Battery manufacturing method

Abstract

This invention provides a method for manufacturing a battery with a high productivity for producing batteries having wound electrodes. In a preferred embodiment of the battery manufacturing method disclosed herein, the method includes: a wound body fabrication step (S1) of fabricating a wound body by winding a separator, a first electrode, and a second electrode onto a core; a forming step (S2) of forming the wound body into a flat shape; and a placement step (S3) of placing the fabricated wound electrodes within a battery casing.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing a battery. Background Technology

[0002] For example, Patent Document 1 discloses a battery in which a positive electrode tab assembly is provided at one end along the length of the wound electrode body and a negative electrode tab assembly is provided at the other end. Furthermore, it discloses a technique for connecting the tab assembly to the electrode current collector while the tab assembly is bent.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2021 / 060010

[0006] Another example of the manufacturing method of this wound electrode body is as follows: a current collector having a long strip and positive and negative electrodes (hereinafter sometimes referred to together as "electrodes") formed at multiple locations along the length of the current collector are wound onto a winding core through a diaphragm and then formed into a flat shape. During the manufacturing of the wound electrode body, the electrodes on the outer periphery of the wound electrode body may sometimes shift from their intended positions, making it difficult to collect the electrodes. As a result, the yield of the wound electrode body may decrease, and therefore this method is not preferred. Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The purpose of this disclosure is to provide a technology for producing batteries with wound electrodes in high productivity.

[0009] Methods for solving problems

[0010] To achieve the above objectives, this disclosure provides a method for manufacturing a battery, the battery comprising: a flat, wound electrode body formed by winding a first electrode and a second electrode with a polarity different from the first electrode through a separator; and a battery casing housing the wound electrode body. In the battery, a plurality of tabs connected to the first electrode are provided at one end of the wound electrode body in the winding axis direction, the plurality of tabs being connected to a current collector of the first electrode. The wound electrode body has a first region located on one side of the winding axis and a second region located on the other side of the winding axis in the thickness direction. The plurality of tabs includes a first tab, a second tab, a third tab, and a fourth tab. The first tab is located in the tabs present in the first region at a position closest to the winding axis of the winding electrode body in the thickness direction. The second tab is located in the tabs present in the second region at a position closest to the winding axis of the winding electrode body in the thickness direction. The third tab is located in the tabs present in the first region at a position furthest from the winding axis of the winding electrode body in the thickness direction. The fourth tab is located in the tabs present in the second region at a position furthest from the winding axis of the winding electrode body in the thickness direction. At one end, the distance between the center of the root width of the first tab and the center of the root width of the second tab in the vertical direction relative to the thickness direction is defined as G1, and the distance between the center of the root width of the third tab and the center of the root width of the fourth tab in the vertical direction is defined as G2. The battery manufacturing method includes: a winding electrode body fabrication step, in which the winding electrode body is fabricated; and a placement step, in which the fabricated winding electrode body is placed inside the battery casing. In the winding electrode body fabrication step, when the winding electrode body is fabricated with G1 = 0, the value of G1 is changed to G2 < S relative to the winding condition G2 = S (S > 0), thereby fabricating the winding electrode body. According to this battery manufacturing method, a winding electrode body that appropriately suppresses the offset of the tabs on the outer periphery of the winding electrode body can be obtained, as detailed later. Therefore, batteries equipped with winding electrode bodies can be obtained with high productivity.

[0011] In the battery manufacturing method disclosed herein, it is preferred that the winding electrode body manufacturing process includes a winding body manufacturing process, in which the separator, the first electrode, and the second electrode are wound onto a core to form a winding body. Furthermore, it is preferred that the process includes a forming step of shaping the winding body into a flat shape.

[0012] In a preferred embodiment of the battery manufacturing method of this type, during the winding body manufacturing process, the value of G1 is changed by controlling the timing at which the first electrode begins to wind into the core. This structure allows for easy suppression of tab offset on the outer periphery of the wound electrode body, and is therefore preferred.

[0013] In a preferred embodiment of the battery manufacturing method with this structure, the value of G1 is changed by controlling the position in which the wound body is formed into a flat shape during the forming process. According to this structure, the offset of the tabs on the outer periphery of the wound electrode body can be easily suppressed, and therefore it is preferred.

[0014] In a preferred embodiment of the battery manufacturing method with this structure, a cutting step is included, in which the first electrode plate is cut to form the starting end of the winding of the first electrode before the first electrode is wound onto the core. In this cutting step, the value of G1 is changed by controlling the cutting position of the first electrode plate. According to this structure, the offset of the tabs on the outer periphery of the wound electrode body can be easily suppressed, and therefore it is preferred.

[0015] In one embodiment of the battery manufacturing method disclosed herein, in the winding body manufacturing process, a plurality of the winding bodies are manufactured using a plurality of the winding cores.

[0016] In one embodiment of the battery manufacturing method disclosed herein, in the winding body manufacturing process, a winding electrode body manufacturing apparatus having a plurality of said cores is used to continuously manufacture the winding body.

[0017] In one embodiment of the battery manufacturing method disclosed herein, when multiple wound electrode bodies are fabricated using multiple winding cores, the G2 value of each of the multiple wound electrode bodies is controlled to be below 2 mm. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating a method for manufacturing a battery according to one embodiment.

[0019] Figure 2A This is a schematic diagram illustrating the positive electrode (positive electrode plate) of one embodiment.

[0020] Figure 2B This is a schematic diagram illustrating the negative electrode (negative electrode sheet) of one embodiment.

[0021] Figure 3 This is a schematic diagram illustrating the winding body manufacturing process in a battery manufacturing method according to one embodiment.

[0022] Figure 4A This is a schematic diagram illustrating a forming process in a battery manufacturing method according to one embodiment.

[0023] Figure 4B This is a schematic diagram illustrating a forming process in a battery manufacturing method according to one embodiment.

[0024] Figure 5A This is a schematic diagram showing the positive electrode side end face of the wound electrode body before adjusting the winding conditions of one embodiment.

[0025] Figure 5B It is a schematic representation relative to Figure 5A A diagram of the positive side end face of the wound electrode body under the condition that the value of G1 is changed in a way that satisfies the relationship G2 < S.

[0026] Figure 6 It is a perspective view schematically showing a sealing plate with a positive terminal, a negative terminal, a first positive current collector, a first negative current collector, a positive insulating component, and a negative insulating component installed.

[0027] Figure 7 It is Figure 6 A 3D view of the sealing plate turned upside down.

[0028] Figure 8 It is a schematic perspective view of an electrode body with a positive second collector and a negative second collector installed.

[0029] Figure 9 This is a schematic perspective view of the electrode assembly mounted on the sealing plate.

[0030] Figure 10 This is a schematic cross-sectional view illustrating the battery configuration process of one embodiment.

[0031] Figure 11A This is a schematic diagram showing the positive electrode side end face of the wound electrode body before adjusting the winding conditions of the second embodiment.

[0032] Figure 11B It is a schematic representation relative to Figure 11A A diagram of the positive side end face of the wound electrode body under the condition that the value of G1 is changed in a way that satisfies the relationship G2 < S.

[0033] Figure 12 This is a schematic diagram showing the end face of the positive electrode side of the wound electrode body according to the third embodiment.

