Solid-state battery package

Abstract

Provided is a solid-state battery package including a substrate, a solid-state battery provided on the substrate, a covering insulating layer provided to cover the main surface and side surfaces of the solid-state battery, and a covering inorganic film provided on the covering insulating layer. The covering inorganic film includes a wet-plated composite layer. The wet-plated composite layer has at least a first wet-plated layer and a second wet-plated layer provided on the first wet-plated layer. The first wet-plated layer has ductility and the second wet-plated layer has resistance to deterioration.

Description

[Technical Field]

[0001] The present disclosure relates to solid-state battery packages, and more particularly to solid-state batteries packaged in a manner conducive to 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 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 into solid-state batteries that use solid electrolytes instead of liquid electrolytes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-220107 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-5279 Summary of the Invention [Problem to be solved by the invention]

[0006] Solid-state batteries may be mounted on a printed wiring board or the like together with other electronic components. In this case, the solid-state battery arranged on the substrate may be covered with a covering material to prevent water vapor from passing through. It is also known that the electrode layers (positive electrode layer / negative electrode layer) of solid-state batteries may expand and contract during charging and discharging. Therefore, depending on the degree of expansion and contraction of the solid-state battery, cracks may occur in the covering material. Furthermore, depending on the manufacturing process or usage environment, the covering material itself may be altered and defects may occur. Such cracks and defects due to alteration of the covering material may reduce the overall function of preventing water vapor from passing through.

[0007] The present disclosure has been made in view of the above-mentioned problems. That is, a main object of the present disclosure is to provide a solid-state battery package that can further improve the water vapor permeation prevention property. [Means for solving the problem]

[0008] In order to achieve the above object, in one embodiment of the present disclosure, A substrate; a solid-state battery provided on the substrate; a covering insulating layer provided so as to cover a main surface and a side surface of the solid-state battery; a coated inorganic film provided on the coated insulating layer, The coated inorganic film includes a wet-plated composite layer, the wet-plated composite layer has at least a first wet-plated layer and a second wet-plated layer provided on the first wet-plated layer; A solid-state battery package is provided, wherein the first wet-plated layer is ductile and the second wet-plated layer is resistant to deterioration.

[0009] In addition, in one embodiment of the present disclosure, A substrate; a solid-state battery provided on the substrate; a covering insulating layer provided so as to cover a main surface and a side surface of the solid-state battery; a coated inorganic film provided on the coated insulating layer, The coated inorganic film includes a wet-plated composite layer, the wet-plated composite layer has at least a first wet-plated layer and a second wet-plated layer provided on the first wet-plated layer; the first wet-plated layer contains, as a main component, at least one metal selected from the group consisting of Cu, Sn, Zn, Bi, Au, and Ag; the second wet-plated layer contains, as a main component, at least one metal selected from the group consisting of Ni, Cr, Pd, Pt, and Zn; A solid-state battery package is provided, wherein the first wet-plated layer and the second wet-plated layer have different compositions. [Effects of the Invention]

[0010] A solid-state battery package according to an embodiment of the present disclosure has high water vapor transmission resistance. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view schematically showing the internal configuration of a solid state battery according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view schematically illustrating the configuration of a packaged solid-state battery according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is an enlarged cross-sectional view schematically showing the inorganic coating film in the portion A of the packaged solid-state battery shown in FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view schematically illustrating a coating inorganic film of a packaged solid state battery according to an embodiment of the present disclosure. [Figure 5] FIG. 5 is an enlarged cross-sectional view schematically showing a coating inorganic film of a packaged solid state battery according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a cross-sectional view schematically illustrating the configuration of a packaged solid-state battery according to an embodiment of the present disclosure. [Figure 7A] FIG. 7A is a cross-sectional view illustrating a process for manufacturing a solid-state battery package according to an embodiment of the present disclosure. [Figure 7B]FIG. 7B is a cross-sectional view illustrating a process for manufacturing a solid-state battery package according to an embodiment of the present disclosure. [Figure 7C] FIG. 7C is a cross-sectional view illustrating a process for manufacturing a solid-state battery package according to an embodiment of the present disclosure. [Figure 7D] FIG. 7D is a cross-sectional view illustrating a process for manufacturing a solid-state battery package according to an embodiment of the present disclosure. [Figure 7E] FIG. 7E is a cross-sectional view illustrating a process for manufacturing a solid-state battery package according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] The solid-state battery package of the present disclosure will be described in detail below. While the description will be made with reference to drawings as necessary, the contents shown in the drawings are merely schematic and illustrative for the purpose of understanding the present disclosure, and the appearance, dimensional ratio, etc. may differ from the actual product.

[0013] In this specification, the term "solid-state battery package" refers, in a broad sense, to a solid-state battery device configured to protect a solid-state battery from the external environment, and, in a narrow sense, to a solid-state battery device that includes a mountable substrate and protects a solid-state battery from the external environment.

[0014] The term "cross-sectional view" as used herein refers to the shape of a solid-state battery viewed from a direction substantially perpendicular to the stacking direction (in other words, the shape of a solid-state battery cut along a plane parallel to the thickness direction of the layers). The terms "planar view" and "planar shape" as used herein refer to a sketch of an object viewed from above or below along the thickness direction of the layers (i.e., the stacking direction).

[0015] The terms "upper and lower directions" and "left and right directions" used directly or indirectly in this specification correspond to the upper and lower directions and left and right directions in the drawings, respectively. Unless otherwise specified, the same symbols or signs indicate the same members or parts or the same meanings. In a preferred embodiment, the vertical downward direction (i.e., the direction in which gravity acts) can be considered to correspond to the "lower direction" / "bottom side," and the opposite direction can be considered to correspond to the "upper direction" / "top side."

[0016] Furthermore, in this specification, "on" a substrate, film, layer, etc., includes not only cases where it is in contact with the upper surface of the substrate, film, or layer, but also cases where it is not in contact with the upper surface of the substrate, film, or layer. In other words, "on" a substrate, film, or layer includes cases where a new film or layer is formed above the substrate, film, or layer, and / or cases where another film or layer is interposed between the substrate, film, or layer. Furthermore, "on" does not necessarily mean the upper side in the vertical direction. "On" merely indicates the relative positional relationship of the substrate, film, layer, etc.

[0017] [Basic structure of secondary batteries] The term "secondary battery" as used herein refers to a battery that can be repeatedly charged and discharged. Therefore, the secondary battery according to the present disclosure is not limited to the name, and may also include, for example, an electricity storage device.

[0018] In the present disclosure, the term "solid-state battery" broadly refers to a battery whose components are made of solids, and in a 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 in the present disclosure is a stacked 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. 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 discharge. According to a preferred embodiment of the present disclosure, 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 energy storage device. In the present disclosure, a solid-state battery contained in a package can also be referred to as a "solid-state battery element."

[0019] The basic configuration of the solid-state battery of the present disclosure will be described below. The configuration of the solid-state battery described here is merely an example for understanding the invention and is not intended to limit the invention.

[0020] [Basic structure of solid-state batteries] A solid-state battery has at least positive and negative electrode layers and a solid electrolyte. Specifically, as shown in Fig. 1, a solid-state battery 100 includes a solid-state battery stack including battery constituent units each consisting of a positive electrode layer 110, a negative electrode layer 120, and at least a solid electrolyte 130 interposed therebetween.

[0021] The layers constituting the solid-state battery 100 may be formed by firing, and the positive electrode layer 110, the negative electrode layer 120, and the solid electrolyte 130 may form fired layers. Preferably, the positive electrode layer 110, the negative electrode layer 120, and the solid electrolyte 130 are each fired together, and therefore the solid-state battery stack preferably forms a fired body.

[0022] The positive electrode layer 110 is an electrode layer containing at least a positive electrode active material. The positive electrode layer may further contain a solid electrolyte. In a preferred embodiment, the positive electrode layer is made of a sintered body containing at least positive electrode active material particles and solid electrolyte particles. On the other hand, the negative electrode layer is an electrode layer containing at least a negative electrode active material. The negative electrode layer may further contain a solid electrolyte. In a preferred embodiment, the negative electrode layer is made of a sintered body containing at least a negative electrode active material particles and solid electrolyte particles.

