All-solid-state battery

Abstract

The disclosed all-solid-state battery (10) comprises: a laminate (100) including at least one power generation element (110); an insulating film (120) disposed so as to surround the laminate (100); and an exterior body (130) that accommodates the laminated body (110) and the insulating film (120) therein. The exterior body (130) is formed using a metal laminate film. The pressure in the exterior body (130) is reduced.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an all-solid-state battery. BACKGROUND

[0002] Currently, all-solid-state batteries are attracting attention. An all-solid-state battery includes a power generation element that does not substantially contain a liquid component. The power generation element is housed in an outer packaging body. In the past, a scheme for the outer packaging body of an all-solid-state battery has been proposed.

[0003] Claim 1 of Patent Literature 1 (Japanese Patent Application Publication No. 2018-133175) recites “A method for manufacturing a laminated all-solid-state battery, comprising: housing an all-solid-state battery laminate having one or more all-solid-state battery elements in an outer packaging body composed of a laminated film, the all-solid-state battery elements sequentially laminating a negative current collector layer having a negative electrode current collector tab, a negative electrode active material layer, a solid electrolyte layer, a positive electrode active material layer, and a positive current collector layer having a positive electrode current collector tab; pressing the all-solid-state battery laminate housed in the outer packaging body in a laminating direction from an outer side of the outer packaging body; injecting a filling material into the outer packaging body while maintaining the pressing; and sealing the outer packaging body”.

[0004] Patent Literature 1: Japanese Patent Application Publication No. 2018-133175 SUMMARY

[0005] The outer packaging body formed of a laminated film is required to satisfy conditions such as processability, insulating property, and heat resistance. However, a laminated film that sufficiently satisfies all of these conditions is difficult to obtain or is expensive. Furthermore, in a case where the inside of the outer packaging body is depressurized, a short circuit is likely to occur between the power generation element and a metal layer of the laminated film, as a result of which the reliability of the battery decreases. Under such circumstances, one object of the present disclosure is to provide an all-solid-state battery that is high in reliability and advantageous in terms of manufacturing.

[0006] One aspect of the present disclosure relates to an all-solid-state battery. The all-solid-state battery includes: a laminate including at least one power generation element; an insulating film disposed so as to surround the laminate; and an outer packaging body housing the laminate and the insulating film inside, the outer packaging body being formed using a metal laminated film, an inside of the outer packaging body being depressurized.

[0007] According to the present disclosure, an all-solid-state battery that is high in reliability and advantageous in terms of manufacturing can be obtained. The novel features of the application are set forth with particularity in the appended claims. A better understanding of the present application can be obtained when the following detailed description of the application is considered in conjunction with the following drawings, in which: BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1Ais a plan view schematically showing an example of the all-solid-state battery of Embodiment 1. Figure 1B is Figure 1A a cross-sectional view at a line IB-IB of Figure 2 is an expanded view schematically showing an example of the insulating film. Figure 3 is an expanded view schematically showing another example of the insulating film. Figure 4 is a view schematically showing an example of the outer packaging body and the laminate before sealing. Figure 5 is a perspective view schematically showing an example of the laminate. DETAILED DESCRIPTION

[0009] Embodiments of the present disclosure are illustrated below, but the present disclosure is not limited to the examples described below. In the following description, there are cases in which specific numerical values, materials, and the like are exemplified, but other numerical values, other materials can also be applied as long as the invention of the present disclosure can be implemented. In the present specification, the description of "numerical value A to numerical value B" includes the numerical value A and the numerical value B, and can also be interpreted as "numerical value A or more and numerical value B or less". In the following description, in a case where a lower limit and an upper limit of a numerical value related to a specific property, condition, or the like are exemplified, any one of the exemplified lower limit and any one of the exemplified upper limit can be arbitrarily combined as long as the lower limit does not reach the upper limit or more.

[0010] (all-solid-state battery) The all-solid-state battery of the present embodiment is sometimes referred to as "all-solid-state battery (B)" or "battery (B)" below. The all-solid-state battery (B) includes a laminate including at least one power generation element, an insulating film disposed so as to surround the laminate, and an outer packaging body that internally houses the laminate and the insulating film. The laminate is sometimes referred to as "laminate (S)" below. The insulating film is sometimes referred to as "insulating film (F)" below. The outer packaging body is formed using a metal build-up film. The inside of the outer packaging body is reduced in pressure.

[0011] In the laminate (S), a plurality of layers that constitute the laminate (S) are laminated in a lamination direction SD. In the all-solid-state battery (B), by pressing the laminate (S) including the power generation element in the lamination direction SD, the characteristics can be improved. By reducing the pressure inside the outer packaging body, the laminate (S) can be pressed in the lamination direction SD by the atmospheric pressure. Further, by sealing the outer packaging body in a state where the pressure inside the outer packaging body is reduced, the volatile components such as moisture present inside the outer packaging body can be reduced.

