Battery manufacturing method

Abstract

This method for manufacturing a battery includes: a first cutting step for cutting, at a first cutting position, a laminate provided with at least one battery cell having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer positioned between the positive electrode layer and the negative electrode layer, to form a first cut surface; and a second cutting step for cutting the laminate, which has been cut in the first cutting step, at a second cutting position that is more on an inner side than the first cut surface to form a second cut surface. In the second cutting step, Rz1<W<5Rz1 is satisfied (wherein W represents the distance between the first cut surface and the formed second cut surface, and Rz1 represents the surface roughness of the first cut surface).

Description

【Technical Field】 【0001】 The present disclosure relates to a method for manufacturing a battery. 【Background Art】 【0002】 Conventionally, a battery in which a current collector and an active material layer are laminated is known. 【0003】 For example, Patent Document 1 discloses a battery laminate formed by laminating unit cells each constituted by laminating a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer in this order. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2020-13729 【Patent Document 2】 Japanese Patent Application Laid-Open No. 2015-76315 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 In order to increase the capacity density of a battery, it is required to improve the effective volume contributing to power generation. For this purpose, it is effective to cut a battery cell and remove a portion that does not contribute to power generation. However, when a battery cell is cut, burrs and sagging (so-called drooping) of battery components occur on the cut surface, and a short circuit is likely to occur, resulting in a problem that the operating reliability of the battery is reduced. For example, Patent Document 2 discloses a method for manufacturing a battery in which the voltage is measured after cutting the end of a battery cell, and if the voltage gradually decreases, the end of the battery cell is cut again. However, Patent Document 2 does not disclose a cutting method capable of suppressing the generation of burrs and sagging on the cut surface. 【0006】 This disclosure addresses the above problems and aims to provide a method for manufacturing a battery that can achieve both high volumetric energy density and high reliability of the battery. 【Means for Solving the Problems】 【0007】 A method for manufacturing a battery according to one aspect of the present disclosure includes a first cutting step of cutting a laminate including at least one battery cell having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer positioned between the positive electrode layer and the negative electrode layer at a first cutting position to form a first cut surface, and a second cutting step of cutting the laminate cut in the first cutting step at a second cutting position inside the first cut surface to form a second cut surface. In the second cutting step, when the distance between the first cut surface and the second cut surface formed is W and the surface roughness of the first cut surface is Rz1, Rz1 < W < 5Rz1 is satisfied. 【Advantages of the Invention】 【0008】 According to the present disclosure, it is possible to achieve both high volumetric energy density and high reliability of the battery. 【Brief Description of the Drawings】 【0009】 [Figure 1A] FIG. 1A is a cross-sectional view showing a cross-sectional configuration of a battery according to Embodiment 1. [Figure 1B] FIG. 1B is a top view of the battery according to Embodiment 1. [Figure 2A] FIG. 2A is a cross-sectional view showing a cross-sectional configuration of a laminate according to Embodiment 1. [Figure 2B] FIG. 2B is a top view of the laminate according to Embodiment 1. [Figure 3] FIG. 3 is a cross-sectional view for explaining a method for manufacturing a battery according to Embodiment 1. [Figure 4] FIG. 4 is a top view for explaining another example in the second direction in the second cutting step. [Figure 5] FIG. 5 is a cross-sectional view showing a cross-sectional configuration of a laminate according to Embodiment 2. [Figure 6]FIG. 6 is a cross-sectional view showing a cross-sectional configuration of another laminate according to Embodiment 2. [Figure 7] FIG. 7 is a cross-sectional view for explaining a method of manufacturing a battery according to Embodiment 2. 【Embodiments for Carrying Out the Invention】 【0010】 (Summary of the Present Disclosure) A method of manufacturing a battery according to one aspect of the present disclosure includes a first cutting step of cutting a laminate including at least one battery cell having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer positioned between the positive electrode layer and the negative electrode layer at a first cutting position to form a first cut surface, and a second cutting step of cutting the laminate cut in the first cutting step at a second cutting position inside the first cut surface to form a second cut surface. In the second cutting step, when the distance between the first cut surface and the second cut surface formed is W and the surface roughness of the first cut surface is Rz1, Rz1 < W < 5Rz1 is satisfied. 【0011】 Thereby, in the first cutting step and the second cutting step, it is possible to remove a portion that does not contribute to the power generation of the battery by cutting the laminate, so that the ratio of the effective volume, which is the volume that contributes to the power generation in the battery, can be improved. Further, in the second cutting step, by cutting the laminate under the condition that Rz1 < W < 5Rz1 is satisfied, the flatness of the second cut surface is improved, and the number and size of burrs and sagging of the components of the laminate generated on the second cut surface are suppressed, and the occurrence of a short circuit between the positive electrode layer and the negative electrode layer can be suppressed. Therefore, by the method of manufacturing a battery according to the present aspect, it is possible to achieve both a high capacity density and high reliability of the battery. 【0012】 Further, for example, the W may be not more than three times the thickness of the laminate. 【0013】 Thereby, the flatness of the second cut surface is improved, the generation of burrs and sagging is suppressed, and the quality of the second cut surface can be improved. 【0014】 Further, for example, the first cutting step and the second cutting step may be continuously performed as a series of steps. 【0015】 Thereby, the laminate can be continuously cut without sandwiching other steps, so that the productivity can be improved. 【0016】 Further, for example, when the position of the laminate is used as a reference, the first direction in which the cutting of the laminate proceeds at the first cutting position and the second direction in which the cutting of the laminate proceeds at the second cutting position may be different. Further, for example, the second direction may be a direction perpendicular to the first direction. 【0017】 Thereby, since the laminate can be cut by changing the cutting direction between the first cutting step and the second cutting step, the laminate can be cut by adjusting in a direction according to the quality of the cut surface and the ease of cutting. 【0018】 Further, for example, the second direction may be a direction perpendicular to the stacking direction of the laminate. 【0019】 Thereby, even if burrs or the like are generated in the second cutting step, the burrs or the like are formed so as to extend orthogonally to the stacking direction of the laminate. Therefore, the occurrence of short circuits can be suppressed, and the reliability of the manufactured battery can be improved. 【0020】 Further, for example, the at least one battery cell is a plurality of battery cells, and the plurality of battery cells may be stacked. 