Solid battery

Abstract

Provided is a solid state battery in which moisture is prevented from penetrating into the solid state battery. Provided is a solid state battery made into a package that comprises a solid state battery layered body 100 composed of a layered part 140, which is obtained by layering a positive electrode layer 110, a negative electrode layer 120, and a solid electrolyte 130 interposed between the positive electrode layer 110 and the negative electrode layer 120, wherein a humectant is mixed into the component elements of the solid state battery.

Description

Technical Field

[0001] The present invention relates to a solid battery packaged to be suitable for substrate mounting.

Background Art

[0002] Conventionally, secondary batteries capable of repeated charging and discharging have been used in various applications. For example, secondary batteries are used as power sources for electronic devices such as smartphones and notebook personal computers.

[0003] In such secondary batteries, a liquid electrolyte is generally used as a medium for ion movement contributing to charging and discharging. That is, a so-called electrolytic solution is used in secondary batteries. However, in such secondary batteries, safety is generally required in terms of preventing leakage of the electrolytic solution. In addition, since organic solvents and the like used in the electrolytic solution are flammable substances, safety is also required in that regard.

[0004] Therefore, research has been underway on solid batteries configured using a solid electrolyte instead of the electrolytic solution.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The inventor of the present application has noticed that there are problems to be overcome in conventional secondary batteries and has found the necessity of taking countermeasures therefor. Specifically, the inventor of the present application has found the following problems.

[0007] The solid-state battery may be considered to be used by being mounted on a substrate such as a printed wiring board together with other electronic components, and in that case, one suitable for mounting is required. On the other hand, the solid-state battery needs to take certain measures against moisture in the air. This is because if moisture enters the inside of the solid-state battery, there is a risk of causing deterioration of battery characteristics.

[0008] Here, Patent Document 1 discloses a secondary battery in which a positive electrode material and a negative electrode material electrically coupled to a current collector are laminated via a non-fluid electrolyte layer, and a battery element containing an ionic metal component and a moisture absorbent are sealed with a synthetic resin housing. Patent Document 1 also discloses that the moisture absorbent is added inside the housing or in the synthetic resin layer of the housing.

[0009] However, in the secondary battery disclosed in Patent Document 1, there is a risk that moisture may enter from the gap between the moisture absorbent and the secondary battery, and it is difficult to say that it is a solid-state battery in which moisture entry is sufficiently prevented.

[0010] The present invention has been made in view of such problems. That is, the main object of the present invention is to provide a solid-state battery technology that reduces the entry of moisture into the solid-state battery while considering mounting on a substrate.

Means for Solving the Problems

[0011] The inventor of the present application has tried to solve the above problems by dealing with them in a new direction instead of corresponding on the extension line of the prior art. As a result, the inventor has arrived at an invention of a solid-state battery in which the above main object is achieved.

[0012] The solid-state battery of the present invention is a packaged solid-state battery including a solid-state battery laminate having a laminate portion in which a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer are laminated, a moisture absorbent is mixed into the components of the solid-state battery.

Effects of the Invention

[0013] The solid-state battery according to the present invention can reduce the intrusion of moisture into the solid-state battery.

[0014] More specifically, in the packaged solid-state battery of the present invention, since a moisture absorbent is incorporated into the components of the solid-state battery, there is no need to separately provide a member for absorbing moisture, and the moisture inside the solid-state battery can be absorbed. Therefore, it is possible to reduce the intrusion of moisture into the solid-state battery.

[0015] Also, since a moisture absorbent is incorporated into the components of the solid-state battery, an increase in the volume of the solid-state battery laminate can be suppressed. Therefore, miniaturization of the package can be achieved without reducing the energy density per unit volume of the solid-state battery.

Brief Description of the Drawings

[0016]

Figure 1

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Figure 6A

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DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, the solid-state battery of the present invention will be described in detail. Although the description will be made with reference to the drawings as necessary, the illustrated content is merely schematic and exemplary for understanding the present invention, and the appearance or dimensional ratio may differ from the actual object.

[0018] As used herein, the "packaged solid-state battery" broadly means a solid-state battery protected from the external environment, and narrowly refers to a solid-state battery in which water vapor in the external environment is prevented from entering the inside of the solid-state battery. The "water vapor" referred to here means moisture represented by water vapor in the atmosphere, and in a preferred embodiment, it means not only water vapor having a gaseous form but also moisture including liquid water. In particular, as the liquid water, condensed dew water obtained by condensing gaseous water may also be included. Preferably, the solid-state battery of the present invention in which such moisture permeation is prevented is packaged so as to be suitable for board mounting, and particularly is packaged so as to be suitable for surface mounting. Therefore, in a preferred embodiment, the battery of the present invention is an SMD (SMD: Surface Mount Device) type battery. Note that the "water vapor" referred to in this specification may also be referred to as "moisture" or the like.

[0019] As used in the present invention, the "solid battery" refers broadly to a battery whose components are made of solids, and narrowly to an all-solid battery whose components (preferably all components) are made of solids. In a preferred embodiment, the solid battery in the present invention is a laminated solid battery configured such that each layer forming a battery configuration unit is laminated on top of the others, and preferably each such layer is made of a sintered body. Note that the "solid battery" includes not only a so-called "secondary battery" capable of repeated charging and discharging, but also a "primary battery" capable of only discharging. According to a preferred embodiment of the present invention, the "solid battery" is a secondary battery. The "secondary battery" is not to be overly restricted by its name and may include, for example, a power storage device. Note that the "sintering" as used in the present invention only requires that sintering be achieved at least in part.

[0020] As used in this specification, the "side cross-section" is based on the form when viewed from a direction substantially perpendicular to the thickness direction based on the lamination direction of each layer constituting the solid battery (specifically, the form when cut with a plane parallel to the thickness direction). The "vertical direction" and "horizontal direction" directly or indirectly used in this specification correspond to the vertical direction and horizontal direction in the drawing, respectively. Unless otherwise specified, the same reference numerals or symbols indicate the same members, parts, or the same meaning content. In a preferred embodiment, the vertically downward direction (i.e., the direction in which gravity acts) corresponds to the "downward direction", and the opposite direction corresponds to the "upward direction".

[0021] As used in this specification, the "top surface" means the surface that is relatively positioned on the upper side among the surfaces constituting the battery, and the "bottom surface" means the surface that is relatively positioned on the lower side among the surfaces constituting the battery. Assuming a typical solid battery having two opposing main surfaces, the "top surface" as used in this specification refers to one of such main surfaces, and the "bottom surface" refers to the other of such main surfaces.

[0022] First, the basic configuration of the solid battery of the present invention will be described below. The configuration of the solid battery described here is merely an example for understanding the invention and does not limit the invention.

[0023] [Basic Structure of Solid-State Battery] The solid-state battery 1 includes a solid-state battery laminate 100 (Fig. 1(a)). The solid-state battery laminate 100 has a stacked portion 140 including a battery constituent unit composed of a positive electrode layer 110, a negative electrode layer 120, and at least a solid electrolyte 130 interposed therebetween. The solid-state battery laminate 100 is supported by a support substrate. Further, the solid-state battery 1 may have a coating insulating film 30 covering the solid-state battery laminate 100 and a coating inorganic film 50 covering the coating insulating film 30.

[0024] In the stacked portion 140, each layer constituting it is formed by firing, and the positive electrode layer, the negative electrode layer, and the solid electrolyte may form a sintered layer. Preferably, the positive electrode layer, the negative electrode layer, and the solid electrolyte are integrally sintered with each other, so the stacked portion may form an integral sintered body. In this specification, the direction (vertical direction) in which the positive electrode layer and the negative electrode layer are stacked is defined as the "stacking direction", and the direction intersecting the stacking direction is the horizontal direction in which the positive electrode layer and the negative electrode layer extend.

