JP2023143252A - solid battery package - Google Patents

Abstract

To provide a solid battery package which copes with: cracking of the solid battery package caused by charging/discharging of a solid battery; removal of a coating part; and fracture of an internal structure of the solid battery due to lack of binding force of the coating part.SOLUTION: A solid battery package comprises: a substrate 200; a solid battery 100 provided on the substrate; and a coating part 150 made at least of a coating insulation layer 160 provided on the substrate in a manner coating the solid battery and a coating inorganic layer 170 provided outside the coating insulation layer. The coating insulation layer contains resin and has an elastic modulus of 100 MPa or higher and a fracture strain of 2.5% or higher.SELECTED DRAWING: Figure 2

Description

The present invention relates to solid state battery packages. More specifically, the present invention relates to solid state batteries packaged to be suitable for board mounting.

BACKGROUND ART Secondary batteries that can be repeatedly charged and discharged have been used for various purposes. For example, secondary batteries are used as power sources for electronic devices such as smartphones and notebook computers.

In secondary batteries, a liquid electrolyte is generally used as a medium for ion movement that contributes to charging and discharging. In other words, so-called electrolytes are used in secondary batteries. However, in such secondary batteries, safety is generally required in terms of preventing electrolyte leakage. Furthermore, since the organic solvent used in the electrolyte is a flammable substance, safety is also required in this respect.

Therefore, research is underway on solid-state batteries that use solid electrolytes instead of electrolytes.

International Publication No. 2020/031424

It is conceivable that a solid-state battery will be used by being mounted on a printed wiring board or the like together with other electronic components, and in that case, a structure suitable for mounting is required. For example, a solid-state battery package formed by disposing a solid-state battery on a substrate facilitates mounting by having the substrate take charge of electrical connection with the outside. Further, in a solid state battery package, a covering portion that covers a solid state battery arranged on a substrate is sometimes provided.

Here, the present inventor found that there are points to be improved in the following points. Specifically, in a solid-state battery package, cracks occur in the solid-state battery and the members that make up the solid-state battery package (hereinafter also referred to as "package constituent members") due to changes in volume due to charging and discharging of the solid-state battery, causing the solid-state battery to deteriorate. There is a possibility that the covering portion covering the solid state battery may peel off from the substrate on which it is placed. Furthermore, there is a possibility that the internal structure of the solid-state battery may be destroyed due to insufficient binding force of the covering portion that covers the solid-state battery.

The present invention has been made in view of this problem. That is, an object of the present invention is to deal with the occurrence of cracks in solid-state battery packages caused by charging and discharging of solid-state batteries, the occurrence of peeling of coating parts, and the destruction of the internal structure of solid-state batteries due to insufficient binding force of coating parts. Our objective is to provide solid state battery packages.

In one embodiment of the present invention, the present invention includes a substrate, a solid state battery provided on the substrate, a covering insulating layer provided on the substrate to cover the solid state battery, and a covering provided outside the covering insulating layer. and a covering portion made up of at least an inorganic layer,
A solid battery package is provided in which the covering insulating layer contains a resin, has an elastic modulus of 100 MPa or more, and a breaking strain of 2.5% or more.

According to the solid-state battery package according to an embodiment of the present invention, cracks in the solid-state battery package due to charging and discharging of the solid-state battery, peeling of the coating part, and internal parts of the solid-state battery due to insufficient binding force of the coating part. Destruction of the structure can be suppressed.

FIG. 1 is a cross-sectional view schematically showing the internal structure of a solid-state battery. FIG. 2 is a cross-sectional view schematically showing the configuration of a solid-state battery package according to an embodiment of the present invention. FIG. 3A is a process cross-sectional view schematically showing a manufacturing process of a solid-state battery package according to an embodiment of the present invention. FIG. 3B is a process cross-sectional view schematically showing a manufacturing process of a solid battery package according to an embodiment of the present invention. FIG. 3C is a process cross-sectional view schematically showing a manufacturing process of a solid battery package according to an embodiment of the present invention. FIG. 3D is a process cross-sectional view schematically showing a manufacturing process of a solid state battery package according to an embodiment of the present invention. FIG. 3E is a process cross-sectional view schematically showing a manufacturing process of a solid battery package according to an embodiment of the present invention.

In a broad sense, the term "solid battery package" as used herein refers to a solid battery device (or solid battery product) configured to protect a solid battery from the external environment, and in a narrow sense, This refers to a solid-state battery that has a permeation barrier that prevents water vapor from the external environment from entering the solid-state battery. "Water vapor" here refers to moisture represented by water vapor in the atmosphere, and in a preferred embodiment, it refers to moisture that includes not only water vapor in gas form but also liquid water. There is. Preferably, such a moisture permeation-proof solid state battery package is packaged to be suitable for board mounting, particularly for surface mounting. Therefore, in a preferred embodiment, the battery of the present invention is an SMD type battery. This refers to a solid-state battery product that is equipped with a board that facilitates mounting and that protects the solid-state battery from the external environment.

In this specification, "cross-sectional view" refers to the form viewed from a direction approximately perpendicular to the thickness direction based on the stacking direction of each layer constituting the solid-state battery (simply put, a plane parallel to the thickness direction). (form when cut out). The "vertical direction" and "horizontal direction" used directly or indirectly in this specification correspond to the vertical direction and the horizontal direction in the drawings, respectively. Unless otherwise specified, the same reference numerals or symbols indicate the same members/parts or the same meanings. In a preferred embodiment, the vertically downward direction (that is, the direction in which gravity acts) corresponds to the "downward direction"/"bottom side", and the opposite direction corresponds to the "upward direction"/"top side". I can do it.

In the present invention, the term "solid battery" refers to a battery whose components are made of solid materials, and in a narrow sense, it refers to batteries whose components (preferably all components) are made of solid materials. Refers to solid-state batteries. In a preferred embodiment, the solid-state battery of the present invention is a stacked solid-state battery configured such that the layers constituting the battery constituent units are stacked on each other, and preferably each layer is made of a sintered body. Note that the term "solid battery" includes 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 battery" is a secondary battery. The term "secondary battery" is not excessively limited by its name, and may include, for example, power storage devices.

Below, first, the basic structure of the solid state battery package of the present invention will be explained. The configuration of the solid-state battery described here is merely an example for understanding the invention, and does not limit the invention.

[Basic configuration of solid-state battery]
A solid-state battery has at least positive and negative electrode layers and a solid electrolyte. Specifically, as shown in FIG. 1, the solid-state battery 100 includes a solid-state battery stack including a battery structural unit consisting of a positive electrode layer 110, a negative electrode layer 120, and at least a solid electrolyte 130 interposed therebetween.

In a solid-state battery, each layer constituting the solid-state battery may be formed by firing, and a positive electrode layer, a negative electrode layer, a solid electrolyte, and the like may form the fired layers. Preferably, the positive electrode layer, the negative electrode layer, and the solid electrolyte are each integrally fired, and therefore, it is preferable that the solid battery stack forms an integrally fired body.

