Battery

Abstract

This battery (1000) is provided with 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 the following (I) and (II). (I) At least one selected from the first electrode layer (100), the second electrode layer (200), and the electrolyte layer (300) contains at least one titanium-containing material selected from the group consisting of halogenated titanium oxide and titanium oxide. (II) The battery (1000) is further provided with a side surface layer, which is disposed on the side surface of at least one of the first electrode layer (100), the second electrode layer (200), and the electrolyte layer (300), and which contains at least one titanium-containing material selected from the group consisting of halogenated titanium oxide and titanium oxide.

Description

Technical Field

[0001] This disclosure relates to batteries. Background Technology

[0002] Patent Document 1 discloses a battery using a solid electrolyte comprising Li, Ti, M, and F, which is a coated active material. Furthermore, M is at least one selected from the group consisting of Ca, Mg, Al, Y, and Zr. In Patent Document 1, the aforementioned solid electrolyte is contained within a coating layer of the coated active material. Existing technical documents Patent documents

[0003] Patent Document 1: International Publication No. 2023 / 037817 Summary of the Invention The problem that the invention aims to solve

[0004] In the prior art, batteries with high reliability are required. Therefore, this disclosure provides a battery with improved mechanical strength and reliability. means for solving problems

[0005] The battery disclosed herein has the following features: First electrode layer Second electrode layer, and An electrolyte layer disposed between the first electrode layer and the second electrode layer. The battery satisfies at least one of the following configurations selected from the group consisting of (I) and (II): (I) At least one of the following is selected from the group consisting of the first electrode layer, the second electrode layer and the electrolyte layer, and includes at least one titanium-containing material selected from the group consisting of titanium halide and titanium oxide. (II) The battery further comprises a side layer containing at least one titanium-containing material selected from the group consisting of the first electrode layer, the second electrode layer and the electrolyte layer, disposed on at least one side of the battery. The aforementioned halide titanium oxide is represented by the following compositional formula (1), TiO α1 X1 β1 …Formula (1) In the above composition formula (1), X1 is at least one of the groups composed of F, Cl, Br and I, α1 satisfies 0.95≤α≤1.05, and β1 satisfies 1.95≤α≤2.05. The above-mentioned titanium oxide is represented by the following compositional formula (2), TiO α2 …Formula (2) In the above composition (2), the above α2 satisfies 1.95≤α≤2.05. Invention Effects

[0006] This disclosure enables the provision of batteries with improved reliability. Attached Figure Description

[0007] [ Figure 1 ] Figure 1 These are cross-sectional and top views showing the general configuration of the battery 1000 according to the first embodiment. [ Figure 2 ] Figure 2 These are cross-sectional and top views showing the schematic configuration of the battery 1100 according to the second embodiment. [ Figure 3 ] Figure 3 These are cross-sectional and top views showing the schematic configuration of the battery 1200 according to the third embodiment. [ Figure 4 ] Figure 4 These are cross-sectional and top views showing the schematic configuration of the battery 1300 according to the fourth embodiment. [ Figure 5 ] Figure 5 These are cross-sectional and top views showing the schematic configuration of the battery 1400 according to the fifth embodiment. [ Figure 6 ] Figure 6 These are cross-sectional and top views showing the schematic configuration of the battery 1500 according to the sixth embodiment. Detailed Implementation

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

[0009] The embodiments described below are general or specific examples. The numerical values, shapes, materials, arrangement and connection methods of the constituent elements, manufacturing processes, and order of manufacturing processes shown in the following embodiments are examples and are not intended to limit this disclosure. In addition, the constituent elements in the following embodiments that are not described in the independent claims representing the highest concept are described as arbitrary constituent elements.

[0010] In this specification, terms such as parallelism indicating the relationship between elements, and terms such as rectangle indicating the shape of elements, and numerical ranges do not only indicate a strict meaning, but also imply that there are substantially equal ranges, such as differences of a few percent.

[0011] Each figure is a schematic diagram and not necessarily a strict representation. Therefore, for example, the scale may not be consistent across different figures. In each figure, substantially identical components are labeled with the same reference numerals, and repetitive descriptions are omitted or simplified.

[0012] In this specification and accompanying drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional orthogonal coordinate system. In various embodiments, the z-axis direction is set as the thickness direction of the battery. Furthermore, unless otherwise specified in this specification, "thickness direction" refers to the direction perpendicular to the surfaces of the stacked layers in the battery.

[0013] In this manual, "top view" refers to viewing the battery along the stacking direction of its layers. "Thickness" in this manual refers to the length of the battery and its layers along the stacking direction.

[0014] In this specification, unless otherwise specified, in the battery and its layers, "side surface" refers to the surface along the stacking direction of the layers in the battery, and "main surface" refers to the surface other than the side surface.

[0015] In this instruction manual, the terms "inner" and "outer" in terms of "inner side" and "outer side" refer to the center side of the battery when the battery is viewed along the stacking direction of each layer in the battery, and the peripheral side of the battery is the "outer side".

[0016] In this specification, the terms "upper" and "lower" in the context of battery configuration do not refer to the absolute spatial direction (vertically above) and downward direction (vertically below), but rather are used as terms defined by relative positional relationships based on the stacking order in a layered configuration. Furthermore, the terms "upper" and "lower" apply not only to cases where two components are arranged with a gap between them and other components exist between them, but also to cases where two components are arranged close together and connected.

[0017] [First Implementation Method] The battery of the 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 is disposed between the first electrode layer and the second electrode layer.

[0019] The battery of the first embodiment satisfies at least one configuration selected from the group consisting of (I) and (II) below: (I) At least one of the group consisting of a first electrode layer, a second electrode layer and an electrolyte layer includes at least one titanium-containing material selected from the group consisting of titanium halide and titanium oxide. (II) The battery of the first embodiment further includes a side layer containing at least one titanium-containing material selected from the group consisting of a first electrode layer, a second electrode layer and an electrolyte layer disposed on at least one side.

[0020] The above-mentioned halide titanium oxide is represented by the following composition formula (1). TiO α1 X1 β1 ...Equation (1) In the above composition formula (1), X1 is at least one of the groups composed of F, Cl, Br and I, α1 satisfies 0.95≤α1≤1.05, and β1 satisfies 1.95≤β1≤2.05.

[0021] The above-mentioned titanium oxide is represented by the following composition formula (2). TiO α2 …Formula (2) In the above composition (2), α2 satisfies 1.95≤α2≤2.05.

[0022] In the above composition (1), α1 can be 1. In the above composition (1), β1 can be 2. The above-mentioned titanium halide can be represented by TiOX12.

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

[0024] The aforementioned titanium-containing material is relatively hard, for example, harder than the solid electrolyte contained in the battery. Therefore, the battery of the first embodiment containing the aforementioned titanium-containing material has improved mechanical strength, flexural strength, and impact resistance. Thus, the battery of the first embodiment can improve mechanical strength and reliability. The content and location of the aforementioned titanium-containing material can be adjusted arbitrarily according to the desired purpose. Therefore, the battery of the first embodiment can achieve the desired reliability.

[0025] The aforementioned effects can be achieved when the battery of the first embodiment satisfies either of the configurations described in (I) and (II) above. For example, when the configuration described in (I) is satisfied, the strength of the electrode layer and / or electrolyte layer, which are power generation elements of the battery, can be improved, thus increasing the reliability of the battery. Furthermore, when the configuration described in (II) is satisfied, the side layer containing the aforementioned titanium-containing material can effectively suppress structural defects (i.e., cracks or peelings originating from the side of the battery) that are easily affected by external impacts and heat-induced shocks, thus improving the reliability of the battery.

[0026] In this specification, “titanium-containing material” refers to at least one of the groups consisting of titanium halide as shown in formula (1) and titanium oxide as shown in formula (2).

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

[0028] Figure 1 These are cross-sectional and top views showing the general configuration of the battery 1000 according to the first embodiment.

[0029] Figure 1 (a) shows a cross-sectional view of the battery 1000 according to the first embodiment. Figure 1 (b) is a top view of the battery 1000 of the first embodiment, viewed from below along the z-axis. Figure 1 (a) shows Figure 1 The cross section at the location shown by line II in (b).