[0023] 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 the transfer of electrons caused by the movement (conduction) of ions between the positive electrode layer and the negative electrode layer via the solid electrolyte. Each electrode layer, the positive electrode layer and the negative electrode layer, may be a layer capable of absorbing and releasing lithium ions or sodium ions. In other words, the solid-state battery may be an all-solid-state secondary battery in which lithium ions or sodium ions move between the positive electrode layer and the negative electrode layer via the solid electrolyte to charge and discharge the battery.

[0024] (Cathode active material) The positive electrode active material contained in the positive electrode layer 110 may be at least one selected from the group consisting of, for example, 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, and / or LiMnPO4. An example of a lithium-containing layered oxide is LiCoO2 and / or LiCo 1 / 3 Ni 1 / 3 Mn 1 / 3 Examples of lithium-containing oxides having a spinel structure include LiMn2O4 and / or LiNi 0.5 Mn 1.5O4, 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.

[0025] In addition, examples of positive electrode active materials capable of absorbing 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(PO2O7), and sodium-containing layered oxides such as NaFeO2 can be mentioned.

[0026] 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.

[0027] (Negative electrode active material) The negative electrode active material contained in the negative electrode layer 120 may be at least one selected from the group consisting of an oxide containing at least one element selected from the group consisting of titanium (Ti), silicon (Si), tin (Sn), chromium (Cr), iron (Fe), niobium (Nb), and molybdenum (Mo), a carbon material such as graphite, a graphite-lithium compound, a lithium alloy, a lithium-containing phosphate compound having a Nasicon structure, a lithium-containing phosphate compound having an olivine structure, and a lithium-containing oxide 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 and / or LiTi2(PO4)3. An example of a lithium-containing phosphate compound having an olivine structure is Li3Fe2(PO4)3 and / or LiCuPO4. An example of a lithium-containing oxide having a spinel structure is Li4Ti5O. 12 etc.

[0028] In addition, examples of negative electrode active materials capable of absorbing 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.

[0029] In the solid-state battery, the positive electrode layer and the negative electrode layer may be made of the same material, or may be made of different materials.

[0030] The positive electrode layer and / or the negative electrode layer may contain a conductive material, such as at least one of metal materials, such as silver, palladium, gold, platinum, aluminum, copper, and nickel, and carbon.

[0031] 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 lithium oxide, sodium oxide, potassium oxide, boron oxide, silicon oxide, bismuth oxide, and phosphorus oxide.

[0032] There are no particular limitations on the thickness of the positive electrode layer and the negative electrode layer, but for example, they may each independently be 2 μm or more and 50 μm or less, particularly 5 μm or more and 30 μm or less.

[0033] (Positive electrode current collecting layer / Negative electrode current collecting layer) Although not essential elements of the electrode layer, the positive electrode layer and the negative electrode layer may each include 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 the form of a foil. However, if emphasis is placed on improving electronic conductivity by co-firing, reducing the manufacturing cost of the solid-state battery, and / or reducing the internal resistance of the solid-state battery, the positive electrode current collector layer and the negative electrode current collector layer may each have the form of a sintered body. The positive electrode current collector constituting the positive electrode current collector and the negative electrode current collector constituting the negative electrode current collector may each have the form of a sintered body. layer It is preferable to use a material with high electrical conductivity, such as silver, palladium, gold, platinum, aluminum, copper, and / or nickel. The positive electrode current collector and the negative electrode current collector may each have an electrical connection for electrical connection to the outside and may be configured to be electrically connectable to the end electrodes. When the positive electrode current collector and the negative electrode current collector 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 collector and the negative electrode current collector 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 collector and the negative electrode current collector 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. As described above, positive electrode current collector and negative electrode current collector layers are not necessarily required for solid-state batteries, and solid-state batteries without such positive electrode current collector and negative electrode current collector layers are also conceivable. In other words, the solid-state battery included in the package of the present disclosure may be a solid-state battery without a current collecting layer.

[0034] (solid electrolyte) The solid electrolyte is a material capable of conducting lithium ions or sodium ions. In particular, the solid electrolyte 130 constituting a battery unit in a solid-state battery may form a layer capable of conducting lithium ions between the positive electrode layer 110 and the negative electrode layer 120 (see FIG. 1). The solid electrolyte may be provided at least between the positive electrode layer and the negative electrode layer. In other words, the solid electrolyte may be present around the positive electrode layer and / or the negative electrode layer so as to protrude from between the positive electrode layer and the negative electrode layer. Specific solid electrolytes include, for example, one or more of a crystalline solid electrolyte, a glass-based solid electrolyte, and a glass-ceramic-based solid electrolyte.

[0035] The crystalline solid electrolyte is, for example, an oxide-based crystalline material and a sulfide-based crystalline material. Examples of the oxide-based crystalline material include a lithium-containing phosphate compound having a Nasicon structure, an oxide having a perovskite structure, an oxide having a garnet-type or garnet-like structure, and an oxide glass ceramic-based lithium ion conductor. 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 titanium (Ti), germanium (Ge), aluminum (Al), gallium (Ga) and zirconium (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 sulfide-based crystal materials include thio-LISICON, for example, Li 3.25 Ge 0.25 P 0.75 S4 and Li10 GeP2S 12 The crystalline solid electrolyte may include a polymer material (for example, polyethylene oxide (PEO)).

[0036] Glass-based solid electrolytes include, for example, oxide-based glass materials and sulfide-based glass materials. Examples of oxide-based glass materials include 50Li4SiO4·50Li3BO3. Examples of sulfide-based glass materials include 30Li2S·26B2S3·44LiI, 63Li2S·36SiS2·1Li3PO4, 57Li2S·38SiS2·5Li4SiO4, 70Li2S·30P2S5, and 50Li2S·50GeS2.

[0037] The glass ceramic solid electrolyte is, for example, an oxide-based glass ceramic material or a sulfide-based glass ceramic material. As the oxide-based glass ceramic material, for example, a phosphate compound containing lithium, aluminum, and titanium as constituent elements (LATP) or a phosphate compound containing lithium, aluminum, and germanium as constituent elements (LAGP) can be used. LATP is, for example, Li 1.07 Al 0.69 Ti 1.46 (PO4)3, etc. Also, LAGP is, for example, Li 1.5 Al 0.5 Ge 1.5 (PO4), etc. Examples of sulfide-based glass ceramic materials include Li7P3S 11 and Li 3.25 P 0.95 Examples include S4.

[0038] In addition, examples of solid electrolytes capable of conducting sodium ions include sodium-containing phosphate compounds having a Nasicon structure, oxides having a perovskite structure, and oxides having a garnet or garnet-like structure. Examples of sodium-containing phosphate compounds having a Nasicon structure include Na 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).

[0039] The solid electrolyte may contain a sintering aid. The sintering aid contained in the solid electrolyte 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.

[0040] The thickness of the solid electrolyte is not particularly limited. The thickness of the solid electrolyte layer located between the positive electrode layer and the negative electrode layer may be, for example, 1 μm to 15 μm, particularly 1 μm to 5 μm.

[0041] (end face electrode) A solid-state battery generally has end electrodes 140. In particular, the end electrodes are provided on the side surfaces of the solid-state battery. More specifically, a positive end electrode 140A connected to the positive electrode layer 110 and a negative end electrode 140B connected to the negative electrode layer 120 are provided (see FIG. 1). Such end electrodes preferably contain a material with high conductivity. Specific materials for the end electrodes are not particularly limited, but may include at least one selected from the group consisting of silver, gold, platinum, aluminum, copper, tin, and nickel.

[0042] [Basic structure of solid-state battery package] The present disclosure relates to a packaged solid-state battery, that is, a solid-state battery package having a mountable substrate and a configuration in which the solid-state battery is protected from the external environment.

[0043] Fig. 2 is a cross-sectional view schematically illustrating the configuration of a packaged solid-state battery according to an embodiment of the present disclosure. As shown in Fig. 2, a solid-state battery package 1000 according to an embodiment of the present disclosure includes a substrate 200 for supporting the solid-state battery 100. Specifically, the solid-state battery package 1000 includes the mountable substrate 200 and the solid-state battery 100 that is provided on the substrate 200 and protected from the external environment.

