Method for manufacturing electrode, device for manufacturing electrode, and method for manufacturing electrode film

Abstract

The present invention provides: a method for manufacturing an electrode, the method comprising a step for forming an electrode film by leveling an electrode material supplied onto a current collector foil and a step for separating an excess portion by applying vibrations to a portion of the electrode film; a device for manufacturing an electrode, the device comprising a transport stage that transports a current collector foil, a blade that forms an electrode film by leveling an electrode material supplied onto the current collector foil, and a shaping tool that separates an excess portion by applying vibrations to a portion of the electrode film; a device for manufacturing an electrode; and a method for manufacturing an electrode film.

Description

Electrode manufacturing method, electrode manufacturing apparatus, and electrode film manufacturing method

[0001] The present disclosure relates to a method for manufacturing an electrode, an apparatus for manufacturing an electrode, and a method for manufacturing an electrode film.

[0002] The electrode layer of a quasi-solid-state battery can be formed without a drying process by premixing the active material, conductive additive, and electrolyte. Furthermore, because the electrode layer of a quasi-solid-state battery can be formed without a binder, it is attracting attention as a battery with excellent recyclability. Furthermore, the electrode layer of a quasi-solid-state battery may not require a liquid leveling agent.

[0003] For this reason, in a quasi-solid-state battery, the electrode material for forming the electrode layer may be in a slurry or clay state with low fluidity. In order to form an electrode layer using an electrode material with low fluidity, it has been disclosed that the electrode slurry is applied using a frame and a blade (Patent Document 1 or Patent Document 2).

[0004] Patent Document 1: JP 2017-533548 A Patent Document 2: JP 2021-530829 A

[0005] When forming the electrode layer, the electrode slurry is applied using a frame and a blade, and when the frame is removed, the edge of the electrode film may rise and become thick in some places. Also, when the width is restricted by using a frame or the like to apply a load to form the electrode layer, the peripheral part may rise up compared to the center part, resulting in an electrode film with a thicker peripheral part.

[0006] When the shape of the electrode film is non-uniform in terms of thickness, etc., as described above, problems such as chipping of the electrode film in subsequent processes and limitations on improvement of energy density may occur.

[0007] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a method for manufacturing an electrode having an electrode film that is precisely shaped, an electrode manufacturing apparatus, and a method for manufacturing an electrode film that is precisely shaped.

[0008] Specific means for solving the problems include the following aspects. <1> A method for manufacturing an electrode, comprising: forming an electrode film by leveling an electrode material supplied onto a current collector foil; and separating an excess portion by applying vibration to a portion of the electrode film. <2> A method for manufacturing an electrode according to <1>, comprising recovering the separated excess portion. <3> A method for manufacturing an electrode according to <1> or <2>, comprising recognizing the shape of the electrode film from an image of the electrode film acquired using an imaging device, and determining a position to apply vibration based on the shape. <4> A method for manufacturing an electrode according to any one of <1> to <3>, wherein the vibration has an amplitude of 0.1 μm to 50 μm and a frequency of 100 Hz to 30 kHz. <5> A method for manufacturing an electrode according to any one of <1> to <4>, wherein the step of forming the electrode film comprises continuously supplying electrode material onto a conveyed current collector foil, and the excess portion is a portion of an end portion of the electrode film in the width direction. <6> The method for manufacturing an electrode according to any one of <1> to <5>, wherein the step of separating the excess portion includes forming a recess in the excess portion prior to applying vibration to the portion of the electrode film. <7> The method for manufacturing an electrode according to any one of <1> to <6>, wherein the excess portion is a portion of the outer surface of the electrode film. <8> The method for manufacturing an electrode according to any one of <1> to <7>, wherein the electrode material includes an electrolyte. <9> An electrode manufacturing apparatus comprising: a conveying stage for conveying a current collecting foil; a blade for forming an electrode film by leveling the electrode material supplied on the current collecting foil; and a shaping tool for separating the excess portion by applying vibration to the portion of the electrode film. <10> The electrode manufacturing apparatus according to <9>, comprising: a recovery machine for recovering the separated excess portion. <11> The electrode manufacturing apparatus according to <9> or <10>, comprising: an imaging device for acquiring an image of the electrode film, wherein the shaping tool applies vibration to a portion determined based on the shape of the electrode film recognized from the image. <12> The electrode manufacturing apparatus according to <11>, wherein the photographing device has an illumination device that illuminates the surface of the electrode film with diffused illumination. <13> The electrode manufacturing apparatus according to any one of <9> to <12>, wherein the forming tool has a piezoelectric vibration element that vibrates with an amplitude of 0.1 μm to 50 μm and a frequency of 100 Hz to 30 kHz.<14> The electrode manufacturing apparatus according to any one of <9> to <13>, further comprising a guide roller that forms a recessed shape in a part of an end portion of the electrode film in the width direction prior to application of vibration. <15> A method for manufacturing an electrode film, comprising a step of applying vibration to a part of an electrode film formed by leveling an electrode material supplied on a substrate, thereby separating an excess part.

