Method for manufacturing electrodes
The method of producing a long electrode composite sheet and cutting it to a predetermined shape addresses the limitation of rectangular shapes, enabling flexible battery design and reducing waste while maintaining high quality.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2026-05-18
AI Technical Summary
Existing manufacturing methods for electrode bodies are limited to rectangular shapes, restricting the ability to freely design the shape of the battery based on its space requirements.
A method involving the production of a long electrode composite sheet by mixing active material particles with a fibrillatable binder, cutting it to a predetermined contour shape using a laser, and optionally attaching it to a current collector or transparent film, allowing for the manufacture of electrode bodies of any shape without using solvents.
Enables the production of electrode bodies with customizable shapes, reduces waste through reusable materials, and maintains high quality by avoiding contamination from laser-induced film burning.
Smart Images
Figure 2026081002000001_ABST
Abstract
Description
Technical Field
[0001] The technology disclosed in this specification relates to a method for manufacturing an electrode body.
Background Art
[0002] Patent Document 1 describes a method for manufacturing an electrode body. This manufacturing method includes a step of coating a solution of an electrode mixture containing active material particles on a current collector. In this step, two or more die heads with different coating ranges are used. By operating these two or more die heads at different timings, the solution of the electrode mixture is coated on a non-rectangular range on the current collector. Thereby, a non-rectangular electrode body can be manufactured.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the above-described manufacturing method, the shape in which the solution of the electrode mixture can be coated is limited to a combination of rectangular shapes. That is, even if a non-rectangular electrode can be manufactured, its shape is limited to a combination of rectangular shapes. For example, depending on the space where the battery is arranged, it is preferable that the shape of the battery can be freely designed. For this purpose, a technology capable of manufacturing an electrode body with a free shape is required.
[0005] In view of the above circumstances, this specification provides a technology for manufacturing an electrode body with a free shape.
Means for Solving the Problems
[0006] The technology disclosed herein is embodied in a method for manufacturing an electrode body. In a first embodiment, the manufacturing method comprises the steps of: producing a long electrode composite sheet by forming a mixture in which active material particles are mixed with at least a fibrillable binder into a sheet by rolling; and cutting an electrode composite sheet having a predetermined contour shape from the long electrode composite sheet.
[0007] In the manufacturing method described above, a long electrode composite sheet is first produced from the mixture. Then, an electrode composite sheet having a predetermined contour shape is cut from the long electrode composite sheet. With this configuration, electrode bodies of any shape can be manufactured.
[0008] In a second embodiment, the manufacturing method in the first embodiment further comprises the step of attaching an electrode composite sheet having a predetermined contour shape onto a current collector. With this configuration, an electrode body having an electrode composite sheet on a current collector can be manufactured in any shape.
[0009] In a third embodiment, in the first or second embodiment, the cutting step may include irradiating a long electrode composite sheet with a laser along a predetermined contour shape. Since the laser irradiation position can be changed relatively easily, the above configuration makes it possible to manufacture electrode bodies of any shape relatively easily.
[0010] In a fourth embodiment, the manufacturing method in any of the first to third embodiments may further include a step of attaching a long electrode composite sheet onto a transparent film. In this case, the laser irradiation step may involve irradiating the long electrode composite sheet on the film with a laser. For example, when a laser is irradiated onto a long electrode composite sheet on a current collector, the long electrode composite sheet may be cut, while the current collector may deteriorate. In this regard, the laser penetrates the film. Therefore, when a laser is irradiated onto a long electrode composite sheet on a film, only the long electrode composite sheet is cut. Since the film is not burned by the laser, contamination of the electrode composite sheet due to the burning of the film can be avoided. Subsequently, a high-quality electrode body can be manufactured by attaching the electrode composite sheet, which has been cut into a predetermined contour shape, onto the current collector.
