Solid-state battery

Abstract

To provide solid-state battery technology for preventing intrusion of moisture into a solid-state battery.SOLUTION: A packaged solid-state battery comprising a solid-state battery laminate 100 which includes a lamination part 140 in which 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 are laminated. A hygroscopic material is added to components of the solid-state battery.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a solid-state battery packaged for substrate mounting. [Background technology]

[0002] Secondary batteries that can be repeatedly charged and discharged have been used for a variety of purposes, including as power sources for electronic devices such as smartphones and laptop computers.

[0003] In such secondary batteries, a liquid electrolyte is generally used as a medium for ion migration that contributes to charging and discharging. In other words, a so-called electrolytic solution is used in secondary batteries. However, such secondary batteries generally require safety in terms of preventing leakage of the electrolytic solution. In addition, organic solvents and the like used in the electrolytic solution are flammable, so safety is also required in this respect.

[0004] Therefore, research is being conducted on solid-state batteries that are constructed using solid electrolytes instead of liquid electrolytes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-243357 Summary of the Invention [Problem to be solved by the invention]

[0006] The inventors of the present invention have realized that there are problems to be overcome with conventional secondary batteries and have found the need to take measures to address these problems. Specifically, the inventors have found the following problems:

[0007] Solid-state batteries are expected to be mounted on a substrate such as a printed wiring board together with other electronic components, and in such cases, they require suitable mounting. On the other hand, it is necessary to take necessary measures against moisture in the air, as moisture entering the solid-state battery may cause deterioration of the battery characteristics.

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

[0009] However, the secondary battery disclosed in Patent Document 1 has a risk of moisture infiltrating through the gap between the moisture absorbent and the secondary battery, and it is difficult to say that the secondary battery is a solid-state battery in which moisture infiltration is sufficiently prevented.

[0010] The present invention has been made in view of the above-mentioned problems. That is, a main object of the present invention is to provide a technology for a solid-state battery that reduces the penetration of moisture into the solid-state battery while taking into consideration mounting on a substrate. [Means for solving the problem]

[0011] The inventors of the present application attempted to solve the above problems by taking a new approach rather than simply extending the conventional technology, and as a result, they have invented a solid-state battery that achieves the above-mentioned main object.

[0012] The solid-state battery of the present invention is a packaged solid-state battery including a solid-state battery stack having a stacked 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 stacked, A moisture absorbent material 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 penetration of moisture into the solid-state battery.

[0014] More specifically, in the packaged solid-state battery of the present invention, since the moisture absorbent material is mixed into the components of the solid-state battery, moisture can be absorbed within the solid-state battery without the need for a separate member for absorbing moisture, thereby making it possible to reduce the penetration of moisture into the solid-state battery.

[0015] Furthermore, since moisture absorbents are mixed into the components of the solid-state battery, the increase in volume of the solid-state battery stack can be suppressed, which allows for a smaller package without reducing the energy density per unit volume of the solid-state battery. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1(a) is a side cross-sectional view schematically showing a solid-state battery according to an embodiment of the present invention, and FIG. 1(b) is a side cross-sectional view schematically showing a solid-state battery according to another embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional side view schematically showing a solid state battery according to another embodiment of the present invention. [Figure 3] FIG. 3(a) is a side cross-sectional view schematically showing a solid state battery according to another embodiment of the present invention, and FIG. 3(b) is a side cross-sectional view schematically showing a solid state battery according to another embodiment of the present invention. [Figure 4] FIG. 4(a) is a side cross-sectional view schematically showing a solid state battery according to another embodiment of the present invention, and FIG. 4(b) is a side cross-sectional view schematically showing a solid state battery according to another embodiment of the present invention. [Figure 5] FIG. 5(a) is a side cross-sectional view schematically showing a solid state battery according to another embodiment of the present invention, and FIG. 5(b) is a side cross-sectional view schematically showing a solid state battery according to another embodiment of the present invention. [Figure 6A] FIG. 6A is a side cross-sectional view (a VIA-VIA cross-sectional view of FIG. 6B) that schematically shows the configuration of a solid state battery according to another embodiment of the present invention. [Figure 6B] FIG. 6B is a cross-sectional view taken along line VIB-VIB of FIG. 6A. [Figure 7] 7A to 7C are process cross-sectional views (side cross-sectional views) showing the manufacturing flow of a solid state battery according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The solid-state battery of the present invention will be described in detail below. Although the description will be made with reference to the drawings as necessary, the contents shown in the drawings are merely schematic and illustrative for understanding the present invention, and the appearance or dimensional ratio may differ from the actual product.

[0018] In the present invention, the term "packaged solid-state battery" broadly refers to a solid-state battery protected from the external environment, and in a narrower sense refers to a solid-state battery that is designed to prevent water vapor from the external environment from penetrating into the battery. The term "water vapor" here refers to moisture, such as atmospheric water vapor. In a preferred embodiment, it refers to moisture that encompasses not only gaseous water vapor but also liquid water. In particular, liquid water may include condensed water formed by condensation of gaseous water. Preferably, the solid-state battery of the present invention, which is protected from moisture permeation, is packaged to be suitable for substrate mounting, particularly for surface mounting. Therefore, in a preferred embodiment, the battery of the present invention is an SMD (Surface Mount Device) type battery. Note that "water vapor" as used herein may also be referred to as "moisture."

[0019] In the present invention, the term "solid-state battery" broadly refers to a battery whose components are made of solids, and in the narrow sense refers to an all-solid-state battery whose components (particularly preferably all components) are made of solids. In a preferred embodiment, the solid-state battery of the present invention is a laminated solid-state battery in which each layer constituting a battery unit is stacked on top of each other, and preferably each such layer is made of a sintered body. Note that the term "solid-state battery" encompasses not only so-called "secondary batteries" that can be repeatedly charged and discharged, but also "primary batteries" that can only be discharged. According to a preferred embodiment of the present invention, the "solid-state battery" is a secondary battery. The term "secondary battery" should not be overly limited to its name, and can also include, for example, an electricity storage device. Note that "sintering" in the present invention is sufficient as long as sintering is achieved at least partially.

[0020] The term "side cross section" as used herein refers to the shape when viewed from a direction approximately perpendicular to the thickness direction based on the stacking direction of each layer constituting the solid-state battery (in simple terms, the shape when cut along a plane parallel to the thickness direction). The terms "upper-lower direction" and "left-right direction" used directly or indirectly in this specification correspond to the upper-lower direction and left-right direction in the drawings, respectively. Unless otherwise specified, the same symbols or symbols indicate the same components or parts or have the same meaning. In a preferred embodiment, the vertical 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 herein, the "top surface" refers to a surface that is positioned relatively higher among the surfaces constituting the battery, and the "bottom surface" refers to a surface that is positioned relatively lower among the surfaces constituting the battery. Assuming a typical solid-state battery having two opposing main surfaces, the "top surface" refers to one of the main surfaces, and the "bottom surface" refers to the other of the main surfaces.