[0025] (Positive Electrode Layer and Negative Electrode Layer) The positive electrode layer 110 is an electrode layer including at least a positive electrode active material. The positive electrode layer may further include a solid electrolyte. In a preferred embodiment, the positive electrode layer is composed of a sintered body including at least positive electrode active material particles and solid electrolyte particles. On the other hand, the negative electrode layer 120 is an electrode layer including at least a negative electrode active material. The negative electrode layer may further include a solid electrolyte. In a preferred embodiment, the negative electrode layer is composed of a sintered body including at least negative electrode active material particles and solid electrolyte particles. Fig. 1(a) illustrates a configuration in which three layers of the positive electrode layer 110 and four layers of the negative electrode layer 120 are stacked, but the number of stacked layers is not limited to this example, and dozens to hundreds of layers may be stacked. The film thickness of the positive electrode layer or the negative electrode layer may be 5 μm or more and 60 μm or less, preferably 8 μm or more and 50 μm or less. It may also be 5 μm or more and 30 μm or less.

[0026] The positive electrode active material and the negative electrode active material are substances that participate in the transfer of electrons in a solid battery. Through the solid electrolyte, ions move (conduct) between the positive electrode layer and the negative electrode layer, and charge and discharge are performed by the transfer of electrons. The positive electrode layer and the negative electrode layer are preferably layers that can occlude and release lithium ions or sodium ions in particular. That is, the solid battery is preferably an all-solid-state secondary battery in which lithium ions or sodium ions move between the positive electrode layer and the negative electrode layer through the solid electrolyte to perform charge and discharge of the battery.

[0027] (Positive electrode active material) Examples of the positive electrode active material contained in the positive electrode layer include at least one selected from the group consisting of lithium-containing phosphate compounds having a NASICON-type structure, lithium-containing phosphate compounds having an olivine-type structure, lithium-containing layered oxides, and lithium-containing oxides having a spinel-type structure. An example of the lithium-containing phosphate compound having a NASICON-type structure is Li3V2(PO4)3 and the like. Examples of the lithium-containing phosphate compound having an olivine-type structure include Li3Fe2(PO4)3, LiFePO4, LiMnPO4 and the like. An example of the lithium-containing layered oxide is LiCoO2, LiCo 1 / 3 Ni 1 / 3 Mn 1 / 3 O2 and the like. An example of the lithium-containing oxide having a spinel-type structure is LiMn2O4, LiNi 0.5 Mn 1.5 O4 and the like. The type of lithium compound is not particularly limited, but may be, for example, a lithium transition metal composite oxide and a lithium transition metal phosphate compound. The lithium transition metal composite oxide is a general term for oxides containing lithium and one or more transition metal elements as constituent elements, and the lithium transition metal phosphate compound is a general term for phosphate compounds containing lithium and one or more transition metal elements as constituent elements. The type of transition metal element is not particularly limited, but is, for example, cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), and the like.

[0028] In addition, examples of the positive electrode active material capable of occluding and releasing sodium ions include at least one selected from the group consisting of sodium-containing phosphate compounds having a NASICON structure, sodium-containing phosphate compounds having an olivine structure, sodium-containing layered oxides, and sodium-containing oxides having a spinel structure. For example, in the case of sodium-containing phosphate compounds, at least one selected from the group consisting of Na3V2(PO4)3, NaCoFe2(PO4)3, Na2Ni2Fe(PO4)3, Na3Fe2(PO4)3, Na2FeP2O7, Na4Fe3(PO4)2(P2O7), and NaFeO2 as the sodium-containing layered oxide can be mentioned.

[0029] In addition, the positive electrode active material may be, for example, an oxide, a disulfide, a chalcogenide, or a conductive polymer. Examples of the oxide may include titanium oxide, vanadium oxide, or manganese dioxide. Examples of the disulfide include titanium disulfide or molybdenum sulfide. Examples of the chalcogenide may include niobium selenide. Examples of the conductive polymer may include disulfide, polypyrrole, polyaniline, polythiophene, polyparastyrene, polyacetylene, or polyacene.

[0030] (Negative electrode active material) Examples of the negative electrode active material contained in the negative electrode layer include oxides containing at least one element selected from the group consisting of Ti, Si, Sn, Cr, Fe, Nb, and Mo, carbon materials such as graphite, graphite-lithium compounds, lithium alloys, lithium-containing phosphate compounds having a NASICON structure, lithium-containing phosphate compounds having an olivine structure, and lithium-containing oxides having a spinel structure. Examples of the lithium alloy include Li-Al. Examples of the lithium-containing phosphate compound having a NASICON structure include Li3V2(PO4) 3、 LiTi2(PO4)3 and the like. Examples of the lithium-containing phosphate compound having an olivine structure include Li3Fe2(PO4)3, LiCuPO4 and the like. Examples of the lithium-containing oxide having a spinel structure include Li4Ti5O12 include the following.

[0031] In addition, examples of the negative electrode active material capable of occluding and releasing sodium ions include at least one selected from the group consisting of sodium-containing phosphate compounds having a NASICON structure, sodium-containing phosphate compounds having an olivine structure, and sodium-containing oxides having a spinel structure.

[0032] The positive electrode layer and / or the negative electrode layer may contain a conductive material. Examples of the conductive material contained in the positive electrode layer and the negative electrode layer include at least one selected from metal materials such as silver, palladium, gold, platinum, aluminum, copper, and nickel, and carbon.

[0033] Furthermore, the positive electrode layer and / or the negative electrode layer may contain a sintering aid. Examples of the sintering aid include at least one selected from the group consisting of aluminum oxide, lithium oxide, sodium oxide, potassium oxide, boron oxide, silicon oxide, bismuth oxide, and phosphorus oxide.

[0034] (Solid electrolyte) The solid electrolyte 130 is a material capable of conducting lithium ions. In particular, the solid electrolyte 130 that forms a battery constituent unit in a solid battery forms a layer capable of conducting lithium ions between the positive electrode layer 110 and the negative electrode layer 120. Specific examples of the solid electrolyte include, for example, lithium-containing phosphate compounds having a NASICON structure, oxides having a perovskite structure, oxides having a garnet type or garnet type similar structure, and oxide glass ceramics-based lithium ion conductors. Examples of the lithium-containing phosphate compound having a NASICON structure include Li x M y (PO4)3 (1 ≦ x ≦ 2, 1 ≦ y ≦ 2, M is at least one selected from the group consisting of Ti, Ge, Al, Ga, and Zr). As an example of the lithium-containing phosphate compound having a NASICON structure, for example, Li 1.2 Al 0.2 Ti 1.8(PO4)3 and the like can be mentioned. As an example of an oxide having a perovskite structure, La 0.55 Li 0.35 TiO3 and the like can be mentioned. As an example of an oxide having a garnet type or garnet type similar structure, Li7La3Zr2O 12 and the like can be mentioned. As the oxide glass ceramic-based lithium ion conductor, for example, a phosphate compound (LATP) containing lithium, aluminum and titanium as constituent elements, and a phosphate compound (LAGP) containing lithium, aluminum and germanium as constituent elements can be used. Note that, as the solid electrolyte, for example, a glass electrolyte may be used.

[0035] The solid electrolyte layer may contain a sintering aid. The sintering aid contained in the solid electrolyte layer may be selected from, for example, the same materials as the sintering aids that can be contained in the positive electrode layer and the negative electrode layer.

[0036] (Positive electrode current collector layer and negative electrode current collector layer) The positive electrode layer 110 and the negative electrode layer 120 may each be provided with a positive electrode current collector layer and a negative electrode current collector layer. The positive electrode current collector layer and the negative electrode current collector layer may each have a foil form, but from the viewpoints of reducing the manufacturing cost of the solid battery by integral firing and reducing the internal resistance of the solid battery, etc., they may have a sintered body form. Note that, when the positive electrode current collector layer and the negative electrode current collector layer have a sintered body form, they may be composed of a sintered body containing a conductive material and a sintering aid. The conductive material contained in the positive electrode current collector layer and the negative electrode current collector layer may be selected from, for example, the same materials as the conductive materials that can be contained in the positive electrode layer and the negative electrode layer. The sintering aid contained in the positive electrode current collector layer and the negative electrode current collector layer may be selected from, for example, the same materials as the sintering aids that can be contained in the positive electrode layer and the negative electrode layer. Note that, in the solid battery, the positive electrode current collector layer and the negative electrode current collector layer are not necessarily essential, and a solid battery in which such a positive electrode current collector layer and a negative electrode current collector layer are not provided is also conceivable. That is, the solid battery in the present invention may be a solid battery without a current collector layer.

