Method for manufacturing power storage device, recording device, and power storage device manufacturing apparatus

Abstract

To provide a power storage device manufacturing method and apparatus which are capable of predicting individual differences in electrode materials to be used in cells in advance and grasping them afterwards.SOLUTION: A first cord 18 is formed along a length direction in an unformed region 16a of a current collector 16 of a lithium ion secondary battery. A first inspection device and a second inspection device use the first cord 18 to record inspection information in a recording device while identifying the position of an active material layer 17. As a result, it is possible to subsequently obtain the inspection information on the active material layer 17 corresponding to the position of first cord 18 in the length direction of the current collector 16, which makes it possible to predict or subsequently grasp individual differences in electrode materials used in cells.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing an electricity storage device, a recording apparatus, and an apparatus for manufacturing an electricity storage device. [Background technology]

[0002] JP 2015-16708 A discloses a method for manufacturing an electrode by cutting an electrode material having a coated portion of an active material mixture and an exposed portion of the metal foil on at least one side of a long metal foil. In this manufacturing method, the electrode material is cut into strips to form strips. A plurality of strips are stacked to manufacture an electrode. In this manufacturing method, the coated portion of the electrode material is inspected to check whether or not a defective portion exists in the coated portion. If a defective portion exists in the coated portion, a mark is applied to the exposed portion. When the electrode material is cut, a mark detection device detects the mark, thereby making it possible to determine whether or not a defective portion exists in the coated portion. A portion of the electrode material including a coated portion determined to have a defective portion is not cut into a strip and is not used in the manufacture of an electrode. In addition, the mark is applied to the electrode material outside the region to be cut into strips, so the mark is not included in the strip. This allows the electrode to be manufactured using only strips that do not include defective portions in the coated portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-167078 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned electrode manufacturing method, the thickness of the active material mixture is not completely uniform during the coating process of the active material mixture. Therefore, in the finally assembled cell, there are individual differences in the electrode materials used in the cell. Such individual differences cannot be predicted in advance or understood after the fact. [Means for solving the problem]

[0005] The manufacturing method for an electricity storage device disclosed herein includes a step of attaching first identifiers at predetermined intervals to unformed areas that are preset along the length of a strip-shaped current collector in order to identify the positions of the areas; a step of forming an active material layer in a portion of the strip-shaped current collector excluding the unformed areas; and an inspection step of recording inspection information obtained by inspecting the state of the active material layer while identifying the position of the strip-shaped current collector by linking it to the first identifier.

[0006] According to this method for manufacturing an electricity storage device, it becomes possible to subsequently obtain inspection information for the active material layer that corresponds to the position, in the length direction of the current collector, to which the first identifier is attached. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a lithium-ion secondary battery 10. As shown in FIG. [Diagram 2] FIG. 2 is a schematic vertical cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is a schematic diagram of the electrode body 20. [Figure 4] 4(a) to (f) are schematic diagrams showing the manufacturing process of the electrode sheet 15. [Diagram 5] FIG. 5 is a schematic diagram of the electricity storage device manufacturing apparatus 1. As shown in FIG. [Figure 6] FIG. 6 is a diagram showing an example of the database DT constructed by the recording device 210. As shown in FIG. [Figure 7] FIG. 7 is a flow diagram showing a method for manufacturing the lithium ion secondary battery 10. [Figure 8]FIG. 8 is a flow diagram showing a method for manufacturing the lithium ion secondary battery 10 in a different order from that shown in the flow diagram of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The disclosure herein is explained below. Unless otherwise specified, the disclosure herein is not intended to limit the invention described in the claims of this application. Each drawing is drawn diagrammatically and does not necessarily reflect the actual product. In addition, the same reference numerals are appropriately used for members and parts that perform the same function, and duplicated explanations are omitted. In this specification, a notation such as "X to Y" indicating a numerical range means "X or more and Y or less" unless otherwise specified.

[0009] The present disclosure relates to a method for manufacturing an electric storage device. The method for manufacturing an electric storage device disclosed herein is used to manufacture, for example, a lithium ion secondary battery. The electrode body of the lithium ion secondary battery has, for example, a positive electrode current collector made of aluminum or an aluminum alloy and a negative electrode current collector made of copper or a copper alloy.

[0010] <Lithium-ion secondary battery 10> FIG. 1 is a perspective view of a lithium-ion secondary battery 10. FIG. 2 is a schematic longitudinal sectional view taken along line II-II in FIG. 1. FIG. 3 is a schematic view of an electrode body 20. FIG. 2 illustrates a state in which the inside of the lithium-ion secondary battery 10 is exposed along one wide surface of a battery case 41 having a substantially rectangular parallelepiped shape. FIG. 2 also illustrates a partial sectional view in which the electrode body 20 is partially broken. The lithium-ion secondary battery 10 illustrated in FIG. 2 is a so-called sealed battery in which the battery case 41 containing the electrode body 20 is sealed. In this embodiment, the battery case 41 is configured as a metal case having a substantially rectangular parallelepiped shape. The symbol X in the drawing indicates the long side direction of the battery case 41. The symbol Y (see FIG. 1) indicates the short side direction perpendicular to the long side direction. The symbol Z indicates the height direction perpendicular to the short side direction and the long side direction. The structure of the battery case 41 is not limited to this form. For example, the battery case 41 may be a cylindrical case, or may be a so-called bag-shaped laminate case that covers the electrode body 20.

[0011] As shown in FIG. 2, the lithium ion secondary battery 10 includes an electrode assembly 20 and a battery case 41. The battery case 41 includes a case body 41a having an opening 41a1 and a sealing plate 41b that closes the opening 41a1 of the case body 41a. The case body 41a accommodates the electrode assembly 20. The sealing plate 41b is provided with internal terminals 55, 65 and external terminals 51, 61 attached thereto via a gasket 70 and an insulator 80. In this embodiment, the internal terminal 55 is connected to the positive electrode collector 21a of the electrode assembly 20. The external terminal 51 is connected to the internal terminal 55, and constitutes the positive electrode terminal 50 outside the battery case 41. The internal terminal 65 is connected to the negative electrode collector 22a of the electrode assembly 20 (see FIG. 3). The external terminal 61 is connected to the internal terminal 65, and constitutes the negative electrode terminal 60 outside the battery case 41.

[0012] <Electrode body 20> As shown in FIG. 3, in the electrode body 20, the positive electrode element 21 and the negative electrode element 22 face each other with a separator interposed therebetween. The positive electrode element 21 includes a positive electrode current collector 21a and a positive electrode active material layer 21b formed on the positive electrode current collector 21a and containing a positive electrode active material. The negative electrode element 22 includes a negative electrode current collector 22a and a negative electrode active material layer 22b formed on the negative electrode current collector 22a and containing a negative electrode active material. The positive electrode element 21 and the negative electrode element 22 may each be in a sheet shape. In this case, the positive electrode element may be, for example, a sheet-like member in which the positive electrode active material layer 21b is formed on both sides of the positive electrode current collector 21a made of a metal foil having a predetermined width and thickness. The negative electrode element may be a sheet-like member in which the negative electrode active material layer 22b is formed on both sides of the negative electrode current collector 22a made of a metal foil having a predetermined width and thickness. The sheet-like positive electrode element 21 is called a positive electrode sheet, and the sheet-like negative electrode sheet is called a negative electrode sheet.

[0013] For example, the electrode body 20 may be a so-called wound electrode body. The electrode body 20 is composed of a positive electrode sheet 21 as a positive electrode element, a negative electrode sheet 22 as a negative electrode element, and separator sheets 31 and 32 as separators. The positive electrode sheet 21, the first separator sheet 31, the negative electrode sheet 22, and the second separator sheet 32 ​​are each a long strip-shaped member, and are wound while overlapping with their length and width directions aligned. The electrode body 20 is housed in a battery case 41 in a state where it is covered with an insulating film (not shown) or the like.

[0014] The positive electrode sheet 21 and the negative electrode sheet 22 are formed, for example, by cutting a rolled electrode sheet. As shown in Fig. 4(b), the electrode sheet 15 includes a current collector 16 and an active material layer 17. Figs. 4(a) to (f) are schematic diagrams of the manufacturing process of the electrode sheet 15. Details of Figs. 4(a) to 4(f) will be described later.

[0015] The current collector 16 is a long strip-shaped metal member. A metal material having a required electrical conductivity can be used as the current collector 16. For example, aluminum, an aluminum alloy, etc. can be used as the positive electrode current collector. For example, copper, a copper alloy, etc. can be used as the negative electrode current collector. An active material layer 17 is formed on at least one surface of the strip-shaped current collector 16. In this embodiment, the active material layer 17 is formed on one surface of the current collector 16. The active material layer 17 is a layer containing an electrode active material. For example, a lithium transition metal composite oxide can be used as the positive electrode active material. For example, a carbon material, a silicon-based material, and a mixed oxide thereof can be used as the negative electrode active material. The electrode active material layer may contain additives other than the electrode active material, such as a binder and a conductive material.

