Electrode stack and method for manufacturing electrode stack

Abstract

To provide an electrode stack that reduces short-circuiting and a method for manufacturing such an electrode stack.SOLUTION: An electrode stack 10 of the present disclosure includes a first current collector layer 11, a first electrode active material layer 12, a solid electrolyte layer 13, a second electrode active material layer 14, and a second current collector layer 15 in this order. The electrode stack of the present disclosure has a side surface cut in a direction that is not the stacking direction of the electrode stack. A method of the present disclosure for manufacturing the electrode stack 10 includes the following steps: (a) providing a preliminary stack 20 in which a first current collector layer, a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer are stacked in this order; and (b) cutting the side of the preliminary stack in a direction that is not the stacking direction of the electrode stack.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an electrode stack and a method for manufacturing an electrode stack. [Background technology]

[0002] A battery using an electrode laminate having, in this order, a first current collector layer, a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer as a power generating element of the battery is known. In the process of stacking the layers constituting the electrode laminate, the edges of the layers may be misaligned in the plane direction. In such a case, a method is known in which the edges of the electrode laminate are cut in the stacking direction of the electrode laminate in order to align the positions of the edges of the layers in the plane direction.

[0003] However, when the edges of the electrode stack are cut all at once with a circular saw blade or the like, burrs may be generated in the current collector layer and / or the electrode active material layer, which may cause short circuits between different electrodes. Therefore, a solution to this problem is desired.

[0004] For example, Patent Document 1 discloses a secondary battery having an electrode laminate in which a positive electrode current collector layer, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer are laminated in this order, and in which the positive electrode active material layer or the negative electrode active material layer has an exposed portion at the laminated surface between the positive electrode current collector layer and the positive electrode active material layer or the laminated surface between the negative electrode current collector layer and the negative electrode active material layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-137711 Summary of the Invention [Problem to be solved by the invention]

[0006] In an electrode stack in which the positions of the ends in the surface direction are aligned, there is room for improvement in terms of suppressing the occurrence of short circuits.

[0007] An object of the present disclosure is to provide an electrode stack in which the occurrence of short circuits is suppressed, and a method for manufacturing such an electrode stack. [Means for solving the problem]

[0008] The present inventors have found that the above problems can be solved by the following means. <Aspect 1> An electrode laminate having, in this order, a first current collector layer, a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer, The electrode stack has a side surface cut in a direction other than the stacking direction of the electrode stack. Electrode stack. <Aspect 2> 2. The electrode stack according to aspect 1, wherein the side surface has an uneven shape in a direction perpendicular to the stacking direction of the electrode stack. <Aspect 3> A method for producing the electrode stack according to embodiment 1 or 2, comprising the steps of: (a) providing a preliminary laminate in which a first current collector layer, a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer are laminated in this order; and (b) Cutting the side surface of the preliminary laminate in a direction other than the lamination direction of the electrode laminate. <Aspect 4> Aspect 4. The method according to aspect 3, wherein in step (b), the side surface of the pre-laminate is cut with a cutting tool having a rotation axis inclined at an angle of 30° or less with respect to the lamination direction of the electrode laminate. <Aspect 5> 5. The method of claim 4, wherein the cutting tool has a helix angle of 0°. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide an electrode stack in which the occurrence of short circuits is suppressed, and a method for manufacturing such an electrode stack. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the cutting direction in an electrode laminate of the present disclosure having side surfaces cut in a direction other than the stacking direction of the electrode laminate. [Figure 2] FIG. 2 is a schematic plan view showing an example of the shape of an end portion of an electrode laminate according to the present disclosure. [Figure 3] FIG. 3 is a schematic plan view illustrating a method for producing an electrode stack according to the present disclosure. [Figure 4] FIG. 4 is a cross-sectional image showing the cut surface of the electrode laminate of the present disclosure when the electrode laminate is side-cut using an end mill with a helix angle of 0°. [Figure 5] FIG. 5 is a schematic cross-sectional view illustrating how the side surface of the electrode stack is cut in the stacking direction of the electrode stack. [Figure 6] FIG. 6 is a cross-sectional image showing a cut surface of an electrode laminate according to the prior art when the electrode laminate is cut using a circular saw blade. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the present disclosure. Furthermore, the dimensional relationships in the drawings do not reflect the actual dimensional relationships.

