Secondary battery and manufacturing method for the same

Abstract

To easily impregnate an electrolyte into an electrode body while maintaining the strength of a spacer.SOLUTION: A first spacer 610 is disposed between a first sealing plate and an electrode body. The first spacer 610 includes a first base portion 630, a first outer wall 640, and a first inner wall 650. A plurality of through holes 632 is provided in the first base portion 630. The first outer wall 640 extends from the outer edge of the surface of the first base portion 630 facing the first sealing plate toward the first sealing plate and has a first portion 643 and a second portion 644 facing each other. The first inner wall 650 is provided to connect the first portion 643 and the second portion 644 of the first outer wall 640.SELECTED DRAWING: Figure 13

Description

[Technical Field]

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

[0002] Prior art documents disclosing the structure of a rechargeable battery include U.S. Patent Application Publication No. 2016 / 0099444 (Patent Document 1), which discloses disposing an insulating plate (20) between an electrode assembly (10) and a sealing plate (40). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2016 / 0099444 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to improve the reliability of secondary batteries, it is necessary to easily impregnate the electrode body with an electrolyte while maintaining the strength of the spacer disposed between the electrode body and the case.

[0005] The present technology has been developed to solve the above-mentioned problems, and aims to provide a secondary battery and a manufacturing method thereof that can easily impregnate an electrolyte into an electrode body while maintaining the strength of the spacer. [Means for solving the problem]

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

[0007] [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, The above case is a case body having a first opening at one end and a second opening at the other end; a first sealing plate that seals the first opening; a second sealing plate that seals the second opening, The electrode body is a first electrode tab disposed on the first sealing plate side and electrically connected to the first electrode; a second electrode tab disposed on the second sealing plate side and electrically connected to the second electrode, a first spacer is disposed between the first sealing plate and the electrode body; The first spacer is a first base portion provided with a plurality of through holes; a first outer peripheral wall extending from an outer peripheral edge of a surface of the first base portion facing the first sealing plate toward the first sealing plate and having a first portion and a second portion opposed to each other; The secondary battery includes a first inner wall provided to connect the first portion and the second portion of the first outer peripheral wall.

[0008] [2] the first outer peripheral wall further has a third portion and a fourth portion that are provided so as to intersect with the first portion and the second portion and that face each other; the first spacer further includes a second inner wall provided to connect the third portion and the fourth portion of the first outer peripheral wall, The secondary battery according to [1], wherein the first inner wall and the second inner wall are provided so as to intersect with each other.

[0009] [3] the first base portion has a plurality of compartments separated by the first outer peripheral wall, the first inner side wall, and the second inner side wall; The secondary battery according to [2], wherein the plurality of through holes are provided in at least the plurality of partitions of the first base portion.

[0010] [4] The first spacer is a second base portion disposed spaced apart from the first base portion; a second outer peripheral wall extending from an outer peripheral edge of a surface of the second base portion facing the first sealing plate toward the first sealing plate, The secondary battery according to any one of [1] to [3], wherein the first electrode tab is disposed between the first base portion and the second base portion.

[0011] [5] the second outer peripheral wall has a fifth portion and a sixth portion opposed to each other, The secondary battery according to [4], wherein the first spacer includes a third inner wall provided to connect the fifth portion and the sixth portion of the second outer peripheral wall.

[0012] [6] The secondary battery according to [5], wherein the second base portion is provided with a through hole.

[0013] [7] The secondary battery according to any one of [4] to [6], wherein the first spacer includes a connecting portion that connects the first base portion and the second base portion.

[0014] [8] the first electrode tab has a curved portion; The secondary battery according to [7], wherein the connecting portion has a curved surface that faces the curved portion.

[0015] [9] The secondary battery according to any one of [1] to [8], wherein a second spacer is disposed between the second sealing plate and the electrode body.

[0016] The present technology provides the following method for manufacturing a secondary battery.

[0017]

[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, The above case is a case body having a first opening at one end and a second opening at the other end; a first sealing plate that seals the first opening; a second sealing plate that seals the second opening, The electrode body is a first electrode tab disposed on the first sealing plate side and electrically connected to the first electrode; a second electrode tab disposed on the second sealing plate side and electrically connected to the second electrode, a first spacer is disposed between the first sealing plate and the electrode body; The first spacer is a first base portion provided with a plurality of through holes; a first outer peripheral wall extending from an outer peripheral edge of a surface of the first base portion facing the first sealing plate toward the first sealing plate and having a first portion and a second portion opposed to each other; a first inner wall provided so as to connect the first portion and the second portion of the first outer peripheral wall, a step of fabricating the electrode body; assembling the first spacer to the electrode body; and inserting the first spacer and the electrode body into the case body.

[0018]

[11] a step of joining the first sealing plate and the second sealing plate to the case body after inserting the first spacer and the electrode body into the case body;

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

[10] , further comprising the steps of: joining the first sealing plate and the second sealing plate to the case body, then positioning the second sealing plate higher than the first sealing plate in the vertical direction, and injecting an electrolyte into the case through an injection hole provided in the second sealing plate with the first spacer positioned below the electrode body.

[0019]

[12] the first outer peripheral wall further has a third portion and a fourth portion that are provided so as to intersect with the first portion and the second portion and that face each other; the first spacer further includes a second inner wall provided to connect the third portion and the fourth portion of the first outer peripheral wall, The method for manufacturing a secondary battery according to

[10] or

[11] , wherein the first inner side wall and the second inner side wall are provided so as to intersect with each other.

[0020]

[13] The first spacer is a second base portion disposed spaced apart from the first base portion; a second outer peripheral wall extending from an outer peripheral edge of a surface of the second base portion facing the first sealing plate toward the first sealing plate, The method for manufacturing a secondary battery according to any one of

[10] to

[12] , wherein the first electrode tab is disposed between the first base portion and the second base portion.

[0021]

[14] the second outer peripheral wall has a fifth portion and a sixth portion opposed to each other, The method for manufacturing a secondary battery according to

[13] , wherein the first spacer includes a third inner wall provided to connect the fifth portion and the sixth portion of the second outer peripheral wall.

[0022]

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

[10] to

[14] , further comprising the step of covering the electrode body and the first spacer with an insulating sheet after assembling the first spacer to the electrode body. [Effects of the Invention]

[0023] According to the present technology, the electrode body can be easily impregnated with an electrolyte while maintaining the strength of the spacer. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a front view showing the configuration of a secondary battery according to Embodiment 1. FIG. [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. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] 1. FIG. 1 is a cross-sectional view of the secondary battery taken along the line XI-XI in FIG. [Figure 12] 1. FIG. 2 is a cross-sectional view of the secondary battery shown in FIG. [Figure 13] FIG. 1 is a first perspective view showing the configuration of a spacer. [Figure 14] FIG. 2 is a second perspective view showing the configuration of the spacer. [Figure 15] 3 is a flowchart showing a method for manufacturing a secondary battery according to the first embodiment. [Figure 16] 1 is a perspective view showing a state in which current collectors are joined to two electrode bodies included in the secondary battery according to Embodiment 1. FIG. [Figure 17] 17 is a cross-sectional view taken along the line XVII-XVII of the electrode body and current collector shown in FIG. 16. FIG. [Figure 18] FIG. 10 is a perspective view showing a state in which a spacer is attached to an electrode body. [Figure 19] FIG. 2 is a perspective view showing a state before the electrode body and the spacer are covered with an insulating sheet. [Figure 20] FIG. 10 is a perspective view showing the state after the electrode body and the spacer are covered with an insulating sheet. [Figure 21] FIG. 2 is a perspective view showing a state in which a sealing plate is attached to a current collector on the positive electrode side. [Figure 22]FIG. 2 is a perspective view showing the configuration of a secondary battery. [Figure 23] FIG. 10 is a front view showing the configuration of a spacer according to a second embodiment. [Figure 24] FIG. 11 is a front view showing the configuration of a spacer according to a third embodiment. [Figure 25] FIG. 10 is a front view showing the configuration of a spacer according to a fourth embodiment. [Figure 26] FIG. 11 is a front view showing the configuration of a spacer according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0025] 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.

[0026] 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 mentioned in the present embodiments.

[0027] In this specification, the words "comprise," "include," and "have" are open-ended, meaning that when a certain feature is included, other features may or may not be included.

