Apparatus for manufacturing electrode body and method for manufacturing electrode body

Abstract

The present invention aims to provide an electrode body manufacturing device that can effectively remove metal foreign matter and ensure high-quality electrode bodies. The electrode body manufacturing device includes a coater that applies a composite material paste containing an electrode active material to a base material that serves as a current collector. In addition, the manufacturing device includes an attractive magnet disposed opposite an applied layer of the composite material paste formed on the base material. The manufacturing device is configured in such a manner that the attractive magnet attracts metal foreign matter mixed into the composite material paste, thereby changing the surface shape of the applied layer.

Description

Technical Field

[0001] This invention relates to an apparatus for manufacturing an electrode and a method for manufacturing an electrode. Background Technology

[0002] Conventionally, electrode bodies in lithium-ion secondary batteries, for example, are formed by coating a composite paste containing electrode active materials onto a substrate serving as a current collector. Furthermore, methods for removing metallic foreign matter mixed into the composite paste using a magnet have been disclosed, for example in Patent Documents 1 and 2. Existing technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2003-10728 Patent Document 2: Japanese Patent Application Publication No. 2004-73944 Summary of the Invention The problem that the invention aims to solve

[0004] However, in the field of battery manufacturing, there is a constant demand for further improvements in quality and efficiency. Therefore, in reality, the existing technologies described above do not necessarily meet the ever-evolving requirements. Methods for solving problems

[0005] An apparatus for manufacturing an electrode body according to one aspect of the present disclosure includes: a coating machine that coats a composite paste containing an electrode active material onto a substrate serving as a current collector; and an attracting magnet disposed opposite to the coating layer of the composite paste formed on the substrate, thereby attracting metallic foreign matter mixed into the composite paste and causing a change in the surface shape of the coating layer.

[0006] The manufacturing apparatus for the electrode body can be configured such that the metal foreign object attracted by the magnet forms a protrusion on the surface of the coating layer.

[0007] The manufacturing apparatus for the electrode body can be configured such that the surface shape of the coating layer changes when the attracting magnet attracts the metal foreign object with a length of 50 μm or more.

[0008] The manufacturing apparatus for the electrode body may further include a visual inspection machine that inspects for changes in the surface shape produced by the coating layer.

[0009] The aforementioned electrode manufacturing apparatus may further include: a discharge port disposed in the aforementioned coating machine for dispensing the aforementioned composite material paste; and an adsorption magnet disposed in the aforementioned discharge port for adsorbing metallic foreign matter mixed into the aforementioned composite material paste.

[0010] According to another aspect of the present disclosure, an electrode manufacturing apparatus includes: a coating machine that coats a composite paste containing an electrode active material onto a substrate serving as a current collector; a discharge port disposed in the coating machine for discharging the composite paste; and an adsorption magnet disposed in the discharge port for adsorbing metallic foreign matter mixed into the composite paste.

[0011] In the aforementioned electrode manufacturing apparatus, the aforementioned adsorption magnet can be positioned in the aforementioned discharge port at a position downstream of the conveying direction of the aforementioned substrate, which is being continuously conveyed.

[0012] In the aforementioned electrode manufacturing apparatus, the thickness of the coating layer of the aforementioned composite material paste formed on the aforementioned substrate can be 20 μm or more and 50 μm or less.

[0013] According to another aspect of the present disclosure, the method for manufacturing an electrode includes the following steps: applying a composite paste containing an electrode active material to a substrate serving as a current collector; and using an attractive magnet opposite to the coating layer of the composite paste formed on the substrate to attract metallic foreign matter mixed into the composite paste, thereby changing the surface shape of the coating layer.

[0014] The above-described electrode manufacturing method may include a step of using an adsorption magnet disposed at the outlet for dispensing the composite paste to the substrate to adsorb metallic foreign matter mixed into the composite paste.