[0037] (External terminal) A pair of external terminals 150 are provided on the side surface of the stacked portion 140 located in a direction intersecting the stacking direction. For example, external terminals may be provided from the side surface to the bottom surface of the stacked portion 140. More specifically, a positive electrode side external terminal 150A connected to the positive electrode layer 110 and a negative electrode side external terminal 150B connected to the negative electrode layer 120 are provided. The positive electrode side external terminal 150A is formed on one side surface (left side in the illustrated example), and the negative electrode side external terminal 150B may be provided so as to face the positive electrode side external terminal 150A (right side in the illustrated example). Such a pair of external terminals 150 preferably comprises a material having a high conductivity. Specific materials for the external terminals are not particularly limited, and examples thereof include at least one selected from the group consisting of silver, gold, platinum, aluminum, copper, tin, and nickel.

[0038] (Non-active material part) An inactive material portion 170 may be provided between the positive electrode layer 110 and the external terminal 150B on the negative electrode side and between the negative electrode layer 120 and the external terminal 150A on the positive electrode side (see Fig. 1(b)). The inactive material portion 170 is provided to insulate between the positive electrode layer 110 and the external terminal 150B on the negative electrode side and between the negative electrode layer 120 and the external terminal 150A on the positive electrode side. That is, the inactive material portion preferably has at least electronic insulation. As the material of the inactive material portion, a material commonly used as an "inactive material" of a solid battery may be used, and it may be composed of a resin material, a glass material, and / or a ceramic material, etc. From the viewpoint of manufacturing by firing, it may have a sintered body form. For example, at least one selected from the group consisting of soda lime glass, potassium glass, borate glass, borosilicate glass, barium borosilicate glass, bismuth zinc borate glass, bismuth silicate glass, phosphate glass, aluminophosphate glass, and zinc phosphate glass can be mentioned. Also, although not particularly limited, examples of the ceramic material can include at least one selected from the group consisting of aluminum oxide, boron nitride, silicon dioxide, silicon nitride, zirconium dioxide, aluminum nitride, silicon carbide, and barium titanate. Note that the inactive material portion can also be referred to as a "margin portion" or a "negative portion" due to its form.

[0039] (Insulating outermost layer) An insulating outermost layer 160 may be provided on the outermost side of the stacked portion 140. The insulating outermost layer 160 can generally be formed on the outermost side of the stacked portion 140 and is for protecting the solid-state battery laminate electrically, physically, and / or chemically. In particular, the insulating outermost layer 160 includes an insulating outermost layer 160A on the top surface side and an insulating outermost layer 160B on the bottom surface side of the solid-state battery laminate 100. As a material constituting the insulating outermost layer, it is preferably excellent in insulation, durability, and / or moisture resistance and environmentally safe, and may include, for example, a resin material, a glass material, and / or a ceramic material. Further, the insulating outermost layer may have a sintered body form for manufacturing by integral firing and may be constituted by a sintered body (for example, silicon oxide) containing a sintering aid that can be included in the above-described positive electrode layer and negative electrode layer. Note that the top surface and the bottom surface of the solid-state battery laminate may be used as the stacked portion 140 without providing the insulating outermost layer 160.

[0040] (Coating insulating film) The solid-state battery may be provided with a coating insulating film 30 provided so as to cover at least the solid-state battery laminate 100. As shown in FIG. 1, the solid-state battery laminate 100 provided on the support substrate 10 is entirely wrapped by the coating insulating film 30.

[0041] The coating insulating film 30 preferably corresponds to a resin. That is, the coating insulating film 30 preferably includes a resin material and is preferably formed so as to form a base material. As can be seen from the embodiment shown in FIG. 1, this means that the solid-state battery laminate 100 provided on the support substrate 10 is sealed with the resin material of the coating insulating film 30. The coating insulating film 30 made of such a resin material preferably contributes to reducing the intrusion of moisture in combination with the coating inorganic film 50.

[0042] The material of the coating insulating film may be of any type as long as it exhibits insulation properties. For example, when the coating insulating film contains a resin, the resin may be either a thermosetting resin or a thermoplastic resin. Although not particularly limited, specific resin materials for the coating insulating film may include, for example, epoxy resins, silicone resins, and / or liquid crystal polymers, etc. The thickness of the coating insulating film, which is merely an illustration, may be 30 μm or more and 1000 μm or less, for example, 50 μm or more and 300 μm or less.

[0043] In addition, in a solid-state battery, the coating insulating film is not necessarily essential, and a solid-state battery without a coating insulating film is also conceivable.

[0044] (Coating inorganic film) Furthermore, the solid-state battery may be provided with a coating inorganic film 50 that covers the coating insulating film 30. As shown in FIG. 1, since the coating inorganic film is positioned on the coating insulating film, it has a form that largely encloses the solid-state battery laminate on the support substrate as a whole together with the coating insulating film.

[0045] The coating inorganic film preferably has a thin film form. The material of the coating inorganic film is not particularly limited as long as it contributes to an inorganic film having a thin film form, and it may be a metal, glass, oxide ceramics, or a mixture thereof, etc. In a preferred embodiment, the coating inorganic film contains a metal component. That is, the coating inorganic film is preferably a metal thin film. Although merely an illustration, the thickness of such a coating inorganic film may be 0.1 μm or more and 100 μm or less, for example, 1 μm or more and 50 μm or less.

[0046] Particularly depending on the manufacturing method, the coating inorganic film 50 may be a dry plating film. Such a dry plating film is a film obtained by a vapor phase method such as physical vapor deposition (PVD) or chemical vapor deposition (CVD), and has a very small thickness on the nano-order or micron-order. Such a thin dry plating film contributes to more compact packaging.

[0047] The dry plating film may be composed of at least one metal component, semi-metal component, inorganic oxide, and / or glass component selected from the group consisting of, for example, aluminum (Al), nickel (Ni), palladium (Pd), silver (Ag), tin (Sn), gold (Au), copper (Cu), titanium (Ti), platinum (Pt), silicon / silicon (Si), and SUS. The dry plating film composed of such components is chemically and / or thermally stable, so it is excellent in chemical resistance, weather resistance, and / or heat resistance, etc., and a solid battery with improved long-term reliability can be provided.

[0048] In addition, in a solid battery, it is not necessarily the case that a coating inorganic film is essential, and a solid battery without a coating insulating film can also be considered.

[0049] (Support substrate) The support substrate 10 is a substrate provided so as to support the solid battery laminate 100. The support substrate is positioned on one side forming the main surface of the solid battery for "support". Also, because it is a "substrate", it preferably has a thin plate-like form as a whole.

[0050] The support substrate 10 may be, for example, a resin substrate or a ceramic substrate, and a substrate having water resistance is preferred. In a certain preferred embodiment, the support substrate 10 is a ceramic substrate. That is, the support substrate 10 is composed of a ceramic, and it occupies the base material component of the substrate. The support substrate made of ceramic is a preferred substrate in terms of contributing to preventing water vapor permeation and heat resistance in substrate mounting. Such a ceramic substrate can be obtained through firing, for example, by firing a green sheet laminate. In this regard, the ceramic substrate may be, for example, an LTCC substrate (LTCC: Low Temperature Co-fired Ceramics), or an HTCC substrate (HTCC: High Temperature Co-fired Ceramic). It is only an example, but the thickness of the support substrate may be 20 μm or more and 1000 μm or less, for example, 100 μm or more and 300 μm or less.