[0028] When geometric terms and terms expressing positional and directional relationships, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along" are used in this specification, 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 by changing the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0029] 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.

[0030] In this specification, the first direction (X direction) may be referred to as the "width direction" of the secondary battery, electrode body, and case body, the second direction (Z direction) may be referred to as the "height direction" of the secondary battery or case body, and the third direction (Y direction) may be referred to as the "thickness direction" of the secondary battery or case body. Note that, to facilitate understanding of the present technology, detailed shapes of each component may be omitted in some parts of the drawings.

[0031] (Embodiment 1) (Overall battery configuration) Fig. 1 is a front view of a secondary battery 1 according to embodiment 1. Figs. 2 to 5 are diagrams 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.

[0032] 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.

[0033] 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 sealing plate 120 (first sealing plate), and a sealing plate 130 (second sealing plate).

[0034] 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.

[0035] 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.

[0036] As shown in Figures 1 and 2, sealing plates 120 and 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 (for example, by laser welding). The corners of the "rectangular tube" may have an R shape. Furthermore, the secondary battery in the present technology is not necessarily limited to a rectangular secondary battery.

[0037] 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.

[0038] 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.

[0039] 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 shape of the gas release valve 150 can be changed as appropriate.

[0040] 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.

[0041] 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.

[0042] As shown in Fig. 3, an opening 113 (first opening) is provided at an end of a first side in a first direction (X direction) of case body 110. Opening 113 is sealed by sealing plate 120. A joint 115 is formed in opening 113 to seal opening 113. Opening 113 and sealing plate 120 have a generally rectangular shape with the Y direction as the short side direction and the Z direction as the long side direction. The generally rectangular shape includes a rectangular shape or a substantially rectangular shape such as a rectangular shape with rounded corners.

[0043] A negative electrode terminal 301 is provided on the sealing plate 120 (first sealing plate). The position of the negative electrode terminal 301 can be changed as appropriate.

[0044] 4, an opening 114 (second opening) is provided at an end of a second side of case body 110 opposite the first side in the first direction (X direction). That is, opening 114 is located at an end opposite opening 113, and openings 113 and 114 face each other. Opening 114 is sealed by sealing plate 130. A joint 115 is formed in opening 114 to seal opening 114. Opening 114 and 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.

[0045] A positive electrode terminal 302 and a liquid injection hole 134 are provided on the sealing plate 130 (second sealing plate). The liquid injection hole 134 may be of any size that allows electrolyte to be injected into the case 100, and is desirably smaller than the insertion hole for the positive electrode terminal 302 provided in the sealing plate 130. The liquid injection hole 134 is desirably positioned offset from the center of the sealing plate 130 in the Z direction. The positions of the positive electrode terminal 302 and the liquid injection hole 134 can be changed as appropriate.

[0046] The sealing plates 120 and 130 are made of metal. Specifically, the sealing plates 120 and 130 are made of aluminum, an aluminum alloy, iron, an iron alloy, or the like.

[0047] The negative electrode terminal 301 (first electrode terminal) is electrically connected to the negative electrode of the electrode body 200. The negative electrode terminal 301 is attached to the sealing plate 120, that is, the case 100.

[0048] The positive electrode terminal 302 (second electrode terminal) is electrically connected to the positive electrode of the electrode body 200. The positive electrode terminal 302 is attached to the sealing plate 130, that is, the case 100.

[0049] 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.

[0050] 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.

[0051] The liquid inlet 134 is sealed with a sealing member (not shown), which may be, for example, a blind rivet or other metal member.

[0052] The electrode assembly 200 is a flat electrode assembly in which positive and negative electrode plates, described below, are stacked. Specifically, the electrode assembly 200 is a laminated electrode assembly in which multiple positive and negative electrode plates are alternately stacked with a separator 800, described below, interposed therebetween. However, in this specification, the term "electrode assembly" is not limited to a laminated electrode assembly, but may also refer to a wound electrode assembly in which strip-shaped positive and negative electrode plates are wound together with a strip-shaped separator interposed therebetween. The separator may be formed, for example, of a polyolefin microporous membrane. When the electrode assembly is a laminated electrode assembly including multiple positive and negative electrode plates, the positive electrode tabs provided on each positive electrode plate may be stacked to form a positive electrode tab group, and the negative electrode tabs provided on each negative electrode plate may be stacked to form a negative electrode tab group.

[0053] As shown in Fig. 6, the case 100 houses the electrode assembly 200. Fig. 6 illustrates a first electrode assembly 201, which will be described later. The first electrode assembly 201 is housed in the case 100 so that its longitudinal direction is parallel to the X direction.

[0054] Specifically, one or more laminated 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 dimethyl carbonate (DMC) in a volume ratio (25°C) of 30:30:40, in which LiPF is dissolved at a concentration of 1.2 mol / L. A solid electrolyte may be used instead of the electrolytic solution.

[0055] The electrode assembly 200 includes a first electrode assembly 201. The first electrode assembly 201 includes a substantially rectangular main body portion, a negative electrode tab group 220, and a positive electrode tab group 250.

[0056] The main body is composed of a negative electrode plate 210 and a positive electrode plate 240, which will be described later. The negative electrode tab group 220 is located at the end of a first side of the first electrode body 201 in a first direction (X direction) relative to the main body. In this embodiment, the first side is the sealing plate 120 side. The positive electrode tab group 250 is located at the end of a second side of the first electrode body 201 in the first direction (X direction) relative to the main body. In this embodiment, the second side is the sealing plate 130 side.

[0057] The negative electrode tab group 220 and the positive electrode tab group 250 are formed so as to protrude from the center portion of the electrode body 200 toward the sealing plate 120 or the sealing plate 130, respectively.

[0058] 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.

[0059] The negative electrode current collector 400A is disposed on the sealing plate 120 via a resin insulating member. The negative electrode current collector 400A is electrically connected to the negative electrode tab group 220 and the negative electrode terminal 301. The negative electrode current collector 400A is made of a conductive material (more specifically, a metal), and may be made of, for example, copper or a copper alloy. Details of the negative electrode current collector 400A will be described later.

[0060] The positive electrode current collector 400B is disposed on the sealing plate 130 via a resin insulating member. The positive electrode current collector 400B is electrically connected to the positive electrode tab group 250 and the positive electrode terminal 302. The positive electrode current collector 400B is made of a conductive material (more specifically, a metal), and may be made of, for example, aluminum or an aluminum alloy. The positive electrode tab group 250 may be electrically connected to the sealing plate 130 directly or via the positive electrode current collector 400B. In this case, the sealing plate 130 may serve as the positive electrode terminal 302. Details of the positive electrode current collector 400B will be described later.

[0061] (Configuration of electrode body 200) 7 is a cross-sectional view of the negative electrode plate 210 (a cross-sectional view taken along line VII-VII in FIG. 8), and FIG. 8 is a front view showing the negative electrode plate 210. As shown in FIG.

[0062] As shown in FIGS. 7 and 8, the negative electrode plate 210, which is the first electrode, has a polarity different from that of the positive electrode plate 240, which is the second electrode. A plurality of negative electrode tabs 230 (first electrode tabs) made of negative electrode cores 211 are provided at one end in the width direction of the negative electrode plate 210. When the negative electrode plates 210 are stacked, the plurality of negative electrode tabs 230 are stacked to form a negative electrode tab group 220. The negative electrode tab group 220 is electrically connected to the first electrode. The length of each of the negative electrode tabs 230 in the protruding direction of the plurality of negative electrode plates 210 is adjusted as appropriate, taking into consideration the state in which the negative electrode tab group 220 is connected to the negative electrode current collector 400A. The shape of the negative electrode tab 230 is not limited to that exemplified in FIG. 7.

[0063] FIG. 9 is a cross-sectional view of the positive electrode plate 240 (cross-sectional view taken along line IX-IX in FIG. 10), and FIG. 10 is a front view showing the positive electrode plate 240. As shown in FIG.