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 composed of a fired 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 composed of a sintered body containing at least negative electrode active material particles and solid electrolyte particles.

A positive electrode active material and a negative electrode active material are materials that participate in the transfer of electrons in a solid battery. Ions move (conduct) between the positive electrode layer and the negative electrode layer via the solid electrolyte, and electrons are exchanged to perform charging and discharging. It is particularly preferable that each electrode layer of the positive electrode layer and the negative electrode layer is a layer capable of intercalating and deintercalating lithium ions or sodium ions. That is, the solid battery is preferably an all-solid-state secondary battery in which lithium ions or sodium ions move between a positive electrode layer and a negative electrode layer via a solid electrolyte to charge and discharge the battery.

(Cathode active material)
Examples of the positive electrode active material contained in the positive electrode layer 110 include a lithium-containing phosphoric acid compound having a Nasicon-type structure, a lithium-containing phosphoric acid compound having an olivine-type structure, a lithium-containing layered oxide, and a lithium-containing lithium-containing layered oxide. At least one selected from the group consisting of oxides and the like can be mentioned. An example of a lithium-containing phosphoric acid compound having a Nasicon type structure includes Li ₃ V ₂ (PO ₄ ) ₃ and the like. Examples of lithium-containing phosphate compounds having an olivine structure include Li ₃ Fe ₂ (PO ₄ ) ₃ , LiFePO ₄ , and/or LiMnPO ₄ . Examples of lithium-containing layered oxides include LiCoO ₂ and/or LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ . Examples of lithium-containing oxides having a spinel structure include LiMn ₂ O ₄ and/or LiNi _0.5 Mn _1.5 O ₄ . 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 types of transition metal elements as constituent elements, and lithium transition metal phosphate compounds are oxides containing lithium and one or more types of transition metal elements as constituent elements. It is a general term for phosphoric acid compounds containing transition metal elements as constituent elements. The type of transition metal element is not particularly limited, and examples thereof include cobalt (Co), nickel (Ni), manganese (Mn), and iron (Fe).

In addition, as positive electrode active materials capable of intercalating and releasing sodium ions, sodium-containing phosphoric acid compounds having a Nasicon-type structure, sodium-containing phosphoric acid compounds having an olivine-type structure, sodium-containing layered oxides, and spinel-type structures are used. At least one selected from the group consisting of sodium-containing oxides and the like can be mentioned. For example, in the case of sodium-containing phosphate compounds, Na ₃ V ₂ (PO ₄ ) ₃ , NaCoFe ₂ (PO ₄ ) ₃ , Na ₂ Ni ₂ Fe (PO ₄ ) ₃ , Na ₃ Fe ₂ (PO ₄ ) ₃ , Na The sodium- _containing layered oxide may include at least one selected from _the group consisting _{of 2FeP2O7} , _Na4Fe3 ( _PO4 ) ₂ ( _P2O7 ), and _NaFeO2 as the sodium _- containing layered oxide.

In addition, 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 is, for example, titanium disulfide or molybdenum sulfide. The chalcogenide may be, for example, niobium selenide. The conductive polymer may be, for example, disulfide, polypyrrole, polyaniline, polythiophene, polyparastyrene, polyacetylene or polyacene.

(Negative electrode active material)
The negative electrode active material contained in the negative electrode layer 120 includes, for example, titanium (Ti), silicon (Si), tin (Sn), chromium (Cr), iron (Fe), niobium (Nb), and molybdenum (Mo). oxides containing at least one element selected from the group, carbon materials such as graphite, graphite-lithium compounds, lithium alloys, lithium-containing phosphoric acid compounds having a Nasicon-type structure, lithium-containing phosphoric acid compounds having an olivine-type structure, and , a lithium-containing oxide having a spinel structure, and the like. An example of a lithium alloy is Li-Al. Examples of lithium-containing phosphoric acid compounds having a Nasicon type structure include Li ₃ V ₂ (PO ₄ ) ₃ and/or LiTi ₂ (PO ₄ ) ₃ . Examples of the lithium-containing phosphoric acid compound having an olivine structure include Li ₃ Fe ₂ (PO ₄ ) ₃ and/or LiCuPO ₄ . An example of a lithium-containing oxide having a spinel structure is Li ₄ Ti ₅ O ₁₂ and the like.

In addition, negative electrode active materials capable of intercalating and releasing sodium ions include sodium-containing phosphoric acid compounds having a Nasicon-type structure, sodium-containing phosphoric acid compounds having an olivine-type structure, and sodium-containing oxides having a spinel-type structure. At least one selected from the group consisting of:

Note that in the solid-state battery, the positive electrode layer and the negative electrode layer may be made of the same material.

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

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

The thickness of the positive electrode layer and the negative electrode layer is not particularly limited, but may be, for example, independently 2 μm or more and 50 μm or less, particularly 5 μm or more and 30 μm or less.

(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 collecting layer and a negative electrode current collecting layer. The positive electrode current collecting layer and the negative electrode current collecting layer may each have a foil form. However, if more emphasis is placed on improving electronic conductivity through integral firing, reducing manufacturing costs of solid-state batteries, and/or reducing internal resistance of solid-state batteries, then the positive electrode current collecting layer and the negative electrode current collecting layer should each form a fired body. It may have. As the positive electrode current collector constituting the positive electrode current collector layer and the negative electrode current collector constituting the negative electrode current collector, it is preferable to use a material with high electrical conductivity, such as silver, palladium, gold, platinum, aluminum, copper, etc. , and/or nickel may be used. The positive electrode current collector and the negative electrode current collector may each have an electrical connection part for electrically connecting with the outside, and may be configured to be electrically connectable to the end surface electrode. Note that when the positive electrode current collecting layer and the negative electrode current collecting layer have the form of fired bodies, they may be constituted by fired bodies containing a conductive material and a sintering aid. The conductive material contained in the positive electrode current collection layer and the negative electrode current collection layer may be selected from the same materials as the conductive materials that may be contained in the positive electrode layer and the negative electrode layer, for example. The sintering aid contained in the positive electrode current collecting layer and the negative electrode current collecting layer may be selected from the same materials as the sintering aid that may be contained in the positive electrode layer and the negative electrode layer, for example. As described above, a positive electrode current collecting layer and a negative electrode current collecting layer are not necessarily required in a solid state battery, and a solid state battery that is not provided with such a positive electrode current collecting layer and a negative electrode current collecting layer is also conceivable. That is, the solid state battery included in the package of the present invention may be a solid state battery without a current collecting layer.

(solid electrolyte)
A solid electrolyte is a material that can conduct lithium ions or sodium ions. In particular, the solid electrolyte 130, which constitutes a battery constituent unit in a solid battery, may form a layer between the positive electrode layer 110 and the negative electrode layer 120 that can conduct lithium ions (see FIG. 1). Note that the solid electrolyte only needs to be provided at least between the positive electrode layer and the negative electrode layer. That is, 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, a glass-ceramic solid electrolyte, and the like.