[0009] According to the embodiments of the present disclosure, there are provided a method for manufacturing an electrode having a precisely formed electrode film, an electrode manufacturing apparatus, and a method for manufacturing a precisely formed electrode film.

[0010] FIG. 1 is a schematic plan view showing the configuration of an electrode manufacturing apparatus when viewed from above, illustrating the process of manufacturing an electrode film. FIG. 2 is an explanatory diagram illustrating the configuration of the electrode manufacturing apparatus when viewed from the width direction. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 4 is a schematic side view showing an example of a molding tool when viewed from the side. FIG. 5 is an explanatory diagram illustrating how the tip of the molding tool is applied to an excess portion of the electrode film. FIG. 6 is a schematic side view showing an example of a molding tool having a recovery device when viewed from the side. FIG. 7 is an explanatory diagram illustrating the arrangement of guide rollers when an example of an electrode manufacturing apparatus is viewed from diagonally above the electrode layer. FIG. 8 is an explanatory diagram illustrating how the tip of the molding tool is applied to an electrode film with grooves formed therein. FIG. 9 is an explanatory diagram illustrating the arrangement of a photographing device and a lighting device when an example of an electrode manufacturing apparatus is viewed from the width direction. FIG. 10 is a plan view showing an example of an image of the electrode film acquired by the photographing device. FIG. 11 is a cross-sectional view taken along line B-B in FIG. 10. FIG. 12 is an explanatory diagram illustrating how the excess portion in the thickness direction is separated by a forming tool when the electrode film is viewed from the width direction.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the object of the present disclosure. Components indicated by the same reference numerals in each drawing are the same components. Explanations of duplicated components and reference numerals in each drawing may be omitted. Reference numerals may be assigned to some of the components in each drawing. The sizes of the components in each drawing are conceptual, and the relative size relationships between the components are not limited thereto.

[0012] In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the upper and lower limits. In the numerical ranges described in stages in the present disclosure, the upper or lower limit described in a certain numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described in the present disclosure, the upper or lower limit described in a certain numerical range may be replaced with a value shown in the examples.

[0013] In this specification, "orthogonal" does not mean strictly 90°, but means 90°±10°, preferably 90°±5°.

[0014] In the present disclosure, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. In the present disclosure, the amount of each component in a composition means the total amount of the multiple substances present in the composition when multiple substances corresponding to each component are present in the composition, unless otherwise specified. In the present disclosure, a combination of two or more preferred aspects or forms is a more preferred aspect or form.

[0015] In the present disclosure, the term "transport direction" refers to the direction in which the electrode film or the like is transported, and the term "width direction" refers to the direction perpendicular to the transport direction (the width direction of the electrode film or the like).

[0016] The background to the embodiment of the present disclosure will be explained. The electrode material for the electrode layer in a quasi-solid-state battery has the characteristics that, by mixing an electrolyte solution with an electrode active material and a conductive additive in advance, the electrode layer can be formed without a drying process and does not contain a large amount of binder. Furthermore, the electrolyte solution that is pre-mixed is prone to volatilization, unlike process solvents such as NMP (N-methyl-2-pyrrolidone) used in general lithium-ion batteries. As a result, the fluidity of the electrode material is low, and the electrode film formed from the electrode material dries from the surface and is prone to crumbling at the edges. A quasi-solid-state battery refers to a secondary battery having an electrode layer in which an electrolyte solution is mixed with an electrode active material and a conductive additive.

[0017] Furthermore, when electrode materials for quasi-solid-state batteries are not used for leveling with a liquid, the edges of the electrode film tend to become thick. The reasons for this are as follows: When forming an electrode film using a stencil-shaped frame, after the stencil is removed, the edges of the electrode film may lift due to the upward pulling force of the stencil, resulting in the formation of horns or other irregularities, resulting in a thick film (see Patent Document 1). Furthermore, when forming an electrode film by restricting the width using a frame or other device and applying a load, the pressure at both ends is lower than that at the center, often resulting in the film rising up and becoming thick (see Patent Document 2). These thickened edges can cause the electrolyte membrane to chip during subsequent transportation, stacking with a separator, and sealing in a case. Even when the electrolyte membrane does not chip, the weight of the electrolyte membrane increases, resulting in a decrease in energy density.

