Electrode, method for manufacturing an electrode, and battery

Abstract

The objective is to prevent the resin material from penetrating the active material layer at its edges. [Solution] A method for manufacturing an electrode, comprising: an undercoat layer step of covering a current collector foil with an undercoat layer; a granular layer step of arranging granules that will become an active material layer on the undercoat layer to form a granular layer; and a resin part step of covering the ends of the granular layer with a resin material and curing the resin material to form a resin part, wherein the ends of the granular layer include an inclined surface on the upper surface, and in the granular layer step, the average particle size of the granules arranged in at least a part of the ends of the granular layer is less than 5 μm.

Description

Technical Field

[0001] The present invention relates to an electrode, a method for manufacturing an electrode, and a battery.

Background Art

[0002] Patent Document 1 describes a method for manufacturing an electrode for a lithium-ion secondary battery including an active material layer, which includes applying an adhesive to the edge of the active material in order to suppress peeling at the edge of the active material and slipping of the active material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When curing the resin material applied to the end of the active material layer, the resin material may penetrate into the active material layer. In this case, the resin material penetrating into the active material layer may not be sufficiently cured. An example of the problem to be solved by the present invention is to suppress the penetration of the resin material into the active material layer at the end of the active material layer.

Means for Solving the Problems

[0005] According to the present invention, there are provided an electrode, a method for manufacturing an electrode, and a battery described below. [1] An undercoat layer step of coating a current collector foil with an undercoat layer; A granule layer step of arranging granules to be an active material layer on the undercoat layer to form a granule layer; A resin part step of covering the end of the granule layer with a resin material and curing the resin material to form a resin part; including The end of the granular layer includes an inclined surface on its upper surface. A method for manufacturing an electrode, wherein, in the granular layer step, the average particle size of the active material particles constituting the granules, which are arranged at least in a portion of the edge of the granular layer, is less than 5 μm. [2] The method for manufacturing an electrode according to [1], wherein the average particle size of the active material particles constituting the granules on the central side of the granule layer, rather than the edges, is 5 μm or more and 30 μm or less. [3] The granular layering process comprises a first step of forming the edges of the granular layer and a second step of forming regions other than the edges of the granular layer, wherein the average particle size of the active material particles constituting the granular material used in the second step is greater than the average particle size of the active material particles constituting the granular material used in the first step. A method for manufacturing an electrode as described in [1] or [2]. [4] The first and second steps are carried out in parallel. [3] The method for manufacturing an electrode as described above. [5] A method for manufacturing an electrode according to any one of [1] to [4], characterized in that the granular material is a granulated body comprising a plurality of active material particles and a binder. [6] It includes a current collector foil, an undercoat layer, a granular layer as an active material layer, and a resin part made of a resin material that covers the edges of the granular layer. The end of the granular layer includes an inclined surface on its upper surface. An electrode in which the average particle size of the active material particles constituting the granules at a portion of the edge of the granular layer is less than 5 μm. [7] The electrode according to [6], wherein the average particle size of the active material particles constituting the granules on the central side of the granular layer, rather than at the edges, is 5 μm or more and 30 μm or less. [8] The electrode according to [6] or [7], characterized in that the granular material is a granulated body comprising a plurality of active material particles and a binder. [9] A battery comprising the electrodes described in any of [6] to [8]. [Effects of the Invention]

[0006] According to the present invention, at the end of the active material layer, it is possible to suppress the penetration of the resin material into the active material layer.

Brief Description of the Drawings

[0007] [Figure 1] It is a schematic diagram of an electrode for a lithium-ion secondary battery. [Figure 2] It is a schematic diagram of the first manufacturing apparatus. [Figure 3] It is a schematic diagram of the second manufacturing apparatus. [Figure 4] It is a diagram showing the end of the electrode. [Figure 5] It is a flowchart diagram of the method for manufacturing an electrode according to the present embodiment. [Figure 6] It is a top view of the electrode according to the present embodiment. [Figure 7] It is a diagram showing the first example of the fifth step. [Figure 8] It is a diagram showing the second example of the fifth step. [Figure 9] It is a diagram showing the first example of the granule supply unit. [Figure 10] It is a diagram showing the first example of the active material layer. [Figure 11] It is a diagram showing the second example of the granule supply unit. [Figure 12] It is a diagram showing the second example of the active material layer. [Figure 13] It is a diagram showing the third example of the granule supply unit. [Figure 14] It is a diagram showing the third example of the active material layer.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description will be omitted as appropriate.