[0012] <Electrode laminate> As illustrated in Fig. 1, an electrode laminate 10 of the present disclosure has, in this order, a first current collector layer 11, a first electrode active material layer 12, a solid electrolyte layer 13, a second electrode active material layer 14, and a second current collector layer 15. As illustrated in Fig. 2, an electrode laminate of the present disclosure has a side surface that is cut in a direction other than the stacking direction of the electrode laminate, particularly a side surface that is cut in a direction perpendicular to the stacking direction of the electrode laminate. Here, the deviation of the cutting direction from the direction perpendicular to the stacking direction of the electrode laminate (i.e., the surface direction of the electrode laminate) may be 30° or less, 20° or less, 10° or less, 5° or less, 2° or less, 1° or less, or about 0°.

[0013] The present inventors have considered that one of the causes of burrs occurring in the current collector layer and / or electrode active material layer when an electrode laminate is cut in its stacking direction is that stress is applied to the cut surface of the electrode laminate in the stacking direction of the electrode laminate. In particular, when cutting with a cutting tool such as a circular saw blade or a metal saw, it is thought that centrifugal force caused by the rotation of the cutting tool is applied to the cross section of the electrode laminate in addition to stress in the stacking direction. In this case, there are portions of the cross section of the electrode laminate where force is applied locally, which is thought to result in the occurrence of burrs in the current collector layer and / or electrode active material layer, and ultimately lead to the occurrence of short circuits between different electrodes.

[0014] Here, Fig. 5 is a schematic cross-sectional view illustrating how the side surface of an electrode laminate is cut in the stacking direction of the electrode laminate, and Fig. 6 is a cross-sectional image showing the cut surface of an electrode laminate according to the prior art when the electrode laminate is cut using a circular saw blade. In Fig. 6, multiple lines are shown in a direction that is not perpendicular to the stacking direction of the electrode laminate, and these multiple lines are marks left during cutting, called tool marks. In Fig. 6, the spacing between the lines becomes narrower toward the bottom of the figure, and burrs are seen to have occurred at the bottom.

[0015] In this regard, the present inventors have found that an electrode laminate having side surfaces cut in a direction other than the stacking direction of the electrode laminate suppresses the generation of burrs, and therefore suppresses the occurrence of short circuits between different electrodes. The reason for this is thought to be that by cutting the side surfaces of the electrode laminate in a direction other than the stacking direction of the electrode laminate, excessive stress is not applied to the cross section of the electrode laminate in the stacking direction of the electrode laminate.

[0016] In the present disclosure, the term "electrode stack" refers to a stack that constitutes a unit battery. Here, this "unit battery" may be composed of a stack of a positive electrode current collector layer, a positive electrode active material layer, an electrolyte layer (separator layer), a negative electrode active material layer, and a negative electrode current collector layer.

[0017] In the present disclosure, the "stacking direction of the electrode stack" means the "direction parallel to the stacking direction of the electrode stack."

[0018] In the present disclosure, each layer constituting the electrode stack and the broad surface constituting the broad layered surface of the electrode stack are referred to as the "main surface," and the surface that constitutes the thickness and spans between these main surfaces is referred to as the "side surface."

[0019] In the present disclosure, "cutting" means scraping off an electrode stack as a workpiece with a blade, i.e., deforming and scooping off the electrode stack. In contrast, "slicing" means dividing the electrode stack without deforming it. While cutting always generates chips, cutting does not necessarily generate chips. Therefore, the meanings of the two terms are different.

[0020] As illustrated in FIG. 1, an electrode laminate 10 of the present disclosure has a first current collector layer 11, a first electrode active material layer 12, a solid electrolyte layer 13, a second electrode active material layer 14, and a second current collector layer 15, in this order.

