Battery, battery system, and method for manufacturing a battery

Abstract

This battery (1000) is provided with: an electric power generation element (100) which comprises a negative electrode active material layer (110), a positive electrode active material layer (120), and a solid electrolyte layer (130) that is arranged between the negative electrode active material layer (110) and the positive electrode active material layer (120); a sealing material (700) which seals a first surface (100a) that is a lateral surface of the electric power generation element (100); and a negative electrode collector (210) which is positioned on the negative electrode active material layer (110) side of the electric power generation element (100). This battery (1000) is provided with a void (230) that is surrounded by the sealing material (700), the first surface (100a) and the negative electrode collector (210); and the internal pressure of the void (230) is less than 1 atm. The negative electrode collector (210) has a recess (211) that is curved so as to be recessed toward the void (230).

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses an air battery that takes in air with a laminated film including a void holding member including at least one selected from the group consisting of a porous film, a non-woven fabric, and a woven fabric, and an oxygen barrier film, seals holes, and causes a battery container to have a negative pressure during continuous discharge.

[0003] Patent Document 2 discloses that in the manufacturing process of a power storage module using a liquid battery, the internal space is divided into odd-numbered internal spaces and even-numbered internal spaces, and the internal pressure is changed once for each and inspected.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the prior art, further improvement in battery characteristics and reliability is desired.

[0006] In addition, in a battery including a solid electrolyte, high battery characteristics such as high capacity expression and excellent charge-discharge cycle characteristics, and high reliability in various usage environments are required.

[0007] In order to achieve the characteristics of a battery including a solid electrolyte, it is important to increase the conductivity of ions and electrons and apply an external restraining force from the normal direction of the main surface of the battery to maintain this.

[0008] On the other hand, applying a mechanism to exert an external restraining force was inconvenient for obtaining the capacity density per unit volume and capacity density per unit weight of the battery.

[0009] Therefore, this disclosure provides a battery that achieves both high battery performance and high reliability. [Means for solving the problem]

[0010] A battery in one aspect of the present disclosure comprises a power generation element having an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer; a sealing material sealing a first surface which is a side surface of the power generation element; and an electrode current collector located on the electrode layer side of the power generation element, wherein there is a void surrounded by the sealing material, the first surface, and the electrode current collector, the internal pressure of the void is less than 1 atm, and the electrode current collector has a first recess that curves inward toward the void.

[0011] Furthermore, a battery system in one aspect of this disclosure comprises a container having an internal space that becomes a reduced-pressure environment, and the battery disposed in the internal space.

[0012] Furthermore, a method for manufacturing a battery in one aspect of the present disclosure is a method for manufacturing a battery comprising a power generation element having an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, comprising a depressurization step of exposing a first surface, which is a side surface of the power generation element in a laminate including the power generation element, to a depressurization atmosphere, and a sealing step of sealing the first surface with a sealing material under the depressurization atmosphere. [Effects of the Invention]

[0013] According to this disclosure, it is possible to achieve both high battery characteristics and high reliability in batteries and the like. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a cross-sectional view showing the schematic configuration of a battery according to Embodiment 1. [Figure 2]FIG. 2 is a cross-sectional view showing a schematic configuration of a battery according to Modification 1 of Embodiment 1. [Figure 3] FIG. 3 is a cross-sectional view showing a schematic configuration of a battery according to Modification 2 of Embodiment 1. [Figure 4] FIG. 4 is a cross-sectional view showing a schematic configuration of a battery according to Comparative Example 1. [Figure 5] FIG. 5 is a cross-sectional view showing a schematic configuration of a battery according to Comparative Example 2. [Figure 6] FIG. 6 is a flowchart of a method for manufacturing a battery according to Embodiment 1. [Figure 7] FIG. 7 is a schematic diagram for explaining a first example of a method for sealing a first surface according to Embodiment 1. [Figure 8] FIG. 8 is a schematic diagram for explaining a second example of a method for sealing a first surface according to Embodiment 1. [Figure 9] FIG. 9 is a schematic diagram for explaining a third example of a method for sealing a first surface according to Embodiment 1. [Figure 10] FIG. 10 is a schematic diagram showing a schematic configuration of a battery system according to Embodiment 2. [Figure 11] FIG. 11 is a schematic diagram showing a schematic configuration of another battery system according to Embodiment 2.

MODE FOR CARRYING OUT THE INVENTION

[0015] (SUMMARY OF THE DISCLOSURE) A battery in one aspect of the present disclosure includes a power generation element having an electrode layer, a counter electrode layer, and a solid electrolyte layer positioned between the electrode layer and the counter electrode layer, a sealing material that seals a first surface which is a side surface of the power generation element, and an electrode current collector positioned on the electrode layer side in the power generation element. There is a void surrounded by the sealing material, the first surface, and the electrode current collector, the internal pressure of the void is less than 1 atm, and the electrode current collector has a first recess curved so as to be concave toward the void.

[0016] As a result, the battery in this embodiment can achieve both high battery characteristics and high reliability. By sealing the first surface with a sealing material, the power generation element can be reinforced. The first surface is one of the locations where the mechanical strength can be the weakest within the power generation element 100. On the other hand, if there is a void surrounded by the first surface, the sealing material, and the electrode current collector, when the battery becomes hot, the gas in the void tries to thermally expand, causing the internal pressure of the void to become higher than atmospheric pressure and generating peeling forces between and within the layers of the power generation element. Gas expansion in the void occurs not only in the case of heating but also when the battery is placed in a decompression environment such as high altitude or outer space. In the battery of this embodiment, since the void has a negative pressure of less than 1 atm, it becomes difficult for peeling forces due to void expansion to occur even in a high-temperature environment or a decompression environment. Also, because the negative-pressure void is surrounded by the electrode current collector, a force acts to attract the electrode current collector toward the power generation element side, forming a first recess in the electrode current collector and causing a force in the direction of restraining the layers of the power generation element to act on the power generation element. As a result, the resistance between and within the layers of the power generation element can be reduced, and even when the electrode layer and the counter electrode layer expand and contract due to repeated charge and discharge cycles, delamination and the like are less likely to occur. That is, the presence of the negative-pressure void that recesses the electrode current collector enables improvement of battery characteristics and suppression of damage by the function of restraining the power generation element, compared to the case where such a void does not exist. Therefore, the battery in this embodiment can achieve both high battery characteristics and high reliability.

[0017] Also, for example, the internal pressure of the void may be 0.9 atm or less.

[0018] As a result, the force in the direction of restraining the layers of the power generation element by the void becomes greater.

[0019] Also, for example, it includes a counter electrode current collector located on the counter electrode layer side of the power generation element, the void is surrounded by the sealing material, the first surface, the electrode current collector, and the counter electrode current collector, and the counter electrode current collector may have a second recess that curves concave toward the void.

[0020] This allows the forces constraining the power generation element to act from both the electrode layer side and the counter electrode layer side of the power generation element, making it less likely for delamination or other issues to occur between layers of the power generation element.

[0021] Furthermore, for example, the sealing material may be in contact with the side surface of the electrode current collector, and when viewed from the direction normal to the main surface of the power generation element, the positions of the side surface of the electrode current collector in contact with the sealing material and the first surface may overlap.

