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 group consisting of the first electrode layer (100), the second electrode layer (200), and the electrolyte layer (300) contains a halogenated Al. (II) The battery (1000) is further provided with a side surface layer containing a halogenated Al disposed on a side surface of at least one selected from the group consisting of the first electrode layer (100), the second electrode layer (200), and the electrolyte layer (300). The halogenated Al is represented by the following compositional formula (1). In formula (1), X1 is at least one selected from the group consisting of F, Cl, Br, and I, and alpha satisfies 2.95 < = alpha < = 3.05.

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. Methods for solving problems

[0005] The battery disclosed herein includes: 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 a configuration that is selected from at least one of the following groups (I) and (II): (I) At least one of the group consisting of the first electrode layer, the second electrode layer and the electrolyte layer contains Al halide. (II) The battery further comprises a side layer containing Al halide disposed on at least one side selected from the group consisting of the first electrode layer, the second electrode layer and the electrolyte layer. The halogenated Al is represented by the following compositional formula (1), AlX1 α …Formula (1) In the above composition formula (1), X1 is selected from at least one of the groups consisting of F, Cl, Br and I, and α satisfies 2.95≤α≤3.05. 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 2These 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 superior 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 has a configuration that is selected from at least one of the following groups (I) and (II): (I) Select at least one of the group consisting of the first electrode layer, the second electrode layer and the electrolyte layer, which contains Al halide. (II) The battery of the first embodiment further includes a side layer containing Al halide disposed on at least one side selected from the group consisting of a first electrode layer, a second electrode layer and an electrolyte layer.

[0020] The above-mentioned halogenated Al is represented by the following composition formula (1). AlX1 α …Formula (1) In the above composition formula (1), X1 is at least one of the groups selected from F, Cl, Br and I, and α satisfies 2.95≤α≤3.05.

[0021] In the above composition (1), α can be 3. That is, the above-mentioned Al halide can also be represented by AlX13.

[0022] Al halides, for example, when X1 is Cl, Br, or I, have relatively low melting points and are soft, thus they can effectively function as binders and stress-absorbing materials. Conversely, Al halides, for example, when X1 is F, have relatively high melting points and are hard, thus they can effectively function as reinforcing materials. These effects of Al halides can be adjusted by selecting the halogen element X1 in the Al halide. Therefore, in order to effectively combine improvements in mechanical strength based on stress absorption and improvements in mechanical strength based on reinforcement, multiple halogen elements can be included according to the target characteristics, or halogen elements can be selected with the aim of improving either mechanical strength based on stress absorption or mechanical strength based on reinforcement. Therefore, the battery of the first embodiment, by containing Al halides, can effectively improve the strength against stresses caused by external impacts, thermal shocks, and the expansion and contraction of the battery during charging and discharging or heating and cooling. Therefore, the battery of the first embodiment can improve mechanical strength and reliability.

[0023] The aforementioned effects can be achieved when the battery of the first embodiment satisfies either configuration (I) or (II) described above. For example, when the configuration (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 (II) is satisfied, the side layer containing Al halide can effectively suppress structural defects (i.e., cracks or peelings generated from the side) that are easily manifested by external impacts and heat-induced impacts, and that are prone to occur from the side of the battery, thus improving the reliability of the battery.

[0024] The following describes a configuration example of the battery according to the first embodiment. 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.

[0025] Figure 1 These are cross-sectional and top views showing the general configuration of the battery 1000 according to the first embodiment.

[0026] 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).

[0027] like Figure 1As 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 Al halide. The contained Al halide may also be particulate Al halide (hereinafter referred to as "Al halide particles") 400. As described above, the battery 1000 is, for example, an all-solid-state battery.

[0028] 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 Al halide 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 Al halide particles 400, is located between the first active material layer 120 and the second active material layer 220, and is in contact with both the first and second active material layers 120. It should be noted that... Figure 1 In the battery 1000 shown, halide Al particles 400 are only contained in the first electrode layer 100 and the solid electrolyte layer 300, but halide Al particles 400 may also be contained in the second electrode layer 200.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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".

[0034] (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.

[0035] 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.

[0036] The current collector can be a high-strength electrolytic copper foil or a cladding material made by stacking dissimilar metal foils.

[0037] The thickness of the current collector is, for example, 10 μm or more and 100 μm or less.

[0038] To improve adhesion to the active material layer, the surface of the current collector can be processed into a rough surface with unevenness.

[0039] Adhesive components such as organic adhesives can be coated onto the surface of the current collector. Additionally, insulating, conductive, or semiconductor particles can be attached to the surface of the current collector. This strengthens the interface between the current collector and other layers (such as the active material layer), improving the mechanical and thermal reliability of the battery 1000, as well as its cycle characteristics.

[0040] (Active substance layer) The first active material layer 120 is, for example, a positive electrode active material layer. The first active material layer 120 is sandwiched between the first current collector 110 and the solid electrolyte layer 300. The first active material layer 120 may be in contact with the main surface of the first current collector 110. The first active material layer 120 may be in contact with the main surface of the solid electrolyte layer 300.

[0041] The second active material layer 220 is, for example, a negative electrode active material layer. The second active material layer 220 is sandwiched between the second current collector 210 and the solid electrolyte layer 300. The second active material layer 220 may be in contact with the main surface of the second current collector 210. The second active material layer 220 may be in contact with the main surface of the solid electrolyte layer 300.

[0042] The positive electrode active material layer contains a positive electrode active material.

[0043] The positive electrode active material is a material that intercalates or deintercalates metal ions such as lithium (Li) ions or magnesium (Mg) ions into or from its crystal structure at a potential higher than that of the negative electrode, and is oxidized or reduced accordingly. 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.

[0044] 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. [[ID={13]]

[0045] 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 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 (for example, LiMn2O4, Li2MnO3, or LiMnO2).

[0046] [[ID={22]]Examples of the phosphate compound containing lithium and a transition metal element are lithium iron phosphate (LiFePO4) having an olivine structure.