[0016] The electrode sheet 15 is formed by applying an electrode mixture slurry to the current collector 16 to become the active material layer 17 and drying it. The electrode mixture slurry is a paste-like material formed by mixing a positive electrode active material or a negative electrode active material, a conductive material, a binder, and the like in a solvent. The electrode mixture slurry is applied by a coating device 102 (see FIG. 5) described later. An unformed region 16a is set in the current collector 16. The unformed region 16a is arranged at a preset position along the length direction of the current collector 16. In this embodiment, the unformed region 16a is set at both ends of the current collector 16 in the width direction. The electrode mixture slurry is applied to the current collector 16 in a region other than the unformed region 16a. As a result, an active material layer 17 is formed in the region of the current collector 16 other than the unformed region 16a.

[0017] <Positive electrode sheet 21> The positive electrode sheet 21 is the above-mentioned electrode sheet 15, in which a positive electrode current collector is used as the current collector 16, and a positive electrode active material layer is formed as the active material layer 17. As shown in FIG. 3, the positive electrode sheet 21 has a positive electrode current collector 21a of a predetermined width and thickness, and a positive electrode active material layer 21b containing a positive electrode active material is formed on one side of the positive electrode current collector 21a, except for an unformed portion 21a1 set at a constant width at one end of the width direction. A plurality of positive electrode tabs 21t are intermittently provided at predetermined positions along the length direction of the positive electrode sheet 21 in the unformed portion 21a1. The plurality of positive electrode tabs 21t each protrude in the width direction of the positive electrode sheet 21.

[0018] For example, in the lithium ion secondary battery 10, the positive electrode active material layer 21b releases lithium ions during charging and absorbs lithium ions during discharging. Examples of the positive electrode active material include lithium transition metal composite materials. Various positive electrode active materials other than lithium transition metal composite materials have been proposed, and unless otherwise specified, are not limited to lithium transition metal composite materials. The positive electrode active material layer 21b may be a layer in which an electrode mixture slurry is applied and dried. In this embodiment, a positive electrode protective layer 21p is provided on the edge of the positive electrode active material layer 21b on the positive electrode current collector 21a (unformed portion 21a1). The positive electrode protective layer 21p is a layer that protects the unformed portion 21a1 and may be a layer containing an inorganic filler (for example, alumina).

[0019] <Negative electrode sheet 22> The negative electrode sheet 22 is the above-mentioned electrode sheet 15, in which a negative electrode current collector is used as the current collector 16, and a negative electrode active material layer is formed as the active material layer 17. The negative electrode sheet 22 is a negative electrode current collector 22a having a predetermined width and thickness, and a negative electrode active material layer 22b containing a negative electrode active material is formed on one side of the negative electrode collector 22a, except for an unformed portion 22a1 set at a constant width on one edge in the width direction. In this embodiment, a plurality of negative electrode tabs 22t are intermittently provided at predetermined positions along the length direction of the negative electrode sheet 22 in the unformed portion 22a1. The plurality of negative electrode tabs 22t each protrude toward the width direction of the negative electrode sheet 22. In this embodiment, the positions at which the plurality of negative electrode tabs 22t are provided are determined so that the positions of the plurality of negative electrode tabs 22t are aligned in a wound state.

[0020] For the negative electrode current collector 22a, a material having required resistance such as electrolyte resistance and oxidation resistance is used in consideration of the operating potential at the negative electrode. For example, in the lithium ion secondary battery 10, copper or a copper alloy mainly made of copper is generally used for the negative electrode current collector 22a. In the sheet-like negative electrode element 22, copper or a copper foil mainly made of copper may be used for the negative electrode current collector 22a. For the negative electrode active material contained in the negative electrode active material layer 22b, a material capable of absorbing charge carriers during charging and releasing the charge carriers during discharging is used. For example, in the lithium ion secondary battery, a material such as natural graphite is used that can absorb lithium ions during charging and release the lithium ions absorbed during charging during discharging. In general, various negative electrode active materials have been proposed other than natural graphite, and are not particularly limited. The negative electrode active material layer 22b may be formed, for example, by applying a mixture of the negative electrode active material, a conductive material, a binder, and the like in a solvent, and then drying the mixture.

[0021] For the separator sheets 31 and 32, for example, a porous resin sheet through which an electrolyte having required heat resistance can pass is used. Various proposals have been made for the separator sheets 31 and 32 as well, and they are not particularly limited. The separator sheets 31 and 32 may have functional layers such as an adhesive layer or a heat resistance layer (Heat Resistance Layer: HRL) on the surface of a base material made of a porous resin sheet. The heat resistance layer is, for example, a layer containing inorganic fillers such as alumina, silica, boehmite, magnesia, titania, etc. and a binder such as PVdF. The heat resistance layer may also serve as an adhesive layer.

[0022] Here, as shown in FIG. 3, the width Ln of the negative electrode active material layer 22b is formed wider than the width Lp of the positive electrode active material layer 21b, for example. The width Ls of the separator sheets 31 and 32 is wider than the negative electrode active material layer 22b. That is, as shown in FIG. 3, Lp < Ln < Ls. The positive electrode sheet 21, the first separator sheet 31, the negative electrode sheet 22, and the second separator sheet 32 are aligned in the length direction and wound up in order after being stacked. Here, the negative electrode active material layer 22b covers the positive electrode active material layer 21b with the separator sheets 31 and 32 interposed therebetween. The negative electrode active material layer 22b is covered with the separator sheets 31 and 32. The positive electrode tab 21t of the positive electrode current collector 21a and the negative electrode tab 22t of the negative electrode current collector 22a are provided so as to protrude from the separator sheets 31 and 32 in opposite directions in the width direction. The positive electrode protective layer 21p faces the edge of the negative electrode sheet 22 on the side opposite to the side where the negative electrode tab 22t is provided with the separator sheets 31 and 32 interposed therebetween.

[0023] As shown in FIG. 2, the electrode body 20 is in a flat state along one plane including the winding axis WL (see FIG. 3) so that it can be housed in the case body 41a of the battery case 41. A positive electrode tab 21t is arranged on one side along the winding axis WL of the electrode body 20, and a negative electrode tab 22t is arranged on the other side. Here, as the electrode body 20, a wound electrode body in which a positive electrode sheet 21, a first separator sheet 31, a negative electrode sheet 22, and a second separator sheet 32 ​​are stacked and wound is exemplified. The configuration of the electrode body 20 is not limited to such a wound electrode body. Although not shown, the electrode body 20 may be, for example, a so-called stacked electrode body in which a positive electrode sheet and a negative electrode sheet of a predetermined shape are stacked with a separator sheet sandwiched therebetween.

[0024] <Battery case 41> The battery case 41 houses the electrode body 20. In this embodiment, the battery case 41 has a case body 41a and a sealing plate 41b. The case body 41a is a bottomed member having an opening 41a1 on one side surface facing the bottom surface, and in this embodiment, has a substantially rectangular parallelepiped shape with one side surface open. The sealing plate 41b is a plate material attached to the opening 41a1 of the case body 41a. In this embodiment, the case body 41a and the sealing plate 41b are each formed of aluminum or an aluminum alloy mainly containing aluminum, from the viewpoint of ensuring weight reduction and required rigidity. In the embodiment shown in FIG. 1, a wound type electrode body 20 is exemplified, but the structure of the electrode body 20 is not limited to such a form. The structure of the electrode body 20 may be, for example, a laminated structure in which a positive electrode sheet and a negative electrode sheet are alternately laminated with a separator sheet interposed therebetween. In addition, a plurality of electrode bodies 20 may be housed in the battery case 41.

[0025] An electrolyte (not shown) can be accommodated in the battery case 41. As the electrolyte, a non-aqueous electrolyte in which a supporting salt is dissolved in a non-aqueous solvent can be used. Examples of the non-aqueous solvent include carbonate-based solvents such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. Examples of the supporting salt include fluorine-containing lithium salts such as LiPF6.

[0026] <Case body 41a> As shown in Fig. 2, the case body 41a has a substantially rectangular parallelepiped shape with one side open. The case body 41a has a bottom surface portion 42 constituting a substantially rectangular bottom surface, a pair of wide surface portions 43, 44 (see Fig. 1), and a pair of narrow surface portions 45, 46. The pair of wide surface portions 43, 44 each rise from a long side of the bottom surface portion 42. The pair of narrow surface portions 45, 46 each rise from a short side of the bottom surface portion 42. An opening 41a1 surrounded by the pair of wide surface portions 43, 44 and the pair of narrow surface portions 45, 46 is formed on one side of the case body 41a.

