solid-state batteries

Abstract

The present invention provides a solid-state battery capable of reducing cracks caused by battery expansion during charging. A solid-state battery 100 comprises: a battery element 140 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; end face electrodes 151, 152 which are provided to the end faces of the battery element 140; and an insulation layer 170 which is provided between the positive electrode layer 110 or the negative electrode layer 120 and the end face electrodes 151, 152, wherein the insulation layer 170 contains a heat-resistant resin.

Description

[Technical Field]

[0001] The present disclosure relates to solid-state batteries. [Background technology]

[0002] Secondary batteries that can be repeatedly charged and discharged have been used for various purposes, such as power sources for electronic devices such as smartphones and laptops.

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

[0004] Therefore, research has been conducted on solid-state batteries that use solid electrolytes instead of liquid electrolytes, and Patent Documents 1 to 5, for example, have been disclosed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-185973 [Patent Document 2] International Publication No. 2020 / 138040 [Patent Document 3] Japanese Patent Application Publication No. 2019-153535 [Patent Document 4] Japanese Patent Application Laid-Open No. 2009-193728 [Patent Document 5] Japanese Patent Application Laid-Open No. 2015-050149 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 discloses an all-solid-state battery having a structure in which an electrode body is embedded in a solid electrolyte in a stacked state with a current collector layer interposed therebetween. The inventors of the present application found that when this all-solid-state battery is charged by applying an external voltage to the battery, cracks occur in the solid electrolyte due to the expansion of the electrode body and current collector layer.

[0007] Here, Patent Document 2 describes an all-solid-state battery having a margin layer provided on the same plane as the positive electrode layer or the negative electrode layer, and a void adjacent to one end of the positive electrode layer or the negative electrode layer, as a method for suppressing cracks caused by volumetric expansion and contraction of the electrode layer during charging and discharging of the all-solid-state battery.

[0008] Furthermore, Patent Document 3 discloses an all-solid-state battery that has a structure completely different from the all-solid-state batteries described in Patent Documents 1 and 2, in which current collector layers are provided on the upper and lower end faces in the stacking direction, and the side faces of the current collector layers are covered with resin layers.

[0009] Furthermore, Patent Document 4 describes an all-solid-state battery that suppresses internal short circuits even when expansion and contraction of the solid electrolyte layer occurs due to charging and discharging, and that has an electrically insulating frame with a hollow structure and an adhesion-improving region that is formed at the interface between the solid electrolyte layer and the electrically insulating frame and prevents internal short circuits.

[0010] Furthermore, Patent Document 5 describes an all-solid-state battery that includes an insulator on the outer periphery of a solid electrolyte layer as an all-solid-state battery that prevents short-circuiting between a positive electrode layer and a negative electrode layer.

[0011] However, the all-solid-state batteries described in the above-mentioned patent documents have not sufficiently improved cracks caused by battery expansion during charging, and there is room for further improvement. Therefore, an object of the present disclosure is to provide a solid-state battery that can further reduce cracks caused by battery expansion during charging. [Means for solving the problem]

[0012] The inventors of the present application attempted to solve the above problems by taking a new approach rather than simply extending the conventional technology, and as a result, they have invented a solid-state battery that achieves the above-mentioned main object.

[0013] The present disclosure provides a battery element including a stack of a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer; an end electrode provided on an end surface of the battery element; an insulating layer provided between the positive electrode layer or the negative electrode layer and the end electrode, The solid-state battery includes the insulating layer containing a heat-resistant resin. [Effects of the Invention]

[0014] In the solid state battery according to the present disclosure, the insulating layer contains a heat-resistant resin, which can further reduce cracks caused by expansion of the battery during charging. [Brief explanation of the drawings]

[0015] [Figure 1A] FIG. 1 is a cross-sectional view of a solid-state battery according to a first embodiment of the present disclosure. [Figure 1B] FIG. 1B is a cross-sectional view taken along the line ii in FIG. 1A. [Figure 1C] FIG. 4 is a cross-sectional view of a modified example of the solid state battery according to the first embodiment of the present disclosure. [Figure 1D] FIG. 1B is a cross-sectional view taken along the line ii-ii in FIG. 1A. [Figure 2A] FIG. 4 is a cross-sectional view of a solid state battery according to a second embodiment of the present disclosure. [Figure 2B] 2B is a cross-sectional view taken along the line iii-iii in FIG. 2A. [Figure 3A] FIG. 10 is a cross-sectional view of a solid state battery according to a third embodiment of the present disclosure. [Figure 3B] FIG. 10 is a cross-sectional view of a modified example of the solid state battery according to the third embodiment of the present disclosure. [Figure 3C] FIG. 10 is a cross-sectional view of another modified example of the solid state battery according to the third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] The "solid-state battery" of the present disclosure will be described in detail below. While the description will be made with reference to drawings as necessary, the contents shown are merely shown as schematic and illustrative examples for the purpose of understanding the present disclosure, and the appearance and / or dimensional ratios may differ from the actual product. For convenience of explanation, unless otherwise specified, the same reference numerals or symbols will indicate the same components or parts or the same meanings.

[0017] In the present disclosure, the term "solid-state battery" refers in a broad sense to a battery whose components are made of solids, and in a narrow sense to an all-solid-state battery whose components (particularly preferably all components) are made of solids. In a preferred embodiment, the solid-state battery in the present disclosure is a stacked-type solid-state battery configured such that each layer constituting a battery unit is stacked on top of each other, and preferably each such layer is made of a sintered body.

[0018] The term "solid-state battery" encompasses not only so-called "secondary batteries" that can be repeatedly charged and discharged, but also "primary batteries" that can only be discharged. In a preferred embodiment of the present disclosure, the "solid-state battery" is a secondary battery. The term "secondary battery" is not limited to the name, and can also encompass electrochemical devices such as "power storage devices."

[0019] In this specification, the term "plan view" refers to a sketch of an object viewed from above or below along the thickness direction based on the stacking direction of the layers constituting the solid-state battery.

[0020] The term "cross-sectional view" as used in this specification refers to the shape when viewed from a direction approximately perpendicular to the thickness direction based on the stacking direction of each layer constituting the solid-state battery (in other words, the shape when cut along a plane parallel to the stacking direction).

