Solid-state battery and electronic device

Abstract

Provided are a solid-state battery and an electronic device capable of alleviating stress generated by volume change. The solid-state battery is provided with: a plurality of solid-state battery elements (141) in which a positive electrode layer (110), a negative electrode layer (120), and a solid electrolyte layer (130) interposed between the positive electrode layer (110) and the negative electrode layer (120) are laminated; and an interlayer conduction layer (170) positioned between the solid-state battery elements (141), the interlayer conduction layer (170) being sandwiched between the positive electrode layer (110) or the negative electrode layer (120) of one solid-state battery element (141) and the positive electrode layer (110) or the negative electrode layer (120) of the other solid-state battery element (141), and the positive electrode layer (110) or the negative electrode layer (120) sandwiching the interlayer conduction layer (170) containing a solid electrolyte. The solid electrolyte ratio of the positive electrode layer (110) or the negative electrode layer (120) sandwiching the interlayer conduction layer (170) is 40% by weight or more and 60% by weight or less with respect to the whole of the positive electrode layer (110) or the negative electrode layer (120), and the solid electrolyte ratio of the interlayer conduction layer (170) is 10% by weight or more and 35% by weight or less with respect to the whole of the interlayer conduction layer (170).

Description

Technical Field

[0001] The present disclosure relates to solid-state batteries and electronic devices. Background Art

[0002] Conventionally, 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.

[0003] In a secondary battery, a liquid electrolyte is generally used as a medium for ion movement that facilitates charge and discharge. That is, the so-called electrolyte is used in a secondary battery. However, in such a secondary battery, safety is generally required in terms of preventing leakage of the electrolyte. In addition, since the organic solvent used in the electrolyte is a flammable substance, safety is also required in this regard.

[0004] Therefore, solid batteries using solid electrolytes instead of electrolyte solutions have been studied.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2018-166020 Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] Generally speaking, it is known that when a battery is charged or discharged, the positive electrode or the negative electrode undergoes a volume change, and the stress generated by the volume change may cause the battery to rupture. Various countermeasures are being studied to prevent the battery from rupturing.

[0010] For example, Patent Document 1 discloses a structure in which the interfaces of the positive electrode layer and the solid electrolyte layer and the negative electrode layer and the solid electrolyte are interlaced as a fully solid battery that does not break, warp, or have interlayer cracks or peeling. According to Patent Document 1, by increasing the bonding strength between the layers, cracks, warping, cracks between the layers, or peeling are less likely to occur (see paragraph

[0022] of Patent Document 1).

[0011] However, the all-solid-state battery described in Patent Document 1 does not have a structure that releases stress generated by volume change (relaxed structure), and there is a risk that the battery may rupture due to stress accumulation.

[0012] The present disclosure has been made in view of such technical problems. That is, the main purpose of the present disclosure is to provide a solid battery and an electronic device that can alleviate stress generated by volume change.

[0013] Technical solutions for solving technical problems

[0014] The inventors of the present application have attempted to solve the above technical problems by taking measures in a new direction instead of extending the existing technology. As a result, a solid battery that can achieve the above main purpose has been completed.

[0015] The solid battery involved in the present disclosure comprises:

[0016] A plurality of solid battery elements, each of which is stacked with a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer; and

[0017] The interlayer conducting layer is located between the solid battery elements.

[0018] The interlayer conductive layer is sandwiched between the positive electrode layer or negative electrode layer of one solid battery element and the positive electrode layer or negative electrode layer of another solid battery element.

[0019] The positive electrode layer or the negative electrode layer sandwiching the interlayer conductive layer contains a solid electrolyte.

[0020] The solid electrolyte ratio of the positive electrode layer or the negative electrode layer sandwiching the interlayer conductive layer is 40 wt % or more and 60 wt % or less based on the entire positive electrode layer or the negative electrode layer.

[0021] The solid electrolyte ratio of the interlayer conductive layer is 10 wt % or more and 35 wt % or less based on the entire interlayer conductive layer.

[0022] Furthermore, the electronic device according to the present disclosure has the above-mentioned solid battery mounted on its surface.

[0023] Effects of the Invention

[0024] According to the present disclosure, a solid battery and an electronic device capable of relaxing stress generated due to volume change can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional view of the main parts of the solid battery disclosed in the present invention.

[0026] Figure 2 This is a cross-sectional view of a main part of a modified example of the solid battery disclosed in the present invention.

[0027] Figure 3 This is a cross-sectional view of a main part of a modified example of the solid battery disclosed in the present invention.

[0028] Figure 4 is a cross-sectional view of the solid battery of the present disclosure.

[0029] Figure 5 It is a process cross-sectional view showing the manufacturing process of the solid battery of the present disclosure. DETAILED DESCRIPTION

[0030] The following is a detailed description of the "solid battery" and the "electronic device" with a solid battery mounted on the surface of the present disclosure. Although the description is made with reference to the accompanying drawings as needed, the contents of the drawings are only schematically and exemplarily shown for the purpose of understanding the present disclosure, and the appearance and size ratio may be different from the actual object.

[0031] First, the "solid battery" involved in the embodiment of the present disclosure is described. The "solid battery" mentioned in the present disclosure refers to a battery whose constituent elements are composed of solids in a broad sense, and refers to an all-solid battery whose battery constituent elements (particularly preferably all battery constituent elements) are composed of solids in a narrow sense. In a preferred embodiment, the solid battery in the present disclosure is a stacked solid battery constructed in a manner that the layers constituting the battery structural unit are stacked on each other, and preferably such layers are sintered bodies. It should be noted that the "solid battery" includes not only the so-called "secondary battery" that can be repeatedly charged and discharged, but also a "primary battery" that can only be discharged. According to a preferred embodiment of the present disclosure, the "solid battery" is a secondary battery. The "secondary battery" is not overly rigid in its name, for example, it can also include power storage devices, etc.

[0032] The "overhead observation" mentioned in this specification refers to the form when the object is observed from the upper or lower side along the thickness direction based on the stacking direction of each layer constituting the solid battery. In addition, the "cross-sectional observation" mentioned in this specification refers to the form when the object is observed from a direction roughly perpendicular to the thickness direction based on the stacking direction of each layer constituting the solid battery (in short, the form when the surface is cut parallel to the thickness direction). The "up and down directions" and "left and right directions" used directly or indirectly in this specification are respectively equivalent to the up and down directions and left and right directions in the figure. Unless otherwise specified, the same figure mark or symbol represents the same part / part or the same meaning. In a preferred embodiment, it can be understood that the vertical direction downward (i.e., the direction of gravity) is equivalent to the "downward direction", and the opposite direction is equivalent to the "upward direction". In addition, in the description of this specification, the reference to direction or orientation is only for the convenience of explanation, unless otherwise clearly stated, it is not intended to limit the scope of the present disclosure. For example, relative terms such as "outside (or outside)", "inside (or inside)" and their derivative terms should be understood to refer to the direction as recorded or illustrated. That is, unless otherwise specifically stated, the invention is not necessarily limited to a specific direction / orientation / form, etc. In addition, the same applies to terms such as "set", "configure" and their derivatives, which are not limited to direct methods, but may also be methods involving other elements such as intervening objects, unless otherwise specifically stated.

[0033] [Structure of solid-state batteries]

[0034] Solid state battery 100 (refer to Figures 1 to 4 ) has a stacked body 140, which includes: a solid battery element 141, which includes a battery structural unit composed of a positive electrode layer 110, a negative electrode layer 120 and at least a solid electrolyte layer 130 interposed therebetween; and an interlayer conductive layer 170, which is located between each solid battery element 141. The interlayer conductive layer 170 is sandwiched between the positive electrode layer 110 or the negative electrode layer 120 of one solid battery element 141 and the positive electrode layer 110 or the negative electrode layer 120 of another solid battery element 141. The positive electrode layer 110 or the negative electrode layer 120 sandwiching the interlayer conductive layer 170 contains a solid electrolyte, and the solid electrolyte ratio of the positive electrode layer 110 or the negative electrode layer 120 sandwiching the interlayer conductive layer 170 is greater than 40 weight% and less than 60 weight% based on the layer containing the solid electrolyte, and the solid electrolyte ratio of the interlayer conductive layer 170 is greater than 10 weight% and less than 35 weight% based on the layer containing the solid electrolyte.