[0034] Figure 13 This is a schematic diagram showing the end face of the positive electrode side of the wound electrode body according to the fourth embodiment.

[0035] Figure 14 This is a perspective view schematically showing one embodiment of a battery.

[0036] Figure 15 It is along Figure 14 A schematic longitudinal sectional view of the XV-XV line.

[0037] Figure 16 It is along Figure 14 A schematic longitudinal section view of the XVI-XVI lines.

[0038] Figure 17 It is along Figure 14 A schematic cross-sectional view of the XVII-XVII line.

[0039] Figure 18 This is a schematic diagram showing the structure of a wound electrode body according to one embodiment.

[0040] Figure 19 This is a schematic diagram illustrating the structure of a winding electrode fabrication apparatus according to other embodiments.

[0041] Figure 20 This is a schematic diagram illustrating the structure of a winding core in other embodiments.

[0042] Explanation of reference numerals in the attached figures

[0043] 10 Battery casing

[0044] 12 outer body

[0045] 14 Sealing board

[0046] 15 injection holes

[0047] 16 Sealing components

[0048] 17 Gas discharge valve

[0049] 18 and 19 terminal insertion holes

[0050] 20 electrode assembly

[0051] 20a~20c electrode body

[0052] 22 Positive electrode

[0053] 24 Negative electrode

[0054] 26. Diaphragm

[0055] 27. The end where the positive electrode winding begins.

[0056] 28. The end of the positive electrode winding.

[0057] 30 Positive extremes

[0058] 32 Positive electrode external conductive component

[0059] 40 Negative extremes

[0060] 42 External conductive component of negative electrode

[0061] 50 Positive current collector

[0062] 60 Negative current collector

[0063] 70 Positive electrode internal insulation components

[0064] 80 Negative electrode internal insulation components

[0065] 90 sealing gasket

[0066] 92 External insulation components

[0067] 100 batteries

[0068] 200 winding body

[0069] 201, 301, and 401 core coils

[0070] 202 and 302 conveyor rollers

[0071] 204 Stamping Machine

[0072] 300 Winding Electrode Manufacturing Apparatus

[0073] 401a First Structural Section

[0074] 401b Second Structural Section Detailed Implementation

[0075] Hereinafter, several preferred embodiments of the technology disclosed herein will be described with reference to the accompanying drawings. Furthermore, matters necessary for the implementation of this disclosure other than those specifically mentioned in this specification (e.g., the general structure and manufacturing process of the battery not representing this disclosure) can be understood as design matters by those skilled in the art based on prior art. This disclosure can be implemented based on the content disclosed in this specification and common technical knowledge in the art. Additionally, the following description is not intended to limit the technology disclosed herein to the following embodiments. Furthermore, the expression "A to B" indicating scope in this specification includes meanings of more than A and less than B, and also includes meanings of more than A and less than B.

[0076] Furthermore, in this specification, "battery" refers to all energy storage devices capable of extracting electrical energy, encompassing both primary and secondary batteries. Additionally, in this specification, "secondary battery" refers to all energy storage devices capable of repeated charging and discharging, encompassing so-called storage batteries (chemical batteries) such as lithium-ion secondary batteries and nickel-metal hydride batteries, as well as capacitors (physical batteries) such as electric double-layer capacitors.

[0077] <Battery Overall Structure>

[0078] First, the overall structure of the battery 100 obtained by the battery manufacturing method of this embodiment will be described. Here, Figure 14 It is a 3D image of battery 100. Figure 15 It is along Figure 14 A schematic longitudinal sectional view of the XV-XV line. Figure 16 It is along Figure 14 A schematic longitudinal section view of the XVI-XVI lines. Figure 17 It is along Figure 15 A schematic cross-sectional view along lines XVII-XVII. In the following description, reference numerals L, R, F, Rr, U, and D in the figures represent left, right, front, back, top, and bottom, respectively, and reference numerals X, Y, and Z in the figures represent the direction of the short side of the battery 100, the direction of the long side orthogonal to the short side (also called the length direction of the electrode body), and the up-down direction, respectively. However, these are merely directions for ease of explanation and do not limit the arrangement of the battery 100.

[0079] like Figure 15 As shown, the battery 100 includes a battery casing 10 and an electrode assembly 20. In addition to the battery casing 10 and the electrode assembly 20, the battery 100 of this embodiment also includes a positive terminal 30, a positive external conductive member 32, a negative terminal 40, a negative external conductive member 42, an external insulating member 92, a positive current collector 50, a negative current collector 60, a positive internal insulating member 70, and a negative internal insulating member 80. Furthermore, although not shown in the figures, the battery 100 of this embodiment also includes an electrolyte. The battery 100 here is a lithium-ion secondary battery. The internal resistance of the battery 100 can be, for example, approximately 0.2 to 2.0 mΩ.

[0080] The battery casing 10 is a frame that houses the electrode assembly 20. Here, the battery casing 10 has a flat, bottomed cuboid shape (square). The material of the battery casing 10 can be the same as conventionally used materials, without particular limitation. The battery casing 10 is preferably made of a metal with a specified strength. Specifically, the tensile strength of the metal used in the battery casing 10 is suitable to be 50 N / mm². 2 ~200N / mm 2The stiffness of the metal used in the battery casing 10 is preferably around 20 GPa to 100 GPa. Examples of such metal materials include aluminum, aluminum alloys, iron, and iron alloys.

[0081] Additionally, the battery casing 10 includes an outer body 12, a sealing plate 14, and a gas vent valve 17. The outer body 12 is a flat, square container with one side forming an opening 12h. Specifically, as... Figure 14 As shown, the outer casing 12 has a generally rectangular bottom wall 12a, a pair of first side walls 12b extending upward U from the short side of the bottom wall 12a and facing each other, and a pair of second side walls 12c extending upward U from the long side of the bottom wall 12a and facing each other. The area of ​​the second side walls 12c is smaller than the area of ​​the first side walls 12b. An opening 12h is formed on the upper surface of the outer casing 12 surrounded by the pair of first side walls 12b and the pair of second side walls 12c. A sealing plate 14 is mounted on the outer casing 12 to block the opening 12h of the outer casing 12. The sealing plate 14 is a generally rectangular plate when viewed from above. The sealing plate 14 faces the bottom wall 12a of the outer casing 12. The battery casing 10 is formed by joining (e.g., welding) the sealing plate 14 to the periphery of the opening 12h of the outer casing 12. The joining of the sealing plate 14 can be performed, for example, by welding such as laser welding.

[0082] like Figure 14 and Figure 15 As shown, a gas vent valve 17 is formed on the sealing plate 14. The gas vent valve 17 is configured to open when the pressure inside the battery housing 10 reaches a predetermined value, thereby venting gas from the battery housing 10. In addition to the gas vent valve 17, the sealing plate 14 also has an injection hole 15 and two terminal insertion holes 18 and 19. The injection hole 15 is an opening that communicates with the internal space of the outer casing 12 and is provided for injecting electrolyte during the manufacturing process of the battery 100. The injection hole 15 is sealed by a sealing member 16. A blind rivet is preferably used as the sealing member 16, for example. This allows the sealing member 16 to be securely fixed inside the battery housing 10.

