Electrode laminate and method for manufacturing electrode laminate

Abstract

The invention relates to an electrode laminate and a method for manufacturing the electrode laminate. This electrode laminate has 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 in this order. An electrode laminate according to the present disclosure has a side surface that is cut in a direction that is not a lamination direction of the electrode laminate. A method for manufacturing an electrode laminate according to the present disclosure includes: (a) providing a preliminary laminate 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 laminated in this order; and (b) cutting the side surface of the preliminary laminate in a direction that is not the lamination direction of the electrode laminate.

Description

Technical Field

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

[0002] As a power generation element of a battery, a battery using an electrode stack having 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 in this order is known. In the process of stacking the layers constituting the electrode stack, the ends of the layers sometimes deviate in the surface direction. In such a case, in order to align the positions of the ends of the layers in the surface direction, a method of cutting the ends of the electrode stack in the stacking direction of the electrode stack is known.

[0003] However, when the ends of an electrode stack are cut collectively (cut together) using a circular saw or the like, burrs may be generated in the current collector layer and / or the electrode active material layer, which may cause a short circuit between different electrodes.

[0004] For example, Japanese Patent Application Laid-Open No. 2023-137711 discloses the following secondary battery, which is a secondary battery having an electrode stack in which a positive electrode collector layer, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode collector layer are stacked in sequence, and the secondary battery has an exposed portion on the stacking surface of the positive electrode collector layer and the positive electrode active material layer or the stacking surface of the negative electrode collector layer and the negative electrode active material layer, where the surface of the positive electrode active material layer or the negative electrode active material layer is exposed. Summary of the Invention

[0005] From the viewpoint of suppressing the occurrence of short circuits, there is still room for improvement in electrode stacks in which the ends in the planar direction are aligned.

[0006] An object of the present disclosure is to provide an electrode stack in which occurrence of a short circuit is suppressed, and a method for producing such an electrode stack.

[0007] The inventors of the present application have discovered that the above-mentioned problems can be solved by the following means.

[0008] Solution 1

[0009] An electrode stack comprises, in 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, wherein the electrode stack has a side surface cut in a direction other than the stacking direction of the electrode stack.

[0010] Option 2

[0011] The electrode stack according to claim 1, wherein the side surface has a concavo-convex shape in a direction perpendicular to a stacking direction of the electrode stack.

[0012] Option 3

[0013] The method for producing an electrode stack according to claim 1 or 2 comprises the following steps:

[0014] (a) providing a preliminary laminate having 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 laminated in this order; and

[0015] (b) Cutting the side surface of the preliminary stack in a direction other than the stacking direction of the electrode stack.

[0016] Option 4

[0017] The method according to claim 3, wherein in the step (b), the side surface of the preliminary stack is cut using a cutter having a rotation axis inclined at 30° or less with respect to the stacking direction of the electrode stack.

[0018] Option 5

[0019] The method according to claim 4, wherein the helix angle (twist angle) of the tool is 0°.

[0020] According to the present disclosure, it is possible to provide an electrode stack in which occurrence of a short circuit is suppressed, and a method for producing such an electrode stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals represent like elements, and wherein:

[0022] Figure 1 A schematic cross-sectional view showing an example of a direction in which a side surface is cut in an electrode stack of the present disclosure that is not a stacking direction of the electrode stack;

[0023] Figure 2 A schematic plan view showing an example of the shape of an end portion of an electrode stack according to the present disclosure;

[0024] Figure 3 A schematic plan view illustrating a method for manufacturing an electrode stack according to the present disclosure;

[0025] Figure 4 A cross-sectional image of a cut surface of the electrode stack of the present disclosure is shown when the side of the electrode stack is cut using an end mill with a helix angle of 0°;

[0026] Figure 5 A schematic cross-sectional view illustrating a state where the side surface of the electrode stack is cut in the stacking direction of the electrode stack; and

[0027] Figure 6 The figure shows a cross-sectional image of a cut surface of an electrode stack according to the conventional technique when the electrode stack is cut using a circular saw. DETAILED DESCRIPTION

[0028] The following describes the embodiments of the present disclosure in detail with reference to the accompanying drawings. Furthermore, the present disclosure is not limited to the following embodiments and can be implemented with various modifications within the scope of the disclosed subject matter. Furthermore, the dimensional relationships in the accompanying drawings do not reflect the actual dimensional relationships.

