Secondary battery

Abstract

To readily impregnate an electrolyte into an electrode body.SOLUTION: A case 100 accommodates an electrode body 200. The case 100 includes a case body 110, a first sealing plate 130, and a second sealing plate 120. The case body 110 has a first opening at one end and a second opening at the other end. The first sealing plate 130 seals the first opening. The second sealing plate 120 seals the second opening. A first spacer 610 is positioned between the first sealing plate 130 and the electrode body 200. A second spacer 620 is positioned between the second sealing plate 120 and the electrode body 200. A filling hole 134 is provided in the first sealing plate 130. In the first direction perpendicular to the first sealing plate 130, a length D2 of the second spacer 620 is shorter than a length D1 of the first spacer 610.SELECTED DRAWING: Figure 16

Description

[Technical Field]

[0001] The present technology relates to a secondary battery. [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 required to easily impregnate the electrode body with an electrolyte solution.

[0005] The present technology has been made to solve the above-mentioned problems, and has an object to provide a secondary battery in which an electrolyte can be easily impregnated into an electrode body. [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; a second spacer is disposed between the second sealing plate and the electrode body; The first sealing plate has a liquid injection hole, The liquid injection hole is sealed with a sealing member, The secondary battery, wherein the length of the second spacer is shorter than the length of the first spacer in a first direction perpendicular to the first sealing plate.

[0008] [2] The first spacer is a first base portion; The secondary battery according to [1], further comprising: 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.

[0009] [3] the first outer peripheral wall has a first portion and a second portion opposed to each other, The secondary battery according to [2], wherein the first spacer includes a first inner wall provided to connect the first portion and the second portion of the first outer peripheral wall.

[0010] [4] The secondary battery according to [2] or [3], wherein the first outer peripheral wall has a first protrusion formed on an end face of the first outer peripheral wall on the side of the first sealing plate.

[0011] [5] The second spacer is A second base portion; The secondary battery according to [2] or [3], further comprising: a second outer peripheral wall extending from an outer peripheral edge of the surface of the second base portion facing the second sealing plate toward the second sealing plate.

[0012] [6] the second outer peripheral wall has a third portion and a fourth portion opposed to each other, The secondary battery according to [5], wherein the second spacer includes a second inner wall provided to connect the third portion and the fourth portion of the second outer peripheral wall.

[0013] [7] The secondary battery according to [5] or [6], wherein the second outer peripheral wall has a second protrusion formed on an end face of the second outer peripheral wall on the second sealing plate side.

[0014] [8] a first protrusion is formed on an end surface of the first outer peripheral wall on the first sealing plate side; The secondary battery according to [7], wherein the length of the first projections is longer than the length of the second projections in the first direction. [Effects of the Invention]

[0015] According to the present technology, the electrode body can be easily impregnated with an electrolyte. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a front view showing a configuration of a secondary battery according to an embodiment; [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] 7 is a cross-sectional view of a negative electrode plate (a cross-sectional view taken along line VII-VII in FIG. 8). [Figure 8] FIG. [Figure 9] 11 is a cross-sectional view of the positive electrode plate (cross-sectional view taken along line IX-IX in FIG. 10). [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. 10 is a first perspective view showing the configuration of a first spacer. [Figure 14] FIG. 2 is a second perspective view showing the configuration of the first spacer. [Figure 15] FIG. 10 is a perspective view showing the configuration of a second spacer. [Figure 16] 4A and 4B are cross-sectional views comparing the configurations of a first spacer and a second spacer. [Figure 17] FIG. 4 is a schematic diagram showing the configuration around a second spacer. [Figure 18] FIG. 2 is a schematic diagram showing the configuration around a first spacer. [Figure 19] 3 is a flowchart showing a method for manufacturing a secondary battery according to an embodiment. [Figure 20] 1 is a perspective view showing a state in which current collectors are joined to two electrode bodies included in a secondary battery according to one embodiment. [Figure 21] 21 is a cross-sectional view taken along the line XXI-XXI of the electrode body and current collector shown in FIG. 20. [Figure 22] FIG. 10 is a perspective view showing a state in which a spacer is attached to an electrode body. [Figure 23] FIG. 2 is a perspective view showing a state before the electrode body and the spacer are covered with an insulating sheet. [Figure 24] FIG. 10 is a perspective view showing the state after the electrode body and the spacer are covered with an insulating sheet. [Figure 25] 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 26] FIG. 2 is a perspective view showing the configuration of a secondary battery. DETAILED DESCRIPTION OF THE INVENTION

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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).

[0021] 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.

[0022] 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.

[0023] (Overall battery configuration) Fig. 1 is a front view of a secondary battery 1 according to one embodiment. Figs. 2 to 5 are views of 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.