[0083] Here, the electrode assembly 20 includes three electrode bodies: 20a, 20b, and 20c. Furthermore, the number of electrode bodies housed inside a battery casing 10 is not particularly limited; it can be one or more (multiple). Additionally, as... Figure 15 As shown, on one side of the long side direction Y of each electrode body ( Figure 15 A positive current collector 50 is arranged on the left side, and on the other side in the long side direction Y ( Figure 15A negative current collector 60 is arranged on the right side. Furthermore, electrode bodies 20a, 20b, and 20c are each connected in parallel. However, electrode bodies 20a, 20b, and 20c can also be connected in series. Here, the electrode body assembly 20 is held in an electrode body holder 29 (see reference 20a) made of resin sheet. Figure 16 In the covered state, it is housed inside the outer body 12 of the battery housing 10 in such a way that the shaft WL is wound along the bottom wall 12a.

[0084] The following detailed explanation uses electrode 20a as an example, but the same structure can also be used for electrode 20b and 20c. Figure 18 As shown, the electrode body 20a has a positive electrode 22, a negative electrode 24, and a separator 26. Here, the electrode body 20a is a wound electrode body in which a strip-shaped positive electrode 22 and a strip-shaped negative electrode 24 are stacked with two strip-shaped separators 26 in between, and wound around a winding shaft WL. The structure of the positive electrode 22, negative electrode 24, and separator 26 of the electrode body 20a will be explained in the section on battery manufacturing method described later.

[0085] The electrode body 20a has a flat shape. The electrode body 20a is disposed inside the outer casing 12 with its winding axis WL approximately parallel to the long side direction Y. Specifically, as... Figure 16 As shown, the electrode body 20a has: a pair of curved portions (R portions) 20r, which face the bottom wall 12a of the outer body 12 and the sealing plate 14; and a flat portion 20f, which connects to the pair of curved portions 20r and faces the second side wall 12c of the outer body 12. The flat portion 20f extends along the second side wall 12c.

[0086] At one end of the positive current collector 22c along the long side direction Y ( Figure 18 Multiple positive electrode tabs 22t are provided at the left end of the strip. These multiple positive electrode tabs 22t are spaced apart (intermittently) along the length of the strip-shaped positive electrode 22. The multiple positive electrode tabs 22t face one side of the axial direction of the winding shaft WL. Figure 18 The left side of the diaphragm (26) protrudes outwards. Furthermore, as... Figure 5B As shown, in the positive electrode side end face of the wound electrode body (electrode body 20a, 20b, 20c) obtained by the battery manufacturing method of this embodiment, the outermost third tab 22t3 and fourth tab 22t4 are arranged such that the distance G2 (G2) between the center C3 of the root width of the third tab 22t3 and the center C4 of the root width of the fourth tab 22t4 in the perpendicular direction Z with respect to the thickness direction X (in other words, the stacking direction of the wound electrode body) of the wound electrode body is... AThe value of ) is less than S. By positioning the outermost positive electrode tab 22t, which is particularly prone to displacement, in a suitable position for collecting foil, the collection of foil for the positive electrode tab 22t can be implemented more reliably. As a result, the yield of the wound electrode body can be suppressed, and thus the battery 100 equipped with the wound electrode body can be obtained with high productivity. Furthermore, the root width of the positive electrode tab 22t represents the width of the boundary portion between the positive current collector 22c (the main body portion) and the positive electrode tab 22t (refer to...). Figure 18 (22w). Regarding the root width of the negative electrode tab 24t, it also indicates the corresponding part of the negative electrode 24.

[0087] like Figure 17 As shown, multiple positive electrode tabs 22t are located at one end of the winding shaft WL along its axial direction. Figure 17 The left end of each electrode is stacked to form a positive electrode tab assembly 23. Furthermore, each of the multiple positive electrode tabs 22t is connected to the positive current collector 50 in a bent state. This increases the size of the main body of the electrode assembly 20 housed within the battery casing 10, thus enabling a higher energy density battery 100. Figure 15 As shown, the positive electrode tab group 23 is electrically connected to the positive terminal 30 via the positive electrode current collector 50. Specifically, the positive electrode tab group 23 and the positive electrode second current collector 52 are connected at the connection point J (see reference). Figure 17 Furthermore, the positive electrode second collector 52 is electrically connected to the positive electrode terminal 30 via the positive electrode first collector 51.

[0088] At one end of the axial direction of the winding shaft WL of the negative current collector 24c ( Figure 18 Multiple negative electrode tabs 24t are provided at the right end of the strip. These multiple negative electrode tabs 24t are spaced apart (intermittently) along the length of the strip-shaped negative electrode 24. Each of the multiple negative electrode tabs 24t faces one side of the axial direction. Figure 18 (The right side) protrudes outward from the diaphragm 26.

[0089] like Figure 17 As shown, multiple negative electrode tabs 24t are located at one end in the axial direction ( Figure 17 The right end of each electrode assembly 24t is stacked to form a negative electrode tab group 25. The negative electrode tab group 25 is preferably positioned symmetrically to the positive electrode tab group 23 in the axial direction. Furthermore, each of the plurality of negative electrode tabs 24t is connected to the negative electrode current collector 60 in a bent state. This increases the size of the main body of the electrode assembly 20 housed within the battery casing 10, thus enabling a higher energy density battery 100. Figure 15 As shown, the negative electrode tab assembly 25 is electrically connected to the negative terminal 40 via the negative electrode current collector 60. Specifically, the negative electrode tab assembly 25 and the negative electrode second current collector 62 are connected at the connection point J (see reference). Figure 17Furthermore, the negative electrode second collector 62 is electrically connected to the negative electrode terminal 40 via the negative electrode first collector 61.

[0090] like Figure 15 As shown, the positive terminal 30 is inserted into one end of the sealing plate 14 in the Y direction along its long side. Figure 15 The positive terminal 30 is inserted into the terminal insertion hole 18 at the left end of the sealing plate 14. The positive terminal 30 is preferably made of metal, more preferably of, for example, aluminum or an aluminum alloy. On the other hand, the negative terminal 40 is inserted into the end formed on the other side of the long side in the Y direction of the sealing plate 14. Figure 15 The positive terminal 30 and negative terminal 40 are inserted into the terminal insertion holes 19 at the right end of the battery casing 10. Furthermore, the negative terminal 40 is preferably made of metal, and more preferably of copper or a copper alloy. Here, these electrode terminals (positive terminal 30, negative terminal 40) protrude from the same side of the battery casing 10 (specifically, the sealing plate 14). However, the positive terminal 30 and negative terminal 40 may also protrude from different sides of the battery casing 10. Additionally, the electrode terminals (positive terminal 30, negative terminal 40) preferably inserted into the terminal insertion holes 18, 19 are fixed to the sealing plate 14 by riveting or the like.