[0035] According to the solid battery 100 disclosed in the present invention, the solid electrolyte ratio of the interlayer conductive layer 170 is smaller than the solid electrolyte ratio of the positive electrode layer 110 or the negative electrode layer 120 sandwiching the interlayer conductive layer 170. Here, if the solid electrolyte ratio is small, the strength of the layer structure is reduced. Therefore, the strength of the interlayer conductive layer 170 is lower than the strength of the positive electrode layer 110 or the negative electrode layer 120 sandwiching the interlayer conductive layer 170. Therefore, if stress is accumulated inside the solid battery, the stress can be concentrated on the interlayer conductive layer 170 with low strength. As an example, by causing cracks in the interlayer conductive layer 170, the stress can be relieved.

[0036] In addition, the interlayer conductive layer 170 contributes less to the solid battery characteristics than the solid battery element 141. Therefore, even if stress is concentrated on the interlayer conductive layer 170 and a load is applied to cause cracks, the effect on the solid battery characteristics is small. In other words, by applying a load to the interlayer conductive layer 170 side, the load applied to the solid battery element 141 side can be reduced, thereby preventing the deterioration of the solid battery characteristics.

[0037] Furthermore, the production adaptability of the solid battery can be maintained by setting the solid electrolyte ratio of the positive electrode layer 110 or the negative electrode layer 120 sandwiching the interlayer conductive layer 170 and the solid electrolyte ratio of the interlayer conductive layer 170 to the above numerical range.

[0038] 1. Solid battery elements

[0039] The solid battery element 141 is a battery structural unit composed of a positive electrode layer 110, a negative electrode layer 120, and at least a solid electrolyte layer 130 interposed therebetween. A plurality of the solid battery elements 141 may be stacked with an interlayer conductive layer 170 interposed therebetween. Figure 1 In the embodiment, two solid battery elements 141 may be stacked with an interlayer conductive layer 170 interposed therebetween. Figure 3 In the embodiment, four solid battery elements 141 may be stacked with the interlayer conductive layer 170 interposed therebetween. More specifically, the plurality of solid battery elements 141 may be electrically connected in parallel to each other. By electrically connecting the plurality of solid battery elements in parallel, the desired battery characteristics can be obtained.

[0040] Each layer of the solid battery element 141 can be formed by sintering. That is, the positive electrode layer 110, the negative electrode layer 120 and the solid electrolyte layer 130 can also form a sintered layer. Preferably, the positive electrode layer 110, the negative electrode layer 120 and the solid electrolyte layer 130 can be sintered integrally with each other and composed of a sintered body. More preferably, the stacked body 140 in which the interlayer conductive layer 170 is sandwiched between a plurality of solid battery elements 141 can also be sintered integrally to form an integral sintered body. It should be noted that in this specification, the direction (vertical direction) in which the positive electrode layer and the negative electrode layer are stacked is referred to as the "stacking direction", and the direction intersecting the stacking direction is the horizontal direction in which the positive electrode layer and the negative electrode layer extend.

[0041] 1-1. Positive electrode layer and negative electrode layer

[0042] The positive electrode layer 110 may be an electrode layer including at least a positive electrode active material layer 111 and a positive electrode collector layer 112. In a preferred embodiment, the positive electrode active material layer 111 may be composed of a sintered body containing at least positive electrode active material particles and solid electrolyte particles. In addition, the positive electrode collector layer 112 may further contain a solid electrolyte. On the other hand, the negative electrode layer 120 may be an electrode layer including at least a negative electrode active material layer 121 and a negative electrode collector layer 122. In a preferred embodiment, the negative electrode active material layer 121 may be composed of a sintered body containing at least negative electrode active material particles and solid electrolyte particles. In addition, the negative electrode collector layer 122 may further contain a solid electrolyte.

[0043] Here, the positive electrode active material and the negative electrode active material are substances that participate in the transfer of electrons in the solid battery. Charging and discharging are performed by moving (or conducting) ions between the positive electrode layer and the negative electrode layer via the solid electrolyte and transferring electrons between the positive electrode layer and the negative electrode layer via the external terminal.

[0044] Example Figures 1 to 3) illustrates a structure of a positive electrode layer 110 formed by stacking one positive electrode active material layer 111 and one positive electrode collector layer 112 for each solid battery element 141, and a negative electrode layer 120 formed by stacking one negative electrode active material layer 121 and one negative electrode collector layer 122. However, the number of stacking is not limited to this example, and the active material layer and the collector layer can also be more than 2 layers. The film thickness of the positive electrode layer 110 or the negative electrode layer 120 can be more than 5μm and less than 60μm, preferably more than 8μm and less than 50μm. In addition, it can also be more than 5μm and less than 30μm.

[0045] (Positive Electrode Active Material Layer)

[0046] The positive electrode active material contained in the positive electrode active material layer 111 may be, for example, a lithium-containing compound or a sodium-containing compound. That is, it is capable of inserting and extracting lithium ions or sodium ions. The type of lithium-containing compound is not particularly limited, and may be, for example, a lithium transition metal composite oxide and / or a lithium transition metal phosphate compound. Lithium transition metal composite oxides are a general term for oxides containing lithium and one or more transition metal elements as constituent elements. Lithium transition metal phosphate compounds are 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, and may be, for example, cobalt (Co), nickel (Ni), manganese (Mn) and / or iron (Fe).

[0047] Lithium transition metal composite oxides are, for example, Li x M1O2 and Li y Compounds represented by M2O4, etc. Lithium transition metal phosphate compounds are, for example, Li z Compounds represented by M3PO4, etc. wherein M1, M2 and M3 are each one or more transition metal elements. The values ​​of x, y and z are arbitrary.

[0048] Specifically, lithium transition metal composite oxides include LiCoO2, LiNiO2, LiVO2, LiCrO2, LiMn2O4, LiCo 1 / 3 Ni 1 / 3 Mn 1 / 3 O2 and LiNi 0.5 Mn 1.5O4, etc. In addition, lithium transition metal phosphate compounds are, for example, LiFePO4, LiCoPO4 and LiMnPO4, etc. Lithium transition metal composite oxides (especially LiCoO2) may contain trace amounts (about a few %) of additive elements. As additive elements, for example, there can be listed one or more elements selected from the group consisting of aluminum (Al), magnesium (Mg), nickel (Ni), manganese (Mn), titanium (Ti), boron (B), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), tungsten (W), zirconium (Zr), yttrium (Y), niobium (Nb), calcium (Ca), strontium (Sr), bismuth (Bi), sodium (Na), potassium (K) and silicon (Si).

[0049] In addition, as a positive electrode active material capable of embedding and de-embedding sodium ions, at least one selected from the group consisting of a sodium-containing phosphate compound having a NASICON structure, a sodium-containing phosphate compound having an olivine structure, a sodium-containing layered oxide, and a sodium-containing oxide having a spinel structure can be listed. For example, at least one selected from the group consisting of Na3V2(PO4)3, NaCoFe2(PO4)3, Na2Ni2Fe(PO4)3, Na3Fe2(PO4)3, Na2FeP2O7, Na4Fe3(PO4)2(P2O7) and NaFeO2 as a sodium-containing layered oxide can be listed.

[0050] 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 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, polyphenylene glycol, polyacetylene, or polyacene.

[0051] The content of the positive electrode active material in the positive electrode active material layer 111 is usually 50% by weight or more, for example 60% by weight or more, relative to the total amount of the positive electrode active material layer 111. The positive electrode active material layer 111 may also contain two or more positive electrode active materials, in which case their total content may be within the above range. By making the content of the active material 50% by mass or more, the energy density of the battery can be particularly improved.

[0052] (Negative Electrode Active Material Layer)

[0053] Examples of the negative electrode active material contained in the negative electrode active material layer 121 include carbon materials, metal-based materials, lithium alloys, and / or lithium-containing compounds.

[0054] Specifically, the carbon material is, for example, graphite, graphitizable carbon, non-graphitizable carbon, mesocarbon microbeads (MCMB), and / or highly oriented graphite (HOPG).

[0055] Metallic materials are a general term for materials containing any one or more of metal elements and semi-metal elements that can form alloys with lithium as constituent elements. The metallic materials can be simple substances, alloys, or compounds. The purity of the simple substances described here is not necessarily limited to 100%, so the simple substances may also contain trace amounts of impurities.