[0029] Electrode stack

[0030] like Figure 1 As shown in FIG, the 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. Figure 2 As exemplified in , the electrode stack of the present disclosure has side surfaces that are cut in a direction other than the stacking direction of the electrode stack, particularly side surfaces that are cut in a direction perpendicular to the stacking direction of the electrode stack. The deviation of the cut direction from the direction perpendicular to the stacking direction of the electrode stack (i.e., the surface direction of the electrode stack) may be 30° or less, 20° or less, 10° or less, 5° or less, 2° or less, 1° or less, or approximately 0°.

[0031] The inventors of this application believe that one of the reasons for the generation of burrs in the current collector layer and / or electrode active material layer due to cutting the electrode stack in its stacking direction is that stress is applied to the cut surface of the electrode stack in the stacking direction of the electrode stack. In particular, when cutting with a tool such as a circular saw or a metal saw, it is believed that in addition to the stress in the stacking direction, the cross-section of the electrode stack is also subjected to centrifugal force accompanying the rotation of the tool. In this case, there are portions of the cross-section of the electrode stack to which force is locally applied, which is believed to result in the generation of burrs in the current collector layer and / or electrode active material layer, and thus the occurrence of short circuits between different electrodes.

[0032] in, Figure 5 This is a schematic cross-sectional view illustrating a state in which the side surface of the electrode stack is cut in the stacking direction of the electrode stack. Figure 6 The figure shows a cross-sectional image of a cut surface of an electrode stack according to the conventional technique when the electrode stack is cut using a circular saw. Figure 6In FIG. 1 , a plurality of lines are shown in a direction not perpendicular to the stacking direction of the electrode stack. These lines are traces of cutting, called tool marks. Figure 6 In the figure, the intervals between the lines become narrower as the figure goes downward, and the bottom portion shows the appearance of burrs.

[0033] In this regard, the inventors of the present application have discovered that, in an electrode stack having side surfaces cut in a direction other than the stacking direction of the electrode stack, the generation of burrs is suppressed, thereby suppressing the occurrence of short circuits between different electrodes. This is believed to be because, by cutting the side surfaces of the electrode stack in a direction other than the stacking direction of the electrode stack, excessive stress is not applied in the stacking direction of the electrode stack at the cross-section of the electrode stack.

[0034] In the present disclosure, the term "electrode stack" refers to a stack comprising a battery cell. This "battery cell" may be composed of a stack comprising 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.

[0035] Regarding the present disclosure, “the stacking direction of the electrode stack” means “a direction parallel to the stacking direction of the electrode stack.”

[0036] In the present disclosure, in each layer constituting the electrode stack and the electrode stack, the wide surface constituting the layered width is referred to as a “main surface”, and the surface constituting the thickness so as to span between the main surfaces is referred to as a “side surface”.

[0037] In this disclosure, "cutting" refers to removing the electrode stack as a workpiece using a tool, that is, deforming and then picking up the electrode stack. "Cutting," on the other hand, refers to separating the electrode stack without deforming it. While cutting always generates chips, cutting does not always. Therefore, the two terms have different meanings.

[0038] like Figure 1 As illustrated in FIG, the 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.