[0091] As mentioned above, such as Figure 15 As shown, the positive terminal 30 is located inside the outer casing 12 via the positive current collector 50 (positive first current collector 51, positive second current collector 52) and the positive terminals 22 of each electrode body (see reference). Figure 15 Electrical connection. The positive terminal 30 is insulated from the sealing plate 14 by the positive internal insulating member 70 and the sealing gasket 90. Furthermore, the positive internal insulating member 70 has a base portion 70a located between the positive first current collector 51 and the sealing plate 14, and a protrusion 70b protruding from the base portion 70a toward the electrode assembly 20. The positive terminal 30, which protrudes to the outside of the battery casing 10 through the terminal insertion hole 18, is connected to the positive external conductive member 32 at the outside of the sealing plate 14. On the other hand, as... Figure 15 As shown, the negative terminal 40 is connected inside the outer casing 12 to the negative terminals 24 of each electrode body (see reference 60) via the negative current collector 60 (the first negative current collector 61 and the second negative current collector 62). Figure 15Electrical connection. The negative terminal 40 is insulated from the sealing plate 14 by the negative internal insulating member 80 and the sealing gasket 90. Furthermore, similar to the positive internal insulating member 70, the negative internal insulating member 80 also has a base portion 80a located between the negative first current collector 61 and the sealing plate 14, and a protrusion 80b protruding from the base portion 80a toward the electrode assembly 20. The negative terminal 40, which protrudes to the outside of the battery casing 10 through the terminal insertion hole 19, is connected to the negative external conductive member 42 at the outside of the sealing plate 14. An external insulating member 92 is sandwiched between the external conductive members (positive external conductive member 32, negative external conductive member 42) and the outer surface of the sealing plate 14. This external insulating member 92 insulates the external conductive members 32 and 42 from the sealing plate 14. Furthermore, the protrusions 70b and 80b of the aforementioned internal insulating members (positive electrode internal insulating member 70 and negative electrode internal insulating member 80) are disposed between the sealing plate 14 and the electrode assembly 20. Through these protrusions 70b and 80b of the internal insulating members, the upward movement of the electrode assembly 20 is restricted, preventing contact between the sealing plate 14 and the electrode assembly 20.

[0092] <Battery Manufacturing Method>

[0093] Next, the battery manufacturing method of this embodiment will be described. First, the battery manufacturing method disclosed herein includes a winding electrode body fabrication step and an arrangement step of placing the fabricated winding electrode body within a battery casing. Furthermore, the battery manufacturing method of this embodiment includes, in the winding electrode body fabrication step: a winding body fabrication step, in which a separator, a first electrode, and a second electrode are wound onto a core to fabricate a winding body; and a forming step, in which the winding body is formed into a flat shape. That is, as... Figure 1 As shown, the battery manufacturing method of this embodiment includes a winding body manufacturing process (step S1), a forming process (step S2), and a configuration process (step S3). Each step will be described in detail below.

[0094] Furthermore, in this embodiment, the case where the first electrode is used as the positive electrode and the technology disclosed herein is applied to the positive electrode is described, but it is not limited to this. The first electrode may also be used as the negative electrode and the technology disclosed herein may be applied to the negative electrode, or the technology disclosed herein may be applied to both the positive and negative electrodes.

[0095] (Step S1) Winding body manufacturing process

[0096] In this process, firstly, prepare the long strip-shaped diaphragm 26 and the positive electrode 22 (refer to...). Figure 2A ) and negative electrode 24 (refer to) Figure 2B The structure of the diaphragm 26, the positive electrode 22, and the negative electrode 24 will be described below.

[0097] like Figure 2A As shown, the positive electrode 22 has a positive current collector 22c and a positive active material layer 22a and a positive protective layer 22p fixed on at least one surface of the positive current collector 22c. However, the positive protective layer 22p is not necessary and can be omitted in other embodiments. The positive current collector 22c is strip-shaped. The positive current collector 22c is made of conductive metals such as aluminum, aluminum alloy, nickel, and stainless steel. The positive current collector 22c is a metal foil, specifically an aluminum foil.

[0098] In addition, such as Figure 2A As shown, the positive electrode 22 has multiple positive electrode tabs 22t. These tabs 22t are spaced apart (intermittently) along the length of the strip-shaped positive electrode 22. The positive electrode tabs 22t are part of the positive current collector 22c and are made of metal foil (aluminum foil). However, the positive electrode tabs 22t can also be components different from the positive current collector 22c. At least a portion of the positive electrode tabs 22t forms an area where the positive current collector 22c is exposed without the positive active material layer 22a and the positive protective layer 22p. The positive electrode tabs 22t are trapezoidal, but the technology disclosed herein can also be applied to cases where the positive electrode tabs are of other shapes (e.g., rectangular). In some embodiments, the width of the positive current collector 22c in the direction perpendicular to its length (see reference...) Figure 18 The current (22V) is, for example, 10cm or more, preferably 20cm or more, and more preferably 25cm or more. The same applies to the negative current collector 24c.

[0099] Additionally, the dimensions of the multiple positive electrode tabs 22t (length along the long side direction Y and width orthogonal to the long side direction Y, refer to...) Figure 18 Considering the connection state with the positive current collector 50 described later, adjustments can be made appropriately based on its formation position, for example. Here, the dimensions of the plurality of positive electrode tabs 22t are different from each other in such a way that the outer ends are aligned when bent. Furthermore, the technique disclosed herein can also be applied to cases where the dimensions of the positive electrode tabs are the same. In addition, in some embodiments, when the number of layers of the positive electrode in the wound electrode body is set to M and the number of positive electrode tabs on the positive electrode is set to N, the ratio (N / M) is, for example, 0.5 or more, preferably 0.6 or more, more preferably 0.8 or more, and even more preferably 0.9 or more (or 1). Furthermore, M is preferably 10 or more, more preferably 20 or more, and even more preferably 30 or more. The same applies to the negative electrode.

[0100] like Figure 2AAs shown, the positive electrode active material layer 22a is arranged in a strip shape along the length direction of the strip-shaped positive electrode current collector 22c. The positive electrode active material layer 22a contains a positive electrode active material (such as a lithium transition metal composite oxide, such as a lithium nickel cobalt manganese composite oxide) capable of reversibly absorbing and releasing charge carriers. When the total solid content of the positive electrode active material layer 22a is set to 100% by mass, the positive electrode active material can account for approximately 80% by mass or more, typically 90% by mass or more, for example, 95% by mass or more. The positive electrode active material layer 22a may also contain any components other than the positive electrode active material, such as conductive materials, binders, various additives, etc. As a conductive material, carbon materials such as acetylene black (AB) can be used. As a binder, polyvinylidene fluoride (PVdF) can be used, for example.

[0101] like Figure 2A As shown, the positive electrode protective layer 22p is disposed in the long side direction Y at the boundary between the positive electrode current collector 22c and the positive electrode active material layer 22a. Here, the positive electrode protective layer 22p is disposed at one end of the winding shaft WL of the positive electrode current collector 22c along its longitudinal direction Y. Figure 2A (The upper end). However, the positive electrode protective layer 22p can also be provided at both ends in the axial direction. The positive electrode protective layer 22p is provided in a strip shape along the positive electrode active material layer 22a. The positive electrode protective layer 22p contains inorganic filler (e.g., alumina). When the solid composition of the positive electrode protective layer 22p is set to 100% by mass, the inorganic filler can account for approximately 50% by mass or more, typically 70% by mass or more, for example 80% by mass or more. The positive electrode protective layer 22p can contain any component other than the inorganic filler, such as conductive materials, binders, various additives, etc. The conductive materials and binders can be the same as those exemplified as materials that can be included in the positive electrode active material layer 22a.

