Battery and manufacturing method thereof

Abstract

This battery is provided with: an electric power generation element which comprises a positive electrode layer, a negative electrode layer and an electrolyte layer that is positioned between the positive electrode layer and the negative electrode layer; an inner terminal electrode which is electrically connected to the electric power generation element; and a laminate film which contains the electric power generation element and the inner terminal electrode. The laminate film comprises a metal layer, an inner resin layer that is positioned closer to the electric power generation element than the metal layer, and an outer resin layer that is positioned on the other side of the inner resin layer with respect to the metal layer. The inner resin layer is provided with an inner opening from which the metal layer is exposed; and the inner terminal electrode is electrically connected to the metal layer in the inner opening. In a region where the inner terminal electrode and the metal layer are in contact with each other, the inner terminal electrode and the metal layer respectively have relief surfaces; and the relief surface of the inner terminal electrode and the relief surface of the metal layer are engaged with each other.

Description

[Technical field]

[0001] The present disclosure relates to batteries and methods for making same. [Background technology]

[0002] Conventional batteries have a problem in that the power generating element may become misaligned with respect to the exterior body when the power generating element is enclosed in an exterior body such as a laminate film. Batteries that use an adhesive layer to prevent this misalignment are known (for example, see Patent Document 1).

[0003] Patent Document 1 discloses a battery including an all-solid-state battery laminate having at least one unit all-solid-state battery, a positive electrode terminal and a negative electrode terminal connected to a positive electrode current collector layer and a negative electrode current collector layer, respectively, and an exterior body bottom member constituting an exterior body that encapsulates the all-solid-state battery laminate. Furthermore, in this battery, an adhesive layer is present at at least one location between the positive electrode current collector layer or the negative electrode current collector layer of the all-solid-state battery laminate and the exterior body bottom member, and between the positive electrode terminal and the negative electrode terminal and the exterior body bottom member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-164892 A Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional batteries, it is difficult to easily position the power generating element and the laminate film relative to each other and to increase reliability. Therefore, an object of the present disclosure is to provide a battery and a manufacturing method thereof in which the power generating element and the laminate film can be easily positioned relative to each other and which is highly reliable. [Means for solving the problem]

[0006] A battery according to one aspect of the present disclosure comprises: a power generating element including a positive electrode layer, a negative electrode layer, and an electrolyte layer located between the positive electrode layer and the negative electrode layer; an inner terminal electrode electrically connected to the power generating element; and a laminate film that accommodates the power generating element and the inner terminal electrode, the laminate film having a metal layer, an inner resin layer located on the power generating element side of the metal layer, and an outer resin layer located on the opposite side of the inner resin layer with respect to the metal layer, the inner resin layer having an inner opening through which the metal layer is exposed, the inner terminal electrode being electrically connected to the metal layer at the inner opening, the inner terminal electrode and the metal layer each having an uneven surface in a region where the inner terminal electrode and the metal layer are in contact, and the uneven surface of the inner terminal electrode and the uneven surface of the metal layer are interlocked.

[0007] A battery manufacturing method according to one embodiment of the present disclosure is a battery manufacturing method for manufacturing a battery including a power generating element including a positive electrode layer, a negative electrode layer, and an electrolyte layer located between the positive electrode layer and the negative electrode layer, an inner terminal electrode, and a laminate film that houses the power generating element and the inner terminal electrode, the method including a preparation step of preparing the laminate film having a metal layer and an inner resin layer located on the power generating element side of the metal layer, the inner resin layer having an inner opening through which the metal layer is exposed, an arrangement step of arranging a structure in the inner opening, and a pressing step of pressing the inner terminal electrode electrically connected to the power generating element so as to be electrically connected to the metal layer at the inner opening in which the structure was arranged in the arrangement step. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a battery and a manufacturing method thereof that can easily perform relative positioning of a power generating element and a laminate film and that is highly reliable. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a battery according to a first embodiment. [Figure 2A] FIG. 2A is an enlarged cross-sectional view of the periphery of the structure in region II of FIG. [Figure 2B] FIG. 2B is an exploded cross-sectional view of the structure in region II of FIG. 1 at an enlarged scale. [Diagram 3] FIG. 3 is a plan view clearly showing the positional relationship between the inner terminal electrode, the inner opening, and the structure according to the first embodiment. [Figure 4A] FIG. 4A is a cross-sectional view showing a step of a method for manufacturing the battery according to Embodiment 1. [Figure 4B] FIG. 4B is a cross-sectional view showing a step of the method for manufacturing the battery according to embodiment 1. [Figure 4C] FIG. 4C is a cross-sectional view showing a step of the method for manufacturing the battery according to embodiment 1. [Diagram 5] FIG. 5 is a plan view clearly showing the positional relationship between an inner terminal electrode, an inner opening, and a structure according to a modification of the first embodiment. [Figure 6] FIG. 6 is an enlarged cross-sectional view of the periphery of a structural body of a battery according to a modification of the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a schematic configuration of a battery according to the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a schematic configuration of a battery according to the third embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a schematic configuration of a battery according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Findings that have led to one aspect of the present disclosure) The present inventors have found that in a battery, particularly an all-solid-state battery, when a power generating element is encapsulated in a laminate film, the following problems arise.

[0011] In the conventional configuration, the volatile substances of the adhesive in the adhesive layer volatilize during the sealing process, which may cause a decrease in the performance of the power generating element. In addition, there is a problem that the adhesive shrinks as it hardens, and the stress generated at that time causes distortion of the power generating element. The distortion may reduce the reliability of the battery, such as by causing a decrease in performance of the power generating element, damage to the power generating element, or misalignment due to peeling of the power generating element from the adhesive part. Furthermore, it is necessary to accurately position the power generating element at the location where the adhesive layer is formed, which causes a problem of making the process more complicated than necessary.

[0012] An object of the present disclosure is to provide a highly reliable battery in which the power generating element and the laminate film can be easily positioned relative to each other, and a method for manufacturing the same.

[0013] An outline of one aspect of the present disclosure is as follows.

[0014] A battery according to one aspect of the present disclosure comprises: a power generating element including a positive electrode layer, a negative electrode layer, and an electrolyte layer located between the positive electrode layer and the negative electrode layer; an inner terminal electrode electrically connected to the power generating element; and a laminate film that accommodates the power generating element and the inner terminal electrode, the laminate film having a metal layer, an inner resin layer located on the power generating element side of the metal layer, and an outer resin layer located on the opposite side of the inner resin layer with respect to the metal layer, the inner resin layer having an inner opening through which the metal layer is exposed, the inner terminal electrode being electrically connected to the metal layer at the inner opening, the inner terminal electrode and the metal layer each having an uneven surface in a region where the inner terminal electrode and the metal layer are in contact, and the uneven surface of the inner terminal electrode and the uneven surface of the metal layer are interlocked.

[0015] This allows the positioning of the power generating element relative to the laminate film to be easily achieved by utilizing the uneven surface of the inner terminal electrode and the uneven surface of the metal layer. Specifically, the uneven surface of the inner terminal electrode and the uneven surface of the metal layer mesh with each other to position the power generating element. In addition, when the power generating element is housed in the laminate film during the battery manufacturing process, misalignment of the power generating element can be suppressed by the uneven surface of the inner terminal electrode and the uneven surface of the metal layer meshing with each other.

[0016] In addition, since there is no need to use an adhesive to position the power generating element, it is possible to suppress the evaporation of volatile substances in the adhesive during the encapsulation process. This makes it possible to suppress the deterioration of the performance of the power generating element caused by the volatile substances. In addition, since there is no need to use an adhesive, it is also possible to suppress distortion of the power generating element caused by hardening of the adhesive.

