Secondary battery and method of manufacturing the same

Abstract

To provide a secondary battery that can be manufactured efficiently and stably, and a manufacturing method therefor.SOLUTION: A secondary battery 1 includes an electrode body 200 including a first electrode and a second electrode having a polarity different from that of the first electrode and an outer body 100 that accommodates the electrode body 200 and an electrolyte. The outer body 100 includes a first wall and a second wall arranged opposite each other. The first wall includes a first through-hole 141 and a first sealing member 141a that seals the first through-hole 141. The second wall includes a second through-hole 142 and a second sealing member 142a that seals the second through-hole 142. The first sealing member 141a is different from a first electrode terminal 131 and a second electrode terminal 132. The second sealing member 142a is different from the first electrode terminal 131 and the second electrode terminal 132.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present technology relates to a secondary battery and a method for manufacturing the 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 using a rectangular battery with the positive terminal on one side of the battery case and the negative terminal on the other, it is easy to create a low-profile battery pack. However, there is room for further improvement in order to create a battery with a higher volumetric energy density and one that can be manufactured efficiently and stably. For example, it takes time to impregnate a high-capacity, high-density electrode assembly with an electrolyte.

[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 the 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: an electrode assembly including a first electrode and a second electrode having a polarity different from that of the first electrode; an exterior housing that accommodates the electrode assembly and an electrolyte; a first electrode terminal electrically connected to the first electrode and provided on the exterior housing; and a second electrode terminal electrically connected to the second electrode and provided on the exterior housing; the exterior housing includes a first wall and a second wall that are arranged to face each other, the first wall includes a first through hole and a first sealing member that seals the first through hole, the second wall includes a second through hole and a second sealing member that seals the second through hole, the first sealing member is different from the first electrode terminal and the second electrode terminal, and the second sealing member is different from the first electrode terminal and the second electrode terminal.

[0008] [2] The secondary battery according to [1], wherein the exterior body includes a case main 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 wall is the first sealing plate, the second wall is the second sealing plate, a first electrode terminal is provided on the first sealing plate, and a second electrode terminal is provided on the second sealing plate, the electrode body includes a first electrode tab group at one end including a plurality of first electrode tabs electrically connected to the first electrodes, and a second electrode tab group at the other end including a plurality of second electrode tabs electrically connected to the second electrodes, the first electrode tab group being electrically connected to the first electrode terminal, and the second electrode tab group being electrically connected to the second electrode terminal.

[0009] [3] The secondary battery according to [2], wherein the first electrode tab group is bent and joined to the first electrode terminal or a first electrode current collecting member connected to the first electrode terminal, and the second electrode tab group is bent and joined to the second electrode terminal or a second electrode current collecting member connected to the second electrode terminal.

[0010] [4] A secondary battery described in any one of [1] to [3], wherein, in the longitudinal direction of the first wall, the first through hole is positioned offset from the center of the first wall toward the first direction, and in the longitudinal direction of the second wall, the second through hole is positioned offset from the center of the second wall toward the first direction.

[0011] [5] An electrode assembly including a first electrode and a second electrode having a polarity different from that of the first electrode; an exterior housing accommodating the electrode assembly and an electrolyte; a first electrode terminal electrically connected to the first electrode and provided on the exterior housing; and a second electrode terminal electrically connected to the second electrode and provided on the exterior housing, wherein the exterior housing includes a first wall and a second wall arranged to face each other, the first wall includes a first through-hole and a first sealing member that seals the first through-hole, and the second wall includes a first through-hole and a first sealing member that seals the second through-hole and and a second sealing member that seals the second through hole, wherein the first sealing member is different from the first electrode terminal and the second electrode terminal, and the second sealing member is different from the first electrode terminal and the second electrode terminal, the method for manufacturing a secondary battery comprising: a liquid injection step of injecting an electrolyte into an outer casing from at least one of the first through hole and the second through hole; a first sealing step of sealing the first through hole with the first sealing member; and a second sealing step of sealing the second through hole with the second sealing member.

[0012] [6] The method for manufacturing a secondary battery according to [5], wherein the liquid injection step involves injecting an electrolyte into the outer casing through one of the first through hole and the second through hole, and discharging gas from the outer casing to the outside through the other of the first through hole and the second through hole.

[0013] [7] A method for manufacturing a secondary battery according to [5] or [6], wherein the second electrode has a second electrode active material layer, and when the distance between the first wall and the end of the second electrode active material layer on the first wall side in a direction connecting the first wall and the second wall is defined as D1 and the distance between the second wall and the end of the second electrode active material layer on the second wall side is defined as D2, the relationship D2>D1 is satisfied, and the method includes a step of injecting an electrolyte solution into the exterior body from the second through hole in the liquid injection step. [Effects of the Invention]

[0014] 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 explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a front view of the secondary battery. [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] FIG. 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 blank before being formed into a negative electrode plate. [Figure 7] 7 is a cross-sectional view taken along the line VII-VII of the negative electrode plate shown in FIG. 6. FIG. [Figure 8] FIG. 2 is a front view showing a negative electrode plate formed from a negative electrode original plate. [Figure 9] FIG. 2 is a front view showing a positive electrode plate before it is formed into a positive electrode plate. [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. 2 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] 10A and 10B are diagrams showing a process of inserting the electrode body into the case body. [Figure 17] 10A to 10C are diagrams showing a step of providing a spacer between the sealing plate and the electrode body. [Figure 18] FIG. 10 is a cross-sectional view showing a state in which a spacer is provided between the sealing plate and the electrode body. [Figure 19] 10A and 10B are diagrams showing modified examples of the spacer; [Figure 20] 10A and 10B are diagrams showing an example of a mechanism for pressing an electrode body via a sealing plate and a spacer. [Figure 21] FIG. 21 is a diagram showing the mechanism shown in FIG. 20 as viewed from the Z-axis direction. [Figure 22] FIG. 10 is a perspective view of a spacer of another type. [Figure 23] FIG. 10 is a perspective view of a spacer of another type. [Figure 24] FIG. 10 is a perspective view of a spacer of another type. [Figure 25] FIG. 2 is a flow chart showing each step of a method for manufacturing a secondary battery. DETAILED DESCRIPTION OF THE INVENTION

[0016] 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.

