Method for manufacturing secondary battery
By using spacers and insulating sheets in the manufacturing process of secondary batteries, the insertion and connection process of electrode bodies is optimized, and the problem of insufficient energy density of existing secondary batteries is solved, thereby achieving an increase in energy density and manufacturing stability.
Patent Information
- Application Number
- CN202410721191.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-06-08
- Filing Date
- 2024-06-05
- Publication Date
- 2024-12-10
AI Technical Summary
The energy density of existing secondary batteries is insufficient and needs to be further improved to meet higher energy needs.
By adopting a manufacturing method, the electrode is optimized by providing a spacer at the opposite opening of the housing body and pressing the electrode body with the spacer to tightly insert it into the housing body, and combining the sealing process of the insulating sheet covering and the sealing plate. The insertion and connection process of the body is to improve the volume occupancy and energy density of the electrode body.
The energy density of the secondary battery is improved, the damage to the electrode body during the insertion process is reduced, the manufacturing efficiency and stability is improved, and the internal space of the battery is increased to accommodate more electrode plates, which improves the vehicle carryingability.
Smart Images
Figure CN119108651A_ABST
Abstract
Description
Technical Field
[0001] The present technology relates to a method for manufacturing a secondary battery. Background Art
[0002] Japanese Patent Gazette No. 4537353 discloses a square secondary battery in which an electrode group (25) is housed in a casing (14) having openings (14a, 14b) at both ends, and electrode terminals (21, 23) are respectively mounted on covers (33, 33') for sealing the openings (14a, 14b).
[0003] There is a need to further improve the energy density of secondary batteries. From the viewpoint of improving the energy density, the battery described in Japanese Patent No. 4537353 still has room for further improvement. Summary of the invention
[0004] An object of the present technology is to provide a method for manufacturing a secondary battery capable of obtaining a secondary battery with high energy density.
[0005] The present technology provides the following method for manufacturing a secondary battery.
[0006] [1] A method for manufacturing a secondary battery, comprising the following steps: preparing a shell body having a first opening and a second opening opposite to the first opening; forming an electrode body, wherein the electrode body includes a first electrode and a second electrode having a polarity different from that of the first electrode, the electrode body having a first electrode sheet connected to the first electrode at a first end thereof, and having a second electrode sheet connected to the second electrode at a second end located on the opposite side to the first end; placing the first electrode end provided on a first sealing plate The invention relates to a process for electrically connecting the first electrode terminal to the first electrode sheet; a process for inserting the electrode body from the second end side into the shell body through the first opening after electrically connecting the first electrode terminal to the first electrode sheet; a process for electrically connecting the second electrode terminal provided on the second sealing plate to the second electrode sheet after inserting the electrode body into the shell body; a process for sealing the first opening with the first sealing plate after inserting the electrode body into the shell body; and a process for sealing the second opening with the second sealing plate after electrically connecting the second electrode terminal to the second electrode sheet.
[0007] [2] The method for manufacturing a secondary battery according to [1] further comprises the step of disposing a separator between the first sealing plate and the electrode body, and inserting the electrode body into the case body by pressing the electrode body with the first sealing plate via the separator.
[0008] [3] In the method for manufacturing a secondary battery according to [2], in the step of inserting the electrode body into the case body, the separator abuts against a position of the first end portion of the electrode body that is separated from the first electrode sheet.
[0009] [4] In the method for manufacturing a secondary battery according to [2] or [3], the step of arranging the separator includes fixing the separator to the first sealing plate.
[0010] [5] In the method for manufacturing a secondary battery according to [2] or [3], the step of arranging the separator includes fixing the separator to the electrode body.
[0011] [6] The method for manufacturing a secondary battery according to any one of [1] to [5], further comprising the step of covering the electrode body before being inserted into the case body with an insulating electrode body holder.
[0012] [7] In the method for manufacturing a secondary battery described in [1], there is further provided a step of arranging an isolating member between the first sealing plate and the electrode body, and after holding the electrode body and inserting a portion of the electrode body into the shell body, the electrode body is pressed by the first sealing plate via the isolating member, thereby inserting the electrode body into the shell body until the first sealing plate abuts against the shell body.
[0013] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a front view of a secondary battery.
[0015] Figure 2 It means observing from the direction of arrow II Figure 1 A diagram showing the state of a secondary battery.
[0016] Figure 3 It means observing from the direction of arrow III Figure 1 A diagram showing the state of a secondary battery.
[0017] Figure 4 It means observing from the direction of arrow IV Figure 1 A diagram showing the state of a secondary battery.
[0018] Figure 5 yes Figure 1 A front cross-sectional view of a secondary battery is shown.
[0019] Figure 6 It is a front view showing a negative electrode original plate before forming a negative electrode plate.
[0020] Figure 7 yes Figure 6 VII-VII cross-sectional view of the negative electrode original plate shown.
[0021] Figure 8It is a front view showing a negative electrode plate formed from a negative electrode original plate.
[0022] Fig. 9 It is a front view showing a positive electrode original plate before forming a positive electrode plate.
[0023] Fig.10 yes Fig. 9 XX cross-sectional view of the positive electrode original plate shown.
[0024] Fig.11 It is a front view showing a positive electrode plate formed from a positive electrode original plate.
[0025] Fig.12 It is a diagram showing an electrode body and a current collector taken out from a secondary battery.
[0026] Fig.13 It is a diagram showing the connection structure between the negative electrode sheet group and the negative electrode current collector.
[0027] Fig.14 yes Fig.13 Front view of the connection structure shown.