【0021】 Thereby, in a laminate in which a plurality of battery cells are stacked, short circuits between the plurality of battery cells and between the positive electrode layer and the negative electrode layer in each battery cell can be suppressed, and the effective volume ratio occupied by the battery can be improved. Therefore, it is possible to achieve both high capacity density and high reliability of a laminated battery having a high capacity or a high output. 【0022】 Furthermore, for example, the laminate may be cut by shearing in both the first cutting step and the second cutting step. 【0023】 This allows the laminate to be cut simply by shearing it with a blade, reducing the degradation of battery cells and thus improving battery productivity and effective volume. 【0024】 Furthermore, for example, in the second cutting step, the laminate may be cut with an ultrasonic cutter. 【0025】 This further improves the flatness of the second cross-section. 【0026】 Furthermore, for example, the surface roughness of the second cross-section may be less than or equal to the thickness of the solid electrolyte layer. Also, for example, the second cross-section may be flat. 【0027】 This further improves the reliability of the battery. For example, if the surface roughness of the second cross-section is less than or equal to the thickness of the solid electrolyte layer, even if a protrusion is formed on one of the positive electrode layer or negative electrode layer at the second cross-section, the protrusion will not reach the other layer in the event of deformation, thus effectively suppressing the occurrence of short circuits. 【0028】 The embodiments of this disclosure will be described below with reference to the drawings. 【0029】 The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, processes, and order of processes shown in the following embodiments are examples only and are not intended to limit this disclosure. Furthermore, any components in the following embodiments that are not described in an independent claim will be described as optional components. 【0030】 Furthermore, each figure is a schematic diagram and not necessarily a strictly accurate representation. Therefore, for example, the scale may not necessarily match in each figure. Also, in each figure, substantially identical components are given the same reference numerals, and redundant explanations are omitted or simplified. 【0031】 Furthermore, in this specification, terms indicating relationships between elements such as parallel, perpendicular, or orthogonal, terms indicating the shape of elements such as rectangles or circles, and numerical ranges are not expressions that represent only strict meanings, but rather expressions that include substantially equivalent ranges, such as differences of a few percent. 【0032】 Furthermore, in this specification and the drawings, the x, y, and z axes represent the three axes of a three-dimensional Cartesian coordinate system. The x and y axes correspond to the first side and the second side perpendicular to the first side of the rectangle, respectively, when the plan view shape of the battery is rectangular. The z axis corresponds to the stacking direction of each layer of the laminate and the battery. 【0033】 Furthermore, in this specification, the "stacking direction" coincides with the direction normal to the main surface of the current collector and the active material layer. Also, in this specification, "plan view" means a view from a direction perpendicular to the main surface of the battery or stack, unless otherwise specified. When it is written as "plan view of a certain surface," such as "plan view of a cross-section," it means a view of that "certain surface" from the front. 【0034】 Furthermore, in this specification, the terms "upper" and "lower" do not refer to the upward (vertically upward) and downward (vertically downward) directions in absolute spatial perception, but rather to terms defined by the relative positional relationship based on the stacking order in a stacked configuration. In addition, the terms "upper" and "lower" apply not only when two components are spaced apart and another component exists between them, but also when two components are placed in close proximity and touching each other. In the following description, the negative side of the z-axis is referred to as "lower" or "bottom," and the positive side of the z-axis is referred to as "upper" or "top." 【0035】 (Embodiment 1) [composition] First, the configuration of the battery according to Embodiment 1 will be explained using Figures 1A and 1B. 【0036】 Figure 1A is a cross-sectional view showing the cross-sectional configuration of the battery 1 according to this embodiment. Figure 1B is a top view of the battery 1 according to this embodiment. Note that Figure 1A represents the cross-section along the line Ia-Ia in Figure 1B. 【0037】 First, let me explain the overview of battery 1. 【0038】 As shown in Figures 1A and 1B, the battery 1 according to this embodiment comprises a battery cell 10 having a positive electrode layer 11, a negative electrode layer 12, and a solid electrolyte layer 13 located between the positive electrode layer 11 and the negative electrode layer 12, a positive electrode current collector 14, and a negative electrode current collector 15. The battery 1 is, for example, an all-solid-state battery. 【0039】 The plan view shape of battery 1 is, for example, a rectangle. The shape of battery 1 is, for example, a flattened rectangular parallelepiped. Here, flattening means that the thickness (i.e., the length in the z-axis direction) is shorter than the length of each side of the main face (i.e., the respective lengths in the x-axis and y-axis directions) or the maximum width. The plan view shape of battery 1 may also be a square, parallelogram, rhombus, or other quadrilateral, or a hexagon or octagon, or other polygon. Furthermore, although the shape of battery 1 is, for example, a rectangular parallelepiped, it may also be a cube, a pyramidal 【0040】 In battery 1, in a plan view, the positive electrode current collector 14, positive electrode layer 11, solid electrolyte layer 13, negative electrode layer 12, and negative electrode current collector 15 are all the same in shape and size, and their contours coincide. 【0041】 Battery 1 has parallel main surfaces 16 and 17 facing each other with the battery cell 10 in between, and four side surfaces connecting the main surfaces 16 and 17. Main surface 16 is the uppermost surface of battery 1. Main surface 17 is the lowermost surface of battery 1. 【0042】 Each of the four sides extends, for example, perpendicularly from each edge of the main surface 17 toward the main surface 16. The four sides of the battery 1 are, for example, two pairs of sides that are parallel to each other. One pair of sides of the two pairs are the second cut surfaces 120 and 120a formed in the second cutting process described later. The battery 1 only needs to have at least one of its sides be the second cut surface. Furthermore, from the viewpoint of increasing capacity density and reliability, all sides of the battery 1 may be the second cut surface. 【0043】 The battery cell 10 is located between the positive electrode current collector 14 and the negative electrode current collector 15. Although the battery 1 comprises one battery cell 10, the number of battery cells 10 is not limited to one; there may be two or more. For example, the battery according to this embodiment may be a stacked battery in which multiple battery cells 10 are stacked with at least one of the positive electrode current collector 14 and the negative electrode current collector 15 in between. 【0044】 Battery 1 is manufactured by cutting the ends of the laminate 1a, which will be described later. The laminate configuration of battery 1 is the same as that of laminate 1a. Details of each layer of battery 1 will be described later as part of the explanation of laminate 1a. 【0045】 In this embodiment, the battery 1 may further have tabs or leads, which are electrodes for external extraction, connected to at least one of the positive electrode current collector 14 and the negative electrode current collector 15. Furthermore, to maintain the airtightness of the battery 1 and to protect it, the battery 1 may be laminated with an outer casing, or the battery 1 may be resin-sealed. Also, to protect the cut surface, at least a portion of the second cut surfaces 120 and 120a may be covered with an insulating material. As the insulating material, a material having at least electrical insulating properties may be used, and a material having impact resistance, heat resistance, flexibility, and gas barrier properties may also be used. As the insulating material, for example, polymers such as epoxy resin, acrylic resin, methacrylic resin, aramid resin, and polyimide resin, or inorganic adhesive materials can be used. 