[0011] In the fifth embodiment, in any of the first to fourth embodiments, the remaining portion of the long electrode composite sheet after the cutting process may be reused in the subsequent manufacturing of other electrode bodies in the process of producing long electrode composite sheets. This configuration reduces the amount of waste during manufacturing. [Brief explanation of the drawing]
[0012] [Figure 1] A diagram schematically showing the configuration of the electrode body 10 in the embodiment. [Figure 2] A flowchart illustrating one embodiment of the manufacturing method for the electrode body 10. [Figure 3] A diagram illustrating the process of producing a long electrode composite sheet 22 by forming a sheet from a mixture 20 using a rolling mill 100. [Figure 4] A diagram illustrating the process of cutting an electrode composite sheet 14 having a predetermined contour shape from a long electrode composite sheet 22 using a laser device 106. [Figure 5] A diagram illustrating the process of recovering the remaining portion 26 of the long electrode composite sheet after the cutting process using a peeling device 108. [Figure 6] A diagram illustrating the process of attaching an electrode composite sheet 14 having a predetermined contour shape onto a current collector 12 using a transfer device 112. [Figure 7] A diagram illustrating a modified example of the process of cutting an electrode composite sheet 14 having a predetermined contour shape from a long electrode composite sheet 22. [Modes for carrying out the invention]
[0013] The electrode body 10 will be described with reference to the drawings. The electrode body 10 is used, for example, as the negative electrode of a lithium-ion secondary battery. However, the electrode body 10 is not necessarily limited to the negative electrode of a lithium-ion secondary battery, but can also be used as the positive electrode of a lithium-ion secondary battery. Furthermore, this technology allows the electrode body 10 to be used not only as an electrode for a lithium-ion secondary battery, but also as an electrode for any type of secondary battery or as an electrode for an all-solid-state battery.
[0014] As shown in Figure 1, the electrode body 10 comprises a current collector 12 and an electrode composite sheet 14. The current collector 12 is a conductive sheet. The current collector 12 is, for example, aluminum foil or copper foil. The thickness of the current collector 12 is, for example, 5 μm or more and 50 μm or less. The electrode composite sheet 14 is placed on the current collector 12. In this embodiment, the electrode composite sheet 14 is a self-supporting sheet material. A self-supporting sheet material here means a sheet material that can maintain a sheet shape on its own without requiring a support such as the current collector 12. Therefore, the electrode body 10 does not necessarily need to include a current collector 12. That is, in another embodiment, the electrode composite sheet 14 may constitute the electrode body 10 by itself. The thickness of the electrode composite sheet 14 is, for example, 10 μm or more and 500 μm or less.
[0015] The electrode composite sheet 14 includes active material particles 16 and a binder 18 that binds the active material particles 16 to each other. At least a part of the binder 18 is fibrillated. As will be described later, the binder 18 is made of a fibrillatable material such as polytetrafluoroethylene (PTFE). Note that a part of the binder 18 may be made of a non-fibrillatable material such as polyvinylidene fluoride (PVdF). Further, the electrode composite sheet 14 may further contain a conductive assistant or the like.
[0016] The active material particles 16 include negative electrode active material particles. Examples of the negative electrode active material particles include carbon materials such as graphite, hard carbon, and soft carbon, materials that form an alloy with lithium such as silicon (Si), and these lithium alloys (for example, Li 1 / 3 , 1 / 3 , 3 / 2 , 1 / 3 , 1 / 2 M, where M is C, Si, Sn, Sb, Al, Mg, Ti, Bi, Ge, Pb, or P, etc., and X is a natural number). The negative electrode active material particles may be composed of a single type of material or a plurality of types of materials. When the electrode body 10 is used as the positive electrode of a lithium-ion secondary battery, the active material particles 16 include positive electrode active material particles instead of negative electrode active material particles. Examples of the positive electrode active material particles include rock salt layer-type active materials such as lithium nickel-based composite oxides, lithium cobalt-based composite oxides, lithium manganese-based composite oxides, lithium nickel manganese-based composite oxides (for example, LiNi 1 / 2 Mn 3 / 2 O4), lithium nickel manganese cobalt-based composite oxides (for example, LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 O2), spinel-type active materials such as lithium manganese oxide, and olivine-type active materials such as lithium iron phosphate (LFP) and lithium manganese iron phosphate (LMFP).
[0017] As described above, the binder 18 is made of a fibrillatable material. A fibrillatable material is a material that can be fibrillated when a shearing force is applied. Examples of fibrillatable materials include polytetrafluoroethylene (PTFE), cellulose, acrylic resin, and ultra-high molecular weight polyethylene. A material that is one of these fibrillatable materials and can function as a binder is referred to as a fibrillatable binder in this specification. The fibrillatable binder may be composed of a single type of material or a plurality of types of materials.
[0018] Next, referring to FIGS. 2-6, an example of a method for manufacturing the electrode body 10 will be described. In the manufacturing method of this example, the electrode body 10 can be manufactured without using a solvent. That is, the manufacturing method is a so-called dry process.
