Method for manufacturing end-insulated electrode assembly

Abstract

To provide a method for manufacturing an electrode assembly with improved volumetric efficiency.SOLUTION: A method for manufacturing end-insulated electrode assemblies includes (a) providing an electrode body, (b) cutting an end of the electrode body to form an end surface, and (c) forming an insulating portion on the end surface, and in the step (c), a coating tool having an insulator coating liquid held in a plurality of protrusions and recesses between the plurality of protrusions is brought into contact with the end surface to form the insulating portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an electrode assembly with improved volumetric efficiency. [Background technology]

[0002] In the automotive industry, growing environmental awareness has led to the development of electric vehicles, hybrid vehicles, etc., and this has led to a growing demand for high-voltage secondary batteries. Meanwhile, in the field of portable electronic devices, the widespread adoption and development of these devices has led to a demand for small, lightweight, high-capacity secondary batteries capable of long periods of continuous operation.

[0003] Known high-voltage, high-capacity batteries include, for example, batteries that include an electrode assembly having, in this order, a negative electrode current collector layer, a negative electrode active material layer, a solid electrolyte layer, a positive electrode active material layer, and a positive electrode current collector layer.

[0004] In such batteries, the current collector layer of one electrode may come into contact with the current collector layer and / or active material layer of the other electrode, causing a short circuit. This short circuit is particularly likely to occur when the area of ​​the current collector layer of one electrode is larger than the area of ​​the current collector layer of the other electrode. Therefore, technologies to prevent such short circuits have been developed.

[0005] Conventionally, a method is known in which an insulating coating liquid is applied to the end of an electrode body to form an insulating portion, thereby preventing short circuits.

[0006] For example, Patent Document 1 describes a method for producing a stacked all-solid-state battery, which includes applying an insulator coating liquid to the end of an electrode assembly by immersing the end in the insulator coating liquid. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2018-049696 Summary of the Invention [Problem to be solved by the invention]

[0008] When the end surfaces of the electrode body are immersed in an insulator coating liquid, the total thickness of the electrode body in the areas where the insulating portion is formed becomes thicker than the thickness of the electrode body in the areas where the insulating portion is not formed, which may result in a decrease in volumetric efficiency. That is, in conventional methods, when the end surfaces of the electrode body are immersed in the coating liquid, the coating liquid may run up onto the top and bottom surfaces of the electrode body, increasing the thickness in the stacking direction.

[0009] In this context, the present disclosure seeks to provide a method for manufacturing end insulated electrode bodies with improved volumetric efficiency. [Means for solving the problem]

[0010] The problems of the present disclosure can be solved by the following aspects of the present invention: <Aspect 1> (a) providing an electrode assembly; (b) cutting the end of the electrode body to form an end surface; and (c) forming an insulating portion on the end surface; Including, In the step (c), a coating tool having an insulating coating liquid held in a plurality of convex portions and concave portions between the plurality of convex portions is brought into contact with the end surface to form the insulating portion. Method for manufacturing end-insulated electrode bodies. <Aspect 2> 2. The method for manufacturing an electrode body with insulated ends according to claim 1, wherein the electrode body includes at least a current collector and an active material layer, and in (b), the method includes cutting the ends of the electrode body to form flush end surfaces. <Aspect 3> 3. The method for manufacturing an electrode assembly according to aspect 1 or 2, wherein the width of the convex portion of the coating tool is equal to or less than twice the thickness of the electrode assembly. <Aspect 4> The method for manufacturing an electrode assembly according to any one of aspects 1 to 3, wherein the depth of the recess of the coating tool is equal to or less than one time the thickness of the electrode assembly. <Aspect 5> (a') forming a strip-shaped electrode body; (b') cutting the end of the strip-shaped electrode body to form an end surface; (c') forming an insulating portion on the end surface of the strip-shaped electrode body transported between transport rollers; Including, In the step (c'), a coating roller having an insulating coating liquid on its outer surface, the insulating liquid being held in a plurality of convex portions and in concave portions between the plurality of convex portions, is brought into contact with the end surface to form the insulating portion; and A method for manufacturing an end-insulated electrode body, wherein in (c'), the outer peripheral surface of the coating roller is configured to be inside the reference transport position of the end surface of the electrode body. [Effects of the Invention]

