Battery

Abstract

A battery according to the present invention comprises an electrode layer, a counter electrode layer which is disposed so as to face the electrode layer, a solid electrolyte layer which is provided between the electrode layer and the counter electrode layer, and an insulating layer which is provided between the electrode layer and the solid electrolyte layer, wherein the electrode layer has a current collector and an electrode active material layer which is provided between the current collector and the solid electrolyte layer and between the current collector and the insulating layer, the insulating layer is provided at end parts of the electrode active material layer in a plan view, and the insulating layer is provided in a region having a length of not more than 1 mm from the outer periphery of the electrode active material layer in the plan view.

Description

[Technical Field]

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

[0002] Patent Documents 1 and 2 disclose batteries equipped with insulating members. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2012 / 164642 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-207286 Summary of the Invention [Problem to be solved by the invention]

[0004] In the prior art, there is a need for improved reliability of batteries. Therefore, an object of the present disclosure is to provide a highly reliable battery. [Means for solving the problem]

[0005] A battery according to one aspect of the present disclosure includes an electrode layer, a counter electrode layer disposed opposite the electrode layer, a solid electrolyte layer located between the electrode layer and the counter electrode layer, and an insulating layer located between the electrode layer and the solid electrolyte layer, wherein the electrode layer has a current collector and electrode active material layers located between the current collector and the solid electrolyte layer and between the current collector and the insulating layer, and the insulating layer is located at an end of the electrode active material layer in a planar view, and the insulating layer is located in a region having a length of 1 mm or less from the outer periphery of the electrode active material layer in a planar view. [Effects of the Invention]

[0006] According to the present disclosure, a highly reliable battery can be provided. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic top view showing an example of a battery according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an example of a battery according to a comparative example. [Figure 4] FIG. 4 is a schematic cross-sectional view showing another example of a battery according to a comparative example. [Figure 5] FIG. 5 is a flowchart illustrating a method for manufacturing a battery according to the first embodiment. [Figure 6A] FIG. 6A is a schematic top view and a schematic cross-sectional view showing an example of a current collector in which an electrode active material layer and an insulating layer are stacked according to Embodiment 1. FIG. [Figure 6B] FIG. 6B is a schematic top view showing another example of the current collector in which an electrode active material layer and an insulating layer according to embodiment 1 are stacked. [Figure 6C] FIG. 6C is a schematic top view and a schematic cross-sectional view showing another example of a current collector in which an electrode active material layer and an insulating layer according to embodiment 1 are stacked. [Figure 7A] FIG. 7A is a schematic cross-sectional view showing an example of a laminated electrode plate according to the first embodiment. [Figure 7B] FIG. 7B is a schematic cross-sectional view showing another example of the laminated electrode plate according to the first embodiment. [Figure 7C] FIG. 7C is a schematic cross-sectional view showing another example of the laminated electrode plate according to the first embodiment. [Figure 8] FIG. 8 is a diagram illustrating a cutting step in the battery manufacturing method according to the first embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view showing an example of a battery according to Modification 1 of Embodiment 1. As shown in FIG. [Figure 10] FIG. 10 is a schematic cross-sectional view showing another example of the battery according to the first modification of the first embodiment. [Figure 11] FIG. 11 is a diagram illustrating a cutting step in a battery manufacturing method according to Modification 1 of Embodiment 1. In FIG. [Figure 12] FIG. 12 is a schematic cross-sectional view showing an example of a battery according to the second embodiment. [Figure 13] FIG. 13 is a schematic cross-sectional view showing another example of the battery according to the second embodiment. [Figure 14] FIG. 14 is a flowchart illustrating a method for manufacturing a battery according to the second embodiment. [Figure 15] FIG. 15 is a schematic cross-sectional view showing an example of a multilayer electrode plate according to the second embodiment. [Figure 16] FIG. 16 is a schematic cross-sectional view showing an example of a laminated electrode plate according to Modification 1 of Embodiment 2. As shown in FIG. [Figure 17] FIG. 17 is a schematic cross-sectional view showing an example of a multilayer electrode plate according to Modification 1 of Embodiment 2. As shown in FIG. [Figure 18] FIG. 18 is a schematic cross-sectional view showing another example of a laminated electrode plate according to the first modification of the second embodiment. [Figure 19] FIG. 19 is a schematic cross-sectional view showing another example of a laminated electrode plate according to the first modification of the second embodiment. [Figure 20] FIG. 20 is a schematic cross-sectional view showing an example of a battery according to Modification 1 of Embodiment 2. As shown in FIG. [Figure 21] FIG. 21 is a schematic cross-sectional view showing another example of the battery according to the first modification of the second embodiment. [Figure 22] FIG. 22 is a schematic cross-sectional view showing an example of a battery according to the third embodiment. [Figure 23] FIG. 23 is a schematic cross-sectional view showing another example of the battery according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (Findings that formed the basis of this disclosure) When manufacturing batteries such as all-solid-state batteries having a solid electrolyte layer containing a solid electrolyte, it is common to make the area of ​​the anode active material layer larger than the area of ​​the cathode active material layer. This is intended to stabilize battery performance and improve battery reliability by making the capacity of the anode active material layer larger than the capacity of the cathode active material layer and suppressing metal precipitation derived from metal ions not incorporated into the anode active material layer. Another purpose is to suppress electric field concentration at the edge of the anode active material layer and suppress dendrite growth (metal precipitation) at the edge, thereby improving battery reliability. Furthermore, when the area of ​​the anode active material layer is increased, for example, a solid electrolyte layer is disposed around the cathode active material layer disposed opposite it. This prevents the edge of the cathode active material layer from being exposed, thereby reducing the likelihood of peeling between the cathode active material layer and the solid electrolyte layer, thereby improving reliability.

[0009] However, it is difficult to precisely control the area of ​​the positive electrode active material layer and the area of ​​the negative electrode active material layer in this way to manufacture a battery. Alternatively, to ensure reliability, the positive electrode active material layer must be formed while taking into account the dimensional accuracy during formation. This results in a problem of a smaller positive electrode active material layer, resulting in a decrease in the volumetric energy density of the battery. Furthermore, increasing the dimensional accuracy of the positive electrode active material layer raises concerns about an increase in the number of processes, such as inspection, and an increase in equipment costs.

[0010] Therefore, the present disclosure provides a highly reliable battery, particularly a highly reliable battery with an increased energy density.

[0011] An outline of one aspect of the present disclosure is as follows.

[0012] A battery according to one aspect of the present disclosure includes an electrode layer, a counter electrode layer disposed opposite the electrode layer, a solid electrolyte layer located between the electrode layer and the counter electrode layer, and an insulating layer located between the electrode layer and the solid electrolyte layer, wherein the electrode layer has a current collector and electrode active material layers located between the current collector and the solid electrolyte layer and between the current collector and the insulating layer, and the insulating layer is located at an end of the electrode active material layer in a planar view, and the insulating layer is located in a region having a length of 1 mm or less from the outer periphery of the electrode active material layer in a planar view.

[0013] As a result, there is a region where the electrode active material layer, insulating layer, and solid electrolyte layer are stacked in this order at the end of the electrode active material layer in a planar view. Therefore, even if the solid electrolyte layer peels off at the end of the electrode active material layer and solid electrolyte layer, where peeling is likely to occur due to a heterogeneous junction interface, exposure of the electrode active material layer is suppressed, and damage or short circuits caused by contact between the electrode active material layer and other components are less likely to occur. This makes it possible to improve the reliability of the battery.

[0014] This also makes it possible to limit the area in which the electrode active material layer is less likely to function as an electrode due to the presence of the insulating layer to a range within a certain distance from the outer periphery of the electrode active material layer, thereby increasing the volumetric energy density of the battery.

[0015] Furthermore, for example, the side surface of the insulating layer and the side surface of the electrode active material layer are flush with each other.

[0016] As a result, the side surfaces of the insulating layer and the electrode active material layer are flush with each other, and the area of ​​the insulating layer can be easily adjusted to manufacture a battery by, for example, cutting the insulating layer and the electrode active material layer together. Therefore, although the presence of the insulating layer suppresses the exchange of metal ions between the electrode active material layer and the solid electrolyte layer, forming a region where the electrode active material layer has difficulty functioning as an electrode, this region can be minimized by adjusting the area of ​​the insulating layer. Therefore, the volumetric energy density of the battery can be increased.

[0017] Furthermore, for example, the electrode layer may be a positive electrode layer, and the counter electrode layer may be a negative electrode layer.

[0018] As a result, metal ions from the electrode active material layer in the region overlapping the insulating layer in plan view, i.e., the positive electrode active material layer in the region overlapping the insulating layer in plan view, are unlikely to reach the solid electrolyte layer, and therefore the positive electrode active material layer in that region is unlikely to function as an electrode. Therefore, the effect of substantially reducing the area of ​​the positive electrode active material layer is obtained. As a result, the area of ​​the positive electrode active material layer is likely to be substantially smaller than the area of ​​the counter electrode active material layer of the negative electrode layer, i.e., the area of ​​the negative electrode active material layer. Therefore, the capacity of the negative electrode active material layer is likely to be larger than the capacity of the positive electrode active material layer, which suppresses metal precipitation derived from metal ions not incorporated into the negative electrode active material layer, thereby further improving the reliability of the battery.

[0019] Furthermore, for example, the insulating layer may include a resin.

[0020] This allows the resin contained in the insulating layer to bite into the electrode active material layer and the solid electrolyte layer, creating an anchor effect that improves the bonding between the insulating layer and the electrode active material layer and the solid electrolyte layer, and makes it possible to suppress peeling between the insulating layer and the electrode active material layer and the solid electrolyte layer.

[0021] Furthermore, for example, the insulating layer may include a metal oxide.

[0022] This makes the insulating layer hard, so that even if the insulating layer is formed thinly during battery manufacturing, the insulating layer is less likely to deform when stacked with other layers, and a thin insulating layer of uniform thickness can be formed.

[0023] Furthermore, for example, the thickness of the insulating layer may be 5 μm or less, and for example, the thickness of the insulating layer may be 2 μm or less.

[0024] This reduces the thickness of the insulating layer located between the electrode active material layer and the solid electrolyte layer. Therefore, even when high-pressure pressing is performed on each layer of a battery stacked on a current collector for the purpose of increasing the volumetric energy density of the battery, the insulating layer can reduce the impact of the pressing on each layer, making it easier for each layer, such as the electrode active material layer, to be compressed uniformly. As a result, the likelihood of each layer being compressed unevenly, resulting in peeling, etc., can be reduced. This allows for a highly reliable battery to be realized while increasing the energy density.

[0025] Furthermore, for example, the counter electrode layer may have a counter electrode active material layer disposed opposite to the electrode active material layer, and side surfaces of the solid electrolyte layer, the current collector, the electrode active material layer, the counter electrode active material layer, and the insulating layer may be exposed.

[0026] This allows the layers that contribute to the charge / discharge performance of the battery to be present all the way to the ends of the battery, thereby increasing the volumetric energy density of the battery.

[0027] Furthermore, for example, the side surface of the electrode layer, the side surface of the counter electrode layer, the side surface of the solid electrolyte layer, and the side surface of the insulating layer may be flush with each other.

[0028] This eliminates steps and irregularities on the side surfaces of each layer of the battery. Therefore, there are no spaces that do not contribute to the charge / discharge performance of the battery, which would otherwise be formed by the irregularities, and this prevents a substantial decrease in the energy density of the battery. Therefore, the volumetric energy density of the battery can be increased.

[0029] Furthermore, for example, the counter electrode layer may have a counter electrode active material layer disposed opposite the electrode active material layer, and the electrode active material layer and the counter electrode active material layer may have the same shape and position in a planar view.

[0030] This makes it possible to reduce the difference in capacity between the counter electrode active material layer and the electrode active material layer, thereby maximizing the capacity of the counter electrode active material layer or the electrode active material layer.

