Method for manufacturing a secondary battery

Abstract

To provide a method for manufacturing a secondary battery with high reliability stably and efficiently.SOLUTION: A method for manufacturing a secondary battery 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; and inserting the electrode body into the case body from the second end part through a first opening. The step of inserting the electrode body into the case body includes drawing the electrode body from the second opening side.SELECTED DRAWING: Figure 36

Description

Technical Field

[0001] This technology relates to a method for manufacturing a secondary battery.

Background Art

[0002] Japanese Patent No. 4537353 (Patent Document 1) discloses 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 respectively attached to cap plates (33, 33') that seal the openings (14a, 14b).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, when manufacturing the secondary battery described in Patent Document 1, when housing the electrode group (25) in the case (14) having openings (14a, 14b) at both ends, lamination displacement, winding displacement, curling, etc. of the electrode plate and separator in the electrode body may occur. From the viewpoint of stably and efficiently manufacturing a highly reliable secondary battery, there is room for further improvement in the battery described in Patent Document 1.

[0005] An object of this technology is to provide a method for manufacturing a secondary battery capable of stably and efficiently manufacturing a highly reliable secondary battery.

Means for Solving the Problems

[0006] This technology provides the following method for manufacturing a secondary battery.

[0007] [1] A step of preparing a case body having a first opening and a second opening facing the first opening; a first electrode and a second electrode having a polarity different from that of the first electrode, and having a first electrode tab connected to the first electrode at a first end portion, and a second electrode tab connected to the second electrode at a second end portion opposite to the first end portion; a step of electrically connecting a first electrode terminal provided on a first sealing plate and the first electrode tab; a step of inserting the electrode body into the case body from the second end portion side through the first opening; a step of electrically connecting a second electrode terminal provided on a second sealing plate and the second electrode tab; a step of sealing the first opening with the first sealing plate after electrically connecting the first electrode terminal and the first electrode tab; and a step of sealing the second opening with the second sealing plate after electrically connecting the second electrode terminal and the second electrode tab. The step of inserting the electrode body into the case body includes attracting the electrode body from the second opening side. A method for manufacturing a secondary battery.

[0008] [2] The method for manufacturing a secondary battery according to [1], further comprising a step of covering the electrode body before being inserted into the case body with an insulating electrode body holder.

[0009] [3] The method for manufacturing a secondary battery according to [2], wherein the step of inserting the electrode body into the case body includes attracting the electrode body through the electrode body holder.

[0010] [4] Further comprising a step of disposing a spacer between the first sealing plate and the electrode body, and the step of inserting the electrode body into the case body includes attracting the electrode body holder through the spacer. The method for manufacturing a secondary battery according to [3].

[0011] [5] The method for manufacturing a secondary battery according to any one of [1] to [4], wherein the step of inserting the electrode body into the case body includes holding the electrode body, inserting a part of the electrode body into the case body, and then attracting the electrode body from the second opening side.

[0012] [6] The step of inserting the electrode body into the case body includes inserting a jig into the case body so as to penetrate the case body from the second opening toward the first opening, and then pulling the electrode body from the second opening side through the jig. The manufacturing method of the secondary battery according to any one of [1] to [4].

Advantages of the Invention

[0013] According to the present technology, in the step of inserting the electrode body into the case body, by pulling the electrode body from the second opening side, damage to the electrode body and the like can be effectively suppressed. As a result, it becomes possible to stably and efficiently manufacture a highly reliable secondary battery.

Brief Description of the Drawings

[0014]

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Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present technology will be described. In addition, the same or corresponding parts may be given the same reference numerals, and the description thereof may not be repeated.

[0016] In addition, in the embodiments described below, when referring to the number, amount, etc., unless otherwise specified, the scope of the present technology is not necessarily limited to the number, amount, etc. Also, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Further, the present technology is not limited to those that necessarily exhibit all the effects mentioned in this embodiment.

[0017] In this specification, the descriptions of "comprise", "include", and "have" are in an open-ended format. That is, when including a certain configuration, other configurations outside the said configuration may or may not be included.

[0018] In addition, in this specification, when geometric terms and terms representing positional and directional relationships, such as "parallel", "orthogonal", "45° oblique", "coaxial", "along", etc., are used, these terms allow for manufacturing errors or slight variations. When terms representing relative positional relationships, such as "upper side" and "lower side", are used in this specification, these terms are used to indicate the relative positional relationship in one state, and depending on the installation direction of each mechanism (for example, flipping the entire mechanism upside down, etc.), the relative positional relationship can be inverted or rotated at any angle.