[0047] As the positive electrode active material, sulfides such as sulfur (S) and lithium sulfide (Li2S) can be used. In this case, lithium niobate (LiNbO3) or the like can be coated or added to the positive electrode active material particles.

[0048] The positive electrode active material can use only one of these materials, or can use two or more of these materials in combination. [[ID={29]]

[0049] The positive electrode active material layer may contain Al halide. This allows the Al halide 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, thus improving the mechanical strength of the positive electrode active material layer and 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, Al halide can also be Al halide particles 400.

[0050] 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 Al halide, 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.

[0051] 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.

[0052] The positive electrode active material layer can have a thickness of more than 5 μm and less than 300 μm.

[0053] The negative electrode active material layer contains negative electrode active materials.

[0054] The negative electrode active material layer is a layer mainly composed of negative electrode materials such as negative electrode active materials.

[0055] 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, and well-known negative electrode active materials can be used.

[0056] 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 0.17Lithium 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 )

[0057] The negative electrode active material can use only one of these materials, or it can use two or more of these materials in combination.

[0058] 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.

[0059] The negative electrode active material layer can have a thickness of, for example, greater than 5 μm and less than 300 μm.

[0060] In addition, the negative electrode active material layer may also contain halogenated Al in the same way as the positive electrode active material layer described above.

[0061] (Solid electrolyte layer) The solid electrolyte layer 300 contains a solid electrolyte.

[0062] The solid electrolyte layer 300, for example, contains a solid electrolyte as its main component. Here, the main component refers to the component that is most abundant in the solid electrolyte layer 300 by mass proportion. As described above, the solid electrolyte layer 300 contains, for example, Al halide. The Al halide is, for example, Al halide particles 400.

[0063] The solid electrolyte can be any known battery-grade solid electrolyte with ionic conductivity. For example, a solid electrolyte that conducts metal ions such as lithium ions or magnesium ions can be used as the solid electrolyte contained in the solid electrolyte layer 300.

[0064] As a solid electrolyte, sulfide solid electrolytes, oxide solid electrolytes, or halide solid electrolytes can be used.

[0065] Sulfide-based solid electrolytes are, for example, 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.

[0066] Oxide-based solid electrolytes are, for example, 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.

[0067] Halide solid electrolytes are, for example, solid electrolytes containing Li, at least one element selected from the group consisting of metal elements other than Li and metalloid elements, and halogen elements.

[0068] "Metalloid elements" are B, Si, Ge, As, Sb, and Te. "Metal elements" are 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).

[0069] Halide solid electrolytes preferably contain 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 inevitably mixed in as an impurity. In this case, the sulfur mixed in as an impurity in the halide solid electrolyte is, for example, 1 mol% or less. Halide solid electrolytes are more preferably sulfur-free. A sulfur-free solid electrolyte does not generate hydrogen sulfide even when exposed to the atmosphere, and thus has excellent safety.

[0070] The solid electrolyte layer 300, for example, contains a halide solid electrolyte. According to this configuration, the thermal expansion characteristics of the halide solid electrolyte contained in the solid electrolyte layer 300 and the halide Al particles 400 are similar, making them easily compatible. Therefore, the interface between the halide Al particles 400 and the halide solid electrolyte becomes robust. This suppresses structural defects caused by delamination at the interface between the halide Al 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 halide Al against thermal shock and thermal cycling is further enhanced. As a result, the reliability of the battery 1000 of the first embodiment is further improved.

[0071] The halide solid electrolyte can contain Al. 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 Al halide and the Al contained in the halide solid electrolyte, the Al halide is firmly bonded to the solid electrolyte, easily forming an integrated bonding interface. Therefore, when the solid electrolyte layer contains Al halide, the Al halide 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 Al-containing halide solid electrolyte exhibits excellent atmospheric stability and heat resistance of around 700°C to 800°C; therefore, even when AlF3 with a high melting point is included as the Al halide, the effect of containing AlF3 can be obtained at high temperatures.

[0072] The halide solid electrolyte may contain a first halide solid electrolyte having a crystalline phase represented by the following formula (2). Li3AlX26…Equation (2) In formula (2), X2 is at least one of the groups composed of F, Cl, Br and I.

[0073] The first halide solid electrolyte exhibits, for example, high ionic conductivity (above 1 μS / cm), atmospheric stability, and heat resistance. Therefore, by including the first halide solid electrolyte, the ionic conductivity and reliability of the solid electrolyte layer 300 are improved. The crystalline phase represented by Li3AlX26 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).

[0074] The first halide solid electrolyte may contain the crystalline phase shown in the following formula (3). Li3AlF6…Equation (3)

[0075] 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.

[0076] The halide solid electrolyte may further include a second halide solid electrolyte having a different composition from the first halide solid electrolyte. This configuration can further improve the adhesion of the solid electrolyte in the solid electrolyte layer 300, densify the solid electrolyte layer 300, or improve ionic conductivity.

[0077] The second halide solid electrolyte can have a lower melting point than the first halide solid electrolyte. Therefore, during the manufacture of the solid electrolyte layer 300 (e.g., during pressurization for lamination), the second halide solid electrolyte, due to its lower melting point and more flexible properties, easily deforms and fills the voids between the first halide solid electrolytes. This facilitates densification of the solid electrolyte layer 300. It should be noted that the second halide solid electrolyte, with its lower melting point, particularly increases deformability during commonly used heat pressing. Through densification, the ionic conductivity in the solid electrolyte layer 300 is improved, and structural defects (e.g., voids and cracks) are suppressed. By reducing the fine voids and cracks that become the starting point for significant characteristic deterioration due to external stress and thermal cycling, a highly reliable solid electrolyte layer 300 can be obtained. Therefore, a battery 1000 with excellent performance and high reliability can be achieved.