[0022] The basic structure of the solid-state battery of the present invention will be described below. The structure of the solid-state battery described here is merely an example for understanding the invention and is not intended to limit the invention.

[0023] [Basic structure of solid-state batteries] The solid-state battery 1 includes a solid-state battery stack 100 (FIG. 1(a)), which has a stack section 140 including battery structural units each consisting of a positive electrode layer 110, a negative electrode layer 120, and at least a solid electrolyte 130 interposed therebetween. The solid-state battery stack 100 is supported by a support substrate. The solid-state battery 1 may further include a coated insulating film 30 that coats the solid-state battery stack 100, and a coated inorganic film 50 that coats the coated insulating film 30.

[0024] The laminated section 140 is formed by firing each of its constituent layers, and the positive electrode layer, negative electrode layer, solid electrolyte, etc. may form a sintered layer. Preferably, the positive electrode layer, negative electrode layer, and solid electrolyte are each fired integrally with one another, and therefore the laminated section may form an integral sintered body. In this specification, the direction in which the positive electrode layers and negative electrode layers are stacked (vertical direction) is referred to as the "stacking direction," and the direction intersecting the stacking direction is the horizontal direction in which the positive electrode layers and negative electrode layers extend.

[0025] (Positive and negative electrode layers) The positive electrode layer 110 is an electrode layer comprising at least a positive electrode active material. The positive electrode layer may further comprise a solid electrolyte. In a preferred embodiment, the positive electrode layer is composed of a sintered body comprising at least positive electrode active material particles and solid electrolyte particles. On the other hand, the negative electrode layer 120 is an electrode layer comprising at least a negative electrode active material. The negative electrode layer may further comprise a solid electrolyte. In a preferred embodiment, the negative electrode layer is composed of a sintered body comprising at least negative electrode active material particles and solid electrolyte particles. FIG. 1(a) illustrates a configuration in which three positive electrode layers 110 and four negative electrode layers 120 are stacked, but the number of stacked layers is not limited to this example and may be several tens to several hundreds. The thickness of the positive electrode layer or the negative electrode layer may be 5 μm to 60 μm, preferably 8 μm to 50 μm. Alternatively, it may be 5 μm to 30 μm.

[0026] The positive electrode active material and the negative electrode active material are materials involved in the transfer of electrons in a solid-state battery. Charging and discharging are performed by transferring (conducting) ions between the positive electrode layer and the negative electrode layer via the solid electrolyte, and transferring electrons. The positive electrode layer and the negative electrode layer are preferably layers capable of absorbing and releasing lithium ions or sodium ions in particular. In other words, the solid-state battery is preferably an all-solid-state secondary battery in which charging and discharging are performed by transferring lithium ions or sodium ions between the positive electrode layer and the negative electrode layer via the solid electrolyte.

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

[0028] In addition, the positive electrode active material capable of absorbing and releasing sodium ions may be 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(PO2O7), and as a sodium-containing layered oxide, NaFeO2 may be used.

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

[0030] (Negative electrode active material) The negative electrode active material contained in the negative electrode layer may be, for example, at least one selected from the group consisting of 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. An example of a lithium alloy is Li-Al. An example of a lithium-containing phosphate compound having a Nasicon structure is Li3V2(PO4) 3、 Examples of lithium-containing phosphate compounds having an olivine structure include Li3Fe2(PO4)3 and LiCuPO4. Examples of lithium-containing oxides having a spinel structure include Li4Ti5O12 etc.

[0031] In addition, the negative electrode active material capable of absorbing and releasing sodium ions may be 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, which may include at least one of 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, such as 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, which constitutes a battery constituent unit in a solid-state battery, forms a layer capable of conducting lithium ions between the positive electrode layer 110 and the negative electrode layer 120. Specific examples of solid electrolytes include lithium-containing phosphate compounds having a Nasicon structure, oxides having a perovskite structure, oxides having a garnet or garnet-like structure, and oxide glass ceramic-based lithium ion conductors. Examples of lithium-containing phosphate compounds 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). An example of a lithium-containing phosphate compound having a Nasicon structure is, for example, Li 1.2 Al 0.2 Ti 1.8(PO4)3, etc. An example of an oxide with a perovskite structure is La 0.55 Li 0.35 Examples of oxides with garnet or garnet-like structures include Li7La3Zr2O 12 Examples of oxide glass ceramic lithium ion conductors that can be used include a phosphate compound containing lithium, aluminum, and titanium as constituent elements (LATP) and a phosphate compound containing lithium, aluminum, and germanium as constituent elements (LAGP).The solid electrolyte may also be, for example, a glass electrolyte.

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

[0036] (Positive electrode current collecting layer and negative electrode current collecting layer) The positive electrode layer 110 and the negative electrode layer 120 may each include a positive electrode current collecting layer and a negative electrode current collecting layer. The positive electrode current collecting layer and the negative electrode current collecting layer may each be in the form of a foil, but may also be in the form of a sintered body from the viewpoints of reducing the manufacturing cost of the solid-state battery by co-firing and reducing the internal resistance of the solid-state battery. When the positive electrode current collecting layer and the negative electrode current collecting layer are in the form of a sintered body, 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 collecting layer and the negative electrode current collecting layer may be selected, for example, from materials similar to the conductive materials that may be contained in the positive electrode layer and the negative electrode layer. The sintering aid contained in the positive electrode current collecting layer and the negative electrode current collecting layer may be selected, for example, from materials similar to the sintering aids that may be contained in the positive electrode layer and the negative electrode layer. Note that a positive electrode current collecting layer and a negative electrode current collecting layer are not necessarily required for a solid-state battery; a solid-state battery without such a positive electrode current collecting layer and a negative electrode current collecting layer is also conceivable. In other words, the solid-state battery of the present invention may be a current collecting layer-less solid-state battery.

[0037] (external terminal) A pair of external terminals 150 are provided on the side surfaces of the laminated section 140, which are positioned in a direction intersecting the stacking direction. For example, the external terminals may be provided from the side surfaces to the bottom surface of the laminated section 140. More specifically, a positive electrode external terminal 150A connected to the positive electrode layer 110 and a negative electrode external terminal 150B connected to the negative electrode layer 120 are provided. The positive electrode external terminal 150A may be formed on one side surface (the left side in the illustrated example), and the negative electrode external terminal 150B may be provided facing the positive electrode external terminal 150A (the right side in the illustrated example). Such a pair of external terminals 150 is preferably made of a material with high conductivity. Specific materials for the external terminals are not particularly limited, but may include at least one selected from the group consisting of silver, gold, platinum, aluminum, copper, tin, and nickel.