[0021] As long as the electrode laminate has, at least in part, the layers constituting the electrode laminate in the above-described order, the order in which the layers are stacked in other parts is not particularly limited. For example, a first electrode active material layer 12, a solid electrolyte layer 13, a second electrode active material layer 14, and a second current collector layer 15 may be stacked in this order on both sides of a first current collector layer 11. That is, the second current collector layer 15, the second electrode active material layer 14, the solid electrolyte layer 13, the first electrode active material layer 12, the first current collector layer 11, the first electrode active material layer 12, the solid electrolyte layer 13, the second electrode active material layer 14, and the second current collector layer 15 may be stacked in this order. In this case, the "first current collector layer" and the "first electrode active material layer" may be counter electrodes to the "second current collector layer" and the "second electrode active material layer," respectively. That is, when the "first current collector layer" and the "first electrode active material layer" are respectively a "positive electrode current collector layer" and a "positive electrode active material layer," the "second current collector layer" and the "second electrode active material layer" may be respectively a "negative electrode current collector layer" and a "negative electrode active material layer." Similarly, when the "first current collector layer" and the "first electrode active material layer" are respectively a "negative electrode current collector layer" and a "negative electrode active material layer," the "second current collector layer" and the "second electrode active material layer" may be respectively a "positive electrode current collector layer" and a "positive electrode active material layer."

[0022] Alternatively, for example, the first current collector layer 11, the first electrode active material layer 12, the solid electrolyte layer 13, the second electrode active material layer 14, the second current collector layer 15, the first electrode active material layer 12, the solid electrolyte layer 13, the second electrode active material layer 14, and the first current collector layer 11 may be stacked in this order. In this case, the "first current collector layer" and the "second current collector layer" may both be current collectors that function as both a positive electrode current collector and a negative electrode current collector, and the "first electrode active material layer" and the "second electrode active material layer" may be either a "positive electrode active material layer" or a "negative electrode active material layer," respectively. That is, in this case, the electrode laminate 10 of the present disclosure may be a bipolar electrode.

[0023] 1, the electrode stack 10 of the present disclosure has side surfaces that are cut in a direction other than the stacking direction of the electrode stack. With this configuration, it is possible to suppress the occurrence of short circuits between different electrodes.

[0024] The shape of the cut side surface of the electrode stack is not particularly limited. For example, the side surface of the electrode stack 10 may have an uneven shape in a direction other than the stacking direction of the electrode stack, and in particular, may have an uneven shape in a direction perpendicular to the stacking direction of the electrode stack, as exemplified in Figure 2. Note that Figure 2 is a schematic plan view showing an example of the shape of the end portion of the electrode stack of the present disclosure.

[0025] An example of a method for forming a concave-convex shape on the side surface of an electrode stack in a direction other than the stacking direction of the electrode stack is side cutting (also called side processing) using a cutting tool such as an end mill with a helix angle greater than 0°. In particular, an example of a method for forming a concave-convex shape on the side surface of an electrode stack in a direction perpendicular to the stacking direction of the electrode stack is side cutting using a cutting tool such as an end mill with a helix angle of 0°. In the present disclosure, "side cutting" refers to cutting the side surface of the electrode stack with a cutting tool while moving the cutting tool and / or the electrode stack so that the cutting tool and the main surface of the electrode stack, which is the workpiece, are perpendicular to each other. In other words, it refers to cutting the side surface of the electrode stack with a cutting tool while moving the cutting tool and / or the electrode stack having a rotation axis inclined at approximately 0° with respect to the stacking direction of the electrode stack. An end mill, in particular, can be used for side cutting. The method for cutting the side surface of an electrode stack will be described in detail in the method for manufacturing an electrode stack described below.

[0026] The width W of the concave portion of the uneven shape is not particularly limited. For example, a member for fixing and / or protecting the electrode laminate may be placed on the side surface of the cut electrode laminate. In such a case, the width W may be narrow from the viewpoint of facilitating the attachment of the member to the side surface of the electrode laminate. From the viewpoint of productivity, the width W may be wide. The width W can be adjusted by the feed amount per rotation of the cutting tool, the number of blades, etc.