[0017] Thus, with the battery according to this embodiment, the relative positioning of the power generating element and the laminate film can be easily performed, and a highly reliable battery can be realized.

[0018] Furthermore, for example, the metal layer may have a metal layer body and a structure, and the convex portions of the uneven surface of the metal layer may be part of the structure.

[0019] This allows the positioning of the power generating element relative to the laminate film to be easily achieved by utilizing the structure. Specifically, the positioning of the power generating element can be achieved by embedding the structure between the metal layer body and the inner terminal electrode. Furthermore, by embedding the structure between the metal layer body and the inner terminal electrode, it is possible to suppress misalignment of the power generating element when the power generating element is housed in the laminate film during the battery manufacturing process.

[0020] In addition, since there is no need to use an adhesive to position the power generating element, it is possible to suppress the evaporation of volatile substances in the adhesive during the encapsulation process. This makes it possible to suppress the deterioration of the performance of the power generating element caused by the volatile substances. In addition, since there is no need to use an adhesive, it is also possible to suppress distortion of the power generating element caused by hardening of the adhesive.

[0021] Thus, with the battery according to this embodiment, the relative positioning of the power generating element and the laminate film can be easily performed, and a highly reliable battery can be realized.

[0022] For example, the structure may be conductive.

[0023] This can improve electrical conductivity from the power generating element to the metal layer via the inner terminal electrode, thereby further improving the reliability of the battery.

[0024] Also, for example, the structure may be made of a metal.

[0025] This makes it possible to easily improve electrical conductivity from the power generating element to the metal layer via the inner terminal electrode, thereby further improving the reliability of the battery.

[0026] Furthermore, for example, the structures may be spherical particles.

[0027] This allows the contact areas of the inner terminal electrode and the metal layer main body with the structure to be small during the manufacturing process of the battery, so that strong pressure is applied to the contact points of the inner terminal electrode and the metal layer main body with the structure. This makes it easier for the structure to be embedded in the metal layer main body and the inner terminal electrode, and makes it possible to suppress misalignment of the power generating element. This further increases the reliability of the battery.

[0028] Furthermore, for example, the inner terminal electrode may be in contact with a side surface and a main surface of the power generating element.

[0029] This allows the inner terminal electrode to be supported on multiple surfaces of the power generating element, which can further reduce positional deviation of the power generating element during the battery manufacturing process, thereby further improving the reliability of the battery.

[0030] Also, for example, the outer resin layer may be provided with an outer opening through which the metal layer is exposed.

[0031] This allows current to be extracted from the power generating element through the metal layer at the outer opening, improving the degree of freedom in designing how current is extracted from the battery.

[0032] Also, for example, the battery according to one aspect of the present disclosure may further include an outer terminal electrode electrically connected to the metal layer at the outer opening.

[0033] This allows the outer terminal electrodes to extract current from the outer openings, improving the degree of freedom in designing the arrangement of the outer terminal electrodes, etc.

[0034] Also, for example, the thickness of the metal layer at the inner opening may be greater than the thickness of the metal layer in a region where the metal layer is not exposed.

[0035] This allows the size of the convex portions of the uneven surface to be increased, and the positional displacement of the power generating element during the battery manufacturing process to be further suppressed. Furthermore, damage to the metal layer can be suppressed at the points where the convex portions of the uneven surface contact the metal layer. Therefore, the reliability of the battery can be further improved. In addition, since the thickness of all the metal layers in the laminate film is not increased, the weight of the laminate film is unlikely to increase. Therefore, the weight energy density of the battery is improved. Furthermore, since the laminate film can maintain its flexibility, the productivity of the battery is improved and costs can be reduced.

[0036] Furthermore, for example, the electrolyte layer may be a solid electrolyte layer containing a solid electrolyte having lithium ion conductivity.

[0037] This makes it possible to easily perform relative positioning of the power generating element and the laminate film in a battery containing a solid electrolyte having lithium ion conductivity, and also makes it possible to increase reliability.

[0038] Furthermore, a manufacturing method for a battery according to one aspect of the present disclosure is a manufacturing method for a battery including a power generating element including a positive electrode layer, a negative electrode layer, and an electrolyte layer located between the positive electrode layer and the negative electrode layer, an inner terminal electrode, and a laminate film that houses the power generating element and the inner terminal electrode, the manufacturing method including a manufacturing method for a battery including: a power generating element including a positive electrode layer, a negative electrode layer, and an electrolyte layer located between the positive electrode layer and the negative electrode layer; an inner terminal electrode; and a laminate film that houses the power generating element and the inner terminal electrode, the manufacturing method including a manufacturing method for a battery including: a power generating element including a positive electrode layer, a negative electrode layer, and an electrolyte layer located between the positive electrode layer and the negative electrode layer; an inner terminal electrode;

[0039] With this, the structure is embedded between the metal layer body and the inner terminal electrode, so that the position of the power generating element can be determined, and also, when the power generating element is accommodated in the laminate film in the battery manufacturing process, the structure is embedded between the metal layer body and the inner terminal electrode, so that the position of the power generating element can be prevented from being shifted when the power generating element is accommodated in the laminate film in the battery manufacturing process.

[0040] In addition, since there is no need to use an adhesive to position the power generating element, it is possible to suppress the evaporation of volatile substances in the adhesive during the encapsulation process. This makes it possible to suppress the deterioration of the performance of the power generating element caused by the volatile substances. In addition, since there is no need to use an adhesive, it is also possible to suppress distortion of the power generating element caused by hardening of the adhesive.

[0041] Thus, according to this embodiment, the relative positioning of the power generating element and the laminate film can be easily performed, and a highly reliable battery can be manufactured.

[0042] Hereinafter, the embodiment will be specifically described with reference to the drawings.

[0043] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component arrangement and connection, manufacturing process, and manufacturing process sequence shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in the independent claims are described as optional components.

[0044] In addition, each figure is a schematic diagram and is not necessarily illustrated precisely. Therefore, for example, the scales in each figure do not necessarily match. In addition, in each figure, substantially the same configurations are given the same reference numerals, and duplicated explanations are omitted or simplified.

[0045] Furthermore, in this specification, terms indicating the relationship between elements, such as parallel or perpendicular, terms indicating the shape of elements, such as rectangular or circular, and numerical ranges are not expressions that only express a strict meaning, but are expressions that include a substantially equivalent range, for example, a difference of about a few percent.

[0046] In addition, in this specification, "plan view" means a view of the battery along the stacking direction of the battery, and the view in this case is taken as a plan view. In this specification, "thickness" means the length of the battery and each layer in the stacking direction.

[0047] In addition, in this specification, "inside" and "outside" as in "inside" and "outside" refer to the direction toward the center of the battery and the direction away from the center of the battery, unless otherwise specified.

[0048] In this specification, the terms "upper" and "lower" in the battery configuration do not refer to the upper direction (vertically upward) and lower direction (vertically downward) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacking configuration. In addition, the terms "upper" and "lower" are applied not only to the case where two components are arranged with a gap between them and another component is present between the two components, but also to the case where two components are arranged in close contact with each other and the two components are in contact with each other.

[0049] In the present specification and drawings, the x-axis, y-axis, and z-axis indicate the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the upper surface of the power generating element is parallel to the xy plane, and the direction perpendicular to the xy plane is the z-axis direction. In each embodiment described below, the positive direction of the z axis may be referred to as the upward direction, and the negative direction of the z axis may be referred to as the downward direction.

[0050] (Embodiment 1) [1. Battery Overview] First, an overview of the battery according to the first embodiment will be described with reference to Fig. 1 and Fig. 2A. Fig. 1 is a cross-sectional view showing a schematic configuration of a battery 1 according to the present embodiment. Fig. 2A is an enlarged cross-sectional view of the periphery of a structure 10 in a region II in Fig. 1.