[0051] Further, the support substrate 10 functions as a terminal substrate of the solid battery laminate 100. That is, the solid battery packaged in such a form that the substrate is interposed can be mounted on another secondary substrate such as a printed wiring board. For example, the solid battery can be surface-mounted through the support substrate via solder reflow or the like. From such a fact, it can be said that the packaged solid battery is an SMD type battery. In particular, when the terminal substrate is made of a ceramic substrate, the solid battery can be an SMD type battery with high heat resistance and capable of solder mounting.

[0052] Due to the terminal substrate, it is preferable to have wiring, and in particular, it is preferable to include wiring 17 (see FIG. 1) that electrically connects the upper and lower surfaces or the upper and lower surface layers. That is, a support substrate in a certain preferred embodiment includes wiring that electrically connects the upper and lower surfaces of the substrate, and serves as a terminal substrate for the external terminals of the packaged solid battery.

[0053] The wiring 17 in the terminal substrate is not particularly limited, and may have any form as long as it contributes to the electrical connection between the upper and lower surfaces of the substrate. Since it contributes to the electrical connection, the wiring 17 in the terminal substrate can also be said to be a conductive portion of the substrate. Such a conductive portion of the substrate may have forms such as a wiring layer, a via, and / or a land. For example, in the embodiment shown in FIG. 1, vias 14 and / or lands 16 are provided on the support substrate 10. The "via" referred to here refers to a member for electrically connecting in the vertical direction of the support substrate, that is, the substrate thickness direction. For example, a field via or the like is preferable, and it may also be in the form of an inner via. Further, the "land" referred to in this specification refers to a terminal portion / connection portion for electrical connection provided on the upper main surface and / or the lower main surface of the support substrate (preferably a terminal portion / connection portion connected to a via), and may be, for example, a square land or a round land or the like.

[0054] [Features of the Solid Battery of the Present Invention] In the solid-state battery of the present invention, a moisture absorbent is mixed into the components of the packaged solid-state battery. Here, the phrase "a moisture absorbent is mixed into the components of the solid-state battery" as used in this specification means that a moisture absorbent that absorbs moisture is contained in the members constituting the solid-state battery, and the moisture absorbent is mixed in the members. That is, among the external terminal 150, the non-active material portion 170, the insulating outermost layer 160, the coating insulating film 30, and the support substrate 10, which are the basic components of the above-described solid-state battery, at least one or more contain a moisture absorbent that absorbs moisture. Therefore, it is different from a secondary battery in which a moisture-absorbing member is separately provided, which has been conventionally known, or a secondary battery in which a moisture absorbent is added to a housing provided outside the components of the battery. Note that examples of the mode of mixing the moisture absorbent include a mode in which the moisture absorbent is uniformly mixed into the components and a mode in which the moisture absorbent is locally and unevenly mixed into the components.

[0055] The moisture absorbent to be mixed includes a material that absorbs moisture, and examples thereof include at least one selected from the group consisting of synthetic zeolite, silica gel, phosphorus pentoxide, barium oxide, calcium oxide, and an organometallic structure. In particular, a moisture-absorbing film mixed with synthetic zeolite generates heat during the operation of the solid-state battery, has good temperature resistance even when the synthetic zeolite becomes high temperature, does not deliquesce, and has a good adsorption rate per unit weight, so it is suitable. Note that the moisture absorbent to be mixed may be a moisture absorbent formed by combining two or more kinds of moisture absorbents. Further, as the moisture absorbent, a powder form may be used, or it may be aggregated into a solid form.

[0056] Hereinafter, embodiments in which a moisture absorbent is mixed into each basic component in the solid-state battery will be described.

[0057] <Embodiment in which a moisture absorbent is mixed into the external terminal> In one embodiment of the present invention, a moisture absorbent is mixed into the external terminal 150 (see Fig. 1(a)). Specifically, the moisture absorbent is mixed into the metal paste that constitutes the external terminal. In the drawing, the hatched member (external terminal 150) has the moisture absorbent mixed therein. As described above, the moisture absorbent is preferably synthetic zeolite. And the content of the moisture absorbent is preferably such that it does not impair the functions of the external terminal (for example, conductivity, etc.). Although it will be described in detail in the examples below, it is preferably 1% by volume or more and 25% by volume or less based on the entire external terminal. As another embodiment of the solid battery shown in Fig. 1(a), as shown in Fig. 1(b), an inactive material portion 170 may be provided. Also, as another embodiment, although not shown, the top and bottom surfaces of the solid battery laminate may be the laminate portion 140 without providing the insulating outermost layer 160.

[0058] Here, in a conventionally known solid battery laminate, on the side surface located in a direction intersecting the lamination direction, since electrode materials such as external terminals are exposed, there is a risk that moisture may enter from the external terminal or the vicinity of the external terminal, causing deterioration of the solid battery. Therefore, in an embodiment of the present invention, a moisture absorbent is mixed into the external terminal. According to such an embodiment, since the moisture absorbent mixed into the external terminal absorbs moisture, the intrusion of moisture into the solid battery laminate can be reduced.

[0059] Furthermore, in this embodiment, since the moisture absorbent is mixed into the external terminal itself, an increase in volume can be suppressed as compared with the case of providing a moisture-absorbing member separately from the external terminal. Therefore, a decrease in the energy density per volume of the solid battery can be suppressed, and miniaturization of the package can be achieved.

[0060] <Embodiment in which a moisture absorbent is mixed into the inactive material portion 170> In another embodiment of the present invention, a moisture absorbent may be incorporated into the inactive substance portion 170 (see FIG. 2). Specifically, the moisture absorbent is incorporated into the insulating sintered body constituting the inactive substance portion 170. In the drawing, the moisture absorbent is incorporated into the hatched member (inactive substance portion 170). As described above, the moisture absorbent is preferably synthetic zeolite. And the content of the moisture absorbent is preferably set to such an extent that it does not impair the functions of the inactive substance portion (for example, insulation or coating property, etc.). Although it will be described in detail in the examples described later, it is preferably 1% by volume or more and 80% by volume or less based on the entire inactive substance portion. As another embodiment, although not shown, the top and bottom surfaces of the solid battery laminate may be used as the laminate portion 140 without providing the outermost insulating layer 160.

[0061] In this embodiment, by incorporating a moisture absorbent into the inactive substance portion provided in a part of the laminate portion, the moisture absorbent can absorb the moisture that penetrates at a position closer to the solid battery laminate. Therefore, it is possible to more effectively suppress the intrusion of moisture that penetrates into the solid battery.

[0062] <Embodiment in which a moisture absorbent is incorporated into the outermost insulating layer 160> In another embodiment of the present invention, a moisture absorbent may be incorporated into the outermost insulating layer 160 (see FIGS. 3(a) and 3(b)). Specifically, the moisture absorbent is incorporated into the resin material or sintered material constituting the outermost insulating layer 160. In the drawing, the moisture absorbent is incorporated into the hatched member (outermost insulating layer 160). As described above, the moisture absorbent is preferably synthetic zeolite. And the content of the moisture absorbent is preferably set to such an extent that it does not impair the functions of the outermost insulating layer (for example, insulation or coating property, etc.). Although it will be described in detail in the examples described later, it is preferably 1% by volume or more and 80% by volume or less based on the entire outermost insulating layer. As another embodiment of the solid battery shown in FIG. 3(a), an inactive substance portion 170 as shown in FIG. 3(b) may be provided.

[0063] In this embodiment, by incorporating a moisture absorbent into the outermost insulating layers on the upper and lower surfaces of the stacked portion, it is possible to reduce the unexpected intrusion of moisture from the stacking direction (vertical direction).