[0024] 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.

[0025] 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 (second sealing plate), and a sealing plate 130 (first sealing plate).

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] As shown in Fig. 3, an opening 113 (second 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.

[0035] A negative electrode terminal 301 is provided on the sealing plate 120 (second sealing plate). The position of the negative electrode terminal 301 can be changed as appropriate.

[0036] 4, an opening 114 (first 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.

[0037] A positive electrode terminal 302 and a liquid inlet 134 are provided on the sealing plate 130 (first sealing plate). The liquid inlet 134 is sealed with a sealing member. The liquid inlet 134 may be of any size that allows the 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 inlet 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 inlet 134 can be changed as appropriate.

[0038] 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.

[0039] The negative electrode terminal 301 (second 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.

[0040] The positive electrode terminal 302 (first 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.

[0041] 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.

[0042] 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.

[0043] The liquid inlet hole 134 is sealed with a sealing member (not shown), which may be, for example, a blind rivet or other metal member.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] (Configuration of electrode body 200) As shown in FIGS. 7 and 8, the negative electrode plate 210, which is the second electrode, has a polarity different from that of the positive electrode plate 240, which is the first electrode. A plurality of negative electrode tabs 230 (second 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 (second electrode tabs) is electrically connected to the second electrode. The length of each of the negative electrode tabs 230 in the protruding direction of the plurality of negative electrode plates 210 is appropriately adjusted 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.

[0054] As shown in FIGS. 9 and 10, a plurality of positive electrode tabs 260 (first 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 (first electrode tabs) is electrically connected to the first 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.

[0055] 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.

[0056] 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.

[0057] (Connection structure between electrode body 200 and current collector 400) 11, the electrode assembly 200 includes a first electrode assembly 201 and a second electrode assembly 202. Each of the first electrode assembly 201 and the second electrode assembly 202 includes a positive electrode (first electrode) and a negative electrode (second electrode). The electrode assembly 200 may be composed of three or more electrode assemblies.

[0058] 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.

[0059] 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.

[0060] The negative electrode tab group 220 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 second 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 second electrode is connected.

[0061] The negative electrode tab group 270 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 second 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 second electrode is connected.

[0062] 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.

[0063] 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.

[0064] Negative electrode current collector 400A includes current collector 410 and current collector 430.

[0065] 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.

[0066] 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. 20 ). 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] A spacer 600 (second spacer 620), which will be described later, is disposed between the sealing plate 120 (second sealing plate) and the main body of the electrode assembly 200 (excluding the negative electrode tab group 220). The spacer 600 is made of an insulating resin material. The second spacer 620 suppresses movement of the electrode assembly 200 in the X direction within the case 100, and suppresses damage to the negative electrode tab groups 220, 270, the electrode assembly 200, and the like. In addition, the second spacer 620 protects the negative electrode tab groups 220, 270 by allowing the negative electrode tab groups 220, 270 to pass through the interior of the second spacer 620.

[0073] 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).

[0074] 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.

[0075] 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.

[0076] The positive electrode tab group 250 (first electrode tab) 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 first 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 first electrode is connected.

[0077] 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 first 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 first electrode is connected.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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. 20 ) described below. The joining point 421 can be formed by, for example, ultrasonic welding, resistance welding, laser welding, crimping, or the like. In the present embodiment, the positive electrode tab groups 250, 280 and the current collector 420 are joined by, for example, ultrasonic welding.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] A spacer 600 (first spacer 610) is disposed between the sealing plate 130 (first sealing plate) and the main body of the electrode assembly 200 (excluding the positive electrode tab groups 250, 280). The first spacer 610 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 first spacer 610 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 first spacer 610.

[0089] 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).

[0090] Between the electrode body 200 and the case body 110, the above-mentioned resin insulating sheet 700 (electrode body holder) is disposed.

[0091] 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.

[0092] The first spacer 610 includes a first base portion 630, a first outer peripheral wall 640, a first inner wall 641, a third inner wall 642, a third base portion 635, a third outer peripheral wall 643, a fifth inner wall 644, and a first connecting portion 650.

[0093] 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 130. The first base portion 630 can be disposed so as to abut against an end surface of the electrode body 200.

[0094] 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 side wall 641, and a third inner side wall 642 of the first base portion 630. In the present embodiment, four first partitions 631 are formed.

[0095] 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.

[0096] 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 first through holes 632.

[0097] 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 130 (first sealing plate) toward the sealing plate 130 (first sealing plate). The first outer peripheral wall 640 is arranged 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.

[0098] The first outer peripheral wall 640 has a substantially rectangular shape when viewed from a direction perpendicular to the first base portion 630. The first outer peripheral wall 640 has a first portion 640A, a second portion 640B, a fifth portion 640C, and a sixth portion 640D. The first portion 640A and the second portion 640B face each other in the short-side direction. The fifth portion 640C and the sixth portion 640D face each other in the long-side direction.