[0018] However, when using such electrode materials, while there is an advantage in not using a dispersion solvent, it is difficult to control the edge shape during film formation, and furthermore, it can be difficult to maintain the edge shape from the viewpoint of reducing the use of binders.

[0019] The inventors of the present invention have noticed that even if the electrode material forming the electrode film has a very high viscosity in the kneaded state, drying to some extent can reduce the binding strength of the active material with the electrolyte and increase fluidity. Furthermore, they have noticed that if the electrode film is formed into a film and does not completely dry, the apparent color changes depending on the thickness. They have found that processing the electrode film after forming the electrode material is effective for shaping the edges, etc., and after extensive research, they have found that applying vibrations makes it possible to precisely separate excess portions of the electrode film, leading to the completion of an embodiment of the present disclosure.

[0020] According to the electrode manufacturing method, electrode manufacturing apparatus, and electrode film manufacturing method disclosed herein, even when an electrode material that does not contain a binder or the like and has low fluidity is used, the edges, thickness, etc. can be suitably processed after film formation, and a precisely shaped electrode film can be manufactured. This allows the edge shape, thickness shape, etc. to be suitably formed, and in subsequent processes, problems such as chipping of the electrode film due to thick film portions at the edges can be suppressed. Furthermore, because the shape of the entire electrode film can be precisely adjusted, when the electrode film is formed into a battery, the energy density of the battery can be improved.

[0021] <Electrode Manufacturing Apparatus> The electrode manufacturing apparatus of the present disclosure includes a conveying stage, a blade, and a forming tool. The conveying stage conveys a current collecting foil. The blade forms an electrode film by leveling the electrode material supplied onto the current collecting foil. The forming tool applies vibration to the excess portion of the electrode film to separate the excess portion.

[0022] An example of an electrode manufacturing apparatus according to the present disclosure will be described with reference to the drawings. As shown in Figures 1 and 2, an electrode manufacturing apparatus 10 according to the present disclosure includes a conveying stage 11 having a conveying direction DL indicated by an arrow, and a blade 12 and a forming tool 13 arranged on the conveying stage 11 in this order from the upstream side of the conveying direction DL.

[0023] The conveying stage 11 carries the current collecting foil 14 on which it is placed. The blade 12 uses a regulating plate 16 to smooth the string-like electrode material 15 supplied onto the placed current collecting foil 14 from above, thereby forming a film-like electrode film 17.

[0024] Various types of blades can be used as the blade 12, and known blades such as ultrasonic blades that apply ultrasonic waves to the electrode material 15 and piezo blades that apply vibrations can be used. A plurality of blades 12 can be used, and a plurality of blades of different types may be used. When a plurality of blades 12 are used, the blades 12 can be lined up in the conveyance direction DL.

[0025] The forming tool 13 is configured to apply vibration to at least a portion of the electrode film 17. The forming tool 13 can be, for example, a forming tool 13 having a vibrating tip. Vibration can be applied to a desired position on the electrode film 17 by bringing the vibrating tip of the forming tool 13 into contact with a portion (such as an excess portion) of the electrode film 17 or by embedding the vibrating tip into a portion (such as an excess portion) of the electrode film 17. The portion to which vibration is applied easily peels off from the electrode film 17, so that, for example, the excess portion can be easily separated from the electrode film 17.

[0026] The excess portion of the electrode film 17 is a portion that differs from the intended shape of the electrode film 17. The intended shape of the end portion of the electrode film 17 in the width direction DW is preferably a sharp rectangle without protruding corners, thick film portions, or chips. It is also preferable that the electrode film 17 is formed over the entire current collector foil 14, so that the current collector foil 14 is not exposed. However, particularly when the fluidity of the electrode material 15 is low, the electrode film 17 formed into a film by smoothing the electrode material 15 using the blade 12 may have excess portions that differ from the intended shape of the electrode film due to thick film portions at the end portion in the width direction DW perpendicular to the conveyance direction DL of the electrode film 17, differences in thickness due to surface irregularities, and the like.

