All-solid-state battery and method for manufacturing the same

Abstract

To provide an all-solid battery capable of absorbing displacement of an electrode body.SOLUTION: An all-solid battery comprises: an electrode body in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated; and an exterior member that houses the electrode body. The exterior member has: a first region opposed to the outermost lamination surface of the electrode body; and a second region formed between the first region and the central part of the electrode body in the lamination direction of the electrode body. The second region is provided with a displacement absorbing part that can absorb displacement of the electrode body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an all-solid-state battery and a method for manufacturing an all-solid-state battery. [Background technology]

[0002] In light of climate-related disasters, there has been growing interest in electric vehicles as a way to reduce CO2 emissions, and the use of secondary batteries in automotive applications is also being considered. All-solid-state batteries, which have a solid electrolyte between the positive and negative electrodes, are attracting attention because they are safer, have a wider usable temperature range, and have shorter charging times than conventional lithium secondary batteries.

[0003] As a countermeasure against expansion and contraction that may occur due to charging and discharging of an all-solid-state battery, Patent Document 1 discloses a technology for restraining an all-solid-state battery in a plane direction that intersects with the stacking direction of electrode layers, etc., when the battery expands and contracts in response to an applied voltage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-140022 Summary of the Invention [Problem to be solved by the invention]

[0005] The thickness of the exterior material of an all-solid-state battery in the stacking direction (thickness of the deep-drawn portion) is determined to match the expanded thickness when fully charged, so as to prevent cracks and the like caused by stress at the welded portion of the exterior material when the electrode body of the electrode element enclosed inside expands in volume.

[0006] When using a material with large volume expansion (such as Si or Li metal), various stresses act on the all-solid-state battery due to changes in the surface properties of the exterior member during production of the all-solid-state battery and during full discharge and full charge after sealing, and the action of these various stresses may affect the performance of the all-solid-state battery.

[0007] In view of the above problems, an object of the present invention is to provide an all-solid-state battery capable of absorbing displacement of an electrode body. [Means for solving the problem]

[0008] An all-solid-state battery according to one aspect of the present invention includes: an electrode assembly including a positive electrode layer, a solid electrolyte layer, and a negative electrode layer stacked together; An all-solid-state battery comprising: an exterior member that houses the electrode body; The exterior member is a first region facing the lamination surface of the outermost layer of the electrode body; ,before The first area End of and the above Peripheral edge of exterior member and a second region formed between the first region and the second region, The second region is provided with a displacement absorbing section that can absorb the displacement of the electrode body. And, The displacement absorbing portion has a plurality of steps formed therein, the plurality of steps are formed at different inclination angles with respect to a normal to the surface formed in the first region, Among the plurality of steps, the step formed in a direction away from the center of the stacking direction of the electrode body is formed at an inclination angle smaller than the inclination angle of the step formed in the center. There are.

[0009] A method for producing an all-solid-state battery according to another aspect of the present invention includes: an exterior member that houses the electrode body, the exterior member having a first region facing a lamination surface of the outermost layer of the electrode body; ,before The first area End of and the above Peripheral edge of exterior member and a second region formed between the outer casing member and the outer casing member, and the second region is provided with a displacement absorbing portion capable of absorbing displacement of the electrode body; A method for manufacturing an all-solid-state battery comprising: By pressing the material of the exterior member, a plurality of steps are formed in the displacement absorbing portion. death, the plurality of steps are formed at different inclination angles with respect to a normal to the surface formed in the first region, Among the plurality of steps, a step formed in a direction away from a center portion in the stacking direction of the electrode body is formed at an inclination angle smaller than an inclination angle of a step formed in the center portion. do. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an all-solid-state battery capable of absorbing displacement of an electrode body. [Brief explanation of the drawings]

[0011] [Figure 1] 1A is a plan view of an all-solid-state battery according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA in FIG. 1A. [Figure 2] 1A to 1C are diagrams illustrating an outline of a flow of a manufacturing method for an all-solid-state battery according to an embodiment. [Figure 3] 5A to 5C are diagrams schematically illustrating a process in a step of forming an exterior member. [Figure 4] FIG. 4 is a diagram illustrating the schematic shape of a jig used in a process of forming an exterior member. [Figure 5] An enlarged view of part B in Figure 1(A). [Figure 6] FIG. 10 is a diagram showing a comparative example between a conventional example and an all-solid-state battery according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.