[0017] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiments.

[0018] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0019] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0020] 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. Furthermore, the term "electrode plate" may collectively refer to positive and negative plates.

[0021] (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.

[0022] 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.

[0023] 1 to 5, secondary battery 1 includes an exterior body 100, an electrode assembly 200, and a current collector 300. Exterior body 100 includes a case main body 110, a first sealing plate 121 as a first wall, and a second sealing plate 122 as a second wall.

[0024] 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 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 illustration is vertically upward, and the lower side of the illustration is vertically downward. Therefore, FIG. 2 shows the state as viewed from the bottom.

[0025] When configuring a battery pack 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 constraining member to form a battery module, or the battery pack may be directly supported on the side surface of the battery pack case without using a constraining member.

[0026] 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.

[0027] 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 rectangular 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 "rectangular tube" may be rounded.

[0028] In this embodiment, the case body 110 is formed so that its length in the width direction (X-axis direction) of the secondary battery 1, that is, in the direction connecting the first sealing plate 121, which is the first wall, and the second sealing plate 122, which is the second wall (X-axis direction), is longer than the thickness direction (Y-axis direction) and height direction (Z-axis direction) of the secondary battery 1.

[0029] The dimension (width) of the case body 110 in the X-axis 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-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 for the construction of a relatively low-height secondary battery 1, which improves the mountability in, for example, a vehicle.

[0030] As shown in FIG. 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. The first sealing plate 121 is provided with a negative electrode terminal 131 (first electrode terminal), a first through-hole 141, and a gas release valve 151. The positions of the negative electrode terminal 131 and the gas release 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. The first through-hole 141 is positioned offset in the long side direction (Z direction) of the first sealing plate 121 from the center CL of the first sealing plate 121 toward the first direction (upward in the figure). The first through-hole 141 is sealed by a first sealing member 141a.

[0031] As shown in FIG. 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. The second sealing plate 122 is provided with a positive electrode terminal 132 (second electrode terminal), a second through-hole 142, and a gas release valve 152. The positions of the positive electrode terminal 132 and the gas release 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. The second through-hole 142 is positioned offset in the long side direction (Z direction) of the second sealing plate 122 from the center CL of the second sealing plate 122 toward the first direction (upward in the figure). The second through-hole 142 is sealed by a second sealing member 142a.

[0032] The first sealing member 141a and the second sealing member 142a can be fixed to the case body 110 by caulking using, for example, blind rivets or other metal members. The first sealing member 141a and the second sealing member 142a may also be fixed to the case body 110 by welding.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] As shown in the figure, first through-hole 141 and first sealing member 141a are different from negative terminal 131, and first sealing member 141a does not function as negative terminal 131. Therefore, first sealing member 141a preferably does not have the polarity of negative terminal 131. Furthermore, first sealing plate 121 preferably does not have the polarity of negative terminal 131 either. For example, a resin seal, a rubber part, or the like may be interposed between first sealing plate 121 and case body 110.

[0038] Similarly, as shown in the figure, second through-hole 142 and second sealing member 142a are different from positive terminal 132, and second sealing member 142a does not function as positive terminal 132. Therefore, second sealing member 142a preferably does not have the polarity of positive terminal 132. Furthermore, second sealing plate 122 preferably does not have the polarity of positive terminal 132. For example, a resin seal, a rubber part, or the like may be interposed between second sealing plate 122 and case body 110.

[0039] There are cases where the exterior housing 100 is electrically connected to the negative electrode plate 210 or the positive electrode plate 220. In this case, the first sealing member 141a and the second sealing member 142a may have one of the polarities. However, even in this case, the first sealing member 141a and the second sealing member 142a are not used as terminals, and separate terminals are provided. Therefore, the first sealing member 141a is different from the negative electrode terminal 131 and the positive electrode terminal 132, and the second sealing member 142a is different from the positive electrode terminal 132 and the negative electrode terminal 131.

[0040] 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.

[0041] The electrode assembly 200 is a flat-shaped electrode assembly having positive and negative electrode plates, which will be described later. Specifically, the electrode assembly 200 is a wound-type electrode assembly in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound together with a strip-shaped separator (not shown) interposed therebetween. However, in this specification, the "electrode assembly" is not limited to a wound-type electrode assembly, but may also be a stacked-type electrode assembly in which multiple positive electrode plates and multiple negative electrode plates are alternately stacked. The electrode assembly may include multiple positive electrode plates and multiple negative electrode plates, and the positive electrode tabs provided on each positive electrode plate may be stacked to form a positive electrode tab group, or the negative electrode tabs provided on each negative electrode plate may be stacked to form a negative electrode tab group.