[0015] According to another aspect of the present disclosure, the method for manufacturing an electrode includes the following steps: applying a composite paste containing an electrode active material to a substrate serving as a current collector; and using an adsorption magnet disposed at an outlet for discharging the composite paste from the substrate to adsorb metallic foreign matter mixed into the composite paste. The effects of the invention

[0016] According to the present invention, metallic foreign objects can be effectively removed, ensuring high quality. Attached Figure Description

[0017] Figure 1 It is a 3D diagram of a secondary battery. Figure 2 This is an exploded view of the electrode. Figure 3 This is a side view of a secondary battery. Figure 4 This is a schematic diagram of the manufacturing apparatus used in the manufacture of the electrode. Figure 5 This is an illustration of the adsorption magnet located at the outlet of the composite paste. Figure 6This is an illustration of metallic foreign matter contained in the coating layer of a composite paste. Figure 7 This is an illustration of the shape changes produced by a metallic foreign object attracted by a magnet and the surface of the coating layer. Detailed Implementation

[0018] The following description, with reference to the accompanying drawings, describes one embodiment of the electrode manufacturing apparatus and manufacturing method. like Figure 1 As shown, the secondary battery 1 includes an electrode body 10 integrally formed by a positive electrode 3, a negative electrode 4, and a separator 5, and a housing 20 for housing the electrode body 10. The secondary battery 1 of this embodiment is a lithium-ion secondary battery in which a non-aqueous electrolyte (not shown) is impregnated in the electrode body 10 within the housing 20.

[0019] In detail, in the secondary battery 1 of this embodiment, the positive electrode 3, the negative electrode 4, and the separator 5 have sheet-like shapes and are laminated. Furthermore, by winding these laminated bodies of the positive electrode 3, the negative electrode 4, and the separator 5, the positive and negative electrodes and the separator 5 are arranged alternately in their radial direction with the separator 5 sandwiched between the positive electrode 3 and the negative electrode 4 to form an electrode body.

[0020] Furthermore, the housing 20 of this embodiment includes a flat and generally square box-shaped housing body 21, and a cover member 22 that closes the open end 21x of the housing body 21. Also, the electrode body 10 of this embodiment has a flat shape corresponding to the box shape of the housing 20.

[0021] If further details are needed, then as follows: Figure 2 As shown, in the secondary battery 1 of this embodiment, the positive electrode 3 and the negative electrode 4 each include an electrode sheet 35. The electrode sheet 35 includes: a current collector 31 having a sheet-like shape; and an electrode active material layer 32 deposited on the current collector 31.

[0022] Specifically, for the electrode sheet 35P used for the positive electrode 3, a composite paste 37P containing a lithium transition metal oxide as a positive electrode active material is coated onto a substrate 36P containing aluminum or the like, which constitutes the positive electrode current collector 31P. Similarly, for the electrode sheet 35N used for the negative electrode 4, a composite paste 37N containing a carbon-based material as a negative electrode active material is coated onto a substrate 36N containing copper or the like, which constitutes the negative electrode current collector 31N. Furthermore, these composite pastes 37P and 37N each contain a binder material. In the secondary battery 1 of this embodiment, by drying these composite pastes 37P and 37N, corresponding positive electrode active material layers 32P and 32N are formed on the positive and negative electrode sheets 35P and 35N, respectively.

[0023] Furthermore, in the secondary battery 1 of this embodiment, the positive and negative electrode sheets 35P and 35N are respectively shaped into strips. In the electrode body 10 of this embodiment, the positive and negative electrode sheets 35P and 35N, which are laminated with spacers 5, are arranged along the width direction of the strip. Figure 2 The winding is performed around the winding axis L (with the center in the left-right direction).

[0024] It should be noted that, Figure 2 In this process, the spacer 5 and each electrode 35 are wound in a manner in which the electrode sheet 35P constituting the positive electrode 3 is wound inward. However, Figure 2 To illustrate an example of the structure of the electrode body 10, sometimes the spacers 5 and each electrode sheet 35 are wound in such a way that the electrode sheet 35N constituting the negative electrode 4 is wound inside. This determines whether the electrode sheet 35 disposed on the outermost shell of the electrode body 10 is the electrode sheet 35P constituting the positive electrode 3 or the electrode sheet 35N constituting the negative electrode 4.