[0031] Furthermore, when the electrode layer is a positive electrode layer and the counter electrode layer is a negative electrode layer, the positive electrode active material layer and the negative electrode active material layer have the same shape and position in a plan view, and the insulating layer is located at the end of the positive electrode active material layer in a plan view. Therefore, the positive electrode active material layer at a position opposite the end of the negative electrode active material layer is unlikely to function as an electrode. As a result, electric field concentration at the end of the negative electrode active material layer is suppressed, and dendrite growth at the end is suppressed. Therefore, the reliability of the battery is improved.

[0032] Furthermore, for example, the side surface of the battery may be inclined with respect to the stacking direction so that the area of ​​the counter electrode layer is larger than the area of ​​the electrode layer in a plan view.

[0033] As a result, the side surface of the solid electrolyte layer is also inclined with respect to the stacking direction on the side surface of the battery, making the side surface of the solid electrolyte layer larger than when the side surface is not inclined. As a result, the distance between the electrode layer and the counter electrode layer separated by the solid electrolyte layer on the side surface of the battery is increased. Therefore, the electrode layer and the counter electrode layer are less likely to come into contact with each other, and short circuits are suppressed.

[0034] Furthermore, for example, the side surface of the battery may be a cut surface.

[0035] Since the side surfaces that become the ends of the battery are formed by cutting, the area of ​​the insulating layer can be adjusted by changing the cutting position, thereby reducing the area of ​​the region where the presence of the insulating layer makes it difficult for the electrode active material layer to function as an electrode, thereby increasing the volumetric energy density of the battery. Furthermore, since the side surfaces of the battery are cut surfaces, the side surfaces of the electrode layer, the side surfaces of the counter electrode layer, the side surfaces of the solid electrolyte layer, and the side surfaces of the insulating layer can easily be made flush with each other.

[0036] Furthermore, for example, the shape of the cut surface may be rectangular or trapezoidal.

[0037] This results in a shape in which the edges of the cut surface are straight, and therefore there is no space that does not contribute to the charge / discharge performance of the formed battery due to the edges being non-straight, which prevents a substantial decrease in the energy density of the battery, thereby increasing the energy density of the battery.

[0038] Furthermore, for example, the insulating layer may be positioned on the outer periphery of the electrode active material layer in a plan view and may have a frame shape.

[0039] This provides the effect of providing an insulating layer at any position on the outer periphery of the electrode active material layer in plan view.

[0040] Furthermore, for example, the solid electrolyte layer may include a solid electrolyte having lithium ion conductivity.

[0041] This makes it possible to improve the reliability of a lithium ion battery containing a solid electrolyte.

[0042] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0043] The embodiments described below are all comprehensive or specific examples, and the numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0044] Furthermore, in this specification, terms indicating the relationship between elements, such as parallel and flush, terms indicating the shape of elements, such as flat and rectangular, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0045] In addition, the drawings are not necessarily strict illustrations, and the same reference numerals are used to designate substantially the same components in the drawings, and redundant explanations are omitted or simplified.

[0046] In this specification and drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the z-axis direction is the stacking direction of the battery. The positive direction of the z-axis is the upper side in the z-axis direction, and the negative direction of the z-axis is the lower side in the z-axis direction. In this specification, "planar view" means the case where the battery is viewed along the z-axis. In this specification, "thickness" refers to the length of each layer in the stacking direction.

[0047] Furthermore, in this specification, the terms "above" and "below" in the battery configuration do not refer to the upward direction (vertically upward) and downward direction (vertically downward) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacking configuration. Furthermore, the terms "above" and "below" are applied not only to a case where two components are arranged with a gap between them and another component exists between them, but also to a case where two components are arranged closely together and the two components are in contact with each other.

[0048] (Embodiment 1) The following describes the battery according to embodiment 1. The battery according to embodiment 1 is a single cell including one electrode active material layer and one counter electrode active material layer.

[0049] [composition] First, the configuration of a battery according to embodiment 1 will be described with reference to the drawings. Fig. 1 is a schematic top view showing an example of a battery according to this embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1.

[0050] 1 and 2 , a battery 50 according to this embodiment includes an electrode layer 10, a counter electrode layer 20 disposed opposite 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 this order. The battery 50 also includes an insulating layer 13 located between the electrode layer 10 and the solid electrolyte layer 30.

[0051] The electrode layer 10 has a current collector 11 and an electrode active material layer 12 located between the current collector 11 and the solid electrolyte layer 30, and between the current collector 11 and the insulating layer 13. The current collector 11 and the electrode active material layer 12 have the same shape and are located in the same position in a plan view.

[0052] 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 .

[0053] The battery 50 is, for example, an all-solid-state battery. The side surfaces of the battery 50 are parallel to the stacking direction. The side surfaces of the battery 50 are flat planes. In other words, the side surfaces of the electrode layer 10, the counter electrode layer 20, the solid electrolyte layer 30, and the insulating layer 13 are flush with each other and lie on the same flat plane. That is, the side surfaces of the electrode layer 10, the counter electrode layer 20, the solid electrolyte layer 30, and the insulating layer 13 are flush with each other. Note that the side surfaces are surfaces that extend from the end of the main surface in a direction intersecting with the main surface when a plane perpendicular to the stacking direction is taken as the main surface of each component of the battery 50. Furthermore, at the end of the electrode layer 10 in the direction perpendicular to the stacking direction, the side surfaces of the insulating layer 13, the electrode active material layer 12, and the current collector 11 are flush with each other. Furthermore, at the end of the counter electrode layer 20 in a direction perpendicular to the stacking direction, the side surface of the counter electrode active material layer 22 and the side surface of the current collector 21 are flush with each other. That is, at the end of the battery 50 in a direction perpendicular to the stacking direction, the side surfaces of the current collector 11, the electrode active material layer 12, the insulating layer 13, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 are flush with each other and form the same flat plane. As a result, there are no steps or irregularities on the side surfaces of the layers of the battery 50, and therefore no spaces that do not function as a battery due to the irregularities are formed, thereby improving the volumetric energy density of the battery 50. Furthermore, because the side surfaces of the layers can be made flush by cutting the layers together, the area of ​​the insulating layer 13 can be easily adjusted when manufacturing the battery 50.

[0054] 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 blade such as a cutter, and is, for example, a surface having cut marks such as fine grooves. By forming the cut surface on the battery 50 in this way, the position where the insulating layer 13 is formed can be adjusted, and the area of ​​the portion that does not contribute to the charge / discharge performance of the battery 50 (the portion where the insulating layer 13 is formed, described in detail later) can be reduced, thereby improving the volumetric energy density. Furthermore, by using the cut surface, the side surface of the electrode layer 10, the side surface of the counter electrode layer 20, the side surface of the solid electrolyte layer 30, and the side surface of the insulating layer 13 can easily be made flush with each other. The cut marks may be smoothed by polishing or the like. The shape of the cut surface is not limited, but in the case of the battery 50, it is rectangular.

[0055] Furthermore, in the battery 50, the side surfaces of the current collector 11, insulating layer 13, electrode active material layer 12, solid electrolyte layer 30, counter electrode active material layer 22, and current collector 21 are exposed. As a result, the layers that contribute to the charge / discharge performance of the battery 50 are present all the way to the ends of the battery 50, thereby improving the volumetric energy density of the battery 50.

[0056] In the battery 50, the current collector 11, the electrode active material layer 12, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 have the same shape and are positioned in a planar view. The current collector 11, the electrode active material layer 12, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 each have a rectangular shape in a planar view, but are not particularly limited thereto and may be a circular, elliptical, polygonal, or the like.

[0057] The current collector 11 is in contact with the lower surface of the electrode active material layer 12 and covers the lower surface of the electrode active material layer 12. The thickness of the current collector 11 is, for example, not less than 5 μm and not more than 100 μm.

[0058] Known materials can be used as the material for the current collector 11. For example, the current collector 11 is a foil, plate, or mesh-like material made of copper, aluminum, nickel, iron, stainless steel, platinum, gold, or an alloy of two or more of these metals.

[0059] The electrode active material layer 12 is laminated above the current collector 11 so as to cover the current collector 11. The lower surface of the electrode active material layer 12 is in contact with the current collector 11. An insulating layer 13 is laminated on an end of the electrode active material layer 12 in a planar view. The upper surface of the electrode active material layer 12 is in contact with the insulating layer 13 and the solid electrolyte layer 30. The electrode active material layer 12 and the counter electrode active material layer 22 face each other with the solid electrolyte layer 30 interposed therebetween. The electrode active material layer 12 has a region that does not overlap with the insulating layer 13 in a planar view. Furthermore, the electrode active material layer 12 and the counter electrode active material layer 22 have the same shape and position in a planar view. The thickness of the electrode active material layer 12 is, for example, 5 μm or more and 300 μm or less. The materials used for the electrode active material layer 12 will be described later.

[0060] The insulating layer 13 is a layer that is insulating against electrons and metal ions. The insulating layer 13 is located between the electrode active material layer 12 and the solid electrolyte layer 30. The insulating layer 13 is located at the end of the electrode active material layer 12 in a planar view. The upper surface and the inner side surface of the insulating layer 13 in a planar view are in contact with the solid electrolyte layer 30. The insulating layer 13 is in contact with the electrode active material layer 12 at the end of the electrode active material layer 12 in a planar view. The side surfaces of the insulating layer 13 and the side surfaces of the electrode active material layer 12 are flush with each other. The lower surface of the insulating layer 13 is in contact with the electrode active material layer 12. The insulating layer 13 overlaps with the counter electrode active material layer 22 in a planar view.

[0061] In the illustrated example, the insulating layer 13 is frame-shaped and located on the outer periphery of the electrode active material layer 12 in a plan view. That is, the insulating layer 13 is located between the electrode active material layer 12 and the solid electrolyte layer 30 at all ends of the electrode active material layer 12 in the direction perpendicular to the stacking direction.

[0062] The insulating layer 13 contains, for example, at least one of a resin and a metal oxide. Examples of the resin include silicone resin, epoxy resin, acrylic resin, and polyimide resin. The resin may be a thermosetting resin or an ultraviolet-curing resin. When the insulating layer 13 contains a resin, the resin penetrates into the electrode active material layer 12 and the solid electrolyte layer 30, thereby enhancing the bonding between the insulating layer 13 and the electrode active material layer 12 and the solid electrolyte layer 30, for example, through an anchor effect. Examples of the metal oxide include silicon oxide, titanium oxide, and aluminum oxide. When the insulating layer 13 contains a metal oxide, the insulating layer 13 becomes hard. Therefore, even if the insulating layer 13 is formed thin during the manufacturing of the battery 50, the insulating layer 13 is less likely to deform when stacked with other layers, and a thin insulating layer 13 with a uniform thickness can be formed.

[0063] The thickness of the insulating layer 13 is thinner than the electrode active material layer 12 and the solid electrolyte layer 30, for example, sufficiently thinner than the electrode active material layer 12 and the solid electrolyte layer 30. Because the thickness of the insulating layer 13 is thinner than the electrode active material layer 12 and the solid electrolyte layer 30, even when a high-pressure press is performed during lamination of the electrode active material layer 12, the solid electrolyte layer 30, etc., the influence of the insulating layer 13 can be reduced, and the electrode active material layer 12, the solid electrolyte layer 30, etc. can be easily compressed uniformly. The thickness of the insulating layer 13 is, for example, 5 μm or less, from the viewpoint of easily compressing the electrode active material layer 12, the solid electrolyte layer 30, etc., even when a high-pressure press is performed during lamination of the electrode active material layer 12, the solid electrolyte layer 30, etc. From the viewpoint of battery characteristics, the thickness of the insulating layer 13 may be 2 μm or less or 1 μm or less. For example, the insulating layer 13 is completely insulating; however, depending on the desired battery characteristics, the insulating layer 13 may have slight conductivity depending on the constituent material and thickness of the insulating layer 13.