[0028] Fig.15 yes Fig.13 A cross-sectional view of the connection structure shown.
[0029] Fig.16 It is a diagram showing the step of inserting the electrode body into the case body.
[0030] Fig.17 This is a diagram showing a step of placing a separator between a sealing plate and an electrode body.
[0031] Fig.18 It is a cross-sectional view showing a state where a separator is arranged between a sealing plate and an electrode body.
[0032] Fig.19 It is a diagram showing a modified example of the spacer.
[0033] Fig. 20 This is a diagram showing an example of a mechanism for pressing the electrode body via a sealing plate and a separator.
[0034] Fig.21 It means viewing from the Z axis direction Fig. 20 A diagram showing the state of the mechanism.
[0035] Fig. 22 It is a diagram showing a modified example of the spacer (part 1).
[0036] Fig.23 This is a diagram (part 2) showing a modified example of the spacer.
[0037] Fig.24It is a figure (part 3) showing a modification example of the spacer.
[0038] Fig.25 It is a figure (fourth) showing a modification example of the spacer.
[0039] Fig.26 FIG. 5 is a diagram showing a modified example of the spacer.
[0040] Fig. 27 FIG. 6 is a sixth diagram showing a modified example of the spacer.
[0041] Fig.28 It is a flowchart showing each process of the manufacturing method of a secondary battery. DETAILED DESCRIPTION
[0042] Hereinafter, embodiments of the present technology will be described. In addition, the same reference numerals are given to the same or corresponding parts, and the description thereof may not be repeated.
[0043] In addition, in the embodiments described below, when the number, amount, etc. are mentioned, the scope of the present technology is not necessarily limited to the number, amount, etc., unless otherwise specified. In addition, in the following embodiments, except for the cases where there are special records, each component is not necessarily essential to the present technology. In addition, the present technology is not necessarily limited to the technology that has all the effects mentioned in the present embodiment.
[0044] In addition, in this specification, the descriptions of "comprise", "include", and "have" are open forms. That is, when a certain structure is included, other structures other than the structure may or may not be included.
[0045] In addition, in this specification, when geometrical terms and terms indicating position and direction relationships are used, such as "parallel", "orthogonal", "oblique 45 degrees", "coaxial", "along", etc., these terms allow for manufacturing errors or some changes. In this specification, when terms such as "upper side" and "lower side" are used to indicate relative positional relationships, these terms are used to indicate relative positional relationships in one state, and the relative positional relationship can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, turning the entire mechanism upside down, etc.).
[0046] In this specification, "battery" is not limited to lithium-ion batteries, and may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, "electrode" may be collectively referred to as positive electrode and negative electrode. In addition, "electrode plate" may be collectively referred to as positive electrode plate and negative electrode plate.
[0047] (Overall structure of the battery)
[0048] Figure 1 It is a front view of the secondary battery 1 according to the present embodiment. Figure 2 to Figure 4 They are respectively viewed from the direction of arrow II, arrow III, and arrow IV. Figure 1 The diagram shows the state of the secondary battery 1. Figure 5 yes Figure 1 The secondary battery 1 is shown in front cross-sectional view.
[0049] The secondary battery 1 can be mounted on an electric vehicle (BEV), a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), etc. However, the use of the secondary battery 1 is not limited to vehicle-mounted use.
[0050] like Figure 1 to Figure 5 As shown, the secondary battery 1 includes an outer casing 100, an electrode body 200, and a current collector 300. The outer casing 100 includes a case body 110, a sealing plate 121 (first sealing plate), and a sealing plate 122 (second sealing plate).
[0051] In this application specification, there is Figure 1 to Figure 5 The X-axis direction (first direction) shown is called the “width direction” of the secondary battery 1 or the shell body 110, and similarly, the Y-axis direction (second direction) is called the “thickness direction” of the secondary battery 1 or the shell body 110, and similarly, the Z-axis direction (third direction) is called the “height direction” of the secondary battery 1 or the shell body 110.
[0052] When forming a battery pack including secondary batteries 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 of the battery pack housing without using a constraining member.
[0053] The case body 110 is formed of a cylindrical, preferably rectangular, member. This provides a rectangular secondary battery 1. The case body 110 is made of metal. Specifically, the case body 110 is made of aluminum, aluminum alloy, iron, or iron alloy.
[0054] like Figure 1 , Figure 2 As shown in FIG. 1 , sealing plates 121 and 122 are provided at both ends of the housing body. The housing body 110 is formed by, for example, bringing the ends of the plate-like members subjected to bending into contact with each other (at Figure 2The square tube shape can be formed by joining the joint portion 110A shown in the example in FIG. 1 (e.g., laser welding) to each other. The corner of the "square tube shape" may also have an R shape.
[0055] In the present embodiment, the shell body 110 is formed in the width direction (X-axis direction) of the secondary battery 1 to be longer than the thickness direction (Y-axis direction) and height direction (Z-axis direction) of the secondary battery 1. The dimension (width) of the shell body 110 in the X-axis direction is preferably more than 30 cm. Thus, a relatively large (high-capacity) secondary battery 1 can be formed. The dimension (height) of the shell body 110 in the Z-axis direction is preferably less than 20 cm, more preferably less than 15 cm, and further preferably less than 10 cm. Thus, a secondary battery 1 with a relatively low height (low height) can be formed, for example, the mountability on a vehicle is improved.