[0012] The outer packaging body is required to have processability for processing into a shape for housing the laminate. Further, since the outer packaging body is formed using the metal build-up film, high insulation is required in the absence of the insulating film (F). Furthermore, in the all-solid-state battery in which the insulating film (F) is not used, if the outer packaging body melts, short-circuiting occurs, and thus the outer packaging body is required to have high heat resistance in the absence of the insulating film (F). A metal build-up film satisfying all of these requirements is not easily obtained or is very expensive. Further, in a case where satisfaction of the requirements other than the processability is emphasized, the processability can sometimes be reduced to make the manufacture of the battery difficult.

[0013] In the all-solid-state battery (B), since the insulating film (F) is used, the outer packaging body can also have low insulation. Furthermore, by using an insulating film (F) having high heat resistance, an outer packaging body having less high heat resistance can also be used. Thus, the conditions required for the metal build-up film used for the outer packaging body can be relaxed. As a result, an all-solid-state battery having high reliability can be manufactured at low cost and / or with good productivity. The use temperature of the all-solid-state battery (B) is not particularly limited. The all-solid-state battery (B) can also be used in a high-temperature atmosphere of 100°C or higher.

[0014] The pressure inside the outer packaging body is preferably 1.0 x 10 2 Pa or lower, and particularly preferably 1.0 x 10 -1 Pa or lower. By making the pressure inside the outer packaging body 1.0 x 10 -1 Pa or lower, a good effect can be obtained.

[0015] The insulating film (F) is preferably not sealed. For example, it is preferable that the insulating film (F) have a communication portion connecting the inside and the outside of the space surrounded by the insulating film (F). Examples of the communication portion include a gap, a through-hole, and the like. By the insulating film (F) not being sealed, the insulating film (F) can be depressurized. As a result, the laminate (S) can be sufficiently pressurized.

[0016] The laminated body (S) can also have a cuboid shape with six faces. In this case, at least a portion of the insulating film (F) is preferably arranged between the six faces of the laminated body (S) and the outer packaging body (metal laminate film). With this structure, all the faces of the laminated body (S) can be protected. The insulating film (F) can also have a plurality of faces P that respectively face the six faces. The plurality of faces P can also directly face the six faces of the laminated body (S). In other words, the plurality of faces P can also be in contact with the six faces of the laminated body (S). Alternatively, at least a portion of the plurality of faces P can face the faces of the laminated body (S) with other members (e.g., insulating films) interposed therebetween. The plurality of faces P are arranged in substantially parallel to the faces (faces of the laminated body (S)) that face them, respectively. The insulating film (F) can also be arranged so as to cover a large portion of the six faces of the cuboid-shaped laminated body (S). For example, the insulating film (F) can be arranged so as to cover 90% or more (area ratio) of the six faces, or can be arranged so as to cover the entire six faces. By folding the insulating film (F) into a box shape, the six faces can be covered. Examples of the manner in which the insulating film (F) covers the faces of the laminated body (S) include the following first and second manners. In the first manner, the insulating film (F) covers the faces of the laminated body (S) in a state in which the insulating film (F) is in contact with the faces of the laminated body (S). In the second manner, the insulating film (F) covers the faces of the laminated body (S) in a state in which other members are arranged between the insulating film (F) and the faces of the laminated body (S). That is, the all-solid-state battery (B) can include other members (e.g., insulating members other than the insulating film (F)) arranged between the laminated body (S) and the insulating film (F).

[0017] A portion of the insulating film (F) can also be arranged between all twelve edges of the cuboid-shaped laminated body (S) and the outer packaging body. That is, the insulating film (F) can be arranged so as to cover all the twelve edges of the cuboid-shaped laminated body (S), or can be arranged so as to be in contact with the twelve edges. The insulating film (F) can be arranged so as to cover 90% or more (length ratio) of the twelve edges of the cuboid-shaped laminated body (S), or can be arranged so as to cover the entire twelve edges. With this structure, in particular, short-circuiting at the corners of the laminated body (S) can be suppressed. At least a portion of the insulating film (F) can also be arranged between the six faces and all the twelve edges of the cuboid-shaped laminated body (S) and the outer packaging body.

[0018] The insulating film (F) can also surround the laminated body (S) by folding a single film. Alternatively, the insulating film (F) can be composed of a plurality of films. For example, the insulating film (F) can include a film that covers one major face of the laminated body (S) and a film that covers the other major face.