[0099] First portion 640A and second portion 640B are provided so as to intersect with fifth portion 640C and sixth portion 640D. First portion 640A, second portion 640B, fifth portion 640C, and sixth portion 640D are connected to one another.

[0100] The first inner side wall 641 is provided so as to connect the first portion 640A and the second portion 640B of the first outer peripheral wall 640. The third inner side wall 642 is provided so as to connect the fifth portion 640C and the sixth portion 640D of the first outer peripheral wall 640. The first inner side wall 641 and the third inner side wall 642 are each formed so as to pass through an inner region of the first base portion 630 that is away from the outer peripheral edge. The first inner side wall 641 and the third inner side wall 642 are provided so as to intersect with each other.

[0101] First inner side wall 641 and third inner side wall 642 extend from the surface of first base portion 630 facing sealing plate 130 (first sealing plate) toward sealing plate 130 (first sealing plate). First inner side wall 641 and third inner side wall 642 are continuous with first base portion 630, which makes it easy to ensure strength.

[0102] The third base portion 635 is a portion that extends in one plane. The third base portion 635 extends in a substantially rectangular shape on the YZ plane. The third base portion 635 extends so as to face the electrode body 200 and the sealing plate 130. The third base portion 635 is disposed at a distance from the first base portion 630.

[0103] The third base portion 635 has a plurality of third partitions 636. The plurality of third partitions 636 are formed by being separated by a fifth inner wall 644 of the third base portion 635. In the present embodiment, two third partitions 636 are formed.

[0104] A plurality of third through holes 637 are provided in the third base portion 635. The plurality of third through holes 637 penetrate the third base portion 635 in the X direction. Each of the plurality of third through holes 637 has an elongated hole shape.

[0105] The plurality of third through holes 637 are provided in at least the plurality of third partitions 636 of the third base portion 635. It is preferable that at least one of the plurality of third through holes 637 is provided in each of the plurality of third partitions 636. It is also preferable that the plurality of third through holes 637 are provided in each of the plurality of third partitions 636.

[0106] The third outer peripheral wall 643 extends from the outer peripheral edge of the surface of the third base portion 635 facing the sealing plate 130 (first sealing plate) toward the sealing plate 130 (first sealing plate). The third outer peripheral wall 643 is arranged so as to surround the entire outer peripheral edge of the third base portion 635. Therefore, the overall shape of the first spacer 610 has a shape that is recessed toward the electrode body 200 side. Note that the third outer peripheral wall 643 does not necessarily have to be annular, and may have a portion cut out.

[0107] The third outer peripheral wall 643 has a generally rectangular shape when viewed in a direction perpendicular to the third base portion 635. The third outer peripheral wall 643 has a seventh portion 643A and an eighth portion 643B. The seventh portion 643A and the eighth portion 643B face each other in the longitudinal direction.

[0108] Fifth inner wall 644 is provided to connect seventh portion 643A and eighth portion 643B of third outer peripheral wall 643. Fifth inner wall 644 extends from the surface of third base portion 635 facing sealing plate 130 (first sealing plate) toward sealing plate 130 (first sealing plate). Fifth inner wall 644 is continuous with third base portion 635, which makes it easy to ensure strength.

[0109] A plurality of first protrusions 645 are formed on first outer peripheral wall 640 and third outer peripheral wall 643. The plurality of first protrusions 645 protrude toward sealing plate 130 (first sealing plate) in the direction in which first outer peripheral wall 640 and third outer peripheral wall 643 extend from first base portion 630.

[0110] The multiple first protrusions 645 are provided on a longitudinal end (fifth portion 640C) side of first outer peripheral wall 640 and a longitudinal end (seventh portion 643A) side of third outer peripheral wall 643. The multiple first protrusions 645 are formed on the end surfaces of first outer peripheral wall 640 and third outer peripheral wall 643 facing sealing plate 130 (first sealing plate). The number of first protrusions 645 may be one. Furthermore, first protrusion 645 does not necessarily have to be provided on first spacer 610.

[0111] The first connecting portion 650 connects the first base portion 630 and the third base portion 635. The first connecting portion 650 connects the first outer peripheral wall 640 and the third outer peripheral wall 643, thereby connecting the first base portion 630 and the third base portion 635. The first connecting portion 650 is located on one side of the first spacer 610 in the short side direction.

[0112] The first connecting portion 650 has a first curved surface 651. The first curved surface 651 has a shape that is recessed from the upper end side of the outer peripheral wall toward the base portion side.