[0064] As shown in FIGS. 9 and 10, a plurality of positive electrode tabs 260 (second electrode tabs) made of positive electrode cores 241 are provided at one end in the width direction of the molded positive electrode plate 240. When the positive electrode plates 240 are stacked, the plurality of positive electrode tabs 260 are stacked to form a positive electrode tab group 250. The positive electrode tab group 250 is electrically connected to the second electrode. The length of each of the positive electrode tabs 260 in the protruding direction of the plurality of positive electrode plates 240 is adjusted as appropriate, taking into consideration the state in which the positive electrode tab group 250 is connected to the positive electrode current collector 400B. The shape of the positive electrode tab 260 is not limited to the example shown in FIG. 10.

[0065] A positive electrode protective layer 243 is provided at the base of the positive electrode tab 260. The positive electrode protective layer 243 does not necessarily have to be provided at the base of the positive electrode tab 260.

[0066] 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 negative electrode tab group 220 is smaller than the thickness of the positive electrode tab group 250.

[0067] (Connection structure between electrode body 200 and current collector 400) Fig. 11 is a cross-sectional view taken along line XI-XI of the secondary battery shown in Fig. 1. As shown in Fig. 11, the electrode body 200 includes a first electrode body 201 and a second electrode body 202. Each of the first electrode body 201 and the second electrode body 202 includes a positive electrode (second electrode) and a negative electrode (first electrode). The electrode body 200 may be composed of three or more electrode bodies.

[0068] 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.

[0069] The first electrode body 201 includes a negative electrode tab group 220. The negative electrode tab group 220 is electrically connected to a current collector 410 (negative electrode current collector) at a first end 205 in the X direction. The second electrode body 202 includes a negative electrode tab group 270. The negative electrode tab group 270 is electrically connected to the current collector 410 (negative electrode current collector) at a third end 207 in the X direction.

[0070] The negative electrode tab group 220 (first electrode tab) has a curved portion 221 and a tip portion 222. The curved portion 221 is a portion of the negative electrode tab group 220 that is curved on the side where the first electrode is connected, relative to the tip portion 222. The tip portion 222 is a portion of the negative electrode tab group 220 that is located at the end opposite the side where the first electrode is connected.

[0071] The negative electrode tab group 270 (first electrode tab) has a curved portion 271 and a tip portion 272. The curved portion 271 is a portion of the negative electrode tab group 270 that is curved on the side where the first electrode is connected, relative to the tip portion 272. The tip portion 272 is a portion of the negative electrode tab group 270 that is located at the end opposite the side where the first electrode is connected.

[0072] The negative electrode tab group 220 and the negative electrode tab group 270 are curved in opposite directions so that the tip portions 222, 272 approach each other. In the present embodiment, the tip portions 222, 272 are spaced apart, but this configuration is not limiting, and the tip portions 222, 272 may be in contact with each other.

[0073] The negative electrode current collector 400A electrically connects the negative electrode terminal 301 to the negative electrode tab group 220 and the negative electrode tab group 270. The negative electrode current collector 400A in this embodiment is connected to the negative electrode terminal 301 between the electrode body 200 and the sealing plate 120.

[0074] Negative electrode current collector 400A includes current collector 410 and current collector 430.

[0075] Current collector 410 is a plate-like member. Current collector 410 has its longitudinal direction in the Z direction and its transverse direction in the Y direction. Current collector 410 is formed from a single, integrated part. Current collector 430 is a plate-like member. Current collector 430 has its longitudinal direction in the Z direction and its transverse direction in the Y direction. Current collector 410 and current collector 430 are arranged in parallel in the X direction. In this way, current collector 410 and current collector 430 are formed from separate parts.

[0076] The negative electrode tab groups 220, 270 are joined to the current collector 410 at joining points 411, which will be described later (see FIG. 16 ). The joining points 411 can be formed by, for example, ultrasonic welding, resistance welding, laser welding, crimping, or the like. In the present embodiment, the negative electrode tab groups 220, 270 and the current collector 410 are joined by, for example, ultrasonic welding.

[0077] The current collector 430 is joined to the current collector 410 at a joint (not shown) located at an end in the Z direction. The current collector 430 is connected to the negative electrode terminal 301. The connection between the current collector 430 and the negative electrode terminal 301 can be formed by, for example, crimping and / or welding.

[0078] Negative electrode terminal 301 is exposed to the outside of sealing plate 120. Negative electrode terminal 301 is connected to plate-shaped member 303. Negative electrode terminal 301 preferably includes region 301a made of copper or a copper alloy and region 301b made of aluminum or an aluminum alloy, and region 301a made of copper or a copper alloy is preferably connected to current collector 430.

[0079] The plate-shaped member 303 is located outside the sealing plate 120. The plate-shaped member 303 is arranged so as to fit along the sealing plate 120. The plate-shaped member 303 is conductive. The plate-shaped member 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 plate-shaped member 303 can be formed by, for example, laser welding.

[0080] An insulating member 510 is disposed between the plate-shaped member 303 and the sealing plate 120. An insulating member 520 is disposed between the negative electrode terminal 301 and the sealing plate 120. An insulating member 530 is disposed between the current collector 430 and the sealing plate 120.

[0081] However, the negative electrode terminal 301 may be electrically connected to the sealing plate 120. Alternatively, the sealing plate 120 may serve as the negative electrode terminal 301.

[0082] A spacer 600 (first spacer 610) is disposed between the sealing plate 120 (first sealing plate) and the main body of the electrode assembly 200 (excluding the negative electrode tab groups 220, 270). The first spacer 610 is made of an insulating resin material. The first spacer 610 suppresses movement of the electrode assembly 200 within the case 100 in the X direction, and suppresses damage to the negative electrode tab groups 220, 270 and the electrode assembly 200. In addition, the first spacer 610 protects the negative electrode tab groups 220, 270 by allowing the negative electrode tab groups 220, 270 to pass through the inside of the first spacer 610.

[0083] A resin insulating sheet 700 (electrode body holder) is disposed between the electrode body 200 and the case body 110. The insulating sheet 700 may be made of, for example, resin. More specifically, the material of the insulating sheet 700 is, for example, polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), or polyolefin (PO).

[0084] Fig. 12 is a cross-sectional view taken along the line XII-XII of the secondary battery shown in Fig. 1. The connection structure between the electrode body 200 and the current collector 400 on the positive electrode side of the secondary battery 1 in this embodiment differs from the structure on the negative electrode side in that the portion corresponding to the current collector 410 on the negative electrode side is composed of two parts.

[0085] The first electrode body 201 includes a positive electrode tab group 250. The positive electrode tab group 250 is electrically connected to a current collector 420 (positive electrode current collector) at a second end 206 in the X direction. The second electrode body 202 includes a positive electrode tab group 280. The positive electrode tab group 280 is electrically connected to the current collector 420 (positive electrode current collector) at a fourth end 208 in the X direction.

[0086] The positive electrode tab group 250 has a curved portion 251 and a tip portion 252. The curved portion 251 is a portion of the positive electrode tab group 250 that is curved on the side where the second electrode is connected, relative to the tip portion 252. The tip portion 252 is a portion of the positive electrode tab group 250 that is located at the end opposite the side where the second electrode is connected.

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

[0088] The positive electrode tab group 250 and the positive electrode tab group 280 are curved in opposite directions so that the tip portions 252, 282 approach each other. In the present embodiment, the tip portions 252, 272 are spaced apart, but this configuration is not limiting, and the tip portions 252, 282 may be in contact with each other.

[0089] The positive electrode current collector 400B electrically connects the positive electrode terminal 302 and the positive electrode tab groups 250, 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 sealing plate 130.

[0090] Positive electrode current collector 400B includes current collector 420 (first current collecting member) and current collector 450 (second current collecting member). Plate 460 is interposed as an insulating member between current collector 420 (first current collecting member) and current collector 450 (second current collecting member), but is electrically joined at a position different from the cross section shown in the drawing.

[0091] Current collector 420 is a plate-like member. Current collector 420 has a longitudinal direction in the Z direction and a lateral direction in the Y direction. Current collector 420 is composed of one current collector and another current collector. In other words, current collector 420 is composed of two parts.

[0092] The positive electrode tab groups 250, 280 are joined to a current collector 420 composed of two parts at a joining point 421 (see FIG. 16 ) described below. The joining point 421 can be formed by, for example, ultrasonic welding, resistance welding, laser welding, crimping, or the like. In this embodiment, the positive electrode tab groups 250, 280 and the current collector 420 are joined by, for example, ultrasonic welding.