[0019] The laminated body (S) can also have a shape other than a rectangular parallelepiped shape. For example, the laminated body (S) can also have a shape of a plate or a column in which a planar shape is circular or polygonal. In this case, the insulating film (F) and the outer packaging body have shapes corresponding to the shape of the laminated body (S). In any case, it is preferable that the insulating film (F) be arranged so as to cover both main surfaces of the laminated body (S). That is, it is preferable that at least a portion of the insulating film (F) be arranged between both main surfaces of the laminated body (S) and the outer packaging body. The insulating film (F) can also have a plurality of surfaces P opposite to both main surfaces of the laminated body (S). The plurality of surfaces P can also directly oppose both main surfaces of the laminated body (S). In other words, the plurality of surfaces P can also be in contact with both main surfaces of the laminated body (S). Alternatively, at least a portion of the plurality of surfaces P can oppose the surfaces of the laminated body (S) with other members (for example, the insulating film) interposed therebetween. The plurality of surfaces P are respectively arranged substantially in parallel to the surfaces (the main surfaces of the laminated body (S)) opposite thereto. The insulating film (F) can also have a shape of a bag that is not sealed, regardless of the shape of the laminated body (S).

[0020] The laminated body (S) can also have two main surfaces and a side surface connecting the two main surfaces. In this case, it is preferable that at least a portion of the insulating film (F) be arranged between each of the two main surfaces and the side surface of the laminated body (S) and the outer packaging body. The insulating film (F) can also have a plurality of surfaces P opposite to each of the two main surfaces and the side surface. The plurality of surfaces P can also directly oppose each of the two main surfaces and the side surface of the laminated body (S). In other words, the plurality of surfaces P can also be in contact with each of the two main surfaces and the side surface of the laminated body (S). Alternatively, at least a portion of the plurality of surfaces P can oppose the surfaces of the laminated body (S) with other members (for example, the insulating film) interposed therebetween. The plurality of surfaces P are respectively arranged substantially in parallel to the surfaces (the surfaces of the laminated body (S)) opposite thereto. Examples of the shape of the laminated body (S) having two main surfaces and a side surface connecting the two main surfaces include a shape of a plate or a column in which a planar shape is circular or polygonal, and a rectangular parallelepiped shape.

[0021] The laminated body (S) can also include a positive electrode current collector having a positive electrode tab and a negative electrode current collector having a negative electrode tab. The positive electrode tab can be connected to the positive electrode lead by the first connecting portion. The negative electrode tab can be connected to the negative electrode lead by the second connecting portion. The insulating film (F) can cover the first connecting portion and the second connecting portion. The tab and the lead are connected by welding or the like. Therefore, a slight unevenness is easily generated at the connecting portion, as a result of which a short circuit at the connecting portion is easily generated. By covering the connecting portion with the insulating film (F), a short circuit at the connecting portion can be suppressed, in particular.

[0022] The insulating film (F) can include a layer containing at least one resin selected from the group consisting of a fluororesin and a polyimide resin, or can be composed of the at least one resin. The insulating film (F) can be a film composed of a fluororesin, or a film composed of a polyimide resin, or can contain both of the resins. These resins are preferred because of their high insulating properties and heat resistance. Since fluororesins are easy to slide, the process of housing the insulating film (F) surrounding the laminate (S) in the outer packaging body becomes easy. Therefore, a fluororesin layer can exist on at least the outer side of the insulating film (F). The insulating film (F) can also be a film composed of a fluororesin. Examples of the fluororesin include polytetrafluoroethylene (PTFE), soluble polytetrafluoroethylene (PFA: Perfluoroalkoxy alkanes), ethylene-tetrafluoroethylene copolymer (ETFE), and the like.

[0023] The insulating film (F) can be composed of one kind of resin, or can be composed of a plurality of kinds of resins. The insulating film (F) can be a single-layer film, or can be a film composed of a plurality of layers.

[0024] The insulating film (F) can contain an inorganic filler or the like for improving heat resistance and insulating properties, or can not contain an inorganic filler or the like. The inorganic filler is not particularly limited, and a publicly known inorganic filler used for insulating films, sealing resins, and the like can be used. For example, the inorganic filler can be particles of alumina, particles of silica, or the like.

[0025] The heat resistance temperature of the insulating film (F) can also be higher than the heat resistance temperature of the metal laminate film. According to this structure, since the heat resistance of the metal laminate film does not need to be improved so much, the selection range of the metal laminate film is expanded.

[0026] The insulating film (F) can also contain a resin layer composed of a resin having a melting point higher than the melting point of all the resins constituting the resin layer contained in the metal laminate film. According to this structure, since the heat resistance of the metal laminate film does not need to be improved so much, the selection range of the metal laminate film is expanded. The insulating film (F) can also contain a resin layer composed of a resin having a melting point of 200°C or higher. Examples of the resin having a melting point of 200°C or higher include polytetrafluoroethylene (PTFE), soluble polytetrafluoroethylene (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), polyimide, and the like.