[0056] Metal elements and semi-metal elements include, for example, silicon (Si), tin (Sn), aluminum (Al), indium (In), magnesium (Mg), boron (B), gallium (Ga), germanium (Ge), lead (Pb), bismuth (Bi), cadmium (Cd), titanium (Ti), chromium (Cr), iron (Fe), niobium (Nb), molybdenum (Mo), silver (Ag), zinc (Zn), hafnium (Hf), zirconium (Zr), yttrium (Y), palladium (Pd) and / or platinum (Pt), etc.

[0057] Specifically, metal materials include Si, Sn, SiB4, TiSi2, SiC, Si3N4, SiO v (0<v≤2)、LiSiO、SnO w (0<w≤2), SnSiO3, LiSnO and / or Mg2Sn, etc.

[0058] Lithium-containing compounds include, for example, lithium transition metal composite oxides. The definition of lithium transition metal composite oxides is as described above. Specifically, lithium transition metal composite oxides include, for example, Li3V2(PO4)3, Li3Fe2(PO4)3, Li4Ti5O 12 , LiTi2(PO4)3 and / or LiCuPO4, etc.

[0059] The negative electrode active material capable of inserting and releasing sodium ions may 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.

[0060] The content of the negative electrode active material in the negative electrode active material layer 121 is usually 50% by weight or more, for example 60% by weight or more, relative to the total amount of the negative electrode active material portion. The negative electrode active material portion may contain two or more negative electrode active materials, in which case their total content may be within the above range. By making the content of the active material 50% by mass or more, the energy density of the battery can be particularly improved.

[0061] As a preferred form of active material layer, the positive electrode active material layer 111 and / or the negative electrode active material layer 121 may contain a conductive material. As conductive materials contained in the positive electrode active material layer 111 and / or the negative electrode active material layer 121, for example, carbon materials and metal materials are included. Specifically, carbon materials are, for example, graphite and carbon nanotubes. Metal materials are, for example, copper (Cu), magnesium (Mg), titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), indium (In), gold (Au), platinum (Pt), silver (Ag) and / or palladium (Pd), and may also be alloys of two or more thereof.

[0062] In addition, the positive electrode active material layer 111 and / or the negative electrode active material layer 121 may also contain a binder. As the binder, for example, any one or more of synthetic rubber and polymer materials are used. Specifically, the synthetic rubber is, for example, styrene-butadiene rubber, fluorine-based rubber and / or EPDM rubber. For example, the polymer material can be selected from at least one of the group consisting of polyvinylidene fluoride, polyimide and acrylic resin.

[0063] The positive electrode active material layer 111 and / or the negative electrode active material layer 121 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.

[0064] The thickness of the positive electrode active material layer 111 and the negative electrode active material layer 121 is not particularly limited, and may be, for example, independently 2 μm to 100 μm, and particularly 5 μm to 50 μm.

[0065] In addition, the positive electrode active material layer 111 or the negative electrode active material layer 121 located on both sides of the interlayer conductive layer 170 described later may be arranged at a position further inside than the active material layer of the opposing counter electrode. Figure 1 ), the positive electrode active material layer 111 may also be arranged at a position closer to the inside than the opposite negative electrode active material layer 121. The above arrangement is because if there is a positive electrode portion that is not opposite to the negative electrode, dendrites may be generated on the negative electrode side and a short circuit may occur. In addition, in the solid battery disclosed in the present invention, in the region A where the active material layers of the electrodes are opposite to each other, compressive stress is applied by charging and discharging, and in the region B where the active material layers of the electrodes are not opposite to each other, tensile stress is applied by charging and discharging, but the stress can be more appropriately relieved by the interlayer conductive layer 170 described later.

[0066] (Positive Electrode Collector Layer and Negative Electrode Collector Layer)

[0067] The positive electrode collector layer 112 and the negative electrode collector layer 122 preferably have higher electronic conductivity than the positive electrode active material layer 111 and the negative electrode active material layer 121. In other words, the positive electrode collector layer 112 and the negative electrode collector layer 122 are used to collect electricity from each other in the positive electrode layers 110 or from each other in the negative electrode layers 120. As specific constituent materials, the positive electrode collector layer 112 and the negative electrode collector layer 122 may contain a conductive material and a solid electrolyte.

[0068] The conductive material used for the positive electrode current collector layer 112 can be, for example, at least one selected from the group consisting of carbon materials, silver, palladium, gold, platinum, aluminum, copper, nickel-lithium transition metal composite oxides, and lithium transition metal phosphate compounds.

[0069] The conductive material used for the negative electrode current collector layer 122 may be at least one selected from the group consisting of carbon materials, silver, palladium, gold, platinum, aluminum, copper, and nickel.

[0070] The specific material of the solid electrolyte will be described in detail in “1-2. Solid electrolyte layer” described later.

[0071] The ratio of solid electrolyte is 40% by weight or more and 60% by weight or less based on the whole of the positive collector layer 112 or the negative collector layer 122. It should be noted that in the present disclosure, the positive collector layer 112 and the negative collector layer 122 are composed of a conductive material and a solid electrolyte, so when the solid electrolyte ratio in the collector layer is 40% by weight based on the whole, the conductive material is 60% by weight. In addition, when the solid electrolyte ratio in the collector layer is 60% by weight based on the whole, the conductive material is 40% by weight. If this numerical range is met, the strength of the positive collector layer 112 and the negative collector layer 122 can be improved. Therefore, even if stress is accumulated inside the solid battery, the rupture of the positive collector layer 112 and the negative collector layer 122 can be reduced. It should be noted that the details of the numerical range of the solid electrolyte ratio will be described in detail in the "Examples" described later.

[0072] The positive electrode collector layer 112 and / or the negative electrode collector layer 122 may have the form of a sintered body. That is, it may be composed of a sintered body containing an active material, a binder and / or a sintering aid in addition to the above-mentioned conductive material and solid electrolyte. In addition, the positive electrode collector layer 112 and / or the negative electrode collector layer 122 may contain a heat-resistant resin. When a heat-resistant resin is contained in the collector layer, cracking caused by expansion of the collector layer can be suppressed.

[0073] The thickness of each of the positive electrode current collector layer 112 and the negative electrode current collector layer 122 is not particularly limited, and may be, for example, independently 1 μm to 100 μm, and particularly 1 μm to 50 μm.

[0074] As a preferred mode of the positive electrode collector layer 112 and the negative electrode collector layer 122, the positive electrode collector layer 112 or the negative electrode collector layer 122 sandwiching the interlayer conductive layer 170 can be exposed from the positive electrode active material layer 111 or the negative electrode active material layer 121 located on both sides of the interlayer conductive layer 170. The "mode in which the collector layer sandwiching the interlayer conductive layer is exposed from the active material layer located on both sides of the interlayer conductive layer" mentioned in this specification refers to a mode in which the collector layer sandwiching the interlayer conductive layer is exposed relative to the active material layer located on both sides of the interlayer conductive layer. In other words, it refers to a mode in which the collector layer sandwiching the interlayer conductive layer is exposed because the length of the collector layer is longer than the active material layer located on both sides of the interlayer conductive layer. In the example shown in the figure ( Figure 1 ), the positive electrode collector layer 112 extends in a manner exposed from the solid battery element 141, but the positive electrode active material layer 111 does not need to extend in a manner exposed from the solid battery element 141. By adopting such a structure, the positive electrode collector layer 112 and the negative electrode collector layer 122 exposed from the solid battery element 141 can be properly wired with the terminal electrodes 151 and 152. In addition, the positive electrode active material layer 111 or the negative electrode active material layer 121 that participates in the transfer of electrons can be properly protected without being exposed.

[0075] 1-2. Solid electrolyte layer

[0076] The solid electrolyte constituting the solid electrolyte layer 130 is a material capable of conducting lithium ions or sodium ions. In particular, the solid electrolyte constituting the battery structural unit in the solid battery forms a layer capable of conducting lithium ions or sodium ions between the positive electrode layer 110 and the negative electrode layer 120. It should be noted that the solid electrolyte layer is at least provided between the positive electrode layer 110 and the negative electrode layer 120. As a specific solid electrolyte contained in the solid electrolyte layer, for example, any one or more of a crystalline solid electrolyte, a glass-based solid electrolyte, and a glass-ceramic solid electrolyte can be contained.