[0027] As shown in Figure 3, referring to the cross-sectional view of line A-A in Figure 1, in the electrode film 17 formed by leveling the electrode material 15 with the blade 12, excess portions 22 that are larger than the intended shape of the electrode film 17 may be generated at both ends 21 in the width direction DW. The forming tool 13 applies vibration to these excess portions 22. The vibration-applied excess portions 22 are easily peeled off and separated from the electrode film 17.

[0028] 4, the forming tool 13 includes, for example, an actuator 31, a vibration element 32, and a vibrating tip 33. The actuator 31 may include a width direction actuator 31a and a height direction actuator 31b. The actuator 31 adjusts the position of the vibration element 32, etc.

[0029] The vibration element 32 generates vibrations, vibrating the tip 33. A piezoelectric vibration element is preferably used as the vibration element 32 due to the type of vibrations generated. The tip 33 is preferably knife-shaped with a sharp tip so that it can contact the excess portion 22 of the electrode film 17 and pierce the excess portion 22 to more reliably apply vibrations. The material of the tip 33 is preferably one that prevents the electrode material from adhering to the tip 33 when it comes into contact with it. For example, a metal such as aluminum, or a plastic such as PEEK (Poly Ether Ether Ktone), can be used.

[0030] 5, vibration is applied to the excess portion 22 of the electrode film 17 by acting on the tip portion 33 on the excess portion 22 of the end portion 21 of the electrode film 17. Specifically, for example, the tip portion 33 is brought into contact with the excess portion 22, or the knife-shaped tip portion 33 is fixed in the width direction DW and partially buried in the excess portion 22.

[0031] The forming tool 13 may be configured to be movable in the width direction DW of the electrode film 17, the thickness direction of the electrode film 17, the angle of the tip portion 33, etc., or may be configured to be fixed in at least one of these directions. As shown in Fig. 6, the forming tool 13 may be attached to a support member 34. The support member 34 is configured to be fixable or movable. By moving the support member 34, the position of the forming tool 13 can be moved and adjusted, and the forming tool 13 can be fixed at a desired position.

[0032] When the electrode material 15 is a clay-like electrode material with high viscosity, i.e., low fluidity, the excess portion 22 is easily peeled off by applying vibration to the shaping tool 13 after it has been formed into the electrode film 17 by the blade 12. Therefore, the excess portion 22 can be separated from the electrode film 17 without adverse effects such as chipping of the portion that is to be left as the electrode film 17. After the shaping tool 13 has separated the excess portion 22, the end of the electrode film 17 can be formed into a substantially rectangular shape without protrusions such as corners.

[0033] In the electrode manufacturing apparatus 10, the forming tool 13 preferably includes a piezoelectric vibrating element as the vibrating element 32, and vibrates with an amplitude of 0.1 μm to 50 μm and a frequency of 100 Hz to 30 kHz. The amplitude is more preferably 1.0 μm to 10 μm. The frequency is more preferably 400 Hz to 30 kHz. By vibrating the forming tool 13 within the above range, the excess portion 22 of the electrode film 17 can be more preferably separated from the electrode film 17 without adversely affecting the portion that is desired to remain as the electrode film 17. Note that multiple piezoelectric vibrating elements of the same type or different types may be used. Vibrations within the above ranges can be achieved by using multiple piezoelectric vibrating elements of the same type or different types.

[0034] Furthermore, the electrode manufacturing apparatus 10 preferably includes a recovery machine that recovers a separated material, which is the separated excess portion 22. If the excess portion 22 can be reused, the separated material can be recovered and reused as the electrode material 15. For example, if the electrode material 15 is an electrode material 15 for a quasi-solid battery that does not contain a binder, the recovered separated material can be reused again as the electrode material 15.

[0035] The recovery device may be configured to recover the separated material, for example, with a suction function. Preferably, the recovery device recovers the separated material by suction. Preferably, the recovery device is configured to recover the separated material near the tip 33 of the molding tool 13.

[0036] 6, the recovery machine preferably includes a suction unit (not shown) that provides a suction function, and a suction tube 41 that recovers the separated portion by the suction function. The suction tube 41 is preferably disposed near the tip 33, for example, by being attached to a support member 34 that supports the forming tool 13.