[0021] The terms "upper-lower direction" and "left-right direction" used directly or indirectly in this specification correspond to the upper-lower direction and left-right direction in the drawings, respectively. In a preferred embodiment, the downward vertical direction (i.e., the direction in which gravity acts) can be considered to correspond to the "lower direction," and the opposite direction can be considered to correspond to the "upper direction."

[0022] [Solid-state battery configuration] -First embodiment- The solid-state battery 100 includes a battery element 140 formed by laminating a positive electrode layer 110, a negative electrode layer 120, and at least a solid electrolyte layer 130 interposed therebetween, end electrodes 151, 152 provided on end surfaces of the battery element 140 and electrically connected to the battery element 140, and an insulating layer 170 provided between the positive electrode layer 110 or the negative electrode layer 120 and the end electrodes 151, 152 (see FIG. 1 ). Note that, in this embodiment, a solid-state battery 100 will be described in which the positive electrode layer 110 and the negative electrode layer 120 are capable of absorbing and releasing lithium ions, but the present invention is not limited to this example, and the solid-state battery may also be one in which the positive electrode layer 110 and the negative electrode layer 120 absorb and release sodium ions.

[0023] The battery element 140 may be formed by firing each layer constituting the battery element 140. The positive electrode layer 110, the negative electrode layer 120, the solid electrolyte layer 130, and the like may form fired layers. Preferably, the positive electrode layer 110, the negative electrode layer 120, the solid electrolyte layer 130, and the insulating layer 170 are each fired integrally with one another, and therefore the battery element 140 may form an integrally fired body. In this specification, the direction in which the positive electrode layer 110 and the negative electrode layer 120 are stacked (vertical direction) is referred to as the "stacking direction," and the direction intersecting the stacking direction is referred to as the horizontal direction in which the positive electrode layer 110 and the negative electrode layer 120 extend.

[0024] 1. Positive and negative electrode layers The positive electrode layer 110 is an electrode layer including at least a positive electrode active material layer 111. The positive electrode layer 110 may further include a solid electrolyte. In a preferred embodiment, the positive electrode layer 110 is made of a sintered body including at least positive electrode active material particles and solid electrolyte particles. On the other hand, the negative electrode layer 120 is an electrode layer including at least a negative electrode active material layer 121. The negative electrode layer 120 may further include a solid electrolyte. In a preferred embodiment, the negative electrode layer 120 is made of a sintered body including at least a negative electrode active material particles and solid electrolyte particles.

[0025] Here, the positive electrode active material and the negative electrode active material are materials involved in the transfer of electrons in a solid-state battery. Charging and discharging are performed by the movement (or conduction) of ions between the positive electrode layer and the negative electrode layer via the solid electrolyte, and the transfer of electrons between the positive electrode layer and the negative electrode layer via external terminals. The positive electrode layer 110 and the negative electrode layer 120 may include a current collector layer.

[0026] 1 shows an example of a configuration in which three positive electrode layers 110 and two negative electrode layers 120 are stacked, but the number of layers is not limited to this example and may be one layer, or several tens to several hundreds of layers. The thickness of the positive electrode layer or the negative electrode layer may be 5 μm or more and 60 μm or less, preferably 8 μm or more and 50 μm or less. It may also be 5 μm or more and 30 μm or less.

[0027] (Cathode active material layer) The positive electrode active material contained in the positive electrode active material layer 111 is, for example, a lithium-containing compound or a sodium-containing compound. The type of lithium-containing compound is not particularly limited, but may be, for example, a lithium transition metal composite oxide and / or a lithium transition metal phosphate compound. The lithium transition metal composite oxide is a general term for oxides containing lithium and one or more transition metal elements as constituent elements. The lithium transition metal phosphate compound is a general term for phosphate compounds containing lithium and one or more transition metal elements as constituent elements. The type of transition metal element is not particularly limited, but may be, for example, cobalt (Co), nickel (Ni), manganese (Mn), and / or iron (Fe).

[0028] The lithium transition metal composite oxide is, for example, Li x M1O2 and Li y Lithium transition metal phosphate compounds include compounds represented by the formula: Li z The compounds are represented by the formula M3PO4, where M1, M2, and M3 each represent one or more transition metal elements, and the values ​​of x, y, and z are arbitrary.

[0029] Specifically, the lithium transition metal composite oxide is, for example, LiCoO2, LiNiO2, LiVO2, LiCrO2, LiMn2O4, LiCo 1 / 3 Ni 1 / 3 Mn 1 / 3 O2, and LiNi 0.5 Mn 1.5 O4, etc. Examples of lithium transition metal phosphate compounds include LiFePO4, LiCoPO4, and LiMnPO4. Lithium transition metal composite oxides (particularly LiCoO2) may contain trace amounts (of the order of a few percent) of additive elements. Examples of additive elements include 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).

[0030] In addition, the positive electrode active material capable of absorbing and releasing sodium ions may be at least one selected from the group consisting of sodium-containing phosphate compounds having a Nasicon structure, sodium-containing phosphate compounds having an olivine structure, sodium-containing layered oxides, and sodium-containing oxides having a spinel structure.

[0031] 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 contain two or more types of positive electrode active materials, in which case the total content thereof may be within the above range. When the content of the active material is 50% by weight or more, the energy density of the battery can be particularly increased.

[0032] (Negative electrode active material layer) The negative electrode active material contained in the negative electrode active material layer 121 is, for example, a carbon material, a metal-based material, a lithium alloy and / or a lithium-containing compound.

[0033] Specifically, the carbon material is, for example, graphite, graphitizable carbon, non-graphitizable carbon, mesocarbon microbeads (MCMB) and / or highly oriented graphite (HOPG).

[0034] Metallic materials are a general term for materials containing, as constituent elements, one or more of metal elements and semimetal elements that can form an alloy with lithium. This metallic material may be a simple substance, an alloy, or a compound. The purity of the simple substance described here is not necessarily limited to 100%, and the simple substance may contain trace amounts of impurities.

[0035] Metal elements and metalloid 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).

[0036] Specifically, the metal-based material may be, for example, Si, Sn, SiB4, TiSi2, SiC, Si3N4, or SiO v (0 <v≦2)、LiSiO、SnOw (0 <w≦2)、SnSiO3、LiSnOおよび / またはMg2Snなどである。

[0037] The lithium-containing compound is, for example, a lithium transition metal composite oxide. The definition of the lithium transition metal composite oxide is as described above. Specifically, If The oxides include, for example, Li3V2(PO4)3, Li3Fe2(PO4)3, and Li4Ti5O. 12 , LiTi2(PO4)3, and / or LiCuPO4.