[0009] Figure 1 shows an example of an electrode according to this embodiment, specifically an electrode 10 for a lithium-ion secondary battery. As shown in Figure 1, the electrode 10 for a lithium-ion secondary battery includes a current collector foil 11 as an example of a substrate, with an active material layer 12a formed on one side of the current collector foil 11 and an active material layer 12b formed on the other side. An adhesive layer 13a is formed between the current collector foil 11 and the active material layer 12a, and an adhesive layer 13b is formed between the current collector foil 11 and the active material layer 12b. Note that the current collector foil 11 may have only one of the active material layer 12a and adhesive layer 13a, or only one of the active material layer 12b and adhesive layer 13b. When the electrode 10 for a lithium-ion secondary battery is a negative electrode plate, the active material layers 12a and 12b are formed of negative electrode active material. When the electrode 10 for a lithium-ion secondary battery is a positive electrode plate, the active material layers 12a and 12b are formed of positive electrode active material. Furthermore, the lithium-ion secondary battery electrode 10 may also be a bipolar electrode in which one of the active material layers 12a and 12b is the negative electrode active material layer and the other is the positive electrode active material layer. Details of the materials will be described later. Furthermore, a lithium-ion secondary battery has a positive electrode comprising a positive electrode current collector foil made of a metal such as aluminum foil and a positive electrode active material layer containing a positive electrode active material provided on at least one side thereof, and a negative electrode comprising a negative electrode current collector foil made of a metal such as copper foil and a negative electrode active material layer containing a negative electrode active material provided on at least one side thereof. The positive electrode and the negative electrode are laminated via a separator made of nonwoven fabric or a polypropylene microporous film, for example, so that the positive electrode active material layer and the negative electrode active material layer face each other. This electrode pair is housed in a container made of an outer material made of a soft aluminum film or a rectangular or cylindrical outer material made of a hard metal. Also, for example, a positive electrode tab is connected to the positive electrode current collector foil and a negative electrode tab is connected to the negative electrode current collector foil, and these tabs are led out of the container. An electrolyte is injected into the container and sealed. The container can have a structure that houses an electrode group in which multiple electrode pairs are laminated, or a structure that houses a single electrode pair.

[0010] As shown in Figure 1, at least one end, preferably both ends, of the active material layer 12a and the active material layer 12b is covered with the resin portion 14. This suppresses the shedding of granules.

[0011] For example, the active material layer 12a increases in thickness from the edge over a predetermined range, and then its thickness hardly changes thereafter. The resin part 14 covers, for example, the entire area of ​​at least the portion of the active material layer 12a where the thickness increases. The same applies when the resin part 14 covers the active material layer 12b.

[0012] Figure 2 is a schematic diagram of the first electrode manufacturing apparatus 100 according to this embodiment. Figure 3 is a schematic diagram of the second electrode manufacturing apparatus 200 according to this embodiment.

[0013] As shown in Figure 2, the first manufacturing apparatus 100 includes, for example, an adhesive layer forming section 110, a granular material supply section 120, a first press roll 130, a resin part forming section 140, an unwinding roll 150a, and a winding roll 150b. The second manufacturing apparatus 200 includes a second press roll 210, an unwinding roll 220a, and a winding roll 220b. Details of each component will be described below.