[0019] In this specification, the "battery" is not limited to a lithium-ion battery and may include other batteries such as a nickel-metal hydride battery and a sodium-ion battery. In this specification, the "electrode" may be a general term for the positive electrode and the negative electrode. Also, the "electrode plate" may be a general term for the positive electrode plate and the negative electrode plate.

[0020] (Overall configuration of the battery) FIG. 1 is a front view of the secondary battery 1 according to this embodiment. FIGS. 2 to 4 are views showing the state of the secondary battery 1 shown in FIG. 1 as viewed from the directions of arrow II, arrow III, and arrow IV, respectively. FIG. 5 is a front cross-sectional view of the secondary battery 1 shown in FIG. 1.

[0021] The secondary battery 1 can be mounted on an electric vehicle (BEV: Battery Electric Vehicle), a plug-in hybrid vehicle (PHEV: Plug-in Hybrid Electric Vehicle), a hybrid vehicle (HEV: Hybrid Electric Vehicle), etc. However, the use of the secondary battery 1 is not limited to in-vehicle use.

[0022] As shown in FIGS. 1 to 5, the secondary battery 1 includes an exterior body 100, an electrode body 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).

[0023] In this specification, the X-axis direction (first direction) shown in FIGS. 1 to 5 is referred to as the "width direction" of the secondary battery 1 to the case body 110, and similarly, the Y-axis direction (second direction) is referred to as the "thickness direction" of the secondary battery 1 to the case body 110, and similarly, the Z-axis direction (third direction) may be referred to as the "height direction" of the secondary battery 1 to the case body 110.

[0024] When constructing a battery pack including the secondary battery 1, a plurality of 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 case of the battery pack without using a constraining member.

[0025] The case body 110 is made of a cylindrical, preferably rectangular cylindrical member. Thereby, a rectangular secondary battery 1 can be obtained. The case body 110 is made of metal. Specifically, the case body 110 is made of aluminum, an aluminum alloy, iron, or an iron alloy.

[0026] As shown in FIGS. 1 and 2, sealing plates 121 and 122 are provided at both ends of the case body, respectively. The case body 110 can be formed into a rectangular cylindrical shape, for example, by abutting the end edges of plate-like members subjected to bending processing (joint portion 110A illustrated in FIG. 2) and joining them to each other (for example, laser welding). The corners of the "rectangular cylindrical shape" may have an R shape.

[0027] In the present embodiment, the case body 110 is formed longer in the thickness direction (Y-axis direction) and the height direction (Z-axis direction) of the secondary battery 1 than in the width direction (X-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. Thereby, a relatively large (high-capacity) secondary battery 1 can 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 still more preferably about 10 cm or less. Thereby, a secondary battery 1 with a relatively low height (low height) can be configured, and for example, the mountability on a vehicle is improved.

[0028] As shown in FIG. 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. The sealing plate 121 is provided with a negative electrode terminal 131 (first electrode terminal), a liquid injection hole 141, and a gas discharge valve 151. The positions of the negative electrode terminal 131, the liquid injection hole 141, and the gas discharge valve 151 can be changed as appropriate. The opening 111 and the sealing plate 121 have a substantially rectangular shape in which the Y-axis direction is the short side direction and the Z-axis direction is the long side direction.

[0029] As shown in FIG. 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. The sealing plate 122 is provided with a positive electrode terminal 132 (second electrode terminal), a liquid injection hole 142, and a gas discharge valve 152. The positions of the positive electrode terminal 132, the liquid injection hole 142, and the gas discharge valve 152 can be changed as appropriate. The opening 112 and the sealing plate 122 have a substantially rectangular shape in which the Y-axis direction is the short side direction and the Z-axis direction is the long side direction.

[0030] 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, or an iron alloy.

[0031] The negative electrode terminal 131 is electrically connected to the negative electrode of the electrode body 200. The positive electrode terminal 132 is electrically connected to the positive electrode of the electrode body 200.

[0032] The negative electrode terminal 131 is made of a conductive material (more specifically, metal), and can be made of, for example, copper or a copper alloy. A portion or layer made of aluminum or an aluminum alloy may be provided on the outer surface portion of the negative electrode terminal 131.

[0033] The positive electrode terminal 132 is made of a conductive material (more specifically, metal), and can be made of, for example, aluminum or an aluminum alloy.