Examples of the crystalline solid electrolyte include oxide-based crystal materials and sulfide-based crystal materials. Examples of oxide-based crystal materials include lithium-containing phosphate compounds having a Nasicon structure, oxides having a perovskite structure, oxides having a garnet type or garnet-like structure, oxide glass ceramics-based lithium ion conductors, etc. It will be done. Lithium-containing phosphoric acid compounds having a Nasicon structure include Li _{x My} (PO ₄ ) ₃ (1≦x≦2, 1≦y≦2, M is titanium (Ti), germanium (Ge), aluminum (Al ), gallium (Ga), and zirconium (Zr). An example of a lithium-containing phosphoric acid compound having a Nasicon structure includes Li _1.2 Al _0.2 Ti _1.8 (PO ₄ ) ₃ and the like. Examples of oxides having a perovskite structure include La _0.55 Li _0.35 TiO ₃ and the like. An example of an oxide having a garnet type or garnet type similar structure includes Li ₇ La ₃ Zr ₂ O ₁₂ and the like. Examples of the sulfide-based crystal material include thio-LISICON, such as Li _3.25 Ge _0.25 P _0.75 S4 and Li ₁₀ GeP ₂ S ₁₂ . The crystalline solid electrolyte may include a polymeric material (eg, polyethylene oxide (PEO), etc.).

Examples of the glass-based solid electrolyte include oxide-based glass materials and sulfide-based glass materials. Examples of the oxide glass material include 50Li ₄ SiO ₄ .50Li ₃ BO ₃ . Sulfide glass materials _include , for example, 30Li ₂ S.26B ₂ S 3.44LiI, _{63Li 2} S.36SiS 2.1Li _{3 PO 4} , 57Li ₂ S.38SiS 2.5Li ₄ SiO ₄ and 70Li ₂ S. Examples include 30P ₂ S ₅ and 50Li 2 S.50GeS _{2 .}

Examples of the glass-ceramic solid electrolyte include oxide-based glass-ceramic materials and sulfide-based glass-ceramic materials. As the oxide-based glass-ceramic material, for example, a phosphoric acid compound (LATP) containing lithium, aluminum, and titanium as constituent elements, and a phosphoric acid compound (LAGP) containing lithium, aluminum, and germanium as constituent elements can be used. LATP is, for example, Li _1.07 Al _0.69 Ti _1.46 (PO ₄ ) ₃ . Furthermore, LAGP is, for example, Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ). Furthermore, examples of the sulfide-based glass ceramic materials include Li ₇ P ₃ S ₁₁ and Li _3.25 P _0.95 S ₄ .

Examples of the solid electrolyte that can conduct sodium ions include sodium-containing phosphoric acid compounds having a Nasicon structure, oxides having a perovskite structure, and oxides having a garnet type or garnet type similar structure. As a sodium-containing phosphate compound having a Nasicon structure, Na _{x My} (PO ₄ ) ₃ (1≦x≦2, 1≦y≦2, M is from the group consisting of Ti, Ge, Al, Ga and Zr) at least one selected type).

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

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 or more and 15 μm or less, particularly 1 μm or more and 5 μm or less.

(end face electrode)
Solid state batteries are generally provided with end electrodes 140. In particular, end electrodes are provided on the sides of the solid state battery. More specifically, a positive end surface electrode 140A connected to the positive electrode layer 110 and a negative end surface electrode 140B connected to the negative electrode layer 120 are provided (see FIG. 1). Preferably, such end electrodes include a material with high electrical 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.

[Configuration of solid battery package of the present invention]
The configuration of a solid state battery package according to an embodiment of the present invention will be described below. A solid state battery package is a packaged battery.

Specifically, as shown in FIG. 2, a solid state battery package 1000 according to an embodiment of the present invention has a package structure including a substrate 200 and a covering section 150 including a covering insulating layer 160 and a covering inorganic layer 170. have. In such a battery package product, a substrate 200, a covering insulating layer 160, and a covering inorganic layer are placed around the solid-state battery 100 so that the solid-state battery 100 is completely surrounded (without exposing all the surfaces forming the solid-state battery to the outside). 170 are provided.

The substrate 200 is a substrate provided so that the solid battery 100 is supported. A substrate is positioned on one side forming the main surface of the solid state battery to provide "support". Further, since it is a "substrate", it preferably has a thin plate-like shape as a whole.

The substrate 200 may be a resin substrate or a ceramic substrate. In a preferred embodiment, the substrate 200 is a ceramic substrate. That is, the substrate 200 includes ceramic, which constitutes the base material component of the substrate. A substrate made of ceramic is a preferable substrate since it contributes to preventing water vapor permeation and has heat resistance during board mounting. Such a ceramic rack substrate can be obtained through firing, for example, by firing a green sheet laminate. In this regard, the ceramic substrate may be, for example, an LTCC substrate (LTCC: Low Temperature Co-fired Ceramics) or an HTCC substrate (HTCC: High Temperature Co-fired Ceramics). Although this is just an example, the thickness of the substrate may be 20 μm or more and 1000 μm or less, for example, 100 μm or more and 300 μm or less.

Further, since the substrate 200 can be provided to support a solid-state battery, it can also be understood as a support substrate. Further, since the substrate 200 is a terminal substrate, it is preferable that the substrate 200 has wiring or an electrode layer. A substrate 200 according to a preferred embodiment includes electrode layers (an upper main surface electrode layer 210, a lower main surface electrode layer 220) that electrically connects the upper and lower main surfaces of the substrate, and is a packaged solid state. It is a member for the external terminal of the battery (see Figure 2). In a solid-state battery package including such a substrate, the electrode layer of the substrate and the terminal portion of the solid-state battery are connected to each other. Preferably, the electrode layer of the substrate and the end face electrode of the solid state battery are electrically connected to each other. For example, the end face electrode 140A on the positive electrode side of the solid state battery is electrically connected to the substrate electrode layer (210A, 220A) on the positive electrode side. On the other hand, the end face electrode 140B on the negative electrode side of the solid battery is electrically connected to the substrate electrode layer (210B, 220B) on the negative electrode side. As a result, the electrode layers on the positive and negative sides of the board (in particular, the electrode layers located on the lower side/bottom side of the packaged product, or the lands connected thereto) can be used as the positive and negative terminals of the battery package, respectively. It will be served.

Note that in order to enable electrical connection between the solid battery 100 and the substrate electrode layer 210 of the substrate 200, the end electrode 140 of the solid battery 100 and the substrate electrode layer 210 of the substrate 200 are connected via the bonding member 600. I can do it. This joining member 600 is responsible for at least the electrical connection between the end face electrode 140 of the solid battery 100 and the substrate 200, and may contain, for example, a conductive adhesive. For example, the bonding member 600 may be made of an epoxy conductive adhesive containing a metal filler such as Ag. Alternatively, the bonding member 600 is at least selected from the group consisting of silver (Ag), copper (Cu), palladium (Pd), gold (Au), platinum (Pt), aluminum (Al), nickel (Ni), and the like. It may be formed using a paste containing one type.