[0037] The electrode manufacturing apparatus 10 preferably includes a guide roller (see reference numeral 51 in FIG. 7 ) that forms a concave shape in the excess portion 22 at the end of the electrode film 17 prior to the application of vibration. The guide roller is a device for forming a concave shape at the end of the electrode film 17 at a position that separates the electrode film 17 from the excess portion 22. The concave shape on the electrode film 17 formed by the guide roller allows the excess portion 22 to be more effectively separated when the molding tool 13 applies vibration to the excess portion 22 located outside the concave shape in the width direction DW.

[0038] The guide roller preferably forms a recessed shape in the electrode film 17 without separating the excess portion 22 from the electrode film 17. Specifically, the guide roller is preferably configured to press the electrode film 17 from the top surface at a position 30% to 70% of the thickness of the electrode film 17. More preferably, the position is 40% to 60% of the thickness of the electrode film 17. The position at which the guide roller presses the electrode film 17 is preferably adjusted depending on conditions such as the type of electrode material 15 and the conveying speed. By imparting a recessed shape defining the excess portion 22 of the electrode film 17 with the guide roller and applying vibration to the recessed excess portion 22 of the electrode film 17 with the forming tool 13, the formed electrode film 17 is prevented from remaining the excess portion 22, the formation of corners, or chipping of the electrode film 17, and can be formed into a desirable substantially rectangular shape. The guide roller may vibrate. Vibration may be applied to the electrode film 17 by vibrating the guide roller.

[0039] The guide roller may be, for example, a member capable of forming a recessed shape on the upper surface of the electrode film 17 being transported, and may be, for example, disk-shaped. The tip of the guide roller is preferably blunt so as not to damage the current collecting foil 14. Therefore, the guide roller is preferably a wheel-shaped disk. The guide roller is preferably made of a material to which the electrode material 15 does not adhere when forming a recessed shape on the electrode film 17, and examples of the material that can be used include metals such as aluminum and plastics such as PEEK (Poly Ether Ether Ketone).

[0040] 7 , for example, the guide rollers 51 are disposed on top of both ends of the electrode film 17 in the width direction DW, and have a concave shape at the position that separates the electrode film 17 from the excess portion 22. The guide rollers 51 rotate around a shaft 52 in accordance with the transport of the electrode film 17. The guide rollers 51 and the shaft 52 are supported by a guide roller support member 53.

[0041] The forming tool 13 is disposed downstream of the guide rollers 51 in the conveying direction, but because the electrode film dries from the recessed portions formed by the guide rollers 51, it is preferable that the forming tool 13 be disposed at a position where it can more appropriately separate the excess portion 22 when applying vibration to the excess portion 22. For example, depending on the type of electrode material 15, the conveying speed, etc., the forming tool 13 may be disposed downstream of the guide rollers 51 in the conveying direction DL and as close as possible.

[0042] 8, the guide roller 51 forms a groove 71 at the end of the electrode film 17. The tip 33 of the forming tool 13 preferably applies vibration to the excess portion 22 in the width direction DW, outside the groove 71. This makes it possible to separate the excess portion 22 more efficiently.

[0043] The electrode manufacturing apparatus 10 preferably includes a photographing device that captures an image of the electrode film 17. The process preferably includes a step of recognizing the shape of the electrode film from the image of the electrode film captured using the photographing device and determining a position to apply vibration based on the shape. When the photographing device is included, the forming tool 13 preferably applies vibration to the excess portion 22 determined based on the shape of the electrode film recognized from the captured image.

[0044] The electrode film 17, which has been formed into a film by leveling the electrode material 15 with the blade 12, can be photographed with an imaging device in a direction perpendicular to the electrode film 17, for example, from vertically above. The photographed image can provide an image of the entire electrode film 17 in the width direction DW, and by processing the photographed image showing the electrode film 17, it can be determined, for example, what kind of excess portion 22 exists at what position on the end of the electrode film 17 in the width direction DW.

[0045] Any type of imaging device may be used as long as it can grasp the shape of the electrode film 17. For example, an optical camera having an imaging sensor such as a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) may be used. Note that the shape of the electrode film 17 may also be grasped using a laser scanner or the like. When using an optical camera as the imaging device, one camera may be used, or two or more cameras may be used in a stereo camera system. From the viewpoint of cost-effectiveness, it is preferable to use one optical camera.