[0025] In addition, such as Figures 1-3 As shown, the cover member 22 of the housing 20 has a positive terminal 38P and a negative terminal 38N protruding outward from the housing 20. Furthermore, each electrode sheet 35 has an uncoated portion 39 where the electrode active material layer 32 is not formed on the current collector 31. In the secondary battery 1 of this embodiment, these uncoated portions 39 are used to electrically connect the electrode sheet 35P constituting the positive electrode 3 to the positive terminal 38P, and the electrode sheet 35N constituting the negative electrode 4 to the negative terminal 38N.

[0026] Specifically, in this embodiment, the electrode body 10 is wound along its winding axis L along the length direction of the cover member 22, which is a long strip-shaped, generally rectangular plate. Figure 1 The electrode (in the left-right direction) is housed within the casing 20. Furthermore, in this state, the uncoated portion 39P of the electrode 35P constituting the positive electrode 3 is connected to the positive terminal 38P via the connecting member 40P. Similarly, the uncoated portion 39N of the electrode 35N constituting the negative electrode 4 is connected to the negative terminal 38N via the connecting member 40N.

[0027] Furthermore, an electrolyte 41 is injected into the casing 20. That is, in this embodiment, the electrolyte 41 of the secondary battery 1, which is a lithium-ion secondary battery, uses an electrolyte in which a lithium salt, as a supporting salt, is dissolved in an organic solvent. In the secondary battery 1 of this embodiment, the electrode body 10, which is sealed in the casing 20, is thus impregnated with the electrolyte 41.

[0028] (Electrode sheet manufacturing apparatus and manufacturing method) Next, the manufacturing apparatus and manufacturing method of the electrode sheet 35 used in the formation of the electrode body 10, which is configured as described above, will be explained in detail.

[0029] like Figure 4 As shown, the manufacturing apparatus 50 for the electrode sheet 35 used in the formation of the electrode body 10 includes: a conveying device 51 for continuously conveying the substrate 36, which serves as the current collector 31; and a coating machine 52 for coating a composite paste 37 onto the surface 36s of the substrate 36.

[0030] In detail, the substrate 36 of this embodiment is formed into a strip-shaped foil. That is, the substrate 36 is called a "current collector foil" because of its shape and its function as a current collector 31. In addition, in the manufacturing apparatus 50 of this embodiment, the substrate 36 is wound on a plurality of rollers 53 constituting the conveying device 51. The conveying device 51 of this embodiment is configured to continuously convey the strip-shaped substrate 36 by rotating these individual rollers 53.

[0031] Furthermore, the coating machine 52 of this embodiment includes a coating die 56, which has an outlet 55 for dispensing a composite material paste 37 onto the substrate 36. Specifically, in the manufacturing apparatus 50 of this embodiment, the coating die 56 is arranged radially outside a roller 53x, one of the plurality of rollers 53 constituting the conveying device 51, which is called a "B roller". Thus, the coating machine 52 of this embodiment is configured to continuously coat the composite material paste 37 dispensed from the outlet 55 onto the surface 36s of the substrate 36 opposite the coating die 56.

[0032] In further detail, in the manufacturing apparatus 50 of this embodiment, the thickness of the coating layer 60 of the composite material paste 37 formed on the substrate 36 through this series of processes, i.e., the portion serving as the electrode active material layer 32, is set to, for example, approximately 30 μm. Furthermore, the electrode sheet 35 formed by coating the substrate 36 with the composite material paste 37 is sequentially cut to predetermined length and width dimensions after the coating layer 60 has dried. As described above, the electrode body 10 (see reference 5) is formed by winding the positive and negative electrode sheets 35P and 35N, which have been shaped therefrom, together with the spacer 5. Figure 2 ).