[0056] like Figure 3 As shown, an opening 111 (first opening) is provided at one end of the housing body 110. The opening 111 is sealed by a sealing plate 121. The sealing plate 121 is provided with a negative terminal 131 (first electrode terminal), a liquid injection hole 141, and an exhaust valve 151. The positions of the negative terminal 131, the liquid injection hole 141, and the exhaust valve 151 can be appropriately changed. The opening 111 and the sealing plate 121 have a roughly rectangular shape with the Y-axis direction being the short side direction and the Z-axis direction being the long side direction.
[0057] like Figure 4 As shown, an opening 112 (second opening) is provided at the other end of the housing body 110. The opening 112 is sealed by a sealing plate 122. The sealing plate 122 is provided with a positive terminal 132 (second electrode terminal), a liquid injection hole 142, and an exhaust valve 152. The positions of the positive terminal 132, the liquid injection hole 142, and the exhaust valve 152 can be appropriately changed. The opening 112 and the sealing plate 122 have a roughly rectangular shape with the Y-axis direction being the short side direction and the Z-axis direction being the long side direction.
[0058] The sealing plates 121 and 122 are made of metal. Specifically, the sealing plates 121 and 122 are made of aluminum, aluminum alloy, iron, iron alloy, or the like.
[0059] 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 .
[0060] The negative electrode terminal 131 is made of a conductive material (more specifically, a metal), for example, copper or a copper alloy, etc. A portion or layer made of aluminum or an aluminum alloy may be provided on the outer surface of the negative electrode terminal 131 .
[0061] The positive electrode terminal 132 is made of a conductive material (more specifically, a metal), and can be made of, for example, aluminum or an aluminum alloy.
[0062] The liquid injection holes 141 and 142 are sealed by a sealing member (not shown). As the sealing member, for example, a blind rivet or other metal member can be used.
[0063] The exhaust valves 151 and 152 rupture when the pressure in the outer casing 100 reaches a predetermined value or more, and exhaust the gas in the outer casing 100 to the outside.
[0064] 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 formed by winding a strip-shaped positive electrode plate and a strip-shaped negative electrode plate together via a strip-shaped separator not shown. However, in this specification, the "electrode body" is not limited to a wound electrode body, and may also be a stacked electrode body formed by alternately stacking a plurality of positive plates and a plurality of negative plates. The electrode body includes a plurality of positive plates and a plurality of negative plates, and the positive electrode sheets provided on each positive plate may also be stacked to form a positive electrode sheet group, and the negative electrode sheets provided on each negative plate may also be stacked to form a negative electrode sheet group.
[0065] like Figure 5 As shown, the outer casing 100 accommodates the electrode body 200. The electrode body 200 is accommodated in the outer casing 100 so that the winding axis thereof is parallel to the X-axis direction.
[0066] Specifically, a single or a plurality of wound electrode bodies and an electrolyte (electrolyte) not shown are housed inside an insulating sheet 600 to be described later and arranged inside the outer casing 100. As the electrolyte (non-aqueous electrolyte), for example, LiPF 20 dissolved in a non-aqueous solvent prepared by mixing ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) in a volume ratio (25° C.) of 30:30:40 can be used. 6 In addition, a solid electrolyte can also be used instead of the electrolyte.
[0067] The electrode body 200 includes a negative electrode sheet group 210A (first electrode sheet group) provided at the end (first end) on the sealing plate 121 side, and a positive electrode sheet group 220A (second electrode sheet group) provided at the end (second end) on the sealing plate 122 side. The negative electrode sheet group 210A and the positive electrode sheet group 220A are connected to the negative electrode and the positive electrode of the electrode body 200, respectively. The negative electrode sheet group 210A and the positive electrode sheet group 220A are formed to protrude from the main body portion (the portion where the positive electrode plate and the negative electrode plate are stacked via the separator) of the electrode body 200 toward the sealing plates 121 and 122, respectively.
[0068] 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 formed of a plate-like 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 .
[0069] 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 sheet group 210A and the negative electrode terminal 131. The negative electrode current collector 310 is made of a conductive material (more specifically, metal), such as copper or a copper alloy.
[0070] The positive electrode collector 320 is arranged on the sealing plate 122 via an insulating member 420 made of resin. The positive electrode collector 320 is electrically connected to the positive electrode sheet group 220A and the positive terminal 132. The positive electrode collector 320 is composed of a conductive material (more specifically, a metal), for example, aluminum or an aluminum alloy. In addition, the positive electrode sheet group 220A can also be electrically connected to the sealing plate 122 directly or via the positive electrode collector 320. In this case, the sealing plate 122 can also serve as the positive terminal 132.
[0071] (Structure of Electrode Body 200)
[0072] Figure 6 2 is a front view showing a negative electrode original plate 210S before forming a negative electrode plate 210 (first electrode). Figure 7 yes Figure 6 The VII-VII cross-sectional view of the negative electrode original plate 210S shown in FIG. Figure 8 1 is a front view showing a negative electrode plate 210 formed from a negative electrode original plate 210S.
[0073] The negative electrode plate 210 is manufactured by processing the negative electrode original plate 210S. Figure 6 and Figure 7 As shown, 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.
[0074] The negative electrode core 211 has a negative electrode active material layer 212 formed thereon except for one end portion of both surfaces. The negative electrode active material layer 212 is formed by applying a negative electrode active material layer slurry using a die coater.
[0075] 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.
[0076] The negative electrode core 211 coated with the negative electrode active material layer slurry is dried to remove the water contained in the negative electrode active material layer slurry, thereby forming the negative electrode active material layer 212. Furthermore, the negative electrode original plate 210S including the negative electrode core 211 and the negative electrode active material layer 212 is formed by compressing 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 based on energy line irradiation, metal mold processing, or tool processing.