[0113] The first curved surface 651 faces the curved portion 251 of the positive electrode tab group 250. As a result, the first curved surface 651 follows the curved portion 251.

[0114] A first cutout portion 652 is formed in the first spacer 610. The first cutout portion 652 is surrounded by the first base portion 630, the third base portion 635, and the first connecting portion 650.

[0115] The electrode tabs can be inserted into the first cutout portions 652 through the first cutout portions 652. As a result, the positive electrode tab groups 250, 280 (first electrode tabs) are arranged between the first base portion 630 and the third base portion 635.

[0116] When the positive electrode tab group 250, 280 is inserted into the first cutout portion 652, the curved portion 251 of the electrode tab fits along the first curved surface 651, thereby suppressing deformation of the curved portion 251. The first cutout portion 652 is disposed at a position facing the first curved surface 651 in the short direction. This makes it easy to fit the curved portion 251 along the first curved surface 651 when placing the positive electrode tab group 250 inside the first cutout portion 652 from the first cutout portion 652.

[0117] The above-described first base portion 630 and third base portion 635 are located on the end face side of the electrode body 200. The first base portion 630 and third base portion 635 may or may not abut against the end face of the electrode body 200. When the first base portion 630 and the third base portion 635 do not abut against the end face of the electrode body 200, the shortest distance from the first base portion 630 and the third base portion 635 to the electrode body 200 is preferably within 2 mm, and more preferably within 1 mm.

[0118] The area of ​​first base portion 630 is preferably larger than the area of ​​third base portion 635. In the X direction, it is preferable that the portion of first base portion 630 or third base portion 635 where no through-hole is provided faces liquid injection hole 134. This makes it possible to suppress damage to the electrode body caused by the electrolyte solution being jetted when the electrolyte solution is injected.

[0119] 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 first spacer 610 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 first spacer 610 is also wrapped in the insulating sheet 700, making the outer dimensions of the first spacer 610 smaller than those of the electrode body 200 can improve the ease of insertion of the electrode body 200 into the case body 110.

[0120] The thickness in the X direction of first base portion 630 and third base portion 635 is, for example, preferably 0.1 mm or more, more preferably 1 mm or more, and more preferably 0.6 mm or more. The thickness in the YZ plane of first outer peripheral wall 640 and third outer peripheral wall 643 is preferably 0.15 mm or more, more preferably 2 mm or more, and more preferably 0.6 mm or more. The height in the X direction of first outer peripheral wall 640 and third outer peripheral wall 643 is preferably 6 mm or more, more preferably 15 mm or more, and more preferably 12 mm or more.

[0121] 15, the second spacer 620 has a longitudinal direction and a lateral direction. The longitudinal direction is along the Z direction. The lateral direction is along the Y direction.

[0122] The second spacer 620 is disposed between the sealing plate 120 (second sealing plate) and the electrode body 200 (see FIG. 11). Similar to the first spacer 610, the second spacer 620 insulates the electrode body 200 from the case 100.

[0123] 15, the second spacer 620 has the same basic structure as the first spacer 610. The second spacer 620 differs from the first spacer 610 in that the height of the second spacer 620 in the X direction is lower than the height of the first spacer 610.

[0124] The second spacer 620 includes a second base portion 660, a second outer peripheral wall 670, a second inner wall 671, a fourth inner wall 672, a fourth base portion 665, a fourth outer peripheral wall 673, a sixth inner wall 674, and a second connecting portion 680.

[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 120. 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 second outer peripheral wall 670, a second inner wall 671, and a fourth inner wall 672 of the second base portion 660. In the present embodiment, four second partitions 661 are formed.

[0127] 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 the multiple second through holes 662 are provided in each of the multiple second partitions 661.

[0129] 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 (second sealing plate) toward the sealing plate 120 (second sealing plate). The second outer peripheral wall 670 is arranged so as to surround the entire outer peripheral edge of the second base portion 660. Therefore, the overall shape of the second spacer 620 has a shape that is recessed toward the electrode body 200 side. Note that the second outer peripheral wall 670 does not necessarily have to be annular, and may have a portion cut out.

[0130] The second outer peripheral wall 670 has a substantially rectangular shape when viewed from a direction perpendicular to the second base portion 660. The second outer peripheral wall 670 has a third portion 670A, a fourth portion 670B, a ninth portion 670C, and a tenth portion 670D. ​​The third portion 670A and the fourth portion 670B face each other in the short-side direction. The ninth portion 670C and the tenth portion 670D face each other in the long-side direction.

[0131] The third portion 670A and the fourth portion 670B are provided so as to intersect with the ninth portion 670C and the tenth portion 670D. ​​The third portion 670A, the fourth portion 670B, the ninth portion 670C, and the tenth portion 670D are connected to one another.