[0030] like Figure 1 As shown, the battery 1000 includes a first electrode layer 100, a second electrode layer 200 disposed opposite to and parallel to 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 in which the first electrode layer 100, the solid electrolyte layer 300, and the second electrode layer 200 are sequentially disposed in the stacking direction. For example, the first electrode layer 100 and the solid electrolyte layer 300 contain a titanium-containing material. The titanium-containing material may also be 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. Additionally, 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, located between the first active material layer 120 and the second active material layer 220, and in contact with both the first and second active material layers 120. Furthermore, in... Figure 1 In the battery 1000 shown, titanium-containing material particles 400 are only present in the first electrode layer 100 and the solid electrolyte layer 300, but titanium-containing material particles 400 may also be present in the second electrode layer 200.

[0032] exist Figure 1 In the example shown, the approximate top-view shape of 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 is rectangular. However, in the battery of the first embodiment, the shapes of these components are not limited to rectangles.

[0033] In addition, Figure 1 In the example shown, 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 when viewed from above, but are not limited thereto. 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 of 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 current collector and the first active material layer 120 is a positive active material layer. Furthermore, the second current collector 210 is a negative current collector and the second active material layer 220 is a negative active material layer.

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

[0036] In the following description, the positive electrode active material layer and the negative electrode active material layer are sometimes collectively referred to as the "active material layer". In addition, the positive electrode current collector and the negative electrode current collector are sometimes simply referred to as the "current collector".

[0037] (Current collector) Current collectors are formed from conductive materials. Examples of materials for current collectors include stainless steel, nickel (Ni), aluminum (Al), iron (Fe), titanium (Ti), copper (Cu), palladium (Pd), gold (Au), or platinum (Pt), or alloys of two or more of these. Foil-like, plate-like, or mesh-like structures made of these materials can be used as current collectors.

[0038] The material of the current collector can be selected by considering the manufacturing process, operating temperature, operating pressure, and the operating potential or conductivity of the battery applied to the current collector. Additionally, the material of the current collector can also be selected based on the tensile strength or heat resistance required by the battery.

[0039] The current collector can be a high-strength electrolytic copper foil or a cladding material made by stacking dissimilar metal foils.

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

[0041] In order to improve the adhesion to the active material layer, the surface of the current collector can be processed into a rough surface with irregularities.

[0042] An adhesive component such as an organic binder can be coated on the surface of the current collector. In addition, insulating particles, conductive particles or semiconductor particles can adhere to the surface of the current collector. Thereby, the bonding property of the interface between the current collector and other layers (such as the active material layer) is strengthened, and the mechanical and thermal reliability, as well as the cycle characteristics, etc. of the battery 1000 can be improved.

[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 can be in contact with the main surface of the first current collector 110. The first active material layer 120 can be in contact with the main 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 can be in contact with the main surface of the second current collector 210. The second active material layer 220 can be in contact with the main 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 that embeds or deintercalates metal ions such as lithium (Li) ions or magnesium (Mg) ions within the crystal structure at a potential higher than that of the negative electrode, and then undergoes oxidation or reduction. The type of the positive electrode active material can be appropriately selected according to the type of the 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. This compound is, for example, an oxide containing lithium and a transition metal element, or a phosphate compound containing lithium and a transition metal element.

[0048] Examples of the oxide containing lithium and a transition metal element are LiNi x M 1-x O2 (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 satisfies 0 < x ≤ 1), such as a lithium nickel composite oxide, a layered oxide such as lithium cobalt oxide (LiCoO2) and lithium nickel oxide (LiNiO2), or a lithium manganate having a spinel structure (such as LiMn2O4, Li2MnO3 or LiMnO2).

[0049] An example of a phosphoric acid compound containing lithium and transition metal elements is lithium iron phosphate (LiFePO4), which has an olivine structure.

[0050] As positive electrode active materials, sulfides such as sulfur (S) and lithium sulfide (Li2S) can be used. In this case, lithium niobate (LiNbO3) or similar materials can be coated or added onto the positive electrode active material particles.

[0051] The positive electrode active material can use only one of these materials, or it can use two or more of these materials in combination.

[0052] The positive electrode active material layer may contain titanium-containing materials. This allows the titanium-containing material to absorb external stress and stress caused by the expansion and contraction of the positive electrode active material due to charging and discharging, as well as the expansion and contraction caused by thermal cycling. Therefore, the mechanical strength of the positive electrode active material layer can be improved, suppressing defect formation. Furthermore, the compatibility between the positive electrode active material layer and the solid electrolyte layer 300 can be adjusted (e.g., the expansion and contraction caused by charging and discharging or by thermal cycling). Figure 1 As shown, the titanium-containing material can be titanium-containing material particles 400.

[0053] To improve lithium-ion conductivity or electronic conductivity, the positive electrode active material layer may contain materials other than the positive electrode active material and titanium-containing materials, in addition to the positive electrode active material itself. That is, the positive electrode active material layer can be an additive layer. Examples of such materials include inorganic solid electrolytes, sulfide-based solid electrolytes, conductive additives such as acetylene black, or adhesives such as polyethylene oxide and polyvinylidene fluoride. The solid electrolyte can be, for example, a halide solid electrolyte. Examples of halide solid electrolytes included in the positive electrode active material layer are the same as those included in the solid electrolyte layer 300 described later.

[0054] By mixing positive electrode active material and other additives such as solid electrolyte in a specified ratio, the ionic conductivity and electronic conductivity within the positive electrode active material layer can be improved.

[0055] The positive electrode active material layer can have a thickness of more than 5 μm and less than 300 μm.

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

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

[0058] Negative electrode active material refers to a substance that inserts or extracts metal ions such as lithium (Li) or magnesium (Mg) ions within its crystal structure at a lower potential than that of the positive electrode, followed by oxidation or reduction. The type of negative electrode active material can be appropriately selected according to the type of battery; well-known negative electrode active materials can be used.

[0059] Examples of negative electrode active materials include carbon materials such as natural graphite, artificial graphite, graphite carbon fibers, and resin-sintered carbon, or alloy materials combined with solid electrolytes. Examples of alloy materials include LiAl, LiZn, Li3Bi, Li3Cd, Li3Sb, Li4Si, and Li... 4.4 Pb, Li 4.4 Sn, Li 0.17 Lithium alloys such as C and LiC6, lithium titanate (Li4Ti5O) 12 Lithium oxides of transition metals, such as zinc oxide (ZnO) or silicon oxide (SiO), are used in the formation of lithium oxides. x Metal oxides such as )

[0060] The negative electrode active material can use only one of these materials, or it can use two or more of these materials in combination.

[0061] To improve lithium-ion conductivity or electronic conductivity, the negative electrode active material layer may contain materials other than the negative electrode active material. Examples of such materials include inorganic solid electrolytes, sulfide-based solid electrolytes, conductive additives such as acetylene black, or adhesives such as polyethylene oxide and polyvinylidene fluoride. The solid electrolyte may, for example, be a halide solid electrolyte. Examples of halide solid electrolytes included in the negative electrode active material layer are the same as those included in the solid electrolyte layer 300 described later.

[0062] The negative electrode active material layer can have a thickness of, for example, greater than 5 μm and less than 300 μm.

[0063] In addition, the negative electrode active material layer can also contain titanium-containing materials in the same way as the positive electrode active material layer described above.

[0064] (Solid electrolyte layer) The solid electrolyte layer 300 contains a solid electrolyte.

[0065] The solid electrolyte layer 300, for example, contains a solid electrolyte as its main component. Here, the main component refers to the component that has the highest content in the solid electrolyte layer 300 by mass proportion. As described above, the solid electrolyte layer 300 may, for example, contain a titanium-containing material. The titanium-containing material may, for example, be titanium-containing material particles 400.

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

[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 are Li2S-P2S5-based, Li2S-SiS2-based, Li2S-B2S3-based, Li2S-GeS2-based, Li2S-SiS2-LiI-based, Li2S-SiS2-Li3PO4-based, Li2S-Ge2S2-based, Li2S-GeS2-P2S5-based, or Li2S-GeS2-ZnS-based.