[0051] As shown in FIG. 1, the battery 1 includes a power generating element 2, inner terminal electrodes 71 and 72, and a laminate film 3.

[0052] In the battery 1, the power generating element 2 and the inner terminal electrodes 71 and 72 are housed and sealed by the laminate film 3. The laminate film 3 has a first laminate film 31, a second laminate film 32, and a sealing portion 5. The first laminate film 31 has an inner resin layer 311, a metal layer 312, and an outer resin layer 313. The second laminate film 32 has an inner resin layer 321, a metal layer 322, and an outer resin layer 323. The inner resin layer 321 of the second laminate film 32 is provided with inner openings 91 and 92 through which the metal layer 322 is exposed. The metal layer 322 of the second laminate film 32 has a metal layer main body 11 and a structure 10.

[0053] The inner terminal electrodes 71 and 72 are in contact with the side surfaces 22 and 23, respectively, and the main surface (here, the bottom surface 21) of the power generating element 2, respectively, to extract current from the power generating element 2. The inner terminal electrodes 71 and 72 are configured to be electrically connected to the metal layer 322 at the inner openings 91 and 92, respectively.

[0054] 2A, in the present embodiment, in a region where the inner terminal electrode 71 and the metal layer 322 contact each other, the inner terminal electrode 71 and the metal layer 322 have an uneven surface 61 and an uneven surface 81, respectively. The uneven surface 61 of the inner terminal electrode 71 and the uneven surface 81 of the metal layer 322 mesh with each other.

[0055] Furthermore, the protrusions of the uneven surface 81 of the metal layer 322 are part of the structure 10 .

[0056] In other words, the structure 10 is embedded in both the inner terminal electrode 71 and the metal layer main body 11 .

[0057] As shown in FIG. 1, the inner terminal electrode 72 and the metal layer 322 in the inner opening 92 also have a similar configuration.

[0058] First, the function of the structure 10 will be described below. The structure 10 mainly exerts its function in the process of sealing the power generating element 2 to the laminate film 3. The sealing process is carried out in a reduced pressure space using a reduced pressure chamber. Details will be described later with reference to Figs. 4A to 4C, but the sealing process will be briefly described below.

[0059] In the sealing step, first, the second laminate film 32 having the inner openings 91 and 92 is placed in a decompression chamber. The inner openings 91 and 92 are provided so as to extend along the y-axis direction in FIG.

[0060] Furthermore, the power generating element 2 provided with the inner terminal electrodes 71 and 72 is placed above the second laminate film 32. At this time, the structure 10 is placed above the metal layer main body 11 at each of the inner openings 91 and 92, and further, the power generating element 2 is placed so that the inner terminal electrodes 71 and 72 are located above the inner openings 91 and 92 via the structure 10. In this state, the power generating element 2 and the inner terminal electrodes 71 and 72 are pressed against each other, so that the structure 10 is embedded in each of the inner terminal electrodes 71 and 72 and the metal layer main body 11. As a result, the structure 10 makes it difficult for the power generating element 2 to move relative to the second laminate film 32, that is, the position of the power generating element 2 is determined. In other words, the position of the power generating element 2 is determined.

[0061] In order to encapsulate the power generating element 2 together with the structure 10, the first laminate film 31 is disposed so as to cover the power generating element 2. In this state, the pressure inside the vacuum chamber is reduced, and an end of the first laminate film 31 and an end of the second laminate film 32 are bonded together. As a result, a sealing portion 5 is formed so as to surround the first laminate film 31 and the second laminate film 32.

[0062] When the pressure is returned to normal pressure after bonding, the first laminate film 31 and the second laminate film 32 are covered along the power generating element 2 due to the atmospheric pressure. When the pressure is returned to normal pressure, the power generating element 2 is subjected to an external force due to the air flow of the atmosphere when the pressure rises to normal pressure and the deformation or movement of the laminate film 3 due to this air flow. In a state where the structure 10 is not provided, the power generating element 2 may move due to these external forces and become displaced. In the battery 1 according to this embodiment, the structure 10 is embedded in each of the inner terminal electrodes 71 and 72 and the metal layer main body 11. Therefore, even if these external forces are applied to the power generating element 2, the movement of the power generating element 2 is restricted, and the displacement of the power generating element 2 is suppressed.

[0063] Furthermore, since there are no adhesive joints, there is no risk of performance degradation of the power generating element 2 due to volatile substances in the adhesive, damage due to deformation of the power generating element 2, or peeling off from adhesive joints due to deformation of the power generating element 2.

[0064] [2. Configuration] Next, a specific configuration of the battery 1 according to the present embodiment will be described again with reference to Fig. 1. As shown in Fig. 1, the battery 1 according to the present embodiment includes a power generating element 2 made of a laminate including a positive electrode layer, a negative electrode layer, and a solid electrolyte layer, inner terminal electrodes 71 and 72, and a laminate film 3. The battery 1 is, for example, an all-solid-state battery.

[0065] First, the specific configuration of the power generating element 2 will be described.

[0066] The power generating element 2 includes at least one battery cell 20. In this embodiment, the power generating element 2 includes three battery cells 20. The three battery cells 20 are stacked so as to be electrically connected in series. Each of the battery cells 20 has a structure in which a positive electrode layer, an electrolyte layer, and a negative electrode layer are stacked in this order. Each of the battery cells 20 includes a first electrode layer, a second electrode layer, and a solid electrolyte layer. The first electrode layer includes a first current collector and a first active material layer. The first active material layer is located between the first current collector and the solid electrolyte layer. The second electrode layer includes a second current collector and a second active material layer. The second active material layer is located between the second current collector and the solid electrolyte layer.

[0067] In the following, an example will be described in which the first electrode layer is a positive electrode layer and the second electrode layer is a negative electrode layer. That is, the first current collector is a positive electrode current collector, and the first active material layer is a positive electrode active material layer. The second current collector is a negative electrode current collector, and the second active material layer is a negative electrode active material layer. That is, in this embodiment, each of the battery cells 20 has a structure in which a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector are stacked in this order.

[0068] The first electrode layer may be a negative electrode layer and the second electrode layer may be a positive electrode layer. That is, the first current collector may be a negative electrode current collector and the first active material layer may contain a negative electrode active material. The second current collector may be a positive electrode current collector and the second active material layer may contain a positive electrode active material.

[0069] The first current collector, the first active material layer, the solid electrolyte layer, the second active material layer, and the second current collector each have a rectangular shape in plan view. The plan view shapes of the first current collector, the first active material layer, the solid electrolyte layer, the second active material layer, and the second current collector are not particularly limited and may be square or may be a shape other than a rectangle, such as a circle, an ellipse, or a polygon. In other words, the battery cell 20 in which the first current collector, the first active material layer, the solid electrolyte layer, the second active material layer, and the second current collector are stacked has the same shape as described above.

[0070] In the present embodiment, the first current collector, the first active material layer, the solid electrolyte layer, the second active material layer, and the second current collector are the same size and have the same outline in a plan view, but this is not limited thereto. For example, the first active material layer may be smaller than the second active material layer. The first active material layer and the second active material layer may be smaller than the solid electrolyte layer.

[0071] The first and second current collectors may be made of known conductive materials, such as a foil, plate, or mesh made of copper, aluminum, nickel, iron, stainless steel, platinum, gold, or an alloy of two or more of these metals.

[0072] The first active material layer, which is a positive electrode active material layer, contains at least a positive electrode active material. The first active material layer may contain at least one of a solid electrolyte, a conductive assistant, and a binding agent (i.e., a binder) as necessary.