【0046】 [Battery manufacturing method] Next, the manufacturing method of the battery 1 according to this embodiment will be described using Figures 2A, 2B, 3, and 4. 【0047】 The manufacturing method of the battery 1 according to this embodiment includes, for example, a laminate formation step, a first cutting step, and a second cutting step. 【0048】 First, let's explain the laminate formation process. 【0049】 Figure 2A is a cross-sectional view showing the cross-sectional structure of the laminate 1a according to this embodiment. Figure 2B is a top view of the laminate 1a according to this embodiment. Note that Figure 2A represents the cross-section along the line IIa-IIa in Figure 2B. Also, in Figure 2B, the plan view shape of the battery cell 10 is shown by a dashed line. 【0050】 In the laminate formation process, a laminate 1a is formed. As shown in Figures 2A and 2B, the laminate 1a according to this embodiment comprises a battery cell 10 having a positive electrode layer 11, a negative electrode layer 12, and a solid electrolyte layer 13 located between the positive electrode layer 11 and the negative electrode layer 12, a positive electrode current collector 14, and a negative electrode current collector 15. 【0051】 The laminate 1a has parallel main surfaces 16a and 17a facing each other with the battery cell 10 in between. Main surface 16a is the uppermost surface of the laminate 1a. Main surface 17a is the lowermost surface of the laminate 1a. 【0052】 The positive electrode layer 11 is located between the positive electrode current collector 14 and the solid electrolyte layer 13. The positive electrode layer 11 is positioned in contact with the main surface of the positive electrode current collector 14 on the negative electrode layer 12 side. Note that other layers, such as a conductive junction layer, may be provided between the positive electrode layer 11 and the positive electrode current collector 14. 【0053】 The positive electrode layer 11 includes a positive electrode material, such as a positive electrode active material. Various materials capable of releasing and inserting metal ions, such as lithium ions or magnesium ions, can be used as the positive electrode active material. In the case of a material capable of releasing and inserting lithium ions, examples of positive electrode active materials that can be used include lithium cobalt oxide composite oxide (LCO), lithium nickel oxide composite oxide (LNO), lithium manganese oxide composite oxide (LMO), lithium-manganese-nickel composite oxide (LMNO), lithium-manganese-cobalt composite oxide (LMCO), lithium-nickel-cobalt composite oxide (LNCO), lithium-nickel-manganese-cobalt composite oxide (LNMCO), and lithium-nickel-cobalt-aluminum composite oxide (LNCAO). 【0054】 Furthermore, the positive electrode layer 11 may contain a solid electrolyte, such as an inorganic solid electrolyte. As the inorganic solid electrolyte, sulfide solid electrolytes or oxide solid electrolytes may be used. As the sulfide solid electrolyte, for example, a mixture of lithium sulfide (Li2S) and phosphorus pentasulfide (P2S5) may be used. Alternatively, as the sulfide solid electrolyte, sulfides such as Li2S-SiS2, Li2S-B2S3, or Li2S-GeS2 may be used, and sulfides to which at least one of Li3N, LiCl, LiBr, Li3PO4, and Li4SiO4 has been added as an additive may also be used. 【0055】 Examples of oxide solid electrolytes include Li7La3Zr2O 12 (LLZ), Li 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP) or (La,Li)TiO3(LLTO) are used. 【0056】 The surface of the positive electrode active material may be coated with a solid electrolyte. 【0057】 Furthermore, the positive electrode layer 11 may contain at least one of the following materials: conductive materials such as acetylene black, Ketjenblack (registered trademark), and carbon nanofibers, and binding binders such as polyvinylidene fluoride. 【0058】 For example, the positive electrode layer 11 is produced by coating the main surface of the positive electrode current collector 14 with a paste-like coating made by kneading the materials containing the positive electrode layer 11 together with a solvent, and then drying it. In order to increase the density of the positive electrode layer 11, the positive electrode layer 11 coated on the positive electrode current collector 14, also called the positive electrode plate, may be pressed after drying. The thickness of the positive electrode layer 11 is, for example, 5 μm to 300 μm, but is not limited to this. 【0059】 The negative electrode layer 12 is located between the negative electrode current collector 15 and the solid electrolyte layer 13. The negative electrode layer 12 is positioned in contact with the main surface of the negative electrode current collector 15 on the positive electrode layer 11 side. The negative electrode layer 12 is also positioned opposite the positive electrode layer 11. Note that other layers, such as a conductive junction layer, may be provided between the negative electrode layer 12 and the negative electrode current collector 15. 【0060】 The negative electrode layer 12 includes, for example, a negative electrode active material as an electrode material. Various materials capable of releasing and inserting ions such as lithium ions or magnesium ions can be used as the negative electrode active material. In the case of a material capable of releasing and inserting lithium ions, the negative electrode active material contained in the negative electrode layer 12 may be a single material or mixture thereof such as graphite, metallic lithium, or silicon, or a negative electrode active material such as lithium-titanium oxide (LTO). 【0061】 Furthermore, as the material containing the negative electrode layer 12, a solid electrolyte such as an inorganic solid electrolyte may be used. As an inorganic solid electrolyte, for example, the inorganic solid electrolyte exemplified as the material containing the positive electrode layer 11 may be used. 【0062】 Furthermore, the negative electrode layer 12 may contain at least one of the following materials: conductive materials such as acetylene black, Ketjen black, and carbon nanofibers, and binding binders such as polyvinylidene fluoride. 【0063】 For example, the negative electrode layer 12 is produced by coating the main surface of the negative electrode current collector 15 with a paste-like coating made by kneading the materials containing the negative electrode layer 12 together with a solvent, and then drying it. In order to increase the density of the negative electrode layer 12, the negative electrode layer 12 coated on the negative electrode current collector 15, also called the negative electrode plate, may be pressed after drying. The thickness of the negative electrode layer 12 is, for example, 5 μm to 300 μm, but is not limited to this. 【0064】 The positive electrode layer 11 is in contact with the main surface of the positive electrode current collector 14. The positive electrode current collector 14 may also include a current collector layer containing a conductive material in the portion that is in contact with the positive electrode layer 11. The negative electrode layer 12 is in contact with the main surface of the negative electrode current collector 15. The negative electrode current collector 15 may also include a current collector layer containing a conductive material in the portion that is in contact with the negative electrode layer 12. 【0065】 The positive electrode current collector 14 and the negative electrode current collector 15 are each conductive foil-shaped, plate-shaped, or mesh-shaped members. The positive electrode current collector 14 and the negative electrode current collector 15 may each be, for example, a conductive thin film. As materials for constituting the positive electrode current collector 14 and the negative electrode current collector 15, metals such as stainless steel (SUS), aluminum (Al), copper (Cu), and nickel (Ni) can be used. The positive electrode current collector 14 and the negative electrode current collector 15 may be formed using different materials. 