[0013] FIG. 1 is a diagram showing the configuration of an all-solid-state battery 1 according to an embodiment of the present invention. FIG. 1(A) shows a plan view of the all-solid-state battery 1 according to the embodiment, and FIG. 1(B) shows a cross-sectional view of the all-solid-state battery 1 taken along line AA in FIG. 1(A). In the coordinate system in the figure, the X axis indicates the longitudinal direction of the all-solid-state battery 1 (extension direction of the lead tabs), the Y axis indicates the width direction of the all-solid-state battery 1 (a direction perpendicular to the extension direction of the lead tabs), and the Z axis indicates the thickness direction of the all-solid-state battery 1 (stacking direction of the electrode body 2). FIG. 1(A) is a diagram showing the all-solid-state battery 1 in the XY plane, and FIG. 1(B) is a diagram showing the all-solid-state battery 1 in the XZ plane.

[0014] The all-solid-state battery 1 includes an electrode body 2 (also referred to as a laminate in this embodiment) which is an energy storage element and is formed by laminating a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, an exterior member 18 which seals the periphery of the housed electrode body 2, lead tabs 13 and 14, and current collecting tabs 15 and 16.

[0015] The electrode body 2 in FIG. 1(B) has a two-layer structure of a positive electrode layer and a negative electrode layer. The positive electrode layer has two positive electrode layers 21 and 23, and the negative electrode layer has two negative electrode layers 22 and 24. A solid electrolyte layer 25 is provided between the positive electrode layer 21 and the negative electrode layer 22. A solid electrolyte layer 25 is also provided between the positive electrode layer 23 and the negative electrode layer 24. The positive electrode layer and the negative electrode layer may be single-phase (one-phase) or may be composed of multiple layers. When multiple positive electrode layers and multiple negative electrode layers are provided, a solid electrolyte layer is provided between each positive electrode layer and negative electrode layer, as shown in FIG. 1(B). The example in FIG. 1(B) illustrates a two-layer structure of a positive electrode layer and a negative electrode layer, but is not limited to this example, and the positive electrode layer and the negative electrode layer may be three or more layers.

[0016] The positive electrode layers 21 and 23 each have a positive electrode active material layer 111 and a positive electrode current collector 112. The positive electrode current collector 112 is common to the two positive electrode layers 21 and 23. The positive electrode current collector 112 is disposed at the center in the thickness direction (Z direction) of the electrode body 2, and the positive electrode active material layer 111 of the positive electrode layer 21 and the positive electrode active material layer 111 of the positive electrode layer 23 are laminated on the upper and lower sides of the positive electrode current collector 112.

[0017] The negative electrode layer 22 is disposed (stacked) on the upper surface side of the positive electrode layer 21 in the thickness direction (Z direction) of the electrode body 2, and the negative electrode layer 24 is disposed (stacked) on the lower surface side of the positive electrode layer 23 in the thickness direction (Z direction) of the electrode body 2. The negative electrode layers 22 and 24 are stacked so as to sandwich the positive electrode layers 21 and 23. The negative electrode layers 22 and 24 each have a negative electrode active material layer 121 and a negative electrode current collector 122. The two negative electrode current collectors 122 are each formed in a layered form on the outermost layers of the electrode body 2. The configuration of the positive electrode layer and the negative electrode layer is not limited to the stacking order shown in FIG. 1(B), and they may be stacked so that two positive electrode layers sandwich two negative electrode layers.