[0038] (Inactive substance part) An inactive material portion 170 may be provided between the positive electrode layer 110 and the negative electrode external terminal 150B and between the negative electrode layer 120 and the positive electrode external terminal 150A (see FIG. 1(b)). The inactive material portion 170 serves to insulate the positive electrode layer 110 from the negative electrode external terminal 150B and the negative electrode layer 120 from the positive electrode external terminal 150A. In other words, the inactive material portion preferably has at least electronic insulation properties. Materials commonly used as "inactive materials" in solid-state batteries may be used as the material for the inactive material portion, and may be composed of resin, glass, and / or ceramic materials. From the viewpoint of manufacturing by firing, the inactive material portion may be in the form of a sintered body. Examples of the ceramic material include at least one selected from the group consisting of soda-lime glass, potash glass, borate glass, borosilicate glass, barium borosilicate glass, bismuth zinc borate glass, bismuth silicate glass, phosphate glass, aluminophosphate glass, and zinc phosphate glass. The ceramic material may be at least one selected from the group consisting of aluminum oxide, boron nitride, silicon dioxide, silicon nitride, zirconium oxide, aluminum nitride, silicon carbide, and barium titanate, but is not limited thereto. The inactive material portion may also be referred to as a "blank portion" or a "negative portion" due to its shape.

[0039] (Outermost insulating layer) An insulating outermost layer 160 may be provided on the outermost surface of the laminated unit 140. The insulating outermost layer 160 is generally formed on the outermost surface of the laminated unit 140 to electrically, physically, and / or chemically protect the solid-state battery laminate. In particular, the insulating outermost layer 160 includes an insulating outermost layer 160A on the top surface side of the solid-state battery laminate 100 and an insulating outermost layer 160B on the bottom surface side. The material constituting the insulating outermost layer is preferably excellent in insulation properties, durability, and / or moisture resistance, and environmentally safe, and may include, for example, a resin material, a glass material, and / or a ceramic material. Furthermore, since the insulating outermost layer is manufactured by co-firing, it may be in the form of a sintered body, or may be composed of a sintered body (e.g., silicon oxide) containing the sintering aid that can be contained in the positive electrode layer and the negative electrode layer described above. Note that the insulating outermost layer 160 may not be provided, and the top and bottom surfaces of the solid-state battery laminate may serve as the laminated unit 140.

[0040] (covered insulation film) The solid-state battery may be provided with an insulating film 30 provided so as to cover at least the solid-state battery stack 100. As shown in FIG. 1 , the solid-state battery stack 100 provided on the support substrate 10 is largely enclosed as a whole by the insulating film 30.

[0041] The insulating coating film 30 preferably corresponds to a resin. In other words, the insulating coating film 30 preferably contains a resin material, which serves as a base material. As can be seen from the embodiment shown in FIG. 1 , this means that the solid state battery stack 100 provided on the support substrate 10 is sealed with the resin material of the insulating coating film 30. The insulating coating film 30 made of such a resin material, in combination with the inorganic coating film 50, effectively contributes to reducing the penetration of moisture.

[0042] The insulating coating material may be any material that exhibits insulating properties. For example, if the insulating coating material contains a resin, the resin may be either a thermosetting resin or a thermoplastic resin. Specific examples of the resin material for the insulating coating material include, but are not limited to, epoxy resins, silicone resins, and / or liquid crystal polymers. By way of example only, the thickness of the insulating coating material 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, the insulating coating film is not essential for the solid-state battery, and a solid-state battery that does not have the insulating coating film may also be considered.

[0044] (coated inorganic film) Furthermore, the solid-state battery may be provided with a coated inorganic film 50 that covers the coated insulating film 30. As shown in Fig. 1, the coated inorganic film is positioned on the coated insulating film, and therefore, together with the coated insulating film, has a form that largely envelops the solid-state battery stack on the support substrate as a whole.

[0045] The coated inorganic film preferably has a thin film form. The material of the coated inorganic film is not particularly limited as long as it contributes to the formation of an inorganic film having a thin film form, and may be metal, glass, oxide ceramics, or a mixture thereof. In a preferred embodiment, the coated inorganic film contains a metal component. That is, the coated inorganic film is preferably a metal thin film. By way of example only, the thickness of such a coated 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] Depending on the manufacturing method, the inorganic coating film 50 may be a dry-plated film. Such a dry-plated film is obtained by a vapor-phase method such as physical vapor deposition (PVD) or chemical vapor deposition (CVD), and has an extremely small thickness on the order of nanometers or microns. Such a thin dry-plated film contributes to more compact packaging.

[0047] The dry-plated film may be composed of, for example, at least one metal component or semimetal component selected from the group consisting of aluminum (Al), nickel (Ni), palladium (Pd), silver (Ag), tin (Sn), gold (Au), copper (Cu), titanium (Ti), platinum (Pt), silicon (Si), and stainless steel, an inorganic oxide, and / or a glass component. Dry-plated films composed of such components are chemically and / or thermally stable, and therefore may result in solid-state batteries with excellent chemical resistance, weather resistance, and / or heat resistance, and improved long-term reliability.

[0048] In addition, a coating inorganic film is not necessarily required for a solid-state battery, and a solid-state battery that does not have a coating insulating film may also be considered.

[0049] (support substrate) The support substrate 10 is a substrate provided to support the solid state battery stack 100. The support substrate is positioned on one side of the main surface of the solid state battery to provide support. As a "substrate," the support substrate preferably has a thin plate-like shape as a whole.

[0050] The support substrate 10 may be, for example, a resin substrate or a ceramic substrate, with a water-resistant substrate being preferred. In a preferred embodiment, the support substrate 10 is a ceramic substrate. That is, the support substrate 10 comprises ceramic, which constitutes the base material of the substrate. A ceramic support substrate contributes to preventing water vapor transmission and is also preferred in terms of heat resistance during 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 (Low Temperature Co-fired Ceramics) or an HTCC substrate (High Temperature Co-fired Ceramics). By way of example only, 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] The support substrate 10 also functions as a terminal substrate for the solid-state battery stack 100. That is, a solid-state battery packaged with a substrate interposed therebetween can be mounted on another secondary substrate such as a printed wiring board. For example, the solid-state battery can be surface-mounted via the support substrate through solder reflow or the like. For this reason, the packaged solid-state battery can be considered an SMD-type battery. In particular, when the terminal substrate is made of a ceramic substrate, the solid-state battery has high heat resistance and can be an SMD-type battery that can be solder-mounted.