[0046] When an optical camera is used as the imaging device, an illumination device may be used to better grasp the shape of the electrode film 17. Examples of illumination devices include diffuse illumination and illumination that emits specific patterned light, with diffuse illumination being preferred. The captured image of the electrode film 17 not only allows for the shape of the electrode film 17, including the excess portion 22 at the widthwise end portion (DW), to be grasped, but also displays different colors on the surface of the electrode film 17 corresponding to the degree of dryness, shadows, etc. of the electrode film 17. The inventors have found that these different colors roughly correspond to the thickness of the electrode film 17. Therefore, by using diffuse illumination, even if the acquired image is monochrome, for example, image analysis of the acquired image allows for the understanding of differences in the shape of the electrode film 17 in thickness based on pixel values ​​corresponding to color intensity. Therefore, the thickness of each position on the surface of the electrode film 17 can be grasped.

[0047] The captured image may be subjected to various types of image processing so that differences in thickness of the electrode film 17 can be grasped in more detail. The imaging device may also be an imaging device that captures video. The image processing may use a model that learns the image data and the actual thickness of the electrode film 17 as learning data, or a machine learning model that is an unsupervised model that inputs the captured image and outputs the thickness of the electrode film 17.

[0048] The photographing device, lighting device, etc. are preferably arranged in a direction perpendicular to the transported long electrode film 17, for example, at a position where they can photograph the electrode film 17 from vertically above. The photographed image of the electrode film 17 obtained by the photographing device may be processed, and the position of the forming tool 13 or the tip 33 may be automatically moved based on the image processing results.

[0049] 9 , the photographing device 61 is preferably disposed between the blade 12 and the forming tool 13 in the conveying direction DL. In addition, the lighting device 62 is preferably disposed in accordance with the position of the photographing device 61 so as to correspond to the photographing range of the photographing device 61. With regard to the positions in the conveying direction DL, the photographing device 61 and the lighting device 62 are disposed as close as possible to the position where the forming tool 13 forms the electrode film 17, so that the shape data of the electrode film 17 obtained by image processing and the actual shape of the electrode film 17 formed by the forming tool 13 more closely match.

[0050] The electrode manufacturing apparatus of the present disclosure may separate not only the excess portion 22 present at the end of the electrode film 17 in the width direction DW, but also the excess portion 22 that is part of the outer surface of the electrode film 17 .

[0051] 10, in an image 80 of the electrode film 17 included in the captured image obtained by the imaging device 61, for example, width portions W1, W2, and W3 are darker in color than the surrounding areas. As shown in Fig. 11, in a cross section of the electrode film 17 taken along line B-B in the image 80 shown in Fig. 10, width portions W1, W2, and W3 are thick film portions, corresponding to the color darkness of the image 80. As described above, the thickness of the electrode film 17 can be determined from the captured image of the electrode film 17 obtained by the imaging device 61.

[0052] The thickness of the electrode film 17 is preferably constant because it is subsequently laminated. Therefore, it is preferable to designate the portion of the electrode film 17 that is thicker than a predetermined thickness as the excess portion 22. As shown in FIG. 12 , the excess portion 22 in the thickness direction is preferably separated by the tip portion 33. In this case, it is preferable to separate the excess portion 22 by moving the tip portion 33 toward the excess portion 22 on the upper surface of the electrode film 17 and applying vibration to the excess portion 22 of the electrode film 17 so as to scrape the excess portion 22 from downstream in the conveyance direction. Separation of the excess portion 22 in the thickness direction is preferably performed during conveyance. Note that separation of the excess portion 22 at the end of the electrode film 17 in the width direction DW is also preferably performed during conveyance.

[0053] <Electrode Manufacturing Method> The electrode manufacturing method of the present disclosure includes a step of forming an electrode film by leveling an electrode material supplied onto a current collector foil (hereinafter referred to as the "electrode film forming step"), and a step of separating an excess portion by applying vibration to a portion of the electrode film (hereinafter referred to as the "excess portion separating step"). The electrode manufacturing method of the present disclosure can be suitably realized using an electrode manufacturing apparatus 10 (see FIGS. 1 and 2) that includes a conveying stage 11 that conveys a current collector foil 14, a blade 12 that forms an electrode film 17 by leveling an electrode material 15 supplied onto the current collector foil 14, and a forming tool 13 that applies vibration to a portion of the electrode film 17 to separate the excess portion. Note that description of content that overlaps with the content described above will be omitted here.

[0054] The electrode film forming process is a process in which an electrode material 15 is supplied onto a current collecting foil 14 placed on a conveying stage 11, and the electrode material 15 is leveled by a blade 12. After the electrode film forming process, the excess portion 22 of the electrode film 17 is separated by applying vibration to the excess portion 22 by, for example, a forming tool 13.

