Secondary battery and method for manufacturing secondary battery

Abstract

To provide a secondary battery which can be manufactured efficiently and stably and a method for manufacturing a secondary battery.SOLUTION: In a secondary battery 1, a case body 110 has a first opening 111 in one end part and a second end part 112 in the other end part. The first opening 111 is sealed by a first sealing plate 121. The second opening 112 is sealed by a second sealing plate 122. A first through-hole 141 is provided in a region closer to the second opening 112 side than an edge part on the second opening 112 side of the electrode body 200 and the first through-hole 141 is sealed by a first sealing member 701. With that structure, the secondary battery 1 can be manufactured more efficiently and more stably.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

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

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

[0004] By forming a rectangular battery with a positive terminal on one side of the battery case and a negative terminal on the other end, it is easy to form a low-height assembled battery. However, there is room for further improvement in order to produce a battery that can be manufactured efficiently and stably.

[0005] An object of the present technology is to provide a secondary battery that can be produced efficiently and stably, and a method for producing a secondary battery. [Means for solving the problem]

[0006] The present technology provides the following secondary battery and method for manufacturing the secondary battery.

[0007] [1] A secondary battery comprising: a first electrode, a second electrode having a polarity different from that of the first electrode, an electrode body disposed between the first electrode and the second electrode and including a separator, and an exterior body that accommodates the electrode body and an electrolyte, wherein the exterior body includes 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, and a second sealing plate that seals the second opening, wherein the first sealing plate is provided with a first electrode terminal electrically connected to the first electrode, the second sealing plate is provided with a second electrode terminal electrically connected to the second electrode, a first electrode tab group electrically connected to the first electrode is provided at one end of the electrode body, and a second electrode tab group electrically connected to the second electrode is provided at the other end of the electrode body, and a first through hole is provided in the case body in a region closer to the second opening side than the end of the electrode body on the second opening side, and the first through hole is sealed with a first sealing member.

[0008] [2] The secondary battery described in [1], wherein a second through hole is provided in the case body in a region closer to the first opening side than the end of the electrode body on the first opening side, and the second through hole is sealed with a second sealing member.

[0009] [3] The secondary battery according to [1] or [2], wherein D2>D1 satisfies the relationship D1 between the first sealing plate and an end of the electrode body facing the first sealing plate, and D2 satisfies the relationship D2>D1 between the second sealing plate and an end of the electrode body facing the second sealing plate.

[0010] [4] A battery comprising: a first electrode; a second electrode having a polarity different from that of the first electrode; an electrode assembly arranged between the first electrode and the second electrode and including a separator; and an exterior housing for accommodating the electrode assembly and an electrolyte, wherein the exterior housing includes a case body having a first opening at one end and a second opening at the other end, a first sealing plate for sealing the first opening, and a second sealing plate for sealing the second opening, wherein the first sealing plate is provided with a first electrode terminal electrically connected to the first electrode, and the second sealing plate is provided with a second electrode terminal electrically connected to the second electrode. a first electrode tab group electrically connected to the first electrode is provided at one end of the electrode body, and a second electrode tab group electrically connected to the second electrode is provided at the other end of the electrode pair, and a first through hole is provided in the case body in a region closer to the second opening side than the end of the electrode body on the second opening side, and the first through hole is sealed with a first sealing member, the method for manufacturing a secondary battery having such a configuration includes the steps of: injecting an electrolyte solution into the outer casing from the first through hole; and sealing the first through hole with the first sealing member. Effect of the Invention

[0011] According to the present technology, it is possible to provide a secondary battery that can be produced efficiently and stably, and a method for producing a secondary battery. [Brief description of the drawings]

[0012] [Figure 1] FIG. [Diagram 2] 2 is a diagram showing the secondary battery shown in FIG. 1 as viewed from the direction of arrow II. [Diagram 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. [Diagram 5] 2 is a front cross-sectional view of the secondary battery shown in FIG. [Figure 6] FIG. 2 is a front view showing a negative electrode original plate before the negative electrode plate is formed. [Figure 7] 7 is a cross-sectional view taken along the line VII-VII of the negative electrode original plate shown in FIG. 6. [Figure 8] FIG. 2 is a front view showing a negative electrode plate formed from the negative electrode original plate. [Figure 9] FIG. 2 is a front view showing a positive electrode original plate before the positive electrode plate is formed. [Figure 10] 10 is a cross-sectional view taken along the line XX in FIG. 9 . [Figure 11] FIG. 2 is a front view showing a positive electrode plate formed from a positive electrode original plate. [Figure 12] FIG. 2 is a diagram showing an electrode assembly and a current collector taken out from a secondary battery. [Figure 13] FIG. 4 is a diagram showing a connection structure between a negative electrode tab group and a negative electrode current collector. [Figure 14] FIG. 14 is a front view of the connection structure shown in FIG. [Figure 15] FIG. 14 is a cross-sectional view of the connection structure shown in FIG. [Figure 16] 11A to 11C are diagrams showing a process of inserting the electrode body into the case body. [Figure 17] 11A to 11C are views showing a step of providing a spacer between the first sealing plate and the electrode body. [Figure 18] 11 is a cross-sectional view showing a state in which a spacer is provided between the first sealing plate and the electrode body. FIG. [Figure 19] FIG. 13 is a diagram showing a modified example of the spacer. [Figure 20] 11A and 11B are diagrams showing an example of a mechanism for pressing an electrode body via a first sealing plate and a spacer. [Figure 21] 21 is a diagram showing the mechanism shown in FIG. 20 as viewed from the Z-axis direction. FIG. [Figure 22] FIG. 13 is a perspective view of a spacer of another embodiment. [Figure 23] FIG. 13 is a perspective view of a spacer of another embodiment. [Figure 24] FIG. 13 is a perspective view of a spacer of another embodiment. [Diagram 25] FIG. 2 is a flow chart showing each step of a method for producing a secondary battery. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 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 will not be repeated.

[0014] In the embodiments described below, when referring to the number, amount, etc., the scope of the present technology is not necessarily limited to the number, amount, etc., unless otherwise specified. In addition, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. In addition, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiment.

[0015] In this specification, the words "comprise", "include" and "have" are open-ended, i.e., when a certain configuration is included, other configurations may or may not be included.