[0027] <Sealing plate 41b> The sealing plate 41b seals the opening 41a1 of the case body 41a. In this embodiment, as shown in FIG. 1, the sealing plate 41b is rectangular in plan view. In this embodiment, the sealing plate 41b is provided with a liquid inlet 41b1 and a safety valve 41b3. The liquid inlet 41b1 is closed by attaching a sealing member 41b2 after the sealing plate 41b is attached to the opening 41a1 of the case body 41a and the electrolyte is injected into the case body 41a. Note that FIG. 2 shows a state in which the sealing plate 41b is assembled to the opening 41a1 of the case body 41a and welded. In FIG. 2, the sealing member 41b2 is not attached to the sealing plate 41b. The safety valve 41b3 is thin-walled and is a portion that breaks when the pressure inside the battery case 41 becomes greater than a predetermined pressure.

[0028] As shown in FIG. 2, a positive electrode terminal 50 and a negative electrode terminal 60 are attached to the sealing plate 41b. The positive electrode terminal 50 includes an external terminal 51 and an internal terminal 55. The negative electrode terminal 60 includes an external terminal 61 and an internal terminal 65. The internal terminals 55, 65 are attached to the inside of the sealing plate 41b via an insulator 80. The external terminals 51, 61 are attached to the outside of the sealing plate 41b via a gasket 70. The internal terminals 55, 65 each extend into the inside of the case body 41a. The unformed portion 21a1 of the positive electrode collector 21a of the electrode body 20 and the unformed portion 22a1 of the negative electrode collector 22a are attached to the internal terminals 55, 65 attached to both sides in the long side direction of the sealing plate 41b, respectively.

[0029] The internal terminals 55, 65 are made of metal. For example, aluminum or an aluminum alloy may be used as the positive electrode internal terminal 55 from the viewpoint of improving the bonding strength with the positive electrode tab 21t. For example, copper or a copper alloy may be used as the negative electrode internal terminal 65 from the viewpoint of improving the bonding strength with the negative electrode tab 22t and because it has the required resistance such as electrolyte resistance and oxidation resistance.

[0030] The external terminals 51, 61 are made of metal. The metal used as the external terminals 51, 61 is appropriately selected depending on the type of external connection parts such as bus bars. For example, aluminum, aluminum alloy, copper, copper alloy, etc. can be used as the external terminals 51, 61. For example, the external terminals 51, 61 may be configured by joining a plurality of metals by dissimilar metal joining. Although not shown, a mounting hole is formed in the sealing plate 41b. In the mounting hole, an insulator 80 is attached to the inside of the sealing plate 41b, and a gasket 70 is attached to the outside of the sealing plate 41b. One of the internal terminals 55, 65 and the external terminals 51, 61 is provided with a shaft portion, and is inserted into the mounting hole with the gasket 70 and the insulator 80 interposed therebetween. The internal terminals 55, 65 and the external terminals 51, 61 are joined by a shaft portion inserted into the mounting hole.

[0031] The gasket 70 and the insulator 80 are preferably made of a material having excellent chemical resistance and weather resistance. In this embodiment, the gasket 70 is made of tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA). The material used for the gasket 70 is not limited to PFA. The gasket 70 may be made of, for example, polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), or the like. The insulator 80 is made of polyphenylene sulfide resin (PPS). The material used for the insulator 80 is not limited to PPS.

[0032] In the lithium ion secondary battery 10, the positive electrode terminal 50 and the negative electrode terminal 60 are attached to the sealing plate 41b at the time of manufacture, with the gasket 70 and the insulator 80 attached to the sealing plate 41b. Next, the positive electrode tab 21t is joined to the internal terminal 55 of the positive electrode terminal 50, and the negative electrode tab 22t is joined to the internal terminal 65 of the negative electrode terminal 60, thereby attaching the electrode body 20 to the sealing plate 41b. Next, while inserting the electrode body 20 into the case body 41a from the opening 41a1, the sealing plate 41b is attached to the opening 41a1 (see FIG. 1) of the case body 41a. At this time, the winding axis WL (see FIG. 3) of the electrode body 20 is arranged along the long side direction X of the case body 41a. The positive electrode tab 21t of the electrode body 20 is directed to the narrow surface portion 45. The negative electrode tab 22t is directed to the narrow surface portion 46. 2, the peripheral edge of the sealing plate 41b is joined to the edge of the opening 41a1 of the case body 41a. This joining may be achieved, for example, by continuous welding without any gaps. This welding may be achieved, for example, by laser welding.

[0033] A plurality of electrode bodies 20 may be housed in the battery case 41. Various structures may be adopted for the internal terminals 55, 65, the external terminals 51, 61, the gasket 70, and the insulator 80. For example, the internal terminals 55, 65, the external terminals 51, 61, the gasket 70, and the insulator 80 may have an appropriate structure according to the structure of the electrode body 20 housed therein. In addition, one of the positive electrode terminal 50 and the negative electrode terminal 60 may be provided with a mechanism (CID (Current Interrupt Device)) that interrupts the current as the internal pressure increases by generating gas therein during overcharge.

[0034] The configuration of the lithium ion secondary battery 10 to be manufactured has been described above.

[0035] The positive electrode sheet 21 and the negative electrode sheet 22 are formed, for example, by applying an active material mixture to a long strip-shaped current collector 16. In manufacturing the cell, a required length of electrode sheet 15 is cut from a long strip-shaped electrode sheet 15 and incorporated into the electrode body 20. The present inventors thought that if the thickness of the active material layer 17 along the length direction of the electrode sheet 15 used in the cell could be grasped after the fact during or after the cell is assembled, it would be possible to improve the quality of the electrode body 20 during assembly and to predict individual differences between batteries.

[0036] Therefore, the present inventors have devised the idea of ​​including the following steps in the manufacturing method of the electricity storage device. Step A: A step of attaching first codes 18 for identifying positions of pre-defined unformed regions 16a along the length of a strip-shaped current collector 16 at pre-defined intervals. Step B: A step of forming an active material layer 17 on the portion of the strip-shaped current collector 16 excluding the unformed region 16a. Step C: An inspection step of recording inspection information on the state of the active material layer 17 while identifying the position of the strip-shaped current collector 16 by linking it to the first code 18.

[0037] According to this method for manufacturing an electricity storage device, it is possible to later obtain inspection information of active material layer 17 corresponding to the position where first code 18 is attached in the length direction of current collector 16. Therefore, the thickness of the active material mixture along the length direction of electrode sheet 15 used in the cell during or after the cell is assembled can be later determined. Therefore, for example, it becomes possible to predict or later determine individual differences in the electrode materials used in the cell.

[0038] 4(a) to (f) are schematic diagrams of the manufacturing process of the electrode sheet 15 as described above. FIG. 4(a) is a diagram showing a process of attaching a first code 18 for identifying a position on the strip-shaped current collector 16 at a predetermined interval in the unformed region 16a set in advance along the length direction of the strip-shaped current collector 16. Here, the cutting line CL shown by a two-dot chain line is a line showing a cutting position when forming the tabs 21t, 22t (see FIG. 3). In this specification, forming the tabs 21t, 22t by cutting the cutting line CL is referred to as tab cutting. Details of the first code 18 will be described later. FIG. 4(b) is a diagram showing a process of forming an active material layer 17 on a portion of the strip-shaped current collector 16 excluding the unformed region 16a. In addition, inspection information obtained by inspecting the state of the active material layer 17 while identifying the position of the strip-shaped current collector 16 in the state shown in FIG. 4(b) is recorded, linked to the first code 18. FIG. 4(c) is a diagram showing a process of cutting electrode sheet 15 in half in the width direction from the state shown in FIG. 4(b).

[0039] Here, the unformed region 16a includes a tab forming region 16aa and a code marking region 16ab. The tab forming region 16aa is a region of the unformed region 16a that will become tabs 21t and 22t (see FIG. 3) described later by cutting off the code marking region 16ab. A first code 18 is formed in the code marking region 16ab. The first code 18 is an example of a first identifier in the present invention. The first code 18 is, for example, a two-dimensional code such as a QR code (registered trademark). The first code 18 may be, for example, a one-dimensional code (barcode). Here, the one-dimensional code is formed with a plurality of straight lines extending in one direction. Therefore, when forming a one-dimensional code, it is necessary to form the code while appropriately stopping the conveyance of the electrode sheet 15, which is inefficient. Therefore, the first code 18 may be a one-dimensional code, but is preferably a two-dimensional code. Alternatively, the first identifier may be a predetermined mark or the like.