[0055] By including the above steps, according to the electrode manufacturing method of the present disclosure, even when an electrode material that does not contain a binder or the like and has low fluidity is used, the edges, thickness, etc. can be suitably processed after film formation, and a precisely formed electrode film can be manufactured.

[0056] In the excess portion separating step, the vibration applied to the portion of the electrode film 17 preferably has an amplitude of 0.1 μm to 50 μm and a frequency of 100 Hz to 30 kHz. Such vibration can be achieved, for example, by a forming tool 13 equipped with a piezoelectric vibrating element (see FIG. 4).

[0057] The electrode film forming process includes continuously supplying the electrode material 15 onto the conveyed current collector foil 14, and the excess portion 22 is preferably a portion of the edge of the electrode film 17 in the width direction DW. By continuously supplying the electrode material 15 onto the conveyed current collector foil 14, for example, it is possible to manufacture an electrode while fixing the blade 12, the forming tool 13, etc. in predetermined positions. Furthermore, by making the excess portion 22 a portion of the edge of the electrode film 17 in the width direction DW, it is possible to separate the excess portion 22 at the edge of the electrode film 17, which may cause problems in subsequent processes (see FIG. 3 ).

[0058] The electrode manufacturing method of the present disclosure may further include a step of recovering the separated excess portion (hereinafter referred to as the "recovery step"). The recovery step is a step of recovering the excess portion 22 separated in the excess portion separation step. Therefore, the recovery step is performed after the excess portion separation step. The recovery step can be preferably performed by using, for example, a recovery machine having a suction tube 41 (see FIG. 6).

[0059] The recovery step can recover the surplus portion 22. The recovered surplus portion 22 can be reused as the electrode material 15 depending on the type of the electrode material 15, so it is preferable to have the recovery step.

[0060] The excess portion separating step preferably includes forming a recess in the excess portion 22 at the end of the electrode film 17 in the width direction DW, prior to applying vibration to the excess portion 22. The recess can be preferably formed by using a guide roller 51 or the like (FIG. 7).

[0061] Preferably, the method further includes a step of recognizing the shape of the electrode film from an image of the electrode film acquired using a photographing device and determining the surplus portion based on the shape (hereinafter also referred to as an "surplus portion determining step"). The surplus portion determining step is performed after the electrode film forming step and before the surplus portion separating step. The surplus portion determining step can be realized by an electrode manufacturing apparatus 10 including a photographing device 61 that acquires an image of the electrode film 17 (see FIG. 9).

[0062] The excess portions 22 are preferably part of the outer surface of the electrode film 17 (see FIG. 11 ). Therefore, the electrode manufacturing method of the present disclosure preferably performs at least one of separating the excess portions 22 that are part of both ends of the electrode film 17 in the width direction DW and separating the excess portions 22 that are part of the outer surface of the electrode film 17, and more preferably performs both.

[0063] The electrode material 15 preferably contains an electrolyte solution. The electrode manufacturing method of the present disclosure can be preferably used when the electrode material 15 contains an electrolyte solution, for example, when the electrode is an electrode for a quasi-solid-state battery. Electrode materials 15 containing an electrolyte solution, particularly those with compositions intended to improve battery performance, have high viscosity and low fluidity. Even with such electrode materials 15, a precisely shaped electrode film can be formed by the above steps according to the manufacturing method of the present disclosure.

[0064] <Method for manufacturing electrode film> The method for manufacturing an electrode film according to the present disclosure includes a step of applying vibration to a portion of an electrode film formed by leveling an electrode material supplied onto a substrate, thereby separating an excess portion. The method for manufacturing an electrode film according to the present disclosure is the same as the method for manufacturing an electrode described above, except that the current collector foil 14 is used as the substrate. For example, a precisely shaped electrode film can be formed by performing the above-described electrode film formation step and excess portion separation step using a substrate other than the current collector foil 14.

[0065] The present disclosure will be described in more detail below based on examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present disclosure. Therefore, the scope of the present disclosure should not be interpreted as being limited by the examples shown below.

[0066] Example An electrode film 17 was produced using an electrode manufacturing apparatus 10 shown in Fig. 1. An electrode material 15 was produced by the following procedure.