[0016] Furthermore, 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 one state, and the relative positional relationships can be inverted or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0017] In this specification, the term "battery" is not limited to lithium ion batteries, but may include other batteries such as nickel-metal hydride batteries and sodium ion batteries. In this specification, the term "electrode" may collectively refer to positive and negative electrodes. In addition, the term "electrode plate" may collectively refer to positive and negative plates.

[0018] (Overall battery configuration) Fig. 1 is a front view of a secondary battery 1 according to the present embodiment. Figs. 2 to 4 are views of the secondary battery 1 shown in Fig. 1 as viewed from the directions of arrows II, III, and IV, respectively. Fig. 5 is a front cross-sectional view of the secondary battery 1 shown in Fig. 1.

[0019] 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 on a vehicle.

[0020] 1 to 5, the secondary battery 1 includes an exterior body 100, an electrode assembly 200, and a current collector 300. The exterior body 100 includes a case main body 110, a first sealing plate 121, and a second sealing plate 122.

[0021] In this specification, the X-axis direction (first direction) shown in Figs. 1 to 5 may be referred to as the "width direction" of the secondary battery 1 or the case body 110, the Y-axis direction (second direction) may be referred to as the "thickness direction" of the secondary battery 1 or the case body 110, and the Z-axis direction (third direction) may be referred to as the "height direction" of the secondary battery 1 or the case body 110. In addition, in the description of this disclosure, the Z-axis direction is assumed to coincide with the vertical direction. Therefore, in the secondary battery 1 shown in Fig. 1, the upper side of the figure is vertically upward, and the lower side of the figure is vertically downward. Therefore, Fig. 2 shows the state as viewed from the bottom.

[0022] When configuring an assembled battery including the 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-axis direction) by a restraining member to form a battery module, or the assembled battery may be directly supported on the side surface of a battery pack case without using a restraining member.

[0023] 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.

[0024] 1 and 2, a first sealing plate 121 and a second sealing plate 122 are provided at both ends of the case body. The case body 110 can be formed into a square tube shape, for example, by abutting the edges of bent plate-like members (joint 110A shown in FIG. 2) and joining them together (for example, by laser welding). The corners of the "square tube" may have a rounded shape.

[0025] In this embodiment, the case body 110 is formed to be longer in the width direction (X-axis direction) of the secondary battery 1 than in the thickness direction (Y-axis direction) and height direction (Z-axis direction) of the secondary battery 1. Thus, a pair of opposing first walls 110Y are defined by the illustrated surface and the surface on the opposite side, and a pair of opposing second walls 110Z are defined by the illustrated upper surface and lower surface, with the area of ​​the pair of first walls 110Y being larger than the area of ​​the pair of second walls 110Z.

[0026] The dimension (width) of the case body 110 in the X-axis direction is preferably about 30 cm or more. This allows a relatively large (high capacity) secondary battery 1 to be constructed. The dimension (height) of the case body 110 in the Z-axis 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 a relatively low height secondary battery 1 to be constructed, improving the mountability in a vehicle, for example.

[0027] 3, a first opening 111 is provided at one end of the case body 110. The first opening 111 is sealed by a first sealing plate 121. A negative electrode terminal 131 (first electrode terminal) and a gas exhaust valve 151 are provided on the first sealing plate 121. The positions of the negative electrode terminal 131 and the gas exhaust valve 151 can be changed as appropriate. The first opening 111 and the first sealing plate 121 have a substantially rectangular shape with the Y-axis direction as the short side direction and the Z-axis direction as the long side direction.

[0028] 4, a second opening 112 is provided at one end of the case body 110. The second opening 112 is sealed by a second sealing plate 122. A positive electrode terminal 132 (second electrode terminal) and a gas exhaust valve 152 are provided on the second sealing plate 122. The positions of the positive electrode terminal 132 and the gas exhaust valve 152 can be changed as appropriate. The second opening 112 and the second sealing plate 122 have a substantially rectangular shape with the Y-axis direction as the short side direction and the Z-axis direction as the long side direction.

[0029] First sealing plate 121 and second sealing plate 122 are made of metal. Specifically, first sealing plate 121 and second sealing plate 122 are made of aluminum, an aluminum alloy, iron, an iron alloy, or the like.

[0030] The negative electrode terminal 131 is electrically connected to the negative electrode of the electrode assembly 200. The positive electrode terminal 132 is electrically connected to the positive electrode of the electrode assembly 200.

[0031] The negative electrode terminal 131 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 131 may be provided with a portion or layer made of aluminum or an aluminum alloy.

[0032] The positive electrode terminal 132 is made of a conductive material (more specifically, a metal), and may be made of, for example, aluminum or an aluminum alloy.

[0033] Gas exhaust valves 151 and 152 break when the pressure inside exterior body 100 reaches or exceeds a predetermined value, and exhaust gas inside exterior body 100 to the outside.

[0034] The electrode body 200 is a flat-shaped electrode body having a positive electrode plate and a negative electrode plate, which will be described later. Specifically, the electrode body 200 is a wound-type electrode body in which a band-shaped positive electrode plate and a band-shaped negative electrode plate are both wound via a band-shaped separator (not shown). However, in this specification, the "electrode body" is not limited to a wound-type electrode body, and may be a laminated electrode body in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately laminated. The electrode body may include a plurality of positive electrode plates and a plurality of negative electrode plates, and the positive electrode tabs provided on each positive electrode plate may be laminated to form a positive electrode tab group, or the negative electrode tabs provided on each negative electrode plate may be laminated to form a negative electrode tab group.

[0035] In this embodiment, a first through hole 141 and a second through hole 142 are provided on the second wall 110Z side of the illustrated upper surface side of the case body 110. The first through hole 141 is sealed by a first sealing member 701. The second through hole 142 is sealed by a second sealing member 702. The first sealing member 701 and the second sealing member 702 can be fixed to the case body 110 by crimping using, for example, blind rivets or other metal members. The first sealing member 701 and the second sealing member 702 may also be fixed to the case body 110 by welding.

[0036] As will be described later in the "Manufacturing Process of Secondary Battery 1", when the first through hole 141 is used as an electrolyte injection hole, the second through hole 142 functions as a gas (air) vent hole in the case body 110. On the other hand, when the second through hole 142 is used as an electrolyte injection hole, the first through hole 141 functions as an exhaust hole for gas (air) in the case body 110.