[0027] The outer packaging body can also include a first outer packaging member and a second outer packaging member that is attached to the first outer packaging member. At least one of these outer packaging members can also have a recess for housing at least a portion of the laminate (S). More specifically, at least a portion of the laminate (S) and at least a portion of the insulating film (F) that surrounds the laminate (S) are housed in the recess (the same applies to the recess described below). The outer packaging body can also include a first outer packaging member having a recess for housing at least a portion of the laminate (S) and a second outer packaging member attached to the first outer packaging member. The recess has a size that can house at least a portion of the laminate (S). In the case where the laminate (S) is in the shape of a rectangular solid, the recess is a recess in the shape of a rectangular solid. For example, the outer packaging body can also include a first outer packaging member having a recess in the shape of a rectangular solid and a second outer packaging member attached to the first outer packaging member.

[0028] The second outer packaging member can also be flat. Alternatively, the second outer packaging member can have a recess for housing a portion of the laminate (S). In the case where the metal laminate film is shaped with a recess, at the corner of the recess, the insulating resin layer becomes thin and is likely to short circuit. By using the insulating film (F), it is possible to suppress short circuit. In addition, the first outer packaging member and the second outer packaging member can be connected. For example, one sheet of material can be folded to serve as the first outer packaging member and the second outer packaging member.

[0029] Examples of the components of the all-solid-state battery (B) are described below. However, the components described below are examples, and other components can also be used. In addition, examples of all-solid-state lithium ion batteries are mainly described below.

[0030] The all-solid-state battery (B) is a battery that does not contain an electrolyte solution. The all-solid-state battery (B) includes a laminate (S). The laminate (S) includes at least one power generating element. The laminate (S) can include a plurality of power generating elements laminated. The power generating element is not particularly limited and a power generating element used in a known all-solid-state battery can also be used. As an example, the power generating element includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer. The power generating element can be formed only of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer, or can include other layers. Examples of such other layers include a thin conductive layer composed of a material containing a conductive powder, and the like. Examples of each layer are described below.

[0031] (Positive electrode layer) The positive electrode layer contains a positive electrode active material, and can contain other components as necessary. Examples of the other components include components used for a positive electrode of a known all-solid-state battery. The positive electrode layer can contain a positive electrode active material and a solid electrolyte from the viewpoint of improving the lithium ion conductivity in the positive electrode layer. The solid electrolyte can employ a solid electrolyte that exhibits lithium ion conductivity, or a solid electrolyte used for a solid electrolyte layer of a known all-solid-state battery. Generally, the positive electrode active material is used in the state of a particle (powder). The positive electrode layer can be formed by compression molding of a powder of the positive electrode active material, a positive electrode mixture (a powder of the positive electrode active material and an additive, etc.).

[0032] The positive electrode active material can employ a material that can be used as a positive electrode active material in an all-solid-state battery. In the case of an all-solid-state lithium ion battery, examples of the positive electrode active material include lithium-containing complex oxides, and compounds other than oxides. Examples of the lithium-containing complex oxides include lithium cobaltate, lithium nickelate, lithium manganate, and other lithium-containing complex oxides (LiNi 0.8 Co 0.15 Al 0.05 O2, etc.). Examples of the compounds other than oxides include olivine compounds (LiMPO4), sulfur-containing compounds (Li2S, etc.), and the like. In the above formula, M represents a transition metal. The positive electrode active material can be used alone, or two or more kinds can be used in combination.

[0033] (Negative electrode layer) The negative electrode layer contains a negative electrode active material, and can contain other components as necessary. Examples of the other components include components used for a negative electrode of a known all-solid-state battery. The negative electrode layer can contain a negative electrode active material and a solid electrolyte that exhibits lithium ion conductivity. Generally, the negative electrode active material is used in the state of a particle (powder). The negative electrode layer can be formed by compression molding of a powder of the negative electrode active material, a negative electrode mixture (a powder of the negative electrode active material and an additive, etc.).

[0034] The negative active material can employ a material that can be used as a negative active material in a full solid-state battery. In the case of a full solid-state lithium ion battery, the negative active material can use a predetermined material (carbonaceous material, single body or alloy of metal and metalloid, or compound, etc.) capable of reversibly occluding and releasing lithium ions. Examples of the carbonaceous material include graphite (natural graphite, artificial graphite, etc.), hard carbon, amorphous carbon, etc. Examples of the single body, alloy of metal and metalloid include lithium metal and alloy, Si single body, etc. Examples of the compound can cite oxide (titanium oxide, silicon oxide, etc.), sulfide, nitride, hydrate, silicide (lithium silicide, etc.), etc. The negative active material can be used singly in one kind, or two or more kinds in combination. For example, silicon oxide and carbonaceous material can be used in combination. As the negative active material, a particle including graphite particles and amorphous carbon coating the graphite particles can also be used.

[0035] (Solid electrolyte layer) The solid electrolyte layer disposed between the positive electrode and the negative electrode contains a solid electrolyte that conducts a charge carrier. Generally, the solid electrolyte is used in a state of a particle (powder). The solid electrolyte layer can be formed by compression molding a material containing a solid electrolyte powder.