[0018] Examples of the active material constituting the positive electrode active material layer 111 include NCM-based (ternary active materials) materials in which cobalt, nickel, and manganese are mixed, such as lithium cobalt oxide, lithium nickel oxide, and lithium manganese oxide.

[0019] Examples of the active material constituting the negative electrode active material layer 121 include lithium-based materials and silicon-based materials. Other examples of the material constituting the negative electrode active material layer 121 include carbon materials such as graphite, soft carbon, and hard carbon, tin-based materials, and transition metal oxides (for example, lithium titanate: LTO).

[0020] The solid electrolyte layer 25 is made of, for example, a solid electrolyte having ionic conductivity, and examples of the material include a sulfide-based solid electrolyte material, an oxide-based solid electrolyte material, a nitride-based solid electrolyte material, and a halide-based solid electrolyte material.

[0021] The positive electrode current collector 112 and the negative electrode current collector 122 are made of, for example, a metal foil, a metal sheet, or a metal plate made of aluminum, copper, SUS, or the like. The positive electrode active material layer 111, the negative electrode active material layer 121, and the solid electrolyte layer 25 may be formed by binding particles of the materials that make them up with an organic polymer compound binder. The positive electrode active material layer 111 or the negative electrode active material layer 121 may contain an electronic conductive additive such as carbon (particles or fibers) or metal powder. A solid electrolyte powder may also be disposed in the positive electrode active material layer 111 or the negative electrode active material layer 121 to establish an ion conductive path.

[0022] The exterior member 18 is a container that houses the electrode assembly 2. The exterior member 18 is formed by folding a single sheet-like material in two, or by bonding multiple sheets of sheet-like material together. The material of the exterior member 18 is formed, for example, by covering the front and back surfaces of a metal layer with an insulating layer.

[0023] The exterior member 18 has a rectangular shape formed by four sides 18a to 18d in a plan view from the Z direction, and the peripheral edge of the exterior member 18 is sealed when the electrode body 2 is housed inside. The peripheral edge of the exterior member 18 is sealed by bonding the material of the exterior member 18 together by adhesion, welding, or the like.

[0024] Of the four sides 18a to 18d of the exterior member 18, strip-shaped lead tabs 13 and 14 are provided so as to cross the opposing sides 18a and 18b, and the electrode body 2 is located between the lead tabs 13 and 14.

[0025] As shown in FIG. 1(B), peripheral edges 183a and 183b of the exterior member 18 are sealed so as to sandwich the lead tab 13, and peripheral edges 183c and 183d of the exterior member 18 are sealed so as to sandwich the lead tab 14.

[0026] One end of the lead tab 13 is located outside the exterior member 18, and the other end is located inside the exterior member 18. The other end of the lead tab 13 is connected to the positive electrode current collector 112 inside the exterior member 18 via a current collecting tab 15, and the lead tab 13 forms a tab for the positive electrode. The lead tab 13 and the current collecting tab 15 are formed, for example, from a conductive metal sheet or metal plate.

[0027] One end of the lead tab 14 is located outside the exterior member 18, and the other end is located inside the exterior member 18. The other end of the lead tab 14 is connected to the negative electrode current collector 122 inside the exterior member 18 via a current collecting tab 16, and the lead tab 14 forms a tab for the negative electrode. The lead tab 14 and the current collecting tab 16 are formed, for example, from a conductive metal sheet or metal plate. The electrode body 2 can be charged or discharged by connecting the lead tabs 13 and 14 to a charger or an electrical load.