[0034] The liquid injection holes 141 and 142 are sealed by a sealing member (not shown). As the sealing member, for example, a blind rivet and other metal members can be used.

[0035] The gas discharge valves 151 and 152 break when the pressure inside the outer casing 100 reaches a predetermined value or more, and discharge the gas inside the outer casing 100 to the outside.

[0036] The electrode body 200 is a flat electrode body having a positive electrode plate and a negative electrode plate described later. Specifically, the electrode body 200 is a wound electrode body in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are both wound via a strip-shaped separator (not shown). However, in this specification, the "electrode body" is not limited to a wound electrode body, and may be a stacked electrode body in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately stacked. 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 stacked to form a positive electrode tab group, and the negative electrode tabs provided on each negative electrode plate may be stacked to form a negative electrode tab group.

[0037] As shown in FIG. 5, the outer casing 100 houses the electrode body 200. The electrode body 200 is housed in the outer casing 100 such that its winding axis is parallel to the X-axis direction.

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

[0039] The electrode body 200 includes a negative electrode tab group 210A (first electrode tab group) provided at an end portion (first end portion) on the sealing plate 121 side, and a positive electrode tab group 220A (second electrode tab group) provided at an end portion (second end portion) on the sealing plate 122 side. The negative electrode tab group 210A and the positive electrode tab group 220A are respectively connected to the negative electrode and the positive electrode of the electrode body 200. The negative electrode tab group 210A and the positive electrode tab group 220A are formed so as to respectively protrude from the main body portion of the electrode body 200 (the portion where the positive electrode plate and the negative electrode plate are laminated via the separator) toward the sealing plates 121 and 122.

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

[0041] The negative electrode current collector 310 is disposed on the 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 can be made of, for example, copper or a copper alloy.

[0042] 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 can be made of, for example, aluminum or an aluminum alloy. Note that 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.

[0043] (Configuration of the electrode body 200) FIG. 6 is a front view showing a negative electrode plate precursor 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 precursor 210S shown in FIG. 6, and FIG. 8 is a front view showing the negative electrode plate 210 formed from the negative electrode plate precursor 210S.

[0044] The negative electrode plate 210 is manufactured by processing the negative electrode plate precursor 210S. As shown in FIGS. 6 and 7, the negative electrode plate precursor 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.

[0045] The negative electrode active material layer 212 is formed on the negative electrode core 211 except for one end of both sides. The negative electrode active material layer 212 is formed by applying a negative electrode active material layer slurry with a die coater.

[0046] The negative electrode active material layer slurry is prepared by kneading graphite as a 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 about 98:1:1.

[0047] The negative electrode active material layer 212 is formed by drying the negative electrode core 211 coated with the negative electrode active material layer slurry to remove the water contained in the negative electrode active material layer slurry. Further, by compressing the negative electrode active material layer 212, a negative electrode plate precursor 210S including the negative electrode core 211 and the negative electrode active material layer 212 is formed. The negative electrode plate 210 is formed by cutting the negative electrode plate precursor 210S into a predetermined shape. The negative electrode plate precursor 210S can be cut by laser processing, die processing, or cutter processing by irradiation with energy rays.

[0048] As shown in FIG. 8, a plurality of negative electrode tabs 210B made of a negative electrode core 211 are provided at one end in the width direction of the negative electrode plate 210 formed from the negative electrode base 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 positions and the lengths in the protruding directions of the respective plurality of negative electrode tabs 210B are appropriately adjusted in consideration of the state in which the negative electrode tab group 210A is connected to the negative electrode current collector 310. Note that the shape of the negative electrode tab 210B is not limited to that illustrated in FIG. 8.

[0049] FIG. 9 is a front view showing a positive electrode base plate 220S before the positive electrode plate 220 (second electrode) is formed, FIG. 10 is a cross-sectional view taken along the line X-X of the positive electrode base plate 220S shown in FIG. 9, and FIG. 11 is a front view showing the positive electrode plate 220 formed from the positive electrode base plate 220S.

[0050] The positive electrode plate 220 is manufactured by processing the positive electrode base plate 220S. As shown in FIGS. 9 and 10, the positive electrode base 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.

[0051] The positive electrode active material layer 222 is formed on the positive electrode core 221 except for one end on both sides. 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.

[0052] The positive electrode active material layer slurry is prepared by kneading lithium nickel cobalt manganese composite oxide as a 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 about 97.5:1:1.5.

[0053] The positive electrode protective layer 223 is in contact with the positive electrode core 221 and is formed at 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 with a die coater. The positive electrode protective layer 223 has an electrical resistance greater than that of the positive electrode active material layer 222.