[0019] As shown in FIG. 2, the manufacturing method of the example includes a step (S10) of producing a long electrode composite sheet 22 by forming a mixture 20 in which at least a fibrillatable binder 18 is mixed with the active material particles 16 into a sheet shape by rolling. In this step, as shown in FIG. 3, for example, a rolling device 100 is used. The rolling device 100 includes a pair of rollers 102 and can roll the mixture 20 passing between the pair of rollers 102. Thereby, the mixture 20 is formed into a series of sheet shapes, and a long electrode composite sheet 22 is produced. In the above-mentioned mixture 20, part or all of the binder 18 may be fibrillated in advance. The specific method of fibrillating the binder 18 is not particularly limited. Although it is an example, at least a part of the binder 18 can be fibrillated in advance by kneading the mixture 20 before being supplied to the rolling device 100 using a kneader.
[0020] As shown in Figure 2, the manufacturing method of the embodiment further comprises a step (S12) of attaching a long electrode composite sheet 22 onto a transparent film 24. In this step, as shown in Figure 3, for example, the rolling mill 100 described above is used. The rolling mill 100 further comprises an adhesive roller 104. The adhesive roller 104 is positioned opposite one of the pair of rollers 102 described above. The long electrode composite sheet 22 formed by the pair of rollers 102 is supplied between one of the pair of rollers 102 and the adhesive roller 104. The transparent film 24 is supplied to the outer circumferential surface of the adhesive roller 104 from the outside. As a result, the long electrode composite sheet 22 is attached to the film 24 as it passes between one of the pair of rollers 102 and the adhesive roller 104.
[0021] As shown in Figure 2, the manufacturing method of the embodiment further includes a step (S14) of cutting out an electrode composite sheet 14 having a predetermined contour shape from a long electrode composite sheet 22. In this step, as shown in Figure 4, for example, a laser device 106 is used. The laser device 106 irradiates the long electrode composite sheet 22 on the film 24 with a laser along the predetermined contour shape. As a result, an electrode composite sheet 14 having a predetermined contour shape is cut out from the long electrode composite sheet 22 on the film 24. Here, the laser passes through the transparent film 24. Therefore, only the long electrode composite sheet 22 is cut by the laser, and the film 24 is not cut.
[0022] As shown in Figure 2, the manufacturing method of the embodiment further includes a step (S16) to recover the remaining portion 26 of the long electrode composite sheet that remains after the cutting step (S14). In this step, as shown in Figure 5, for example, a peeling device 108 is used. The peeling device 108 is equipped with a roller 110, and the roller 110 can press the electrode composite sheet 14 against the film 24 while peeling the remaining portion 26 of the electrode composite sheet from the film 24. As a result, the remaining portion 26 of the long electrode composite sheet that remains after the cutting step (S14) is recovered. The recovered remaining portion 26 of the long electrode composite sheet can be reused in the manufacturing of other electrode bodies carried out thereafter in a step (S10) to produce a long electrode composite sheet 22. In this case, the recovered remaining portion 26 of the long electrode composite sheet may be crushed by a mixer or the like and then mixed with the mixture 20 used in the step (S10).
[0023] As shown in Figure 2, the manufacturing method of the embodiment further includes a step (S18) of attaching an electrode composite sheet 14 having a predetermined contour shape onto a current collector 12. In this step, as shown in Figure 6, for example, a transfer device 112 is used. The transfer device 112 comprises a first roller 114 and a second roller 116. A film 24 that holds the electrode composite sheet 14 and a sheet-shaped current collector 12 are supplied between the first roller 114 and the second roller 116. As a result, the electrode composite sheet 14 on the film 24 is transferred onto the current collector 12 as it passes between the first roller 114 and the second roller 116. The electrode body 10 is manufactured by cutting the current collector 12, to which the electrode composite sheet 14 has been attached, into a predetermined shape.
[0024] In the manufacturing method described above, first, a long electrode composite sheet 22 is made from the mixture 20. Then, an electrode composite sheet 14 having a predetermined contour shape is cut from the long electrode composite sheet 22. With this configuration, an electrode body 10 of any shape can be manufactured.
[0025] In the above-described embodiment, as shown in Figure 2, the method for manufacturing the electrode body 10 includes a step (S18) of attaching an electrode composite sheet 14 having a predetermined contour shape onto the current collector 12. With this configuration, the electrode body 10 having the electrode composite sheet 14 on the current collector 12 can be manufactured in any shape.
[0026] In the above-described embodiment, as shown in Figure 4, the cutting step (S14) includes irradiating a long electrode composite sheet 22 with a laser along a predetermined contour shape. Since the laser irradiation position can be changed relatively easily, the above configuration makes it possible to manufacture electrode bodies 10 of any shape relatively easily.