Covering insulating layer 160 is a layer provided to cover at least top surface 100A and side surface 100B of solid battery 100. As shown in FIG. 2, the solid state battery 100 provided on the substrate 200 is largely surrounded by the covering insulating layer 160. In a preferred embodiment, the covering insulating layer 160 is provided on the entire battery surface area on the top surface 100A and side surface 100B of the solid battery 100 (at least all of the battery "top" region and battery "side" region). .

As can be seen from the above description, the term "top surface" as used herein refers to a surface located relatively above among the surfaces constituting the battery. Assuming a typical solid state battery with two opposing main surfaces, the term "top surface" used herein refers to one of the main surfaces, particularly the main surface near the substrate. (That is, the main surface on the side different from the mounting surface side of an SMD type battery described later). Therefore, in the present invention, "a covering insulating layer provided to cover the top surface and side surfaces of a solid-state battery" refers to a surface other than the surface that would be in contact with the flat surface when the solid-state battery is placed on a flat surface. This essentially means that at least a covering insulating layer is provided on the battery surface other than the area.

Preferably, the covering insulating layer 160 corresponds to a resin layer. That is, it is preferable that the insulating cover layer 160 contains resin, and that resin forms the base material of the insulating cover layer 160. As can be seen from the illustrated embodiment, this means that the solid state battery provided on the substrate 200 is sealed with the resin material of the covering insulating layer 160. The covering insulating layer 160 made of such a resin material, together with the covering inorganic layer 170, contributes to a suitable water vapor barrier.

The material of the covering insulating layer 160 includes resin. Further, the covering insulating layer 160 may be of any type as long as it exhibits insulating properties, has an elastic modulus of 100 MPa or more in the operating temperature range of the solid battery package, and has a breaking strain of 2.5% or more. The resin contained in the insulating cover layer 160 is not particularly limited, and may be either a thermosetting resin or a thermoplastic resin. The operating temperature range of the solid state battery package is assumed to be, for example, from room temperature (25°C) to a high temperature of 125°C. Specific examples of the resin contained in the covering insulating layer 160 include epoxy resin, silicone resin, and/or liquid crystal polymer. For example, the insulating coating layer 160 may have an elastic modulus of 10 GPa or less and a breaking strain of 10% or less. Further, the elastic modulus of the covering insulating layer 160 may be, for example, 100 MPa or more at a temperature from 25° C. to 125° C. Preferably, it is 100 MPa or more and 10 GPa or less. The breaking strain of the covering insulating layer 160 is preferably 2.5% or more, for example. Preferably, it is 2.5% or more and 10% or less. Note that the glass transition temperature (Tg) of the insulating coating layer 160 is not particularly limited, but it is preferably −50° C. or higher. In addition, since the elastic modulus tends to decrease rapidly when the glass transition temperature (Tg) is exceeded, it is desirable that the glass transition temperature (Tg) is equal to or higher than the operating temperature range. More preferably, the glass transition temperature (Tg) is 125°C or higher. Although this is just an example, the thickness of the covering insulating layer may be 30 μm or more and 1000 μm or less, for example, 50 μm or more and 300 μm or less.

The covering inorganic layer 170 is provided to cover the covering insulating layer 160. As illustrated, since the covering inorganic layer 170 is positioned on the covering insulating layer 160, the covering inorganic layer 170 has a form that largely envelops the solid battery 100 on the substrate 200 together with the covering insulating layer 160. Note that, from the viewpoint of suitably providing a water vapor permeation barrier for the solid state battery 100, it is preferable that the covering inorganic layer 170 also covers the side surface 250 of the substrate 200.

Preferably, the covering inorganic layer 170 has a thin film form. The material of the covering inorganic layer 170 is not particularly limited as long as it contributes to an inorganic layer having a thin film form, and may be metal, glass, oxide ceramics, or a mixture thereof. In one preferred embodiment, the inorganic coating layer 170 includes a metal component. That is, the covering inorganic layer 170 is preferably a metal thin film. By way of example only, the thickness of such a coating inorganic layer may be 0.1 μm or more and 100 μm or less, for example, 1 μm or more and 50 μm or less.

Particularly depending on the manufacturing method, the covering inorganic layer 170 may be a dry plating layer. Such a dry plating layer is a film obtained by a vapor phase method such as physical vapor deposition (PVD) or chemical vapor deposition (CVD), and has a very small thickness on the order of nanometers or micrometers. are doing. Such thin dry plating layers lend themselves to more compact solid state battery packages.

The dry plating layer is made of, for example, aluminum (Al), nickel (Ni), palladium (Pd), silver (Ag), tin (Sn), gold (Au), copper (Cu), titanium (Ti), platinum (Pt). ), silicon/silicon (Si), SUS, etc., at least one metal component/metalloid component, an inorganic oxide, and/or a glass component. Dry plating layers made of such components are chemically and/or thermally stable, so solid battery packages with excellent chemical resistance, weather resistance, and/or heat resistance, and improved long-term reliability can be created. can be brought about.

In the present invention, a solid state battery is packaged with a covering insulating layer and a covering inorganic layer provided on a substrate so as to surround the solid state battery. In particular, solid state batteries are packaged to be suitable for surface mounting. In this respect, in the present invention, the board is preferably a terminal board. In other words, the substrate according to a certain preferred embodiment serves as a terminal substrate for external terminals of a solid state battery package.

In a solid-state battery that includes a substrate as a terminal board, the solid-state battery can be mounted on another secondary substrate such as a printed wiring board with the substrate interposed. For example, a solid state battery can be surface mounted via a substrate through solder reflow or the like. For this reason, it can be said that the solid state battery package of the present invention is an SMD (Surface Mount Device) type battery. Particularly when the terminal board is made of a ceramic substrate, the solid battery package of the present invention can be an SMD type battery that has high heat resistance and can be soldered.

Since it is a terminal board, it is preferable that it has wiring, an electrode layer, etc. In particular, the board may have an electrode layer that electrically connects the upper and lower main surfaces. That is, the substrate 200 according to a certain preferred embodiment includes an electrode layer that electrically connects the upper and lower main surfaces of the substrate, and serves as a member for the external terminal of the solid battery package 1000. In the solid state battery package 1000 including such a board, the electrode layer of the board and the terminal portion of the solid state battery are connected to each other. Specifically, the electrode layer of the substrate 200 and the end face electrode 100B of the solid battery 100 are electrically connected to each other. For example, the end face electrode on the positive side of a solid state battery is electrically connected to the electrode layer on the positive side of the substrate, while the end face electrode on the negative side of the solid state battery is electrically connected to the electrode layer on the negative side of the substrate. be done. By electrically connecting in this way, the electrode layers on the positive and negative sides of the substrate serve as the positive and negative terminals of the solid battery package 1000, respectively.