[0037] 5, the exterior body 100 houses the electrode body 200. The electrode body 200 is housed in the exterior body 100 so that the winding axis of the electrode body 200 is parallel to the X-axis direction.

[0038] Specifically, one or more wound electrode bodies are housed together with an electrolytic solution (electrolyte) (not shown) inside an insulating sheet 600 (described later) arranged in the exterior housing 100. As the electrolytic solution (non-aqueous electrolytic solution), for example, LiPF6 dissolved at a concentration of 1.2 mol / L in a non-aqueous solvent in which ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) are mixed in a volume ratio (25°C) of 30:30:40 can be used. Note that a solid electrolyte may be used instead of the electrolytic solution.

[0039] The electrode body 200 includes a negative electrode tab group 210A (first electrode tab group) provided at an end (first end) on the first sealing plate 121 side, and a positive electrode tab group 220A (second electrode tab group) provided at an end (second end) on the second sealing plate 122 side. The negative electrode tab group 210A and the positive electrode tab group 220A are connected to the negative electrode and the positive electrode of the electrode body 200, respectively. The negative electrode tab group 210A and the positive electrode tab group 220A are formed so as to protrude from a main body portion (a portion where a positive electrode plate and a negative electrode plate are laminated with a separator interposed therebetween) of the electrode body 200 toward the first sealing plate 121 and the second sealing plate 122. As a result, the negative electrode tab group 210A and the positive electrode tab group 220A are arranged such that their respective main surfaces face the pair of first walls 110Y, and their respective end side surfaces face the pair of second walls 110Z.

[0040] The current collector 300 includes a negative electrode current collector 310 (first current collector) and a positive electrode current collector 320 (second current collector). The negative electrode current collector 310 and the positive electrode current collector 320 are each made of a plate-shaped member. The electrode body 200 is electrically connected to the negative electrode terminal 131 and the positive electrode terminal 132 via the current collector 300.

[0041] The negative electrode current collector 310 is disposed on the first sealing plate 121 via a resin insulating member. The negative electrode current collector 310 is electrically connected to the negative electrode tab group 210A and the negative electrode terminal 131. The negative electrode current collector 310 is made of a conductive material (more specifically, a metal), and may be made of, for example, copper or a copper alloy.

[0042] The positive electrode current collector 320 is disposed on the second sealing plate 122 via a resin insulating member. The positive electrode current collector 320 is electrically connected to the positive electrode tab group 220A and the positive electrode terminal 132. The positive electrode current collector 320 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 220A may be electrically connected to the second sealing plate 122 directly or via the positive electrode current collector 320. In this case, the second sealing plate 122 may also serve as the positive electrode terminal 123.

[0043] If the distance between the first sealing plate 121 and the end of the electrode body 200 on the first sealing plate 121 side is D1, and the distance between the second sealing plate 122 and the end of the electrode body 200 on the second sealing plate 122 side is D2, then the relationship is D2>D1. Here, the end 200t1 of the electrode body 200 on the first sealing plate 121 side is the end of the separator, and similarly, the end 200t2 of the electrode body 200 on the second sealing plate 122 side is the end of the separator.

[0044] Here, the separator is disposed between the positive electrode and the negative electrode, and the width (X direction in the figure) of the separator is greater than the width of the negative electrode plate 210 and the positive electrode plate 220 constituting the electrode body 200 described later, so that the separator end protrudes beyond the ends of the negative electrode plate 210 and the positive electrode plate 220. Therefore, the separator end means the end of the separator protruding beyond the ends of the negative electrode plate 210 and the positive electrode plate 220. Note that the negative electrode tab 210B protruding from the negative electrode plate 210 and the positive electrode tab 220B protruding from the positive electrode plate 220 are not included in the width of the negative electrode plate 210 and the positive electrode plate 220 constituting the electrode body 200.

[0045] Thus, the space between the electrode body 200 and the sealing plate is larger on the second sealing plate 122 side than on the first sealing plate 121 side. Therefore, when using as an electrolyte injection hole, it is preferable to use the first through hole 141 located on the second sealing plate 122 side provided at a position not facing the electrode body 200 as the electrolyte injection hole. Therefore, it is preferable to use the second through hole 142 located on the first sealing plate 121 side as an exhaust hole for gas (air) inside the case body 110. The second through hole 142 may be used as an electrolyte injection hole.

[0046] Preferably, the first through hole 141 and the second through hole 142 are provided in the space between the electrode body 200 and the sealing plate, with all of the hole openings not facing the electrode body 200, but it is sufficient that only a portion of the hole openings is provided in the space between the electrode body 200 and the sealing plate.

[0047] It is not necessary to provide both the first through hole 141 and the second through hole 142; by providing at least the first through hole 141, it is possible to use it as an injection hole for the electrolyte while also serving as an exhaust hole for the gas (air) inside the exterior body 100.

[0048] (Configuration of electrode body 200) FIG. 6 is a front view showing the negative electrode original plate 210S before the negative electrode plate 210 (first electrode) is formed, FIG. 7 is a cross-sectional view taken along VII-VII of the negative electrode original plate 210S shown in FIG. 6, and FIG. 8 is a front view showing the negative electrode original plate 210S formed.

[0049] The negative electrode plate 210 is manufactured by processing a negative electrode original plate 210S. As shown in Figures 6 and 7, the negative electrode original plate 210S includes a negative electrode core 211 and a negative electrode active material layer 212. The negative electrode core 211 is a copper foil or a copper alloy foil.

[0050] A negative electrode active material layer 212 is formed on both sides of the negative electrode core 211 except for one end portion. The negative electrode active material layer 212 is formed by applying a negative electrode active material layer slurry with a die coater.

[0051] The negative electrode active material layer slurry is prepared by kneading graphite as the negative electrode active material, styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC) as binders, and water as a dispersion medium so that the mass ratio of graphite:SBR:CMC is approximately 98:1:1.

