Battery

Abstract

A battery 1000 according to the present disclosure comprises a first electrode layer 100, a second electrode layer 200, and an electrolyte layer 300. The battery 1000 satisfies at least one configuration selected from the group consisting of (I) and (II).　(I) At least one selected from the group consisting of the first electrode layer 100, the second electrode layer 200, and the electrolyte layer 300 includes at least one titanium-containing material selected from the group consisting of halogenated titanium oxide and titanium oxide.　(II) The battery 1000 furthermore comprises a side surface layer including at least one titanium-containing material selected from the group consisting of halogenated titanium oxide and titanium oxide, the side surface layer being disposed on a side surface of at least one selected from the group consisting of the first electrode layer 100, the second electrode layer 200, and the electrolyte layer 300.

Description

battery

[0001] The present disclosure relates to batteries.

[0002] Patent Document 1 discloses a battery using a solid electrolyte containing Li, Ti, M, and F that coats an active material. M is at least one selected from the group consisting of Ca, Mg, Al, Y, and Zr. In Patent Document 1, the solid electrolyte is contained in a coating layer that coats the active material.

[0003] International Publication No. 2023 / 037817

[0004] There is a need in the art for a highly reliable battery. Therefore, the present disclosure provides a battery with improved reliability by increasing mechanical strength.

[0005] The battery of the present disclosure comprises: a first electrode layer; a second electrode layer; and an electrolyte layer disposed between the first electrode layer and the second electrode layer, wherein the battery satisfies at least one configuration selected from the group consisting of (I) and (II) below: (I) At least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer contains at least one titanium-containing material selected from the group consisting of halogenated titanium oxide and titanium oxide. (II) The battery further comprises a side layer disposed on a side surface of at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer, the side layer containing at least one titanium-containing material selected from the group consisting of halogenated titanium oxide and titanium oxide. The halogenated titanium oxide is represented by the following composition formula (1): TiO α1 X1 β1 ...Formula (1) In the composition formula (1), the X1 is at least one selected from the group consisting of F, Cl, Br, and I, the α1 satisfies 0.95≦α≦1.05, and the β1 satisfies 1.95≦α≦2.05, and the titanium oxide is represented by the following composition formula (2): TiO α2 Formula (2) In the composition formula (2), α2 satisfies 1.95≦α≦2.05.

[0006] The present disclosure can provide batteries with improved reliability.

[0007] FIG. 1 is a cross-sectional view and a plan view showing the schematic configuration of a battery 1000 according to a first embodiment. FIG. 2 is a cross-sectional view and a plan view showing the schematic configuration of a battery 1100 according to a second embodiment. FIG. 3 is a cross-sectional view and a plan view showing the schematic configuration of a battery 1200 according to a third embodiment. FIG. 4 is a cross-sectional view and a plan view showing the schematic configuration of a battery 1300 according to a fourth embodiment. FIG. 5 is a cross-sectional view and a plan view showing the schematic configuration of a battery 1400 according to a fifth embodiment. FIG. 6 is a cross-sectional view and a plan view showing the schematic configuration of a battery 1500 according to a sixth embodiment.

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0009] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, component placement and connection configurations, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concepts are described as optional components.

[0010] In this specification, terms indicating the relationship between elements, such as parallelism, terms indicating the shape of elements, such as rectangle, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0011] The drawings are schematic diagrams and are not necessarily drawn to scale. Therefore, for example, the scales of the drawings do not necessarily match. In the drawings, the same reference numerals are used for substantially the same components, and redundant explanations are omitted or simplified.

[0012] In this specification and the drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the z-axis direction is the thickness direction of the battery. Furthermore, in this specification, unless otherwise specified, the "thickness direction" refers to the direction perpendicular to the plane on which each layer of the battery is stacked.

[0013] In this specification, the term "plan view" refers to the view of the battery along the stacking direction of the layers in the battery. The term "thickness" refers to the length of the battery and each layer in the stacking direction.

[0014] In this specification, unless otherwise specified, in a battery and each layer, a "side surface" means a surface along the stacking direction of each layer in the battery, and a "main surface" means a surface other than the side surface.

[0015] In this specification, the terms "inside" and "outside" refer to the center side of the battery as "inside" and the peripheral side of the battery as "outside" when the battery is viewed along the stacking direction of the layers in the battery.

[0016] In this specification, the terms "upper" and "lower" in the battery configuration do not refer to the upper direction (vertically upper) and lower direction (vertically lower) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacking configuration. Furthermore, the terms "upper" and "lower" are used not only when two components are arranged with a gap between them and another component is present between them, but also when two components are arranged closely together and the two components are in contact with each other.

[0017] First Embodiment A battery according to a first embodiment will be described below.

[0018] The battery according to the first embodiment includes a first electrode layer, a second electrode layer, and an electrolyte layer, the electrolyte layer being disposed between the first and second electrode layers.

[0019] The battery according to the first embodiment satisfies at least one of the following conditions (I) and (II): (I) at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer contains at least one titanium-containing material selected from the group consisting of halogenated titanium oxides and titanium oxides. (II) The battery according to the first embodiment further includes a side layer disposed on a side surface of at least one selected from the group consisting of halogenated titanium oxides and titanium oxides.

[0020] The titanium oxide halide is represented by the following composition formula (1): TiO α1 X1 β1 In the above composition formula (1), X1 is at least one selected from the group consisting of F, Cl, Br, and I, α1 satisfies 0.95≦α1≦1.05, and β1 satisfies 1.95≦β1≦2.05.

[0021] The titanium oxide is represented by the following composition formula (2): TiO α2 Formula (2) In the composition formula (2), α2 satisfies 1.95≦α2≦2.05.

[0022] In the composition formula (1), α1 may be 1. In the composition formula (1), β1 may be 2. The titanium oxide halide may be represented by TiOX12.

[0023] In the composition formula (2), α2 may be 2. That is, the titanium oxide may be represented by TiO2.

[0024] The titanium-containing material is relatively hard, for example harder than the solid electrolyte contained in the battery. Therefore, the battery according to the first embodiment, which includes the titanium-containing material, has increased mechanical strength, improving its flexural strength and impact resistance. Therefore, the battery according to the first embodiment can have increased mechanical strength and improved reliability. The content and location of the titanium-containing material may be adjusted as desired depending on the purpose. This allows the battery according to the first embodiment to achieve the desired reliability.

[0025] The above-described effects can be achieved whether the battery according to the first embodiment satisfies either of the above-described structures (I) or (II). For example, when the structure (I) is satisfied, the strength of the electrode layer and / or electrolyte layer, which are the power-generating elements of the battery, can be improved, thereby improving the reliability of the battery. Furthermore, when the structure (II) is satisfied, the side layer containing the titanium-containing material can effectively suppress structural defects (i.e., cracks or peeling originating from the side) that tend to be caused by external and thermal shocks and that are likely to be manifested from the side of the battery, thereby improving the reliability of the battery.

[0026] Hereinafter, in this specification, the term "titanium-containing material" means at least one selected from the group consisting of titanium oxide halide represented by the above composition formula (1) and titanium oxide represented by the above composition formula (2).

[0027] A configuration example of the battery according to the first embodiment will be described below. The configuration example described below is an example in which the battery according to the first embodiment satisfies the configuration (I) above and the electrolyte layer is a solid electrolyte layer. That is, the battery of the configuration example described below is, for example, an all-solid-state battery.

[0028] FIG. 1 is a cross-sectional view and a plan view showing a schematic configuration of a battery 1000 according to a first embodiment.

[0029] Fig. 1(a) shows a cross-sectional view of a battery 1000 according to the first embodiment. Fig. 1(b) is a plan view of the battery 1000 according to the first embodiment as seen from below in the z-axis direction. Fig. 1(a) shows a cross section taken along line II in Fig. 1(b).

[0030] As shown in FIG. 1 , the battery 1000 includes a first electrode layer 100, a second electrode layer 200 arranged parallel to and facing the first electrode layer 100, and a solid electrolyte layer 300 located between the first electrode layer 100 and the second electrode layer 200. In other words, the battery 1000 is a battery including the first electrode layer 100, the solid electrolyte layer 300, and the second electrode layer 200, arranged in this order in the stacking direction. For example, the first electrode layer 100 and the solid electrolyte layer 300 contain a titanium-containing material. The contained titanium-containing material may be a particulate titanium-containing material (hereinafter referred to as "titanium-containing material particles") 400. As described above, the battery 1000 is, for example, an all-solid-state battery.

[0031] The first electrode layer 100 includes a first current collector 110 and a first active material layer 120. For example, the first active material layer 120 includes titanium-containing material particles 400. The second electrode layer 200 includes a second current collector 210 and a second active material layer 220. The solid electrolyte layer 300 includes titanium-containing material particles 400, is located between the first active material layer 120 and the second active material layer 220, and is in contact with each of the first active material layer 120 and the second active material layer 220. In the battery 1000 shown in FIG. 1 , the titanium-containing material particles 400 are contained only in the first electrode layer 100 and the solid electrolyte layer 300, but the second electrode layer 200 may also include titanium-containing material particles 400.

[0032] 1 , the first current collector 110, the first active material layer 120, the solid electrolyte layer 300, the second active material layer 220, and the second current collector 210 each have a roughly rectangular shape in a plan view. However, in the battery according to the first embodiment, the shapes of these components are not limited to a rectangle.