[0040] The first code 18 is provided at predetermined intervals along the length of the electrode sheet 15. The first code 18 is formed, for example, by a laser beam. In this embodiment, the first code 18 is provided, for example, every 1 m along the length of the electrode sheet 15. The first code 18 is provided in the code marking area 16ab. The first code 18 has information for identifying the position at which the first code 18 is formed on the current collector 16. The information for identifying the position at which the first code 18 is formed on the current collector 16 is referred to as identification information. The identification information is, for example, a consecutive number such as 0, 1, 2, 3 ... registered in order from the first code 18 provided at the front end of the electrode sheet 15.

[0041] Furthermore, the present inventors have devised the invention to include the following steps in the method for producing an electricity storage device. Step D: A tab cutting process step of reading the first code 18 of the strip-shaped current collector 16, identifying the position of the strip-shaped current collector 16, and performing a tab cut on the unformed region 16a. Step E: A step of attaching the second cord 19 to the predetermined positions of the tabs 21t, 22t formed in the tab cutting process. Step F: A winding step of reading the second code 19 and winding up the strip-shaped current collector 16 that has been subjected to the tab cutting process.

[0042] Fig. 4(d) is a schematic diagram showing a tab cutting process in which tabs are cut in the unformed region 16a. Fig. 4(e) is a schematic diagram showing a process in which a second code 19 is attached to predetermined positions of the tabs 21t and 22t formed in the tab cutting process. Fig. 4(f) is a diagram showing a process in which the second code 19 is read and the strip-shaped current collector 16 that has been subjected to the tab cutting process is wound up.

[0043] The second codes 19 are provided at predetermined intervals along the length direction of the electrode sheet 15. The second codes 19 are an example of a second identifier in the present invention. The second codes 19 are provided at predetermined positions of the tabs 21t, 22t formed by tab cutting. That is, the second codes 19 are provided in the tab forming region 16aa. Like the first codes 19, the second codes 19 each have identification information. In addition, the second codes 19 are linked to the identification information of all the first codes 18 included in the positive electrode sheet 21 and the negative electrode sheet 22. The second codes are, for example, two-dimensional codes such as QR codes (registered trademark). However, like the first codes 18, they may be one-dimensional codes.

[0044] Furthermore, the present inventors have devised the invention to include the following steps in the method for producing an electricity storage device. Step G: A step of housing the electrode body 20 in a battery case 41 while reading the second code 19 of the electrode body 20 obtained in the winding step. Step H: A step of acquiring the unique number attached to the battery case 41 Step I: A step of linking and recording the unique number of the battery case 41 and the second code of the electrode body 20 housed in the battery case 41.

[0045] Here, the battery case 41 (see FIG. 2) in this embodiment is assigned a unique number. The unique number is a number that allows each battery case 41 to be identified, and is a unique number that is determined, for example, by the date of manufacture or the order of manufacture. Although not shown in the figure, for example, the unique number is engraved on the outer surface of the battery case 41. The unique number is read, for example, by a camera. The unique number may be assigned to the battery case 41 in advance, or may be assigned by the electricity storage device manufacturing apparatus 1 described later. However, the method of identifying the battery case 41 is not limited to this. To identify the battery case 41, for example, a unique barcode or the like may be printed on it.

[0046] <Electricity storage device manufacturing equipment 1> FIG. 5 is a schematic diagram of an electricity storage device manufacturing apparatus 1. The above-mentioned electricity storage device manufacturing method can be realized by an electricity storage device manufacturing apparatus 1 as shown in FIG. 5. The electricity storage device manufacturing apparatus 1 shown in FIG. 5 will be described below. Here, the electricity storage device manufacturing apparatus 1 manufactures lithium ion secondary batteries 10 (see FIG. 1). The electricity storage device manufacturing apparatus 1 includes a code providing line 1a and an electrode manufacturing line 1b. The code providing line 1a includes an unwinding roll 100, a first laser marking device 101, a coating device 102, and a winding roll 103. The electrode manufacturing line 1b includes an unwinding roll 104, a first inspection device 105, a compression device 106, a second inspection device 107, a half cutting device 108, a cutting device 109, a second laser marking device 110, and a winding roll 111. The power storage device manufacturing apparatus 1 further includes a control device 200, which is connected to each of the apparatuses 100-111.

[0047] The electrode sheet 15 is wound around unwinding rolls 100 and 104. The electrode sheet 15 is transported along a preset transport path and wound around the winding rolls 103 and 111. The unwinding rolls 100 and 104 and the winding rolls 103 and 111 may be attached to an auto-splice device that switches between a roll that has been unwound and wound and a new roll. In this embodiment, the unwinding roll 100 and the winding roll 103 are driven by a transport device 150. The unwinding roll 104 and the winding roll 111 are driven by a transport device 170. Although not shown in detail, in the electricity storage device manufacturing apparatus 1, a guide roll 120 is arranged along a predetermined transport path, and the electrode sheet 15 is transported along the transport path. Although not shown in the figure, for example, a guide roll, a dancer roll, a feed roll, etc. may be appropriately arranged on the transport path. The transport device 150, the various devices 100 to 111 incorporated in the electricity storage device manufacturing apparatus 1, the transport device 170, and the like are each configured to be controlled by a control device 200.

[0048] In this embodiment, the coating device 102, the first inspection device 105, the second inspection device 107, the half-cutting device 108, the second laser marking device 110, and the winding roll 111 are each provided with a sensor (not shown) for reading the first code 18. In addition, the sensor is also attached near the unwinding roll 104, and the sensor is connected to the compression device 106 and the cutting device 109 by wire or wirelessly. In addition, the sensor can be realized by, for example, a camera. In addition, the electricity storage device manufacturing apparatus 1 is provided with a winding device (not shown) and an assembly device (not shown) downstream of the winding roll 111. The winding device is a device that overlaps and winds the positive electrode sheet 21, the negative electrode sheet 22, and the separator sheets 31 and 32 (see FIG. 2) to create the electrode body 20. In addition, the assembly device may also be provided with a sensor that reads the first code 18. The assembly device is a device that manufactures the lithium-ion secondary battery 10 by housing the prepared electrode body 20 in a battery case 41 (see FIG. 1) and injecting an electrolyte solution, etc. However, since the assembly method using the winding device and the assembly device is similar to known techniques, illustrations thereof are omitted.

[0049] <Conveyor device 150, 170> The conveying devices 150 and 170 each convey the electrode sheet 15. Although not particularly limited, the conveying speed of the electrode sheet 15 can be set to about 10 m / min to 160 m / min in the code application line 1a and the electrode production line 1b. In this embodiment, a motor is used as the conveying devices 150 and 170. The conveying devices 150 and 170 drive the rotation of the unwinding rolls 100 and 104 and the winding rolls 103 and 111 so that the electrode sheet 15 can be conveyed at a predetermined conveying speed. The rotation speed of the unwinding rolls 100 and 104 and the winding rolls 103 and 111 driven by the conveying device 150 may be controlled by the control device 200. The rotation speed of the unwinding rolls 100 and 104 and the winding rolls 103 and 111 can be controlled according to a predetermined program so that the conveying speed of the electrode sheet 15 is constant. The rotation speeds of the unwinding rolls 100, 104 and the winding rolls 103, 111 can be controlled, for example, according to the amount of electrode sheet 15 wound around the unwinding rolls 100, 104 and the winding rolls 103, 111. Note that the electricity storage device manufacturing apparatus 1 may include stepped rollers or the like.

[0050] <First laser engraving device 101> The first laser engraving device 101 is a device that forms the first code 18 on the electrode sheet 15. The first laser engraving device 101 is an example of a first identifier assigning device in the present invention. The first laser engraving device 101 is equipped with a laser emission unit (not shown) and forms the desired first code 18. The first laser engraving device 101 forms the first code 18 having identification information on the electrode sheet 15. Note that the method of assigning the QR code (registered trademark) to the electrode sheet 15 is not limited to engraving with a laser beam. The device that assigns the first code 18 may be, for example, a device that prints the QR code (registered trademark).

[0051] <Coating device 102> The coating device 102 is a device that coats the current collector 16 with the active material layer 17. The coating device 102 is an example of an active material layer forming device in the present invention. The coating device 102 coats the current collector 16 with the adjusted electrode mixture slurry. When a positive electrode sheet 21 is produced in the electrode production line 1b, the current collector 16 is a positive electrode current collector, and the active material layer 17 is a positive electrode active material layer. When a negative electrode sheet 22 is produced in the electrode production line 1b, the current collector 16 is a negative electrode current collector, and the active material layer 17 is a negative electrode active material layer. A known coating device can be used to coat the electrode active material layer on the current collector. Examples of the coating device that can be used include a slit coater, a gravure coater, a die coater, and a comma coater. The current collector 16 can be supported by a backup roll, and the active material layer 17 can be coated on the surface opposite to the surface supported by the backup roll. The active material layer 17 may be coated on both sides of the current collector 16. The coating device may be provided with a drying device for drying the active material layer 17 coated on the current collector 16. As the drying device, a device for drying the active material layer 17 by hot air, infrared rays, or the like may be used. In this embodiment, the coating device 102 is configured to coat the electrode material slurry after reading the first code 18 by a sensor. In addition, the coating device 102 links the identification information of the read first code 18 with information on the coating conditions and transmits them to the control device 200. The coating conditions are, for example, the amount of electrode material slurry to be applied.