[0038] In addition, the negative electrode active material capable of absorbing and releasing sodium ions may be at least one selected from the group consisting of sodium-containing phosphate compounds having a Nasicon structure, sodium-containing phosphate compounds having an olivine structure, and sodium-containing oxides having a spinel structure.

[0039] 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 types of negative electrode active materials, in which case the total content thereof may be within the above range. By making the content of the active material 50% by weight or more, the energy density of the battery can be particularly increased.

[0040] (Additional Configuration of Positive Electrode Active Material Layer and Negative Electrode Active Material Layer) The positive electrode active material layer 111 and / or the negative electrode active material layer 121 may contain a conductive material. Examples of the conductive material contained in the positive electrode active material layer 111 and / or the negative electrode active material layer 121 include carbon materials and metal materials. Specifically, examples of the carbon materials include graphite and carbon nanotubes. Examples of the metal materials include 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 of these metals.

[0041] The positive electrode active material layer 111 and / or the negative electrode active material layer 121 may contain a binder. The binder may be, for example, one or more of synthetic rubber and polymeric materials. Specifically, the synthetic rubber may be, for example, styrene-butadiene rubber, fluorine-containing rubber, and / or ethylene propylene diene. The polymeric material may be, for example, at least one selected from the group consisting of polyvinylidene fluoride, polyimide, and acrylic resin.

[0042] The positive electrode active material layer 111 and / or the negative electrode active material layer 121 may contain a sintering aid. The sintering aid may be at least one selected from the group consisting of lithium oxide, sodium oxide, potassium oxide, boron oxide, silicon oxide, bismuth oxide, and phosphorus oxide.

[0043] There are no particular limitations on the thickness of each of the positive electrode active material layer 111 and the negative electrode active material layer 121, and for example, each may independently be 2 μm or more and 100 μm or less, and particularly 5 μm or more and 50 μm or less.

[0044] (Positive electrode current collector layer and negative electrode current collector layer) The positive electrode current collector layer 112 and the negative electrode current collector layer 122 preferably have higher electronic conductivity than the positive electrode active material layer 111 and the negative electrode active material layer 121 .

[0045] The positive electrode current collector layer 112 may be made of, for example, at least one material 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.

[0046] The negative electrode current collector layer 122 may be made of, for example, at least one material selected from the group consisting of carbon materials, silver, palladium, gold, platinum, aluminum, copper, and nickel.

[0047] The positive electrode current collector layer 112 and / or the negative electrode current collector layer 122 may each have an electrical connection portion for electrical connection to the outside, and may be configured to be electrically connectable to a terminal electrode. The positive electrode current collector layer 112 and the negative electrode current collector layer 122 may each be in the form of a foil, but from the viewpoint of improving conductivity and reducing manufacturing costs by sintering them together, they are preferably in the form of an integrated sintering.

[0048] When the positive electrode current collector layer 112 and / or the negative electrode current collector layer 122 are in the form of a sintered body, they may be composed of a sintered body containing, for example, a conductive material, an active material, a solid electrolyte, a binder, and / or a sintering aid. The conductive material contained in the positive electrode current collector layer 112 and the negative electrode current collector layer 122 may be selected from, for example, the same materials as the conductive material that may be contained in the positive electrode active material layer 111 and / or the negative electrode active material layer 121. The solid electrolyte, binder, and / or sintering aid contained in the positive electrode current collector layer 112 and the negative electrode current collector layer 122 may be selected from, for example, the same materials as the solid electrolyte, binder, and / or sintering aid that may be contained in the positive electrode active material layer 111 and / or the negative electrode active material layer 121.

[0049] The positive electrode current collector layer 112 and / or the negative electrode current collector layer 122 may contain a heat-resistant resin. When the current collector layer contains a heat-resistant resin, cracks caused by expansion of the current collector layer can be suppressed.

[0050] There are no particular limitations on the thickness of each of the positive electrode current collector layer 112 and the negative electrode current collector layer 122, and for example, each may independently be 1 μm or more and 100 μm or less, and particularly 1 μm or more and 50 μm or less.

[0051] 2.Solid electrolyte layer 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 constituent unit in a solid-state battery forms a layer capable of conducting lithium ions or sodium ions between the positive electrode layer 110 and the negative electrode layer 120. The solid electrolyte only needs to be provided at least between the positive electrode layer 110 and the negative electrode layer 120. In other words, the solid electrolyte may also be present around the positive electrode layer 110 and / or the negative electrode layer 120 so as to protrude from between the positive electrode layer 110 and the negative electrode layer 120. Specific solid electrolytes include, for example, one or more of a crystalline solid electrolyte, a glass-based solid electrolyte, and a glass-ceramic-based solid electrolyte.

[0052] The crystalline solid electrolyte may be, for example, an oxide-based crystalline material or a sulfide-based crystalline material. The oxide-based crystalline material may be, for example, a Li-based crystalline material having a Nasicon structure. 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, and an example is Li 1.3 Al 0.3 Ti 1.7 (PO4)3), La with perovskite structure 0.51 Li 0.34 TiO 2.94 , and Li7La3Zr2O with garnet structure 12 In addition, sulfide-based crystal materials include thio-LISICON, and Li 3.25 Ge 0.25 P 0.75 S4 and Li 10 GeP2S 12 The crystalline solid electrolyte may include a polymer material (for example, polyethylene oxide (PEO)).

[0053] Glass-based solid electrolytes include, for example, oxide-based glass materials and sulfide-based glass materials. Examples of oxide-based glass materials include 50Li4SiO4·50Li3BO3. Examples of sulfide-based glass materials include 30Li2S·26B2S3·44LiI, 63Li2S·36SiS2·1Li3PO4, 57Li2S·38SiS2·5Li4SiO4, 70Li2S·30P2S5, and 50Li2S·50GeS2.

[0054] The glass ceramic solid electrolyte may be, for example, an oxide-based glass ceramic material or a sulfide-based glass ceramic material. The oxide-based glass ceramic material may be, for example, a phosphate compound containing lithium, aluminum, and titanium as constituent elements (LATP) or a phosphate compound containing lithium, aluminum, and germanium as constituent elements (LAGP). LATP may be, for example, Li 1.07 Al 0.69 Ti 1.46 (PO4)3, etc. LAGP is also used, for example, Li 1.5 Al 0.5 Ge 1.5 (PO4), etc. Examples of sulfide-based glass ceramic materials include Li7P3S 11 and Li 3.25 P 0.95 Examples include S4.