In a terminal board having such a conductive portion, the external terminal of the battery package can be drawn out at any position at the bottom of the package. Moreover, as can be seen from the form shown in FIG. 2, such an external terminal lead-out shape can be provided as a smooth surface within the same plane as the mounting package without substantial irregularities. In a solid battery equipped with such a substrate, a terminal can be taken out of the package at the shortest distance from the battery, so a battery package product with less loss can be provided. It can also be said that the terminals of the battery package product can be placed at optimal positions for the peripheral circuitry and the casing in which the battery is used.

In the terminal board according to the present invention, the opposing upper and lower surfaces are electrically connected to each other. Therefore, the type of terminal board is not particularly limited as long as it is of such a type. For example, an interposer that can be connected vertically and that can mount components may be used as the terminal board. The substrate material of the interposer may be ceramic.

In a solid-state battery that includes a substrate as a terminal substrate, wiring on the substrate and terminal portions of the solid-state battery are electrically connected to each other. That is, the conductive portion of the substrate and the end face electrode of the solid state battery are electrically connected to each other. Preferably, the conductive portion of the substrate and the end face electrode of the solid state battery are electrically connected to each other. For example, the end face electrode on the positive side of a solid state battery is electrically connected to the conductive part on the positive side of the substrate, while the end face electrode on the negative side of the solid state battery is electrically connected to the conductive part on the negative side of the substrate. It is connected to the. Thereby, the conductive portions (particularly the lower lands/bottom lands) on the positive and negative sides of the support substrate can be used as the positive and negative terminals, respectively, of the solid battery package product.

The solid state battery package of the present invention may further include a member that contributes to a suitable electrical connection between the terminal board and the solid state battery. For example, the solid state battery of the present invention may further include a conductive connection portion on the substrate that electrically connects the end electrode 100B and the conductive portion 17 to each other. The conductive connection portion includes at least one selected from the group consisting of silver (Ag), copper (Cu), palladium (Pd), gold (Au), platinum (Pt), aluminum (Al), nickel (Ni), etc. It may be formed using a paste comprising seeds.

The solid battery package, which is packaged with a substrate, a covering insulating layer, and a covering inorganic layer, is a battery that has particularly excellent water vapor permeation prevention properties. In other words, in the battery package product according to the present invention, deterioration of battery characteristics due to water vapor (more specifically, deterioration of battery characteristics due to water vapor) due to at least the insulating layer and the inorganic layer covering the top and side surfaces of the solid-state battery on the substrate. The phenomenon in which the characteristics of solid-state batteries deteriorate due to the ingress of water vapor from the environment is more reliably prevented.

Preferably, the coated inorganic layer is a water vapor barrier film. That is, a coated inorganic layer covers the top and side surfaces of the solid state battery so as to preferably serve as a barrier to prevent moisture from entering the solid state battery. The term "barrier" as used herein is broadly defined as having water vapor permeation blocking properties to the extent that water vapor in the external environment does not pass through the coating inorganic layer and cause characteristic deterioration that is inconvenient for solid-state batteries. In a narrow sense, it means that the water vapor permeability is less than 5.0×10 ⁻³ g/(m ² ·Day). Therefore, to put it simply, the water vapor barrier film preferably has a water vapor permeability of 0 or more and less than 5×10 ⁻³ g/(m ² ·Day). In addition, the "water vapor permeability" referred to in this specification refers to the transmittance obtained by the MA method using a gas permeability measuring device manufactured by MORESCO, model WG-15S, under measurement conditions of 85° C. and 85% RH. is pointing to.

In one preferred embodiment, the covering insulating layer and the covering inorganic layer are integrated with each other. Therefore, the covering inorganic layer together with the covering insulating layer forms a water vapor barrier for the solid state battery. In other words, the combination of the integrated covering insulating layer and covering inorganic layer better prevents water vapor from the external environment from entering the solid state battery.

In the present invention, the substrate supporting the solid-state battery is positioned so as to cover the lower side (bottom side) of the solid-state battery, and thus contributes to preventing water vapor from permeating from the lower side (bottom side). That is, the substrate is preferably a water vapor barrier substrate. The term "barrier" used here has the same meaning as above, and means that water vapor in the external environment does not pass through the coating inorganic layer and has the property of preventing water vapor permeation to the extent that it does not cause characteristic deterioration that is disadvantageous for solid-state batteries. In a narrow sense, this means that the water vapor permeability of the substrate is 5.0×10 ⁻³ g/(m ² ·Day). Therefore, the water vapor barrier substrate preferably has a water vapor permeability of 0 or more and less than 5×10 ⁻³ g/(m ² ·Day). In this way, when the supporting substrate is a water vapor barrier substrate, the barrier effect is produced by the substrate itself, so that there is no need to provide a covering inorganic layer on the bottom side of the substrate. In other words, although the covering inorganic layer is provided so as to largely envelop the solid-state battery, it is not particularly necessary to provide it on a part of the substrate (specifically, the bottom surface) (in other words, there is no need to provide it on a part of the substrate In a preferred embodiment, the coated inorganic layer is provided on most, but not all, sides of the battery package.

When the substrate is a ceramic substrate, the effect of preventing water vapor permeation of the substrate is more likely to be achieved. If the substrate has water vapor barrier properties, water vapor permeation from the top and side sides of the solid-state battery can be mainly prevented by the covering insulating layer and the covering inorganic layer, while water vapor transmission from the bottom side (bottom side) of the solid-state battery can be prevented mainly by the covering insulating layer and the covering inorganic layer. can be mainly prevented by the substrate. Considering that the substrate is preferably a terminal substrate, it can be said that prevention of water vapor permeation from the lower side (bottom side) of the solid state battery is mainly achieved by the terminal substrate.

In the present invention, the solid battery on the substrate is covered with an inorganic coating layer via an insulating coating layer, and the insulating coating layer contains a resin and has an elastic modulus in the operating temperature range of the solid battery package. is 100 MPa or more, and the fracture strain is 2.5% or more. Note that the usage temperature range of the solid battery package is assumed to be, for example, from room temperature (25°C) to a high temperature of 125°C. Therefore, the covering insulating layer can suitably serve as a buffer material. Specifically, even if expansion and contraction of a solid-state battery occurs due to charging/discharging or thermal expansion, this effect does not directly affect the covering inorganic layer, but is caused by the intervening insulating layer. A buffering effect can alleviate that effect. Therefore, it is possible to suppress the occurrence of cracks in the solid-state battery package due to charging and discharging of the solid-state battery, the occurrence of peeling of the coating, and the destruction of the internal structure of the solid-state battery due to insufficient binding force of the coating. As a result, a more suitable water vapor barrier can be provided by suppressing the occurrence of cracks in the solid battery package and peeling of the coating. Moreover, by suppressing the destruction of the internal structure of the solid-state battery, the battery characteristics of the solid-state battery can be suitably provided. Note that such a buffering effect can be particularly large when the solid battery package has an elastic modulus of 100 MPa or more and 10 GPa or less and a fracture strain of 2.5% or more and 10% or less in the operating temperature range of the solid battery package.