[0132] The second inner wall 671 is provided to connect the third portion 670A and the fourth portion 670B of the second outer peripheral wall 670. The fourth inner wall 672 is provided to connect the ninth portion 670C and the tenth portion 670D of the second outer peripheral wall 670. The second inner wall 671 and the fourth inner wall 672 are each formed to pass through an inner region of the second base portion 660 that is away from the outer peripheral edge. The second inner wall 671 and the fourth inner wall 672 are provided to intersect with each other.

[0133] Second inner side wall 671 and fourth inner side wall 672 extend from the surface of second base portion 660 facing sealing plate 120 (second sealing plate) toward sealing plate 120 (second sealing plate). Because second inner side wall 671 and fourth inner side wall 672 are continuous with second base portion 660, strength can be more easily ensured compared to when second inner side wall 671 and fourth inner side wall 672 are provided with a gap from second base portion 660.

[0134] The fourth base portion 665 is a portion that extends in one plane. The fourth base portion 665 extends in a substantially rectangular shape on the YZ plane. The fourth base portion 665 extends so as to face the electrode body 200 and the sealing plate 120. The fourth base portion 665 is disposed apart from the second base portion 660.

[0135] The fourth base portion 665 has a plurality of fourth partitions 666. The plurality of fourth partitions 666 are formed by being separated by a sixth inner wall 674 of the fourth base portion 665. In the present embodiment, two fourth partitions 666 are formed.

[0136] A plurality of fourth through holes 667 are provided in the fourth base portion 665. The plurality of fourth through holes 667 penetrate the fourth base portion 665 in the X direction. Each of the plurality of fourth through holes 667 has an elongated hole shape.

[0137] The multiple fourth through holes 667 are provided in at least the multiple fourth partitions 666 of the fourth base portion 665. It is preferable that at least one of the multiple fourth through holes 667 is provided in each of the multiple fourth partitions 666. It is also preferable that the multiple fourth through holes 667 are provided in each of the multiple fourth partitions 666.

[0138] The fourth outer peripheral wall 673 extends from the outer peripheral edge of the surface of the fourth base portion 665 facing the sealing plate 120 (second sealing plate) toward the sealing plate 120 (second sealing plate). The fourth outer peripheral wall 673 is arranged so as to surround the entire outer peripheral edge of the fourth base portion 665. Therefore, the overall shape of the second spacer 620 has a shape that is recessed toward the electrode body 200 side. Note that the fourth outer peripheral wall 673 does not necessarily have to be annular, and may have a portion cut out.

[0139] The fourth outer peripheral wall 673 has a generally rectangular shape when viewed from a direction perpendicular to the fourth base portion 665. The fourth outer peripheral wall 673 has an eleventh portion 673A and a twelfth portion 673B. The eleventh portion 673A and the twelfth portion 673B face each other in the longitudinal direction.

[0140] The sixth inner wall 674 is provided so as to connect the eleventh portion 673A and the twelfth portion 673B of the fourth outer peripheral wall 673. The sixth inner wall 674 extends from the surface of the fourth base portion 665 facing the sealing plate 120 (second sealing plate) toward the sealing plate 120 (second sealing plate). Because the sixth inner wall 674 is continuous with the fourth base portion 665, it is easier to ensure strength compared to when the sixth inner wall 674 is provided with a gap between it and the fourth base portion 665.

[0141] A plurality of second protrusions 675 are formed on second outer peripheral wall 670 and fourth outer peripheral wall 673. The plurality of second protrusions 675 protrude toward sealing plate 120 (second sealing plate) in the direction in which second outer peripheral wall 670 and fourth outer peripheral wall 673 extend from second base portion 660.

[0142] The multiple second protrusions 675 are provided on a longitudinal end (ninth portion 670C) side of second outer peripheral wall 670 and a longitudinal end (eleventh portion 673A) side of fourth outer peripheral wall 673. The multiple second protrusions 675 are formed on the end surfaces of second outer peripheral wall 670 and fourth outer peripheral wall 673 facing sealing plate 120 (second sealing plate). The number of second protrusions 675 may be one. Furthermore, second protrusion 675 does not necessarily have to be provided on second spacer 620.

[0143] The second connecting portion 680 connects the second base portion 660 and the fourth base portion 665. The second connecting portion 680 connects the second outer peripheral wall 670 and the fourth outer peripheral wall 673, thereby connecting the second base portion 660 and the fourth base portion 665. The second connecting portion 680 is located on one side of the second spacer 620 in the short side direction.

[0144] The second connecting portion 680 has a second curved surface 681. The second curved surface 681 has a shape that is recessed from the upper end side of the outer peripheral wall toward the base portion side.

[0145] The second curved surface 681 faces the curved portion 221 of the negative electrode tab group 220. As a result, the second curved surface 681 follows the curved portion 221.