[0052] Since it is a terminal substrate, it preferably has wiring, and in particular, it preferably has wiring 17 (see FIG. 1) that electrically connects the upper and lower surfaces or the upper and lower surface layers. In other words, a preferred embodiment of the support substrate has wiring that electrically connects the upper and lower surfaces of the substrate, and serves as a terminal substrate for the external terminals of a packaged solid-state battery.

[0053] The wiring 17 in the terminal substrate is not particularly limited and may have any form as long as it contributes to electrical connection between the upper and lower surfaces of the substrate. Because it contributes to electrical connection, the wiring 17 in the terminal substrate can also be considered a conductive portion of the substrate. Such a conductive portion of the substrate may have the form of 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 in the support substrate 10. The term "via" here refers to a member for electrically connecting the support substrate in the vertical direction, i.e., the thickness direction of the substrate. For example, a filled via is preferred, and it may also take the form of an inner via. Furthermore, the term "land" in this specification refers to a terminal portion / connection portion for electrical connection (preferably a terminal portion / connection portion connected to a via) provided on the upper and / or lower main surface of the support substrate. For example, it may be a square land or a round land.

[0054] [Features of the solid-state battery of the present invention] In the solid-state battery of the present invention, a moisture-absorbing material is mixed into the components of the packaged solid-state battery. Here, "a moisture-absorbing material mixed into the components of the solid-state battery" means that the moisture-absorbing material is contained in the components constituting the solid-state battery and is mixed into the components. In other words, the moisture-absorbing material is mixed into at least one or more of the basic components of the above-described solid-state battery, namely, the external terminal 150, the inactive material portion 170, the outermost insulating layer 160, the insulating coating film 30, and the support substrate 10. This differs from previously known secondary batteries that have a separate moisture-absorbing material or that have a moisture-absorbing material added to a housing provided outside the battery components. The moisture-absorbing material can be mixed uniformly into the components or unevenly into the components.

[0055] The moisture absorbent to be mixed in 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 metal-organic frameworks. In particular, a moisture-absorbing film containing synthetic zeolite is preferable because it has good temperature resistance and does not deliquesce, even when the synthetic zeolite reaches high temperatures due to heat generation caused by the operation of the solid-state battery, and also has a good adsorption rate per unit weight. The moisture absorbent to be mixed in may be a combination of two or more moisture absorbents. The moisture absorbent may be in powder form or may be agglomerated into a solid.

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

[0057] <An embodiment in which moisture absorbent material is mixed into the external terminal> In one embodiment of the present invention, a moisture-absorbing material is mixed into the external terminal 150 (see FIG. 1(a)). Specifically, the moisture-absorbing material is mixed into the metal paste that constitutes the external terminal. In the illustration, the moisture-absorbing material is mixed into the hatched member (external terminal 150). As described above, the moisture-absorbing material is preferably synthetic zeolite. The moisture-absorbing material content is preferably set to a level that does not impair the functionality (e.g., conductivity) of the external terminal. As will be described in detail in the examples below, a content of 1% to 25% by volume of the entire external terminal is preferred. As another embodiment of the solid-state battery shown in FIG. 1(a), an inactive material portion 170 may be provided, as shown in FIG. 1(b). In another embodiment, although not shown, the insulating outermost layer 160 may not be provided, and the top and bottom surfaces of the solid-state battery stack may serve as stack portions 140.

[0058] In conventional solid-state battery stacks, electrode materials such as external terminals are exposed on the side surfaces intersecting the stacking direction, which can lead to moisture intrusion from the external terminals or their vicinity, causing degradation of the solid-state battery. Therefore, in an embodiment of the present invention, a moisture-absorbing material is mixed into the external terminals. According to this embodiment, the moisture-absorbing material mixed into the external terminals absorbs moisture, thereby reducing moisture intrusion into the solid-state battery stack.

[0059] Furthermore, in this embodiment, since the moisture-absorbing material is mixed into the external terminals themselves, the increase in volume can be suppressed compared to when a moisture-absorbing material is provided separately from the external terminals, which prevents a decrease in the energy density per volume of the solid-state battery and allows for a more compact package.

[0060] <Embodiment in which moisture-absorbing material is mixed into the inactive material portion 170> In another embodiment of the present invention, a moisture-absorbing material may be mixed into the inactive material portion 170 (see FIG. 2). Specifically, the moisture-absorbing material is mixed into the insulating sintered body that constitutes the inactive material portion 170. In the illustration, the moisture-absorbing material is mixed into the hatched portion (the inactive material portion 170). As described above, the moisture-absorbing material is preferably synthetic zeolite. The moisture-absorbing material content is preferably set to a level that does not impair the functionality of the inactive material portion (e.g., insulating properties or coating properties). As will be described in detail in the examples below, a content of 1% by volume or more and 80% by volume or less of the entire inactive material portion is preferred. In another embodiment, not shown, the insulating outermost layer 160 may not be provided, and the top and bottom surfaces of the solid-state battery stack may serve as the stack portion 140.

[0061] In this embodiment, by incorporating a moisture absorbent material into the inactive material portion of the laminate, the moisture absorbent material can absorb moisture that penetrates closer to the solid-state battery laminate, thereby more effectively suppressing moisture penetration into the solid-state battery.

[0062] <Embodiment in which moisture-absorbing material is mixed into the outermost insulating layer 160> In another embodiment of the present invention, a moisture-absorbing material may be mixed into the outermost insulating layer 160 (see FIGS. 3(a) and 3(b)). Specifically, the moisture-absorbing material is mixed into the resin or sintered material that constitutes the outermost insulating layer 160. In the illustration, the moisture-absorbing material is mixed into the hatched member (the outermost insulating layer 160). As described above, the moisture-absorbing material is preferably synthetic zeolite. The content of the moisture-absorbing material is preferably set to a level that does not impair the functionality of the outermost insulating layer (e.g., insulation or coating properties). As will be described in detail in the examples below, a content of 1% by volume or more and 80% by volume or less of the entire outermost insulating layer is preferred. In another embodiment of the solid-state battery shown in FIG. 3(a), an inactive material portion 170 may be provided, as shown in FIG. 3(b).

[0063] In this embodiment, by mixing a moisture absorbent material into the outermost insulating layers on the upper and lower surfaces of the laminated portion, it is possible to reduce unexpected moisture penetration from the lamination direction (vertical direction).

