battery

Abstract

A battery (50) includes an electrode layer (10), an opposite electrode layer (20) disposed opposite the electrode layer, and a solid electrolyte layer (30) between the electrode layer and the opposite electrode layer. The electrode layer includes a current collector (11), an electrode active material layer (12) between the current collector and the solid electrolyte layer, and an insulating layer (13) between the current collector and the solid electrolyte layer at an end of the electrode layer and joined to the current collector. The electrode active material layer has a region (12a) that does not overlap the insulating layer in plan view. The battery has a gap (14) between the current collector and the solid electrolyte layer and in contact with the insulating layer.

Description

Technical Field

[0001] This disclosure relates to batteries. Background Technology

[0002] Patent Document 1 and Patent Document 2 disclose batteries with insulating components.

[0003] Prior art literature

[0004] Patent Document 1: International Publication No. 2012 / 164642

[0005] Patent Document 2: Japanese Patent Application Publication No. 2016-207286 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the prior art, there is a pursuit of improving battery reliability. Therefore, the object of this disclosure is to provide a battery with high reliability.

[0008] Methods for solving problems

[0009] One technical solution disclosed herein relates to a battery comprising an electrode layer, a counter electrode layer disposed opposite to the electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer. The electrode layer has a current collector, an electrode active material layer, and an insulating layer. The electrode active material layer is located between the current collector and the solid electrolyte layer. The insulating layer is located at the end of the electrode layer between the current collector and the solid electrolyte layer and is bonded to the current collector. The electrode active material layer has a region that does not overlap with the insulating layer when viewed from above. The battery has a gap located between the current collector and the solid electrolyte layer and in contact with the insulating layer.

[0010] The effects of the invention

[0011] According to this disclosure, a highly reliable battery can be provided. Attached Figure Description

[0012] Figure 1 This is a schematic top view showing an example of the battery involved in Embodiment 1.

[0013] Figure 2 It means Figure 1 A diagram of the cross section at the location shown by line II-II.

[0014] Figure 3 This is a schematic cross-sectional view showing an example of a battery involved in the comparative example.

[0015] Figure 4 This is a schematic cross-sectional view showing another example of the battery involved in the comparative example.

[0016] Figure 5 This is a schematic cross-sectional view showing an example of a battery involved in a variation of Embodiment 1.

[0017] Figure 6 This is a schematic cross-sectional view showing an example of a battery involved in a variation 2 of embodiment 1.

[0018] Figure 7 This is a schematic cross-sectional view showing an example of a battery involved in variation 3 of embodiment 1.

[0019] Figure 8 This is a schematic cross-sectional view showing an example of a battery involved in variation 4 of embodiment 1.

[0020] Figure 9 This is a flowchart illustrating the battery manufacturing method according to Embodiment 1.

[0021] Figure 10A These are schematic top views and schematic cross-sectional views illustrating an example of a current collector with a stacked insulating layer according to Embodiment 1.

[0022] Figure 10B This is a schematic top view showing another example of a current collector with stacked insulating layers according to Embodiment 1.

[0023] Figure 10C These are schematic top views and schematic cross-sectional views illustrating another example of a current collector with stacked insulating layers according to Embodiment 1.

[0024] Figure 11A This is a diagram illustrating an example of the method for forming a void according to Embodiment 1.

[0025] Figure 11B This is a diagram illustrating another example of the method for forming voids according to Embodiment 1.

[0026] Figure 12A This is a schematic cross-sectional view showing an example of the laminated electrode plate according to Embodiment 1.

[0027] Figure 12B This is a schematic cross-sectional view showing another example of the laminated electrode plate involved in Embodiment 1.

[0028] Figure 12C This is a schematic cross-sectional view showing another example of the laminated electrode plate involved in Embodiment 1.

[0029] Figure 13 This is a diagram illustrating the cutting process in the battery manufacturing method according to Embodiment 1.

[0030] Figure 14This is a schematic cross-sectional view showing an example of the battery involved in Embodiment 2. Detailed Implementation

[0031] (The insights that form the basis of this disclosure)

[0032] In manufacturing all-solid-state batteries and similar batteries that include a solid electrolyte layer containing a solid electrolyte, the area of ​​the negative electrode active material layer is typically larger than that of the positive electrode active material layer. The purpose is to suppress metal deposition from metal ions that have not entered the negative electrode active material layer by making the capacity of the negative electrode active material layer greater than that of the positive electrode active material layer, thereby stabilizing battery performance and improving battery reliability. Furthermore, it aims to suppress dendrite growth (metal deposition) at the ends of the negative electrode active material layer by suppressing the concentration of the electric field thereto, thus improving battery reliability. Additionally, by increasing the area of ​​the negative electrode active material layer, a solid electrolyte layer is disposed, for example, around the relatively arranged positive electrode active material layer. This surrounds the positive electrode active material layer, which expands and contracts during charging and discharging, with the solid electrolyte layer, preventing delamination of the positive electrode active material layer from other layers, thereby improving reliability.

[0033] However, manufacturing batteries with such precise control over the areas of the positive and negative active material layers is difficult. Furthermore, to ensure reliability, the dimensional accuracy of the positive active material layer during formation must be considered. Therefore, a smaller positive active material layer leads to a decrease in the battery's volumetric energy density. Additionally, there are concerns that increasing the dimensional accuracy of the positive active material layer would increase the number of inspection processes and equipment costs.

[0034] Therefore, this disclosure provides a battery with high reliability. In particular, this disclosure provides a battery with improved energy density and high reliability.

[0035] The following is a summary of a technical solution disclosed herein.

[0036] One technical solution disclosed herein relates to a battery comprising an electrode layer, a counter electrode layer disposed opposite to the electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer. The electrode layer has a current collector, an electrode active material layer, and an insulating layer. The electrode active material layer is located between the current collector and the solid electrolyte layer. The insulating layer is located at the end of the electrode layer between the current collector and the solid electrolyte layer and is bonded to the current collector. The electrode active material layer has a region that does not overlap with the insulating layer when viewed from above. The battery has a gap located between the current collector and the solid electrolyte layer and in contact with the insulating layer.

[0037] Therefore, although the electrode active material layer of the battery expands and contracts during charging and discharging, the positive electrode active material layer and the gaps located between the current collector and the solid electrolyte layer can mitigate the stress caused by the expansion and contraction of the electrode active material layer during charging and discharging. Thus, interlayer delamination between the electrode active material layer and other components is less likely to occur, thereby improving battery reliability.

[0038] Furthermore, by having an insulating layer bonded to the current collector, regions with different properties are formed on the current collector. Therefore, by utilizing the differences in properties, it is possible to easily manufacture a battery with gaps formed in contact with the insulating layer.

[0039] Alternatively, for example, it can be configured such that the side surface of the insulating layer and the side surface of the current collector are the same.

[0040] Therefore, since the side of the insulating layer and the side of the current collector are on the same side, the area of ​​the insulating layer can be easily adjusted to manufacture the battery by cutting the current collector with the insulating layer stacked on it. Thus, although the presence of the insulating layer and the gaps in contact with it creates areas where the electrode active material layer cannot function as an electrode, these areas can be minimized by adjusting the area of ​​the insulating layer. This allows for an increase in the volumetric energy density of the battery.

[0041] Alternatively, for example, it can be configured such that the electrode layer is a positive electrode layer and the counter electrode layer is a negative electrode layer.

[0042] Therefore, through the insulating layer and the gaps in contact with it, the area of ​​the positive electrode active material layer—the layer where electrons from the current collector can easily reach—is reduced. As a result, the actual area of ​​the positive electrode active material layer is smaller compared to the area of ​​the negative electrode active material layer. Therefore, since the capacity of the negative electrode active material layer is larger than that of the positive electrode active material layer, the deposition of metal from metal ions that have not entered the negative electrode active material layer can be suppressed, further improving the reliability of the battery.

[0043] Furthermore, even without gaps, electrons cannot directly reach the electrode active material layer (i.e., the positive electrode active material layer) in the region overlapping the insulating layer when viewed from above, thus making it difficult for the positive electrode active material layer in this region to function as an electrode. Therefore, while this effectively reduces the area of ​​the positive electrode active material layer, the presence of gaps connecting it to the insulating layer further suppresses electrons from winding around between the insulating layer and the solid electrolyte layer. Consequently, the impact of electron winding is reduced, allowing for a more accurate matching of the capacity ratio between the negative and positive electrode active material layers.

[0044] Alternatively, for example, it can be configured such that the void is also in contact with the solid electrolyte layer.

[0045] Therefore, since the voids are in contact with both the insulating layer and the solid electrolyte layer, they are formed across the space between them. Consequently, the voids also facilitate the mitigation of stress originating from the solid electrolyte layer side.

[0046] Furthermore, by creating a gap between the insulating layer and the solid electrolyte layer, electrons from the current collector can be prevented from moving between the insulating layer and the solid electrolyte layer, and, when viewed from above, into the gap and the area outside the gap. This allows for a reduction in the area of ​​the electrode active material layer, which functions as an electrode, and a more accurate matching of the capacity ratio between the negative and positive electrode active material layers.

[0047] Alternatively, for example, the gap can be configured such that, when viewed from above, it overlaps with the inner end of the interface between the insulating layer and the current collector.

[0048] Therefore, when a gap is formed across the insulating layer and the solid electrolyte layer, the gap is formed at a position that prevents electrons from the current collector from moving to the outer region of the inner end of the interface between the insulating layer and the solid electrolyte layer. Thus, the area of ​​the electrode active material layer, which functions as an electrode, can be reduced in proportion to the area of ​​the insulating layer.

[0049] Alternatively, for example, the gap can be positioned between the insulating layer and the solid electrolyte layer, and between the insulating layer and the electrode active material layer, with the electrode active material layer not in contact with the insulating layer.

[0050] As a result, the gaps inside the battery become larger, which can further mitigate the stress caused by the expansion and contraction of the electrode active material layer during charging and discharging.

[0051] Alternatively, for example, the insulating layer may be configured to contain resin.

[0052] Therefore, the anchoring effect of the resin contained in the insulating layer entering the current collector can improve the bonding between the insulating layer and the current collector and suppress the peeling of the insulating layer and the current collector.

[0053] Alternatively, for example, the insulating layer may be configured to contain inorganic fillers.

[0054] Therefore, because the insulating layer hardens, it is difficult for the insulating layer to deform when it is stacked with other layers during battery manufacturing, thus forming an insulating layer of uniform thickness.