[0055] When emphasis is placed on the viewpoints of excellent atmospheric stability and ease of integral sintering, the solid electrolyte may comprise at least one material selected from the group consisting of an oxide-based crystalline material, an oxide-based glass material, and an oxide-based glass ceramic material.

[0056] In addition, examples of solid electrolytes capable of conducting sodium ions include sodium-containing phosphate compounds having a Nasicon structure, oxides having a perovskite structure, and oxides having a garnet or garnet-like structure. Examples of sodium-containing phosphate compounds having a Nasicon structure include Na x M y(PO4)3 (1≦x≦2, 1≦y≦2, M is at least one selected from the group consisting of Ti, Ge, Al, Ga and Zr).

[0057] 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, for example, materials similar to the binder and / or sintering aid that may be contained in the positive electrode active material portion and / or the negative electrode active material portion.

[0058] 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.

[0059] 3. Insulation layer The insulating layer 170 acts as an electrode separator (also referred to as a "blank portion" or "blank layer") for electrically insulating the positive electrode layer 110 and the negative electrode layer side end surface electrode 152, or the negative electrode layer 120 and the positive electrode layer side end surface electrode 151 (see FIG. 1A). The insulating layer 170 may be made of a material that does not conduct electricity (insulating material). The insulating layer 170 may also be porous. In the case of an insulating layer 170 made of a material that does not conduct electricity, the electrical resistivity should be less than 10 12 Materials with a resistance of Ω·m or higher are preferred.

[0060] The insulating layer 170 contains a heat-resistant resin. In this specification, the term "heat-resistant resin" refers to a resin that can withstand the heat caused by charging the battery and the firing of the layers that make up the solid-state battery (the firing temperature is approximately 300°C to 800°C).

[0061] Examples of heat-resistant resins include imide-based resins and / or imidazole-based resins. Examples of imide-based resins include polyimide resins (for example, glass transition temperature: 300 to 500°C, thermal decomposition temperature: about 600°C) and polyamide-imide resins (for example, glass transition temperature: 250 to 350°C, thermal decomposition temperature: about 370°C). In addition, imidazole systemAn example of the resin is polybenzimidazole resin (for example, glass transition temperature: 420 to 435°C, thermal decomposition temperature: approximately 600°C). The thermal decomposition temperature can be measured by thermogravimetry / differential thermal analysis (TD-DTA).

[0062] The insulating layer 170 is provided around the positive electrode layer 110 (the positive electrode active material layer 111 and the positive electrode current collector layer 112) to separate the positive electrode layer 110 from the negative electrode layer-side end electrode 152 (see FIG. 1B ). The insulating layer 170 is provided around the negative electrode layer 120 (the negative electrode active material layer 121 and the negative electrode current collector layer 122) to separate the negative electrode layer 120 from the positive electrode layer-side end electrode 151. That is, the insulating layer 170 may be disposed between the negative electrode layer 120 and the positive electrode layer-side end electrode 151 and / or between the positive electrode layer 110 and the negative electrode layer-side end electrode 152.

[0063] On the other hand, since the positive electrode layer 110 (the positive electrode active material layer 111 and the positive electrode current collector layer 112) and the positive electrode layer side end electrode 151 are electrically connected, no insulating layer 170 is disposed between the positive electrode layer 110 and the positive electrode layer side end electrode 151. Similarly, since the negative electrode layer 120 (the negative electrode active material layer 121 and the negative electrode current collector layer 122) and the negative electrode layer side end electrode 152 are electrically connected, no insulating layer 170 is disposed between the negative electrode layer 120 and the negative electrode layer side end electrode 152.

[0064] That is, the solid-state battery according to the first embodiment of the present disclosure is a solid-state battery in which the insulating layer 170 is arranged to a minimum extent. In other words, the insulating layer 170 does not have to be provided around the solid electrolyte layer 130 as shown in FIG. 1D .

[0065] The insulating layer 170 may further contain a filler in addition to the heat-resistant resin. The filler is preferably an insulating filler. The filler is preferably electronically insulating and may be ionically conductive. The filler may have a higher Young's modulus than the heat-resistant resin. This can reduce the wetting and spreading of the heat-resistant resin during manufacturing, making it easier to co-fire. It can also improve the strength of the insulating layer 170.

[0066] The filler content is preferably 74 vol % or less in terms of volume ratio relative to the entire insulating layer 170. If it exceeds 74 vol %, the gaps between the fillers cannot be filled with the heat-resistant resin, and air bubbles may be trapped.

[0067] An example of the filler may include an inorganic material. Examples of the inorganic material include ceramic and / or glass materials. The ceramic material is not particularly limited, but may include at least one selected from the group consisting of aluminum oxide (Al2O3), boron nitride (BN), silicon dioxide (SiO2), silicon nitride (Si3N4), zirconium oxide (ZrO2), aluminum nitride (AlN), silicon carbide (SiC), and barium titanate (BaTiO3). The glass material is not particularly limited, but may include at least one selected from the group consisting of silica glass, soda-lime glass, potash glass, borate glass, borosilicate glass, barium borosilicate glass, zinc borate glass, barium borate glass, bismuth borosilicate glass, bismuth zinc borate glass, bismuth silicate glass, phosphate glass, aluminophosphate glass, and zinc phosphate glass.

[0068] (Examples of modified insulating layers) 1C , the insulating layer 170 of the first embodiment of the present disclosure may include a first insulating layer 171 containing a heat-resistant resin and a second insulating layer 172 not containing a heat-resistant resin. The first insulating layer 171 containing a heat-resistant resin may be disposed between the negative electrode layer 120 and the positive electrode layer-side end electrode 151 and / or between the positive electrode layer 110 and the negative electrode layer-side end electrode 152. In other words, the second insulating layer 172 not containing a heat-resistant resin may be disposed around the positive electrode layer 110 and the negative electrode layer 120 at a position not facing the end electrodes 151 and 152.