[0054] 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 about 83:3:14.

[0055] The positive electrode core 221 coated with the positive electrode active material layer slurry and the positive electrode protective layer slurry is dried to remove the NMP contained in the positive electrode active material layer slurry and the positive electrode protective layer slurry, thereby forming the positive electrode active material layer 222 and the positive electrode protective layer 223. Further, by compressing the positive electrode active material layer 222, a positive electrode raw plate 220S including the positive electrode core 221, the positive electrode active material layer 222, and the positive electrode protective layer 223 is formed. The positive electrode plate 220 is formed by cutting the positive electrode raw plate 220S into a predetermined shape. The positive electrode raw plate 220S can be cut by laser processing, die processing, or cutter processing by irradiation with energy rays.

[0056] As shown in FIG. 11, a plurality of positive electrode tabs 220B made of the positive electrode core 221 are provided at one end in the width direction of the positive electrode plate 220 formed from the positive electrode raw plate 220S. When the positive electrode plate 220 is wound, the plurality of positive electrode tabs 220B are laminated to form a positive electrode tab group 220A. The position and the 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. Note that the shape of the positive electrode tab 220B is not limited to that illustrated in FIG. 11.

[0057] A positive electrode protective layer 223 is provided at the base of each of the plurality of 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.

[0058] 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.

[0059] (Connection structure between the electrode body 200 and the current collector 300) FIG. 12 is a view 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 and 202, each of which is a wound electrode body. In the example shown in FIG. 12, a structure in which two wound electrode bodies are stacked is shown, but the electrode body 200 may be composed of one wound electrode body, may be composed of three or more wound electrode bodies, or may be composed of a laminated electrode body.

[0060] The negative electrode tab group 210A is joined to the negative electrode current collector 310 at the joint portion 310A, and the positive electrode tab group 220A is joined to the positive electrode current collector 320 at the joint portion 320A. The joint portions 310A and 320A can be formed by, for example, ultrasonic bonding, resistance welding, laser welding, caulking, etc. The joint portions 310A and 320A constitute a conductive path 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.

[0061] FIG. 13 is a view showing the connection structure between the negative electrode tab group 210A and the negative electrode current collector 310. FIGS. 14 and 15 are a front view and a cross-sectional view of the connection structure shown in FIG. 13, respectively.

[0062] As shown in FIGS. 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 the joint portion 313.

[0063] The negative electrode tab group 210A is joined to the first conductive member 311 of the negative electrode current collector 310 at the joint portion 310A. The first conductive member 311 is connected to the second conductive member 312 at the joint portion 313. The joint portion 313 can be formed by, for example, ultrasonic bonding, resistance welding, laser welding, caulking, or the like.

[0064] The first conductive member 311 and the second conductive member 312 are attached to the inner surface side of the sealing plate 121 via a resin insulating member 410.

[0065] The negative electrode terminal 131 is attached to the sealing plate 121 via a resin insulating member 410A. The negative electrode terminal 131 is exposed outside the 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 inner surface side of the 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, caulking, or the like. 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 caulked on the second conductive member 312, and then the caulked portion and the second conductive member 312 are welded at the joint portion 131A, whereby the negative electrode terminal 131 and the second conductive member 312 are connected.

[0066] As an assembly procedure for each component, 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. Subsequently, 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 disposed on the insulating member 410 such that a part of the first conductive member 311 overlaps the second conductive member 312. Subsequently, the first conductive member 311 and the second conductive member 312 are welded and connected at the joint portion 313. Note that the insulating members 410 and 410A may be composed of a single member.

[0067] However, the negative electrode terminal 131 may be electrically connected to the sealing plate 121. Further, the sealing plate 121 may serve as the negative electrode terminal 131.

[0068] In FIGS. 13 to 15, the negative electrode current collector 310 composed of two parts (the first conductive member 311 and the second conductive member 312) is illustrated. However, the negative electrode current collector 310 may be composed of one part.

[0069] In FIGS. 13 to 15, the connection structure on the negative electrode side is shown. However, regarding the positive electrode side, the basic connection structure is the same as that on the negative electrode side.

[0070] (Insertion process of the electrode body 200) FIG. 16 is a diagram showing the 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 disposed between the electrode body 200 and the case body 110.

[0071] The insulating sheet 600 can be constituted by, for example, resin. More specifically, the material of the insulating sheet 600 is, for example, polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), or polyolefin (PO).