[0011] SUMMARY OF THE INVENTION The present invention provides a method for manufacturing end insulated electrode assemblies with improved volumetric efficiency. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 shows an example of an electrode assembly produced by a conventional manufacturing method. [Figure 2] FIG. 2 shows an example of step (c) in one embodiment of the production method of the present invention. [Figure 3] FIG. 3 shows an example of an electrode assembly produced by the manufacturing method of the present invention. [Figure 4] FIG. 4 shows an example of step (c') in another embodiment of the production method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The method for manufacturing an electrode assembly of the present invention will be described with reference to the drawings. The drawings are illustrative and do not limit the present invention. The drawings are not to scale. In the drawings, H represents the height direction, L represents the length direction, and W represents the width direction.

[0014] <<Electrode assembly manufacturing method>>

[0015] The method for manufacturing an end-insulated electrode assembly according to the present invention includes the steps of: (a) providing an electrode assembly; (b) cutting the end of the electrode body to form an end surface; and (c) forming an insulating portion on the end surface; Including, In (c), a coating tool having an insulating coating liquid held in the plurality of protrusions and the recesses between the plurality of protrusions is brought into contact with the end surface to form an insulating portion.

[0016] Conventionally, a manufacturing method is known in which an insulating portion is formed by applying an insulating coating liquid to the end of an electrode body, and the insulating portion can be formed by immersing the end of the electrode body in the insulating coating liquid.

[0017] In conventional electrode structures, insulation is ensured using insulating tape to prevent short circuits between the positive and negative electrodes. However, when cutting the ends all at once, it is necessary to form an insulating section only on the end faces. However, because there are no steps on the end faces, when applying insulating resin to the end faces, the insulating resin overflows onto the top and bottom surfaces of the electrode body, creating an issue of increased thickness.

[0018] Fig. 1 shows an example of edge insulation in a conventional electrode assembly manufacturing method. The electrode assembly 10 includes a second active material layer 101, a solid electrolyte layer 102, a first active material layer 103, and a first current collector layer 104. As illustrated in Fig. 1, in the conventional method, an insulating portion 105 is formed not only on an end surface 106 but also on top and bottom surfaces 107a and 107b of the electrode assembly 10. The thickness T of the insulating portion 105 in the stacking direction H of the electrode assembly 10 is I is the thickness T of the electrode body 10 in the stacking direction H of the electrode body 10 L It exceeds that.

[0019] In contrast, according to the present disclosure, when applying the insulating coating liquid, a coating tool having multiple convex portions and concave portions that hold the insulating coating liquid between the convex portions is brought into contact with the end surface to form the insulating portion.

[0020] 2 shows an example of step (c) according to one embodiment of the manufacturing method of the present invention. In step (c), an insulating portion is formed on the cut end surface of the electrode body 20. In the embodiment of FIG. 2, the insulating portion is formed by bringing a coating tool 221 into contact with the end surface 206 of the electrode body 20. This coating tool 221 has a plurality of protrusions 222 and recesses 223 between them, and the recesses 223 hold the coating liquid 211.

[0021] According to the present invention, the insulator coating liquid 211 is supplied from the recessed portion 223, so that the insulator coating liquid 211 does not run onto the upper and lower surfaces of the electrode body 20, and an insulating portion is formed only on the end surface 206. Therefore, volumetric efficiency is improved. More specifically, when they come into contact, the protruding portion 222 of the coating tool 221 is pressed against the end surface 206 of the electrode body 20, so that excessive pressure is not applied directly to the insulator coating liquid 211 contained in the recessed portion 223 when forming the insulating portion. As a result, the insulator coating liquid 211 does not run onto the upper and lower surfaces of the electrode body 20, and the coating liquid 211 can be applied only to the end surface 206.

[0022] Note that the insulator coating liquid 211 may not adhere to the end surface 206 that comes into contact with the protrusion 222. However, over time, the coating liquid 211 supplied from the recess 223 becomes familiar on the end surface 206, and as a result, the insulating portion comes to cover the entire end surface 206 of the electrode body 20.