[0069] Examples of oxide-based solid electrolytes are lithium-containing metal oxides, lithium-containing metal nitrides, lithium phosphate (Li3PO4), or lithium-containing transition metal oxides. 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). Examples of lithium-containing transition metal oxides are lithium titanium oxides.

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

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

[0072] The halide solid electrolyte preferably contains substantially no sulfur. That the halide solid electrolyte contains substantially no sulfur means that the halide solid electrolyte contains no sulfur as a constituent element except for sulfur that is inevitably mixed in as an impurity. In this case, sulfur mixed in as an impurity in the halide solid electrolyte is, for example, 1 mol% or less. The halide solid electrolyte is more preferably sulfur-free. A sulfur-free solid electrolyte does not generate hydrogen sulfide even when exposed to air, so its safety is excellent.

[0073] The solid electrolyte layer 300, for example, contains a halide solid electrolyte. For instance, when the titanium-containing material particles 400 contain titanium oxide halide, the thermal expansion characteristics of the halide solid electrolyte in the solid electrolyte layer 300 and the titanium-containing material particles 400 are easily matched since they are halides. Therefore, the interface between the titanium-containing material particles 400 and the halide solid electrolyte becomes robust. This suppresses structural defects caused by delamination at the interface between the titanium-containing material particles 400 and the halide solid electrolyte due to thermal shock or thermal cycling. In other words, according to this configuration, the effectiveness of the titanium-containing material against thermal shock and thermal cycling is further improved. As a result, the reliability of the battery 1000 of the first embodiment is further improved.

[0074] The halide solid electrolyte can contain Ti. Based on this configuration, a solid electrolyte layer 300 containing a solid electrolyte with, for example, high ionic conductivity of 1 μS / cm or higher can be obtained. Furthermore, due to the presence of Ti in both the titanium-containing material and the halide solid electrolyte, the titanium-containing material is firmly bonded to the solid electrolyte, easily forming an integrated interface. Therefore, when the solid electrolyte layer contains a titanium-containing material, the titanium-containing material can coexist stably with the solid electrolyte within the solid electrolyte layer (e.g., without forming fine defects around it). Thus, a battery with further improved reliability can be obtained. Moreover, the Ti-containing halide solid electrolyte exhibits excellent atmospheric stability and heat resistance of around 650°C to 700°C; therefore, even when TiFO2 with a high melting point is included as the titanium-containing material, the effects of TiFO2 inclusion can be obtained at high temperatures.

[0075] The halide solid electrolyte may contain a first halide solid electrolyte having a crystalline phase represented by the following composition (3). Li2TiX26…Equation (3) In formula (3), X2 is at least one of the groups composed of F, Cl, Br and I.

[0076] The first halide solid electrolyte exhibits, for example, high ionic conductivity and atmospheric stability of 1 μS / cm or higher. Therefore, by including the first halide solid electrolyte, the ionic conductivity of the solid electrolyte layer 300 is improved. The crystalline phase represented by Li₂TiX₂₆ can be confirmed by the diffraction pattern of the aforementioned micro-part X-ray diffraction (XRD) or by powder XRD of the powder sample obtained by cutting the solid electrolyte. Furthermore, the composition of the solid electrolyte can be evaluated, for example, by elemental analysis using electron probe microanalysis (EPMA) or energy-dispersive X-ray spectrometry (EDS).

[0077] The first halide solid electrolyte may contain the crystalline phase shown in the following formula (4). Li2TiF6…Equation (4)

[0078] Therefore, the first halide solid electrolyte exhibits further improved atmospheric stability. Consequently, variations in the solid electrolyte's properties caused by environmental changes during the manufacturing process can be suppressed, allowing for the reproducible production of a solid electrolyte layer 300 with the desired properties. Furthermore, since strict dew point, temperature, and humidity management are not required, manufacturing advantages such as reduced production costs are also achieved.

[0079] The halide solid electrolyte may further include a second halide solid electrolyte having a different composition from the first halide solid electrolyte. This configuration further improves the adhesion of the solid electrolyte in the solid electrolyte layer 300, making the solid electrolyte layer 300 denser, increasing its strength, and improving its ionic conductivity.

[0080] The second halide solid electrolyte can 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 at high temperatures. Therefore, when the second halide solid electrolyte is further included in the solid electrolyte layer 300 containing the first halide solid electrolyte, the hardness of the solid electrolyte layer 300 increases. Consequently, the solid electrolyte layer 300 becomes more robust, with improved flexural strength and impact resistance, thus increasing its reliability. Therefore, a battery 1000 with improved reliability can be achieved.

[0081] The second halide solid electrolyte can be harder than the first halide solid electrolyte. Therefore, when the second halide solid electrolyte is further included in the solid electrolyte layer 300 containing the first halide solid electrolyte, the hardness of the solid electrolyte layer 300 increases. Consequently, the solid electrolyte layer 300 becomes more robust, with improved flexural strength and impact resistance, thus increasing its reliability. Therefore, a battery 1000 with improved reliability can be achieved. It should be noted that the softness of the second halide solid electrolyte compared to the first halide solid electrolyte can be evaluated using methods such as micro-Vickers hardness testing.

[0082] The second halide solid electrolyte may contain the crystalline phase shown in the following formula (5). Li3MF6…(5) In the above composition formula (5), M is at least one element selected from the group consisting of metallic and semi-metallic elements with a trivalent valence.

[0083] The second halide solid electrolyte, which contains the crystalline phase shown in formula (5), is harder than the first halide solid electrolyte. Therefore, when the second halide solid electrolyte is further included in the solid electrolyte layer containing the first halide solid electrolyte, the hardness of the solid electrolyte layer 300 increases. Consequently, the solid electrolyte layer 300 becomes more robust, with improved flexural strength and impact resistance, thus increasing its reliability. Therefore, a battery 1000 with improved reliability can be achieved.

[0084] In formula (5), M can contain Al, and M can be Al. Therefore, the ionic conductivity of the second halide solid electrolyte increases to the same level as the first halide solid electrolyte (e.g., 1 μS / cm or higher). Thus, a solid electrolyte layer 300 with high ionic conductivity and high reliability can be obtained. Therefore, a battery 1000 with excellent performance and reliability can be obtained. Furthermore, when M is Al, i.e., when the second halide solid electrolyte has a Li3AlF6 composition, it can possess stable and flexible properties up to a relatively high temperature. Therefore, by further adding such a second halide solid electrolyte to the solid electrolyte layer 300, the solid electrolyte layer 300 can be densified, further improving the ionic conductivity of the solid electrolyte layer 300. In addition, Li3AlF6 has excellent heat resistance of around 700°C to 800°C; therefore, even when containing TiFO2, which has a high melting point, as a titanium-containing material, the effect of containing TiFO2 can be obtained at high temperatures.

[0085] In addition to the solid electrolyte, the solid electrolyte layer 300 may also contain adhesives such as polyethylene oxide or polyvinylidene fluoride.

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

[0087] Solid electrolytes can be composed of aggregates of particles. Alternatively, they can be composed of sintered structures.

[0088] (Titanium-containing materials) The titanium-containing material contained in the battery 1000 of the first embodiment can be in particulate form, like the titanium-containing material particles 400. When the titanium-containing material is in particulate form, it can be contained within the coating layer of the solid electrolyte particles and the active material particles, or within the solid electrolyte particles. That is, when the electrode layer and the solid electrolyte layer contain titanium-containing material, the options for the form of the titanium-containing material are expanded. Furthermore, for example, by using micronized titanium-containing material particles (e.g., particles with a particle size of 1 μm or less), the solid electrolyte layer 300 or the coating layer such as the active material particles can be made thinner, thereby increasing the battery capacity.

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

[0090] Titanium-containing material particles 400, for example, can have an average particle size of 0.3 μm or more and 20 μm or less. Figure 1 In this context, titanium-containing material particles 400 are defined as particles with a spherical shape, but they can also have particle shapes other than spherical, such as scale-like shapes.

[0091] The titanium-containing material particles 400 preferably have a small particle size. 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. Consequently, this increases the bonding area between the titanium-containing material particles 400 and the active material or solid electrolyte present therein. 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 (e.g., miniaturizing the particle size to less than 1 μm).