[0077] like Figure 8 As shown, at one end in the width direction of the negative electrode plate 210 formed by the negative electrode original plate 210S, a plurality of negative electrode sheets 210B formed by the negative electrode core 211 are provided. When the negative electrode plate 210 is wound, the plurality of negative electrode sheets 210B are stacked to form a negative electrode sheet group 210A. The positions of the plurality of negative electrode sheets 210B and the lengths of the protruding directions are appropriately adjusted in consideration of the state in which the negative electrode sheet group 210A is connected to the negative electrode collector 310. In addition, the shape of the negative electrode sheet 210B is not limited to Figure 8 The shape illustrated in .
[0078] Fig. 9 2 is a front view showing a positive electrode original plate 220S before forming a positive electrode plate 220 (second electrode). Fig.10 yes Fig. 9 The XX cross-sectional view of the positive electrode original plate 220S shown in FIG. Fig.11 1 is a front view showing a positive electrode plate 220 formed of a positive electrode original plate 220S.
[0079] The positive electrode plate 220 is manufactured by processing the positive electrode original plate 220S. Fig. 9 and Fig.10 As shown, 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.
[0080] The positive electrode core body 221 has a positive electrode active material layer 222 formed thereon except for one end portion of both surfaces. The positive electrode active material layer 222 is formed on the positive electrode core body 221 by applying a positive electrode active material layer slurry using a die coater.
[0081] 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 binding material, a carbon material as a conductive material, and N-methyl-2-pyrrolidone (NMP) as a dispersion medium in such a manner that the mass ratio of lithium nickel cobalt manganese composite oxide:PVdF:carbon material becomes approximately 97.5:1:1.5.
[0082] The positive electrode protection 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 protection layer 223 is formed on the positive electrode core 221 by applying the positive electrode protection layer slurry using a die coater. The positive electrode protection layer 223 has a resistance greater than that of the positive electrode active material layer 222.
[0083] The positive electrode protective layer slurry was 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 was about 83:3:14.
[0084] 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 original plate 220S including the positive electrode core 221, the positive electrode active material layer 222 and the positive electrode protective layer 223 is formed by compressing the positive electrode active material layer 222. The positive electrode plate 220 is formed by cutting the positive electrode original plate 220S into a predetermined shape. The positive electrode original plate 220S can be cut by laser processing based on energy line irradiation, metal mold processing, or tool processing.
[0085] like Fig.11 As shown, at one end in the width direction of the positive plate 220 formed by the positive original plate 220S, a plurality of positive electrode sheets 220B formed by the positive electrode core 221 are provided. When the positive plate 220 is wound, the plurality of positive electrode sheets 220B are stacked to form a positive electrode sheet group 220A. The positions of the plurality of positive electrode sheets 220B and the lengths of the protruding directions are appropriately adjusted in consideration of the state in which the positive electrode sheet group 220A is connected to the positive electrode collector 320. In addition, the shape of the positive electrode sheet 220B is not limited to Fig.11 The shape illustrated in .
[0086] A positive electrode protection layer 223 is provided at the root of each of the plurality of positive electrode sheets 220B. The positive electrode protection layer 223 does not necessarily need to be provided at the root of the positive electrode sheet 220B.
[0087] In a typical example, the thickness of the negative electrode sheet 210B (one sheet) is smaller than the thickness of the positive electrode sheet 220B (one sheet). In this case, the thickness of the negative electrode sheet group 210A is smaller than the thickness of the positive electrode sheet group 220A.
[0088] (Connection Structure of Electrode Body 200 and Current Collector 300)
[0089] Fig.12 FIG. 2 is a diagram showing an electrode body 200 and a current collector 300 taken out of a secondary battery 1. Fig.12 As shown in FIG. 1 , the electrode body 200 is formed by stacking two electrode bodies 201 and 202, each of which is a wound electrode body. Fig.12 In the example shown, 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, three or more wound electrode bodies, or a stacked electrode body.
[0090] The negative electrode sheet group 210A is joined to the negative electrode collector 310 at the joint 310A, and the positive electrode sheet group 220A is joined to the positive electrode collector 320 at the joint 320A. The joints 310A and 320A can be formed by, for example, ultrasonic bonding, resistance welding, laser welding, riveting, etc. The joints 310A and 320A constitute a conductive path between the negative electrode sheet group 210A and the positive electrode sheet group 220A and the negative terminal 131 and the positive terminal 132.
[0091] Fig.13 It is a diagram showing the connection structure between the negative electrode sheet group 210A and the negative electrode current collector 310 . Fig.14 , Fig.15 They are Fig.13 The front view and cross-sectional view of the connection structure shown.
[0092] like Figure 13 to Figure 15 As shown, 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.
[0093] The negative electrode sheet group 210A is joined to the first conductive member 311 of the negative electrode current collector 310 at the joint 310A. The first conductive member 311 is connected to the second conductive member 312 at the joint 313. The joint 313 can be formed by, for example, ultrasonic bonding, resistance welding, laser welding, riveting, or the like.
[0094] 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.
[0095] The negative terminal 131 is mounted on the sealing plate 121 via an insulating member 410A made of resin. The negative terminal 131 is configured to be exposed on the outside of the sealing plate 121 and reach the second conductive member 312 of the negative electrode collector 310 provided on the inner surface side of the sealing plate 121. The negative terminal 131 and the second conductive member 312 can be connected, for example, by ultrasonic bonding, resistance welding, laser welding, riveting, etc. In the present embodiment, a through hole is provided in the second conductive member 312, the negative terminal 131 is inserted into the through hole, and after the negative terminal 131 is riveted on the second conductive member 312, the riveted portion and the second conductive member 312 are welded at the joint 131A, thereby connecting the negative terminal 131 to the second conductive member 312.