[0064] Furthermore, from the viewpoint of the effective area contributing to power generation, i.e., from the viewpoint of volumetric energy density, the insulating layer 13 is located in a region having a length of 1 mm or less from the outer periphery of the electrode active material layer 12 in a plan view. Furthermore, when the insulating layer 13 is formed in a frame or line shape, the width of the insulating layer 13 is, for example, 1 mm or less, or may be 0.5 mm or less, or may be 0.1 mm or less, from the viewpoint of volumetric energy density. The width of the insulating layer 13 is changed, for example, depending on the desired battery characteristics.

[0065] The current collector 21 is in contact with the upper surface of the counter electrode active material layer 22 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 21 can be the same as that of the current collector 11 described above.

[0066] The counter electrode active material layer 22 is laminated on the solid electrolyte layer 30 and disposed opposite the electrode active material layer 12. The upper surface of the counter electrode active material layer 22 contacts 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 material used for the counter electrode active material layer 22 will be described later.

[0067] The solid electrolyte layer 30 is located between the electrode active material layer 12 and the counter electrode active material layer 22. The solid electrolyte layer 30 is laminated above the electrode active material layer 12 so as to cover the insulating layer 13 on the electrode active material layer 12. The upper surface of the solid electrolyte layer 30 is in contact with the counter electrode active material layer 22. The lower surface of the solid electrolyte layer 30 is in contact with the insulating layer 13 and the electrode active material layer 12. The thickness of the solid electrolyte layer 30 is, for example, 5 μm or more and 150 μm or less.

[0068] The solid electrolyte layer 30 includes at least a solid electrolyte and may include a binder material as needed. The solid electrolyte layer 30 may include a solid electrolyte having lithium ion conductivity.

[0069] As the solid electrolyte, known materials that conduct metal ions, such as lithium ion conductors, sodium ion conductors, or magnesium ion conductors, can be used. Examples of solid electrolytes that can be used include solid electrolyte materials such as sulfide solid electrolytes, halogen-based solid electrolytes, and oxide solid electrolytes. As the sulfide solid electrolyte, materials that can conduct lithium ions, such as a composite of lithium sulfide (LiS) and diphosphorus pentasulfide (P2S5), can be used. Furthermore, sulfides such as LiS-SiS2, LiS-B2S3, or LiS-GeS2 can also be used. Sulfides obtained by adding at least one of LiN, LiCl, LiBr, LiPO4, and Li4SiO4 to the above sulfides as an additive can also be used.

[0070] As an oxide solid electrolyte, materials that can conduct lithium ions include, for example, Li7La3Zr2O 12 (LLZ), Li 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP) or (La,Li)TiO3(LLTO) are used.

[0071] As the binder material, for example, elastomers are used, and organic compounds such as polyvinylidene fluoride, acrylic resin, or cellulose resin may also be used.

[0072] In the present embodiment, one of the electrode layer 10 having the electrode active material layer 12 and the counter electrode layer 20 having the counter electrode active material layer 22 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.

[0073] The positive electrode active material layer contains at least a positive electrode active material, and may contain at least one of a solid electrolyte, a conductive additive, and a binder material, as necessary.

[0074] The positive electrode active material may be a known material capable of absorbing and releasing (inserting and desorbing, or dissolving and depositing) lithium ions, sodium ions, or magnesium ions. Examples of the positive electrode active material capable of extracting and inserting lithium ions include lithium cobalt oxide composite oxide (LCO), lithium nickel oxide composite oxide (LNO), lithium manganese oxide composite oxide (LMO), lithium-manganese-nickel composite oxide (LMNO), lithium-manganese-cobalt composite oxide (LMCO), lithium-nickel-cobalt composite oxide (LNCO), and lithium-nickel-manganese-cobalt composite oxide (LNMCO).

[0075] The solid electrolyte may be any of the above-described solid electrolyte materials. The conductive additive may be, for example, a conductive material such as acetylene black, carbon black, graphite, or carbon fiber. The binder may be any of the above-described binder materials.

[0076] The negative electrode active material layer contains at least a negative electrode active material, and may contain, as necessary, at least one of a solid electrolyte, a conductive additive, and a binder material, similar to those of the positive electrode active material layer.

[0077] The negative electrode active material may be a known material capable of occluding and releasing (inserting and desorbing, or dissolving and precipitating) lithium ions, sodium ions, or magnesium ions. Examples of materials capable of occluding and inserting lithium ions include carbon materials such as natural graphite, artificial graphite, graphite carbon fiber, and resin-baked carbon, metallic lithium, lithium alloys, and oxides of lithium and transition metal elements.

[0078] In manufacturing a battery, as described above, it is common to make the area of ​​the negative electrode active material layer larger than the area of ​​the positive electrode active material layer in a plan view in order to improve reliability. Furthermore, by locating the end of the negative electrode active material layer on the outer side of the end of the positive electrode active material layer, electric field concentration at the end of the negative electrode active material layer can be suppressed, thereby suppressing dendrite growth (metal deposition).

[0079] Here, comparative batteries 950 and 950a in which the area of ​​the negative electrode active material layer is larger than the area of ​​the positive electrode active material layer in a plan view will be described. Figures 3 and 4 are schematic cross-sectional views showing examples of comparative batteries.

[0080] 3 , 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 includes a current collector 911 and a positive electrode active material layer 912 located between the current collector 911 and the solid electrolyte layer 930. The negative electrode layer 920 includes a current collector 921 and a negative electrode active material layer 922 located between the current collector 921 and the solid electrolyte layer 930. The solid electrolyte layer 930 covers the side surfaces of the positive electrode active material layer 912 and the negative electrode active material layer 922, and is in contact with the current collector 911 and the current collector 921. In the battery 950, the area of ​​the negative electrode active material layer 922 is larger than the area of ​​the positive electrode active material layer 912 in a plan view, and the end of the negative electrode active material layer 922 is located outside the end of the positive electrode active material layer 912. In this way, in the battery 950, the area of ​​the negative electrode active material layer 922 is larger than the area of ​​the positive electrode active material layer 912, thereby suppressing metal deposition. Furthermore, because the solid electrolyte layer 930 is present at the end of the battery 950, even if the current collector 911 and the current collector 921 peel off from the end, exposure of the positive electrode active material layer 912 and the negative electrode active material layer 922 is suppressed.

[0081] Region 2C, where the positive electrode active material layer 912 and the negative electrode active material layer 922 are present, functions as a battery. On the other hand, region 2A, where neither the positive electrode active material layer 912 nor the negative electrode active material layer 922 are present, does not function as a battery. Region 2B, where the negative electrode active material layer 922 is present but the positive electrode active material layer 912 is not present, also does not function as a battery. Region 2B is a region corresponding to the difference in area between the positive electrode active material layer 912 and the negative electrode active material layer 922. As region 2B and region 2A become wider in plan view, the proportion of the region that does not contribute to power generation in the battery 950 increases, and the volumetric energy density of the battery 950 decreases. On the other hand, as region 2B becomes narrower in plan view, higher alignment accuracy is required in manufacturing processes such as the process of stacking each layer. This higher required accuracy raises concerns about an increase in the number of processes, such as inspections, and an increase in equipment costs.

[0082] Furthermore, regions 2A, 2B, and 2C differ in the type and number of layers present in the thickness direction, other than current collectors 911 and 921. That is, region 2A contains only one layer, solid electrolyte layer 930; region 2B contains two layers, negative electrode active material layer 922 and solid electrolyte layer 930; and region 2C contains three layers, positive electrode active material layer 912, negative electrode active material layer 922, and solid electrolyte layer 930. In all-solid-state batteries constructed with powder materials, high-pressure pressing may be included in the manufacturing process to form favorable interfaces between the powder materials (e.g., interfaces with favorable bonding between the powder materials and low grain boundary resistance), thereby improving battery reliability and increasing the volumetric energy density through high packing. In this case, regions 2A, 2B, and 2C differ in the type and number of constituent layers, and each layer also differs in its compressibility. Therefore, when the entire battery 950 is pressed, the degree of compression may differ in each region, i.e., there is a concern that compression may not be uniform. For example, in regions 2A and 2B, the compression is insufficient compared to region 2C, which may result in peeling of layers and other deterioration in reliability.

[0083] That is, battery 950 has problems in that it is difficult to manufacture battery 950 and reliability is not sufficiently improved. Furthermore, region 2A, which is the only layer in the thickness direction that is solid electrolyte layer 930, is a portion that does not particularly contribute to the basic charge / discharge performance of the battery, and therefore, from the viewpoint of improving the volumetric energy density, it is preferable that region 2A is small.

[0084] 4 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 battery 950a differs from the battery 950 in that the solid electrolyte layer 930a does not cover the side surface of the negative electrode active material layer 922a. While the battery 950a does not have a region without the positive electrode active material layer 912 and the negative electrode active material layer 922, as in the region 2A, the battery 950a does have a region 3A without the positive electrode active material layer 912a. Therefore, the region 3A does not contribute to power generation, and the same problems as those in the region 2B also occur in the region 3A of the battery 950a.

[0085] On the other hand, as described above, the battery 50 includes an electrode layer 10, a counter electrode layer 20 disposed opposite the electrode layer 10, and a solid electrolyte layer 30 located between the electrode layer 10 and the counter electrode layer 20. The battery 50 further includes an insulating layer 13 located between the electrode layer 10 and the solid electrolyte layer 30. The electrode layer 10 includes a current collector 11 and an electrode active material layer 12 located between the current collector 11 and the solid electrolyte layer 30 and between the current collector 11 and the insulating layer 13. The electrode active material layer 12 has a region that does not overlap with the insulating layer 13 in a planar view. The insulating layer 13 is located at an end of the electrode active material layer 12 in a planar view. The side surfaces of the insulating layer 13 and the electrode active material layer 12 are flush with each other. Furthermore, the side surfaces of the current collector 11, the electrode active material layer 12, the insulating layer 13, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 are flush with each other.

[0086] As a result, at the ends of the electrode active material layer 12 and the solid electrolyte layer 30 where peeling is likely to occur, the insulating layer 13 is present between the electrode active material layer 12 and the solid electrolyte layer 30, so that even if the solid electrolyte layer 30 peels off, exposure of the electrode active material layer 12 is suppressed, and damage or short circuits caused by contact between the electrode active material layer 12 and other members are less likely to occur, thereby improving the reliability of the battery 50.

[0087] Because the side surfaces of the current collector 11, insulating layer 13, electrode active material layer 12, solid electrolyte layer 30, counter electrode active material layer 22, and current collector 21 are flush with each other, the area of ​​the insulating layer 13 can be easily adjusted to manufacture the battery 50 by, for example, cutting each layer together. Therefore, although the presence of the insulating layer 13 suppresses the exchange of metal ions between the electrode active material layer 12 and the solid electrolyte layer 30 and creates a region where the electrode active material layer 12 does not easily function as an electrode, this region can be minimized by adjusting the area of ​​the insulating layer 13. This allows the volumetric energy density of the battery to be increased.

[0088] Furthermore, since the insulating layer 13 is located between the electrode active material layer 12 and the solid electrolyte layer 30, the electrode active material layer 12 is also present below the insulating layer 13. Therefore, even when a high-pressure press treatment is performed, the entire region is more likely to be compressed uniformly than, for example, when a solid electrolyte layer is present on the side of the electrode active material layer, as in the battery according to the comparative example described above. Therefore, peeling of the layers of the battery 50 is less likely to occur, and the high-pressure press treatment can improve the reliability and volumetric energy density of the battery 50.

