Method for manufacturing secondary battery

Abstract

To improve energy density of a secondary battery.SOLUTION: A method for manufacturing a secondary battery sequentially includes the steps of: preparing a case body having a first opening and a second opening facing each other; preparing an electrode body, the electrode body including a first electrode, a second electrode with a different polarity from that of the first electrode, a first electrode tab connected to the first electrode in a first end part, and a second electrode tab connected to the second electrode in a second end part, the first end part and the second end part being located on opposite sides; electrically connecting the first electrode terminal provided in the first sealing plate and the first electrode tab to each other; inserting the electrode body into the case body from the second end part through the first opening after electrically connecting the first electrode terminal and the first electrode tab; electrically connecting a second electrode terminal provided in a second sealing plate and the second electrode tab to each other after inserting the electrode body into the case body; sealing the first opening by the first sealing plate after inserting the electrode body into the case body; and sealing the second opening by the second sealing plate after electrically connecting the second electrode terminal and the second electrode tab with each other.SELECTED DRAWING: Figure 28

Description

[Technical field]

[0001] The present technology relates to 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 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] There is a demand for further improvement in the energy density of secondary batteries. From the viewpoint of improving the energy density, there is room for further improvement in the battery described in Patent Document 1.

[0005] An object of the present technology is to provide a manufacturing method for a secondary battery that can obtain a secondary battery with high energy density. [Means for solving the problem]

[0006] The present technology provides the following method for producing a secondary battery.

[0007] [1] A method for manufacturing a secondary battery, comprising the steps of: preparing a case body having a first opening and a second opening opposing the first opening; preparing an electrode body including a first electrode and a second electrode having a polarity different from that of the first electrode, the electrode body having a first electrode tab connected to the first electrode at a first end and a second electrode tab connected to the second electrode at a second end opposite the first end; electrically connecting a first electrode terminal provided on a first sealing plate and the first electrode tab; inserting the electrode body into the case body from the second end side through the first opening after electrically connecting the first electrode terminal and the first electrode tab;

[0008] [2] The method for manufacturing a secondary battery according to [1], further comprising the step of placing a spacer between the first sealing plate and the electrode body, and inserting the electrode body into the case body by pressing the electrode body through the spacer with the first sealing plate.

[0009] [3] The method for manufacturing a secondary battery described in [2], wherein in the step of inserting the electrode body into the case body, the spacer abuts at a position spaced apart from the first electrode tab at the first end of the electrode body.

[0010] [4] The method for producing a secondary battery according to [2] or [3], wherein the step of arranging the spacer includes fixing the spacer to the first sealing plate.

[0011] [5] The method for producing a secondary battery according to [2] or [3], wherein the step of arranging the spacer includes fixing the spacer to the electrode body.

[0012] [6] The method for producing a secondary battery according to any one of [1] to [5], further comprising a step of covering the electrode assembly with an insulating electrode assembly holder before the electrode assembly is inserted into the case body.

[0013] [7] The method for manufacturing a secondary battery described in [1], further comprising a step of placing a spacer between the first sealing plate and the electrode body, wherein the electrode body is held and a part of the electrode body is inserted into the case body, and then the electrode body is inserted into the case body until the first sealing plate abuts against the case body by pressing the electrode body through the spacer with the first sealing plate. Effect of the Invention

[0014] According to the present technology, the height of the secondary battery can be reduced and the mountability of the secondary battery in a vehicle can be improved by inserting the electrode body into a case body having a first opening and a second opening facing each other, and providing a first electrode terminal and a second electrode terminal on a first sealing plate and a second sealing plate that seal the first opening and the second opening, respectively. Furthermore, after electrically connecting the first electrode terminal and the first electrode tab, the electrode body is inserted into the case body from the second end side through the first opening, that is, by attaching the first sealing plate to the first electrode tab before inserting the electrode body into the case body, it is possible to form the length of the first electrode tab relatively short compared to the case where the first sealing plate is attached to the first electrode tab after inserting the electrode body into the case body. As a result, the volume occupied by the electrode body in the space inside the case body can be increased, and the energy density of the secondary battery can be improved. [Brief description of the drawings]