[0044] As shown in FIG. 2 , the substrate 200 has a main surface larger than that of the solid-state battery 100, for example. The substrate 200 may be a resin substrate or a ceramic substrate. In short, the substrate 200 may be a printed wiring board, a flexible substrate, an LTCC substrate, an HTCC substrate, or the like. When the substrate 200 is a resin substrate, the substrate 200 may be a substrate configured to contain a resin as a base material, for example, a substrate having a laminate structure including a resin layer. The resin material of such a resin layer may be any thermoplastic resin and / or any thermosetting resin. Furthermore, the resin layer may be configured, for example, by impregnating glass fiber cloth with a resin material such as epoxy resin.

[0045] The substrate may be a component for the external terminals of the packaged solid-state battery. In other words, it can be said that the substrate serves as a terminal substrate for the external terminals of the solid-state battery. A solid-state battery package including such a substrate can mount the solid-state battery on another secondary substrate such as a printed wiring board with the substrate interposed therebetween. For example, the solid-state battery can be surface-mounted via the substrate through solder reflow or the like. For this reason, the solid-state battery package of the present disclosure may be an SMD (Surface Mount Device) type battery package.

[0046] Such a substrate can be provided to support a solid-state battery, and can therefore also be considered a support substrate. Furthermore, since the substrate is a terminal substrate, it may have wiring or an electrode layer, and in particular, it may have an electrode layer that electrically connects the upper and lower surfaces or the upper and lower surface layers. That is, a preferred embodiment of the substrate has wiring or an electrode layer 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. In this embodiment, the wiring of the substrate can be used to connect the external terminals from the solid-state battery, eliminating the need to pack the external terminals with a covering material (described later) before connecting them to the package, and increasing the design freedom of the external terminals.

[0047] A substrate 200 according to a preferred embodiment includes electrode layers (upper principal surface electrode layer 210 and lower principal surface electrode layer 220) that electrically connect the upper and lower principal surfaces of the substrate, and serves as a component for the external terminals of a packaged solid-state battery (see FIG. 2). In a solid-state battery package including such a substrate, the electrode layers of the substrate and the terminal portions of the solid-state battery are connected to each other. For example, the electrode layers of the substrate and the end surface electrodes of the solid-state battery are electrically connected to each other. For example, the end surface electrode 140A on the positive electrode side of the solid-state battery may be electrically connected to the electrode layers (210A, 220A) on the positive electrode side of the substrate. On the other hand, the end surface electrode 140B on the negative electrode side of the solid-state battery may be electrically connected to the electrode layers (210B, 220B) on the negative electrode side of the substrate. This allows the electrode layers on the positive and negative electrode sides of the substrate (particularly the electrode layers located on the lower / bottom side of the packaged product, or the lands connected thereto) to serve as the positive and negative terminals of the battery package, respectively.

[0048] In order to enable electrical connection between the solid-state battery 100 and the substrate electrode layer 210 of the substrate 200, the end surface electrode 140 of the solid-state battery 100 and the substrate electrode layer 210 of the substrate 200 can be connected via a bonding member 600. This bonding member 600 is responsible for at least the electrical connection between the end surface electrode 140 of the solid-state battery 100 and the substrate 200, and may include, for example, a conductive adhesive. As an example, the bonding member 600 may be made of an epoxy-based conductive adhesive containing a metal filler such as Ag.

[0049] Furthermore, in an embodiment of the present disclosure, not only the substrate 200 but also the solid-state battery package 1000 itself may be configured to be able to prevent water vapor transmission as a whole. For example, the solid-state battery package 1000 according to an embodiment of the present disclosure may be covered with a covering material 150 so that the solid-state battery 100 provided on the substrate 200 is entirely enclosed. Specifically, the solid-state battery 100 on the substrate 200 may be packaged so that the main surface 100A and the side surface 100B are enclosed by the covering material 150. With this configuration, all surfaces constituting the solid-state battery 100 are not exposed to the outside, and water vapor transmission can be prevented.

[0050] In this specification, "water vapor" is not limited to gaseous water, but also includes liquid water. In other words, the term "water vapor" is used to broadly encompass gaseous water, liquid water, and the like, regardless of the physical state. Therefore, "water vapor" can also be referred to as moisture, and liquid water in particular can include condensed water formed by condensation of gaseous water. Since the intrusion of water vapor into a solid-state battery can cause deterioration of battery characteristics, the above-described packaged solid-state battery configuration contributes to extending the battery characteristics and life of the solid-state battery.

[0051] For example, as shown in FIG. 2, the coating material 150 can be composed of a coating insulating layer 160 and a coating inorganic film 170. The solid-state battery 100 can have a configuration in which it is covered with the coating insulating layer 160 and the coating inorganic film 170 as the coating material 150. The coating inorganic film 170 is provided so as to cover the coating insulating layer 160. As shown in FIG. 3, the coating inorganic film 170 is positioned on the coating insulating layer 160, and therefore has a configuration in which, together with the coating insulating layer 160, it largely envelops the solid-state battery 100 on the substrate 200 as a whole. Furthermore, the coating inorganic film 170 can also take a configuration in which it covers the side surface 250 of the substrate 200.

[0052] [Features of the Solid-State Battery Package of the Present Disclosure] The inventors of the present application have conducted extensive research into solutions for suitably suppressing cracking of the solid-state battery package 1000, and as a result have devised the present disclosure having the following technical idea.

[0053] Specifically, the present disclosure has the technical idea of ​​"making the coated inorganic film 170 have a structure with multiple wet-plated layers." More specifically, the present disclosure has the technical idea of ​​"making the coating material have a structure including a coated inorganic film with multiple wet-plated layers with different properties."

[0054] To achieve the above technical idea, the present disclosure has the following technical features. FIG. 3 is an enlarged cross-sectional view schematically showing the coated inorganic film 170 in part A of the solid-state battery package 1000 shown in FIG. 2. As shown in the figure, the coated inorganic film has a structure consisting of multiple layers. In this specification, a "film" has multiple layers as components. In other words, in this specification, a "layer" can be one of the elements that make up the film. The coated inorganic film provided in the solid-state battery package of the present disclosure may have a multilayer structure having at least a wet-plated composite layer 172 including multiple wet-plated layers.

[0055] In this specification, the term "wet-plated composite layer" refers to a layer composed of at least two wet-plated layers. In particular, since the term "composite layer" in this specification refers to a laminate including two or more layers, the term "wet-plated composite layer" can also be interpreted as a laminate composed of multiple wet-plated layers stacked together. More specifically, as shown in FIG. 3, the wet-plated composite layer 172 may be composed of at least a first wet-plated layer 172a and a second wet-plated layer 172b disposed on the first wet-plated layer 172a.

[0056] The first wet-plated layer 172a and the second wet-plated layer 172b may have different properties. Specifically, the first wet-plated layer 172a may have ductility, while the second wet-plated layer 172b may have resistance to deterioration.

[0057] For example, the first wet-plated layer 172a may be a plating layer that is relatively more ductile than the second wet-plated layer 172b. In this specification, the "ductility" of a plating layer can also be interpreted as "flexibility." Therefore, the first wet-plated layer 172a may be a plating layer that is relatively more flexible than the second wet-plated layer 172b. The ductility (or flexibility) of a plating layer can be measured by a known ductility or flexibility test method, and may be evaluated, for example, by a bending test in accordance with ASTM B490-09. Furthermore, for example, the first wet-plated layer 172a may be a layer that is capable of a volume change that is equal to or greater than the volume change rate due to expansion and contraction of a solid-state battery during use.

[0058] The ductile first wet-plated layer 172a can improve the plating layer's ability to follow volume changes caused by the expansion and contraction of solid-state batteries. Therefore, stresses acting in conjunction with such expansion and contraction are more mitigated, and the occurrence of cracks in the wet-plated composite layer is more effectively suppressed. In other words, the ductile first wet-plated layer 172a can more effectively suppress cracks in the wet-plated composite layer caused by the expansion and contraction of solid-state batteries, potentially extending the life of the coated inorganic film.