[0096] As the assembly order of each component, first, the negative terminal 131 and the second conductive component 312 are mounted on the sealing plate 121 together with the insulating components 410 and 410A. Next, the first conductive component 311 connected to the electrode body 200 is mounted on the second conductive component 312. At this time, the first conductive component 311 is arranged on the insulating component 410 in a manner that a part of the first conductive component 311 overlaps with the second conductive component 312. Next, the first conductive component 311 and the second conductive component 312 are welded and connected at the joint 313. In addition, the insulating components 410 and 410A may also be composed of one component.
[0097] The negative electrode terminal 131 may also be electrically connected to the sealing plate 121. In addition, the sealing plate 121 may also play the role of the negative electrode terminal 131.
[0098] In addition, Figure 13 to Figure 15 In FIG. 1 , the negative electrode current collector 310 is exemplified as being composed of two members (the first conductive member 311 and the second conductive member 312 ), but the negative electrode current collector 310 may be composed of a single member.
[0099] exist Figure 13 to Figure 15 , the connection structure on the negative electrode side is shown, but the basic connection structure on the positive electrode side is also the same as that on the negative electrode side.
[0100] (Step of Inserting Electrode Body 200)
[0101] Fig.16 2 is a diagram showing the process of inserting the electrode body 200 into the case body 110. Fig.16 As shown, an insulating sheet 600 (electrode body holder) made of resin is arranged between the electrode body 200 and the case body 110 .
[0102] The insulating sheet 600 may be made of, for example, resin. More specifically, the insulating sheet 600 may be made of, for example, polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), or polyolefin (PO).
[0103] The insulating sheet 600 does not necessarily need to cover the entire surface of the electrode body 200. Preferably, the insulating sheet 600 covers 50% or more of the outer surface of the electrode body, and more preferably covers 70% or more of the area. Preferably, the insulating sheet 600 covers the entirety of at least four of the six surfaces of the substantially rectangular parallelepiped (flat) electrode body 200, except for the two surfaces each having the negative electrode sheet group 210A and the positive electrode sheet group 220A.
[0104] Fig.17 This is a diagram showing a step of placing the separator 510 between the sealing plate 121 and the electrode body 200 . Fig.18 It is a cross-sectional view showing a state where the separator 510 is arranged between the sealing plate 121 and the electrode body 200 .
[0105] like Fig.17 , Fig.18 As shown, the negative electrode sheet group 210A from the electrode body 200 toward the sealing plate 121 is bent from the center of the sealing plate 121 in the Y-axis direction toward the end and then folded back toward the center. A separator 510 is provided to accommodate the bent negative electrode sheet group 210A (bent portion).
[0106] The spacer 510 includes a first spacer 511 and a second spacer 512. The first spacer 511 and the second spacer 512 are each slid along the Y-axis direction from the end side toward the center side of the sealing plate 121 and engaged with each other. As a result, the spacer 510 is fixed to the first sealing plate 121 via the insulating member 410, and the stability of the position of the spacer 510 is increased.
[0107] like Fig.18 As shown, the separator 510 forms an internal space for accommodating the negative electrode current collector 310, and the front end portion of the negative electrode sheet group 210A is also accommodated in the internal space of the separator 510. The separator 510 has a hole portion for allowing the negative electrode sheet group 210A to pass through.
[0108] The material of the separator 510 is not particularly limited, but an insulating material such as resin is preferably used. More specifically, a sheet made of polyolefin (PO) is preferably used. Insulating sheet 600 may be interposed between separator 510 and electrode body 200 .
[0109] Refer again Fig.16In the manufacturing method of the secondary battery 1 of the present embodiment, after the negative electrode terminal 131 is electrically connected to the negative electrode sheet group 210A, the electrode body 200 is inserted into the case body 110 from the end side of the positive electrode sheet group 220A side through the opening 111. When the electrode body 200 is inserted to a predetermined position of the case body 110, the positive electrode sheet group 220A protrudes from the opening 112 of the case body 110 to the outside of the case body 110. Thus, after the electrode body 200 is inserted into the case body 110, the positive electrode terminal 132 and the positive electrode sheet group 220A can be connected.
[0110] When the negative electrode terminal 131 mounted on the sealing plate 121 is electrically connected to the negative electrode sheet group 210A after the electrode body 200 is inserted into the case body 110, the negative electrode sheet group 210A is required to have a length that sufficiently protrudes from the outside of the case body 110 of the electrode body 200 accommodated in the case body 110. By electrically connecting the negative electrode terminal 131 mounted on the sealing plate 121 to the negative electrode sheet group 210A before the electrode body 200 is inserted into the case body 110, the length of the negative electrode sheet group 210A can be shortened 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.
[0111] In addition, Fig.16 In the example, after the separator 510 for accommodating the bent portion of the negative electrode sheet group 210A is arranged, the electrode body 200 is inserted into the case body 110. In this way, the bent portion of the negative electrode sheet group 210A can be protected during the insertion process of the electrode body 200.
[0112] In addition, Fig.16 In the example, the electrode body 200 is inserted into the case body 110 in a state where the electrode body 200 is covered by the insulating sheet 600 . This can prevent the electrode body 200 from being damaged when being inserted into the case body 110 .