[0039] As long as the electrode stack comprises the layers constituting the electrode stack in the order described above in at least one portion, the order in which the layers are stacked in the remaining portions is not particularly limited. For example, the first electrode active material layer 12, solid electrolyte layer 13, second electrode active material layer 14, and second current collector layer 15 may be stacked in that order on both sides of the first current collector layer 11. That is, the second current collector layer 15, second electrode active material layer 14, solid electrolyte layer 13, first electrode active material layer 12, first current collector layer 11, first electrode active material layer 12, solid electrolyte layer 13, second electrode active material layer 14, and second current collector layer 15 may be stacked in that order. In this case, the "first current collector layer" and the "first electrode active material layer" may serve as counter electrodes to the "second current collector layer" and the "second electrode active material layer," respectively. That is, the "first current collector layer" and the "first electrode active material layer" may serve as the "positive electrode current collector layer" and the "positive electrode active material layer," respectively. In this case, the "second current collector layer" and the "second electrode active material layer" may be the "negative electrode current collector layer" and the "negative electrode active material layer," respectively. Similarly, the "first current collector layer" and the "first electrode active material layer" may be the "negative electrode current collector layer" and the "negative electrode active material layer," respectively. In this case, the "second current collector layer" and the "second electrode active material layer" may be the "positive electrode current collector layer" and the "positive electrode active material layer," respectively.

[0040] 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. The "first electrode active material layer" and the "second electrode active material layer" may each be either a "positive electrode active material layer" or a "negative electrode active material layer." That is, in this case, the electrode stack 10 of the present disclosure may be a bipolar electrode.

[0041] like Figure 1 As shown in FIG, 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.

[0042] The shape of the side surface of the electrode stack to be cut is not particularly limited. For example, the side surface of the electrode stack 10 may have a concave-convex shape in a direction other than the stacking direction of the electrode stack, in particular, Figure 2 As shown in the example, the electrode stack may have a concave-convex shape in a direction perpendicular to the stacking direction of the electrode stack. Figure 2This is a schematic plan view showing an example of the shape of the end portion of the electrode stack of the present disclosure.

[0043] As a method for forming a concave-convex shape on the side of the electrode stack in a direction other than the stacking direction of the electrode stack, a method of performing side cutting (also referred to as side processing) using a tool such as an end mill having a helix angle (twist angle) greater than 0° can be exemplified. In particular, as a method for forming a concave-convex shape on the side of the electrode stack in a direction perpendicular to the stacking direction of the electrode stack, a method of performing side cutting using a tool such as an end mill having a helix angle of 0° can be exemplified. With respect to the present disclosure, the so-called "side cutting" means cutting the side of the electrode stack with a tool while moving the tool and / or the electrode stack in a manner orthogonal to the main surface of the electrode stack as the processed member. That is, it means moving a tool and / or the electrode stack having a rotation axis with an inclination of approximately 0° relative to the stacking direction of the electrode stack while cutting the side of the electrode stack with a tool. For side cutting, an end mill can be used in particular. Furthermore, the method for cutting the side of the electrode stack will be described in detail in the method for manufacturing the electrode stack described later.

[0044] The width W of the concave-convex portion is not particularly limited. For example, a member for securing and / or protecting the electrode stack may be placed on the side of the cut electrode stack. In such cases, the width W may be narrower to facilitate securing the member to the side of the electrode stack. For productivity, the width W may be wider. The width W can be adjusted based on the feed rate per rotation of the cutter, the number of blades, and other factors.

[0045] Furthermore, in Figure 2 In the embodiment, a pair of opposing side surfaces of the electrode stack have concavo-convex shapes, but at least one side surface may have the concavo-convex shape.

[0046] The shape of the electrode stack is not particularly limited. For example, the shape of the main surface of the electrode stack before the side surface is cut can be a quadrilateral such as a square, rectangle, rhombus, trapezoid, or parallelogram. Furthermore, the shape of the main surface can be a polygon other than a quadrilateral, or a shape with a curve such as a circle. The cross-sectional shape of the side surface can be a quadrilateral such as a square, rectangle, rhombus, trapezoid, or parallelogram.

[0047] In particular, the main surface of the electrode stack before the side surfaces are cut can be rectangular, and the cross-sectional shape of the side surfaces can be rectangular. In other words, the electrode stack before the side surfaces are cut can be a cuboid. In this case, the side surfaces formed by the long sides of the electrode stack can be cut.

[0048] The size of the electrode stack is not particularly limited and can be appropriately set depending on the application of the battery and the like.