[0073] As the positive electrode active material, a known material capable of absorbing and releasing (inserting and desorbing, or dissolving and depositing) lithium ions, sodium ions, or magnesium ions can be used. As the positive electrode active material, in the case of a material capable of extracting and inserting lithium ions, for example, lithium cobalt oxide composite oxide (LCO), lithium nickel oxide composite oxide (LNO), lithium manganese oxide composite oxide (LMO), lithium-manganese-nickel composite oxide (LMNO), lithium-manganese-cobalt composite oxide (LMCO), lithium-nickel-cobalt composite oxide (LNCO), or lithium-nickel-manganese-cobalt composite oxide (LNMCO) can be used.

[0074] As the solid electrolyte, known materials such as lithium ion conductors, sodium ion conductors, and magnesium ion conductors can be used. As the solid electrolyte, both inorganic solid electrolytes and polymer solid electrolytes (including gel-like solid electrolytes) can be used. As the inorganic solid electrolyte, for example, a sulfide solid electrolyte or an oxide solid electrolyte can be used.

[0075] As the sulfide solid electrolyte, in the case of a material capable of conducting lithium ions, for example, a compound consisting of lithium sulfide (Li2S) and diphosphorus pentasulfide (P2S5) is used. As the sulfide solid electrolyte, a sulfide such as Li2S-SiS2, Li2S-B2S3, or Li2S-GeS2 may be used. Alternatively, as the sulfide solid electrolyte, a sulfide obtained by adding at least one of Li3N, LiCl, LiBr, Li3PO4, and Li4SiO4 as an additive to the above sulfide may be used.

[0076] As an oxide solid electrolyte, materials that can conduct lithium ions include, for example, Li7La3Zr2O 12 (LLZ), Li 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP) or (La,Li)TiO3(LLTO) are used.

[0077] The conductive assistant may be, for example, a conductive material such as acetylene black, carbon black, graphite, or carbon fiber, etc. The binder may be, for example, a bonding binder such as polyvinylidene fluoride.

[0078] The second active material layer, which is a negative electrode active material layer, contains at least a negative electrode active material. The second active material layer may contain at least one of a solid electrolyte, a conductive assistant, and a binder, as in the positive electrode active material layer, if necessary.

[0079] As the negative electrode active material, a known material capable of occluding and releasing (inserting and desorbing, or dissolving and precipitating) lithium ions, sodium ions, or magnesium ions can be used. As the negative electrode active material, in the case of a material capable of extracting and inserting lithium ions, for example, a carbon material such as natural graphite, artificial graphite, graphite carbon fiber, or resin-baked carbon, metallic lithium, a lithium alloy, or an oxide of lithium and a transition metal element can be used.

[0080] The solid electrolyte layer includes at least a solid electrolyte. The solid electrolyte layer may include a binder, if necessary. The solid electrolyte layer may include a solid electrolyte having lithium ion conductivity. As the solid electrolyte and binder included in the solid electrolyte layer, the above-mentioned solid electrolytes and binders can be used.

[0081] The power generating element 2 may include one or more battery cells 20. When the power generating element 2 includes a plurality of battery cells 20 as in the present embodiment, the plurality of battery cells 20 may be stacked. The plurality of battery cells 20 may be stacked in any manner so long as they function as a battery, and may be stacked, for example, so as to be electrically connected in series. Alternatively, the plurality of battery cells 20 may be stacked so as to be connected in parallel. The number of battery cells 20 included in the power generating element 2 may be two, or may be three or more, and is not particularly limited.

[0082] The multiple battery cells 20 may have a structure in which adjacent battery cells 20 share a positive electrode current collector or a negative electrode current collector. In other words, the positive electrode layer or negative electrode layer included in one battery cell 20 may not include a current collector, and may include a positive electrode active material layer or negative electrode active material layer provided on the current collector of the adjacent battery cell 20. In the multiple battery cells 20, the side surfaces 22 and 23 may be covered with a sealing member composed of a sealing resin or the like.

[0083] Next, the laminate film 3 composed of the first and second laminate films 31 and 32 will be described.

[0084] The laminate film 3 is a flexible film-shaped exterior body that houses the power generating element 2 and the inner terminal electrodes 71 and 72. The laminate film 3 is provided to cover the surface of the power generating element 2 and protect the power generating element 2 from moisture, air, and the like. The laminate film 3 has a first laminate film 31, a second laminate film 32, and a sealing portion 5 where the first laminate film 31 and the second laminate film 32 are bonded together.

[0085] For example, after the power generating element 2 is covered and housed under reduced pressure, the pressure in the external space of the laminate film 3 increases to atmospheric pressure, causing the laminate film 3 to adhere closely to the power generating element 2. For this reason, in the example shown in Fig. 1, gaps exist between the laminate film 3 and the side surfaces 22 and 23 of the power generating element 2, but in reality, the gaps are small enough to be considered nonexistent.

[0086] The first laminate film 31 is a film that covers the top surface 24 side of the power-generating element 2, and the second laminate film 32 is a film that covers the bottom surface 21 side of the power-generating element 2. The first laminate film 31 has a metal layer 312, an inner resin layer 311, and an outer resin layer 313. The second laminate film 32 has a metal layer 322, an inner resin layer 321, and an outer resin layer 323.

[0087] The inner resin layers 311 and 321 are located closer to the power generating element 2 than the metal layers 312 and 322, respectively, and the outer resin layers 313 and 323 are located on the opposite side of the inner resin layers 311 and 321 from the metal layers 312 and 322, respectively. That is, in each of the first and second laminate films 31 and 32, the outer resin layers 313 and 323, the metal layers 312 and 322, and the inner resin layers 311 and 321 are laminated in this order toward the center of the battery.

[0088] Here, the inner resin layer 321 of the second laminate film 32 is provided with inner openings 91 and 92, which are spaces through which the metal layer 322 is exposed. That is, in the inner openings 91 and 92, the metal layer 322 is not covered by the inner resin layer 321. As described later, the inner terminal electrodes 71 and 72 of the battery 1 are electrically connected to the metal layer 322 at the inner openings 91 and 92, respectively. Therefore, in the inner openings 91 and 92, the inner resin layer 321 is removed to match the shapes of the inner terminal electrodes 71 and 72.

[0089] In the regions where the inner terminal electrodes 71 and 72 contact the metal layer 322, the metal layer 322 has an uneven surface 81. That is, the uneven surface 81 is the upper surface of the metal layer 322 at the inner openings 91 and 92.

[0090] Here, the metal layer 322 and the uneven surface 81 will be described in more detail with reference to FIGS. 2A and 2B.

[0091] FIG. 2B is an exploded cross-sectional view of an enlarged perimeter of structure 10 in region II of FIG.

[0092] 2A and 2B, in the present embodiment, the metal layer 322 has a metal layer body 11 and structures 10. The structures 10 are particles located between the metal layer body 11 and the inner terminal electrodes 71 and 72.

[0093] The structure 10 is a spherical particle. The structure 10 may be a rectangular parallelepiped or a cube. The size of the structure 10 is defined as the length of the maximum side of the smallest rectangular parallelepiped that can completely accommodate one structure 10. The size of the structure 10 is preferably several μm or more and several tens of μm or less. The structure 10 is conductive and is made of a metal, particularly a low resistance metal. Specifically, the structure 10 is made of, for example, stainless steel. The structure 10 may also be made of molybdenum, tungsten, or the like. The structure 10 may also be made of, for example, a resin that is not conductive, but in this case, the structure 10 may be made conductive by covering the surface with a conductive material.