[0022] As a result, the side surface, which is the end of the electrode current collector, is sealed with a sealing material at the point where it overlaps with the first surface, thus protecting the end of the electrode current collector, which is prone to damage because it forms the corner of the battery.

[0023] Furthermore, for example, the first surface is composed of the side surface of the electrode layer, the side surface of the counter electrode layer, and the side surface of the solid electrolyte layer, and when viewed from the direction normal to the main surface of the power generation element, the positions of the side surface of the electrode layer, the side surface of the counter electrode layer, and the side surface of the solid electrolyte layer constituting the first surface may overlap.

[0024] As a result, the electrode layer and counter electrode layer are present all the way to the side edges of the power generation element, thus improving the battery capacity.

[0025] Furthermore, a battery system in one aspect of this disclosure comprises a container having an internal space that becomes a reduced-pressure environment, and the battery disposed in the internal space.

[0026] As a result, since the battery system is equipped with the aforementioned batteries, even if the internal space of the container becomes a reduced-pressure environment, peeling forces on the power generation elements due to the expansion of air gaps are less likely to occur.

[0027] Furthermore, for example, the pressure in the reduced-pressure environment may be 0.95 atm or less.

[0028] This makes it less likely for the battery to experience peeling forces on the power generation elements due to air gap expansion, even when placed in a reduced pressure environment of 0.95 atm or less.

[0029] Furthermore, for example, the internal pressure of the plurality of voids may be less than or equal to the pressure of the reduced-pressure environment.

[0030] This makes it difficult for delamination forces to occur due to the expansion of voids. In addition, the voids exert a force on the power generation element that restrains each layer of the power generation element.

[0031] Furthermore, a method for manufacturing a battery in one aspect of the present disclosure is a method for manufacturing a battery comprising a power generation element having an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, comprising a depressurization step of exposing a first surface, which is a side surface of the power generation element in a laminate including the power generation element, to a depressurization atmosphere, and a sealing step of sealing the first surface with a sealing material under the depressurization atmosphere.

[0032] This makes it possible to create a negative pressure of less than 1 atm within the gap even if a gap is formed between the first surface and the sealing material during the sealing step. Specifically, when the first surface is sealed with the sealing material, the first surface is placed in a reduced pressure atmosphere of less than 1 atm. Therefore, even if a gap is formed when the first surface is sealed, the internal pressure of the gap becomes a negative pressure of less than 1 atm. As a result, if a gap is formed in the battery, peeling force on the power generation element due to the expansion of the gap is less likely to occur, even if the battery was manufactured in a high-temperature or reduced-pressure environment.

[0033] Furthermore, for example, the method for manufacturing the battery may further include a lamination step of forming the laminate which includes the power generation element, in which the electrode layer and the counter electrode layer are laminated so as to face each other via the solid electrolyte layer.

[0034] This allows for the preparation of laminates of any shape.

[0035] Furthermore, for example, the pressure of the reduced-pressure atmosphere may be 0.9 atm or less.

[0036] This makes it possible to keep the internal pressure of any gaps formed during the sealing step below 0.9 atm.

[0037] Furthermore, for example, the pressure of the reduced-pressure atmosphere may be 0.1 atm or less.

[0038] This makes it possible to keep the internal pressure of any gaps formed during the sealing step below 0.1 atm.

[0039] Alternatively, for example, in the sealing step, the first surface may be sealed by immersing a portion of the laminate in the sealing material.

[0040] This allows the first surface to be easily sealed with a sealing material under reduced pressure conditions.

[0041] Furthermore, for example, in the sealing step, the first surface may be sealed by applying the sealing material to the first surface.

[0042] This allows the first surface to be easily sealed with a sealing material under reduced pressure conditions.

[0043] Embodiments of the present disclosure will be described below with reference to the drawings.

[0044] The embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit this disclosure. Furthermore, any components in the following embodiments that are not described in an independent claim will be described as optional components.

[0045] Furthermore, each figure is a schematic diagram and not necessarily a strictly accurate representation. Therefore, for example, the scale may not necessarily match in each figure. Also, in each figure, substantially identical components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0046] Furthermore, in this specification, terms indicating relationships between elements such as parallelism, terms indicating the shape of elements such as rectangles, and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, such as differences of a few percent.

[0047] Furthermore, in this specification, "plan view" means the view from the direction normal to the main surface of the power generation element.

[0048] (Embodiment 1) [composition] First, the configuration of the battery according to this embodiment will be described.

[0049] Figure 1 is a cross-sectional view showing the schematic configuration of the battery 1000 according to Embodiment 1.

[0050] As shown in Figure 1, the battery 1000 according to Embodiment 1 comprises a negative electrode current collector 210, a positive electrode current collector 220, a power generation element 100, and a sealing material 700. The battery 1000 is, for example, an all-solid-state battery.

[0051] In battery 1000, there is a gap of 230. Details of the gap 230 will be described later.

[0052] The power generation element 100 is located between the negative electrode current collector 210 and the positive electrode current collector 220. The power generation element 100 has a positive electrode active material layer 120, a negative electrode active material layer 110, and a solid electrolyte layer 130 located between the positive electrode active material layer 120 and the negative electrode active material layer 110. The negative electrode active material layer 110 and the positive electrode current collector 220 face each other via the solid electrolyte layer 130. The negative electrode active material layer 110 is an example of an electrode layer, and the positive electrode active material layer 120 is an example of a counter electrode layer. Furthermore, the negative electrode current collector 210 is an example of an electrode current collector, and the positive electrode current collector 220 is an example of a counter electrode current collector. Note that the positive electrode active material layer 120 and the positive electrode current collector 220 may be an electrode layer and an electrode current collector, respectively, and the negative electrode active material layer 110 and the negative electrode current collector 210 may be a counter electrode layer and a counter electrode current collector, respectively.

[0053] Furthermore, in this specification, the negative electrode current collector 210 and the positive electrode current collector 220 may be collectively referred to simply as "current collectors," and the negative electrode active material layer 110 and the positive electrode active material layer 120 may be collectively referred to simply as "active material layers."

[0054] The negative electrode active material layer 110 includes, for example, a negative electrode active material as an electrode material. The negative electrode active material layer 110 is positioned opposite the positive electrode active material layer 120.

[0055] As the negative electrode active material contained in the negative electrode active material layer 110, for example, negative electrode active materials such as graphite and metallic lithium may be used. As the material of the negative electrode active material, various materials that can release and insert ions such as lithium (Li) or magnesium (Mg) may be used.

[0056] Furthermore, as the material containing the negative electrode active material layer 110, a solid electrolyte such as an inorganic solid electrolyte may be used. As the inorganic solid electrolyte, for example, a sulfide solid electrolyte or an oxide solid electrolyte may be used. As the sulfide solid electrolyte, for example, a mixture of lithium sulfide (Li2S) and phosphorus pentasulfide (P2S5) may be used. Furthermore, as the material containing the negative electrode active material layer 110, at least one of a conductive material such as acetylene black and a binding binder such as polyvinylidene fluoride may be used.