[0078] The second halide solid electrolyte can be more flexible than the first halide solid electrolyte. Therefore, during the manufacturing of the solid electrolyte layer (e.g., under pressure for lamination), the more flexible second halide solid electrolyte is easily deformed and fills the voids between the first halide solid electrolytes. This facilitates densification of the solid electrolyte layer 300. Densification improves the ionic conductivity of the solid electrolyte layer 300 and suppresses structural defects (e.g., voids and cracks). By reducing the fine voids and cracks that become the starting point for significant performance degradation due to external stress and thermal cycling, a highly reliable solid electrolyte layer 300 can be obtained. Therefore, a battery 1000 with excellent performance and high reliability can be achieved. It should be noted that the softness comparison between the second halide solid electrolyte and the first halide solid electrolyte can be evaluated using methods such as micro-Vickers hardness.

[0079] The second halide solid electrolyte may contain the crystalline phase shown in the following formula (4). Li2MF6…(4) In the composition formula (4), M is at least one element selected from the group consisting of metallic and semi-metallic elements with a valence of 4.

[0080] The second halide solid electrolyte, containing the crystalline phase shown in formula (4), is softer than the first halide solid electrolyte. Therefore, the solid electrolyte layer 300 containing such a second halide solid electrolyte is easily densified. Consequently, the ionic conductivity in the solid electrolyte layer 300 is improved, and structural defects (such as voids and cracks) are suppressed. Since the fine voids and cracks that become the starting point for significant performance degradation due to external stress and thermal cycling are reduced, a highly reliable solid electrolyte layer 300 can be obtained. Therefore, a battery 1000 with good performance and excellent reliability can be realized.

[0081] In formula (4), M can contain Ti, and M can be Ti. 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 more). 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 Ti, i.e., the second halide solid electrolyte has a Li₂TiF₆ composition, it can have stable and flexible properties up to a relatively high temperature, thus allowing the solid electrolyte layer 300 to be densified, further improving the ionic conductivity of the solid electrolyte layer 300 (e.g., 3 μS / cm or more). Therefore, the effect of containing Al halide can be obtained at relatively high temperatures.

[0082] In addition to the solid electrolyte, the solid electrolyte layer 300 may also contain adhesives such as polyethylene oxide or polyvinylidene fluoride.

[0083] 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.

[0084] Solid electrolytes can be composed of aggregates of particles. Alternatively, they can be composed of sintered structures.

[0085] (Al halogenated) The Al halide contained in the battery 1000 of the first embodiment can be in particulate form, like the Al halide particles 400. When the Al halide 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 Al halide is contained in both the electrode layer and the solid electrolyte layer, the options for the form of the Al halide are expanded. Furthermore, for example, by using micronized Al halide 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.

[0086] Halogenated Al particles 400 are uniformly dispersed, for example, within the first electrode layer 100 and the solid electrolyte layer 300.

[0087] Halogenated Al particles 400 can, for example, have an average particle size of 0.3 μm or more and 20 μm or less. Figure 1 The diagram shows that the halide Al particles 400 have a spherical particle shape, but they can also have particle shapes other than spherical, such as scale-like shapes.

[0088] Preferably, the Al halide particles 400 have a small particle size. This allows the Al halide particles 400 to be uniformly dispersed throughout the first electrode layer 100 and the solid electrolyte layer 300, thus increasing the surface area of ​​the Al halide particles 400. Consequently, this increases the bonding area between the Al halide particles 400 and the surrounding active material or solid electrolyte. Therefore, the mechanical reliability (flexural strength) of the first electrode layer 100 and the solid electrolyte layer 300 is further improved by miniaturizing the Al halide particles 400 (e.g., miniaturizing the particle size to less than 1 μm).

[0089] Al halides may include, for example, AlF3. Al halides can be AlF3. By including AlF3 in the Al halides, the mechanical bonding (i.e., anchoring effect) between solid electrolyte particles and active material particles is improved through the inclusion of hard AlF3 particles. For example, by including AlF3, which is harder than the solid electrolyte, inside the solid electrolyte particles, the solid electrolyte particles can be made harder. Furthermore, by including AlF3 in the coating layer of the solid electrolyte particles and / or active material particles, AlF3 also acts as an anchor that strengthens the bonding between particles. Therefore, batteries with excellent folding resistance and impact resistance can be obtained. AlF3 has excellent heat resistance (e.g., about 1000°C). Therefore, by including AlF3, excellent reliability can be obtained for battery 1000 even at high temperatures.

[0090] AlF3 can have orthorhombic and / or trigonal crystal structures. The desired crystal system can be obtained by adjusting the heat treatment conditions.

[0091] AlF3, with its orthorhombic crystal structure, exhibits stable and excellent heat resistance even at high temperatures, such as around 400°C. AlF3 with its orthorhombic crystal structure possesses heat resistance, for example, over a temperature range above 400°C and below 1000°C. Furthermore, AlF3 with its orthorhombic crystal structure is hard, thus contributing to improved mechanical strength of the battery 1000. Therefore, by including AlF3 with its orthorhombic 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. Typically, organic binders contained in all-solid-state batteries soften rapidly above their glass transition temperature, for example, above 100°C and below 250°C. Therefore, by including AlF3 with its orthorhombic crystal structure in the electrode layer and / or solid electrolyte layer 300, the reduction in mechanical strength of the battery 1000 at high temperatures, such as above 100°C, can be suppressed.

[0092] When AlF3, with its orthorhombic crystal structure, is in particle form, at least a portion of the surface of the AlF3 particles can be coated with a coating layer containing a solid electrolyte. According to this configuration, the solid electrolyte coated with AlF3 particles functions as a binder. Therefore, the bonding strength between AlF3 particles and between AlF3 particles and other particles (e.g., solid electrolyte particles and active material particles) is improved, further enhancing battery reliability. For example, by including AlF3 particles with this configuration in the solid electrolyte layer, the ionic conductivity of the solid electrolyte layer also becomes good.