[0028] In an embodiment of the present invention, the exterior member 18 has a flexible structure (displacement absorbing section) capable of absorbing displacement of the electrode body 2 due to expansion and contraction of the electrode body 2. The exterior member 18 has a first region 181 facing a surface (stacking surface of the outermost layer) of the electrode body 2 that intersects with the thickness direction (stacking direction) of the electrode body 2, and a second region 182 formed between the first region 181 and a central portion of the electrode body 2 (for example, lead tabs 13 and 14 in FIG. 1 ) in the stacking direction of the electrode body 2. The second region 182 is provided with a displacement absorbing section capable of absorbing displacement. In a side view of the exterior member 18, this displacement absorbing section has multiple steps 182a to 182d formed therein. The displacement absorbed by the displacement absorbing section includes at least one of displacement in the stacking direction (Z direction) of the electrode body 2, displacement in the longitudinal direction (X direction) of the electrode body 2, and displacement in the width direction (Y direction) of the electrode body 2. Here, the cross-sectional shape of the plurality of steps 182a-182d may include irregularities formed on the surface of the exterior member 18 along the stacking direction (Z direction) of the electrode body 2. For example, the cross-sectional shape of the plurality of steps 182a-182d may be a cross-sectional shape formed by combining straight lines in a stepped manner at a predetermined angle, or a cross-sectional shape formed by combining arcs or triangular waveforms in a waveform, or a combination of both.

[0029] 3, which will be described below, illustrates an example of a cross-sectional shape formed by combining straight lines at predetermined angles (θ1 to θ4) between adjacent steps in a stepped manner, but the cross-sectional shape of the multiple steps 182a to 182d of this embodiment is not limited to this example.The cross-sectional shape of the multiple steps 182a to 182d in FIG. 3 can also be formed by combining arcs with a predetermined curvature or triangular waveforms in a waveform.

[0030] (Manufacturing method) FIG. 2 is a diagram illustrating an outline of the flow of a method for manufacturing an all-solid-state battery 1 according to an embodiment of the present invention. In step S201, a package member 18 is formed in advance by a separate flow. In step S202, the positive electrode layers 21 and 23, the solid electrolyte layer 25, and the negative electrode layers 22 and 24 described in FIG. 1 are manufactured, and the manufactured electrode layers are stacked to manufacture an electrode body 2. Then, in step S203, the electrode body 2 is housed in the package member 18 formed in S201, and the periphery of the package member 18 is sealed. Note that the flowchart in FIG. 2 is illustrative, and steps S201 and S202 may be reversed.

[0031] 3 is a diagram schematically illustrating the process of forming the exterior member 18 (deep drawing process) in step S201, and shows an example in which four steps are formed as the configuration of the displacement absorbing section (ST31 to ST34). Note that the number of steps is not limited to this example.

[0032] 4A and 4B are diagrams illustrating the schematic shape of a jig used in the process of forming the exterior member 18. Fig. 4A shows the schematic planar shape of the jig in the XY plane, and Fig. 4B shows the schematic side shape of the jig in the XZ plane. The planar shape of the jig has a dimension Li in the X direction (longitudinal direction) and a dimension Wi in the Y direction (width direction). Four corners 401 have a radius Ri.

[0033] In addition, an inclined portion 402 forming a step is formed at the lower end of the jig. The inclined portion 402 has an inclination angle θi inclined with respect to the normal to the surface (region surface) formed in the first region 181, which is a plane facing the lamination surface of the electrode body 2. For example, as shown in FIG. 4, if the dimension of the lower end surface of the jig in the X direction (longitudinal direction) is Lzi and the depth of the inclined portion in the Z direction is Zi, the inclination angle can be calculated by θi = (Li - Lzi) / Zi. A similar inclined portion is also formed in the Y direction (width direction) of the lower end surface of the jig. If the dimension of the lower end surface of the jig in the Y direction (width direction) is Wzi (not shown) and the depth of the inclined portion in the Z direction is Zi, the inclination angle can be calculated by θi = (Wi - Wzi) / Zi. The inclination angle θi of the inclined portion 402 is the same in the X direction (longitudinal direction) and the Y direction (width direction).