[0052] The negative electrode core 211 coated with the negative electrode active material layer slurry is dried to remove water contained in the negative electrode active material layer slurry, thereby forming the negative electrode active material layer 212. Furthermore, the negative electrode active material layer 212 is compressed to form a negative electrode original plate 210S including the negative electrode core 211 and the negative electrode active material layer 212. The negative electrode original plate 210S is cut into a predetermined shape to form the negative electrode plate 210. The negative electrode original plate 210S can be cut by laser processing using energy beam irradiation, die processing, cutter processing, or the like.

[0053] As shown in Fig. 8, a plurality of negative electrode tabs 210B each made of a negative electrode core 211 are provided at one end in the width direction of a negative electrode plate 210 formed from a negative electrode original plate 210S. When the negative electrode plate 210 is wound, the plurality of negative electrode tabs 210B are stacked to form a negative electrode tab group 210A. The position and length in the protruding direction of each of the plurality of negative electrode tabs 210B are appropriately adjusted taking into consideration the state in which the negative electrode tab group 210A is connected to the negative electrode current collector 310. The shape of the negative electrode tab 210B is not limited to that exemplified in Fig. 8.

[0054] FIG. 9 is a front view showing the positive electrode original plate 220S before the positive electrode plate 220 (second electrode) is formed, FIG. 10 is a cross-sectional view taken along line XX of the positive electrode original plate 220S shown in FIG. 9, and FIG. 11 is a front view showing the positive electrode plate 220 formed from the positive electrode original plate 220S.

[0055] The positive electrode plate 220 is manufactured by processing a positive electrode original plate 220S. As shown in Figures 9 and 10, the positive electrode original plate 220S includes a positive electrode core 221, a positive electrode active material layer 222, and a positive electrode protective layer 223. The positive electrode core 221 is an aluminum foil or an aluminum alloy foil.

[0056] A positive electrode active material layer 222 is formed on both sides of the positive electrode core 221 except for one end portion. The positive electrode active material layer 222 is formed on the positive electrode core 221 by applying a positive electrode active material layer slurry with a die coater.

[0057] The positive electrode active material layer slurry is prepared by kneading lithium nickel cobalt manganese composite oxide as the positive electrode active material, polyvinylidene fluoride (PVdF) as a binder, a carbon material as a conductive material, and N-methyl-2-pyrrolidone (NMP) as a dispersion medium, so that the mass ratio of lithium nickel cobalt manganese composite oxide:PVdF:carbon material is approximately 97.5:1:1.5.

[0058] The positive electrode protective layer 223 is in contact with the positive electrode core 221 and is formed at one end in the width direction of the positive electrode active material layer 222. The positive electrode protective layer 223 is formed on the positive electrode core 221 by applying a positive electrode protective layer slurry with a die coater. The positive electrode protective layer 223 has a larger electric resistance than the positive electrode active material layer 222.

[0059] The positive electrode protective layer slurry is prepared by kneading alumina powder, a carbon material as a conductive material, PVdF as a binder, and NMP as a dispersion medium so that the mass ratio of alumina powder:carbon material:PVdF is approximately 83:3:14.

[0060] The positive electrode core 221 coated with the positive electrode active material layer slurry and the positive electrode protective layer slurry is dried, and the NMP contained in the positive electrode active material layer slurry and the positive electrode protective layer slurry is removed to form the positive electrode active material layer 222 and the positive electrode protective layer 223. Furthermore, the positive electrode active material layer 222 is compressed to form a positive electrode original plate 220S including the positive electrode core 221, the positive electrode active material layer 222, and the positive electrode protective layer 223. The positive electrode original plate 220S is cut into a predetermined shape to form the positive electrode plate 220. The positive electrode original plate 220S can be cut by laser processing using energy beam irradiation, die processing, cutter processing, or the like.

[0061] As shown in Fig. 11, a plurality of positive electrode tabs 220B made of a positive electrode core 221 are provided at one end in the width direction of a positive electrode plate 220 formed from a positive electrode original plate 220S. When the positive electrode plate 220 is wound, the plurality of positive electrode tabs 220B are stacked to form a positive electrode tab group 220A. The position and length in the protruding direction of each of the plurality of positive electrode tabs 220B are appropriately adjusted in consideration of the state in which the positive electrode tab group 220A is connected to the positive electrode current collector 320. The shape of the positive electrode tabs 220B is not limited to that exemplified in Fig. 11.

[0062] A positive electrode protective layer 223 is provided at the base of each of the positive electrode tabs 220B. The positive electrode protective layer 223 does not necessarily have to be provided at the base of the positive electrode tab 220B. The thickness of the positive electrode protective layer 223 is preferably smaller than the thickness of the positive electrode active material layer 222.

[0063] In a typical example, the thickness of the negative electrode tab 210B (one piece) is smaller than the thickness of the positive electrode tab 220B (one piece). In this case, the thickness of the negative electrode tab group 210A is smaller than the thickness of the positive electrode tab group 220A.

[0064] (Connection structure between electrode body 200 and current collector 300) Fig. 12 is a diagram showing the electrode body 200 and the current collector 300 taken out from the secondary battery 1. As shown in Fig. 12, the electrode body 200 is formed by stacking two electrode bodies 201, 202, each of which is a wound type electrode body. In the example shown in Fig. 12, a structure in which two wound type electrode bodies are stacked is shown, but the electrode body 200 may be composed of one wound type electrode body, may be composed of three or more wound type electrode bodies, or may be composed of a laminated type electrode body.

[0065] The negative electrode tab group 210A is joined to the negative electrode current collector 310 at a joint 310A, and the positive electrode tab group 220A is joined to the positive electrode current collector 320 at a joint 320A. The joints 310A, 320A can be formed by, for example, ultrasonic bonding, resistance welding, laser welding, crimping, or the like.

[0066] Fig. 13 is a diagram showing a connection structure between negative electrode tab group 210A and negative electrode current collector 310. Fig. 14 and Fig. 15 are a front view and a cross-sectional view, respectively, of the connection structure shown in Fig. 13.

[0067] 13 to 15, the negative electrode current collector 310 is connected to the negative electrode terminal 131 between the electrode body 200 and the first sealing plate 121. The negative electrode current collector 310 includes a first conductive member 311 and a second conductive member 312. The first conductive member 311 and the second conductive member 312 are joined at a joint 313.