[0023] 3 shows an example of an electrode body 30 with insulated end faces, manufactured by the manufacturing method of the present invention. The electrode body 30 of the present invention in FIG. 3 includes a laminated structure having, in this order, a second active material layer 301, a solid electrolyte layer 302, a first active material layer 303, a first current collector layer 304, the first active material layer 303, the solid electrolyte layer 302, and the second active material layer 301. An insulating portion 305 is formed only on an end face 306 of the electrode body 30. Preferably, the thickness T of the insulating portion 305 in the lamination direction H of the electrode body 30 is 1 / 2 mm. L is the thickness T of the electrode body 30 in the stacking direction H of the electrode body 30 I does not exceed.

[0024] For example, an electrode stack can be formed by disposing a second current collector layer on top of this electrode body 30 (particularly on top of the second active material layer 301) whose end faces are insulated.

[0025] Each step of the present invention will now be described in more detail.

[0026] <Process (a)> (electrode body) The manufacturing method of the present invention includes providing an electrode body (step a). The electrode body may have a laminated structure including at least a current collector and an active material layer laminated thereon. The providing method may be a known method. Other aspects of the electrode body will be described later.

[0027] In one embodiment of the present invention, the electrode body may be in the form of a strip. When the electrode body is in the form of a strip, the electrode body may be transported in the length direction using transport rollers.

[0028] <Process (b)> (Cutting the ends) The manufacturing method of the present invention includes cutting the end of the electrode body to form an end surface (step b). One embodiment of the present invention includes cutting the end of an electrode body having a laminated structure of at least two layers (e.g., a two-layer structure of at least a current collector and an active material layer) to form a flush end surface, and the cutting is performed parallel to the lamination direction. In this case, the area where an insulating portion needs to be formed can be reduced, thereby saving the insulator coating liquid. Cutting methods include known methods, such as general thermal cutting methods, such as laser cutting, gas cutting, and plasma cutting.

[0029] In one embodiment of the present invention, the electrode body may be transported by transport rollers, and the electrode body may be cut while being transported by the transport rollers.

[0030] <Process (c)> The manufacturing method of the present invention includes forming an insulating portion on the cut end surface of the electrode body (step c).

[0031] (insulation part) The shape of the insulating portion is not particularly limited. In the electrode body with insulated edges produced by the manufacturing method of the present invention, the thickness of the electrode body at the insulating portion is relatively reduced, and preferably does not exceed the thickness of the electrode body.

[0032] (coating tools) In this step (c), a coating tool is used that has a plurality of protrusions and recesses that hold the insulating coating liquid between the protrusions.

[0033] (Convex and concave parts) The coating tool has a plurality of protrusions and recesses between the protrusions, which are configured to hold an insulating coating liquid.

[0034] In one embodiment of the present invention, the width of the projections of the coating tool (in the embodiment of FIG. 2, w c The thickness of the coating tool (corresponding to the thickness of the insulator coating liquid) is 2 times or less, 1.5 times or less, or 1 time or less the thickness of the electrode body. In this case, the area of ​​the end face to which the insulator coating liquid is applied becomes relatively large, thereby making it relatively easy to prevent short circuits. The width of the convex portion of the coating tool can be 0.1 times or more the thickness of the electrode body. The width of the convex portion may be 1 to 250 μm, preferably 50 to 200 μm, and more preferably 100 to 175 μm.

[0035] In one embodiment of the present invention, the depth of the recess in the coating tool (h in the embodiment of FIG. 2) c The depth of the recesses in the coating tool may be 0.1 times or more the thickness of the electrode body. The depth of the recesses may be the same as the height of the protrusions. The depth of the recesses may be 1 to 200 μm, preferably 50 to 150 μm, and more preferably 75 to 125 μm.

[0036] The shape of the coating tool and the shapes of the protrusions and recesses are not particularly limited. For example, the shapes of the protrusions and recesses may be determined so that the insulator coating fluid forms a striped pattern that extends linearly perpendicular to the lamination direction.

[0037] In one embodiment of the present invention, the coating tool can be an intaglio plate or a coating roller.