[0093] AlF3 with a trigonal crystal structure is softer than AlF3 with an orthorhombic crystal structure, for example, softer than solid electrolytes. Therefore, by including AlF3 with a trigonal crystal structure in the electrode layer and / or solid electrolyte layer 300, the adhesion of solid electrolyte particles and active material particles at high temperatures can be improved.

[0094] AlF3, which combines orthorhombic and trigonal crystal structures, can also be included in the electrode layer and / or solid electrolyte layer 300. This allows for adjustment of mechanical strength, heat resistance, and adhesion by controlling the ratio of crystal systems.

[0095] The AlF3 contained in the electrode layer and / or solid electrolyte layer 300 may comprise a first crystalline phase having an orthorhombic crystal structure and a second crystalline phase having a trigonal crystal structure. With this configuration, AlF3 exhibiting relatively high heat resistance at temperatures, for example, around 200°C to 400°C, and being softer than single-crystal AlF3 with an orthorhombic crystal structure, can be achieved. Therefore, by including such AlF3 in the battery 1000, the adhesion between the solid electrolyte particles and the active material particles at high temperatures can be improved. Consequently, AlF3 can absorb the expansion, contraction, and heat generation of the active material caused by thermal cycling and charge-discharge cycling.

[0096] The crystal system of AlF3 can be identified, for example, by the diffraction pattern 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, it can be confirmed by lattice images obtained by high-resolution transmission electron microscopy (TEM).

[0097] AlF3 can also be in particle form, with the content of the first crystalline phase exceeding that of the second crystalline phase in the surface region of the AlF3 particles, and the content of the second crystalline phase exceeding that of the first crystalline phase in the interior region of the AlF3 particles. This allows for the use of composite particles containing both orthorhombic and trigonal crystal structures within a single particle. With this configuration, AlF3 particles exhibit an anchoring effect due to their hard surface even at high temperatures, while also possessing deformability due to their softer interior. Therefore, it is easier to densify solid electrolyte layers and / or electrode layers containing AlF3 particles, and the interparticle bonding between solid electrolyte particles and active material particles is also improved. Consequently, batteries with further improved reliability can be obtained.

[0098] 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.

[0099] When AlF3 is a composite particle as described above, i.e., when AlF3 containing both orthorhombic and trigonal crystal structures is in particle form, at least a portion of the surface of the AlF3 particles can be coated with a coating layer containing a solid electrolyte. This improves the bonding between AlF3 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.

[0100] In the case where Al halide comprises particulate AlF3, the AlF3 particles may include a first particle consisting of AlF3 with an orthorhombic crystal structure, and a second particle comprising a first crystalline phase with an orthorhombic crystal structure and a second crystalline phase with a trigonal crystal structure. Therefore, by controlling the mixing ratio of the first and second particles, the heat resistance, mechanical strength, deformability, and density of AlF3 can be adjusted according to the application.

[0101] The average particle size of the second particle can be larger than that of the first particle. Therefore, the voids that are easily generated around the larger second particles can be reduced by the highly deformable second crystalline phase, allowing for densification of the electrolyte layer and electrode layer. This improves the electrical characteristics and reliability of the battery 1000.

[0102] The content of Al halide in the solid electrolyte layer 300 can be, for example, 0.01 vol% or more and 5 vol% or less, and in the first electrode layer 100 can be, for example, 0.01 vol% or more and 3 vol% or less. Such Al halide content can be confirmed by elemental analysis of high-resolution composition maps such as EPMA obtained by ion milling or similar processes.

[0103] Al halide 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 it can be contained in the solid electrolyte layer 300 and / or the electrode layer in other forms.

[0104] For example, Al halide 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 for external stress and thermal cycling, etc., of the solid electrolyte layer 300 and / or electrode layer.

[0105] In the case of a coating layer selected from at least one of the first electrode layer 100 and the second electrode layer 200, comprising at least a portion of the surface of active material particles and the coated active material particles, the coating layer may contain Al halide. 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.

[0106] In the case of a coating layer selected from at least one of the first electrode layer 100, the second electrode layer 200, and the solid electrolyte layer 300, which comprises solid electrolyte particles and at least a portion of the surface covered by the solid electrolyte particles, the coating layer may contain Al halide. 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.

[0107] At least one of the first electrode layer 100, the second electrode layer 200, and the solid electrolyte layer 300 may contain solid electrolyte particles, and the solid electrolyte particles may contain Al halide. For example, Al halide may be encapsulated inside the solid electrolyte particles. In other words, at least a portion of the surface of the Al halide particles may be covered by a coating layer containing solid electrolyte. According to this configuration, the hardness of the solid electrolyte particles contained in the electrode layers and / or the solid electrolyte layer 300, which are power generation elements of the battery, can be adjusted according to the purpose, for example, making them softer to improve deformability, or making them harder to improve strength, etc. Therefore, the reliability of the power generation elements relative to external stress and thermal cycling is improved, and thus the reliability of the battery 1000 can be further improved. It should be noted that the hardness of the solid electrolyte particles can be adjusted by selecting halogen elements in the Al halide material or by combining multiple halogen elements. In addition, since the Al halide material is contained inside the solid electrolyte particles, the reduction in the ionic conductivity between the solid electrolyte particles caused by the Al halide material is reduced.

[0108] It should be noted that solid electrolyte particles containing Al halides can be produced, for example, by using raw materials containing Al halides or substances that generate Al halides 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 Al halides can be produced by using synthesis conditions where Al halides are present inside the particles and the synthesized solid electrolyte is present on the particle surface. For example, in the heat treatment during the synthesis of the solid electrolyte, solid electrolyte particles containing Al halides are easily produced 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 the starting materials, solid electrolyte particles containing Al halides are also easily produced by shortening the mixing time and / or dispersion time compared to usual. In addition to these methods, solid electrolyte particles containing Al halides can also be produced by coating the surface of the Al halides with a film of solid electrolyte.

[0109] Alternatively, the interface between the solid electrolyte layer 300 and the electrode layer can contain Al halide. 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.