[0033] 1 , the current collector 110, the first active material layer 120, the solid electrolyte layer 300, the second active material layer 220, and the second current collector 210 are all the same size and have the same outline in a plan view, but this is not limiting. For example, the first active material layer 120 may be smaller than the second active material layer 220. The first active material layer 120 and the second active material layer 220 may be smaller than the solid electrolyte layer 300. For example, a portion of the solid electrolyte layer 300 may be in contact with at least one of the first current collector 110 and the second current collector 210.

[0034] In the battery 1000 according to the first embodiment, for example, the first electrode layer 100 is a positive electrode layer, and the second electrode layer 200 is a negative electrode layer. In this case, specifically, the first current collector 110 is a positive electrode current collector, and the first active material layer 120 is a positive electrode active material layer. Furthermore, the second current collector 210 is a negative electrode current collector, and the second active material layer 220 is a negative electrode active material layer.

[0035] The first electrode layer 100 may be a negative electrode, and the second electrode layer 200 may be a positive electrode. Specifically, the first current collector 110 may be a negative electrode current collector, and the first active material layer 120 may be a negative electrode active material layer. The second current collector 210 may be a positive electrode current collector, and the second active material layer 220 may be a positive electrode active material layer.

[0036] In the following description, the positive electrode active material layer and the negative electrode active material layer may be collectively referred to simply as "active material layers." Furthermore, the positive electrode current collector and the negative electrode current collector may be collectively referred to simply as "current collectors."

[0037] (Current Collector) The current collector is formed of a conductive material. Examples of the material for the current collector include stainless steel, nickel (Ni), aluminum (Al), iron (Fe), titanium (Ti), copper (Cu), palladium (Pd), gold (Au), platinum (Pt), or an alloy of two or more of these. As the current collector, a foil, plate, or mesh made of these materials can be used.

[0038] The material of the current collector may be selected in consideration of the manufacturing process, the temperature and pressure used, the operating potential of the battery applied to the current collector, or electrical conductivity, and may also be selected according to the tensile strength or heat resistance required for the battery.

[0039] The current collector may be a high-strength electrolytic copper foil or a clad material in which foils of different metals are laminated.

[0040] The thickness of the current collector is, for example, 10 μm or more and 100 μm or less.

[0041] The surface of the current collector may be roughened to have irregularities in order to improve adhesion to the active material layer.

[0042] The surface of the current collector may be coated with an adhesive component such as an organic binder. Furthermore, insulating particles, conductive particles, or semiconducting particles may be attached to the surface of the current collector. This strengthens the bonding at the interface between the current collector and other layers (e.g., active material layers), thereby improving the mechanical and thermal reliability and cycle characteristics of the battery 1000.

[0043] (Active Material Layer) The first active material layer 120 is, for example, a positive electrode active material layer. The first active material layer 120 is sandwiched between the first current collector 110 and the solid electrolyte layer 300. The first active material layer 120 may be in contact with a major surface of the first current collector 110. The first active material layer 120 may be in contact with a major surface of the solid electrolyte layer 300.

[0044] The second active material layer 220 is, for example, a negative electrode active material layer. The second active material layer 220 is sandwiched between the second current collector 210 and the solid electrolyte layer 300. The second active material layer 220 may be in contact with a major surface of the second current collector 210. The second active material layer 220 may be in contact with a major surface of the solid electrolyte layer 300.

[0045] The positive electrode active material layer contains a positive electrode active material.

[0046] The positive electrode active material is a material in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted or extracted into or from the crystalline structure at a potential higher than that of the negative electrode, and oxidation or reduction occurs accordingly. The type of the positive electrode active material can be appropriately selected depending on the type of battery, and known positive electrode active materials can be used.

[0047] The positive electrode active material is, for example, a compound containing lithium and a transition metal element, such as an oxide containing lithium and a transition metal element, or a phosphate compound containing lithium and a transition metal element.

[0048] An example of an oxide containing lithium and a transition metal element is LiNi x M 1-x Examples of the lithium-nickel composite oxide include lithium nickel composite oxides such as LiCoO2 (where M is at least one selected from the group consisting of Co, Al, Mn, V, Cr, Mg, Ca, Ti, Zr, Nb, Mo, and W, and 0<x≦1 is satisfied), layered oxides such as lithium cobalt oxide (LiCoO2) and lithium nickel oxide (LiNiO2), or lithium manganese oxides having a spinel structure (e.g., LiMn2O4, Li2MnO3, or LiMnO2).

[0049] An example of a phosphate compound containing lithium and a transition metal element is lithium iron phosphate (LiFePO4) having an olivine structure.

[0050] The positive electrode active material may be sulfur (S) or a sulfide such as lithium sulfide (LiS). In this case, the positive electrode active material particles may be coated with or may have lithium niobate (LiNbO) or the like added thereto.

[0051] The positive electrode active material may be made of only one of these materials, or a combination of two or more of these materials.

[0052] The positive electrode active material layer may contain a titanium-containing material. This allows the titanium-containing material to absorb stresses due to external stress, expansion and contraction of the positive electrode active material caused by charge and discharge, and expansion and contraction of the positive electrode active material caused by thermal cycling, thereby improving the mechanical strength of the positive electrode active material layer and suppressing the occurrence of defects. Furthermore, the compatibility of the positive electrode active material layer with the solid electrolyte layer 300 (e.g., expansion and contraction caused by charge and discharge or thermal cycling) can be adjusted. As shown in FIG. 1 , the titanium-containing material may be titanium-containing material particles 400.

[0053] To enhance lithium ion conductivity or electron conductivity, the positive electrode active material layer may contain, in addition to the positive electrode active material, a material other than the positive electrode active material and the titanium-containing material. That is, the positive electrode active material layer may be a mixture layer. Examples of such materials include inorganic solid electrolytes, solid electrolytes such as sulfide-based solid electrolytes, conductive additives such as acetylene black, or binders such as polyethylene oxide and polyvinylidene fluoride. The solid electrolyte may be, for example, a halide solid electrolyte. Examples of the halide solid electrolyte contained in the positive electrode active material layer are the same as the examples of the halide solid electrolyte contained in the solid electrolyte layer 300 described below.

[0054] By mixing the positive electrode active material with other additive materials such as a solid electrolyte in a predetermined ratio, the positive electrode active material layer can improve the ionic conductivity and electronic conductivity in the positive electrode active material layer.

[0055] The positive electrode active material layer may have a thickness of, for example, 5 μm or more and 300 μm or less.

[0056] The negative electrode active material layer contains a negative electrode active material.

[0057] The negative electrode active material layer is a layer mainly composed of a negative electrode material such as a negative electrode active material.

[0058] The negative electrode active material is a material in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted or extracted into or from the crystalline structure at a potential lower than that of the positive electrode, and oxidation or reduction occurs accordingly. The type of the negative electrode active material can be appropriately selected depending on the type of battery, and known negative electrode active materials can be used.

[0059] Examples of the negative electrode active material include carbon materials such as natural graphite, artificial graphite, graphite carbon fiber, and resin-baked carbon, or alloy-based materials mixed with a solid electrolyte. Examples of alloy-based materials include LiAl, LiZn, LiBi, LiCd, LiSb, LiSi, and Li. 4.4 Pb, Li 4.4 Sn, Li 0.17 C, and lithium alloys such as LiC6, lithium titanate (Li4Ti5O 12 ), zinc oxide (ZnO), or silicon oxide (SiO x ) are metal oxides such as

[0060] The negative electrode active material may be made of only one of these materials, or a combination of two or more of these materials.

[0061] To enhance lithium ion conductivity or electron conductivity, the negative electrode active material layer may contain, in addition to the negative electrode active material, a material other than the negative electrode active material. Examples of such materials include solid electrolytes such as inorganic solid electrolytes and sulfide solid electrolytes, conductive additives such as acetylene black, or binders such as polyethylene oxide and polyvinylidene fluoride. The solid electrolyte may be, for example, a halide solid electrolyte. Examples of the halide solid electrolyte contained in the negative electrode active material layer are the same as the examples of the halide solid electrolyte contained in the solid electrolyte layer 300 described below.

[0062] The negative electrode active material layer may have a thickness of, for example, 5 μm or more and 300 μm or less.

[0063] The negative electrode active material layer may contain a titanium-containing material, similar to the positive electrode active material layer described above.

[0064] (Solid Electrolyte Layer) The solid electrolyte layer 300 includes a solid electrolyte.

[0065] The solid electrolyte layer 300 contains, for example, a solid electrolyte as a main component. Here, the main component refers to the component that is contained in the largest amount by mass in the solid electrolyte layer 300. As described above, the solid electrolyte layer 300 contains, for example, a titanium-containing material. The titanium-containing material is, for example, titanium-containing material particles 400.

[0066] The solid electrolyte may be any known ion-conductive solid electrolyte for batteries. For example, a solid electrolyte that conducts metal ions such as lithium ions or magnesium ions can be used as the solid electrolyte contained in the solid electrolyte layer 300.

[0067] As the solid electrolyte, a sulfide solid electrolyte, an oxide solid electrolyte, or a halide solid electrolyte can be used.

[0068] Examples of sulfide-based solid electrolytes include LiS-P2S5-based, LiS-SiS2-based, LiS-B2S3-based, LiS-GeS2-based, LiS-SiS2-LiI-based, LiS-SiS2-Li3PO4-based, LiS-Ge2S2-based, LiS-GeS2-P2S5-based, and LiS-GeS2-ZnS-based.