In such battery package products, it is preferable that a resin layer is molded between the solid battery and the barrier film/barrier substrate, which has strong mechanical strength and is resistant to deformation due to stress from inside and outside. Therefore, it is possible to install battery package products in high-precision equipment.

Furthermore, in the battery package product of the present invention, although water vapor permeation is prevented, the members contributing to this are a covering inorganic thin film integrated with a covering insulating layer, and a substrate that may have a thin plate shape. Therefore, the package size does not become inconveniently large. That is, in a preferred embodiment, the solid state battery package can be provided as a high energy density battery (packaged battery).

Solid state battery packages can be embodied in a variety of ways. For example, the following aspects are possible.

(Aspects of filler content)
In such an embodiment, the covering insulating layer 160 may contain a filler. Preferably, an inorganic filler is dispersed in the resin contained in the insulating cover layer 160.

The filler is preferably mixed into the insulating cover layer and integrated with the base material (for example, resin) of the insulating cover layer. The shape of the filler is not particularly limited, and may be granular, spherical, acicular, plate-like, fibrous, and/or amorphous. The size of the filler is also not particularly limited, and may be 10 nm or more and 100 μm or less, for example, a nano filler of 10 nm or more and less than 100 nm, a micro filler of 100 nm or more and less than 10 μm, or a macro filler of 10 μm or more and 100 μm or less. . Examples of the filler material include, but are not limited to, silica, alumina, metal oxides such as titanium oxide and zirconium oxide, minerals such as mica, and glass.

The filler is preferably a water vapor permeation prevention filler. In a preferred embodiment, the insulating coating layer contains a water vapor permeation preventive filler in its resin material. This makes it easier for the covering insulating layer to serve as a more suitable water vapor permeation barrier together with the covering inorganic layer.

The water vapor permeation preventing filler is not particularly limited, but may be a plate-shaped filler or the like. Further, the water vapor permeation preventing filler may be made of a material such as silica or alumina. Furthermore, it may be made of a mica-based material such as synthetic mica. More preferably, it is silica. The water vapor permeation prevention filler contained in the resin material preferably has a content of 1% by weight or more and 95% by weight or less based on the entire insulating coating layer, for example, 1% by weight or more and 95% by weight or less based on the entire insulating coating layer. The content may be from 30% to 60% by weight, or from 30% to 60% by weight.

(Aspects of sputtered film)
In such an embodiment, the covering inorganic layer is a sputtered film. That is, a sputtered thin film is provided as a dry plating layer provided so as to cover the covering insulating layer.

A sputtered film is a thin film obtained by sputtering. In other words, a film formed by sputtering ions onto a target to knock out the atoms and depositing the resulting insulating layer on the covering insulating layer is used as the covering inorganic thin film.

Such a sputtered film is a dense and/or homogeneous film even though it has a very thin morphology on the nano- or micro-order, and is therefore preferable as a water vapor permeation barrier for solid-state batteries. Furthermore, since the sputtered film is formed by atomic deposition, it has relatively high adhesion and can be more preferably integrated with the covering inorganic thin film. Therefore, the sputtered film can easily constitute a water vapor barrier film for a solid-state battery together with the covering insulating layer. That is, the sputtered film provided to cover at least the top and side surfaces of the solid-state battery together with the covering insulating layer can be more suitably used as a barrier to prevent water vapor from the external environment from entering the solid-state battery.

In a preferred embodiment, the sputtered film contains at least one member selected from the group consisting of, for example, Al (aluminum), Cu (copper), and Ti (titanium), and has a thickness of 1 μm or more and 100 μm or less, For example, it is 5 μm or more and 50 μm or less. In addition, although not particularly limited, the sputtered film has substantially the same thickness regardless of whether it is located on the top surface of the solid-state battery or on the side surface of the solid-state battery. It is preferable. This is because it is possible to more uniformly prevent water vapor from the external environment from entering the solid state battery as a whole package.

Note that the dry plating layer represented by such a sputtered film can be realized with a more suitable thickness from the viewpoint of a water vapor barrier. For example, a thicker film can be provided by relatively increasing the number of sputtering operations, while a thinner film can be provided by relatively decreasing the number of sputtering operations. Further, it is also possible to provide a coated inorganic layer with a laminated structure by, for example, changing the type of target during sputtering. In other words, the covering inorganic layer can also be provided as a multilayer structure consisting of at least two layers. The multi-layer structure is not limited to materials of different types, but may also be formed between materials of the same type. A covering inorganic layer having such a multilayer structure can easily constitute a water vapor barrier for a solid-state battery.

A wet plating layer may be provided on the dry plating layer. A wet plating layer generally has a faster film formation rate than a dry plating layer. Therefore, when a thick film is provided as a covering inorganic layer, efficient film formation can be achieved by combining a dry plating layer with a wet plating layer.

[Method for manufacturing solid battery package]
The object of the present invention is obtained by preparing a solid battery including a battery constituent unit having a positive electrode layer, a negative electrode layer, and a solid electrolyte between these electrodes, and then packaging the solid battery. be able to.

The production of solid-state battery packages can be broadly divided into the production of the solid-state battery itself (hereinafter also referred to as "pre-packaged battery"), which corresponds to the pre-packaging stage, the preparation of the substrate, and packaging.

≪Method of manufacturing pre-packaged battery≫
The pre-packaged battery can be manufactured by a printing method such as a screen printing method, a green sheet method using a green sheet, or a combination thereof. In other words, the pre-packaged battery itself may be manufactured according to the conventional manufacturing method of solid-state batteries (therefore, the solid electrolyte, organic binder, solvent, optional additives, positive electrode active material, negative electrode active material, etc. described below), etc. (The raw material used in the production of known solid-state batteries may be used.)

In the following, one manufacturing method will be exemplified and explained for a better understanding of the present invention, but the present invention is not limited to this method. Further, the following chronological matters such as the order of description are merely for convenience of explanation, and are not necessarily restricted thereto.

(Laminated block formation)
- Prepare a slurry by mixing the solid electrolyte, organic binder, solvent, and optional additives. Next, a sheet having a thickness of about 10 μm after firing is obtained from the prepared slurry by sheet molding.
・Create a positive electrode paste by mixing the positive electrode active material, solid electrolyte, conductive aid, organic binder, solvent, and optional additives. Similarly, a negative electrode paste is prepared by mixing the negative electrode active material, solid electrolyte, conductive aid, organic binder, solvent, and optional additives.
- Print a positive electrode paste on the sheet, and also print a current collecting layer and/or a negative layer as necessary. Similarly, a negative electrode paste is printed on the sheet, and if necessary, a current collecting layer and/or a negative layer are printed.
- Obtain a laminate by alternately stacking sheets printed with positive electrode paste and sheets printed with negative electrode paste. Note that the outermost layer (top layer/bottom layer) of the laminate may be an electrolyte layer, an insulating layer, or an electrode layer.