[0034] Inclined portions with an inclination angle θi are formed in the four directions of the X direction (longitudinal direction) and Y direction (width direction) of the jig, and when the material of the exterior member 18 is pressed by a deep drawing process using the jig, steps with an inclination angle θi are formed in the four directions of the longitudinal direction and width direction of the exterior member 18 in a side view in the XZ direction. Also, corners with a radius Ri are formed at the four corners where the sides of the exterior member 18 in the longitudinal direction and width direction intersect in a plan view in the XY direction.

[0035] Although an example is shown in which different jigs 301 to 304 are used in each of the steps ST1 to ST4 in Figure 3, the use of different jigs 301 to 304 is not limited to this, and an apparatus having a single jig in which the shapes of each of the jigs 301 to 304 are formed in multiple stages may also be used.

[0036] The inclined portions (402 in FIG. 4) of the jigs 301 to 304 shown in FIG. 3 have different inclination angles θ1 to θ4, respectively. The relationships between the inclination angles θ1 to θ4 are such that θ2 is smaller than θ1 (θ2<θ1), θ3 is smaller than θ2 (θ3<θ2), and θ4 is smaller than θ3 (θ4<θ3).

[0037] Also, the corner portions (401 in FIG. 4) of the jigs 301 to 304 have different radii Ri. Let the radius of jig 301 be R1, the radius of jig 302 be R2, the radius of jig 303 be R3, and the radius of jig 304 be R4. Here, the relationship of the radii is such that R2 is smaller than R1 (R2 < R1), R3 is smaller than R2 (R3 < R2), and R4 is smaller than R3 (R4 < R3).

[0038] In ST31 of FIG. 3, by pressing the material of the exterior member 18 with the jig 301, a step 182a (first step) is formed. Here, FIG. 5 is a diagram showing an enlarged state of part B in FIG. 1(A). In the plan view of the exterior member 18, corner portions 501a to 501d with different radii R1 to R4 are formed at the corners of the plurality of steps 182a to 182d. In ST31, a corner portion 501a with a radius R1 is formed at the corner of the step 182a.

[0039] In ST32, by pressing the material of the exterior member 18 with the jig 302, a step 182b (second step) is formed. Also, in ST32, a corner portion 501b with a radius R2 is formed at the corner of the step 182b.

[0040] In ST33, by pressing the material of the exterior member 18 with the jig 303, a step 182c (third step) is formed. Also, in ST33, a corner portion 501c with a radius R3 is formed at the corner of the step 182c.

[0041] Then, in ST34, by pressing the material of the exterior member 18 with the jig 304, a step 182d (fourth step) is formed. Also, in ST34, a corner portion 501d with a radius R4 is formed at the corner of the step 182d. The dimension Li in the X direction and the dimension Wi in the Y direction of the jig 304 are assumed to be equal to the dimensions in the X direction and the Y direction of the electrode body 2, and the step 182d formed by the jig 304 is formed so as to be able to abut against the side surface of the electrode body 2.

[0042] As described above, in the forming step (S201) of the exterior member 18, the material of the exterior member 18 is pressed multiple times using the jigs 301-304, etc., to form multiple steps 182a-182d in the displacement absorbing portion of the second region 182. Note that in the example of Fig. 3, an example is described in which the multiple steps 182a-182d are formed using the jigs 301-304, etc., in ST31-S34, but the formation of the steps is not limited to this example. For example, if the jigs 301-304 are combined into a single jig, the multiple steps 182a-182d can be formed in the displacement absorbing portion of the second region 182 by pressing the material of the exterior member 18 at least once.

[0043] Because the inclination angles of the inclined portions of the jigs 301 to 304 are different, the plurality of steps 182a to 182d formed in ST31 to ST34 are formed at different inclination angles θ1 to θ4, respectively, with respect to the normal 403 of the surface formed in the first region 181. In addition, because the radii of the corners of the jigs 301 to 304 are different, the corners of the plurality of steps 182a to 182d formed in ST31 to ST34 are formed at different radii R1 to R4, respectively.