[0064] <Embodiment in which a moisture absorbent is incorporated into the coating insulating film 30> In another embodiment of the present invention, a moisture absorbent may be incorporated into the coating insulating film 30 (Figs. 4(a) and 4(b)). Specifically, the moisture absorbent is incorporated into the resin material constituting the coating insulating film. In the drawings, the hatched member (coating insulating film 30) has the moisture absorbent incorporated therein. As described above, the moisture absorbent is preferably synthetic zeolite. The content of the moisture absorbent is preferably such that it does not impair the functions of the coating insulating film 30 (for example, insulation or coating properties, etc.). Although it will be described in detail in the examples below, it is preferably 1% by volume or more and 45% by volume or less based on the entire coating insulating film. As another embodiment of the solid battery shown in Fig. 4(a), an inactive material portion 170 as shown in Fig. 4(b) may be provided. As another embodiment, although not shown, the top and bottom surfaces of the solid battery laminate may be the stacked portion 140 without providing the outermost insulating layer 160.

[0065] In this embodiment, since the coating insulating film incorporated with the moisture absorbent is provided so as to cover the solid battery laminate, it is possible to absorb moisture that substantially penetrates into the solid battery from all directions.

[0066] <Embodiment in which a moisture absorbent is incorporated into the support substrate 10> In another embodiment of the present invention, a moisture absorbent may be incorporated into the support substrate 10. Specifically, the moisture absorbent is incorporated into the base material constituting the support substrate. In FIGS. 5(a) and 5(b), the hatched member (support substrate 10) indicates that the moisture absorbent is incorporated. As described above, the moisture absorbent is preferably synthetic zeolite. The content of the moisture absorbent is preferably such that it does not impair the functions of the support substrate (e.g., durability, water resistance, etc.). Although it will be described in detail in the examples below, it is preferably 1% by volume or more and 45% by volume or less based on the entire support substrate. As another embodiment of the solid-state battery shown in FIG. 5(a), an inactive material portion 170 as shown in FIG. 5(b) may be provided. As another embodiment, although not shown, the top and bottom surfaces of the solid-state battery laminate may be the laminate portion 140 without providing the outermost insulating layer 160.

[0067] In this embodiment, by incorporating a moisture absorbent into the support substrate that supports the solid-state battery laminate, it is possible to prevent the intrusion of moisture into the solid-state battery.

[0068] Regarding the reference for the entire external terminal, the entire inactive material portion, the entire outermost insulating layer, the entire coating insulating film, and the entire support substrate in the above-described content of the moisture absorbent, it may be the time when the solid-state battery is completed.

[0069] <Another Embodiment 1> Another embodiment will be described with reference to FIGS. 6A and 6B. Referring to FIGS. 6A and 6B. FIG. 6A is a side cross-sectional view schematically showing the configuration of a solid-state battery according to another embodiment of the present invention (the cross-sectional view taken along line VIA-VIA in FIG. 6B), and FIG. 6B is the cross-sectional view taken along line VIB-VIB in FIG. 6A. As in the present embodiment, the solid-state battery laminate may be supported by the support substrate such that the stacking direction of the stacked portion 140 is parallel to the support surface of the support substrate (see FIG. 6B). The member in which the moisture absorbent is mixed may be one or more of the external terminal, the non-active material portion, the outermost insulating layer, the coated insulating film, and the support substrate. Even in such an embodiment, since the moisture absorbent absorbs moisture by the component in which the moisture absorbent is mixed, the intrusion of moisture into the solid-state battery can be reduced. Further, according to the present embodiment, even if expansion occurs in the stacking direction due to charge and discharge or the like, deformation of the support substrate accompanying the expansion can be reduced. Note that the "parallel" as used in this specification is not limited to a state of being completely parallel, but also includes a substantially parallel state.

[0070] <Another Embodiment 2> In the description of the above embodiments, an embodiment has been described in which a moisture absorbent that absorbs moisture is incorporated into one of the components including the external terminals, the non-active material part, the insulating outermost layer, the coating insulating film, and the support substrate. However, the present invention is not limited to this example, and the moisture absorbent may be incorporated into a plurality of components (two or more or all). Specific embodiments include an embodiment in which the moisture absorbent is incorporated into the external terminals and the non-active material part, an embodiment in which the moisture absorbent is incorporated into the external terminals and the insulating outermost layer, an embodiment in which the moisture absorbent is incorporated into the external terminals and the coating insulating film, an embodiment in which the moisture absorbent is incorporated into the external terminals and the support substrate, an embodiment in which the moisture absorbent is incorporated into the non-active material part and the insulating outermost layer, an embodiment in which the moisture absorbent is incorporated into the non-active material part and the coating insulating film, an embodiment in which the moisture absorbent is incorporated into the non-active material part and the support substrate, an embodiment in which the moisture absorbent is incorporated into the insulating outermost layer and the coating insulating film, an embodiment in which the moisture absorbent is incorporated into the insulating outermost layer and the support substrate, an embodiment in which the moisture absorbent is incorporated into the coating insulating film and the support substrate, an embodiment in which the moisture absorbent is incorporated into the external terminals, the non-active material part, and the insulating outermost layer, an embodiment in which the moisture absorbent is incorporated into the external terminals, the non-active material part, and the coating insulating film, an embodiment in which the moisture absorbent is incorporated into the external terminals, the non-active material part, and the support substrate, an embodiment in which the moisture absorbent is incorporated into the external terminals, the insulating outermost layer, and the coating insulating film, an embodiment in which the moisture absorbent is incorporated into the external terminals, the insulating outermost layer, and the support substrate, an embodiment in which the moisture absorbent is incorporated into the external terminals, the coating insulating film, and the support substrate, an embodiment in which the moisture absorbent is incorporated into the non-active material part, the insulating outermost layer, and the coating insulating film, an embodiment in which the moisture absorbent is incorporated into the non-active material part, the insulating outermost layer, and the support substrate, an embodiment in which the moisture absorbent is incorporated into the non-active material part, the coating insulating film, and the support substrate, an embodiment in which the moisture absorbent is incorporated into the insulating outermost layer, the coating insulating film, and the support substrate, an embodiment in which the moisture absorbent is incorporated into the external terminals, the non-active material part, the insulating outermost layer, and the coating insulating film, an embodiment in which the moisture absorbent is incorporated into the external terminals, the non-active material part, the insulating outermost layer, and the support substrate, an embodiment in which the moisture absorbent is incorporated into the external terminals, the non-active material part, the coating insulating film, and the support substrate, an embodiment in which the moisture absorbent is incorporated into the external terminals, the coating insulating film, the insulating outermost layer, and the support substrate, and an embodiment in which the moisture absorbent is incorporated into the non-active material part, the coating insulating film, the insulating outermost layer, and the support substrate.

[0071] [Method for manufacturing a solid-state battery package of the present invention] The object of the present invention can be obtained by preparing a solid-state battery including a battery constituent unit having a solid electrolyte between a positive electrode layer, a negative electrode layer, and electrodes thereof, and then subjecting the solid-state battery to a packaging process.

[0072] As shown in FIG. 7, the manufacturing of the solid-state battery of the present invention is carried out through a process including the manufacturing of a stacked portion 140 (FIG. 7(a)), the formation of an external terminal 150 (FIG. 7(b)), the fixing to a support substrate 10 (FIG. 7(c)), and the formation of a coating insulating film 30 and a coating inorganic film 50 (FIG. 7(d)). Hereinafter, it will be described step by step.

[0073] <Manufacturing of the stacked portion> The stacked portion 140 can be manufactured by a printing method such as a screen printing method, a green sheet method using a green sheet, or a combination thereof. That is, the stacked portion itself may be produced according to a conventional manufacturing method of a solid-state battery (therefore, raw material substances such as a solid electrolyte, an organic binder, a solvent, an optional additive, a positive electrode active material, and a negative electrode active material may be those used in the manufacturing of known solid-state batteries).

[0074] Hereinafter, for better understanding of the present invention, one manufacturing method will be illustrated and described, but the present invention is not limited to this method. Also, matters over time such as the following description order are merely for convenience of explanation and are not necessarily binding thereto.