[0042] As will be described later in the "Manufacturing Process of Secondary Battery 1" section, 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 a gas (air) exhaust hole in the case body 110.

[0043] 5, the exterior body 100 houses the electrode assembly 200. The electrode assembly 200 is housed in the exterior body 100 so that its winding axis is parallel to the X-axis direction.

[0044] Specifically, one or more wound electrode bodies are housed together with an electrolytic solution (electrolyte), not shown, inside an insulating sheet 600 (described later) that is disposed within the exterior housing 100. The electrolytic solution (non-aqueous electrolytic solution) may be, for example, a non-aqueous solvent obtained by mixing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) in a volume ratio (at 25°C) of 30:30:40, in which LiPF6 is dissolved at a concentration of 1.2 mol / L. Note that a solid electrolyte may be used instead of the electrolytic solution.

[0045] The electrode assembly 200 includes a negative electrode tab group 210A (first electrode tab group) provided at the end (first end) on the first sealing plate 121 side, and a positive electrode tab group 220A (second electrode tab group) provided at the 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 positive electrode of the electrode assembly 200, respectively. The negative electrode tab group 210A and the positive electrode tab group 220A are formed so as to protrude from the main body portion of the electrode assembly 200 (the portion where the positive electrode plate and the negative electrode plate are stacked with the separator interposed between them) towards the first sealing plate 121 and the second sealing plate 122.

[0046] 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 assembly 200 is electrically connected to the negative electrode terminal 131 and the positive electrode terminal 132 via the current collector 300.

[0047] 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.

[0048] 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 aluminum or an aluminum alloy, for example. 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.

[0049] If the distance between the first sealing plate 121 and the end 200t1 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 200t2 of the electrode body 200 on the second sealing plate 122 side is D2, then the relationship D2 > D1 is satisfied. Preferably, D1 / D2 > 1.2, and more preferably, D1 / D2 > 1.5. Here, the end 200t1 of the electrode body 200 on the first sealing plate 121 side is the end of a positive electrode active material layer 222, which will be described later, and similarly, the end 200t2 of the electrode body 200 on the second sealing plate 122 side is the end of the positive electrode active material layer 222.

[0050] 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 used as an electrolyte injection hole, it is preferable to use the second through-hole 142 as the electrolyte injection hole. Therefore, it is preferable to use the first through-hole 141 located on the first sealing plate 121 side as an exhaust hole for gas (air) inside the case body 110.

[0051] (Configuration of electrode body 200) FIG. 6 is a front view showing a negative electrode plate 210S before the negative electrode plate 210 (first electrode) is formed, FIG. 7 is a cross-sectional view taken along line VII-VII of the negative electrode plate 210S shown in FIG. 6, and FIG. 8 is a front view showing the negative electrode plate 210 formed from the negative electrode plate 210S.

[0052] 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.

[0053] A negative electrode active material layer 212 is formed on both surfaces of the negative electrode substrate 211 except for one end portion. The negative electrode active material layer 212 is formed by applying a negative electrode active material layer slurry using a die coater.

[0054] 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.

[0055] The negative electrode substrate 211 coated with the negative electrode active material layer slurry is dried to remove water contained in the negative electrode active material layer slurry, thereby forming the negative electrode active material layer 212. The negative electrode active material layer 212 is then compressed to form a negative electrode base plate 210S including the negative electrode substrate 211 and the negative electrode active material layer 212. The negative electrode base plate 210S is cut into a predetermined shape to form the negative electrode plate 210. The negative electrode base plate 210S can be cut by laser processing using energy beam irradiation, mold processing, cutter processing, or the like.

[0056] As shown in FIG. 8, a plurality of negative electrode tabs 210B each made of a negative electrode core 211 is 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 adjusted as appropriate, taking into account 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 tabs 210B is not limited to the example shown in FIG. 8.

[0057] FIG. 9 is a front view showing a positive electrode plate 220S before the positive electrode plate 220 (second electrode) is formed, FIG. 10 is a cross-sectional view of the positive electrode plate 220S shown in FIG. 9 taken along line XX, and FIG. 11 is a front view showing a positive electrode plate 220 formed from the positive electrode plate 220S.

[0058] 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.

[0059] A positive electrode active material layer 222 is formed on both surfaces 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 using a die coater.

[0060] 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.

[0061] The positive electrode protective layer 223 is in contact with the positive electrode core 221 and is formed on one end of the positive electrode active material layer 222 in the width direction. The positive electrode protective layer 223 is formed on the positive electrode core 221 by applying a positive electrode protective layer slurry using a die coater. The positive electrode protective layer 223 has a larger electrical resistance than the positive electrode active material layer 222.

[0062] 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.

[0063] The positive electrode substrate 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, thereby forming the positive electrode active material layer 222 and the positive electrode protective layer 223. The positive electrode active material layer 222 is then compressed to form a positive electrode base plate 220S including the positive electrode substrate 221, the positive electrode active material layer 222, and the positive electrode protective layer 223. The positive electrode base plate 220S is cut into a predetermined shape to form the positive electrode plate 220. The positive electrode base plate 220S can be cut by laser processing using energy beam irradiation, mold processing, cutter processing, or the like.

[0064] As shown in FIG. 11 , a plurality of positive electrode tabs 220B each made of a positive electrode core 221 is 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 adjusted as appropriate, taking into account 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 the example shown in FIG. 11 .

[0065] A positive electrode protective layer 223 is provided at the base of each of the multiple 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.

[0066] 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.