[0110] It should be noted that the presence of Al halide in battery 1000 can be determined by EPMA, EDS, and X-ray fluorescence (XRF) analysis. Furthermore, its morphology and composition can be determined by compositional analysis (point analysis or surface analysis) of EPMA and EDS on a polished cross-section processed using an ion polishing machine or similar method.

[0111] By densifying the solid electrolyte layer 300 and / or electrode layer by including at least one of AlCl3, AlBr3 and AlI3 as a low-melting-point and soft Al halide, resistance loss can also be achieved through low resistance.

[0112] Thus, by incorporating Al halide into the solid electrolyte layer 300 and / or electrode layer, which are prone to structural defects due to external impacts, charge-discharge cycles, and thermal cycles, the degradation of structural defects and material properties can be suppressed. Therefore, the degradation of the properties of the solid electrolyte layer 300 and / or electrode layer can be reduced, enabling a highly reliable battery 1000.

[0113] The softness of Al halide can be adjusted according to the purpose. For example, multiple Al halide can be used in combination. This can improve the mechanical strength of the battery 1000 and suppress the generation of structural defects associated with external impact, charge-discharge cycles, and thermal cycles.

[0114] [Second Implementation] The battery according to the second embodiment will be described below. Items described in the first embodiment may be omitted as appropriate.

[0115] Figure 2 These are cross-sectional and top views showing the schematic configuration of the battery 1100 according to the second embodiment.

[0116] 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.

[0117] 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.

[0118] The difference in the solid electrolyte layer 301 of the battery 1100 in the second embodiment is that the Al halide particles 400, which are Al halide, 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 that is in contact with the second active material layer 220. With this configuration, it is possible to selectively include Al halide in 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. As a result, the reliability of the battery 1100 can be improved efficiently.

[0119] Furthermore, as a variation of the battery 1100 in the second embodiment, an example is provided where the concentration of Al halide particles 400 in the region of the solid electrolyte layer 301 that is in contact with the first active material layer 120 is higher than the concentration of Al halide particles 400 in the region of the solid electrolyte layer 301 that is in contact with the second active material layer 220. With this configuration, the reliability of the battery 1100 can be significantly improved.

[0120] [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.

[0121] Figure 3 These are cross-sectional and top views showing the schematic configuration of the battery 1200 according to the third embodiment.

[0122] 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.

[0123] 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.

[0124] 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 Al halide particles 400 as Al halide. The second layer 302b does not contain Al halide. 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 the solid electrolyte material on the positive electrode layer side uses a halide solid electrolyte and the solid electrolyte material on the negative electrode layer side uses a sulfide solid electrolyte 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 Al halide in layers that use materials prone to structural defects. Therefore, the reliability of the battery 1200 can be efficiently improved.

[0125] 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 Al halide particles 400, and the concentration of Al halide particles 400 in the first layer 302a is higher than the concentration of Al halide particles 400 in the second layer 302b. With this configuration, the reliability of the battery 1200 can also be significantly improved.

[0126] [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.

[0127] Figure 4 These are cross-sectional and top views showing the schematic configuration of the battery 1300 according to the fourth embodiment.

[0128] 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).

[0129] like Figure 4As 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 Al halide 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.

[0130] 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.

[0131] In the battery 1300 of the fourth embodiment, the side layer 500 contains Al halide. The description of the Al halide contained in the side layer 500 is the same as that of the Al halide described in the first embodiment, so detailed description is omitted here.

[0132] The side layer 500 may, for example, contain halide Al particles and an organic adhesive for bonding. The side layer 500 may be formed, for example, by applying a paste containing halide Al 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.

[0133] The thickness of the side layer 500 can be, for example, greater than 1 μm and less than 30 μm.

[0134] It should be noted that the battery 1300 of the fourth embodiment also satisfies the configuration of including Al halide in the power generation element, i.e., the configuration described in (I) above, but it may not satisfy the configuration described in (I) above. That is, it may not include Al halide in the power generation element.

[0135] [Fifth Implementation] The battery according to the fifth embodiment will be described below. Items described in the above embodiments may be omitted as appropriate.

[0136] Figure 5 These are cross-sectional and top views showing the schematic configuration of the battery 1400 according to the fifth embodiment.

[0137] 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).

[0138] like Figure 5As shown, the battery 1400 of the fifth embodiment differs from the battery 1000 of the first embodiment in that only the first electrode layer 100 contains Al halide particles 400 as Al halide.

[0139] 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 battery 1400 can be achieved.

[0140] [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.

[0141] Figure 6 These are cross-sectional and top views showing the schematic configuration of the battery 1500 according to the sixth embodiment.

[0142] 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).

[0143] like Figure 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 Al halide contained in the first electrode layer and the solid electrolyte layer is different in each layer.

[0144] In the first electrode layer 101 and the solid electrolyte layer 303, the concentration of Al halide particles 400 is higher on the peripheral side (lateral side). Furthermore, in Figure 6 In the battery 1500 shown, the concentration of halide Al particles 400 changes gradually and continuously towards the outer periphery, but it can also be a configuration that changes in stages.

[0145] With this configuration, in the battery 1500, the outer periphery of the first electrode layer 101 (e.g., the first active material layer 121), which is easily damaged by external impacts (or easily peeled off (interlayer or intralayer) due to charging / discharging and thermal cycling), and the solid electrolyte layer 303, can be surrounded by an increased concentration of Al halide 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 Al halide particles 400, when viewed from above, can be circular, polygonal, or other shapes besides rectangular; by designing it to surround the outer periphery and protect the battery interior, high reliability can be achieved.

[0146] 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 Al halide.

[0147] In the case of a liquid battery, at least one of the first electrolyte layer and the second electrode layer comprises Al halide. In this case, the Al halide is contained, for example, 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 Al halide.

[0148] [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.

[0149] 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.