[0055] Alternatively, for example, it can be set that the coefficient of linear expansion of the insulating layer is greater than that of the electrode active material layer.

[0056] Therefore, by heating the electrode active material layer stacked on top of the insulating layer, the electrode active material layer, being less prone to expansion than the insulating layer, breaks off at the points where it contacts the insulating layer, creating voids. Thus, it is possible to easily manufacture batteries with voids forming at the points where they contact the insulating layer.

[0057] Alternatively, for example, the insulating layer can be positioned in a region where, when viewed from above, the distance between the insulating layer and the outer periphery of the current collector is less than 1 mm.

[0058] Therefore, by having an insulating layer and gaps in contact with the insulating layer, the area where the electrode active material layer is difficult to function as an electrode can be made to be a range below a certain distance from the outer periphery of the current collector, thereby increasing the volumetric energy density of the battery.

[0059] Alternatively, for example, the thickness of the insulating layer can be set to be more than 50% and less than 100% of the thickness of the electrode active material layer.

[0060] Therefore, because the space between the solid electrolyte layer and the insulating layer is narrowed, it is easier to form voids between them. Furthermore, for example, when forming the electrode active material layer using a wet coating method, because the amount of slurry coated on the insulating layer is reduced, voids are more easily formed by utilizing the surface tension of the insulating layer to repel the slurry and thus create voids.

[0061] Alternatively, for example, it can be configured such that the side surface of the electrode layer, the side surface of the counter electrode layer, and the side surface of the solid electrolyte layer are the same.

[0062] Therefore, by cutting each layer together, the sides of each layer can be made to be the same, thus making it easy to adjust the area of ​​the insulating layer to manufacture the battery.

[0063] Alternatively, for example, it can be set that the side of the battery is a cut surface.

[0064] Therefore, by cutting off the side of the battery end, the area of ​​the insulating layer can be reduced by adjusting the area of ​​the cutting position, thus reducing the area of ​​the region where the electrode active material layer cannot function as an electrode due to the presence of the insulating layer and the gaps in contact with it, thereby improving the volumetric energy density of the battery. Furthermore, by making the side of the battery a cut surface, it is easy to make the side of the electrode layer, the side of the counter electrode layer, and the side of the solid electrolyte layer the same surface.

[0065] Alternatively, for example, the insulating layer can be configured such that it is frame-shaped when viewed from above and is disposed on the outer periphery of the electrode layer.

[0066] Therefore, a gap can be provided at any position on the outer periphery of the electrode layer to connect with the insulating layer.

[0067] Alternatively, for example, the solid electrolyte layer can be configured to contain a solid electrolyte with lithium-ion conductivity.

[0068] Therefore, the reliability of lithium-ion batteries containing solid electrolytes can be improved.

[0069] The embodiments will now be described in detail with reference to the accompanying drawings.

[0070] Furthermore, the embodiments described below are general or specific examples. The values, shapes, materials, constituent elements, arrangement positions of constituent elements, and connection methods shown in the following embodiments are merely examples and do not limit this disclosure.

[0071] Furthermore, in this specification, terms such as parallel and same surface that indicate the relationship between elements, and terms such as flat and rectangular that indicate the shape of elements, as well as numerical ranges, do not only indicate strict expressions, but also indicate substantially equal ranges, such as expressions of differences of a few percent or so.

[0072] Furthermore, the figures may not be strictly illustrated. In each figure, substantially identical structures are labeled with the same reference numerals, and repetitive descriptions are omitted or simplified.

[0073] 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 each embodiment, the z-axis direction is used as the stacking direction of the battery. Furthermore, the positive direction of the z-axis is defined as upward along the z-axis, and the negative direction is defined as downward along the z-axis. In this specification, "top view" refers to viewing the battery along the z-axis. Additionally, "thickness" in this specification refers to the length of each layer along its stacking direction.

[0074] Furthermore, in this specification, the terms "above" and "below" in the context of battery structure do not refer to the absolute spatial directions of upward (vertical above) and downward (vertical below), but rather are used as terms defining relative positional relationships based on the stacking order in a layered structure. Moreover, the terms "above" and "below" apply not only to situations where two components are spaced apart and other components exist between them, but also to situations where two components are closely fitted together and connected.

[0075] In addition, in this specification, "inner" and "outer" in terms of "inner side" and "outer side" refer to the inner and outer sides when viewing the battery along the stacking direction. That is, the central side of each layer is the inner side, and the outer periphery of each layer is the outer side.

[0076] (Implementation Method 1)

[0077] The battery according to Embodiment 1 will be described below. The battery according to Embodiment 1 is a single cell that includes an electrode active material layer and a counter electrode active material layer.

[0078] [structure]

[0079] First, the structure of the battery according to Embodiment 1 will be described with reference to the accompanying drawings. Figure 1 This is a schematic top view showing an example of a battery involved in this embodiment. Figure 2 It means Figure 1 A diagram showing an example of a cross-section at the location indicated by line II-II.

[0080] like Figure 1 and Figure 2 As shown, the battery 50 according to this embodiment includes an electrode layer 10, a counter electrode layer 20 disposed opposite to the electrode layer 10, and a solid electrolyte layer 30 located between the electrode layer 10 and the counter electrode layer 20. That is, the battery 50 has a structure in which the electrode layer 10, the solid electrolyte layer 30 and the counter electrode layer 20 are stacked in sequence.

[0081] The electrode layer 10 has a current collector 11, an electrode active material layer 12 located between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 located at the end of the electrode layer 10 between the current collector 11 and the solid electrolyte layer 30 and bonded to the current collector 11 when viewed from above. The electrode active material layer 12 is composed of electrode active material layers 12a and 12b separated by a gap 14 described later. In the illustrated example, the insulating layer 13 is bonded to the current collector 11, but it may also be bonded to the current collector 11 via an adhesive layer or the like.

[0082] The counter electrode layer 20 has a current collector 21 and a counter electrode active material layer 22 located between the current collector 21 and the solid electrolyte layer 30.

[0083] In addition, the battery 50 has a gap 14 located between the current collector 11 and the solid electrolyte layer 30 and in contact with the insulating layer 13. That is, the battery 50 has a gap 14 located between the current collector 11 and the solid electrolyte layer 30, exposing the insulating layer 13.

[0084] Battery 50 is, for example, an all-solid-state battery. The side surfaces of battery 50 are parallel to the stacking direction. Furthermore, the side surfaces of battery 50 are flat planes. In other words, the side surfaces of electrode layer 10, counter electrode layer 20, and solid electrolyte layer 30 are on the same flat plane without any step difference. That is, the side surfaces of electrode layer 10, counter electrode layer 20, and solid electrolyte layer 30 are the same surface. Additionally, "side surface" refers to the surface extending from the end of the main surface in a direction intersecting the main surface, when the plane perpendicular to the stacking direction is designated as the main surface. Furthermore, at the end of electrode layer 10 in the direction perpendicular to the stacking direction, the side surfaces of insulating layer 13, electrode active material layer 12b, and current collector 11 are the same surface. Furthermore, at the end of counter electrode layer 20 in the direction perpendicular to the stacking direction, the side surfaces of counter electrode active material layer 22 and current collector 21 are the same surface. In other words, at the end of the battery 50 in the direction perpendicular to the stacking direction, the side surfaces of the current collector 11, insulating layer 13, electrode active material layer 12b, solid electrolyte layer 30, counter electrode active material layer 22, and current collector 21 are all the same surface, forming a flat plane. Therefore, by cutting each layer together, the side surfaces of each layer can be made to be the same surface, allowing for easy adjustment of the areas of the insulating layer 13 and electrode active material layer 12b to manufacture the battery 50.

[0085] The side surface of the battery 50 is, for example, a cut surface. Specifically, the side surface of the battery 50 is a surface formed by cutting with a cutting edge such as a knife, and for example, a surface with tiny grooves or other cutting marks. In this way, by forming a cut surface on the battery 50, the positions of the insulating layer 13 and the electrode active material layer 12b can be adjusted, thereby reducing the area of ​​the part that does not contribute to the charge and discharge performance of the battery 50 (specifically, the part where the electrode active material layer 12b and the void 14 are located when viewed from above, as detailed later), and improving the volumetric energy density. In addition, since it is a cut surface, it is easy to make the side surface of the electrode layer 10, the side surface of the counter electrode layer 20, and the side surface of the solid electrolyte layer 30 the same surface. Furthermore, the cutting marks can also be smoothed by grinding or the like. There is no limitation on the shape of the cut surface, but in the case of the battery 50, it is rectangular.

[0086] In addition, the top view shape of the current collector 11, the electrode active material layer 12a, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 is rectangular, but not particularly limited, and can also be circular, elliptical, or polygonal, etc.

[0087] The current collector 11 is in contact with and covers the lower surfaces of the electrode active material layer 12 (specifically, electrode active material layer 12a) and the insulating layer 13. In a top view, the insulating layer 13 is stacked at the end of the current collector 11, and the gap 14 is in contact with the insulating layer 13. The thickness of the current collector 11 is, for example, 5 μm or more and 100 μm or less.

[0088] As the material for the current collector 11, known materials can be used. For example, the current collector 11 can be a foil, plate, or mesh made of copper, aluminum, nickel, iron, stainless steel, platinum or gold, or alloys of two or more of them.

[0089] The upper surfaces of electrode active material layers 12a and 12b are in contact with the solid electrolyte layer 30. Electrode active material layers 12a and 12b are opposite to the counter electrode active material layer 22, sandwiching the solid electrolyte layer 30. The lower surface of electrode active material layer 12a is in contact with the current collector 11. Electrode active material layer 12b, viewed from above, is frame-shaped and surrounds electrode active material layer 12a. Electrode active material layer 12b is stacked above the current collector 11, covering the insulating layer 13 on the current collector 11. Electrode active material layer 12 has a region that does not overlap with the insulating layer 13 when viewed from above. Specifically, when viewed from above, electrode active material layer 12a does not overlap with the insulating layer 13, while electrode active material layer 12b overlaps with the insulating layer 13. The thickness of electrode active material layer 12a is, for example, 5 μm or more and 300 μm or less. The material used for electrode active material layer 12 will be described later.

[0090] In addition, the electrode active material layer 12a and the electrode active material layer 12b are completely separated without contact, but they can also be partially connected.