[0057] The negative electrode active material layer 110 can be manufactured by coating the surface of the negative electrode current collector 210 with a paste-like coating made by kneading the materials containing the negative electrode active material layer 110 together with a solvent, and then drying the coating. To increase the density of the negative electrode active material layer 110, the negative electrode plate containing the negative electrode active material layer 110 and the negative electrode current collector 210 may be pressed after drying. The thickness of the negative electrode active material layer 110 is, for example, 5 μm to 300 μm, but is not limited to this.

[0058] The positive electrode active material layer 120 contains, for example, a positive electrode active material as an electrode material. The positive electrode active material is the material that constitutes the counter electrode to the negative electrode active material. Possible positive electrode active materials to be contained in the positive electrode active material layer 120 include, for example, lithium cobalt oxide composite oxide (LCO), lithium nickel oxide composite oxide (LNO), lithium manganese oxide composite oxide (LMO), lithium-manganese-nickel oxide composite oxide (LMNO), lithium-manganese-cobalt oxide composite oxide (LMCO), lithium-nickel-cobalt oxide composite oxide (LNCO), and lithium-nickel-manganese-cobalt oxide composite oxide (LNMCO). Various materials that can release and insert ions such as Li or Mg can be used as the material for the positive electrode active material.

[0059] Furthermore, as the material containing the positive electrode active material layer 120, a solid electrolyte such as an inorganic solid electrolyte may be used. As the inorganic solid electrolyte, the materials exemplified above as inorganic solid electrolytes used in the negative electrode active material may be used. The surface of the positive electrode active material may be coated with a solid electrolyte. Furthermore, as the material containing the positive electrode active material layer 120, at least one of a conductive material such as acetylene black and a binding binder such as polyvinylidene fluoride may be used.

[0060] The positive electrode active material layer 120 can be manufactured by coating the surface of the positive electrode current collector 220 with a paste-like coating made by kneading the materials containing the positive electrode active material layer 120 together with a solvent, and then drying the coating. To increase the density of the positive electrode active material layer 120, the positive electrode plate containing the positive electrode active material layer 120 and the positive electrode current collector 220 may be pressed after drying. The thickness of the positive electrode active material layer 120 is, for example, 5 μm to 300 μm, but is not limited to this.

[0061] The solid electrolyte layer 130 is positioned between the negative electrode active material layer 110 and the positive electrode active material layer 120. The solid electrolyte layer 130 is in contact with each of the negative electrode active material layer 110 and the positive electrode active material layer 120. The size and plan view shape of the solid electrolyte layer 130 are the same as the size and plan view shape of the negative electrode active material layer 110 and the positive electrode active material layer 120, respectively. Therefore, when viewed from the direction normal to the main surface of the power generation element 100, the position of the side surface of the solid electrolyte layer 130 coincides with the position of the side surface of the negative electrode active material layer 110 and the side surface of the positive electrode active material layer 120, respectively. In this specification, a side surface is a surface that connects the two main surfaces of each component.

[0062] The solid electrolyte layer 130 is a layer containing an electrolyte material. Generally known electrolytes for batteries can be used as the electrolyte material. The thickness of the solid electrolyte layer 130 may be 5 μm to 300 μm, or 5 μm to 100 μm. In the example shown in Figure 1, the solid electrolyte layer 130 is a single layer, but the power generation element 100 may have a structure in which multiple solid electrolyte layers 130 are stacked.

[0063] The solid electrolyte layer 130 may contain a solid electrolyte. As the solid electrolyte, for example, an inorganic solid electrolyte may be used. As the inorganic solid electrolyte, the materials exemplified above as inorganic solid electrolytes used in the negative electrode active material may be used. In addition to the electrolyte material, the solid electrolyte layer 130 may contain a binding binder such as polyvinylidene fluoride.

[0064] In battery 1000, the negative electrode active material layer 110, the positive electrode active material layer 120, and the solid electrolyte layer 130 are maintained in a parallel plate shape. This suppresses the occurrence of cracking or collapse due to bending. Alternatively, the negative electrode active material layer 110, the positive electrode active material layer 120, and the solid electrolyte layer 130 may be smoothly curved together.

[0065] The negative electrode current collector 210 and the positive electrode current collector 220 are positioned opposite the power generation element 100, with the power generation element 100 in between them. In a plan view, the negative electrode current collector 210 and the positive electrode current collector 220 are each larger than the power generation element 100, and the entire power generation element 100 is located inside the outer circumference of the negative electrode current collector 210 and the positive electrode current collector 220. In other words, in a plan view, the negative electrode current collector 210 and the positive electrode current collector 220 each protrude from the outer circumference of the power generation element 100.

[0066] The negative electrode current collector 210 and the positive electrode current collector 220 are both conductive materials. The negative electrode current collector 210 and the positive electrode current collector 220 may each be, for example, a conductive thin film. As materials for constituting the negative electrode current collector 210 and the positive electrode current collector 220, metals such as stainless steel (SUS), aluminum (Al), copper (Cu), and nickel (Ni) can be used.

[0067] The negative electrode current collector 210 is located on the negative electrode active material layer 110 side of the power generation element 100. The negative electrode current collector 210 is arranged, for example, in contact with the negative electrode active material layer 110. The negative electrode current collector 210 has a recess 211 that curves toward the air gap 230, which will be described later. The recess 211 is an example of a first recess.

[0068] For example, metal foils such as SUS foil, Al foil, Cu foil, and Ni foil can be used as the negative electrode current collector. The thickness of the negative electrode current collector 210 is, for example, 5 μm to 100 μm, but is not limited to this. The negative electrode current collector 210 may also have a current collector layer in the portion in contact with the negative electrode active material layer 110, which may be a layer containing a conductive material, for example.

[0069] The positive electrode current collector 220 is located on the positive electrode active material layer 120 side of the power generation element 100. The positive electrode current collector 220 is, for example, positioned in contact with the positive electrode active material layer 120. The positive electrode current collector 220 has a recess 221 that curves inward toward the air gap 230, which will be described later. The recess 221 is an example of a second recess.

[0070] For example, metal foils such as SUS foil, Al foil, Cu foil, and Ni foil can be used as the positive electrode current collector 220. The thickness of the positive electrode current collector 220 is, for example, 5 μm to 100 μm, but is not limited to this. The positive electrode current collector 220 may also have a current collector layer in the portion in contact with the positive electrode active material layer 120, which may be a layer containing a conductive material.

[0071] The sealing material 700 seals the first surface 100a, which is the side surface of the power generation element 100. In other words, the sealing material 700 covers the first surface 100a so that it is not exposed to the outside world of the battery 1000. In this specification, sealing the first surface 100a means covering the first surface 100a so that it is not exposed to the outside world of the battery. Therefore, the expression "sealing the first surface 100a" is used in both cases: when the sealing material 700 is in contact with at least a part of the first surface 100a and directly covers it (i.e., directly seals), and when the sealing material 700 is not in contact with the first surface 100a, as in the case of the battery 1000, and indirectly covers it through a gap 230 that is independent of the outside world (i.e., indirectly seals).