[0072] The insulating sheet 600 does not necessarily need to cover the entire surface of the electrode body 200. The insulating sheet 600 preferably covers an area of about 50% or more, more preferably about 70% or more of the outer surface of the electrode body. The insulating sheet 600 preferably covers the entire four surfaces other than the two surfaces on which at least the negative electrode tab group 210A and the positive electrode tab group 220A are respectively formed among the six surfaces of the substantially rectangular parallelepiped (flat shape) electrode body 200.

[0073] FIG. 17 is a diagram showing the process of disposing the spacer 510 between the sealing plate 121 and the electrode body 200. FIG. 18 is a cross-sectional view showing the state in which the spacer 510 is disposed between the sealing plate 121 and the electrode body 200.

[0074] As shown in FIGS. 17 and 18, the negative tab group 210A extending from the electrode body 200 toward the sealing plate 121 curves from the central portion to the end portion of the sealing plate 121 in the Y-axis direction and then turns back in the opposite direction and curves toward the central portion. A spacer 510 is arranged to accommodate the curved negative tab group 210A (curved portion).

[0075] The spacer 510 includes a first spacer 511 and a second spacer 512. The first spacer 511 and the second spacer 512 engage with each other by sliding along the Y-axis direction from the end side to the central side of the sealing plate 121. Thereby, the spacer 510 is fixed to the sealing plate 121 via the insulating member 410, and the stability of the position of the spacer 510 is increased.

[0076] As shown in FIG. 18, the spacer 510 forms an internal space for accommodating the negative current collector 310, and the tip portion of the negative tab group 210A is also accommodated in the internal space of the spacer 510. The spacer 510 has a hole portion through which the negative tab group 210A passes.

[0077] 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). Also, an insulating sheet 600 may be interposed between the spacer 510 and the electrode body 200.

[0078] Referring to FIG. 16 again, in the method for manufacturing the secondary battery 1 according to the present embodiment, the electrode body 200 is drawn from the opening 112 side, and the electrode body 200 is inserted into the case body 110 from the end side on the positive tab group 220A side.

[0079] When the electrode body 200 is inserted into the case body 110 only by pushing it from the opening 111 side, the electrode body 200 is likely to have lamination displacement, winding displacement, curling, etc. of the electrode plate and the separator in the electrode body 200 (in this specification, the above are collectively referred to as "damage to the electrode body"). By pulling the electrode body 200 from the opening 112 side and inserting it into the case body 110, damage to the electrode body 200 can be effectively suppressed. Alternatively, by inserting the electrode body 200 into the case body 110 by pulling the electrode body 200, compared with the case where the electrode body 200 is inserted into the case body 110 only by pushing, damage to the end face where the negative tab group 210A is provided on the electrode body 200 and the negative tab group 210A can be more effectively suppressed. Therefore, it becomes possible to stably and efficiently manufacture the highly reliable secondary battery 1.

[0080] In addition to pulling the electrode body 200, the electrode body 200 may be pushed in.

[0081] In addition, before the insertion process, by covering the electrode body 200 with the insulating sheet 600, damage to the electrode body 200 can be more effectively suppressed.

[0082] Also, in the example of FIG. 16, after electrically connecting the negative electrode terminal 131 and the negative tab group 210A, the electrode body 200 is inserted into the case body 110 from the end side on the positive tab group 220A side through the opening 111. When the negative electrode terminal 131 attached to the sealing plate 121 and the negative tab group 210A are electrically connected after the electrode body 200 is inserted into the case body 110, the length of the negative tab group 210A of the electrode body 200 housed in the case body 110 protruding sufficiently outside the case body 110 is required for the negative tab group 210A. By electrically connecting the negative electrode terminal 131 attached to the sealing plate 121 and the negative tab group 210A before inserting the electrode body 200 into the case body 110, the length of the negative tab group 210A can be reduced compared with the case of connecting after inserting the electrode body 200 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.

[0083] During the insertion process of 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 such that the X-axis direction (the width direction of the case body 110) intersects the horizontal direction at an angle of about ±45° or less. For example, in the vertical direction, the case body 110 is tilted such that the upper end of the opening 111 into which the electrode body 200 is inserted is located above the upper end of the opening 112, and the electrode body 200 can be inserted into the case body 110.

