Battery manufacturing method and battery

Abstract

This battery manufacturing method comprises: a cutting step for cutting a laminate having a structure in which an electrode layer, a solid electrolytic layer, and a counter electrode layer are laminated in the stated order, to form a cut surface by collectively cutting the electrode layer, the solid electrolytic layer, and the counter electrode layer; and a cleaning step for removing attached matter attached to the cut surface and generated by cutting the laminate in the cutting step.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a battery and a battery.

Background Art

[0002] Patent Document 1 discloses a battery formed by laminating a negative electrode having a negative electrode active material layer formed on a negative electrode current collector and a positive electrode having a positive electrode active material layer formed on a positive electrode current collector with at least a non-aqueous electrolyte interposed therebetween, wherein the negative electrode current collector and the positive electrode current collector are laminated such that the protruding directions of burrs present at the peripheral edges thereof are substantially the same.

[0003] Patent Document 2 discloses a cleaning device for removing surface deposits from a long metal foil, in which a slit and conveyed long metal foil is sandwiched from both surfaces by an adhesive roll having a length larger than the full width of the long metal foil, so that deposits on both surfaces of the long metal foil adhere to the surface of the adhesive roll, thereby removing the surface deposits from the long metal foil.

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problem to be Solved by the Invention

[0005] In the prior art, further improvement in the reliability of batteries is desired.

[0006] For example, in a battery in which a solid electrolyte layer is disposed between a positive electrode layer and a negative electrode layer, short-circuiting is likely to occur at the end face of the battery. In particular, when the solid electrolyte layer is thinned to increase the capacity density, short-circuiting is more likely to occur.

[0007] Accordingly, the present disclosure provides a method for manufacturing a battery having high reliability and a battery having high reliability. [Means for solving the problem]

[0008] A method for manufacturing a battery according to one aspect of the present disclosure includes a cutting step of forming a cut surface by cutting a laminate having a battery cell having a structure in which an electrode layer, a solid electrolyte layer, and a counter electrode layer are stacked in this order, so as to cut the electrode layer, the solid electrolyte layer, and the counter electrode layer together; and a cleaning step of removing any deposits that adhere to the cut surface generated by cutting the laminate in the cutting step.

[0009] A battery according to one aspect of the present disclosure comprises a battery cell having a structure in which an electrode layer, a solid electrolyte layer, and a counter electrode layer are stacked in this order, wherein the electrode layer comprises an electrode current collector and an electrode active material layer located between the electrode current collector and the solid electrolyte layer, and the side surface of the electrode current collector is provided with a plurality of linear patterns that extend in a direction inclined with respect to the stacking direction of the battery cell when the side surface of the electrode current collector is viewed from above. [Effects of the Invention]

[0010] According to this disclosure, a method for manufacturing a battery and a battery with high reliability can be provided. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 shows a side view and a top view of a battery according to an embodiment. [Figure 2] Figure 2 is an enlarged side view of region II in Figure 1. [Figure 3] Figure 3 is a flowchart showing an example of a battery manufacturing method according to the embodiment. [Figure 4] Figure 4 is a perspective view illustrating the lamination and cutting processes. [Figure 5] Figure 5 is a plan view of the laminate formed by the cutting process. [Figure 6] Figure 6 is a cross-sectional view of the laminate formed by the cutting process. [Figure 7] FIG. 7 is a diagram for explaining a polishing direction in a polishing step. [Figure 8A] FIG. 8A is a perspective view for explaining an example of a polishing method in a polishing step. [Figure 8B] FIG. 8B is a top view for explaining an example of a polishing method in a polishing step. [Figure 9] FIG. 9 is a cross-sectional view showing a state of deposits after a polishing step. [Figure 10A] FIG. 10A is a perspective view for explaining an example of a cleaning method in a first removal step. [Figure 10B] FIG. 10B is a top view for explaining an example of a cleaning method in a first removal step. [Figure 11] FIG. 11 is a plan view and a cross-sectional view for explaining a second removal step. [Figure 12A] FIG. 12A is a plan view and a cross-sectional view for explaining a state of spraying a gas containing ionic gas in a second removal step. [Figure 12B] FIG. 12B is a plan view and a cross-sectional view for explaining an ion gas space in a second removal step. MODE FOR CARRYING OUT THE INVENTION

[0012] (Findings underlying the present disclosure) One of the important qualities for improving the reliability of a battery including a 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 is suppression of short circuits. To suppress short circuits, for example, an end portion of the battery is cut in the battery manufacturing process. This makes it possible to align the cut surface shapes of the respective layers of the battery cell, and uniformly separate the positive electrode layer and the negative electrode layer as much as possible, thereby suppressing short circuits. Short circuits can also be suppressed by removing current collectors, active materials, and the like adhering to the end portions of the battery. Furthermore, cutting the end portions of the battery enables removal of the end portions of the battery cell, which are less likely to function as a battery during battery manufacturing, so the capacity density of the battery can also be increased. In addition, since the size of the battery can be easily adjusted by cutting, the capacity accuracy of the battery can be improved.

[0013] However, in the step of cutting a battery into a predetermined size, micro conductive paths may be formed due to cutting powder from the conductive current collector and active material layer, and foreign matter adhering during the cutting step, resulting in conduction between the positive electrode and the negative electrode. Therefore, it is desired to suppress a decrease in reliability due to short circuits even for batteries manufactured through cutting processing.

[0014] Accordingly, the present disclosure provides a highly reliable battery manufacturing method and a battery even for a battery manufactured through a cutting step.

[0015] An outline of one aspect of the present disclosure is as follows.

[0016] A battery manufacturing method according to one aspect of the present disclosure includes: a cutting step of forming a cut surface by cutting a laminate having a battery cell having a structure in which an electrode layer, a solid electrolyte layer, and a counter electrode layer are laminated in this order such that the electrode layer, the solid electrolyte layer, and the counter electrode layer are cut all at once; and a cleaning step of removing deposits adhering to the cut surface that are generated by cutting the laminate in the cutting step.