[0075] First, a solid electrolyte, an organic binder, a solvent, and an optional additive are mixed to prepare a slurry. Next, a sheet having a thickness of about 10 μm after firing is obtained by sheet forming from the prepared slurry. Next, a positive electrode active material, a solid electrolyte, a conductive material, an organic binder, a solvent, and an optional additive are mixed to create a positive electrode paste. Similarly, a negative electrode active material, a solid electrolyte, a conductive material, an organic binder, a solvent, and an optional additive are mixed to create a negative electrode paste. Then, the positive electrode paste is printed on the sheet, and if necessary, a current collecting layer and / or an inactive material portion are printed.

[0076] Here, when manufacturing a solid battery in which a moisture absorbent is incorporated into the non-active material part 170, the moisture absorbent is incorporated into the paste of the non-active material part. The moisture absorbent is preferably synthetic zeolite, and its content is preferably 1% by volume or more and 80% by volume or less based on the entire non-active material part.

[0077] Similarly, a negative electrode paste is printed on the sheet, and if necessary, a current collector layer and / or a non-active material part are printed. When manufacturing a solid battery in which a moisture absorbent is incorporated into the non-active material part 170, the moisture absorbent is incorporated into the paste of the non-active material part.

[0078] Thereafter, the sheet printed with the positive electrode paste and the sheet printed with the negative electrode paste are alternately laminated to obtain a laminate. An insulating outermost layer, which is an electrolyte layer or an insulating layer, is provided on the uppermost layer and / or the lowermost layer of the laminate for protecting the solid battery.

[0079] When manufacturing a solid battery in which a moisture absorbent is incorporated into the insulating outermost layer 160, the moisture absorbent is incorporated into the paste of the electrolyte layer or the insulating layer constituting the insulating outermost layer. The moisture absorbent is preferably synthetic zeolite, and its content is preferably 1% by volume or more and 80% by volume or less based on the entire insulating outermost layer.

[0080] After the laminate is pressure-bonded and integrated, it is cut to a predetermined size. The obtained cut laminate is subjected to degreasing and firing. Thereby, a sintered laminate (laminated part 140) is obtained. Note that the laminate may be subjected to degreasing and firing before cutting, and then cutting may be performed.

[0081] <Formation of External Terminals> The external terminal on the positive electrode side can be formed by applying a conductive paste to the positive electrode exposed side surface in the laminated part 140. Similarly, the external terminal on the negative electrode side can be formed by applying a conductive paste to the negative electrode exposed side surface in the laminated part 140.

[0082] When manufacturing a solid-state battery in which a moisture-absorbing material is incorporated into the external terminal 150, a desired moisture-absorbing material is incorporated into the conductive paste that becomes the external terminal 150. The moisture-absorbing material is preferably synthetic zeolite, and its content is preferably 1% by volume or more and 25% by volume or less based on the entire external terminal.

[0083] It is preferable to provide the external terminals 150 on the positive electrode side and the negative electrode side so as to reach the lower surface of the sintered laminate, because they can be connected to the mounting land in a small area in the next process (more specifically, the external terminals provided so as to reach the lower surface of the sintered laminate will have a folded-back portion on the lower surface, and such a folded-back portion can be electrically connected to the mounting land). As components of the external terminal, at least one selected from silver, gold, platinum, aluminum, copper, tin, and nickel can be selected.

[0084] Note that the external terminals on the positive electrode side and the negative electrode side are not limited to being formed after sintering of the laminate, and may be formed before firing and subjected to co-sintering.

[0085] <Fixing to the support substrate> The support substrate 10 is provided with vias and / or lands in order to enable surface mounting on the secondary substrate. For example, it can be obtained by laminating and firing a plurality of green sheets. This is particularly true when the support substrate is a ceramic substrate. The preparation of the support substrate can be carried out, for example, in accordance with the preparation of an LTCC substrate.

[0086] When manufacturing a solid-state battery in which a moisture-absorbing material is incorporated into the support substrate 10, the moisture-absorbing material is incorporated into the base material that becomes the support substrate. The moisture-absorbing material is preferably synthetic zeolite, and its content is preferably 1% by volume or more and 45% by volume or less based on the entire support substrate.

[0087] The vias and / or lands in the support substrate are manufactured, for example, by a method of forming holes (diameter size: about 50 μm or more and 200 μm or less) by punch press or carbon dioxide laser and filling the holes with a conductive paste material, or by a method using a printing method.

[0088] After manufacturing the support substrate 10, the solid battery laminate 100 is disposed on the support substrate 10 such that the conductive portion of the support substrate 10 and the external terminal 150 of the solid battery laminate 100 are electrically connected to each other. Then, a conductive paste may be applied onto the support substrate 10 so as to electrically connect the conductive portion of the support substrate 10 and the external terminal 150 of the solid battery laminate 100 to each other. As the conductive paste, in addition to an Ag conductive paste, a conductive paste that does not require cleaning such as a flux after formation, such as a nanopaste, an alloy-based paste, or a brazing material, can be used.

[0089] <Formation of Coating Insulating Film and Coating Inorganic Film> Next, a coating insulating film 30 is formed so as to cover the solid battery laminate 100 on the support substrate 10. Therefore, the raw material of the coating insulating film 30 is supplied so as to entirely cover the solid battery laminate 100 on the support substrate 10. When the coating insulating film 30 is made of a resin material, a resin precursor is provided on the support substrate 10 and subjected to curing or the like to mold the coating insulating film 30.

[0090] When manufacturing a solid battery in which a moisture absorbent is incorporated into the coating insulating film 30, the moisture absorbent is incorporated into the resin material that becomes the coating insulating film 30. The moisture absorbent is preferably synthetic zeolite, and its content is preferably 1% by volume or more and 45% by volume or less based on the entire coating insulating film.

[0091] In a certain preferred embodiment, the coating insulating film 30 may be molded by applying pressure with a mold. By way of example only, the coating insulating film 30 that seals the solid battery laminate 100 on the support substrate 10 may be molded through a compression mold. If it is a resin material generally used in a mold, the form of the raw material of the coating insulating film may be granular, and its type may be thermoplastic. Note that such molding is not limited to mold molding, and may be performed through polishing, laser processing, and / or chemical treatment.

[0092] Next, a coated inorganic film 50 is formed. The coated inorganic film 50 may be, for example, a dry plating film as the coated inorganic film by performing dry plating. More specifically, dry plating is performed to form the coated inorganic film 50 on the exposed surfaces other than the bottom surface of the coating precursor (i.e., other than the bottom surface of the support substrate). In a preferred embodiment, sputtering is performed to form a sputtered film on the exposed outer surfaces other than the bottom surface of the coating precursor.

[0093] By going through the above steps, the solid-state battery package according to the present invention can be finally obtained. Note that the step of mixing the above-described moisture absorbent is preferably performed in a dry atmosphere in order to prevent moisture from being absorbed while the moisture absorbent is being mixed. Also, in the subsequent steps after the moisture-absorbing film is mixed, it is preferably performed in a dry atmosphere in order to prevent the moisture absorbent from absorbing moisture.

Examples

[0094] [First Example] A first example related to the present invention will be described. In the first example, in particular, a solid-state battery in which a moisture absorbent is mixed in an external terminal (Fig. 1(a)), a solid-state battery in which a moisture absorbent is mixed in a coated resin film (Fig. 4(a)), a solid-state battery in which a moisture absorbent is mixed in a support substrate (Fig. 5(a)), and an example of a solid-state battery in which a moisture absorbent is mixed in all of the external terminal, the coated resin film, and the support substrate.

[0095] Demonstration tests were conducted on the solid-state batteries of the following Examples 1-1 to 1-14 and Comparative Examples.