[0049] Hereinafter, each member that can constitute the electrode stack according to the present disclosure will be described.

[0050] It should be noted that in order to facilitate understanding of the present disclosure, the various components of the electrode stack of a lithium-ion secondary battery as a solid battery are described as an example, but the battery of the present disclosure is not limited to a lithium-ion secondary battery. In the present disclosure, "solid battery" means a battery that uses at least a solid electrolyte as an electrolyte. Therefore, a solid battery can use a combination of a solid electrolyte and a liquid electrolyte as an electrolyte. In addition, the solid battery of the present disclosure can be an all-solid battery, that is, a battery that uses only a solid electrolyte as an electrolyte.

[0051] Positive electrode collector layer

[0052] The conductive material used for the positive electrode current collector layer is not particularly limited, and examples thereof include SUS, aluminum, copper, nickel, iron, titanium, and carbon.

[0053] The shape of the positive electrode current collector layer is not particularly limited, and examples thereof include foil, plate, and mesh. Among these, foil is preferred.

[0054] 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 laminated in the extended portion.

[0055] Positive electrode active material layer

[0056] 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 application and purpose of use, for example, additives used in the positive electrode active material layer of a solid battery, such as a conductive additive or a binder, may be contained.

[0057] There is no particular limitation on the material of the positive electrode active material. 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, by Li 1+x Mn 2-x-y M y A heterogeneous 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.

[0058] 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.

[0059] 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.

[0060] Solid electrolyte layer

[0061] The solid electrolyte layer contains at least a solid electrolyte. The solid electrolyte is not particularly limited, and any material that can be used as a solid electrolyte for solid batteries can be used. For example, the solid electrolyte can be a sulfide solid electrolyte, an oxide solid electrolyte, or a polymer electrolyte.

[0062] Examples of sulfide solid electrolytes include sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, and argyrodite-type solid electrolytes, but are not limited thereto. Specific examples of sulfide solid electrolytes include Li2S-P2S5 (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 a combination thereof. Specific examples of the sulfide solid electrolyte are not limited to these.

[0063] Examples of oxide solid electrolytes include 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 Ti2-x (PO4)3、Li 1+x Al x Ge 2-x (PO4)3, Li3PO4, Li 3+x PO 4-x N x (LiPON), etc. Examples of the oxide solid electrolyte are not limited to these.

[0064] Examples of the polymer electrolyte include polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof, but are not limited thereto.

[0065] The solid electrolyte may be glass or crystallized glass (glass ceramic). In addition, the solid electrolyte layer may contain a conductive additive, a binder, etc. as needed in addition to the above-mentioned solid electrolyte. For the conductive additive and the binder, reference may be made to the above-mentioned description related to the positive electrode active material layer.

[0066] Negative electrode active material layer

[0067] 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 application and purpose of use, for example, a conductive additive, a binder, and other additives used in the negative electrode active material layer of a solid battery may be contained.

[0068] The material of the negative electrode active material is not particularly limited, but is preferably capable of occluding and releasing metal ions such as lithium ions. For example, the negative electrode active material may be an oxidative negative electrode active material, an alloy negative electrode active material, or a carbon material, but is not limited thereto.

[0069] The oxidative negative electrode active material is not particularly limited, and examples thereof include lithium titanate (LTO) particles.

[0070] There is no particular limitation on the alloy-based negative electrode active material, 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, or solid solutions thereof. In addition, Si alloy-based negative electrode active materials may contain elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. In addition, Sn alloy-based negative electrode active materials may contain elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc. In addition, Sn alloy-based negative electrode active materials may contain elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc.

[0071] The carbon material is not particularly limited, and examples thereof include hard carbon, soft carbon, and graphite.

[0072] Regarding the solid electrolyte used in the negative electrode active material layer, reference may be made to the above description regarding the solid electrolyte layer. Regarding the conductive additive and the binder, reference may be made to the above description regarding the positive electrode active material layer.