[0093] The current collector 440 is joined to the current collector 420 at a joint (not shown) located at an end in the Z direction. The current collector 440 is connected to the positive electrode terminal 302. The connection between the current collector 440 and the positive electrode terminal 302 can be formed by, for example, crimping and / or welding.

[0094] Positive electrode terminal 302 is exposed to the outside of sealing plate 130 and is provided so as to reach current collector 440 of positive electrode current collector 400B provided on the inside surface side of sealing plate 130. Positive electrode terminal 302 is connected to plate-shaped member 304.

[0095] The plate-shaped member 304 is located outside the sealing plate 130. The plate-shaped member 304 is arranged so as to fit along the sealing plate 130. The plate-shaped member 304 is conductive. The plate-shaped member 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 plate-shaped member 304 can be formed by, for example, laser welding.

[0096] An insulating member 510 is disposed between the plate-shaped member 304 and the sealing plate 130. An insulating member 520 is disposed between the positive electrode terminal 302 and the sealing plate 130. An insulating member 470 is disposed between the current collector 440 and the sealing plate 130.

[0097] However, the positive electrode terminal 302 may be electrically connected to the sealing plate 130. Alternatively, the sealing plate 130 may serve as the positive electrode terminal 302.

[0098] A spacer 600 (second spacer 620) is disposed between the sealing plate 130 (second sealing plate) and the main body of the electrode assembly 200 (excluding the positive electrode tab groups 250, 280). The second spacer 620 is made of an insulating resin material. The second spacer 620 suppresses movement of the electrode assembly 200 within the case 100 in the X direction, and suppresses damage to the positive electrode tab groups 250, 280 and the electrode assembly 200. The second spacer 620 also protects the positive electrode tab groups 250, 280 by allowing the positive electrode tab groups 250, 280 to pass through the interior of the second spacer 620.

[0099] The spacer 600 is made of, for example, resin, and may be made of, for example, polypropylene (PP), polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), or ethylene propylene diene rubber (EPDM).

[0100] Between the electrode body 200 and the case body 110, the above-mentioned resin insulating sheet 700 (electrode body holder) is disposed.

[0101] Fig. 13 is a first perspective view showing the shape of the spacer. Fig. 14 is a second perspective view showing the shape of the spacer. A spacer 600 shown in Figs. 13 and 14 is a first spacer 610 arranged on the negative electrode side, for example.

[0102] 13 and 14, the first spacer 610 has a longitudinal direction and a lateral direction. The longitudinal direction is along the Z direction. The lateral direction is along the Y direction.

[0103] The first spacer 610 includes a first base portion 630, a first outer peripheral wall 640, a first inner wall 650, a second inner wall 651, a second base portion 660, a second outer peripheral wall 670, a third inner wall 680, and a connecting portion 690.

[0104] The first base portion 630 is a portion that extends in one plane. The first base portion 630 extends in a substantially rectangular shape on the YZ plane. The first base portion 630 extends so as to face the electrode body 200 and the sealing plate 120. The first base portion 630 can be disposed so as to abut against an end surface of the electrode body 200.

[0105] The first base portion 630 has a plurality of first partitions 631. The plurality of first partitions 631 are formed by being separated by a first outer peripheral wall 640, a first inner wall 650, and a second inner wall 651 of the first base portion 630. In the present embodiment, four first partitions 631 are formed.

[0106] A plurality of first through holes 632 are provided in the first base portion 630. The plurality of first through holes 632 penetrate the first base portion 630 in the X direction. Each of the plurality of first through holes 632 has an elongated hole shape.

[0107] The multiple first through holes 632 are provided in at least the multiple first partitions 631 of the first base portion 630. It is preferable that at least one of the multiple first through holes 632 is provided in each of the multiple first partitions 631. It is also preferable that each of the multiple first partitions 631 is provided with multiple through holes.

[0108] At least two of the plurality of first through holes 632 are provided in each of the plurality of first partitions 631. In the present embodiment, for example, two or four of the plurality of first through holes 632 are provided in each of the plurality of first partitions 631. The number of the plurality of first through holes 632 provided in each of the plurality of first partitions 631 may be non-uniform. Note that the shape and number of the plurality of first through holes 632 may be selected as appropriate and are not limited to the shape and number shown in the drawing.

[0109] When viewed from a direction perpendicular to the first base portion 630, the total area of ​​the multiple first through holes 632 is preferably such that the ratio of (total area of ​​through holes formed in the first base portion) / (area of ​​the portion of the first base portion where the outer wall and inner wall are not formed) is 0.3 or more, more preferably 0.5 or more, and even more preferably 0.6 or more.

[0110] The first outer peripheral wall 640 extends from the outer peripheral edge of the surface of the first base portion 630 facing the sealing plate 120 (first sealing plate) toward the sealing plate 120 (first sealing plate). The first outer peripheral wall 640 is disposed so as to surround the entire outer peripheral edge of the first base portion 630. Therefore, the overall shape of the first spacer 610 has a shape that is recessed toward the electrode body 200 side. Note that the first outer peripheral wall 640 does not necessarily have to be annular, and may have a portion cut out.

[0111] The first outer peripheral wall 640 has a pair of first walls 641 and a pair of second walls 642. The pair of first walls 641 and the pair of second walls 642 are arranged to intersect with each other.

[0112] The pair of first walls 641 and the pair of second walls 642 give the first outer peripheral wall 640 a substantially rectangular shape when viewed from a direction perpendicular to the first base portion 630. The pair of first walls 641 and the pair of second walls 642 are connected to each other via other portions of the first walls 641. This makes it easier to maintain the strength of the first outer peripheral wall 640.

[0113] The pair of first walls 641 has one first wall 643 (first portion) and the other first wall 644 (second portion). The one first wall 643 and the other first wall 644 face each other.

[0114] One first wall 643 extends in the longitudinal direction. One first wall 643 is continuous with the connecting portion 690. The other first wall 644 faces the one first wall 643 in the short direction and extends in the longitudinal direction.

[0115] The pair of second walls 642 has one second wall 645 (third portion) and the other second wall 646 (fourth portion). One second wall 645 and the other second wall 646 face each other.

[0116] One of the second walls 645 extends in the short-side direction. One of the second walls 645 is located at an end in the longitudinal direction. The other of the second walls 646 faces the one of the second walls 645 in the longitudinal direction and extends in the short-side direction of the first spacer 610. The other of the second walls 646 is continuous with the connecting portion 690.

[0117] One second wall 645 and the other second wall 646 are provided so as to intersect with one first wall 643 and the other first wall 644. In the present embodiment, one second wall 645 and the other second wall 646 are provided so as to be perpendicular to one first wall 643 and the other first wall 644. One second wall 645 and the other second wall 646 each connect end portions of one first wall 643 and the other first wall 644.

[0118] A plurality of protrusions 647 are provided on the first outer peripheral wall 640. The plurality of protrusions 647 are provided on one second wall 645 of the first outer peripheral wall 640. The plurality of protrusions 647 are lined up on one second wall 645 at intervals from each other. By providing the plurality of protrusions 647, the injected electrolyte does not accumulate inside the first spacer 610, and can easily flow into the internal space of the case 100. Note that the plurality of protrusions 647 do not necessarily have to be provided on the first spacer 610.

[0119] The first inner wall 650 is provided so as to connect one first wall 643 and the other first wall 644. The first inner wall 650 is formed so as to pass through an inner region of the first base portion 630 that is separated from the outer peripheral edge.

[0120] First inner side wall 650 extends from the surface of first base portion 630 on the sealing plate 120 (first sealing plate) side toward sealing plate 120 (first sealing plate). First inner side wall 650 is continuous with first base portion 630, which makes it easier to ensure strength.

[0121] The second inner wall 651 is provided so as to connect one second wall 645 and the other second wall 646. The second inner wall 651 is formed so as to pass through an inner region of the first base portion 630 that is separated from the outer peripheral edge.

[0122] Second inner side wall 651 extends from the surface of first base portion 630 on the sealing plate 120 (first sealing plate) side toward sealing plate 120 (first sealing plate). Since second inner side wall 651 is continuous with first base portion 630, it is easier to ensure strength.

[0123] The first inner wall 650 and the second inner wall 651 are provided so as to intersect with each other. In this embodiment, the first inner wall 650 and the second inner wall 651 are perpendicular to each other.