[0014] [Adhesive layer forming section 110] The adhesive layer forming section 110 applies an adhesive to at least one surface of the current collector foil 11 to form an adhesive layer. The type of current collector foil is not particularly limited, but examples include aluminum and copper. The adhesive applied to at least one surface of the current collector foil 11 preferably contains a conductive material, but is not limited to that. The adhesive layer is formed entirely or partially by, for example, applying and drying the adhesive. The adhesive layer may be formed uniformly or in a pattern. While there are no specific restrictions on the type of adhesive, examples include fluororesins such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), and polyvinyl fluoride (PVF); conductive polymers such as polyanilines, polythiophenes, polyacetylenes, and polypyrroles; synthetic rubbers such as styrene-butadiene rubber (SBR), butadiene rubber (BR), chloroprene rubber (CR), isoprene rubber (IR), and acrylonitrile-butadiene rubber (NBR); water-soluble resins such as polyvinylpyrrolidone; or polysaccharides such as carboxymethylcellulose (CMC), xanthan gum, guar gum, and pectin; and acrylic resins such as acrylates and methacrylates. Furthermore, while there are no specific restrictions on the type of conductive material, examples include carbon black such as acetylene black and Ketjenblack, activated carbon, graphite, mesoporous carbon, fullerenes, carbon nanotubes, carbon nanofibers, carbon nanobrushes, and other carbon fibers. Furthermore, the adhesive layer may include two or more layers. For example, the adhesive layer may include a first adhesive layer formed to contact one side of the current collector foil 11, and a second adhesive layer formed to contact the side of the first adhesive layer opposite to the current collector foil 11. Furthermore, if the second adhesive layer does not contain a conductive material, or if the conductivity of the conductive material in the second adhesive layer is lower than that of the conductive material in the first adhesive layer, it is preferable that the second adhesive layer be formed to partially or patternably overlap the first adhesive layer. This ensures that at least a portion of the first adhesive layer does not overlap the second adhesive layer, thereby contacting the active material layer 12 and ensuring sufficient electrical conductivity between the current collector foil 11 and the active material layer 12. The pattern shape may be dot-like, or for example, striped, grid-like, etc. The shape of the dots may be a fixed shape such as a circle, ellipse, polygon (triangle, square, pentagon, hexagon, etc.), or it may be an irregular shape. The arrangement of the dots, the spacing between adjacent dots, the spacing of the stripes, and the spacing of the intersections of the grid lines may be regular or random. The adhesive layer forming section 110 includes, as an example, an adhesive application section 111 and an adhesive drying section 112.

[0015] As the unwinding roll 150a and the winding roll 150b rotate and the current collector foil 11 is transported, adhesive is continuously applied to one surface of the current collector foil 11 by the adhesive application unit 111. Methods for applying the adhesive include, but are not limited to, die application, comma application, lip application, transfer application, inkjet application, doctor blade application, and screen printing. Subsequently, the adhesive drying unit 112 dries the adhesive, forming an adhesive layer. The drying temperature is, for example, 80°C to 180°C. The drying time is, for example, 1 second to 30 seconds. The thickness of the adhesive layer is, for example, 0.01 μm to 2 μm.

[0016] [Granulate supply section 120] Next, the granular material supply unit 120 supplies granules containing the active material onto the adhesive layer described above. The granules supplied by the granular material supply unit 120 are at least one of the following: active material particles, which are granules composed of the active material, and granulated material, which is obtained by mixing and dispersing the above-mentioned active material particles together with a binder and a conductive additive in a solvent, and then removing the solvent by drying to form aggregates of active material particles. In the following description, unless otherwise specified, the granular material supply unit 120 will supply granulated material containing multiple active material particles and a binder. The detailed configuration of the granular material supply unit 120 will be described later. When the granular material supply unit 120 supplies granulated material, as an example, the average particle size D50 of the granules is 10 μm or more and 110 μm or less, and the average particle size D50 of the active material particles constituting the granules is 0.1 μm or more and less than 5 μm. The average particle size D50 of the granulated material and the average particle size D50 of the active material particles constituting the granulated material can be calculated by measuring the cross-section of the active material layer 12 using a scanning electron microscope (SEM).

[0017] Furthermore, a squeegee section 121 may be provided downstream of the granular material supply section 120. The squeegee section 121 levels the granular material supplied onto the adhesive layer by the granular material supply section 120. The squeegee section 121 is positioned at a predetermined distance from the current collector foil 11, and the granular material is leveled as the current collector foil 11 is transported beneath the squeegee section 121. The shape of the squeegee section 121 is not particularly limited, but as an example, it may be a roller that rotates in accordance with the transport of the current collector foil 11, or it may be plate-shaped. The predetermined distance is, as an example, 50 μm to 300 μm.

[0018] [First press roll 130] The first press roll 130 temporarily presses the granular layer described above to fix the granules in place. The linear pressure applied by the first press roll 130 during pressing is, for example, between 0.1 ton / cm and 1 ton / cm.

[0019] [Resin part forming part 140] The resin forming section 140 forms a resin section 14 at the end of the granular material layer (hereinafter referred to as the granular material layer) supplied by the granular material supply section 120. Details of the end will be described later. The resin forming section 140 includes, as an example, a resin coating section 141 and a resin curing section 142.