[0072] The first surface 100a is, for example, the outer end surface when viewed from the direction normal to the main surface of each layer, in the direction in which the negative electrode active material layer 110, the solid electrolyte layer 130, and the positive electrode active material layer 120 are stacked and aligned. The first surface 100a is composed of the side surface of the negative electrode active material layer 110, the side surface of the solid electrolyte layer 130, and the side surface of the positive electrode active material layer 120. In this embodiment, the side surface of the negative electrode active material layer 110, the side surface of the solid electrolyte layer 130, and the side surface of the positive electrode active material layer 120 that constitute the first surface 100a overlap. As a result, the negative electrode active material layer 110 and the positive electrode active material layer 120 are present up to the side edge of the power generation element 100, thereby improving the battery capacity.

[0073] The sealing material 700 is located between the positive electrode current collector 220 and the negative electrode current collector 210, and is in contact with both the positive electrode current collector 220 and the negative electrode current collector 210. The sealing material 700 may be in contact with at least one side surface of the positive electrode current collector 220 and the negative electrode current collector 210. Alternatively, the sealing material 700 may cover the portion of the positive electrode current collector 220 and the negative electrode current collector 210 from at least one side surface to the end of the surface opposite to the power generation element 100. The sealing material 700 is not in contact with the first surface 100a of the power generation element 100. Thus, in the battery 1000, the first surface 100a is indirectly sealed by the sealing material 700. The sealing material 700 seals, for example, all sides of the power generation element 100. The power generation element 100 is, for example, a flat rectangular parallelepiped, in which case the sealing material 700 seals all four sides (four first surfaces 100a) of the power generation element 100. However, the sealing material 700 may seal only one to three of the four sides of the power generation element 100.

[0074] The encapsulant 700 may be, for example, a generally known material for encapsulating batteries. The encapsulant 700 is composed of, for example, an insulating resin material. The resin material is a material mainly composed of resin. The resin material includes, for example, at least one of epoxy resin, acrylic resin, polyimide resin, and silsesquioxane. The resin that is the main component of the resin material may be, for example, a thermosetting resin or an ultraviolet curing resin, but a thermoplastic resin may also be used. The resin material may also contain particulate metal oxide material. Examples of metal oxide material include silicon oxide, aluminum oxide, titanium oxide, zinc oxide, cerium oxide, iron oxide, tungsten oxide, zirconium oxide, calcium oxide, zeolite, and glass.

[0075] In battery 1000, there is a gap 230 surrounded by the encapsulant 700, the first surface 100a, the positive electrode current collector 220, and the negative electrode current collector 210. The gap 230 is located between the first surface 100a and the encapsulant 700. Parts of the encapsulant 700, the first surface 100a, the positive electrode current collector 220, and the negative electrode current collector 210 are exposed to the gap 230. The gap 230 is an independent bubble (hollow part) formed by the inner surfaces of the encapsulant 700, specifically the surface 700a on the first surface 100a side, the first surface 100a, the negative electrode current collector 210, specifically the surface 210a on the power generation element 100 side, and the positive electrode current collector 220, specifically the surface 220a on the power generation element 100 side.

[0076] The air gap 230 is under negative pressure, which is lower than atmospheric pressure. In other words, the internal pressure of the air gap 230 is less than 1 atm. Because the air gap 230 is under negative pressure, the portions of the negative electrode current collector 210 and the positive electrode current collector 220 adjacent to the air gap 230 curve inward towards the air gap 230, forming a recess 211 in the negative electrode current collector 210 and a recess 221 in the positive electrode current collector 220. Thus, because the negative electrode current collector 210 and the positive electrode current collector 220 each have recesses 211 and 221, as will be described in detail later, the force restraining the power generation element 100 acts from both the negative electrode active material layer 110 side and the positive electrode active material layer 120 side of the power generation element 100, making it less likely for delamination of the power generation element 100 to occur.

[0077] From the viewpoint of improving the reliability of battery 1000, the internal pressure of the air gap 230 may be 0.9 atm or less, 0.5 atm or less, or 0.1 atm or less. Also, the internal pressure of the air gap 230 may be greater than, for example, 0 atm. In this specification, the pressures such as the internal pressure of the air gap 230 are pressures at room temperature. Room temperature is, for example, 23°C. Also, in this specification, the numerical values ​​of the pressures such as the internal pressure of the air gap 230 are numerical values ​​in absolute pressure.

[0078] [Example 1] The following describes Modification 1 of Embodiment 1. In the following description of Modification 1, the differences from Embodiment 1 will be the main focus, and the similarities will be omitted or simplified.

[0079] Figure 2 is a cross-sectional view showing the schematic configuration of a battery 1100 according to a modified example 1 of Embodiment 1.

[0080] As shown in Figure 2, the battery 1100 differs from the battery 1000 according to Embodiment 1 mainly in that it has air gaps 231, 232, 233 and 240 instead of air gap 230.

[0081] In the battery 1100, the sealing material 700 is in contact with a portion of the first surface 100a. Thus, in the battery 1100, the first surface 100a is directly sealed by the sealing material 700.

[0082] In the battery 1100, there is a gap 231 surrounded by the encapsulant 700, the first surface 100a, and the negative electrode current collector 210. The gap 231 is located between the first surface 100a and the encapsulant 700. Parts of the encapsulant 700, the first surface 100a, and the negative electrode current collector 210 are exposed to the gap 231. The gap 231 is an independent bubble formed by the inner surface of the encapsulant 700 on the first surface 100a side and the inner surface composed of the first surface 100a and the negative electrode current collector 210 on the power generation element 100 side. The gap 231 is formed where the first surface 100a falls inward into the power generation element 100.

[0083] The negative electrode current collector 210 has a recess 211 that is curved so as to be recessed toward the air gap 231.

[0084] Furthermore, in the battery 1100, there are air gaps 232 and 233 surrounded by the encapsulant 700, the first surface 100a, and the positive electrode current collector 220. Air gaps 232 and 233 are located between the first surface 100a and the encapsulant 700. Parts of the encapsulant 700, the first surface 100a, and the positive electrode current collector 220 are exposed to air gaps 232 and 233. Air gaps 232 and 233 are independent air bubbles formed by the inner surface of the encapsulant 700 on the first surface 100a side and the inner surface of the positive electrode current collector 220 on the power generation element 100 side. Air gap 232 is formed where the first surface 100a is recessed into the inside of the power generation element 100. Furthermore, the void 233 is formed to protrude from the first surface 100a into the sealing material 700.

[0085] The positive electrode current collector 220 has a recess 221 that is curved so as to be recessed toward the gap 232 or the gap 233.

[0086] Furthermore, in the battery 1100, there is a void 240 surrounded by the encapsulating material 700 and the first surface 100a. The void 240 is located between the first surface 100a and the encapsulating material 700. Parts of the encapsulating material 700 and the first surface 100a are exposed to the void 240. The void 240 is an independent bubble formed by the inner surface of the encapsulating material 700, which is composed of the surface 700a on the first surface 100a side and the first surface 100a. The void 240 is formed in a recessed area on at least one of the first surface 100a and the surface 700a.