[0124] The first inner wall 650 is disposed longitudinally offset from the center of one first wall 643 or the other first wall 644. The second inner wall 651 is disposed transversely at approximately the center of one second wall 645 or the other second wall 646. Note that both the first inner wall 650 and the second inner wall 651 may be configured to connect only one of the pair of first walls 641 or the pair of second walls 642.

[0125] The second base portion 660 is a portion that extends in one plane. The second base portion 660 extends in a substantially rectangular shape on the YZ plane. The second base portion 660 extends so as to face the electrode body 200 and the sealing plate 130. The second base portion 660 is disposed at a distance from the first base portion 630. The second base portion 660 can be disposed so as to abut against the end surface of the electrode body 200.

[0126] The second base portion 660 has a plurality of second partitions 661. The plurality of second partitions 661 are formed by being separated by a third inner wall 680 of the second base portion 660. In the present embodiment, two second partitions 661 are formed.

[0127] A through hole is provided in the second base portion 660. In the present embodiment, the second base portion 660 is provided with a plurality of second through holes 662. The plurality of second through holes 662 penetrate the second base portion 660 in the X direction. Each of the plurality of second through holes 662 has an elongated hole shape.

[0128] The multiple second through holes 662 are provided in at least the multiple second partitions 661 of the second base portion 660. It is preferable that at least one of the multiple second through holes 662 is provided in each of the multiple second partitions 661. It is also preferable that multiple through holes are provided in each of the multiple second partitions 661.

[0129] For example, two second through holes 662 are provided in each of the second partitions 661. The number of second through holes 662 provided in each of the second partitions 661 may be non-uniform. Note that the shape and number of the second through holes 662 may be selected appropriately and are not limited to the shape and number shown in the figure.

[0130] When viewed from a direction perpendicular to the second base portion 660, the total area of ​​the multiple second through holes 662 is preferably such that the ratio of (total area of ​​through holes formed in the second base portion) / (area of ​​the portion of the second base portion where the outer wall and inner wall are not formed) is 0.3 or more, more preferably 0.5 or more, and even more preferably 0.6 or more.

[0131] The second outer peripheral wall 670 extends from the outer peripheral edge of the surface of the second base portion 660 facing the sealing plate 120 (first sealing plate) toward the sealing plate 120 (first sealing plate). The second outer peripheral wall 670 is disposed so as to surround the entire outer peripheral edge of the second base portion 660. Therefore, the overall shape of the first spacer 610 has a shape that is recessed toward the electrode body 200 side.

[0132] The second outer peripheral wall 670 has a pair of third walls 671 and a pair of fourth walls 672. The pair of third walls 671 and the pair of fourth walls 672 are arranged to intersect with each other.

[0133] The pair of third walls 671 and the pair of fourth walls 672 give the second outer peripheral wall 670 a substantially rectangular shape when viewed from a direction perpendicular to the second base portion 660. The pair of third walls 671 and the pair of fourth walls 672 are connected to each other and are continuous. This makes it easier to maintain the strength of the second outer peripheral wall 670.

[0134] The pair of third walls 671 has one third wall 673 (fifth portion) and the other third wall 674 (sixth portion). The one third wall 673 and the other third wall 674 face each other.

[0135] One third wall 673 extends in the longitudinal direction. One third wall 673 is continuous with the connecting portion 690. The other third wall 674 faces the one third wall 673 in the short direction and extends in the longitudinal direction.

[0136] The pair of fourth walls 672 includes one fourth wall 675 and the other fourth wall 676. The one fourth wall 675 and the other fourth wall 676 face each other.

[0137] One fourth wall 675 extends in the short direction. One fourth wall 675 is located at an end in the longitudinal direction. The other fourth wall 676 faces the one fourth wall 675 in the longitudinal direction and extends in the short direction. The other fourth wall 676 is continuous with the connecting portion 690.

[0138] One fourth wall 675 and the other fourth wall 676 are provided so as to intersect with one third wall 673 and the other third wall 674. In the present embodiment, one fourth wall 675 and the other fourth wall 676 are provided so as to be perpendicular to one third wall 673 and the other third wall 674. One fourth wall 675 and the other fourth wall 676 each connect end portions of one third wall 673 and the other third wall 674.

[0139] A plurality of protrusions 647 are provided on second outer peripheral wall 670. The plurality of protrusions 647 are provided on one fourth wall 675 of second outer peripheral wall 670. The plurality of protrusions 647 are lined up on one fourth wall 675 at intervals from each other.

[0140] The third inner wall 680 is provided so as to connect the fourth wall 675 on one side and the fourth wall 676 on the other side.

[0141] Third inner side wall 680 extends from the surface of second base portion 660 facing sealing plate 120 (first sealing plate) toward sealing plate 120 (first sealing plate). Because third inner side wall 680 is continuous with second base portion 660, strength can be more easily ensured compared to when third inner side wall 680 is provided with a gap between it and second base portion 660.

[0142] The connecting portion 690 connects the first base portion 630 and the second base portion 660. The connecting portion 690 connects the first outer peripheral wall 640 and the second outer peripheral wall 670, thereby connecting the first base portion 630 and the second base portion 660. The connecting portion 690 is located on one side in the short side direction.

[0143] The connecting portion 690 has a curved surface 691. The curved surface 691 has a shape that is recessed from the upper end side of the outer peripheral wall toward the base portion side.

[0144] The curved surface 691 faces the curved portion 221 of the negative electrode tab group 220. As a result, the curved surface 691 follows the curved portion 221.

[0145] The first spacer 610 has a notch 692. The notch 692 is surrounded by the first base portion 630, the second base portion 660, and the connecting portion 690.

[0146] The electrode tabs can be inserted into the cutouts 692 through the cutouts 692. As a result, the negative electrode tab groups 220, 270 (first electrode tabs) are arranged between the first base portion 630 and the second base portion 660.

[0147] When the negative electrode tab groups 220, 270 are inserted into the cutout portion 692, the curved portion 221 of the electrode tab fits along the curved surface 691, thereby suppressing deformation of the curved portion 221. The cutout portion 692 is disposed at a position facing the curved surface 691 in the short direction. This makes it easy to fit the curved portion 221 along the curved surface 691 when placing the negative electrode tab groups 220, 270 inside the cutout portion 692 through the cutout portion 692.

[0148] The first base portion 630 and the second base portion 660 described above are located on the end face side of the electrode body 200. The first base portion 630 and the second base portion 660 may or may not abut the end face of the electrode body 200. When the first base portion 630 and the second base portion 660 do not abut the end face of the electrode body 200, the shortest distance from the first base portion 630 and the second base portion 660 to the electrode body 200 is preferably within 2 mm, and more preferably within 1 mm. Furthermore, the area of ​​the first base portion 630 is preferably larger than the area of ​​the second base portion 660.

[0149] The outer shape of the first spacer 610 is shaped to follow the outer shape of the electrode body 200 in the X direction. The outer dimensions of the spacer 600 are preferably smaller than the outer dimensions of the electrode body 200. Because the electrode body 200 is wrapped in the insulating sheet 700 and the spacer 600 is also wrapped in the insulating sheet 700, making the outer dimensions of the spacer 600 smaller than those of the electrode body 200 can improve the ease of insertion of the electrode body 200 into the case body 110.

[0150] The thickness in the X direction of first base portion 630 and second base portion 660 is, for example, preferably 0.1 mm or more, more preferably 1 mm or more, and even more preferably 0.6 mm or more. The thickness in the YZ plane of first outer peripheral wall 640 and second outer peripheral wall 670 is preferably 0.15 mm or more, more preferably 2 mm or more, and even more preferably 0.6 mm or more. The height in the X direction of first outer peripheral wall 640 and second outer peripheral wall 670 is preferably 6 mm or more, more preferably 15 mm or more, and even more preferably 12 mm or more.

[0151] By providing the first through hole 632 and the second through hole 662 in the first spacer 610, when the secondary battery 1 shown in Figure 1 is placed with the Z direction facing upward (the openings 113 (first opening) and openings 114 (second opening) at both ends of the case body 110 are arranged on the left and right), even if the electrolyte is pushed out of the electrode body during charging (when the electrode plates generally expand) and flows out of this part, it is made easier to return to the electrode body during discharging (when the electrode plates generally contract).