[0027] Although FIG. 2 illustrates an example in which a pair of opposing side surfaces of the electrode laminate have an uneven shape, it is sufficient that at least one side surface has an uneven shape.

[0028] The shape of the electrode laminate is not particularly limited. For example, the shape of the main surface of the electrode laminate before the side surface is cut can be a quadrangle such as a square, rectangle, rhombus, trapezoid, or parallelogram. The shape of the main surface can also be a polygon other than a quadrangle, or a shape having a curve such as a circle. The cross-sectional shape of the side surface can be a quadrangle such as a square, rectangle, rhombus, trapezoid, or parallelogram.

[0029] In particular, the shape of the main surface of the electrode stack before the side surface is cut may be rectangular, and the cross-sectional shape of the side surface may be rectangular. That is, the electrode stack before the side surface is cut may be a rectangular parallelepiped. In this case, the side surface formed by the long side of the electrode stack may be cut.

[0030] The size of the electrode laminate is not particularly limited and can be set appropriately according to the intended use of the battery, etc.

[0031] Hereinafter, each of the components that can constitute the electrode stack according to the present disclosure will be described.

[0032] To facilitate understanding of the present disclosure, the components of an electrode stack of a lithium-ion secondary battery, which is a solid-state battery, will be described as an example. However, the battery of the present disclosure is not limited to a lithium-ion secondary battery. In the present disclosure, a "solid-state battery" refers to a battery that uses at least a solid electrolyte as an electrolyte. Therefore, a solid-state battery may use a combination of a solid electrolyte and a liquid electrolyte as the electrolyte. The solid-state battery of the present disclosure may also be an all-solid-state battery, i.e., a battery that uses only a solid electrolyte as the electrolyte.

[0033] (Positive electrode current collector layer) The conductive material used for the positive electrode current collector layer is not particularly limited, and may be, for example, SUS, aluminum, copper, nickel, iron, titanium, carbon, or the like.

[0034] The shape of the positive electrode current collector layer is not particularly limited, and examples thereof include foil, plate, mesh, etc. Among these, the foil shape is preferred.

[0035] The positive electrode current collector layer may extend from the uncut side surface of the electrode stack, and a plurality of positive electrode current collector layers may be collected in the extending portion.

[0036] (Cathode active material layer) The positive electrode active material layer contains at least a positive electrode active material, and preferably further contains a solid electrolyte described below. In addition, depending on the intended use and purpose, it may contain additives used in positive electrode active material layers of solid-state batteries, such as a conductive additive or a binder.

[0037] The material of the positive electrode active material is not particularly limited. For example, the positive electrode active material may be lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese oxide (LiMn2O4), Li 1.5 Co 1 / 3 Ni 1 / 3 Mn 1 / 3 O2, LiCo 1 / 3 Ni 1 / 3 Mn 1 / 3 O2, Li 1+x Mn 2-x-y M y It may be a different element-substituted Li-Mn spinel having a composition represented by O4 (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn), or the like.

[0038] The conductive additive is not particularly limited, and may be, for example, a carbon material such as VGCF (Vapor Grown Carbon Fiber) or carbon nanofiber, or a metal material.

[0039] The binder is not particularly limited, and may be, for example, polyvinylidene fluoride (PVdF), carboxymethyl cellulose (CMC), butadiene rubber (BR), styrene butadiene rubber (SBR), or a combination thereof.

[0040] (solid electrolyte layer) The solid electrolyte layer includes at least a solid electrolyte. The solid electrolyte is not particularly limited, and any material that can be used as a solid electrolyte for a solid-state battery can be used. For example, the solid electrolyte may be a sulfide solid electrolyte, an oxide solid electrolyte, a polymer electrolyte, or the like.

[0041] Examples of sulfide solid electrolytes include, but are not limited to, sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, and argyrodite-type solid electrolytes. Specific examples of sulfide solid electrolytes include Li2S-P2S5-based (Li7P3S 11 , Li3PS4, Li8P2S9, etc.), Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-LiBr-Li2S-P2S5, Li2S-P2S5-GeS2(Li 13 GeP3S 16 , Li 10 GeP2S 12 etc.), LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li 7-x PS 6-x Cl x etc.; or combinations thereof, but are not limited to these.