[0052] <First inspection device 105> The first inspection device 105 is a device that measures the width and in-line film thickness of the active material layer 17 applied to the current collector 16 upstream of the compression device 106. In this embodiment, the first inspection device 105 is configured to perform measurements after reading the first code 18 by a sensor. The first inspection device 105 measures the width and film thickness of the portion of the current collector 16 where the active material layer 17 is formed. However, the first inspection device 105 is not particularly limited as long as it can inspect the active material layer 17. In this embodiment, a device that can measure the width and film thickness without contact is used as the first inspection device 105. The first inspection device 105 is configured to inspect the active material layer 17 at the same position as the position of the first code 18 in the length direction of the current collector 16. The first inspection device 105 may be capable of measuring one position in the width direction of the electrode sheet 15, may be capable of measuring multiple positions, or may be capable of measuring the entire range in the width direction. The first inspection device 105 associates the identification information of the first code 18 with the inspection information and transmits them to the control device 200.

[0053] <Compression device 106> The compression device 106 is a device that compresses the electrode sheet 15 transported by the transport device 150. The active material layer 17 of the electrode sheet 15 is compressed in the vertical direction by the compression device 106, and can be adjusted to a required thickness and density. The compression device 106 is configured to read the first code 18 using a sensor provided near the unwinding roll 104 and the transport amount of the electrode sheet 15. When the transport distance of the first code 18 read by the sensor near the unwinding roll 104 reaches a predetermined distance, the compression device 106 recognizes that the first code 18 has reached the compression device 106. At this time, the compression device 106 obtains identification information of the first code 18 from the sensor. The compression device 106 may be equipped with, for example, an encoder that measures the transport distance of the electrode sheet 15. The compression device 106 has a pair of rolling rolls 106a and 106b. The electrode sheet 15 is sandwiched between a pair of rolling rolls 106a and 106b. The active material layer 17 is compressed by being rolled through the gap between the pair of rolling rolls 106a and 106b. The pair of rolling rolls 106a and 106b are each connected to a press cylinder (not shown) that can be raised and lowered. The gap between the pair of rolling rolls 106a and 106b is changed by raising and lowering the press cylinder. The length of the gap between the pair of rolling rolls 106a and 106b, the linear pressure applied to the electrode sheet 15 by the pair of rolling rolls 106a and 106b, and the speed of the electrode sheet 15 when passing through the pair of rolling rolls 106a and 106b, i.e., the rotation speed of the pair of rolling rolls 106a and 106b, are controlled by the control device 200. The compression device 106 links the identification information of the read first code 18 with the information on the above-mentioned control conditions and transmits them to the control device 200.

[0054] <Second inspection device 107> Second inspection device 107 is similar to first inspection device 105, except that it is arranged downstream of compression device 106. A detailed description will be omitted here. Information on the inspection results obtained by inspecting active material layer 17 using first inspection device 105 or second inspection device 107 will be referred to as inspection information. First inspection device 105 and second inspection device 107 are examples of inspection devices in the present invention.

[0055] <Half cutting device 108> The half-cutting device 108 is a device that cuts the electrode sheet 15 transported by the transport device 150 at the center in the width direction of the electrode sheet 15, and is also called a slitter. The half-cutting device 108 transmits a slit width, which is the length from one end of the electrode sheet 15 to the center in the width direction of the electrode sheet 15, to the control device 200. One half-cut electrode sheet 15 and the other half-cut electrode sheet 15 pass through a cutting device 109, and are then wound up onto different winding rolls 111, respectively.

[0056] <Cutting device 109> The cutting device 109 is a device that performs tab cutting of the electrode sheet 15 from the front end side in the length direction of the electrode sheet 15. The cutting device 109 is an example of a tab cutting device in the present invention. In this embodiment, the cutting device 109 performs cutting by laser light. The cutting device 109 is configured to perform tab cutting after reading the first code 18. The method of reading the first code 18 by the cutting device 109 is similar to that of the compression device 106. The cutting device 109 transmits the conditions for performing tab cutting together with the identification information of the first code 18 to the control device 200. The conditions for performing tab cutting are, for example, the degree of output of the laser light. By passing through the cutting device 109, the positive electrode sheet 21 or the negative electrode sheet 22 is generated.

[0057] <Second laser engraving device 110> The second laser engraving device 110 is a device that forms the second code 19 on the electrode sheet 15 after the tab cut. The second laser engraving device 110 is an example of a second identifier assigning device. The method by which the second laser engraving device 110 assigns the second code 19 is similar to that of the first laser engraving device 101, and therefore a description thereof will be omitted here.

[0058] Control device 200 The control device 200 may be, for example, a microcomputer. The control device 200 includes, for example, a communication interface, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The control device 200 is connected to each device of the power storage device manufacturing apparatus 1, and is connected to the first laser marking device 101, the coating device 102, the first inspection device 105, the compression device 106, the second inspection device 107, the half-cutting device 108, the cutting device 109, the second laser marking device 110, and the conveying device 150, and is configured to be able to control each of them.

[0059] The control device 200 has a recording device 210. The recording device 210 is a device that records the identification information of the first code 18 and the inspection information in association with each other. In addition, the recording device 210 stores the identification information of the second code 19 in association with the position where the second code 19 is attached in the current collector 16. The recording device 210 is, for example, a device that records information such as a hard disk drive. The recording device 210 records information associated with the identification information of the first code 18 transmitted from each device connected to the control device 200 for each piece of identification information, and constructs a database. FIG. 6 is a diagram showing an example of a database DT constructed by the recording device 210. The configuration of the recording device 210 is not particularly limited. The recording device 210 may be an external server device such as a cloud server.

[0060] The above has described the power storage device manufacturing apparatus 1 for the electrode sheet 15. Next, a manufacturing method for the lithium ion secondary battery 10 will be described. FIG. 7 is a flow diagram showing the manufacturing method for the lithium ion secondary battery 10. The manufacturing method for the lithium ion secondary battery 10 disclosed here includes a first identifier providing step S1, a coating step S2, a first inspection step S3, a compression step S4, a second inspection step S5, a half-cutting step S6, a tab cutting process step S7, a second identifier providing step S8, a winding step S9, and an assembly step S10.

[0061] In the first identifier imparting step S1, a first code 18 is imparted to the electrode sheet 15 unwound from the unwinding roll 100. The first code 18 is formed by a first laser engraving device 101. When forming the first code 18, the first laser engraving device 101 imparts identification information to the first code 18. At this time, the control device 200 records the identification information in a database DT included in the recording device 210.

[0062] In the coating step S2 shown in Fig. 7, the coating device 102 forms an active material layer 17 on the current collector 16. The coating device 102 reads the first code 18 and applies the electrode mixture slurry while identifying its position. The coating conditions at this time are controlled by the control device 200. The coating device 102 links the identification information of the first code 18 with the coating conditions at that position and transmits them to the control device 200. The control device 200 records the coating conditions in linkage with the identification information of the first code 18 recorded in the database DT (see Fig. 6).

[0063] After the coating step S2, the electrode sheet 15 is taken up by the winding roll 103 and moved to the unwinding roll 104. The method for moving the electrode sheet 15 taken up by the winding roll 103 is not particularly limited, but for example, the electrode sheet 15 is transported to the unwinding roll 104 by an operator. The transported electrode sheet 15 is unwound from the unwinding roll 104.

[0064] In the first inspection step S3, inspection information obtained by inspecting the state of active material layer 17 is recorded while identifying the position of band-shaped current collector 16 in association with first code 18. In this embodiment, first inspection device 105 measures the width and in-line film thickness of active material layer 17, and the width and in-line film thickness of active material layer 17 at the longitudinal position where first code 18 is applied are sent to control device 200 in association with identification information of first code 18. Control device 200 is configured to record in database DT the width and in-line film thickness of active material layer 17 at the longitudinal position where first code 18 is applied in association with identification information of first code 18.

[0065] In the compression step S4, the active material layer 17 is compressed by the compression device 106. The compression device 106 reads the identification information of the first code 18 at the location to be compressed and then performs compression. After the first code 18 is read by a sensor provided near the unwinding roll 104, the compression device 106 recognizes that the conveyed amount of the electrode sheet 15 has reached a predetermined distance and obtains the identification information of the first code 18 from the sensor. The compression device 106 compresses the rolling rolls 106a and 106b while being controlled under predetermined conditions. The compression device 106 associates the read identification information of the first code 18 with the compression conditions at that position and transmits them to the control device 200. The compression device 106 transmits, for example, a value of the linear pressure to the control device 200.