[0020] The resin coating section 141 applies resin material to the edges of the granular layer. For example, the resin coating section 141 applies resin material to a portion of the granular layer that is 1 mm or less from the edge. Then, the resin curing section 142 cures the applied resin material to form the resin section 14. The method by which the resin curing section 142 cures the resin material is photocuring, for example, by irradiating it with light such as ultraviolet light. In this case, the resin material is an ultraviolet-curable resin, and examples include MX-300L, MX-60, MX-80, and SLD-5101 from Sanyurec Co., Ltd., UV-7510B and UV-7605B from Mitsubishi Chemical Corporation, and Elfort 4000 from Resonac Co., Ltd.

[0021] Next, the current collector foil 11 is removed from the winding roll 150b and attached to the second manufacturing device 200.

[0022] [Second press roll 210] Next, the current collector foil 11 is conveyed by the rotation of the unwinding roll 220a and the winding roll 220b of the second manufacturing apparatus 200. The second press roll 210 forms the active material layer by performing a final press on the pre-pressed granular layer. The linear pressure when the second press roll 210 presses is, for example, between 0.3 ton / cm and 6.5 ton / cm.

[0023] Figure 4 shows details of the end of the active material layer formed by the above process. As shown in the figure, the end of the active material layer 12 includes an inclined portion 21. The inclined portion 21 has an inclined surface on its upper part, and the angle of inclination of the inclined surface is determined by the angle of repose of the granules, etc. The inclined portion 21 is a part where the granules were not supplied in sufficient quantity, and where insufficient linear pressure was not applied in the first pressing process by the first press roll 130 and the second pressing process by the second press roll 220, potentially resulting in a lower density of the granules. The end of the active material layer 12 also includes a flat portion 22 located inside the inclined portion 21. The flat portion 22 is a part where more granules are supplied than in the inclined portion 21, and where the granules are pushed towards the inclined portion 21 when pressed, potentially resulting in a lower density of the granules. As an example, the inclined portion 21 is the part with a thickness of 95% or less of the average thickness D of the active material layer 12, and the flat portion 22 is the part within 2 mm of the inclined portion 21.

[0024] [Method for manufacturing electrodes] Figure 5 illustrates the method for manufacturing an electrode according to this embodiment. As shown in the figure, the electrode manufacturing method is performed in the following order: first step (step S10) of coating the current collector foil 11 with an undercoat layer (adhesive layer); second step (step S20) of arranging granules that will become the active material layer 12 on the undercoat layer to form a granular layer; third step (step S30) of pressing the granular layer; and fourth step (step S40) of covering the edges of the granular layer with a resin material and curing the resin material to form a resin part 14. The electrode manufacturing method may also include a fifth step (step S50) of cutting the current collector foil 11 and the active material layer 12.

[0025] The first step, as described above, is performed by forming an adhesive layer using the adhesive layer forming unit 110. The second step is performed by supplying granules (granulated material) that will become the active material layer using the granule supply unit 120. Details of the second step will be described later.

[0026] Furthermore, the third step is carried out by pressing the material against at least one of the first press roll 130 and the second press roll 210.

[0027] Furthermore, the fourth step is carried out by forming the resin part 14 using the resin part forming part 140. In the fourth step, at least a portion of the side and top surfaces of the granular layer may be covered with the resin part 14. Specifically, it is preferable that the top surface of the granular layer is covered with the resin part 14 in a range of 1 mm or less from the edge of the granular layer. This helps to suppress the shedding of granules. However, in the fourth step, only the side surfaces of the granular layer may be covered with the resin part 14.

[0028] Figure 6 shows a top view of the current collector foil 11, active material layer 12, and resin portion 14 after the first to fourth processes. As shown in the figure, the resin portion 14 is formed at the end of the active material layer 12 in the width direction, which is perpendicular to the transport direction. The width W of the resin portion 14 in the width direction is, for example, 2 mm to 10 mm.

[0029] The fifth step will be explained using Figures 7 and 8. In the fifth step, the current collector foil 11 and the active material layer 12 shown in Figure 6 are cut along the dashed line shown in Figure 7 or Figure 8. This yields the electrode shown in Figure 1. In other words, Figure 1 shows the A-A' cross section in Figure 7 or Figure 8.

[0030] In the case of the cutting pattern shown in Figure 8, one end of the active material layer 12 is cut off. Therefore, when cutting using the cutting pattern shown in Figure 8 in the fifth step, it is sufficient to form the resin portion 14 only on one end of the active material layer 12 in the fourth step.