[0015] [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 and 11B are diagrams showing a step of arranging a spacer between the sealing plate and the electrode body. [Figure 18] 11 is a cross-sectional view showing a state in which a spacer is disposed between a sealing plate and an electrode body. FIG. [Figure 19] FIG. 13 is a diagram showing a modified example of the spacer. [Figure 20] 13A and 13B are diagrams showing an example of a mechanism for pressing an electrode body via a 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 diagram showing a modified example of the spacer. [Figure 23] FIG. 2 is a diagram showing a modified example of the spacer (part 2). [Figure 24] FIG. 11 is a diagram (part 3) showing a modified example of the spacer. [Diagram 25] FIG. 4 is a diagram showing a modified example of the spacer. [Figure 26] FIG. 5 is a diagram showing a modified example of the spacer. [Figure 27]FIG. 6 is a diagram showing a modified example of the spacer. [Figure 28] FIG. 2 is a flow chart showing each step of a method for producing a secondary battery. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 will not be repeated.

[0017] 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.

[0018] 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.

[0019] 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).

[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. In addition, 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 on a vehicle.

[0023] 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 body 110, a sealing plate 121 (first sealing plate), and a sealing plate 122 (second sealing plate).

[0024] In this specification, the X-axis direction (first direction) shown in Figures 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.

[0025] 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.

[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] As shown in Figures 1 and 2, sealing plates 121, 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 ends of bent plate-like members (joint 110A shown in Figure 2) and joining them together (for example, by laser welding). The corners of the "square tube" may have a rounded shape.

[0028] 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. 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 configured. 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 (low height) secondary battery 1 to be configured, improving the mountability in a vehicle, for example.

[0029] 3, an opening 111 (first opening) is provided at one end of the case body 110. The opening 111 is sealed by a sealing plate 121. A negative electrode terminal 131 (first electrode terminal), a liquid injection hole 141, and a gas exhaust valve 151 are provided on the sealing plate 121. The positions of the negative electrode terminal 131, the liquid injection hole 141, and the gas exhaust valve 151 can be changed as appropriate. The opening 111 and the 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.

[0030] 4, an opening 112 (second opening) is provided at one end of the case body 110. The opening 112 is sealed by a sealing plate 122. A positive electrode terminal 132 (second electrode terminal), a liquid injection hole 142, and a gas exhaust valve 152 are provided on the sealing plate 122. The positions of the positive electrode terminal 132, the liquid injection hole 142, and the gas exhaust valve 152 can be changed as appropriate. The opening 112 and the 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.

[0031] The sealing plates 121 and 122 are made of metal. Specifically, the sealing plates 121 and 122 are made of aluminum, an aluminum alloy, iron, an iron alloy, or the like.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The liquid inlet holes 141 and 142 are sealed with a sealing member (not shown) which may be, for example, a blind rivet or other metal member.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The electrode body 200 includes a negative electrode tab group 210A (first electrode tab group) provided at an end (first end) on the sealing plate 121 side, and a positive electrode tab group 220A (second electrode tab group) provided at an end (second end) on the 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 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 of the electrode body 200 (a portion where a positive electrode plate and a negative electrode plate are stacked with a separator interposed therebetween) toward the sealing plates 121, 122, respectively.

[0041] 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.

[0042] The negative electrode current collector 310 is disposed on the sealing plate 121 via a resin insulating member 410. 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.

[0043] The positive electrode current collector 320 is disposed on the sealing plate 122 via a resin insulating member 420. 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 sealing plate 122 directly or via the positive electrode current collector 320. In this case, the sealing plate 122 may also serve as the positive electrode terminal 132.