[0064] <Embodiment in which moisture absorbent material is mixed into insulating coating film 30> In another embodiment of the present invention, a moisture-absorbing material may be mixed into the insulating coating film 30 (FIGS. 4(a) and 4(b)). Specifically, the moisture-absorbing material is mixed into the resin material constituting the insulating coating film. In the drawings, the moisture-absorbing material is mixed into the hatched member (the insulating coating film 30). As described above, synthetic zeolite is preferably used as the moisture-absorbing material. The moisture-absorbing material content is preferably set to a level that does not impair the functionality (e.g., insulating properties or coating properties) of the insulating coating film 30. As will be described in detail in the examples below, a content of 1% by volume or more and 45% by volume or less of the entire insulating coating film is preferred. As another embodiment of the solid-state battery shown in FIG. 4(a), an inactive material portion 170 may be provided, as shown in FIG. 4(b). In another embodiment, although not shown, the insulating outermost layer 160 may not be provided, and the top and bottom surfaces of the solid-state battery stack may be stacked as stacked portions 140.

[0065] In this embodiment, the covering insulating film containing the moisture absorbent material is provided so as to cover the solid state battery stack, and therefore can absorb moisture that enters the solid state battery from substantially all directions.

[0066] <Embodiment in which moisture-absorbing material is mixed into support substrate 10> In another embodiment of the present invention, a moisture-absorbing material may be mixed into the support substrate 10. Specifically, the moisture-absorbing material is mixed into the base material constituting the support substrate. In FIGS. 5(a) and 5(b), the hatched member (support substrate 10) indicates a structure in which the moisture-absorbing material is mixed. As described above, the moisture-absorbing material is preferably synthetic zeolite. The moisture-absorbing material content is preferably set to a level that does not impair the functionality of the support substrate (e.g., durability, water resistance, etc.). As will be described in detail in the examples below, a content of 1% to 45% by volume of the entire support substrate is preferred. As another embodiment of the solid-state battery shown in FIG. 5(a), an inactive material portion 170 may be provided, as shown in FIG. 5(b). In another embodiment, although not shown, the insulating outermost layer 160 may not be provided, and the top and bottom surfaces of the solid-state battery stack may be stacked portions 140.

[0067] In this embodiment, by incorporating a moisture absorbent material into the support substrate that supports the solid state battery stack, it is possible to prevent moisture from entering the solid state batteries.

[0068] The reference time for the content of the moisture absorbent as described above for the entire external terminals, the entire inactive material portion, the entire outermost insulating layer, the entire insulating coating layer, and the entire supporting substrate may be the time when the solid-state battery is completed.

[0069] <Other embodiment 1> Another embodiment will be described with reference to FIGS. 6A and 6B. Another embodiment will be described with reference to FIGS. 6A and 6B. FIG. 6A is a side cross-sectional view (VIA-VIA cross-sectional view in FIG. 6B) showing a schematic configuration of a solid-state battery according to another embodiment of the present invention, and FIG. 6B is a VIB-VIB cross-sectional view in FIG. 6A. As in this embodiment, the solid-state battery stack may be supported by a support substrate so that the stacking direction of the stacked portion 140 is parallel to the support surface of the support substrate 10 (see FIG. 6B). The component containing the moisture absorbent may be one or more of the external terminal, the inactive material portion, the outermost insulating layer, the insulating coating film, and the support substrate. Even in this embodiment, moisture is absorbed by the components containing the moisture absorbent, thereby reducing moisture penetration into the solid-state battery. Furthermore, according to this embodiment, even if expansion occurs in the stacking direction due to charging / discharging or the like, deformation of the support substrate associated with the expansion can be reduced. Note that, in this specification, "parallel" does not necessarily mean a completely parallel state, but also includes a substantially parallel state.

[0070] <Other embodiment 2> In the above-described embodiment, an embodiment has been described in which a moisture-absorbing material that absorbs moisture is mixed into one of the components of the external terminal, the inactive material portion, the outermost insulating layer, the covering insulating film, and the support substrate, but this example is not limiting, and a moisture-absorbing material may be mixed into multiple components (two or more or all). Specific embodiments include a mode in which a moisture absorbent material is mixed into the external terminal and the inactive material portion, a mode in which a moisture absorbent material is mixed into the external terminal and the outermost insulating layer, a mode in which a moisture absorbent material is mixed into the external terminal and the covering insulating film, a mode in which a moisture absorbent material is mixed into the external terminal and the supporting substrate, a mode in which a moisture absorbent material is mixed into the inactive material portion and the outermost insulating layer, a mode in which a moisture absorbent material is mixed into the inactive material portion and the covering insulating film, a mode in which a moisture absorbent material is mixed into the inactive material portion and the supporting substrate, a mode in which a moisture absorbent material is mixed into the outermost insulating layer and the covering insulating film, a mode in which a moisture absorbent material is mixed into the outermost insulating layer and the supporting substrate, a mode in which a moisture absorbent material is mixed into the covering insulating film and supporting substrate, a mode in which a moisture absorbent material is mixed into the external terminal, the inactive material portion and the outermost insulating layer, a mode in which a moisture absorbent material is mixed into the external terminal, the inactive material portion and the covering insulating film, a mode in which a moisture absorbent material is mixed into the external terminal, the inactive material portion and the supporting substrate, a mode in which a moisture absorbent material is mixed into the external terminal, the inactive material portion and the covering insulating film, a mode in which a moisture absorbent material is mixed into the external terminal, the inactive material portion and the supporting substrate, A mode in which a moisture absorbent material is mixed into the film, a mode in which a moisture absorbent material is mixed into the external terminal, the outermost insulating layer and the supporting substrate, a mode in which a moisture absorbent material is mixed into the external terminal, the covering insulating film and the supporting substrate, a mode in which a moisture absorbent material is mixed into the inactive material part, the outermost insulating layer and the covering insulating film, a mode in which a moisture absorbent material is mixed into the inactive material part, the outermost insulating layer and the supporting substrate, a mode in which a moisture absorbent material is mixed into the inactive material part, the covering insulating film and the supporting substrate, a mode in which a moisture absorbent material is mixed into the outermost insulating layer, the covering insulating film and the supporting substrate Examples of embodiments include a mode in which a moisture-absorbing material is mixed into the external terminal, inactive material portion, outermost insulating layer, and coated insulating film; a mode in which a moisture-absorbing material is mixed into the external terminal, inactive material portion, outermost insulating layer, and supporting substrate; a mode in which a moisture-absorbing material is mixed into the external terminal, inactive material portion, coated insulating film, and supporting substrate; a mode in which a moisture-absorbing material is mixed into the external terminal, coated insulating film, outermost insulating layer, and supporting substrate; a mode in which a moisture-absorbing material is mixed into the inactive material portion, coated insulating film, outermost insulating layer, and supporting substrate.

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

[0072] As shown in Fig. 7, the solid state battery of the present invention is manufactured through processes including manufacturing a laminated portion 140 (Fig. 7(a)), forming an external terminal 150 (Fig. 7(b)), fixing to a support substrate 10 (Fig. 7(c)), and forming a coated insulating film 30 and a coated inorganic film 50 (Fig. 7(d)). The steps are explained below in order.