[0069] The oxide-based solid electrolyte is, for example, a lithium-containing metal oxide, a lithium-containing metal nitride, lithium phosphate (Li3PO4), or a lithium-containing transition metal oxide. Examples of lithium-containing metal oxides are Li2O-SiO2 or Li2O-SiO2-P2O5. Examples of lithium-containing metal nitrides are Li x P y O 1-z N z (0<z≦1) An example of the lithium-containing transition metal oxide is lithium titanium oxide.

[0070] The halogenated solid electrolyte is, for example, a solid electrolyte containing Li, at least one element selected from the group consisting of metal elements and metalloid elements other than Li, and a halogen element.

[0071] "Metalloid elements" are B, Si, Ge, As, Sb, and Te. "Metal elements" are all elements in Groups 1 to 12 of the periodic table (excluding hydrogen) and all elements in Groups 13 to 16 of the periodic table (excluding B, Si, Ge, As, Sb, Te, C, N, P, O, S, and Se).

[0072] It is desirable that the halide solid electrolyte be substantially free of sulfur. The term "substantially free of sulfur" means that the halide solid electrolyte does not contain sulfur as a constituent element, except for sulfur inevitably mixed in as an impurity. In this case, the amount of sulfur mixed in the halide solid electrolyte as an impurity is, for example, 1 mol % or less. It is more desirable that the halide solid electrolyte be free of sulfur. A sulfur-free solid electrolyte is excellent in safety because it does not generate hydrogen sulfide even when exposed to the atmosphere.

[0073] The solid electrolyte layer 300 includes, for example, a halide solid electrolyte. For example, when the titanium-containing material particles 400 include a halide titanium oxide, the thermal expansion characteristics of the halide solid electrolyte included in the solid electrolyte layer 300 and the titanium-containing material particles 400 are easily matched because they are both halides. This strengthens the bonding interface between the titanium-containing material particles 400 and the halide solid electrolyte. This suppresses the occurrence of structural defects caused by peeling at the bonding interface between the titanium-containing material particles 400 and the halide solid electrolyte due to thermal shock or thermal cycling. In other words, this configuration further improves the effectiveness of the titanium-containing material against thermal shock and thermal cycling. As a result, the reliability of the battery 1000 according to the first embodiment is further improved.

[0074] The halide solid electrolyte may contain Ti. This configuration allows for a solid electrolyte layer 300 containing a solid electrolyte with high ionic conductivity, e.g., 1 μS / cm or greater. Furthermore, the presence of Ti, which is commonly contained in both the titanium-containing material and the halide solid electrolyte, facilitates the strong bonding between the titanium-containing material and the solid electrolyte, facilitating the formation of an integrated bonded interface. This allows the titanium-containing material to coexist stably with the solid electrolyte within the solid electrolyte layer (e.g., without forming microscopic defects around it). This results in a battery with improved reliability. Furthermore, because halide solid electrolytes containing Ti have atmospheric stability and excellent heat resistance from approximately 650°C to 700°C, the benefits of including TiFO2 can be achieved even at high temperatures, even when TiFO2, which has a high melting point, is included as the titanium-containing material.

[0075] The halide solid electrolyte may include a first halide solid electrolyte including a crystalline phase represented by the following composition formula (3): Li2TiX26 Formula (3) In composition formula (3), X2 is at least one selected from the group consisting of F, Cl, Br, and I.

[0076] The first halide solid electrolyte has high ionic conductivity, e.g., 1 μS / cm or more, and atmospheric stability. Therefore, the inclusion of the first halide solid electrolyte improves the ionic conductivity of the solid electrolyte layer 300. The crystalline phase represented by LiTiX can be confirmed by the diffraction pattern of the micro-area X-ray diffraction (XRD) described above or by powder XRD using a powder sample obtained by cutting out the solid electrolyte. The composition of the solid electrolyte can also be evaluated by elemental analysis using, for example, an electron probe microanalyzer (EPMA) or energy dispersive X-ray spectroscopy (EDS).

[0077] The first halide solid electrolyte may include a crystalline phase represented by the following composition formula (4): Li2TiF6 Formula (4)

[0078] This provides the first halide solid electrolyte with improved atmospheric stability. This suppresses fluctuations in the properties of the solid electrolyte caused by environmental changes during the manufacturing process, allowing for reproducible production of solid electrolyte layer 300 with desired properties. Furthermore, strict dew point, temperature, and humidity control are no longer necessary, resulting in benefits in manufacturing, such as reduced manufacturing costs.

[0079] The halide solid electrolyte may further include a second halide solid electrolyte having a different composition from the first halide solid electrolyte, which further improves the binding strength of the solid electrolyte in the solid electrolyte layer 300, thereby making the solid electrolyte layer 300 denser, stronger, and more ionic conductive.

[0080] The second halide solid electrolyte may have a higher melting point than the first halide solid electrolyte. Because the second halide solid electrolyte has a higher melting point than the first halide solid electrolyte, it can maintain a harder state than the first halide solid electrolyte at high temperatures. Thus, when the solid electrolyte layer 300 containing the first halide solid electrolyte further contains the second halide solid electrolyte, the hardness of the solid electrolyte layer 300 increases. This strengthens the solid electrolyte layer 300, improving its flexural strength and impact resistance, and improving the reliability of the solid electrolyte layer 300. This allows for the realization of a battery 1000 with improved reliability.

[0081] The second halide solid electrolyte may be harder than the first halide solid electrolyte. Thus, when the solid electrolyte layer 300 containing the first halide solid electrolyte further contains the second halide solid electrolyte, the hardness of the solid electrolyte layer 300 increases. This strengthens the solid electrolyte layer 300, improving its flexural strength and impact resistance, and improving the reliability of the solid electrolyte layer 300. This allows for the realization of a battery 1000 with improved reliability. The softness of the second halide solid electrolyte and the first halide solid electrolyte can be compared using a method such as micro-Vickers testing.

[0082] The second halide solid electrolyte may include a crystalline phase represented by the following composition formula (5): Li3MF6 (5) In the composition formula (5), M is at least one element selected from the group consisting of metal elements and semimetal elements having a valence of trivalent.

[0083] The second halide solid electrolyte containing the crystalline phase represented by composition formula (5) is harder than the first halide solid electrolyte. Therefore, when a solid electrolyte layer containing a first halide solid electrolyte further contains a second halide solid electrolyte, the hardness of the solid electrolyte layer 300 increases. This strengthens the solid electrolyte layer 300, improving its flexural strength and impact resistance, and improving the reliability of the solid electrolyte layer 300. This allows for the realization of a battery 1000 with improved reliability.

[0084] In composition formula (5), M may contain Al or may be Al. This increases the ionic conductivity of the second halide solid electrolyte to the same level as that of the first halide solid electrolyte (e.g., 1 μS / cm or higher). This allows for a solid electrolyte layer 300 with high ionic conductivity and high reliability. This allows for a battery 1000 with excellent performance and reliability. Furthermore, when M is Al, i.e., when the second halide solid electrolyte has a composition of LiAlF, the solid electrolyte layer 300 can be stable and flexible up to relatively high temperatures. Therefore, adding such a second halide solid electrolyte to the solid electrolyte layer 300 can densify the solid electrolyte layer 300 and further improve the ionic conductivity of the solid electrolyte layer 300. Furthermore, because LiAlF has excellent heat resistance up to approximately 700°C to 800°C, even when TiFO, which has a high melting point, is included as a titanium-containing material, the effects of including TiFO can be obtained up to high temperatures.

[0085] The solid electrolyte layer 300 may contain, in addition to the solid electrolyte, a binder such as polyethylene oxide or polyvinylidene fluoride.

[0086] The thickness of the solid electrolyte layer 300 may be 5 μm or more and 500 μm or less, 10 μm or more and 500 μm or less, or 5 μm or more and 150 μm or less.

[0087] The solid electrolyte material may be composed of an agglomerate of particles, or may be composed of a sintered structure.

[0088] (Titanium-Containing Material) The titanium-containing material contained in the battery 1000 according to the first embodiment may be in particulate form, such as the titanium-containing material particles 400. When the titanium-containing material is in particulate form, it can be contained in the coating layers of the solid electrolyte particles and the active material particles, or can be contained inside the solid electrolyte particles. This broadens the options for the form of the titanium-containing material when it is contained in the electrode layer and the solid electrolyte layer. Furthermore, for example, finely pulverized titanium-containing material particles (e.g., particles with a particle diameter of 1 μm or less) can make the solid electrolyte layer 300 thinner or the coating layers of the active material particles thinner, thereby improving the capacity of the battery.

[0089] The titanium-containing material particles 400 are, for example, uniformly dispersed within the first electrode layer 100 and the solid electrolyte layer 300 .

[0090] The titanium-containing material particles 400 may have an average particle size of, for example, 0.3 μm or more and 20 μm or less. In FIG. 1, the titanium-containing material particles 400 are shown to have a spherical particle shape, but they may also have a particle shape other than a spherical shape, such as a scale shape.

[0091] It is desirable that the particle diameter of the titanium-containing material particles 400 be small. This allows the titanium-containing material particles 400 to be uniformly dispersed throughout the first electrode layer 100 and the solid electrolyte layer 300, thereby increasing the surface area of ​​the titanium-containing material particles 400 and, as a result, increasing the bonding area between the titanium-containing material particles 400 and the surrounding active material or solid electrolyte. Therefore, the mechanical reliability (flexural strength) of the first electrode layer 100 and the solid electrolyte layer 300 is further improved by miniaturizing the titanium-containing material particles 400 (for example, miniaturizing the particle diameter to 1 μm or less).