[0089] In the battery 50, for example, the electrode layer 10 having the electrode active material layer 12 is a positive electrode layer having a positive electrode active material layer, and the counter electrode layer 20 having the counter electrode active material layer 22 is a negative electrode layer having a negative electrode active material layer. In this case, metal ions from the positive electrode active material layer (electrode active material layer 12) in contact with the insulating layer 13 are unlikely to reach the solid electrolyte layer 30, so the positive electrode active material layer in region 1A shown in FIGS. 1 and 2 is unlikely to function as an electrode. On the other hand, the positive electrode active material layer in region 1B functions as an electrode. Therefore, in the battery 50, region 1A is unlikely to function as a battery, and region 1B functions as a battery. In the 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 in a planar view, the positive electrode active material layer in region 1A is unlikely to function as an electrode, which effectively reduces the area of ​​the positive electrode active material layer in a planar view. That is, in the battery 50, even if the positive electrode active material layer and the negative electrode active material layer have the same area in plan view, metal deposition is suppressed.

[0090] Furthermore, because the positive electrode active material layer and the negative electrode active material layer have the same shape and position in a plan view and the insulating layer 13 is located at the end of the positive electrode active material layer (electrode active material layer 12) in a plan view, the positive electrode active material layer at a position opposite the end of the negative electrode active material layer is unlikely to function as an electrode. As a result, electric field concentration at the end of the negative electrode active material layer is suppressed, and dendrite growth at the end is suppressed. This improves the reliability of the battery 50.

[0091] Furthermore, in manufacturing the battery 50, since the actual area of ​​the positive electrode active material layer can be adjusted by the insulating layer 13, there is no need to precisely form the positions and areas of the positive electrode active material layer and the negative electrode active material layer. This makes it possible to easily manufacture the battery 50. For example, the battery 50 can be easily manufactured by cutting a laminate in which the positive electrode layer (electrode layer 10), the insulating layer 13, the solid electrolyte layer 30, and the negative electrode layer (counter electrode layer 20) are stacked in a region including the insulating layer 13.

[0092] [Manufacturing method] Next, a method for manufacturing the battery according to this embodiment will be described. Note that the method for manufacturing the battery 50 described below is an example, and the method for manufacturing the battery 50 is not limited to the following example.

[0093] The manufacturing method of the battery 50 includes a first stacking step, a second stacking step, a cutting step, and a third stacking step. Each step will be described in detail below.

[0094] (1) First lamination process First, the first lamination step will be described. Fig. 5 is a flowchart illustrating the method for manufacturing a battery according to this embodiment.

[0095] In the first lamination step, an insulating layer 13 is laminated on the surface opposite to the current collector 11 side of the electrode active material layer 12 laminated on at least one surface of the current collector 11. Specifically, first, the current collector 11 is prepared (step S11 in FIG. 5). Then, the electrode active material layer 12 is laminated on at least one surface of the prepared current collector 11 (step S12 in FIG. 5). For example, the electrode active material layer 12 is formed on the upper surface of the current collector 11, thereby laminating the electrode active material layer 12 on the current collector 11. Then, an insulating layer 13 is laminated on the surface of the electrode active material layer 12 opposite to the current collector 11 side (step S13 in FIG. 5).

[0096] 6A, 6B, and 6C are schematic diagrams illustrating an example of a current collector 11 on which an electrode active material layer 12 and an insulating layer 13 are stacked. (a) of FIG. 6A is a schematic top view illustrating an example of the current collector 11 on which an electrode active material layer 12 and an insulating layer 13 are stacked, and (b) of FIG. 6A is a schematic cross-sectional view taken along line VIa(b)-VIa(b) in (a) of FIG. 6A. The insulating layer 13 is formed, for example, in a lattice pattern as shown in FIG. 6A. FIG. 6B is a schematic top view illustrating another example of the current collector 11 on which an electrode active material layer 12 and an insulating layer 13 are stacked. Although a cross-sectional view is not shown in FIG. 6B, the current collector 11 on which an electrode active material layer 12 and an insulating layer 13 are stacked shown in FIG. 6B has the same cross-sectional structure as that shown in (b) of FIG. 6A. The insulating layer 13 may be formed in a stripe pattern as shown in FIG. 6B. By laminating the insulating layer 13 in such a relatively simple shape in plan view having elongated portions such as a grid or stripes, the insulating layer 13 can be easily formed on the electrode active material layer 12. Furthermore, in the cutting step described below, the insulating layer 13 is divided along the longitudinal direction of the insulating layer 13, so that batteries 50 having the insulating layer 13 formed along the edge of the battery 50 can be easily formed. In Figures 6A and 6B, rectangular regions 1E and 1F drawn with dotted lines correspond to the size of one battery 50. In this way, the electrode active material layer 12 and the insulating layer 13 may be laminated on the current collector 11 so that the current collector 11 can be divided into multiple batteries in a later manufacturing step.

[0097] 6C(a) is a top view showing yet another example of a current collector 11 in which an electrode active material layer 12 and an insulating layer 13 are laminated, and Fig. 6C(b) is a cross-sectional view taken along line VIc(b)-VIc(b) in Fig. 6C(a). As shown in Fig. 6C, a lattice-shaped insulating layer 13 having a plurality of different patterns (for example, lattice spacing) may be formed on the electrode active material layer 12.

[0098] In this way, the insulating layer 13 is laminated in a grid or stripe pattern, and in the cutting process described below, the insulating layer 13 is divided along the longitudinal direction of the grid or stripe of the insulating layer 13, thereby making it possible to simultaneously manufacture multiple batteries 50 each having the same shape or different shapes, thereby improving the manufacturing efficiency of the batteries 50.

[0099] The electrode active material layer 12 is formed in sequence, for example, by a wet coating method. By using the wet coating method, the electrode active material layer 12 can be easily laminated on the current collector 11. As the wet coating method, a coating method such as a die coating method, a doctor blade method, a roll coater method, a screen printing method, or an inkjet method can be used, but the wet coating method is not limited to these methods.

[0100] When the wet coating method is used, a coating step is carried out in which a material for forming the electrode active material layer 12 (the material for the positive electrode active material layer or the negative electrode active material layer described above) and a solvent are appropriately mixed to obtain a slurry.

[0101] The solvent used in the paint-making step may be a known solvent used in producing a known all-solid-state battery (for example, a lithium-ion all-solid-state battery).

[0102] The slurries for each layer obtained in the coating process are applied to the current collector 11 to form the electrode active material layer 12. After the application of the slurry, for example, a heat treatment is performed to remove the solvent and binder material. If necessary, a high-pressure press treatment may be performed after the application of the slurry to promote filling of the material. This forms the electrode active material layer 12 on the current collector 11.

[0103] Various processes can be considered for forming the insulating layer 13, but from the perspective of mass production, for example, a coating process is used. For example, in a continuous process such as a roll-to-roll process, a coating material in which an insulating material (e.g., a metal oxide) is dispersed in a solvent is applied to the electrode active material layer 12 using a high-precision coating method such as a gravure roll method or an inkjet method, and the coating is then dried to evaporate the solvent, thereby obtaining the insulating layer 13. This allows the insulating layer 13 to be laminated thinly, resulting in a thin insulating layer 13 with a uniform thickness. Therefore, when a high-pressure press is performed to laminate other layers in the second lamination step described below, the insulating layer 13 is less likely to be affected, and the other layers are more likely to be compressed uniformly. Furthermore, using such a high-precision coating method increases the precision of the area of ​​the electrode active material layer 12 that is essentially effective as an electrode.

[0104] When a resin is used as the material of the insulating layer 13, a solution in which the resin is dissolved or dispersed may be applied onto the electrode active material layer 12, or an ultraviolet curable resin or a thermosetting resin may be applied onto the electrode active material layer 12 and then cured. The formation of the insulating layer 13 is not limited to a continuous process such as a roll-to-roll process, and may be a batch process in which the insulating layer 13 is formed for each current collector 11.

[0105] The solvent used to form the insulating layer 13 may be a general organic solvent or aqueous solvent that disperses or dissolves metal oxides or resins.

[0106] (2)Second lamination process Next, the second lamination step will be described. In the second lamination step, a solid electrolyte layer 30 and a counter electrode active material layer 22 are laminated in this order on the current collector 11 on which the electrode active material layer 12 and the insulating layer 13 have been laminated in the first lamination step, such that the solid electrolyte layer 30 covers the electrode active material layer 12 and the insulating layer 13. As a result, a power generation element 40 in which the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 are laminated in this order is formed on the current collector 11. In addition, in the second lamination step, a coating structure is formed in which the solid electrolyte layer 30 covers the electrode active material layer 12 and the insulating layer 13. Specifically, the solid electrolyte layer 30 and the counter electrode active material layer 22 are laminated in this order on the current collector 11 on which the electrode active material layer 12 and the insulating layer 13 have been laminated (steps S14 and S15 in FIG. 5). For example, a solid electrolyte layer 30 is laminated on a current collector 11 on which an electrode active material layer 12 and an insulating layer 13 are laminated, so as to cover the electrode active material layer 12 and the insulating layer 13, and a counter electrode active material layer 22 is further laminated thereon. If necessary, the solid electrolyte layer 30 and the counter electrode active material layer 22 laminated in steps S14 and S15 are subjected to a high-pressure press treatment (step S16 in FIG. 5). If necessary, the solid electrolyte layer 30 and the counter electrode active material layer 22 laminated in steps S14 and S15 are also subjected to a heat treatment. This forms a power generation element section 40 in which the insulating layer 13 is provided between the electrode active material layer 12 and the solid electrolyte layer 30, thereby obtaining a laminated electrode plate in which the power generation element section 40 is laminated on the current collector 11.

[0107] 7A, 7B, and 7C are schematic cross-sectional views showing examples of a laminated electrode plate according to the present embodiment. As shown in Fig. 7A, in a laminated electrode plate 41, a power generating element 40, in which an electrode active material layer 12, a solid electrolyte layer 30, and a counter electrode active material layer 22 are laminated in this order, is laminated on a current collector 11. In the power generating element 40, an insulating layer 13 is laminated on the electrode active material layer 12. The laminated electrode plate 41 is formed so that the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 have the same area and position in a plan view. The upper surface of the counter electrode active material layer 22 is exposed.

[0108] The structure of the laminated electrode plate 41 is not limited to this example. For example, as shown in Fig. 7B, the laminated electrode plate 41a is formed so that the side and upper surfaces of the electrode active material layer 12 are covered with the solid electrolyte layer 30, and the side and upper surfaces of the solid electrolyte layer 30 are covered with the counter electrode active material layer 22. In this way, the side and upper surfaces of the electrode active material layer 12 are covered with the solid electrolyte layer 30, which suppresses the occurrence of a short circuit due to contact between the electrode active material layer 12 and the counter electrode active material layer 22 in the second lamination step.

[0109] 7C , for example, the laminated electrode plate 41b is formed so that the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 have decreasing areas in this order in a planar view. In a planar view, 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. Because the counter electrode active material layer 22 is designed to be located inside the solid electrolyte layer 30, even if the stacking position in a planar view is shifted when stacking the counter electrode active material layer 22, the solid electrolyte layer 30 prevents the occurrence of a short circuit due to contact between the electrode active material layer 12 and the counter electrode active material layer 22.

[0110] The laminated electrode plate in this embodiment may have any of the structures of the laminated electrode plates 41, 41a, and 41b, and may have a structure other than the laminated electrode plates 41, 41a, and 41b as long as the power generating element part 40, which includes a structure in which an insulating layer 13 is laminated on an electrode active material layer 12, is laminated on a current collector 11.

[0111] The solid electrolyte layer 30 and the counter electrode active material layer 22 that constitute the power generating element section 40 are formed in order, for example, by using a wet coating method similar to that used to form the electrode active material layer 12 described above.

[0112] When the wet coating method is used, a coating process is carried out in which materials for forming the solid electrolyte layer 30 and the counter electrode active material layer 22 (the above-mentioned materials for the solid electrolyte layer 30 and the positive electrode active material layer or the negative electrode active material layer) are appropriately mixed with a solvent to obtain a slurry.