[0068] The negative electrode tab group 210A is joined to a first conductive member 311 of the negative electrode current collector 310 at a joint 310A. The first conductive member 311 is connected to a second conductive member 312 at a joint 313. The joint 313 can be formed by, for example, ultrasonic bonding, resistance welding, laser welding, crimping, or the like.

[0069] The first conductive member 311 and the second conductive member 312 are attached to the inner surface side of the first sealing plate 121 via a resin insulating member 410. The insulating member 410 is provided so as to reach from the outer surface side to the inner surface side of the first sealing plate 121 via a through hole provided in the first sealing plate 121. Note that the insulating member 410 may be made up of multiple components including a member disposed between the negative electrode terminal 131 and the first sealing plate 121, and components disposed between the first conductive member 311 and the second conductive member 312 and the first sealing plate 121.

[0070] The negative electrode terminal 131 is attached to the first sealing plate 121 via a resin insulating member 410A. The negative electrode terminal 131 is provided so as to be exposed to the outside of the first sealing plate 121 and reach the second conductive member 312 of the negative electrode current collector 310 provided on the inner surface side of the first sealing plate 121. The negative electrode terminal 131 and the second conductive member 312 can be connected by, for example, ultrasonic bonding, resistance welding, laser welding, crimping, or the like. In this embodiment, a through hole is provided in the second conductive member 312, the negative electrode terminal 131 is inserted into the through hole, the negative electrode terminal 131 is crimped on the second conductive member 312, and then the crimped portion and the second conductive member 312 are welded at a joint portion 131A to connect the negative electrode terminal 131 and the second conductive member 312.

[0071] As a procedure for assembling each part, first, the negative electrode terminal 131 and the second conductive member 312 are attached to the first sealing plate 121 together with the insulating members 410 and 410A. Then, the first conductive member 311 connected to the electrode body 200 is attached to the second conductive member 312. At this time, the first conductive member 311 is placed on the insulating member 410 so that a portion of the first conductive member 311 overlaps with the second conductive member 312. Then, the first conductive member 311 and the second conductive member 312 are welded and connected at the joint 313. Note that the insulating members 410 and 410A may be composed of a single member.

[0072] However, the negative electrode terminal 131 may be electrically connected to the first sealing plate 121. Also, the first sealing plate 121 may play the role of the negative electrode terminal 131.

[0073] 13 to 15, the negative electrode current collector 310 is illustrated as being made up of two components (the first conductive member 311 and the second conductive member 312), but the negative electrode current collector 310 may be made up of a single component.

[0074] Although the connection structure on the negative electrode side is shown in Figs. 13 to 15, the basic connection structure on the positive electrode side is similar to that on the negative electrode side.

[0075] (Step of Inserting the Electrode Body 200) 16 is a diagram showing a process of inserting the electrode body 200 into the case body 110. As shown in FIG. 16, a resin insulating sheet 600 (electrode body holder) is disposed between the electrode body 200 and the case body 110.

[0076] The insulating sheet 600 may be made of, for example, resin. More specifically, the material of the insulating sheet 600 may be, for example, polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), or polyolefin (PO).

[0077] The insulating sheet 600 does not necessarily have to cover the entire surface of the electrode body 200. The insulating sheet 600 preferably covers an area of ​​about 50% or more, and more preferably about 70% or more, of the outer surface of the electrode body. Of the six faces of the approximately rectangular parallelepiped (flat) electrode body 200, the insulating sheet 600 preferably covers the entire four faces other than at least the two faces on which the negative electrode tab group 210A and the positive electrode tab group 220A are formed, respectively.

[0078] Fig. 17 is a diagram showing a process of arranging a spacer 510 between the first sealing plate 121 and the electrode body 200. Fig. 18 is a cross-sectional view showing a state in which the spacer 510 is arranged between the first sealing plate 121 and the electrode body 200.

[0079] 17 and 18, the negative electrode tab group 210A extending from the electrode body 200 toward the first sealing plate 121 is curved so as to extend from the center in the Y-axis direction of the first sealing plate 121 toward the end, and then turn back toward the center. A spacer 510 is provided to accommodate the curved negative electrode tab group 210A (curved portion).

[0080] The spacer 510 includes a first spacer 511 and a second spacer 512. The first spacer 511 and the second spacer 512 are engaged with each other by sliding them along the Y-axis direction from the end side toward the center side of the first sealing plate 121. In this way, the spacer 510 is fixed to the first sealing plate 121 via the insulating member 410, and the stability of the position of the spacer 510 is increased.

[0081] 18, the spacer 510 forms an internal space for accommodating the negative electrode current collector 310, and the tip portion of the negative electrode tab group 210A is also accommodated in the internal space of the spacer 510. The spacer 510 has a hole that allows the negative electrode tab group 210A to pass therethrough.

[0082] The material of the spacer 510 is not particularly limited, but it is preferable to use an insulating material such as resin. More specifically, it is preferable to use a sheet made of polyolefin (PO). In addition, an insulating sheet 600 may be interposed between the spacer 510 and the electrode body 200.

[0083] 16 again, in the method for manufacturing the secondary battery 1 according to the present embodiment, after the negative electrode terminal 131 and the negative electrode tab group 210A are electrically connected, the electrode body 200 is inserted into the case body 110 from the end side on the positive electrode tab group 220A side through the first opening 111. When the electrode body 200 is inserted to a predetermined position in the case body 110, the positive electrode tab group 220A protrudes from the second opening 112 of the case body 110 to the outside of the case body 110. As a result, after the electrode body 200 is inserted into the case body 110, the positive electrode terminal 132 and the positive electrode tab group 220A can be connected.

[0084] When the negative electrode terminal 131 attached to the first sealing plate 121 and the negative electrode tab group 210A are electrically connected after the electrode body 200 is inserted into the case body 110, the negative electrode tab group 210A is required to have a length that allows the negative electrode tab group 210A of the electrode body 200 stored in the case body 110 to sufficiently protrude outside the case body 110. By electrically connecting the negative electrode terminal 131 attached to the first sealing plate 121 and the negative electrode tab group 210A before inserting the electrode body 200 into the case body 110, the length of the negative electrode tab group 210A can be reduced compared to the case where the electrode body 200 is attached after the electrode body 200 is inserted into the case body 110. As a result, the volume occupancy rate of the negative electrode plate 210 and the positive electrode plate 220 in the internal space of the case body 110 can be increased.