[0113] During the insertion process of the electrode body 200, the case body 110 can be held at a predetermined angle. As one example, the electrode body 200 is preferably inserted in a state where the case body 110 is held so that the X-axis direction (the width direction of the case body 110) intersects with the horizontal direction at an angle of less than ±45°. For example, the case body 110 is tilted so 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 in the vertical direction, so that the electrode body 200 can be inserted into the case body 110.
[0114] The step of inserting the electrode body 200 is not limited to a method of pressing the electrode body 200 from the opening 111 side, and for example, a method of pulling the electrode body 200 from the opening 112 side may be used.
[0115] Fig.19 5 is a diagram showing a modified example of the spacer 510. Figure 16 to Figure 18 In the example of FIG. 1 , the spacer 510 is disposed at a portion of the sealing plate 121 in the height direction (Z-axis direction). Fig.19 As shown, the separator 510 may also be arranged over substantially the entire area in the height direction of the sealing plate 121. At this time, the separator 510 may also have a portion protruding toward the electrode body 200 side more than the vicinity of the negative electrode sheet group 210A (the second area) at a position separated from the negative electrode sheet group 210A in the Z-axis direction (the first area). A step difference (preferably a step difference of 1 mm or more) may also be formed at the boundary between the first area and the second area. In this way, damage to the negative electrode sheet group 210A caused when the electrode body 200 is inserted into the case body 110 can be suppressed.
[0116] (Mechanism for pressing the electrode body)
[0117] Fig. 20 This is a diagram showing an example of a mechanism for pressing the electrode body 200 via the sealing plate 121 and the separator 510A. Fig.21 It means viewing from the Z axis direction Fig. 20 The spacer 510A is a modified example of the spacer 510 described above.
[0118] like Fig. 20 , Fig.21 As shown, the separator 510A is arranged in a position avoiding the negative electrode sheet group 210A and the negative electrode collector 310 (a position separated from the negative electrode sheet group 210A and the negative electrode collector 310) in the height direction (Z-axis direction) of the sealing plate 121 and the electrode body 200. More specifically, the separator 510A is arranged in two positions in a manner of clamping the negative electrode sheet group 210A in the Z-axis direction. Preferably, the separator 510A presses the portion of the electrode body 200 where the negative electrode sheet group 210A is not provided. It is particularly preferred to press the portion where the diaphragm protrudes compared to the end of the negative plate 210. The separator 510A may also be arranged only on one side of the negative electrode sheet group 210A in the Z-axis direction. The separator 510A may be fixed to the sealing plate 121 and / or the electrode body 200, for example, by bonding, welding, tape bonding, etc. In addition, the separator 510A may also be in contact with the negative electrode sheet group 210A.
[0119] It is preferable to provide a through hole, a cutout, a slit, etc. in the spacer 510A at a position opposite to the injection hole 141. In addition, it is preferable to provide a through hole, a cutout, a slit, etc. in the spacer 510A at a position opposite to the exhaust valve 151. Thus, the function of the injection hole 141 or the exhaust valve 151 can be more reliably ensured.
[0120] exist Fig. 20 , Fig.21 In the example, the electrode body 200 is inserted into the case body 110 by pressing the electrode body 200 via the separator 510A. The electrode body 200 may be further inserted by holding the electrode body 200 at the beginning of the insertion process of the electrode body 200 and pressing the electrode body 200 via the separator 510A after a part of the electrode body 200 is inserted into the case body 110.
[0121] Next, use Figure 22 to Figure 27 A further modification example of the spacer 510A will be described.
[0122] Fig. 22 The separator 510B shown has two protrusions 510B1. The two protrusions 510B1 each have a tapered shape whose width in the Y-axis direction decreases toward the front end. The front ends of the two protrusions 510B1 are respectively inserted between the electrode bodies 201, 202 and the inner surface of the shell body 110. During the insertion process of the electrode body 200, the electrode bodies 201, 202 can be pressed into the inside of the shell body 110 via the protrusions 510B1.
[0123] Fig.23 The separator 510C shown has a protrusion 510C1. The protrusion 510C1 has a tapered shape whose width in the Y-axis direction decreases toward the front end. The front end of the protrusion 510C1 is inserted between the electrode bodies 201 and 202. In the insertion process of the electrode body 200, the electrode bodies 201 and 202 can be pressed into the inside of the case body 110 via the protrusion 510C1.
[0124] The shapes of the protrusions 510B1 and 510C1 can be changed as appropriate. For example, the tips of the protrusions 510B1 and 510C1 may have a curved shape (R shape).
[0125] Fig.24 The separator 510D shown is fixed to the insulating sheet 600 at the joint 510D1. The joint 510D1 can be formed by, for example, heat welding, bonding, fitting, tape bonding, etc. In the insertion process of the electrode body 200, the electrode bodies 201 and 202 can be pressed into the inside of the case body 110 via the separator 510D and the insulating sheet 600.
[0126] exist Fig.24In the example of FIG. 1 , the insulating sheet 600 partially covers the spacer 510D, but the insulating sheet 600 may completely cover the spacer 510D. In addition, the insulating sheets 600 may be provided with a joint portion 510D1 instead of the spacer 510D and the insulating sheet 600 or in addition to the joint portion 510D1.
[0127] Fig.25 The separator 510E shown also serves as an insulating portion for insulating the negative electrode current collector 310 from the sealing plate 121. With this structure, the separator 510E can be used to more stably press the electrode body 200 during the insertion process of the electrode body 200. In addition, the separator 510E can be fitted into the recess 121A provided in the sealing plate 121.