【0066】 The thickness of the positive electrode current collector 14 and the negative electrode current collector 15 is, for example, 5 μm or more and 100 μm or less, but is not limited to this. 【0067】 The solid electrolyte layer 13 is placed between the positive electrode layer 11 and the negative electrode layer 12. The solid electrolyte layer 13 is in contact with both the positive electrode layer 11 and the negative electrode layer 12. The solid electrolyte layer 13 is a layer containing an electrolyte material. As the electrolyte material, generally known electrolytes for batteries can be used. The thickness of the solid electrolyte layer 13 may be 5 μm or more and 300 μm or less, or 5 μm or more and 100 μm or less. 【0068】 The solid electrolyte layer 13 contains a solid electrolyte. As the solid electrolyte, for example, an inorganic solid electrolyte may be used. As the inorganic solid electrolyte, the inorganic solid electrolyte exemplified as the material contained in the positive electrode layer 11 may be used. 【0069】 The solid electrolyte layer 13 may also contain, in addition to the electrolyte material, a binding binder such as polyvinylidene fluoride. 【0070】 For example, the solid electrolyte layer 13 can be produced by applying a paste-like coating, which is made by kneading the materials containing the solid electrolyte layer 13 together with a solvent, onto the main surfaces of the positive electrode layer 11 and / or the negative electrode layer 12 and drying it. Alternatively, the solid electrolyte layer 13 may be produced by applying the paste-like coating onto a release film and drying it. 【0071】 For example, a laminate 1a is manufactured by stacking a positive electrode current collector 14, a positive electrode layer 11, a solid electrolyte layer 13, a negative electrode layer 12, and a negative electrode current collector 15 in this order and pressing them together. For example, a flat plate press, a roll press, or a hydrostatic press can be used for pressing. Furthermore, heating may be used during pressing to improve the adhesion and density of each layer. The heating temperature should be set within a range that does not cause chemical changes in the materials of each layer due to heat, for example, between 60°C and 200°C. 【0072】 Furthermore, in this embodiment, the positive electrode layer 11, the negative electrode layer 12, and the solid electrolyte layer 13 are maintained in a parallel plate shape. This suppresses the occurrence of cracks or collapse due to bending. Alternatively, the positive electrode layer 11, the negative electrode layer 12, and the solid electrolyte layer 13 may be smoothly curved together. 【0073】 Furthermore, in the battery cell 10, the positive electrode layer 11, the negative electrode layer 12, and the solid electrolyte layer 13 are provided with their respective sides on the same plane, but are not limited to this. For example, in a plan view, the positions of the sides of the positive electrode layer 11, the negative electrode layer 12, and the solid electrolyte layer 13 may be different. Also, for example, in the battery cell 10, at least one side of the positive electrode layer 11 and the negative electrode layer 12 may be covered by the solid electrolyte layer 13, and the solid electrolyte layer 13 may be in contact with at least one of the positive electrode current collector 14 and the negative electrode current collector 15. 【0074】 Furthermore, in the laminate 1a, for example, there is a portion on the main surface of the positive electrode current collector 14 facing the battery cell 10 where the positive electrode layer 11 is not provided. Also, in the laminate 1a, for example, there is a portion on the main surface of the negative electrode current collector 15 facing the battery cell 10 where the negative electrode layer 12 is not provided. Thus, in the laminate 1a, there are regions on the current collector where the positive electrode layer 11 and the negative electrode layer 12 are not present and the battery does not function. However, as will be described later, the capacity density of the battery 1 can be improved by cutting off the ends of the laminate 1a. Note that the solid electrolyte layer 13 may be in contact with at least one of the portion of the positive electrode current collector 14 where the positive electrode layer 11 is not provided and the portion of the negative electrode current collector 15 where the negative electrode layer 12 is not provided. 【0075】 Next, the first cutting process and the second cutting process will be described. 【0076】 Figure 3 is a cross-sectional view illustrating the manufacturing method of the battery 1 according to this embodiment. 【0077】 In the first cutting step, as shown in Figure 3(a), the laminate 1a formed in the laminate formation step is cut at the first cutting positions 111 and 111a, indicated by dashed lines in the figure, to form the first cutting surfaces 110 and 110a. This forms the laminate 1b shown in Figure 3(b). The first cutting surfaces 110 and 110a are the sides connecting the main surface 16b and the main surface 17b of the laminate 1b. 【0078】 In the first cutting step, the laminate 1a is cut at a first cutting position 111 that passes through the positive electrode layer 11, negative electrode layer 12, and solid electrolyte layer 13 of the battery cell 10. Specifically, in the first cutting step, as shown in Figures 3(a) and (b), all components of the laminate 1a, namely the positive electrode layer 11, negative electrode layer 12, solid electrolyte layer 13, positive electrode current collector 14, and negative electrode current collector 15, are cut together to form a planar first cutting surface 110. The first cutting position 111 is a position that passes through two main surfaces 16a and 17a of the laminate 1a. The direction in which the first cutting surface 110 extends is not particularly limited. For example, the first cutting surface 110 is perpendicular to the main surfaces 16a and 17a. 【0079】 Furthermore, the first cutting position 111 is not particularly limited. The first cutting position 111 may be a position where the end of the laminate 1a is cut off, or it may be a position where the laminate 1a is divided into multiple laminates. 【0080】 The cutting method in the first cutting step can be, for example, shearing with a cutting tool, cutting with an end mill, grinding, laser cutting, or jet cutting, but is not limited to these methods. From the viewpoint of improving productivity and effective volume, the cutting method in the first cutting step may be shearing using a cutting tool or the like. 【0081】 Furthermore, in the first cutting process, for example, with respect to the position of the laminate 1a, the cutting proceeds along a first direction C10, which is a fixed direction, at the first cutting position 111. The direction in which the cutting proceeds is, for example, in the case of shearing using a cutting tool, the direction in which the cutting tool moves relative to the laminate 1a when viewed from above with respect to the first cut surface 110 that is formed. The first direction C10 is, for example, a direction perpendicular to the main surfaces 16a and 17a when viewed from above with respect to the first cut surface 110, in other words, a direction parallel to the stacking direction of the laminate 1a. This makes it possible to cut the laminate 1a along the direction connecting the main surfaces 16a and 17a in the shortest distance, thereby improving the productivity of the battery 1. Note that the first direction C10 is not particularly limited and may be a direction that intersects the direction perpendicular to the main surfaces 16a and 17a. 