[0067] =Positive Electrode Composition= (1) 45 g of ethylene carbonate, 10 g of propylene carbonate, and 45 g of diethyl carbonate were mixed with 13.4 g of a 0.9 mol / L LiPF6 solution (electrolyte), and then 2.3 g of vinylene carbonate (VC) was further mixed to prepare electrolyte solution X1. (2) 2 g of a conductive additive (Ketjen black: "Carbon ECP600JD" manufactured by Lion Specialty Chemicals) and 174 g of a positive electrode active material (iron phosphate: "LFP NCO M121" manufactured by Aleees) were stirred for 30 seconds at 1500 rpm (revolutions per minute) in a mixer (Awatori Rentaro ARE-310, manufactured by Thinky Corporation) to prepare a kneaded mixture Y1 (176 g). (3) Electrolyte solution X1 (64 g) was added to kneaded mixture Y1 (176 g), and the mixture was stirred at 1500 rpm for 120 seconds using a mixer (Thinky Corporation) to obtain a positive electrode composition.

[0068] The positive electrode composition was supplied onto a conveying stage 11 conveyed at a conveying speed of 100 mm / s, and formed into a film using two ultrasonic blades 12. Then, the tip 33 of the forming tool 13 was pressed into the portion of the electrode film 17 protruding beyond the end of the electrode film 17 in the width direction DW. The forming tool 13 had a piezoelectric vibrating element, and the tip 33 vibrated at a frequency of 600 Hz and an amplitude of 6 μm. Observation of the end after application of the tip 33 revealed that the excess portion 22 had separated, and no chipping or cornering of the electrode film 17 was observed.

[0069] Comparative Example: Except for not vibrating the molding tool 13, the excess portion 22 was separated using the molding tool 13 in the same manner as in the Example. When the end portion after the tip portion 33 was applied was observed, the excess portion 22 remained on the electrode film 17, separation was not performed well, and ruptures were observed in the electrode film 17.

[0070] It has been demonstrated that the electrode manufacturing apparatus and the like disclosed herein can manufacture an electrode film that is precisely formed even when an electrode material has low fluidity.

[0071] The disclosure of Japanese Patent Application No. 2024-058211, filed on March 29, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A method for manufacturing an electrode, comprising: a step of forming an electrode film by leveling an electrode material supplied onto a current collecting foil; and a step of applying vibration to a part of the electrode film to separate an excess portion.

2. The method for producing an electrode according to claim 1, further comprising a step of recovering the separated excess portion.

3. A method for manufacturing an electrode according to claim 1, further comprising a step of recognizing the shape of the electrode film from an image of the electrode film acquired using an imaging device, and determining the position to apply the vibration based on the shape.

4. The method for manufacturing an electrode according to claim 1, wherein the vibration has an amplitude of 0.1 μm to 50 μm and a frequency of 100 Hz to 30 kHz.

5. The method for manufacturing an electrode according to claim 1, wherein the step of forming the electrode film includes continuously supplying the electrode material onto the conveyed current collector foil, and the excess portion is a part of the width direction end portion of the electrode film.

6. The method for manufacturing an electrode according to claim 1, wherein the step of separating the excess portion includes forming a recess in the excess portion prior to applying vibration to a portion of the electrode film.

7. The method for manufacturing an electrode according to claim 1, wherein the excess portion is a part of the outer surface of the electrode film.

8. The method for manufacturing an electrode according to claim 1, wherein the electrode material includes an electrolyte.

9. An electrode manufacturing device comprising: a conveying stage for conveying a current collecting foil; a blade for forming an electrode film by leveling the electrode material supplied onto the current collecting foil; and a forming tool for separating an excess portion of the electrode film by applying vibration to a portion of the electrode film.

10. The electrode manufacturing apparatus according to claim 9, further comprising a recovery machine for recovering the separated excess portion.

11. An electrode manufacturing apparatus as described in claim 9, further comprising a photographing device for acquiring an image of the electrode film, wherein the forming tool applies vibration to the part determined based on the shape of the electrode film recognized from the image.

12. The electrode manufacturing apparatus according to claim 11, wherein the photographing device has an illumination device that illuminates the surface of the electrode film with diffused illumination.

13. The electrode manufacturing apparatus according to claim 9, wherein the forming tool has a piezoelectric vibrating element that vibrates with an amplitude of 0.1 μm to 50 μm and a frequency of 100 Hz to 30 kHz.

14. The electrode manufacturing apparatus according to claim 9, further comprising a guide roller for forming a recess in a part of the widthwise end of the electrode film prior to application of the vibration.

15. A method for manufacturing an electrode film, comprising a step of applying vibration to a part of an electrode film formed by leveling an electrode material supplied on a substrate, thereby separating an excess portion.

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