[0091] As described above, the insulating layer 13 is in contact with the gap 14 and is located between the current collector 11 and the solid electrolyte layer 30. The upper surface of the insulating layer 13 is in contact with the electrode active material layer 12b and the gap 14, and the inner side of the insulating layer 13, when viewed from above, is in contact with the electrode active material layer 12a. When viewed from above, the insulating layer 13 is in contact with the electrode active material layer 12b at the end of the electrode layer 10. The side surface of the insulating layer 13 and the side surface of the current collector 11 are the same. In addition, the side surface of the insulating layer 13 and the side surface of the electrode active material layer 12 (specifically, the electrode active material layer 12b) are the same. The lower surface of the insulating layer 13 is in contact with the current collector 11. In addition, when viewed from above, the insulating layer 13 overlaps with the counter electrode active material layer 22.

[0092] In the illustrated example, the insulating layer 13 appears as a frame when viewed from above and is located on the outer periphery of the electrode layer 10. That is, the insulating layer 13 is located between the current collector 11 and the solid electrolyte layer 30 at all ends of the electrode layer 10 in a direction perpendicular to the stacking direction.

[0093] The insulating layer 13 may contain at least one of a resin and an inorganic filler. Examples of resins include silicone resin, epoxy resin, acrylic resin, or polyimide resin. The resin may be a thermosetting resin or a UV-curable resin. By including the resin in the insulating layer 13, the bonding strength between the insulating layer 13 and the current collector 11 can be improved by utilizing the anchoring effect of the resin within the current collector 11. Furthermore, by adjusting the surface tension of the resin, for example, when forming the electrode active material layer using a wet coating method, an insulating layer 13 with a surface tension that repels the slurry containing the electrode active material can be formed, making it easier to form voids 14. Examples of inorganic fillers include particles of metal oxides such as silicon dioxide, titanium dioxide, aluminum oxide, or aluminum nitride. By including the inorganic filler in the insulating layer 13, the insulating layer 13 becomes harder, making it less prone to deformation when laminated with other layers, thus enabling the formation of an insulating layer 13 of uniform thickness. Furthermore, by selecting a material with a coefficient of linear expansion greater than that of the electrode active material layer 12, it is easy to form voids 14 through heat treatment or the like as the material for the insulating layer 13. Details regarding the method for forming voids 14 will be described later.

[0094] The thickness of the insulating layer 13 is less than or equal to the thickness of the electrode active material layer 12a in the electrode active material layer 12. For example, the thickness of the insulating layer 13 is 50% or more and 100% or less of the thickness of the electrode active material layer 12a. Alternatively, the thickness of the insulating layer 13 may be 50% or more and less than 100% of the thickness of the electrode active material layer 12a. Therefore, for example, when forming the electrode active material layer 12 using a wet coating method, although slurry is applied to both the current collector 11 and the insulating layer 13, the amount of slurry applied to the insulating layer 13 is reduced. Consequently, when voids 14 are formed by repelling the slurry due to the surface tension of the insulating layer 13, voids 14 are easily formed. Furthermore, when voids 14 are formed using the difference in the coefficients of linear expansion between the insulating layer 13 and the electrode active material layer 12, voids 14 are easily formed because the electrode active material layer 12 on the insulating layer 13 is thin.

[0095] The insulating layer 13 may be completely insulating, but depending on the required battery characteristics, it may also be slightly conductive through the constituent materials and thickness of the insulating layer 13.

[0096] Furthermore, from the viewpoint of the effective area contributing to power generation, i.e., the volumetric energy density, the insulating layer 13 is, for example, located in a region where, when viewed from above, the distance from the outer periphery of the current collector 11 is 1 mm or less. Also, from the viewpoint of volumetric energy density, when the insulating layer 13 is formed in a frame shape or a line shape, the width of the insulating layer 13 is, for example, 1 mm or less, 0.5 mm or less, or 0.1 mm or less. The width of the insulating layer 13 varies, for example, depending on the required battery characteristics.

[0097] The gap 14 is located between the current collector 11 and the solid electrolyte layer 30. Additionally, the gap 14 is located between the insulating layer 13 and the solid electrolyte layer 30, and is in contact with the insulating layer 13. Specifically, the gap 14 is in contact with the upper surface of the insulating layer 13. Furthermore, the gap 14 is also in contact with the solid electrolyte layer 30. The gap 14, located between the insulating layer 13 and the solid electrolyte layer 30, exposes both the insulating layer 13 and the solid electrolyte layer 30. Therefore, the gap 14 divides the electrode active material layer 12 into electrode active material layer 12a and electrode active material layer 12b. That is, the gap 14 is located between electrode active material layer 12a and electrode active material layer 12b. Thus, the presence of the gap 14 prevents electricity from winding into the electrode active material layer 12b. Therefore, the electrode active material layer 12b located above the insulating layer 13 does not contribute to the charge / discharge performance, allowing for a more accurate matching of the capacity ratio between the electrode active material layer 12 and the counter electrode active material layer 22.

[0098] Furthermore, when viewed from above, the gap 14 overlaps with the inner end 13b of the interface 13a between the insulating layer 13 and the current collector 11. Thus, the gap 14 is formed at a position that prevents electrons from the current collector 11 from moving between the insulating layer 13 and the solid electrolyte layer 30, and towards the outer region of the inner end 13b of the interface 13a between the insulating layer 13 and the current collector 11. Therefore, the area of ​​the electrode active material layer 12, which functions as an electrode, can be reduced in proportion to the area of ​​the insulating layer 13.

[0099] Furthermore, the gap 14 is provided along the length of the insulating layer 13 when viewed from above. Therefore, the gap 14 is frame-shaped when viewed from above, and is formed along the circumference of the frame-shaped insulating layer 13. Specifically, the gap 14 is formed along the inner circumference of the frame-shaped insulating layer 13 when viewed from above, at a position overlapping with the insulating layer 13. The gap 14 is not formed on the inner side of the insulating layer 13 when viewed from above. As a result, the outer side of the region 1B (details to be described later), where the electrode active material layer 12 does not function as a battery, is the same as the region where the insulating layer 13 is formed. Therefore, the region where it does not function as a battery does not expand beyond the region where the insulating layer 13 is formed, which can improve the volumetric energy density of the battery 50.

[0100] Furthermore, from the viewpoint of suppressing the decrease in volumetric energy density, the gap 14 is located, for example, in a region where the distance between the gap 14 and the outer periphery of the current collector 11 is less than 1.5 mm when viewed from above. The gap 14 can be located in a region where the distance between the gap 14 and the outer periphery of the current collector 11 is less than 1 mm when viewed from above, or it can be located in a region where the distance between the gap 14 and the outer periphery of the current collector 11 is less than 0.5 mm.

[0101] The current collector 21 is in contact with and covers the upper surface of the counter electrode active material layer 22. The thickness of the current collector 21 is, for example, 5 μm or more and 100 μm or less. The material of the current collector 11 described above can be used as the material of the current collector 21.

[0102] The counter electrode active material layer 22 is stacked on the solid electrolyte layer 30, and is disposed opposite to the electrode active material layers 12 (specifically, electrode active material layers 12a and 12b). The upper surface of the counter electrode active material layer 22 is in contact with the current collector 21. The thickness of the counter electrode active material layer 22 is, for example, 5 μm or more and 300 μm or less. The materials used in the counter electrode active material layer 22 will be described later.

[0103] The solid electrolyte layer 30 is located between the electrode active material layer 12 and the counter electrode active material layer 22. The thickness of the solid electrolyte layer 30 is, for example, 5 μm or more and 150 μm or less.

[0104] The solid electrolyte layer 30 contains at least a solid electrolyte and may also contain a binder material if necessary. The solid electrolyte layer 30 may contain a solid electrolyte that is lithium-ion conductive.

[0105] As a solid electrolyte, known materials that conduct metal ions, such as lithium-ion conductors, sodium-ion conductors, or magnesium-ion conductors, can be used. Solid electrolyte materials used include, for example, sulfide solid electrolytes, halogen-based solid electrolytes, or oxide solid electrolytes. As a sulfide solid electrolyte, when using materials capable of conducting lithium ions, a composite composed of lithium sulfide (Li₂S) and phosphorus pentasulfide (P₂S₅) can be used, for example. Furthermore, as a sulfide solid electrolyte, sulfides such as Li₂S-SiS₂, Li₂S-B₂S₃, or Li₂S-GeS₂ can be used, or sulfides obtained by adding at least one of Li₃N, LiCl, LiBr, Li₃PO₄, and Li₄SiO₄ as additives to the above sulfides can also be used.

[0106] As an oxide solid electrolyte, when using materials capable of conducting lithium ions, for example, Li7La3Zr2O can be used. 12 (LLZ), Li 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP) or (La,Li)TiO3(LLTO), etc.

[0107] As an adhesive material, elastomers can be used, or organic compounds such as polyvinylidene fluoride, acrylic resin or cellulose resin can be used.

[0108] In this embodiment, in the electrode layer 10 having an electrode active material layer 12 and the counter electrode layer 20 having a counter electrode active material layer 22, one is a positive electrode layer having a positive electrode active material layer and the other is a negative electrode layer having a negative electrode active material layer.

[0109] The positive electrode active material layer contains at least a positive electrode active material, and may also contain at least one of a solid electrolyte, a conductive additive, and a binder material, depending on the requirements.

[0110] As positive electrode active materials, known materials capable of adsorbing and releasing (inserting and desorbing, or dissolving and precipitating) lithium ions, sodium ions, or magnesium ions can be used. When using materials capable of desorbing and inserting lithium ions as positive electrode active materials, examples include lithium cobalt oxide composites (LCO), lithium nickel oxide composites (LNO), lithium manganese oxide composites (LMO), lithium-manganese-nickel composites (LMNO), lithium-manganese-cobalt composites (LMCO), lithium-nickel-cobalt composites (LNCO), or lithium-nickel-manganese-cobalt composites (LNMCO).

[0111] The aforementioned solid electrolyte materials can be used as solid electrolytes. Additionally, conductive materials such as acetylene black, carbon black, graphite, or carbon fiber can be used as conductive additives. Furthermore, the aforementioned adhesive materials can be used as binders.

[0112] The negative electrode active material layer contains at least a negative electrode active material, and may also contain at least one of the same solid electrolyte, conductive additives, and binder materials as the positive electrode active material layer, as needed.

[0113] As the negative electrode active material, known materials capable of adsorbing and releasing (inserting and desorbing, or dissolving and precipitating) lithium ions, sodium ions, or magnesium ions can be used. When using materials capable of desorbing and inserting lithium ions as the negative electrode active material, examples include carbon materials such as natural graphite, artificial graphite, graphite carbon fibers, or resin-calcined carbon, metallic lithium, lithium alloys, or oxides of lithium with transition metal elements.