[0033] (Magnetic attraction for metallic foreign objects) Next, the magnet for attracting metallic foreign objects provided in the manufacturing apparatus 50 of this embodiment will be described. like Figure 4 and Figure 5As shown, in the manufacturing apparatus 50 of this embodiment, the coating die 56 of the coating machine 52 is equipped with an adsorption magnet 70. For example, the adsorption magnet 70 is disposed at the discharge port 55 of the composite material paste 37 formed at the front end of the coating die 56. Furthermore, in the manufacturing apparatus 50 of this embodiment, the adsorption magnet 70 is used to adsorb the metallic foreign matter M mixed into the composite material paste 37 coated onto the substrate 36 through the discharge port 55. As a result, the manufacturing apparatus 50 of this embodiment can effectively remove the metallic foreign matter M from the composite material paste 37.

[0034] In detail, in the manufacturing apparatus 50 of this embodiment, the adsorption magnet 70 extends throughout the width direction of the substrate 36, which has a strip foil shape and is continuously conveyed by the conveying device 51. Figure 4 A long strip shape extending over approximately the entire area in the direction perpendicular to the paper surface. Furthermore, the adsorbent magnet 70 is located downstream of the substrate 36 in the conveying direction (…). Figure 4 and Figure 5 The position (upper side) is provided at the outlet 55 of the composite paste 37. In other words, the adsorption magnet 70 is disposed in the outlet 55 of the composite paste 37 at a position downstream of the substrate 36 in the conveying direction. In other words, the adsorption magnet 70 is positioned at the outlet 55 in the direction of the substrate 36 flowing on the roller 53x opposite the coating die 56 of the coating machine 52. Thus, the manufacturing apparatus 50 of this embodiment can effectively adsorb metallic foreign matter M in the composite paste 37 to the adsorption magnet 70 based on magnetic force.

[0035] That is, at the outlet 55, which serves as the outlet for the composite paste 37 moving within the flow path 72 of the coating machine 52, the composite paste 37 is stretched thinly, corresponding to the thickness D of the coating layer 60 formed on the substrate 36. Furthermore, the flow rate of the composite paste 37 is accelerated based on the discharge pressure of the composite paste 37, thereby reducing the viscosity of the composite paste 37 to, for example, about 1500 mPa·s (millipascal-seconds) by applying a high shear force. As a result, in the manufacturing apparatus 50 of this embodiment, the adsorption magnet 70 easily captures metallic foreign matter M in the composite paste 37.

[0036] Furthermore, the manufacturing apparatus 50 of this embodiment is configured such that, based on the cylindrical shape of the roller 53x opposite the coating die 56, the coated substrate 36 is separated from the adsorption magnet 70 provided at the outlet 55 of the composite paste 37 in the discharge direction of the composite paste 37. Therefore, in the manufacturing apparatus 50 of this embodiment, metallic foreign matter M adsorbed by the adsorption magnet 70 is less likely to re-adhere to the composite paste 37 coated on the substrate 36.

[0037] Furthermore, in the manufacturing apparatus 50 of this embodiment, metallic foreign matter M captured by the adsorption magnet 70 can be wiped off the outside of the coating die 56 having the outlet 55 of the composite paste 37. Thus, the manufacturing apparatus 50 of this embodiment can easily and conveniently remove metallic foreign matter M mixed into the composite paste 37.