【0082】 Next, in the second cutting step, as shown in Figure 3(b), the laminate 1b formed in the first cutting step is cut at second cutting positions 121 and 121a, indicated by dashed lines in the figure, located inside the first cutting surfaces 110 and 110a, and at distances W and Wa, respectively, from the first cutting surfaces 110 and 110a, to form second cutting surfaces 120 and 120a. This forms the battery 1 shown in Figure 3(c). 【0083】 In the second cutting process, as shown in Figures 3(b) and 3(c), the laminate 1b is cut at a second cutting position 121 located a distance W inward from the first cutting surface 110 to form a planar second cutting surface 120. Distance W is the distance between the first cutting surface 110 and the formed second cutting surface 120. Since the second cutting surface 120 is formed at the second cutting position 121, distance W can also be said to be the distance between the first cutting surface 110 and the second cutting position 121. The second cutting position 121 is a position that does not pass through the first cutting surface 110. The first cutting surface 110 and the second cutting surface 120 (in other words, the second cutting position 121) may be parallel. As a result, the distance between the first cutting surface 110 and the second cutting position 121 remains constant, which stabilizes the quality of the second cutting surface and reduces the volume removed in the second cutting process. 【0084】 In the second cutting step, for example, in the same manner as in the first cutting step, all the components of the laminate 1b, i.e., the positive electrode layer 11, the negative electrode layer 12, the solid electrolyte layer 13, the positive electrode current collector 14, and the negative electrode current collector 15, are cut together to form the second cut surface 120. The second cutting position 121 is a position passing through the two main surfaces 16b and 17b of the laminate 1b. 【0085】 The second cutting position 121 is in the vicinity of the first cut surface 110. In the second cutting step, the relationship between the surface roughness Rz1 of the first cut surface 110 and the distance W satisfies Rz1 < W < 5Rz1. For example, in the second cutting step, the second cutting position 121 is set at a position inside the distance W that satisfies the above relationship from the upper edge of the first cut surface 110, and the laminate 1b is cut. When the distance W is less than or equal to the surface roughness Rz1 of the first cut surface 110, there is a possibility that burrs or the like present on the surface of the first cut surface 110 cannot be sufficiently removed. Also, when the distance W is five times or more the surface roughness Rz1 of the first cut surface 110, the surface roughness Rz2 of the second cut surface 120 is unlikely to decrease, and it becomes difficult to obtain the effects of the present disclosure. The relationship between the surface roughness Rz1 of the first cut surface 110 and the distance W satisfies Rz1 < W < 5Rz1 at any position. In this specification, the surface roughness such as the surface roughness Rz1 is the maximum height roughness measured by a measurement method conforming to JIS B0601 2013. 【0086】 From the viewpoint of improving the flatness of the second cut surface, the relationship between the surface roughness Rz1 of the first cut surface 110 and the distance W may satisfy Rz1 < W < 4Rz1. 【0087】 Also, the distance W between the first cut surface 110 and the second cutting position 121 may be three times or less the thickness of the laminate 1b, or may be two times or less. Thereby, the surface roughness Rz2 of the second cut surface 120 can be more effectively reduced. 【0088】 Furthermore, the second cross-section 120 is perpendicular to, for example, the main surfaces 16b and 17b of the laminate 1b. As a result, the positions of the end faces of each layer of the battery 1 exposed at the second cross-section 120 are aligned when viewed from the stacking direction, thereby increasing the effective volume of the battery. For example, at the second cross-section 120, the sides of the positive electrode layer 11, negative electrode layer 12, solid electrolyte layer 13, positive electrode current collector 14, and negative electrode current collector 15 of the battery 1 are exposed and flush. Also, for example, when viewed from the stacking direction of the battery 1, the positions of the sides of the positive electrode layer 11, negative electrode layer 12, solid electrolyte layer 13, positive electrode current collector 14, and negative electrode current collector 15 coincide at the second cross-section 120. 【0089】 The cutting method in the second cutting process can include, but is not limited to, shearing with a cutting tool, cutting with an end mill, grinding, laser cutting, or jet cutting. From the viewpoint of improving productivity and effective volume, the cutting method in the second cutting process may be shearing using a cutting tool. In addition, with shearing, the temperature of the laminate 1b does not rise easily during cutting, and the battery cells 10 do not deteriorate easily during cutting. Furthermore, from the viewpoint of improving the flatness of the second cut surface 120, the shearing process may be cutting using an ultrasonic cutter that transmits high-frequency vibrations to the cutting edge. 【0090】 Furthermore, in the second cutting process, for example, with the position of the laminate 1b as the reference, the cutting proceeds along a second direction C20, which is a constant direction at the second cutting position 121. The direction in which the cutting proceeds is the same as the first direction C10, for example, in the case of shearing using a cutting tool, the direction in which the cutting tool moves relative to the laminate 1b when viewed from above with respect to the formed second cutting surface 120. The second direction C20 is, for example, a direction perpendicular to the main surfaces 16b and 17b when the second cutting surface 120 is viewed from above. Therefore, the second direction C20 is parallel to and in the same direction as the first direction C10. As a result, the laminate 1b can be cut along the direction connecting the main surfaces 16b and 17b in the shortest distance, thereby improving the productivity of the battery 1. Furthermore, when comparing the relationship between the first direction C10 and the second direction C20, even if the first cutting position 111 and the second cutting position 121 are not parallel, the comparison is made assuming that the first cutting position 111 and the second cutting position 121 are parallel. 【0091】 Furthermore, the second direction C20 is not particularly limited, and the first direction C10 and the second direction C20 are not limited to being in a parallel positional relationship. Figure 4 is a top view illustrating another example of the second direction in the second cutting process. As shown in Figure 4, the first direction C10 and the second direction C21 are not parallel but in different directions. Specifically, the second direction C21 is perpendicular to the first direction C10 and perpendicular to the stacking direction of the laminate 1b (for example, the longitudinal direction of the first cutting surface 110). With the first direction C10 and the second direction C21 in this manner, it becomes easy to position the first cutting position 111 at any position on the laminate 1a in the first cutting process. Also, since the direction in which cutting progresses in the second cutting process is perpendicular to the stacking direction of the laminate 1b, even if burrs etc. are generated by cutting, the burrs etc. are formed to extend perpendicular to the stacking direction. Therefore, the occurrence of short circuits between each layer of the laminate 1b is suppressed, and the reliability of the battery 1 can be improved. The above example is not applicable if the first direction C10 and the second direction C21 are different directions. By having different first and second directions C10 and C21, the laminates 1a and 1b can be cut in the first and second cutting processes by adjusting the direction according to the quality of the cut surface and the ease of cutting. 