[0113] The slurries for each layer obtained in the coating process are applied to the electrode active material layer 12 and the insulating layer 13 on the current collector 11 in the order of the solid electrolyte layer 30 and the counter electrode active material layer 22. In this case, the next layer may be applied after the previous layer has been applied, or the next layer may be applied while the previous layer is being applied. In other words, steps S14 and S15 may be performed simultaneously. After the slurries for each layer are applied sequentially and all layers are coated, a heat treatment to remove the solvent and binder material and a high-pressure press treatment to promote the filling of the materials for each layer may be performed. The heat treatment and high-pressure press treatment may be performed after each layer is coated. In other words, step S16 may be performed between steps S14 and S15. The heat treatment and high-pressure press treatment may be performed simultaneously after all layers, i.e., the solid electrolyte layer 30 and the counter electrode active material layer 22, are coated. The high-pressure pressing may be performed using, for example, a roll press or a plate press, etc. At least one of the heat treatment and the high-pressure pressing may not be performed.

[0114] By performing the layered coating method in this manner, it is possible to improve the bonding strength and reduce the interfacial resistance at the interfaces of the current collector 11, electrode active material layer 12, insulating layer 13, solid electrolyte layer 30, and counter electrode active material layer 22. It is also possible to improve the bonding strength and reduce the grain boundary resistance in the powder materials used in the electrode active material layer 12, solid electrolyte layer 30, and counter electrode active material layer 22. In other words, good interfaces are formed between the layers of the power generating element section 40 and between the powder materials within each layer.

[0115] The first lamination step and the second lamination step may be carried out in a continuous process such as a roll-to-roll method.

[0116] (3) Cutting process and third lamination process Next, the cutting step and the third lamination step will be described. FIG. 8 is a diagram illustrating the cutting step in the manufacturing method of a battery according to this embodiment. In the cutting step, the current collector 11 on which the power generating element section 40 formed in the first lamination step and the second lamination step is laminated, i.e., the laminated electrode plate 41, 41a, or 41b, is cut collectively in the lamination direction at positions where the insulating layer 13 is to be divided (step S17 in FIG. 5). As shown in FIG. 8, the laminated electrode plate 41 is cut, for example, with a blade or laser light at positions indicated by dashed lines C1, C2, C3, and C4 where the insulating layer 13 is disposed. At the positions indicated by dashed lines C1, C2, C3, and C4, the current collector 11, the electrode active material layer 12, the insulating layer 13, the solid electrolyte layer 30, and the counter electrode active material layer 22 are laminated in this order, and these are cut collectively. This eliminates the need to laminate the layers of the power generating element section 40 in the shape after cutting, making it easier to manufacture the battery 50. For example, when the insulating layer 13 is laminated in a lattice or stripe pattern having long portions as shown in Figures 6A, 6B, and 6C in plan view, the current collector 11 on which the power generating element section 40 is laminated is cut all at once along the long direction of the lattice or stripe of the insulating layer 13. This results in a battery 50 in which the insulating layer 13 is located over the entire end area on the cut surface side of the manufactured battery 50.

[0117] Next, in the third lamination step, a current collector 21 is laminated as an additional current collector on the surface of the power generating element section 40 of the laminated electrode plate 41 after being cut in the cutting step, opposite to the current collector 11 side (the surface perpendicular to the lamination direction of the power generating element section 40 on which the current collector 11 is not laminated) (step S18 in FIG. 5). Specifically, the current collector 21 is joined to the upper surface of the exposed counter electrode active material layer 22 of the cut laminated electrode plate 41 by a press process or the like. The press process is performed, for example, at a pressure lower than that of the high-pressure press process in step S16. As a result, the battery 50 shown in FIGS. 1 and 2 is obtained.

[0118] The cutting step and the third lamination step may be performed in reverse order. That is, the current collector 21 may be laminated on the surface of the laminated electrode plate 41 before cutting in the cutting step, opposite the side of the power generating element section 40 facing the current collector 11, and then the laminated electrode plate 41 on which the current collector 21 is laminated may be cut in the lamination direction at a position for dividing the insulating layer 13. Furthermore, in the third lamination step, a conductive substrate or housing may be laminated as an additional current collector, instead of the current collector 21, on the side of the power generating element section 40 facing opposite the side facing the current collector 11.

[0119] As described above, the manufacturing method of the battery 50 includes a cutting step of cutting the current collector 11, the electrode active material layer 12, the insulating layer 13, the solid electrolyte layer 30, and the counter electrode active material layer 22 at positions where they are stacked. As a result, the side surfaces of the current collector 11, the electrode active material layer 12, the insulating layer 13, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 are exposed at the ends in a direction perpendicular to the stacking direction. After cutting, a sealing member or the like may be disposed to cover the exposed side surfaces to protect them. In other words, if the side surfaces are covered with another member such as a sealing member, the side surfaces of all layers may not be exposed.

[0120] In this way, by including the cutting step of cutting the positions where the current collector 11, the electrode active material layer 12, the insulating layer 13, the solid electrolyte layer 30, and the counter electrode active material layer 22 are stacked, the end portions of each of the current collector 11, the electrode active material layer 12, the insulating layer 13, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 in a direction perpendicular to the stacking direction are exposed.

[0121] (4) Effects, etc. As described above, the manufacturing method of the battery 50 according to this embodiment includes a first lamination step, a second lamination step, a cutting step, and a third lamination step. In the first lamination step, the insulating layer 13 is laminated on a portion of the surface of the electrode active material layer 12 opposite the current collector 11 side. In the second lamination step, the solid electrolyte layer 30 and the counter electrode active material layer 22 are laminated in this order on the current collector 11 on which the electrode active material layer 12 and the insulating layer 13 are laminated, so that the solid electrolyte layer 30 covers the insulating layer 13 and the electrode active material layer 12. In the cutting step, the current collector 11 on which the power generating element section 40 is laminated is cut all at once in the lamination direction at a position where the insulating layer 13 is to be divided. In the third lamination step, the current collector 21 is laminated on the surface of the power generating element section 40 opposite the current collector 11 side before or after cutting in the cutting step.

[0122] As a result, the current collector 11 on which the power generating element section 40 is laminated is cut all at once in the lamination direction at the position for dividing the insulating layer 13. Therefore, it is not necessary to laminate each layer of the power generating element section 40 in the shape after cutting, and the battery 50 can be easily manufactured.

[0123] Furthermore, the current collector 11, on which the power generating element 40 including the insulating layer 13 laminated on the electrode active material layer 12 is laminated, is cut in the lamination direction at the position where the insulating layer 13 is divided, resulting in a battery in which the insulating layer 13 is laminated on the end of the electrode active material layer 12 in a planar view. Furthermore, the solid electrolyte layer 30 is laminated so as to cover the insulating layer 13 laminated on the electrode active material layer 12. Therefore, even if the solid electrolyte layer 30 peels off at the end of the electrode active material layer 12 and the solid electrolyte layer 30, where peeling is likely to occur at the bonding interface, the insulating layer 13 is exposed, thereby suppressing exposure of the electrode active material layer 12. As a result, damage or short circuits due to contact between the electrode active material layer 12 and other components are less likely to occur. This allows for the manufacture of highly reliable batteries.

[0124] Furthermore, the dimensions of the insulating layer 13 can be determined simply by adjusting the cutting position. Therefore, although the presence of the insulating layer 13 inhibits the exchange of lithium ions between the electrode active material layer 12 and the solid electrolyte layer 30 and forms a region where the electrode active material layer 12 does not easily function as an electrode, this region can be minimized by adjusting the dimensions of the insulating layer 13. Therefore, a battery 50 with a high volumetric energy density can be easily manufactured.

[0125] 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 insulating layer 13 is laminated on the end of the positive electrode active material layer. This prevents metal ions from the positive electrode active material layer from directly reaching the end of the solid electrolyte layer 30, thereby suppressing the function of the positive electrode active material layer at the end as an electrode. In other words, the effective area of ​​the positive electrode active material layer is reduced in plan view. Furthermore, because the power generating element 40 is cut in the lamination direction, the positive electrode active material layer and the negative electrode active material layer (counter electrode active material layer 22) have the same shape, position, and area in plan view. Therefore, the effective area (area functioning as an electrode) of the positive electrode active material layer is smaller than that of the negative electrode active material layer, and the positive electrode active material layer is located inside the negative electrode active material layer in plan view. As a result, metal deposition in the negative electrode active material layer is suppressed as described above. This further improves the reliability of the manufactured battery 50.

[0126] Furthermore, by cutting in the stacking direction, the current collector 11 (for example, laminated electrode plate 41, 41a, or 41b) on which the power generating element section 40 is stacked is cut all at once, and a battery is obtained in which the insulating layer 13 is stacked on the end of the electrode active material layer 12. Therefore, it is not necessary to individually stack the positive electrode active material layer and the negative electrode active material layer having different areas for each unit cell, and the battery 50 can be manufactured easily and efficiently.

[0127] Without the insulating layer 13, even if the current collector 11 on which the power generating element 40 is laminated is cut in one go, the solid electrolyte layer 30 is also laminated on the end of the electrode active material layer 12. This means that when the end of the solid electrolyte layer 30 peels off, exposure of the electrode active material layer 12 cannot be prevented. Furthermore, a battery is produced in which there is no substantial difference in area between the electrode active material layer 12 and the counter electrode active material layer 22. Therefore, even if the battery can be easily manufactured, this method is difficult to adopt as a manufacturing method because it reduces the reliability of the battery. On the other hand, in the manufacturing method according to the present embodiment, as described above, the current collector 11 on which the power generating element 40 is laminated is cut in one go at a position where the insulating layer 13 is to be divided. Therefore, by cutting the current collector 11 on which the power generating element 40 is laminated in one go, not only can the battery be easily manufactured, but also exposure of the electrode active material layer 12 can be prevented, the area of ​​the electrode active material layer 12 that functions as an electrode can be reduced, and the area of ​​the insulating layer 13 can be adjusted. In this way, by combining the first lamination process of laminating the insulating layer 13 on the electrode active material layer 12 with the cutting process of cutting the current collector 11, on which the power generating element part 40 including a structure in which the insulating layer 13 is laminated on the electrode active material layer 12, at a position where the insulating layer 13 is to be divided, it is possible to easily manufacture a battery that is both highly reliable and has a high volumetric energy density.

[0128] (5) Other manufacturing methods The method for manufacturing a battery according to this embodiment is not limited to the above example, and may be, for example, the manufacturing method shown below.

[0129] First, a current collector 11 is prepared in the shape shown in Figures 1 and 2. Then, an electrode active material layer 12 is laminated on the current collector 11 using a coating process or the like in the shape shown in Figures 1 and 2. Furthermore, an insulating layer 13 is formed on the electrode active material layer 12 laminated on the current collector 11 in the shape shown in Figures 1 and 2. A solid electrolyte layer 30 is laminated by lamination coating on the entire surface of the electrode active material layer 12 on which the insulating layer 13 has been formed, to obtain an electrode plate.

[0130] Next, a current collector 21 having the shape shown in Figures 1 and 2 is prepared. Then, a counter electrode active material layer 22 and a solid electrolyte layer 30 are laminated in this order on the entire surface of the current collector 21 by layer coating to obtain a counter electrode plate.

[0131] Next, the obtained electrode plate and counter electrode plate are stacked so that their solid electrolyte layers 30 are in contact with each other. The stacked body is pressed from both sides in the stacking direction using a flat press, thereby obtaining a battery 50.

[0132] [Variation 1] The following describes Modification 1 of Embodiment 1. In the following description of Modification 1 of Embodiment 1, differences from Embodiment 1 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0133] 9 is a schematic cross-sectional view showing an example of a battery according to this modification. As shown in Fig. 9, battery 51 differs from battery 50 of embodiment 1 in that the side surface of battery 51 is inclined with respect to the stacking direction.

[0134] Battery 51 includes electrode layer 10a, counter electrode layer 20a disposed opposite electrode layer 10a, and solid electrolyte layer 30a located between electrode layer 10a and counter electrode layer 20a. Battery 51 further includes insulating layer 13a located between electrode layer 10a and solid electrolyte layer 30a.