[0036] The solid electrolyte can employ a material that can be used as a solid electrolyte in a full solid-state battery. In the case of a full solid-state lithium ion battery, the solid electrolyte can employ a substance having lithium ion conductivity. Examples of such a solid electrolyte include inorganic solid electrolytes such as sulfide (sulfide-based solid electrolyte), hydride (hydride-based solid electrolyte), etc.

[0037] Examples of the sulfide include Li2S-SiS2, Li2S-P2S5, Li2S-GeS2, Li2S-B2S3, Li2S-Ga2S3, Li2S-Al2S3, Li2S-GeS2-P2S5, Li2S-Al2S3-P2S5, Li2S-P2S3, Li2S-P2S3-P2S5, LiX-Li2S-P2S5, LiX-Li2S-SiS2, LiX-Li2S-B2S3 (X: I, Br, or Cl), etc. Examples of the hydride include LiBH4-LiI-based complex hydride and LiBH4-LiNH2-based complex hydride, etc.

[0038] (Positive electrode current collector) Generally, a metal layer (positive electrode current collector) is disposed on the outside of the positive electrode layer of the power generating element. The metal layer (positive electrode current collector) can also use a metal foil. Examples of the material of the positive electrode current collector (e.g., metal foil) include aluminum, magnesium, stainless steel, titanium, iron, cobalt, zinc, tin, or alloys thereof, etc. The positive electrode current collector can also include a positive electrode tab protruding from the laminated portion of the laminate (S).

[0039] (negative current collector) A metal layer (negative current collector) is generally provided on the outer side of the negative electrode layer of the power generating element. The metal layer (negative current collector) can also be a metal foil. Examples of the material of the metal layer (negative current collector) include copper, nickel, stainless steel, titanium, or alloys thereof, etc. The negative current collector can also include a negative electrode tab that protrudes from the laminated portion of the laminate (S).

[0040] (positive lead, negative lead) The all-solid-state battery (B) can also include leads (positive lead, negative lead). The positive lead is connected to the positive electrode tab, and the negative lead is connected to the negative electrode tab. The method of connecting the leads to the tabs (positive electrode tab, negative electrode tab) is not limited, and the leads can be connected by welding or the like. The leads are formed of a metal (for example, copper, aluminum, stainless steel, titanium, etc.) having electrical conductivity.

[0041] (insulating film (F)) The insulating film (F) can be the insulating film described above. The thickness of the insulating film is not particularly limited, and is preferably in the range of 10 μm to 200 μm, and particularly preferably in the range of 50 μm to 100 μm.

[0042] (outer package) As described above, the outer package can be formed using a metal laminate film. The outer package can use an outer package composed of a metal laminate film. The metal laminate film includes a metal layer sandwiched by two insulating resin layers. The gas tightness inside the outer package is improved by the metal layer. The metal layer can also be an aluminum layer (for example, an aluminum foil). The resin layers present on both sides of the metal layer can each include a plurality of resin layers laminated. Since the all-solid-state battery (B) includes the insulating film (F), various metal laminate films can be used.

[0043] A heat sealable resin layer (fusion layer) is provided on one surface of the metal laminate film. By fusing the fusion layers to each other and heating, the inside of the outer package can be sealed. Examples of the heat sealable resin layer include polypropylene, acid-modified polypropylene, etc. The thickness of the metal laminate film is not particularly limited, and is preferably in the range of 100 μm to 300 μm.

[0044] The all-solid-state battery (B) can also include a case that houses the outer package (the outer package that houses the laminate (S) and the insulating film (F)). The case can also be a metal case. The metal case can include a square tubular portion that houses the outer package that seals the laminate (S) and the insulating film (F). The square tubular portion can include two plate-shaped portions that are bent in a manner that protrudes toward the inside when the outer package is not housed. With the two plate-shaped portions, the two main surfaces of the laminate (S) can be pressed toward the inside.

[0045] Method for manufacturing all-solid-state battery (B) The all-solid-state battery (B) is manufactured by a manufacturing method including a step (i), a step (ii), and a step (iii). Since matters described for the all-solid-state battery (B) can be applied to the manufacturing method, sometimes the repeated description is omitted. The step (i) is a step of forming a laminate (S). The step (ii) is a step of disposing an insulating film (F) so as to surround the laminate (S). The step (iii) is a step of housing the laminate (S) surrounded by the insulating film (F) in an outer package and sealing the outer package. Examples of each step are described below. In addition, the all-solid-state battery (B) can also be manufactured by a step other than the steps described below. Matters described below with respect to the manufacturing steps can also be applied to the all-solid-state battery (B).