[0059] Furthermore, since second wet-plated layer 172b has resistance to deterioration, deterioration of the plating layer due to external influences (e.g., corrosion due to moisture or electrolytes in the atmosphere, oxidation in high-temperature and high-humidity environments, and / or damage) can be further reduced. This can more effectively prevent defects in the wet-plated composite layer due to deterioration of the plating layer. Therefore, the configuration of the coated inorganic film disclosed herein can more effectively prevent cracks and defects in the wet-plated composite layer, thereby providing a solid-state battery package that can more effectively prevent water vapor transmission.

[0060] Here, "alteration" in this specification encompasses both physical and chemical alteration of the plating layer. More specifically, "alteration" refers to a change in the appearance and / or properties of the plating layer, for example, due to deformation, discoloration, and / or corrosion of the plating layer. Therefore, "alteration resistance" in this specification encompasses deformation resistance, scratch resistance, discoloration resistance, and / or corrosion resistance. From the perspective of extending the life of solid-state batteries, it is preferable that the second wet-plated layer has excellent resistance to alteration, particularly in high-temperature and high-humidity environments. For example, it is preferable that no change in appearance is observed even when the second wet-plated layer is maintained for 72 hours in an environment with a temperature of approximately 85°C and a relative humidity of approximately 85%.

[0061] The coated inorganic film including the wet-plated composite layer preferably functions as a water vapor barrier film. That is, the coated inorganic film covers the top and side surfaces of the solid-state battery so as to suitably serve as a barrier to prevent moisture from penetrating into the solid-state battery. In the broad sense, the term "barrier" as used herein means having a water vapor barrier property to the extent that water vapor from the external environment does not pass through the coated inorganic film and cause undesirable performance degradation of the solid-state battery. In the narrow sense, the term "barrier" means a barrier having a water vapor permeability of 1.0×10 -3 g / (m 2 Therefore, in short, the water vapor barrier film preferably has a thermal conductivity of 0 to 1.0×10 -3 g / (m 2 It can be said that the water vapor transmission rate is less than 1000 kJ / day. Note that the "water vapor transmission rate" here refers to the transmission rate obtained using a gas transmission rate measuring device, model GTms-1, manufactured by Advance Riko Co., Ltd., under measurement conditions of 40°C, 90% RH, and a differential pressure of 1 atm.

[0062] In a preferred embodiment, the coating insulating layer and the coating inorganic film are integrated with each other. Thus, the coating inorganic film forms a water vapor barrier for the solid-state battery together with the coating insulating layer. In other words, the combination of the integrated coating insulating layer and the coating inorganic film more effectively prevents water vapor from the external environment from penetrating into the solid-state battery.

[0063] In one embodiment, the coated inorganic film may further include a dry-plated layer. That is, a coated inorganic film composed of a dry-plated layer and a wet-plated composite layer may be provided on the coated insulating layer. The dry-plated layer may be, for example, a sputtered film. That is, the solid-state battery package of the present disclosure may be provided with a sputtered thin film as the dry-plated film. A sputtered film is a thin film obtained by sputtering. That is, a film deposited by sputtering ions onto a target and expelling the atoms may be used as the dry-plated layer.

[0064] The sputtered film has a very thin morphology on the nano- or micro-order, yet is a relatively dense and / or uniform layer, which can contribute to preventing water vapor permeation in solid-state batteries. Furthermore, because the sputtered film is formed by atomic deposition, it can adhere more favorably to the target. Therefore, the sputtered film can be more favorably used as a barrier to prevent water vapor from the external environment from penetrating into solid-state batteries. Therefore, by further including a sputtered film as a dry-plated layer in the coated inorganic film, it is possible to further improve the water vapor permeation prevention properties of the solid-state battery. The dry-plated layer may also be formed by other dry plating methods, such as vacuum deposition or ion plating. In a preferred embodiment, the dry-plated layer may include at least one selected from the group consisting of Al (aluminum), Cu (copper), Ti (titanium), and stainless steel (SUS).

[0065] Thus, the coated inorganic film may be composed of a single dry-plated layer and a wet-plated composite layer having a multi-layer structure of two or more layers. In a wet-plated composite layer having a multi-layer structure, adjacent wet-plated layers may have different plating compositions. In other words, the wet-plated composite layer may have a multi-layer structure in which wet-plated layers having different plating compositions are stacked adjacently. That is, the coated inorganic film has a multi-layer structure of three or more layers. This means that a coated inorganic film in which dry-plated layers and wet-plated composite layers are stacked in any order on a coated insulating layer may be provided.

[0066] 4, the wet-plated composite layer 172 is provided on the dry-plated layer 171. That is, the dry-plated layer 171 may be provided on the covering insulating layer 160 so as to cover the covering insulating layer 160, and the wet-plated composite layer 172 may be provided on top of the dry-plated layer 171. In other words, the dry-plated layer 171 and the wet-plated composite layer 172 may be laminated in this order on the covering insulating layer 160.

[0067] When forming a dry plating layer by sputtering, the sputtered film can be formed so that it penetrates into the covering insulating layer, thereby allowing the sputtered film to adhere more favorably to the covering insulating layer. Therefore, the sputtered film, together with the covering insulating layer, can more favorably contribute to preventing water vapor from passing through the solid-state battery. Furthermore, in sputtering, the sputtered film penetrates into the covering insulating layer, allowing for more favorable adhesion to the covering insulating layer. In other words, the sputtered film, which is provided so as to cover at least the main and side surfaces of the solid-state battery together with the covering insulating layer, can more favorably serve as a barrier to prevent water vapor from the external environment from penetrating the solid-state battery. Furthermore, providing a dry plating layer inside the wet plating layer can more favorably prevent the plating solution used to form the wet plating layer from penetrating into the solid-state battery. Therefore, providing a dry plating layer on the covering insulating layer can provide a more reliable solid-state battery package.

[0068] The thickness of the dry-plated layer is preferably 1 μm or more and 10 μm or less, more preferably 2 μm or more and 8 μm or less, and even more preferably 3 μm or more and 6 μm or less. By setting the thickness of the dry-plated layer within the above range, the dry-plated layer can more effectively contribute to preventing water vapor from penetrating into the solid-state battery.

[0069] In a preferred embodiment, as shown in FIG. 4 , the first wet-plated layer 172a is disposed relatively inwardly of the second wet-plated layer 172b. That is, in the wet-plated composite layer, the first wet-plated layer 172a may be disposed relatively inwardly, and the second wet-plated layer 172b may be disposed relatively outwardly. For example, the second wet-plated layer 172b may be disposed so as to cover the first wet-plated layer 172a. That is, in one embodiment of the present disclosure, the coated inorganic film may be a multilayer inorganic film formed by stacking, in this order, a dry-plated layer on a coated insulating layer, a ductile first wet-plated layer 172a, and a deterioration-resistant second wet-plated layer 172b. By positioning the ductile first wet-plated layer 172a more inwardly than the second wet-plated layer 172b, the first wet-plated layer functions as a stress relief layer that relieves stress caused by the expansion and contraction of a solid-state battery. This further reduces the stress on the second wet-plated layer, making it possible to more effectively prevent cracking of the second wet-plated layer. Furthermore, by providing the second wet-plated layer 172b, which has resistance to deterioration, on the outer side of the first wet-plated layer 172a, deterioration of the plating layers located further inward can be reduced. This reduces the occurrence of defects due to deterioration of the plating layers, making it possible to provide a highly reliable solid-state battery package with better water vapor permeation resistance.

[0070] In a preferred embodiment, as shown in FIG. 4, the second wet-plated layer 172b is the outermost layer of the coating inorganic film. That is, the second wet-plated layer 172b may constitute the outermost layer of the solid-state battery package so as to entirely cover the main and side surfaces of the solid-state battery package. Specifically, the outer main and side surfaces of the solid-state battery package may be covered with the deterioration-resistant second wet-plated layer 172b. This means that the second wet-plated layer 172b is a layer exposed to the external environment. By using the deterioration-resistant second wet-plated layer as the outermost layer of the solid-state battery package, deterioration of the coating material due to the influence of the external environment can be suppressed. Therefore, the second wet-plated layer can also be interpreted as a protective layer that protects the solid-state battery package from the external environment. In this way, the second wet-plated layer protects the wet-plated film and dry-plated layer located closer to the solid-state battery package, which may more effectively suppress deterioration of the entire wet-plated composite layer due to the external environment. Therefore, the above-described structure can more suitably prevent the occurrence of damage to the covering material due to the influence of the external environment, and can provide a solid battery package with improved water vapor permeation prevention properties.