[0146] The second spacer 620 has a second cutout 682. The second cutout 682 is surrounded by the second base portion 660, the fourth base portion 665, and the second connecting portion 680.

[0147] The electrode tabs can be inserted into the second cutout portions 682 through the second cutout portions 682. As a result, the negative electrode tab groups 220, 270 (second electrode tabs) are arranged between the second base portion 660 and the fourth base portion 665.

[0148] When the negative electrode tab groups 220, 270 are inserted into the second cutout portions 682, the curved portions 221 of the electrode tabs fit along the second curved surface 681, thereby suppressing deformation of the curved portions 221. The second cutout portions 682 are disposed at positions facing the second curved surface 681 in the short direction. This makes it easy to align the curved portions 221 with the second curved surface 681 when disposing the negative electrode tab groups 220, 270 inside the second cutout portions 682 from the second cutout portions 682.

[0149] The second base portion 660 and the fourth base portion 665 described above are located on the end face side of the electrode body 200. The second base portion 660 and the fourth base portion 665 may or may not abut the end face of the electrode body 200. When the second base portion 660 and the fourth base portion 665 do not abut the end face of the electrode body 200, the shortest distance from the second base portion 660 and the fourth base portion 665 to the electrode body 200 is preferably within 2 mm, and more preferably within 1 mm. The area of ​​the second base portion 660 is preferably larger than the area of ​​the fourth base portion 665.

[0150] The outer shape of the second spacer 620 is shaped to follow the outer shape of the electrode body 200 in the X direction. The outer dimensions of the second spacer 620 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 second spacer 620 is also wrapped in the insulating sheet 700, making the outer dimensions of the second spacer 620 smaller than those of the electrode body 200 can improve the ease of insertion of the electrode body 200 into the case body 110.

[0151] The thickness of second base portion 660 and fourth base portion 665 in the X direction is, for example, preferably 0.1 mm or more, more preferably 1 mm or more, and more preferably 0.6 mm or more. The thickness of second outer peripheral wall 670 and fourth outer peripheral wall 673 in the YZ plane is preferably 0.15 mm or more, more preferably 2 mm or more, and more preferably 0.6 mm or more. The height of second outer peripheral wall 670 and fourth outer peripheral wall 673 in the X direction is preferably 6 mm or more, more preferably 15 mm or more, and more preferably 12 mm or more.

[0152] 16, the first direction is a direction perpendicular to the sealing plate 130 (first sealing plate). Specifically, the first direction is a direction perpendicular to the end face of the sealing plate 130 that faces the first spacer 610.

[0153] The first spacer 610 has a length D1 from the end face P1 of the base on the electrode body side to the tip T1 of the first protrusion, and the second spacer 620 has a length D2 from the end face P2 of the base on the electrode body side to the tip T2 of the second protrusion.

[0154] In the first direction (X direction), the length D2 of the second spacer 620 is shorter than the length D1 of the first spacer 610. In this embodiment, the ratio of the length D1 of the first spacer 610 to the length D2 of the second spacer 620 can be, for example, D1:D2=1.5 to 2:1.

[0155] When the secondary battery 1 is arranged with the first direction (X direction) as the vertical direction, the electrode assembly 200 is arranged above the second spacer 620. The second spacer 620 supports the electrode assembly 200 from below. In this case, by making the length D2 of the second spacer 620 shorter than the length D1 of the first spacer 610, the installation height of the electrode assembly 200 in the case 100 can be made lower than when the first spacer 610 and the second spacer 620 have the same length.

[0156] As shown in FIG. 17, second protrusion 675 of second spacer 620 in this embodiment abuts against sealing plate 120 (second sealing plate).

[0157] When the second spacer 620 supports the electrode assembly 200 from below with the first direction (X direction) as the vertical direction, the second protrusion 675 abuts against the sealing plate 120 (second sealing plate), so that the electrode assembly 200 can be reliably supported by the second spacer 620. This makes it possible to more effectively prevent damage to the negative electrode tab group 220 and the negative electrode tab group 270.

[0158] As shown in FIG. 18, first protrusion 645 of first spacer 610 in this embodiment is disposed with a gap G from sealing plate 130 (first sealing plate).

[0159] Since the first protrusion 645 is arranged with a gap G in the sealing plate 130 (first sealing plate), the electrolyte inside the first spacer 610 can be easily discharged to the outside of the first spacer 610, thereby preventing the electrolyte from accumulating inside the first spacer 610.