[0069] In the present disclosure, cracks due to battery expansion during charging occur relatively frequently mainly in positions where the end electrodes 151, 152 face the positive electrode layer 110 and the negative electrode layer 120. Therefore, it is sufficient to provide a first insulating layer 171 containing a heat-resistant resin (e.g., polyimide resin) at least in these positions. In other words, the second insulating layer 172 in the remaining portions surrounding the positive electrode layer 110 and the negative electrode layer 120 may be made of an insulating material other than a heat-resistant resin (e.g., the ceramic material and / or glass material described above) as long as it has insulating properties. According to this modified embodiment, an insulating layer containing a heat-resistant resin can be efficiently disposed in positions where cracks due to battery expansion during charging occur.

[0070] 4.Protective layer The protective layer 160 may be formed on the outermost surface of the solid-state battery as needed, and may be provided for electrical, physical, and / or chemical protection. The material constituting the protective layer 160 is preferably excellent in insulation, durability, and / or moisture resistance, and environmentally safe. For example, it is preferable to use glass, ceramics, thermosetting resin, and / or photocurable resin.

[0071] 5. End electrode The solid-state battery is provided with external terminals that enable connection to the outside. In particular, positive and negative end electrodes 151, 152 are provided in pairs on the side surfaces of the solid-state battery. More specifically, the positive electrode layer-side end electrode 151 connected to the positive electrode layer 110 and the negative electrode layer-side end electrode 152 connected to the negative electrode layer 120 may be provided in pairs. Such end electrodes 151, 152 are preferably made of a material with high electronic conductivity. Although not particularly limited, the end electrodes 151, 152 may be made of at least one material selected from the group consisting of silver, gold, platinum, aluminum, copper, tin, and nickel.

[0072] The end electrodes 151, 152 may contain a binder and / or a sintering aid. The binder and / or sintering aid contained in the end electrodes 151, 152 may be selected from, for example, materials similar to the binder and / or sintering aid that may be contained in the positive electrode active material portion and / or the negative electrode active material portion.

[0073] As described above, the present disclosure First embodiment In the solid-state battery shown in Fig. 1, the insulating layer 170 contains a heat-resistant resin, and even if the battery expands during charging, the insulating layer can provide resistance to expansion due to the heat-resistant resin. This can further reduce cracks caused by charging the battery.

[0074] 6. Additional Features In the present disclosure, the fracture strain characteristic ε , which is specific to the material, is used as an index for determining cracks caused by battery expansion during charging. cr and elastic strain characteristic ε e and the fracture strain characteristic ε cr <Elastic strain characteristics ε e It may be determined that a crack will occur when the following condition holds true.

[0075] Fracture strain characteristic ε of the positive electrode layer 110 or the negative electrode layer 120 cr0 , and the fracture strain characteristic ε of the insulating layer 170 cr1 On the other hand, the elastic strain characteristic ε of the positive electrode layer 110 or the negative electrode layer 120 e0 , and the elastic strain characteristic ε of the insulating layer 170 e1 can be calculated using the following formula: ε e0 =-E1×α / (E0+E1) ε e1 = E0×α / (E0+E1) The Young's modulus of the positive electrode layer 110 or the negative electrode layer 120 is E0, the expansion coefficient of the positive electrode layer 110 or the negative electrode layer 120 is α, and the Young's modulus of the insulating layer 170 is E1. The elastic strain characteristic ε e0A negative value of indicates contraction of the positive electrode layer 110 or the negative electrode layer 120, and the elastic strain characteristic ε e1 A positive value of indicates expansion of the insulating layer 170.

[0076] And ε cr0 > -E1×α / (E0+E1) and ε cr1 > E0 × α / (E0 + E1) is satisfied, cracks caused by battery expansion during charging are suppressed. Details of this judgment index will be described in the Examples. By satisfying the above formula, cracks caused by battery expansion during charging can be appropriately reduced.

[0077] In a preferred embodiment, the Young's modulus E1 of the insulating layer 170 may be set to 0.1 GPa or more and 70 GPa or less. The reasons for this numerical range will be described in detail in the Examples. By satisfying the above Young's modulus requirement, cracks caused by battery expansion during charging can be further reduced.

[0078] -Second embodiment- Next, a solid-state battery according to a second embodiment of the present disclosure will be described below with reference to Figures 2A and 2B. The solid-state battery according to the second embodiment differs from the solid-state battery according to the first embodiment in that the current collector layers 112, 122 and the insulating layer 170 are different in configuration. This different configuration will be described below.

[0079] (current collector layer) The current collector layers 112, 122 of the second embodiment may be configured to be partially exposed from the active material layers 111, 121 (see FIG. 2A ). In other words, the length of the current collector layers 112, 122 may be longer than the length of the active material layers 111, 121 in the direction in which the end electrodes 151, 152 face each other (horizontal direction). More specifically, the current collector layers 112, 122 may be electrically connected to the end electrodes 151, 152 without electrically connecting the active material layers 111, 121 to the end electrodes 151, 152. According to this embodiment, the amount of active material layers 111, 121 used can be reduced.

[0080] (insulating layer) In the second embodiment, the insulating layer 170 may be disposed around the periphery of the solid electrolyte layer 130 in a plan view. In this manner, the insulating layer 170 can function as a protective film that protects the periphery of the solid electrolyte layer 130.

[0081] Furthermore, the current collector layers 112, 122 are disposed within the insulating layer 170. In other words, the active material layers 111, 121 are not disposed within the insulating layer 170. According to this embodiment, the current collector layers 112, 122 and the end electrodes 151, 152 can be appropriately electrically connected to each other.

[0082] In other words, when the insulating layer 170 contains the positive and negative electrode current collector layers 112, 122, it is sufficient that the positive electrode current collector layer 112 and the positive electrode layer-side end electrode 151 are electrically connected. In this case, the insulating layer 170 may be disposed between the positive electrode active material layer 111 and the positive electrode layer-side end electrode 151. It is sufficient that the negative electrode current collector layer 122 and the negative electrode layer-side end electrode 152 are electrically connected. In this case, the insulating layer 170 may be disposed between the negative electrode active material layer 121 and the negative electrode layer-side end electrode 152.

[0083] -Third embodiment- Next, a solid-state battery according to a third embodiment of the present disclosure will be described below with reference to Figures 3A to 3C. The solid-state battery according to the third embodiment differs from the solid-state battery according to the first embodiment in that the positive electrode layer 110, the negative electrode layer 120, the insulating layer 170, and the protective layer 160 are different in configuration. This different configuration will be described below.