[0092] Titanium-containing materials, for example, include TiOF2. The titanium-containing material can be TiOF2. By including TiOF2 in the titanium-containing material, the mechanical bonding (i.e., anchoring effect) between solid electrolyte particles and active material particles is improved through the inclusion of hard TiOF2 particles. For example, by including TiOF2, which is harder than the solid electrolyte, inside the solid electrolyte particles, the solid electrolyte particles can be made harder. Furthermore, for example, when TiOF2 is included in the coating layer of solid electrolyte particles and / or active material particles, TiOF2 also acts as an anchor that strengthens the bonding between particles. Therefore, a battery with excellent folding resistance and impact resistance can be obtained. TiOF2 has excellent heat resistance (e.g., about 1000°C). Therefore, by including TiOF2, excellent reliability can be obtained for battery 1000 even at high temperatures.

[0093] TiOF2 can have a cubic crystal structure. This crystal system can be obtained through heat treatment.

[0094] TiOF2, with its cubic crystal structure, is stable at room temperature and, for example, at high temperatures around 400°C, exhibits excellent heat resistance. Furthermore, the cubic crystal structure of TiOF2 contributes to the hardness of the battery 1000, thus improving its mechanical strength. Therefore, by including TiOF2 with a cubic crystal structure in the electrode layer and / or solid electrolyte layer 300, both the heat resistance and mechanical strength of the battery 1000 can be improved. While TiOF2 with a cubic crystal structure transitions to a hexagonal crystal structure above approximately 400°C, the improvement in mechanical strength is maintained at high temperatures due to the melting point of TiOF2 being above 1000°C. Typically, organic binders contained in all-solid-state batteries soften rapidly above their glass transition temperature, for example, between 100°C and 250°C. Therefore, by including TiOF2 with a cubic crystal structure in the electrode layer and / or solid electrolyte layer 300, it is possible to suppress the reduction of mechanical strength of the battery 1000 at high temperatures, such as above 100°C.

[0095] The crystal structure of TiO2 used as a titanium-containing material can be rutile or anatase. Since the phase transition point from anatase to rutile is approximately 900℃, rutile exhibits the best high-temperature stability. Therefore, the preferred crystal structure for TiO2 is rutile.

[0096] When the titanium-containing material is in particulate form, at least a portion of the surface of the titanium-containing material particles can be coated with a coating layer containing a solid electrolyte. According to this configuration, the solid electrolyte coated with the titanium-containing material particles acts as a binder. Therefore, the bonding between the titanium-containing material particles and with other particles (e.g., solid electrolyte particles and active material particles) is improved, further enhancing battery reliability. For example, by including titanium-containing material particles with such a configuration in the solid electrolyte layer, the ionic conductivity of the solid electrolyte layer also becomes good.

[0097] Titanium-containing materials can include both TiOF2 and TiO2, which have a cubic crystal structure. Therefore, titanium-containing materials possess excellent bonding properties between TiOF2 and TiO2 through the common element Ti, and also exhibit improved hardness. Furthermore, by including a titanium-containing material in the battery that simultaneously contains TiOF2 and TiO2, which has high thermal stability, the adhesion between solid electrolyte particles and active material particles at high temperatures can be improved. Thus, a battery with excellent mechanical strength and heat resistance can be obtained. This increased strength suppresses deformation of the electrode layer and / or solid electrolyte layer 300 caused by external impacts, thereby suppressing the formation of structural defects (interlayer or intralayer delamination and cracks). Mechanical strength and heat resistance can be adjusted by combining cubic crystal structure TiOF2, 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-partial X-ray diffraction (micro-partial XRD) on the sides of the electrode layer and the solid electrolyte layer 300 exposed on the side of the battery 1000. Alternatively, they can be confirmed by lattice images obtained by high-resolution transmission electron microscopy (TEM).

[0099] Alternatively, the titanium-containing material can be in particle form, with a higher content of TiOF2 than TiO2 on the surface of the particles and a higher content of TiO2 than TiOF2 in the interior. According to this configuration, the titanium-containing material particles contain a large amount of hard and heat-resistant TiO2 inside the particles and a large amount of heat-resistant TiOF2 on the surface. By further including 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 with the halide solid electrolyte particles due to the shared presence of halogen elements. Therefore, according to this configuration, a power generation element with high mechanical strength and heat resistance can be obtained. Thus, a highly reliable battery can be obtained.

[0100] It should be noted that the morphology of the composite particles described above can be evaluated, for example, by SEM observation of the cross-section of the battery after ion milling.

[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 particles can 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. Consequently, the reliability of the solid electrolyte layer and electrode layer against thermal shock and external stress is improved.

[0102] Titanium-containing materials are in particle form. These particles can consist of a first particle composed of TiOF2 with a cubic crystal structure and a second particle consisting of both TiOF2 and TiO2 with cubic crystal structures. Therefore, by controlling the mixing ratio of the first and second particles, the heat resistance and mechanical strength of the titanium-containing material can be adjusted according to the application.

[0103] The average particle size of the second particle can be larger than that of the first particle. This results in increased hardness due to the second particle, and the first particle, being softer and more deformable than the second particle, reduces voids and unevenness that easily form around the second particle. Therefore, by reducing voids and unevenness, the structure of the electrolyte layer and electrode layer is homogenized, improving mechanical strength and impact resistance. Consequently, a highly reliable battery can be obtained.

[0104] The content of titanium-containing material in the solid electrolyte layer 300 can be, for example, 0.01% by volume or more and 5% by volume or less, and in the first electrode layer 100 can be, for example, 0.01% by volume or more and 3% by volume or less. Such titanium-containing material content can be confirmed by elemental analysis using high-resolution composition maps such as EPMA of cross-sections processed by ion milling or the like.

[0105] Titanium-containing materials can be dispersed in the solid electrolyte layer 300 and / or the electrode layer and exist between or in the gaps between solid electrolyte particles and / or active material particles, or they can be contained in the solid electrolyte layer 300 and / or the electrode layer in other forms.

[0106] For example, a titanium-containing material may be included in at least a portion of the coating layer on the surface of the coated solid electrolyte material particles and / or active material particles. This improves the mechanical bonding (i.e., anchoring effect) between solid electrolyte particles and / or active material particles, thereby enhancing the reliability of the battery 1000 against external stresses and thermal cycling of the solid electrolyte layer 300 and / or electrode layers.

[0107] In the case where at least one of the coating layers selected from the group consisting of the first electrode layer 100 and the second electrode layer 200 comprises at least a portion of the surface of the active material particles and the coated active material particles, the coating layer may contain a titanium-containing material. According to this configuration, the adhesion and mechanical bonding (i.e., anchoring effect) between the active material particles can be improved. Therefore, the strength of the electrode layer relative to external stress and thermal cycling is improved, and the generation of structural defects such as cracks in the electrode layer can be suppressed. Therefore, the reliability of the battery 1000 can be further improved.

[0108] When at least one of the coating layers selected from the group consisting of a first electrode layer 100, a second electrode layer 200, and a solid electrolyte layer 300, comprising at least a portion of the surface of solid electrolyte particles and the coated solid electrolyte particles, the coating layer may contain a titanium-containing material. This configuration improves the adhesion and mechanical bonding (i.e., anchoring effect) between the solid electrolyte particles contained in the electrode layers and / or the solid electrolyte layer 300, which are power-generating elements of the battery 1000. Therefore, the strength of the power-generating elements relative to external stresses and thermal cycling is enhanced, thereby further improving the reliability of the battery 1000.

[0109] At least one of the following layers can be selected from the group consisting of a first electrode layer 100, a second electrode layer 200, and a solid electrolyte layer 300: solid electrolyte particles may be included, and titanium-containing materials may be included within the solid electrolyte particles. For example, titanium material may also be included within the solid electrolyte particles. In other words, at least a portion of the surface of the titanium-containing particles may be covered by a coating layer containing solid electrolyte. According to this configuration, the solid electrolyte particles included in the electrode layers and / or electrolyte layers, which are power-generating elements of the battery, can be made harder internally, thus increasing their strength. Therefore, the hardness of the solid electrolyte particles can be adjusted according to the desired purpose. In addition, since the surface portion of the solid electrolyte particles can be made softer than the interior portion, the surface portion of the particles can have bonding and deformability. Therefore, the bonding between particles can be improved. By including such solid electrolyte particles in the power-generating elements, the reliability of the power-generating elements against external stress and thermal cycling is improved, thus further improving the reliability of the battery. It should be noted that the hardness of the solid electrolyte particles can be adjusted, for example, by selecting the halogen element in the titanium halide contained as a titanium-containing material, or by combining multiple halogen elements. In addition, since the titanium-containing material is contained inside the solid electrolyte particles, the reduction in the ionic conductivity between the solid electrolyte particles caused by the titanium-containing material is reduced.