[0038] (Coating roller) When the coating tool is a coating roller, the coating roller has, on its outer circumferential surface, a plurality of protrusions and recesses that hold the insulating coating liquid between them. By bringing the coating roller into contact with the end surface of the electrode assembly, the insulating coating liquid is supplied from the recesses to the end surface, thereby forming the insulating portion.

[0039] The shapes of the convex and concave portions are not particularly limited, but for example, the convex and concave portions may extend at an angle of 0 to 90 degrees, preferably 45 to 90 degrees, and more preferably parallel to the rotation axis of the coating roller.

[0040] The thickness of the coating roller in the direction of its rotation axis is usually greater than the thickness of the electrode assembly in the stacking direction.

[0041] (contact) In step (c), the coating tool is brought into contact with the end face of the electrode body to form an insulating portion. At this time, the insulator coating liquid is supplied from the recessed portion, so that the insulator coating liquid does not run onto the upper and lower surfaces of the electrode body, and the insulating portion is formed only on the end face. Therefore, volumetric efficiency is improved. More specifically, when contacting, the convex portion of the coating tool is pressed against the end face of the electrode body, so that excessive pressure is not directly applied to the insulator coating liquid contained in the recessed portion. As a result, the insulator coating liquid does not run onto the upper and lower surfaces of the electrode body, and the coating liquid can be applied only to the end face.

[0042] (scraping) Preferably, when filling the recesses of the coating tool with the insulator coating liquid, excess insulator coating liquid is scraped off. In this case, excess insulator coating liquid can be removed from the protrusions, which has the effect of supplying an accurate amount of insulator coating liquid to the end face. In addition, this prevents the coating liquid from being crushed between the protrusions and the end face and running up onto the upper and lower surfaces of the electrode body. This scraping can be performed, for example, with a doctor blade.

[0043] The details of the insulating coating liquid will be described later.

[0044] <Additional process> (Lamination process) The manufacturing method of the present invention may include other steps. In particular, it may include a step of stacking the electrode assemblies according to the present invention that have been subjected to the edge insulation treatment. For example, it may include a step of arranging additional current collector layers or other electrode assemblies on the upper and lower surfaces of the electrode assemblies that have been subjected to the edge insulation treatment, thereby manufacturing an electrode stack.

[0045] <Application method using a coating roller> One embodiment of the production method of the present invention comprises: (a') forming a strip-shaped electrode body; (b') cutting the end of the strip-shaped electrode body to form an end surface; (c') forming an insulating portion on the end surface of the strip-shaped electrode body transported between the transport rollers; Including, In (c'), an insulating portion is formed by bringing a coating roller having an insulating coating liquid on its outer surface, the insulating liquid being held in a plurality of protrusions and recesses between the plurality of protrusions, into contact with the end surface. The electrode body may have a laminate structure including at least a current collector and an active material layer, and in this case, the step (b') may include cutting the end of the electrode body to form a flush end surface.

[0046] In one aspect of this method, the outer circumferential surface of the coating roller is further configured to be on the inside with respect to a reference transport position of the end surface of the electrode body.

[0047] 4 shows an example of step (c') according to another embodiment of the method for manufacturing an electrode assembly according to the present invention. In step (c'), an insulating portion 405 is formed on the cut end surface of a strip-shaped electrode assembly 40. In the embodiment of FIG. 4, the strip-shaped electrode assembly 40 is transported between transport rollers 431. The insulating portion 405 is formed by bringing a coating roller 421, which has a recess 423 on its outer surface and contains an insulator coating liquid 411, into contact with the end surface 406 of the strip-shaped electrode assembly 40.

[0048] The relative position of the coating roller with respect to the transported electrode body is adjusted to thereby more reliably form the insulating portion. In particular, by positioning the coating roller on the inside with respect to the transport position of the transported strip-shaped electrode body (i.e., more inward in the direction of the electrode body than the normal transport position of the end face of the transported electrode body), more reliably form the insulating portion.

[0049] For example, the outer peripheral surface of the coating roller may be configured to be on the inside (i.e., closer to the electrode body) of the reference transport position of the end face. The "reference transport position" is the reference position when the electrode body is transported.