[0017] As a result, the deposits generated on the cut surface during the cutting process are conductive, as described above, and can cause short circuits. However, these deposits are removed during the cleaning process, thus suppressing the occurrence of short circuits. Therefore, according to this embodiment, a battery with high reliability can be manufactured.

[0018] Furthermore, for example, the manufacturing method may include a polishing step of polishing the cut surface before the cleaning step.

[0019] When laminates are cut, the resulting deposits tend to become embedded in the laminate at the cut surface, making them difficult to remove. Polishing the cut surface allows the embedded deposits to be detached, making them easier to remove during the cleaning process. Therefore, the reliability of the manufactured batteries can be further improved.

[0020] Furthermore, for example, in the polishing step, the cut surface may be polished along a direction perpendicular to the lamination direction of the laminate.

[0021] As a result, the frictional force generated during polishing does not act in the direction of the laminate's stacking, preventing it from delaminating each layer of the laminate at the cut surface. Therefore, damage to the laminate during polishing can be suppressed, further improving the reliability of the manufactured batteries.

[0022] Furthermore, for example, the cleaning process may include a first removal step of removing the adhering substances by contact.

[0023] In this way, by bringing the removal member into contact with the cut surface and removing the attached material, high removal efficiency can be achieved.

[0024] Furthermore, for example, the first removal step may include wiping off the adhering material from the cut surface.

[0025] This allows the adhering material to come into contact with the wiping material and be collected, efficiently removing the adhering material from the cut surface.

[0026] Alternatively, for example, in the first removal step, a nonwoven fabric may be used to wipe off any adhering material from the cut surface.

[0027] As a result, the attached material is trapped in the nonwoven fabric, making it easier for the material to be captured and retained by the nonwoven fabric. Therefore, the material attached to the cut surface is removed more efficiently.

[0028] Furthermore, for example, the first removal step may include attaching an adhesive member to the cut surface and then peeling it off to cause the adhering material to stick to the adhesive member.

[0029] This allows for the removal of attached materials simply by applying and peeling off the adhesive material without sliding it across the cut surface, thus suppressing damage to the laminate during material removal.

[0030] Furthermore, for example, the cleaning step may include a second removal step which includes at least one of blowing gas onto the cut surface and sucking up the deposits adhering to the cut surface.

[0031] Furthermore, in the second removal step, ion-containing gas may be blown onto the battery using an electrostatic removal device, and ion-containing gas in the space around the battery may be sucked out using an electrostatic removal device.

[0032] The ionized gas neutralizes the charge between the cut surface and the attached material, reducing adhesion, and allows for the removal of the attached material without contacting the cut surface with an object, thus suppressing damage to the laminate during the removal of attached material.

[0033] Furthermore, a battery according to one aspect of the present disclosure comprises a battery cell having a structure in which an electrode layer, a solid electrolyte layer, and a counter electrode layer are stacked in this order, wherein the electrode layer comprises an electrode current collector and an electrode active material layer located between the electrode current collector and the solid electrolyte layer, and the side surface of the electrode current collector is provided with a plurality of linear patterns that extend in a direction inclined with respect to the stacking direction of the battery cell when the side surface of the electrode current collector is viewed from above.

[0034] For example, when the side surface of a battery is polished, multiple linear patterns are formed by the polishing process. Since these linear patterns are formed along the polishing direction, if the linear patterns are inclined relative to the stacking direction of the battery cells, the polishing direction will also be inclined relative to the stacking direction. Therefore, the frictional force generated by polishing will be applied in a direction inclined relative to the stacking direction, and will not be applied in the direction of the stacking structure, which would cause the layers of the stack to peel off at the cross-section. As a result, the battery is less prone to damage during manufacturing, leading to a highly reliable battery.

[0035] Furthermore, for example, when viewing the side surface of the electrode current collector in plan view, the angle between the stacking direction of the battery cells and the direction in which the plurality of linear patterns extend may be 45° or more and 90° or less.

[0036] As a result, more than half of the frictional force generated by the aforementioned polishing does not act in the direction of the laminate's stacking, which would cause the layers of the laminate to peel off at the cut surface. Therefore, damage during battery manufacturing is further suppressed.

[0037] Furthermore, for example, the plurality of linear patterns may extend in a direction perpendicular to the stacking direction of the battery cells when the side surface of the electrode current collector is viewed from above.

[0038] As a result, the frictional force generated by the polishing process is applied perpendicular to the lamination direction, and not in the direction of lamination, which would cause the layers of the laminate to peel off at the cross-section. Therefore, damage during battery manufacturing is further suppressed.

[0039] Furthermore, for example, the multiple linear patterns may be polished patterns.

[0040] This process polishes the sides of the battery, making it easier to remove any deposits that may have adhered to the sides during manufacturing. As a result, a more reliable battery can be achieved.

[0041] Embodiments of the present disclosure will be described below with reference to the drawings.

[0042] The embodiments described below are all general 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.

[0043] 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.

[0044] Furthermore, in this specification, terms indicating relationships between elements such as parallel and perpendicular, terms indicating the shape of elements such as rectangles, and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, such as differences of a few percent.

[0045] 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.

[0046] 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.

[0047] 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. Moreover, 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, unless otherwise specified, 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."

[0048] (Embodiment) [composition] First, the configuration of the battery according to this embodiment will be described.

[0049] Figure 1 shows a side view and a top view of the battery 100 according to this embodiment. Specifically, Figure 1(a) is a plan view of the side 150 of the battery 100 as seen from the front. Figure 1(b) is a plan view of the main surface of the battery 100 as seen from above, that is, as seen along the stacking direction. Figure 2 is an enlarged side view of region II in Figure 1. In Figure 1, the polishing patterns 111a and 121a shown in Figure 2 are omitted from the illustration.