[0092] The titanium-containing material may include, for example, TiOF2. The titanium-containing material may be TiOF2. When the titanium-containing material contains TiOF2, the mechanical bonding (i.e., anchoring effect) between solid electrolyte particles and active material particles is improved by the presence of hard TiOF2 particles. For example, when TiOF2, which is harder than the solid electrolyte, is contained inside the solid electrolyte particles, the solid electrolyte particles can be made harder. Furthermore, when TiOF2 is contained in the coating layer of the solid electrolyte particles and / or active material particles, TiOF2 also serves as an anchor that strengthens the bonding between the particles. This results in a battery with excellent flexural strength and impact resistance. TiOF2 has excellent heat resistance (e.g., approximately 1000°C). Therefore, the inclusion of TiOF2 provides excellent reliability for the battery 1000, even at high temperatures.

[0093] TiOF2 may have a cubic crystal structure, which can be obtained by adjusting the heat treatment conditions.

[0094] TiOF2, which has a cubic crystal structure, is stable at room temperature and at high temperatures, for example, around 400°C, providing excellent heat resistance. Furthermore, because TiOF2, which has a cubic crystal structure, is hard, it also contributes to improving the mechanical strength of the battery 1000. Therefore, by incorporating TiOF2, which has a cubic crystal structure, into the electrode layer and / or solid electrolyte layer 300, both the heat resistance and mechanical strength of the battery 1000 can be improved. TiOF2, which has a cubic crystal structure, transitions to a hexagonal crystal structure at temperatures above approximately 400°C. However, because the melting point of TiOF2 is above 1000°C, the improvement in mechanical strength is maintained up to high temperatures. Generally, organic binders incorporated into all-solid-state batteries rapidly soften above their glass transition point, for example, between 100°C and 250°C. Therefore, by including TiOF2 having a cubic crystal structure in the electrode layer and / or solid electrolyte layer 300, it is possible to suppress a decrease in the mechanical strength of the battery 1000 at high temperatures, for example, above 100°C.

[0095] The crystalline structure of TiO2 used as the titanium-containing material may be rutile or anatase. Rutile has the best high-temperature stability because the phase transition point from anatase to rutile is approximately 900°C. Therefore, the crystalline structure of TiO2 is preferably rutile.

[0096] When the titanium-containing material is particulate, at least a portion of the surface of the titanium-containing material particles may be coated with a coating layer containing a solid electrolyte. This configuration allows the solid electrolyte coating the titanium-containing material particles to act as a binder. This improves the bonding between the titanium-containing material particles themselves or between the titanium-containing material particles and other particles (e.g., solid electrolyte particles and active material particles), further improving the reliability of the battery. For example, by including titanium-containing material particles in the solid electrolyte layer, the ionic conductivity of the solid electrolyte layer is also improved.

[0097] The titanium-containing material may contain both TiOF2, which has a cubic crystal structure, and TiO2. This allows the titanium-containing material to have excellent bonding strength between TiOF2 and TiO2 due to the common element Ti, while also exhibiting improved hardness. Furthermore, by incorporating a titanium-containing material containing TiO2, which has high thermal stability, into a battery, the adhesion of solid electrolyte particles and active material particles at high temperatures can be improved. This results in a battery with excellent mechanical strength and heat resistance. This improved strength can suppress deformation of the electrode layer and / or solid electrolyte layer 300 due to external impact, thereby reducing the occurrence of structural defects (interlayer or intralayer peeling and cracking). Mechanical strength and heat resistance can be adjusted by combining TiOF2, which has a cubic crystal structure, rutile titanium oxide, and anatase titanium oxide in any ratio.

[0098] The crystal systems of TiO2 and TiOF2 can be identified, for example, by the diffraction patterns obtained by micro-X-ray diffraction (micro-XRD) of the side surfaces of the electrode layer and solid electrolyte layer 300 exposed on the side surface of the battery 1000. Alternatively, they can be confirmed by lattice images of a high-resolution transmission electron microscope (TEM).

[0099] The titanium-containing material may be particulate, with the surface region of the titanium-containing material particles containing a higher TiOF content than the TiO content, and the inner region of the titanium-containing material particles containing a higher TiO content than the TiOF content. According to this configuration, the titanium-containing material particles contain a large amount of hard, heat-resistant TiO in the particle interior and a large amount of heat-resistant TiOF in the surface layer. By further incorporating such titanium-containing material particles in, for example, a solid electrolyte layer and / or electrode layer containing halide solid electrolyte particles, the titanium-containing material particles can have high bonding strength with the halide solid electrolyte particles due to the common halogen element. Therefore, this configuration allows for a power generating element with high mechanical strength and heat resistance to be obtained. This results in a highly reliable battery.

[0100] The morphology of the composite particles as described above can be evaluated, for example, by observing an ion-polished cross section of the battery using an SEM.

[0101] When the titanium-containing material is a composite particle as described above, at least a portion of the surface of the titanium-containing material particle may be coated with a coating layer containing a solid electrolyte. This improves the bonding strength between the titanium-containing material and the solid electrolyte contained in the electrolyte layer or electrode layer. This increases the reliability of the solid electrolyte layer or electrode layer against thermal shock and external stress.

[0102] The titanium-containing material may be in particulate form and include first particles made of TiOF2 having a cubic crystal structure and second particles containing TiOF2 and TiO2, both of which also have a cubic crystal structure. This allows the heat resistance and mechanical strength of the titanium-containing material to be adjusted according to the application by controlling the mixing ratio of the first particles and the second particles.

[0103] The average particle diameter of the second particles may be larger than the average particle diameter of the first particles. This allows the second particles to have an effect of improving hardness, while the first particles, which are softer and more deformable than the second particles, can reduce voids or irregularities that tend to form around the second particles. Therefore, by reducing voids and irregularities, the electrolyte layer and electrode layer have a homogenized structure, improving their mechanical strength and impact resistance. This results in a highly reliable battery.

[0104] The content of the titanium-containing material may be, for example, 0.01 vol % or more and 5 vol % or less in the solid electrolyte layer 300, and may be, for example, 0.01 vol % or more and 3 vol % or less in the first electrode layer 100. The content of such titanium-containing material can be confirmed by elemental analysis using a high-resolution composition map such as an EPMA of a cross section treated by ion polishing or the like.

[0105] The titanium-containing material may be dispersed in the solid electrolyte layer 300 and / or the electrode layer, and may be present between particles or in voids of the solid electrolyte particles and / or active material particles, or may be contained in the solid electrolyte layer 300 and / or the electrode layer in another form.

[0106] For example, a titanium-containing material may be contained in a coating layer that covers at least a portion of the surface of the solid electrolyte material particles and / or the active material particles, thereby enhancing the mechanical bonding (i.e., anchoring effect) between the solid electrolyte particles and / or the active material particles, and improving the reliability of the battery 1000 against external stress, thermal cycling, and the like of the solid electrolyte layer 300 and / or the electrode layer.

[0107] When at least one selected from the group consisting of the first electrode layer 100 and the second electrode layer 200 includes active material particles and a coating layer that covers at least a portion of the surface of the active material particles, the coating layer may contain a titanium-containing material. This configuration can enhance the binding and mechanical bonding between the active material particles (i.e., the anchoring effect). This improves the strength of the electrode layer against external stress and thermal cycles, thereby suppressing the occurrence of structural defects such as cracks in the electrode layer. This can further improve the reliability of the battery 1000.

[0108] When at least one selected from the group consisting of the first electrode layer 100, the second electrode layer 200, and the solid electrolyte layer 300 includes solid electrolyte particles and a coating layer that covers at least a portion of the surface of the solid electrolyte particles, the coating layer may contain a titanium-containing material. This configuration can enhance the binding and mechanical bonding (i.e., anchor effect) between the solid electrolyte particles included in the electrode layer and / or the solid electrolyte layer 300, which are the power-generating elements of the battery 1000. This improves the strength of the power-generating elements against external stress, thermal cycles, and the like, thereby further improving the reliability of the battery 1000.

[0109] At least one selected from the group consisting of the first electrode layer 100, the second electrode layer 200, and the solid electrolyte layer 300 may contain solid electrolyte particles, and the solid electrolyte particles may contain a titanium-containing material. For example, the titanium-containing material may be encapsulated within the solid electrolyte particles. In other words, at least a portion of the surface of the titanium-containing material particles may be coated with a coating layer containing a solid electrolyte. This configuration allows the solid electrolyte particles contained in the electrode layer and / or electrolyte layer, which are the power generation elements of the battery, to have a harder interior and improved strength, thereby allowing the hardness of the solid electrolyte particles to be adjusted according to the purpose. Furthermore, the surface layer of the solid electrolyte particles can be made softer than the interior of the particles, allowing the surface layer of the particles to have bondability and deformability. This improves the bondability between particles. The inclusion of such solid electrolyte particles in the power generation element improves the reliability of the power generation element against external stresses and thermal cycles, thereby further improving the reliability of the battery. The hardness of the solid electrolyte particles can be adjusted, for example, by selecting a halogen element in the halogenated titanium oxide contained as the titanium-containing material, or by incorporating multiple halogen elements in combination. Furthermore, since the titanium-containing material is contained inside the solid electrolyte particles, the decrease in ionic conductivity between the solid electrolyte particles due to the titanium-containing material is reduced.