【0092】 The surface roughness Rz2 of the second cross-section 120 may be, for example, greater than 0 and less than or equal to the thickness of the solid electrolyte layer 13. By having a surface roughness Rz2 of the second cross-section 120 that is less than or equal to the thickness of the solid electrolyte layer 13, even if a protrusion is formed on one of the positive electrode layer 11 and the negative electrode layer 12 at the second cross-section 120, the protrusion will not reach the other in the event of deformation, etc., thereby effectively suppressing the occurrence of short circuits. Furthermore, the surface roughness Rz2 of the second cross-section 120 may be less than the thickness of the solid electrolyte layer 13. 【0093】 Furthermore, the surface roughness Rz2 of the second cross-section 120 may be 30 μm or less, or 20 μm or less. Also, the second cross-section 120 may be flat. This can improve the reliability of the battery 1. In this specification, "flat" means substantially flat, for example, that the surface roughness Rz2 is 10 μm or less. 【0094】 Furthermore, the first cutting process and the second cutting process may be carried out continuously as a series of processes. This can improve productivity. Here, carrying out the processes continuously as a series of processes means that the first cutting process and the second cutting process are carried out without any other processes being performed between the first cutting process and the second cutting process, such as processing or measuring the laminate 1a. For example, in the first cutting process, the laminate 1a may be fixed in place for cutting, and the second cutting process may be carried out while the laminate 1a is still fixed after cutting. Also, the first cutting process and the second cutting process may be carried out using cutting equipment on a continuous manufacturing line. Furthermore, the second cutting process may be carried out within one minute after the completion of the first cutting process. 【0095】 Through the process described above, a battery 1 having second cross-sections 120 and 120a as shown in Figure 3(c) is manufactured. 【0096】 In the above description, the formation of the first cut surface 110 and the second cut surface 120 has been mainly described. However, the same applies to the first cut surface 110a and the second cut surface 120a, so detailed description thereof will be omitted. Also, in the present embodiment, the number of the first cut surface and the second cut surface is two for each, but it is not limited thereto, and at least one surface for each may be sufficient. That is, in the battery 1 according to the present embodiment, at least one side surface may be the second cut surface. From the viewpoint of further improving the capacity density and reliability, all the side surfaces of the battery 1 may be the second cut surface. 【0097】 According to the manufacturing method of the battery 1 according to the present embodiment, a first cutting step of forming the first cut surface 110 and a second cutting step of forming the second cut surface 120 at a second cutting position 121 close to the first cut surface 110 are performed. Thereby, since it is possible to remove a portion that does not contribute to the power generation of the battery 1, etc., the ratio of the effective volume, which is the volume contributing to the power generation in the battery 1, can be improved. Further, in the second cutting step, by satisfying the relationship between the surface roughness Rz1 of the first cut surface 110 and the distance W as Rz1 < W < 5Rz1, the vicinity of the first cut surface 110 where burrs and sag formed in the first cutting step are likely to be formed is cut away, and the battery 1 having the second cut surface 120 with fewer burrs and sag and being flatter than the first cut surface 110 can be manufactured. Thereby, it is possible to achieve both the high capacity density and the high reliability of the battery 1. 【0098】 (Embodiment 2) Next, a manufacturing method of the battery according to Embodiment 2 will be described. In Embodiment 2, the number of battery cells included in the laminate is different from that in Embodiment 1. Hereinafter, the differences will be described, and the description of the common points will be omitted or simplified. 【0099】 Figure 5 is a cross-sectional view showing the cross-sectional configuration of the laminate 2a according to this embodiment. In this embodiment, the laminate 2a is formed in the laminate formation process, and the laminate 2a is cut in the first cutting process. As shown in Figure 5, the laminate 2a has a plurality of battery cells 10, a positive electrode current collector 14, and a negative electrode current collector 15. The plurality of battery cells 10 are stacked so that adjacent battery cells 10 are electrically connected via the current collectors. In the laminate 2a, negative electrode layers 12 are arranged on the upper and lower main surfaces of the negative electrode current collector 15. In other words, the plurality of battery cells 10 are stacked so that they are electrically connected in parallel by the like electrodes of adjacent battery cells 10 being electrically connected via the current collectors. Therefore, the stacking order is reversed for adjacent battery cells 10. Each battery cell 10 is sandwiched between the positive electrode current collector 14 and the negative electrode current collector 15 without any other battery cells 10 in between. 【0100】 The negative electrode layer 12 is produced by coating a paste-like coating, which is made by kneading the materials for the negative electrode layer 12 together with a solvent, onto both main surfaces of the negative electrode current collector 15 and allowing it to dry. In order to increase the density of the negative electrode layer 12, the negative electrode layer 12 coated onto the negative electrode current collector 15, also called the negative electrode plate, may be pressed after drying. 【0101】 The solid electrolyte layer 13 and the positive electrode layer 11 are manufactured in the same manner as in Embodiment 1. The laminate 2a is also crimped in the same manner as in Embodiment 1. 【0102】 The laminate 2a may have a structure in which the positions of the negative electrode layer 12 and the positive electrode layer 11 are swapped. Also, although the number of battery cells 10 in the laminate 2a is two, there may be three or more. For example, the number of battery cells 10 can be increased by placing positive electrode layers 11 on both sides of the positive electrode current collector 14 and stacking the battery cells 10. In addition, in the laminate 2a, the battery cells 10 may be stacked in such a way that the opposite poles of adjacent battery cells 10 are electrically connected in series via the current collector. In this case, the positive electrode layer 11 is placed on one main surface of at least one positive electrode current collector 14 or negative electrode current collector 15, and the negative electrode layer 12 is placed on the other main surface. 【0103】 Furthermore, when stacking multiple battery cells 10, they may be stacked with a conductive layer in between. Figure 6 is a cross-sectional view showing the cross-sectional configuration of the stacked body 3a according to this embodiment. In this embodiment, the stacked body 3a may be cut in the first cutting step. 【0104】 As shown in Figure 6, the laminate 3a comprises a plurality of laminates 1a, each having a battery cell 10, and a conductive layer 31. The plurality of laminates 1a are stacked such that adjacent laminates 1a are electrically connected via the conductive layer 31. In other words, the conductive layer 31 is located between adjacent laminates 1a. In the laminate 3a, a positive electrode current collector 14 is placed on one main surface of the conductive layer 31, and a negative electrode current collector 15 is placed on the other main surface. In other words, in the laminate 3a, the plurality of battery cells 10 are stacked such that the opposite poles of adjacent battery cells 10 are electrically connected in series via the positive electrode current collector 14, the negative electrode current collector 15, and the conductive layer 31. Therefore, the stacking order of the plurality of laminates 1a is the same. 