[0110] It should be noted that solid electrolyte particles containing titanium materials can be produced, for example, by using raw materials containing titanium-containing materials or substances that generate titanium-containing materials as intermediates as starting materials for synthesizing solid electrolyte particles, and by controlling the synthesis conditions of the solid electrolyte (e.g., heat treatment conditions or mechanical energy conditions imparted during mechanochemical processing). That is, solid electrolyte particles containing titanium materials can be produced by using synthesis conditions where titanium-containing materials exist inside the particles and synthesized solid electrolytes exist on the particle surface. For example, in the heat treatment during the synthesis of solid electrolytes, it is easy to produce solid electrolyte particles containing titanium materials by setting the heat treatment temperature lower than usual and / or setting the heat treatment time shorter than usual. Furthermore, in the mixing and / or dispersion of starting materials, it is also easy to produce solid electrolyte particles containing titanium materials by shortening the mixing time and / or dispersion time compared to usual. In addition to these methods, solid electrolyte particles containing titanium materials can also be produced by coating the surface of titanium-containing material particles with a film of solid electrolyte.

[0111] Alternatively, the interface between the solid electrolyte layer 300 and the electrode layer can contain a titanium-containing material. With this configuration, the adhesion between the solid electrolyte layer 300 and the electrode layer is improved, thus suppressing interlayer delamination that is easily caused by external impacts and thermal cycling.

[0112] It should be noted that the titanium-containing material within battery 1000 can be determined using EPMA, EDS, and X-ray fluorescence (XRF) analysis. Furthermore, its morphology and composition can be analyzed using compositional analysis (point or surface analysis) of EPMA and EDS from polished cross-sections processed using an ion polishing machine or similar method.

[0113] Thus, by incorporating titanium-containing materials into the solid electrolyte layer 300 and / or electrode layer, which are prone to structural defects during external impacts, charge-discharge cycles, and thermal cycles, the degradation of structural defects and material properties can be suppressed. Therefore, the degradation of the characteristics of the solid electrolyte layer 300 and / or electrode layer can be reduced, enabling the realization of a highly reliable battery 1000.

[0114] Titanium-containing materials can have their flexibility adjusted according to the intended purpose. For example, multiple titanium-containing materials can be used in combination. This can improve the mechanical strength of the battery 1000 and suppress the formation of structural defects associated with external impacts, charge-discharge cycles, and thermal cycles.

[0115] When comparing the battery 1000 of this embodiment with the battery described in Patent Document 1, the following differences exist.

[0116] Patent Document 1 discloses a solid electrolyte containing Li, Ti, M, and F (M = Al, etc.) as the coated active material, which includes TiO bonds and TiOF bonds. However, in Patent Document 1, the bonding state with Ti in the solid electrolyte containing Li, Ti, M, and F is described as including TiO bonds and TiOF bonds. Therefore, Patent Document 1 does not describe the inclusion of titanium-containing materials as components in the solid electrolyte layer or electrode layer. Therefore, the technology described in Patent Document 1 differs from the technology of the battery of the first embodiment of this 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 implies that increasing mechanical strength or battery reliability can be achieved by including titanium-containing materials in the electrode layer and solid electrolyte layer. In contrast, the battery 1000 of the first embodiment improves mechanical strength and battery reliability by including titanium-containing materials.

[0118] [Second Implementation] The battery according to the second embodiment will be described below. Items described in the first embodiment may be omitted as appropriate.

[0119] Figure 2 These are cross-sectional and top views showing the schematic configuration of the battery 1100 according to the second embodiment.

[0120] Figure 2 (a) is a cross-sectional view of the battery 1100 according to the second embodiment. Figure 2 (b) is a top view of the battery 1100 of the second embodiment viewed from the bottom in the z-axis direction. Figure 2 (a) indicates Figure 2 (b) Sectional view at the dashed line II-II.

[0121] like Figure 2 As shown, the solid electrolyte layer of the battery 1100 in the second embodiment is different from that of the battery 1000 in the first embodiment.

[0122] The difference in the solid electrolyte layer 301 of the battery 1100 in the second embodiment is that the titanium-containing material particles 400, which are titanium-containing materials, are included in a manner biased towards the region of the solid electrolyte layer 301 that is in contact with the first active material layer 120, and are not included in the region of the solid electrolyte layer 301 that is in contact with the second active material layer 220. With this configuration, the electrode layer, which is prone to structural defects, such as the region of the electrode layer containing active materials with large expansion or contraction during charging and discharging or with a large coefficient of thermal expansion, can be selectively included with titanium-containing materials. As a result, the reliability of the battery 1100 can be improved efficiently.

[0123] It should be noted that, as a variation of the battery 1100 in the second embodiment, an example is provided where the concentration of titanium-containing material particles 400 in the region of the solid electrolyte layer 301 that contacts the first active material layer 120 is higher than the concentration of titanium-containing material particles 400 in the region of the solid electrolyte layer 301 that contacts the second active material layer 220. With this configuration, the reliability of the battery 1100 can be significantly improved.

[0124] [Third Implementation Method] The battery according to the third embodiment will be described below. Items described in the above embodiments may be omitted as appropriate.

[0125] Figure 3 These are cross-sectional and top views showing the schematic configuration of the battery 1200 according to the third embodiment.

[0126] Figure 3 (a) is a cross-sectional view of the battery 1200 according to the third embodiment. Figure 3 (b) is a top view of the battery 1200 of the third embodiment viewed from the bottom in the z-axis direction. Figure 3 (a) indicates Figure 3 (b) Section at the position shown by line Ⅲ-Ⅲ.

[0127] like Figure 3 As shown, the solid electrolyte layer of the battery 1200 in the third embodiment is different from that of the battery 1000 in the first embodiment.

[0128] The solid electrolyte layer 302 in the battery 1100 of 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 with different compositions. The first layer 302a contains titanium-containing material particles 400 as the titanium-containing material. The second layer 302b does not contain titanium-containing material. For example, from the viewpoint of electrochemical stability, sometimes 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 are made of different materials. As an example, a configuration in which a halide solid electrolyte is used on the positive electrode side and a sulfide solid electrolyte is used on the negative electrode side can be used. In the case where such a solid electrolyte layer is formed by multiple layers composed of two or more different materials, selective defect suppression can be achieved by selectively including titanium-containing materials in layers that are prone to structural defects. Therefore, the reliability of the battery 1200 can be efficiently improved.

[0129] It should be noted that, as a variation of the battery 1300 in the third embodiment, a configuration can be provided in which both the first layer 302a and the second layer 302b contain titanium-containing material particles 400, and the concentration of titanium-containing material particles 400 in the first layer 302a is higher than the concentration of titanium-containing material particles 400 in the second layer 302b. With this configuration, the reliability of the battery 1200 can also be effectively improved.

[0130] [Fourth Implementation Method] The battery according to the fourth embodiment will be described below. Items described in the above embodiments may be omitted as appropriate.

[0131] Figure 4 These are cross-sectional and top views showing the schematic configuration of the battery 1300 according to the fourth embodiment.

[0132] Figure 4 (a) is a cross-sectional view of the battery 1300 according to the fourth embodiment. Figure 4 (b) is a top view of the battery 1300 of the fourth embodiment, viewed from below along the z-axis. Figure 4 (a) shows Figure 4 The cross section at the location shown by line IV-IV in (b).

[0133] like Figure 4 As shown, the battery 1300 of the fourth embodiment differs from the battery 1000 of the first embodiment in that it further includes a side layer 500 containing a titanium-containing material disposed on at least one side selected from the group consisting of the first electrode layer 100, the second electrode layer 200, and the electrolyte layer 300. That is, the battery 1300 of the fourth embodiment satisfies the configuration described in (II) above.