[0084] When pulling the electrode body 200, the electrode body 200 may be directly held, or the electrode body 200 may be indirectly held via other components such as the insulating sheet 600. In this specification, "pulling the electrode body 200" includes both the case where the electrode body 200 is directly held and pulled, and the case where the electrode body 200 is indirectly held and pulled. Further, as the force for pulling the electrode body 200, centrifugal force or gravity may be utilized.

[0085] Further, after inserting a jig (not shown) into the case body 110 so as to penetrate the case body 110 from the opening 112 toward the opening 111, the electrode body 200 may be pulled from the opening 112 side via the jig.

[0086] (Configuration of the insulating sheet 600) Next, with reference to FIGS. 19 to 35, the specific configuration of the insulating sheet 600 as the electrode body holder will be described.

[0087] FIGS. 19 to 22 are diagrams showing an example of a developed view of the insulating sheet 600. As shown in FIG. 19, the insulating sheet 600 is bent to form a rectangular tube-shaped electrode body holder. The overlapping portions of the insulating sheet 600 are fixed to each other by, for example, heat welding, tape attachment, or the like.

[0088] As shown in FIG. 19, the tape 700 may be arranged to cover the regions on the side surfaces (both end surfaces in the X-axis direction) of the electrode body 200 where there are no electrode tab groups, and may be attached across the two large-area surfaces (surfaces extending in the X-Z direction) of the insulating sheet 600.

[0089] As shown in FIG. 20, instead of the tape 700, spacers 510 and 520 may be arranged on both sides of the electrode body 200. Through holes 510A and 520A for inserting the electrode tab groups are respectively provided in the spacers 510 and 520. The spacers 510 and 520 are fixed to the insulating sheet 600 by, for example, heat welding, tape sticking, etc.

[0090] At both ends of the insulating sheet 600 in the X-axis direction, different structures may be adopted. For example, the tape 700 shown in FIG. 19 may be adopted at one end, and the spacers 510 and 520 shown in FIG. 20 may be adopted at the other end.

[0091] As shown in FIG. 21, bending portions 610 may be provided at both ends of the insulating sheet 600 in the X-axis direction, and the regions on the side surfaces of the electrode body 200 where there are no electrode tab groups may be covered with the insulating sheet 600. As shown in FIG. 22, the bending portions 610 and the spacers 510 and 520 may be used in combination. The bending portions 610, the spacers 510 and 520, and the tape 700 may be used in combination.

[0092] FIGS. 23 to 34 are diagrams showing the structures of the ends of the insulating sheet 600. In the examples shown in FIGS. 23 and 24, through holes 620 are provided at the ends of the insulating sheet 600. By providing the through holes 620, it is easier to hold the insulating sheet 600 in the process of inserting the electrode body 200 into the case body 110. That is, the through holes 620 constitute the holding portions of the insulating sheet 600 during the insertion process of the electrode body 200.

[0093] The holding part of the insulating sheet 600 becomes unnecessary after the electrode body 200 is inserted into the case body 110. Therefore, the insulating sheet 600 may be formed with an excess in the longitudinal direction (X-axis direction), and after the electrode body 200 is inserted into the case body 110, the insulating sheet 600 may be cut off or folded.

[0094] Figs. 25 and 26 are diagrams showing modified examples of the through holes 620. As shown in Fig. 25, a pair of through holes 620A may be formed on the long side surface, and a pair of through holes 620B may be formed on the short side surface. Alternatively, as shown in Fig. 26, a protruding portion 630 may be provided at the end of the insulating sheet 600, and a through hole 620 may be provided in the protruding portion 630.

[0095] Figs. 27 to 29 are diagrams showing a structure in which a cut portion 640 is provided instead of the through hole 620. As shown in Figs. 27 to 29, by providing a cut portion 640 and a tongue piece portion 650 at the end of the insulating sheet 600, the holding portion of the insulating sheet 600 during the insertion process of the electrode body 200 can be configured.

[0096] Figs. 30 to 32 are diagrams showing a structure in which a folded-back portion 660 is provided instead of the tongue piece portion 650. In the example shown in Figs. 30 to 32, a cut portion 640 is formed, and a folded-back portion 660 protruding from the end of the insulating sheet 600 is provided. By providing a folded-back portion 660 at the end of the insulating sheet 600, the holding portion of the insulating sheet 600 during the insertion process of the electrode body 200 can be configured.

[0097] Figs. 33 and 34 are diagrams showing further modified examples of the structure of the end of the insulating sheet 600. Fig. 35 is an enlarged view showing the engaging portion 520C in the structure shown in Fig. 34.