[0073] Negative electrode collector layer

[0074] The conductive material used in the negative electrode current collector layer is not particularly limited, and examples thereof include SUS, aluminum, copper, nickel, iron, titanium, carbon, etc., but are not limited thereto.

[0075] The shape of the negative electrode current collector layer is not particularly limited, and examples thereof include foil, plate, and mesh. Among these, foil is preferred.

[0076] 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 laminated in the extended portion.

[0077] Method for manufacturing electrode stack

[0078] The 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 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 sequentially stacked; and Figure 3 As shown in the example, (b) the side surface of the preliminary stack is cut in a direction other than the stacking direction of the electrode stack. By manufacturing the electrode stack using such a method, the occurrence of short circuits between different electrodes can be suppressed.

[0079] The method disclosed herein includes: (a) providing a preliminary stacked body 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.

[0080] There is no particular limitation on the method for providing a preliminary laminate. For example, a preliminary laminate can be provided by stacking the layers constituting the preliminary laminate in a desired order. There is no particular limitation on the method for stacking the layers. For example, the following method can be cited: forming the first electrode active material layer 12, the solid electrolyte layer 13, and the second electrode active material layer 14 by powder pressing, and stacking the layers together with the first collector layer 11 and the second collector layer 15 in a desired order. In addition, the following method can be cited: applying the composite slurry of each layer capable of forming the first electrode active material layer 12, the solid electrolyte layer 13, and the second electrode active material layer 14 to a substrate and drying them, and stacking the layers in a desired order. The substrate of the first electrode active material layer 12 can be, for example, the first collector layer 11. The substrate of the solid electrolyte layer 13 can be, for example, a peelable metal foil such as aluminum foil. The substrate of the second electrode active material layer 14 can be, for example, the second collector layer 15.

[0081] like Figure 3 As shown in FIG. 1 , the method of the present disclosure includes (b) cutting the side surface of the preliminary stack 20 in a direction other than the stacking direction of the electrode stack. Figure 3 In FIG, the circular arrow indicates the direction of rotation of the cutter 30, and the straight arrow indicates the direction of movement of the preliminary stack 20. In addition, the straight, widely spaced dotted lines indicate the cut areas in the electrode stack, and the narrowly spaced dotted lines composed of curved and straight lines indicate the cut areas as the cutter 30 rotates. Figure 3 It is a schematic plan view showing how the side surface is cut by the blade 30 rotating in the direction indicated by the circular arrow and the preliminary stack 20 moving in the direction indicated by the straight arrow.

[0082] In step (b), a tool 30 having a rotation axis inclined at 30° or less relative to the stacking direction of the electrode stack can be used to cut the side of the preliminary stack. The inclination can be 20° or less, 10° or less, 5° or less, 2° or less, 1° or less, or about 0°. In particular, a tool having a rotation axis parallel to the stacking direction of the electrode stack can be used to cut the side of the preliminary stack. In the present disclosure, the so-called "parallel rotation axis" means a rotation axis inclined at about 0° relative to the stacking direction of the electrode stack.

[0083] There is no particular limitation on the method of cutting the side of the preliminary stack using a tool having a rotating axis inclined at 30° or less relative to the stacking direction of the electrode stack. For example, a method of cutting the side using a tool such as an end mill can be adopted. In this case, the helix angle of the tool may be less than 30°, less than 20°, less than 10°, less than 5°, less than 2°, or less than 1°, and in particular may be about 0°. The so-called "helix angle of the tool is 0°" means that the blade in the tool is not spiral (twisted). By applying a tool with a small helix angle to the method disclosed in the present invention, it is possible to suppress the application of excessive force to the stacking direction of the electrode stack on the cross-section of the electrode stack, thereby suppressing the occurrence of short circuits between different electrodes. This effect is particularly effective when the helix angle of the tool is 0°.

[0084] Figure 4 : This is a cross-sectional image of the cut surface of the electrode stack of the present disclosure when the electrode stack is cut sideways using an end mill with a helix angle of 0°. Figure 4 As shown in the figure, when an electrode stack is cut using an end mill with a helix angle of 0°, the tool mark is formed approximately perpendicular to the stacking direction of the electrode stack, that is, approximately parallel to the plane direction, in the cross-section of the electrode stack. This means that the force applied to the stacking direction of the electrode stack in the cross-section is particularly small.