[0066] In the second inspection step S5, inspection information obtained by inspecting the state of active material layer 17 is recorded while identifying the position of band-shaped current collector 16 in association with first code 18. In this embodiment, second inspection device 107 measures the width and in-line film thickness of active material layer 17, and the width and in-line film thickness of active material layer 17 at the longitudinal position where first code 18 is applied are sent to control device 200 in association with identification information of first code 18. Control device 200 is configured to record in database DT the width and in-line film thickness of active material layer 17 at the longitudinal position where first code 18 is applied in association with identification information of first code 18.

[0067] In the half-cutting step S6, the electrode sheet 15 is cut at the center in the width direction by the half-cutting device 108. At this time, the half-cutting device 108 transmits the slit width conditions to the control device 200.

[0068] In the tab cutting process S7, the cutting device 109 performs tab cutting on the electrode sheet 15. The cutting device 109 reads the identification information of the first cord 18 engraved in the tab forming region 16aa where the tab cutting is performed, and performs the tab cutting while identifying the position. That is, the tab cutting is performed while identifying the longitudinal position on the electrode sheet 15. The method by which the cutting device 109 obtains the identification information of the first cord 18 is the same as that in the compression process S4. The cutting device 109 links the read identification information of the first cord 18 with the cutting conditions and transmits them to the control device 200. The cutting conditions are, for example, the degree of output of the laser light at the time of the tab cutting. The code engraved region 16ab is cut off and discarded by the tab cutting.

[0069] In the second identifier providing step S8, the second code 19 is provided to the tab formed in the tab cutting process step S7. When the sheet to be formed is a positive electrode sheet 21, the second code 19 is provided to the tab 21t (see FIG. 2). When the sheet to be formed is a negative electrode sheet 22, the second code 19 is provided to a location corresponding to the tab 22t (see FIG. 2). The method of providing the second code 19 is, for example, forming it with a laser beam, similar to the first code 18. In the database DT, the identification information of the second code 19 and its position on the current collector 16 are linked and stored. For example, a number, which is the identification information, and a distance from the front end of the current collector 16 in the longitudinal direction to the second code 19 are linked and stored.

[0070] In the winding step S9, as shown in FIG. 3, the positive electrode sheet 21 and the negative electrode sheet 22 that have been subjected to the tab cutting process are overlapped and wound with the separator sheets 31 and 32 interposed therebetween. In this way, the electrode body 20 is produced. At this time, the winding device may read the second code 19 formed on the tab 21t of the positive electrode sheet 21 and the tab 22t of the negative electrode sheet 22. In this way, even after the winding step S9, inspection information on the active material layer 17 along the length direction of the positive electrode sheet 21 and the negative electrode sheet 22 included in the electrode body 20 can be acquired after the fact through the second code 19.

[0071] In the assembly process S10 shown in FIG. 7, the electrode body 20 is accommodated in and sealed in the battery case 41 by a known method. In addition, in the assembly process S10, it is preferable that the unique number given to the battery case 41 is read. The read unique number is sent to the control device 200. The control device 200 is configured to link the unique number with the second code 19 included in the electrode body 20 accommodated in the battery case 41 and record it in the database DT. The assembly device links the unique number with the identification number of the second code 19 and accommodates the electrode body 20 in the battery case 41. When the electrode body 20 is accommodated in and sealed in the battery case 41, injection of the electrolyte, initial charging, and aging processing are performed. Here, in the injection of the electrolyte and the initial charging, the injection amount of the electrolyte and the initial charging time are calculated based on each piece of information recorded in the database DT in association with the identification information of the first code 18. For example, when the measured film thickness is relatively large, the amount of electrolyte that the electrode body 20 can absorb is large, so the amount of electrolyte injected is increased. Also, for example, when the film density is relatively large, the electrode body 20 is less likely to absorb electrolyte, so the amount of electrolyte injected is increased. Note that the amount of electrolyte injected may be determined by an operator while looking at the inspection information in the database DT, or may be automatically calculated by the control device 200 using the inspection information in the database DT. The aging process may be performed by a known method.

[0072] The flow of manufacturing the lithium ion secondary battery 10 is not limited to the above-mentioned order. For example, the electrode sheet 15 may be wound up after the half-cutting step and before the tab-cutting step. At this time, the half-cut electrode sheet 15 is unwound while the tab-cutting step and the second cord 19 are applied, and the assembly step is then performed.

[0073] In addition, the position where the second cord 19 is attached is not limited to the tabs 21t and 22t. The second cord 19 may be attached to an outer portion of the wound electrode body 20. Alternatively, the second cord 19 may be attached to the outer side when the lithium ion secondary battery 10 is assembled.

[0074] As described above, in the embodiment described above, first codes 18 are formed at equal intervals in the longitudinal direction of current collector 16 in unformed region 16a. In first inspection step S3 and second inspection step S5, the inspection information of active material layer 17 is recorded in recording device 210 while the position in the longitudinal direction of current collector 16 is identified by first code 18. As a result, the inspection information of active material layer 17 at each position on current collector 16 is recorded in database DT of recording device 210 in association with the identification information. It is possible to subsequently identify the inspection information of active material layer 17 corresponding to the position to which first code 18 is attached, and it becomes possible to predict or subsequently grasp the individual differences in the electrode materials used in the cells.

[0075] In the above-described embodiment, the identification information of the first code 18 is obtained using a sensor provided near the unwinding roll 104 and the transport amount of the electrode sheet 15, and then the tab cutting is performed. The second code 19 is attached to predetermined positions of the tabs 21t and 22t formed in the tab cutting process. In this case, information associated with the first code 18 can be obtained through the identification information of the second code 19. Therefore, inspection information of the active material layer 17 along the length direction of the positive electrode sheet 21 and the negative electrode sheet 22 after the tab cutting can be obtained afterwards through the identification information of the second code 19.

[0076] The second code 19 may be provided before the tab is cut. FIG. 8 is a flow diagram showing a method for manufacturing the lithium ion secondary battery 10 in a different order from the flow diagram shown in FIG. 7. Steps S1 to S6, S9, and S10 are the same as those in the flow diagram shown in FIG. 7. As shown in FIG. 8, the second identifier providing step S8 may be performed before the tab cutting process step S7. That is, after the second code 19 is provided, the tabs 21t and 22t are formed by the tab cutting process. At this time, the first code 18 and the second code 19 may be read, and the first code 18 and the second code 19 may be linked and stored according to the positions along the length direction of the positive electrode sheet 21 and the negative electrode sheet 22. In this case, too, after the tab cutting is performed, the inspection information of the active material layer 17 along the length direction of the positive electrode sheet 21 and the negative electrode sheet 22 linked to the first code 18 can be obtained through the identification information of the second code 19.

[0077] The embodiment described above further includes a winding step of winding up the positive electrode sheet 21 and the negative electrode sheet 22 that have been subjected to the tab cutting process while reading the second code 19. In this case, inspection information of the active material layer 17 corresponding to the position where the first code 18 was attached in the long strip-shaped positive electrode sheet 21 and the negative electrode sheet 22 can be obtained from the electrode body 20 through the identification information of the second code 19. Therefore, inspection information of the active material layer 17 along the length direction of the positive electrode sheet 21 and the negative electrode sheet 22 included in the electrode body 20 can be obtained afterwards.

[0078] In the above-described embodiment, the method further includes a step of accommodating the wound electrode body 20 in the battery case 41, a step of acquiring a unique number attached to the battery case 41, and a step of linking the unique number with the second code 19 of the electrode body 20 accommodated in the battery case 41 and recording the same in the recording device 210. In this case, the identification information of the second code 19 of the electrode body 20 accommodated in the battery case 41 can be acquired through the unique number of the battery case 41. Furthermore, through the identification information of the second code 19, inspection information of the active material layer 17 corresponding to the position where the first code 18 was attached among the long strip-shaped positive electrode sheet 21 and negative electrode sheet 22 can be acquired through the identification information of the second code 19. Therefore, after the electrode body 20 is accommodated in the battery case 41, inspection information of the active material layer 17 along the length direction of the positive electrode sheet 21 and the negative electrode sheet 22 included in the electrode body 20 accommodated in the battery case 41 can be acquired through the unique number of the battery case 41.

[0079] The above-described embodiment further includes a step of housing the wound electrode body 20 in the battery case 41, and a step of determining the amount of electrolyte to be injected and the initial charging time based on information recorded in association with the identification information of the first code 18. For example, the amount of electrolyte required and the optimal length of the initial charging time change depending on the thickness of the film formed on the electrode body 20 during coating. By determining the amount of electrolyte and the length of the initial charging time based on information recorded in association with the identification information of the first code 18, the quality of the manufactured lithium ion secondary battery 10 can be maintained.