[0096] Example 1-1 · Solid-state battery: The solid-state battery shown in Fig. 1(a) - Type of moisture-absorbing material: Synthetic zeolite (Zeolum (registered trademark) A-5, Tosoh Corporation) - Volume fraction of the moisture-absorbing material: 1 wt% based on the entire external terminal

[0097] Example 1-2 · Solid-state battery: The solid-state battery shown in Fig. 1(a) - Hygroscopic material type: Synthetic zeolite - Volume fraction of hygroscopic material: 5 wt% based on the entire external terminal

[0098] Example 1-3 · Solid battery: The solid battery shown in Fig. 1(a) - Hygroscopic material type: Synthetic zeolite - Volume fraction of hygroscopic material: 20 wt% based on the entire external terminal

[0099] Example 1-4 · Solid battery: The solid battery shown in Fig. 1(a) - Hygroscopic material type: Silica gel (Toyota Chemical Industries Co., Ltd. Toyota Silica Gel A type) - Volume fraction of hygroscopic material: 5 wt% based on the entire external terminal

[0100] Example 1-5 · Solid battery: The solid battery shown in Fig. 4(a) - Hygroscopic material type: Synthetic zeolite - Volume fraction of hygroscopic material: 1 wt% based on the entire coating resin film

[0101] Example 1-6 · Solid battery: The solid battery shown in Fig. 4(a) - Hygroscopic material type: Synthetic zeolite - Volume fraction of hygroscopic material: 10 wt% based on the entire coating resin film

[0102] Example 1-7 · Solid battery: The solid battery shown in Fig. 4(a) - Hygroscopic material type: Synthetic zeolite - Volume fraction of hygroscopic material: 40 wt% based on the entire coating resin film

[0103] Example 1-8 · Solid battery: The solid battery shown in Fig. 4(a) - Hygroscopic material type: Silica gel - Volume fraction of the moisture-absorbing material: 10% by weight based on the entire coating resin film

[0104] Example 1-9 · Solid battery: The solid battery shown in Fig. 5(a) - Type of moisture-absorbing material: Synthetic zeolite - Volume fraction of the moisture-absorbing material: 1% by weight based on the entire support substrate

[0105] Example 1-10 · Solid battery: The solid battery shown in Fig. 5(a) - Type of moisture-absorbing material: Synthetic zeolite - Volume fraction of the moisture-absorbing material: 10% by weight based on the entire support substrate

[0106] Example 1-11 · Solid battery: The solid battery shown in Fig. 5(a) - Type of moisture-absorbing material: Synthetic zeolite - Volume fraction of the moisture-absorbing material: 40% by weight based on the entire support substrate

[0107] Example 1-12 · Solid battery: The solid battery shown in Fig. 5(a) - Type of moisture-absorbing material: Silica gel - Volume fraction of the moisture-absorbing material: 10% by weight based on the entire support substrate

[0108] Example 1-13 · Solid battery: A solid battery in which a moisture absorbent is mixed into all of the external terminals, the coating resin film, and the support substrate - Type of moisture-absorbing material: Synthetic zeolite - Volume fraction of the moisture-absorbing material: 5% by weight based on each component

[0109] Example 1-14 · Solid battery: A solid battery in which a moisture absorbent is mixed into all of the external terminals, the coating resin film, and the support substrate - Type of moisture-absorbing material: Silica gel - Volume fraction of the moisture-absorbing material: 5% by weight based on each component

[0110] Comparative Example · Solid battery: A solid battery without a conventionally known moisture absorbent mixed therein

[0111] As the content of the demonstration test, for the solid batteries of Examples 1-1 to 1-14 and the comparative example, a solid battery without the coating inorganic film 50 formed thereon was stored at 23°C for 1 week in an environment with a relative humidity of 20% (dew point of about 0°C), and the change rate of the discharge capacity after storage and the discharge capacity before storage was confirmed. In addition, for calculating the change in the discharge capacity, a method of confirming the change in the discharge capacity when discharging to 2.0V after charging to 4.2V with a charge-discharge device was adopted. Further, since the above demonstration test was conducted on a solid battery in a state where moisture is relatively likely to enter, it was performed on a solid battery without a coating inorganic film. The results of the demonstration test are shown in Table 1 below.

[0112]

Table 1

[0113] From the above results of the demonstration test, the volume fraction of the moisture absorbent mixed in the external terminal was such that the change rate of the discharge capacity was favorable compared to the comparative example when it was 1% by volume or more and 20% by volume or less based on the entire external terminal. In addition, the upper limit of the volume fraction may be 20% by volume or more as long as it does not affect the function of the external terminal (for example, conductivity, etc.).

[0114] Also, the volume fraction of the moisture absorbent mixed in the coating resin film was such that the change rate of the discharge capacity was favorable compared to the comparative example when it was 1% by volume or more and 40% by volume or less based on the entire coating resin film. In addition, the upper limit of the volume fraction may be 40% by volume or more as long as it does not affect the function of the coating resin film (for example, insulation or coating property, etc.).

[0115] In addition, when the volume fraction of the moisture absorbent mixed in the support substrate was 1% by volume or more and 40% by volume or less based on the entire support substrate, the rate of change of the discharge capacity was good as compared with the comparative example. Note that the upper limit of the volume fraction may be 40% by volume or more as long as it does not affect the functions of the support substrate (for example, durability or water resistance).

[0116] In addition, when a moisture absorbent was mixed in all of the external terminals, the coating resin film, and the support substrate, even when the volume fraction was about 5% based on each component, the rate of change of the discharge capacity was very good.

[0117] [Second Embodiment] A second embodiment related to the present invention will be described. In the second embodiment, in particular, examples of a solid battery in which a moisture absorbent is mixed in the non-active material portion (FIG. 2), a solid battery in which a moisture absorbent is mixed in the outermost insulating layer (FIG. 3(a)), and a solid battery in which a moisture absorbent is mixed in both the non-active material portion and the outermost insulating layer are given.

[0118] An experimental test was conducted on the solid batteries of Examples 2-1 to 2-13 and the comparative example below.

[0119] Example 2-1 · Solid battery: The solid battery shown in FIG. 2 - Type of moisture absorbent material: Synthetic zeolite - Volume fraction of the moisture absorbent material: 1% by weight based on the entire non-active material portion

[0120] Example 2-2 · Solid battery: The solid battery shown in FIG. 2 - Type of moisture absorbent material: Synthetic zeolite - Volume fraction of the moisture absorbent material: 40% by weight based on the entire non-active material portion

[0121] Example 2-3 · Solid battery: The solid battery shown in FIG. 2 - Type of moisture absorbent material: Synthetic zeolite - Volume fraction of the moisture absorbent material: 20% by weight based on the entire non-active material portion

[0122] Example 2-4 · Solid battery: The solid battery shown in Fig. 2 - Type of moisture-absorbing material: Synthetic zeolite - Volume fraction of moisture-absorbing material: 74% by weight based on the entire non-active material part

[0123] Example 2-5 · Solid battery: The solid battery shown in Fig. 2 - Type of moisture-absorbing material: Silica gel - Volume fraction of moisture-absorbing material: 40% by weight based on the entire non-active material part

[0124] Example 2-6 · Solid battery: The solid battery shown in Fig. 2 - Type of moisture-absorbing material: Synthetic zeolite - Volume fraction of moisture-absorbing material: 30% by weight based on the entire non-active material part

[0125] Example 2-7 · Solid battery: The solid battery shown in Fig. 3(a) - Type of moisture-absorbing material: Synthetic zeolite - Volume fraction of moisture-absorbing material: 1% by weight based on the entire outermost insulating layer

[0126] Example 2-8 · Solid battery: The solid battery shown in Fig. 3(a) - Type of moisture-absorbing material: Synthetic zeolite - Volume fraction of moisture-absorbing material: 40% by weight based on the entire outermost insulating layer

[0127] Example 2-9 · Solid battery: The solid battery shown in Fig. 3(a) - Type of moisture-absorbing material: Synthetic zeolite - Volume fraction of moisture-absorbing material: 20% by weight based on the entire outermost insulating layer