(Battery sintered body formation)
After the laminate is crimped and integrated, it is cut into a predetermined size. The obtained cut laminate is subjected to degreasing and firing. Thereby, a sintered laminate is obtained. Note that the laminate may be degreased and fired before cutting, and then the laminate may be cut.

(End face electrode formation)
The end electrode on the positive electrode side can be formed by applying a conductive paste to the exposed side surface of the positive electrode in the sintered laminate. Similarly, the end electrode on the negative electrode side can be formed by applying a conductive paste to the exposed side surface of the negative electrode in the sintered laminate. It is preferable to provide the end electrodes on the positive and negative electrodes so as to cover the main surface of the sintered laminate, since this allows connection to the mounting land in a small area in the next process (more specifically, it is preferable to The end surface electrode provided so as to extend to the main surface has a folded portion on the principal surface, and such a folded portion can be electrically connected to the mounting land). The component of the end electrode may be selected from at least one selected from silver, gold, platinum, aluminum, copper, tin, and nickel.

Note that the end electrodes on the positive electrode side and the negative electrode side are not limited to being formed after sintering the laminate, but may be formed before firing and subjected to simultaneous sintering.

By going through the steps described above, a desired pre-packaged battery (corresponding to the solid state battery 100 shown in FIG. 3C) can finally be obtained.

≪Preparation of substrate≫
The substrate can be prepared, for example, by laminating and firing a plurality of green sheets. This is especially true when the substrate is a ceramic substrate. The substrate can be prepared, for example, in a similar manner to the preparation of an LTCC substrate.

A board used as a terminal board may have vias and/or lands. In such cases, for example, holes (diameter size: approximately 50 μm to approximately 200 μm) may be formed in the green sheet using a punch press or a carbon dioxide laser, and the holes may be filled with a conductive paste material, or a printing method may be used. Precursors of conductive portions/wirings such as vias, lands and/or wiring layers may be formed by performing the following steps. Further, the substrate preferably includes a non-connected metal layer that is not electrically connected as a water vapor permeation prevention layer. In such a case, a metal layer (precursor thereof) serving as a non-connected metal layer may be formed on the green sheet. Such a metal layer may be formed by a printing method or by arranging metal foil or the like. Next, a green sheet laminate is formed by stacking a predetermined number of such green sheets and bonding them under thermocompression, and the green sheet laminate is fired to obtain a substrate. Note that the lands and the like can also be formed after the green sheet laminate is fired.

Although this is just one example and does not limit the present invention, a green sheet in the case where the substrate is obtained as a ceramic substrate will be described in detail. The green sheet itself may be a sheet-like member comprising a ceramic component, a glass component and an organic binder component. For example, the ceramic component may be alumina powder (average particle size: about 0.5 to 10 μm), and the glass component may be borosilicate glass powder (average particle size: about 1 to 20 μm). . The organic binder component may be, for example, at least one component selected from the group consisting of polyvinyl butyral resin, acrylic resin, vinyl acetate copolymer, polyvinyl alcohol, and vinyl chloride resin. By way of example only, the green sheet may contain 40-50 wt% alumina powder, 30-40 wt% glass powder, and 10-30 wt% organic binder components (based on the total weight of the green sheet). In addition, from another point of view, green sheets are based on the weight ratio of solid components (50 to 60 wt% of alumina powder and 40 to 50 wt% of glass powder: based on the weight of solid components) and organic binder components. Component weight: Organic binder component weight may be about 80-90:10-20. The green sheet component may contain other components as necessary, such as plasticizers that impart flexibility to the green sheet such as phthalate esters and dibutyl phthalate, and dispersants for ketones such as glycol. It may contain organic solvents, organic solvents, etc. The thickness of each green sheet itself may be approximately 30 μm to 500 μm.

By going through the steps described above, a desired substrate 200 (see FIG. 3A) can finally be obtained.

≪Packaging≫
For packaging, the battery and substrate obtained above are used. 3A to 3E schematically show the process of obtaining a solid battery package by packaging.

First, as shown in FIGS. 3A to 3C, the pre-packaged battery 100 is placed on the substrate 200. That is, an "unpackaged solid-state battery" is placed on the substrate (hereinafter, the battery used for packaging is also simply referred to as a "solid-state battery").

Preferably, the solid-state battery is placed on the substrate such that the conductive portion of the substrate and the end face electrode of the solid-state battery are electrically connected to each other. For example, a conductive paste may be provided on the substrate, thereby electrically connecting the conductive portion of the substrate and the end electrode of the solid state battery to each other. More specifically, the conductive parts on the positive and negative sides of the main surface of the substrate (in particular, the lower lands/bottom lands) are aligned so that they are aligned with the end face electrodes of the positive and negative electrodes of the solid-state battery, respectively. and conductive paste (for example, Ag conductive paste) is used to connect and connect the wires. That is, a precursor of a bonding member responsible for electrical connection between the solid-state battery and the substrate may be provided in advance. In addition to Ag conductive paste, the precursor of such a joining member can be provided by printing a conductive paste that does not require cleaning with flux or the like after formation, such as nanopaste, alloy paste, brazing material, etc. . Next, the solid-state battery is placed on the substrate so that the end electrode of the solid-state battery and the precursor of the bonding member are in contact with each other, and the electrical connection between the solid-state battery and the substrate is established from the precursor by subjecting it to heat treatment. A joining member that contributes to this process is formed.

Next, as shown in FIG. 3D, a covering insulating layer 160 is formed so as to cover the solid state battery 100 on the substrate 200. Therefore, the raw material for the covering insulating layer is provided so that the solid state battery on the substrate is completely covered. When the insulating cover layer is made of a resin material, the insulating cover layer is formed by providing a resin precursor on the substrate and subjecting it to curing. In a preferred embodiment, the covering insulating layer may be formed by applying pressure with a mold. By way of example only, the overlying insulating layer encapsulating the solid state battery on the substrate may be formed through compression molding. As long as the resin material is generally used in molds, the raw material for the insulating coating layer may be in the form of granules, and may be thermoplastic. Note that such molding is not limited to mold molding, and may be performed through polishing, laser processing, and/or chemical treatment.

Thereafter, as shown in FIG. 3E, a covering inorganic layer 170 is formed. Specifically, the covering inorganic layer 170 is formed on "a covering precursor in which each solid-state battery 100 is covered with a covering insulating layer 160 on a substrate 200". For example, dry plating may be performed to form a dry plating layer as the covering inorganic layer. More specifically, dry plating is performed to form a coating inorganic layer on exposed surfaces other than the bottom surface of the coating precursor (ie, other than the bottom surface of the substrate). In some preferred embodiments, sputtering is performed to form a sputtered film on the exposed outer surface of the coating precursor other than the bottom surface.