[0135] The electrode layer 10a includes a current collector 11a and an electrode active material layer 12a located between the current collector 11a and the solid electrolyte layer 30a. The counter electrode layer 20a includes a current collector 21a and a counter electrode active material layer 22a located between the current collector 21a and the solid electrolyte layer 30a and between the current collector 21a and the insulating layer 13a. The insulating layer 13a is located at an end of the electrode active material layer 12a in a plan view.

[0136] A side surface 51s connecting two main surfaces perpendicular to the stacking direction of the battery 51 is inclined with respect to the stacking direction in a direction such that the area of ​​the counter electrode layer 20a is larger than the area of ​​the electrode layer 10a in a plan view. In other words, the side surface 51s is inclined with respect to the stacking direction in a direction such that the width of the counter electrode layer 20a is larger than the width of the electrode layer 10a in a cross section obtained by cutting the battery 51 in the stacking direction. That is, in the battery 51, the area of ​​the main surface 22s of the counter electrode active material layer 22a facing the electrode active material layer 12a is larger than the area of ​​the main surface 12s of the electrode active material layer 12a facing the counter electrode active material layer 22a. Furthermore, when viewed from the stacking direction, the main surface 12s is located inside the main surface 22s. In the battery 50a, for example, the electrode layer 10a including the electrode active material layer 12a is a positive electrode layer including a positive electrode active material layer, and the counter electrode layer 20a including the counter electrode active material layer 22a is a negative electrode layer including a negative electrode active material layer. In this case, the area of ​​the negative electrode active material layer is larger than the area of ​​the positive electrode active material layer in a plan view, and therefore, metal deposition is suppressed in the battery 50a.

[0137] Furthermore, on the side surface 51s, the side surfaces of the solid electrolyte layer 30 and the insulating layer 13a are also inclined with respect to the stacking direction, so that the exposed surfaces of the solid electrolyte layer 30 and the insulating layer 13a become larger and the distance between the electrode active material layer 12a and the counter electrode active material layer 22a on the side surface 51s becomes longer, making it more difficult for the electrode active material layer 12a and the counter electrode active material layer 22a to come into contact with each other, thereby suppressing short circuits.

[0138] All of the side surfaces 51s of the battery 51, including side surfaces 51s not shown, are inclined with respect to the stacking direction, and the area of ​​the main surface 22s is larger than the area of ​​the main surface 12s. Note that it is not necessary for all of the side surfaces 51s of the battery 51 to be inclined with respect to the stacking direction, as long as at least one side surface 51s is inclined with respect to the stacking direction.

[0139] FIG. 10 is a schematic cross-sectional view showing another example of a battery according to this modification. As shown in FIG. 10, a battery 52 includes an electrode layer 10b, a counter electrode layer 20b, and a solid electrolyte layer 30b. The battery 52 further includes an insulating layer 13b located between the electrode layer 10b and the solid electrolyte layer 30b. The electrode layer 10b includes a current collector 11b and an electrode active material layer 12b. The insulating layer 13b is located at an end of the electrode active material layer 12b in a planar view. The counter electrode layer 20b includes a current collector 21b and a counter electrode active material layer 22b. In the battery 52, one side surface 52s is inclined with respect to the stacking direction in a direction such that the area of ​​the counter electrode layer 20b is larger than the area of ​​the electrode layer 10b in a planar view.

[0140] The batteries 51 and 52 are manufactured, for example, by cutting the battery 50 according to the first embodiment in a direction oblique to the stacking direction. The batteries 51 and 52 may also be manufactured by cutting the battery 50 in a cutting step in a manufacturing method thereof in a direction oblique to the stacking direction. That is, the side surfaces 51s and 52s may be cut surfaces. The shape of the cut surface is trapezoidal in the case of the battery 51, and rectangular in the case of the battery 52.

[0141] FIG. 11 is a diagram illustrating the cutting step in the battery manufacturing method according to this modification. As shown in FIG. 11, batteries 51 and 52 are manufactured by cutting the battery in a direction inclined at an angle θ from the stacking direction in the cutting step described above. The angle θ may be determined based on the width of the insulating layer formed, the desired battery characteristics, and the like. The angle θ is, for example, smaller than 45 degrees. The angle θ may be 30 degrees or smaller. Furthermore, when the angle θ is zero, a battery 50 is manufactured. For example, if the total thickness of the current collector 21, counter electrode active material layer 22, and solid electrolyte layer 30 is 0.1 mm and the width of the insulating layer from the side of the battery is 0.1 mm, if the angle of the cut surface is larger than 45 degrees, the insulating layer will be removed by cutting, and the effect of the insulating layer will not be obtained.

[0142] (Embodiment 2) Next, a battery according to embodiment 2 will be described. The battery according to embodiment 2 is a stacked battery in which unit cells are stacked. In the following description, differences from embodiment 1 will be mainly described, and descriptions of commonalities will be omitted or simplified as appropriate.

[0143] [composition] First, the configuration of the battery according to embodiment 2 will be described with reference to the drawings. Fig. 12 is a schematic cross-sectional view showing an example of a battery according to this embodiment. As shown in Fig. 12, battery 100 has a structure in which unit cells are stacked, each having a structure that does not include current collector 21 in battery 50 according to embodiment 1.

[0144] The battery 100 includes a plurality of batteries 50a and a current collector 21. The battery 50a has a structure including a counter electrode layer 23 that does not include the current collector 21 of the counter electrode layer 20 in the battery 50. That is, the battery 50a includes an electrode layer 10, a counter electrode layer 23 that is disposed opposite the electrode layer 10 and is composed of a counter electrode active material layer 22, and a solid electrolyte layer 30 that is located between the electrode layer 10 and the counter electrode layer 23. The battery 50a further includes an insulating layer 13 that is located between the electrode layer 10 and the solid electrolyte layer 30.

[0145] In the battery 100, the multiple batteries 50a are stacked such that the current collector 11 of one of the adjacent batteries 50a faces the counter electrode active material layer 22 of the other. This results in a structure in which the function of the current collector 11 is shared by the adjacent batteries 50a. Furthermore, the current collector 21 is stacked on the counter electrode active material layer 22 of the uppermost battery 50a. This makes the battery 100 a series-stacked battery. This makes it possible to realize a series-stacked high-voltage battery 100 that exhibits the same effects as the battery 50 according to the first embodiment.

[0146] 12, the number of stacked batteries 50a is five, but may be two to four, or six or more. Battery 50b, which is the uppermost cell stacked, is composed of battery 50a and current collector 21, and has the same stacking configuration and shape as battery 50 according to embodiment 1.

[0147] The side surface of the battery 100 is, for example, a cut surface. The side surface of the battery 100 is also a flat plane. In other words, the side surfaces of the multiple batteries 50a and the current collector 21 are flush with each other. Each layer may be exposed on the side surface of the battery 100, or a sealing member or the like may be provided. FIG. 13 is a schematic cross-sectional view showing another example of a battery according to the present embodiment. As shown in FIG. 13, the battery 100a has a structure in which the side surface of the battery 100 is covered with a sealing member 60. In other words, the side surface of each layer constituting the battery 100a is covered with the sealing member 60. This prevents the side surface of each layer from being exposed, thereby increasing the strength of the battery 100a and improving the reliability of the battery 100a.

[0148] The sealing member 60 of the battery 100a is formed, for example, by placing the battery 100 with its side surface facing upward and applying the sealing member to the side surface from above using a dispenser or the like. The sealing member 60 can be made of a material that is a known sealing member material for batteries (for example, lithium-ion solid-state batteries).

[0149] [Manufacturing method] Next, a method for manufacturing the battery according to this embodiment will be described. Note that the method for manufacturing the battery 100 described below is an example, and the method for manufacturing the battery 100 is not limited to the following example.

[0150] The manufacturing method for the battery 100 includes a first stacking step, a second stacking step, a cutting step, and a third stacking step, similar to the manufacturing method for the battery 50. Each step will be described in detail below.

[0151] (1) First lamination process First, the first lamination step will be described. Fig. 14 is a flowchart for explaining the method for manufacturing a battery according to this embodiment.

[0152] In the first lamination step, first, a plurality of current collectors 11 are prepared (step S21 in FIG. 14). Then, an electrode active material layer 12 is laminated on only one surface of each of the prepared plurality of current collectors 11 (step S22 in FIG. 14). Then, an insulating layer 13 is laminated on the surface of the electrode active material layer 12 opposite to the current collector 11 side (step S23 in FIG. 14). In steps S21, S22, and S23, the same methods as in steps S11, S12, and S13 described above can be used. As a result, a plurality of current collectors 11 on which electrode active material layers 12 and insulating layers 13 are laminated can be obtained, for example, as shown in FIGS. 6A, 6B, and 6C.

[0153] (2)Second lamination process Next, the second lamination step will be described. In the manufacturing method according to this embodiment, the second lamination step includes a laminate formation step and a laminate lamination step. In the laminate formation step, a solid electrolyte layer 30 and a counter electrode active material layer 22 are laminated on each of a plurality of current collectors 11, on which the electrode active material layer 12 and the insulating layer 13 are laminated, so that the solid electrolyte layer 30 covers the electrode active material layer 12 and the insulating layer 13. This results in a plurality of laminated electrode plates (e.g., laminated electrode plates 41, 41a, or 41b shown in FIGS. 7A, 7B, and 7C) in which power generating element sections 40 are laminated on the current collectors 11. Specifically, the solid electrolyte layer 30 and the counter electrode active material layer 22 are laminated in this order on each of the plurality of current collectors 11, on which the electrode active material layer 12 and the insulating layer 13 are laminated, so that the solid electrolyte layer 30 covers the electrode active material layer 12 and the insulating layer 13 (steps S24 and S25 in FIG. 14). Furthermore, if necessary, the solid electrolyte layer 30 and the counter electrode active material layer 22 laminated in steps S24 and S25 are each subjected to high-pressure pressing (step S26 in FIG. 14). Furthermore, if necessary, the solid electrolyte layer 30 and the counter electrode active material layer 22 laminated in steps S24 and S25 are each subjected to heat treatment. The high-pressure pressing and heat treatment may also be performed on the electrode active material layer 12 laminated in step S22 in the first lamination process. In steps S24, S25, and S26, the same methods as those in steps S14, S15, and S16 described above may be used.

[0154] Next, in the laminate stacking step, the plurality of laminate electrode plates formed in the laminate formation step are stacked such that the insulating layers 13 of the plurality of laminate electrode plates overlap in plan view (step S27 in FIG. 14). This forms a multilayer electrode plate in which the plurality of laminate electrode plates are stacked. FIG. 15 is a schematic cross-sectional view showing an example of a multilayer electrode plate according to the present embodiment. FIG. 15 shows a multilayer electrode plate 45 in which laminate electrode plates 41 are stacked. As shown in FIG. 15, in the laminate stacking step, the plurality of laminate electrode plates 41 are stacked such that the counter electrode active material layer 22 of one of the adjacent laminate electrode plates 41 faces the current collector 11 of the other. For example, the stacked plurality of laminate electrode plates 41 are pressed from both sides in the stacking direction to join the plurality of laminate electrode plates 41 together, thereby forming the multilayer electrode plate 45. In the multilayer electrode plate 45, of the adjacent laminated electrode plates 41, the current collector 11 of the upper laminated electrode plate 41 and the counter electrode active material layer 22 of the lower laminated electrode plate 41 are in contact with each other.

[0155] If the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 are subjected to high-pressure pressing when forming the laminated electrode plate 41, high-pressure pressing is not required in the pressing process when forming the multilayer electrode plate 45. For example, the pressure of the pressing process for joining the laminated electrode plates 41 together in step S27 is lower than the pressure of the high-pressure pressing process in step S26. This allows the multilayer electrode plate 45 to be formed without destroying the interfaces formed in the laminate formation step.