[0044] With regard to the inclination angle of each step when viewed from the side, among the multiple steps 182a to 182d, the steps (e.g., steps 182b, 182c, or 182d) formed in a direction away from the central portion of the stacking direction of the electrode body 2 (e.g., lead tabs 13 and 14 in Figure 1) are formed at an inclination angle θ1 that is smaller than the inclination angle θ1 of the step (e.g., step 182a) formed in the central portion.

[0045] Among the multiple steps 182a to 182d, a step (for example, 182d) formed in a position close to the surface (laminated surface of the outermost layer) of the electrode body 2 is formed at an inclination angle (for example, approximately zero) that allows it to come into contact with the side surface of the electrode body 2. At least a portion of the step 182d comes into contact with the side surface of the electrode body 2 housed in the exterior member 18.

[0046] With regard to the radius of each step when viewed in a plane, among the multiple steps 182a to 182d, the radius of the corner of a step (e.g., step 182b, 182c, or 182d) formed in a direction away from the center of the stacking direction of the electrode body 2 (e.g., lead tabs 13 and 14 in Figure 1) is formed to a radius (R2 to R4) that is smaller than the radius R1 of the corner of the step (e.g., step 182a) formed in the center.

[0047] Furthermore, among the multiple steps 182a to 182d, the step (for example, 182d) formed at a position close to the surface of the electrode body 2 (the stacking surface of the outermost layer (122 in Figure 1)) has a corner radius that is formed to a radius (for example, approximately 90 degrees) that allows it to abut against the side surface of the electrode body 2.

[0048] By forming the step 182d with an inclination angle (in a side view) and a radius (in a plan view) that allow it to abut against the side surface of the electrode body 2, when the electrode body 2 is housed in the exterior member 18, the electrode body 2 is held by abutment with the step 182d, and displacement of the electrode body 2 in the XY directions within the exterior member 18 due to vibration can be prevented. Furthermore, when the electrode body 2 is housed in the exterior member 18, the surface of the electrode body 2 (the stacked surface of the outermost layer (122 in FIG. 1)) abuts against an area having a two-dimensional extent that is formed in the first region 181 of the exterior member 18. The area formed in the first region 181 is parallel to the stacked surface of the outermost layer of the electrode body 2. This makes it possible to prevent displacement of the electrode body 2 in the Z direction within the exterior member 18 due to vibration.

[0049] (Comparison between the conventional example and the embodiment) FIG. 6 is a diagram showing a comparative example between a conventional all-solid-state battery 600 and the all-solid-state battery 1 according to the embodiment.

[0050] (When creating a cell) When fabricating a cell in the conventional example, a deep-drawn portion 682 is formed in the Z direction of the exterior member 618 to provide a predetermined gap (space) between the electrode assembly 602 and the exterior member 618, anticipating expansion and displacement of the electrode assembly 602 when fully charged. For this reason, the electrode assembly 602 is configured to be supported only by the lead tabs 613, 614. Because the electrode assembly 602 cannot be suspended in mid-air, the lead tabs 613, 614 are lengthened to absorb the gap by displacement of the lead tabs 613, 614. According to the configuration of the conventional example, in order to alleviate stress and prevent excessive stress from acting near the lead tabs 613, 614, it is necessary to form the lead tabs 613, 614 longer, but in this case, the energy density decreases.

[0051] On the other hand, according to the configuration of the all-solid-state battery 1 of the embodiment, the plurality of steps 182 (182a to 182d) of the displacement absorbing section can absorb the displacement of the electrode assembly 2 in the stacking direction, so there is no need to provide a predetermined gap between the electrode assembly 2 and the exterior member 18. As a result, the electrode assembly 2 is held in contact with the exterior member 18 (for example, 181, 182d in FIG. 1). Therefore, the lead tabs 13, 14 and the electrode assembly 2 can be aligned to the center in the Z direction while suppressing stress acting on the lead tabs 13, 14. Furthermore, according to the configuration of the all-solid-state battery 1 of the embodiment, it is possible to suppress a decrease in energy density in the lead tabs 13, 14, which may occur in conventional examples.