[0087] The air gaps 231, 232, 233, and 240 are each under negative pressure lower than atmospheric pressure. That is, the internal pressure of each of the air gaps 231, 232, 233, and 240 is less than 1 atm. From the viewpoint of improving the reliability of the battery 1100, the internal pressures of each of the air gaps 231, 232, 233, and 240 may be 0.9 atm or less, 0.5 atm or less, or 0.1 atm or less. Also, the internal pressures of each of the air gaps 231, 232, 233, and 240 may be greater than, for example, 0 atm.

[0088] In addition, in the battery 1100, there may be gaps among gaps 231, 232, 233, and 240 that do not exist, for example, at least one of gaps 231, 232, and 233 may exist.

[0089] [Differentiation 2] The following describes a modified example 2 of Embodiment 1. In the description of Modified Example 2 below, the differences between it and Embodiment 1 and Modified Example 1 of Embodiment 1 will be the main focus, and the similarities will be omitted or simplified.

[0090] Figure 3 is a cross-sectional view showing the schematic configuration of a battery 1200 according to a modified example 2 of Embodiment 1.

[0091] As shown in Figure 3, the battery 1200 differs from the battery 1000 according to Embodiment 1 mainly in that it has air gaps 231, 232, and 240 instead of air gap 230. The battery 1200 also differs from the battery 1000 according to Embodiment 1 in that, when viewed from the direction normal to the main surface of the power generation element 100, the first surface 100a overlaps with the side surface 210b of the negative electrode current collector 210 and the side surface 220b of the positive electrode current collector 220.

[0092] In the battery 1200, the sealing material 700 is in contact with a portion of the first surface 100a. Thus, in the battery 1200, the first surface 100a is directly sealed by the sealing material 700.

[0093] In the battery 1200, the side surface 210b of the negative electrode current collector 210 and the side surface 220b of the positive electrode current collector 220 each overlap with the first surface 100a when viewed from the direction normal to the main surface of the power generation element 100. In a plan view, the outer circumferences of the negative electrode current collector 210 and the positive electrode current collector 220 each coincide, for example, with the outer circumference of the power generation element 100. Furthermore, the sealing material 700 is in contact with the side surfaces 210b and 220b. In other words, the sealing material 700 seals the first surface 100a, the side surfaces 210b and 220b. In this way, the side surfaces 210b and 220b, which are the ends of the current collectors, are sealed by the sealing material 700 at the position where they overlap with the first surface 100a, thus protecting the ends of the current collectors that form the corners of the battery 1200.

[0094] Furthermore, in the battery 1200, there are air gaps 231, 232, and 240 similar to those in the modified example 1 of Embodiment 1.

[0095] In addition, in the battery 1200, there may be gaps among gaps 231, gap 232, and gap 240 that do not exist, for example, at least one of gaps 231 and 232 may exist.

[0096] [Effects, etc.] Next, the effects of the batteries 1000, 1100, and 1200 described above will be explained. In batteries 1000, 1100, and 1200, the power generation element 100 can be reinforced by sealing the first surface 100a with the sealing material 700. Since the first surface 100a is composed of the side surfaces of each layer of the power generation element 100, it is one of the parts of the power generation element 100 that can have the weakest mechanical strength.

[0097] Here, the effect of having a negative pressure in the void in the battery according to this embodiment will be explained using the description of the battery according to the comparative example. The battery according to the comparative example has a void with an internal pressure of 1 atm or more.

[0098] Figure 4 is a cross-sectional view showing the schematic configuration of battery 1000X according to Comparative Example 1. Figure 5 is a cross-sectional view showing the schematic configuration of battery 1100X according to Comparative Example 2. Figures 4 and 5 show the state of battery 1000X and battery 1100X after being used for a while after being manufactured, respectively. In battery 1000X, instead of the void 230 of battery 1000 according to Embodiment 1, there is a void 230X with an internal pressure of 1 atm or more in the same location. Also, in battery 1100X, instead of the voids 231, voids 232, voids 233, and voids 240 of battery 1100 according to Modification 1 of Embodiment 1, there are voids 231X, voids 232X, voids 233X, and voids 240X with an internal pressure of 1 atm or more in the same locations. In batteries 1000X and 1100X, the negative electrode current collector 210X and the positive electrode current collector 220X do not have recesses 211 and 221.

[0099] In batteries 1000X and 1100X, no delamination points 250 are formed immediately after manufacturing. However, because the internal pressure of voids such as void 230X is 1 atm or higher, when the temperature rises due to the operating environment, ambient temperature, and heat generation, the gas in the voids attempts to expand due to thermal expansion, causing the internal pressure of the voids to become significantly higher than atmospheric pressure, resulting in delamination forces between and within each layer of the power generation element 100. Expansion of the gas in voids such as void 230X occurs not only at high temperatures, but also when battery 1000X is placed in a reduced-pressure environment such as high altitude or outer space. Therefore, as schematically shown in Figures 4 and 5, interlayer delamination and intralayer delamination occur due to the rise in internal pressure of voids such as void 230X, and multiple delamination points 250 are formed. Intralayer delamination is, for example, delamination at the interface between the materials constituting each layer within each layer.

[0100] In contrast, in the batteries 1000, 1100, and 1200 according to Embodiment 1 and its various modifications described above, the voids such as the void 230 in contact with the first surface 100a are under negative pressure. Therefore, unlike the voids in the batteries according to the comparative examples described above, peeling forces to the power generation element 100 due to the voids are less likely to occur, even in high-temperature or low-pressure environments. As a result, in batteries 1000, 1100, and 1200, interlayer delamination and intralayer delamination in the power generation element 100 due to void expansion are less likely to occur.

[0101] Furthermore, because negative pressure gaps such as the air gap 230 are in contact with the negative electrode current collector 210 and / or the positive electrode current collector 220, a force acts to pull the negative electrode current collector 210 and / or the positive electrode current collector 220 toward the power generation element 100, forming the recesses 211 and / or 221. As a result, the negative pressure gaps such as the air gap 230, as well as the recesses 211 and / or 221, exert a force that restrains each layer of the power generation element 100, reducing the resistance between and within each layer of the power generation element 100. In addition, even if the positive electrode active material layer 120 and the negative electrode active material layer 110 expand and contract due to repeated charge-discharge cycles, delamination and other issues are less likely to occur. In other words, the presence of negative pressure gaps, such as the gap 230 that indents the negative electrode current collector 210 and / or positive electrode current collector 220, allows for improved battery characteristics and suppression of damage by restraining the power generation element 100, compared to the case where such gaps are absent. Furthermore, an external restraining force is applied to the power generation element 100 without the need for restraining devices, thus avoiding the reduction in battery capacity per unit volume and per unit weight that would occur with the provision of such devices.

[0102] As described above, batteries 1000, 1100, and 1200 can achieve both high battery performance and high reliability.

[0103] [Manufacturing method] Next, a description of the battery manufacturing method according to this embodiment will be provided.

[0104] Figure 6 is a flowchart of the battery manufacturing method according to this embodiment. The battery manufacturing method according to this embodiment includes, for example, a stacking step, a depressurization step, and a sealing step.