[0071] The first wet-plated layer 172a is a ductile metal or alloy plating. The plating composition of the first wet-plated layer 172a is not particularly limited as long as it can alleviate stress that may occur during expansion and contraction of the solid-state battery. However, it is preferable that the first wet-plated layer 172a primarily contains at least one metal selected from the group consisting of Cu (copper), Sn (tin), Zn (zinc), Bi (bismuth), Au (gold), and Ag (silver). Furthermore, to avoid melting of the plating layer due to heating during solder reflow during surface mounting of the solid-state battery package, the melting point of the first wet-plated layer is preferably equal to or higher than the solder reflow temperature. Therefore, the melting point of the first wet-plated layer may be, for example, 300°C or higher, 350°C or higher, 400°C or higher, or 500°C or higher. To achieve high ductility, a high melting point, and low cost, the first wet-plated layer preferably contains Cu as its primary component.

[0072] The second wet-plated layer 172b is a metal plating or alloy plating having resistance to deterioration. The plating composition of the second wet-plated layer 172b is not particularly limited as long as a plating layer having resistance to deterioration is obtained, but it is preferable that the second wet-plated layer 172b contains at least one metal selected from the group consisting of Ni (nickel), Cr (chromium), Pd (palladium), Pt (platinum), and Zn as the main component. In terms of cost and environmental impact, it is preferable that the second wet-plated layer contains Ni as the main component. In addition, the plating composition of the first wet-plated layer is 2 The plating compositions of the wet-plated layers may be different from each other, that is, the first wet-plated layer and the second wet-plated layer may have different plating compositions from each other.

[0073] The wet-plated layers constituting the wet-plated composite layer may have different thicknesses. The ductile first wet-plated layer 172a preferably has the largest thickness in the wet-plated composite layer. That is, the first wet-plated layer 172a preferably has a thickness greater than the second wet-plated layer 172b. In other words, the deterioration-resistant second wet-plated layer may be thinner than the first wet-plated layer. A relatively thick first wet-plated layer can more effectively relieve stress caused by expansion and contraction of the innermost solid-state battery, thereby reducing stress transmitted to the outermost plating layers. Therefore, the first wet-plated layer functions more effectively as a stress-relieving layer, thereby more effectively preventing cracking of the outermost plating layers. Meanwhile, although the second wet-plated layer requires a certain thickness to exhibit deterioration resistance, a relatively small thickness is desirable from the perspective of compact solid-state battery packaging.

[0074] Thickness of the first wet-plated layer t a is the thickness of the second wet-plated layer t b The thickness of the wet-plated layer may be, for example, 2 to 50 times, 2 to 25 times, or 2 to 10 times, relative to the thickness of the solid-state battery. When the thickness of the wet-plated layer is within the above range, the occurrence of cracks due to expansion and contraction of the solid-state battery can be further reduced, and deterioration of the plated layer can be suppressed.

[0075] Thickness of the first wet-plated layer with ductility t a The thickness t of the first wet-plated layer is preferably 10 μm or more and 100 μm or less, more preferably 15 μm or more and 70 μm or less, and particularly preferably 20 μm or more and 40 μm or less. a By setting the thickness within the above range, it is possible to suitably suppress the occurrence of cracks due to the expansion and contraction of the solid-state battery.

[0076] Thickness of the second wet-plated layer with resistance to deterioration, t b is preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 15 μm or less, and particularly preferably 2 μm or more and 10 μm or less. By setting the thickness of the second wet-plated layer within the above range, deterioration of the plated layer can be suitably reduced, and the occurrence of defects in the plated composite layer due to such deterioration can be more suitably suppressed.

[0077] In one embodiment of the present disclosure, the wet-plated composite layer has a multilayer structure of three or more layers. Specifically, as shown in FIG. 5, the first wet-plated layer 172a may be disposed between the second wet-plated layer 172b and the third wet-plated layer 172c. This means that the wet-plated composite layer may have a multilayer structure in which the third wet-plated layer 172c, the first wet-plated layer 172a, and the second wet-plated layer 172b are stacked in this order. In one embodiment, the third wet-plated layer 172c is disposed between the dry-plated layer 171 and the first wet-plated layer 172a. In other words, the coated inorganic film 170 may have a multilayer structure in which the dry-plated layer 171, the third wet-plated layer 172c, the first wet-plated layer 172a, and the second wet-plated layer 172b are stacked in this order.

[0078] The third wet-plated layer 172c may be ductile or resistant to deterioration. That is, a third wet-plated layer 172c having ductility or resistance to deterioration may be further disposed inside the first wet-plated layer. By including a third wet-plated layer having ductility or resistance to deterioration in the wet-plated composite layer, water vapor permeation into the solid-state battery can be more effectively prevented. In particular, when the third wet-plated layer is ductile, it can adapt to the expansion and contraction that accompanies the charge and discharge of the solid-state battery. Therefore, the third wet-plated layer, together with the first wet-plated layer, can reduce stress applied to the coating and contribute to preventing cracking of the coated inorganic film. Furthermore, when the third wet-plated layer is resistant to deterioration, deterioration of the plating layer can be more effectively suppressed during use of the solid-state battery package. Therefore, the occurrence of defects in the coated inorganic film due to deterioration of the plating layer is reduced, and a highly reliable solid-state battery package with better water vapor permeation prevention properties can be provided.

[0079] In a preferred embodiment, the third wet-plated layer 172c has chemical resistance. In this specification, "chemical resistance" refers to resistance to solutions containing alkaline or acidic chemicals. More specifically, "chemical resistance" refers to the resistance of the third wet-plated layer 172c to solutions containing alkaline or acidic chemicals. layer The chemical resistance of the third wet-plated layer 172c refers to the property of being resistant to corrosion by the plating solution used to form the wet-plated layer on top of the third wet-plated layer 172c. The chemical resistance of the third wet-plated layer 172c can suppress corrosion of the third wet-plated layer 172c when a further plating layer is formed on the third wet-plated layer 172c. Therefore, for example, as shown in FIG. 5, when the third wet-plated layer 172c is provided on the dry-plated layer 171, the third wet-plated layer protects the dry-plated layer located inside it from the plating solution when the wet-plated layers are stacked, thereby contributing to more effectively preventing the plating solution from penetrating into the covering insulating layer and the solid-state battery.

[0080] During plating, corrosion of the substrate by the plating solution can cause defects in the plating layer formed on the outer side. Defects in the plating layer reduce the plating layer's function as a water vapor barrier film. By including a chemical-resistant third wet-plated layer in the coating inorganic film, it may be possible to further improve the water vapor barrier properties of solid-state battery packages.

[0081] The plating composition of the third wet-plated layer 172c may contain, for example, at least one metal selected from the group consisting of Cu, Sn, Zn, Bi, Au, Ag, Ni, Cr, Pd, Pt, and Co (cobalt) as a main component. If emphasis is placed on the chemical resistance of the third wet-plated film, the third wet-plated layer 172c preferably has a plating composition containing, for example, at least one metal selected from the group consisting of Ni, Cr, Pd, Pt, and Co (cobalt) as a main component. The plating composition of the third wet-plated layer 172c may be different from that of the first wet-plated layer 172a. Third wet-plated layer When attaching more importance to the adhesion with the plating layer to be formed thereon, it is more preferable that the third wet-plated layer has a plating composition containing Ni as the main component.

[0082] The third wet-plated layer 172c may have a thickness necessary to provide chemical resistance. From the viewpoint of suppressing cracks caused by expansion and contraction of the solid-state battery, the third wet-plated layer has a thickness t a For example, the thickness of the third wet-plated layer t c is preferably 2 μm or more and 20 μm or less, more preferably 2 μm or more and 15 μm or less, and even more preferably 5 μm or more and 10 μm or less. By setting the thickness of the third wet-plated layer within the above range, corrosion by the plating solution is more effectively prevented. Therefore, the occurrence of defects in the plated composite layer due to such corrosion is more effectively suppressed, and the water vapor permeation resistance of the solid-state battery package can be improved.