[0044] (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 line VII-VII of the negative electrode original plate 210S shown in FIG. 6, and FIG. 8 is a front view showing the negative electrode plate 210 formed from the negative electrode original plate 210S.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] A positive electrode protection layer 223 is provided at the base of each of the positive electrode tabs 220B. The positive electrode protection layer 223 does not necessarily have to be provided at the base of the positive electrode tab 220B.

[0059] 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.

[0060] (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.

[0061] 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, etc. The joints 310A, 320A form conductive paths between the negative electrode tab group 210A and the positive electrode tab group 220A and the negative electrode terminal 131 and the positive electrode terminal 132.

[0062] 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.

[0063] 13 to 15, the negative electrode current collector 310 is connected to the negative electrode terminal 131 between the electrode body 200 and the 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.

[0064] 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.

[0065] The first conductive member 311 and the second conductive member 312 are attached to the inner surface side of the sealing plate 121 via an insulating member 410 made of resin.

[0066] The negative electrode terminal 131 is attached to the 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 sealing plate 121 and reach the second conductive member 312 of the negative electrode current collector 310 provided on the inner side of the sealing plate 121. The negative electrode terminal 131 and the second conductive member 312 can be connected to each other 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.

[0067] As a procedure for assembling each part, first, the negative electrode terminal 131 and the second conductive member 312 are attached to the 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 with the second conductive member 312. Next, 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.

[0068] However, the negative electrode terminal 131 may be electrically connected to the sealing plate 121. Also, the sealing plate 121 may serve as the negative electrode terminal 131.

[0069] 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.

[0070] 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.

[0071] (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.

[0072] 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).

[0073] 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.

[0074] Fig. 17 is a diagram showing a process of arranging a spacer 510 between the 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 sealing plate 121 and the electrode body 200.

[0075] 17 and 18, the negative electrode tab group 210A extending from the electrode body 200 toward the sealing plate 121 is curved from the center in the Y-axis direction of the sealing plate 121 toward the end, and then bent back toward the center. A spacer 510 is arranged to accommodate the curved negative electrode tab group 210A (curved portion).

[0076] 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 sealing plate 121. As a result, the spacer 510 is fixed to the sealing plate 121 via the insulating member 410, and the positional stability of the spacer 510 is increased.

[0077] 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.

[0078] 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.

[0079] 16 again, in the method of 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 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 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.

[0080] When the negative electrode terminal 131 attached to the 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 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 connection is made 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.

[0081] 16, a spacer 510 for accommodating the curved portion of the negative electrode tab group 210A is placed, and then the electrode body 200 is inserted into the case body 110. In this manner, the curved portion of the negative electrode tab group 210A can be protected during the process of inserting the electrode body 200.

[0082] 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.

[0083] 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 where 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 opening 111 into which the electrode body 200 is inserted is positioned higher than the upper end of the opening 112 in the vertical direction.

[0084] 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 opening 111 side, but may be a mode in which the electrode body 200 is pulled from the opening 112 side, for example.

[0085] 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 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 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.

[0086] (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 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.

[0087] 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 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 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.

[0088] It is preferable to provide a through hole, a notch, a slit, or the like in the spacer 510A at a position facing the liquid inlet 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 liquid inlet 141 or the gas exhaust valve 151.

[0089] 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 so that a portion of the electrode body 200 is inserted into the case body 110, and then the electrode body 200 may be further inserted by pressing the electrode body 200 via the spacer 510A.

[0090] Next, further modified examples of the spacer 510A will be described with reference to FIGS.

[0091] 22 has two protrusions 510B1. The two protrusions 510B1 each have a tapered shape in which the width in the Y-axis direction decreases toward the tip. The tips of the two protrusions 510B1 are inserted between the electrode bodies 201, 202 and the inner surface of the case body 110. In the process of inserting the electrode body 200, the electrode bodies 201, 202 can be pressed into the inside of the case body 110 via the protrusions 510B1.