[0085] 16, the electrode assembly 200 is inserted into the case body 110 after arranging a spacer 510 that accommodates the curved portion of the negative electrode tab group 210A. In this manner, it is possible to protect the curved portion of the negative electrode tab group 210A during the insertion process of the electrode assembly 200. It is preferable that the spacer 510 has an opening 510h for passing the electrolyte at a position facing the second through hole 142. The shape of the opening 510h is not limited to a circle, and may be any shape that allows the electrolyte to pass through.

[0086] 16, the electrode body 200 is inserted into the case body 110 in a state where the electrode body 200 is covered with the insulating sheet 600. This makes it possible to suppress damage to the electrode body 200 when it is inserted into the case body 110.

[0087] During the step of inserting the electrode body 200, the case body 110 can be held at a predetermined angle. As an example, it is preferable to insert the electrode body 200 in a state in which the case body 110 is held so that the X-axis direction (width direction of the case body 110) intersects with the horizontal direction at an angle of about ±45° or less. For example, the electrode body 200 can be inserted into the case body 110 with the case body 110 tilted so that the upper end of the first opening 111 into which the electrode body 200 is inserted is positioned higher than the upper end of the second opening 112 in the vertical direction.

[0088] The step of inserting the electrode body 200 is not limited to a mode in which the electrode body 200 is pushed in from the first opening 111 side, and may be a mode in which the electrode body 200 is pulled from the second opening 112 side, for example.

[0089] When the positive electrode tab group 220A is viewed from the first through hole 141 provided in the second wall 110Z, the positive electrode tab group 220A may be bent to avoid the first through hole 141. This is because the injection of the electrolyte can be improved. Similarly, when the negative electrode tab group 210A is viewed from the second through hole 142 provided in the second wall 110Z, the negative electrode tab group 210A may be bent to avoid the second through hole 142. This configuration can improve the injection of the electrolyte in the manufacturing process of the secondary battery 1 described later.

[0090] FIG. 19 is a diagram showing a modified example of the spacer 510. In the examples of FIGS. 16 to 18, the spacer 510 is disposed in a part of the height direction (Z-axis direction) of the first sealing plate 121, but as shown in FIG. 19, the spacer 510 may be disposed over substantially the entire area of ​​the height direction of the first sealing plate 121. In this case, the spacer 510 may have a portion that protrudes toward the electrode body 200 side from the vicinity of the negative electrode tab group 210A (second region) at a position (first region) spaced apart from the negative electrode tab group 210A in the Z-axis direction. A step (preferably a step of about 1 mm or more) may be formed at the boundary between the first region and the second region. In this way, damage to the negative electrode tab group 210A when the electrode body 200 is inserted into the case body 110 can be suppressed.

[0091] (Mechanism for pressing the electrode body) Fig. 20 is a diagram showing an example of a mechanism for pressing the electrode body 200 via the first sealing plate 121 and the spacer 510A. Fig. 21 is a diagram showing the mechanism shown in Fig. 20 as viewed from the Z-axis direction. The spacer 510A is a modified example of the spacer 510 described above.

[0092] As shown in FIG. 20 and FIG. 21, the spacer 510A is disposed in a position (apart from the negative electrode tab group 210A and the negative electrode current collector 310) avoiding the negative electrode tab group 210A and the negative electrode current collector 310 in the height direction (Z-axis direction) of the first sealing plate 121 and the electrode body 200. More specifically, the spacer 510A is disposed in two separate locations so as to sandwich the negative electrode tab group 210A in the Z-axis direction. The spacer 510A preferably presses a portion of the electrode body 200 where the negative electrode tab group 210A is not provided. In particular, it is preferable to press a portion where the separator protrudes beyond the end of the negative electrode plate 210. The spacer 510A may be provided only on one side of the negative electrode tab group 210A in the Z-axis direction. The spacer 510A may be fixed to the first sealing plate 121 and / or the electrode body 200 by a method such as adhesion, welding, or tape attachment. The spacer 510A may be in contact with the negative electrode tab group 210A.

[0093] It is preferable to provide a through hole, a notch, a slit, or the like in the spacer 510A at a position facing the first through hole 141. It is also preferable to provide a through hole, a notch, a slit, or the like in the spacer 510A at a position facing the gas exhaust valve 151. This makes it possible to more reliably ensure the function of the first through hole 141 or the gas exhaust valve 151.

[0094] 20 and 21, the electrode body 200 is inserted into the case body 110 by pressing the electrode body 200 via the spacer 510A. At the beginning of the insertion process of the electrode body 200, the electrode body 200 may be held and after a portion of the electrode body 200 is inserted into the case body 110, the electrode body 200 may be further inserted by pressing the electrode body 200 via the spacer 510A.

[0095] Instead of the above-mentioned spacers, spacers may be provided that are fixed to the electrode assembly 200. The spacers are fixed to the electrode assembly 200 by, for example, attaching a tape.

[0096] In addition, from the viewpoint of protecting the positive electrode tab group 220A, the spacer 510 and the spacer 510A may be provided on the positive electrode tab group 220A side. It is preferable that the spacer to be provided on the positive electrode tab group 220A side also has an opening for passing the electrolyte at a position facing the first through hole 141. The shape of the opening may be any shape as long as it allows the electrolyte to pass through.

[0097] Here, spacers of other configurations will be illustrated with reference to Figures 22 to 24. Figure 22 is a perspective view of a spacer 510B of another configuration, Figure 23 is a perspective view of a spacer 510C of another configuration, and Figure 24 is a perspective view of a spacer 510D of another configuration.

[0098] 22 has a rectangular opening 510h1 provided on the side facing the electrode body 200. In the case of this spacer 510B, the opening 510h1 is located at a position not facing the first through hole 141 (or the second through hole 142).

[0099] 23 is provided with a slit-shaped opening 510h2 arranged obliquely on the side facing the electrode body 200. When the slit-shaped opening 510h2 is provided, a sufficient opening area is ensured, a flow path area necessary for degassing and liquid injection is ensured, and further, there is an advantage that the injected solvent is less likely to accumulate.