[0077] Crystalline solid electrolytes include, for example, oxide-based crystalline materials and sulfide-based crystalline materials. Examples of oxide-based crystalline materials include lithium-containing phosphate compounds having a NASICON structure, oxides having a perovskite structure, oxides having a garnet-type or garnet-like structure, and oxide glass-ceramic lithium ion conductors. Examples of lithium-containing phosphate compounds having a NASICON structure include lithium-containing phosphate compounds selected from 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). As an example of a lithium-containing phosphate compound having a NASICON structure, for example, Li 1.2 Al 0.2 Ti 1.8 (PO4)3, etc. As an example of an oxide having a perovskite structure, La 0.55 Li 0.35 TiO3, etc. As an example of an oxide having a garnet-type or garnet-like structure, Li7La3Zr2O 12 In addition, sulfide-based crystalline materials include thio-LISICON, such as Li 3.25 Ge 0.25 P 0.75 S4 and Li 10 GeP2S 12 The crystalline solid electrolyte may contain a polymer material (for example, polyethylene oxide (PEO)).

[0078] Glass-based solid electrolytes include, for example, oxide-based glass materials and sulfide-based glass materials. Examples of oxide-based glass materials include Li2O-SiO2, Li2O-Al2O3-TiO2-P2O5, 54Li2O·11SiO2·35B2O3, 50Li4SiO4·50Li3BO3, 23.3Li2O-76.7GeO2 and / or 60Li2O-40P2O5. In other words, the oxide-based glass material may contain at least one selected from the group consisting of lithium, silicon and boron. In addition, lithium oxide is essential in the oxide-based glass material, and may contain at least one selected from the group consisting of germanium oxide, silicon oxide, boron oxide and phosphorus oxide. In addition, sulfide-based glass materials include, for example, 30Li2S·26B2S3·44LiI, 63Li2S·36SiS2·1Li3PO4, 57Li2S·38SiS2·5Li4SiO4, 70Li2S·30P2S5 and / or 50Li2S·50GeS2.

[0079] Glass ceramic solid electrolytes include oxide glass ceramic materials and sulfide glass ceramic materials. As oxide glass ceramic materials, for example, phosphate compounds containing lithium, aluminum, and titanium as constituent elements (LATP) and phosphate compounds containing lithium, aluminum, and germanium as constituent elements (LAGP) can be used. LATP, for example, is Li 1.07 Al 0.69 Ti 1.46 (PO4)3, etc. In addition, LAGP is, for example, Li1.5 Al 0.5 Ge 1.5 (PO4) etc. In other words, the oxide-based glass ceramic material may contain at least one selected from the group consisting of lithium, silicon and boron. For example, 90Li3BO3-10Li2SO4 may be cited. In addition, lithium oxide is essential in the oxide-based glass ceramic material, and may contain at least one selected from the group consisting of germanium oxide, silicon oxide, boron oxide and phosphorus oxide. In addition, as a sulfide-based glass ceramic material, for example, there is Li7P3S 11 and Li 3.25 P 0.95 S4 et al.

[0080] If more emphasis is placed on excellent atmospheric stability and the ability to be easily sintered as a whole, the solid electrolyte may contain at least one selected from the group consisting of oxide-based crystalline materials, oxide-based glass materials, and oxide-based glass-ceramic materials.

[0081] In addition, as solid electrolytes capable of conducting sodium ions, for example, sodium-containing phosphate compounds having a NASICON structure, oxides having a perovskite structure, oxides having a garnet-type or garnet-like structure, etc. can be listed. As sodium-containing phosphate compounds having a NASICON structure, 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).

[0082] The solid electrolyte layer may contain a binder and / or a sintering aid. The binder and / or sintering aid contained in the solid electrolyte layer may be selected from the same materials as the binder and / or sintering aid that may be contained in the positive electrode active material part and / or the negative electrode active material part.

[0083] The thickness of the solid electrolyte layer is not particularly limited, and may be, for example, 1 μm or more and 15 μm or less, and particularly 1 μm or more and 5 μm or less.

[0084] As a preferred embodiment of the solid electrolyte layer 130, the solid electrolyte layer 130 may cover one side of the interlayer conductive layer 170 and one side of the positive electrode layer 110 or the negative electrode layer 120 sandwiching the interlayer conductive layer 170. Figure 1 ), the solid electrolyte layer 130 can cover the single side of the positive electrode active material layer 111 and the positive electrode collector layer 112 sandwiching the interlayer conductive layer 170 and the single side of the interlayer conductive layer 170. By such a covering method, since the single side of the positive electrode layer 110 or the negative electrode layer 120 is covered by the solid electrolyte layer, it is possible to prevent the electrode layer from accidentally short-circuiting.

[0085] As a more preferred covering method of the solid electrolyte layer 130, the solid electrolyte layer 130 may be covered in a manner that spans the collector layer and the active material layer sandwiching the interlayer conductive layer 170. In other words, except for the side surface of the collector layer exposed from the solid battery element, the outer surface of the collector layer and the outer surface of the active material layer may be covered by the solid electrolyte layer 130. By the above-mentioned covering method, it is possible to effectively prevent the electrode layer from accidentally short-circuiting.

[0086] 2. Interlayer conductive layer

[0087] The interlayer conductive layer 170 is located between the solid battery elements 141. Specifically, the interlayer conductive layer 170 is sandwiched between the positive electrode layer 110 or the negative electrode layer 120 of one solid battery element 141 and the positive electrode layer 110 or the negative electrode layer 120 of another solid battery element 141.

[0088] exist Figure 1 In the example shown, the interlayer conductive layer 170 may be sandwiched by the positive electrode layer 110. It should be noted that the example is not limited thereto, and the interlayer conductive layer 170 may also be sandwiched by the negative electrode layer 120 (see Figure 2 That is, the interlayer conductive layer 170 may be sandwiched between electrode layers of the same polarity. Thus, the electrode layers of the same polarity can be conductively connected.

[0089] The interlayer conducting layer 170 has electrical conductivity, so that the positive electrode layers 110 or the negative electrode layers 120 that are in contact with the interlayer conducting layer 170 on both sides in the stacking direction can be electrically connected to each other.

[0090] The constituent material used for the interlayer conducting layer 170 may include a conductive material and a solid electrolyte.

[0091] The conductive material used in the interlayer conductive layer 170 that electrically connects the positive electrode current collector layers 112 to each other can be at least one selected from the group consisting of carbon materials, silver, palladium, gold, platinum, aluminum, copper, nickel, lithium transition metal composite oxides, and lithium transition metal phosphate compounds.

[0092] The conductive material used for the interlayer conductive layer 170 that electrically connects the negative electrode current collector layers 122 to each other can be at least one selected from the group consisting of carbon materials, silver, palladium, gold, platinum, aluminum, copper, and nickel.

[0093] The specific material of the solid electrolyte can use the material described in detail in "1-2. Solid electrolyte layer". In addition, the solid electrolyte ratio is 10% by weight or more and 35% by weight or less based on the entire interlayer conductive layer 170. It should be noted that in the present disclosure, the interlayer conductive layer is composed of a conductive material and a solid electrolyte. Therefore, when the solid electrolyte ratio in the interlayer conductive layer is 10% by weight based on the entirety, the conductive material is 90% by weight, and when the solid electrolyte ratio in the interlayer conductive layer is 35% by weight based on the entirety, the conductive material is 65% by weight. If it is included in this numerical range, the strength of the interlayer conductive layer 170 can be made lower than the strength of the positive electrode layer 110 or the negative electrode layer 120 sandwiching the interlayer conductive layer 170. Therefore, if stress is accumulated inside the solid battery, the stress can be concentrated on the interlayer conductive layer 170 with low strength. As an example, the stress can be relieved by causing cracks in the interlayer conductive layer 170. It should be noted that if the solid electrolyte content of the interlayer conductive layer 170 is less than 10 wt%, it is difficult to maintain the shape of the sintered body. Therefore, the interlayer conductive layer 170 has a solid electrolyte content of at least 10 wt%. The details of the numerical range of the solid electrolyte ratio will be described in detail in the "Examples" described later.

[0094] Next, as additional structures of the solid battery of the present disclosure, a terminal electrode, an insulating outer layer, a cover insulating film, an inorganic film, and a supporting substrate are described.