[0134] With this configuration, the battery 1300 of the fourth embodiment can suppress external stress from the sides and suppress the generation of structural defects in the side portion. As a result, the battery 1200 can achieve further high reliability.

[0135] In the battery 1300 of the fourth embodiment, the side layer 500 includes a titanium-containing material. The description of the titanium-containing material included in the side layer 500 is the same as that of the titanium-containing material described in the first embodiment, so detailed description is omitted here.

[0136] The side layer 500 may, for example, contain titanium-containing material particles and an organic adhesive for bonding. The side layer 500 may be formed, for example, by applying a paste containing titanium-containing material particles and an organic adhesive to the side of at least one of the first electrode layer 100, the second electrode layer 200 and the electrolyte layer 300, and then drying the coating.

[0137] The thickness of the side layer 500 can be, for example, greater than 1 μm and less than 30 μm.

[0138] It should be noted that the battery 1300 of the fourth embodiment also satisfies the configuration of including titanium-containing materials in the power generation elements, i.e., the configuration described in (I) above, but it may not satisfy the configuration described in (I) above. That is, the power generation elements may not include titanium-containing materials.

[0139] [Fifth Implementation] The battery according to the fifth embodiment will be described below. Items described in the above embodiments may be omitted as appropriate.

[0140] Figure 5 These are cross-sectional and top views showing the schematic configuration of the battery 1400 according to the fifth embodiment.

[0141] Figure 5 (a) is a cross-sectional view of the battery 1400 according to the fifth embodiment. Figure 5 (b) is a top view of the battery 1400 of the fifth embodiment, viewed from below along the z-axis. Figure 5 (a) shows Figure 5 The cross section at the location shown by the VV line in (b).

[0142] like Figure 5 As shown, the difference between the battery 1400 of the fifth embodiment and the battery 1000 of the first embodiment is that titanium-containing material particles 400, which are titanium-containing materials, are included only in the first electrode layer 100.

[0143] This configuration helps to suppress structural defects that are prone to occur in layers that expand and contract significantly during charge-discharge and thermal cycles (such as electrode layers). As a result, high reliability of the 1400 battery is achieved.

[0144] [Sixth Implementation Method] The battery according to the sixth embodiment will be described below. Items described in the above embodiments may be omitted as appropriate.

[0145] Figure 6 These are cross-sectional and top views showing the schematic configuration of the battery 1500 according to the sixth embodiment.

[0146] Figure 6 (a) is a cross-sectional view of the battery 1500 according to the sixth embodiment. Figure 6 (b) is a top view of the battery 1500 of the sixth embodiment, viewed from below along the z-axis. Figure 6 (a) shows Figure 6 The cross section at the location shown by line VI-VI in (b).

[0147] likeFigure 6 As shown, the battery 1500 of the sixth embodiment differs from the battery 1000 of the first embodiment in that it has a configuration in which the concentration of titanium-containing material contained in the first electrode layer and the solid electrolyte layer is different in each layer.

[0148] In the first electrode layer 101 and the solid electrolyte layer 303, the concentration of titanium-containing material particles 400 is higher on the outer peripheral side (lateral side). Furthermore, in Figure 6 In the battery 1500 shown, the concentration of titanium-containing material particles 400 changes gradually and continuously towards the outer periphery, but it can also change in stages.

[0149] With this configuration, in the battery 1500, 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 easily damaged by external impacts (or easily peeled off (interlayer or intralayer) due to charging / discharging and thermal cycling), can be surrounded by an increased concentration of titanium-containing material particles 400. This effectively suppresses structural defects in the outer periphery of the power generation elements, where structural defects are prone to occur. Furthermore, the high concentration of titanium-containing material particles 400, when viewed from above, can be circular, polygonal, or other shapes besides rectangular; by setting it to surround the outer periphery and protect the battery interior, high reliability can be achieved.

[0150] In the first to sixth embodiments, an all-solid-state battery was described as an example; however, the battery of this disclosure is not limited to an all-solid-state battery and may also be a liquid battery. That is, in the battery of this disclosure, the electrolyte layer may, for example, be composed of an electrolyte and a separator impregnated with the electrolyte. Even in a liquid battery, similar to the all-solid-state batteries described in the first to sixth embodiments, a highly reliable battery can be achieved by including a titanium-containing material.

[0151] In the case of a liquid battery, at least one of the first electrolyte layer and the second electrode layer comprises a titanium-containing material. In this case, the titanium-containing material is, for example, contained in a coating layer covering at least a portion of the surface of the active material particles contained in the coated electrolyte layer. The coating layer may, for example, comprise a solid electrolyte and a titanium-containing material.

[0152] [Battery manufacturing method] Next, an example of the battery manufacturing method of this embodiment will be described. Hereinafter, the manufacturing method of the battery 1000 of the first embodiment described above will be explained.

[0153] The following describes an example where 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 active material layer, the first current collector 110 is a positive current collector, the second active material layer 220 is a negative active material layer, and the second current collector 210 is a negative current collector.

[0154] First, pastes for printing the positive and negative active material layers are prepared. The solid electrolyte used in the respective mixtures of the positive and negative active material layers is, for example, a powder containing halides as the main component, with an average particle size of approximately 3 μm (Li3AlF6-Li2TiF6). As this powder, for example, a powder with high ionic conductivity (e.g., 1 × 10⁻⁶) is used. -3 S / cm~3×10 -3 Powder with a density of S / cm.

[0155] As a positive electrode active material, for example, Li-Ni-Co-Al composite oxide (LiNi) with an average particle size of about 5 μm and a layered structure is used. 0.8 Co 0.15 Al 0.05 O2) powder. In addition, as a titanium-containing material, TiOF2 powder with an average particle size of about 1 μm was prepared.

[0156] A positive electrode active material layer is prepared by dispersing the above-mentioned positive electrode active material, the above-mentioned solid electrolyte powder, and TiOF2 powder in an organic solvent, etc., and then using a paste to produce a three-roll mill.

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

[0158] Next, copper foil with a thickness of approximately 30 μm is prepared as the material to be used as the positive and negative current collectors. Using screen printing, a paste for the positive and negative active material layers is printed onto one surface of each copper foil in a specified shape and with a thickness of approximately 50 μm to 100 μm. The pastes for the positive and negative active material layers are dried at 80°C to 130°C to a thickness of 30 μm to 60 μm. It should be noted that the paste for the positive active material layer contains TiOF2 powder. Thus, a current collector (copper foil) with positive and negative active material layers respectively formed is obtained.

[0159] Next, a solid electrolyte layer paste containing TiOF2 powder, dispersed in an organic solvent or the like, is prepared. Using a metal mask, the aforementioned solid electrolyte layer paste containing TiOF2 powder is printed onto the main surface of the positive electrode active material layer formed on the positive electrode current collector, with a thickness of, for example, approximately 100 μm. Similarly, using a metal mask, the aforementioned solid electrolyte layer paste containing TiOF2 powder is printed onto the main surface of the negative electrode active material layer formed on the negative electrode current collector, with a thickness of, for example, approximately 100 μm. Then, the positive and negative electrode active material layers with the solid electrolyte layer paste printed on their main surfaces 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 stacked in a manner that they are in contact with each other and opposite each other, and the resulting stack is stored in a rectangular mold.

[0161] Next, an insert with a thickness of approximately 50 μm to 100 μm and an elastic modulus of 5 × 10⁻⁶ is inserted between the pressure mold and the aforementioned laminate. 6 An elastomer sheet with a pressure of approximately 1 MPa is used. With this configuration, pressure is applied to the laminate via the elastomer sheet. Then, while heating the pressure mold from 50°C to 80°C at a pressure of 300 MPa to 350 MPa, pressure is applied for, for example, approximately 90 seconds. This yields a battery having a positive electrode layer, a negative electrode layer, and an electrolyte layer disposed between the positive and negative electrode layers.

[0162] The methods for manufacturing batteries are not limited to the examples mentioned above.