[0080] In the embodiment described above, the identification information of the first code 18 and the inspection results performed by the first inspection device 105 and the second inspection device 107 are recorded in the database DT of the recording device 210 in association with each other. By reading the first code 18, the positions of the positive electrode current collector 21a and the negative electrode current collector 22a used in the electrode body 20 on the current collector 16 can be identified, and inspection information of the active material layer 17 at those positions can be obtained.

[0081] In the above-described embodiment, the second code 19 is formed on the tabs 21t and 22t. The second code 19 has identification information. The identification information of the second code 19 is recorded in a database DT of the recording device 210. By reading the second code 19 when the electrode body 20 is formed, the position of the active material layer 17 included in the electrode body 20 on the current collector 16 can be collated. By collating the position of the active material layer 17 included in the electrode body 20, inspection information of the active material layer 17 at that position can be obtained.

[0082] In the above-described embodiment, the database DT of the recording device 210 records the identification information of the second code 19 and the inspection information of the active material layer 17 at that position in association with each other. The tabs 21t and 22t on which the second code 19 is formed are part of the electrode body 20, unlike the code marking area 16ab. Therefore, by reading the second code 19 included in the electrode body 20, the positions of the positive electrode collector 21a and the negative electrode collector 22a used in the electrode body 20 on the current collector 16 can be specified, and the inspection information of the active material layer 17 at that position can be obtained. For example, the amount of electrolyte to be injected into the lithium ion secondary battery 10 and the initial charging time can be estimated using the inspection information.

[0083] In the above-described embodiment, the identification number of the second code 19 and the unique number of the battery case 41 are linked and recorded in the database DT of the recording device 210. Therefore, by reading the unique number of the battery case 41, the electrode body 20 accommodated in the battery case 41 can be identified.

[0084] In the embodiment described above, the identification number of second code 19, the position of the current collector, and the inspection information of active material layer 17 at that position are linked and stored in database DT of recording device 210. Therefore, by reading the unique number of battery case 41, it is possible to specify the identification number linked to that unique number, and further specify the position of strip-shaped current collector 16 and the inspection information of active material layer 17 at that position from the specified identification number.

[0085] In the above-described embodiment, the battery case 41 is assigned a unique number, but this is not limiting. The unique number may be assigned to the sealing plate 41b. In this case, similarly to the above-described embodiment, the unique number is linked to the second code 19 and recorded in the recording device 210. Therefore, the identification information of the second code 19 of the electrode body 20 can be obtained through the unique number of the sealing plate 41b. Furthermore, through the identification information of the second code 19, the inspection information of the active material layer 17 corresponding to the position where the first code 18 was attached among the long strip-shaped positive electrode sheet 21 and negative electrode sheet 22 can be obtained through the identification information of the second code 19. Therefore, after the electrode body 20 is accommodated in the battery case 41, the inspection information of the active material layer 17 along the length direction of the positive electrode sheet 21 and the negative electrode sheet 22 included in the electrode body 20 accommodated in the battery case 41 can be obtained through the unique number of the sealing plate 41b.

[0086] The inspection information included in the database DT described above is not limited to the above. The information included in the database DT may include, for example, information such as the specific gravity of the electrode material slurry and the width when applied. The database DT may also include the lot number of the current collector 16 used.

[0087] In the above-described embodiment, the first cord 18 and the second cord 19 are formed on the electrode sheet 15, but this is not limited thereto. Only one of the first cord 18 and the second cord 19 may be formed on the electrode sheet 15.

[0088] 5, the electricity storage device manufacturing apparatus 1 is provided with a first inspection apparatus 105 and a second inspection apparatus 107 before and after (upstream and downstream) the compression apparatus 106, respectively, but is not limited to this embodiment. For example, the inspection apparatus may be one that inspects active material layer 17 after compression by compression apparatus 106. That is, the electricity storage device manufacturing apparatus 1 may not be provided with first inspection apparatus 105, but may be provided with second inspection apparatus 107.

[0089] The invention disclosed herein has been described in various ways. Unless otherwise specified, the embodiments described herein do not limit the present invention. Furthermore, the embodiments of the invention disclosed herein can be modified in various ways, and each component or each process described herein can be omitted or combined as appropriate, unless a particular problem occurs.

[0090] In the above-described embodiment, the identification information of the first code 18 is obtained using a sensor provided near the unwinding roll 104 and the transport amount of the electrode sheet 15. However, the cutting device 109 may also be equipped with a sensor that reads the first code 18. The tab cut is performed while the electrode sheet 15 is transported. Here, the electrode sheet 15 may break during the tab cut. At this time, the pass line is set while the electrode sheet 15 is transported at a relatively low speed. In order to grasp the position of the electrode sheet 15 when setting the pass line, the first code 18 may be read using a sensor provided in the cutting device 109.

[0091] As described above, this specification includes the disclosures set forth in the following sections.

[0092] Section 1: A step of attaching first identifiers at predetermined intervals to unformed regions that are set in advance along a length direction of a strip-shaped current collector, the first identifiers being for identifying positions on the strip-shaped current collector; forming an active material layer on a portion of the strip-shaped current collector excluding the unformed region; an inspection step of recording inspection information obtained by inspecting a state of the active material layer while identifying a position of the strip-shaped current collector in association with the first identifier; A method for manufacturing an electricity storage device, comprising:

[0093] Section 2: a tab cut processing step of reading the first identifier of the strip-shaped current collector and performing a tab cut on the unformed region while identifying a position of the strip-shaped current collector; applying a second identifier to the tab formed in the tab cutting process at a predetermined position; A method for producing the electricity storage device according to claim 1, comprising:

[0094] Section 3: a second identifier assigning step of assigning a second identifier to an area in which a tab will be formed by tab cutting, among the unformed area; a tab cut processing step of performing the tab cut on the unformed area to which the second identifier is assigned; A method for producing the electricity storage device according to claim 1, comprising: Section 4: 4. The method for producing an electricity storage device according to claim 2, further comprising a winding step of reading the second identifier and winding up the strip-shaped current collector that has been subjected to the tab cutting process.

[0095] Section 5: a step of accommodating the electrode body obtained in the winding step in a battery case while reading the second identifier of the electrode body; obtaining a unique number attached to the battery case; a step of linking and recording the unique number of the battery case and the second identifier of the electrode body contained in the battery case; A method for producing the electricity storage device according to claim 4, comprising:

[0096] Item 6: a step of accommodating the electrode body obtained in the winding step in a battery case having an opening while reading the second identifier of the electrode body; sealing the opening with a sealing plate having a unique number; acquiring a unique number attached to the sealing plate; a step of recording the unique number of the sealing plate and the second identifier of the electrode body contained in the sealing plate in association with each other; A method for producing the electricity storage device according to claim 4, comprising:

[0097] Section 7: a step of accommodating the electrode body obtained in the winding step in a battery case while reading the second identifier of the electrode body; determining an amount of electrolyte to be injected and an initial charging time based on information recorded in association with the first identifier; A method for producing the electricity storage device according to claim 4, comprising:

[0098] Section 8: a first identifier for identifying a position on the strip-shaped current collector at a predetermined interval in an unformed region that is set in advance along the length of the strip-shaped current collector; Inspection information of the active material layer formed on the strip-shaped current collector while identifying the position of the strip-shaped current collector in association with the first identifier; and A recording device configured to record the above in a linked manner.

[0099] Section 9: 9. The recording device according to claim 8, further configured to record a second identifier attached to a predetermined position of a tab formed in the unformed region of the strip-shaped current collector and a position of the strip-shaped current collector to which the second identifier is attached in association with each other.

[0100] Section 10: 10. The recording device according to claim 9, configured to be able to obtain inspection information of the strip-shaped current collector and the active material layer at a position along a longitudinal direction of the current collector, based on the second identifier.

[0101] Section 11: A second identifier attached to a tab of an electrode assembly made from the strip-shaped current collector; a unique number of the battery case given to the battery case in which the electrode body is housed; and The recording device according to claim 8, further configured to record in association with the above.

[0102] Section 12: 12. The recording device according to claim 11, configured to be able to obtain the position of the strip-shaped current collector used in the electrode body contained in the battery case and inspection information of the active material layer at that position, based on the unique number of the battery case.