[0050] By configuring the coating roller so that its outer peripheral surface faces inward, a relatively stable insulating portion can be formed. More specifically, even if the electrode body shifts from the reference conveyance position to the side opposite the coating roller, contact between the convex portions of the coating roller and the end face of the electrode body is maintained. On the other hand, even if the electrode body shifts from the reference conveyance position to the coating roller side, the convex portions of the coating roller are pressed against the end face of the electrode body, so excessive pressure is not applied to the insulator coating liquid contained in the recesses. As a result, the insulator coating liquid does not climb up onto the top and bottom surfaces of the electrode body.

[0051] 4 shows a state in which the strip-shaped electrode body is shifted from the reference conveyance position A-A' to the side opposite to the coating roller 421, in which case the coating roller 421 is in contact with the end face 406 near the center of the roller pitch of the conveyance roller 431. Even in such a case, contact between the convex portion 422 of the coating roller 421 and the end face 406 of the electrode body 40 is maintained, so that the insulating portion 405 can be formed stably.

[0052] In one embodiment of the present invention, the electrode body may be transported by transport rollers, and a coating roller may be brought into contact with the end surface of the electrode body while the electrode body is being transported by the transport rollers.

[0053] In this embodiment, when viewed in plan, the outer peripheral surface of the coating roller may be inward from the reference conveyance position of the end surface by, for example, 10 to 1000 μm, preferably 200 to 800 μm, more preferably 400 to 600 μm.

[0054] (Transport roller) The electrode body can be transported by using a known transport roller.

[0055] <Other configurations in the method for manufacturing the electrode assembly> Other components in the method for manufacturing an electrode assembly according to the present disclosure will be described in more detail below.

[0056] (electrode body) The electrode body is not particularly limited and may be a known electrode body used in secondary batteries, etc. The thickness, size, and shape of the electrode body are not particularly limited and can be designed appropriately depending on, for example, the desired battery characteristics, etc.

[0057] For example, the electrode body may include a negative electrode current collector and a negative electrode active material layer (negative electrode). Alternatively, for example, the electrode body may include a positive electrode current collector and a positive electrode active material layer (positive electrode). A laminate may be formed by stacking a negative electrode, a positive electrode, and a separator. In this case, the negative electrodes and positive electrodes may be alternately arranged, and a separator may be arranged between the negative electrodes and the positive electrodes in these layers. A plurality of negative electrodes and a plurality of positive electrodes may be alternately stacked with a separator arranged between them. Such a laminate may be wound in the longitudinal direction. For such an embodiment, reference may be made to JP 2024-013996 A, JP 2024-062656 A, etc.

[0058] The electrode assembly may further include a solid electrolyte layer in addition to the current collector and active material layer. For example, the electrode assembly may include a solid electrolyte layer, a first active material layer, a first current collector, a first active material layer, and a solid electrolyte layer, in this order. Such an electrode assembly can be used in an all-solid-state battery; see, for example, JP 2018-049696 A. An electrode stack can be formed by alternately stacking such electrode assemblies with insulated edges and electrode members having a second current collector and a second active material layer. The electrode assembly may include a second active material layer, a solid electrolyte layer, a first active material layer, a first current collector, a first active material layer, a solid electrolyte layer, and a second active material layer, in this order. In this case, for example, a second current collector can be stacked to form an electrode stack.

[0059] In this embodiment, the first current collector may be a negative electrode current collector, the second current collector may be a positive electrode current collector, the first electrode active material layer may be a negative electrode active material layer, and the second electrode active material layer may be a positive electrode active material layer. For example, the electrode assembly may have a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, a negative electrode current collector, a negative electrode active material layer, a solid electrolyte layer, a positive electrode active material layer, and a positive electrode current collector, in this order. The thickness, size, and shape of each layer are not particularly limited.