[0152] Similarly to the first spacer 610, the second spacer 620 insulates the electrode body 200 from the case 100. It is desirable that the second spacer 620 has a configuration that is mirror-symmetrical to the first spacer 610 with the electrode body 200 at the center.

[0153] The area of ​​the first base portion of the second spacer 620 is preferably larger than the area of ​​the second base portion. In the X direction, it is preferable that the portion of the first base portion or the second base portion of the second spacer 620 where no through-hole is provided faces the liquid injection hole 134. This makes it possible to suppress damage to the electrode body 200 caused by the electrolyte being jetted when the electrolyte is injected.

[0154] (Manufacturing process of secondary battery 1) A method for manufacturing a secondary battery according to this embodiment will be described below.

[0155] 15, 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). It is preferable that a portion of the tip of each of the negative electrode tab group 220, the positive electrode tab group 250, the negative electrode tab group 270, and the positive electrode tab group 280 is cut off so that the tip lengths are the same when bundled.

[0156] 15 to 17, after the first electrode body 201 and the second electrode body 202 are fabricated, the positive electrode tab groups 250, 280 are joined to the current collector 420 (step S2). The positive electrode tab groups 250, 280 are joined to the current collector 420 at joining locations 421.

[0157] Next, the first electrode body 201, the current collector 410, and the second electrode body 202 are arranged in this order in the DR1 direction. The negative electrode tab group 220 is arranged on one side of the current collector 410 in the DR1 direction. With the negative electrode tab group 270 arranged on the other side of the current collector 410 in the DR1 direction, the negative electrode tab group 220 and the negative electrode tab group 270 are joined to the current collector 410 (step S3). The negative electrode tab group 220 and the negative electrode tab group 270 are joined to the current collector 410 at joining positions 411.

[0158] In the height direction of the first electrode body 201 and the second electrode body 202, the current collectors 410 and 420 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 smaller. The current collectors 410 and 420 are not limited to this configuration. The current collectors 410 and 420 may also be arranged 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.

[0159] The order of the steps of joining the current collector 410 and the current collector 420 to the first electrode body 201 and the second electrode body 202, respectively, is not limited to the above and may be changed. The step of joining the current collector 420 to the first electrode body 201 and the second electrode body 202, respectively, is preferably performed before the step of overlapping the first electrode body 201 and the second electrode body 202, which will be described later, and is preferably performed before the step of joining the current collector 410 to the first electrode body 201 and the second electrode body 202.

[0160] Next, after joining the negative electrode tab group 220 and the negative electrode tab group 270 to the current collector 410, the negative electrode tab group 220 and the negative electrode tab group 270 are folded in the thickness direction of the first electrode body 201 and the second electrode body 202 (the 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 S4). In other words, the first electrode body 201 and the second electrode body 202 are gathered together.

[0161] "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 current collector, and the second electrode body do not have to be arranged on a straight line in the DR1 direction, and the first electrode body or the second electrode body may be inclined with respect to the current collector in the DR1 direction.

[0162] The negative electrode tab group 220 and the negative electrode tab group 270 are bent so that their leading ends face each other. The positive electrode tab group 250 and the positive electrode tab group 280 are also bent so that their leading ends face each other.

[0163] Fig. 18 is a perspective view showing a state in which a spacer is attached to an electrode body, and Fig. 19 is a perspective view showing a state before the electrode body and spacer are covered with an insulating sheet.

[0164] As shown in FIGS. 15, 18, and 19, the spacer 600 and the insulating sheet 700 are assembled to the electrode body 200 (step S5).

[0165] 18 , a second spacer 620 is illustrated, and the second spacer 620 is assembled to the electrode assembly 200. The second spacer 620 is assembled to the electrode assembly 200 from the Y direction (a direction perpendicular to the X direction). The second spacer 620 is assembled to the electrode assembly 200 so that the positive electrode tab groups 250, 280 are housed inside the cutouts 692. Because the electrode tabs can be inserted into the second spacer 620 through the cutouts, the spacer 600 can be assembled to the electrode assembly 200 more easily than when holes for inserting the electrode tabs are provided in the spacer and the electrode tabs are inserted through the holes.

[0166] The first spacer 610 is also assembled to the electrode assembly 200 by accommodating the negative electrode tab group into the cutout portion through the cutout portion.

[0167] 19 , after the first spacer 610 and the second spacer 620 are assembled to the electrode assembly 200, the electrode assembly 200, the first spacer 610, and the second spacer 620 are covered with an insulating sheet 700. In this manner, with the first spacer 610 arranged at one end of the electrode assembly 200 and the second spacer 620 arranged at the other end, the electrode assembly 200, the first spacer 610, and the second spacer 620 are covered with the insulating sheet 700.

[0168] By covering the spacer 600 with the insulating sheet 700, the negative electrode tab group and the positive electrode tab group positioned inside the spacer 600 can be protected more securely.

[0169] The insulating sheet 700 is fixed to the spacer 600. The insulating sheet 700 is fixed to the spacer 600 by thermally welding the insulating sheet 700 to the first region R1 and the second region R2 of the spacer 600.

[0170] FIG. 20 is a perspective view showing the electrode assembly and spacer after being covered with an insulating sheet. As shown in FIG. 20, the insulating sheet in this embodiment covers the entire axial circumference of the electrode assembly and spacer in the X direction. Note that the insulating sheet 700 does not necessarily need to cover the entire surface of the electrode assembly 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 assembly. Of the six faces of the electrode assembly 200 having a substantially rectangular parallelepiped (flat) shape, the insulating sheet 700 preferably covers the entire four faces other than the two faces on which the negative electrode tab group 220 and the positive electrode tab group 250 are formed, respectively. The multiple protrusions 647 provided on the spacer 600 are preferably exposed from the insulating sheet 700.

[0171] 15 and 20, next, the current collector 410 is electrically connected to the negative electrode terminal 301 via the current collector 430 (step S6). Note that step S6 can also be performed before step S5.

[0172] Specifically, the negative electrode tab group 220 and the negative electrode tab group 270 are bent so that the leading ends 222, 272 face each other.

[0173] The negative electrode terminal 301 and the current collector 430 are attached to the sealing plate 120 via an insulating member. The current collector 430 is brought into contact with the current collector 410 in the X direction. The connection of the plate-like member 303 to the negative electrode terminal 301 may be made at any time. The current collector 430 and the current collector 410 are joined by laser welding between the sealing plate 120 and the insulating sheet 700.

[0174] 21 is a perspective view showing a state in which a sealing plate is attached to the current collector on the positive electrode side. Next, as shown in FIG. 21, the spacer 600 and the electrode assembly 200 are inserted into the case body 110 through the opening 113, with the current collector 420 side first (step S7).

[0175] The sealing plate 120 and the main body portion of the electrode body 200 (the first electrode body 201 and the second electrode body 202) are brought closer to each other, thereby bending the negative electrode tab group 220 and the negative electrode tab group 270. As shown in Fig. 11 , the negative electrode tab group 220 and the negative electrode tab group 270 are bent along the shape of the spacer 600 so that the folded-back portions of the curved portions 221, 271 approach the case main body 110 in the Y direction.

[0176] After the sealing plate 120 is brought into contact with the case body 110, the sealing plate 120 is temporarily joined to the case body 110. By temporarily joining, the sealing plate 120 is partially joined to the opening 113 of the case body 110. As a result, the sealing plate 120 is positioned relative to the case body 110.

[0177] When inserting the electrode body 200 into the case body 110, the electrode body 200 may be pulled from the current collector 420 side or pushed from the current collector 410 side. When the electrode body 200 is pushed from the current collector 410 side, the negative electrode tab group 220 and the negative electrode tab group 270 can be bent at the same time.

[0178] After the electrode body 200 is inserted into the case body 110, the current collector 420 is electrically connected to the positive electrode terminal 302 (step S8).

[0179] Specifically, the positive electrode terminal 302 is attached to the sealing plate 130 via an insulating member. After the first electrode body 201 and the second electrode body 202 are inserted into the case body 110, the current collector 450 is brought into contact with the current collector 420 protruding from the opening 114 in the X direction. The connection of the plate-shaped member 304 to the positive electrode terminal 302 may be made at any time.