[0110] Solid electrolyte particles encapsulating a titanium-containing material can be prepared, for example, by using a titanium-containing material or a material containing a substance that produces a titanium-containing material as an intermediate product as a starting material for synthesizing the solid electrolyte particles and controlling the synthesis conditions for the solid electrolyte (e.g., heat treatment conditions or conditions for the mechanical energy applied during mechanochemical treatment). That is, solid electrolyte particles encapsulating a titanium-containing material can be prepared by using synthesis conditions that allow the titanium-containing material to be present inside the particles and the synthesized solid electrolyte to be present on the particle surface. For example, solid electrolyte particles encapsulating a titanium-containing material can be prepared by setting the heat treatment temperature lower than usual and / or setting the heat treatment time shorter than usual during the heat treatment for synthesizing the solid electrolyte. Furthermore, solid electrolyte particles encapsulating a titanium-containing material can be prepared by shortening the mixing time and / or the dispersion time during the mixing and / or dispersion of the starting materials. In addition to these methods, it is also possible to prepare solid electrolyte particles containing titanium-containing material by coating the surface of titanium-containing material particles with a film of solid electrolyte.

[0111] A titanium-containing material may be included in the bonding interface between the solid electrolyte layer 300 and the electrode layer. This configuration improves the bonding between the solid electrolyte layer 300 and the electrode layer, thereby suppressing delamination that is likely to occur due to external impacts and thermal cycles.

[0112] The presence of titanium-containing materials in the battery 1000 can be determined by EPMA, EDS, and X-ray fluorescence spectroscopy (XRF). The morphology and composition can be analyzed by composition analysis (point analysis or area analysis) using EPMA, EDS, etc. of a polished cross section processed with an ion polisher or the like.

[0113] In this way, by incorporating a titanium-containing material into the solid electrolyte layer 300 and / or the electrode layers, which are prone to structural defects due to external impacts, charge / discharge cycles, and thermal cycles, structural defects and deterioration of material properties can be suppressed, thereby reducing deterioration of the properties of the solid electrolyte layer 300 and / or the electrode layers and achieving a highly reliable battery 1000.

[0114] The softness of the titanium-containing material may be adjusted depending on the purpose. For example, multiple types of titanium-containing materials may be used in combination. This improves the mechanical strength of the battery 1000 and reduces the occurrence of structural defects due to external impacts, charge / discharge cycles, and thermal cycles.

[0115] When the configuration of the battery 1000 according to this embodiment is compared with the configuration of the battery described in Patent Document 1, the following differences are found.

[0116] Patent Document 1 discloses that a solid electrolyte containing Li, Ti, M, and F (M=Al, etc.) that coats an active material contains TiO bonds and TiOF bonds. However, Patent Document 1 also discloses that the bonding state with Ti in a solid electrolyte containing Li, Ti, M, and F includes TiO bonds and TiOF bonds. For this reason, Patent Document 1 does not disclose that a titanium-containing material is included as a component in the solid electrolyte layer or electrode layer. For this reason, the technology described in Patent Document 1 differs from the technology of the battery according to the first embodiment of the present disclosure, which improves the reliability (e.g., mechanical strength and thermal shock resistance) of the solid electrolyte layer and / or electrode layer.

[0117] Furthermore, Patent Document 1 neither discloses nor suggests that the mechanical strength and reliability of the battery can be improved by incorporating a titanium-containing material into the electrode layer and the solid electrolyte layer. In contrast, the battery 1000 according to the first embodiment includes a titanium-containing material, thereby improving the mechanical strength and reliability of the battery.

[0118] Second Embodiment A battery according to a second embodiment will be described below. The matters described in the first embodiment may be omitted as appropriate.

[0119] FIG. 2 is a cross-sectional view and a plan view showing a schematic configuration of a battery 1100 according to the second embodiment.

[0120] Fig. 2(a) is a cross-sectional view of the battery 1100 of the second embodiment. Fig. 2(b) is a plan view of the battery 1100 of the second embodiment as viewed from below in the z-axis direction. Fig. 2(a) shows a cross-sectional view taken along dotted line II-II in Fig. 2(b).

[0121] As shown in FIG. 2, the battery 1100 according to the second embodiment differs from the battery 1000 according to the first embodiment in the configuration of the solid electrolyte layer.

[0122] The solid electrolyte layer 301 in the battery 1100 according to the second embodiment differs in that titanium-containing material particles 400 contained as the titanium-containing material are unevenly distributed in a region of the solid electrolyte layer 301 that contacts the first active material layer 120, and are not contained in a region that contacts the second active material layer 220. This configuration allows the titanium-containing material to be selectively contained in an electrode layer that is prone to structural defects, for example, in a region on the electrode layer side that contains an active material that expands and contracts significantly during charging and discharging or has a large thermal expansion coefficient. This allows the reliability of the battery 1100 to be efficiently improved.

[0123] A modified example of the battery 1100 according to the second embodiment may have a configuration in which the concentration of the titanium-containing material particles 400 in the region of the solid electrolyte layer 301 that is in contact with the first active material layer 120 is higher than the concentration of the titanium-containing material particles 400 in the region of the solid electrolyte layer 301 that is in contact with the second active material layer 220. This configuration also makes it possible to efficiently improve the reliability of the battery 1100.

[0124] Third Embodiment A battery according to a third embodiment will now be described. The matters described in the above embodiments may be omitted as appropriate.

[0125] FIG. 3 is a cross-sectional view and a plan view showing a schematic configuration of a battery 1200 according to a third embodiment.

[0126] Fig. 3(a) is a cross-sectional view of the battery 1200 of the third embodiment. Fig. 3(b) is a plan view of the battery 1200 of the third embodiment as viewed from below in the z-axis direction. Fig. 3(a) shows a cross section taken along line III-III in Fig. 3(b).

[0127] As shown in FIG. 3, the battery 1200 according to the third embodiment differs from the battery 1000 according to the first embodiment in the configuration of the solid electrolyte layer.

[0128] The solid electrolyte layer 302 in the battery 1100 according to the second embodiment includes a first layer 302a in contact with the first electrode layer 100 and a second layer 302b in contact with the second electrode layer 200. The first layer 302a and the second layer 302b contain solid electrolytes having different compositions. The first layer 302a contains titanium-containing material particles 400 as a titanium-containing material. The second layer 302b does not contain a titanium-containing material. For example, from the standpoint of electrochemical stability, the solid electrolyte material in contact with the first electrode layer 100 and the solid electrolyte material in contact with the second electrode layer 200 may be made of different materials. As an example, a configuration may be used in which a halide solid electrolyte is used as the solid electrolyte material on the positive electrode layer side and a sulfide solid electrolyte is used as the solid electrolyte material on the negative electrode layer side. In such a case where the solid electrolyte layer is formed of two or more layers made of different materials, selectively incorporating a titanium-containing material into the layer in which a material prone to structural defects is used can selectively suppress the defects, thereby efficiently improving the reliability of the battery 1200.

[0129] A modified example of the battery 1300 according to the third embodiment may be a configuration in which both the first layer 302 a and the second layer 302 b contain titanium-containing material particles 400, and the concentration of the titanium-containing material particles 400 in the first layer 302 a is higher than the concentration of the titanium-containing material particles 400 in the second layer 302 b. This configuration also makes it possible to efficiently improve the reliability of the battery 1200.

[0130] Fourth Embodiment A battery according to a fourth embodiment will now be described. The matters described in the above embodiments may be omitted as appropriate.

[0131] FIG. 4 is a cross-sectional view and a plan view showing a schematic configuration of a battery 1300 according to a fourth embodiment.

[0132] Fig. 4(a) is a cross-sectional view of the battery 1300 of the fourth embodiment. Fig. 4(b) is a plan view of the battery 1300 of the fourth embodiment as viewed from below in the z-axis direction. Fig. 4(a) shows a cross section taken along line IV-IV in Fig. 4(b).

[0133] 4, the battery 1300 according to the fourth embodiment differs from the battery 1000 according to the first embodiment in that it further includes a side layer 500 containing a titanium-containing material disposed on at least one side surface selected from the group consisting of the first electrode layer 100, the second electrode layer 200, and the electrolyte layer 300. In other words, the battery 1300 according to the fourth embodiment satisfies the above-mentioned configuration (II).

[0134] With this configuration, the battery 1300 according to the fourth embodiment can suppress external stress from the side surfaces and the occurrence of structural defects in the side surfaces, thereby achieving even higher reliability of the battery 1200.

[0135] In the battery 1300 according to the fourth embodiment, the lateral layer 500 contains a titanium-containing material. The titanium-containing material contained in the lateral layer 500 is the same as that described in the first embodiment, and therefore will not be described in detail here.

[0136] The side layer 500 may contain, for example, titanium-containing material particles and an organic binder for binding. The side layer 500 can be formed, for example, by applying a paste containing the titanium-containing material particles and the organic binder to at least one side surface selected from the group consisting of the first electrode layer 100, the second electrode layer 200, and the electrolyte layer 300, and drying the coating.

[0137] The thickness of the lateral layer 500 may be, for example, not less than 1 μm and not more than 30 μm.

[0138] The battery 1300 according to the fourth embodiment has a configuration in which the titanium-containing material is also contained in the power-generating element, i.e., it simultaneously satisfies the above-mentioned configuration (I), but it does not necessarily have to satisfy the above-mentioned configuration (I). In other words, the titanium-containing material does not have to be contained in the power-generating element.