[0092] 23 has a protrusion 510C1. The protrusion 510C1 has a tapered shape in which the width in the Y-axis direction decreases toward the tip. The tip of the protrusion 510C1 is inserted between the electrode bodies 201, 202. In the process of inserting the electrode body 200, the electrode bodies 201, 202 can be pressed into the case body 110 via the protrusion 510C1.

[0093] The shape of the protrusions 510B1 and 510C1 can be changed as appropriate. For example, the tip of the protrusions 510B1 and 510C1 may have a curved shape (R shape).

[0094] 24 is fixed to the insulating sheet 600 at a joint 510D1. The joint 510D1 can be formed by, for example, thermal welding, adhesion, fitting, taping, etc. In the process of inserting the electrode body 200, the electrode bodies 201, 202 can be pressed into the inside of the case body 110 via the spacer 510D and the insulating sheet 600.

[0095] 24 shows a structure in which the insulating sheet 600 partially covers the spacer 510D, but the insulating sheet 600 may completely cover the spacer 510D. Also, instead of the joint 510D1 between the spacer 510D and the insulating sheet 600, or in addition to the joint 510D1, a joint between the insulating sheets 600 may be provided.

[0096] 25 also serves as an insulating part that provides insulation between the negative electrode current collector 310 and the sealing plate 121. With this configuration, the spacer 510E can more stably press the electrode body 200 in the step of inserting the electrode body 200. The spacer 510E can be fitted into a recess 121A provided in the sealing plate 121.

[0097] Two spacers 510F (FIG. 26) are disposed separately on either side of the negative electrode current collector 310. The insulating member 410 includes a first insulating member 411 (gasket) provided between the negative electrode terminal 131 and the sealing plate 121, and a second insulating member 412 provided between the negative electrode current collector 310 and the sealing plate 121. The spacer 510F fits into a recess 121A provided in the sealing plate 121.

[0098] 25 and 26, the spacers 510E, 510F can be fixed to the sealing plate 121 by a recessed and protruding fit between the spacers 510E, 510F and the sealing plate 121. Other fixing means (adhesive, welding, taping, etc.) may be used instead of or in addition to this recessed and protruding fit. Latch fixing may also be used.

[0099] 27 is disposed so as to cross the curved portion of the negative electrode tab group 210A in the Z-axis direction. In the process of inserting the electrode body 200, the electrode body 200 can be pressed into the case body 110 via the spacer 510G.

[0100] Instead of each of the spacers described above, a spacer may be disposed that is fixed to the electrode assembly 200. The spacer is fixed to the electrode assembly 200 by, for example, attaching a tape.

[0101] (Manufacturing process of secondary battery 1) FIG. 28 is a flow diagram showing each step of the manufacturing method of the secondary battery 1. As shown in FIG. 28, 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 sealing plates 121, 122 and the electrode tab group of the electrode body 200 are electrically connected. At this time, the negative electrode terminal 131 and the negative electrode tab group 210A are first electrically connected (S31), and then a spacer 510 is placed between the 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 from the opening 112 of the case body 110 to the outside 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).

[0102] 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.

[0103] After the connection between the electrode terminals and the electrode tab group (S30) is completed, the openings 111, 112 are sealed with sealing plates 121, 122, respectively (S60). The sealing step with sealing plates 121, 122 is performed by, for example, laser welding.

[0104] The process (S61) of sealing the opening 111 with the negative electrode side sealing plate 121 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 opening 112 with the positive electrode side sealing plate 122 may be performed after the process (S32) of electrically connecting the positive electrode terminal 132 and the positive electrode tab group 220A.

[0105] Therefore, for example, the step (S61) of sealing opening 111 with 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 opening 111 with sealing plate 121 may be performed after the step (S62) of sealing opening 112 with sealing plate 122. Furthermore, at least some of the steps (S61, S62) of sealing with sealing plates 121, 122 can be performed simultaneously.

[0106] (summary) The above-mentioned content of the method for manufacturing the secondary battery 1 according to the present embodiment can be summarized as follows.