[0083] Furthermore, as a modification of the solid-state battery of the above-described embodiment, the coated inorganic film may extend from the side surface of the substrate to the main surface of the substrate. Specifically, as shown in FIG. 6, the coated inorganic film may extend to the lower main surface of the substrate (i.e., the bottom main surface of the substrate). In such a case, the bonding area between the coated inorganic film and the substrate is relatively increased, and peeling of the coated inorganic film is further suppressed. Furthermore, although not shown, a metal pad may be provided between the lower main surface of the substrate and the coated inorganic film to further strengthen the bond between the coated inorganic film and the substrate. Such a metal pad may be provided, for example, on the periphery of the lower main surface of the substrate.

[0084] The thickness of each layer of the solid-state battery and the substrate may be based on an electron microscope image. For example, the thickness of each layer constituting the solid-state battery and the substrate may be based on an image acquired using an ion milling device (Hitachi High-Tech Corporation, Model No. SU-8040). In other words, the thickness in this specification may refer to a value calculated from dimensions measured from an image acquired by such a method.

[0085] The thickness of each layer of the coating material may be based on an electron microscope image of a cross section. For example, the solid-state battery package may be cut perpendicular to the main surface, and the image of the resulting cross section may be obtained using an ion milling device (model SU-8040, manufactured by Hitachi High-Technologies Corporation). In other words, the thickness of the coating material in this specification may refer to a value calculated from dimensions measured from an image obtained by such a method.

[0086] [Solid-state battery package manufacturing method] The subject matter of the present disclosure 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.

[0087] The production of the solid-state battery of the present disclosure can be broadly divided into the production of the solid-state battery itself (hereinafter also referred to as "battery before packaging"), which corresponds to the stage before packaging, the preparation of the substrate, and packaging.

[0088] <Manufacturing method of unpackaged batteries> The pre-packaged battery can be manufactured by a printing method such as screen printing, a green sheet method using a green sheet, or a combination of these methods. That is, the pre-packaged battery 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).

[0089] In the following, one manufacturing method will be described as an example for better understanding of the present disclosure, but the present disclosure 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.

[0090] (Laminated block formation) A solid electrolyte, an organic binder, a solvent, and optional additives are mixed to prepare a slurry, which is then fired to form a sheet containing the solid electrolyte. A paste for a positive electrode is prepared by mixing a positive electrode active material, a solid electrolyte, a conductive material, an organic binder, a solvent, and any additives. Similarly, a paste for a negative electrode is prepared by mixing a negative electrode active material, a solid electrolyte, a conductive material, an organic binder, a solvent, and any additives. Print the positive electrode paste onto the sheet, and if necessary, print the current collecting layer and / or negative layer. Similarly, print the negative electrode paste onto the sheet, and if necessary, print the current collecting layer and / or negative layer. A laminate is obtained by alternately stacking sheets printed with a positive electrode paste and sheets printed with a negative electrode paste. The outermost layer (top layer and / or bottom layer) of the laminate may be an electrolyte layer, an insulating layer, or an electrode layer.

[0091] (Battery firing body formation) After the laminate is pressure-bonded and integrated, it is cut to a predetermined size. The cut laminate is then degreased and fired to obtain a fired laminate. Note that the laminate may be degreased and fired before cutting, and then cut.

[0092] (Edge electrode formation) The positive electrode end electrode can be formed by applying a conductive paste to the exposed positive electrode side of the fired laminate. Similarly, the negative electrode end electrode can be formed by applying a conductive paste to the exposed negative electrode side of the fired laminate. The positive and negative electrode end electrodes may be provided so as to extend to the main surfaces of the fired laminate. The component of the end electrode can be at least one selected from silver, gold, platinum, aluminum, copper, tin, and nickel.

[0093] The end electrodes on the positive and negative electrodes do not necessarily have to be formed after firing of the laminate, but may be formed before firing and then subjected to simultaneous firing.

[0094] By going through the steps described above, a desired pre-packaged battery (corresponding to solid-state battery 100 shown in FIG. 7C) can finally be obtained.

[0095] <Preparation of substrate> In this step, the substrate is prepared.

[0096] Although not particularly limited, when a resin substrate is used as the substrate, its preparation may be carried out by stacking multiple layers and then heating and pressurizing them. For example, a substrate precursor is formed using a resin sheet composed of a base fiber cloth impregnated with a resin raw material. After the substrate precursor is formed, this substrate precursor is subjected to heating and pressure in a press. On the other hand, when a ceramic substrate is used as the substrate, its preparation may be carried out, for example, by thermocompression bonding multiple green sheets to form a green sheet laminate and then firing the green sheet laminate to obtain a ceramic substrate. The ceramic substrate may be prepared, for example, in a manner similar to the preparation of an LTCC substrate. A semi-lacquer substrate may have vias and / or lands. In such cases, for example, holes may be formed in the green sheets using a punch press or carbon dioxide laser, and the holes may be filled with a conductive paste material, or precursors of conductive portions such as vias and lands may be formed by a printing method or the like. Note that lands, etc., may also be formed after firing the green sheet laminate.

[0097] By going through the above steps, the desired substrate 200 (see FIG. 7A) can finally be obtained.

[0098] Packaging Next, the battery and substrate obtained above are packaged (see FIGS. 7B to 7E).

[0099] First, the pre-packaged battery 100 is placed on the substrate 200 (see FIGS. 7C and 7D). In other words, an "unpackaged solid-state battery" is placed on the substrate (hereinafter, a battery used for packaging will also be simply referred to as a "solid-state battery").

[0100] Preferably, the solid-state battery is placed on the substrate so that the conductive portions of the substrate and the end electrodes of the solid-state battery are electrically connected to each other. For example, a conductive paste may be applied to the substrate, thereby electrically connecting the conductive portions of the substrate and the end electrodes of the solid-state battery. More specifically, the conductive portions (particularly the lower lands / bottom lands) on the positive and negative sides of the substrate's main surface are aligned with the positive and negative end electrodes of the solid-state battery, respectively, and then bonded using a conductive paste (e.g., Ag conductive paste). That is, a precursor of a bonding member that provides electrical connection between the solid-state battery and the substrate may be provided in advance. Such a bonding member precursor can be provided by printing a conductive paste that does not require cleaning after formation, such as Ag conductive paste, nanopaste, alloy paste, or brazing filler. Next, the solid-state battery is placed on the substrate so that the end electrodes of the solid-state battery and the precursor of the bonding member are in contact with each other, and the resulting mixture is subjected to a heat treatment, whereby a bonding member that contributes to the electrical connection between the solid-state battery and the substrate is formed from the precursor.

[0101] Next, the covering material 150 is formed. The covering material includes a covering insulating layer 160 and a covering inorganic film 170 is provided (see FIG. 7E).

[0102] First, the covering insulating layer 160 is formed to cover the solid-state battery 100 on the substrate 200. Therefore, raw materials for the covering insulating layer are provided so as to completely cover the solid-state battery on the substrate. When the covering insulating layer is made of a resin material, a resin precursor is applied to the substrate and cured to form the covering insulating layer. In a preferred embodiment, the covering insulating layer may be formed by applying pressure using a mold. As a mere example, the covering insulating layer that seals the solid-state battery on the substrate may be formed using a compression mold. If the covering insulating layer is made of a resin material commonly used in molding, the raw materials for the covering insulating layer may be in the form of granules or may be thermoplastic. This molding is not limited to mold molding, but may also be performed using polishing, laser processing, and / or chemical treatment.

[0103] After the coating insulating layer 160 is formed, the coating inorganic film 170 is formed. Specifically, the coating inorganic film 170 is formed on the "coating precursor in which the individual solid state batteries 100 are covered with the coating insulating layer 160 on the substrate 200."

[0104] The coated inorganic film may be formed by plating the coated precursor. In one embodiment, the coated inorganic film is formed on the coated precursor by forming a wet-plated composite layer on an exposed surface other than the bottom surface of the coated precursor (i.e., other than the bottom surface of the support substrate). In another embodiment, the wet-plated composite layer is formed so that at least one plating layer of the wet-plated composite layer extends to the bottom surface of the coated precursor.