By going through the above steps, it is possible to obtain a packaged product in which the solid battery on the substrate is completely covered with the insulating layer and the inorganic layer. In other words, the "solid battery package" according to the present invention can finally be obtained.

Regarding such packaging, an advantage is that it is relatively easy to draw out the terminals of solid-state batteries in terms of design and bonding process. Furthermore, as solid-state batteries become smaller, the area ratio of the package to the battery becomes smaller, and the packaging according to the present invention can make this area extremely small, which can particularly contribute to the miniaturization of small-capacity batteries.

Although the embodiments of the present invention have been described above, these are merely typical examples. Those skilled in the art will readily understand that the present invention is not limited thereto, and that various embodiments can be considered without changing the gist of the present invention.

Examples of the present invention will be described below.

A demonstration experiment regarding the present invention was conducted. The structure of the solid-state battery package was as shown in Figure 2. Furthermore, the process shown in FIG. 3 was adopted as the process for obtaining the solid battery package.
Specifically, a solid battery package 1000 was manufactured that includes a covering insulating layer 160 using the resins described in Comparative Examples 1 to 5 and Examples 1 to 9 shown in Table 1 below.

The values of the glass transition temperature (Tg) and elastic modulus of the resin used for the insulating coating layer were those obtained by a method based on the JIS standard JIS K 7244 "Testing method for dynamic mechanical properties of plastics." The elastic modulus was measured by the dynamic viscoelasticity (DMA) method, and the storage elastic modulus at 25°C and 125°C was used. As the glass transition temperature (Tg), the peak value of the loss tangent (tan δ) obtained by dynamic viscoelasticity measurement was adopted.
Loss tangent (tanδ) = E'' (loss modulus) / E' (storage modulus)

For materials with an elastic modulus of 1 GPa or more, the fracture strain of the resin used for the coating insulation layer is the value obtained by a method compliant with JIS standard JIS K7171 (Plastics - How to determine bending properties), and for materials with an elastic modulus of less than 1 GPa. For the material, values obtained by a method based on the JIS standard JIS K7161 (Plastics - How to determine tensile properties) were adopted. For materials with an elastic modulus of 1 GPa or more, a three-point bending test was performed to calculate the bending fracture strain. For materials with an elastic modulus of less than 1 GPa, a tensile test was conducted and the tensile fracture strain was calculated.

After producing the solid battery package, a charge/discharge test was conducted for 50 cycles. The operation of the solid-state battery package after the charge-discharge test was checked to confirm that it operated normally, and the presence or absence of any abnormalities in the solid-state battery package after the charge-discharge cycle was investigated.

The measurement results are shown in Table 1 below.

According to the above results, in the solid-state battery packages of Comparative Examples 1 to 3, destruction of the internal solid-state battery was confirmed after the charge-discharge cycle, and the packages did not operate normally. This is because a resin with an elastic modulus of 100 MPa or less was used, so the binding force of the solid-state battery was low, and structural destruction of the solid-state battery progressed due to repeated charging and discharging. In Comparative Examples 4 and 5, cracks and peeling between the substrate and the resin were observed within the solid battery package. This is because the breaking strain is 2.5% or less, so the elongation rate of the insulating coating layer is small, and cracks occur due to expansion of the solid-state battery during charging and discharging, and interface peeling between the insulating coating layer and the substrate occurs, resulting in malfunction. This is because I woke him up. It was confirmed that Examples 1 to 9 in which a covering insulating layer with an elastic modulus of 100 MPa or more and a breaking strain of 2.5% or more operated normally even after charge/discharge cycles. Therefore, it has been found that the covering insulating layer covering the solid battery preferably has an elastic modulus of 100 MPa or more and a breaking strain of 2.5% or more. This makes it possible to suppress cracks in the solid-state battery package and peeling of the coating due to charging and discharging of the solid-state battery, as well as damage to the internal structure of the solid-state battery due to insufficient binding force of the coating. I understand.

A solid state battery package according to an embodiment of the present invention can be used in various fields where battery use or power storage is expected. By way of example only, the packaged solid state battery of the present invention can be used in the electronics packaging field. In addition, the fields of electricity, information, and communication where mobile devices are used (e.g., mobile devices such as mobile phones, smartphones, notebook computers, digital cameras, activity monitors, arm computers, electronic paper, etc.), household and small industrial applications, etc. (e.g. power tools, golf carts, household/nursing care/industrial robots), large industrial applications (e.g. forklifts, elevators, harbor cranes), transportation systems (e.g. hybrid vehicles, electric vehicles) , buses, trains, electrically assisted bicycles, electric motorcycles, etc.), power system applications (e.g., various power generation, road conditioners, smart grids, home-installed power storage systems, etc.), as well as the IoT field, space and deep sea. The electrode of the present invention can also be used in applications (for example, fields such as space probes and underwater research vessels).

100 Solid state battery 100A Top surface (upper surface) of solid state battery
100B Side surface of solid battery 110 Positive electrode layer 120 Negative electrode layer 130 Solid electrolyte 140 End electrode 140A End electrode on positive electrode side 140B End electrode on negative electrode side 150 Covering section 160 Covering insulating layer 170 Covering inorganic layer 200 Substrate 210 Substrate electrode layer (substrate upper side)
210A Substrate electrode layer on positive electrode side 210B Substrate electrode layer on negative electrode side 220 Substrate electrode layer (mounting side/lower side of substrate)
220A Plate electrode layer on positive electrode side (mounting side/bottom side of board)
220B Negative side board electrode layer (mounting side/bottom side of board)
250 Side surface of substrate 600 Bonding member 600' Conductive paste 1000 Battery package product (solid battery package)

Claims (7)

A substrate and
a solid state battery provided on the substrate;
a covering portion configured of at least an insulating covering layer provided on the substrate to cover the solid-state battery and an inorganic covering layer provided outside the insulating covering layer;
A solid battery package, wherein the covering insulating layer contains a resin, has an elastic modulus of 100 MPa or more, and a breaking strain of 2.5% or more. The solid battery package according to claim 1, wherein the elastic modulus is 10 GPa or less and the fracture strain is 10% or less. The solid battery package according to claim 1 or 2, wherein the resin is at least one selected from the group consisting of epoxy resin, silicone resin, and liquid crystal polymer. The solid battery package according to any one of claims 1 to 3, wherein the resin contains a filler. The solid battery package according to any one of claims 1 to 4, wherein the covering inorganic layer is provided to cover the covering insulating layer and the side surface of the substrate. The solid state battery package according to any one of claims 1 to 5, wherein the solid state battery is made of a sintered body. The solid-state battery package according to claim 1, wherein the positive electrode layer and negative electrode layer of the solid-state battery are layers capable of intercalating and deintercalating lithium ions.

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