[0103] Section 13: a first identifier assigning device that assigns first identifiers at predetermined intervals to unformed regions that are set in advance along a length direction of a strip-shaped current collector, the first identifiers being for identifying positions on the strip-shaped current collector; an active material layer forming device for forming an active material layer on a portion of the strip-shaped current collector excluding the unformed region; an inspection device that inspects a state of the active material layer while identifying a position of the strip-shaped current collector in association with the first identifier; a recording device for recording inspection information obtained by the inspection device; An electricity storage device manufacturing apparatus comprising:

[0104] Section 14: a tab cut device that reads the first identifier of the strip-shaped current collector and performs a tab cut on the unformed region while identifying a position of the strip-shaped current collector; a second identifier applying device that applies a second identifier to a predetermined position of the tab formed by the tab cutting device; The electricity storage device manufacturing apparatus according to claim 13, further comprising:

[0105] Section 15: a second identifier assigning device that assigns a second identifier to an area in which a tab is to be formed by tab cutting, among the unformed area; a tab cut device that performs the tab cut on the unformed area to which the second identifier is assigned by the second identifier assigning device; The electricity storage device manufacturing apparatus according to claim 13, further comprising:

[0106] Section 16: 16. The electricity storage device manufacturing apparatus according to claim 14, further comprising a winding device that reads the second identifier and winds up the strip-shaped current collector on which the tab cut has been performed.

[0107] Section 17: The electricity storage device manufacturing apparatus of claim 16, further comprising an assembly device that links the second identifier of the electrode body created by the winding device with a unique number assigned to a battery case that houses the electrode body, and houses the electrode body in the battery case.

[0108] Section 18: an assembly device that reads the second identifier of the electrode body created by the winding device, houses the electrode body in a battery case having an opening, and seals the opening with a sealing plate having a unique number; a recording device that records the unique number of the sealing plate and the second identifier of the electrode body contained in the sealing plate in association with each other; 17. The electricity storage device manufacturing apparatus according to claim 16, further comprising:

[0109] Section 19: an assembly device that reads the second identifier of the electrode body created by the winding device and houses the electrode body in a battery case; A control device that determines an injection amount of electrolyte and an initial charging time based on information recorded in association with the first identifier; 17. The electricity storage device manufacturing apparatus according to claim 16, further comprising: [Explanation of symbols]

[0110] 1. Energy storage device manufacturing equipment 1a Code Assignment Line 1b Electrode manufacturing line 10 Lithium-ion secondary battery (energy storage device) 15 Electrode sheet 16 Current collector 16a Unformed area 16aa tab-forming region 16ab code engraving area 17 Active material layer 18 First Code (First Identifier) 19 Secondary code (secondary identifier) 20 Electrode body 21 Positive electrode sheet 21a Positive electrode current collector 21a1 Unformed part 21b Positive electrode active material layer 21p positive electrode protective layer 21t Positive electrode tab 22 Negative electrode sheet 22a Negative electrode current collector 22a1 Unformed part 22b Negative electrode active material layer 22p negative electrode protective layer 22t negative electrode tab 31, 32 Separator sheet 41 Battery case 41a Case body 41a1 opening 41b Sealing plate 41b1 Liquid injection hole 41b2 Sealing member 41b3 Safety valve 42 Bottom part 43,44 Wide surface section 45, 46 Narrow side part 50 Positive terminal 51,61 External terminal 55, 65 Internal terminal 60 Negative terminal 61 External terminal 70 Gasket 80 Insulator 100, 104 Unwinding roll 101 Laser engraving device 102 Coating equipment 103, 111 Winding roll 106 Compression Device 106a, 106b Rolling roll 108 Half cutting device 109 Cutting device 110 Laser engraving device 120 rolls 150 Transport Equipment 200 Control device 210 Recording Device CL cutting line DT database S1 First identifier assignment step S2 Coating process S3 First inspection process S4 Compression process S5 Second inspection process S6 Half cutting process S7 Tab cutting process S8 Second identifier assignment step S9 Winding process S10 Assembly process

Claims

1. providing a first identifier for identifying a position on the strip-shaped current collector at a predetermined interval in an unformed region that is set in advance along a length direction of the strip-shaped current collector; forming an active material layer on a portion of the strip-shaped current collector excluding the unformed region; an inspection step of recording inspection information obtained by inspecting a state of the active material layer while identifying a position of the strip-shaped current collector in association with the first identifier; A method for manufacturing an electricity storage device, comprising:

2. a tab cut processing step of reading the first identifier of the strip-shaped current collector and performing a tab cut on the unformed region while identifying a position of the strip-shaped current collector; applying a second identifier to the tab formed in the tab cutting process at a predetermined position; A method for producing the electricity storage device according to claim 1 , comprising:

3. a second identifier assigning step of assigning a second identifier to an area in which a tab will be formed by tab cutting, among the unformed area; a tab cut processing step of performing the tab cut on the unformed area to which the second identifier is assigned; A method for producing the electricity storage device according to claim 1 , comprising:

4. The method for producing an electricity storage device according to claim 2 , further comprising a winding step of reading the second identifier and winding up the strip-shaped current collector on which the tab cut has been performed.

5. a step of accommodating the electrode body obtained in the winding step in a battery case while reading the second identifier of the electrode body; obtaining a unique number attached to the battery case; a step of linking and recording the unique number of the battery case and the second identifier of the electrode body contained in the battery case; The method for producing the electricity storage device according to claim 4 , comprising:

6. a step of accommodating the electrode body obtained in the winding step in a battery case having an opening while reading the second identifier of the electrode body; sealing the opening with a sealing plate having a unique number; acquiring a unique number attached to the sealing plate; a step of recording the unique number of the sealing plate and the second identifier of the electrode body contained in the sealing plate in association with each other; The method for producing the electricity storage device according to claim 4 , comprising:

7. a step of accommodating the electrode body obtained in the winding step in a battery case while reading the second identifier of the electrode body; determining an amount of electrolyte to be injected and an initial charging time based on information recorded in association with the first identifier; The method for producing the electricity storage device according to claim 4 , comprising:

8. a first identifier for identifying a position on the strip-shaped current collector at a predetermined interval in an unformed region that is set in advance along a length direction of the strip-shaped current collector; Inspection information of an active material layer formed on the strip-shaped current collector while identifying a position of the strip-shaped current collector in association with the first identifier; and A recording device configured to record the above in a linked manner.

9. 9. The recording device according to claim 8, further configured to record a second identifier attached to a predetermined position of a tab formed in the unformed region of the strip-shaped current collector and a position of the strip-shaped current collector to which the second identifier is attached in association with each other.

10. 10. The recording device according to claim 9, configured to be able to obtain inspection information of the strip-shaped current collector and the active material layer at a position along the length of the current collector based on the second identifier.

11. A second identifier attached to a tab of an electrode assembly made from the strip-shaped current collector; a unique number of the battery case given to the battery case in which the electrode body is housed; and The recording device according to claim 8 , further configured to record in association with the above.

12. The recording device according to claim 11, configured to obtain the position of the strip-shaped current collector used in the electrode body contained in the battery case and inspection information of the active material layer at that position based on the unique number of the battery case.

13. a first identifier assigning device that assigns first identifiers at predetermined intervals to unformed regions that are set in advance along a length direction of a strip-shaped current collector, the first identifiers being for identifying positions on the strip-shaped current collector; an active material layer forming device for forming an active material layer on a portion of the strip-shaped current collector excluding the unformed region; an inspection device that inspects a state of the active material layer while identifying a position of the strip-shaped current collector in association with the first identifier; a recording device for recording inspection information obtained by the inspection device; An electricity storage device manufacturing apparatus comprising:

14. a tab cut device that reads the first identifier of the strip-shaped current collector and performs a tab cut on the unformed region while identifying a position of the strip-shaped current collector; a second identifier applying device that applies a second identifier to a predetermined location of the tab formed by the tab cutting device; The power storage device manufacturing apparatus according to claim 13 , further comprising:

15. a second identifier assigning device that assigns a second identifier to an area in which a tab is to be formed by tab cutting, among the unformed area; a tab cut device that performs the tab cut on the unformed area to which the second identifier is assigned by the second identifier assigning device; The power storage device manufacturing apparatus according to claim 13 , further comprising:

16. 16. The electricity storage device manufacturing apparatus according to claim 14, further comprising a winding device that reads the second identifier and winds up the strip-shaped current collector on which the tab cut has been performed.

17. The electricity storage device manufacturing apparatus of claim 16, further comprising an assembly device that links the second identifier of the electrode body created by the winding device with a unique number assigned to a battery case that houses the electrode body, and houses the electrode body in the battery case.

18. an assembly device that reads the second identifier of the electrode body created by the winding device, houses the electrode body in a battery case having an opening, and seals the opening with a sealing plate having a unique number; a recording device that records the unique number of the sealing plate and the second identifier of the electrode body contained in the sealing plate in association with each other; The power storage device manufacturing apparatus according to claim 16 , further comprising:

19. an assembly device that reads the second identifier of the electrode body created by the winding device and houses the electrode body in a battery case; A control device that determines an injection amount of electrolyte and an initial charging time based on information recorded in association with the first identifier; The power storage device manufacturing apparatus according to claim 16 , further comprising:

Images