[0150] First, pastes for printing the positive and negative active material layers are prepared. The solid electrolyte used as the compound for each 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). This powder, for example, uses a high ionic conductivity (e.g., 1 × 10⁻⁶). -3 S / cm~3×10 -3 Powder with a density of S / cm.

[0151] 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 halide Al material, fluorinated Al powder with an average particle size of about 1 μm was prepared.

[0152] A positive electrode active material layer is prepared by dispersing a mixture containing the above-mentioned positive electrode active material, the above-mentioned solid electrolyte powder, and fluorinated Al (AlF3) powder in an organic solvent, etc., using a three-roll mill as a paste.

[0153] 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.

[0154] 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 AlF3 powder. Thus, a current collector (copper foil) with positive and negative active material layers respectively formed is obtained.

[0155] Next, a solid electrolyte layer containing Al(AlF3) powder dispersed in an organic solvent or the like is prepared. Using a metal mask, the aforementioned solid electrolyte layer paste containing AlF3 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 AlF3 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.

[0156] 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.

[0157] 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.

[0158] The methods for manufacturing batteries are not limited to the examples mentioned above.

[0159] 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.

[0160] [Other Implementation Methods] (Supplementary Explanation) The following technology has been disclosed through the above description of the embodiments.

[0161] (Technology 1) A battery includes 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 a configuration that is selected from at least one of the following groups (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, which contains Al halide; (II) The battery further comprises a side layer containing Al halide disposed on at least one side selected from the group consisting of the first electrode layer, the second electrode layer and the electrolyte layer. The halogenated Al is represented by the following compositional formula (1), AlX1α…Equation (1) In the above composition formula (1), X1 is selected from at least one of the groups consisting of F, Cl, Br and I, and α satisfies 2.95≤α≤3.05.

[0162] Al halides, for example, when X1 is Cl, Br, or I, have relatively low melting points and are soft, thus they can effectively function as binders and stress-absorbing materials. Conversely, Al halides, for example, when X1 is F, have relatively high melting points and are hard, thus they can effectively function as reinforcing materials. These effects of Al halides can be adjusted by selecting the halogen element X1 in the Al halide. Therefore, to effectively combine improvements in mechanical strength based on stress absorption and improvements in mechanical strength based on reinforcement, multiple halogen elements can be included according to the target characteristics, or halogen elements can be selected with the aim of improving either mechanical strength based on stress absorption or mechanical strength based on reinforcement. Therefore, the battery of Technology 1, by including Al halides, can effectively improve its strength against external impacts, thermal shocks, and stresses caused by the expansion and contraction of the battery during charging and discharging or heating and cooling. Therefore, the battery of Technology 1 can improve mechanical strength and reliability.

[0163] 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 side layer containing Al halide can effectively suppress structural defects (i.e., cracks or peelings originating from the side) that are easily manifested by external shocks and heat-induced shocks and tend to originate from the side of the battery, thus improving the reliability of the battery.

[0164] (Technology 2) According to the battery of technology 1, the electrolyte layer is a solid electrolyte layer.

[0165] This configuration enables the provision of all-solid-state batteries with improved reliability.

[0166] (Technology 3) According to the battery of technology 2, the solid electrolyte layer comprises a halide solid electrolyte.

[0167] According to this configuration, the thermal expansion characteristics of the halide solid electrolyte and the Al halide contained in the solid electrolyte layer are easily matched because they are halides. Therefore, the interface between the Al halide and the solid halide electrolyte becomes robust. This suppresses structural defects caused by delamination at the interface between the Al halide and the solid halide electrolyte due to thermal shock or cycling. In other words, according to the above configuration, the effectiveness of Al halide against thermal shock and cycling is further enhanced. Therefore, a battery with higher reliability can be obtained.

[0168] (Technology 4) According to the battery of technology 1, the electrolyte layer is composed of an electrolyte and a separator impregnated with the electrolyte.

[0169] Based on this configuration, a liquid battery with improved reliability can be provided.

[0170] (Technology 5) The battery according to any one of techniques 1 to 4, wherein the battery satisfies (I) and has 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 of the solid electrolyte particles, the coating layer comprising the Al halide.

[0171] 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.

[0172] (Technology 6) The battery according to any one of techniques 1 to 4, wherein the battery satisfies (I) and at least one of the first electrode layer, the second electrode layer and the electrolyte layer comprises solid electrolyte particles, wherein the Al halide is contained inside the solid electrolyte particles.

[0173] According to this configuration, the hardness of the solid electrolyte particles contained in the electrode layer and / or electrolyte layer, which are the power generation elements of the battery, can be adjusted according to the desired purpose. For example, making them softer to improve deformability, or making them harder to improve strength, etc. Therefore, the reliability of the power generation elements relative to 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 by selecting halogen elements in the Al halide material, or by combining multiple halogen elements. In addition, since the Al halide material is contained inside the solid electrolyte particles, the reduction in ionic conductivity between the solid electrolyte particles caused by the Al halide material is reduced.

[0174] (Technology 7) The battery according to any one of techniques 1 to 6, wherein the battery satisfies (I) and 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 of the active material particles, the coating layer comprising the Al halide.

[0175] This structure improves the adhesion and mechanical bonding between active material particles (i.e., anchoring effect). Therefore, the electrode layer's strength is enhanced relative to external stresses and thermal cycling, suppressing structural defects such as cracks in the electrode layer. Consequently, battery reliability can be further improved.

[0176] (Technology 8) In the battery according to any one of techniques 1 to 7, the Al halide is in particulate form.

[0177] This configuration allows for the easy inclusion of Al halide in the coating layer of solid electrolyte particles and active material particles, or within the solid electrolyte particles. Furthermore, for example, by using micronized Al halide material particles (e.g., particles with a particle size of 1 μm or less), the electrolyte layer or the coating layer such as the active material particles can be made thinner, thereby increasing the battery capacity.

[0178] (Technology 9) The battery according to any one of techniques 1 to 8, wherein the halogenated Al comprises AlF3.