[0060] (current collector) The current collector may include a metal layer (metal foil) or a resin layer (resin foil), and the material is not particularly limited and may be a known material. Examples of current collectors include metal foil, resin foil, resin-coated metal foil, and metal-coated resin foil. Examples of current collectors include a positive electrode current collector and a negative electrode current collector. The positive electrode current collector may include a metal layer, and the material used for the metal layer is not particularly limited and may be, for example, stainless steel (SUS), Ni, Cr, Au, Pt, Al, Fe, Ti, Zn, or the like. The negative electrode current collector may include a metal layer, and the material used for the metal layer is not particularly limited and may be, for example, SUS, Cu, Ni, Fe, Ti, Co, Zn, or the like.

[0061] The resin layer (resin foil) may include a base resin and a conductive filler dispersed in the base resin. This resin layer may be any conductive layer known for resin current collectors. For example, the description of the resin current collector layer can be found in JP 2024-037018 A. The conductive resin layer may be a single layer, or an electrode body of two or more conductive resin sublayers.

[0062] The matrix resin may be any thermoplastic resin or thermosetting resin, such as polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polycycloolefin (PCO), polyethylene terephthalate (PET), polyethernitrile (PEN), polytetrafluoroethylene (PTFE), styrene butadiene rubber (SBR), polyacrylonitrile (PAN), polymethyl acrylate (PMA), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVdF), epoxy resin, silicone resin, or a mixture thereof. From the viewpoint of electrical stability, the matrix resin is preferably polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), or polycycloolefin (PCO), more preferably polyethylene (PE), polypropylene (PP), or polymethylpentene (PMP), or a mixture thereof.

[0063] The conductive filler can be selected from any material having electrical conductivity. From the viewpoint of suppressing ion permeation within the current collector, the conductive filler is preferably a material that does not have conductivity with respect to the ions used as the charge transfer medium. Specifically, the conductive filler may be, but is not limited to, a carbon material, aluminum, gold, silver, copper, iron, platinum, chromium, tin, indium, antimony, titanium, nickel, etc. These conductive fillers may be used alone or in combination of two or more. Furthermore, an alloy material such as stainless steel (SUS) may be used as the conductive filler. From the viewpoint of corrosion resistance, the conductive filler is preferably aluminum, stainless steel, a carbon material, or nickel, more preferably a carbon material. Furthermore, these conductive fillers may be formed by coating a ceramic material or a resin material with the above-mentioned metal by plating or the like.

[0064] The conductive resin layer may optionally contain, in addition to the matrix resin and conductive filler, a dispersant for dispersing the conductive filler in the matrix resin. The conductive resin layer may also optionally contain other components, such as a colorant, an ultraviolet absorber, or a plasticizer. The total amount of components other than the matrix resin and conductive filler added may be 0.001 parts by weight or more, 0.01 parts by weight or more, 0.1 parts by weight or more, or 1 part by weight or more, or 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, 5 parts by weight or less, or 3 parts by weight or less, per 100 parts by weight of the conductive resin layer.

[0065] (active material layer) The positive electrode active material layer and the negative electrode active material layer each contain an active material for each electrode, and preferably further contain a solid electrolyte, a binder, and a conductive material.

[0066] The material used for the positive electrode active material layer is not particularly limited and may be a known positive electrode active material such as lithium cobalt oxide. A sulfide-based solid electrolyte may preferably be used as the solid electrolyte. A fluorine-containing resin such as polyvinylidene fluoride (PVDF) may be used as the binder. Examples of the conductive material include known conductive materials such as carbon nanofiber (e.g., VGCF manufactured by Showa Denko K.K.) and acetylene black.

[0067] The material used for the negative electrode active material layer is not particularly limited and may be a known negative electrode active material, such as graphite. The solid electrolyte and binder in the negative electrode active material layer may be any of the materials described above as being usable for the positive electrode active material layer. Examples of the conductive material in the negative electrode active material layer include known conductive materials such as acetylene black.

[0068] (separator) In the case of a liquid battery, the separator may include, for example, a porous resin sheet, and in the case of an all-solid-state battery, the separator may include, for example, a solid electrolyte layer.

[0069] The separator may be, for example, a nonwoven fabric made of a porous resin such as polypropylene, etc. Other examples of the separator include porous polymer membranes such as porous polyethylene membranes, porous polyolefin membranes, and porous polyvinyl chloride membranes, or lithium ion or ion conductive polymer electrolyte membranes, either alone or in combination.