[0073] <Laminated part manufacturing> The laminated portion 140 can be manufactured by a printing method such as screen printing, a green sheet method using a green sheet, or a combination of these. In other words, the laminated portion itself may be manufactured in accordance with a conventional method for manufacturing solid-state batteries (therefore, raw materials such as the solid electrolyte, organic binder, solvent, optional additives, positive electrode active material, and negative electrode active material described below may be those used in the manufacture of known solid-state batteries).

[0074] In the following, one production method will be described as an example for better understanding of the present invention, but the present invention is not limited to this method. Furthermore, the chronological order of the following description is merely for the convenience of explanation and is not necessarily binding.

[0075] First, a solid electrolyte, an organic binder, a solvent, and optional additives are mixed to prepare a slurry. The prepared slurry is then formed into a sheet with a thickness of approximately 10 μm after firing. Next, a positive electrode paste is prepared by mixing a positive electrode active material, a solid electrolyte, a conductive material, an organic binder, a solvent, and optional additives. Similarly, a negative electrode paste is prepared by mixing a negative electrode active material, a solid electrolyte, a conductive material, an organic binder, a solvent, and optional additives. The positive electrode paste is then printed onto the sheet, and a current collecting layer and / or inactive material portion are printed as needed.

[0076] When manufacturing a solid-state battery in which a moisture absorbent is mixed into the inactive material portion 170, the moisture absorbent is mixed into the paste of the inactive material portion. 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 total volume of the inactive material portion.

[0077] In the same manner, the negative electrode paste is printed on the sheet, and if necessary, the current collecting layer and / or the inactive material portion is printed. When manufacturing a solid-state battery in which a moisture absorbent material is mixed into the inactive material portion 170, the moisture absorbent material is mixed into the paste for the inactive material portion.

[0078] Then, sheets printed with the positive electrode paste and sheets printed with the negative electrode paste are alternately stacked to obtain a laminate. An electrolyte layer or an insulating outermost layer is provided on the top and / or bottom layers of the laminate to protect the solid-state battery.

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

[0080] After the laminate is pressure-bonded and integrated, it is cut to a predetermined size. The resulting cut laminate is then degreased and fired. This results in a sintered laminate (laminate part 140). Note that the laminate may be degreased and fired before cutting, and then cut.

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

[0082] When manufacturing a solid-state battery in which a moisture absorbent material is mixed into the external terminal 150, the desired moisture absorbent material is mixed into the conductive paste that will become the external terminal 150. The moisture absorbent 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 that the positive and negative external terminals 150 are provided so as to extend to the underside of the sintered laminate, since this allows them to be connected to the mounting lands in a small area in the next process (more specifically, the external terminals provided so as to extend to the underside of the sintered laminate have folded portions on the underside, and such folded portions can be electrically connected to the mounting lands). The component of the external terminals may be at least one selected from silver, gold, platinum, aluminum, copper, tin, and nickel.

[0084] The positive and negative external terminals may not necessarily be formed after the sintering of the laminate, but may be formed before firing and then sintered simultaneously.

[0085] <Fixing to a supporting substrate> The support substrate 10 has vias and / or lands to enable surface mounting to a secondary substrate. For example, it can be obtained by stacking and firing multiple green sheets. This is particularly true when the support substrate is a ceramic substrate. The support substrate can be prepared, for example, in a manner similar to that used for preparing an LTCC substrate.

[0086] When manufacturing a solid state battery in which a moisture absorbent material is mixed into the support substrate 10, the moisture absorbent material is mixed into the base material that will become the support substrate. The moisture absorbent 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 by, for example, forming holes (diameter size: approximately 50 μm or more and 200 μm or less) using a punch press or a carbon dioxide laser, and filling the holes with a conductive paste material, or by using a printing method.

[0088] After manufacturing the support substrate 10, the solid state battery laminate 100 is placed on the support substrate 10 so that the conductive portion of the support substrate 10 and the external terminal 150 of the solid state battery laminate 100 are electrically connected to each other. Then, a conductive paste may be provided on the support substrate 10, thereby electrically connecting the conductive portion of the support substrate 10 and the external terminal 150 of the solid state battery laminate 100 to each other. As the conductive paste, in addition to Ag conductive paste, a nanopaste, an alloy-based paste, a brazing material, or other conductive paste that does not require washing with flux or the like after formation can be used.

[0089] <Formation of insulating and inorganic coating films> Next, the coated insulating film 30 is formed so as to cover the solid state battery stack 100 on the support substrate 10. Therefore, the raw material of the coated insulating film 30 is provided so as to cover the entire solid state battery stack 100 on the support substrate 10. When the coated insulating film 30 is made of a resin material, a resin precursor is provided on the support substrate 10 and cured to form the coated insulating film 30.

[0090] When manufacturing a solid state battery in which a moisture absorbent is mixed into the insulating film 30, the moisture absorbent is mixed into the resin material that will become the 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 total volume of the insulating film.

[0091] In a preferred embodiment, the insulating film 30 may be molded by applying pressure with a mold. By way of example only, the insulating film 30 that seals the solid state battery stack 100 on the support substrate 10 may be molded using a compression mold. If the insulating film is made of a resin material that is generally used in molding, the raw material may be in the form of granules, and may be thermoplastic. Note that this molding is not limited to mold molding, and may also be performed by polishing, laser processing, and / or chemical treatment.

[0092] Next, the coated inorganic film 50 is formed. The coated inorganic film 50 may be formed by, for example, dry plating to form a dry-plated film. More specifically, dry plating is performed to form the coated inorganic film 50 on the exposed surfaces other than the bottom surface of the coated 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 coated precursor.

[0093] By going through the above steps, the solid-state battery package according to the present invention can finally be obtained. Note that the step of mixing the moisture absorbent material is preferably carried out in a dry atmosphere to prevent the moisture absorbent material from absorbing moisture while being mixed in. Furthermore, the step after mixing the moisture absorption film is also preferably carried out in a dry atmosphere to prevent the moisture absorbent material from absorbing moisture. [Example]

[0094] [First Example] A first embodiment related to the present invention will be described. The first embodiment is particularly directed to a solid-state battery in which a moisture absorbent is mixed into the external terminals (FIG. 1(a)), a solid-state battery in which a moisture absorbent is mixed into the coating resin film (FIG. 4(a)), a solid-state battery in which a moisture absorbent is mixed into the support substrate (FIG. 5(a)), and a solid-state battery in which a moisture absorbent is mixed into all of the external terminals, the coating resin film, and the support substrate.

[0095] Demonstration tests were carried out on the solid state batteries of Examples 1-1 to 1-14 and Comparative Example below.