[0038] (A magnet that attracts metallic foreign objects) Next, the magnet for attracting metallic foreign objects provided in the manufacturing apparatus 50 of this embodiment will be described. like Figure 4 As shown, in the manufacturing apparatus 50 of this embodiment, in addition to the adsorption magnet 70 provided at the outlet 55 of the composite paste 37 as described above, an attraction magnet 80 is also provided opposite to the coating layer 60 of the composite paste 37 formed on the substrate 36. That is, the attraction magnet 80 is located downstream of the substrate 36 in the conveying direction of the conveying device 51 compared to the coating position where the coating die 56 is provided to coat the substrate 36 with the composite paste 37. Figure 4 The middle position is on the right. In other words, the attracting magnet 80 is positioned downstream of the substrate 36 in the transport direction of the substrate 36, relative to the coating position where the composite paste 37 is applied to the substrate 36 using the coating die 56. Specifically, the attracting magnet 80 is positioned opposite the coating layer 60 formed on the substrate 36, approximately a few millimeters away from the surface 60s of the coating layer 60. It should be noted that the attracting magnet 80, like the adsorption magnet 70 described above, has an elongated shape extending throughout the entire width direction of the substrate 36, which has a strip-shaped foil and is continuously transported by the transport device 51. Furthermore, the manufacturing apparatus 50 of this embodiment includes an appearance inspection machine 81 positioned downstream of the attracting magnet 80 in the transport direction. Moreover, the manufacturing apparatus 50 of this embodiment can effectively remove metallic foreign matter M mixed into the composite paste 37 based on the inspection results of the appearance inspection machine 81.

[0039] That is, in the manufacturing apparatus 50 of this embodiment, the metallic foreign matter M contained in the coating layer 60 of the composite paste 37 is attracted by the magnetic force of the attracting magnet 80. Furthermore, the surface shape of the coating layer 60 formed on the substrate 36 changes due to the movement of the metallic foreign matter M attracted by the attracting magnet 80. The manufacturing apparatus 50 of this embodiment is configured to detect the shape change on the surface 60s of the coating layer 60 using an appearance inspection machine 81 located downstream of the attracting magnet 80.

[0040] If detailed explanation is required, then as follows: Figure 6 and Figure 7As shown, in the manufacturing apparatus 50 of this embodiment, the attracting magnet 80 attracts the metallic foreign matter M contained in the coating layer 60 of the composite paste 37, thereby causing, for example, a change in the orientation of the metallic foreign matter M.

[0041] Specifically, the coating layer 60 of the composite paste 37 contains elongated granular metallic foreign objects M (X>D) with a length X longer than the thickness D of the coating layer 60. In this case, the orientation of the metallic foreign object M tends to be such that its length direction is along the surface 36s of the substrate 36, i.e., a so-called "lying state". In the manufacturing apparatus 50 of this embodiment, by attracting such "lying state" metallic foreign objects M with the attracting magnet 80, the orientation of the metallic foreign object M changes to a so-called "standing state". That is, the orientation of the metallic foreign object M contained in the coating layer 60 of the composite paste 37 changes in the direction of the length direction of the metallic foreign object M toward the thickness direction of the coating layer 60. As a result, in the manufacturing apparatus 50 of this embodiment, the metallic foreign object M attracted by the attracting magnet 80 forms a protrusion 85 on the surface 60s of the coating layer 60.

[0042] In further detail, the manufacturing apparatus 50 of this embodiment is configured such that when the attracting magnet 80 attracts a metallic foreign object M having a length X of 50 μm or more, the surface shape of the coating layer 60 changes in the portion containing the metallic foreign object M. Furthermore, in the manufacturing apparatus 50 of this embodiment, if the appearance inspection machine 81 detects such a shape change on the surface 60s of the coating layer 60, the portion where the surface shape change is detected is marked. Moreover, in the manufacturing apparatus 50 of this embodiment, the marked portion is not used during the formation of the electrode body 10 by winding the electrode sheet 35, thereby effectively removing the metallic foreign object M mixed into the composite paste 37.

[0043] That is, even when using the adsorption magnet 70 disposed at the outlet 55 of the composite paste 37, there is a possibility that the metallic foreign matter M mixed in with the composite paste 37 may not be captured. In view of this, the manufacturing apparatus 50 of this embodiment uses the removal method described above, which uses an adsorption magnet 80 to remove the metallic foreign matter M. This allows for further improvement in its quality.