[0107] As shown in FIG. 28, the method for manufacturing the secondary battery 1 includes a step (S10) of preparing a case body 110 having an opening 111 and an opening 112 facing the opening 111, a step (S20) of producing an electrode body 200 including a negative electrode plate 210 and a positive electrode plate 220, the electrode body 200 having a negative electrode tab group 210A including a negative electrode tab 210B connected to the negative electrode plate 210 at one end and a positive electrode tab group 220A including a positive electrode tab 220B connected to the positive electrode plate 220 at the other end, a step (S31) of electrically connecting a negative electrode terminal 131 provided on a sealing plate 121 to the negative electrode tab group 210A, and a step (S32) of electrically connecting the negative electrode terminal 131 to the negative electrode tab group 210A. the step (S50) of inserting the electrode body 200 into the case body 110 through the opening 111 from the end side on the positive electrode tab group 220A side after electrically connecting the electrode body 200 to the positive electrode tab group 220A; the step (S32) of electrically connecting the positive electrode terminal 132 provided on the sealing plate 122 to the positive electrode tab group 220A after inserting the electrode body 200 into the case body 110; the step (S61) of inserting the electrode body 200 into the case body 110 and sealing the opening 111 with the sealing plate 121; and the step (S62) of electrically connecting the positive electrode terminal 132 to the positive electrode tab group 220A and then sealing the opening 112 with the sealing plate 122.

[0108] In a manufacturing method of a secondary battery 1 according to an example, the electrode body 200 may be covered with an insulating sheet 600 before being inserted into the case body 110. However, in the present technology, the insulating sheet 600 covering the electrode body 200 is not necessarily required.

[0109] The method for manufacturing a secondary battery 1 according to an example further includes a step (S40) of arranging a spacer 510 between the sealing plate 121 and the electrode body 200. However, in the present technology, the step (S40) of arranging the spacer 510 is not necessarily required.

[0110] By disposing the spacer 510, the electrode body 200 can be inserted into the case body 110 by pressing the electrode body 200 via the spacer 510. When pressing the electrode body 200 via the spacer 510, the electrode body 200 may be pressed via the spacer 510 by pressing the sealing plate 121 from the X-axis direction, or the electrode body 200 may be pressed via the spacer 510 by moving the sealing plate 121 toward the electrode body 200 while holding it (clamping it in the Y-axis direction).

[0111] In the manufacturing method of the secondary battery 1, the electrode body 200 is held and a part of the electrode body 200 is inserted into the case body 110, and then the electrode body 200 is pressed by the sealing plate 121 via the spacer 510, so that the electrode body 200 can be inserted into the case body 110 until the sealing plate 121 abuts against the case body 110. As a result, at least the entire part of the electrode body 200 except for the positive electrode tab group 220A is disposed within the case body 110.

[0112] In the secondary battery 1 according to one example, in the step (S50) of inserting the electrode body 200 into the case body 110, the spacer 510 abuts on a position spaced from the negative electrode tab group 210A at the end of the electrode body 200 on the sealing plate 121 side. It is preferable that the spacer 510 presses the exposed portion of the separator included in the electrode body 200 directly or indirectly via an insulating sheet 600 or the like. However, the position at which the spacer 510 abuts on the electrode body 200 is changed as appropriate. Also, the spacer 510 does not necessarily have to abut on the electrode body 200.

[0113] In this embodiment, the spacer disposed on the negative electrode side has been described, but a similar spacer may be disposed on the positive electrode side. Spacers may be disposed on both the negative electrode side and the positive electrode side, or a spacer may be disposed on only one of the negative electrode side and the positive electrode side.