【0105】 The material of the conductive layer 31 is not particularly limited, and for example, a conductive adhesive having electrical conductivity and adhesive properties can be used. As the conductive adhesive, for example, a mixture of metal particles and resin, a conductive polymer, or a low melting point metal can be used. Furthermore, the laminate 3a does not necessarily have to have a conductive layer 31, and the positive electrode current collector 14 and the negative electrode current collector 15 may be directly joined between adjacent laminates 1a. 【0106】 The laminate 3a is manufactured, for example, by applying a conductive adhesive as the material for the conductive layer 31 onto the positive electrode current collector 14 or the negative electrode current collector 15 of the laminate 1a formed by the method described above, and then joining the two laminates 1a together via the conductive adhesive. 【0107】 In the laminate 3a, the number of multiple laminates 1a is two, but it may be three or more. The number of multiple laminates 1a in the laminate 3a can be adjusted by increasing the number of laminates 1a and conductive layers 31 to be joined. In addition, in the laminate 3a, the multiple battery cells 10 may be laminated in such a way that adjacent battery cells 10 with the same poles are electrically connected in parallel by electrically connecting the positive electrode current collector 14 or the negative electrode current collector 15 and the conductive layer 31. 【0108】 By performing the first cutting step and the second cutting step using the laminated body 2a or laminated body 3a prepared in this manner, a laminated battery having a structure in which multiple battery cells 10 are stacked can be manufactured. 【0109】 Figure 7 is a cross-sectional view illustrating the battery manufacturing method according to this embodiment. As shown in Figure 7, in the first cutting step, the laminate 2a is cut at first cutting positions 211 and 211a, indicated by dashed lines in the figure, to form a first cut surface. Next, in the second cutting step, the cut laminate 2a is further cut at second cutting positions 221 and 221a, indicated by dashed lines in the figure, which are inside the first cut surface, to form a second cut surface. In this case, in the first and second cutting steps, all of the multiple battery cells 10 provided in the laminate 2a are cut at once. Details of the first and second cutting steps are as described in Embodiment 1. By manufacturing a battery through the same first and second cutting steps as described above, it is possible to achieve both high capacity density and high reliability in the manufactured laminated battery. Similarly, when using the laminate 3a, it is possible to achieve both high capacity density and high reliability in the manufactured laminated battery. 【0110】 (Examples) The details of this disclosure will be described below in detail based on the following examples. However, this disclosure is not limited in any way by the following examples. 【0111】 [Preparation of evaluation laminates] A slurry was formed by mixing lithium cobalt oxide powder, which is the positive electrode active material, a lithium sulfide-phosphorus pentasulfide mixture, which is the solid electrolyte, and xylene solvent. This slurry was then coated onto a 12 μm thick aluminum foil, which is the positive electrode current collector, and dried to produce a positive electrode plate having a positive electrode layer. 【0112】 Furthermore, graphite powder, which is the negative electrode active material, the same solid electrolyte as above, and xylene solvent were mixed to form a slurry. This slurry was then coated onto a 15 μm thick stainless steel foil, which is the negative electrode current collector, and dried to produce a negative electrode plate having a negative electrode layer. 【0113】 Next, the same solid electrolyte and xylene solvent as described above were mixed to form a slurry, which was then coated onto the negative electrode layer and dried to produce a solid electrolyte layer. The positive electrode plate and the negative electrode plate were then stacked with the solid electrolyte layer on the negative electrode layer in between, and the laminate was produced by pressurizing under conditions of heating at 120°C. The thickness of the laminate at this time was 150 μm. The thickness of the solid electrolyte layer was 30 μm. 【0114】 The fabricated laminate was cut using a shear to form a first cross-section. The surface roughness Rz1 of the first cross-section was measured using a laser microscope (Keyence Corporation). The surface roughness Rz1 of the formed first cross-section was 84 μm. 【0115】 Furthermore, the laminate with the first cross-section was cut in a direction perpendicular to the first cross-section to divide it into 15 pieces, obtaining 15 evaluation laminates, each having one of the divided first cross-sections, and approximately 15 mm square. 【0116】 [Example 1] Next, the evaluation laminate was cut using an ultrasonic cutter at a second cutting position 100 μm inward from the first cutting surface to form a second cutting surface, thereby obtaining a battery with a second cutting surface. In other words, the above-described second cutting step was performed under the condition that the distance W between the first cutting surface and the formed second cutting surface was 100 μm. The same operation was repeated three times using different evaluation laminates to produce three batteries. 【0117】 The surface roughness Rz2 of the second cross-section of the fabricated batteries was measured using a laser microscope (Keyence Corporation). Furthermore, the potential difference between the positive and negative electrode layers of the fabricated batteries was measured with a tester to evaluate whether or not a short circuit occurred. Table 1 shows the measurement results for the surface roughness Rz2 of the second cross-section and the short-circuit evaluation results. The surface roughness Rz2 of the second cross-section in Table 1 is the average value of three batteries. The number of short circuits in Table 1 is the number of batteries out of the three in which a short circuit was confirmed. Table 1 also shows the surface roughness Rz1 of the first cross-section, the distance W, W / Rz1, and W / T (where T is the thickness of the evaluation laminate). 【0118】 As shown in Table 1, in the battery of Example 1, the surface roughness Rz2 of the second cross-section was 9 μm, and the number of short circuits was 0. 【0119】 [Example 2] A battery was fabricated in the same manner as in Example 1, except that the distance W was changed to 200 μm. In addition, the surface roughness Rz2 of the second cross-section and the short-circuit evaluation were performed on the battery fabricated in the same manner as in Example 1. The measurement results of the surface roughness Rz2 of the second cross-section and the short-circuit evaluation results are shown in Table 1. As shown in Table 1, in the battery of Example 2, the surface roughness Rz2 of the second cross-section was 6 μm, and the number of short circuits was 0. 【0120】 [Example 3] A battery was fabricated in the same manner as in Example 1, except that the distance W was changed to 300 μm. In addition, the surface roughness Rz2 of the second cross-section and the short-circuit evaluation were performed on the battery fabricated in the same manner as in Example 1. The measurement results of the surface roughness Rz2 of the second cross-section and the short-circuit evaluation results are shown in Table 1. As shown in Table 1, in the battery of Example 3, the surface roughness Rz2 of the second cross-section was 10 μm, and the number of short circuits was 0. 【0121】 [Example 4] A battery was fabricated in the same manner as in Example 1, except that the distance W was changed to 400 μm. Also, the surface roughness Rz2 of the second cut surface of the battery fabricated in the same manner as in Example 1 was measured, and short-circuit evaluation was performed. The measurement results of the surface roughness Rz2 of the second cut surface and the short-circuit evaluation results are shown in Table 1. As shown in Table 1, for the battery in Example 4, the surface roughness Rz2 of the second cut surface was 18 μm, and the number of short circuits was 0. 