[0042] An example of an oxide solid electrolyte is Li7La3Zr2O 12、 Li 7-x La3Zr 1-x Nb x O 12、 Li 7-3x La3Zr2Al x O 12 , Li 3x La 2 / 3-x TiO3, Li 1+x Al x Ti 2-x (PO4)3, Li1+x Al x Ge 2-x (PO4)3, Li3PO4, Li 3+x PO 4-x N x (LiPON), etc., but are not limited to these.

[0043] Polymer electrolytes include, but are not limited to, polyethylene oxide (PEO), polypropylene oxide (PPO), and the like, and copolymers thereof.

[0044] The solid electrolyte may be glass or crystallized glass (glass ceramic). The solid electrolyte layer may contain, in addition to the solid electrolyte described above, a conductive additive, a binder, and the like, as needed. For the conductive additive and the binder, see the above description of the positive electrode active material layer.

[0045] (Negative electrode active material layer) The negative electrode active material layer contains at least a negative electrode active material, and preferably further contains the above-mentioned solid electrolyte. In addition, depending on the intended use and purpose, it may contain additives used in negative electrode active material layers of solid-state batteries, such as a conductive additive and a binder.

[0046] The material of the negative electrode active material is not particularly limited, but is preferably capable of absorbing and releasing metal ions such as lithium ions. For example, the negative electrode active material may be, but is not limited to, an oxide-based negative electrode active material, an alloy-based negative electrode active material, a carbon material, or the like.

[0047] The oxide-based negative electrode active material is not particularly limited, and examples thereof include lithium titanate (LTO) particles.

[0048] The alloy-based negative electrode active material is not particularly limited, and examples thereof include Si alloy-based negative electrode active materials and Sn alloy-based negative electrode active materials. Examples of Si alloy-based negative electrode active materials include silicon, silicon oxide, silicon carbide, silicon nitride, and solid solutions thereof. The Si alloy-based negative electrode active material can also contain elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. The Sn alloy-based negative electrode active material can also contain tin, tin oxide, tin nitride, or solid solutions thereof. The Sn alloy-based negative electrode active material can also contain elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc.

[0049] The carbon material is not particularly limited, and examples thereof include hard carbon, soft carbon, graphite, and the like.

[0050] For the solid electrolyte used in the negative electrode active material layer, the above description regarding the solid electrolyte layer can be referred to, and for the conductive additive and binder, the above description regarding the positive electrode active material layer can be referred to.

[0051] (negative electrode current collector layer) The conductive material used for the negative electrode current collector layer is not particularly limited, and may be, for example, SUS, aluminum, copper, nickel, iron, titanium, carbon, or the like, but is not limited to these.

[0052] The shape of the negative electrode current collector layer is not particularly limited, and examples thereof include foil, plate, mesh, etc. Among these, foil is preferred.

[0053] The negative electrode current collector layer may extend from the uncut side surface of the electrode stack, and a plurality of negative electrode current collector layers may be collected in the extending portion.

[0054] <<Method for manufacturing electrode laminate>> The method of the present disclosure for producing an electrode stack 10 includes the following steps: (a) providing a preliminary stack 20 in which a first current collector layer 11, a first electrode active material layer 12, a solid electrolyte layer 13, a second electrode active material layer 14, and a second current collector layer 15 are stacked in this order, and (b) cutting the side surface of the preliminary stack in a direction other than the stacking direction of the electrode stack, as illustrated in Figure 3. By producing an electrode stack in this manner, it is possible to prevent short circuits from occurring between different electrodes.

[0055] The method of the present disclosure includes (a) providing a pre-laminate 20 in which a first current collector layer 11, a first electrode active material layer 12, a solid electrolyte layer 13, a second electrode active material layer 14, and a second current collector layer 15 are laminated in this order.