[0114] In battery manufacturing, as mentioned above, to improve reliability, the area of ​​the negative electrode active material layer is typically larger than that of the positive electrode active material layer when viewed from above. Furthermore, by positioning the end of the negative electrode active material layer further outward than the end of the positive electrode active material layer, it is possible to suppress the concentration of the electric field at the end of the negative electrode active material layer, thereby suppressing dendrite growth (metal precipitation).

[0115] Here, we will describe batteries 950 and 950a, which are comparative examples in which the area of ​​the negative electrode active material layer is larger than the area of ​​the positive electrode active material layer when viewed from above. Figure 3 and Figure 4This is a schematic cross-sectional view showing an example of a battery involved in the comparative example.

[0116] like Figure 3 As shown, the battery 950 includes a positive electrode layer 910, a negative electrode layer 920, and a solid electrolyte layer 930 located between the positive electrode layer 910 and the negative electrode layer 920. The positive electrode layer 910 has a current collector 911 and a positive active material layer 912 located between the current collector 911 and the solid electrolyte layer 930. The negative electrode layer 920 has a current collector 921 and a negative active material layer 922 located between the current collector 921 and the solid electrolyte layer 930. The solid electrolyte layer 930 covers the sides of the positive active material layer 912 and the negative active material layer 922 and is in contact with the current collector 911 and the current collector 921. In the battery 950, when viewed from above, the area of ​​the negative active material layer 922 is larger than the area of ​​the positive active material layer 912, and the end of the negative active material layer 922 is located further outward than the end of the positive active material layer 912. Thus, in the battery 950, metal deposition is suppressed by making the area of ​​the negative electrode active material layer 922 larger than the area of ​​the positive electrode active material layer 912. Furthermore, since a solid electrolyte layer 930 is present at the end of the battery 950, exposure of the positive electrode active material layer 912 and the negative electrode active material layer 922 can be suppressed even if the current collectors 911 and 921 are peeled off from the end.

[0117] Region 2C, containing both positive electrode active material layer 912 and negative electrode active material layer 922, functions as a battery. Region 2A, lacking both positive and negative electrode active material layers 912 and 922, does not function as a battery. Similarly, region 2B, containing a negative electrode active material layer 922 but lacking a positive electrode active material layer 912, also does not function as a battery. Region 2B is the region whose area difference is comparable to that of the positive and negative electrode active material layers 912. Viewed from above, as regions 2B and 2A become wider, the proportion of regions in the battery 950 that do not contribute to power generation increases, leading to a decrease in the volumetric energy density of the battery 950. Conversely, as region 2B becomes narrower when viewed from above, the alignment precision required in manufacturing processes such as the layer stacking process increases, resulting in an increase in the number of inspection processes and equipment costs due to the increased precision requirements.

[0118] In other words, there is a problem that makes it difficult to manufacture the battery 950 easily. In addition, the region 2A, where the layer in the thickness direction is only the solid electrolyte layer 930, is a part that does not contribute to the basic charge and discharge performance of the battery. Therefore, from the viewpoint of improving volumetric energy density, it is preferable to have less of region 2A.

[0119] in addition, Figure 4The battery 950a shown includes: a positive electrode layer 910a having a current collector 911a and a positive electrode active material layer 912a; a negative electrode layer 920a having a current collector 921a and a negative electrode active material layer 922a; and a solid electrolyte layer 930a. The difference between battery 950a and battery 950 is that the solid electrolyte layer 930a does not cover the sides of the negative electrode active material layer 922a. While battery 950a does not have a region like region 2A where neither the positive electrode active material layer 912a nor the negative electrode active material layer 922a exists, it does have a region 3A where the positive electrode active material layer 912a is absent. Therefore, region 3A does not contribute to power generation, and the same problem as in region 2B occurs in region 3A of battery 950a.

[0120] On the other hand, as described above, the battery 50 includes an electrode layer 10, a counter electrode layer 20 disposed opposite to the electrode layer 10, and a solid electrolyte layer 30 located between the electrode layer 10 and the counter electrode layer 20. The electrode layer 10 has a current collector 11, an electrode active material layer 12 located between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 located at the end of the electrode layer 10 between the current collector 11 and the electrode active material layer 12 when viewed from above. In addition, the battery 50 has a gap 14 that is in contact with the insulating layer 13 and divides the electrode active material layer 12 into electrode active material layers 12a and 12b. The side surface of the insulating layer 13 and the side surface of the current collector 11 are the same. Moreover, the side surfaces of the current collector 11, the insulating layer 13, the electrode active material layer 12b of the electrode active material layer 12, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 are each the same.

[0121] Therefore, although the electrode active material layer 12 of the battery 50 expands and contracts during charging and discharging, the stress caused by the expansion and contraction of the electrode active material layer 12 can be mitigated through the gap 14 because the electrode active material layer 12 and the gap 14 are located between the current collector 11 and the solid electrolyte layer 30. Thus, the electrode active material layer 12 is less likely to cause interlayer delamination with other components, thereby improving the reliability of the battery 50.

[0122] Furthermore, by forming an insulating layer 13 made of a different material than the current collector 11 on the current collector 11, the gap 14 connected to the insulating layer 13 can be easily formed by taking advantage of the different material properties of the current collector 11, the electrode active material layer 12, and the insulating layer 13.

[0123] Furthermore, at the end of the current collector 11, which is prone to peeling, there is an insulating layer 13 between the current collector 11 and the electrode active material layer 12b. Therefore, even if the current collector 11 peels off, the exposure of the electrode active material layer 12b can be suppressed, making it difficult for damage or short circuits to occur due to contact between the electrode active material layer 12b and other components. This improves the reliability of the battery 50.

[0124] Furthermore, since the sides of the current collector 11, insulating layer 13, electrode active material layer 12b, solid electrolyte layer 30, counter electrode active material layer 22, and current collector 21 are all on the same surface, the area of ​​insulating layer 13 can be easily adjusted to manufacture the battery 50 by cutting each layer together. Therefore, although the electrode active material layer 12b does not function as an electrode due to the presence of the gap 14 in contact with insulating layer 13, this area can be minimized by adjusting the area of ​​the insulating layer. This allows for an increase in the volumetric energy density of the battery.

[0125] Furthermore, in battery 50, for example, electrode layer 10 having electrode active material layer 12 is a positive electrode layer having a positive electrode active material layer, and counter electrode layer 20 having counter electrode active material layer 22 is a negative electrode layer having a negative electrode active material layer. In this case, due to the presence of gap 14, electrons will not directly reach the positive electrode active material layer (electrode active material layer 12b in electrode active material layer 12) located above insulating layer 13 from current collector 11. Figure 1 and Figure 2 The positive electrode active material layer in region 1A, which is located outside region 1B, does not function as an electrode. Even with only the insulating layer 13 present, electrons have difficulty reaching the positive electrode active material layer located above the insulating layer 13, but the presence of the gap 14 further hinders electron movement. On the other hand, the positive electrode active material layer in region 1B functions as an electrode. Therefore, in battery 50, the region outside region 1B, which includes region 1A, does not function as a battery, while region 1B functions as a battery. In battery 50, although the areas of the positive electrode active material layer and the negative electrode active material layer (counter electrode active material layer 22) are the same when viewed from above, the area of ​​the positive electrode active material layer when viewed from above is substantially reduced because the positive electrode active material layer outside region 1B does not function as an electrode.

[0126] Furthermore, since the positive electrode active material layer (i.e., electrode active material layer 12b) located opposite the end of the negative electrode active material layer does not function as an electrode, the concentration of the electric field towards the end of the negative electrode active material layer is suppressed, thereby inhibiting dendrite growth at the end. This improves the reliability of the battery 50.

[0127] Furthermore, in the manufacturing of battery 50, the area of ​​the actual positive electrode active material layer can be adjusted by the gap 14 in contact with the insulating layer 13, thus eliminating the need for precise formation of the positions and areas of the positive and negative electrode active material layers. This allows for easy manufacturing of battery 50. For example, battery 50 can be easily manufactured by cutting the laminate formed by stacking the positive electrode layer (electrode layer 10), the solid electrolyte layer 30, and the negative electrode layer (counter electrode layer 20) in the region containing the insulating layer 13.

[0128] [Variation Example 1]

[0129] Hereinafter, a variation of Embodiment 1 will be described. In addition, in the following description of Variation 1, the focus will be on the differences from Embodiment 1, and the description of the commonalities will be omitted or simplified.

[0130] Figure 5 This is a schematic cross-sectional view showing an example of a battery involved in this variation. Figure 5 Showing in with Figure 2 The cross-section of battery 50a at the same location. For example... Figure 5 As shown, the battery 50a involved in this modified example differs from the battery 50 of Embodiment 1 in that it has a gap 14a instead of a gap 14.

[0131] The battery 50a in this modified example includes an electrode layer 10a, a counter electrode layer 20 disposed opposite to the electrode layer 10a, and a solid electrolyte layer 30 located between the electrode layer 10a and the counter electrode layer 20. In addition, the battery 50a has a gap 14a located between the current collector 11 and the solid electrolyte layer 30 and in contact with the insulating layer 13.

[0132] Electrode layer 10a has a current collector 11, an electrode active material layer 12c located between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 located at the end of electrode layer 10 between the current collector 11 and the solid electrolyte layer 30 and bonded to the current collector 11 when viewed from above. Electrode active material layer 12c is composed of electrode active material layer 12d and electrode active material layer 12e separated by a gap 14a.

[0133] The electrode active material layer 12c has a region that does not overlap with the insulating layer 13 when viewed from above. Specifically, when viewed from above, the electrode active material layer 12d does not overlap with the insulating layer 13, while the electrode active material layer 12e completely overlaps with the insulating layer 13, having the same shape and position.

[0134] The gap 14a is located between the insulating layer 13 and the electrode active material layer 12d, and is in contact with the insulating layer 13. Specifically, the gap 14a is in contact with the inner side of the insulating layer 13. The gap 14a is also in contact with the current collector 11 and the solid electrolyte layer 30. The gap 14a is located between the current collector 11 and the solid electrolyte layer 30, exposing the current collector 11, the insulating layer 13, and the solid electrolyte layer 30. As a result, the contact area between the gap 14a and the electrode active material layer 12d is increased, thus further mitigating the stress caused by the expansion and contraction of the electrode active material layer 12d during charging and discharging.