[0160] As shown in Fig. 18, first protrusions 645 have a length D3 from the end of the outer peripheral wall to the tip. As shown in Fig. 17, second protrusions 675 have a length D4 from the end of the outer peripheral wall to the tip. In the first direction (X direction), length D3 of first protrusions 645 is longer than length D4 of second protrusions 675. This makes it easier to ensure a large gap between sealing plate 130 and first spacer 610. In the present embodiment, the ratio of length D3 of first protrusions 645 to length D4 of second protrusions 675 is preferably, for example, D3:D4 = 1.2 to 1.5:1.

[0161] (Manufacturing process of secondary battery 1) A method for manufacturing a secondary battery according to this embodiment will be described below.

[0162] 19, 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.

[0163] 19 to 21, 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] 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. 20 and 21) 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.

[0168] "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.

[0169] 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.

[0170] As shown in FIGS. 19, 22, and 23, the spacer 600 and the insulating sheet 700 are assembled to the electrode body 200 (step S5).

[0171] 22 , a first spacer 610 is illustrated, and the first spacer 610 is assembled to the electrode assembly 200. The first spacer 610 is assembled to the electrode assembly 200 so that the positive electrode tab groups 250, 280 are housed inside the first cutout portions 652. Because the electrode tabs can be inserted into the first spacer 610 through the first cutout portions 652, 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.

[0172] The second spacer 620 is also assembled to the electrode assembly 200 by accommodating the negative electrode tab groups 220 and 270 into the second cutout portions 682 through the second cutout portions 682 .

[0173] 23 , 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.

[0174] 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.

[0175] The insulating sheet 700 is welded to the spacer 600. The insulating sheet 700 is welded 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.

[0176] As shown in FIG. 24 , the insulating sheet in this embodiment covers the entire axial circumference of the electrode assembly and the 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, which is substantially rectangular (flat), 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 respectively formed. The first protrusions 645 and the second protrusions 675 provided on the spacer 600 are preferably exposed from the insulating sheet 700.

[0177] 19 and 24, 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.

[0178] 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.

[0179] 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.

[0180] 25, the spacer 600 and the electrode assembly 200 are then inserted into the case body 110 through the opening 113, with the current collector 420 side first (step S7). In this way, the electrode assembly 200 is placed inside the case 100.

[0181] 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.

[0182] 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.

[0183] 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.

[0184] 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).

[0185] 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.

[0186] 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.

[0187] As shown in FIG. 26, 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).

[0188] 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.

[0189] 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.

[0190] 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.

[0191] Next, in the vertical direction, sealing plate 130 (first sealing plate) is positioned higher than sealing plate 120 (second sealing plate), and with second spacer 620 positioned below electrode body 200, electrolyte is poured into case 100 through the pouring hole provided in sealing plate 130 (first sealing plate) (step S11). The vertical direction is the first direction (X direction) in which electrode body 200, first sealing plate, and second sealing plate are aligned.

[0192] When injecting the electrolyte, it is preferable to inject the electrolyte while the outer surface of the sealing plate is tilted vertically at an angle of ±30° or less with respect to the horizontal, and it is more preferable to inject the electrolyte while the outer surface is tilted at an angle of ±15° or less with respect to the horizontal.

[0193] 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 second spacer 620 can support the electrode assembly 200.

[0194] Thereafter, degassing charging is performed. During degassing charging, the liquid injection hole 134 may be temporarily sealed. After the injection of the electrolyte solution and other steps are completed, the liquid injection hole 134 is sealed with a sealing member (not shown). Through the above steps, the secondary battery 1 is completed.

[0195] In the secondary battery 1 according to an embodiment of the present technology, the length D2 of the second spacer 620, which is disposed on the opposite side of the sealing plate 130 (first sealing plate) where the liquid injection hole 134 is disposed, is made shorter than the length D1 of the first spacer 610. This makes it possible to lower the installation height of the electrode assembly 200 in the case 100 when the second spacer 620 is disposed below the electrode assembly 200 in the vertical direction, compared to when the first spacer 610 and the second spacer 620 have the same length. This makes it possible to increase the proportion of the electrode assembly 200 immersed in the electrolyte when the electrolyte is injected into the case 100, thereby making it possible to easily impregnate the electrode assembly 200 with the electrolyte. Consequently, it is possible to provide a highly reliable secondary battery 1.

[0196] In the secondary battery 1 according to an embodiment of the present technology, by providing the first outer peripheral wall 640 to the first spacer 610, the first spacer 610 has a three-dimensional structure, which makes it easier to ensure the strength of the first spacer 610 compared to when the first spacer is composed of only a base portion. This makes it possible to efficiently suppress damage to the electrode tab or the electrode body 200.

[0197] In a secondary battery 1 according to one embodiment of the present technology, by providing a first inner wall 641 on the first spacer 610, deformation of the first spacer 610 can be suppressed compared to when the first inner wall 641 is not provided.