[0050] The battery 100 comprises a plurality of battery cells 200. The battery 100 is, for example, an all-solid-state battery.

[0051] As shown in Figure 1, the plan view shape of the battery 100 is, for example, a rectangle. The shape of the battery 100 is, for example, a flattened rectangular parallelepiped. Here, "flattened" 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 the battery 100 may also be a square, parallelogram, rhombus, or other quadrilateral, or a hexagon or octagon, or other polygon. Furthermore, although the shape of the battery 100 is, for example, a rectangular parallelepiped, it may also be a cube, a pyramidal

[0052] A battery cell 200 is the minimum configuration of a battery and is also called a unit cell. Multiple battery cells 200 are stacked so as to be electrically connected in series. In this embodiment, all battery cells 200 in battery 100 are electrically connected in series. In the illustrated example, battery 100 has two battery cells 200, but is not limited to this. For example, battery 100 may have one battery cell 200, or three or more.

[0053] Each of the multiple battery cells 200 has an electrode layer 110, a counter electrode layer 120, and a solid electrolyte layer 130 located between the electrode layer 110 and the counter electrode layer 120. Therefore, each of the multiple battery cells 200 has a structure in which the electrode layer 110, the solid electrolyte layer 130, and the counter electrode layer 120 are stacked in this order. The electrode layer 110 has an electrode current collector 111 and an electrode active material layer 112. The counter electrode layer 120 has a counter electrode current collector 121 and a counter electrode active material layer 122. In each of the multiple battery cells 200, the electrode current collector 111, the electrode active material layer 112, the solid electrolyte layer 130, the counter electrode active material layer 122, and the counter electrode current collector 121 are stacked along the z-axis in this order.

[0054] The electrode layer 110 is one of the positive and negative electrode layers of the battery cell 200. The counter electrode layer 120 is the other of the positive and negative electrode layers of the battery cell 200. In the following explanation, the case where the electrode layer 110 is the negative electrode layer and the counter electrode layer 120 is the positive electrode layer will be described as an example. However, the electrode layer 110 may be the positive electrode layer and the counter electrode layer 120 may be the negative electrode layer.

[0055] The configurations of the multiple battery cells 200 are substantially identical to each other. In two adjacent battery cells 200, the order of the layers constituting the battery cell 200 is the same. In other words, the multiple battery cells 200 are stacked aligned along the z-axis so that the order of the layers constituting the battery cell 200 is the same. Therefore, the multiple battery cells 200 are stacked so that the opposite poles of adjacent battery cells 200 are connected. One electrode current collector 111 and the other counter electrode current collector 121 of adjacent battery cells 200 are electrically connected via an adhesive layer, for example, made of a conductive adhesive (not shown in the figure). One electrode current collector 111 and the other counter electrode current collector 121 of adjacent battery cells 200 may be in direct contact with each other. Also, adjacent battery cells 200 may share one electrode current collector 111 or one counter electrode current collector 121. In other words, in the battery 100, the electrode active material layer 112 and the counter electrode active material layer 122 may be in contact with both main surfaces of one electrode current collector 111, and the electrode active material layer 112 and the counter electrode active material layer 122 may be in contact with both main surfaces of one counter electrode current collector 121.

[0056] The solid electrolyte layer 130 is placed between the electrode active material layer 112 and the counter electrode active material layer 122. The solid electrolyte layer 130 is in contact with both the electrode active material layer 112 and the counter electrode active material layer 122. The thickness of the solid electrolyte layer 130 is, for example, 5 μm to 150 μm.

[0057] The solid electrolyte layer 130 includes at least a solid electrolyte and may optionally include a binder material. The solid electrolyte layer 130 may also include a solid electrolyte having lithium ion conductivity.

[0058] As the solid electrolyte, known materials such as lithium ion conductors, sodium ion conductors, or magnesium ion conductors can be used. For example, solid electrolyte materials such as sulfide solid electrolytes, halogen-based solid electrolytes, or oxide solid electrolytes can be used. As the sulfide solid electrolyte, for example, a mixture of lithium sulfide (Li2S) and phosphorus pentasulfide (P2S5) can be used. Alternatively, sulfides such as Li2S-SiS2, Li2S-B2S3, or Li2S-GeS2 may be used as the sulfide solid electrolyte, and sulfides to which at least one of Li3N, LiCl, LiBr, Li3PO4, and Li4SiO4 has been added as an additive may also be used.

[0059] 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.

[0060] As the binder material, for example, elastomers may be used, and organic compounds such as polyvinylidene fluoride, acrylic resin, or cellulose resin may also be used.

[0061] The electrode active material layer 112 is in contact with the main surface of the electrode current collector 111. The electrode current collector 111 may also include a current collector layer containing a conductive material, which is provided in the portion that is in contact with the electrode active material layer 112.

[0062] The main surface of the counter electrode current collector 121 is in contact with the counter electrode active material layer 122. The counter electrode current collector 121 may also include a current collector layer containing a conductive material, which is provided in the portion that is in contact with the counter electrode active material layer 122.

[0063] Known materials can be used as the materials for the electrode current collector 111 and the counter electrode current collector 121, respectively. For example, foil-like, plate-like, or mesh-like materials made of copper, aluminum, nickel, iron, stainless steel, platinum, or gold, or alloys of two or more of these materials can be used as the materials for the electrode current collector 111 and the counter electrode current collector 121, respectively. The thickness of the electrode current collector 111 and the counter electrode current collector 121 is, for example, 5 μm to 100 μm, but is not limited to this.