[0044] It should be noted that in the manufacturing apparatus 50 of this embodiment, a filter (not shown) is also provided in the flow path 72 of the composite material paste 37 formed in the coating machine 52, which is capable of capturing metallic foreign matter M mixed in with the composite material paste 37. However, the shape of the metallic foreign matter M is not necessarily limited to spherical, and in many cases it is an amorphous shape such as long particles as described above. Therefore, depending on its orientation in the composite material paste 37, it may pass through the filter. Thus, the manufacturing apparatus 50 of this embodiment is configured to use an adsorption magnet 70 and an attraction magnet 80 to remove the metallic foreign matter M that has passed through the filter.

[0045] Next, the function of this embodiment will be explained. That is, in the manufacturing apparatus 50 of this embodiment, metallic foreign matter M mixed into the composite material paste 37 coated onto the substrate 36 is captured by adsorption magnet 70 provided at the outlet 55 of the composite material paste 37. Furthermore, metallic foreign matter M in the composite material paste 37 coated onto the substrate 36 that is not adsorbed by the adsorption magnet 70 is attracted by an attraction magnet 80 disposed opposite to the coating layer 60 of the composite material paste 37 formed on the substrate 36. Based on the shape change generated on the surface 60s of the coating layer 60 by the attraction of the attraction magnet 80 to the metallic foreign matter M, the metallic foreign matter M contained in the coating layer 60 of the composite material paste 37 is removed.

[0046] Next, the effects of this embodiment will be explained. (1) The manufacturing apparatus 50 for the electrode body 10 includes a coating machine 52 for coating a composite material paste 37 containing an electrode active material onto a substrate 36 serving as a current collector 31. Furthermore, the manufacturing apparatus 50 includes an attractive magnet 80 disposed opposite to the coating layer 60 of the composite material paste 37 formed on the substrate 36. The manufacturing apparatus 50 is configured such that the attractive magnet 80 attracts metallic foreign matter M mixed into the composite material paste 37, thereby changing the surface shape of the coating layer 60.

[0047] Based on the above configuration, the metallic foreign matter M contained in the coating layer 60 of the composite paste 37 formed on the substrate 36 can be detected to determine the portion containing the metallic foreign matter M. This allows for the effective removal of the metallic foreign matter M, ensuring high quality.

[0048] In particular, the attracting magnet 80 does not come into contact with the composite paste 37, nor does it adsorb metallic foreign objects M. Therefore, it has the advantages of not requiring high-frequency cleaning and being easy to clean. Furthermore, this allows for further efficiency improvements.

[0049] (2) The manufacturing apparatus 50 is configured such that a metal foreign object M in the composite paste 37 attracted by the magnet 80 forms a protrusion 85 on the surface 60s of the coating layer 60. Thus, the portion containing the metal foreign object M can be easily identified.

[0050] (3) The manufacturing apparatus 50 is configured such that when the attracting magnet 80 attracts a metallic foreign object M with a length X of 50 μm or more, the surface shape of the coating layer 60 changes. As a result, the metallic foreign object M that has a significant impact on battery performance can be effectively removed.

[0051] (4) The manufacturing apparatus 50 is equipped with an appearance inspection machine 81 that detects changes in the surface shape of the coating layer 60 of the composite paste 37. As a result, the detection of metallic foreign matter M contained in the coating layer 60 of the composite paste 37 based on the surface shape change, and the determination of the portion containing the metallic foreign matter M, can be performed automatically.

[0052] (5) The manufacturing apparatus 50 has an adsorption magnet 70 at the outlet 55 of the composite paste 37 provided in the coating machine 52 to adsorb the metal foreign matter M mixed in the composite paste 37. That is, at the outlet 55 of the composite paste 37, the composite paste 37 is stretched thinly, corresponding to the thickness D of the coating layer 60 formed on the substrate 36. Furthermore, the flow rate of the composite paste 37 is accelerated based on the discharge pressure, thereby reducing the viscosity of the composite paste 37 by applying high shear force. Thus, metallic foreign matter M mixed into the composite paste 37 can be effectively adsorbed and captured based on the magnetic force of the adsorption magnet 70.

