the second opening is sealed by the second sealing plate, the electrode body has a second electrode tab and a fourth electrode tab electrically connected to the second electrode at an end on the second sealing plate side, the second electrode tab and the fourth electrode tab are each electrically connected to the second electrode in a curved state. The secondary battery according to claim 1 .

9. the second electrode tab has a second recess that is recessed in a curved state; the fourth electrode tab has a fourth recess that is recessed in a curved state; a second spacer is disposed in the second opening of the case body between the second sealing plate and the electrode body; the second spacer has a second protrusion facing the second electrode tab and a fourth protrusion facing the fourth electrode tab; the second protrusion is positioned to face the second recess, the fourth protrusion is positioned to face the fourth recess; The secondary battery according to claim 8.

10. an electrode assembly including a first electrode and a second electrode having a polarity different from that of the first electrode; a case for accommodating the electrode assembly; Equipped with the case includes a case body having a first opening at one end thereof and a first sealing plate that seals the first opening; the electrode body includes, at an end on the first sealing plate side, a first electrode tab and a third electrode tab, each electrically connected to the first electrode; the first electrode tab and the third electrode tab are each electrically connected to the first electrode in a curved state; the first electrode tab has a first recess that is recessed in a curved state; the third electrode tab has a third recess that is recessed in a curved state; a first spacer is disposed in the first opening of the case body between the first sealing plate and the electrode body; the first spacer has a first protrusion facing the first electrode tab; The first protrusion is positioned to face the first recess. A method for manufacturing a secondary battery, a first connecting step of connecting the first electrode tab and the third electrode tab to the first sealing plate; an electrode tab bending step of bending the first electrode tab to form the first recess by bringing the first sealing plate and a main body portion of the electrode body closer to each other after the first connecting step, and bending the third electrode tab to form the third recess; A method for manufacturing a secondary battery comprising the steps of:

11. In the electrode tab bending step, forming the first recess while contacting the first protrusion of the first spacer with the first electrode tab; The method for manufacturing a secondary battery according to claim 10.

12. the first spacer has a second protrusion facing the third electrode tab; In the electrode tab bending step, forming the third recess while bringing the second protrusion of the first spacer into contact with the third electrode tab; The method for manufacturing a secondary battery according to claim 10.

13. In the electrode tab bending step, forming the third recess while bringing a jig into contact with the third electrode tab; The method for manufacturing a secondary battery according to claim 10.

14. disposing the first spacer on an end surface of the electrode body on the side where the first electrode tab and the third electrode tab are provided, and covering the electrode body and the first spacer with an insulating sheet; The method for manufacturing a secondary battery according to claim 10.

15. the electrode body and the first spacer are wrapped in an insulating sheet, the insulating sheet is connected to the first spacer; The method for manufacturing a secondary battery according to claim 14.

16. The secondary battery is the case includes a second sealing plate, the case body has a second opening at an end opposite to the first opening, the second opening is sealed by the second sealing plate, the electrode body has a second electrode tab and a fourth electrode tab electrically connected to the second electrode at an end on the second sealing plate side, the second electrode tab and the fourth electrode tab are each electrically connected to the second electrode in a curved state; the second electrode tab has a second recess that is recessed in a curved state; the fourth electrode tab has a fourth recess that is recessed in a curved state; a second spacer is disposed in the second opening of the case body between the second sealing plate and the electrode body; the second spacer has a second protrusion facing the second electrode tab; The second protrusion is positioned to face the second recess. The configuration is a step of bringing the second convex portion of the second spacer into contact with the second electrode tab to bend the second electrode tab, The method for manufacturing a secondary battery according to claim 10.

17. a second connecting step of connecting the second electrode tab and the fourth electrode tab to the second sealing plate; an insertion step of inserting the electrode body into the case body from the second opening of the case body, with the first electrode tab and the third electrode tab side leading, after the second connection step, in a state in which the first sealing plate is not connected to the first electrode tab and the third electrode tab; The method for producing a secondary battery according to claim 16.

18. an electrode assembly including a first electrode and a second electrode having a polarity different from that of the first electrode; a case for accommodating the electrode assembly; Equipped with the case includes a case body having a first opening at one end thereof and a first sealing plate that seals the first opening; the electrode body includes, at an end on the first sealing plate side, a first electrode tab and a third electrode tab, each electrically connected to the first electrode; the first electrode tab and the third electrode tab are each electrically connected to the first electrode in a curved state; the first electrode tab has a first recess that is recessed in a curved state; the third electrode tab has a third recess that is recessed in a curved state; a first spacer is disposed in the first opening of the case body between the first sealing plate and the electrode body; the first spacer has a first protrusion facing the first electrode tab; the first protrusion is positioned to face the first recess, the first recess is provided on an outer surface of the first electrode tab on the side of the third electrode tab; the third recess is provided on an outer surface of the third electrode tab on the first electrode tab side, the first spacer is disposed between the first electrode tab and the third electrode tab; Secondary battery.

19. an electrode assembly including a first electrode and a second electrode having a polarity different from that of the first electrode; a case for accommodating the electrode assembly; Equipped with the case includes a case body having a first opening at one end thereof and a first sealing plate that seals the first opening; the electrode body includes, at an end on the first sealing plate side, a first electrode tab and a third electrode tab, each electrically connected to the first electrode; the first electrode tab and the third electrode tab are each electrically connected to the first electrode in a curved state; the first electrode tab has a first recess that is recessed in a curved state; the third electrode tab has a third recess that is recessed in a curved state; a first spacer is disposed in the first opening of the case body between the first sealing plate and the electrode body; the first spacer has a first protrusion facing the first electrode tab; The first protrusion is positioned to face the first recess. A method for manufacturing a secondary battery, a first step of connecting the first electrode tab and the third electrode tab to the first sealing plate and arranging the first convex portion of the first spacer in a position facing the first electrode tab; an electrode tab bending step of bending the first electrode tab to form the first recess and bending the third electrode tab to form the third recess while bringing the first sealing plate and a main body portion of the electrode body closer to each other after the first step; A method for manufacturing a secondary battery comprising the steps of:

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