[0139] Fifth Embodiment A battery according to a fifth embodiment will now be described. Matters described in the above embodiments may be omitted as appropriate.

[0140] FIG. 5 is a cross-sectional view and a plan view showing a schematic configuration of a battery 1400 according to a fifth embodiment.

[0141] Fig. 5(a) is a cross-sectional view of the battery 1400 of the fifth embodiment. Fig. 5(b) is a plan view of the battery 1400 of the fifth embodiment as viewed from below in the z-axis direction. Fig. 5(a) shows a cross section taken along the line V-V in Fig. 5(b).

[0142] As shown in FIG. 5 , the battery 1400 according to the fifth embodiment differs from the battery 1000 according to the first embodiment in that only the first electrode layer 100 contains titanium-containing material particles 400 as the titanium-containing material.

[0143] This configuration can suppress the problem of structural defects occurring in layers (e.g., electrode layers) that expand and contract significantly during charge / discharge cycles and thermal cycles, thereby improving the reliability of the battery 1400.

[0144] Sixth Embodiment A battery according to a sixth embodiment will now be described. The matters described in the above embodiments may be omitted as appropriate.

[0145] FIG. 6 is a cross-sectional view and a plan view showing a schematic configuration of a battery 1500 according to a sixth embodiment.

[0146] Fig. 6(a) is a cross-sectional view of a battery 1500 according to a sixth embodiment. Fig. 6(b) is a plan view of the battery 1500 according to the sixth embodiment, viewed from below in the z-axis direction. Fig. 6(a) shows a cross section taken along line VI-VI in Fig. 6(b).

[0147] As shown in FIG. 6 , the battery 1500 according to the sixth embodiment differs from the battery 1000 according to the first embodiment in that the concentrations of the titanium-containing material contained in the first electrode layer and the solid electrolyte layer are different in each layer.

[0148] The concentration of the titanium-containing material particles 400 is higher on the outer periphery (side surface) of the first electrode layer 101 and the solid electrolyte layer 303. In the battery 1500 shown in Fig. 6, the concentration of the titanium-containing material particles 400 changes gradually and continuously toward the outer periphery, but it may also change in a stepwise manner.

[0149] With this configuration, in the battery 1500, the titanium-containing material particles 400 can be arranged to surround the outer periphery of the first electrode layer 101 (e.g., the first active material layer 121) and the solid electrolyte layer 303, which are prone to damage due to external impact (or peeling (interlayer or intralayer) due to charge / discharge or thermal cycles), with a high concentration of titanium-containing material particles 400. This effectively suppresses structural defects in the outer periphery of the power generating element, where structural defects are likely to occur. Note that the region with a high concentration of titanium-containing material particles 400 may be, for example, rectangular, circular, polygonal, or other shapes in plan view, and by surrounding the outer periphery and providing a shape that can protect the inside of the battery, high reliability can be achieved.

[0150] Although the first to sixth embodiments have been described using all-solid-state batteries as examples, the batteries of the present disclosure are not limited to all-solid-state batteries and may be liquid batteries. That is, in the batteries of the present disclosure, the electrolyte layer may be composed of, for example, an electrolytic solution and a separator impregnated with the electrolytic solution. Even in the case of liquid batteries, a highly reliable battery can be realized by including a titanium-containing material, as in the all-solid-state batteries described in the first to sixth embodiments.

[0151] In the case of a liquid battery, at least one selected from the group consisting of the first electrolyte layer and the second electrode layer contains a titanium-containing material. In this case, the titanium-containing material is contained in, for example, a coating layer that coats at least a portion of the surface of the active material particles contained in the electrolyte layer. This coating layer may contain, for example, a solid electrolyte and a titanium-containing material.

[0152] [Method for Manufacturing Battery] Next, an example of a method for manufacturing the battery according to this embodiment will be described. Hereinafter, a method for manufacturing the battery 1000 according to the first embodiment described above will be described.

[0153] In the following, an example will be described in which the first electrode layer 100 is a positive electrode layer and the second electrode layer 200 is a negative electrode layer. That is, in the following description, the first active material layer 120 is a positive electrode active material layer, the first current collector 110 is a positive electrode current collector, the second active material layer 220 is a negative electrode active material layer, and the second current collector 210 is a negative electrode current collector.

[0154] First, pastes to be used for printing the positive electrode active material layer and the negative electrode active material layer are prepared. As the solid electrolyte to be used for the mixture of the positive electrode active material layer and the negative electrode active material layer, for example, powder of a solid electrolyte (LiAlF-LiTiF) having an average particle size of about 3 μm and containing a halide as a main component is prepared. This powder has, for example, high ionic conductivity (for example, 1×10 -3 S / cm to 3 x 10 -3 S / cm) is used.

[0155] As the positive electrode active material, for example, a layered Li-Ni-Co-Al composite oxide (LiNi) having an average particle diameter of about 5 μm is used. 0.8 Co 0.15 Al 0.05 In addition, a TiOF2 powder having an average particle size of about 1 μm is prepared as the titanium-containing material.

[0156] A paste for a positive electrode active material layer is prepared by dispersing a mixture containing the above-mentioned positive electrode active material, the above-mentioned solid electrolyte powder, and TiOF2 powder in an organic solvent or the like using a triple roll mill.

[0157] As the negative electrode active material, for example, powder of natural graphite having an average particle size of about 10 μm is used. A paste for a negative electrode active material layer is prepared in the same manner as the paste for a positive electrode active material layer, by dispersing a mixture containing the above-mentioned negative electrode active material and the above-mentioned solid electrolyte powder in an organic solvent or the like.

[0158] Next, copper foil with a thickness of, for example, approximately 30 μm is prepared as the material to be used as the positive electrode current collector and the negative electrode current collector. Using a screen printing method, a paste for the positive electrode active material layer and a paste for the negative electrode active material layer are printed on one surface of each copper foil in a predetermined shape and with a thickness of approximately 50 μm to 100 μm. The paste for the positive electrode active material layer and the paste for the negative electrode active material layer are dried at 80°C to 130°C to a thickness of 30 μm to 60 μm. The paste for the positive electrode active material layer contains TiOF2 powder. This results in a current collector (copper foil) on which a positive electrode active material layer and a negative electrode active material layer are respectively formed.

[0159] Next, a paste for a solid electrolyte layer dispersed in an organic solvent or the like is prepared by incorporating TiOF powder. The above-described paste for a solid electrolyte layer containing TiOF powder is printed, for example, to a thickness of about 100 μm on the main surface of a positive electrode active material layer formed on a positive electrode current collector using a metal mask. The above-described paste for a solid electrolyte layer containing TiOF powder is printed, for example, to a thickness of about 100 μm on the main surface of a negative electrode active material layer formed on a negative electrode current collector using a metal mask. Thereafter, the positive electrode active material layer and the negative electrode active material layer, on whose main surfaces the solid electrolyte layer paste has been printed, are dried at 80°C to 130°C.

[0160] Next, the solid electrolyte printed on the positive electrode active material layer formed on the positive electrode current collector and the solid electrolyte printed on the negative electrode active material layer formed on the negative electrode current collector are laminated so as to be in contact with and face each other, and the resulting laminate is placed in a die mold having a rectangular outer shape.

[0161] Next, a layer having a thickness of, for example, about 50 μm to 100 μm and an elastic modulus of 5×10 6 An elastic sheet of about 100 Pa is inserted. With this configuration, pressure is applied to the laminate via the elastic sheet. Thereafter, the pressurizing mold is heated to 50°C to 80°C at a pressure of 300 MPa to 350 MPa for, for example, about 90 seconds. This results in a battery including a positive electrode layer, a negative electrode layer, and an electrolyte layer disposed between the positive electrode layer and the negative electrode layer.

[0162] The method for manufacturing the battery is not limited to the above example.

[0163] In the above-described manufacturing method, the paste for the positive electrode active material layer, the paste for the negative electrode active material layer, and the paste for the solid electrolyte layer are applied by printing, but the present invention is not limited to this. Examples of printing methods that may be used include a doctor blade method, a calendar method, a spin coating method, a dip coating method, an inkjet method, an offset method, a die coating method, and a spray method.

[0164] [Other Embodiments] (Additional Notes) The above description of the embodiments discloses the following techniques.

[0165] (Technology 1) A battery comprising: a first electrode layer; a second electrode layer; and an electrolyte layer disposed between the first electrode layer and the second electrode layer, wherein the battery satisfies at least one configuration selected from the group consisting of the following (I) and (II): (I) At least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer contains at least one titanium-containing material selected from the group consisting of halogenated titanium oxide and titanium oxide. (II) The battery further comprises a side layer disposed on a side surface of at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer, the side layer containing at least one titanium-containing material selected from the group consisting of halogenated titanium oxide and titanium oxide. The halogenated titanium oxide is represented by the following composition formula (1): TiO α1 X1 β1 ...Formula (1) In the composition formula (1), the X1 is at least one selected from the group consisting of F, Cl, Br, and I, the α1 satisfies 0.95≦α1≦1.05, and the β1 satisfies 1.95≦β1≦2.05, and the titanium oxide is represented by the following composition formula (2): TiO α2 ... Formula (2) A battery, wherein in the composition formula (2), α2 satisfies 1.95≦α2≦2.05.