[0098] In the example shown in FIG. 33, the end of the insulating sheet 600 and the spacer 520 are joined at the joint portion 520B. The joint portion 520B can be formed by, for example, thermal welding or the like. By forming the joint portion 520B, the insulating sheet 600 and the spacer 520 can be moved integrally. Therefore, when the spacer 520 is held and the electrode body 200 is attracted, the electrode body 200 can be inserted into the case body 110 while suppressing the application of an excessive load on the electrode body 200.

[0099] In the examples shown in FIGS. 34 and 35, the spacer 520 is engaged at the engaging portion 520C. The engaging portion 520C is formed so as to protrude from the spacer 520. By providing the engaging portion 520C that can be engaged with the through hole 620 of the insulating sheet 600, the insulating sheet 600 and the spacer 520 can be moved integrally. Therefore, when the spacer 520 is held and the electrode body 200 is attracted, the electrode body 200 can be inserted into the case body 110 while suppressing the application of an excessive load on the electrode body 200.

[0100] (Manufacturing process of the secondary battery 1) FIG. 36 is a flowchart showing each step of the manufacturing method of the secondary battery 1. As shown in FIG. 36, in S10, the case body 110 is prepared. Next, in S20, the electrode body 200 is manufactured. In S30, the electrode terminals provided on the sealing plates 121 and 122 and the electrode tab group of the electrode body 200 are electrically connected. In the example of FIG. 36, first, the negative electrode terminal 131 and the negative electrode tab group 210A are electrically connected (S31), then the electrode body 200 is covered with the insulating sheet 600 (S40), and further the electrode body 200 is inserted into the case body 110 (S50). 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).

[0101] In the present technology, the order of connection between the electrode terminal and the electrode tab group (S30), installation of the insulating sheet 600 (S40), and insertion of the electrode body 200 (S50) is not limited to the example of FIG. 36 and can be changed as appropriate. Also, the insulating sheet 600 that covers the electrode body 200 is not necessarily essential.

[0102] For example, in some cases, the operations may be performed in the order of inserting the electrode body 200 (S50), connecting the negative electrode terminal 131 to the negative electrode tab group 210A (S31), and connecting the positive electrode terminal 132 to the positive electrode tab group 220A (S32).

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

[0104] In the example of FIG. 36, after the connection (S30) between the electrode terminals and the electrode tab groups is completed, a process (S61) of sealing the opening 111 with the negative electrode side sealing plate 121 is performed, and then a process (S62) of sealing the opening 112 with the positive electrode side sealing plate 122 is carried out. However, for example, the process (S61) of sealing the opening 111 with the sealing plate 121 may be performed before the process (S32) of electrically connecting the positive electrode terminal 132 to the positive electrode tab group 220A, or the process (S61) of sealing the opening 111 with the sealing plate 121 may be performed after the process (S62) of sealing the opening 112 with the sealing plate 122. Furthermore, at least a part of the processes (S61, S62) of sealing with the sealing plates 121 and 122 can also be performed simultaneously.

[0105] (Summary) Summarizing the above-described content regarding the manufacturing method of the secondary battery 1 according to the present embodiment, it is as follows.

[0106] The manufacturing method of the secondary battery 1 includes, as shown in FIG. 36, 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 and 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 (S30) of electrically connecting a negative electrode terminal 131 and the negative electrode tab group 210A and electrically connecting a positive electrode terminal 132 and the positive electrode tab group 220A, a step (S40) of covering the electrode body 200 before being inserted into the case body 110 with an insulating sheet 600 (electrode body holder), a step (S50) of inserting the electrode body 200 into the case body 110 from the end side on the positive electrode tab group 220A side through the opening 111, and a step (S60) of sealing the openings 111 and 112 with sealing plates 121 and 122.

[0107] Here, the step (S50) of inserting the electrode body 200 into the case body 110 includes pulling the electrode body 200 from the opening 112 side (positive electrode side). Pulling the electrode body 200 may include pulling the electrode body 200 itself through a jig or the like, and pulling other components such as the insulating sheet 600 covering the electrode body 200. When pulling the insulating sheet 600, the insulating sheet 600 may be pulled directly, or the insulating sheet 600 may be pulled through a spacer 520.

[0108] In the step (S50) of inserting the electrode body 200 into the case body 110, after holding the electrode body 200 and inserting a part of the electrode body 200 into the case body 110, the electrode body 200 may be pulled from the opening 112 side. For example, the electrode body 200 can be inserted into the case body 110 while holding the surface located below the electrode body 200 in the vertical direction to support it, or while holding the electrode body 200 in a state of sandwiching both side surfaces of the electrode body 200. At this time, the electrode body 200 may be directly held, or may be held through other members such as the insulating sheet 600.