[0084] (Positive and negative electrode layers) The positive electrode layer 110 according to the third embodiment of the present disclosure has a two-layer structure of a positive electrode current collector layer 112 and a positive electrode active material layer 111, while the negative electrode layer 120 may form a single layer. In other words, the negative electrode layer 120 forms a single layer (single layer).

[0085] Furthermore, the length of the positive electrode layer 110 and the length of the negative electrode layer 120 may be different in the direction (horizontal direction) in which the end electrodes 151, 152 face each other. In this case, it is preferable to make the positive electrode layer longer than the negative electrode layer.

[0086] (insulating layer) In the insulating layer according to the third embodiment of the present disclosure, a first insulating layer 171 containing a heat-resistant resin may be provided between the negative electrode layer 120 and the positive electrode layer side end surface electrode 151. This is mainly because cracks tend to occur in the insulating layer between the negative electrode layer 120 and the positive electrode layer side end surface electrode 151. In addition, 、 And / or, an insulating material other than heat-resistant resin (for example, the above-mentioned ceramic material and / or glass material) may be provided as the second insulating layer 172 between the positive electrode layer 110 and the positive electrode layer-side end surface electrode 151 (FIG. 3A). According to this embodiment, an insulating layer containing heat-resistant resin can be efficiently disposed in a location where cracks are likely to occur due to expansion of the battery during charging.

[0087] As a modification of the solid state battery of this embodiment, as shown in FIG. 3B, Positive Pole layer side end electrode 15 1 Between 、 Between the positive electrode layer 110 and the positive electrode layer side end surface electrode 151 and / or between the positive electrode layer 110 and the negative electrode layer side end surface electrode 152 In this way, by including a heat-resistant resin in the insulating layer 170 located between the positive electrode layer 110 or the negative electrode layer 120 and the end electrodes 151, 152, cracks due to expansion of the battery during charging can be more effectively reduced.

[0088] Furthermore, as a modified example of the solid-state battery of this embodiment, as shown in FIG. 3C , an insulating layer 170 containing a heat-resistant resin may be provided on the outermost surface of the solid-state battery. In other words, the insulating layer 170 may be disposed on a portion of the outermost surface of all of the battery elements 140. By disposing the insulating layer 170 in this manner, cracks caused by expansion of the battery during charging can be more effectively reduced. The outermost layer of the battery element 140 may be a positive electrode layer, a negative electrode layer, a solid electrolyte layer, or a protective layer.

[0089] 3C , the solid-state battery may not be limited to the modified example shown in FIG. 3C , and the insulating layer 170 may be disposed on at least one outermost surface of the battery element 140. In other words, the insulating layer 170 may be disposed on either the upper side or the lower side of the battery element 140, and the overall proportion of the insulating layer 170 may be lower than that of the solid-state battery of FIG. 3C .

[0090] [Solid-state battery manufacturing method] Next, a method for manufacturing a solid-state battery will be described. As an example, a method for manufacturing the solid-state battery shown in the first embodiment will be described, but the above manufacturing method may be applied to the solid-state battery shown in the second embodiment and the solid-state battery shown in the third embodiment.

[0091] The solid-state battery of the present disclosure 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. Hereinafter, for the purpose of understanding the present disclosure, the cases where the printing method and the green sheet method are adopted will be described in detail, but the present disclosure is not limited to these methods.

[0092] (Solid state battery laminate precursor formation process) In this step, several types of pastes are used as inks, such as a paste for a positive electrode active material portion, a paste for a negative electrode active material portion, a paste for a solid electrolyte layer, a paste for a current collector portion, a paste for an insulating layer, and a paste for a protective layer, etc. In other words, the pastes are applied by a printing method to form pastes of a predetermined structure on a support substrate.

[0093] In printing, a solid state battery laminate precursor corresponding to a predetermined solid state battery structure can be formed on a substrate by sequentially stacking printed layers with a predetermined thickness and pattern shape. The type of pattern formation method is not particularly limited as long as it is a method capable of forming a predetermined pattern, and may be, for example, one or more of a screen printing method, a gravure printing method, etc.

[0094] The paste can be prepared by wet mixing predetermined constituent materials for each layer, appropriately selected from the group consisting of a positive electrode active material, a negative electrode active material, a conductive material, a solid electrolyte, an insulating material, a binder, and a sintering aid, with an organic vehicle in which an organic material is dissolved in a solvent. The paste for the positive electrode active material portion may include, for example, a positive electrode active material, a conductive material, a solid electrolyte, a binder, a sintering aid, an organic material, and a solvent. The paste for the negative electrode active material portion may include, for example, a negative electrode active material, a conductive material, a solid electrolyte, a binder, a sintering aid, an organic material, and a solvent. The paste for the solid electrolyte layer may include, for example, a solid electrolyte, a binder, a sintering aid, an organic material, and a solvent. The paste for the positive electrode current collector portion and the paste for the negative electrode current collector portion may include a conductive material, an active material, a solid electrolyte, a binder, a sintering aid, an organic material, and a solvent. The insulating layer paste may include, for example, an insulating material including a heat-resistant resin (imide-based resin and / or imidazole-based resin), a binder, a sintering aid, an organic material, and a solvent. The protective layer paste may include, for example, an insulating material, a binder, an organic material, and a solvent.

[0095] The organic material contained in the paste is not particularly limited, but at least one polymer material selected from the group consisting of polyvinyl acetal resin, cellulose resin, polyacrylic resin, polyurethane resin, polyvinyl acetate resin, polyvinyl alcohol resin, etc. The type of solvent is not particularly limited, but for example, butyl acetate 、 The solvent may be any one or more of organic solvents such as toluene, terpineol, and N-methyl-pyrrolidone.

[0096] In the wet mixing, media can be used, specifically, a ball mill method or a viscomill method can be used, or a wet mixing method without using media can be used, such as a sand mill method, a high-pressure homogenizer method, or a kneader dispersion method.

[0097] The support substrate is not particularly limited as long as it is a support capable of supporting each paste layer, and may be, for example, a release film with a release treatment applied to one surface. Specifically, a substrate made of a polymer material such as polyethylene terephthalate can be used. When each paste layer is subjected to the firing step while being held on the substrate, a substrate that is heat resistant to the firing temperature may be used.

[0098] The applied paste is dried on a heated hot plate to form a positive electrode layer green sheet, a negative electrode layer green sheet, a solid electrolyte layer green sheet, an electrode separation green sheet, and / or a protective layer green sheet, each having a predetermined shape and thickness, on a substrate (e.g., a PET film).