[0166] The titanium-containing material is relatively hard, for example harder than the solid electrolyte contained in the battery. Therefore, the battery of Technology 1 containing the titanium-containing material has increased mechanical strength, improving its flexural strength and impact resistance. Therefore, the battery of Technology 1 can have increased mechanical strength and improved reliability. The content and location of the titanium-containing material may be adjusted as desired depending on the purpose. This allows the battery of Technology 1 to achieve the desired reliability.

[0167] The above effects can be achieved with either the configuration (I) or (II). For example, when the configuration (I) is satisfied, the strength of the electrode layer and / or electrolyte layer, which are the power-generating elements of the battery, can be improved, thereby improving the reliability of the battery. Furthermore, when the configuration (II) is satisfied, the side layer containing the titanium-containing material can effectively suppress structural defects (i.e., cracks or peeling originating from the side) that tend to occur from the side of the battery, where the effects of external impact and thermal impact are likely to become apparent, thereby improving the reliability of the battery.

[0168] (Technology 2) The battery according to Technology 1, wherein the electrolyte layer is a solid electrolyte layer.

[0169] This configuration makes it possible to provide an all-solid-state battery with improved reliability.

[0170] (Technology 3) The battery according to Technology 2, wherein the solid electrolyte layer contains a halide solid electrolyte.

[0171] This configuration results in a more reliable battery. For example, when titanium oxide halide is included as the titanium-containing material, the thermal expansion characteristics of the halide solid electrolyte included in the solid electrolyte layer and the halide oxide halide are easily matched because they are both halides. This strengthens the bonding interface between the titanium oxide halide and the halide solid electrolyte. This suppresses the occurrence of structural defects due to peeling at the bonding interface between the titanium oxide halide and the halide solid electrolyte caused by thermal shock or thermal cycling. In other words, when titanium oxide halide is included as the titanium-containing material, the effect of the titanium-containing material against thermal shock and thermal cycling is further improved. This results in a more reliable battery.

[0172] (Technology 4) The battery according to Technology 1, wherein the electrolyte layer is composed of an electrolytic solution and a separator impregnated with the electrolytic solution.

[0173] This configuration makes it possible to provide a liquid battery with improved reliability.

[0174] (Technology 5) The battery according to any one of Technologies 1 to 4, wherein the battery satisfies (I), and at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer includes solid electrolyte particles and a coating layer that coats at least a portion of a surface of the solid electrolyte particles, and the coating layer includes the titanium-containing material.

[0175] This configuration can enhance the bonding and mechanical bonding (i.e., anchoring effect) between the solid electrolyte particles contained in the electrode layer and / or electrolyte layer, which are the power generating elements of the battery, thereby improving the strength of the power generating elements against external stress and thermal cycles, and thereby further improving the reliability of the battery.

[0176] (Technology 6) The battery according to any one of Technologies 1 to 4, wherein the battery satisfies (I), and at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer includes solid electrolyte particles, and the titanium-containing material is contained inside the solid electrolyte particles.

[0177] According to this configuration, the solid electrolyte particles contained in the electrode layer and / or electrolyte layer, which are the power generating elements of a battery, can have their internal portions harder and improved strength, allowing the hardness of the solid electrolyte particles to be tailored to the intended purpose. Furthermore, the surface portions of the solid electrolyte particles can be made softer than the internal portions of the particles, allowing the surface portions of the particles to have bondability and deformability. This improves the bondability between particles. The inclusion of such solid electrolyte particles in the power generating element improves the reliability of the power generating element against external stresses and thermal cycles, thereby further improving the reliability of the battery. The hardness of the solid electrolyte particles can be adjusted, for example, by selecting a halogen element in the titanium oxide halide contained as the titanium-containing material, or by incorporating multiple halogen elements in combination. Furthermore, the inclusion of the titanium-containing material in the internal portions of the solid electrolyte particles reduces the reduction in ionic conductivity between the solid electrolyte particles due to the titanium-containing material.

[0178] (Technology 7) The battery according to any one of Technologies 1 to 6, wherein the battery satisfies (I), and at least one selected from the group consisting of the first electrode layer and the second electrode layer includes active material particles and a coating layer that coats at least a portion of a surface of the active material particles, and the coating layer includes the titanium-containing material.

[0179] This configuration enhances the mechanical bonding between the active material particles (i.e., the anchoring effect), thereby improving the strength of the electrode layer against external stress and thermal cycles, and suppressing the occurrence of structural defects such as cracks in the electrode layer, thereby further improving the reliability of the battery.

[0180] (Technology 8) The battery according to any one of technologies 1 to 7, wherein the titanium-containing material is in particulate form.

[0181] This configuration makes it easier to incorporate the titanium-containing material into the coating layers of the solid electrolyte particles and active material particles, or into the solid electrolyte particles. Furthermore, for example, finely pulverized titanium-containing material particles can make the electrolyte layer thinner or the coating layers of the active material particles thinner, thereby improving the capacity of the battery.

[0182] (Technology 9) The battery according to any one of technologies 1 to 8, wherein the titanium-containing material includes TiOF2.

[0183] This configuration improves the mechanical bonding (i.e., anchoring effect) between solid electrolyte particles and active material particles due to the presence of hard TiOF particles. For example, when TiOF, which is harder than the solid electrolyte, is contained within the solid electrolyte particles, the solid electrolyte particles can be made harder. Furthermore, when TiOF is contained in the coating layer of the solid electrolyte particles and / or active material particles, TiOF also serves as an anchor that strengthens the bonding between the particles. This results in a battery with excellent flexural strength and impact resistance. TiOF also has excellent heat resistance (e.g., approximately 1000°C). This ensures excellent reliability even at high temperatures.

[0184] (Technology 10) The battery according to Technology 9, wherein the TiOF2 has a cubic crystal structure.

[0185] This results in a highly heat-resistant TiOF2 that is stable even at high temperatures, for example, around 400°C. Therefore, since TiOF2 with excellent mechanical strength and heat resistance can be incorporated into a battery, a more reliable battery can be obtained. The crystal system of TiOF2 can be identified, for example, by the diffraction pattern obtained by micro-XRD of the surface exposed on the side of the battery. Alternatively, it can be confirmed by a lattice image obtained by high-resolution TEM.

[0186] (Technology 11) The battery according to Technology 10, wherein the titanium-containing material is in the form of particles, and at least a portion of the surface of the particles of the titanium-containing material is coated with a coating layer containing a solid electrolyte.

[0187] In this configuration, the solid electrolyte coating the titanium-containing material particles acts as a binder, improving the bonding between the titanium-containing material particles themselves and between the titanium-containing material particles and other particles (e.g., solid electrolyte particles and active material particles), thereby further improving the reliability of the battery.

[0188] (Technology 12) The battery according to any one of technologies 1 to 11, wherein the titanium-containing material includes TiOF2 having a cubic crystal structure and TiO2.

[0189] This allows the titanium-containing material to have excellent bonding strength between TiOF2 and TiO2 due to the common element Ti, while also having improved hardness. Furthermore, by incorporating a titanium-containing material containing TiO2, which has high heat resistance stability, together with TiOF2 into a battery, the binding strength of the solid electrolyte particles and the active material particles at high temperatures can be improved. This results in a battery with excellent mechanical strength and heat resistance.

[0190] (Technology 13) The battery according to Technology 12, wherein the titanium-containing material is in a particulate form, and the content of TiOF2 is greater than the content of TiO2 in a surface region of the particle of the titanium-containing material, and the content of TiO2 is greater than the content of TiOF2 in an internal region of the particle of the titanium-containing material.

[0191] According to this configuration, the titanium-containing material particles contain a large amount of hard, heat-resistant TiO2 inside the particles and a large amount of heat-resistant TiOF2 in the surface layer. By further incorporating such titanium-containing material particles into a solid electrolyte layer and / or electrode layer containing halide solid electrolyte particles, the titanium-containing material particles can have high bonding strength with the halide solid electrolyte particles because they both contain a halogen element. Therefore, this configuration allows for a power generating element with high mechanical strength and heat resistance to be obtained. This results in a highly reliable battery.

[0192] (Technology 14) The battery according to Technology 13, wherein at least a portion of the surface of the particles of the titanium-containing material is coated with a coating layer containing a solid electrolyte.

[0193] This improves the bonding strength between the titanium-containing material and the solid electrolyte contained in the electrolyte layer or electrode layer, thereby increasing the reliability of the solid electrolyte layer or electrode layer against thermal shock and external stress.

[0194] (Technology 15) The battery according to Technology 9, wherein the titanium-containing material is in a particulate form, and the particles of the titanium-containing material include: first particles made of TiOF2 having a cubic crystal structure; and second particles containing TiOF2 and TiO2, also having a cubic crystal structure.

[0195] This allows the heat resistance and mechanical strength of the titanium-containing material to be adjusted depending on the application by controlling the mixing ratio of the first particles and the second particles.

[0196] (Technology 16) The battery according to Technology 15, wherein the average particle diameter of the second particles is larger than the average particle diameter of the first particles.

[0197] This allows the first particles, which are softer and more deformable than the second particles, to reduce voids or irregularities that tend to form around the second particles while still achieving the hardness-enhancing effect of the second particles. Therefore, by reducing voids and irregularities, the electrolyte layer and electrode layer have a homogenized structure, improving their mechanical strength and impact resistance. This results in a highly reliable battery.

[0198] (Technology 17) The battery according to Technology 3, wherein the halide solid electrolyte contains Ti.