[0046] In the step (i), the method for forming the laminate (S) is not particularly limited and can be formed by a publicly known method for forming a laminate of an all-solid-state battery. In one example of the method for forming, the materials of the respective layers are laminated and the laminate (S) is formed by pressing. In another example of the method for forming, each layer is first formed by pressing the material of each layer separately. Then, the laminate (S) can be formed by laminating the formed layers and pressing them collectively. At the time of pressing, the current collector can be pressed together with the material of the laminate (S).

[0047] In the step (ii), for example, the laminate (S) can be disposed on the insulating film (F) which is cut in advance to a predetermined shape, and the insulating film (F) can be folded to surround the laminate (S). The portion of the insulating film (F) which is folded can be formed in advance to be easily foldable by pressure or the like.

[0048] In the step (iii), the laminate (S) surrounded by the insulating film (F) is housed in an outer package and the outer package is sealed. At this time, the outer package is sealed in a state in which the inside of the outer package is depressurized. Since the insulating film (F) is not sealed, the inside of the insulating film (F) is also depressurized. The method for depressurizing the inside of the outer package is not limited and a publicly known method can be employed. For example, heat sealing can be performed in a depressurized atmosphere. Alternatively, the outer package can be sealed by a publicly known vacuum sealing device. As described above, the outer package can employ an outer package in which a recess for housing at least a part of the laminate is formed in advance. By employing such an outer package, the step (iii) becomes easy, and furthermore, the reliability of the sealing of the outer package can be improved.

[0049] The lead (or tab) can protrude from the outer package. The lead (or tab) can be used to exchange electric power between the power generating element of the all-solid-state battery (B) and an external device.

[0050] Hereinafter, an example of the embodiment of the present disclosure will be described with reference to the drawings. In the example of the embodiment described below, the description of the above-described embodiment can be applied, and changes can be made in accordance with the above-described description. The constituent elements of the all-solid-state battery described below that are not essential to the all-solid-state battery of the present disclosure can be omitted. Furthermore, the matters described below can be applied to the above-described embodiment. In addition, the following drawings are schematic drawings, and the actual scale is different. In the following drawings, a part of a component is sometimes omitted for easy viewing of the drawings.

[0051] (Embodiment 1) In Embodiment 1, an example of an all-solid-state battery (B) will be described. Figure 1A A plan view of the all-solid-state battery 10 of Embodiment 1 is shown. Furthermore, Figure 1B A cross-sectional view at line IB-IB of Figure 1A is shown.

[0052] With reference to Figure 1A and Figure 1B , the all-solid-state battery 10 includes a laminate 100, an insulating film 120, an outer packaging body 130, a positive electrode lead 141, and a negative electrode lead 142. The laminate 100 is the above-described laminate (S). The insulating film 120 is the above-described insulating film (F). The outer packaging body 130 is the above-described outer packaging body and is composed of a metal laminate film. The outer packaging body 130 is sealed, and the inside of the outer packaging body 130 is reduced in pressure. In Embodiment 1, an example in which the laminate 100 is a rectangular parallelepiped-shaped laminate having six faces will be described.

[0053] The laminate 100 includes a power generating element 110, a positive electrode current collector 114, and a negative electrode current collector 115. The power generating element 110 includes a positive electrode layer 111, a negative electrode layer 112, and a solid electrolyte layer 113. They are laminated in the arrangement of the positive electrode current collector 114 / positive electrode layer 111 / solid electrolyte layer 113 / negative electrode layer 112 / negative electrode current collector 115 along a laminating direction SD. The laminate 100 has a first main face 100sa and a second main face 100sb opposite to the first main face 100sa. In Embodiment 1, an example in which the power generating element 110 included in the laminate 100 is only one is shown, and the laminate 100 can include a plurality of power generating elements 110 laminated. The power generating element 110 substantially does not contain a liquid component.

[0054] The positive electrode current collector 114 has a positive electrode tab 114a protruding from the laminated portion of the laminate 100. The negative electrode current collector 115 has a negative electrode tab 115a protruding from the laminated portion of the laminate 100. The positive electrode tab 114a is welded to the positive electrode lead 141 at a connection portion 114b. The negative electrode tab 115a is welded to the negative electrode lead 142 at a connection portion 115b.

[0055] Figure 2 represents a state in which the insulation film 120 is developed. By bending the portions of the insulation film 120 shown by the dotted line and the single-dot chain line, the laminate 100 can be surrounded by the insulation film 120. A crease can be provided in advance in the portions of the dotted line and the single-dot chain line before the laminate 100 is surrounded. The portions of the insulation film 120 that overlap can be fixed by an adhesive, a tape, or the like, or can not be fixed. Figure 2 The portions of the insulation film 120 shown by the dotted line and the single-dot chain line are bent, so that the laminate 100 can be surrounded by the insulation film 120. A crease can be provided in advance in the portions of the dotted line and the single-dot chain line before the laminate 100 is surrounded. The portions of the insulation film 120 that overlap can be fixed by an adhesive, a tape, or the like, or can not be fixed.