[0094] In this way, since the structure 10 has electrical conductivity, it is possible to improve electrical conductivity from the power generating element 2 to the metal layer 322 via the inner terminal electrodes 71 and 72 described below. For example, it is possible to suppress loss of electrical conduction between the inner terminal electrodes 71 and 72 and the metal layer 322, that is, it is possible to suppress deterioration in performance of the power generating element 2. Therefore, it is possible to further improve the reliability of the battery 1.

[0095] The material of the structure 10 is not particularly limited, but it is preferable that the structure 10 is made of a metal from the viewpoint of ensuring stable electrical connection between the inner terminal electrodes 71 and 72 and the metal layer 322. This makes it possible to easily increase the electrical conductivity from the power generating element 2 to the metal layer 322, and further increase the reliability of the battery 1.

[0096] Furthermore, when sealing the power generating element 2 in the laminate film 3 and returning the pressure to atmospheric pressure, an external force is generated on the power generating element 2, so the structure 10 should preferably be made of a material that has sufficient hardness, strength, and elasticity to restrict the movement of the power generating element 2 due to this external force.

[0097] In this way, when the metal layer 322 has the structure 10, the uneven surface 81 is the surface of the metal layer body 11 and the structure 10. That is, in this embodiment, the convex portion of the uneven surface 81 is a part of the structure 10. In other words, the other portion of the structure 10 is embedded in the metal layer body 11. Since the structure 10 is spherical, the convex portion of the uneven surface 81 is hemispherical. Also, as shown in FIG. 2A, the uneven surface 81 of the metal layer 322 and the uneven surfaces of the inner terminal electrodes 71 and 72 described later (for example, the uneven surface 61 of the inner terminal electrode 71) are engaged with each other.

[0098] 1 is provided with an insulating region 12. In this embodiment, the insulating region 12 is a region extending in the y-axis direction. The metal layer 322 located on the negative side of the x-axis relative to the insulating region 12 is insulated from the metal layer 322 located on the positive side of the x-axis relative to the insulating region 12 by the insulating region 12.

[0099] The inner resin layers 311 and 321 and the outer resin layers 313 and 323 are resin layers made of resin such as polyethylene resin or polypropylene resin. The metal layer 312 and the metal layer main body 11 are layers made of metal such as aluminum. The thickness of the metal layer 312 and the metal layer main body 11 is, for example, several tens of μm or more and 1 mm or less. In order to suppress the intrusion of moisture or oxygen from the outside of the battery 1, the thickness of the metal layer 312 and the metal layer main body 11 is preferably greater than half the size of one structure 10. The thickness of the metal layer 312 and the metal layer main body 11 is preferably about twice the size of one structure 10 or more and 10 times the size of one structure 10 or less. The first laminate film 31 is a film having a laminated structure made of the above materials, and a known laminate film can be used. In addition, the second laminate film 32 can be a film including the above known laminate film and the structure 10 constituting a part of the metal layer 322. Each of the first and second laminate films 31 and 32 has a three-layer structure in which, for example, inner resin layers 311 and 321, metal layers 312 and 323, and outer resin layers 313 and 323 are laminated in this order. The number of layers in each of the first and second laminate films 31 and 32 is not limited to three, and a laminate film with the number of layers according to the specification and purpose can be used.

[0100] The sealing portion 5 is a portion where the respective ends of the first laminate film 31 and the second laminate film 32 are bonded together. In the present embodiment, the respective outer peripheral ends of the first laminate film 31 and the second laminate film 32 are closely attached and sealed to form the sealing portion 5. The sealing portion 5 is provided, for example, in a ring shape surrounding the power generating element 2 in a plan view.

[0101] The laminate film 3 may be formed by folding a single laminate film. In other words, a part of the single laminate film may be the first laminate film 31, and another part may be the second laminate film 32.

[0102] By having the above-mentioned configuration, the laminate film 3 becomes an exterior body that is highly flexible and has excellent barrier properties against air and moisture.

[0103] The inner terminal electrodes 71 and 72 are terminals that extract current from the power generating element 2. Specifically, the power generating element 2 is provided with a plurality of positive electrode tabs and a plurality of negative electrode tabs that function as electrode extractions, and the inner terminal electrodes 71 and 72 extract current from the plurality of positive electrode tabs and the plurality of negative electrode tabs. One of the inner terminal electrodes 71 and 72 is connected to one of the plurality of positive electrode tabs and the plurality of negative electrode tabs, for example, via solder. Similarly, the other of the inner terminal electrodes 71 and 72 is connected to the other of the plurality of positive electrode tabs and the plurality of negative electrode tabs, for example, via solder.

[0104] The multiple positive electrode tabs are pulled out and bundled to one end (e.g., side surface 22) of the power generating element 2, and the bundled multiple positive electrode tabs are fixed by bundling or the like to the bottom surface 21 of the power generating element 2. The multiple negative electrode tabs are pulled out and bundled to the other end (e.g., side surface 23) of the power generating element 2, and the bundled multiple negative electrode tabs are fixed by bundling or the like to the bottom surface 21 of the power generating element 2.

[0105] The inner terminal electrodes 71 and 72 are terminals that contact the side surfaces 22 and 23 and a main surface (for example, the bottom surface 21) of the power generating element 2, respectively. As shown in FIG. 1, the inner terminal electrodes 71 and 72 are L-shaped in cross section. However, the shape of the inner terminal electrodes 71 and 72 is not limited to the above. The inner terminal electrodes 71 and 72 may be in a plate shape that supports the bottom surface 21 of the power generating element 2. The inner terminal electrodes 71 and 72 may be in a shape that supports the side surfaces 22 and 23, the bottom surface 21, and the top surface 24 of the power generating element 2, respectively.

[0106] The inner terminal electrodes 71 and 72 are electrically connected to the metal layer 322 at the inner openings 91 and 92, respectively. As a result, the metal layer 322 extracts a current from the power generating element 2 via the inner terminal electrodes 71 and 72. As described above, the metal layer 322 located on the negative side of the x-axis relative to the insulating region 12 is insulated by the insulating region 12 from the metal layer 322 located on the positive side of the x-axis relative to the insulating region 12. For this reason, the inner terminal electrodes 71 and 72 are not electrically connected via the metal layer 322.

[0107] Each of the inner terminal electrodes 71 and 72 has an uneven surface in a region where each of the inner terminal electrodes 71 and 72 contacts the metal layer 322. That is, in the present embodiment, the uneven surface of each of the inner terminal electrodes 71 and 72 is the bottom surface of each of the inner terminal electrodes 71 and 72. Note that the bottom surface of each of the inner terminal electrodes 71 and 72 is a surface of each of the inner terminal electrodes 71 and 72 on the negative side of the z-axis.

[0108] 2A and 2B, the inner terminal electrode 71 and the uneven surface 61 of the inner terminal electrode 71 will be described in more detail. As described above, the metal layer 322 has the metal layer body 11 and the spherical structure 10, and the uneven surface 81 of the metal layer 322 is the surface of the metal layer body 11 and the structure 10. Therefore, the convex parts of the uneven surface 81 of the metal layer 322 are spherical, and correspondingly, the concave parts of the uneven surface 61 of the inner terminal electrode 71 are hemispherical. Note that it is sufficient that the concave parts of the uneven surface 61 of the inner terminal electrode 71 have a shape corresponding to the shape of the convex parts of the uneven surface 81 of the metal layer 322.

[0109] 2A, the uneven surface 61 of the inner terminal electrode 71 and the uneven surface 81 of the metal layer 322 are interlocked. That is, the convex portions of the uneven surface 81 of the metal layer 322 are located in the concave portions of the uneven surface 61 of the inner terminal electrode 71. In other words, the structure 10 is embedded in both the inner terminal electrode 71 and the metal layer main body 11. Similarly, in the inner terminal electrode 72, the uneven surface of the inner terminal electrode 72 and the uneven surface 81 of the metal layer 322 are interlocked.