[0179] 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 AlF3 particles. For example, by including AlF3, which is harder than the solid electrolyte, within the solid electrolyte particles, the solid electrolyte particles can be made harder. Furthermore, by including AlF3 in the coating layer of the solid electrolyte particles and / or active material particles, AlF3 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, AlF3 has excellent heat resistance (e.g., approximately 1000°C). Therefore, excellent reliability can be achieved even at high temperatures.

[0180] (Technology 10) According to the battery of technology 9, the AlF3 has an orthorhombic crystal structure.

[0181] Therefore, AlF3 with high heat resistance, for example, can be obtained that remains stable even at high temperatures around 400°C. Thus, batteries containing AlF3 exhibiting excellent mechanical strength and heat resistance can be obtained, resulting in batteries with superior reliability. It should be noted that the crystal system of AlF3 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.

[0182] (Technology 11) According to the battery of technology 10, the AlF3 is in particle form, and at least a portion of the surface of the AlF3 particles is coated with a coating layer containing a solid electrolyte.

[0183] According to this configuration, the solid electrolyte coated with AlF3 particles functions as a binder. Therefore, the bonding strength between AlF3 particles and between AlF3 particles and other particles (e.g., solid electrolyte particles and active material particles) is improved, further enhancing battery reliability. For example, by including AlF3 particles with this configuration in the solid electrolyte layer, the ionic conductivity of the solid electrolyte layer also becomes better.

[0184] (Technology 12) According to the battery of technology 9, the AlF3 comprises a first crystalline phase having an orthorhombic crystal structure and a second crystalline phase having a trigonal crystal structure.

[0185] Thus, AlF3 with relatively high heat resistance at temperatures of, for example, around 200°C to 400°C, and which is softer than AlF3 with an orthorhombic crystal structure, is obtained. Therefore, by including such AlF3 in the battery, the adhesion between solid electrolyte particles and active material particles at high temperatures can be improved. As a result, AlF3 can absorb the expansion, contraction, and heat generation of the active material caused by thermal cycling and charge-discharge cycling.

[0186] (Technology 13) According to the battery of technology 12, the AlF3 is in particle form, and in the surface region of the AlF3 particles, the content of the first crystalline phase is greater than the content of the second crystalline phase, and in the internal region of the AlF3 particles, the content of the second crystalline phase is greater than the content of the first crystalline phase.

[0187] According to this structure, AlF3 particles can achieve an anchoring effect from a hard surface even at high temperatures, and also possess deformability due to the softer interior of the particles. Therefore, it is easy to densify the solid electrolyte layer and / or electrode layer containing AlF3 particles, and the interparticle bonding between the solid electrolyte particles and the active material particles is also improved. Thus, a battery with further improved reliability can be obtained.

[0188] (Technology 14) According to the battery of technology 12 or 13, the AlF3 is in particle form, and at least a portion of the surface of the AlF3 particles is coated with a coating layer containing a solid electrolyte.

[0189] This improves the bonding between AlF3 and the solid electrolyte contained in the electrolyte layer or electrode layer. Consequently, it enhances the reliability of the solid electrolyte layer and electrode layer against thermal shock and external stress.

[0190] (Technology 15) According to the battery of technology 9, the halogenated Al comprises particle-shaped AlF3, wherein the AlF3 particles comprise: a first particle composed of AlF3 having an orthorhombic crystal structure; and a second particle comprising a first crystalline phase having an orthorhombic crystal structure and a second crystalline phase having a trigonal crystal structure.

[0191] Therefore, by controlling the mixing ratio of the first particle to the second particle, the heat resistance, mechanical strength, deformability, and density of AlF3 can be adjusted according to the application.

[0192] (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.

[0193] Therefore, the voids that are easily generated around larger second particles can be reduced by the highly deformable second crystalline phase, which can densify the electrolyte layer and electrode layer. As a result, the electrical characteristics and reliability of the battery are improved.

[0194] (Technology 17) According to the battery of technology 3, the halide solid electrolyte comprises Al.

[0195] 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 Al in both the Al halide and the halide solid electrolyte, the Al halide bonds firmly to the solid electrolyte, easily forming an integrated interface. Therefore, when Al halide is included in the solid electrolyte layer, the Al halide 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.

[0196] (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 (2). Li3AlX26…Equation (2) In the above composition formula (2), X2 is selected from at least one of the groups consisting of F, Cl, Br and I.

[0197] According to this composition, the solid electrolyte layer contains a solid electrolyte with high ionic conductivity, atmospheric stability, and heat resistance, for example, above 1 μS / cm, thus improving the ionic conductivity and reliability of the solid electrolyte layer. The crystalline phase represented by Li3AlX26 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.

[0198] (Technology 19) According to the battery of technology 18, the first halide solid electrolyte comprises a crystalline phase represented by the following compositional formula (3). Li3AlF6…Equation (3).

[0199] 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.

[0200] (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.

[0201] 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, or improving the ionic conductivity.

[0202] (Technology 21) According to the battery of technology 20, the second halide solid electrolyte has a lower melting point than the first halide solid electrolyte.

[0203] Therefore, during the manufacturing of the solid electrolyte layer (e.g., during pressurization for lamination), the second halide solid electrolyte, due to its lower melting point and more flexible properties, easily deforms and fills the voids between the first halide solid electrolytes. This facilitates densification of the solid electrolyte layer. It should be noted that the second halide solid electrolyte, with its lower melting point, particularly increases deformability during commonly used heat pressing. Through densification, the ionic conductivity in the solid electrolyte layer is improved, and structural defects (such as voids and cracks) are suppressed. The reduction of fine voids and cracks, which are the starting point for significant performance degradation due to external stress and thermal cycling, results in a highly reliable solid electrolyte layer. Therefore, a battery with excellent performance and high reliability can be achieved.

[0204] (Technology 22) According to the battery of technology 20 or 21, the second halide solid electrolyte is more flexible than the first halide solid electrolyte.