[0056] A portion of the insulation film 120 is disposed between the six faces and all twelve edges of the laminate 100 and the outer packaging body 130. The insulation film 120 has a face (region) 120a that opposes (contacts) the first major face 100sa, and a face (region) 120b that opposes (contacts) the second major face 100sb. Similarly, the insulation film 120 has faces (regions) that oppose (contact) the other four faces of the laminate 100. The insulation film 120 has regions that cover the twelve edges of the laminate 100. For example, the face (region) 120e covers the side face of the laminate 100. Further, the insulation film 120 has a face (region) 120c that covers one face of the connection portions 114b, 115b, and a face (region) 120d that covers the other face of the connection portions 114b, 115b. The insulation film 120 is bent at the portions of the dotted line so that the faces of the insulation film 120 other than the face 120c and the face 120d oppose the respective faces of the laminate 100. Further, the insulation film 120 is bent at the portions of the single-dot chain line so that the face 120c and the face 120d oppose each other with the connection portions 114b, 115b interposed therebetween. The insulation film 120 is bent so that each face of the insulation film 120 and the surface of the laminate 100 opposing thereto are substantially parallel. As described above, other components can be disposed between the laminate 100 and the insulation film 120. Figure 2 The insulation film 120 shown in FIG. 12 can cover the six faces and the twelve edges of the laminate 100 as a whole (or substantially as a whole). As a result, in particular, short-circuiting of burrs or the like of the positive electrode current collector 114 and the negative electrode current collector 115 with the outer packaging body 130 can be prevented. Further, since the insulation film 120 covers the connection portions 114b, 115b, short-circuiting of burrs or the like of the connection portions 114b, 115b with the outer packaging body 130 can be prevented.

[0057] Figure 2 The insulation film 120 shown in FIG. 12 can cover the six faces and the twelve edges of the laminate 100 as a whole (or substantially as a whole). As a result, in particular, short-circuiting of burrs or the like of the positive electrode current collector 114 and the negative electrode current collector 115 with the outer packaging body 130 can be prevented. Further, since the insulation film 120 covers the connection portions 114b, 115b, short-circuiting of burrs or the like of the connection portions 114b, 115b with the outer packaging body 130 can be prevented.

[0058] The insulation film 120 is not sealed. That is, the insulation film 120 has a gap that connects the inside and the outside of the space surrounded by the insulation film 120. Therefore, the space on the inside of the insulation film 120 is also depressurized.

[0059] Figure 2 An example in which the insulation film 120 is composed of one film is shown. However, the insulation film 120 can also be composed of a plurality of films (for example, two films). Figure 3An example in which the insulating film 120 is composed of two films is shown.

[0060] Figure 3 The insulating film 120 of the example shown has Figure 2 The insulating film 120 is divided at the portion of the surface 120e connecting the surface 120a and the surface 120b. The surface 121e1 and the surface 121e2 correspond to the surface 120e. However, since the side surface of the laminate 100 is covered, it is preferable that the total width of the surface 120e1 and the width of the surface 120e2 is greater than Figure 2 The width of surface 120e.

[0061] Figure 4 The figure schematically shows an example of an outer packaging body 130 before sealing and an example of a laminated body 100 housed in the outer packaging body 130. The outer packaging body 130 is composed of a first outer packaging member 131 and a second outer packaging member 132 bonded to the first outer packaging member 131. The first outer packaging member 131 and the second outer packaging member 132 each have a rectangular recess 130c for accommodating at least a portion of the rectangular laminated body 100. The recess 130c is formed in advance before the process of accommodating the laminated body 100 and the insulating film 120. The outer packaging body 130 can be sealed by bonding the portion around the recess 130c by heat sealing or the like. In addition, at least one of the first outer packaging member 131 and the second outer packaging member 132 may not have the recess 130c.

[0062] Figure 1A and Figure 1B 1 shows an example in which the stacked body 100 includes one power generation element. However, the stacked body 100 may include a plurality of power generation elements. Figure 5 A perspective view showing an example of the laminate 100 in this case is shown.

[0063] Figure 5 The illustrated stack 100 includes multiple power generation elements. Multiple positive electrode tabs 114a and multiple negative electrode tabs 115a protrude from the stack 100. The multiple positive electrode tabs 114a are bent into an L-shape as needed, overlapped, and collectively connected to a positive electrode lead 141. The multiple negative electrode tabs 115a are bent into an L-shape as needed, overlapped, and collectively connected to a negative electrode lead 142.