[0070] (solid electrolyte layer) The solid electrolyte layer contains a solid electrolyte and preferably further contains a binder. As the solid electrolyte in the solid electrolyte layer, the materials described above as those usable for the positive electrode active material layer can be used. As the binder, butadiene rubber (BR) is preferred.

[0071] (insulator coating liquid) The insulator coating liquid is a liquid used to form insulating portions on the end surfaces of the electrode assembly, and therefore may contain a material that will become the insulating portion after being applied.

[0072] The insulating body coating liquid is not particularly limited, but may contain a thermoplastic resin and a curable resin.

[0073] In one embodiment of the present invention, the insulation coating liquid may contain a thermoplastic resin or may be a thermoplastic resin. The thermoplastic resin is not particularly limited and may be a non-reactive type or a reactive type. The non-reactive thermoplastic resin is not particularly limited and may be an ethylene vinyl acetate (EVA)-based, synthetic rubber-based, olefin-based, polyamide-based, or polyester-based resin such as polyethylene terephthalate (PET). The reactive resin is not particularly limited and may be a urethane-based resin.

[0074] When a thermoplastic resin is used, it may be liquefied by heating. The method for solidifying the insulating part containing the liquefied thermoplastic resin is not particularly limited, but examples thereof include a method of cooling the insulating part. The method for cooling the insulating part is not particularly limited, but examples thereof include an air-cooling method.

[0075] In one embodiment of the present invention, the insulator coating liquid may contain a curable resin or may be a curable resin. The curable resin is not particularly limited and may be, for example, a UV-curable resin or an epoxy resin. The insulator coating liquid used in the present invention preferably contains an insulating resin and a solvent that dissolves the resin. The resin concentration in the insulator coating liquid is preferably 70% by mass to 100% by mass for a UV-curable resin and 30% by mass to 70% by mass for an epoxy resin, from the viewpoint that the surface tension and the like of the insulator coating liquid are adjusted, thereby making it relatively easy for the insulator coating liquid to spread over the entire end surface of the electrode body.

[0076] By using this manufacturing method, it is possible to manufacture, for example, an electrode body for an all-solid-state battery, an electrode body for a liquid-based battery, or an electrode body for a polymer battery, each of which has insulated edges. [Explanation of symbols]

[0077] 10, 20, 30, 40 electrode body 101, 301 Second active material layer 102, 302 solid electrolyte layer 103, 303 First active material layer 104, 304 First current collector layer 105, 305, 405 Insulation 106, 206, 306, 406 end face 107a, 107b Upper and lower surfaces 211, 411 Insulator coating liquid 221, 421 Coating tools 222, 422 convex part 223, 423 recess 431 Conveyor roller

Claims

1. (a) providing an electrode assembly; (b) cutting the end of the electrode body to form an end surface; and (c) forming an insulating portion on the end surface; Including, In the step (c), a coating tool having an insulating coating liquid held in a plurality of convex portions and concave portions between the plurality of convex portions is brought into contact with the end surface to form the insulating portion. Method for manufacturing end-insulated electrode bodies.

2. the electrode body includes at least a current collector and an active material layer, and (b) includes cutting an end of the electrode body to form a flush end surface. A method for manufacturing the edge-insulated electrode assembly of claim 1.

3. The method for manufacturing an electrode body with insulated ends according to claim 1 or 2, wherein the width of the convex portion of the coating tool is equal to or less than twice the thickness of the electrode body.

4. The method for manufacturing an end-insulated electrode body according to claim 1 or 2, wherein the depth of the recess of the coating tool is equal to or less than one time the thickness of the electrode body.

5. (a') forming a strip-shaped electrode body; (b') cutting the end of the strip-shaped electrode body to form an end surface; (c') forming an insulating portion on the end surface of the strip-shaped electrode body transported between transport rollers; Including, In the step (c'), a coating roller having an insulating coating liquid on its outer surface, the insulating liquid being held in a plurality of convex portions and in concave portions between the plurality of convex portions, is brought into contact with the end surface to form the insulating portion; and In the method (c'), the outer peripheral surface of the coating roller is configured to be inside the reference transport position of the end surface of the electrode body.

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