[0064] Furthermore, the electrode layer 110 does not necessarily have to include the electrode current collector 111. For example, the current collector, take-off terminal, or adhesive layer with the other battery cell 200 may function as the current collector for the electrode active material layer 112 of the electrode layer 110 or counter electrode layer 120 of another battery cell 200. In other words, the electrode layer 110 may contain only the electrode active material layer 112 of the electrode current collector 111 and the electrode active material layer 112. Also, the counter electrode layer 120 does not necessarily have to include the counter electrode current collector 121. For example, the current collector, take-off terminal, or adhesive layer with the other battery cell 200 may function as the current collector for the counter electrode active material layer 122 of the electrode layer 110 or counter electrode layer 120 of another battery cell 200. In other words, the counter electrode layer 120 may contain only the counter electrode active material layer 122 of the counter electrode current collector 121 and the counter electrode active material layer 122.

[0065] The electrode active material layer 112 is located on the main surface of the electrode current collector 111, on the side facing the counter electrode layer 120. The electrode active material layer 112 is located opposite the counter electrode active material layer 122. The thickness of the electrode active material layer 112 is, for example, 5 μm or more and 300 μm or less, but is not limited to this.

[0066] The electrode active material layer 112 includes at least a negative electrode active material and may optionally include at least one of a solid electrolyte, a conductive additive, and a binder material. As the negative electrode active material, known materials capable of intercalating and releasing (inserting and deintercalating, or dissolving and precipitating) lithium ions, sodium ions, or magnesium ions may be used. As the negative electrode active material, in the case of a material capable of releasing and inserting lithium ions, examples of materials that can be used include natural graphite, artificial graphite, carbon materials such as graphite carbon fiber or resin-fired carbon, metallic lithium, lithium alloys, or oxides of lithium and transition metal elements.

[0067] As the solid electrolyte, the solid electrolyte material described above may be used. As the conductive additive, conductive materials such as acetylene black, carbon black, graphite, or carbon fiber may be used. As the binder material, the binder material described above may be used.

[0068] The electrode active material layer 112 is produced by applying a paste-like coating, which is made by kneading the materials containing the electrode active material layer 112 together with a solvent, onto the main surface of the electrode current collector 111 and drying it. In order to increase the density of the electrode active material layer 112, the electrode layer 110 (also called an electrode plate), which includes the electrode active material layer 112 and the electrode current collector 111, may be pressed after drying.

[0069] The counter electrode active material layer 122 is located on the main surface of the counter electrode current collector 121, on the electrode layer 110 side. The thickness of the counter electrode active material layer 122 is, for example, 5 μm or more and 300 μm or less, but is not limited to this.

[0070] The counter electrode active material layer 122 includes at least a positive electrode active material and may optionally include at least one of a solid electrolyte, a conductive additive, and a binder material.

[0071] As the positive electrode active material, known materials capable of intercalating and releasing (inserting and deintercalating, or dissolving and precipitating) lithium ions, sodium ions, or magnesium ions can be used. Examples of positive electrode active materials capable of releasing and inserting lithium ions include lithium cobalt oxide composite oxide (LCO), lithium nickel oxide composite oxide (LNO), lithium manganese oxide composite oxide (LMO), lithium-manganese-nickel oxide composite oxide (LMNO), lithium-manganese-cobalt oxide composite oxide (LMCO), lithium-nickel-cobalt oxide composite oxide (LNCO), or lithium-nickel-manganese-cobalt oxide composite oxide (LNMCO).

[0072] As the solid electrolyte, the above-mentioned solid electrolyte material may be used. Furthermore, as the conductive additive, the above-mentioned conductive material may be used. Furthermore, as the binder material, the above-mentioned binder material may be used.

[0073] The counter electrode active material layer 122 is produced by applying a paste-like coating, which is made by kneading the materials containing the counter electrode active material layer 122 together with a solvent, onto the main surface of the counter electrode current collector 121 and drying it. In order to increase the density of the counter electrode active material layer 122, the counter electrode layer 120 (also called the counter electrode plate), which includes the counter electrode active material layer 122 and the counter electrode current collector 121, may be pressed after drying.

[0074] In this embodiment, the electrode active material layer 112, the counter electrode active material layer 122, and the solid electrolyte layer 130 are maintained in a parallel plate shape. This suppresses the occurrence of cracks or collapse due to bending. Alternatively, the electrode active material layer 112, the counter electrode active material layer 122, and the solid electrolyte layer 130 may be smoothly curved together.

[0075] In the battery cell 200, the electrode current collector 111, the electrode active material layer 112, the counter electrode active material layer 122, and the counter electrode current collector 121 all have the same shape and size, and their contours coincide when viewed from the z-axis direction.

[0076] Furthermore, on the side surface 150 connecting the two main surfaces of the battery 100 and parallel to the stacking direction of the battery 100, the sides of the electrode current collector 111, electrode active material layer 112, solid electrolyte layer 130, counter electrode active material layer 122, and counter electrode current collector 121 are exposed. The electrode current collector 111, electrode active material layer 112, solid electrolyte layer 130, counter electrode active material layer 122, and counter electrode current collector 121 are arranged so as not to overlap each other when viewed from a direction perpendicular to the stacking direction. Note that the exposed sides may be covered with output terminals or insulating materials. In other words, "exposed" as described above means that each layer stacked in the battery 100 does not cover the sides of the other layers.

[0077] As will be described later, side surface 150 is, for example, a polished cut surface. Therefore, as shown in Figure 2, the side surface 113 of the electrode current collector 111, which constitutes part of side surface 150, is provided with multiple linear polishing patterns 111a. Similarly, the side surface 123 of the counter electrode current collector 121, which also constitutes part of side surface 150, is provided with multiple linear polishing patterns 121a. Polishing patterns 111a and 121a are polishing marks with fine irregularities formed on side surfaces 113 and 123. If side surface 150 is an unpolished cut surface, side surfaces 113 and 123 may each be provided with multiple linear patterns formed by cutting with a cutting blade instead of polishing patterns 111a and 121a.