[0198] In a secondary battery 1 according to one embodiment of the present technology, a first protrusion 645 is formed on the end face of the first outer wall 640 of the first spacer 610 on the sealing plate 130 side of the first outer wall 640, thereby forming a gap between the sealing plate 130 and the first outer wall 640, thereby making it easier for the electrolyte inside the first spacer 610 to move to the outside of the first spacer 610.

[0199] In the secondary battery 1 according to an embodiment of the present technology, by providing the second outer peripheral wall 670 to the second spacer 620, the second spacer 620 has a three-dimensional structure, which makes it easier to ensure the strength of the second spacer 620 compared to when the second spacer is composed of only a base portion. This makes it possible to efficiently suppress damage to the electrode tab or the electrode body 200.

[0200] In the secondary battery 1 according to one embodiment of the present technology, by providing the second inner wall 671 on the second spacer 620, deformation of the second spacer 620 can be suppressed compared to when the second inner wall 671 is not provided.

[0201] In a secondary battery 1 according to one embodiment of the present technology, a second protrusion 675 is formed on the end face of the second outer peripheral wall 670 of the second spacer 620 on the sealing plate 130 side of the second outer peripheral wall 670, thereby forming a gap between the sealing plate 130 and the second outer peripheral wall 670, thereby making it easier for the electrolyte inside the second spacer 620 to move to the outside of the second spacer 620.

[0202] In secondary battery 1 according to an embodiment of the present technology, by making length D3 of first protrusion 645 in the first direction (X direction) longer than length D4 of second protrusion 675, it is possible to increase the gap between first spacer 610 and sealing plate 130 (first sealing plate) compared to second spacer 620. This makes it easier to discharge the electrolyte inside first spacer 610 to the outside of first spacer 610 when pouring electrolyte into case 100 with first spacer 610 arranged above first spacer 610, thereby preventing the electrolyte from accumulating inside first spacer 610.

[0203] 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]

[0204] 1 secondary battery, 100 case, 110 case body, 111 first side portion, 112, 112A, 112B second side portion, 113, 114 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 portion, 206 second end portion, 207 third end portion, 208 fourth end portion, 210 negative electrode plate, 211 negative electrode core body, 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 body, 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 portion, 460 Plate, 470, 510, 520, 530 Insulating member, 600 Spacer, 610 First spacer, 620 Second spacer, 630 First base portion, 631 First partition portion, 632 First through-hole, 635 Third base portion, 636 Third partition portion, 637 Third through-hole, 640 First outer peripheral wall, 640A First portion, 640B Second portion, 640C Fifth portion, 640D Sixth portion, 641 First inner wall, 642 Third inner wall, 643 Third outer peripheral wall, 643A Seventh portion, 643B Eighth portion, 644 Fifth inner wall, 645 First protrusion, 650 First connecting portion, 651 First curved surface, 652 First notch portion, 660 Second base portion, 661 Second partition portion, 662 Second through hole, 665 Fourth base portion, 666 Fourth partition portion, 667 Fourth through hole, 670 Second outer peripheral wall, 670A Third portion, 670B Fourth portion, 670C Ninth portion, 670D Tenth portion, 671 Second inner wall, 672 Fourth inner wall, 673 Fourth outer peripheral wall, 673A Eleventh portion, 673B Twelfth portion, 674 Sixth inner wall, 675 second protrusion, 680 second connecting portion, 681 second curved surface, 682 second 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; a second spacer is disposed between the second sealing plate and the electrode body; The first sealing plate has a liquid injection hole, the liquid injection hole is sealed with a sealing member; a length of the second spacer in a first direction perpendicular to the first sealing plate, the length of the second spacer being shorter than the length of the first spacer;

2. The first spacer is a first base portion; The secondary battery according to claim 1 , further comprising: 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.

3. the first outer peripheral wall has a first portion and a second portion opposed to each other, The secondary battery according to claim 2 , wherein the first spacer includes a first inner wall provided to connect the first portion and the second portion of the first outer peripheral wall.

4. 4. The secondary battery according to claim 2, wherein a first protrusion is formed on the first outer peripheral wall at an end surface of the first outer peripheral wall facing the first sealing plate.

5. The second spacer is A second base portion; 4. The secondary battery according to claim 2, further comprising: a second outer peripheral wall extending from an outer peripheral edge of a surface of the second base portion facing the second sealing plate toward the second sealing plate.

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

7. The secondary battery according to claim 5 , wherein the second outer peripheral wall has a second protrusion formed on an end surface of the second outer peripheral wall facing the second sealing plate.

8. a first protrusion is formed on an end surface of the first outer peripheral wall on the first sealing plate side; The secondary battery according to claim 7 , wherein a length of the first protrusions is longer than a length of the second protrusions in the first direction.

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