[0064] exist Figure 5 In the stacked body 100, a case where multiple power generation elements are connected in parallel is shown. In this case, multiple power generation elements can also be stacked with an insulating layer between them. Alternatively, multiple power generation elements can be stacked in such a way that the same electrode layers of two adjacent power generation elements (positive electrode layers, negative electrode layers) face each other with a current collector between them. Alternatively, Figure 5In a different example shown, a plurality of power generation elements are connected in series. In this case, the positive electrode tab and the negative electrode tab that protrude from the laminate 100 can be provided as one each of the uppermost layer and the lowermost layer. In this case, the positive electrode lead and the negative electrode lead can be omitted by lengthening the tabs.

[0065] (Notes) Through the above description, the following invention modes are disclosed. (Invention Mode 1) A full solid-state battery, comprising: a laminate including at least one power generation element; an insulating film configured to surround the laminate; and an outer packaging body that houses the laminate and the insulating film inside, the outer packaging body is formed using a metal laminate film, the inside of the outer packaging body is reduced in pressure. (Invention Mode 2) The full solid-state battery according to Invention Mode 1, wherein the insulating film is not sealed. (Invention Mode 3) The full solid-state battery according to Invention Mode 1 or 2, wherein the laminate has two main faces and a side face connecting the two main faces, at least a portion of the insulating film is disposed between each of the two main faces and the side face and the outer packaging body. (Invention Mode 4) The full solid-state battery according to Invention Mode 1 or 2, wherein the laminate has a cuboid shape having six faces, at least a portion of the insulating film is disposed between each of the six faces and the outer packaging body. (Invention Mode 5) The full solid-state battery according to any one of Invention Modes 1 to 4, wherein the laminate includes a positive electrode current collector having a positive electrode tab and a negative electrode current collector having a negative electrode tab, the positive electrode tab is connected to a positive electrode lead by a first connecting portion, the negative electrode tab is connected to a negative electrode lead by a second connecting portion, the insulating film covers the first connecting portion and the second connecting portion. (Invention Mode 6) The full solid-state battery according to any one of Invention Modes 1 to 5, wherein The insulating film includes a layer containing at least one resin selected from the group consisting of a fluorine resin and a polyimide resin. (Invention Mode 7) The all-solid-state battery according to any one of Invention Modes 1 to 6, wherein The heat resistance temperature of the insulating film is higher than the heat resistance temperature of the metal multilayer film. (Invention Mode 8) The all-solid-state battery according to any one of Invention Modes 1 to 7, wherein The outer package includes a first outer package member having a recess that accommodates at least a portion of the laminate, and a second outer package member that is attached to the first outer package member. Industrial applicability

[0066] The present disclosure is applicable to all-solid-state batteries. The present invention illustrates presently preferred embodiments, but this disclosure should not be construed as limiting. Various modifications and alterations will occur to those skilled in the art upon reading the above disclosure. It is intended that the scope of the present invention be construed as including all such modifications and alterations as fall within the true spirit and scope of the present invention. Explanation of reference numerals

[0067] 10: all-solid-state battery 100: laminate 110: power generating element 111: positive electrode layer 112: negative electrode layer 113: solid electrolyte layer 114: positive electrode current collector 114a: positive electrode tab 114b, 115b: connection portion 115: negative electrode current collector 115a: negative electrode tab 120: insulating film 130: outer package 130c: recess 131: first outer package member 132: second outer package member 141: positive electrode lead wire 142: negative electrode lead wire.

Claims

1. A solid-state battery, comprising: a laminate including at least one power generating element; an insulating film configured to surround the laminate; and an outer package that houses the laminate and the insulating film inside, the outer package is formed using a metal laminate film, and an inside of the outer package is reduced in pressure.

2. The solid-state battery according to claim 1, wherein the insulating film is not sealed.

3. The solid-state battery according to claim 1 or 2, wherein the laminate has two main faces and a side face connecting the two main faces, and at least a part of the insulating film is disposed between each of the two main faces and the side face and the outer package.

4. The solid-state battery according to claim 1 or 2, wherein the laminate has a shape of a rectangular parallelepiped having six faces, and at least a part of the insulating film is disposed between each of the six faces and the outer package.

5. The solid-state battery according to claim 1 or 2, wherein the laminate includes a positive electrode current collector having a positive electrode tab and a negative electrode current collector having a negative electrode tab, the positive electrode tab is connected to a positive electrode lead by a first connecting portion, the negative electrode tab is connected to a negative electrode lead by a second connecting portion, and the insulating film covers the first connecting portion and the second connecting portion.

6. The solid-state battery according to claim 1 or 2, wherein the insulating film includes a layer containing at least one resin selected from the group consisting of a fluororesin and a polyimide resin.

7. The solid-state battery according to claim 1 or 2, wherein a heat resistance temperature of the insulating film is higher than a heat resistance temperature of the metal laminate film.

8. The solid-state battery according to claim 1 or 2, wherein the outer package includes a first outer package member having a recess that houses at least a part of the laminate, and a second outer package member that is attached to the first outer package member. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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