[0078] The polishing patterns 111a and 121a extend in a direction inclined with respect to the stacking direction of the battery cells 200 when the sides 113 and 123 are viewed from above. Specifically, the polishing patterns 111a and 121a extend in a direction perpendicular to the stacking direction of the battery cells 200 when the sides 113 and 123 are viewed from above. In this specification, extending in a perpendicular direction means extending in a substantially perpendicular direction, for example, the angle between the stacking direction and the direction in which the polishing patterns 111a and 121a extend is 85° or more and 90° or less.

[0079] Furthermore, when the side surfaces 113 and 123 are viewed from above, the angle between the lamination direction and the direction in which the polishing patterns 111a and 121a extend may be 45° or more and 90° or less.

[0080] When the side surface 150 is polished, a particularly noticeable polishing pattern is formed on the electrode current collector 111 and the counter electrode current collector 121, which are formed from metal foil or the like. However, polishing patterns extending in a direction inclined with respect to the stacking direction of the battery cell 200 may also be provided on the side surfaces of the electrode active material layer 112, the counter electrode active material layer 122, and the solid electrolyte layer 130.

[0081] [Battery manufacturing method] Next, a method for manufacturing the battery 100 according to this embodiment will be described. Figure 3 is a flowchart showing an example of a method for manufacturing the battery according to this embodiment.

[0082] First, as a laminate formation step, a laminate 300 is formed (step S11). Then, as a cutting step, the laminate 300 is cut to form a cut surface 150a (step S12).

[0083] Figure 4 is a perspective view illustrating the lamination and cutting processes. Figure 5 is a plan view of the laminate 100a formed by the cutting process. Figure 6 is a cross-sectional view of the laminate 100a formed by the cutting process. Note that Figure 4 shows the state after the laminate 300 has been cut by the cutting process. In this specification, in perspective views such as Figure 4, the same diagonal lines as in the cross-sectional view are added to the sides of each layer for ease of viewing, but this does not mean that the sides of each layer have a diagonal line pattern. Also, Figure 5 is a plan view of the cut surface 150a as seen from the front. Also, Figure 6 shows the cross section along the line VI-VI in Figure 5.

[0084] As shown in Figure 4, the laminate 300 has a battery cell 400 having a structure in which an electrode layer 110, a solid electrolyte layer 130, and a counter electrode layer 120 are stacked in that order. Specifically, the laminate 300 comprises a plurality of stacked battery cells 400. Since the laminate 300 and the battery cells 400 have the same stacking configuration as the battery 100 and battery cells 200 described above, a detailed explanation is omitted. In the illustrated example, the number of battery cells 400 in the laminate 300 is two, but it is not limited to this. For example, the number of battery cells 400 in the laminate 300 may be one, or it may be three or more.

[0085] In the laminate formation process, for example, the electrode current collector 111, the electrode active material layer 112, the solid electrolyte layer 130, the counter electrode active material layer 122, and the counter electrode current collector 121 are sequentially stacked along the z-axis in this order to form the battery cell 400. The battery cell 400 is formed, for example, by coating the current collector or the surface of each layer with a paste-like coating made by kneading the materials of the electrode active material layer 112, the solid electrolyte layer 130, and the counter electrode active material layer 122 together with a solvent, and then drying the coating. The coating method for forming the electrode active material layer 112, the counter electrode active material layer 122, and the solid electrolyte layer 130 can be, for example, screen printing, die coating, spraying, gravure printing, etc., but is not limited to these.

[0086] Next, the formed battery cells 400 are stacked. For example, a conductive adhesive is applied to one main surface of each battery cell 400, and multiple battery cells 400 are joined together via the conductive adhesive. This forms a laminate 300.

[0087] In the cutting process, as shown in Figure 4, the laminate 300 is cut in such a way that the electrode layer 110, the solid electrolyte layer 130, and the counter electrode layer 120 are cut together, thereby forming a cut surface 150a. Therefore, in the cutting process, the laminate 300 is cut at a position that passes through the two main surfaces of the laminate 300, the upper and lower.

[0088] Furthermore, in the cutting process, the laminate 300 is cut by, for example, shearing it with a cutting blade 500. In the cutting process, for example, the laminate 300 is cut by the cutting blade 500 advancing along the lamination direction from above the main surface of the laminate 300. In other words, with respect to the laminate 300, the cutting blade 500 passes through the two main surfaces, upper and lower, of the laminate 300 and moves in a direction parallel to the lamination direction of the laminate 300. Alternatively, with respect to the laminate 300, the cutting blade 500 may pass through the two main surfaces, upper and lower, of the laminate 300 and move in a direction inclined or perpendicular to the lamination direction of the laminate 300.

[0089] By cutting the laminate 300, a laminate 100a is formed, which includes a battery cell 200a and has a cut surface 150a, as shown in Figures 5 and 6.

[0090] During the cutting process, the laminate 300 is cut, crushing each layer of the battery cell 400. As shown in Figure 5, a pattern is generated on the cut surface 150a in which a portion of each layer of the battery cell 200a is oriented to shift in the direction of movement of the cutting blade 500. At least a portion of this pattern is caused by the deposits 160 described below. On the cut surface 150a, the electrode current collector 111, electrode active material layer 112, solid electrolyte layer 130, counter electrode active material layer 122, and counter electrode current collector 121 are exposed. In addition, as shown in Figure 6, deposits 160 (partially omitted in Figure 5), which are generated by cutting the laminate 300 and can cause a short circuit in the battery, adhere to the cut surface 150a. The deposits 160 consist of, for example, materials constituting at least one of the electrode current collector 111, electrode active material layer 112, solid electrolyte layer 130, counter electrode active material layer 122, and counter electrode current collector 121, and are cutting powder generated by crushing due to shearing of the laminate 300. The deposits 160 may also include in-process foreign matter that adhered during the cutting process. Since the deposits 160 originating from the current collector and active material layer are conductive, the electrode layer 110 and the counter electrode layer 120 are electrically connected via the deposits 160, forming minute conductive paths. Therefore, if the deposits 160 remain attached to the cut surface 150a, there is a high possibility of a short circuit occurring, so in this embodiment, the deposits 160 are removed by a cleaning process described later.