[0031] [Second process] The second step will now be described in more detail. In this embodiment, in the second step, the granules are arranged such that the average particle size D50 of the active material particles constituting the granules located at the edges of the granule layer is, for example, less than 5 μm. Alternatively, the granules are arranged such that the average particle size D50 of the granules located at the edges of the granule layer is, for example, 70 μm or less. By performing the above steps, the average particle size of the active material particles at the edges of the granule layer is reduced, and the penetration of the coated resin material at the edges of the granule layer can be suppressed.

[0032] First, the granular material supply unit 120 will be described using Figure 9. In the following description, the x-direction is the width direction of the current collector foil 11, the y-direction is the thickness direction of the current collector foil 11, and the z-direction is the transport direction of the current collector foil 11. The granular material supply unit 120 has a small granular material supply unit 120a and a large granular material supply unit 120b. The small granular material supply unit 120a is provided at each end of the granular material supply unit 120 and is located at least above the portion where the end of the granular material layer is formed. The large granular material supply unit 120b is the portion of the granular material supply unit 120 other than the small granular material supply unit 120a. In other words, the large granular material supply unit 120b is the portion sandwiched between the two small granular material supply units 120a. The small particle supply section 120a is equipped with granules in which the average particle size D50 of the active material particles constituting the granules is less than 5 μm or less than 70 μm (hereinafter referred to as "small particles"), and the large particle supply section 120b is equipped with granules in which the average particle size D50 of the active material particles constituting the granules is 5 μm or more and 20 μm or less, preferably 5 μm or more and 15 μm or less, or 70 μm or more and 120 μm or less (hereinafter referred to as "large particles"). The edge of the granule layer is the region from the edge of the granule layer to a predetermined distance. This predetermined distance is, for example, 0.1 to 5.0 mm.

[0033] As an example, it is preferable that the small grains are single-crystal active material particles and the large grains are polycrystalline particles. However, the small and large grains may both be polycrystalline active material particles, or both may be single-crystal active material particles, as long as it is possible to achieve the desired particle size of the granules. The crystal structure is not limited to this. Note that a single crystal is not necessarily composed of a single particle, but also includes a structure in which several to a dozen or so single crystals are bonded together. On the other hand, polycrystalline particles are polycrystalline bodies (secondary particles) in which tens or hundreds of single-crystal particles (primary particles) are bonded together. The single-crystal particles that make up the primary particles of the polycrystalline body are not the same as the single-crystal particles that make up the small grains in this invention, but are not limited to this. The granules are formed by aggregating these single-crystal particles and polycrystalline particles via a binder. Furthermore, the granules may contain conductive additives as appropriate.

[0034] Figure 10 shows an example of a granular layer formed by the granular material supply unit 120 shown in Figure 9. As shown in the figure, a small granular layer 31, formed by small granules, is located at the end of the granular layer. A large granular layer 32, formed by large granules, is located in the central part of the granular layer, closer to the center than the end of the granular layer. An intermediate layer 33, containing both small and large granules, is formed between the small granular layer 31 and the large granular layer 32.

[0035] Next, another example of the second process will be explained using Figures 11-14. Figure 11 is a perspective view showing a first modified example of the granular material supply unit 120. As shown, the small granular material supply unit 120a and the large granular material supply unit 120b are separated. They are positioned in the order of small granular material supply unit 120a, large granular material supply unit 120b, and squeegee unit 121 from the upstream side in the conveying direction.

[0036] Figure 12 shows a cross-sectional process diagram illustrating the second step when using the granular material supply unit 120 shown in Figure 11. First, the small granular material supply unit 120a places small granules in the portion of the adhesive layer 13 where the edges of the granular layer are located (step S110). Step S110 forms the small granular layer 31. The small granular layer 31 includes a first slope 31a facing outward from the adhesive layer 13 (current collector foil 11) and a second slope 31b facing inward from the adhesive layer 13 (current collector foil 11). Next, the large granular material supply unit 120b places large granules in the portion of the adhesive layer 13 closer to the center than where the edges of the granular layer are located, forming the large granular layer 32 (step S120). At this time, the large granular material supply unit 120b places the large granules so as to cover the second slope 31b of the small granular layer 31. In this way, the average particle size of the granules at the edges of the granular layer can be reduced. Furthermore, the average particle size of the particles can be maintained except at the edges of the particle layer. In the above process, the width W1 in the x-direction of the small particle layer 31 is, for example, 1 mm to 5 mm, and the width W2 in the y-direction is, for example, 20 μm to 150 μm.