[0067] (Connection structure between electrode body 200 and current collector 300) Fig. 12 is a diagram showing the electrode body 200 and current collector 300 removed from the secondary battery 1. As shown in Fig. 12, the electrode body 200 is formed by stacking two electrode bodies 201 and 202, each of which is a wound electrode body. The example shown in Fig. 12 shows a structure in which two wound electrode bodies are stacked, but the electrode body 200 may be composed of one wound electrode body, three or more wound electrode bodies, or a stacked electrode body.

[0068] 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, caulking, or the like.

[0069] Fig. 13 is a diagram showing a connection structure between a negative electrode tab group 210A and a 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.

[0070] 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.

[0071] The negative electrode tab group 210A is joined to the first conductive member 311 of the negative electrode current collector 310 at a joint 310A. The first conductive member 311 is connected to the second conductive member 312 at a joint 313. The joint 313 can be formed by, for example, ultrasonic bonding, resistance welding, laser welding, caulking, or the like.

[0072] First conductive member 311 and second conductive member 312 are attached to the inner surface side of first sealing plate 121 via insulating member 410 made of resin.

[0073] 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 exposed to the outside of the first sealing plate 121 and is provided so as to reach the second conductive member 312 of the negative electrode current collector 310 provided on the inside 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, or crimping. In the present 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 onto the second conductive member 312, and then the crimped portion and the second conductive member 312 are welded at a joint 131A, thereby connecting the negative electrode terminal 131 and the second conductive member 312.

[0074] The procedure for assembling the components is as follows: 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. Next, 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 the second conductive member 312. Next, the first conductive member 311 and the second conductive member 312 are welded together at the joint 313. Note that the insulating members 410 and 410A may be formed from a single member.

[0075] However, negative electrode terminal 131 may be electrically connected to first sealing plate 121. Also, first sealing plate 121 may serve as negative electrode terminal 131.

[0076] 13 to 15 show an example of the negative electrode current collector 310 made up of two parts (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 part.

[0077] 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 the same as that on the negative electrode side.

[0078] (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, an insulating sheet 600 (electrode body holder) made of resin is placed between the electrode body 200 and the case body 110.

[0079] 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).

[0080] The insulating sheet 600 does not necessarily have to cover the entire surface of the electrode assembly 200. The insulating sheet 600 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 approximately rectangular parallelepiped (flat) electrode assembly 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.

[0081] Fig. 17 is a diagram showing a process of placing 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 has been placed between the first sealing plate 121 and the electrode body 200.

[0082] 17 and 18, the negative electrode tab group 210A extending from the electrode body 200 toward the first sealing plate 121 is curved from the center in the Y-axis direction of the first sealing plate 121 toward the edge, and then folded back toward the center. A spacer 510 is provided to accommodate the curved negative electrode tab group 210A (curved portion).

[0083] 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 of the first sealing plate 121. This fixes the spacer 510 to the first sealing plate 121 via the insulating member 410, increasing the stability of the position of the spacer 510.

[0084] 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 through.

[0085] 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). Furthermore, an insulating sheet 600 may be interposed between the spacer 510 and the electrode assembly 200.

[0086] 16 , 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 assembly 200 is inserted into the case body 110 through the first opening 111 from the end side on the positive electrode tab group 220A side. When the electrode assembly 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. This allows the positive electrode terminal 132 to be connected to the positive electrode tab group 220A after the electrode assembly 200 is inserted into the case body 110.

[0087] 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 assembly 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 assembly 200 housed 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 assembly 200 into the case body 110, the length of the negative electrode tab group 210A can be reduced compared to when the connection is made after the electrode assembly 200 is inserted into the case body 110. As a result, the volume occupancy of the negative electrode plate 210 and the positive electrode plate 220 in the internal space of the case body 110 can be increased.

[0088] 16, a spacer 510 that accommodates the curved portion of the negative electrode tab group 210A is placed before the electrode body 200 is inserted into the case body 110. In this way, the curved portion of the negative electrode tab group 210A can be protected during the electrode body 200 insertion process.

[0089] 16, the electrode body 200 is inserted into the case body 110 while covered with the insulating sheet 600. This makes it possible to prevent damage to the electrode body 200 when it is inserted into the case body 110.

[0090] 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 while holding the case body 110 so that the X-axis direction (the width direction of the case body 110) intersects with the horizontal direction at an angle of approximately ±45° or less. For example, the electrode body 200 can be inserted into the case body 110 with the case body 110 tilted in the vertical direction 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.

[0091] 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, but may be a mode in which the electrode body 200 is pulled from the second opening 112 side, for example.

[0092] 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 over a portion of the first sealing plate 121 in the height direction (Z-axis direction). However, as shown in FIG. 19, the spacer 510 may be disposed over substantially the entire height direction of the first sealing plate 121. In this case, the spacer 510 may have a portion that protrudes toward the electrode assembly 200 at a position (first region) spaced apart from the negative electrode tab group 210A in the Z-axis direction relative to the vicinity of the negative electrode tab group 210A (second region). A step (preferably a step of approximately 1 mm or more) may be formed at the boundary between the first region and the second region. This can prevent damage to the negative electrode tab group 210A when the electrode assembly 200 is inserted into the case body 110.

[0093] (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.