[0091] Next, as a polishing step, the cut surface 150a is polished (step S13). Since the deposits 160 are generated by crushing due to shear, as shown in Figure 6, they are often embedded in the battery cell 200a at the cut surface 150a, or in other words, they are bonded to the battery cell 200a. Therefore, the deposits 160 are difficult to detach from the cut surface 150a. For this reason, polishing the cut surface 150a removes the deposits 160 from the cut surface 150a.

[0092] Figure 7 is a diagram illustrating the polishing direction in the polishing process. Note that the attached material 160 is not shown in Figure 7. Also, Figure 7 is a plan view of the cross-section 150a.

[0093] As shown in Figure 7, in the polishing process, polishing is performed along a polishing direction D2 that is inclined at an angle θ with respect to the stacking direction D1 of the laminate 100a. The angle θ is the angle between the stacking direction D1 and the polishing direction D2 when the cut surface 150a is viewed from above. The angle θ is not particularly limited, but from the viewpoint of suppressing delamination of each layer of the battery cell 200a, it may be 45° to 90°. Alternatively, in the polishing process, the cut surface 150a may be polished along a polishing direction D2 that is perpendicular to the stacking direction D1 of the laminate 100a. This substantially eliminates the frictional force due to polishing acting on the edges of each layer of the battery cell 200a in the stacking direction of the laminate 100a, thus significantly suppressing delamination of each layer of the battery cell 200a. In this specification, "perpendicular direction" means a substantially perpendicular direction, for example, the angle θ is 85° to 90°.

[0094] Figure 8A is a perspective view illustrating an example of a polishing method in the polishing process. Figure 8B is a top view illustrating an example of a polishing method in the polishing process. In Figures 8A and 8B, a portion of the polishing member 600 is shown in a cut state. Figure 8B is a plan view of the laminate 100a viewed along the lamination direction. In Figure 8B, for clarity, the attached material 160 is given the same diagonal lines as in the cross-sectional view.

[0095] As shown in Figures 8A and 8B, in the polishing process, the cut surface 150a is polished by sliding an abrasive member 600, such as an abrasive tape, along the cut surface 150a. Specifically, first, the cut surface 150a is pressed against the abrasive member 600 with pressure that does not deform or bend the laminate 100a. Alternatively, the abrasive member 600 may be pressed against the cut surface 150a. Then, the cut surface 150a is polished by sliding either the laminate 100a or the abrasive member 600 along the polishing direction D2 which is perpendicular to the lamination direction D1. Alternatively, both the laminate 100a and the abrasive member 600 may be slid in opposite directions along the polishing direction D2.

[0096] The abrasive member 600 is not particularly limited as long as it is a tool for polishing. The abrasive member 600 is, for example, a material such as an abrasive tape, abrasive paper, or abrasive cloth with an abrasive material applied to its surface. In addition, at least a portion of the abrasive member 600 may be wound around a roll.

[0097] During polishing, the pressure applied to the polishing member 600 against the cut surface 150a, the angle θ, the particle size of the abrasive (in other words, the roughness of the polishing member 600), the sliding speed, and the number of sliding cycles are adjusted according to the condition of the adhering material 160.

[0098] When the cut surface 150a of the laminate 100a is polished, multiple linear polishing patterns extending along the polishing direction D2 are formed on the cut surface 150a. For example, as described above, when the polishing direction D2 is perpendicular to the lamination direction D1, polishing patterns 111a and 121a are formed on the sides of the electrode current collector 111 and the counter electrode current collector 121, as shown in Figure 2.

[0099] Figure 9 is a cross-sectional view showing the state of the deposits 160 after the polishing process. As shown in Figure 9, the polishing process removes the deposits 160 that were embedded in the cut surface 150a. Therefore, the removal of the deposits 160 becomes easier in the subsequent cleaning process.

[0100] Next, as a cleaning step, the deposits 160 adhering to the cut surface 150a are removed (step S14). This results in a battery 100 having the side surface 150 shown in Figure 1. In other words, the laminate 100a containing the battery cells 200a after the cleaning step is the battery 100 containing the battery cells 200, and the cut surface 150a after the cleaning step is the side surface 150.

[0101] The cleaning process includes, for example, a first removal step of removing the adhering material 160 by contact. In the first removal step, the adhering material 160 is removed by bringing a removal member for removing the adhering material 160 into contact with the cut surface 150a and the adhering material 160. As a result, the removal member comes into direct contact with the adhering material 160, thus achieving high removal efficiency.

[0102] The first removal step includes, for example, wiping off any adhering material 160 from the cut surface 150a. Figure 10A is a perspective view illustrating an example of the cleaning method in the first removal step. Figure 10B is a top view illustrating an example of the cleaning method in the first removal step. In Figures 10A and 10B, a portion of the wiping member 700 is shown in a cut state. Figure 10B is a plan view of the laminate 100a viewed along the lamination direction. In Figure 10B, for clarity, the adhering material 160 is given the same diagonal lines as in the cross-sectional view.

[0103] As shown in Figures 10A and 10B, in the first removal step, the adhering material 160 to the cut surface 150a is wiped away by sliding a wiping member 700, for example, a nonwoven fabric, along the cut surface 150a. This causes the adhering material 160 to come into contact with and be collected by the wiping member 700, and the adhering material 160 to the cut surface 150a is efficiently removed. Specifically, first, the cut surface 150a is pressed against the wiping member 700 with a pressure that does not deform or bend the laminate 100a. Alternatively, the wiping member 700 may be pressed against the cut surface 150a. Then, the adhering material 160 to the cut surface 150a is wiped away by sliding either the laminate 100a or the wiping member 700 along a wiping direction D3 perpendicular to the lamination direction D1. Alternatively, both the laminate 100a and the wiping member 700 may be slid in opposite directions along the wiping direction D3. As a result, the frictional force applied to the cut surface 150a during wiping is almost entirely eliminated from the stacking direction of the laminate 100a, thereby significantly suppressing the delamination of each layer of the battery cell 200a.