[0056] The method for providing the preliminary laminate is not particularly limited. For example, the preliminary laminate can be provided by stacking the layers constituting the preliminary laminate in a desired order. The method for stacking the layers is not particularly limited, and examples include a method in which the first electrode active material layer 12, the solid electrolyte layer 13, and the second electrode active material layer 14 are formed by powder compaction, and then the layers are stacked in a desired order together with the first current collector layer 11 and the second current collector layer 15. Another example includes a method in which a composite slurry capable of forming the first electrode active material layer 12, the solid electrolyte layer 13, and the second electrode active material layer 14 is applied to a substrate, dried, and the layers are stacked in a desired order. The substrate of the first electrode active material layer 12 may be, for example, the first current collector layer 11. The substrate of the solid electrolyte layer 13 may be, for example, a peelable metal foil such as aluminum foil. The substrate of the second electrode active material layer 14 may be, for example, the second current collector layer 15.

[0057] As illustrated in Fig. 3, the method of the present disclosure includes (b) cutting the side surface of the pre-laminate 20 in a direction other than the stacking direction of the electrode stack. In Fig. 3, the circular arrow indicates the rotation direction of the cutting tool 30, and the straight arrow indicates the movement direction of the pre-laminate 20. The widely spaced straight dashed lines indicate the region of the electrode stack to be cut, and the closely spaced dashed lines consisting of curves and straight lines indicate the portion that will be cut as the cutting tool 30 rotates. That is, Fig. 3 is a schematic plan view showing how the side surface is cut by the cutting tool 30 rotating in the direction indicated by the circular arrow and the pre-laminate 20 moving in the direction indicated by the straight arrow.

[0058] In step (b), the side surface of the pre-laminate may be cut using a cutting tool 30 having a rotation axis inclined at 30° or less with respect to the stacking direction of the electrode stack. This inclination may be 20° or less, 10° or less, 5° or less, 2° or less, 1° or less, or approximately 0°. In particular, the side surface of the pre-laminate may be cut using a cutting tool having a rotation axis parallel to the stacking direction of the electrode stack. In the context of the present disclosure, a "parallel rotation axis" refers to a rotation axis inclined at approximately 0° with respect to the stacking direction of the electrode stack.

[0059] The method for cutting the side surface of the pre-laminate using a cutting tool having a rotation axis inclined at 30° or less relative to the stacking direction of the electrode stack is not particularly limited, but for example, a method using a cutting tool such as an end mill can be employed. In this case, the twist angle of the cutting tool may be 30° or less, 20° or less, 10° or less, 5° or less, 2° or less, or 1° or less, and may particularly be approximately 0°. "The twist angle of the cutting tool is 0°" means that the blade of the cutting tool is not twisted. By applying a cutting tool with a small twist angle to the method disclosed herein, excessive force applied to the cross section of the electrode stack relative to the stacking direction of the electrode stack can be suppressed, thereby suppressing the occurrence of short circuits between different electrodes. This effect is particularly pronounced when the twist angle of the cutting tool is 0°.

[0060] Fig. 4 is a cross-sectional image showing the cut surface of the electrode laminate of the present disclosure when the side of the electrode laminate is cut using an end mill with a helix angle of 0°. As shown in Fig. 4, when the electrode laminate is cut using an end mill with a helix angle of 0°, tool marks are formed on the cross section of the electrode laminate substantially perpendicular to the stacking direction of the electrode laminate, i.e., substantially parallel to the surface direction. This means that the force applied to the cross section of the electrode laminate in the stacking direction of the electrode laminate is particularly small.

[0061] Furthermore, when the end of the electrode stack is cut using an end mill with a small twist angle, particularly a 0° twist angle, scattering of chips can be suppressed compared to when the end of the electrode stack is cut using a cutting tool such as a circular saw blade or a metal saw, which has the advantage of making post-processing of the chips easier.

[0062] When cutting the side surfaces, the cutting method may be up-cutting or down-cutting. The cutting method may particularly be down-cutting, from the viewpoint that the surface can be finished to a rough finish, which makes it easier to fix a member for fixing and / or protecting the electrode stack, which may be disposed on the side surfaces of the electrode stack.

[0063] Although FIG. 3 illustrates cutting one side surface of the pre-laminate, a pair of opposing side surfaces may be cut simultaneously.