[0163] The manufacturing method described above illustrates an example of coating a paste for the positive electrode active material layer, a paste for the negative electrode active material layer, and a paste for the solid electrolyte layer by printing, but is not limited to this. As printing methods, for example, blade coating, calendering, spin coating, dip coating, inkjet printing, offset printing, die coating, spray coating, etc., can be used.

[0164] [Other Implementation Methods] (Supplementary Explanation) The following technology has been disclosed through the above description of the embodiments.

[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. The battery satisfies at least one of the following configurations selected from the group consisting of (I) and (II): (I) At least one of the following is selected from the group consisting of the first electrode layer, the second electrode layer and the electrolyte layer, and includes at least one titanium-containing material selected from the group consisting of titanium halide and titanium oxide. (II) The battery further comprises a side layer containing at least one titanium-containing material selected from the group consisting of the first electrode layer, the second electrode layer and the electrolyte layer, disposed on at least one side of the battery. The aforementioned halide titanium oxide is represented by the following compositional formula (1), TiO α1 X1 β1 …Formula (1) In the above composition formula (1), X1 is at least one of the groups composed of F, Cl, Br and I, α1 satisfies 0.95≤α1≤1.05, and β1 satisfies 1.95≤β1≤2.05. The above-mentioned titanium oxide is represented by the following compositional formula (2), TiO α2 …Formula (2) In the above composition (2), the above α2 satisfies 1.95≤α2≤2.05.

[0166] The aforementioned titanium-containing material is relatively hard, for example, harder than the solid electrolyte contained in the battery. Therefore, the battery of Technology 1, which includes the aforementioned titanium-containing material, has improved mechanical strength, flexural strength, and impact resistance. Thus, the battery of Technology 1 can improve mechanical strength and reliability. The content and location of the aforementioned titanium-containing material can be adjusted arbitrarily according to the desired purpose. Therefore, the battery of Technology 1 can achieve the desired reliability.

[0167] The aforementioned effects can be achieved in either configuration (I) or (II) described above. For example, in the case of configuration (I) described above, the strength of the electrode layer and / or electrolyte layer, which are the power generation elements of the battery, can be improved, thus increasing the reliability of the battery. Furthermore, in the case of configuration (II) described above, the influence of external impacts and heat-induced shocks can be effectively suppressed by the inclusion of a side layer containing titanium material, thus effectively suppressing structural defects (i.e., cracks or peeling originating from the side) that are easily manifested or generated from the side of the battery, thereby improving the reliability of the battery.

[0168] (Technology 2) According to the battery of technology 1, the electrolyte layer is a solid electrolyte layer.

[0169] This configuration enables the provision of all-solid-state batteries with improved reliability.

[0170] (Technology 3) According to the battery of technology 2, the solid electrolyte layer comprises a halide solid electrolyte.

[0171] Based on this configuration, batteries with higher reliability can be obtained. For example, when titanium halide is included as the titanium-containing material, the thermal expansion characteristics of the halide solid electrolyte and titanium halide in the solid electrolyte layer are easily matched since they are halides. Therefore, the interface between titanium halide and the halide solid electrolyte becomes stronger. As a result, structural defects caused by delamination at the interface between titanium halide and the halide solid electrolyte due to thermal shock or thermal cycling can be suppressed. That is, for example, when titanium halide is included as the titanium-containing material, the effect of the titanium-containing material on thermal shock and thermal cycling is further improved. Therefore, batteries with higher reliability can be obtained.

[0172] (Technology 4) According to the battery of technology 1, the electrolyte layer is composed of an electrolyte and a separator impregnated with the electrolyte.

[0173] Based on this configuration, a liquid battery with improved reliability can be provided.

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

[0175] This configuration improves the adhesion and mechanical bonding (i.e., anchoring effect) between solid electrolyte particles contained in the electrode layer and / or electrolyte layer, which are the power generation elements of the battery. Therefore, the strength of the power generation elements relative to external stresses and thermal cycles is enhanced, thereby further improving battery reliability.

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

[0177] According to this configuration, the solid electrolyte particles contained in the electrode layer and / or electrolyte layer, which are power-generating elements of the battery, can be made harder internally, thus increasing their strength. Therefore, the hardness of the solid electrolyte particles can be adjusted according to the desired effect. Furthermore, since the surface portion of the solid electrolyte particles can be made softer than the interior, the surface portion can possess both bonding and deformability. Therefore, the bonding between particles can be improved. By including such solid electrolyte particles in the power-generating elements, the reliability of the power-generating elements against external stress and thermal cycling is improved, thus further enhancing the reliability of the battery. It should be noted that the hardness of the solid electrolyte particles can be adjusted, for example, by selecting the halogen element in the titanium halide contained as a titanium-containing material, or by combining multiple halogen elements. Additionally, since the titanium-containing material is contained within the solid electrolyte particles, the reduction in ionic conductivity between the solid electrolyte particles caused by the titanium-containing material is reduced.

[0178] (Technology 7) The battery according to any one of techniques 1 to 6, wherein the battery satisfies (I), At least one coating layer selected from the group consisting of the first electrode layer and the second electrode layer, comprising active material particles and at least a portion of the surface covering the active material particles, is used. The coating layer comprises the titanium-containing material.

[0179] This structure enhances the mechanical bonding (i.e., anchoring effect) between active material particles. Consequently, the electrode layer exhibits increased strength relative to external stresses and thermal cycling, suppressing structural defects such as cracks in the electrode layer. This further improves battery reliability.

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

[0181] This configuration allows for the easy inclusion of titanium-containing materials in the coating layer of solid electrolyte particles and active material particles, or within the solid electrolyte particles. Furthermore, for example, by using micronized titanium-containing material particles, the electrolyte layer or the coating layer such as the active material particles can be made thinner, thereby increasing the battery capacity.

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

[0183] Through this configuration, the mechanical bonding (i.e., anchoring effect) between solid electrolyte particles and active material particles is enhanced by the inclusion of hard TiOF2 particles. For example, by including TiOF2, which is harder than the solid electrolyte, within the solid electrolyte particles, the solid electrolyte particles can be made harder. Furthermore, when TiOF2 is included in the coating layer of the solid electrolyte particles and / or active material particles, TiOF2 also acts as an anchor that strengthens the bonding between particles. Therefore, batteries with excellent folding resistance and impact resistance can be obtained. In addition, TiOF2 has excellent heat resistance (e.g., approximately 1000°C). Therefore, excellent reliability can be achieved even at high temperatures.

[0184] (Technology 10) According to the battery of technology 9, the TiOF2 has a cubic crystal structure.

[0185] Thus, TiOF2 with high heat resistance is obtained, which remains stable even at high temperatures, such as around 400°C. Therefore, by incorporating TiOF2, which possesses excellent mechanical strength and heat resistance, batteries with superior reliability can be obtained. It should be noted that the crystal system of TiOF2 can be identified, for example, by the diffraction pattern obtained from microscopic XRD on the exposed surface of the battery side. Alternatively, it can be confirmed by high-resolution TEM lattice images.

[0186] (Technology 11) According to the battery of technology 10, 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] According to this configuration, the solid electrolyte coated with titanium-containing particles acts as a binder. Therefore, the bonding between the titanium-containing particles and with other particles (such as solid electrolyte particles and active material particles) is improved, further enhancing battery reliability.

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

[0189] Therefore, titanium-containing materials can achieve excellent bonding between TiOF2 and TiO2 through the common element Ti, and also have improved hardness. Furthermore, by incorporating titanium-containing materials that simultaneously contain TiOF2 and TiO2, which has high thermal stability, the adhesion between solid electrolyte particles and active material particles at high temperatures can be improved. Thus, batteries with excellent mechanical strength and heat resistance can be obtained.

[0190] (Technology 13) According to the battery of technology 12, the titanium-containing material is in the form of particles, and the content of TiOF2 is greater than the content of TiO2 in the surface region of the particles of the titanium-containing material, and the content of TiO2 is greater than the content of TiOF2 in the internal region of the particles of the titanium-containing material.