[0135] Furthermore, when viewed from above, the gap 14a overlaps with the inner end 13b of the interface 13a between the insulating layer 13 and the current collector 11. When viewed from above, the gap 14a is formed along the inner side surface of the insulating layer 13, extending inward from the inner side surface of the insulating layer 13.

[0136] Thus, in the battery 50a involved in this modified example, the stress caused by the expansion and contraction of the electrode active material layer 12c is mitigated by the presence of gaps 14a, and the region outside region 1B, including region 1A, does not function as a battery, while region 1B functions as a battery, thereby achieving the same effect of improving reliability as battery 50.

[0137] [Variation Example 2]

[0138] Hereinafter, a variation 2 of embodiment 1 will be described. In addition, in the following description of variation 2, the focus will be on the differences from embodiment 1, and the description of the commonalities will be omitted or simplified.

[0139] Figure 6 This is a schematic cross-sectional view showing an example of a battery involved in this variation. Figure 6 Indicates in relation to Figure 2 The cross-section of battery 50b at the same location. For example... Figure 6 As shown, the battery 50b involved in this modified example differs from the battery 50 of Embodiment 1 in that it has a gap 14b instead of a gap 14.

[0140] The battery 50b in this modified example includes an electrode layer 10b, a counter electrode layer 20 disposed opposite to the electrode layer 10b, and a solid electrolyte layer 30 located between the electrode layer 10b and the counter electrode layer 20. In addition, the battery 50b has a gap 14b located between the current collector 11 and the solid electrolyte layer 30 and in contact with the insulating layer 13.

[0141] The electrode layer 10b has a current collector 11, an electrode active material layer 12f located between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 located between the current collector 11 and the solid electrolyte layer 30 and bonded to the current collector 11 when viewed from above. The electrode active material layer 12f is composed of an electrode active material layer 12g and an electrode active material layer 12h separated by a gap 14b.

[0142] The electrode active material layer 12f has a region that does not overlap with the insulating layer 13 when viewed from above. Specifically, when viewed from above, the electrode active material layer 12g does not overlap with the insulating layer 13, while the electrode active material layer 12h overlaps with the insulating layer 13.

[0143] The gap 14b is located between the insulating layer 13 and the solid electrolyte layer 30, and between the insulating layer 13 and the electrode active material layer 12g, and is in contact with the insulating layer 13. Specifically, the gap 14b is in contact with the upper surface of the insulating layer 13 and the inner side surface of the insulating layer 13. In addition, the gap 14b is also in contact with the current collector 11 and the solid electrolyte layer 30. The gap 14b is located between the insulating layer 13 and the solid electrolyte layer 30, and between the current collector 11 and the solid electrolyte layer 30, exposing the current collector 11, the insulating layer 13, and the solid electrolyte layer 30.

[0144] In addition, when viewed from above, the gap 14b overlaps with the inner end 13b of the interface 13a between the insulating layer 13 and the current collector 11.

[0145] Thus, in the battery 50b of this modified example, the stress caused by the expansion and contraction of the electrode active material layer 12f is mitigated by the presence of the void 14b, and the region outside region 1B, including region 1A, does not function as a battery, while region 1B functions as a battery, thereby achieving the same effect of improving reliability as battery 50.

[0146] [Variation Example 3]

[0147] Hereinafter, a variation 3 of embodiment 1 will be described. In addition, in the following description of variation 3, the focus will be on the differences from embodiment 1, and the description of the commonalities will be omitted or simplified.

[0148] Figure 7 This is a schematic cross-sectional view showing an example of a battery involved in this variation. Figure 7 Indicates in relation to Figure 2 The cross-section of a 50c battery at the same location. For example... Figure 7 As shown, the battery 50c involved in this modified example differs from the battery 50 of Embodiment 1 in that it has a gap 14c instead of a gap 14.

[0149] The battery 50c in this modified example includes an electrode layer 10c, a counter electrode layer 20 disposed opposite to the electrode layer 10c, and a solid electrolyte layer 30 located between the electrode layer 10c and the counter electrode layer 20. In addition, the battery 50c has a gap 14c located between the current collector 11 and the solid electrolyte layer 30 and in contact with the insulating layer 13.

[0150] The electrode layer 10c has a current collector 11, an electrode active material layer 12i located between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 located at the end of the electrode layer 10 between the current collector 11 and the solid electrolyte layer 30 and bonded to the current collector 11 when viewed from above.

[0151] The lower surface of the electrode active material layer 12i is in contact with the current collector 11. However, the electrode active material layer 12i is not in contact with the insulating layer 13.

[0152] The gap 14c is located between the insulating layer 13 and the solid electrolyte layer 30, and between the insulating layer 13 and the electrode active material layer 12i, and is in contact with the insulating layer 13. Specifically, the gap 14c is in contact with the entire surface of the upper surface and the inner side surface of the insulating layer 13. That is, the gap 14c exposes the entire upper surface and inner side surface of the insulating layer 13, and the electrode active material layer 12i does not contact the insulating layer 13. As a result, the gap within the battery 50c becomes larger, which can further mitigate the stress caused by the expansion and contraction of the electrode active material layer 12i during charging and discharging.

[0153] In addition, when viewed from above, the gap 14c overlaps with the inner end 13b of the joint surface 13a between the insulating layer 13 and the current collector 11.

[0154] Thus, in the battery 50c involved in this modified example, the stress caused by the expansion and contraction of the electrode active material layer 12i is mitigated by the presence of gaps 14c, and the region outside region 1B does not function as a battery, while region 1B functions as a battery, thereby achieving the same effect of improving reliability as battery 50.

[0155] [Variation Example 4]

[0156] Hereinafter, a variation 4 of embodiment 1 will be described. In addition, in the following description of variation 4, the focus will be on the differences from embodiment 1, and the description of the commonalities will be omitted or simplified.

[0157] Figure 8 This is a schematic cross-sectional view showing an example of a battery involved in this variation. Figure 8 Indicates in relation to Figure 2 A cross-section of the battery at the same location, 50d. For example... Figure 8As shown, the battery 50d involved in this modified example differs from the battery 50 of Embodiment 1 in that it has a gap 14d instead of a gap 14.

[0158] The battery 50d in this modified example includes an electrode layer 10d, a counter electrode layer 20 disposed opposite to the electrode layer 10d, and a solid electrolyte layer 30 located between the electrode layer 10d and the counter electrode layer 20. In addition, the battery 50d has a gap 14d located between the current collector 11 and the solid electrolyte layer 30 and in contact with the insulating layer 13.

[0159] The electrode layer 10d has a current collector 11, an electrode active material layer 12j located between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 located at the end of the electrode layer 10 between the current collector 11 and the solid electrolyte layer 30 and bonded to the current collector 11 when viewed from above. The electrode active material layer 12j is composed of an electrode active material layer 12k and an electrode active material layer 12l separated by a gap 14d.

[0160] The lower surface of the electrode active material layer 12k is in contact with the current collector 11. Additionally, the electrode active material layer 12k is in contact with a portion of the upper surface of the insulating layer 13 and the side surface of the insulating layer 13. The electrode active material layer 12l, when viewed from above, is frame-shaped and surrounds the electrode active material layer 12k. A portion of the electrode active material layer 12k and the electrode active material layer 12l are stacked above the current collector 11, covering the insulating layer 13 on the current collector 11. The electrode active material layer 12j has a region that does not overlap with the insulating layer 13 when viewed from above. Specifically, when viewed from above, a portion of the electrode active material layer 12k does not overlap with the insulating layer 13, while the electrode active material layer 12l overlaps with the insulating layer 13.

[0161] The gap 14d is located between the insulating layer 13 and the solid electrolyte layer 30 and is in contact with the insulating layer 13. In addition, when viewed from above, the gap 14d is formed along the direction of the frame-shaped insulating layer 13 and at the position where it overlaps with the insulating layer 13.

[0162] Thus, in the battery 50d involved in this modified example, the stress of the electrode active material layer 12k during expansion and contraction is mitigated by the presence of gap 14d, and by the region outside region 1B including region 1A not functioning as a battery, while region 1B functions as a battery, the same effect of improving reliability as battery 50 can be obtained.

[0163] [Manufacturing Method]

[0164] Next, the method for manufacturing the battery according to this embodiment will be described. Hereinafter, the method for manufacturing the battery 50 according to Embodiment 1 will be the primary focus of the description. Other batteries 50a, 50b, 50c, and 50d can also be manufactured using the same method. Furthermore, the method for manufacturing the battery 50 described below is only one example, and the method for manufacturing the battery 50 is not limited to the example described below.

[0165] The manufacturing method of battery 50 includes an insulating layer lamination process, a power generation element lamination process, a cutting process, and a current collector lamination process. Each process is described in detail below.

[0166] (1) Insulation layer lamination process

[0167] First, the process of laminating the insulating layer will be explained. Figure 9 This is a flowchart illustrating the battery manufacturing method according to this embodiment.

[0168] In the insulating layer lamination process, an insulating layer 13 is laminated on at least one surface of the current collector 11. Specifically, the current collector 11 is first prepared... Figure 9 Step S11). Then, an insulating layer 13 is laminated on at least one surface of the prepared current collector 11. Figure 9 (Step S12). For example, by forming an insulating layer 13 on the upper surface of the current collector 11, the insulating layer 13 is stacked on the current collector 11.

[0169] Figure 10A , Figure 10B and Figure 10C This is a schematic diagram showing an example of a current collector 11 with an insulating layer 13 stacked on top of each other. Figure 10A (a) is a schematic top view showing an example of a current collector 11 with a stacked insulating layer 13. Figure 10A (b) is Figure 10A A schematic cross-sectional view at the location shown by line Xa(b)-Xa(b) in (a). Insulating layer 13, for example, as shown... Figure 10A The pattern shown is a lattice structure. Additionally, Figure 10B This is a schematic top view showing another example of a current collector 11 with a stacked insulating layer 13. Figure 10B Although no sectional view is shown in the figure, Figure 10B The current collector 11, which has an insulating layer 13 stacked on top of it, has a similarity to... Figure 10A (b) Same cross-sectional construction. Insulating layer 13 can also be as follows: Figure 10BThe insulating layer 13 is formed in a striped pattern. By stacking the insulating layer 13 into a relatively simple top view shape with long stripes, such as a grid or stripes, the insulating layer 13 can be easily formed on the current collector 11. Furthermore, in the cutting process described later, by dividing the insulating layer 13 along its length, a battery 50 with the insulating layer 13 formed along its ends can be easily formed. Figure 10A and Figure 6 In section B, the rectangular areas 1E and 1F marked with dashed lines correspond to the size of a battery 50. Thus, the current collector 11 can also be stacked with the insulating layer 13 in a manner that allows it to be divided into multiple batteries in subsequent manufacturing processes.