[0156] (3) Cutting process and third lamination process Next, the cutting step and the third lamination step will be described. In the cutting step, the multilayer electrode plate 45, i.e., the multiple current collectors 11 on which the multiple power generating element units 40 formed in the second lamination step are stacked, are cut together in the lamination direction at positions that divide the insulating layers 13 (step S28 in FIG. 14). As shown in FIG. 15, the multilayer electrode plate 45 is cut with a blade or laser light, for example, at the positions indicated by dashed lines C5, C6, C7, and C8 where the insulating layers 13 are arranged. At the positions indicated by dashed lines C5, C6, C7, and C8, multiple laminated electrode plates 41 are stacked, and these are cut together. By cutting the multiple laminated electrode plates 41 together in this way, it is not necessary to manufacture and then stack unit cells in the shape of the cut parts. This significantly reduces the number of times that the power generating element units 40 are stacked on the current collectors 11 in the first lamination step and the second lamination step. This allows for efficient production of stacked batteries.

[0157] Next, in the third lamination step, a current collector 21 is laminated as an additional current collector on the surface of the multilayer electrode plate 45 after being cut in the cutting step, opposite the current collector 11 of the power generating element section 40 (step S29 in FIG. 14 ). Specifically, in the cut multilayer electrode plate 45, a current collector 21 is joined by pressing or the like to the surface of the power generating element section 40 opposite the current collector 11 of a laminate electrode plate 41 that does not have another laminate electrode plate 41 laminated on the surface opposite the current collector 11 of the power generating element section 40. In the example shown in FIG. 15 , the current collector 21 is joined onto the exposed counter electrode active material layer 22 on the top surface of the uppermost laminate electrode plate 41. This results in the battery 100 shown in FIG. 12 .

[0158] The cutting step and the third lamination step may be performed in reverse order. That is, current collectors 21 may be laminated on the surface of power generating element section 40 of multilayer electrode plate 45 before cutting in the cutting step, opposite current collectors 11, and then multilayer electrode plate 45 with current collectors 21 laminated thereon may be cut all at once in the lamination direction at the position where insulating layer 13 is to be divided.

[0159] In this way, by using the battery manufacturing method according to this embodiment, a high-voltage battery 100 of the series-stacked type can be manufactured.

[0160] [Variation 1] The following describes Modification 1 of Embodiment 2. In the following description of Modification 1 of Embodiment 2, differences from Embodiments 1 and 2 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0161] A method for manufacturing a battery according to this modification will be described. The method for manufacturing a battery according to this modification differs from the method for manufacturing a battery according to the second embodiment in that a multilayer electrode plate having a structure in which electrode active material layers 12 are laminated on both sides of a current collector 11 is formed.

[0162] First, in the first lamination step, both the electrode active material layer 12 and the insulating layer 13 are laminated on both sides of the current collector 11. The positions of the insulating layers 13 laminated on both sides are the same in a plan view. The same method as in steps S11 and S12 described above can be used to laminate the electrode active material layer 12 and the insulating layer 13 on the current collector 11. For example, the electrode active material layer 12 and the insulating layer 13 are laminated on the side of the current collector 11 on which the electrode active material layer 12 and the insulating layer 13 are not laminated, as shown in FIG. 6A, 6B, or 6C.

[0163] Next, a second lamination step is performed. FIG. 16 is a schematic cross-sectional view showing an example of a laminated electrode plate according to this modification. FIG. 17 is a schematic cross-sectional view showing an example of a multilayer electrode plate according to this modification. First, a solid electrolyte layer 30 and a counter electrode active material layer 22 are laminated and coated in this order on both sides of a current collector 11, each of which has an electrode active material layer 12 and an insulating layer 13 laminated on both sides, so that the solid electrolyte layer 30 covers the electrode active material layer 12 and the insulating layer 13, to form a laminate in which a power generating element section 40 is laminated on both sides of the current collector 11. In laminating the solid electrolyte layer 30 and the counter electrode active material layer 22, each layer may be laminated and coated sequentially on one side of the current collector 11, or the same layer may be laminated and coated simultaneously on both sides of the current collector 11. The resulting laminate is then laminated on a current collector 25 to form a laminated electrode plate 43a shown in FIG. 16. In the laminated electrode plate 43a, a coating structure is formed in which the solid electrolyte layer 30 covers the electrode active material layer 12 and the insulating layer 13.

[0164] The same method as in steps S14 and S15 described above can be used to stack the solid electrolyte layer 30 and the counter electrode active material layer 22 of the laminated electrode plate 43a. Furthermore, if necessary, the stacked electrode active material layer 12, solid electrolyte layer 30, and counter electrode active material layer 22 are each subjected to a high-pressure press treatment similar to step S16. Furthermore, if necessary, the stacked solid electrolyte layer 30 and counter electrode active material layer 22 are each subjected to a heat treatment.

[0165] 17, the plurality of laminated electrode plates 43a are stacked such that the insulating layers 13 of the plurality of laminated electrode plates 43a overlap. At this time, the plurality of laminated electrode plates 43a are stacked such that the counter electrode active material layer 22 of one of the adjacent laminated electrode plates 43a faces the current collector 25 of the other. The stacked plurality of laminated electrode plates 43a are pressed from both sides in the stacking direction, thereby joining the plurality of laminated electrode plates 43a and forming a multilayer electrode plate 47.

[0166] The multilayer electrode plate 47 has a structure in which a current collector 11, a power generating element section 40, and a current collector 25 are stacked. The multilayer electrode plate 47 also has a structure in which the current collector 11 is sandwiched between two power generating element sections 40, each having a structure in which a solid electrolyte layer 30 is stacked so as to cover the electrode active material layer 12 and the insulating layer 13, and the current collector 11 and the current collector 25 are stacked so as to sandwich one of the two power generating element sections 40. As will be described in detail later, a current collector 21 is stacked on the other of the two power generating element sections 40 located at the top, on the side opposite to the current collector 11.

[0167] In this modified example, the number of stacked electrode plates 43a in the multi-layer electrode plate 47 is three, but it may be one or more and two or less, or may be four or more.

[0168] The method for forming the multilayer electrode plate 47 in the first lamination step and the second lamination step is not limited to the above example. FIGS. 18 and 19 are schematic cross-sectional views showing another example of a multilayer electrode plate having an insulating layer according to this modification. In the first lamination step and the second lamination step according to this modification, for example, a multilayer electrode plate 43b having an insulating layer 13 laminated on an electrode active material layer 12 formed on a current collector 11 as shown in FIG. 18 and a multilayer electrode plate 43c having an insulating layer 13 laminated on an electrode active material layer 12 not formed on a current collector 11 as shown in FIG. 19 may be formed. The multilayer electrode plate 43b is formed, for example, by coating a solid electrolyte layer 30 and a counter electrode active material layer 22 in this order on a current collector 11 having an electrode active material layer 12 and an insulating layer 13 laminated on one side thereof. Specifically, the solid electrolyte layer 30 and the counter electrode active material layer 22 are laminated on one surface of the current collector 11 on which the electrode active material layer 12 and the insulating layer 13 are laminated, so that the solid electrolyte layer 30 covers the electrode active material layer 12 and the insulating layer 13. In the laminated electrode plate 43b, a coating structure is formed in which the solid electrolyte layer 30 covers the electrode active material layer 12 and the insulating layer 13.

[0169] In forming the laminated electrode plate 43c, for example, first a base such as a resin film is prepared, and the electrode active material layer 12, the insulating layer 13, the solid electrolyte layer 30, and the counter electrode active material layer 22 are coated and laminated in this order on one surface of the base to form the power generating element part 40. Then, a current collector 25 having the same shape as the current collector 11 in a plan view is laminated on the counter electrode active material layer 22 of the formed power generating element part 40, and the base is removed to form the laminated electrode plate 43c.

[0170] The same methods as those in steps S12, S13, S14, and S15 described above can be used to stack the power generating element parts 40 of the laminated electrode plates 43b and 43c. Furthermore, if necessary, high-pressure pressing is performed on each of the stacked electrode active material layers 12, solid electrolyte layers 30, and counter electrode active material layers 22. Furthermore, if necessary, heat treatment is performed on each of the stacked electrode active material layers 12, solid electrolyte layers 30, and counter electrode active material layers 22.

[0171] Next, the obtained laminated electrode plates 43a and 43c are used to alternately stack the laminated electrode plates 43a and 43b so that the current collector 11 of the laminated electrode plate 43b faces the electrode active material layer of the laminated electrode plate 43c, thereby forming the multilayered electrode plate 47 shown in FIG. 17. In forming the multilayered electrode plate 47, the laminated electrode plates 43b and 43c are alternately stacked so that the insulating layers 13 of the laminated electrode plates 43b and 43c overlap in a plan view. The stacked laminated electrode plates 43b and 43c are pressed from both sides in the stacking direction, thereby joining the laminated electrode plates 43b and 43c, and the multilayered electrode plate 47 is formed.

[0172] When a plurality of types of laminated electrode plates are combined and laminated, such as when laminated electrode plates 43b and 43c are alternately laminated, the laminated configuration is not limited to the configuration of laminated electrode plates 43b and 43c. The laminated electrode plates may have any configuration as long as they can be combined and laminated to form multilayer electrode plate 47. Furthermore, the laminated electrode plate may be formed by dividing it into three or more laminated electrode plates.

[0173] Next, a cutting step is performed. In the cutting step, the multilayer electrode plate 47, i.e., the power generating element 40, current collector 11, and current collector 25 stacked in the first and second stacking steps, are cut together in the stacking direction at positions that divide the insulating layer 13. As shown in Fig. 17, for example, the multilayer electrode plate 47 is cut with a blade or laser light at positions indicated by dashed lines C9, C10, C11, and C12 where the insulating layer 13 is located. At the positions of dashed lines C9, C10, C11, and C12, multiple laminated electrode plates 43a are stacked, and these are cut together.

[0174] Next, a third lamination step is performed. In this step, a current collector 21 is laminated as an additional current collector on the surface of the power generating element section 40 of the multilayer electrode plate 47 after cutting in the cutting step, on which the current collector 11 is not laminated. Specifically, in the cut multilayer electrode plate 47, the current collector 21 is joined by pressing or the like to the exposed surface of the power generating element section 40 that is laminated at the top or bottom of the multiple laminated electrode plates 43a. FIG. 20 is a schematic cross-sectional view showing an example of a battery according to this modification. Through this third lamination step, a battery 102 shown in FIG. 20 is obtained.

[0175] The cutting step and the third lamination step may be performed in reverse order.

[0176] 20 , the battery 102 includes a plurality of batteries 50c and a current collector 21. The battery 50c includes a current collector 25, two counter electrode active material layers 22 located above the current collector 25 and arranged to face each other, two solid electrolyte layers 30 located between the two counter electrode active material layers 22 and arranged to face each other, two electrode active material layers 12 located between the two solid electrolyte layers 30 and arranged to face each other, a current collector 11 located between the two electrode active material layers 12, and two insulating layers 13 located between the electrode active material layers 12 and the solid electrolyte layers 30 and stacked on the ends of the electrode active material layers 12 in a plan view.

[0177] In the battery 102, multiple batteries 50c are stacked such that the current collector 25 of one battery 50c faces the counter electrode active material layer 22 of the other battery 50c. This results in a structure in which the function of the current collector 25 is shared by the adjacent batteries 50c. Furthermore, the current collector 21 is stacked on the counter electrode active material layer 22 of the uppermost battery 50c. The battery 102 has a structure in which electrode active material layers 12 are stacked on both sides of the current collector 11, and counter electrode active material layers 22 are stacked on both sides of the current collector 25. This results in the battery 102 being a parallel-stacked battery. To extract current, the current collector 21 and the current collector 25 are electrically connected by leads or the like, and the current collectors 11 are electrically connected to each other by leads or the like, thereby functioning as a parallel-stacked battery. In the example shown in FIG. 20, the number of stacked batteries 50c is three, but it may be one to two or four or more.