[0105] The wet-plated composite layer may be formed by laminating multiple wet-plated layers by performing wet plating in a predetermined order so that adjacent plating layers have different properties. For example, in one embodiment of the present disclosure, multiple types of wet plating are sequentially performed on the coated precursor, and a first wet-plated layer and a second wet-plated layer are laminated in this order.

[0106] Wet plating can be performed by, for example, electroplating or electroless plating. When the deposition rate of plating is important, it is more preferable to form the wet-plated layer by electroplating. Therefore, in one embodiment of the present disclosure, the wet-plated layer can be formed by electroplating, and the wet-plated layer can also be referred to as an electroplated layer.

[0107] The metal source for the plating solution used in wet plating may take various forms depending on the type of dry plating layer and plating bath, etc. The metal source is not particularly limited, but examples thereof include metal salts of the metals contained in the plating composition, such as inorganic acid salts of sulfates, hydrochlorides, pyrophosphates, or sulfamic acid, and / or organic acid salts of cyanides.

[0108] For example, the first wet-plated layer having ductility may be formed using a plating solution containing an inorganic acid salt such as sulfate, hydrochloride, pyrophosphate, or sulfamic acid of at least one metal selected from the group consisting of Cu (copper), Sn (tin), Zn (zinc), Bi (bismuth), Au (gold), and Ag (silver), and / or an organic acid salt such as cyanide. In view of easier management of the plating solution and superior manufacturing efficiency, it is more preferable that the first wet-plated layer be formed using a copper sulfate plating solution.

[0109] The second wet-plated layer having resistance to deterioration may be formed using a plating solution containing, for example, an inorganic acid salt such as sulfate, hydrochloride, or sulfamic acid of at least one metal selected from the group consisting of Ni (nickel), Cr (chromium), Pd (palladium), Pt (platinum), and Zn, and / or an organic acid salt such as cyanide. In order to emphasize easier management of the plating solution and excellent production efficiency, it is more preferable that the second wet-plated layer be formed by electrolytic nickel plating using a WATT bath, nickel sulfamate bath, or Wood's bath containing nickel sulfate, nickel sulfamate, and / or nickel chloride.

[0110] Furthermore, dry plating and wet plating may be combined to form the coated inorganic film. For example, a dry-plated layer may first be formed by dry plating the coated precursor. More specifically, a dry-plated layer may be formed on an exposed surface other than the bottom surface of the coated precursor (i.e., other than the bottom surface of the support substrate) by dry plating. Next, a wet-plated composite layer may be formed on the dry-plated layer by performing multiple types of wet plating in a predetermined order on the coated precursor on which the dry-plated layer has been formed.

[0111] In one embodiment of the present disclosure, a wet-plated composite layer is formed on the coated precursor by forming the third, first, and second wet-plated layers in this order, with the third wet-plated layer disposed inside the first wet-plated layer. For example, in an embodiment in which the coated inorganic film comprises a dry-plated film, wet plating may be performed on the coated precursor on which the dry-plated film has been formed, such that the third, first, and second wet-plated layers are stacked in this order.

[0112] The third wet-plated layer may be formed using a plating solution containing, for example, an inorganic acid salt such as sulfate, hydrochloride, or sulfamic acid of at least one metal selected from the group consisting of Cu, Sn, Zn, Bi, Au, Ag, Ni, Cr, Pd, Pt, and Co (cobalt), and / or an organic acid salt such as cyanide. To prevent corrosion of the dry-plated layer, it is desirable for the pH of the plating solution used to form the third wet-plated layer to be as close to neutral as possible. For example, the pH of the plating solution is preferably in the range of about 3.0 to about 10.0. For example, the third wet-plated layer may be formed by electrolytic nickel plating using a WATT bath or a nickel sulfamate bath.

[0113] If necessary, the plating solution may contain various supporting electrolytes and additives (stress reducers, brighteners, conductivity aids, reducing agents, antifoaming agents, dispersants, and / or surfactants, etc.). Plating conditions may include current density, temperature, pH, etc., and these conditions may be set as desired. When electroplating is used to form the plating layer, the plating method may be direct current plating or pulse plating.

[0114] By going through the above steps, a packaged product can be obtained in which the solid-state battery on the substrate is entirely covered with the insulating coating layer and the inorganic coating film, i.e., the "solid-state battery package" according to the present disclosure can be finally obtained.

[0115] Although the above description has been made with reference to a configuration in which the covering material 150 covers the solid-state battery 100, the present disclosure may also have a configuration in which the solid-state battery 100 is largely covered with the covering material 150. For example, a coated inorganic insulating layer 150 is provided on the covering insulating layer 160 that encases the solid-state battery 100 on the substrate 200. film 170 may extend to the lower main surface of the substrate 200 (see FIG. 6). film 170 may extend to the side surface of the substrate 200 and may extend beyond the side surface of the substrate 200 to the lower main surface (particularly the peripheral edge portion) of the substrate 200. In such a configuration, a solid-state battery package can be obtained that is more suitably prevented from permeating moisture (permeating moisture from the outside to the solid-state battery laminate).

[0116] Preferably, a water vapor barrier layer may be formed on the substrate in advance, that is, before packaging in which the substrate and the solid-state battery are combined.

[0117] There are no particular limitations on the water vapor barrier layer, as long as it can form the desired barrier layer. For example, a "water vapor barrier layer having Si-O bonds and Si-N bonds" is preferably formed by applying a liquid precursor and irradiating it with ultraviolet light. In other words, the water vapor barrier layer is formed under relatively low temperature conditions (for example, a temperature condition of about 100°C) without using a vapor phase deposition method such as CVD or PVD.

[0118] Specifically, a liquid precursor containing, for example, silazane is prepared, and the liquid precursor is applied to a substrate by spin coating or spray coating, and then dried to form a barrier precursor. The barrier precursor is then exposed to UV light in a nitrogen-containing atmosphere, resulting in a water vapor barrier layer having Si-O and Si-N bonds.

[0119] It is preferable to locally remove the water vapor barrier layer at the joining portion between the conductive portion of the substrate and the end electrode of the solid-state battery so that the water vapor barrier layer is not present at that portion. Alternatively, a mask may be used to prevent the water vapor barrier layer from being formed at the joining portion. That is, a mask may be applied to the joining portion, and the water vapor barrier layer may be formed overall, and then the mask may be removed. [Example]

[0120] A demonstration test was carried out in accordance with the present disclosure. The structure of the solid-state battery package shown in Figure 2 was adopted.

[0121] Specifically, solid-state battery packages were manufactured that included the coated inorganic films of Comparative Examples 1 and 2 and Examples 1 to 4 shown in Table 1 below. A 5 μm-thick Cu dry-plated layer was formed on the side surface of the coated insulating layer and the substrate using a sputtering method, and then various plating processes shown in Table 1 were carried out so that the third wet-plated layer, the first wet-plated layer, and the second wet-plated layer were stacked in this order to form a wet-plated composite layer. All wet plating processes were carried out by electroplating, and wet-plated layers with the thicknesses shown in Table 1 were obtained. In the table, "Cu plating" refers to a wet-plated layer obtained by copper sulfate plating, and "Ni plating" refers to a wet-plated layer obtained by electrolytic nickel plating using a WATT bath.

[0122] [Table 1]

[0123] The thickness of each plating layer shown in Table 1 was determined from a cross section processed using an ion milling device (manufactured by Hitachi High-Tech Corporation, model number SU-8040).

[0124] The solid-state battery packages of the comparative example and the example were charged and discharged 30 times to check the degree of cracking in the outermost wet-plated layer. Note that the outermost wet-plated layer with only minor cracks was also included in this example. The thickness of the battery cell in the discharged state was 3.76 mm, and in the fully charged state it was 3.84 mm.

[0125] The presence or absence of cracks was determined by observation under a microscope at 100x magnification.

[0126] In addition, the solid-state battery packages of the comparative examples and examples were left to stand for 72 hours under conditions of a temperature of 85°C and a humidity of 85%, and then the presence or absence of changes in the appearance of the outermost wet-plated layer (i.e., the presence or absence of altered areas) was confirmed.