[0099] Next, each green sheet is peeled off from the substrate. After peeling, the green sheets of each component of one battery unit are stacked in order along the stacking direction to form a solid-state battery stack precursor. After stacking, a solid electrolyte layer, an electrode separator, and / or a protective layer may be provided on the side regions of the electrode green sheets by screen printing.

[0100] (Firing process) In the firing step, the solid battery laminate precursor is fired. For illustrative purposes, the firing is performed by heating in a nitrogen gas atmosphere containing oxygen gas or in the air. The firing may be performed while applying pressure to the solid battery laminate precursor in the stacking direction (and in some cases, in the stacking direction and a direction perpendicular to the stacking direction).

[0101] Through such firing, a solid state battery stack is formed, and ultimately a desired solid state battery is obtained.

[0102] (End electrode formation process) The end electrodes can be formed by applying a conductive paste to the exposed positive and negative electrode sides of the battery element. It is preferable to provide the positive and negative end electrodes so that they extend to the underside of the battery element, since this allows for connection to the mounting lands with a small area during surface mounting of the solid-state battery. After applying the conductive paste, the end electrodes are fired. This allows the solid-state battery of the present disclosure to be manufactured. [Example]

[0103] A demonstration test was conducted on the "solid-state battery" according to the present disclosure. Specifically, solid-state batteries of Comparative Example, Example 1, and Example 2 shown in Table 1 below were manufactured. The structure of the solid-state battery used was the structure shown in FIG. 3C.

[0104] [Table 1]

[0105] When the solid-state batteries of the comparative example and the example were checked for cracks in the insulating layer 170, the results shown in the following Tables 2 to 4 were obtained. The presence or absence of cracks was confirmed by performing a simulation using the finite element method (software name: Abaqus).

[0106] The "expansion rate" in the table is the characteristic value of the electrode material (positive or negative electrode) due to expansion during charging and discharging. Cr ) is the physical property value of the material used. e ) is the elastic strain characteristic ε of the positive electrode layer 110 or the negative electrode layer 120 as described above. e0 , and the elastic strain characteristic ε of the insulating layer 170 e1 Using the formula to calculate ε e0 =-E1×α / (E0+E1) or ε e1 = E0 × α / (E0 + E1).

[0107] Results for comparative solid-state batteries [Table 2]

[0108] Results for the solid-state battery of Example 1 [Table 3]

[0109] Results for the solid-state battery of Example 2 [Table 4]

[0110] According to the above results, in Examples 1 and 2, since the insulating layer 170 contains a heat-resistant resin (polyimide resin), cracks in the insulating layer 170 during charging and discharging were reduced. On the other hand, in the comparative example, since the insulating layer 170 does not contain a heat-resistant resin, cracks were occasionally observed in the insulating layer 170 during charging and discharging.

[0111] Furthermore, in Examples 1 and 2, the Young's modulus of the insulating layer 170 was in the range of 0.1 GPa or more and 70 GPa or less, and therefore cracks in the insulating layer 170 during charge and discharge were reduced. On the other hand, in the comparative example, the Young's modulus of the insulating layer 170 was 70 GPa or more, and therefore cracks were occasionally observed in the insulating layer 170 during charge and discharge.

[0112] Furthermore, in Examples 1 and 2, the breaking strain (ε Cr )>Elastic strain (ε e ) is satisfied. That is, ε cr0 > -E1×α / (E0+E1) and ε cr1 > E0 × α / (E0 + E1), and cracks in the insulating layer 170 during charge and discharge were reduced. Cr )>Elastic strain (ε e ), the insulating layer has a breakdown strain (ε Cr )>Elastic strain (ε e ) was not satisfied. cr0> -E1×α / (E0+E1) and ε cr1 > E0×α / (E0+E1) was not satisfied, cracks were occasionally observed in the insulating layer 170 during charging and discharging.

[0113] Furthermore, even when the content ratio of the filler (aluminum oxide powder) is set to 74% or less based on the entire insulating layer as in the solid-state battery of Example 2, the thickness of the insulating layer 170 during charging and discharging is crack The results showed a reduction in

[0114] It should be noted that the embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention should not be interpreted solely by the above-described embodiments, but should be defined by the claims. The technical scope of the present invention also includes all modifications within the meaning and scope of the claims. For example, the solid-state battery is not limited to a substantially hexahedral shape, but may also be a polyhedral, cylindrical, or spherical shape. The solid-state battery of the present disclosure also includes the following aspects. <1> a battery element including a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer; an end electrode provided on an end surface of the battery element; an insulating layer provided between the positive electrode layer or the negative electrode layer and the end electrode, The insulating layer includes a heat-resistant resin. <2> the insulating layer is disposed between the positive electrode layer and the end electrode and between the negative electrode layer and the end electrode; <1> The solid-state battery according to claim 1. <3> The end surface electrode is a positive electrode end surface electrode electrically connected to the positive electrode layer; a negative electrode end surface electrode electrically connected to the negative electrode layer, The insulating layer is disposed between the positive electrode end surface electrode and the negative electrode layer. <1> The solid-state battery according to claim 1. <4> The insulating layer is disposed between the negative electrode end surface electrode and the positive electrode layer. <3> The solid-state battery according to claim 1. <5> the positive electrode layer or the negative electrode layer includes an active material layer containing an electrode active material and a current collector layer, the insulating layer is disposed between the active material layer and the end electrode; <1> ~ <4> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <6> the insulating layer is disposed between the solid electrolyte layer and the end electrode; <1> ~ <5> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <7> the positive electrode layer includes a positive electrode current collector layer and a positive electrode active material layer, and the negative electrode layer forms a single layer; <1> ~ <6> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <8> The insulating layer is disposed on at least one outermost surface of the battery element. <1> ~ <7> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <9> the insulating layer is disposed on a part of the outermost surface of all the battery elements; <1> ~ <8> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <10> The Young's modulus of the positive electrode layer or the negative electrode layer is E 0 , the expansion coefficient of the positive electrode layer or the negative electrode layer is α, and the fracture strain of the positive electrode layer or the negative electrode layer is ε cr0 , where E is the Young's modulus of the insulating layer 1 , the breakdown strain of the insulating layer is ε cr1 When ε cr0 > -E 1 ×α / (E 0 +E 1 ) and ε cr1 > E 0 ×α / (E 0 +E 1 ) Satisfy the following: <1> ~ <9> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <11> The Young's modulus of the insulating layer is 0.1 GPa or more and 70 GPa or less. <1> ~ <10> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <12> The insulating layer further includes a filler. <1> ~ <11> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <13> The filler comprises an inorganic material. <12> The solid-state battery according to claim 1. <14> The inorganic material includes aluminum oxide. <13> The solid-state battery according to claim 1. <15> The content ratio of the filler contained in the insulating layer is 74 Vol% or less. <12> ~ <14> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <16> the positive electrode layer, the negative electrode layer, the solid electrolyte layer, and the insulating layer are formed as an integrally fired body; <1> ~ <15> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <17> a battery element including a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer; an end electrode provided on an end surface of the battery element, the positive electrode layer and / or the negative electrode layer includes an electrode active material layer and a current collector layer, The current collector layer comprises a conductive material and a heat-resistant resin. <18> an insulating layer provided between the positive electrode layer or the negative electrode layer and the end electrode; The insulating layer contains a heat-resistant resin. <17> The solid-state battery according to claim 1. <19> The conductive material is a carbon material and / or a metal material. <17> or <18> The solid-state battery according to claim 1. <20> The heat-resistant resin comprises an imide-based resin and / or an imidazole-based resin. <1> ~ <19> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a <21> the positive electrode layer and the negative electrode layer are layers capable of absorbing and releasing lithium ions; <1> ~ <20> 10. The solid-state battery according to claim 9, wherein the solid-state battery is a [Industrial Applicability]