[0128] Isolation member 510F( Fig.26 ) are arranged on both sides of the negative electrode collector 310. In addition, 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 collector 310 and the sealing plate 121. The separator 510F is fitted into the recess 121A provided in the sealing plate 121.
[0129] exist Fig.25 , Fig.26 In the illustrated structure, the spacers 510E and 510F can be fixed to the sealing plate 121 by the concave-convex fit between the spacers 510E and 510F and the sealing plate 121. Other fixing means (adhesion, welding, tape sticking, etc.) can also be used instead of or in addition to the concave-convex fit. In addition, locking fixation can also be used.
[0130] Fig. 27 The separator 510G shown is arranged so as to cross the bent portion of the negative electrode sheet group 210A in the Z-axis direction. In the insertion step of the electrode body 200 , the electrode body 200 can be pressed into the case body 110 via the separator 510G.
[0131] Instead of the above-mentioned separators, a separator fixed to the electrode body 200 may be provided. The separator is fixed to the electrode body 200 by, for example, sticking with a tape.
[0132] (Manufacturing process of secondary battery 1)
[0133] Fig.28 1 is a flow chart showing each step of the method for manufacturing the secondary battery 1. Fig.28As shown, in S10, the shell body 110 is prepared. Next, in S20, the electrode body 200 is made. In S30, the electrode terminals provided on the sealing plates 121 and 122 are electrically connected to the electrode sheet group of the electrode body 200. At this time, first, the negative terminal 131 is electrically connected to the negative electrode sheet group 210A (S31), and then, the separator 510 is arranged between the sealing plate 121 on the negative electrode side and the electrode body 200 (S40), and then the electrode body 200 is inserted into the shell body 110 (S50). At this time, the positive electrode sheet group 220A protrudes from the opening 112 of the shell body 110 to the outside of the shell body 110. After the electrode body 200 is inserted into the shell body 110, the positive terminal 132 is electrically connected to the positive electrode sheet group 220A (S32).
[0134] In this embodiment, an example is described in which the connection between the negative terminal 131 and the negative electrode sheet group 210A (S31), the insertion of the electrode body 200 (S50), and the connection between the positive terminal 132 and the positive electrode sheet group 220A (S32) are carried out in this order, but the scope of the present technology is not limited to this, and sometimes the connection between the positive terminal 132 and the positive electrode sheet group 220A (S32), the insertion of the electrode body 200 (S50), and the connection between the negative terminal 131 and the negative electrode sheet group 210A (S31) are carried out in this order.
[0135] After the connection between the electrode terminal and the electrode sheet group is completed ( S30 ), the openings 111 and 112 are sealed by the sealing plates 121 and 122 ( S60 ). The sealing process by the sealing plates 121 and 122 is performed by, for example, laser welding.
[0136] The process (S61) of sealing the opening 111 by the sealing plate 121 on the negative electrode side can be performed after the process (S50) of inserting the electrode body 200 into the shell body 110, and the process (S62) of sealing the opening 112 by the sealing plate 122 on the positive electrode side can be performed after the process (S32) of electrically connecting the positive terminal 132 and the positive electrode sheet group 220A.
[0137] Therefore, for example, the step (S61) of sealing the opening 111 with the sealing plate 121 may be performed before the step (S32) of electrically connecting the positive terminal 132 to the positive electrode sheet group 220A, or the step (S61) of sealing the opening 111 with the sealing plate 121 may be performed after the step (S62) of sealing the opening 112 with the sealing plate 122. Furthermore, at least a part of the steps (S61, S62) of sealing with the sealing plates 121 and 122 may be performed simultaneously.
[0138] (summary)
[0139] The method for manufacturing the secondary battery 1 according to the present embodiment can be summarized as follows based on the above contents.
[0140] like Fig.28 As shown, the manufacturing method of the secondary battery 1 comprises: a step (S10) of preparing a shell body 110 having an opening 111 and an opening 112 opposite to the opening 111; a step (S20) of making an electrode body 200, wherein the electrode body 200 comprises a negative electrode plate 210 and a positive electrode plate 220, and has a negative electrode sheet group 210A including a negative electrode sheet 210B connected to the negative electrode plate 210 at one end thereof, and has a positive electrode sheet group 220A including a positive electrode sheet 220B connected to the positive electrode plate 220 at the other end thereof; a step (S31) of electrically connecting the negative electrode terminal 131 provided on the sealing plate 121 to the negative electrode sheet group 210A; and a step (S32) of electrically connecting the negative electrode terminal 131 provided on the sealing plate 121 to the negative electrode sheet group 210A. After the terminal 131 is electrically connected to the negative electrode sheet group 210A, the electrode body 200 is inserted into the shell body 110 from the end side of the positive electrode sheet group 220A side through the opening 111 (S50); after the electrode body 200 is inserted into the shell body 110, the positive terminal 132 provided on the sealing plate 122 is electrically connected to the positive electrode sheet group 220A (S32); after the electrode body 200 is inserted into the shell body 110, the opening 111 is sealed by the sealing plate 121 (S61); and after the positive terminal 132 is electrically connected to the positive electrode sheet group 220A, the opening 112 is sealed by the sealing plate 122 (S62).
[0141] In one example of a method for manufacturing the secondary battery 1 , the electrode body 200 before being inserted into the case body 110 may be covered with the insulating sheet 600 . However, in the present technology, the insulating sheet 600 covering the electrode body 200 is not essential.
[0142] The manufacturing method of the secondary battery 1 in one example further includes a step (S40) of disposing the separator 510 between the sealing plate 121 and the electrode body 200. However, in the present technology, the step (S40) of disposing the separator 510 is not essential.