[0094] As shown in FIGS. 20 and 21 , the spacer 510A is disposed in a position (apart from the negative electrode tab group 210A and the negative electrode current collector 310) that avoids 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 assembly 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 against a portion of the electrode assembly 200 where the negative electrode tab group 210A is not provided. In particular, it is preferable for the spacer 510A to press against a portion where the separator protrudes beyond the end of the negative electrode plate 210. The spacer 510A may be disposed on only one side of the negative electrode tab group 210A in the Z-axis direction. The spacer 510A can be fixed to the first sealing plate 121 and / or the electrode assembly 200 by, for example, adhesive bonding, welding, or taping. The spacer 510A may be in contact with the negative electrode tab group 210A.

[0095] 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.

[0096] 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 without being brought into contact with the electrode body 200, and after a portion of the electrode body 200 has been inserted into the case body 110, the electrode body 200 may be further inserted by pressing the electrode body 200 via the spacer 510A.

[0097] Instead of the spacers described above, 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 tape.

[0098] Note that, from the viewpoint of protecting the positive electrode tab group 220A, the spacers 510 and 510A may be provided on the positive electrode tab group 220A side. It is also preferable that the spacer to be provided on the positive electrode tab group 220A side has an opening for passing the electrolyte solution at a position facing the second through hole 142. The opening may have any shape as long as it allows the electrolyte solution to pass through.

[0099] When the thickness (thickness in the direction connecting first sealing plate 121 and second sealing plate 122 (X-axis direction)) of the spacer arranged on the negative electrode tab group 210A side and the spacer arranged on the positive electrode tab group 220A side is compared, 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, it is preferable that the thickness of the spacer arranged on the positive electrode tab group 220A side is larger than the thickness of the spacer arranged on the negative electrode tab group 210A side.

[0100] 17 and 18, the negative electrode tab group 210A is bent and connected to the negative electrode current collector 310, and a negative electrode terminal 131 is further connected to the negative electrode current collector 310. Similarly, the positive electrode tab group 220A is bent and connected to the positive electrode current collector 320, and a positive electrode terminal 132 is further connected to the positive electrode current collector 320 (see FIG. 20). The bonding surfaces of the negative electrode tab group 210A and the negative electrode current collector 310 are preferably arranged parallel to each other along the first sealing plate 121, but do not necessarily have to be parallel. For example, they are preferably arranged within a range of ±30 degrees. Similarly, the bonding surfaces of the positive electrode tab group 220A and the positive electrode current collector 320 are preferably arranged parallel to each other along the second sealing plate 122, but do not necessarily have to be parallel. For example, they are preferably arranged within a range of ±30 degrees.

[0101] 22 to 24, spacers of other configurations are illustrated. Fig. 22 is a perspective view of a spacer 510B of another configuration, Fig. 23 is a perspective view of a spacer 510C of another configuration, and Fig. 24 is a perspective view of a spacer 510D of another configuration. The spacers shown below can be arranged on either the negative electrode tab group 210A side or the positive electrode tab group 220A side.

[0102] 22 has a rectangular opening 510h1 on the side facing the electrode body 200. In the case of this spacer 510B, the opening 510h1 is located at a position facing the first through-hole 141 (or the second through-hole 142).

[0103] 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, and the flow path area necessary for degassing and liquid injection can be ensured, and further, there is an advantage that the injected solvent is less likely to accumulate.

[0104] 24 has a rectangular opening 510h3 at a position that does not face the first through-hole 141 (or the second through-hole 142). The position of this opening 510h3 is perpendicular to the direction in which the electrode tab is curved. As a result, it is possible to prevent the separator from being bent or the electrode (including the tab) from being damaged by the force of the liquid injection, to apply pressure evenly when inserting the electrode assembly, and to prevent the curved electrode tab from protruding from the space within the spacer.

[0105] The outer shape of the spacer and the position and shape of the openings are not limited to those of the above-mentioned spacer, but by providing appropriate openings in the spacer that is arranged for the purpose of protecting the negative electrode tab group 210A and the positive electrode tab group 220A, it is possible to suppress damage to the electrode body, or suppress unintended short circuits, and suppress deterioration in the electrolyte injection property.

[0106] When the first opening 111 is sealed with the first sealing plate 121, the negative electrode terminal 131 and the first sealing plate 121 are insulated from each other. In this case, an insulating member such as a resin member may be disposed between the negative electrode terminal 131 and the first sealing plate 121. The negative electrode terminal 131 and the first sealing plate 121 may be electrically connected. The first sealing plate 121 may also serve as the negative electrode terminal.

[0107] When second opening 112 is sealed with second sealing plate 122, positive electrode terminal 132 and second sealing plate 122 are insulated from each other. In this case, an insulating member such as a resin member may be disposed between positive electrode terminal 132 and second sealing plate 122. Note that positive electrode terminal 132 and second sealing plate 122 may be electrically connected. Second sealing plate 122 may also serve as a second electrode terminal.

[0108] (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 assembly 200 is fabricated. 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 assembly 200. At this time, the negative electrode terminal 131 is first electrically connected to the negative electrode tab group 210A (S31), and then a spacer 510 is placed between the first sealing plate 121 on the negative electrode side and the electrode assembly 200 (S40), and then the electrode assembly 200 is inserted into the case body 110 (S50). At this time, the positive electrode tab group 220A protrudes outside 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).

[0109] In the present embodiment, an example has been described in which the steps are performed in the order of connecting the negative electrode terminal 131 and the negative electrode tab group 210A (S31), inserting the electrode body 200 (S50), and connecting the positive electrode terminal 132 and the positive electrode tab group 220A (S32). 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 connecting the positive electrode terminal 132 and the positive electrode tab group 220A (S32), inserting the electrode body 200 (S50), and connecting the negative electrode terminal 131 and the negative electrode tab group 210A (S31).