[0100] 24, a spacer 510D is provided with a rectangular opening 510h3 on the side facing the first through hole 141 (or the second through hole 142). The position of this opening 510h3 is perpendicular to the curved direction of the electrode tab. As a result, curling of the separator and damage to the electrode (including the tab) due to the force of the liquid injection can be prevented, pressure can be uniformed when inserting the electrode body, and the curved electrode tab can be prevented from protruding from the space inside the spacer.

[0101] The outer shape of the spacer and the position and shape of the openings are not limited to those of the above spacer, but by providing appropriate openings in the spacer arranged for the purpose of protecting the positive electrode tab group 220A and the negative electrode tab group 210A, it is possible to suppress damage to the electrode body, or suppress unintended short circuits, and suppress deterioration of the electrolyte injectability.

[0102] (Manufacturing process of secondary battery 1) FIG. 25 is a flow diagram showing each step of the manufacturing method of the secondary battery 1. As shown in FIG. 25, in S10, the case body 110 is prepared. Next, in S20, the electrode body 200 is produced. In S30, the electrode terminals provided on the first sealing plate 121 and the second sealing plate 122 are electrically connected to the electrode tab group of the electrode body 200. At this time, the negative electrode terminal 131 and the negative electrode tab group 210A are first electrically connected (S31), and then the spacer 510 is placed between the first sealing plate 121 on the negative electrode side and the electrode body 200 (S40), and further the electrode body 200 is inserted into the case body 110 (S50). At this time, the positive electrode tab group 220A protrudes to the outside of the case body 110 from the second opening 112 of the case body 110. After the electrode body 200 is inserted into the case body 110, the positive electrode terminal 132 and the positive electrode tab group 220A are electrically connected (S32).

[0103] In the present embodiment, an example has been described in which the steps are performed in the order of connection (S31) between the negative electrode terminal 131 and the negative electrode tab group 210A, insertion (S50) of the electrode body 200, and connection (S32) between the positive electrode terminal 132 and the positive electrode tab group 220A. However, the scope of the present technology is not limited to this, and there are also cases in which the steps are performed in the order of connection (S32) between the positive electrode terminal 132 and the positive electrode tab group 220A, insertion (S50) of the electrode body 200, and connection (S31) between the negative electrode terminal 131 and the negative electrode tab group 210A.

[0104] After the connection between the electrode terminals and the electrode tab group (S30) is completed, the first opening 111 and the second opening 112 are sealed with the first sealing plate 121 and the second sealing plate 122 (S60). The sealing step with the first sealing plate 121 and the second sealing plate 122 is performed by, for example, laser welding.

[0105] The process (S61) of sealing the first opening 111 with the first sealing plate 121 on the negative electrode side may be performed after the process (S50) of inserting the electrode body 200 into the case body 110, and the process (S62) of sealing the second opening 112 with the second sealing plate 122 on the positive electrode side may be performed after the process (S32) of electrically connecting the positive electrode terminal 132 and the positive electrode tab group 220A.

[0106] Therefore, for example, the step (S61) of sealing first opening 111 with first sealing plate 121 may be performed before the step (S32) of electrically connecting positive electrode terminal 132 and positive electrode tab group 220A, or the step (S61) of sealing first opening 111 with first sealing plate 121 may be performed after the step (S62) of sealing second opening 112 with second sealing plate 122. Furthermore, at least some of the steps (S61, S62) of sealing with first sealing plate 121 and second sealing plate 122 can be performed simultaneously.

[0107] Next, a step (S70) is performed of injecting the electrolyte into the exterior body 100 through the first through hole 141. It is preferable to use the first through hole 141 provided on the second sealing plate 122 side, where the space between the electrode body 200 and the sealing plate is large, as an injection port for the electrolyte. On the other hand, since the second through hole 142 is provided on the opposite side, it is preferable to use this second through hole 142 as an exhaust hole for gas (air, nitrogen, etc.) inside the exterior body 100. This can improve the injection of the electrolyte into the exterior body 100.

[0108] In the case body 110, the electrolyte is injected into the case body 110 from the first through hole 141 arranged in a region on the second opening 112 side of the end of the electrode body 200 on the second opening 112 side, so that the electrolyte can be injected from a region of the case body 110 that does not face the electrode body 200 (excluding the tab group), improving the injection property. In addition, by providing the first through hole 141 in the case body 110, it becomes easier to inject the electrolyte into the case body 110 in a state in which the longitudinal direction of the case body 110 is oriented horizontally or close to the horizontal direction. This makes it possible to more effectively suppress damage to the electrode body 200. Alternatively, dripping of the electrolyte can also be suppressed.

[0109] When injecting the electrolyte into the exterior body 100, it is preferable to place the exterior body 100 on a horizontal surface so that the second wall 110Z in which the first through-hole 141 is provided is on the upper side. On the other hand, the electrolyte may be injected into the exterior body 100 by tilting the exterior body 100 (with the second through-hole 142 on the lower side) so that the second wall 110Z is at an angle of 45 degrees or less, preferably 30 degrees or less, and more preferably 15 degrees or less. This can improve the injectability of the electrolyte into the exterior body 100.

[0110] After the injection of the electrolyte into the exterior body 100 is completed, the first through-hole 141 is sealed with the first sealing member 701 (first sealing step), and the second through-hole 142 is sealed with the second sealing member 702 (second sealing step). Either the first sealing step or the second sealing step may be performed first. The first sealing member 701 and the second sealing member 702 are fixed to the case body 110 by crimping using, for example, blind rivets or other metal members. Alternatively, the first sealing member 701 and the second sealing member 702 are fixed to the case body 110 by welding.

[0111] Here, after one of the first sealing step and the second sealing step is performed, a charging step is performed in which the electrode body 200 is charged, and after this charging step, the other of the first sealing step and the second sealing step is performed. After sealing the through hole on one side, charging is performed and the generated gas is exhausted to the outside of the exterior body 100. Thereafter, by sealing the through hole on the other side, swelling of the exterior body 100 can be suppressed.

[0112] (summary) The above-mentioned contents regarding the secondary battery 1 and the manufacturing method of the secondary battery 1 according to the present embodiment can be summarized as follows.