[0110] The inner terminal electrodes 71 and 72 may be made of a material having electrical conductivity, for example, a metal. The inner terminal electrodes 71 and 72 are made of aluminum, for example, but are not limited to this, and may be made of a material having high electrical conductivity.

[0111] The surfaces of the inner terminal electrodes 71 and 72 are insulated to prevent electrical defects (such as leaks or short circuits) in the battery 1. However, for example, at the location where the inner terminal electrode 71 contacts the power generating element 2 or the metal layer 322, the surface of the inner terminal electrode 71 is not insulated, allowing current to be extracted. The same is true for the inner terminal electrode 72, allowing current to be extracted.

[0112] 3, the positional relationship of the connections between the inner terminal electrodes 71 and 72 and the metal layer 322 will be described. Here, the inner terminal electrode 71 will be used for the description, but the inner terminal electrode 72 has a similar configuration.

[0113] 3 is a plan view clearly showing the positional relationship between the inner terminal electrode 71, the inner opening 91, and the structure 10 according to this embodiment. In plan view, the inner terminal electrode 71 is located inside the rectangular inner opening 91. Furthermore, in plan view, the structure 10 is disposed inside the area occupied by the inner terminal electrode 71 (i.e., the area corresponding to the bottom surface of the inner terminal electrode 71).

[0114] [3. Manufacturing method] Next, a method for manufacturing the battery 1 according to the present embodiment will be described with reference to Fig. 4A to Fig. 4C. Fig. 4A to Fig. 4C are cross-sectional views showing a step of the method for manufacturing the battery 1 according to the present embodiment. Note that the method for manufacturing the battery 1 described below is an example, and the method for manufacturing the battery 1 is not limited to the following example.

[0115] First, a power generating element 2 in which three battery cells 20 are stacked is prepared. Each of the three battery cells 20 can be produced by a known method, such as stacking a positive electrode active material, a solid electrolyte, and a negative electrode active material on a current collector by coating them with the material. The three battery cells are stacked so as to be connected in series, but this is not limited thereto, and the three battery cells 20 may be stacked so as to be connected in parallel. In this manner, the power generating element 2 is formed.

[0116] 4A, the inner terminal electrodes 71 and 72 are connected to the power generating element 2. The inner terminal electrodes 71 and 72 are provided so as to contact the side surfaces 22 and 23 and the main surface (for example, the bottom surface 21) of the power generating element 2, respectively.

[0117] Next, as shown in FIG. 4B, for example, a second laminate film 32 having a three-layer structure in which a resin layer, an aluminum layer and a resin layer are laminated in this order is prepared in a reduced pressure chamber.

[0118] Furthermore, inner openings 91 and 92 are formed in the second laminate film 32. The inner openings 91 and 92 are formed so as to extend along the y-axis direction in FIG. 4B.

[0119] Furthermore, the power generating element 2 to which the inner terminal electrodes 71 and 72 are connected is placed on the second laminate film 32. At this time, the structure 10 is placed above the metal layer main body 11 in each of the inner openings 91 and 92, and further, the power generating element 2 is placed so that the inner terminal electrodes 71 and 72 are located above the inner openings 91 and 92 via the structure 10.

[0120] As shown in FIG. 4B, at this stage, the bottom surfaces 61a and 62a of the inner terminal electrodes 71 and 72, respectively, and the surfaces 81a and 82a of the metal layer body 11 at the inner openings 91 and 92 are flat surfaces.

[0121] The inner terminal electrodes 71 and 72 are pressed so as to be electrically connected to the metal layer 322 at the inner openings 91 and 92 in which the structure 10 is disposed. In other words, by pressing the power generating element 2 and the inner terminal electrodes 71 and 72 together, the structure 10 is embedded in the inner terminal electrodes 71 and 72 and the metal layer main body 11.

[0122] 4C, the first laminate film 31 is placed on the upper surface of the power generating element 2. In other words, the power generating element 2 is sandwiched and covered by the first and second laminate films 31 and 32.

[0123] The ends of the first and second laminate films 31 and 32 are bonded by thermocompression bonding, except for some portions, to form the first and second laminate films 31 and 32 into a bag-shaped laminate film 3.

[0124] In a vacuum chamber, the external space of the bag-shaped laminate film 3 containing the power generating element 2 is reduced in pressure, and under reduced pressure, the non-bonded parts are thermocompressed to seal the power generating element 2 with the laminate film.

[0125] After sealing, the pressure inside the reduced pressure chamber is increased to atmospheric pressure, and the laminate film 3 is subjected to an external force such as an air flow or atmospheric pressure, so that it adheres closely to the power generating element 2. In this way, the battery 1 shown in Fig. 1 is manufactured. Displacement of the power generating element 2 due to an external force when the pressure is increased is suppressed by the structures 10 embedded between each of the inner terminal electrodes 71 and 72 and each of the inner openings 91 and 92.

[0126] Moreover, in this embodiment, the structure 10 has a spherical shape. This can reduce the area of ​​contact between the inner terminal electrode 71 and the metal layer main body 11 and the structure 10 when the power generating element 2 is pressed. In other words, strong pressure is applied to the areas where the inner terminal electrode 71 and the metal layer main body 11 and the structure 10 contact each other, so that the structure 10 is easily embedded in the inner terminal electrode 71 and the metal layer main body 11. The same applies to the inner terminal electrode 72. This can suppress misalignment of the power generating element 2, thereby further improving the reliability of the battery 1.

[0127] In this embodiment, the inner terminal electrodes 71 and 72 are provided so as to contact the side surfaces 22 and 23 and the bottom surface 21 of the power generating element 2, respectively, and the power generating element 2 can be supported on multiple surfaces. This makes it possible to further suppress displacement of the power generating element 2 due to an external force, thereby further improving the reliability of the battery 1.

[0128] In the above example, a step of pressing the power generating element 2 and the inner terminal electrodes 71 and 72 together is provided before the first laminate film 31 is placed on the upper surface of the power generating element 2, but this is not limited to the above. For example, without performing this step, the power generating element 2 and the inner terminal electrodes 71 and 72 may be pressed together by increasing the pressure inside the reduced pressure chamber to atmospheric pressure after sealing.

[0129] (Modification of the first embodiment) Next, a battery according to a modification of the first embodiment will be described with reference to Figs. 5 and 6. Fig. 5 is a plan view clearly showing the positional relationship between the inner terminal electrode 71a, the inner opening 91a, and the structure 10 according to the modification of the present embodiment. More specifically, Fig. 5 corresponds to Fig. 3 described in the first embodiment. Fig. 6 is a cross-sectional view in which the periphery of the structure 10 of the battery according to the modification of the present embodiment is enlarged.

[0130] This modification differs from embodiment 1 in that the positional relationship of the connection between the inner terminal electrode and metal layer 322 is different, and apart from that, the battery according to this modification has the same configuration as battery 1 according to embodiment 1. Here, the description will be given using inner terminal electrode 71a.

[0131] 5, in this modification, the inner opening 91a is located inside the inner terminal electrode 71a in plan view. Furthermore, the structure 10 is disposed at a position where the inner terminal electrode 71a and the metal layer main body 11 contact each other inside the inner opening 91a in plan view.

[0132] In this modification, when the power generating element is pressed in the manufacturing process, the inner resin layer 321 is deformed. For example, as shown in Fig. 6, an area 3211 surrounded by a dashed circle is an area where the inner resin layer 321 is deformed. As a result, the structure 10 is embedded in the inner terminal electrode 71a and the metal layer main body 11. Note that the metal layer main body 11 may be deformed, or the metal layer main body 11 and the inner terminal electrode may be deformed.