[0191] According to this configuration, the titanium-containing material particles contain a large amount of hard and heat-resistant TiO2 inside the particles and a large amount of heat-resistant TiOF2 on the surface. By further including such titanium-containing material particles in, for example, a solid electrolyte layer and / or an electrode layer containing halide solid electrolyte particles, the titanium-containing material particles can have high bonding with the halide solid electrolyte particles due to the shared presence of halogen elements. Therefore, according to this configuration, a power generation element with high mechanical strength and heat resistance can be obtained. Thus, a highly reliable battery can be obtained.

[0192] (Technology 14) According to the battery of technology 13, at least a portion of the surface of the titanium-containing material particles 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. Consequently, the reliability of the solid electrolyte layer and electrode layer against thermal shock and external stress is enhanced.

[0194] (Technology 15) According to the battery of Technology 9, the titanium-containing material is in the form of particles, and the particles of the titanium-containing material include a first particle composed of TiOF2 having a cubic crystal structure and a second particle comprising TiOF2 and TiO2 having a cubic crystal structure.

[0195] Therefore, by controlling the mixing ratio of the first particle to the second particle, the heat resistance and mechanical strength of titanium-containing materials can be adjusted according to the application.

[0196] (Technology 16) According to the battery of technology 15, the average particle size of the second particle is greater than the average particle size of the first particle.

[0197] This allows for increased hardness due to the second particle, and the first particle, being softer and more deformable than the second particle, reduces voids and unevenness that easily form around it. Therefore, by reducing voids and unevenness, the structure of the electrolyte and electrode layers is homogenized, improving mechanical strength and impact resistance. Consequently, a highly reliable battery can be obtained.

[0198] (Technology 17) According to the battery of technology 3, the halide solid electrolyte comprises Ti.

[0199] According to this configuration, a solid electrolyte layer containing a solid electrolyte with high ionic conductivity, for example, 1 μS / cm or higher, can be obtained. Furthermore, due to the presence of Ti in both the titanium-containing material and the halide solid electrolyte, the titanium-containing material is firmly bonded to the solid electrolyte, easily forming an integrated interface. Therefore, when the solid electrolyte layer includes a titanium-containing material, the titanium-containing material can coexist stably with the solid electrolyte within the solid electrolyte layer (e.g., without forming fine defects around it). Thus, a battery with further improved reliability can be obtained.

[0200] (Technology 18) According to the battery of technology 17, the halide solid electrolyte comprises a first halide solid electrolyte containing a crystalline phase represented by the following compositional formula (3). Li2TiX26…Equation (3) In the above composition formula (3), X2 is selected from at least one of F, Cl, Br and I.

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

[0202] (Technology 19) According to the battery of technology 18, the first halide solid electrolyte comprises a crystalline phase represented by the following compositional formula (4). Li2TiF6…Equation (4).

[0203] Therefore, the first halide solid electrolyte exhibits further improved atmospheric stability. Consequently, variations in the solid electrolyte's properties caused by environmental changes during the manufacturing process can be suppressed, allowing for the reproducible production of solid electrolyte layers with the desired characteristics. Furthermore, since strict dew point, temperature, and humidity management are not required, manufacturing advantages such as reduced production costs are also achieved.

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

[0205] Based on this structure, the adhesion of the solid electrolyte in the solid electrolyte layer can be further improved, making the solid electrolyte layer denser, increasing its strength, and improving its ionic conductivity.

[0206] (Technology 21) According to the battery of technology 20, 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 at high temperatures. Thus, when the second halide solid electrolyte is further included in a solid electrolyte layer containing the first halide solid electrolyte, the hardness of the solid electrolyte layer increases. Therefore, the solid electrolyte layer becomes more robust, with improved flexural strength and impact resistance, resulting in increased reliability. Thus, a battery with improved reliability can be achieved.

[0208] (Technology 22) According to the battery of technology 20 or 21, the second halide solid electrolyte is harder than the first halide solid electrolyte.

[0209] Therefore, when a second halide solid electrolyte is further included in the solid electrolyte layer containing the first halide solid electrolyte, the hardness of the solid electrolyte layer increases. Consequently, the solid electrolyte layer becomes more robust, with improved flexural strength and impact resistance, thus enhancing its reliability. This enables the realization of a battery with improved reliability.

[0210] (Technology 23) According to any one of techniques 20 to 22, the battery wherein the second halide solid electrolyte comprises a crystalline phase represented by the following compositional formula (5), Li3MF6…(5) In the above composition formula (5), M is at least one element selected from the group consisting of metallic and semi-metallic elements with a valence of 3.

[0211] Therefore, a second halide solid electrolyte, which is harder than the first halide solid electrolyte, can be used. Thus, when a second halide solid electrolyte is further included in a solid electrolyte layer containing the first halide solid electrolyte, the hardness of the solid electrolyte layer increases. Consequently, the solid electrolyte layer becomes more robust, with improved flexural strength and impact resistance, thus increasing its reliability. Therefore, a battery with improved reliability can be achieved.

[0212] (Technology 24) According to the battery of technology 23, wherein M comprises Al.

[0213] As a result, the ionic conductivity of the second halide solid electrolyte increases to the same level as that of the first halide solid electrolyte (e.g., above 1 μS / cm). Therefore, a solid electrolyte layer with high ionic conductivity and high reliability can be obtained. Consequently, a battery with excellent performance and reliability can be obtained.

[0214] The battery involved in this disclosure has been described above based on the embodiments, but this disclosure is not limited to these embodiments. Various modifications to the embodiments that can be conceived by those skilled in the art, and other ways of constructing by combining some of the constituent elements of the embodiments, are also included within the scope of this disclosure, as long as they do not depart from the spirit of this disclosure.

[0215] Furthermore, the above-described embodiments can be modified, substituted, added, omitted, etc., within the scope of the claims or their equivalents. Industrial applicability

[0216] The batteries disclosed herein can be used as secondary batteries such as all-solid-state batteries and liquid batteries used in various electronic devices or automobiles.

Claims

1. A battery comprising a first electrode layer, Second electrode layer, and An electrolyte layer disposed between the first electrode layer and the second electrode layer. The battery satisfies at least one of the following configurations selected from the group consisting of (I) and (II): (I) At least one of the following is selected from the group consisting of the first electrode layer, the second electrode layer and the electrolyte layer, and includes at least one titanium-containing material selected from the group consisting of titanium halide and titanium oxide; (II) The battery further comprises a side layer containing at least one titanium-containing material selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer, disposed on at least one side surface of at least one of the first electrode layer, the second electrode layer, and the electrolyte layer. The titanium halide is represented by the following compositional formula (1), TiO α1 X1 β1 …Formula (1) In the composition formula (1), X1 is at least one of the groups selected from F, Cl, Br and I, α1 satisfies 0.95 ≤ α1 ≤ 1.05, and β1 satisfies 1.95 ≤ β1 ≤ 2.

05. The titanium oxide is represented by the following compositional formula (2), TiO α2 …Formula (2) In the composition (2), 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 contains a halide solid electrolyte.

4. The battery according to claim 1, wherein, The electrolyte layer consists of an electrolyte and a membrane impregnated with the electrolyte.

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

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

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

8. The battery according to claim 1, wherein, The titanium-containing material is in particle form.

9. The battery according to claim 1, wherein, The titanium-containing material includes 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 particle form. At least a portion of the surface of the titanium-containing material particles is coated with a coating layer containing a solid electrolyte.

12. The battery according to claim 1, wherein, The titanium-containing material comprises TiOF2 and TiO2, which have a cubic crystal system.

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

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

15. The battery according to claim 9, wherein, The titanium-containing material is in particle form. The titanium-containing material particles comprise a first particle composed of TiOF2 with a cubic crystal structure, and a second particle comprising TiOF2 and TiO2 with cubic crystal structures.

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

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 containing a crystalline phase represented by the following compositional formula (3). Li2TiX26…Equation (3) In the composition formula (3), X2 is selected from at least one of the group consisting of F, Cl, Br and I.

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

20. The battery according to claim 18, wherein, The halide solid electrolyte further includes a second halide solid electrolyte having a different composition from the first halide solid electrolyte.

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

22. The battery according to 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 comprises a crystalline phase represented by the following formula (5), Li3MF6…(5) In the composition formula (5), M is at least one element selected from the group consisting of metallic and semi-metallic elements, having a valence of 3.

24. The battery according to claim 23, wherein, The M includes Al.

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