[0199] This configuration allows for a solid electrolyte layer containing a solid electrolyte with high ionic conductivity, for example, 1 μS / cm or higher. Furthermore, the presence of Ti, which is commonly contained in the titanium-containing material and the halide solid electrolyte, facilitates the strong bonding between the titanium-containing material and the solid electrolyte, facilitating the formation of an integrated bonded interface. This allows the titanium-containing material, when included in the solid electrolyte layer, to coexist stably with the solid electrolyte within the solid electrolyte layer (e.g., without forming microscopic defects around it). This results in a battery with improved reliability.

[0200] (Technology 18) The battery according to Technology 17, wherein the halide solid electrolyte includes a first halide solid electrolyte including a crystalline phase represented by the following composition formula (3): Li2TiX26 Formula (3) In the composition formula (3), X2 is at least one selected from the group consisting of F, Cl, Br, and I.

[0201] According to this configuration, the solid electrolyte layer contains a solid electrolyte having a high ionic conductivity, for example, 1 μS / cm or more, thereby improving the ionic conductivity of the solid electrolyte layer. The crystalline phase represented by Li2TiX26 can be confirmed by the diffraction pattern of the micro-XRD described above or by powder XRD using a powder sample obtained by cutting out the solid electrolyte. The composition of the solid electrolyte can also be evaluated by elemental analysis, for example, using EPMA or EDS.

[0202] (Technology 19) The battery according to Technology 18, wherein the first halide solid electrolyte contains a crystalline phase represented by the following composition formula (4): Li2TiF6 Formula (4).

[0203] This allows the first halide solid electrolyte to have improved atmospheric stability. This suppresses fluctuations in the properties of the solid electrolyte caused by environmental changes during the manufacturing process, allowing for reproducible production of solid electrolyte layers with desired properties. Furthermore, strict dew point, temperature, and humidity control are no longer required, resulting in benefits in manufacturing, such as reduced manufacturing costs.

[0204] (Technology 20) The battery according to Technology 18 or 19, wherein the halide solid electrolyte further includes a second halide solid electrolyte having a composition different from that of the first halide solid electrolyte.

[0205] This configuration further improves the binding property of the solid electrolyte in the solid electrolyte layer, making it possible to densify the solid electrolyte layer, increase its strength, and improve its ionic conductivity.

[0206] (Technology 21) The battery according to Technology 20, wherein the second halide solid electrolyte has a higher melting point than the first halide solid electrolyte.

[0207] The second halide solid electrolyte has a higher melting point than the first halide solid electrolyte, and therefore can maintain a harder state than the first halide solid electrolyte at high temperatures. Therefore, when a solid electrolyte layer containing a first halide solid electrolyte further contains a second halide solid electrolyte, the hardness of the solid electrolyte layer increases. This strengthens the solid electrolyte layer, improving its flexural strength and impact resistance, and improving the reliability of the solid electrolyte layer. This allows for the realization of a battery with improved reliability.

[0208] (Technology 22) The battery according to Technology 20 or 21, wherein the second halide solid electrolyte is harder than the first halide solid electrolyte.

[0209] As a result, when a solid electrolyte layer containing a first halide solid electrolyte further contains a second halide solid electrolyte, the hardness of the solid electrolyte layer increases. This strengthens the solid electrolyte layer, improving its flexural strength and impact resistance, and improving the reliability of the solid electrolyte layer. This allows for the realization of a battery with improved reliability.

[0210] (Technology 23) The battery according to any one of Techniques 20 to 22, wherein the second halide solid electrolyte includes a crystalline phase represented by the following composition formula (5): Li3MF6 (5) In the composition formula (5), M is at least one element selected from the group consisting of metal elements and semimetal elements having a valence of trivalent.

[0211] This allows the use of a second halide solid electrolyte that is harder than the first halide solid electrolyte. Therefore, when a solid electrolyte layer containing a first halide solid electrolyte further contains a second halide solid electrolyte, the hardness of the solid electrolyte layer increases. This strengthens the solid electrolyte layer, improving its flexural strength and impact resistance, and improving the reliability of the solid electrolyte layer. This allows for the realization of a battery with improved reliability.

[0212] (Technology 24) The battery according to Technology 23, wherein M contains Al.

[0213] This increases the ionic conductivity of the second halide solid electrolyte to the same level as that of the first halide solid electrolyte (e.g., 1 μS / cm or more). This allows for a solid electrolyte layer with high ionic conductivity and high reliability to be obtained. This allows for a battery with excellent performance and reliability to be obtained.

[0214] While the battery according to the present disclosure has been described above based on the embodiments, the present disclosure is not limited to these embodiments. As long as they do not deviate from the gist of the present disclosure, various modifications conceivable by those skilled in the art to the embodiments and other forms constructed by combining some of the components of the embodiments are also included in the scope of the present disclosure.

[0215] Furthermore, the above-described embodiments can be modified, replaced, added, omitted, and the like in various ways within the scope of the claims or their equivalents.

[0216] The battery according to the present disclosure can be used as a secondary battery such as an all-solid-state battery or a liquid battery for use in various electronic devices or automobiles, for example.

Claims

1. A battery comprising a first electrode layer, a second electrode layer, and an electrolyte layer disposed between the first electrode layer and the second electrode layer, the battery satisfying at least one configuration selected from the group consisting of the following (I) and (II): (I) At least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer contains at least one titanium-containing material selected from the group consisting of halogenated titanium oxide and titanium oxide. (II) The battery further comprises a side layer, which is disposed on the side surface of at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer, and which contains at least one titanium-containing material selected from the group consisting of halogenated titanium oxide and titanium oxide. The halogenated titanium oxide is represented by the following composition formula (1): TiO α1 X1 β1 In the composition formula (1), X1 is at least one selected from the group consisting of F, Cl, Br, and I, α1 satisfies 0.95≦α1≦1.05, and β1 satisfies 1.95≦β1≦2.05, and the titanium oxide is represented by the following composition formula (2): TiO α2 A battery, wherein in the composition formula (2), the α2 satisfies 1.95≦α2≦2.

05.

2. The battery according to claim 1, wherein the electrolyte layer is a solid electrolyte layer.

3. The battery according to claim 2, wherein the solid electrolyte layer comprises a halide solid electrolyte.

4. The battery according to claim 1, wherein the electrolyte layer is composed of an electrolyte solution and a separator impregnated with the electrolyte solution.

5. The battery according to claim 1, wherein the battery satisfies (I), and at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer includes solid electrolyte particles and a coating layer that covers at least a portion of a surface of the solid electrolyte particles, and the coating layer includes the titanium-containing material.

6. The battery according to claim 1, wherein the battery satisfies (I), and at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer includes solid electrolyte particles, and the titanium-containing material is contained inside the solid electrolyte particles.

7. The battery according to claim 1, wherein the battery satisfies (I), and at least one selected from the group consisting of the first electrode layer and the second electrode layer includes active material particles and a coating layer that covers at least a portion of the surface of the active material particles, and the coating layer includes the titanium-containing material.

8. The battery of claim 1, wherein the titanium-containing material is in particulate form.

9. The battery of claim 1, wherein the titanium-containing material comprises TiOF2.

10. The battery according to claim 9, wherein the TiOF2 has a cubic crystal structure.

11. The battery according to claim 10, wherein the titanium-containing material is in particulate form, and at least a portion of the surface of the particles of the titanium-containing material is coated with a coating layer containing a solid electrolyte.

12. The battery of claim 1, wherein the titanium-containing material comprises TiOF2 having a cubic crystal structure and TiO2.

13. The battery according to claim 12, wherein the titanium-containing material is in particulate form, and the TiOF2 content is greater than the TiO2 content in a surface region of the particle of the titanium-containing material, and the TiO2 content is greater than the TiOF2 content in an internal region of the particle of the titanium-containing material.

14. The battery according to claim 13, wherein at least a portion of the surface of the particles of the titanium-containing material is coated with a coating layer containing a solid electrolyte.

15. The battery of claim 9, wherein the titanium-containing material is in particulate form, and the particles of the titanium-containing material include: first particles composed of TiOF2 having a cubic crystal structure; and second particles comprising TiOF2 and TiO2, also having a cubic crystal structure.

16. The battery according to claim 15, wherein the average particle size of the second particles is larger than the average particle size of the first particles.

17. The battery according to claim 3, wherein the halide solid electrolyte contains Ti.

18. The battery according to claim 17, wherein the halide solid electrolyte comprises a first halide solid electrolyte including a crystalline phase represented by the following composition formula (3): Li2TiX26 ... Formula (3) In the composition formula (3), X2 is at least one selected from the group consisting of F, Cl, Br, and I.

19. The battery according to claim 18, wherein the first halide solid electrolyte contains a crystalline phase represented by the following composition formula (4): Li2TiF6 ... formula (4).

20. The battery of claim 18, wherein the halide solid electrolyte further comprises a second halide solid electrolyte having a different composition than the first halide solid electrolyte.

21. The battery of claim 20, wherein the second halide solid electrolyte has a higher melting point than the first halide solid electrolyte.

22. The battery of claim 20, wherein the second halide solid electrolyte is harder than the first halide solid electrolyte.

23. The battery according to claim 20, wherein the second halide solid electrolyte includes a crystalline phase represented by the following composition formula (5): Li3MF6 ... (5) In the composition formula (5), M is at least one element selected from the group consisting of metal elements and semi-metal elements having a valence of three.

24. The battery of claim 23, wherein M comprises Al.

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