[0114] (Action and effect) According to the secondary battery 1 of this embodiment, the electrode body 200 is inserted into the case body 110 having openings 111 and 112 facing each other, and the negative electrode terminal 131 and the positive electrode terminal 132 are provided on the sealing plates 121 and 122 that seal the openings 111 and 112, respectively, thereby reducing the height of the secondary battery 1 and improving the mountability of the secondary battery 1 in a vehicle. Furthermore, after electrically connecting the negative electrode terminal 131 and the negative electrode tab group 210A, the electrode body 200 is inserted into the case body 110 from the positive electrode tab group 220A side through the opening 111. In other words, by attaching the sealing plate 121 to the negative electrode tab group 210A before inserting the electrode body 200 into the case body 110, it is possible to form the length of the negative electrode tab group 210A relatively short, compared to the case in which the sealing plate 121 is attached to the negative electrode tab group 210A after inserting the electrode body 200 into the case body 110. As a result, the volume that the electrode body 200 occupies in the space inside the case body 110 can be increased, and the energy density of the secondary battery 1 can be improved.

[0115] In the above example, a spacer 510 is disposed between the sealing plate 121 and the electrode body 200, and the electrode body 200 is pressed via the spacer to insert the electrode body 200 into the case body 110. This prevents excessive load from being applied to the negative electrode tab group 210A during the electrode body 200 insertion process, and can prevent damage to the negative electrode tab group 210A. Therefore, the secondary battery 1 can be manufactured more efficiently and stably.

[0116] 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]

[0117] 1 secondary battery, 100 exterior body, 110 case body, 110A joint, 111, 112 opening, 121, 122 sealing plate, 121A recess, 131 negative electrode terminal, 131A joint, 132 positive electrode terminal, 141, 142 liquid injection hole, 151, 152 gas exhaust 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, 311 First conductive member, 312 Second conductive member, 313 Joint, 320 Positive electrode current collector, 320A Joint, 410, 410A Insulating member, 411 First insulating member, 412 Second insulating member, 510, 510A, 510B, 510C, 510D, 510E, 510F, 510G Spacer, 510B1, 510C1 Protrusion, 510D1 Joint, 511 First spacer, 512 Second spacer, 600 Insulating sheet.

Claims

1. preparing a case body having a first opening and a second opening opposite the first opening; preparing an electrode assembly including a first electrode and a second electrode having a polarity different from that of the first electrode, the electrode assembly having a first electrode tab connected to the first electrode at a first end and a second electrode tab connected to the second electrode at a second end opposite to the first end; a step of electrically connecting a first electrode terminal provided on a first sealing plate to the first electrode tab; a step of electrically connecting the first electrode terminal and the first electrode tab, and then inserting the electrode body into the case body from the second end side through the first opening; a step of electrically connecting a second electrode terminal provided on a second sealing plate to the second electrode tab after inserting the electrode body into the case body; a step of inserting the electrode body into the case body and then sealing the first opening with the first sealing plate; and then sealing the second opening with the second sealing plate after electrically connecting the second electrode terminal and the second electrode tab.

2. The method further includes a step of disposing a spacer between the first sealing plate and the electrode body, The method for manufacturing a secondary battery according to claim 1 , wherein the electrode body is inserted into the case body by pressing the electrode body with the first sealing plate via the spacer.

3. 3. The method for manufacturing a secondary battery according to claim 2, wherein in the step of inserting the electrode body into the case body, the spacer abuts at a position spaced apart from the first electrode tab at the first end of the electrode body.

4. 4. The method for manufacturing a secondary battery according to claim 2, wherein the step of arranging the spacer includes fixing the spacer to the first sealing plate.

5. The method for producing a secondary battery according to claim 2 or 3, wherein the step of arranging the spacer includes fixing the spacer to the electrode body.

6. The method for manufacturing a secondary battery according to claim 1 , further comprising the step of covering the electrode assembly with an insulating electrode assembly holder before the electrode assembly is inserted into the case body.

7. The method further includes a step of disposing a spacer between the first sealing plate and the electrode body, 2. The method for manufacturing a secondary battery according to claim 1, wherein the electrode body is held and a portion of the electrode body is inserted into the case body, and then the electrode body is pressed by the first sealing plate via the spacer, thereby inserting the electrode body into the case body until the first sealing plate abuts against the case body.

Images