[0133] (Embodiment 2) Next, a battery according to a second embodiment will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view showing a schematic configuration of a battery 1b according to the present embodiment.

[0134] In the second embodiment, the thickness of the metal layer 322b in the inner openings 91 and 92 is different from that in the first embodiment.

[0135] Specifically, battery 1b has the same configuration as battery 1 of embodiment 1, except that the thickness of metal layer 322b at inner openings 91 and 92 is thicker than the thickness of metal layer 322b (here, metal layer main body 11b) in areas where metal layer 322b is not exposed.

[0136] As shown in Fig. 7, in the battery 1b, the second laminate film 32b constituting a part of the laminate film 3b has an inner resin layer 321, a metal layer 322b, and an outer resin layer 323. Furthermore, the metal layer 322b has a structure 10 and a metal layer main body 11b. Here, the metal layer main body 11b in each of the inner openings 91 and 92 is each of the regions 111 and 112 indicated by the dashed lines in Fig. 7. The thickness of the metal layer main body 11b in each of the regions 111 and 112 is thicker than the thickness of the metal layer 322b in the region where the metal layer 322b is not exposed (that is, the region where the metal layer 322b is sandwiched between the inner resin layer 321 and the outer resin layer 323).

[0137] This allows the size of the structure 10 to be increased, and the positional deviation of the power generating element 2 during the manufacturing process to be further suppressed. Furthermore, at the points where the structure 10 and the metal layer main body 11b contact each other, damage to the metal layer main body 11b can be suppressed when the power generating element 2 is pressed during the manufacturing process. This further improves the reliability of the battery 1b. For example, the thickness of the metal layer main body 11b in each of the regions 111 and 112 is, for example, several hundred μm or more and 1 mm or less.

[0138] In addition, since the thickness of all the metal layers 322b in the second laminate film 32 is not increased, the weight of the second laminate film 32 is unlikely to increase. This improves the weight energy density of the battery 1b. Furthermore, since the second laminate film 32 can maintain its flexibility, the productivity of the battery 1b is improved, and the cost can be reduced.

[0139] (Embodiment 3) Next, a battery according to a third embodiment will be described with reference to Fig. 8. Fig. 8 is a cross-sectional view showing a schematic configuration of a battery 1c according to the present embodiment.

[0140] The battery 1c according to the present embodiment has the same configuration as the battery 1 according to the first embodiment, mainly except for the following two points: the structure 10 is not provided, and the cross-sectional shape of the convex portions of the uneven surfaces 61c and 62c and the convex portions of the uneven surfaces 81c and 82c are rectangular.

[0141] In this embodiment, the inner terminal electrodes 71c and 72c have uneven surfaces 61c and 62c, respectively, and the metal layer 322c has uneven surfaces 81c and 82c. The uneven surfaces 61c and 62c and the uneven surfaces 81c and 82c have a rectangular cross-sectional shape of each protrusion, and are stripe-shaped extending along the y-axis direction in a plan view, but are not limited to this. For example, the shape of the protrusions of either the uneven surface 61c or the uneven surface 81c, or either the uneven surface 62c or the uneven surface 82c may be cubic, and the protrusions may be arranged in a matrix or randomly in a plan view.

[0142] The battery 1c according to this embodiment is manufactured in the same manner as the battery 1 according to the first embodiment, and an example thereof is as follows.

[0143] The uneven surfaces 61c and 62c are formed on the bottom surfaces of the inner terminal electrodes 71c and 72c, respectively, before the inner terminal electrodes 71c and 72c are connected to the power generating element 2. The uneven surfaces 61c and 62c are manufactured by, but are not limited to, blasting, etching, laser processing, or the like.

[0144] Thereafter, the power generating element 2 to which the inner terminal electrodes 71c and 72c are connected is placed on the second laminate film 32c of the laminate film 3c, and the power generating element 2 and the inner terminal electrodes 71c and 72c are pressed against each other.

[0145] In this case, before the power generating element 2 and the inner terminal electrodes 71c and 72c are pressed together, the metal layer 322c of the second laminate film 32 has a flat surface at the inner openings 91 and 92. In other words, when the power generating element 2 and the inner terminal electrodes 71c and 72c are pressed together, uneven surfaces 81c and 82c are formed on the metal layer 322c, and the uneven surfaces 61c and 81c mesh with the uneven surfaces 62c and 82c.

[0146] As a result, in the manufacturing process, the uneven surfaces 61c and 62c and the uneven surfaces 81c and 82c make it difficult for the power generating element 2 to move relative to the second laminate film 32c, i.e., the position of the power generating element 2 is determined. In other words, the position of the power generating element 2 is determined. Furthermore, in the manufacturing process, the power generating element 2 is subjected to an external force due to the atmospheric airflow when the pressure rises to normal pressure and the deformation or movement of the laminate film 3c caused by this airflow. Since the uneven surfaces 61c and 81c mesh with the uneven surfaces 62c and 82c, the movement of the power generating element 2 is restricted even if these external forces are applied to the power generating element 2, and the positional deviation of the power generating element 2 is suppressed.

[0147] In addition, since there is no need to use an adhesive to position the power generating element, it is possible to suppress the evaporation of volatile substances in the adhesive during the encapsulation process, thereby suppressing the deterioration of the performance of the power generating element 2 caused by the volatile substances. In addition, since there is no need to use an adhesive, it is also possible to suppress distortion of the power generating element 2 caused by hardening of the adhesive.

[0148] In other words, the power generating element 2 and the laminate film 3c can be easily positioned relative to each other, and a highly reliable battery 1c can be realized.

[0149] Incidentally, uneven surfaces 61c and 62c may be formed on the bottom surfaces of the inner terminal electrodes 71c and 72c after the inner terminal electrodes 71c and 72c are connected to the power generating element 2. Furthermore, before the power generating element 2 and the inner terminal electrodes 71c and 72c are pressed together, the bottom surfaces of the inner terminal electrodes 71c and 72c may be flat, and the metal layer 322c may have uneven surfaces 81c and 82c at the inner openings 91 and 92, respectively. Even in this case, uneven surfaces 61c and 62c are formed on the bottom surfaces of the inner terminal electrodes 71c and 72c, respectively, by pressing the power generating element 2 and the inner terminal electrodes 71c and 72c together.

[0150] (Embodiment 4) Next, a battery according to a fourth embodiment will be described with reference to Fig. 9. Fig. 9 is a cross-sectional view showing a schematic configuration of a battery 1d according to the present embodiment.

[0151] Battery 1d according to the present embodiment has a similar configuration to battery 1c according to embodiment 3, mainly except for the following three points: the cross-sectional shape of the convex portions of uneven surfaces 61d and 62d is semicircular, the cross-sectional shape of the concave portions of uneven surfaces 81d and 82d is semicircular, outer openings 93 and 94 are provided in outer resin layer 323, and battery 1d has outer terminal electrodes 73d and 74d.

[0152] In this embodiment, the inner terminal electrodes 71d and 72d have uneven surfaces 61d and 62d, respectively, and the metal layer 322d has uneven surfaces 81d and 82d. The uneven surfaces 61d and 62d have a stripe shape in which the cross-sectional shape of each protrusion is semicircular and extends along the y-axis direction in a plan view, but are not limited to this. Similarly, the shape of each protrusion of the uneven surfaces 61d and 62d may be hemispherical, and the protrusions may be arranged in a matrix or randomly in a plan view. The shape of the protrusions of the uneven surfaces 61d and 62d is not limited to the above, and for example, the protrusions of the uneven surfaces 61d and 62d may have a curved shape.

[0153] The shape of the recesses of the uneven surfaces 81d and 82d may correspond to the protrusions of the uneven surfaces 61d and 62d, respectively, and may be, for example, a hemispherical depression.