[0052] (After sealing) In the conventional sealing method, the interior of the cell is sealed in a vacuum state where the pressure is reduced to a predetermined level. This causes deformation of the surface of the exterior member 618, including the deep-drawn portion 682, due to the atmospheric pressure outside the cell. During vacuum sealing, the atmospheric pressure acts on the deep-drawn portion 682, potentially resulting in wrinkles. If a material with large volume expansion (e.g., Si or Li metal) is used for the electrode assembly 602, the deep-drawn portion must be made deeper. Increasing the predetermined gap increases the deformation of the surface of the exterior member 618. In this case, the deformed exterior member 618 comes into contact with the electrode assembly 602, and the resulting pressure exerted on the electrode assembly 602 can cause misalignment of the stacked electrode layers. Therefore, the vacuum must be drawn slowly before sealing. This increases the production cycle time and can increase manufacturing costs.

[0053] On the other hand, according to the configuration of the all-solid-state battery 1 of the embodiment, the plurality of steps 182 (182a to 182d) of the displacement absorbing section can absorb displacement of the electrode assembly 2 in the stacking direction. Therefore, even if the surface properties of the exterior member 18 are displaced due to the influence of atmospheric pressure outside the cell, the plurality of steps 182 (182a to 182d) of the displacement absorbing section deform preferentially and absorb the displacement before the first region 181, so that the surface of the first region 181 that abuts against the electrode assembly 2 is not deformed. Furthermore, it is possible to suppress misalignment that may occur in the stacking positions of the electrode layers of the electrode assembly. Furthermore, compared to conventional examples, it is possible to shorten the production takt time and reduce manufacturing costs.

[0054] (When fully charged) In the conventional example, the depth of the deep drawing portion 682 is set to match the thickness of the electrode body 602 when fully charged, so even if the electrode body 602 expands in the Z direction when fully charged, the impact of the stress acting on the exterior member 618 is small.

[0055] However, when expansion exceeding a predetermined maximum thickness occurs in the electrode body 602, a tensile stress in the direction of arrow 620 acts on the deep drawing portion 682 of the exterior member 618. This may also affect the performance of the lead tabs 613, 614 and the peripheral portion 625 (sealing portion).

[0056] On the other hand, according to the configuration of the all-solid-state battery 1 of the embodiment, since the plurality of steps 182 (182a to 182d) of the displacement absorbing portion can absorb the displacement of the electrode body 2, even if expansion in the stacking direction occurs in the electrode body 2, the plurality of steps 182 (182a to 182d) of the displacement absorbing portion follow the expansion in the Z direction of the electrode body 2 and absorb the displacement prior to the first region 181. Therefore, no deformation occurs on the surface of the first region 181 that is in contact with the electrode body 2. Further, since the generation of tensile stress in the direction of arrow 620 is also suppressed, the influence on the lead tabs 13, 14 and the peripheral portions 183a to 183d (FIG. 1) can be reduced as compared with the conventional example. In the configuration of the all-solid-state battery 1 of the embodiment, let the thickness of the all-solid-state battery 1 at the time of cell fabrication be t1, and the thickness of the all-solid-state battery 1 after sealing (State Of Charge (SOC) 0% or less) be t2. Also, let the thickness of the all-solid-state battery 1 at full charge (SOC 100%) be t3, and the thickness of the all-solid-state battery 1 at full discharge (SOC 0%) be t4. In this case, the relationship between the thicknesses is t2 ≦ t1 < t4 < t3. Thus, according to the all-solid-state battery 1 of the present embodiment, even if expansion and contraction with a changing thickness (t2 ≦ t1 < t4 < t3) occurs in the electrode body 2, the plurality of steps 182 (182a to 182d) of the displacement absorbing portion follow the expansion and contraction in the Z direction of the electrode body 2 and absorb the displacement prior to the first region 181.