[0105] As shown in Figure 6, first, in the lamination step, a laminate is formed including a power generation element 100 in which a positive electrode active material layer 120 and a negative electrode active material layer 110 are laminated facing each other via a solid electrolyte layer 130 (step S11). The laminate includes, for example, the power generation element 100, a positive electrode current collector 220 located on the positive electrode active material layer 120 side of the power generation element 100, and a negative electrode current collector 210 located on the negative electrode active material layer 110 side of the power generation element 100, as described later in laminates 300 and 310. Note that the laminate only needs to include at least one of the positive electrode current collector 220 and the negative electrode current collector 210.

[0106] In the lamination step, for example, a laminate containing the power generation element 100 is formed by sequentially laminating a negative electrode current collector 210, a negative electrode active material layer 110, a solid electrolyte layer 130, a positive electrode active material layer 120, and a positive electrode current collector 220 in this order. The laminate is formed, for example, by applying a paste-like coating, which is made by kneading the materials of the negative electrode active material layer 110, the positive electrode active material layer 120, and the solid electrolyte layer 130 together with a solvent, onto the current collector or the surface of each layer, and then drying it. Alternatively, a negative electrode plate may be prepared by laminating the negative electrode active material layer 110 and the solid electrolyte layer 130 in this order on a negative electrode current collector 210, and a positive electrode plate may be prepared by laminating the positive electrode active material layer 120 and the solid electrolyte layer 130 on a positive electrode current collector 220, and the laminate containing the power generation element 100 may be formed by joining the negative electrode plate and the positive electrode plate via the solid electrolyte layer 130. In the lamination step, pressing may be performed during the formation of each layer and the joining of the negative electrode plate and the positive electrode plate to achieve high density and compression bonding.

[0107] Next, in the depressurization step, the first surface 100a, which is the side surface of the power generation element 100 in the laminate, is exposed to a depressurized atmosphere (step S12). Exposing the first surface 100a to a depressurized atmosphere means exposing the first surface 100a to a space where the pressure has been reduced to less than 1 atm, for example, by exhausting the gas in the space. To expose the first surface 100a to a depressurized atmosphere, for example, the entire laminate is placed in a space with a depressurized atmosphere. Alternatively, a portion of the laminate including the first surface 100a may be placed in a container or the like with an internal depressurized atmosphere to expose the first surface 100a to a depressurized atmosphere.

[0108] Next, in the sealing step, the first surface 100a is sealed with the sealing material 700 under a reduced pressure atmosphere (step S13). In the sealing step, for example, the first surface 100a is sealed with the sealing material 700 such that at least a portion of the first surface 100a is separated from the sealing material 700. This creates a void such as the void 230. Because the first surface 100a is sealed under a reduced pressure atmosphere, the internal pressure of the void formed in the sealing step becomes negative pressure, i.e., less than 1 atm.

[0109] The pressure of the reduced-pressure atmosphere may be 0.9 atm or less, 0.5 atm or less, or 0.1 atm or less. This allows for further reduction of the internal pressure of voids such as the void 230 formed in the sealing step. Alternatively, the pressure of the reduced-pressure atmosphere may be greater than, for example, 0 atm.

[0110] In the sealing step, for example, the first surface 100a is sealed by immersing a portion of the laminate in the sealing material 700. Alternatively, in the sealing step, the first surface 100a is sealed by applying the sealing material 700 to the first surface 100a. Examples of methods for applying the sealing material 700 include the doctor blade method, calendering method, spin coating method, dip coating method, inkjet method, offset method, die coating method, and spray method.

[0111] By going through these stacking, depressurization, and sealing steps, the aforementioned battery 1000, battery 1100, or battery 1200, etc., can be obtained.

[0112] Here, the method for sealing the first surface 100a using the sealing material 700 will be explained in detail with reference to Figures 7 to 9.

[0113] First, a first example of a sealing method for the first surface 100a will be described. Figure 7 is a schematic diagram illustrating a first example of a sealing method for the first surface 100a. Figure 7 is a diagram illustrating a sealing method when manufacturing the batteries 1000 and 1100 described above. To manufacture the batteries 1000 and 1100, the laminate 300 is formed using the method described above. In the laminate 300, similar to the batteries 1000 and 1100, the negative electrode current collector 210 and the positive electrode current collector 220 protrude from the power generation element 100.

[0114] As shown in Figure 7, a dipping device 500 is installed in the internal space 905 of the vacuum chamber 900, which is connected to the vacuum pump 910. The vacuum chamber 900 is provided with, for example, a door (not shown) for inserting and removing the laminate 300.

[0115] To seal the first surface 100a, the prepared laminate 300 is first placed in the dipping device 500. For example, the dipping device 500 is equipped with a drive arm, etc., which is not shown in the figure, and the laminate 300 is placed on the drive arm, etc. In the dipping device 500, a liquid sealant 700 is placed in a container. The liquid sealant 700 is, for example, a resin material containing a thermosetting resin or an ultraviolet curing resin before curing. The liquid sealant 700 may also be a resin material containing a thermoplastic resin that has been melted by heating.

[0116] Next, the gas in the internal space 905 is evacuated using the vacuum pump 910 to create a reduced-pressure atmosphere (e.g., a vacuum atmosphere) in the internal space 905. After creating a reduced-pressure atmosphere in the internal space 905, a portion of the laminate 300 is immersed in the sealing material 700 using the dipping device 500. For example, a portion of the laminate 300 is immersed in the sealing material 700 while maintaining the first surface 100a and the liquid surface of the sealing material 700 to be parallel. Then, the laminate 300 with the sealing material 700 formed on it is removed, and if necessary, the sealing material 700 is cured, and any sealing material 700 adhering to unwanted areas is removed to obtain the battery 1000 or battery 1100.

[0117] When manufacturing the battery 1000, a portion of the negative electrode current collector 210 and positive electrode current collector 220 of the laminate 300 that protrudes outward from the first surface 100a of the power generation element 100 is immersed in the sealing material 700. This places the sealing material 700 between the negative electrode current collector 210 and the positive electrode current collector 220, sealing the first surface 100a. Furthermore, by adjusting the depth to which the laminate 300 is immersed in the sealing material 700, specifically, the laminate 300 is immersed in the sealing material 700 so that the first surface 100a is not immersed in the sealing material 700. This forms a gap 230, and the battery 1000 is obtained. In this way, since the sealing of the first surface 100a and the formation of the gap 230 can be achieved simply by immersing a portion of the laminate 300 in the sealing material 700 under a reduced pressure atmosphere, the battery 1000 can be easily manufactured.