[0053] This allows for the easy removal of metallic foreign matter M adsorbed by the adsorbing magnet 70. Thus, metallic foreign matter M mixed into the composite paste 37 can be easily and conveniently removed.

[0054] (6) At a position downstream of the continuously conveying substrate 36 in the conveying direction, an adsorption magnet 70 is provided at the outlet 55 of the composite paste 37. As a result, the metallic foreign matter M mixed into the composite paste 37 can be more effectively adsorbed and captured by the adsorption magnet 70.

[0055] It should be noted that the above implementation methods can be modified as follows. The above implementation methods and the following modifications can be combined with each other to implement them within the scope of technical non-inconsistency.

[0056] In the above embodiment, the adsorption magnet 70 is disposed in the outlet 55 of the composite paste 37 at a position downstream of the continuously conveyed substrate 36 in the conveying direction. However, this is not a limitation, and the arrangement of the adsorption magnet 70 at the outlet 55 of the composite paste 37 can be arbitrarily changed. For example, the adsorption magnet 70 can be disposed in the outlet 55 of the composite paste 37 at a position upstream of the conveying direction of the substrate 36. In other examples, the adsorption magnet 70 can also be disposed on both the upstream and downstream sides of the conveying direction of the substrate 36.

[0057] In the above embodiment, the adsorption magnet 70 has an elongated shape extending throughout the entire width direction of the substrate 36, which has a strip foil shape and is continuously conveyed by the conveying device 51. However, it is not limited to this, and the shape of the adsorption magnet 70 can be arbitrarily changed. For example, multiple adsorption magnets 70 divided into several parts can be used.

[0058] The shape and arrangement of the attracting magnet 80 can be arbitrarily changed. That is, the surface shape of the coating layer 60 can be changed by attracting the metallic foreign matter M mixed in the composite paste 37 by being arranged opposite to the coating layer 60 of the composite paste 37 formed on the substrate 36. For example, multiple attracting magnets 80 can be used. Furthermore, for example, the attracting magnet 80 arranged opposite to the coating layer 60 can be configured to perform a so-called scanning operation, that is, a movable attracting magnet 80 that moves back and forth in the width direction of the strip-shaped substrate 36 can be used. The magnetic force of the attracting magnet 80 can also be arbitrarily changed.

[0059] In the above embodiments, as an example of the shape change produced on the surface 60s of the coating layer 60 by attracting the metallic foreign object M using the attracting magnet 80, a case is illustrated where a protrusion 85 is formed on the surface 60s of the coating layer 60 based on the posture change of the metallic foreign object M mixed into the composite paste 37. However, it is not limited to this. As long as the shape change produced on the surface 60s of the coating layer 60 can be detected by the movement of the metallic foreign object M in the composite paste 37 attracted by the attracting magnet 80, the change in surface shape can be any change. For example, even if a recess is formed in the part where the metallic foreign object M moves in the composite paste 37 by the attraction of the attracting magnet 80, the change in its surface shape can be detected using the visual inspection machine 81.

[0060] • The configuration of the visual inspection machine 81 can also be arbitrarily changed. In the above embodiment, it is also possible to inspect the shape changes that occur on the surface 60s of the coating layer 60, i.e., the parts where there are abnormalities in the electrode sheet 35, by visual inspection without using such a visual inspection machine 81.

[0061] In the above embodiment, the thickness D of the coating layer 60 is set to approximately 30 μm. However, it is not limited to this; the thickness D of the coating layer 60 can be set, for example, in the range of 20 μm or more and 50 μm or less. Therefore, metallic foreign matter M mixed into the composite paste 37 can be effectively removed using magnetic methods.