[0085] Furthermore, when cutting the end of the electrode stack using an end mill with a small helix angle, particularly a helix angle of 0°, the scattering of cutting chips can be suppressed compared to when cutting the end of the electrode stack using a circular saw, a metal saw, or other cutting tool. This has the advantage of facilitating post-processing of cutting chips.

[0086] When side cutting is performed, the cutting method may be upward cutting or downward cutting. From the perspective of being able to roughen the surface and thereby facilitate the attachment of a member that may be disposed on the side of the electrode stack to fix and / or protect the electrode stack, downward cutting is particularly preferred.

[0087] Furthermore, in Figure 3 In the example, one side surface of the preliminary laminate is cut, but for example, a pair of opposing side surfaces may be cut simultaneously.

[0088] Battery

[0089] The battery disclosed herein comprises the electrode stack disclosed herein and a laminate film that seals the electrode stack. This configuration can suppress the occurrence of short circuits between different electrodes in the electrode stack.

[0090] The battery of the present disclosure may be, for example, a lithium-ion secondary battery. As the use of the battery, for example, power sources for vehicles such as hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), battery electric vehicles (BEV), gasoline vehicles, and diesel vehicles can be listed. In particular, it is preferably used as a driving power source for hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), or battery electric vehicles (BEV). In addition, the battery in the present disclosure can be used as a power source for mobile bodies other than vehicles (such as railways, ships, and aircraft), and can be used as a power source for electrical products such as information processing devices.

[0091] Electrode stack

[0092] For the electrode stack, reference can be made to the above description related to the electrode stack of the present disclosure.

[0093] Laminated film

[0094] The battery disclosed herein comprises a laminate film. The laminate film seals the electrode stack. Specifically, the laminate film can be used to wind and seal the electrode stack. Alternatively, the laminate film can be composed of two films. In this case, the two films can sandwich and seal the electrode stack from above and below in the stacking direction of the electrode stack.

[0095] The shape and size of the laminate film are not particularly limited as long as the electrode stack can be sealed.

[0096] The laminate film may include 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 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.

[0097] There are no particular limitations on the layers comprising the laminate film or the thickness of the laminate film. The thickness of the sealant resin layer is, for example, 40 μm to 100 μm. The thickness of the metal layer is, for example, 30 μm to 60 μm. The thickness of the protective resin layer is, for example, 20 μm to 60 μm. The thickness of the laminate film is, for example, 80 μm to 250 μm.

[0098] collector terminal

[0099] The battery of the present disclosure may further include a collector terminal electrically connected to the collector foil of the electrode stack. In this case, the laminate film can seal the electrode stack together with the collector terminal. Specifically, the laminate film can wrap the electrode stack and the collector terminal around the electrode stack, and together with the collector terminal, seal the electrode stack. In addition, the laminate film can be composed of two films. In this case, the two films can be used to clamp the electrode stack and the collector terminal from above and below in the stacking direction of the electrode stack, and together with the collector terminal, seal the electrode stack.

[0100] The collector foil may extend from an uncut side surface of the electrode stack, and thus the collector terminal may be disposed on the uncut side surface of the electrode stack. The collector terminal may be disposed on a pair of opposing side surfaces of the electrode stack.

[0101] 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.

[0102] The material of the current collecting terminal is not particularly limited as long as it has a current collecting function, and may be metal, particularly aluminum, stainless steel, etc.

Claims

1. An electrode stack comprising, 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 a stacking direction of the electrode stack.

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

3. The method for producing an electrode stack according to claim 1 or 2, comprising the following steps: (a) providing a preliminary laminate having 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 laminated 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.

4. The method according to claim 3, wherein: In the step (b), the side surface of the preliminary stack is cut using a cutter having a rotation axis inclined at 30° or less with respect to the stacking direction of the electrode stack.

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

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