[0102] like Figure 2B As shown, the negative electrode 24 has a negative electrode current collector 24c and a negative electrode active material layer 24a fixed on at least one surface of the negative electrode current collector 24c. The negative electrode current collector 24c is strip-shaped. The negative electrode current collector 24c is made of conductive metals such as copper, copper alloy, nickel, and stainless steel. The negative electrode current collector 24c is a metal foil, specifically a copper foil.

[0103] The negative electrode 24 has multiple negative electrode tabs 24t. These tabs 24t are spaced apart (intermittently) along the length of the strip-shaped negative electrode 24. Each negative electrode tab 24t is part of the negative current collector 24c and is made of metal foil (copper foil). However, the negative electrode tabs 24t can also be components different from the negative current collector 24c. At least a portion of the negative electrode tab 24t has an area where the negative current collector 24c is exposed without the negative electrode active material layer 24a formed. The negative electrode tabs 24t are trapezoidal, but the technology disclosed herein can also be applied to cases where the negative electrode tabs are of other shapes (e.g., rectangular). Similar to the multiple positive electrode tabs 22t, the dimensions of each of the multiple negative electrode tabs 24t are different, with the outer ends aligned when bent. Furthermore, the technology disclosed herein can also be applied to cases where the negative electrode tabs are of the same size.

[0104] like Figure 2B As shown, the negative electrode active material layer 24a is arranged in a strip shape along the length direction of the strip-shaped negative electrode current collector 24c. The negative electrode active material layer 24a contains a negative electrode active material (such as a carbon material like graphite) capable of reversibly absorbing and releasing charge carriers. When the total solid content of the negative electrode active material layer 24a is set to 100% by mass, the negative electrode active material can account for approximately 80% by mass or more, typically 90% by mass or more, for example, 95% by mass or more. The negative electrode active material layer 24a may also contain any components other than the negative electrode active material, such as binders, dispersants, and various additives. As a binder, rubbers such as styrene-butadiene rubber (SBR) can be used, for example. As a dispersant, cellulose-based materials such as carboxymethyl cellulose (CMC) can be used, for example.

[0105] The separator 26 is a component that insulates the positive electrode active material layer 22a of the positive electrode 22 from the negative electrode active material layer 24a of the negative electrode 24. As the separator 26, a porous sheet made of resin, such as polyethylene (PE) or polypropylene (PP), is preferably preferred. The separator 26 may also have a substrate portion made of a porous sheet of resin and a heat resistance layer (HRL) disposed on at least one surface of the substrate portion and containing an inorganic filler. Examples of inorganic fillers used include alumina, boehmite, aluminum hydroxide, and titanium dioxide.

[0106] Next, as Figure 3 As shown, the prepared diaphragm 26, positive electrode 22, and negative electrode 24 are conveyed to the winding core 201 using the conveyor roller 202, and the wound body 200 is formed by winding it onto the winding core 201. A cylindrical winding core is used here as the winding core 201. Only the positive electrode tab 22t of the positive electrode 22 is extended from one side of the width direction Y (…). Figure 18 The left side of the middle) protrudes and only the negative electrode tab 24t of the negative electrode 24 is from the other side ( Figure 18 Each sheet is wound in a manner that protrudes from the side edge of the right side of the battery 100. Furthermore, the number of windings is preferably adjusted appropriately considering the performance and manufacturing efficiency of the battery 100 as a target. In some embodiments, the number of windings can be 20 or more, or 30 or more. Moreover, in the battery manufacturing method of this embodiment, it is characterized in that, in the winding electrode body manufacturing process, when the winding electrode body is manufactured with a distance G1 of G1 = 0, the value of G1 is changed to G2 < S relative to the winding condition where a distance G2 = S (S > 0), to manufacture the winding electrode body. Hereinafter, refer to... Figure 5A and Figure 5B The adjustments to G1 and G2 will be explained.

[0107] First of all, Figure 5A and Figure 5B The various constituent elements will be explained. Furthermore, in Figure 5A and Figure 5B For ease of explanation, only the four positive electrode tabs 22t of the multiple positive electrode tabs 22t present in this study are described (specifically, the first tab 22t1, the second tab 22t2, the third tab 22t3, and the fourth tab 22t4). In other words, the electrode body 20a, besides... Figure 5A and Figure 5B In addition to the 22t positive electrode tab described, it also possesses multiple other electrodes. Furthermore, regarding the following... Figure 11A , Figure 11B , Figure 12 and Figure 13Only the positive electrode tab 22t, which is of interest, is described here. Furthermore, for ease of explanation, descriptions of components other than the positive electrode are omitted. The electrode body 20a has a first region P located on one side of the winding axis WL and a second region Q located on the other side of the winding axis WL in the thickness direction X (in other words, the stacking direction of the winding electrode body). The first tab 22t1 is located in the positive electrode tab 22t located in the first region P at the position closest to the winding axis WL in the thickness direction X (innermost circumference), and the second tab 22t2 is located in the positive electrode tab 22t located in the second region Q at the position closest to the winding axis WL in the thickness direction X (innermost circumference). Furthermore, the third electrode tab 22t3 exists in the positive electrode tab 22t present in the first region P at the position furthest from the winding axis WL in the thickness direction X (outermost peripheral side), and the fourth electrode tab 22t4 exists in the positive electrode tab 22t present in the second region Q at the position furthest from the winding axis WL in the thickness direction X (outermost peripheral side). Here, the distance in the vertical direction Z relative to the thickness direction X of the winding electrode body (electrode body 20a), between the center C1 of the root width of the first electrode tab 22t1 and the center C2 of the root width of the second electrode tab 22t2, is recorded as G1, and the distance in the vertical direction Z between the center C3 of the root width of the third electrode tab 22t3 and the center C4 of the root width of the fourth electrode tab 22t4 is recorded as G2. In addition, Figure 5A 27 indicates the beginning of the winding of the positive electrode 22, and 28 indicates the end of the winding of the positive electrode 22.

[0108] Although not illustrated in detail, in this embodiment, the length of the third electrode tab 22t3 in the protruding direction is greater than the length of the first electrode tab 22t1 in the protruding direction, and the length of the fourth electrode tab 22t4 in the protruding direction is smaller than the length of the second electrode tab 22t2 in the protruding direction. Here, the length in the protruding direction of the positive electrode tab 22t represents the shortest distance from the root of the positive electrode tab 22t to the tip of the positive electrode tab 22t in the protruding direction (i.e., the Y direction). Figure 18 (22t2). Furthermore, the corresponding portion is also shown for the negative electrode 24. Additionally, the root width of the third electrode tab 22t3 is greater than the root width of the first electrode tab 22t1, and the root width of the fourth electrode tab 22t4 is smaller than the root width of the second electrode tab 22t2.

[0109] In addition, such as Figure 5B As shown, in this embodiment, center C1 is located further away from the winding shaft WL than center C2. Furthermore, centers C3 and C4 are located closer to the sealing plate 14 than the winding shaft WL.

[0110] Figure 5AThis illustrates the case where the wound electrode body is fabricated with G1 (not shown) near 0, and G2 (here, G2) is used. A The way to make S (S>0). On the other hand, as mentioned above, the closer G2 is to 0, the more reliably the positive electrode tab 22t can be collected. Therefore, in this embodiment, when in Figure 5A When manufacturing the wound electrode body under the winding conditions, G2 (here, G2) is used. A The value of G1 is changed in a manner less than S. In other words, when in Figure 5A When manufacturing the wound electrode body under winding conditions, the value of G1 is changed so that the value of G2 is closer to 0. Furthermore, in... Figure 5B In the middle, the changed G1 is recorded as G1 A .