[0110] 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 using the first sealing plate 121 and the second sealing plate 122 is performed by, for example, laser welding.

[0111] The step (S61) of sealing the first opening 111 with the first sealing plate 121 on the negative electrode side may be performed after the step (S50) of inserting the electrode body 200 into the case body 110, and the step (S62) of sealing the second opening 112 with the second sealing plate 122 on the positive electrode side may be performed after the step (S32) of electrically connecting the positive electrode terminal 132 and the positive electrode tab group 220A.

[0112] 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 may be performed simultaneously.

[0113] Next, a step (S70) is performed in which the electrolyte solution is injected into the exterior body 100 through the second through hole 142. It is preferable to use the second through hole 142 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 solution. On the other hand, since the first through hole 141 is provided on the opposite side, it is preferable to use this first through hole 141 as an exhaust hole for gas (air, nitrogen, etc.) inside the exterior body 100. This can improve the injection of the electrolyte solution into the exterior body 100. It is also possible to inject the electrolyte solution through the first through hole 141 and exhaust the gas through the second through hole 142.

[0114] In the step of injecting the electrolyte solution into the exterior body 100, a device for injecting the electrolyte solution is attached to the second through-hole 142, and a device capable of exhausting air is attached to the first through-hole 141. The device attached to the second through-hole 142 may also be a device capable of exhausting air.

[0115] 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 141a (first sealing step), and the second through-hole 142 is sealed with the second sealing member 142a (second sealing step). Either the first sealing step or the second sealing step may be performed first. The first sealing member 141a and the second sealing member 142a are fixed to the case body 110 by crimping, for example, using blind rivets or other metal members. Alternatively, the first sealing member 141a and the second sealing member 142a are fixed to the case body 110 by welding.

[0116] It is also possible to seal one of the first through-hole 141 and the second through-hole 142, and then inject the electrolyte solution into the exterior body 100 from the other unsealed hole. In this case, after sealing one of the first through-hole 141 and the second through-hole 142, the inclination of the exterior body 100 may be changed so that the other unsealed hole is positioned higher in the vertical direction before injection.

[0117] Here, after performing one of the first sealing step and the second sealing step, 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 can be 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.

[0118] (summary) The above-described contents of the secondary battery 1 and the method for manufacturing the secondary battery 1 according to this embodiment can be summarized as follows.

[0119] This secondary battery 1 includes an electrode assembly 200 including a negative electrode plate 210 and a positive electrode plate 220 having a polarity different from that of the negative electrode plate 210, an exterior body 100 that accommodates the electrode assembly 200 and an electrolyte, a negative electrode terminal 131 that is electrically connected to the negative electrode plate 210 and provided on the exterior body 100, and a positive electrode terminal 132 that is electrically connected to the positive electrode plate 220 and provided on the exterior body 100, and the exterior body 100 includes a first terminal 131 and a second terminal 132 that are arranged to face each other. The secondary battery 1 includes a sealing plate 121 and a second sealing plate 122, the first sealing plate 121 including a first through hole 141 and a first sealing member 141a that seals the first through hole 141, the second sealing plate 122 including a second through hole 142 and a second sealing member 142a that seals the second through hole 142, the first sealing member 141a being different from the negative electrode terminal 131 and the positive electrode terminal 132, and the second sealing member 142a being different from the negative electrode terminal 131 and the positive electrode terminal 132. Since this secondary battery 1 has the first through hole 141 and the second through hole 142, it is possible to provide a secondary battery 1 that can be stably manufactured, with improved liquid injection properties.

[0120] In one example of a secondary battery 1, an exterior body 100 includes a case main 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, wherein a negative electrode terminal 131 is provided on the first sealing plate 121 and a positive electrode terminal 132 is provided on the second sealing plate 122, and the electrode body 200 includes, at one end, a negative electrode tab group 210A consisting of a plurality of negative electrode tabs 210B electrically connected to a negative electrode plate 210, and at the other end, a positive electrode tab group 220A consisting of a plurality of positive electrode tabs 220B electrically connected to a positive electrode plate 220, the negative electrode tab group 210A being electrically connected to the negative electrode terminal 131, and the positive electrode tab group 220A being electrically connected to the positive electrode terminal 132.

[0121] In one example of a secondary battery 1, the negative electrode tab group 210A is bent and joined to the negative electrode terminal 131 or a negative electrode current collector 310 electrically connected to the negative electrode terminal 131, and the positive electrode tab group 220A is bent and joined to the positive electrode terminal 132 or a positive electrode current collector 320 electrically connected to the positive electrode terminal 132.

[0122] In the secondary battery 1 according to one example, in the longitudinal direction (Z direction) of the first sealing plate 121, the first through-hole 141 is disposed offset in the first direction (Z direction) from the center of the first sealing plate 121, and in the longitudinal direction (Z direction) of the second sealing plate 122, the second through-hole 142 is disposed offset in the first direction (Z direction) from the center of the second sealing plate 122. For example, when the direction connecting the first sealing plate 121 and the second sealing plate 122 is oriented substantially horizontally, the first through-hole 141 and the second through-hole 142 are each formed in a position close to the upper surface, making it easier to inject the electrolyte into the exterior body 100.