[0027] In the above-described embodiment, as shown in Figure 2, the method for manufacturing the electrode body 10 further includes a step (S12) of attaching a long electrode composite sheet 22 onto a transparent film 24. In this case, in the step of irradiating with the laser as described above, the laser is irradiated onto the long electrode composite sheet 22 on the film 24. For example, if the laser is irradiated onto the long electrode composite sheet 22 on the current collector 12, the long electrode composite sheet 22 will be cut, while the current collector 12 may deteriorate. In this regard, the laser penetrates the film 24. Therefore, when the laser is irradiated onto the long electrode composite sheet 22 on the film 24, only the long electrode composite sheet 22 is cut. Since the film 24 is not burned by the laser, contamination of the electrode composite sheet 14 due to the burning of the film 24 can be avoided. Subsequently, by attaching the electrode composite sheet 14, which has been cut into a predetermined contour shape, onto the current collector 12, a high-quality electrode body 10 can be manufactured.
[0028] In the above-described embodiment, the remaining portion 26 of the long electrode composite sheet after the cutting process (S14) is reused in the subsequent manufacturing of other electrode bodies in the process (S10) of producing a long electrode composite sheet 22. This configuration reduces the amount of waste generated during manufacturing.
[0029] In the above-described embodiment, the method for manufacturing the electrode body 10 includes the step (S12) of attaching a long electrode material sheet 22 onto a transparent film 24. However, in other embodiments, the method for manufacturing the electrode body 10 does not need to include the step (S12) of attaching a long electrode material sheet 22 onto a transparent film 24. In this case, in the step (S14) of cutting out an electrode material sheet 14 having a predetermined contour shape from the long electrode material sheet 22, a laser may be irradiated from a laser device 106 (see Figure 4) onto the long electrode material sheet 22 being transported by a belt conveyor. In the step (S18) of attaching the electrode material sheet 14 having a predetermined contour shape onto the current collector 12, the electrode material sheet 14 may be placed on the current collector 12 using a transport robot, and then the electrode material sheet 14 may be fixed to the current collector 12 using a pair of rollers.
[0030] In some of the embodiments described above, the step (S14) of cutting out an electrode composite sheet 14 having a predetermined contour shape from a long electrode composite sheet 22 includes the step of irradiating the long electrode composite sheet 22 with a laser along the predetermined contour shape. However, in other embodiments, the step (S14) of cutting out an electrode composite sheet 14 having a predetermined contour shape from a long electrode composite sheet 22 does not have to include the step of irradiating the long electrode composite sheet 22 with a laser along the predetermined contour shape. For example, as shown in Figure 7, an electrode composite sheet 14 having a predetermined contour shape may be cut out from a long electrode composite sheet 22 by a rotary die cutter 118. The rotary die cutter 118 includes a pair of rollers 120. A projection 121 having a contour substantially the same as the predetermined contour shape is formed on the outer circumferential surface of one of the pair of rollers 120. The protruding portion 121 allows for the cutting of an electrode material sheet 14 having a predetermined contour shape from the long electrode material sheet 22 as the long electrode material sheet 22 passes between the pair of rollers 120.
[0031] Although several specific examples have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or in the drawings exhibit technical usefulness individually or in combination. [Explanation of Symbols]
[0032] 10: Electrode body, 12: Current collector, 14: Electrode composite sheet, 16: Active material particles, 18: Binder, 20: Mixture, 22: Long electrode composite sheet, 24: Film, 26: Remainder, 100: Pressing device, 106: Laser device, 108: Peeling device, 112: Transfer device, 118: Rotary die cutter
Claims
1. A method for manufacturing an electrode body, A process for producing a long electrode composite sheet by rolling a mixture in which active material particles are mixed with at least a fibrillable binder, A step of cutting out an electrode composite sheet having a predetermined contour shape from the aforementioned long electrode composite sheet, A manufacturing method that includes the following features.
2. The manufacturing method according to claim 1, further comprising the step of attaching the electrode composite sheet having the predetermined contour shape onto a current collector.
3. The manufacturing method according to claim 1, wherein the cutting step includes irradiating the long electrode composite sheet with a laser along the predetermined contour shape.
4. The process further includes attaching the aforementioned long electrode composite sheet onto a transparent film, The manufacturing method according to claim 3, wherein in the step of irradiating with the laser, the laser is irradiated onto the long electrode composite sheet on the film.
5. The manufacturing method according to claim 1, wherein the remaining portion of the long electrode composite sheet after the cutting step is reused in the process of producing the long electrode composite sheet in the subsequent manufacture of other electrode bodies.