[0154] The laminate film 3d according to the present embodiment includes a first laminate film 31, a second laminate film 32d, and a sealing portion 5. The second laminate film 32d further includes an inner resin layer 321, a metal layer 322d, and an outer resin layer 323.

[0155] The outer resin layer 323 is provided with outer openings 93 and 94 which are spaces through which the metal layer 322d is exposed. That is, in the outer openings 93 and 94, the metal layer 322d is not covered by the outer resin layer 323. In this embodiment, the outer openings 93 and 94 are located on the opposite side of the metal layer 322d to the inner openings 91 and 92, respectively. The outer openings 93 and 94 are provided to extend along the y-axis direction in FIG. 9 .

[0156] The outer terminal electrodes 73d and 74d are terminals electrically connected to the metal layer 322d at the outer openings 93 and 94, respectively. Thus, the outer terminal electrodes 73d and 74d extract current from the power generating element 2 via the metal layer 322d and the inner terminal electrodes 71d and 72d, respectively.

[0157] The outer terminal electrodes 73d and 74d have a flat plate shape and are connected to the metal layer 322d on one surface of the flat plate shape. However, the shape of the outer terminal electrodes 73d and 74d is not limited to the above.

[0158] The positions of the outer openings 93 and 94 are not limited to those described above. The positions of the outer openings 93 and 94 are not particularly limited as long as they allow current to be extracted from the power generating element 2 via the metal layer 322d and the inner terminal electrodes 71d and 72d.

[0159] Battery 1d according to this embodiment is manufactured in the same manner as battery 1 according to the first embodiment, and an example thereof is as follows.

[0160] Before the inner terminal electrodes 71d and 72d are connected to the power generating element 2, the uneven surfaces 61d and 62d are formed on the bottom surfaces of the inner terminal electrodes 71d and 72d, respectively.

[0161] Then, the power generating element 2 to which the inner terminal electrodes 71d and 72d are connected is placed on a second laminate film 32d having inner openings 91 and 92 and outer openings 93 and 94 formed therein, and the power generating element 2 and the inner terminal electrodes 71d and 72d are pressed together.

[0162] In this case, before the power generating element 2 and the inner terminal electrodes 71c and 72c are pressed together, the metal layer 322d has a flat surface at the inner openings 91 and 92. That is, when the power generating element 2 and the inner terminal electrodes 71d and 72d are pressed together, uneven surfaces 81d and 82d are formed on the metal layer 322d, and the uneven surfaces 61d and 81d mesh with the uneven surfaces 62d and 82d.

[0163] This allows easy relative positioning of the power generating element 2 and the laminate film 3d, as in the third embodiment, and also allows a highly reliable battery 1d to be realized.

[0164] Furthermore, outer terminal electrodes 73d and 74d are formed so as to be electrically connected to the metal layer 322d at the outer openings 93 and 94, respectively. By providing the outer openings 93 and 94, it is possible to extract current from the power generating element 2 through the metal layer 322d at the outer openings 93 and 94, respectively. This improves the degree of freedom in designing the extraction of current from the battery 1d, etc. Furthermore, the outer terminal electrodes 73d and 74d can extract current from the outer openings 93 and 94, respectively. This improves the degree of freedom in designing the arrangement of the outer terminal electrodes 73d and 74d, etc.

[0165] (Other embodiments) Although the battery according to one or more aspects has been described based on the embodiment and the modified examples, the present disclosure is not limited to these embodiment and modified examples. As long as it does not deviate from the gist of the present disclosure, various modifications conceived by a person skilled in the art to the embodiment and modified examples, and forms constructed by combining components in different embodiment and modified examples are also included in the scope of the present disclosure.

[0166] For example, the elastic modulus of the structure may be greater than the greater of the elastic modulus of the inner terminal electrode and the elastic modulus of the metal layer body. Also, the hardness of the structure may be greater than the greater of the hardness of the inner terminal electrode and the hardness of the metal layer. Here, the hardness is defined by, for example, Rockwell hardness, Vickers hardness, Brinell hardness, Shore hardness, etc., but is not limited thereto. By adopting the above configuration, the structure can be easily embedded in the inner terminal electrode and the metal layer body.

[0167] Furthermore, each of the above embodiments can be modified, substituted, added, omitted, and the like in various ways within the scope of the claims or their equivalents. [Industrial Applicability]

[0168] Batteries according to the present disclosure can be used, for example, as vehicle batteries or batteries included in various electronic devices. [Explanation of symbols]

[0169] 1, 1b, 1c, 1d batteries 2 Power generation elements 3, 3b, 3c, 3d Laminate film 5 Sealing part 10 Structure 11, 11b Metal layer body 12 Insulation Area 20 Battery Cells 21 Bottom 22, 23 Side 24 Top 31 First Laminating Film 32, 32b, 32c, 32d Second laminating film 61, 61c, 61d, 62c, 62d Concave-convex surfaces 61a, 62a Bottom surfaces 71, 72, 71a, 71c, 72c, 71d, 72d Inner terminal electrodes 73d, 74d Outer terminal electrodes 81, 81c, 81d, 82c, 82d Concave-convex surfaces 81a Surfaces 91, 91a, 92 Inner openings 93, 94 Outer openings 111, 112, 3211 Regions 311 Inner resin layer 312 Metal layer 313 Outer resin layer 321 Inner resin layer 322, 322b, 322c, 322d Metal layers 323 Outer resin layer

Claims

1. a power generating element including a positive electrode layer, a negative electrode layer, and an electrolyte layer located between the positive electrode layer and the negative electrode layer; an inner terminal electrode electrically connected to the power generating element; a laminate film that accommodates the power generating element and the inner terminal electrode; Equipped with The laminate film is A metal layer; an inner resin layer located closer to the power generating element than the metal layer; an outer resin layer located on the opposite side of the inner resin layer with respect to the metal layer; the inner resin layer is provided with an inner opening through which the metal layer is exposed, the inner terminal electrode is electrically connected to the metal layer at the inner opening; the inner terminal electrode and the metal layer each have an uneven surface in a region where the inner terminal electrode and the metal layer are in contact with each other; the uneven surface of the inner terminal electrode and the uneven surface of the metal layer are engaged with each other. battery.

2. The metal layer has a metal layer body and a structure, The convex portions of the uneven surface of the metal layer are part of the structure.

10. The battery of claim 1.

3. The structure has electrical conductivity.

3. The battery of claim 2.

4. The structure is made of metal. The battery according to claim 2 or 3.

5. The structures are spherical particles. The battery according to any one of claims 2 to 4.

6. The inner terminal electrode is in contact with a side surface and a main surface of the power generating element. The battery of any one of claims 1 to 5.

7. The outer resin layer has an outer opening through which the metal layer is exposed. The battery of any one of claims 1 to 6.

8. an outer terminal electrode electrically connected to the metal layer at the outer opening; 8. The battery of claim 7.

9. a thickness of the metal layer at the inner opening is greater than a thickness of the metal layer at a region where the metal layer is not exposed; The battery of any one of claims 1 to 8.

10. The electrolyte layer is a solid electrolyte layer containing a solid electrolyte having lithium ion conductivity. The battery of any one of claims 1 to 9.

11. A method for producing a battery according to any one of claims 1 to 10, comprising the steps of: a preparation step of preparing the laminate film, the laminate film having the metal layer and the inner resin layer located closer to the power generating element than the metal layer, the inner resin layer being provided with the inner opening through which the metal layer is exposed; placing a structure in the inner opening; a pressing step of pressing the inner terminal electrode electrically connected to the power generating element so as to electrically connect the inner terminal electrode to the metal layer in the inner opening in which the structure is placed in the placing step; Including, Manufacturing method.

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