[0104] The wiping member 700 is not particularly limited as long as it is a tool that can capture and wipe away powder or the like. The wiping member 700 may be, for example, a nonwoven fabric, cloth, or film. Among these, the wiping member 700 may be a nonwoven fabric because it has excellent ability to capture and retain the adhering material 160 and can efficiently remove the adhering material 160. By using a nonwoven fabric, the adhering material 160 is trapped in the nonwoven fabric. In addition, at least a part of the wiping member 700 may be wound around a roll.

[0105] Note that the wiping direction D3 is not necessarily perpendicular to the stacking direction D1; wiping can be performed in any wiping direction D3.

[0106] Furthermore, the first removal step may include attaching an adhesive member to the cut surface 150a and then peeling it off, thereby causing the adhering material 160 to adhere to the adhesive member. This allows the adhesive member to capture the adhering material 160 and remove the adhering material 160 from the cut surface 150a. In addition, since the adhering material 160 can be removed simply by attaching and peeling off the adhesive member without sliding it over the cut surface, damage to the laminate 100a can be suppressed. The adhesive member is not particularly limited as long as it is a tool that can adhere the adhering material 160 to it. The adhesive member is a material such as an adhesive tape with an adhesive coating on its surface.

[0107] Furthermore, the first removal step may include sweeping away the adhering material 160 from the cut surface 150a with a sweeping member such as a brush or a scrubbing brush.

[0108] Furthermore, the first removal step may involve removing the attached material 160 using one method, or it may involve removing the attached material 160 using multiple methods.

[0109] The cleaning process may also include a second removal step in which the adhering material 160 is removed in a non-contact manner without bringing any object into contact with the cut surface 150a. The second removal step includes, for example, at least one of blowing gas onto the cut surface 150a and sucking up the adhering material 160 attached to the cut surface 150a. Figure 11 is a plan view and a cross-sectional view illustrating the second removal step. Specifically, Figure 11(a) is a plan view of the cut surface 150a as seen from above. Figure 11(b) shows a cross-section along the line XIb-XIb in Figure 11(a). Figure 11(a) is a view of the inside of the foreign matter suction nozzle as seen through. Also, in Figure 11(a), the adhering material 160 is given the same diagonal lines as in the cross-sectional view for clarity. Furthermore, Figure 11(b) shows the state after the deposits 160 attached to the cut surface 150a have been removed from the state shown in Figure 11(a).

[0110] As shown in Figures 11(a) and (b), in the second removal step, gas is blown onto the cut surface 150a using, for example, a gas injection nozzle 810. The gas injection nozzle 810 is positioned, for example, in a position where the cut surface 150a is extended in a direction parallel to the cut surface 150a, or at a position diagonally above the cut surface 150a. Here, "above" means the opposite side of the cut surface 150a from the laminate 100a side. Furthermore, from the viewpoint of efficiently removing the deposits 160, the gas injection nozzle 810 is blown with gas, for example, along the lamination direction of the laminate 100a.

[0111] The gas injection nozzle 810 is, for example, a nozzle connected to a gas cylinder, gas tank, or compressor. The gas to be sprayed can be any gas that does not react with the constituent materials of the laminate 100a, such as an inert gas like argon or nitrogen, or dry air. Dry air has a dew point temperature of, for example, -60°C or lower.

[0112] Furthermore, the gas sprayed from the gas nozzle may be an ionized gas 910. The ionized gas 910 neutralizes the charged deposits 160, thereby reducing their adhesion and further enhancing the cleaning effect.

[0113] In the second removal step, the adhering material 160 to which gas has been blown is sucked up using a foreign matter suction nozzle 820. The foreign matter suction nozzle 820 is positioned, for example, in a direction parallel to the cut surface 150a, extending the cut surface 150a, and is positioned opposite the gas injection nozzle 810 across the cut surface 150a. Alternatively, the foreign matter suction nozzle 820 may be positioned diagonally below the cut surface 150a. Here, "below" refers to the laminate 100a side of the cut surface 150a. Furthermore, from the viewpoint of efficiently removing the adhering material 160, the foreign matter suction nozzle 820 sucks up the adhering material 160 along the lamination direction of the laminate 100a, for example.

[0114] The foreign object suction nozzle 820 is, for example, a nozzle connected to a suction machine or the like.

[0115] In addition to the above arrangement, the foreign matter suction nozzle 820 may also be installed in an ion gas space 900 filled with ionized gas 910. By neutralizing the charged deposits 160 with the flow of ionized gas 910, the adhesion force is reduced, thereby further enhancing the cleaning effect.

[0116] In this way, by using the gas injection nozzle 810 and the foreign matter suction nozzle 820, the adhering material 160 can be removed efficiently. Furthermore, since the adhering material 160 is removed in a non-contact manner in the second removal step, the possibility of damaging the laminate 100a is reduced, and the reliability of the manufactured battery 100 can be increased. Depending on the condition of the adhering material 160, the adhering material 160 may be removed using only one of the gas injection nozzle 810 and the foreign matter suction nozzle 820.

[0117] The method for removing the attached material 160 using a non-contact method is not limited to the example above. For example, the attached material 160 may be removed by vibrating the laminate 100a using a vibrator or the like, thereby shaking it off from the cut surface 150a.

[0118] Furthermore, in the cleaning process, either only one of the first removal process or the second removal process may be performed, or both may be performed.