[0095] 3. Terminal electrode

[0096] The terminal electrodes are provided on the end faces of the stacked body 140. Figure 4 In the embodiment, terminal electrodes 151 and 152 may be provided on side surfaces of the stacked body 140 located in a direction intersecting with the stacking direction of the stacked body 140 .

[0097] More specifically, the terminal electrode may include a positive electrode side terminal electrode 151 connected to the positive electrode layer 110 and a negative electrode side terminal electrode 152 connected to the negative electrode layer 120, and the positive electrode side terminal electrode 151 is formed on one side (at Figure 4 The terminal electrode 152 on the negative electrode side is arranged to face the terminal electrode 151 on the positive electrode side (in Figure 4 left side).

[0098] The terminal electrodes 151 and 152 may contain a conductive material. A conductive material is a material having electrical conductivity, and specific examples thereof include carbon materials and metal materials. It should be noted that the term "conductivity" in this specification refers to a volume resistivity of 10 7 Ω·cm or less.

[0099] The metal material is not particularly limited as long as it has conductivity, and at least one selected from the group consisting of silver, gold, platinum, aluminum, copper, palladium, zinc, tin and nickel can be cited. In addition, it can also be a composite metal such as Ag coating Cu and / or Ag coating CuNi. It should be noted that silver can be cited as a preferred metal material because of its high conductivity and small change in conductivity even in a high temperature and high humidity environment.

[0100] 4. Insulation outer layer

[0101] As an additional structure of the solid battery of the present disclosure, an insulating outer layer 160 may be provided. Specifically, the insulating outer layer 160 may be provided on the outer side of the stack 140 (see Figures 1 to 3 ). The insulating outer layer 160 can generally be formed on the outermost side of the stack 140 to protect the stack 140 electrically, physically and / or chemically. In particular, the insulating outer layer 160 includes an insulating outer layer 160 on the top side of the solid battery 100 and an insulating outer layer 160 on the bottom side. In addition, the side surface of the stack 140 where the terminal electrodes 151 and 152 are not provided ( Figure 4 An insulating outer layer 160 is provided on the side of the solid battery element 141 in the vertical direction of the paper. The material constituting the insulating outer layer is preferably excellent in insulation, durability and / or moisture resistance, and is safe for the environment, for example, it may contain a resin material, a glass material and / or a ceramic material. In addition, since the insulating outer layer is manufactured by integral firing, it may also have the form of a fired body. It should be noted that the insulating outer layer 160 may not be provided, but may be included in other resin and ceramic packages.

[0102] 5. Cover with insulating film

[0103] As an additional structure of the solid battery of the present disclosure, a cover insulating film 200 may be provided. The cover insulating film 200 may be provided so as to cover the terminal electrodes 151 and 152 and the stacked body 140 (see Figure 4 ). The cover insulating film 200 is preferably equivalent to a resin. That is, the cover insulating film 200 preferably contains a resin material. Figure 4 As can be seen from the illustrated form, the laminate 140 provided on the support substrate 400 is sealed by the resin material of the cover insulating film 200. The cover insulating film 200 composed of such a resin material interacts with the inorganic film 300 described later, and contributes to appropriately reducing the intrusion of moisture.

[0104] The material of the cover insulating film can be any material as long as it exhibits insulating properties. For example, when the cover insulating film contains a resin, the resin can be any one of a thermosetting resin and a thermoplastic resin. Although there is no particular limitation, specific resin materials for the cover insulating film include, for example, epoxy resins, silicone resins, and / or liquid crystal polymers. Although only an example, the thickness of the cover insulating film can be greater than 30 μm and less than 1000 μm, for example, greater than 50 μm and less than 300 μm.

[0105] It should be noted that, in a solid battery, a covering insulating film is not essential, and a solid battery without a covering insulating film can also be considered.

[0106] 6. Inorganic membrane

[0107] As an additional structure of the solid battery of the present disclosure, an inorganic film 300 covering the insulating film 200 may be provided. Figure 4 As shown, the inorganic film 300 is located on the cover insulating film 200 , and thus has a form in which the inorganic film 300 , together with the cover insulating film 200 , largely surrounds the entire laminated body 140 on the support substrate 400 .

[0108] The inorganic film 300 preferably has a thin film form. As long as it is an inorganic film that helps to have a thin film form, the material of the inorganic film is not particularly limited, and can be metal, glass, oxide ceramics, or a mixture thereof. In a preferred embodiment, the inorganic film can contain a metal component. That is, the inorganic film is preferably a metal thin film. Although it is only an example, the thickness of such an inorganic film can be greater than 0.1 μm and less than 100 μm, for example, greater than 1 μm and less than 50 μm.

[0109] In particular, according to the manufacturing method, the inorganic film 300 may be a dry coating film. The dry coating film is a film obtained by a gas phase method such as physical vapor deposition (PVD) and chemical vapor deposition (CVD), and has a very small thickness of nanometer or micrometer level. Such a thin dry coating film contributes to a more compact package.

[0110] The dry plating film may be composed of at least one metal component / semi-metal component selected from the group consisting of aluminum (Al), nickel (Ni), palladium (Pd), silver (Ag), tin (Sn), gold (Au), copper (Cu), titanium (Ti), platinum (Pt), silicon (Si), and SUS, an inorganic oxide, and / or a glass component. The dry plating film composed of such components is chemically and / or thermally stable, so that a solid battery with excellent chemical resistance, weather resistance, and / or heat resistance and further improved long-term reliability can be obtained.

[0111] It should be noted that in a solid battery, an inorganic membrane is not essential, and a solid battery without an inorganic membrane can also be considered.

[0112] 7.Support substrate

[0113] As an additional structure of the solid battery disclosed in the present invention, a support substrate 400 may be provided. The support substrate 400 is a substrate provided in a manner to support the stack 140. In order to provide "support", the support substrate is located on one side of the main surface forming the solid battery. In addition, since it is a "substrate", it is preferably in a thin plate shape as a whole.

[0114] The supporting substrate 400 may be, for example, a resin substrate or a ceramic substrate, preferably a water-resistant substrate. In a preferred embodiment, the supporting substrate 400 may be a ceramic substrate. That is, the supporting substrate 400 includes ceramics, which may occupy the matrix component of the substrate. A supporting substrate composed of ceramics helps prevent water vapor from penetrating, and is also a preferred substrate in terms of heat resistance during substrate mounting. Such a ceramic substrate can be obtained by firing, for example, by firing a green sheet stack. In this regard, the ceramic substrate may be, for example, an LTCC substrate (LTCC: Low Temperature Co-fired Ceramics), or may be an HTCC substrate (HTCC: High Temperature Co-fired Ceramics). Although it is only an example, the thickness of the supporting substrate may be greater than 20 μm and less than 1000 μm, for example, greater than 100 μm and less than 300 μm.

[0115] In addition, the support substrate 400 can function as a terminal substrate of the stack 140. That is, the solid battery packaged in a manner of sandwiching the substrate can be mounted on other secondary substrates such as a printed wiring board. For example, the solid battery can be surface mounted via the support substrate by reflow soldering or the like. Therefore, the packaged solid battery can be an SMD type battery. In particular, when the terminal substrate is composed of a ceramic substrate, the solid battery has high heat resistance and can become an SMD type battery that can be welded and mounted.

[0116] Since it is a terminal substrate, it is preferable to have wiring, and it is particularly preferable to have wiring 410 that electrically connects the upper and lower surfaces or the upper and lower surface layers (see Figure 4 ). That is, a preferred embodiment of the support substrate includes wiring for electrically connecting the upper and lower surfaces of the substrate, and can be a terminal substrate for external terminals of the packaged solid battery.

[0117] The wiring 410 in the terminal substrate is not particularly limited and can have any form as long as it facilitates electrical connection between the upper surface and the lower surface of the substrate. Since it facilitates electrical connection, it can also be said that the wiring 410 in the terminal substrate is a conductive part of the substrate. Such a conductive part of the substrate can have a form such as a wiring layer, a through hole and / or a pad. For example, in Figure 4 In the form shown, a through hole 412 and / or a pad 411 are provided on the support substrate 400. The "through hole" mentioned here refers to a component used to electrically connect the upper and lower directions of the support substrate, that is, the thickness direction of the substrate, such as preferably a filled through hole, etc., and it can also be in the form of an internal through hole, etc. In addition, the "pad" mentioned in this specification refers to a terminal part / connection part (preferably a terminal part / connection part connected to a through hole) for electrical connection provided on the upper main surface and / or the lower main surface of the support substrate, and can be, for example, a square pad, or a circular pad, etc.