[0178] In the battery 50c, the portion consisting of the upper current collector 21, the counter electrode active material layer 22, the solid electrolyte layer 30, the insulating layer 13, the electrode active material layer 12, and the current collector 11 has the same laminated structure and shape as the battery 50 according to the first embodiment.

[0179] The side surface of the battery 102 is a cut surface formed by the above-described manufacturing method. The side surfaces of the multiple batteries 50b and the current collector 21 are flush with each other. That is, a single flat surface is formed on the side surface of the battery 102. Each layer may be exposed on the side surface of the battery 102, or a sealing member or the like may be provided.

[0180] FIG. 21 is a schematic cross-sectional view showing another example of a battery according to this modification. As shown in FIG. 21, a battery 102a has a structure in which the side surfaces of the battery 102 are covered with sealing members 60a and 60b. The side surface of the battery 102 covered by sealing member 60a and the side surface of the battery 102 covered by sealing member 60b are arranged opposite each other. The side surfaces of the battery 102 are covered. Furthermore, in the battery 102a, the entire side surface of the battery 102a is not covered by sealing member 60a or 60b. For example, in order to connect a lead for extracting electricity as described above, sealing member 60a does not cover the exposed portion of current collector 25, and sealing member 60b does not cover the exposed portion of current collector 11.

[0181] In this way, by using the battery manufacturing method according to this modification, it is possible to manufacture a parallel-stacked, high-capacity battery 102 that exhibits the same effects as the battery 50 according to the first embodiment.

[0182] (Embodiment 3) The following describes embodiment 3. In the following description of embodiment 3, differences from embodiments 1 and 2 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0183] Fig. 22 is a cross-sectional view showing a schematic configuration of a battery according to the present embodiment. As shown in Fig. 22, the battery 104 includes a plurality of batteries 50 according to embodiment 1, and has a structure in which the plurality of batteries 50 are stacked. The plurality of batteries 50 are stacked such that one electrode layer 10 and the other counter electrode layer 20 of adjacent batteries 50 in the stacking direction face each other. In other words, the battery 104 is a series-stacked battery. As a result, a high-voltage battery 104 can be realized using the batteries 50 according to embodiment 1.

[0184] The side surface of the battery 104 is a flat plane, in other words, the side surfaces of the plurality of batteries 50 are flush with each other. Note that the plurality of batteries 50 may be stacked with a shift in the direction perpendicular to the stacking direction in order to connect leads or the like.

[0185] The battery 104 is manufactured by stacking a plurality of batteries 50, for example, so that one electrode layer 10 and the other counter electrode layer 20 of adjacent batteries 50 in the stacking direction face each other. Alternatively, the battery 104 may be manufactured by stacking a current collector 21 on the side of a laminated electrode plate 41 (see FIG. 7A ) before cutting, opposite the current collector 11 of the power generating element section 40, stacking a plurality of laminated electrode plates 41 with the current collectors 21 stacked thereon, and then cutting the laminated electrode plates 41 in the stacking direction at positions to divide the insulating layers 13.

[0186] When the battery 50 is stacked, the two current collectors 11 and 21 are adjacent to each other, but the battery may be one in which one of the adjacent current collectors 11 and 21 is missing.

[0187] 23 is a cross-sectional view showing a schematic configuration of another example of a battery according to the present embodiment. As shown in FIG. 23, the battery 105 includes a plurality of batteries 51 according to the first modification of the first embodiment, and has a structure in which the plurality of batteries 51 are stacked. The plurality of batteries 51 are stacked such that one electrode layer 10a and the other counter electrode layer 20a of adjacent batteries 51 in the stacking direction face each other. In other words, the battery 105 is a series-stacked battery. As a result, a high-voltage battery 105 can be realized using the battery 51 according to the first modification of the first embodiment.

[0188] Although the battery 104 and the battery 105 are serially stacked type batteries, they may be parallel stacked type batteries having a structure in which the electrode layers or counter electrode layers of adjacent cells are stacked so as to face each other. In the parallel stacked type battery, a high-capacity battery can be realized.

[0189] By stacking the batteries 50 or 51, which are single cells, in this manner, a high-capacity or high-voltage battery can be realized that can achieve the same effects as the batteries 50 or 51.

[0190] (Other embodiments) While the battery and manufacturing method thereof according to the present disclosure have been described above based on the embodiments, the present disclosure is not limited to these embodiments. As long as they do not deviate from the gist of the present disclosure, various modifications conceivable by those skilled in the art to the embodiments and other forms constructed by combining some of the components of the embodiments are also included within the scope of the present disclosure.

[0191] In the above embodiment, the battery is composed of a current collector, an electrode active material layer, an insulating layer, a solid electrolyte layer, and a counter electrode active material layer, but is not limited thereto. For example, within the range of allowable battery characteristics, a bonding layer or the like may be provided between each layer of the battery to reduce electrical resistance and improve bonding strength.

[0192] Furthermore, in the above-described embodiment, the battery includes an insulating layer located between the electrode active material layer and the solid electrolyte layer at an end of the electrode active material layer in a planar view. However, the battery may further include a second insulating layer located between the counter electrode active material layer and the solid electrolyte layer at an end of the counter electrode active material layer in a planar view. In this case, the length of the second insulating layer from the outer periphery of the counter electrode active material layer in a planar view may be shorter than the length of the insulating layer from the outer periphery of the electrode active material layer. This prevents exposure of the counter electrode active material layer even if the end of the solid electrolyte layer on the counter electrode active material layer side peels off. Furthermore, since the second insulating layer is narrower than the insulating layer in a planar view, the area of ​​the electrode active material layer is effectively smaller than the area of ​​the counter electrode active material layer.

[0193] In the above embodiment, the insulating layer is located on the outer periphery of the electrode layer in a plan view and has a frame shape, but this is not limiting. For example, in a battery, there may be a region on the outer periphery of the electrode layer in a plan view where no insulating layer is provided.

[0194] Furthermore, for example, in the above embodiment, the inner side surface of the insulating layer is in contact with the solid electrolyte layer, but this is not limited thereto. At least a portion of the inner side surface of the insulating layer may be in contact with the electrode active material layer. For example, by adjusting the pressure of the high-pressure press treatment, a portion of the insulating layer is embedded in the electrode active material layer, and a battery is manufactured in which at least a portion of the inner side surface of the insulating layer is in contact with the electrode active material layer. Furthermore, for example, by stacking an insulating layer on a solid electrolyte layer and then stacking an electrode active material layer so as to cover the solid electrolyte layer and the insulating layer, a battery is manufactured in which the inner side surface of the insulating layer is in contact with the electrode active material layer.

[0195] Furthermore, for example, in the above-described embodiment, when the battery is surrounded by a case or a substrate, and a part of the case or the substrate functions as a current collector, the battery does not need to have a current collector on the counter electrode active material layer side. In other words, the counter electrode layer may be composed of the counter electrode active material layer.

[0196] In the above embodiment, the current collector, electrode active material layer, solid electrolyte layer, and counter electrode active material layer have the same shape and position in a plan view, but this is not limited thereto. At least one of the current collector, electrode active material layer, solid electrolyte layer, and counter electrode active material layer may have a different shape or position in a plan view. For example, the current collector may have a terminal portion for connection to a lead or the like that protrudes from the end of the electrode active material layer in a plan view. In other words, the current collector may have a region that is disposed outside the electrode active material layer in a plan view.

[0197] In the above embodiment, in the second lamination step, the power generating element portion is formed by sequentially laminating a solid electrolyte layer and a counter electrode active material layer on a current collector on which an electrode active material layer and an insulating layer are laminated, but this is not limiting. For example, in the second lamination step, the solid electrolyte layer and the counter electrode active material layer may be formed by sequentially laminating them on a sheet-like substrate, and the formed solid electrolyte layer and counter electrode active material layer may be removed from the substrate and laminated on a current collector on which an electrode active material layer and an insulating layer are laminated.

[0198] Furthermore, the above-described embodiments can be modified, replaced, added, omitted, and the like in various ways within the scope of the claims or their equivalents. [Industrial Applicability]

[0199] The battery according to the present disclosure can be used, for example, as a secondary battery such as an all-solid-state battery used in various electronic devices or automobiles. [Explanation of symbols]

[0200] 10, 10a, 10b electrode layer 11, 11a, 11b, 21, 21a, 21b, 25 Current collector 12, 12a, 12b electrode active material layer 12s, 22s main surface 13, 13a, 13b insulating layers 20, 20a, 20b, 23 Counter electrode layer 22, 22a, 22b Counter electrode active material layer 30, 30a, 30b solid electrolyte layer 40 Power generation element 41, 41a, 41b, 43a, 43b, 43c laminated plate 45, 47 Multilayer plate 50, 50a, 50b, 50c, 51, 52, 100, 100a, 101, 102, 102a, 104, 105 batteries 51s, 52s side 60, 60a, 60b Sealing member

Claims

1. an electrode layer; a counter electrode layer disposed opposite the electrode layer; a solid electrolyte layer located between the electrode layer and the counter electrode layer and in contact with the electrode layer; an insulating layer located between the electrode layer and the solid electrolyte layer; Equipped with The electrode layer is A current collector; an electrode active material layer located between the current collector and the solid electrolyte layer, and between the current collector and the insulating layer; the insulating layer is located at an end of the electrode active material layer in a plan view, the insulating layer is located in a region having a length of 1 mm or less from the outer periphery of the electrode active material layer in a plan view, the counter electrode layer has a counter electrode active material layer disposed opposite the electrode active material layer, the side surfaces of the solid electrolyte layer, the current collector, the electrode active material layer, the counter electrode active material layer, and the insulating layer are exposed; battery.

2. a side surface of the insulating layer and a side surface of the electrode active material layer are flush with each other; The battery of claim 1 .

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

4. The insulating layer contains a resin. The battery according to any one of claims 1 to 3.

5. the insulating layer includes a metal oxide; The battery of any one of claims 1 to 4.

6. The thickness of the insulating layer is 5 μm or less. The battery of any one of claims 1 to 5.

7. The thickness of the insulating layer is 2 μm or less. The battery of claim 6.

8. a side surface of the electrode layer, a side surface of the counter electrode layer, a side surface of the solid electrolyte layer, and a side surface of the insulating layer are flush with each other; The battery of any one of claims 1 to 7.

9. the counter electrode layer has a counter electrode active material layer disposed opposite the electrode active material layer, In a plan view, the electrode active material layer and the counter electrode active material layer have the same shape and position. The battery of any one of claims 1 to 8.

10. a side surface of the battery is inclined with respect to the stacking direction in a direction such that the area of ​​the counter electrode layer is larger than the area of ​​the electrode layer in a plan view; The battery of any one of claims 1 to 8.

11. The side surface of the battery is a cut surface. The battery of any one of claims 1 to 10.

12. The shape of the cut surface is rectangular or trapezoidal. The battery of claim 11.

13. The insulating layer is located on the outer periphery of the electrode active material layer in a plan view and has a frame shape.

13. The battery of any one of claims 1 to 12.

14. The solid electrolyte layer contains a solid electrolyte having lithium ion conductivity.

14. The battery of any one of claims 1 to 13.

15. A battery comprising: an electrode layer; a counter electrode layer disposed opposite the electrode layer; a solid electrolyte layer located between the electrode layer and the counter electrode layer and in contact with the electrode layer; an insulating layer located between the electrode layer and the solid electrolyte layer; Equipped with The electrode layer is A current collector; an electrode active material layer located between the current collector and the solid electrolyte layer, and between the current collector and the insulating layer; the insulating layer is located at an end of the electrode active material layer in a plan view, the insulating layer is located in a region having a length of 1 mm or less from the outer periphery of the electrode active material layer in a plan view, a side surface of the battery is inclined with respect to the stacking direction in a direction such that the area of ​​the counter electrode layer is larger than the area of ​​the electrode layer in a plan view; battery.

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