[0118] Furthermore, when manufacturing the battery 1100, for example, a laminate 300 with minute indentations formed on the first surface 100a is prepared, and the laminate 300 is immersed in the sealing material 700 such that the first surface 100a is immersed in the sealing material 700. This forms voids 231, 232, 233, and 240, and the battery 1100 is obtained. Alternatively, the wettability between the first surface 100a and the sealing material 700 may be adjusted so that the first surface 100a is not completely wetted by the sealing material 700, thereby forming voids 231, 232, 233, and 240. Also, when the laminate 300 is immersed in the sealing material 700, the surrounding atmosphere may be incorporated, thereby forming voids 231, 232, 233, and 240. Alternatively, the sealing material 700 may be pre-patterned in positions that do not come into contact with the voids 231, 232, 233, and 240 of the first surface 100a, and the voids 231, 232, 233, and 240 may be formed by immersing the laminate 310 containing the patterned sealing material 700 in liquid sealing material 700. In this case, the laminate 310 is immersed in liquid sealing material 700 in such a way that the patterned sealing material 700 is immersed in the liquid sealing material 700, but the first surface 100a is not immersed in the liquid sealing material 700.

[0119] Next, a second example of the sealing method for the first surface 100a will be described. Figure 8 is a schematic diagram illustrating the second example of the sealing method for the first surface 100a. Figure 8 is a diagram illustrating the sealing method when manufacturing the battery 1200 described above. In the second example of the sealing method for the first surface 100a, a dip device 500 installed in the internal space 905 of the vacuum chamber 900 is used, similar to the first example described above. To manufacture the battery 1200, a laminate 310 is formed using the method described above. In the laminate 310, similar to the battery 1200, the positions of the sides of the negative electrode current collector 210 and the positive electrode current collector 220 overlap with the first surface 100a, which is the side of the power generation element 100, when viewed from the direction normal to the main surface of the power generation element 100.

[0120] As shown in Figure 8, in order to seal the first surface 100a, first, the prepared laminate 310 is placed in the dipping device 500. Next, the gas in the internal space 905 is exhausted by the vacuum pump 910, thereby creating a reduced-pressure atmosphere in the internal space 905. After creating a reduced-pressure atmosphere in the internal space 905, a portion of the laminate 310 is immersed in the sealing material 700, while maintaining the first surface 100a and the liquid level of the sealing material 700 to be parallel. This seals the first surface 100a with the sealing material 700. Then, the laminate 310 with the formed sealing material 700 is removed, and if necessary, the sealing material 700 is cured, and any sealing material 700 adhering to unwanted areas is removed, thereby obtaining the battery 1200. In the manufacturing of the battery 1200, voids 231, voids 232, and voids 240 are formed by preparing a laminate 310 with minute indentations formed on the first surface 100a, adjusting the wettability between the first surface 100a and the sealing material 700, or by pre-forming a pattern of the sealing material 700 on the first surface 100a.

[0121] Next, a third example of the sealing method for the first surface 100a will be described. Figure 9 is a schematic diagram illustrating the third example of the sealing method for the first surface 100a. Figure 9 is a diagram illustrating the sealing method when manufacturing the battery 1200 described above. In the third example of the sealing method for the first surface 100a, a vacuum chamber 900 is used, similar to the first and second examples described above. Also, in the third example of the sealing method for the first surface 100a, a laminate 310 is prepared, similar to the second example.

[0122] As shown in Figure 9, a coating device 510 is installed in the internal space 905 of the vacuum chamber 900. The coating device 510 is a device for applying liquid sealant 700. First, in order to seal the first surface 100a, the laminate 310 is placed in the internal space 905 of the vacuum chamber 900. Next, the gas in the internal space 905 is evacuated by the vacuum pump 910, thereby creating a reduced-pressure atmosphere in the internal space 905. After creating a reduced-pressure atmosphere in the internal space 905, the sealant 700 is applied to the first surface 100a using the coating device 510. This seals the first surface 100a with the sealant 700. In the coating device 510, for example, a nozzle for applying the sealant 700 is driven in a direction along the first surface 100a, as indicated by the arrow in Figure 9. Then, the laminate 310 with the sealant 700 formed on it is removed, and if necessary, the sealant 700 is cured, etc., to obtain the battery 1200. In the manufacture of the battery 1200, a laminate 310 with minute indentations formed on the first surface 100a is prepared, similar to the manufacture of the battery 1100 described above, or the voids 231, void 232, and void 240 are formed by adjusting the wettability between the first surface 100a and the sealing material 700. Alternatively, the voids 231, void 232, and void 240 may be formed by patterning the sealing material 700 using a coating device 510. In this way, the first surface 100a can be sealed and the voids 231, void 232, and void 240 can be formed simply by applying the sealing material 700 to the first surface 100a under a reduced pressure atmosphere, thus enabling the easy manufacture of the battery 1200.

[0123] Furthermore, in the third example, it is also possible to manufacture the battery 1100 by using the laminate 300 instead of the laminate 310.

[0124] The method for manufacturing the battery according to this embodiment is not limited to the examples described above. For example, in the sealing method for the first surface 100a, the internal space 905 may be replaced with an inert gas such as argon or nitrogen before creating a reduced-pressure atmosphere in the internal space 905. Alternatively, a void may be formed by bonding a sealing material 700, which has fine indentations formed on its surface in advance, to the first surface 100a under a reduced-pressure atmosphere.

[0125] Furthermore, it is not necessary to place the entire laminate 300 or laminate 310 in the vacuum chamber 900 as described above. For example, a container having an opening that can accommodate a portion of the laminate 300 or laminate 310 may be prepared, and the opening may be sealed with a portion of the laminate 300 or laminate 310 placed inside. Then, the internal space of the container may be evacuated, and the first surface 100a may be sealed by immersing the laminate 300 or laminate 310 in the sealing material 700 placed inside the container.

[0126] Furthermore, although the above description has focused on single-cell batteries 1000, 1100, and 1200, each having one power generation element 100, the battery configuration and manufacturing method according to this embodiment are also valid for stacked batteries having a configuration in which multiple power generation elements 100 are stacked in a series or parallel structure via a current collector. When a battery has multiple power generation elements 100, the first surface 100a of each of the multiple power generation elements 100 may be individually sealed with the sealing material 700 before stacking the multiple power generation elements 100, or the first surface 100a of each of the multiple power generation elements 100 may be stacked and then sealed together with the sealing material 700.

[0127] Furthermore, by using the manufacturing method according to this embodiment, even if voids other than the voids 230 formed as described above are unintentionally formed due to process conditions, etc., the internal pressure of such voids can be kept below 1 atm, thereby suppressing the generation of peeling force on the power generation element due to the expansion of the voids.

[0128] (Embodiment 2) Next, Embodiment 2 will be described. Embodiment 2 describes a battery system using the battery according to Embodiment 1. The battery 1000, etc. according to Embodiment 1 described above has negative pressure voids such as the void 230, which provides excellent environmental resistance and various advantages in practical operation.

[0129] Figure 10 is a schematic diagram showing the general configuration of the battery system 3000 according to Embodiment 2. As shown in Figure 10, the battery system 3000 comprises a battery 2000 and a container 600.

[0130] The battery 2000 is, for example, a stacked battery having a plurality of batteries 1000 according to Embodiment 1, and having a stacked structure in which the plurality of batteries 1000 are stacked. The battery 2000 may have a plurality of batteries 1100 or batteries 1200 instead of batteries 1000. Note that in Figure 10, the description of the stacked structure of batteries 1000 is omitted, and the battery 2000 is shown as a single rectangle. The fact that the battery 2000 is a stacked battery enables high voltage or high capacity. The battery 2000 is placed in the internal space 605 of the container 600. The batteries provided in the battery system 3000 may be single-cell batteries 1000, 1100, or 1200.