[0064] "battery" The battery of the present disclosure includes the electrode stack of the present disclosure and a laminate film that seals the electrode stack. With this configuration, it is possible to suppress the occurrence of short circuits between different electrodes in the electrode stack.

[0065] The battery of the present disclosure may be, for example, a lithium-ion secondary battery. Examples of uses of the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. In particular, the battery is preferably used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery of the present disclosure may also be used as a power source for mobile objects other than vehicles (for example, trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices.

[0066] <Electrode laminate> For the electrode stack, reference can be made to the above description regarding the electrode stack of the present disclosure.

[0067] <Laminating film> The battery of the present disclosure has a laminate film. The laminate film seals the electrode stack. Specifically, the laminate film may be wound around the electrode stack and seal it. The laminate film may also be composed of two films, and in this case, the electrode stack may be sandwiched and sealed by the two films from above and below in the stacking direction of the electrode stack.

[0068] The shape and size of the laminate film are not particularly limited as long as they can seal the electrode laminate.

[0069] The laminate film may have a sealant resin layer, a metal layer, and a protective resin layer in this order along the thickness direction. Examples of materials for the sealant resin layer include olefin-based resins such as polypropylene (PP) and polyethylene (PE). Examples of materials for the metal layer include aluminum, aluminum alloys, and stainless steel. Examples of materials for the protective resin layer include polyethylene terephthalate (PET) and nylon.

[0070] The thickness of each layer constituting the laminate film and the laminate film itself are not particularly limited. The thickness of the sealant resin layer is, for example, 40 μm or more and 100 μm or less. The thickness of the metal layer is, for example, 30 μm or more and 60 μm or less. The thickness of the protective resin layer is, for example, 20 μm or more and 60 μm or less. The thickness of the laminate film is, for example, 80 μm or more and 250 μm or less.

[0071] <Collector terminal> The battery of the present disclosure may further include a current collecting terminal electrically connected to the current collecting foil of the electrode laminate. In this case, the laminate film may seal the electrode laminate together with the current collecting terminal. Specifically, the electrode laminate and the current collecting terminal may be wound together with the laminate film, and the laminate film may seal the electrode laminate together with the current collecting terminal. Furthermore, the laminate film may be composed of two films, and in this case, the two films may sandwich the electrode laminate and the current collecting terminal from above and below in the stacking direction of the electrode laminate, sealing the electrode laminate together with the current collecting terminal.

[0072] The current collecting foil may extend from the uncut side of the electrode stack, and therefore the current collecting terminal may be disposed on the uncut side of the electrode stack. The current collecting terminal may be disposed on a pair of opposing side surfaces of the electrode stack.

[0073] The shape and size of the current collecting terminal are not particularly limited as long as they can seal the electrode stack together with the laminate film.

[0074] The material of the current collecting terminal is not particularly limited as long as it has a current collecting function, but may be metal, particularly aluminum, stainless steel, or the like. [Explanation of symbols]

[0075] 10 Electrode laminate 11 First current collector layer 12 First electrode active material layer 13 Solid electrolyte layer 14 Second electrode active material layer 15 Second current collector layer 20 Pre-laminate 30 Cutting tools

Claims

1. An electrode laminate having, in this order, a first current collector layer, a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer, The electrode stack has a side surface cut in a direction other than the stacking direction of the electrode stack. Electrode stack.

2. The electrode stack according to claim 1 , wherein the side surface has an uneven shape in a direction perpendicular to a stacking direction of the electrode stack.

3. A method for producing the electrode stack according to claim 1 or 2, comprising the following steps: (a) providing a preliminary laminate in which a first current collector layer, a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer are laminated in this order; and (b) Cutting the side surface of the preliminary laminate in a direction other than the lamination direction of the electrode laminate.

4. The method according to claim 3 , wherein in the step (b), the side surface of the preliminary laminate is cut with a cutting tool having a rotation axis inclined at an angle of 30° or less with respect to the lamination direction of the electrode laminate.

5. The method of claim 4, wherein the helix angle of the cutting tool is 0°.

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