[0111] In this embodiment, by controlling the timing at which the positive electrode 22 begins to wind into the core 201 (hereinafter also referred to as "winding timing"), G2 < S (here, G2) is satisfied. A The value of G1 is changed in a manner that satisfies the relationship between G2 and S. Specifically, the timing of winding the positive electrode 22 onto the core 201 is accelerated to satisfy G2 < S (i.e., G2 < S). A The value of G1 is changed in a manner that satisfies the relationship <S). Furthermore, the value of G1 is changed in a way that satisfies G2 <S (i.e., G2 <S). A The winding timing, as described in <S), varies depending on the type of winding apparatus used, the diaphragm, and the sizes of the positive and negative electrodes. Therefore, those skilled in the art can determine the winding timing by appropriately conducting preliminary tests. As an example of a preliminary test, firstly, the winding timing is measured at... Figure 5A The winding electrode body G2 (i.e., G2) obtained under the winding conditions A The value of '). Next, set the ratio. Figure 5A The winding timing is adjusted later, and the value of G2 of the resulting wound electrode is measured. Then, a winding timing that satisfies the relationship G2 < S is explored. In this way, a winding timing that satisfies... Figure 5B As shown, G2 < S (i.e., G2 < S). A The wound electrode body with the relationship of <S).

[0112] As mentioned above, G2 (here, G2) A The closer the value of G2 is to 0, the better. In some methods, G2 (i.e., G2) is preferred. A The value of G1 is, for example, 15 mm or less, preferably 12 mm or less, more preferably 5 mm or less, and even more preferably 2 mm or less (e.g., 1 mm or less). Additionally, in some embodiments, G1 (here, G1...) AThe value of G1 is, for example, 20 mm or less, preferably 15 mm or less, more preferably 10 mm or less, and even more preferably 5 mm or less. Furthermore, the values ​​of G1 and G2 can be measured, for example, with a ruler. The same applies to G3, which will be described later.

[0113] (Step S2) Forming process

[0114] In this process, the wound body 200 produced in step S1 above is formed into a flat shape. Specifically, in this embodiment, by... Figure 4A After the winding body is configured in the stamping press 204 as shown, stamping is performed in the direction of the hollow arrow to obtain... Figure 4B The flat, wound electrode body (electrode body 20a) is shown. Here, the stamping pressure is preferably adjusted appropriately according to the number of turns, size, etc., of the wound body. Figure 16 As shown, the flat-shaped wound electrode body after stamping has a pair of curved portions 20r with a curved outer surface and a flat portion 20f connecting the pair of curved portions 20r and having a flat outer surface. Additionally, as... Figure 17 As shown, a positive electrode tab group 23, in which positive electrode tabs 22t are stacked, is formed at one end of the flat, rolled electrode body in the width direction Y after stamping, and a negative electrode tab group 25, in which negative electrode tabs 24t are stacked, is formed at the other end. Furthermore, a core portion, with the positive electrode active material layer 22a and the negative electrode active material layer 24a facing each other, is formed at the center of the rolled electrode body in the width direction Y. Additionally, by stamping, the surface layer of the separator 26 can be bonded to the positive electrode 22 (negative electrode 24).

[0115] In this embodiment, a diaphragm 26 is disposed on the outermost peripheral surface of the stamped and formed wound electrode body (electrode body 20a), and the shape of the wound electrode body is maintained by attaching a winding stop tape to the end of the diaphragm 26 at the end of winding. As the winding stop tape, conventionally known winding stop tapes used in wound electrode bodies can be used without particular limitation. Furthermore, as... Figure 5B As shown, in this embodiment, the end of the positive electrode 22 at the end of its winding is disposed at the bend 20r of the electrode body 20a. As described above, the wound electrode body of this embodiment can be manufactured.

[0116] Next, make Figure 6 , Figure 7 The first assembly shown. Specifically, firstly, a positive terminal 30, a positive first current collector 51, a positive internal insulating member 70, a negative terminal 40, a negative first current collector 61, and a negative internal insulating member 80 are installed on the sealing plate 14.

[0117] The positive terminal 30, the first positive current collector 51, and the internal positive current collector 70 are fixed to the sealing plate 14, for example, by riveting. The riveting process involves clamping a sealing gasket 90 between the outer surface of the sealing plate 14 and the positive terminal 30, and then clamping the internal positive current collector 70 between the inner surface of the sealing plate 14 and the first positive current collector 51. Furthermore, the sealing gasket 90 can be made of the same material as the internal positive current collector 70. Specifically, before riveting, the positive terminal 30 is inserted sequentially from above the sealing plate 14 into the through hole of the sealing gasket 90, the terminal insertion hole 18 of the sealing plate 14, the through hole of the internal positive current collector 70, and the through hole 51h of the first positive current collector 51, protruding downwards from the sealing plate 14. Then, the portion of the positive terminal 30 that protrudes downwards from the sealing plate 14 is riveted to apply a compressive force in the vertical direction Z. Therefore, at the top of the positive terminal 30 ( Figure 15 The lower end of the part forms a riveting part.

[0118] Through this riveting process, the sealing gasket 90, the sealing plate 14, the positive electrode internal insulating component 70, and the positive electrode first current collector 51 are integrally fixed to the sealing plate 14, and the terminal insertion hole 18 is sealed. Furthermore, the riveted portion can also be welded to the positive electrode first current collector 51. This further improves the reliability of conductivity.

[0119] The fixing of the negative terminal 40, the first current collector 61, and the internal insulating member 80 can be performed in the same manner as the positive terminal side described above. That is, before riveting, the negative terminal 40 is inserted sequentially from above the sealing plate 14 into the through hole of the sealing gasket, the terminal insertion hole 19 of the sealing plate 14, the through hole of the internal insulating member 80, and the through hole of the first current collector 61, protruding downwards from the sealing plate 14. Then, the portion of the negative terminal 40 that protrudes downwards from the sealing plate 14 is riveted to apply a compressive force in the vertical direction Z. As a result, at the top end of the negative terminal 40 ( Figure 15 The lower end of the part forms a riveting part.

[0120] Next, the positive electrode external conductive member 32 and the negative electrode external conductive member 42 are installed on the outer surface of the sealing plate 14 via the external insulating member 92. Furthermore, the material of the external insulating member 92 can be the same as that of the positive electrode internal insulating member 70. Additionally, the timing of installing the positive electrode external conductive member 32 and the negative electrode external conductive member 42 can be after the configuration process (e.g., after sealing the injection hole 15).

[0121] Next, using the first composite object created above, create... Figure 9 The second assembly shown is a composite material. Specifically, an electrode assembly 20 is fabricated that is integrated with the sealing plate 14. First, three electrodes are prepared as shown... Figure 8The electrode bodies shown are prepared by steps S1 to S2, and are equipped with a positive electrode second current collector 52 and a negative electrode second current collector 62. These electrode bodies 20a, 20b, and 20c are arranged in the short side direction X. At this time, the electrode bodies 20a, 20b, and 20c can all be positioned with the positive electrode second current collector 52 on one side of the long side direction Y. Figure 9 (on the left side) and the negative electrode second current collector 62 is disposed on the other side in the long side direction Y ( Figure 9 They are arranged side by side on the right side.