[0119] As described above, the method for manufacturing the battery 100 according to this embodiment includes a cutting step of cutting the laminate 300 to form a cut surface 150a. Furthermore, the method for manufacturing the battery 100 includes a cleaning step of removing the adhering material 160 from the cut surface 150a of the laminate 100a formed by cutting the laminate 300.

[0120] By cutting the laminate 300, the end faces of each layer can be aligned, thereby suppressing short circuits. Furthermore, the ends of the laminate 300 are less likely to function as a battery, and cutting them increases the capacity density of the manufactured battery 100. Additionally, cutting the laminate 300 to a desired size improves the capacity accuracy of the battery 100. On the other hand, conductive deposits 160 originating from the materials of each layer of the battery cell 200a are attached to the cut surface 150a of the laminate 100a formed by the cutting process. Therefore, minute conductive paths are easily formed between the electrode layer 110 and the counter electrode layer 120 by these deposits 160. Since the deposits 160 are removed through the cleaning process, the occurrence of short circuits due to the formation of such minute conductive paths can be suppressed. Thus, a highly reliable battery 100 can be manufactured.

[0121] Furthermore, the manufacturing method of the battery 100 may include a polishing step of polishing the cut surface 150a before the cleaning step. The deposits 160 generated by cutting the laminate 300 are likely to be embedded in the cut surface 150a, but polishing the cut surface 150a removes the deposits 160 that were embedded in the cut surface 150a. As a result, the deposits 160 become easier to remove. Thus, the reliability of the manufactured battery 100 can be further improved.

[0122] (Other embodiments) The battery and battery manufacturing method described above have been explained based on embodiments, but this disclosure is not limited to these embodiments. Within the scope of this disclosure, various modifications to the embodiments that a person skilled in the art could conceive, as long as they do not deviate from the spirit of this disclosure, and other forms constructed by combining some of the components of the embodiments, are also included.

[0123] For example, in the above embodiment, a polishing step was performed, but this is not limited to that. Depending on the state of adhesion of the adhering material 160, a cleaning step may be performed after the cutting step without performing a polishing step.

[0124] Furthermore, although the above embodiment described the formation of one side surface 150 of the battery 100, other sides of the battery 100 may be formed in the same manner as side surface 150. For example, all sides of the battery 100 may be cross-sections formed by the above manufacturing method.

[0125] Furthermore, in the above embodiment, the battery 100 was stacked so that multiple battery cells 200 were electrically connected in series, but it is not limited to this. Multiple battery cells 200 may be stacked so that they are electrically connected in parallel. In this case, the multiple battery cells 200 are stacked along the z-axis, with the order of each layer constituting the battery cells 200 alternating. That is, adjacent battery cells 200 are stacked so that like poles are electrically connected.

[0126] Furthermore, the above embodiments can be modified, replaced, added, or omitted in various ways within the scope of the claims or their equivalents. [Industrial applicability]

[0127] The battery relating to this disclosure can be used as a battery for electronic devices, electrical appliances, and electric vehicles. [Explanation of Symbols]

[0128] 100 batteries 100a, 300 laminate 110 Electrode layer 111 Electrode current collector 111a, 121a Polishing pattern 112 Electrode active material layer 113, 123, 150 Side view 120 Counterpolar layer 121 Counter electrode current collector 122 Counter electrode active material layer 130 Solid electrolyte layer 150a cutting surface 160 Attached substances 200, 200A, 400 battery cells 500 cutting blade 600 Polishing parts 700 Wiping material 810 Gas injection nozzle 820 Foreign object suction nozzle 900 Ion gas space 910 Ionized gas D1 stacking direction D2 Polishing direction D3 Wiping direction

Claims

1. A cutting step is performed to form a cut surface by cutting a laminate having a battery cell having a structure in which an electrode layer, a solid electrolyte layer, and a counter electrode layer are stacked in this order, so as to cut the electrode layer, the solid electrolyte layer, and the counter electrode layer together. A cleaning step to remove any deposits that adhere to the cut surface as a result of cutting the laminate in the cutting step, The process includes a polishing step of polishing the cut surface before the cleaning step, Battery manufacturing method.

2. In the polishing step, the cut surface is polished along a direction perpendicular to the stacking direction of the laminate. A method for manufacturing a battery according to claim 1.

3. The cleaning process includes a first removal step of removing the adhering material by contact, A method for manufacturing a battery according to claim 1 or 2.

4. The first removal step includes wiping off the adhering material from the cut surface. A method for manufacturing a battery according to claim 3.

5. In the first removal step, the adhering material to the cut surface is wiped off using a nonwoven fabric. A method for manufacturing a battery according to claim 4.

6. The first removal step includes attaching an adhesive member to the cut surface and peeling it off, thereby causing the adhering material to adhere to the adhesive member. A method for manufacturing a battery according to any one of claims 3 to 5.

7. The cleaning step includes a second removal step which includes at least one of blowing gas onto the cut surface and sucking up the deposits adhering to the cut surface. A method for manufacturing a battery according to any one of claims 1 to 6.

8. The battery cell comprises a structure in which an electrode layer, a solid electrolyte layer, and a counter electrode layer are stacked in this order. The electrode layer comprises an electrode current collector and an electrode active material layer located between the electrode current collector and the solid electrolyte layer. The side surface of the electrode current collector is provided with a plurality of linear patterns that extend in a direction inclined with respect to the stacking direction of the battery cells when the side surface of the electrode current collector is viewed from above. The aforementioned multiple linear patterns are polished patterns. battery.

9. When the side surface of the electrode current collector is viewed from above, the angle between the stacking direction of the battery cells and the direction in which the plurality of linear patterns extend is 45° or more and 90° or less. The battery according to claim 8.

10. The plurality of linear patterns extend in a direction perpendicular to the stacking direction of the battery cells when the side surface of the electrode current collector is viewed from above. The battery according to claim 8.

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