[0113] This secondary battery 1 includes a negative electrode original plate 210S, a positive electrode original plate 220S having a polarity different from that of the negative electrode original plate 210S, an electrode assembly 200 including a separator disposed between the negative electrode original plate 210S and the positive electrode original plate 220S, and an exterior body 100 that contains the electrode assembly 200 and an electrolyte. The exterior body 100 includes a case body 110 having a first opening 111 at one end and a second opening 112 at the other end, a first sealing plate 121 that seals the first opening 111, and a second sealing plate 122 that seals the second opening 112. A negative electrode terminal 131 electrically connected to the negative electrode original plate 210S is provided on the first sealing plate 121, and a positive electrode terminal 132 electrically connected to the positive electrode original plate 220S is provided on the second sealing plate 122. A negative electrode tab group 210A electrically connected to a negative electrode original plate 210S is provided at one end of the electrode body 200, and a positive electrode tab group 220A electrically connected to a positive electrode original plate 220S is provided at the other end of the electrode body 200. A first through hole 141 is provided in the case body 110 in a region closer to the second opening 112 side than the end of the electrode body 200 on the second opening 112 side, and the first through hole 141 is sealed with a first sealing member 701.

[0114] In the secondary battery 1 according to one example, a second through hole 142 is provided in the case body 110 in a region closer to the first opening 111 side than the end of the electrode body 200 on the first opening 111 side, and the second through hole 142 is sealed with a second sealing member 702. When manufacturing the secondary battery 1, the first through hole 141 can be used as an injection port for electrolyte, and the second through hole 142 can be used as an exhaust hole for gas (air) inside the exterior body 100.

[0115] In a secondary battery 1 according to one example, when the distance between the first sealing plate 121 and the end of the electrode body 200 on the first sealing plate 121 side is D1 and the distance between the second sealing plate 122 and the end of the electrode body 200 on the second sealing plate 122 side is D2, the relationship D2>D1 is satisfied. Since the space between the electrode body 200 and the sealing plate is larger on the second sealing plate 122 side than on the first sealing plate 121 side, it is preferable to use the first through hole 141 located on the second sealing plate 122 side as an injection hole for the electrolyte.

[0116] The method for manufacturing this secondary battery 1 includes the steps of injecting an electrolyte solution into the exterior body 100 from the first through-hole 141 in the secondary battery 1 having the above-described configuration, and sealing the first through-hole 141 with a first sealing member 701.

[0117] (Action and effect) According to the secondary battery 1 of this embodiment, the secondary battery 1 can be efficiently manufactured and the injection property can be improved. For example, by arranging the secondary battery 1 with the longitudinal direction of the exterior body 100 horizontally, the injection property of the electrolyte into the exterior body 100 can be improved. As a result, the secondary battery 1 can be manufactured more efficiently and stably.

[0118] Although the embodiment of the present technology has been described above, the embodiment disclosed herein should be considered as 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 scope and meaning equivalent to the claims. [Explanation of symbols]

[0119] 1 secondary battery, 100 exterior body, 110 case body, 110A, 131A, 310A, 313, 320A joint, 110Y first wall, 110Z second wall, 111 first opening, 112 second opening, 121 first sealing plate, 122 second sealing plate, 131 negative electrode terminal, 132 positive electrode terminal, 141 first through hole, 142 second through hole, 151, 152 gas exhaust valve, 200, 201, 202 electrode body, 200t1 end of first sealing plate side, 200t2 end of second sealing plate side, 210 negative electrode plate, 210A negative electrode tab group, 210B negative electrode tab, 210S negative electrode base plate, 211 negative electrode core body, 212 negative electrode active material layer, 220 Positive electrode plate, 220A positive electrode tab group, 220B positive electrode tab, 220S positive electrode original plate, 221 positive electrode core, 222 positive electrode active material layer, 223 positive electrode protective layer, 300 current collector, 310 negative electrode current collector, 311 first conductive member, 312 second conductive member, 320 positive electrode current collector, 410 insulating member, 510, 510A, 510B, 510C, 510D spacers, 510h1, 510h, 510h3, 510h2 openings, 511 first spacer, 512 second spacer, 600 insulating sheet, 701 first sealing member, 702 second sealing member.

Claims

1. an electrode assembly including a first electrode, a second electrode having a polarity different from that of the first electrode, and a separator disposed between the first electrode and the second electrode; an exterior body that accommodates the electrode assembly and an electrolyte; Equipped with The exterior body 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, a first electrode terminal electrically connected to the first electrode is provided on the first sealing plate; the second sealing plate is provided with a second electrode terminal electrically connected to the second electrode, a first electrode tab group electrically connected to the first electrodes is provided at one end of the electrode body; a second electrode tab group electrically connected to the second electrodes is provided at the other end of the electrode body; The case body is provided with a first through hole in a region closer to the second opening than an end of the electrode body on the second opening side, The first through hole is sealed by a first sealing member. Secondary battery.

2. a second through hole is provided in the case body in a region closer to the first opening than an end of the electrode body on the first opening side; The second through hole is sealed with a second sealing member. The secondary battery according to claim 1 .

3. a distance between the first sealing plate and an end of the electrode body on the first sealing plate side is defined as D1; When the distance between the second sealing plate and the end of the electrode body on the second sealing plate side is D2, the relationship of D2>D1 is satisfied. The secondary battery according to claim 1 or 2.

4. an electrode assembly including a first electrode, a second electrode having a polarity different from that of the first electrode, and a separator disposed between the first electrode and the second electrode; an exterior body that accommodates the electrode assembly and an electrolyte; Equipped with The exterior body 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, a first electrode terminal electrically connected to the first electrode is provided on the first sealing plate; the second sealing plate is provided with a second electrode terminal electrically connected to the second electrode, a first electrode tab group electrically connected to the first electrodes is provided at one end of the electrode body; a second electrode tab group electrically connected to the second electrodes is provided at the other end of the electrode body; The case body is provided with a first through hole in a region closer to the second opening than an end of the electrode body on the second opening side, The first through hole is sealed by a first sealing member. A method for manufacturing a secondary battery comprising the steps of: injecting the electrolyte into the exterior body through the first through hole; sealing the first through hole with the first sealing member; A method for manufacturing a secondary battery comprising the steps of:

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