[0127] The presence or absence of alteration was measured using a microscope at 10x magnification, and if discoloration, rust, and / or corrosion was confirmed in the outermost wet-plated layer compared to before the test, it was judged to be "present." Table 2 shows the results of measuring the presence or absence of cracks and alteration for the solid-state battery packages of the comparative examples and examples listed in Table 1.

[0128] [Table 2]

[0129] According to the above results, the solid-state battery package of Comparative Example 1, which was provided with Ni plating having deterioration resistance, did not undergo deterioration even under high-temperature and high-humidity conditions, but cracks were observed on the surface after charging and discharging the solid-state battery. Furthermore, the solid-state battery package of Comparative Example 2, which was provided with Cu plating having ductility, did not undergo cracking, but discoloration was observed under high-temperature and high-humidity conditions. On the other hand, the solid-state battery package of Example 5, which had multiple wet-plated layers, more effectively reduced the occurrence of cracks in the outermost layer of the coated inorganic film and deterioration under high-temperature and high-humidity conditions compared to the solid-state battery packages of Comparative Examples 1 and 2, which had a single wet-plated layer. In other words, the coated inorganic film having at least a first wet-plated layer having ductility and a second wet-plated layer having deterioration resistance reduced the occurrence of cracks in the coated inorganic film or defects due to deterioration. Therefore, the present disclosure provides a more reliable solid-state battery package with high water vapor permeability prevention properties.

[0130] Furthermore, in the solid state battery packages of Examples 1 to 4 in which the coated inorganic film had a ductile Cu plating layer with a thickness of 10 μm or more, the occurrence of cracks in the coated inorganic film was more effectively suppressed compared to the solid state battery package of Example 5 in which the coated inorganic film had a Cu plating layer with a thickness of 6 μm. Therefore, by making the ductile plating layer thicker, the occurrence of cracks in the coated inorganic film can be more effectively suppressed.

[0131] Furthermore, in the solid battery packages of Comparative Example 2 and Example 1, which did not have a third wet-plated layer on the dry copper-plated layer, corrosion of the dry-plated layer by the plating solution was observed during the formation of the first wet-plated layer. On the other hand, in the solid battery packages of Comparative Example 1 and Examples 2 to 5, in which a Ni-plated layer was formed on the dry-plated layer, corrosion of the dry-plated layer (e.g., size reduction) was not observed. From the above, it can be understood that the third wet-plated layer contributes to protecting the dry-plated layer from the plating solution used to form the first wet-plated layer. In other words, by further including a third wet-plated layer in the coating inorganic film, corrosion of the plated object during the formation of the outer wet-plated layer is suppressed. Therefore, in the solid battery package of the present disclosure, the use of a third wet-plated layer in addition to the first and second wet-plated layers can more effectively prevent water vapor permeation.

[0132] Although the embodiments of the present disclosure have been described above, they are merely typical examples. Those skilled in the art will readily understand that the present disclosure is not limited thereto, and that various modifications are possible within the scope of the present disclosure. [Industrial Applicability]

[0133] The solid-state battery package of the present disclosure can be utilized in a variety of fields where battery use or storage is envisioned. By way of example only, the solid-state battery package of the present disclosure can be used in the electrical, information, and communications fields where mobile devices and the like are used (for example, the electrical and electronic equipment fields or mobile device fields including mobile phones, smartphones, laptop computers, digital cameras, activity monitors, arm computers, electronic paper, and small electronic devices such as RFID tags, card-type electronic money, and smart watches), household and small industrial applications (for example, power tools, golf carts, and household, nursing care, and industrial robots), large industrial applications (for example, forklifts, elevators, and harbor cranes), transportation systems (for example, hybrid cars, electric cars, buses, trains, electrically assisted bicycles, and electric motorcycles), power system applications (for example, various power generation systems, road conditioners, smart grids, and general household power storage systems), medical applications (for medical devices such as earphone hearing aids), pharmaceutical applications (for example, medication management systems), as well as the IoT field, and space and deep-sea applications (for example, space probes, submersible research vessels, and the like). [Explanation of symbols]

[0134] 100 solid state battery Main surface of 100A solid-state battery Side view of 100B solid-state battery 110 Positive electrode layer 120 negative electrode layer 130 Solid electrolyte or solid electrolyte layer 140 End electrode 140A Positive end electrode 140B Negative electrode end surface 150 Covering material 160 Insulating coating layer 170 Coated Inorganic film 171 Dry plating layer 172 Wet-plated composite layer 172a First wet plating layer 172b Second wet plating layer 172c Third wet plating layer 200 boards 210 Substrate electrode layer (upper side of substrate) 210A Positive side substrate electrode layer 210B Negative electrode layer of substrate 220 Mounting side board electrode layer (bottom side of board) 220A Positive side mounting side board electrode layer 220B Negative side mounting side substrate electrode layer 250 Side of the board 600 Joint materials 600' Precursor for joint components 1000 solid state battery packages t a Thickness of the first wet-plated layer t b Thickness of the second wet plating layer t c Thickness of the third wet plating layer

Claims

1. A substrate; a solid-state battery provided on the substrate; a covering insulating layer provided so as to cover a main surface and a side surface of the solid-state battery; a coated inorganic film provided on the coated insulating layer, The coated inorganic film includes a wet-plated composite layer, the wet-plated composite layer has at least a first wet-plated layer and a second wet-plated layer provided on the first wet-plated layer; the first wet-plated layer contains, as a main component, at least one metal selected from the group consisting of Cu, Sn, Bi, Au, and Ag; The solid-state battery package, wherein the second wet-plated layer contains, as a main component, at least one metal selected from the group consisting of Ni, Cr, Pd, Pt, and Zn.

2. The solid-state battery package according to claim 1 , wherein the coated inorganic film further comprises a dry-plated layer.

3. The solid-state battery package according to claim 2 , wherein the dry-plated layer is provided on the covering insulating layer.

4. The solid-state battery package according to claim 1 , wherein the wet-plated composite layer has a structure of two or more layers.

5. The solid-state battery package according to claim 4 , wherein in the two or more layer structure, adjacent wet-plated layers have different compositions.

6. The solid-state battery package according to claim 1 , wherein the first wet-plated layer is located relatively inside and the second wet-plated layer is located relatively outside.

7. the first wet-plated layer is disposed between the second wet-plated layer and the third wet-plated layer; 2. The solid-state battery package according to claim 1, wherein the third wet-plated layer contains, as a main component, at least one metal selected from the group consisting of Cu, Sn, Zn, Bi, Au, Ag, Ni, Cr, Pd, Pt, and Co.

8. The coated inorganic film further comprises a dry plating layer, the third wet-plated layer is provided on the dry-plated layer; The solid-state battery package according to claim 7 , wherein the third wet-plated layer contains at least one metal selected from the group consisting of Ni, Cr, Pd, Pt, and Co as a main component.

9. The solid-state battery package according to claim 1 , wherein the second wet-plated layer is the outermost layer of the coated inorganic film.

10. The solid-state battery package according to claim 1 , wherein the second wet-plated layer is a layer exposed to an external environment.

11. The solid-state battery package according to claim 1 , wherein the coated inorganic film has a multi-layer structure of three or more layers.

12. The solid-state battery package according to claim 1 , wherein the first wet-plated layer is mainly composed of Cu.

13. The solid-state battery package according to claim 1 , wherein the main component of the second wet-plated layer is Ni.

14. The solid-state battery package according to claim 8 , wherein the third wet-plated layer has Ni as a main component.

15. The solid-state battery package according to claim 1 , wherein the first wet-plated layer is the thickest in the wet-plated composite layer.

16. The solid-state battery package according to claim 1 , wherein the thickness of the first wet-plated layer is greater than the thickness of the second wet-plated layer.

17. The solid-state battery package according to claim 1 , wherein the thickness of the first wet-plated layer is from two to five times the thickness of the second wet-plated layer.

18. The solid-state battery package according to claim 1 , wherein the first wet-plated layer has a thickness of 10 μm or more and 100 μm or less.

19. The solid-state battery package according to claim 1 , wherein the second wet-plated layer has a thickness of 2 μm or more and 20 μm or less.

20. The solid-state battery package according to claim 8 , wherein the third wet-plated layer has a thickness of 2 μm or more and 20 μm or less.

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