[0123] The method for manufacturing this secondary battery 1 includes a liquid injection process for injecting electrolyte into the outer casing 100 through at least one of the first through hole 141 and the second through hole 142 in the secondary battery 1 having the above configuration, a first sealing process for sealing the first through hole 141 with a first sealing member 141a, and a second sealing process for sealing the second through hole 142 with a second sealing member 142a.

[0124] In one example of a method for manufacturing a secondary battery 1, the injection step involves injecting an electrolyte solution into the exterior body 100 from one of the first through-hole 141 and the second through-hole 142, and discharging gas inside the exterior body 100 to the outside of the exterior body 100 from the other of the first through-hole 141 and the second through-hole 142. This allows the electrolyte solution to be injected efficiently by natural exhaust.

[0125] In one example method for manufacturing secondary battery 1, positive electrode plate 220 has positive electrode active material layer 222, and when the distance between first sealing plate 121 and the end of positive electrode active material layer 222 on the first sealing plate 121 side in a direction connecting first sealing plate 121 and second sealing plate 122 is D1 and the distance between second sealing plate 122 and the end of positive electrode active material layer 222 on the second sealing plate 122 side is D2, the relationship D2 > D1 is satisfied, and the injection step includes a step of injecting electrolyte solution into exterior body 100 from second through hole 142. This allows for more efficient injection of electrolyte solution.

[0126] (Action and effect) The secondary battery 1 and its manufacturing method according to this embodiment enable efficient manufacturing of the secondary battery 1 and improved injection of electrolyte. For example, by arranging the secondary battery 1 with the longitudinal direction of the exterior body 100 horizontal, injection of electrolyte into the exterior body 100 can be improved. As a result, the secondary battery 1 can be manufactured more efficiently and stably.

[0127] 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]

[0128] REFERENCE SIGNS LIST 1 secondary battery, 100 outer casing, 110 case body, 110A joint, 111 first opening, 112 second opening, 121 first sealing plate, 122 second sealing plate, 131 negative electrode terminal, 131A joint, 132 positive electrode terminal, 141 first through hole, 141a first sealing member, 142 second through hole, 142a second sealing member, 151, 152 gas release valve, 200, 201, 202 electrode body, 210 negative electrode plate, 210A negative electrode tab group, 210B negative electrode tab, 210S negative electrode base plate, 211 negative electrode core, 212 negative electrode active material layer, 220 positive electrode plate, 220A positive electrode tab group, 220B positive electrode tab, 220S positive electrode base plate, 221 Positive electrode core, 222 positive electrode active material layer, 223 positive electrode protective layer, 300 current collector, 310 negative electrode current collector, 310A joint portion, 311 first conductive member, 312 second conductive member, 313 joint portion, 320 positive electrode current collector, 320A joint portion, 410 insulating member, 411 first insulating member, 412 second insulating member, 510, 510A, 510B, 510C, 510D spacers, 510B1, 510C1 protrusions, 510D1 joint portion, 511 first spacer, 512 second spacer, 600 insulating sheet.

Claims

1. an electrode assembly including a first electrode and a second electrode having a polarity different from that of the first electrode; an exterior body that accommodates the electrode assembly and an electrolyte; a first electrode terminal electrically connected to the first electrode and provided on the exterior body; a second electrode terminal electrically connected to the second electrode and provided on the exterior body; Equipped with the exterior body includes a first wall and a second wall arranged to face each other, the first wall includes a first through hole and a first sealing member that seals the first through hole, the second wall includes a second through hole and a second sealing member that seals the second through hole, the first through-hole is at least one of a liquid inlet and a gas outlet, and the second through-hole is at least a liquid inlet; the second electrode has a second electrode active material layer; In a direction connecting the first wall and the second wall, a distance between the first wall and an end of the second electrode active material layer on the first wall side is defined as D1; When the distance between the second wall and the end of the second electrode active material layer on the second wall side is D2, the relationship D2>D1 is satisfied, The first sealing member is different from the first electrode terminal and the second electrode terminal, the second sealing member is different from the first electrode terminal and the second electrode terminal; Secondary battery.

2. 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, the first wall is the first sealing plate, the second wall is the second sealing plate, the first sealing plate is provided with the first electrode terminal; the second sealing plate is provided with the second electrode terminal; The electrode body is a first electrode tab group including a plurality of first electrode tabs electrically connected to the first electrode at one end; a second electrode tab group including a plurality of second electrode tabs electrically connected to the second electrode at the other end; the first electrode tab group is electrically connected to the first electrode terminals, the second electrode tab group is electrically connected to the second electrode terminals; The secondary battery according to claim 1 .

3. the first electrode tab group is bent and joined to the first electrode terminal or a first electrode current collecting member electrically connected to the first electrode terminal; the second electrode tab group is bent and joined to the second electrode terminal or a second electrode current collecting member electrically connected to the second electrode terminal; The secondary battery according to claim 2 .

4. In the longitudinal direction of the first wall, the first through hole is disposed offset from the center of the first wall toward a first direction, In the longitudinal direction of the second wall, the second through hole is disposed so as to be shifted from the center of the second wall toward the first direction. The secondary battery according to claim 1 .