[0128] Example 2-10 · Solid battery: The solid battery shown in Fig. 3(a) - Hygroscopic material type: Synthetic zeolite - Volume fraction of the hygroscopic material: 74% by weight based on the entire outermost insulating layer

[0129] Example 2-11 · Solid battery: The solid battery shown in Fig. 3(a) - Hygroscopic material type: Synthetic zeolite - Volume fraction of the hygroscopic material: 40% by weight based on the entire outermost insulating layer

[0130] Example 2-12 · Solid battery: The solid battery shown in Fig. 3(a) - Hygroscopic material type: Synthetic zeolite - Volume fraction of the hygroscopic material: 30% by weight based on the entire outermost insulating layer

[0131] Example 2-13 · Solid battery: A solid battery with a hygroscopic agent mixed into both the non-active material part and the outermost insulating layer - Hygroscopic material type: Synthetic zeolite - Volume fraction of the hygroscopic material: 30% by weight based on each component

[0132] Comparative Example · Solid battery: A conventional solid battery without a mixed-in hygroscopic agent

[0133] The content of the demonstration test adopted the same method as the method described in the above-mentioned first embodiment. The demonstration test results are shown in Table 2 below.

[0134]

Table 2

[0135] From the above verification test results, the change rate of the discharge capacity was favorable compared to the comparative example when the volume fraction of the moisture absorbent incorporated into the non-active material part was 1% by volume or more and 74% by volume or less based on the entire non-active material part. In particular, the change rate of the discharge capacity was very favorable when the volume fraction of the moisture absorbent was 30% by volume (see Example 2-6). Note that the upper limit of the volume fraction may be 74% by volume or more as long as it does not affect the functions of the non-active material part (e.g., insulation or coating properties).

[0136] Also, the change rate of the discharge capacity was favorable compared to the comparative example when the volume fraction of the moisture absorbent incorporated into the outermost insulating layer was 1% by volume or more and 74% by volume or less based on the entire outermost insulating layer. In particular, the change rate of the discharge capacity was very favorable when the volume fraction of the moisture absorbent was 30% by volume (see Example 2-12). Note that the upper limit of the volume fraction may be 74% by volume or more as long as it does not affect the functions of the coating resin film (e.g., insulation or coating properties).

[0137] Regarding a solid battery in which synthetic zeolite was incorporated into both the non-active material part and the outermost insulating layer, the change rate of the discharge capacity of the solid battery with both content rates set at 30% by volume based on each constituent standard showed particularly favorable results (see Example 2-13).

[0138] Note that the embodiments disclosed this time are illustrative in all respects and are not a basis for a restrictive interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the claims. Also, the technical scope of the present invention includes all changes within the meaning and scope equivalent to the claims. For example, the solid battery may have a polyhedral shape, a cylindrical shape, or a spherical shape.

Industrial Applicability

[0139] The packaged solid battery of the present invention can be used in various fields where battery use or power storage is assumed. Although it is merely an example, the packaged solid battery of the present invention can be used in the field of electronics mounting. Further, in the electrical, information, and communication fields (for example, the field of electrical and electronic devices or mobile devices including small electronic devices such as mobile phones, smartphones, notebook computers, digital cameras, activity monitors, arm computers, electronic paper, RFID tags, card-type electronic money, smartwatches, etc.) where mobile devices are used, in household and small industrial applications (for example, the field of power tools, golf carts, household, care, and industrial robots), in large industrial applications (for example, the field of forklifts, elevators, quay cranes), in the transportation system field (for example, the field of hybrid vehicles, electric vehicles, buses, trains, electric assist bicycles, electric motorcycles, etc.), in power system applications (for example, the field of various power generation, load conditioners, smart grids, general household installed energy storage systems, etc.), and also in medical applications (the field of medical devices such as earphone hearing aids), pharmaceutical applications (the field of medication management systems), the IoT field, space and deep sea applications (for example, the field of space exploration machines, submersible research vessels, etc.), etc., the present invention can be utilized.

Explanation of Signs

[0140] 1 Solid battery 10 Support substrate 14 Via 16 Land 17 Wiring 30 Coating insulating film 50 Coating inorganic film 100 Solid battery laminate 110 Positive electrode layer 120 Negative electrode layer 130 Solid electrolyte 140 Laminated portion 150 External terminal 150A Positive electrode side external terminal 150B Negative electrode side external terminal 160 Insulating outermost layer 160A Top surface of the insulating outermost layer 160B Bottom surface of the insulating outermost layer 170 Inactive Substance Part

Claims

1. A surface-mounted solid-state battery packaged so as to be surface-mounted, comprising a solid-state battery laminate having a laminate portion in which a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer are laminated, A solid-state battery in which a moisture absorbent is mixed into at least one or more of the external terminals for the solid-state battery laminate, the inactive material portions in the laminate portion, the outermost insulating layer of the laminate portion, the coating insulating film covering the solid-state battery laminate, and the support substrate supporting the solid-state battery laminate, which are the basic components of the solid-state battery.

2. The solid-state battery according to claim 1, wherein the laminate portion further includes an inactive material portion forming a part of a side surface located in a direction intersecting the lamination direction, and the moisture absorbent is mixed into the inactive material portion.

3. The solid-state battery according to claim 1 or 2, wherein the solid-state battery laminate further includes an external terminal on a side surface of the laminate portion located in a direction intersecting the lamination direction, and the moisture absorbent is mixed into the external terminal.

4. Further including a support substrate provided so as to support the solid-state battery laminate, The solid-state battery according to any one of claims 1 to 3, wherein a support surface of the support substrate is parallel to a lamination direction of the solid-state battery laminate.

5. The solid-state battery according to any one of claims 1 to 4, wherein the support substrate includes wiring for electrically connecting the outermost surface of the substrate and serves as a terminal substrate for the external terminals of the solid-state battery.

6. The solid-state battery according to any one of claims 1 to 5, wherein the support substrate is composed of a wiring board having inner via holes.

7. An inactive material portion forming a part of a side surface of the laminate portion located in a direction intersecting the lamination direction, An external terminal provided on a side surface of the laminate portion located in a direction intersecting the lamination direction, The outermost insulating layer of the laminate portion, The coating insulating film covering the solid-state battery laminate, and, The solid-state battery according to any one of claims 1 to 6, wherein the moisture absorbent is mixed into any two or more or all of the support substrate provided so as to support the solid-state battery laminate.

8. The solid-state battery according to any one of claims 1 to 7, wherein the moisture absorbent includes at least one selected from the group consisting of synthetic zeolite, silica gel, phosphorus pentoxide, barium oxide, calcium oxide, and an organometallic structure.

9. Of the non-active material part forming the side surface of the solid battery laminate located in a direction intersecting the stacking direction and / or the outermost insulating layer of the stacked part, the content of at least one synthetic zeolite and / or silica gel is 1% by volume or more and 80% by volume or less based on the entire non-active material part and / or based on the entire outermost insulating layer. The solid battery according to claim 8.

10. The content is 20% by volume or more and 40% by volume or less based on the entire non-active material part and / or based on the entire outermost insulating layer. The solid battery according to claim 9.

11. The content of synthetic zeolite and / or silica gel in the external terminal provided on the side surface of the solid battery laminate located in a direction intersecting the stacking direction is 1% by volume or more and 25% by volume or less based on the entire external terminal. The solid battery according to claim 8.

12. The content of synthetic zeolite and / or silica gel in the coating insulating film covering the solid battery laminate and / or the support substrate provided so as to support the solid battery laminate is 1% by volume or more and 45% by volume or less based on the entire coating insulating film and / or based on the entire support substrate. The solid battery according to claim 8.

13. The solid battery according to any one of claims 1 to 12, wherein the solid battery laminate is composed of a sintered body.

14. The positive electrode layer and the negative electrode layer are layers capable of occluding and releasing lithium ions. The solid battery according to any one of claims 1 to 13.

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