[0037] Figure 13 is a perspective view showing a second modified example of the granular material supply unit 120. As shown in the figure, the small granular material supply unit 120a and the large granular material supply unit 120b are separated. The large granular material supply unit 120b, the squeegee unit 121, and the small granular material supply unit 120a are located in that order from the upstream side in the conveying direction.

[0038] Figure 14 shows a cross-sectional process diagram illustrating a second example of the second step. First, the large particle supply unit 120b places large particles in the central part of the granular layer rather than the part where the edges of the granular layer are located (step S210). Step S210 forms the large particle layer 32. The large particle layer 32 includes a third slope 32a facing outward from the adhesive layer 13 (current collector foil 11). Next, the small particle supply unit 120a places small particles in the part where the edges of the granular layer are located, forming a small particle layer. At this time, the small particle supply unit 120a places the small particles so as to cover the third slope 32a of the large particle layer 32. Even in this way, the average particle size of the particles at the edges of the granular layer can be reduced. Furthermore, the average particle size of the particles other than at the edges of the granular layer can be maintained. In addition, the width W3 in the x-direction of the small particle layer 31 in the above process is, for example, 1 mm or more and 5 mm or less, and the width W4 in the y-direction is, for example, 20 μm or more and 150 μm or less.

[0039] As described above, the electrode manufacturing method according to this embodiment makes it possible to reduce the average particle size of the particles at the edges of the particle layer. This suppresses the penetration of resin material into the particle layer. Furthermore, the average particle size of the particles other than at the edges of the particle layer can be maintained. This makes it possible to improve ion path in the central part of the particle layer.

[0040] The embodiments of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and various other configurations can also be adopted.

[0041] Furthermore, although the flowchart used in the above description shows multiple steps (processes) in order, the execution order of the steps performed in each embodiment is not limited to the order in which they are described. In each embodiment, the order of the illustrated steps can be changed to the extent that it does not impede the content. Also, the above embodiments can be combined to the extent that their contents do not conflict. [Explanation of Symbols]

[0042] 10 electrodes 110 Adhesive layer forming section 120 Granule supply section 130 First press roll 140 Resin part forming part 210 Second press roll

Claims

1. The process involves applying an undercoat layer to the current collector foil, A granular layer step is performed by arranging granules that will become an active material layer in the undercoat layer to form a granular layer, A resin part step in which the edges of the granular layer are covered with a resin material and the resin material is cured to form a resin part, Includes, The end of the granular layer includes an inclined surface on its upper surface. A method for manufacturing an electrode, wherein, in the granular layer step, the average particle size of the active material particles constituting the granules, which are arranged at least in a portion of the edge of the granular layer, is less than 5 μm.

2. The method for manufacturing an electrode according to claim 1, wherein the average particle size of the active material particles constituting the granules on the central side of the granule layer, rather than the edges, is 5 μm or more and 30 μm or less.

3. The granular layering process comprises a first step of forming the ends of the granular layer and a second step of forming regions other than the ends of the granular layer, wherein the average particle size of the active material particles constituting the granular material used in the second step is greater than the average particle size of the active material particles constituting the granular material used in the first step. A method for manufacturing an electrode according to claim 1 or 2.

4. The first and second steps are carried out in parallel. The method for manufacturing an electrode according to claim 3.

5. The method for manufacturing an electrode according to claim 1 or 2, characterized in that the granular material is a granulated body comprising a plurality of active material particles and a binder.

6. It includes a current collector foil, an undercoat layer, a granular layer as an active material layer, and a resin part made of a resin material that covers the edges of the granular layer. The end of the granular layer includes an inclined surface on its upper surface. An electrode in which the average particle size of the active material particles constituting the granules in a portion of the edge of the granular layer is less than 5 μm.

7. The electrode according to claim 6, wherein the average particle size of the active material particles constituting the granules on the central side of the granular layer, rather than the edges, is 5 μm or more and 30 μm or less.

8. The electrode according to claim 6 or 7, characterized in that the granular material is a granulated body comprising a plurality of active material particles and a binder.

9. A battery comprising the electrode described in claim 6 or 7.

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