[0096] Example 1-1 Solid-state battery: The solid-state battery shown in Figure 1(a) - Moisture absorption material type: Synthetic zeolite (Tosoh Corporation Zeoram (registered trademark) A-5) -Volume fraction of moisture absorbing material: 1% by weight based on the entire external terminal

[0097] Example 1-2 Solid-state battery: The solid-state battery shown in Figure 1(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 5% by weight based on the entire external terminal

[0098] Examples 1-3 Solid-state battery: The solid-state battery shown in Figure 1(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 20% by weight based on the entire external terminal

[0099] Examples 1-4 Solid-state battery: The solid-state battery shown in Figure 1(a) - Moisture absorption material type: Silica gel (Toyota Chemical Industry Corporation, Toyota Silica Gel Type A) -Volume fraction of moisture-absorbing material: 5% by weight based on the entire external terminal

[0100] Examples 1-5 Solid-state battery: The solid-state battery shown in Figure 4(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 1% by weight based on the entire coating resin film

[0101] Examples 1-6 Solid-state battery: The solid-state battery shown in Figure 4(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 10% by weight based on the entire coating resin film

[0102] Examples 1-7 Solid-state battery: The solid-state battery shown in Figure 4(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 40% by weight based on the entire coating resin film

[0103] Examples 1-8 Solid-state battery: The solid-state battery shown in Figure 4(a) - Moisture absorption material type: Silica gel -Volume fraction of moisture-absorbing material: 10% by weight based on the entire coating resin film

[0104] Examples 1-9 Solid-state battery: The solid-state battery shown in Figure 5(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 1% by weight based on the entire support substrate

[0105] Examples 1-10 Solid-state battery: The solid-state battery shown in Figure 5(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 10% by weight based on the entire support substrate

[0106] Examples 1-11 Solid-state battery: The solid-state battery shown in Figure 5(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 40% by weight based on the entire support substrate

[0107] Examples 1-12 Solid-state battery: The solid-state battery shown in Figure 5(a) - Moisture absorption material type: Silica gel -Volume fraction of moisture-absorbing material: 10% by weight based on the entire support substrate

[0108] Examples 1-13 Solid-state battery: A solid-state battery in which moisture absorbents are mixed into the external terminals, resin coating, and support substrate. - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 5% by weight based on each component

[0109] Examples 1-14 Solid-state battery: A solid-state battery in which moisture absorbents are mixed into the external terminals, resin coating, and support substrate. - Moisture absorption material type: Silica gel -Volume fraction of moisture-absorbing material: 5% by weight based on each component

[0110] Comparative Example Solid-state battery: A solid-state battery that does not contain conventional moisture absorbents.

[0111] In the demonstration test, the solid state batteries of Examples 1-1 to 1-14 and the comparative example, which did not have coated inorganic film 50 formed thereon, were stored for one week in an environment of 23°C and 20% relative humidity (dew point approximately 0°C), and the rate of change between the change in discharge capacity after storage and the change in discharge capacity before storage was confirmed. The change in discharge capacity was calculated by checking the change in discharge capacity when the battery was charged to 4.2V using a charge / discharge device and then discharged to 2.0V. The demonstration test was conducted on solid state batteries without a coated inorganic film, since the test was conducted under conditions where moisture was relatively likely to enter the solid state battery. The demonstration test results are shown in Table 1 below.

[0112] [Table 1]

[0113] The results of the above demonstration test showed that the rate of change in discharge capacity was better than that of the comparative example when the volume fraction of the moisture absorbent material mixed into the external terminal was between 1% and 20% by volume based on the entire external terminal. Note that the upper limit of the volume fraction may be set to 20% or more by volume as long as it does not affect the functionality (e.g., conductivity) of the external terminal.

[0114] Furthermore, when the volume fraction of the moisture absorbent material mixed into the coating resin film was between 1% and 40% by volume of the entire coating resin film, the rate of change in discharge capacity was better than in the comparative examples. The upper limit of the volume fraction may be set to 40% or more by volume as long as it does not affect the functionality of the coating resin film (e.g., insulation or covering properties).

[0115] Furthermore, when the volume fraction of the moisture absorbent material mixed into the support substrate was between 1% and 40% by volume of the entire support substrate, the rate of change in discharge capacity was better than in the comparative example. The upper limit of the volume fraction may be set to 40% or more by volume as long as it does not affect the functionality of the support substrate (e.g., durability or water resistance).

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

[0117] [Second Example] A second embodiment related to the present invention will be described below. The second embodiment is particularly directed to a solid-state battery in which a moisture absorbent is mixed in the inactive material portion (FIG. 2), a solid-state battery in which a moisture absorbent is mixed in the outermost insulating layer (FIG. 3(a)), and a solid-state battery in which a moisture absorbent is mixed in both the inactive material portion and the outermost insulating layer.

[0118] Demonstration tests were carried out on the solid state batteries of Examples 2-1 to 2-13 and Comparative Example below.

[0119] Example 2-1 Solid-state battery: A solid-state battery as shown in Figure 2 - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 1% by weight based on the total amount of inactive materials

[0120] Example 2-2 Solid-state battery: A solid-state battery as shown in Figure 2 - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 40% by weight based on the total inactive material

[0121] Example 2-3 Solid-state battery: A solid-state battery as shown in Figure 2 - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 20% by weight based on the total inactive material

[0122] Examples 2-4 Solid-state battery: A solid-state battery as shown in Figure 2 - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 74% by weight based on the total inactive material

[0123] Examples 2-5 Solid-state battery: A solid-state battery as shown in Figure 2 - Moisture absorption material type: Silica gel -Volume fraction of moisture-absorbing material: 40% by weight based on the total inactive material

[0124] Examples 2-6 Solid-state battery: A solid-state battery as shown in Figure 2 - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 30% by weight based on the total inactive material

[0125] Examples 2-7 Solid-state battery: The solid-state battery shown in Figure 3(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 1% by weight based on the entire outermost insulating layer

[0126] Examples 2-8 Solid-state battery: The solid-state battery shown in Figure 3(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 40% by weight based on the entire outermost insulating layer

[0127] Examples 2-9 Solid-state battery: The solid-state battery shown in Figure 3(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 20% by weight based on the entire outermost insulating layer

[0128] Example 2-10 Solid-state battery: The solid-state battery shown in Figure 3(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 74% by weight based on the entire outermost insulating layer

[0129] Example 2-11 Solid-state battery: The solid-state battery shown in Figure 3(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 40% by weight based on the entire outermost insulating layer

[0130] Example 2-12 Solid-state battery: The solid-state battery shown in Figure 3(a) - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 30% by weight based on the entire outermost insulating layer

[0131] Example 2-13 Solid-state battery: A solid-state battery in which moisture absorbents are mixed into both the inactive material and the outermost insulating layer. - Moisture absorption material type: Synthetic zeolite -Volume fraction of moisture-absorbing material: 30% by weight based on each component

[0132] Comparative Example Solid-state battery: A solid-state battery that does not contain conventional moisture absorbents.