[0109] In this embodiment, an example in which the electrode body 200 is inserted into the case body 110 by pulling the electrode body 200 from the opening 112 side (positive electrode side) has been described. However, the present technology is not limited to this, and the electrode body 200 may be inserted into the case body 110 by pulling the electrode body 200 from the opening 111 side (negative electrode side).

[0110] (Function and effect) According to the secondary battery 1 according to this embodiment, by inserting the electrode body 200 into the case body 110 having the openings 111 and 112 facing each other, and providing the negative electrode terminal 131 and the positive electrode terminal 132 on the sealing plates 121 and 122 that seal the openings 111 and 112 respectively, the height of the secondary battery 1 can be reduced, and the mountability of the secondary battery 1 on a vehicle can be improved. Further, in the step of inserting the electrode body 200 into the case body 110, by pulling the electrode body 200 from the opening 112 side, damage to the electrode body 200 (such as lamination displacement, winding displacement, and peeling of the electrode plate and the separator) can be effectively suppressed. As a result, it becomes possible to stably and efficiently manufacture a highly reliable secondary battery 1.

[0111] Also, in the above example, after covering the electrode body 200 with the insulating sheet 600, the electrode body 200 is inserted into the case body 110. Thereby, damage to the electrode body 200 in the insertion process of the electrode body 200 can be more effectively suppressed. Therefore, the secondary battery 1 can be manufactured more efficiently and stably.

[0112] As described above, the embodiments of the present technology have been described. However, it should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present technology is indicated by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of reference numerals

[0113] 1 Secondary battery, 100 Exterior body, 110 Case main body, 110A, 131A, 310A, 313, 320A Joints, 111, 112 Openings, 121, 122 Sealing plates, 131 Negative electrode terminal, 132 Positive electrode terminal, 141, 142 Liquid injection holes, 151, 152 Gas discharge valves, 200, 201, 202 Electrode bodies, 210 Negative electrode plate, 210A Negative electrode tab group, 210B Negative electrode tab, 210S Negative electrode raw 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 raw plate, 221 Positive electrode core, 222 Positive electrode active material layer, 223 Positive electrode protective layer, 300 Current collector, 310 Negative electrode current collector, 311 First conductive member, 312 Second conductive member, 320 Positive electrode current collector, 410, 410A Insulating members, 510 Spacer, 510A Through hole, 511 First spacer, 512 Second spacer, 520 Spacer, 520A Through hole, 520B Joint, 520C Engaging portion, 600 Insulating sheet, 610 Bent portion, 620, 620A, 620B Through holes, 630 Protrusion, 640 Notch, 650 Tongue portion, 660 Folded-back portion, 700 Tape.

Claims

1. Preparing a case body having a first opening and a second opening facing the first opening; Fabricating an electrode body including a first electrode and a second electrode having a polarity different from that of the first electrode, the first electrode having a first electrode tab connected to the first electrode at a first end, and the second electrode having a second electrode tab connected to the second electrode at a second end opposite to 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; Electrically connecting a second electrode terminal provided on a second sealing plate and the second electrode tab; After electrically connecting the first electrode terminal and the first electrode tab, sealing the first opening with the first sealing plate; After electrically connecting the second electrode terminal and the second electrode tab, sealing the second opening with the second sealing plate, and The step of inserting the electrode body into the case body includes attracting the electrode body from the second opening side, a method for manufacturing a secondary battery.

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

3. The method for manufacturing a secondary battery according to claim 2, wherein the step of inserting the electrode body into the case body includes attracting the electrode body through the electrode body holder.

4. Further comprising the step of disposing a spacer between the first sealing plate and the electrode body, and The method for manufacturing a secondary battery according to claim 3, wherein the step of inserting the electrode body into the case body includes attracting the electrode body holder through the spacer.

5. The method for manufacturing a secondary battery according to any one of claims 1 to 4, wherein the step of inserting the electrode body into the case body includes holding the electrode body, inserting a part of the electrode body into the case body, and then attracting the electrode body from the second opening side.

6. The method for manufacturing a secondary battery according to any one of claims 1 to 4, wherein the step of inserting the electrode body into the case body includes inserting a jig into the case body so as to penetrate the case body from the second opening toward the first opening, and then attracting the electrode body from the second opening side through the jig.

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