[0131] The container 600 is a sealed container for housing the battery 2000. The container 600 has an internal space 605 that is a reduced-pressure environment. A reduced-pressure environment is an environment where the pressure of the environment in which the battery 2000 is placed is 1 atm or less. In other words, the pressure in the internal space 605 is less than 1 atm. The container 600 may become a reduced-pressure environment by housing the battery 2000 in the container 600 under reduced-pressure conditions, or the internal space 605 may become a reduced-pressure environment by a vacuum pump, or by a vent door or vent connecting the outside of the container 600 to a reduced-pressure environment, etc., although not shown. The container 600 is, for example, a battery case for protecting the power generation element 100, etc., but it is not limited to a battery-specific container such as a battery case, but may be an airplane, aerospace vehicle, or vacuum chamber, etc. The container 600 may be flown by, for example, a flight device, etc., not shown.

[0132] Figure 11 is a schematic diagram showing the general configuration of another battery system 3100 according to Embodiment 2. As shown in Figure 11, the battery system 3100 comprises a battery 2000 and a container 610.

[0133] The container 610 has an internal space 615 that becomes a reduced-pressure environment. The container 610 is also provided with a hole 612 that connects the internal space 615 to the outside of the container 610. When the container 610 is placed in or moved in a reduced-pressure environment, for example, the internal space 615 becomes a reduced-pressure environment through the hole 612. The container 610 is a battery case for protecting a power generation element 100, etc., which is mounted on a mobile body that moves in a high-altitude environment or in outer space, such as an airplane or aerospace vehicle. The container 610 is not limited to a battery case, but may also be an enclosure for equipment used in a high-altitude environment or in outer space, or an enclosure for equipment installed on an airplane or aerospace vehicle, etc.

[0134] Thus, in the battery system 3000 and the battery system 3100, for example, the battery 2000 is placed in a reduced-pressure environment and charged or discharged.

[0135] In this embodiment, the pressure of the reduced-pressure environment may be 0.95 atm or less, or 0.8 atm or less. Also, the pressure of the reduced-pressure environment may be greater than, for example, 0 atm. For example, under flight conditions at high altitude, the environment outside the container 610 is generally reduced-pressure, and the battery system 3100 may be placed in an environment of, for example, 0.95 atm or less, or even 0.8 atm or less. Even in such a reduced-pressure environment, the battery 2000 has, for example, a negative pressure gap 230, so that a peeling force on the power generation element due to the gap trying to expand is less likely to occur.

[0136] Furthermore, the internal pressure of the void 230 in the battery 2000 is, for example, below the pressure of a reduced-pressure environment. This makes it difficult for delamination forces to occur due to the expansion of the void 230. In addition, a force acts on the power generation element 100 in a direction that restrains each layer of the power generation element 100 through the void 230.

[0137] As described above, the battery system according to this embodiment includes the battery 1000 according to Embodiment 1, and therefore, even in a battery system where the battery is placed in a reduced-pressure environment, high reliability of the battery can be ensured.

[0138] (Other embodiments) The batteries and battery systems relating to this disclosure have been described above based on embodiments, but this disclosure is not limited to these embodiments. Within the scope of this disclosure, various modifications to the embodiments that a person skilled in the art could conceive, as long as they do not depart from the spirit of this disclosure, and other forms constructed by combining some of the components of the embodiments, are also included.

[0139] For example, in the above embodiment, the method for manufacturing the battery includes a lamination step, but is not limited to this. The method for manufacturing the battery does not have to include a lamination step; for example, a pre-formed laminate may be prepared, and the depressurization step and sealing step may be performed using the prepared laminate.

[0140] Furthermore, the above embodiments may be modified, replaced, added, or omitted in various ways within the scope of the claims or their equivalents. [Industrial applicability]

[0141] The battery relating to this disclosure can be used as a battery for electronic devices, electrical appliances, electric vehicles, etc. [Explanation of symbols]

[0142] 100 power generation elements 100a, Page 1 110 Negative electrode active material layer 120 Cathode active material layer 130 Solid electrolyte layer 210 Negative electrode current collector 210a, 220a, 700a surface 210b, 220b side 211, 221 recess 220 Positive electrode current collector 230, 231, 232, 233, 240 void 300, 310 laminate 500 Dip device 510 Coating device 600, 610 container 605, 615, 905 interior space 612 holes 700 sealing material 900 Vacuum chamber 910 Vacuum pump 1000, 1100, 1200, 2000 batteries 3000, 3100 battery system

Claims

1. A power generation element having an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, A sealing material that seals the first surface, which is the side surface of the power generation element, An electrode current collector located on the electrode layer side of the power generation element, Equipped with, There is a gap surrounded by the sealing material, the first surface, and the electrode current collector. The internal pressure of the aforementioned void is less than 1 atm. The electrode current collector has a first recess that is curved so as to be recessed toward the gap, The sealing material is in contact with the side surface of the electrode current collector, When viewed from the direction normal to the main surface of the power generation element, the positions of the side surface of the electrode current collector in contact with the sealing material and the first surface overlap. battery.

2. The internal pressure of the aforementioned void is 0.9 atm or less. The battery according to claim 1.

3. The first surface is composed of the side surface of the electrode layer, the side surface of the counter electrode layer, and the side surface of the solid electrolyte layer. When viewed from the direction normal to the main surface of the power generation element, the positions of the side surface of the electrode layer, the side surface of the counter electrode layer, and the side surface of the solid electrolyte layer that constitute the first surface overlap. The battery according to claim 1 or 2.

4. A container having an internal space that becomes a reduced-pressure environment, The battery according to any one of claims 1 to 3 is disposed in the internal space, Equipped with, The internal pressure of the aforementioned void is lower than the pressure of the reduced-pressure environment. Battery system.

5. The pressure in the aforementioned reduced-pressure environment is 0.95 atm or less. The battery system according to claim 4.

6. A method for manufacturing a battery comprising a power generation element having an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, A depressurization step of exposing the first surface, which is a side surface of the power generation element in the laminate containing the power generation element, to a reduced pressure atmosphere, The sealing step involves sealing the first surface with a sealing material under the reduced pressure atmosphere, including, Battery manufacturing method.

7. The process further includes a lamination step of forming the laminate which includes the power generation element, in which the electrode layer and the counter electrode layer are laminated so as to face each other via the solid electrolyte layer, A method for manufacturing a battery according to claim 6.

8. The pressure of the aforementioned reduced-pressure atmosphere is 0.9 atm or less. A method for manufacturing a battery according to claim 6 or 7.

9. The pressure of the aforementioned reduced-pressure atmosphere is 0.1 atm or less. The method for manufacturing a battery according to claim 8.

10. In the sealing step, the first surface is sealed by immersing a portion of the laminate in the sealing material. A method for manufacturing a battery according to any one of claims 6 to 9.

11. In the sealing step, the first surface is sealed by applying the sealing material to the first surface. A method for manufacturing a battery according to any one of claims 6 to 9.

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