[0133] The verification test was carried out in the same manner as in the first embodiment. The results of the verification test are shown in Table 2 below.

[0134] [Table 2]

[0135] The above demonstration test results showed that the rate of change in discharge capacity was better than that of the comparative example when the volume fraction of the moisture absorbent mixed into the inactive material portion was 1% by volume or more and 74% by volume or less based on the total volume of the inactive material portion. In particular, the rate of change in discharge capacity was very good 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 function of the inactive material portion (e.g., insulation or coating properties).

[0136] Furthermore, when the volume fraction of the moisture absorbent mixed into the outermost insulating layer was 1% by volume or more and 74% by volume or less based on the entire outermost insulating layer, the rate of change in discharge capacity was better than in the comparative examples. In particular, the rate of change in discharge capacity was very good 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 functionality of the coating resin film (e.g., insulating properties or coating properties, etc.).

[0137] Furthermore, for solid-state batteries in which synthetic zeolite was mixed into both the inactive material portion and the outermost insulating layer, the rate of change in discharge capacity of the solid-state battery in which the content of both was 30% by volume as the standard for each constituent showed particularly good results (see Example 2-13).

[0138] It should be noted that the embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention should not be interpreted solely by the above-described embodiments, but should be defined by the claims. The technical scope of the present invention also includes all modifications within the meaning and scope of the claims. For example, the solid-state battery may have a polyhedral, cylindrical, or spherical shape. [Industrial Applicability]

[0139] The packaged solid-state battery of the present invention can be used in various fields where battery use or power storage is envisioned. By way of example only, the packaged solid-state battery of the present invention can be used in electronics packaging. The present invention can also be used in the electrical, information, and communications fields where mobile devices and the like are used (for example, electrical and electronic equipment fields including small electronic devices such as mobile phones, smartphones, laptop computers, digital cameras, activity monitors, arm computers, electronic paper, RFID tags, card-type electronic money, and smart watches, or mobile device fields), home and small industrial applications (for example, power tools, golf carts, and home, nursing care, and industrial robots), large industrial applications (for example, forklifts, elevators, and port cranes), transportation systems (for example, hybrid cars, electric cars, buses, trains, electrically assisted bicycles, and electric motorcycles), power system applications (for example, various types of power generation, road conditioners, smart grids, and general home-installed power storage systems), medical applications (for medical devices such as earphone hearing aids), pharmaceutical applications (for example, medication management systems), IoT, and space and deep-sea applications (for example, space probes and submersible research vessels). [Explanation of symbols]

[0140] 1 solid state battery 10 Support substrate 14 Beer 16 rand 17 Wiring 30 Coating insulation film 50 Coated inorganic membrane 100 Solid-state battery stack 110 Positive electrode layer 120 negative electrode layer 130 Solid electrolyte 140 Laminated section 150 external terminal 150A Positive external terminal 150B Negative external terminal 160 Outermost insulating layer 160A Top surface of outermost insulating layer 160B Bottom of outermost insulating layer 170 Inactive Substances

Claims

1. A packaged solid-state battery including a solid-state battery stack having a stacked 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 stacked, A solid-state battery, wherein a moisture absorbent material is mixed into a component of the solid-state battery.

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

3. The solid-state battery according to claim 1 , wherein the moisture absorbent material is mixed into an outermost insulating layer of the laminated portion.

4. The solid-state battery according to any one of claims 1 to 3, wherein the solid-state battery stack further includes an external terminal on a side surface of the stacked portion located in a direction intersecting the stacking direction, and the moisture absorbent material is mixed into the external terminal.

5. 5. The solid state battery according to claim 1, wherein the solid state battery stack is supported by a support substrate, and the moisture absorbent material is mixed into the support substrate.

6. The solid-state battery stack further includes a support substrate provided to support the solid-state battery stack, 6. The solid state battery according to claim 1, wherein a support surface of the support substrate and a stacking direction of the solid state battery stack are parallel to each other.

7. 7. The solid-state battery according to claim 5, wherein the support substrate is provided with wiring that electrically connects the outermost surface of the substrate, and serves as a terminal substrate for external terminals of the solid-state battery.

8. 8. The solid-state battery according to claim 5, wherein the support substrate is a wiring board having inner via holes.

9. 9. The solid-state battery according to claim 1, wherein the moisture absorbent is mixed into an insulating coating film that covers the solid-state battery laminate.

10. an inactive material portion forming a part of a side surface of the laminated portion located in a direction transverse to the lamination direction; an external terminal provided on a side surface of the laminated portion located in a direction intersecting the lamination direction; the insulating outermost layer of the laminate; an insulating film that covers the solid-state battery stack; and The solid state battery according to any one of claims 1 to 9, wherein the moisture absorbent is mixed into any two or more or all of the support substrates provided to support the solid state battery stack.

11. 11. The solid-state battery according to claim 1, wherein the moisture absorbent comprises at least one selected from the group consisting of synthetic zeolite, silica gel, phosphorus pentoxide, barium oxide, calcium oxide, and a metal-organic framework.

12. 12. The solid-state battery according to claim 11, wherein the content of at least one synthetic zeolite and / or silica gel in the inactive material portion forming a side surface of the solid-state battery laminate in a direction intersecting the stacking direction and / or the outermost insulating layer of the laminate is 1% by volume or more and 80% by volume or less based on the entire inactive material portion and / or the entire outermost insulating layer.

13. The solid-state battery according to claim 12 , wherein the content is 20% by volume or more and 40% by volume or less based on the entire inactive material portion and / or the entire outermost insulating layer.

14. 12. The solid state battery according to claim 11, wherein the content of the synthetic zeolite and / or silica gel in the external terminals provided on the side surfaces of the solid state battery stacks in a direction intersecting the stacking direction is 1% by volume or more and 25% by volume or less based on the entire external terminals.

15. 12. The solid state battery according to claim 11, wherein a content of synthetic zeolite and / or silica gel in a coating insulating film that covers the solid state battery stack and / or a support substrate that is provided to support the solid state battery stack is 1% by volume or more and 45% by volume or less based on the entire coating insulating film and / or the entire support substrate.

16. The solid-state battery according to any one of claims 1 to 15, wherein the solid-state battery is packaged so as to be surface-mounted.

17. The solid state battery according to any one of claims 1 to 16, wherein the solid state battery laminate is made of a sintered body.

18. 18. The solid state battery according to claim 1, wherein the positive electrode layer and the negative electrode layer are layers capable of absorbing and releasing lithium ions.

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