[0115] The packaged solid-state battery of the present invention can be used in various fields where battery use or power storage is envisioned. By way of example only, the packaged solid-state battery of the present invention can be used in electronics packaging. The present invention can also be used in the electrical, information, and communications fields where mobile devices and the like are used (for example, electrical and electronic equipment fields including small electronic devices such as mobile phones, smartphones, laptop computers, digital cameras, activity monitors, arm computers, electronic paper, RFID tags, card-type electronic money, and smart watches, or mobile device fields), home and small industrial applications (for example, power tools, golf carts, and home, nursing care, and industrial robots), large industrial applications (for example, forklifts, elevators, and port cranes), transportation systems (for example, hybrid cars, electric cars, buses, trains, electrically assisted bicycles, and electric motorcycles), power system applications (for example, various types of power generation, road conditioners, smart grids, and general home-installed power storage systems), medical applications (for medical devices such as earphone hearing aids), pharmaceutical applications (for example, medication management systems), IoT, and space and deep-sea applications (for example, space probes and submersible research vessels). [Explanation of symbols]

[0116] 100 solid state battery 110 Positive electrode layer 111 Positive electrode active material layer 112 Positive electrode current collector layer 120 negative electrode layer 121 Negative electrode active material layer 122 Negative electrode current collector layer 130 Solid electrolyte layer 140 Battery elements 151 Positive electrode layer side end electrode 152 Negative layer side end electrode 160 protective layer 170 Insulating Layer 171 First insulating layer 172 Second insulating layer

Claims

1. a battery element including a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer; an end electrode provided on an end surface of the battery element; an insulating layer provided between the positive electrode layer or the negative electrode layer and the end electrode, The insulating layer includes a heat-resistant resin.

2. The solid-state battery according to claim 1, wherein the solid electrolyte is a glass-based solid electrolyte or a glass-ceramic-based solid electrolyte.

3. A solid-state battery according to claim 1 or 2, wherein the heat-resistant resin is a polyimide resin having a glass transition temperature of 300°C to 500°C.

4. The solid-state battery according to claim 1 , wherein the insulating layer is disposed between the positive electrode layer and the end electrode and between the negative electrode layer and the end electrode.

5. The end surface electrode is a positive electrode end surface electrode electrically connected to the positive electrode layer; a negative electrode end surface electrode electrically connected to the negative electrode layer, The solid-state battery according to claim 1 , wherein the insulating layer is disposed between the positive electrode end surface electrode and the negative electrode layer.

6. The solid-state battery according to claim 5 , wherein the insulating layer is disposed between the negative electrode end surface electrode and the positive electrode layer.

7. the positive electrode layer or the negative electrode layer includes an active material layer containing an electrode active material and a current collector layer, The solid-state battery according to claim 1 , wherein the insulating layer is disposed between the active material layer and the end electrode.

8. The solid-state battery according to claim 1 , wherein the insulating layer is disposed between the solid electrolyte layer and the end electrode.

9. The solid-state battery according to claim 1 , wherein the positive electrode layer includes a positive electrode current collector layer and a positive electrode active material layer, and the negative electrode layer forms a single layer.

10. The solid-state battery according to claim 1 , wherein the insulating layer is disposed on at least one outermost surface of the battery element.

11. The solid-state battery according to claim 1 , wherein the insulating layer is disposed on a portion of the outermost surface of all of the battery elements.

12. The Young's modulus of the positive electrode layer or the negative electrode layer is E ０ , the expansion coefficient of the positive electrode layer or the negative electrode layer is α, and the fracture strain of the positive electrode layer or the negative electrode layer is ε ｃｒ０ , the Young's modulus of the insulating layer is E １ , the breakdown strain of the insulating layer is ε ｃｒ１ When ε ｃｒ０ > - E １ ×α / (E ０ +e １ )およびε ｃｒ１ > E ０ ×α / (E ０ +e １ ) The solid-state battery according to claim 1 , wherein

13. The solid-state battery according to claim 1 , wherein the insulating layer has a Young's modulus of 0.1 GPa or more and 70 GPa or less.

14. The solid-state battery according to claim 1 , wherein the insulating layer further comprises a filler.

15. 15. The solid-state battery of claim 14, wherein the filler comprises an inorganic material.

16. 16. The solid-state battery of claim 15, wherein the inorganic material comprises aluminum oxide.

17. 17. The solid state battery according to claim 14, wherein the insulating layer contains the filler at a content ratio of 74 vol % or less.

18. The solid-state battery according to claim 1 , wherein the positive electrode layer, the negative electrode layer, the solid electrolyte layer, and the insulating layer are formed as a single fired body.

19. The positive electrode layer and / or the negative electrode layer includes an electrode active material layer and a current collector layer, The solid-state battery according to claim 1 , wherein the current collector layer contains a conductive material and a heat-resistant resin.

20. 20. The solid-state battery according to claim 19, wherein the conductive material is a carbon material and / or a metal material.

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

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