[0180] The positive electrode tab group 250 and the positive electrode tab group 280 connected to the current collector 420 are bent so that the tip portions 252, 282 face each other. As shown in Fig. 12 , the positive electrode tab group 250 and the positive electrode tab group 280 are curved along the shape of the spacer 600 so that the folded-back portions of the curved portions 251, 281 approach the case body 110 in the Y direction.

[0181] Fig. 22 is a perspective view showing the configuration of a secondary battery. As shown in Fig. 22, after the first spacer 610 and the electrode body 200 are inserted into the case body 110, the sealing plate 130 (first sealing plate) and the sealing plate 120 (second sealing plate) are joined to the case body 110 (step S9).

[0182] Specifically, after the sealing plate 130 is brought into contact with the case body 110, the sealing plate 130 is temporarily welded to the case body 110. By temporarily joining, the sealing plate 130 is partially joined to the opening 114 of the case body 110. As a result, the sealing plate 130 is positioned relative to the case body 110.

[0183] Next, sealing plate 120 and sealing plate 130 are joined to case body 110. Sealing plate 120 seals opening 113 of case body 110, and sealing plate 130 seals opening 114 of case body 110. In this way, first electrode body 201 and second electrode body 202 are housed in case 100.

[0184] After the above steps, inspections such as a leak inspection are carried out (step S10). After the leak inspection, the secondary battery 1 is dried to remove moisture from inside the case 100.

[0185] Next, with the sealing plate 130 (second sealing plate) positioned vertically above the sealing plate 120 (first sealing plate) and the first spacer 610 positioned below the electrode assembly 200, electrolyte is poured into the case 100 through an injection hole provided in the sealing plate 130 (second sealing plate) (step S11). Because the spacer 600 is provided around the area where the electrolyte is poured, damage to the electrode assembly 200 and the like is suppressed even if the electrolyte is poured forcefully into the case 100. As a result, the secondary battery 1 of this embodiment allows the electrolyte to be poured in a shorter time than when the spacer 600 is not provided.

[0186] During injection, the angle of the main surface of the sealing plate with respect to the vertical direction is preferably about 90±45° from the vertical direction, and more preferably, the main surface of the sealing plate is perpendicular to the vertical direction during injection.

[0187] The weight of the electrode assembly 200 placed in the case 100 is preferably 500 g or more, and more preferably 1 kg or more. This weight of the electrode assembly 200 does not include the electrolyte. Furthermore, if there are multiple electrode assemblies 200, this weight of the electrode assembly 200 is the total weight. Even if the electrode assembly 200 is heavy, the electrode assembly 200 can be supported by the first spacer 610.

[0188] Thereafter, degassing and charging are performed. During degassing and charging, the liquid injection hole 134 may be temporarily sealed. Thereafter, the liquid injection hole 134 is sealed, and the secondary battery 1 is completed.

[0189] In the secondary battery 1 and the manufacturing method thereof according to the first embodiment of the present technology, by providing the first inner side wall 650 on the first spacer 610, deformation of the first spacer 610 can be suppressed compared to when the first inner side wall 650 is not provided. By providing the first base portion 630 with the plurality of first through holes 632, it is possible to suppress the electrolyte from remaining between the sealing plate 120 and the first spacer 610. This allows the electrolyte to be easily impregnated into the electrode body 200 while maintaining the strength of the spacer 600. Consequently, it is possible to provide a highly reliable secondary battery.

[0190] In the secondary battery 1 and its manufacturing method according to embodiment 1 of the present technology, the first inner wall 650 and the second inner wall 651 are arranged so as to intersect with each other, thereby achieving structural integration compared to when the first inner wall 650 and the second inner wall 651 are arranged separately without intersecting, thereby improving the strength of the first spacer 610.

[0191] In the secondary battery 1 according to embodiment 1 of the present technology, multiple first through holes 632 are provided in at least multiple first partition portions 631 of the first base portion 630, and therefore the multiple first through holes 632 can be distributed among the multiple first partition portions 631, thereby preventing the accumulation of electrolyte while ensuring the strength of the spacer 600.

[0192] In the secondary battery 1 and its manufacturing method relating to embodiment 1 of the present technology, a first electrode tab is arranged between the first base portion 630 and the second base portion 660 of the first spacer 610, so that when force is applied from the first spacer 610 to the electrode body 200, the force applied from the first spacer 610 to the electrode body 200 can be dispersed, and damage to the end portion of the electrode body 200 can be suppressed.

[0193] In the secondary battery 1 and its manufacturing method according to embodiment 1 of the present technology, the strength of the spacer 600 can be improved by including a third inner wall 680 arranged to connect one third wall 673 (fifth portion) of the second outer peripheral wall 670 and the other third wall 674 (sixth portion).

[0194] In the secondary battery 1 according to the first embodiment of the present technology, the second through-hole 662 is provided in the second base portion 660, so that the retention of the electrolyte inside the spacer 600 can be further suppressed.

[0195] In the secondary battery 1 according to embodiment 1 of the present technology, a connecting portion 690 is provided that connects the first base portion 630 and the second base portion 660, so that the first spacer 610 including the first base portion 630 and the second base portion 660 can be configured as an integrated unit, thereby making it easier to assemble the first spacer 610 to the electrode body 200.

[0196] In the secondary battery 1 according to the first embodiment of the present technology, the connecting portion 690 of the first spacer 610 has a curved surface 691 that faces the curved portion 221 of the electrode tab, thereby facilitating the formation of the curved portion 221. Furthermore, since the first spacer 610 fits along the curved portion 221, damage to the electrode tab due to contact between the electrode tab and the spacer 600 can be suppressed.

[0197] In the secondary battery 1 according to embodiment 1 of the present technology, a second spacer 620 is provided between the sealing plate 130 (second sealing plate) and the electrode body 200, so that the electrode body 200 can be sandwiched between the first spacer 610 and the second spacer 620, thereby preventing the electrode body 200 from moving within the case 100.

[0198] In the manufacturing method of the secondary battery 1 according to the first embodiment of the present technology, the first spacer 610 is disposed below the electrode assembly 200, and the electrolyte is poured into the case 100 through the pouring hole 134. This suppresses deformation of the first spacer 610, and therefore the electrode assembly 200 can be stably supported. This suppresses damage to the electrode tabs and the electrode assembly 200. Furthermore, because the electrode assembly 200 can be stably supported, the electrode assembly 200 does not move unnecessarily inside the case 100 even if the pouring speed of the electrolyte increases, and therefore the electrolyte can be poured in a short time, and the pouring performance of the electrolyte can be improved.

[0199] In the manufacturing method of the secondary battery 1 according to the first embodiment of the present technology, by covering the electrode body 200, the first spacer 610, and the second spacer with the insulating sheet 700, the slippery insulating sheet 700 is positioned on the outer periphery, which makes it easier to insert the electrode body 200 and the spacer 600 into the case body 110. In addition, the insulating sheet 700 can effectively prevent damage to the electrode tabs and the electrode body 200.

[0200] Hereinafter, secondary batteries according to embodiments 2 to 5 will be described. The secondary batteries according to embodiments 2 to 5 have different spacer configurations from secondary battery 1 according to embodiment 1 of the present technology, and therefore, description of the configurations that are similar to those of secondary battery 1 according to embodiment 1 of the present technology will not be repeated.

[0201] (Embodiment 2) 23, first spacer 610A according to embodiment 2 is made up of two members: first spacer 611A and first spacer 612A.

[0202] Each of the first spacer 611A and the other first spacer 612A includes a first base portion 630A, a first outer peripheral wall 640A, a first inner wall 650A, a second inner wall 651A, a second base portion 660A, a second outer peripheral wall 670A, a third inner wall 680A, and a connecting portion 690A. The first spacer 610A is provided with two connecting portions 690A.

[0203] When the first spacer 610A is assembled to the electrode assembly, the first spacer 611A and the other first spacer 612A are integrated by connecting the second inner walls 651A to each other and connecting the third inner walls 680A to each other.

[0204] In the secondary battery according to the second embodiment of the present technology, two electrode tabs formed in the electrode body can be supported by two connecting portions 690A, respectively.

[0205] (Embodiment 3) 24, a first spacer 610B according to the third embodiment includes a first base portion 630B and a second base portion 660B. The first spacer 610B does not have a connecting portion.