[0122] Next, as Figure 17 As shown, with the multiple positive electrode tabs 22t bent, the first positive electrode current collector 51 fixed to the sealing plate 14 is joined to the second positive electrode current collector 52 of the electrode bodies 20a, 20b, and 20c, respectively. Similarly, with the multiple negative electrode tabs 24t bent, the first negative electrode current collector 61 fixed to the sealing plate 14 is joined to the second negative electrode current collector 62 of the electrode bodies 20a, 20b, and 20c, respectively. As a joining method, welding methods such as ultrasonic welding, resistance welding, and laser welding can be used. Welding based on high-energy rays such as lasers is particularly preferred. Through this welding process, joint portions are formed in the recesses of the second positive electrode current collector 52 and the second negative electrode current collector 62, respectively.

[0123] (Step S3) Configuration process

[0124] In the configuration process, the second composite object produced above is housed in the internal space of the outer casing 12. Figure 10 This is a schematic cross-sectional view illustrating the configuration process. Specifically, firstly, an insulating resin sheet made of a resin material such as polyethylene (PE) is bent into a bag or box shape to prepare an electrode holder 29. Next, the electrode assembly 20 is housed in the electrode holder 29. Then, the electrode assembly 20, covered by the electrode holder 29, is inserted into the outer casing 12. The outer casing can be made of a metal material such as aluminum, aluminum alloy, iron, or iron alloy. If the electrode assembly 20 is heavy, approximately 1 kg or more, for example, 1.5 kg or more, and further 2 to 3 kg, then... Figure 10 As shown, the electrode assembly 20 is inserted into the outer body 12 by arranging the long sidewall 12b of the outer body 12 in a manner that intersects with the direction of gravity (making the outer body 12 horizontal).

[0125] In this embodiment, after the above-described configuration process, a sealing plate 14 is joined to the edge of the opening 12h of the outer casing 12 to seal the opening 12h. The sealing process can be performed simultaneously with the configuration process or after the configuration process. In the sealing process, it is preferable to weld the outer casing 12 to the sealing plate 14. The welding of the outer casing 12 to the sealing plate 14 can be performed, for example, by laser welding. Afterward, electrolyte is injected through the injection hole 15, and the injection hole 15 is blocked with the sealing member 16, thereby sealing the battery 100. The electrolyte can be the same as before and is not particularly limited. The electrolyte is, for example, a non-aqueous electrolyte containing a non-aqueous solvent and a supporting salt. The non-aqueous solvent includes carbonates such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. The supporting salt is, for example, a fluorinated lithium salt such as LiPF6. However, the electrolyte can also be integrated with the electrode assembly 20 in a solid state (solid electrolyte). As described above, the battery 100 can be manufactured.

[0126] Battery 100 can be used for various purposes, but it is particularly suitable for applications where external forces such as vibration and impact can be applied during use, such as a power source (drive power supply) for a motor mounted on a moving body (typically a passenger car, truck, or other vehicle). There are no particular limitations on the type of vehicle; examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs). Battery 100 can also be suitable for use as a battery pack formed by arranging multiple batteries 100 in a specified arrangement direction and applying load to the arrangement direction using a constraint mechanism.

[0127] The above description illustrates several embodiments of this disclosure, but these embodiments are merely examples. This disclosure can be implemented in various other ways. This disclosure can be implemented based on the content disclosed in this specification and common technical knowledge in the field. The technology described in the claims includes technologies obtained by various modifications and alterations to the embodiments illustrated above. For example, a portion of the above embodiments can be replaced with other modifications, and other modifications can be added to the above embodiments. Furthermore, if a technical feature is not described as an essential technical feature, it can be appropriately omitted.

[0128] For example, Figure 11A This illustrates G2 (specifically G2) when the wound electrode body (electrode body 120a) is fabricated with G1 near 0. B In the second embodiment, by relative to S (S > 0), the way becomes S. Figure 11A The winding conditions are adjusted, and the winding timing is slowed down, thereby changing the value of G1. Furthermore, in... Figure 11B In the middle, the changed G1 is recorded as G1 B In this way, we can obtain Figure 11BG2 as shown (specifically G2) B The electrode body 120a is less than S. Furthermore, regarding the method for determining the winding timing, please refer to the description of the above embodiment.

[0129] For example, Figure 12 This is a schematic diagram showing the positive electrode side end face of the wound electrode body (electrode body 220a) according to the third embodiment. Figure 12 As shown, the positive electrode 22 of the electrode body 220a has a fifth electrode tab 22t5 between the first electrode tab 22t1 and the third electrode tab 22t3, and a sixth electrode tab 22t6 between the second electrode tab 22t2 and the fourth electrode tab 22t4 in the thickness direction X of the electrode body 20a. Furthermore, when the center of the root width of the fifth electrode tab 22t5 is set as C5 and the center of the root width of the sixth electrode tab 22t6 is set as C6, G3 (specifically G3) in the vertical direction Z of the centers C5 and C6 is... C The value is adjusted to G2 < G3 < G1 (i.e., G2 < G3 < G1). C <G3 C <G1 C According to this structure, the multiple positive electrode tabs 22t can be connected to the positive electrode current collector 50 more stably, and therefore it is preferred. Furthermore, regarding the method for determining the winding timing, please refer to the description of the above embodiment.

[0130] In addition, for example, Figure 13 This is a schematic diagram showing the positive electrode side end face of the wound electrode body (electrode body 320a) according to the fourth embodiment. Figure 13 As shown, the positive electrode 22 of the electrode body 320a has a fifth electrode tab 22t5 between the first electrode tab 22t1 and the third electrode tab 22t3, and a sixth electrode tab 22t6 between the second electrode tab 22t2 and the fourth electrode tab 22t4 in the thickness direction X of the electrode body 20a. Furthermore, when the center of the root width of the fifth electrode tab 22t5 is set as C5 and the center of the root width of the sixth electrode tab 22t6 is set as C6, G3 (specifically G3) in the vertical direction Z of the centers C5 and C6 is... D The value is adjusted to G2 < G3 < G1 (i.e., G2 < G3 < G1). D <G3 D <G1 D According to this structure, the multiple positive electrode tabs 22t can be connected to the positive electrode current collector 50 more stably, and therefore it is preferred. Furthermore, regarding the method for determining the winding timing, please refer to the description of the above embodiment.

[0131] For example, in the above embodiment, the value of G1 is changed by adjusting the timing of winding the positive electrode into the core, but this is not a limitation. For example, the value of G1 can also be changed by changing the position of the winding body during the stamping process in step S2. Alternatively, the value of G1 can be adjusted by changing the spacing of the multiple positive electrode tabs along their length or by changing the tension applied to the positive electrode when winding it into the core. Alternatively, a combination of these methods can be used to adjust the value of G1. On the other hand, in the cases listed above, from the viewpoint of changing the value of G1 more easily and with better reproducibility, the method of adjusting the timing of winding the positive electrode into the core and the method of changing the position of the winding body being flattened during stamping are preferred. Furthermore, the same applies to the negative electrode.