[0118] [Structure of electronic devices]

[0119] The electronic device disclosed in the present invention is surface mounted with the above-mentioned solid battery. Specifically, the surface mounting of the solid battery can be performed by wiring of the supporting substrate 400. The "surface mounting" mentioned in this specification refers to the technology of directly fixing the solid battery on the pattern formed on the substrate. As an example, the above-mentioned solid battery 1 can be mounted on a printed substrate and the like and packaged. In addition, electronic components other than solid batteries can also be mounted.

[0120] [Method for manufacturing solid state battery]

[0121] The manufacturing process of the solid battery disclosed in the present invention is carried out through the processes including (1) preparation of a stack, (2) preparation of a terminal electrode material, (3) firing of the stack, (4) coating of the terminal electrode material, (5) solidification of the terminal electrode material, (6) fixing to a supporting substrate, and (7) formation of a covering insulating film and an inorganic film. The following is an explanation in order.

[0122] (1) Preparation of laminate (see Figure 5 (a), (b)

[0123] When manufacturing the laminate, a sheet containing a solid electrolyte, a paste for a positive electrode active material layer, a paste for a positive electrode collector layer, a paste for a negative electrode active material layer, a paste for a negative electrode collector layer, and a paste for an interlayer conductive layer are prepared.

[0124] The sheet containing a solid electrolyte is formed by mixing a solid electrolyte, an organic binder, a solvent, and any additives to prepare a slurry, and then firing the prepared slurry to form a sheet.

[0125] The paste for positive electrode active material is prepared by mixing positive electrode active material, solid electrolyte, conductive material, organic binder, solvent and any additive. The paste for positive electrode collector layer is prepared by mixing solid electrolyte, conductive material, organic binder, solvent and any additive. The solid electrolyte ratio in the paste for positive electrode collector layer is 40% by weight or more and 60% by weight or less based on the whole.

[0126] The negative electrode active material paste is prepared by mixing the negative electrode active material, solid electrolyte, conductive material, organic binder, solvent and any additive. The negative electrode collector layer paste is prepared by mixing the solid electrolyte, conductive material, organic binder, solvent and any additive. The solid electrolyte ratio in the negative electrode collector layer paste is 40% by weight or more and 60% by weight or less based on the whole.

[0127] The interlayer conductive layer paste is prepared by mixing a solid electrolyte, a conductive material, an organic binder, a solvent, and any additives. The solid electrolyte ratio in the interlayer conductive layer paste is 10 wt % or more and 35 wt % or less based on the whole.

[0128] After the above-mentioned paste is prepared, the laminate is prepared. The negative electrode collector paste P22 is printed on the sheet S containing the solid electrolyte, and the negative electrode active material paste P21 is printed on the negative electrode collector paste P22. In addition, the solid electrolyte part N that functions as a solid electrolyte may be printed as needed (see Figure 5 (b)) The solid electrolyte part N refers to a slurry in which a solid electrolyte, an organic binder, a solvent, and any additives are mixed.

[0129] In addition, the positive electrode active material paste P11 is printed on another sheet S containing a solid electrolyte, and the positive electrode current collector layer paste P12 is printed on the positive electrode active material paste P11. A solid electrolyte portion N that functions as a solid electrolyte may also be printed as needed (see Figure 5 (a)). Interlayer conductive layer paste P30 is printed on the positive electrode collector layer paste. Positive electrode collector layer paste P12 and positive electrode active material paste P11 are printed in sequence on the interlayer conductive layer paste P30. As needed, a solid electrolyte part N that acts as a solid electrolyte may also be printed. The sheets printed with the negative electrode paste and the sheets printed with the positive electrode paste are alternately stacked to obtain a laminate. It should be noted that the outermost layer (uppermost layer and / or lowermost layer) of the laminate may be an electrolyte layer, an insulating layer, or an electrode layer.

[0130] (2) Preparation of terminal electrode materials

[0131] First, prepare a terminal electrode material (as an example, a conductive paste) that will become the material of the terminal electrodes 151 and 152. Prepare Ag as the conductive material. Here, as additional elements, a resin and a solvent may be further included as the terminal electrode material. It should be noted that the "terminal electrode material" referred to in this specification refers to a material that can form a flow in the sense of fluid mechanics, or a material that can maintain such a flow. Examples of such materials include liquids such as pastes, solutions or suspensions.

[0132] The solvent is a solvent that dissolves the above-mentioned resin binder, and for example, an organic solvent can be used. The organic solvent is not particularly limited, and alcohols including methanol, ethanol, 1-propanol, 2-propanol, hexanol, and cyclohexanol, glycols including ethylene glycol and propylene glycol, ketones including methyl ethyl ketone, diethyl ketone, and methyl isobutyl ketone, terpenes including α-terpineol, β-terpineol, and γ-terpineol, ethylene glycol monoalkyl ethers, ethylene glycol dialkyl ethers, diethylene glycol monoalkyl ethers, diethylene glycol dialkyl ethers, ethylene glycol monoalkyl ether acetates, ethylene glycol dialkyl ether acetates, diethylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, propylene glycol monoalkyl ether acetates, propylene glycol dialkyl ether acetates, and / or monoalkyl cellosolves can be used alone. In addition, a mixture of at least one solvent selected from these or two or more solvents can also be used. As an example of the organic solvent, an alcohol solvent such as terpineol is preferably used. In addition, a dispersing material may be added to the solvent.

[0133] After the terminal electrode material is prepared, the terminal electrode material is applied to the positive electrode exposed side surface and the negative electrode exposed side surface of the battery body.

[0134] (3) Firing of laminated body

[0135] Although it is only an example, the firing of the laminate is carried out by heating at a desired firing temperature (for example, the firing peak temperature is in the range of 300° C. to 600° C.) in a nitrogen atmosphere containing oxygen or in the air. The firing can be carried out while pressurizing the laminate precursor in the stacking direction (the stacking direction and the direction perpendicular to the stacking direction, depending on the situation).

[0136] (4) Coating of terminal electrode materials

[0137] After the terminal electrode material is prepared, the terminal electrode material is applied to the positive electrode exposed side surface and the negative electrode exposed side surface of the stacked body.

[0138] (5) Curing of terminal electrode materials

[0139] The laminate coated on the positive electrode exposed side surface and the negative electrode exposed side surface is cured at a desired curing temperature (for example, in the range of 100° C. to 300° C.).

[0140] (6) Fixing to Support Base Plate

[0141] In order to enable surface mounting on the secondary substrate, the support substrate is provided with through holes and / or pads. For example, it can be obtained by stacking and firing a plurality of green sheets. This is particularly applicable when the support substrate is a ceramic substrate. The preparation of the support substrate can be carried out, for example, according to the preparation of the LTCC substrate.

[0142] The through holes and / or pads in the support substrate are manufactured by, for example, forming holes (diameter: about 50 μm to 200 μm) using a punch or a carbon dioxide laser and filling the holes with a conductive paste material, or by using a printing method.

[0143] After manufacturing the support substrate, the conductive portion of the support substrate and the terminal electrodes of the laminate are arranged in a manner of being electrically connected to each other. In addition, a conductive paste may be provided on the support substrate, thereby electrically connecting the conductive portion of the support substrate and the terminal electrodes to each other. Regarding the conductive paste, in addition to the Ag conductive paste, a conductive paste such as a nano paste, an alloy paste, a solder, etc. that does not require cleaning of the flux after formation can also be used.

[0144] (7) Formation of cover insulating film and inorganic film

[0145] Next, a cover insulating film is formed so as to cover the laminated body on the support substrate. Therefore, the raw material of the cover insulating film is provided so as to cover the battery body on the support substrate as a whole. When the cover insulating film is composed of a resin material, a resin precursor is placed on the support substrate and cured, etc., to form the cover insulating film.

[0146] In a preferred embodiment, the covering insulating film can also be formed by applying pressure with a mold. Although it is only an example, the covering insulating film of the battery body on the sealing support substrate can also be formed by compression / molding. If it is a resin material generally used in molding, the raw material of the covering insulating film can be in the form of particles, and its type can also be thermoplastic. It should be noted that such molding is not limited to mold molding, and can also be performed by grinding, laser processing and / or chemical treatment.