[0206] In the secondary battery according to the third embodiment of the present technology, the absence of a connecting portion makes it easy to arrange a spacer between the sealing plate and the electrode body regardless of the shape of the electrode tab.

[0207] (Embodiments 4 and 5) 25, a first spacer 610C according to the fourth embodiment includes a first base portion 630C, a first outer peripheral wall 640C, a first inner side wall 650C, a second inner side wall 651C, a second base portion 660C, a second outer peripheral wall 670C, a third inner side wall 680C, a fourth inner side wall 681C, and a connecting portion 690C. A plurality of first inner side walls 650C are provided. A plurality of fourth inner side walls 681C are provided.

[0208] 26 , a first spacer 610D according to the fifth embodiment includes a first base portion 630D, a first outer peripheral wall 640D, a first inner side wall 650D, a second inner side wall 651D, a second base portion 660D, a second outer peripheral wall 670D, a third inner side wall 680D, and a connecting portion 690D. A plurality of second inner side walls 651D are provided. A plurality of third inner side walls 680D are provided.

[0209] In the secondary batteries according to the fourth and fifth embodiments of the present technology, the required strength of the spacer can be easily ensured by increasing the number of inner walls, and the flow of the electrolyte can be ensured by providing through holes.

[0210] Since the second spacer has the same configuration as the first spacer, the second spacer also has the same function and effect as the first spacer.

[0211] 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]

[0212] 1 secondary battery, 100 case, 110 case body, 111 first side portion, 112, 112A, 112B second side portion, 113 opening (first opening), 114 opening (second opening), 115 joint portion, 120, 130 sealing plate, 134 liquid inlet, 150 gas release valve, 200 electrode body, 201 first electrode body, 202 second electrode body, 205 first end, 206 second end, 207 third end, 208 fourth end, 210 negative electrode plate, 211 negative electrode core, 220, 270 negative electrode tab group, 221, 251, 271, 281 curved portion, 222, 252, 272, 282 tip portion, 230 negative electrode tab, 240 positive electrode plate, 241 Positive electrode core, 243; positive electrode protective layer, 250, 280; positive electrode tab group, 260; positive electrode tab, 300; electrode terminal, 301; negative electrode terminal, 301a, 301b; region, 302; positive electrode terminal, 303, 304; plate-shaped member, 400, 410, 420, 430, 440, 450; current collector, 400A; negative electrode current collector, 400B; positive electrode current collector, 411, 421; joint, 460; plate, 470, 510, 520, 530; insulating member, 600; spacer, 610, 610A, 610B; first spacer, 611A; one first spacer, 612A; the other first spacer, 620; second spacer, 630, 630A, 630B, 630C, 630D First base portion, 631; First partition portion, 632; First through-hole, 640, 640A, 640C, 640D; First outer peripheral wall, 641; First wall, 643; One first wall, 644; Other first wall, 642; Second wall, 645; One second wall, 646; Other second wall, 647; Projection, 650, 650A, 650C, 650D; First inner side wall, 651, 651A, 651C, 651D; Second inner side wall, 660, 660A, 660B, 660C, 660D; Second base portion, 661; Second partition portion, 662; Second through-hole, 670, 670A, 670C, 670D; Second outer peripheral wall, 671; Third wall, 673; One third wall, 674; Other third wall, 672; Fourth wall, 675 One fourth wall, 676 the other fourth wall, 680, 680A, 680C, 680D third inner wall, 681C fourth inner wall, 690, 690A, 690C, 690D connecting portion, 691 curved surface, 692 notch portion, 700 insulating sheet, 800 separator, R1 first region, R2 second region.

Claims

1. an electrode body 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; The case is a case body having a first opening at one end and a second opening at the other end; a first sealing plate that seals the first opening; a second sealing plate that seals the second opening, The electrode body is a first electrode tab disposed on the first sealing plate side and electrically connected to the first electrode; a second electrode tab disposed on the second sealing plate side and electrically connected to the second electrode, a first spacer is disposed between the first sealing plate and the electrode body; The first spacer is a first base portion provided with a plurality of through holes; a first outer peripheral wall extending from an outer peripheral edge of a surface of the first base portion facing the first sealing plate toward the first sealing plate and having a first portion and a second portion opposed to each other; a first inner wall provided to connect the first portion and the second portion of the first outer peripheral wall;

2. the first outer peripheral wall further includes a third portion and a fourth portion that are provided so as to intersect with the first portion and the second portion and that face each other; the first spacer further includes a second inner wall provided to connect the third portion and the fourth portion of the first outer peripheral wall, The secondary battery according to claim 1 , wherein the first inner wall and the second inner wall are provided so as to intersect with each other.

3. the first base portion has a plurality of compartments separated by the first outer peripheral wall, the first inner wall, and the second inner wall; The secondary battery according to claim 2 , wherein the plurality of through holes are provided in at least the plurality of partitions of the first base portion.

4. The first spacer is a second base portion spaced apart from the first base portion; a second outer peripheral wall extending from an outer peripheral edge of a surface of the second base portion facing the first sealing plate toward the first sealing plate, The secondary battery according to claim 1 , wherein the first electrode tab is disposed between the first base portion and the second base portion.

5. the second outer peripheral wall has a fifth portion and a sixth portion opposed to each other, The secondary battery according to claim 4 , wherein the first spacer includes a third inner wall provided to connect the fifth portion and the sixth portion of the second outer peripheral wall.

6. The secondary battery according to claim 5 , wherein the second base portion is provided with a through hole.

7. The secondary battery according to claim 4 , wherein the first spacer includes a connecting portion that connects the first base portion and the second base portion.

8. the first electrode tab has a curved portion; The secondary battery according to claim 7 , wherein the connecting portion has a curved surface facing the curved portion.

9. 3. The secondary battery according to claim 1, wherein a second spacer is disposed between the second sealing plate and the electrode assembly.

10. an electrode body 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; The case is a case body having a first opening at one end and a second opening at the other end; a first sealing plate that seals the first opening; a second sealing plate that seals the second opening, The electrode body is a first electrode tab disposed on the first sealing plate side and electrically connected to the first electrode; a second electrode tab disposed on the second sealing plate side and electrically connected to the second electrode, a first spacer is disposed between the first sealing plate and the electrode body; The first spacer is a first base portion provided with a plurality of through holes; a first outer peripheral wall extending from an outer peripheral edge of a surface of the first base portion facing the first sealing plate toward the first sealing plate and having a first portion and a second portion opposed to each other; a first inner wall provided to connect the first portion and the second portion of the first outer peripheral wall, a step of fabricating the electrode body; assembling the first spacer to the electrode body; and inserting the first spacer and the electrode body into the case body.

11. a step of joining the first sealing plate and the second sealing plate to the case body after inserting the first spacer and the electrode body into the case body; 11. The method for manufacturing a secondary battery according to claim 10, further comprising: after joining the first sealing plate and the second sealing plate to the case body, positioning the second sealing plate higher than the first sealing plate in the vertical direction and with the first spacer positioned below the electrode body, injecting electrolyte into the case through an injection hole provided in the second sealing plate.

12. the first outer peripheral wall further includes a third portion and a fourth portion that are provided so as to intersect with the first portion and the second portion and that face each other; the first spacer further includes a second inner wall provided to connect the third portion and the fourth portion of the first outer peripheral wall, The method for manufacturing a secondary battery according to claim 10 or 11, wherein the first inner side wall and the second inner side wall are provided so as to intersect with each other.

13. The first spacer is a second base portion spaced apart from the first base portion; a second outer peripheral wall extending from an outer peripheral edge of a surface of the second base portion facing the first sealing plate toward the first sealing plate, The method for manufacturing a secondary battery according to claim 10 or 11, wherein the first electrode tab is disposed between the first base portion and the second base portion.

14. the second outer peripheral wall has a fifth portion and a sixth portion opposed to each other, The method for manufacturing a secondary battery according to claim 13 , wherein the first spacer includes a third inner wall provided to connect the fifth portion and the sixth portion of the second outer peripheral wall.

15. 12. The method for manufacturing a secondary battery according to claim 10, further comprising the step of covering the electrode body and the first spacer with an insulating sheet after assembling the first spacer to the electrode body.

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