[0132] The positive electrode is preferably manufactured by cutting a positive electrode plate at a predetermined position along its width. The positive electrode plate is formed by connecting multiple positive electrodes together along its length. The positive electrode plate has a region on which a layer of positive active material is formed on a positive current collector extending along its length, and multiple positive electrode tabs disposed at its ends in the width direction. In the positive electrode plate, the positive electrode tabs are preferably arranged at predetermined intervals. By cutting the positive electrode plate along its width, one side of the cut portion becomes the winding end of one positive electrode, and the other side of the cut portion becomes the winding end of another positive electrode.

[0133] Here, by changing the cutting position of the positive electrode plate, the distance from the end where the positive electrode winding begins to the first tab can be changed, thus allowing the value of G1 to be altered. This method is preferred from the viewpoint of changing the value of G1 more easily and with good reproducibility.

[0134] Furthermore, the timing of the beginning of winding the positive electrode by cutting the positive electrode plate is not particularly limited as long as it occurs before winding the positive electrode into the core. Alternatively, the electrode manufacturing apparatus may have a positive electrode plate cutting mechanism, in which the positive electrode plate is cut. The same applies to the negative electrode.

[0135] For example, in the above embodiment, the core is cylindrical, but this is not a limitation. The technology disclosed herein can also be applied to cases where the core is flat.

[0136] For example, in the above embodiments, the technology disclosed herein is applied only to the positive electrode side of the wound electrode body, but is not limited thereto. The technology disclosed herein may also be applied only to the negative electrode side of the wound electrode body, or it may be applied to both the positive and negative electrode sides of the wound electrode body. Furthermore, regarding the negative electrode side of the wound electrode body, the position of the negative electrode tab can be changed based on the description of the positive electrode side.

[0137] For example, in the above embodiment, three identical electrode bodies are provided, but this is not a limitation. The battery disclosed herein may also have multiple electrode bodies with different G2 values. In this case, the G2 value of each electrode body is preferably about 2 mm or less (preferably about 1 mm or less).

[0138] For example, in the case where the battery includes two electrodes, the G1 of one electrode can be set to be greater than the G1 of the other electrode. Alternatively, the difference in G1 between the two electrodes can be set to be greater than the difference in G2 between the two electrodes.

[0139] When manufacturing multiple wound electrode bodies, it is preferable to use multiple cores. This improves productivity. When using multiple cores, sometimes the outer diameters of each core are slightly different. In such cases, when trying to reduce the distance G1 between the center of the root width of the first tab and the center of the root width of the second tab in the direction perpendicular to the thickness direction of the wound electrode body, the deviation in the outer diameter of each core can easily increase the deviation in the distance G2 between the center of the root width of the third tab and the center of the root width of the fourth tab in the direction perpendicular to the thickness direction of the wound electrode body. This is because the third and fourth tabs are located on the outermost periphery. In this case, it is preferable to adjust the winding timing for each wound electrode body made from each core to suppress the deviation in distance G2. However, the deviation in distance G1 in each wound electrode body can also increase.

[0140] In addition, such as Figure 19 As shown, this method is particularly effective when continuously manufacturing multiple wound electrode bodies using a wound electrode body manufacturing apparatus 300 having multiple cores 301 and conveyor rollers 302. Here, when manufacturing each wound electrode body, it is preferable to use electrode plates manufactured under conditions where the tab formation positions are the same. In such electrode plates, the positional relationships of the multiple tabs in each electrode plate are approximately the same.

[0141] In addition, such as Figure 20 As shown with core 401, when the outer diameter of the core can be varied, slight deviations in the outer diameter of each core during winding are easily produced, making it particularly effective. As an example of varying the outer diameter of the core, it is preferable to vary the outer diameter of the core in a manner that makes it smaller than during winding when the winding is being pulled out. Figure 20 As shown, as a method for changing the outer diameter of the core 401, the core 401 is composed of multiple components (here, a first structural part 401a and a second structural part 401b), which can be achieved by changing the distance between the multiple components.

[0142] The embodiments of the technology disclosed herein have been described above. However, the above description is merely illustrative and does not limit the scope of the claims. The technology described in the claims includes technologies obtained by various modifications and alterations to the specific examples illustrated in the above description.

Claims

1. A method for manufacturing a battery, the battery comprising: A flat, wound electrode body, wherein the flat, wound electrode body is formed by winding a first electrode and a second electrode with a different polarity than the first electrode through a diaphragm; and A battery casing that houses the wound electrode body, wherein... In the battery, At one end of the wound electrode body in the winding axis direction, there are multiple tabs that are connected to the first electrode. The plurality of tabs are connected to the current collector of the first electrode. The wound electrode body has a first region located on one side of the winding shaft and a second region located on the other side of the winding shaft in the thickness direction of the wound electrode body. The plurality of electrodes includes a first electrode, a second electrode, a third electrode, and a fourth electrode. The first tab is located in the tabs present in the first region at a position closest to the winding axis of the wound electrode body in the thickness direction of the wound electrode body. The second tab is located in the tab present in the second region at a position closest to the winding axis of the wound electrode body in the thickness direction of the wound electrode body. The third tab is located in the tabs present in the first region at a position furthest from the winding axis of the wound electrode body in the thickness direction of the wound electrode body. The fourth tab is located in the tabs present in the second region at a position furthest from the winding axis of the wound electrode body in the thickness direction of the wound electrode body. At the end of one of them, The distance between the center of the root width of the first electrode and the center of the root width of the second electrode in the vertical direction relative to the thickness direction is defined as G1, and the distance between the center of the root width of the third electrode and the center of the root width of the fourth electrode in the vertical direction is defined as G2. The method for manufacturing the battery includes: The process of fabricating the wound electrode body; and The configuration process of placing the fabricated wound electrode body inside the battery casing. In the winding electrode manufacturing process, when the winding electrode is manufactured with G1 = 0, the value of G1 is changed to G2 < S relative to the winding condition where G2 = S (S > 0), and the winding electrode is manufactured by changing G2 to G2 < S. The winding electrode body manufacturing process includes: The winding body manufacturing process involves winding the diaphragm, the first electrode, and the second electrode onto a core to create a winding body. A forming process, wherein the wound body is formed into a flat shape; and In the cutting process, before the first electrode is wound onto the core, the original plate of the first electrode is cut to form the end from which the winding of the first electrode begins. In the cutting process, the value of G1 is changed by controlling the cutting position of the first electrode plate.

2. The method for manufacturing a battery according to claim 1, wherein, In the winding process, the value of G1 is changed by controlling the timing at which the first electrode begins to wind into the core.

3. The method for manufacturing a battery according to claim 1 or 2, wherein, In the forming process, the value of G1 is changed by controlling the position where the wound body is formed into a flat shape.

4. The method for manufacturing a battery according to claim 1 or 2, wherein, In the winding body manufacturing process, multiple winding bodies are manufactured using multiple cores.

5. The method for manufacturing a battery according to claim 1 or 2, wherein, In the winding body manufacturing process, a winding electrode body manufacturing device having multiple winding cores is used to continuously manufacture the winding body.

6. The method for manufacturing a battery according to claim 1 or 2, wherein, When multiple wound electrode bodies are fabricated using multiple cores, the G2 value of each of the multiple wound electrode bodies is controlled to be below 2 mm.

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