[0147] Next, an inorganic film is formed. For example, the inorganic film can be subjected to dry plating, and dry plating is used as the inorganic film. More specifically, dry plating is performed to form an inorganic film on the exposed surface other than the bottom surface of the covering precursor (i.e., other than the bottom surface of the supporting substrate). In a preferred embodiment, sputtering is performed to form a sputtered film on the exposed outer surface other than the bottom surface of the covering precursor.

[0148] By going through the above steps, the solid state battery of the present disclosure can be finally obtained.

[0149] Example

[0150] A verification test was conducted on the solid state battery of the present disclosure. Specifically, solid state batteries of Examples 1 to 5 and Comparative Examples 1 to 5 shown below were manufactured.

[0151] <Common Structure in the Embodiments>

[0152] As the solid batteries of Examples 1 to 5, Figure 1 As shown, two solid battery elements 141 are stacked with an interlayer conductive layer 170 therebetween, and the interlayer conductive layer 170 is sandwiched by the positive electrode layer 110. As the material of each layer, as an example, the positive electrode active material layer 111 is set to LiCoO2, and the positive electrode collector layer 112, the negative electrode active material layer 121, the negative electrode collector layer 122 and the interlayer conductive layer 170 are set to carbon materials. It should be noted that the material of each layer and the number of stacking are not limited to this example.

[0153] <Structure unique to Example 1>

[0154] In the solid battery of Example 1, the solid electrolyte ratios of the positive electrode current collector layer and the interlayer conductive layer were set as follows.

[0155] Positive electrode collector layer: conductive material (50 wt%), solid electrolyte (50 wt%)

[0156] Interlayer conductive layer: conductive material (80 wt%), solid electrolyte (20 wt%)

[0157] <Structure unique to Example 2>

[0158] In the solid battery of Example 2, the solid electrolyte ratios in the positive electrode current collector layer and the interlayer conductive layer were set as follows.

[0159] Positive electrode collector layer: conductive material (50 wt%), solid electrolyte (50 wt%)

[0160] Interlayer conductive layer: conductive material (90 wt%), solid electrolyte (10 wt%)

[0161] <Structure unique to Example 3>

[0162] In the solid battery of Example 3, the solid electrolyte ratios in the positive electrode current collector layer and the interlayer conductive layer were set as follows.

[0163] Positive electrode collector layer: conductive material (50 wt%), solid electrolyte (50 wt%)

[0164] Interlayer conductive layer: conductive material (65 wt%), solid electrolyte (35 wt%)

[0165] <Structure unique to Example 4>

[0166] In the solid battery of Example 4, the solid electrolyte ratios of the positive electrode current collector layer and the interlayer conductive layer were set as follows.

[0167] Positive electrode collector layer: conductive material (60 wt%), solid electrolyte (40 wt%)

[0168] Interlayer conductive layer: conductive material (80 wt%), solid electrolyte (20 wt%)

[0169] <Structure unique to Example 5>

[0170] In the solid battery of Example 5, the solid electrolyte ratios of the positive electrode current collector layer and the interlayer conductive layer were set as follows.

[0171] Positive electrode collector layer: conductive material (40 wt%), solid electrolyte (60 wt%)

[0172] Interlayer conductive layer: conductive material (80 wt%), solid electrolyte (20 wt%)

[0173] <Structure of Comparative Example 1>

[0174] A solid battery without an interlayer conductive layer was produced as a solid battery of Comparative Example 1. The positive electrode current collector layer was set as follows.

[0175] Positive electrode collector layer: conductive material (80 wt%), solid electrolyte (20 wt%)

[0176] <Structure of Comparative Example 2>

[0177] As the solid battery of Comparative Example 2, the solid electrolyte ratio of the solid battery of Example 1 was set as follows.

[0178] Positive electrode collector layer: conductive material (50 wt%), solid electrolyte (50 wt%)

[0179] Interlayer conductive layer: conductive material (95 wt%), solid electrolyte (5 wt%)

[0180] <Structure of Comparative Example 3>

[0181] As the solid battery of Comparative Example 3, the solid electrolyte ratio of the solid battery of Example 1 was set as follows.

[0182] Positive electrode collector layer: conductive material (50 wt%), solid electrolyte (50 wt%)

[0183] Interlayer conductive layer: conductive material (60 wt%), solid electrolyte (40 wt%)

[0184] <Structure of Comparative Example 4>

[0185] As the solid battery of Comparative Example 4, the solid electrolyte ratio of the solid battery of Example 1 was set as follows.

[0186] Positive electrode collector layer: conductive material (30 wt%), solid electrolyte (70 wt%)

[0187] Interlayer conductive layer: conductive material (80 wt%), solid electrolyte (20 wt%)

[0188] <Structure of Comparative Example 5>

[0189] As the solid battery of Comparative Example 5, the solid electrolyte ratio of the solid battery of Example 1 was set as follows.

[0190] Positive electrode collector layer: conductive material (70 wt%), solid electrolyte (30 wt%)

[0191] Interlayer conductive layer: conductive material (80 wt%), solid electrolyte (20 wt%)

[0192] A high temperature charge-discharge cycle short circuit test and a production suitability test were performed on the solid batteries of Examples 1 to 5 and Comparative Examples 1 to 5. The contents of each test are as follows.

[0193] -High temperature charge and discharge cycle short circuit test-

[0194] Using the charge and discharge test device (TOSCAT-3100) manufactured by Toyo Systems, the charge and discharge cycle test was carried out at the designed voltage / designed current to confirm the short circuit occurrence rate of the solid battery. It should be noted that in this test, the index of the short circuit occurrence rate is as follows.

[0195] ◎: Short circuit rate less than 20%

[0196] ○: Short circuit occurrence rate is greater than 20% and less than 60%

[0197] ×: Short circuit occurrence rate is greater than 60%

[0198] -Production Adaptability Test-

[0199] The production suitability test is to visually check whether there is any shape abnormality during the production of solid batteries. The indicators of the occurrence rate of shape abnormality are as follows.

[0200] ◎: Shape abnormality rate is less than 10%

[0201] ○: Shape abnormality rate is greater than 10% and less than 30%

[0202] ×: Shape abnormality rate is greater than 30%

[0203] The above test results are shown in the following table.

[0204] [Table 1]

[0205]

[0206] According to the above test results, in the solid batteries of Examples 1 to 5, the solid electrolyte ratio of the positive electrode layer sandwiching the interlayer conductive layer is within the range of 40% by weight or more and 60% by weight or less, and the solid electrolyte ratio of the interlayer conductive layer is 10% by weight or more and 35% by weight or less based on the layer containing the solid electrolyte, so the high temperature charge and discharge test and the production adaptability test show good results. In particular, the solid battery of Example 1 shows better results than the verification test of the solid batteries of Examples 2 to 5.

[0207] On the other hand, the solid battery of Comparative Example 1 did not have an interlayer conductive layer, so a short circuit occurred due to the stress of the solid battery. The solid battery of Comparative Example 2 could not maintain the shape of the sintered body due to the low solid electrolyte ratio of the interlayer conductive layer, and it was fundamentally impossible to manufacture a solid battery. The solid batteries of Comparative Examples 3 and 5 could not obtain the stress relief effect brought about by the strength difference because the difference between the solid electrolyte ratio of the interlayer conductive layer and the solid electrolyte ratio of the positive electrode collector layer was small. The solid battery of Comparative Example 4 had a high resistance due to the high solid electrolyte ratio of the positive electrode collector layer, so it could not function as a solid battery, and high-temperature charge and discharge tests could not be performed.

[0208] According to the above-mentioned verification tests (high temperature charge and discharge test and production adaptability test), the following results were obtained: if the solid electrolyte ratio of the positive electrode layer or the negative electrode layer sandwiching the interlayer conductive layer is in the range of more than 40 weight % and less than 60 weight %, and the solid electrolyte ratio of the interlayer conductive layer is more than 10 weight % and less than 35 weight % based on the layer containing the solid electrolyte, then the stress generated by the volume change can be alleviated.

[0209] The embodiments of the solid state battery and electronic device disclosed herein are as follows.