[0205] Therefore, during the manufacturing of the solid electrolyte layer (e.g., under pressure for lamination), the second halide solid electrolyte, with its more flexible properties, easily deforms and fills the voids between the first halide solid electrolytes. This facilitates densification of the solid electrolyte layer. Densification improves the ionic conductivity of the solid electrolyte layer and suppresses structural defects (e.g., voids and cracks). The reduction of fine voids and cracks, which are the starting points for significant performance degradation due to external stress and thermal cycling, results in a highly reliable solid electrolyte layer. Thus, a battery with excellent performance and high reliability can be achieved. It should be noted that the softness comparison between the second halide solid electrolyte and the first halide solid electrolyte can be evaluated using methods such as micro-Vickers hardness.

[0206] (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 (4), Li2MF6…(4) In the above composition formula (4), M is at least one element selected from the group consisting of metallic and semi-metallic elements with a valence of 4.

[0207] Therefore, a second halide solid electrolyte, which is softer than the first halide solid electrolyte, can be used. This facilitates the densification of the solid electrolyte layer. Consequently, the ionic conductivity in the solid electrolyte layer is improved, and structural defects (such as voids and cracks) are suppressed. The reduction of fine voids and cracks, which are the starting points for significant performance degradation due to external stress and thermal cycling, results in a highly reliable solid electrolyte layer. Therefore, a battery with excellent performance and high reliability can be achieved.

[0208] (Technology 24) According to the battery of technology 23, wherein the M comprises Ti.

[0209] 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.

[0210] 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.

[0211] Furthermore, the above-described embodiments can be modified, substituted, added, omitted, etc., within the scope of the claims or their equivalents. Industrial applicability

[0212] 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, a second electrode layer, and an electrolyte layer disposed between the first electrode layer and the second electrode layer, the battery satisfying at least one selected from the group consisting of (I) and (II): (I) at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer contains halogenated Al; (II) the battery further comprises a side layer containing halogenated Al disposed on a side of at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer, the halogenated Al is represented by the following composition formula (1), in the composition formula (1), X1 is at least one selected from the group consisting of F, Cl, Br, and I, and a satisfies 2.95 ≤ a ≤ 3.

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 is composed of an electrolyte solution and a separator impregnated with the electrolyte solution.

5. The battery according to claim 1, wherein the battery satisfies the (I), at least one selected from the group consisting of the first electrode layer, the second electrode layer, and the electrolyte layer contains solid electrolyte particles and a coating layer that coats at least a part of a surface of the solid electrolyte particles, and the coating layer contains the halogenated Al.

6. The battery according to claim 1, wherein the battery satisfies the (I), at least one selected from the group consisting of the first electrode layer and the second electrode layer contains active material particles and a coating layer that coats at least a part of a surface of the active material particles, and the coating layer contains the halogenated Al.

7. The battery according to claim 1, wherein the halogenated Al is in a particulate form.

8. The battery according to claim 1, wherein the halogenated Al contains AlF3. AlX1 α … formula (1) 9. The battery according to claim 8, wherein the AlF3 has a crystal structure of an orthorhombic system.

2. The battery of claim 1, wherein, 10. The battery according to claim 8, wherein the AlF3 is in a particulate form, at least a part of a surface of a particle of the AlF3 is coated with a coating layer containing a solid electrolyte.

3. The battery of claim 2, wherein, 11. The battery according to claim 8, wherein the AlF3 contains a first crystal phase having a crystal structure of an orthorhombic system and a second crystal phase having a crystal structure of a trigonal system.

4. The battery of claim 1, wherein, 12. The battery according to claim 8, wherein the AlF3 is in a particulate form, in a surface region of a particle of the AlF3, a content of the first crystal phase is more than a content of the second crystal phase, and in an inner region of the particle of the AlF3, a content of the second crystal phase is more than a content of the first crystal phase.

5. The battery of claim 1, wherein, 13. The battery according to claim 8, wherein the AlF3 is in a particulate form, at least a part of a surface of a particle of the AlF3 is coated with a coating layer containing a solid electrolyte.

14. The battery according to claim 8, wherein the halogenated Al contains particulate AlF3, a particle of the AlF3 contains a first particle composed of AlF3 having a crystal structure of an orthorhombic system, and a second particle containing a first crystal phase having a crystal structure of an orthorhombic system and a second crystal phase having a crystal structure of a trigonal system.

15. The battery according to claim 14, wherein an average particle diameter of the second particle is larger than an average particle diameter of the first particle.

6. The battery of claim 1, wherein, 16. The battery according to claim 1, wherein the halide solid electrolyte contains Al. ​ ​ 7. The battery of claim 1, wherein, ​ ​ ​ 8. The battery of claim 1, wherein, ​ 9. The battery of claim 1, wherein, ​ 10. The battery of claim 9, wherein, ​ 11. The battery of claim 10, wherein, ​ ​ 12. The battery of claim 9, wherein, ​ 13. The battery of claim 12, wherein, ​ ​ ​ 14. The battery of claim 12, wherein, ​ ​ 15. The battery of claim 9, wherein, ​ ​ 16. The battery of claim 15, wherein, ​ 17. The battery of claim 3, wherein, ​ 18. The battery of claim 17, wherein, The halide solid electrolyte includes a first halide solid electrolyte including a crystal phase represented by a composition formula (2) consisting of Li3AlX26… Formula (2) In the composition formula (2), the X2 is at least one selected from the group consisting of F, Cl, Br, and I.

19. The battery of claim 18, wherein, The first halide solid electrolyte includes a crystal phase represented by a composition formula (3) consisting of Li3AlF6… Formula (3).

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

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

23. The battery of claim 20, wherein, The second halide solid electrolyte includes a crystal phase represented by a composition formula (4) consisting of Li2MF6… (4) In the composition formula (4), the M is at least one element selected from the group consisting of metal elements and semi-metal elements, having a valence number of 4.

24. The battery of claim 23, wherein, The M includes Ti.

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