[0062] • In the above embodiments, the manufacturing apparatus 50 for the electrode body 10 includes both an adsorption magnet 70 and an attraction magnet 80, but it can also be specifically configured to use one of the adsorption magnet 70 and the attraction magnet 80 to remove the metallic foreign matter M mixed into the composite paste 37.

[0063] • In the above embodiments, a conveying device 51 is used to continuously convey the substrate 36 by rotating a plurality of rollers 53 on which the strip substrate 36 is wound. However, the configuration of the conveying device 51 can be arbitrarily changed.

[0064] The terminal shapes of the positive terminal 38P and the negative terminal 38N are not limited to... Figure 1 The shape shown can be changed arbitrarily. The shape of the casing 20 that constitutes the outer shape of the secondary battery 1 is not necessarily limited to a flat square box shape, for example, it can also be a cylindrical shape, etc., and can be changed arbitrarily. Explanation of symbols in attached drawings

[0065] 10…Electrode body 31… Collector 36…substrate 37… Composite Material Paste 50… Manufacturing Equipment 52… Coating machine 60…coating layers 80…attracting magnets M…Metallic foreign object.

Claims

1. An apparatus for manufacturing an electrode, comprising: A coating machine that applies a composite paste containing electrode active materials to a substrate that serves as a current collector. The outlet, located on the coating machine, dispenses the composite material paste. An adsorption magnet, disposed at the outlet, adsorbs metallic foreign matter mixed into the composite paste coated on the substrate; and An attractive magnet is configured opposite to a coating layer of the composite paste formed on the substrate, thereby attracting metallic foreign matter mixed into the composite paste that has not been attracted by the attracting magnet, causing a change in the surface shape of the coating layer.

2. The electrode manufacturing apparatus according to claim 1, wherein the metallic foreign object attracted by the attracting magnet forms a protrusion on the surface of the coating layer.

3. The electrode manufacturing apparatus according to claim 1 or 2, wherein the surface shape of the coating layer changes when the attracting magnet attracts the metal foreign object having a length of 50 μm or more.

4. The electrode manufacturing apparatus according to claim 1 or 2, further comprising a visual inspection machine that inspects changes in the surface shape produced on the coating layer.

5. The electrode manufacturing apparatus according to claim 1, wherein, The adsorption magnet is positioned in the outlet at a location downstream of the continuously conveying substrate.

6. The apparatus for manufacturing an electrode body according to claim 1 or 2, wherein, The thickness of the coating layer of the composite paste formed on the substrate is more than 20 μm and less than 50 μm.

7. An apparatus for manufacturing an electrode, comprising: A coating machine that applies a composite paste containing electrode active materials to a substrate that serves as a current collector. An outlet, located on the coating machine, dispenses the composite material paste; and An adsorption magnet, disposed at the outlet for dispensing the composite paste onto the substrate, adsorbs metallic foreign matter mixed into the composite paste already coated on the substrate. The adsorption magnet is positioned in the outlet at a location downstream of the continuously conveying substrate.

8. The electrode manufacturing apparatus according to claim 7, wherein, The thickness of the coating layer of the composite paste formed on the substrate is more than 20 μm and less than 50 μm.

9. A method for manufacturing an electrode, comprising the following steps: A process of adsorbing metallic foreign matter mixed into the composite paste that has been coated on the substrate by using an adsorption magnet configured at the outlet of the composite paste that is dispensed onto the substrate. The process of coating a composite paste containing electrode active materials onto a substrate serving as a current collector; and A process that alters the surface shape of a coating layer by using an attractive magnet opposite to the coating layer of the composite paste formed on the substrate to attract metallic foreign matter mixed into the composite paste that has not been attracted by the magnet.

10. A method for manufacturing an electrode, comprising the following steps: The process of coating a composite paste containing electrode active materials onto a substrate serving as a current collector; and The process involves using an adsorption magnet configured at the outlet for dispensing the composite paste onto the substrate to adsorb metallic foreign matter mixed into the composite paste. The adsorption magnet is positioned in the outlet at a location downstream of the continuously conveying substrate.

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