【0122】 [Comparative Example 1] A battery was fabricated in the same manner as in Example 1, except that the distance W was changed to 500 μm. Also, the surface roughness Rz2 of the second cut surface of the battery fabricated in the same manner as in Example 1 was measured, and short-circuit evaluation was performed. The measurement results of the surface roughness Rz2 of the second cut surface and the short-circuit evaluation results are shown in Table 1. As shown in Table 1, for the battery in Comparative Example 1, the surface roughness Rz2 of the second cut surface was 55 μm, and the number of short circuits was 2. 【0123】 【Table 1】 【0124】 [Summary] As described above, for the batteries in Examples 1 to 4 in which the second cut surface was formed under the condition that W / Rz1 is greater than 1 and less than 5, that is, Rz1 < W < 5Rz1, the surface roughness Rz2 of the second cut surface was small and less than or equal to the thickness of the solid electrolyte layer, and no short circuit occurred. Thus, it was found that high reliability can be achieved. Also, in this case, the distance W is less than or equal to 3 times the thickness T of the laminate for evaluation. 【0125】 Also, for the batteries in Examples 1 to 3 in which the second cut surface was formed under the condition that W / Rz1 is greater than 1 and less than 4, that is, Rz1 < W < 4Rz1, the surface roughness Rz2 of the second cut surface was 10 μm or less, and a substantially flat second cut surface was formed. Thus, it was found that particularly high reliability can be achieved. Also, in this case, the distance W is less than or equal to 2 times the thickness T of the laminate for evaluation. 【0126】 In contrast, in Comparative Example 1 where the second cut surface was formed under the condition that W / Rz1 is 5 or more and Rz1 < W < 5Rz1 is not satisfied, the surface roughness Rz2 of the second cut surface of the battery was larger than that of the batteries in Examples 1 to 4, and a short circuit occurred. Therefore, it was found that under the production conditions of the battery in Comparative Example 1, the reliability of the battery was lower than that in Examples 1 to 4. Thus, simply cutting the evaluation laminate twice may not be able to improve the reliability of the battery, and it was confirmed that the reliability of the battery can be improved by performing the second cut under the condition that Rz1 < W < 5Rz1. 【0127】 (Other embodiments) As described above, the battery and the method for manufacturing the battery according to the present disclosure have been described based on the embodiments and examples. However, the present disclosure is not limited to these embodiments and examples. Without departing from the gist of the present disclosure, various modifications conceived by those skilled in the art applied to the embodiments or other forms constructed by combining some of the components in the embodiments are also included in the scope of the present disclosure. 【0128】 In addition, various changes, replacements, additions, omissions, etc. can be made to the above embodiments within the scope of the claims or their equivalents. 【Industrial applicability】 【0129】 The battery according to the present disclosure can be used as a battery for, for example, electronic devices, electrical appliances, and electric vehicles. 【Explanation of reference numerals】 【0130】 1 Battery 1a, 1b, 2a, 3a Laminate 10 Battery cell 11 Positive electrode layer 12 Negative electrode layer 13 Solid electrolyte layer 14 Positive electrode current collector 15 Negative electrode current collector 16, 16a, 16b, 17, 17a, 17b Main surface 110, 110a First cut surface 111, 111a, 211, 211a First cutting position 120, 120a, second cut surface 121, 121a, 221, 221a Second cutting position 31 conductive layer C10 Direction 1 C20, C21, Second Direction W, Wa distance

Claims

[Claim 1] A first cutting step of cutting a laminate comprising at least one battery cell having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer located between the positive electrode layer and the negative electrode layer at a first cutting position to form a first cut surface, The process includes a second cutting step of cutting the laminate cut in the first cutting step at a second cutting position inside the first cutting surface to form a second cutting surface, In the second cutting step, the distance between the first cut surface and the second cut surface formed is W, and the surface roughness of the first cut surface, which is the maximum height roughness measured by a measurement method in accordance with JIS B0601 2013, is Rz. １ In that case, Rz １ <W<5Rz １ Satisfying Battery manufacturing method. [Claim 2] A first cutting step of cutting a laminate comprising at least one battery cell having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer located between the positive electrode layer and the negative electrode layer at a first cutting position to form a first cut surface, The process includes a second cutting step of cutting the laminate cut in the first cutting step at a second cutting position inside the first cutting surface to form a second cutting surface, In the second cutting step, if W is the distance between the first cut surface and the second cut surface formed, and Rz 1 is the surface roughness of the first cut surface, which is the maximum height roughness measured by a measurement method in accordance with JIS B0601 2013, then Rz 1 < W < 5Rz 1 is satisfied. With respect to the position of the laminate, the first direction in which the cutting of the laminate progresses at the first cutting position is different from the second direction in which the cutting of the laminate progresses at the second cutting position. Battery manufacturing method. [Claim 3] The second direction is perpendicular to the first direction. A method for manufacturing a battery according to claim 2. [Claim 4] The second direction is a direction perpendicular to the stacking direction of the laminate. A method for manufacturing a battery according to claim 2 or 3. [Claim 5] A first cutting step of cutting a laminate comprising at least one battery cell having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer located between the positive electrode layer and the negative electrode layer at a first cutting position to form a first cut surface, The process includes a second cutting step of cutting the laminate cut in the first cutting step at a second cutting position inside the first cutting surface to form a second cutting surface, In the second cutting step, if W is the distance between the first cut surface and the second cut surface formed, and Rz 1 is the surface roughness of the first cut surface, which is the maximum height roughness measured by a measurement method in accordance with JIS B0601 2013, then Rz 1 < W < 5Rz 1 is satisfied. In the second cutting step, the laminate is cut with an ultrasonic cutter. Battery manufacturing method. [Claim 6] The aforementioned W is three times or less the thickness of the laminate. A method for manufacturing a battery according to any one of claims 1 to 5. [Claim 7] The first cutting step and the second cutting step are performed sequentially as a series of steps. A method for manufacturing a battery according to any one of claims 1 to 6. [Claim 8] The aforementioned at least one battery cell is a plurality of battery cells, The aforementioned multiple battery cells are stacked, A method for manufacturing a battery according to any one of claims 1 to 7. [Claim 9] In the first cutting step and the second cutting step, the laminate is cut by shearing. A method for manufacturing a battery according to any one of claims 1 to 8. [Claim 10] The surface roughness of the second cross-section, which is the maximum height roughness measured by a measurement method in accordance with JIS B0601 2013, is less than or equal to the thickness of the solid electrolyte layer. A method for manufacturing a battery according to any one of claims 1 to 9. [Claim 11] The second cross-section is flat. A method for manufacturing a battery according to any one of claims 1 to 10.

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