[0210] <1> A solid battery having:

[0211] A plurality of solid battery elements, each of which is stacked with a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer; and

[0212] The interlayer conducting layer is located between the solid battery elements.

[0213] The interlayer conductive layer is sandwiched between the positive electrode layer or negative electrode layer of one solid battery element and the positive electrode layer or negative electrode layer of another solid battery element.

[0214] The positive electrode layer or the negative electrode layer sandwiching the interlayer conductive layer contains a solid electrolyte.

[0215] The solid electrolyte ratio of the positive electrode layer or the negative electrode layer sandwiching the interlayer conductive layer is 40 wt % or more and 60 wt % or less based on the layer containing the solid electrolyte,

[0216] The solid electrolyte ratio of the interlayer conductive layer is 10 wt % or more and 35 wt % or less based on the layer containing the solid electrolyte.

[0217] <2> The solid battery according to <1>, wherein the positive electrode layer or the negative electrode layer includes an active material layer containing an electrode active material and a current collector layer in contact with the interlayer conductive layer,

[0218] The current collector layer contains the solid electrolyte.

[0219] <3> The solid state battery according to <2>,

[0220] In cross-sectional view, the current collector layer is provided to an end portion of the solid battery element, and the active material layer is located inside the end portion.

[0221] <4> The solid state battery according to <2> or <3>,

[0222] The active material layers of the electrode layers located on both sides of the interlayer conductive layer are arranged on the inner side than the electrode layers of the counter electrode facing the electrode layers.

[0223] <5> The solid state battery according to <4>,

[0224] The electrode layer of the counter electrode facing the electrode layer includes an active material layer containing an electrode active material and a current collector layer in contact with the interlayer conductive layer.

[0225] The active material layers of the electrode layers located on both sides of the interlayer conductive layer are arranged on the inner side of the active material layers.

[0226] <6> The solid state battery according to any one of <1> to <5>,

[0227] The interlayer conducting layer is sandwiched by electrode layers having the same polarity as each other.

[0228] <7> The solid state battery according to any one of <1> to <6>,

[0229] The plurality of solid battery elements are electrically connected in parallel to each other.

[0230] <8> The solid state battery according to any one of <1> to <7>,

[0231] One side surface of the interlayer conductive layer and one side surface of the positive electrode layer or the negative electrode layer sandwiching the interlayer conductive layer are covered by the solid electrolyte layer.

[0232] <9> The solid state battery according to any one of <1> to <8>,

[0233] The solid electrolyte layer covers the current collector layer and the active material layer sandwiching the interlayer conductive layer.

[0234] <10> The solid state battery according to any one of <1> to <9>,

[0235] The solid battery element is composed of a sintered body.

[0236] <11> The solid state battery according to any one of <1> to <10>,

[0237] The solid battery is packaged in a surface-mounted manner.

[0238] <12> The solid state battery according to any one of <1> to <11>,

[0239] The positive electrode layer and the negative electrode layer serve as layers capable of inserting and releasing lithium ions.

[0240] <13> An electronic device,

[0241] The solid state battery according to any one of <1> to <12> is mounted on the surface.

[0242] It should be noted that the embodiments disclosed this time are illustrative in all aspects and are not the basis for restrictive interpretation. Therefore, the technical scope of the present disclosure is not limited to the above-mentioned embodiments, but is defined based on the records of the claims. In addition, the technical scope of the present disclosure includes the meaning equivalent to the claims and all changes within the scope. For example, a solid battery is not limited to a roughly hexahedral shape, but can also be a polyhedron, a cylindrical shape, or a spherical shape.

[0243] Industrial Applicability

[0244] The packaged solid battery of the present disclosure can be applied to various fields that assume the use of batteries or power storage. Although it is only an example, the packaged solid battery of the present disclosure can be used in the field of electronic installation. In addition, the present disclosure can also be applied to the following fields: electrical / information / communication fields using mobile devices, etc. (for example, electrical / electronic equipment fields or mobile equipment fields including small electronic devices such as mobile phones, smart phones, laptops, digital cameras, activity meters, wristband computers, electronic paper, RFID tags, card-type electronic currency, smart watches, etc.); household / small industrial uses (for example, the fields of power tools, golf carts, and household / nursing / industrial robots); large industrial uses (for example, the fields of forklifts, elevators, and port cranes); transportation system fields (for example, hybrid vehicles, electric vehicles, buses, trams, electric-assisted bicycles, electric motorcycles, etc.); power system uses (for example, various power generation, load regulators, smart grids, ordinary household-installed power storage systems, etc.); and medical uses (medical equipment fields such as headphones and hearing aids); pharmaceutical uses (dosage management systems, etc.); IoT fields; space / deep sea uses (for example, space probes, submersible research vessels, etc.), etc.

[0245] Description of Reference Numerals

[0246] 100: solid battery; 110: positive electrode layer; 111: positive electrode active material layer; 112: positive electrode collector layer; 120: negative electrode layer; 121: negative electrode active material layer; 122: negative electrode collector layer; 130: solid electrolyte layer; 140: laminate; 141: solid battery element; 151: positive electrode layer side terminal electrode; 152: negative electrode layer side terminal electrode; 160: insulating outer layer; 17 0: interlayer conductive layer; 200: covering insulating film; 300: inorganic film; 400: supporting substrate; 410: wiring; 411: pad; 412: through hole; S: sheet; P11: paste for positive electrode active material; P12: paste for positive electrode collector layer; P21: paste for negative electrode active material; P22: paste for negative electrode collector layer; P30: paste for interlayer conductive layer; N: solid electrolyte part.

Claims

1. A solid battery, comprising: A plurality of solid battery elements, each of which is stacked with a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer; and The interlayer conducting layer is located between the solid battery elements. The interlayer conductive layer is sandwiched between the positive electrode layer or negative electrode layer of one solid battery element and the positive electrode layer or negative electrode layer of another solid battery element. The positive electrode layer or the negative electrode layer sandwiching the interlayer conductive layer contains a solid electrolyte. The solid electrolyte ratio of the positive electrode layer or the negative electrode layer sandwiching the interlayer conductive layer is 40 wt % or more and 60 wt % or less based on the layer containing the solid electrolyte, The solid electrolyte ratio of the interlayer conductive layer is 10 wt % or more and 35 wt % or less based on the layer containing the solid electrolyte.

2. The solid battery according to claim 1, wherein: The positive electrode layer or the negative electrode layer includes an active material layer containing an electrode active material and a current collector layer in contact with the interlayer conductive layer. The current collector layer contains the solid electrolyte.

3. The solid battery according to claim 2, wherein: In cross-sectional view, the current collector layer is provided to an end portion of the solid battery element, and the active material layer is located inside the end portion.

4. The solid battery according to claim 2 or 3, wherein: The active material layers of the electrode layers located on both sides of the interlayer conductive layer are arranged on the inner side than the electrode layers of the counter electrode facing the electrode layers.

5. The solid battery according to claim 4, wherein: The electrode layer of the counter electrode facing the electrode layer includes an active material layer containing an electrode active material and a current collector layer in contact with the interlayer conductive layer. The active material layers of the electrode layers located on both sides of the interlayer conductive layer are arranged on the inner side of the active material layers.

6. The solid battery according to any one of claims 1 to 5, wherein The interlayer conducting layer is sandwiched by electrode layers having the same polarity as each other.

7. The solid state battery according to any one of claims 1 to 6, wherein: The plurality of solid battery elements are electrically connected in parallel to each other.

8. The solid battery according to any one of claims 1 to 7, wherein One side surface of the interlayer conductive layer and one side surface of the positive electrode layer or the negative electrode layer sandwiching the interlayer conductive layer are covered by the solid electrolyte layer.

9. The solid battery according to any one of claims 1 to 8, wherein The solid electrolyte layer covers the current collector layer and the active material layer sandwiching the interlayer conductive layer.

10. The solid battery according to any one of claims 1 to 9, wherein The solid battery element is composed of a sintered body.

11. The solid battery according to any one of claims 1 to 10, wherein The solid battery is packaged in a surface-mounted manner.

12. The solid battery according to any one of claims 1 to 11, wherein The positive electrode layer and the negative electrode layer serve as layers capable of inserting and releasing lithium ions.

13. An electronic device, The solid battery according to any one of claims 1 to 12 is mounted on the surface.

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