5. an electrode assembly including a first electrode and a second electrode having a polarity different from that of the first electrode; an exterior body that accommodates the electrode assembly and an electrolyte; a first electrode terminal electrically connected to the first electrode and provided on the exterior body; a second electrode terminal electrically connected to the second electrode and provided on the exterior body; Equipped with the exterior body includes a first wall and a second wall arranged to face each other, the first wall includes a first through hole and a first sealing member that seals the first through hole, the second wall includes a second through hole and a second sealing member that seals the second through hole, The first sealing member is different from the first electrode terminal and the second electrode terminal, the second sealing member is different from the first electrode terminal and the second electrode terminal; A method for manufacturing a secondary battery having the following configuration: the second electrode has a second electrode active material layer; In a direction connecting the first wall and the second wall, a distance between the first wall and an end of the second electrode active material layer on the first wall side is defined as D1; When the distance between the second wall and the end of the second electrode active material layer on the second wall side is D2, the relationship D2>D1 is satisfied, a liquid injection step of injecting an electrolyte into the exterior body through at least one of the first through hole and the second through hole; a first sealing step of sealing the first through hole with the first sealing member; a second sealing step of sealing the second through hole with the second sealing member; Equipped with the liquid injection step is a step of injecting the electrolyte into the exterior body through the second through hole; and performing at least one of a step of injecting the electrolyte solution into the exterior body from the first through hole and a step of discharging gas inside the exterior body to the outside of the exterior body from the first through hole. A method for manufacturing a secondary battery.

6. the liquid injection step includes a step of discharging gas from the exterior body to the outside of the exterior body through the first through hole. The method for manufacturing a secondary battery according to claim 5 .

7. An electrode body including a first electrode and a second electrode having a polarity different from that of the first electrode; an exterior body that accommodates the electrode assembly and an electrolyte; a first electrode terminal electrically connected to the first electrode and provided on the exterior body; a second electrode terminal electrically connected to the second electrode and provided on the exterior body; Equipped with the exterior body includes a first wall and a second wall arranged to face each other, the first wall includes a first through hole and a first sealing member that seals the first through hole, the second wall includes a second through hole and a second sealing member that seals the second through hole, the first through-hole is at least one of a liquid inlet and a gas outlet, and the second through-hole is at least a liquid inlet; The electrode body is a first electrode tab group including a plurality of first electrode tabs electrically connected to the first electrode at one end; a second electrode tab group including a plurality of second electrode tabs electrically connected to the second electrode at the other end; the first electrode tab group is formed in a partial region in a width direction of one end of the electrode body, at one end of the electrode body; the second electrode tab group is formed in a partial region in the width direction of the other end of the electrode body, at the other end of the electrode body; When viewed in a direction perpendicular to the first wall, the first through-holes are disposed at positions that do not overlap with the first electrode tab group, When viewed in a direction perpendicular to the second wall, the second through-holes are disposed at positions that do not overlap with the second electrode tab group, The first sealing member is different from the first electrode terminal and the second electrode terminal, the second sealing member is different from the first electrode terminal and the second electrode terminal; Secondary battery.

8. A spacer is disposed between the second wall and the electrode body, the spacer includes a first region (base portion) that is disposed in a direction corresponding to the second wall; A plurality of openings are formed in the first region. The secondary battery according to claim 7 .

9. An electrode body including a first electrode and a second electrode having a polarity different from that of the first electrode; an exterior body that accommodates the electrode assembly and an electrolyte; a first electrode terminal electrically connected to the first electrode and provided on the exterior body; a second electrode terminal electrically connected to the second electrode and provided on the exterior body; Equipped with the exterior body includes a first wall and a second wall arranged to face each other, the first wall includes a first through hole and a first sealing member that seals the first through hole, the second wall includes a second through hole and a second sealing member that seals the second through hole, the first through-hole is at least one of a liquid inlet and a gas outlet, and the second through-hole is at least a liquid inlet; a spacer is disposed between the second wall and the electrode body; the spacer has an opening in a portion facing the second through hole, The first sealing member is different from the first electrode terminal and the second electrode terminal, the second sealing member is different from the first electrode terminal and the second electrode terminal; Secondary battery.

10. The spacer includes a first region arranged in a direction corresponding to the second wall, and a second region (peripheral wall) protruding from the outer peripheral edge of the first region (base portion) toward the second wall, and the opening is formed in the first region. The secondary battery according to claim 9.

11. A second spacer is disposed between the first wall and the electrode body, and the second spacer has a second opening in a portion facing the first through hole. The secondary battery according to claim 9.

12. An electrode body including a first electrode and a second electrode having a polarity different from that of the first electrode; an exterior body that accommodates the electrode assembly and an electrolyte; a first electrode terminal electrically connected to the first electrode and provided on the exterior body; a second electrode terminal electrically connected to the second electrode and provided on the exterior body; Equipped with the exterior body includes a first wall and a second wall arranged to face each other, the first wall includes a first through hole and a first sealing member that seals the first through hole, the second wall includes a second through hole and a second sealing member that seals the second through hole, the first through-hole is at least one of a liquid inlet and a gas outlet, and the second through-hole is at least a liquid inlet; a spacer is disposed between the second wall and the electrode body; the spacer includes a first region disposed in a direction corresponding to the second wall, and a second region protruding from an outer circumferential edge of the first region toward the second wall; An opening is provided in the second region, No opening is provided in a portion of the first region facing the second through hole, The first sealing member is different from the first electrode terminal and the second electrode terminal, the second sealing member is different from the first electrode terminal and the second electrode terminal; Secondary battery.

13. A spacer is disposed between the first wall and the electrode body, the spacer includes a third region (base portion) disposed in a direction corresponding to the first wall, and a fourth region (outer peripheral wall) protruding from an outer peripheral edge of the third region toward the first wall, an opening is provided in the fourth region; No opening is provided in a portion of the third region facing the first through hole. The secondary battery according to claim 12.

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