[0143] By disposing the separator 510, the electrode body 200 is pressed via the separator 510, so that the electrode body 200 can be inserted into the case body 110. When pressing the electrode body 200 via the separator 510, the electrode body 200 can be pressed via the separator 510 by pressing the sealing plate 121 from the X-axis direction, or the sealing plate 121 can be held (clamped in the Y-axis direction) and moved toward the electrode body 200 to press the electrode body 200 via the separator 510.
[0144] In the method for manufacturing the secondary battery 1, after a portion of the electrode body 200 is inserted into the case body 110 while holding the electrode body 200, the electrode body 200 is pressed by the sealing plate 121 via the separator 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. Thus, at least the entire portion of the electrode body 200 except the positive electrode sheet group 220A is disposed in the case body 110.
[0145] In the secondary battery 1 of one example, in the step (S50) of inserting the electrode body 200 into the shell body 110, the separator 510 abuts against the position separated from the negative electrode sheet group 210A in the end portion of the sealing plate 121 side of the electrode body 200. In addition, it is preferred that the separator 510 directly or indirectly presses the exposed portion of the diaphragm included in the electrode body 200 via the insulating sheet 600 or the like. However, the position where the separator 510 abuts against the electrode body 200 can be appropriately changed. In addition, the separator 510 does not necessarily abut against the electrode body 200.
[0146] In the present embodiment, the separator is described as being arranged on the negative electrode side, but the same separator may be arranged on the positive electrode side. The separator may be arranged on both the negative electrode side and the positive electrode side, or may be arranged on only one of the negative electrode side and the positive electrode side.
[0147] (Function and Effect)
[0148] According to the secondary battery 1 of the present embodiment, the electrode body 200 is inserted into the case body 110 having the openings 111 and 112 facing each other, and the negative electrode terminal 131 and the positive electrode terminal 132 are respectively provided on the sealing plates 121 and 122 that seal the openings 111 and 112, respectively, so that the height of the secondary battery 1 can be reduced and the mountability of the secondary battery 1 on the vehicle can be improved. In addition, by inserting the electrode body 200 from the positive electrode sheet group 220A side into the case body 110 through the opening 111 after the negative electrode terminal 131 is electrically connected to the negative electrode sheet group 210A, that is, by attaching the sealing plate 121 to the negative electrode sheet group 210A before the electrode body 200 is inserted into the case body 110, the length of the negative electrode sheet group 210A can be shortened compared with the case where the sealing plate 121 is attached to the negative electrode sheet group 210A after the electrode body 200 is inserted into the case body 110. As a result, since the volume occupied by the electrode body 200 in the space inside the case body 110 can be increased, the energy density of the secondary battery 1 can be improved.
[0149] In the above example, the separator 510 is disposed between the sealing plate 121 and the electrode body 200, and the electrode body 200 is pressed via the separator to insert the electrode body 200 into the case body 110. As a result, it is possible to suppress excessive load from being applied to the negative electrode sheet group 210A during the insertion process of the electrode body 200, and to suppress damage to the negative electrode sheet group 210A. Therefore, the secondary battery 1 can be manufactured more efficiently and stably.
[0150] Although the embodiments of the present invention have been described, the embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and it is intended to include all changes within the meaning and scope equivalent to the claims.
Claims
1. A method for manufacturing a secondary battery, characterized in that: The following processes are available, namely: A step of preparing a housing body having a first opening and a second opening opposite to the first opening; A step of forming an electrode body, wherein the electrode body includes a first electrode and a second electrode having a polarity different from that of the first electrode, the electrode body having a first electrode sheet connected to the first electrode at a first end thereof, and a second electrode sheet connected to the second electrode at a second end located on the opposite side to the first end; A step of electrically connecting a first electrode terminal provided on a first sealing plate to the first electrode sheet; After the first electrode terminal is electrically connected to the first electrode sheet, the electrode body is inserted into the case body from the second end side through the first opening; After the electrode body is inserted into the housing body, a step of electrically connecting a second electrode terminal provided on a second sealing plate to the second electrode sheet; After the electrode body is inserted into the case body, the first opening is sealed with the first sealing plate; and A step of sealing the second opening with the second sealing plate after the second electrode terminal is electrically connected to the second electrode sheet.
2. The method for manufacturing a secondary battery according to claim 1, characterized in that: further comprising the step of disposing a separator between the first sealing plate and the electrode body, The electrode body is inserted into the case body by pressing the electrode body with the first sealing plate through the separator.
3. The method for manufacturing a secondary battery according to claim 2, characterized in that: In the step of inserting the electrode body into the case main body, the separator abuts against a position of the first end portion of the electrode body that is separated from the first electrode sheet.
4. The method for manufacturing a secondary battery according to claim 2 or 3, characterized in that: The step of arranging the spacer includes fixing the spacer to the first sealing plate.
5. The method for manufacturing a secondary battery according to claim 2 or 3, characterized in that: The step of disposing the separator includes fixing the separator to the electrode body.
6. The method for manufacturing a secondary battery according to any one of claims 1 to 3, characterized in that: The method further includes covering the electrode body before being inserted into the case body with an insulating electrode body holder.
7. The method for manufacturing a secondary battery according to claim 1, wherein: further comprising the step of disposing a separator between the first sealing plate and the electrode body, After the electrode body is held and a part of the electrode body is inserted into the case body, the electrode body is pressed by the first sealing plate via the separator to insert the electrode body into the case body until the first sealing plate contacts the case body.