[0170] in addition, Figure 10C (a) is a schematic top view showing another example of a current collector 11 with a stacked insulating layer 13. Figure 10C (b) is Figure 10C A schematic cross-sectional view at the location indicated by the Xc(b)-Xc(b) line in (a). As shown... Figure 10C As shown, a grid-like insulating layer 13 with various patterns (e.g., grid spacing) can be formed on the current collector 11.

[0171] In this way, by stacking the insulating layers 13 into a grid or stripe pattern and then cutting the insulating layers 13 along the length of the grid or stripes in the cutting process described later, multiple batteries 50 with the same or different shapes can be manufactured simultaneously. As a result, the manufacturing efficiency of the battery 50 is improved.

[0172] Regarding the method for forming the insulating layer 13, various processes can be considered. From a mass production perspective, for example, a coating process can be employed. For instance, in a continuous process such as roll-to-roll, a high-precision coating method such as gravure printing or inkjet printing can be used. A coating containing an insulating material (e.g., inorganic filler) dispersed in a solvent is applied as the material for the insulating layer 13 onto the current collector 11, and then dried to evaporate the solvent, thereby obtaining the insulating layer 13. This results in an insulating layer 13 with uniform thickness and good positional accuracy. Furthermore, by employing such a high-precision coating method, the accuracy of the area of ​​the electrode active material layer 12, which is substantially effective as an electrode, can be improved.

[0173] When using resin as the material for the insulating layer 13, a solution containing dissolved or dispersed resin can be coated onto the current collector 11, or an ultraviolet-curable resin or a thermosetting resin can be coated onto the current collector 11 and cured. Alternatively, a resin containing inorganic fillers can be coated. Furthermore, the formation of the insulating layer 13 is not limited to continuous processes such as roller-to-roll methods, but can also be a batch process in which the insulating layer 13 is formed on each current collector 11.

[0174] Furthermore, the material of the insulating layer 13 may include, for example, an inorganic filler with a coefficient of linear expansion greater than that of the material of the electrode active material layer 12. Additionally, the material of the insulating layer 13 may also contain a material with poor wettability to the slurry of the electrode active material layer 12 (described later), such as a fluorinated resin that repels the slurry. Furthermore, to adjust the surface tension of the insulating layer 13 to repel the slurry, its surface may be covered with a coating material such as a fluorinated coating agent.

[0175] As a solvent for forming the insulating layer 13, general organic solvents or aqueous solvents that disperse or dissolve inorganic fillers and / or resins can be used.

[0176] (2) Power generation element stacking process

[0177] Next, the stacking process of the power generation element will be described. In the stacking process of the power generation element, the power generation element section 40 with the internal gap 14 is formed, for example, by sequentially stacking an electrode active material layer 12, a solid electrolyte layer 30, and a counter electrode active material layer 22 on a current collector 11. For example, on a current collector 11 with an insulating layer 13, the electrode active material layer 12 is stacked in such a way as to cover the insulating layer 13, the gap 14 is formed by heat treatment, and then the solid electrolyte layer 30 and the counter electrode active material layer 22 are sequentially stacked. Figure 9 Steps S13, S14, S15, and S16. Additionally, if necessary, the electrode active material layer 12, the solid electrolyte layer 30, and the electrode active material layer 22 stacked in steps S13, S15, and S16 are subjected to high-pressure pressing treatment. Figure 9 (Step S17). Additionally, as needed, the electrode active material layer 12, the solid electrolyte layer 30, and the electrode active material layer 22 stacked in steps S13, S15, and S16 are heat-treated. As a result, a power generation element 40 is stacked on the current collector 11 on which the insulating layer 13 is stacked, resulting in a stacked electrode plate with gaps 14 dividing the electrode active material layer 12 into electrode active material layers 12a and 12b.

[0178] The electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 constituting the power generation element 40 are formed sequentially, for example, by a wet coating method. By using a wet coating method, the power generation element 40 can be easily stacked on the current collector 11. As a wet coating method, coating methods such as mold coating, blade coating, roller coating, screen printing, or inkjet coating can be used, but are not limited to these methods.

[0179] In the case of using a wet coating method, a coating process is performed in which the materials that form the electrode active material layer 12, the solid electrolyte layer 30 and the counter electrode active material layer 22 (the materials of the positive electrode active material layer, the solid electrolyte layer 30 and the negative electrode active material layer mentioned above) are appropriately mixed with a solvent to obtain a slurry.

[0180] As a solvent used in the coating process, known solvents used in the manufacture of known all-solid-state batteries (such as lithium-ion all-solid-state batteries) can be used.

[0181] The slurry obtained in the coating process is applied to the current collector 11, where the insulating layer 13 is formed, in the following order: electrode active material layer 12, solid electrolyte layer 30, and counter electrode active material layer 22. First, in steps S13 and S14, the electrode active material layer 12 is layered, forming voids 14. For example, after coating, the slurry for applying the electrode active material layer 12 undergoes, for example, heat treatment to remove solvents and binder materials, and high-pressure pressing to promote the filling of each layer. At this time, voids 14 are formed, for example, by the surface tension of the insulating layer 13 and / or the expansion and contraction of the insulating layer 13 during heat treatment. Furthermore, if the insulating layer 13 has a shape with elongated portions, such as a grid or stripe pattern, voids 14 are formed, for example, along the length of the insulating layer 13.

[0182] The process of forming the void 14 in steps S13 and S14 will be described in detail.

[0183] Figure 11A This is a diagram illustrating an example of the method for forming void 14. First, in step S13, as... Figure 11A As shown in (a), a slurry of the material of the electrode active material layer 12 is applied to the current collector 11 on which the insulating layer 13 is stacked, thereby stacking the electrode active material layer 12. Then, in step S14, the current collector 11 on which the electrode active material layer 12 is stacked is heat-treated, causing the current collector 11, the electrode active material layer 12, and the insulating layer 13 to expand. At this time, since the material of the insulating layer 13 is a material with a larger coefficient of linear expansion than the material of the electrode active material layer 12, the electrode active material layer 12 is less likely to expand compared to the insulating layer 13. Therefore, a pull-away force is generated between the electrode active material layer 12 on the insulating layer 13 and the electrode active material layer 12 on the current collector 11 where the insulating layer 13 is not stacked. As a result, as Figure 11AAs shown in (b), a gap 14 is formed that divides the electrode active material layer 12 into electrode active material layer 12a and electrode active material layer 12b. Thus, when the electrode active material layer 12 is formed using a wet coating method, if the insulating layer 13 contains inorganic fillers, by selecting an inorganic filler with a coefficient of linear expansion greater than that of the electrode active material layer 12, it is possible to form an insulating layer 13 with a coefficient of linear expansion greater than that of the electrode active material layer 12, and therefore it is easy to form the gap 14.

[0184] In addition, Figure 11A In this example, the gap 14 is formed at both ends of the upper surface of the insulating layer 13, but the location of the gap is not limited to this example. The location of the gap can be adjusted, for example, by the difference in the coefficients of linear expansion between the insulating layer 13 and the electrode active material layer 12, the bonding strength between the current collector 11 and the electrode active material layer 12, and the coefficient of linear expansion of the current collector 11.

[0185] Alternatively, voids can be formed by using a material that repels slurry (i.e., a material with poor wettability to slurry) in the insulating layer 13. Figure 11B This is a diagram illustrating another example of a method for forming voids. First, in step S13, as... Figure 11B As shown in (a), a slurry of the material of the electrode active material layer 12 is coated onto the current collector 11, which has an insulating layer 13, in a manner that covers the insulating layer 13, thereby stacking the electrode active material layer 12. At this time, as Figure 11B As shown in (b), since the insulating layer 13 contains a slurry that repels the material of the electrode active material layer 12, the slurry in contact with the insulating layer 13 flows, exposing the insulating layer 13. This, for example, forms a void 14c in the battery 50c. Thus, when the electrode active material layer 12 is formed using a wet coating method, if the insulating layer contains resin, the surface tension of the resin can be adjusted to form an insulating layer 13 with a surface tension that repels the slurry, thereby facilitating the formation of voids 14c.

[0186] In addition, Figure 11B In this example, the void 14c is formed such that the upper surface and two sides of the insulating layer 13 are exposed, but the location of the void is not limited to this example. The location of the void can be adjusted, for example, by the wettability of the slurry to the insulating layer 13, the thickness of the slurry of the material of the electrode active material layer 12 covering the insulating layer 13, etc.

[0187] Furthermore, the methods for forming voids are not limited to Figure 11A and Figure 11B The method described herein can also be a method of coating the electrode active material layer 12 with a pattern of voids.

[0188] Next, the solid electrolyte layer 30 and the counter electrode active material layer 22 are laminated in sequence. At this time, the next layer can be laminated after the previous layer has been laminated, or the next layer can be laminated during the previous layer's laminated process. That is, steps S15 and S16 can be performed simultaneously. The slurry is applied layer by layer sequentially. After all layers are coated, for example, heat treatment to remove solvent and binder materials, and high-pressure pressing to promote the filling of each layer, are performed. Alternatively, heat treatment and high-pressure pressing can be performed on each layer after each layer is coated. That is, step S17 can be performed between steps S15 and S16. In the laminated coating of the solid electrolyte layer 30 and the counter electrode active material layer 22, heat treatment and high-pressure pressing can be performed on each layer, or they can be performed together after both layers are laminated. Furthermore, in the high-pressure pressing, for example, a roller press or a flat press can be used. Alternatively, at least one of the heat treatment and high-pressure pressing processes may be omitted.

[0189] By performing this layer-coating method, the interfacial bonding of the current collector 11, insulating layer 13, electrode active material layer 12, solid electrolyte layer 30, and counter electrode active material layer 22 can be improved, and the interfacial resistance can be reduced. Furthermore, the bonding of the powder materials used in electrode active material layer 12, solid electrolyte layer 30, and counter electrode active material layer 22 can be improved, and the grain boundary resistance can be reduced. In other words, a good interface is formed between the layers of the power generation element 40 and between the powder materials within each layer.

[0190] In addition, the insulation layer lamination process and the power generation element lamination process can also be carried out through a series of continuous processes such as roller-to-roll lamination.

[0191] Furthermore, in the power generation element stacking process, the solid electrolyte layer 30 and the counter electrode active material layer 22 are formed by sequentially stacking them on the current collector 11 on which the insulating layer 13 and the electrode active material layer 12 are stacked, but are not limited thereto. For example, in the power generation element stacking process, at least one of the solid electrolyte layer 30 and the counter electrode active material layer 22 can be formed by stacking them on a sheet-like substrate, and the formed solid electrolyte layer 30 and counter electrode active material layer 22 can be removed from the substrate and stacked on the current collector 11 on which the insulating layer 13 and the electrode active material layer 12 are stacked.

[0192] Figure 12A , Figure 12B and Figure 12C This is a schematic cross-sectional view showing an example of a stacked electrode plate according to this embodiment. For example... Figure 12AAs shown, in the stacked electrode plate 41, a power generation element section 40, in which an electrode active material layer 12, a solid electrolyte layer 30, and a counter electrode active material layer 22 are sequentially stacked, is stacked on a current collector 11 on which an insulating layer 13 is stacked. Furthermore, the electrode active material layer 12 is divided into electrode active material layers 12a and 12b, and a gap 14 is formed inside the power generation element section 40, connecting it to the insulating layer 13. Additionally, the upper surface of the counter electrode active material layer 22 is exposed.

[0193] The structure of the laminated electrode 41 is not limited to this example. For example, as... Figure 12B As shown, a laminated electrode plate 41a is formed such that the side and top surfaces of the electrode active material layer 12 are covered by a solid electrolyte layer 30, and the side and top surfaces of the counter electrode active material layer 22 are covered by the solid electrolyte layer 30. Furthermore, in the laminated electrode plate 41a, the electrode active material layer 12 is divided into electrode active material layer 12a and electrode active material layer 12b, and a gap 14 is formed inside the power generation element section 40, connecting it to the insulating layer 13. Thus, the electrode active material layer 12 is covered by the solid electrolyte layer 30, thereby suppressing the occurrence of short circuits caused by contact between the electrode active material layer 12 and the counter electrode active material layer 22 during the power generation element lamination process.

[0194] In addition, for example Figure 12C As shown, the stacked electrode plate 41b is formed with the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 decreasing in area when viewed from above. Furthermore, when viewed from above, the counter electrode active material layer 22 is located inside the solid electrolyte layer 30, and the solid electrolyte layer 30 is located inside the electrode active material layer 12. In the stacked electrode plate 41b, the electrode active material layer 12 is divided into electrode active material layers 12a and 12b, and a gap 14 connecting to the insulating layer 13 is formed inside the power generation element section 40. Because the counter electrode active material layer 22 is located inside the solid electrolyte layer 30, even if the stacking position is misaligned when viewed from above, the solid electrolyte layer 30 can suppress short circuits caused by contact between the electrode active material layer 12 and the counter electrode active material layer 22.

[0195] In this embodiment, the stacked electrode plate can be any of the stacked electrode plates 41, 41a, and 41b, as long as the power generation element part 40 is stacked on the current collector 11 on which the insulating layer 13 is stacked, and the gap between the current collector 11 and the solid electrolyte layer 30 and in contact with the insulating layer 13 is formed inside the power generation element part 40, or it can be a structure other than the stacked electrode plates 41, 41a, and 41b.

[0196] (3) Cutting process and current collector stacking process

[0197] Next, the cutting process and the current collector stacking process will be explained. Figure 13 This diagram illustrates the cutting process in the battery manufacturing method according to this embodiment. In the cutting process, the current collector 11, i.e., the stacked electrode plates 41, 41a, or 41b, which are stacked in the power generation element layer 40 during the power generation element stacking process, are cut along the stacking direction at the location where the insulating layer 13 is separated. Figure 9 Step S18). Figure 13 As shown, for example, at the positions of dashed lines C1, C2, C3, and C4 where the insulating layer 13 is disposed, the stacked electrode plate 41 is cut by means of a blade or laser. At the positions of dashed lines C1, C2, C3, and C4, the current collector 11, the insulating layer 13, the electrode active material layer 12b of the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 are stacked sequentially, and they are cut together. Therefore, it is not necessary to stack each layer of the power generation element 40 in the cut shape, so the battery 50 can be easily manufactured. For example, when the insulating layer 13 is viewed from above, the stacked layers are as follows: Figure 10A , Figure 10B and Figure 10C In the case of a grid or stripe pattern with elongated portions, the current collector 11, on which the power generation element portion 40 is stacked, is cut along the length of the grid or stripe pattern of the insulating layer 13. As a result, the entire region of the insulating layer 13 located on the cut surface side of the manufactured battery 50 is obtained, resulting in a battery 50 having a gap 14 in contact with the insulating layer 13.

[0198] Next, in the current collector stacking process, a current collector 21, serving as an additional current collector, is stacked on the side of the power generation element portion 40 opposite to the current collector 11 side (the side of the power generation element portion 40 perpendicular to the stacking direction where the current collector 11 is not stacked) of the stacked electrode plate 41 after it has been cut in the cutting process. Figure 9 Step S19). Specifically, the current collector 21 is bonded to the upper surface of the exposed counter electrode active material layer 22 of the cut laminated electrode plate 41 by means of a pressing process, etc. The pressing process is performed, for example, at a lower pressure than the high-pressure pressing process in step S17. Thus, a current collector 21 is obtained. Figure 1 and Figure 2 The battery shown is 50.

[0199] Furthermore, the order of the cutting process and the current collector stacking process can be interchanged. That is, the current collector 21 can be stacked on the surface of the power generation element portion 40 in the stacked electrode plate 41 opposite to the current collector 11 side before it is cut in the cutting process, and then the stacked electrode plate 41 with the current collector 21 stacked is cut along the stacking direction at the position where the insulating layer 13 is separated. In addition, in the current collector stacking process, as an additional current collector, a conductive substrate or frame can be stacked on the surface of the power generation element portion 40 opposite to the current collector 11 side instead of the current collector 21.

[0200] Thus, the manufacturing method of battery 50 includes a cutting step that cuts off the stacked positions of current collector 11, insulating layer 13, electrode active material layer 12b, solid electrolyte layer 30, and counter electrode active material layer 22 in electrode active material layer 12. As a result, at the ends in a direction perpendicular to the stacking direction, the sides of each of the current collector 11, insulating layer 13, electrode active material layer 12b, solid electrolyte layer 30, counter electrode active material layer 22, and current collector 21 are exposed. Furthermore, after cutting, sealing members or the like can be provided to cover the exposed sides to protect them. That is, even when the sides are covered with sealing members or other components, sometimes the sides of all layers are not exposed.

[0201] In this way, by a cutting process that includes cutting the stacked positions of the current collector 11, insulating layer 13, electrode active material layer 12b, solid electrolyte layer 30, and counter electrode active material layer 22, the ends of each of the current collector 11, insulating layer 13, electrode active material layer 12b, solid electrolyte layer 30, counter electrode active material layer 22, and current collector 21 in a direction perpendicular to the stacking direction can be exposed.

[0202] (4) Effects, etc.

[0203] As described above, the method for manufacturing the battery 50 according to this embodiment includes an insulating layer stacking process, a power generation element stacking process, a cutting process, and a current collector stacking process. In the insulating layer stacking process, an insulating layer 13 is stacked on a portion of at least one surface of the current collector 11. In the power generation element stacking process, a power generation element portion 40, on which an electrode active material layer 12, a solid electrolyte layer 30, and a counter electrode active material layer 22 are sequentially stacked, and a current collector 11 on which the insulating layer 13 is formed, is stacked. Furthermore, in the power generation element stacking process, a gap 14 is formed inside the power generation element portion 40, located between the current collector 11 and the solid electrolyte layer 30 and in contact with the insulating layer 13. In the cutting process, the current collector 11 on which the power generation element portion 40 is stacked is cut along the stacking direction at the location where the insulating layer 13 is divided. In the current collector stacking process, a current collector 21 is stacked on the surface of the power generation element portion 40 opposite to the current collector 11 side before or after being cut in the cutting process.

[0204] Therefore, the current collector 11, on which the power generation element 40 is stacked, is cut along the stacking direction at the location where the insulating layer 13 is split. Therefore, it is not necessary to stack each layer of the power generation element 40 in the cut shape, thereby making it easy to manufacture the battery 50.

[0205] Furthermore, since the current collector 11, on which the power generation element 40 is stacked, is cut along the stacking direction at the location where the insulating layer 13 is split, a battery is manufactured in which the insulating layer 13 is stacked at the end of the current collector 11 when viewed from above. Additionally, at the end of the current collector 11 in the manufactured battery 50 when viewed from above, the current collector 11, the insulating layer 13, and the electrode active material layer 12b are stacked sequentially. Therefore, even if the current collector 11 peels off at the end where it is prone to peeling, the insulating layer 13 is exposed, and the electrode active material layer 12b in contact with the upper surface of the insulating layer 13 will not function as a battery. Thus, damage or short circuits caused by contact with other components are less likely to occur. Therefore, a highly reliable battery can be manufactured.

[0206] Furthermore, the dimensions of the insulating layer 13 and the electrode active material layer 12b can be determined simply by adjusting the cutting position. Therefore, although the presence of a gap 14 formed in contact with the insulating layer 13 interrupts the electron transfer between the electrode active material layer 12b and the current collector 11, preventing the electrode active material layer 12b from functioning as an electrode, this area can be minimized by adjusting the dimensions of the insulating layer 13 and the electrode active material layer 12b. This allows for the easy manufacture of a battery 50 with a high volumetric energy density.

[0207] Furthermore, when the electrode active material layer 12 is a positive electrode active material layer and the counter electrode active material layer 22 is a negative electrode active material layer, the end of the positive electrode active material layer (electrode active material layer 12) is divided by the gap 14. The end of the positive electrode active material layer (electrode active material layer 12b) cannot function as an electrode because electrons from the current collector 11 cannot reach it. In other words, the substantial area of ​​the positive electrode active material layer when viewed from above is reduced. Therefore, compared to the negative electrode active material layer, the substantial area of ​​the positive electrode active material layer (the area that functions as an electrode) is smaller, and it is located inside the negative electrode active material layer when viewed from above. As a result, as described above, metal deposition in the negative electrode active material layer is suppressed. Consequently, the reliability of the manufactured battery 50 is further improved.

[0208] Furthermore, by cutting along the stacking direction, the current collector 11 (e.g., stacked plates 41, 41a, or 41b) on which the power generation element 40 is stacked is also cut off, resulting in a battery with a gap 14 formed at the end of the power generation element 40 that connects to the insulating layer 13. Therefore, it is not necessary to stack positive and negative active material layers with different area shapes for each individual cell, thereby enabling easy and efficient manufacturing of the battery 50.

[0209] Without the insulating layer 13 and the gap 14, even if the current collector 11 on which the power generation element 40 is stacked is cut off, since the electrode active material layer 12, which is not cut off, is also stacked at the end of the current collector 11, it would result in a battery in which the exposure of the electrode active material layer 12, which functions as a battery, cannot be suppressed when the end of the current collector 11 is peeled off, and the actual area of ​​the electrode active material layer 12 is no different from that of the counter electrode active material layer 22. Therefore, even if the battery can be easily manufactured, it is difficult to use as a manufacturing method due to the reduced reliability of the battery. On the other hand, in the manufacturing method according to this embodiment, as described above, the current collector 11 on which the power generation element 40 is stacked is cut off at the location where the insulating layer 13 is cut off. Therefore, by cutting off the current collector 11 on which the power generation element 40 is stacked, not only can the battery be easily manufactured, but the area of ​​the electrode active material layer 12 that functions as an electrode can also be reduced, and the areas of the insulating layer 13 and the electrode active material layer 12b can be adjusted. Furthermore, by forming the voids 14, the voids 14 can mitigate the stress caused by the expansion and contraction of the electrode active material layer 12, making it difficult for the electrode active material layer 12 to peel off from other components. In this way, by combining the current collector stacking process of stacking the insulating layer 13 on the current collector 11, the power generation element stacking process of stacking the power generation element portion 40 with the voids 14 formed inside and connected to the insulating layer 13, and the cutting process of cutting the current collector 11 with the power generation element portion 40 stacked at the position where the insulating layer 13 is cut off, it is possible to easily manufacture a battery with high reliability and high volumetric energy density.

[0210] (5) Other manufacturing methods

[0211] The battery manufacturing method described in this embodiment is not limited to the examples above; for example, it may also be the manufacturing method shown below.

[0212] First, prepare Figure 1 and Figure 2 The current collector 11 is shown in the diagram. Then, a coating process, etc., is employed to... Figure 1 and Figure 2As shown, an insulating layer 13 is stacked on the current collector 11. An electrode active material layer 12 is formed on the entire surface of the current collector 11 on which the insulating layer 13 is stacked by coating. An electrode plate having gaps 14 is obtained by using the same method as described in the formation of gaps 14 in steps S13 and S14 above.

[0213] Next, prepare Figure 1 and Figure 2 The current collector 21 has the shape shown. Then, the active material layer 22 and the solid electrolyte layer 30 of the counter electrode are sequentially stacked on the entire surface of the current collector 21 by a layer coating process to obtain the counter electrode plate.

[0214] Next, the obtained electrode plate and counter electrode plate are stacked such that the electrode active material layer 12 of the electrode plate is in contact with the solid electrolyte layer 30 of the counter electrode plate. The stacked body is pressed from both sides of the stacking direction using a flatbed press to obtain the battery 50.

[0215] (Implementation Method 2)

[0216] Hereinafter, Embodiment 2 will be described. In addition, in the following description of Embodiment 2, the focus will be on the differences from Embodiment 1, and the description of the commonalities will be omitted or simplified.

[0217] Figure 14 This is a schematic cross-sectional view showing an example of a battery according to this embodiment. For example... Figure 14 As shown, the battery 100 includes multiple batteries 50 according to Embodiment 1, and has a structure in which multiple batteries 50 are stacked. The multiple batteries 50 are stacked such that the electrode layer 10 of one adjacent battery 50 is opposite to the counter electrode layer 20 of the other. That is, the battery 100 is a series-stacked battery. Therefore, using the battery 50 according to Embodiment 1, a high-voltage battery 100 can be achieved.

[0218] The side of battery 100 is a flat plane; in other words, the side of each of the multiple batteries 50 is the same. Furthermore, for connecting leads, etc., the multiple batteries 50 can be stacked in a staggered manner in a direction perpendicular to the stacking direction.

[0219] Battery 100 is manufactured, for example, by stacking multiple batteries 50 such that the electrode layer 10 of one battery 50 is opposite to the counter electrode layer 20 of the other battery 50 in the stacking direction. Alternatively, the stacked electrode plate 41 before cutting (see reference) Figure 12A In the process, a current collector 21 is stacked on the side of the power generation element section 40 opposite to the current collector 11. After stacking multiple stacked electrode plates 41 with current collector 21, the plates are cut along the stacking direction at the position where the insulating layer 13 is divided, thereby manufacturing a battery 100.

[0220] In addition, when the batteries are stacked in 50 layers, they become two adjacent current collectors 11 and 21, but they can also be batteries in which neither of the adjacent current collectors 11 and 21 exists.

[0221] Furthermore, while battery 100 is a series-layered battery, it can also be a parallel-layered battery with a structure in which the electrode layers 10 of adjacent batteries 50 are stacked opposite each other or the counter electrode layers 20 are stacked opposite each other. In parallel-layered batteries, high-capacity batteries can be achieved.

[0222] By stacking the battery 50 as a single cell in this way, it is possible to achieve a battery with high capacity or high voltage that can exhibit the same effect as the battery 50.

[0223] (Other implementation methods)

[0224] The battery and its manufacturing method disclosed herein have been described above based on the embodiments, but this disclosure is not limited to these embodiments. Any solutions obtained by applying various modifications to the embodiments that can be conceived by those skilled in the art, or other solutions obtained 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.

[0225] In the above embodiment, the battery 50 is composed of a current collector 11, an insulating layer 13, an electrode active material layer 12, a solid electrolyte layer 30, a counter electrode active material layer 22, and a current collector 21, but is not limited thereto. For example, within the limits allowed by battery characteristics, bonding layers for reducing resistance and improving bonding strength may be provided between the layers of the battery.

[0226] Furthermore, in the above embodiment, the gap 14 is in contact with the insulating layer 13 and the solid electrolyte layer 30, but it is not limited to this. The gap may also be in contact with the insulating layer 13 but not with the solid electrolyte layer 30.

[0227] Furthermore, based on the structure of the battery 50 in the above embodiment, the battery 50 may have a second insulating layer located between the current collector 21 and the active material layer 22 at the end of the counter electrode layer 20, and a second gap located between the second insulating layer and the solid electrolyte layer 30 and in contact with the second insulating layer. In this case, the length of the second insulating layer measured from the outer periphery of the current collector 21 when viewed from above may be shorter than the length of the insulating layer 13 measured from the outer periphery of the current collector 11.

[0228] Furthermore, in the above embodiment, the insulating layer 13 and the gap 14 are frame-shaped when viewed from above and are located on the outer periphery of the electrode layer 10, but are not limited thereto. For example, in the battery 50, there may be areas on the outer periphery of the electrode layer 10 where the insulating layer 13 and / or the gap 14 are not provided.

[0229] Alternatively, in the embodiments described above, where the battery 50 is surrounded by a frame or substrate, and a portion of the frame or substrate functions as a current collector, the current collector 21 on the counter electrode active material layer 22 side of the battery 50 may not be present. In other words, the counter electrode layer 20 may also be composed of the counter electrode active material layer 22.

[0230] Furthermore, the above embodiments can be modified, substituted, added, omitted, etc., within the scope of the claims or their equivalents.

[0231] Industry availability

[0232] The batteries disclosed herein include, for example, all-solid-state batteries and other secondary batteries that can be used in various electronic devices or automobiles.

[0233] Explanation of reference numerals in the attached figures

[0234] Electrode layers 10, 10a, 10b, 10c, and 10d

[0235] 11, 21 collectors

[0236] Electrode active material layers 12, 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, 12j, 12k, 12l

[0237] 13 Insulation layer

[0238] 13a Joint surface

[0239] 13b end

[0240] 14, 14a, 14b, 14c, 14d gaps

[0241] 20 electrode layers

[0242] 22. Electrode active material layer

[0243] 30 Solid electrolyte layer

[0244] 40. Power Generation Components Department

[0245] 41, 41a, 41b laminated electrode plates

[0246] 50, 50a, 50b, 50c, 50d, 100 batteries

Claims

1. A battery comprising an electrode layer, a counter electrode layer disposed opposite to the electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer. The electrode layer comprises an electrode current collector, an electrode active material layer, and an insulating layer. The electrode active material layer is located between the electrode current collector and the solid electrolyte layer. The insulating layer is located at the end of the electrode layer between the electrode current collector and the solid electrolyte layer and is bonded to the electrode current collector. The electrode active material layer has an area that does not overlap with the insulating layer when viewed from above. The battery has a gap located between the electrode current collector and the solid electrolyte layer and in contact with the insulating layer. The counter electrode layer has a counter electrode current collector and a counter electrode active material layer. The active material layer of the counter electrode is located between the counter electrode current collector and the solid electrolyte layer. The side surfaces of the electrode current collector, the insulating layer, the electrode active material layer, the solid electrolyte layer, the counter electrode active material layer, and the counter electrode current collector are all on the same side.

2. The battery according to claim 1, The electrode layer is a positive electrode layer. The counter electrode layer is a negative electrode layer.

3. The battery according to claim 1 or 2, The void is also in contact with the solid electrolyte layer.

4. The battery according to claim 3, The gap overlaps with the inner end of the interface between the insulating layer and the electrode current collector when viewed from above.

5. The battery according to claim 1 or 2, The gap is located between the insulating layer and the solid electrolyte layer, and between the insulating layer and the electrode active material layer.

6. The battery according to claim 1 or 2, The insulating layer comprises resin.

7. The battery according to claim 1 or 2, The insulating layer contains inorganic fillers.

8. The battery according to claim 1 or 2, The coefficient of linear expansion of the insulating layer is greater than that of the electrode active material layer.

9. The battery according to claim 1 or 2, The insulating layer is located in a region that is less than 1 mm away from the outer periphery of the electrode current collector when viewed from above.

10. The battery according to claim 1 or 2, The thickness of the insulating layer is more than 50% and less than 100% of the thickness of the electrode active material layer.

11. The battery according to claim 1 or 2, The side of the battery is a cut surface.

12. The battery according to claim 1 or 2, The insulating layer, when viewed from above, is frame-shaped and is disposed on the outer periphery of the electrode layer.

13. The battery according to claim 1 or 2, The solid electrolyte layer contains a solid electrolyte that is lithium-ion conductive.

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