[0057] <Summary of the Embodiment> The above embodiment discloses at least the following all-solid-state battery and method for manufacturing an all-solid-state battery.

[0058] Configuration 1. The all-solid-state battery of the above embodiment includes an electrode body (2) in which a positive electrode layer (21, 23), a solid electrolyte layer (25), and a negative electrode layer (22, 24) are stacked, and an exterior member (18) that houses the electrode body, and is an all-solid-state battery (1) comprising: The exterior member (18) is a first region (181) facing the lamination surface of the outermost layer of the electrode body, and a second region (182) formed between the first region and a central portion of the electrode body in the lamination direction of the electrode body; The second region is provided with displacement absorbing sections (182a to 182d) that can absorb displacement of the electrode body.

[0059] According to this embodiment, even if expansion and contraction occur in the electrode body (2), the displacement absorbing section deforms in accordance with the displacement of the electrode body and absorbs the expansion and contraction, thereby providing an all-solid-state battery that can absorb the displacement of the surface properties of the exterior member and the displacement of the electrode body.

[0060] Configuration 2: In the above embodiment, the displacement absorbing portion is formed with a plurality of steps (182a to 182d).

[0061] According to this embodiment, even if the electrode body 2 expands or contracts, the multiple steps (182a to 182d) deform in accordance with the displacement of the electrode body 2, absorbing the expansion and contraction, thereby absorbing the displacement of the surface properties of the exterior member and the displacement of the electrode body.

[0062] Configuration 3. In the above embodiment, the plurality of steps (182a to 182d) are formed at different inclination angles (θ1 to θ4) relative to the normal (403) of the surface formed in the first region.

[0063] Configuration 4. In the above embodiment, of the plurality of steps (182a to 182d), the steps (182b to 182d) formed in a direction away from the center of the stacking direction are formed at inclination angles (θ2 to θ4) that are smaller than the inclination angle (θ1) of the step (182a) formed in the center.

[0064] Configuration 5. In the above embodiment, among the plurality of steps (182a to 182d), at least a portion of the step (182d) formed in a position close to the surface of the electrode body abuts against the side surface of the electrode body (2) housed in the exterior member.

[0065] According to the embodiments of configurations 3 to 5, when the electrode body 2 is housed in the exterior member 18, the electrode body 2 is held by abutting against the step 182d, and displacement of the electrode body 2 in the XY directions within the exterior member 18 due to vibration can be prevented.

[0066] Configuration 6: In the above embodiment, when the electrode body (2) is housed in the exterior member (18), the stacking surface (122) of the outermost layer of the electrode body (2) abuts against the area surface formed in the first area (181).

[0067] Configuration 7: In the above embodiment, the area surface formed in the first area (181) is parallel to the lamination surface of the outermost layer of the electrode body (2).

[0068] According to the sixth and seventh embodiments, it is possible to prevent the electrode body (2) from being displaced in the Z direction within the exterior member (18) due to vibration.

[0069] Configuration 8. The method for manufacturing the all-solid-state battery of the above embodiment includes the steps of: forming an electrode body (2) in which a positive electrode layer (21, 23), a solid electrolyte layer (25), and a negative electrode layer (22, 24) are laminated; an exterior member (18) that houses the electrode body, the exterior member having a first region (181) that faces the stacking surface of the outermost layer of the electrode body, and a second region (182) that is formed between the first region and a central portion of the electrode body in the stacking direction of the electrode body, the second region being provided with a displacement absorbing portion that can absorb displacement of the electrode body; A method for manufacturing an all-solid-state battery (1) comprising: By pressing the material of the exterior member (18), a plurality of steps (182a to 182d) are formed in the displacement absorbing portion.

[0070] According to this embodiment, even if expansion and contraction occurs in the electrode body 2, the displacement absorbing section deforms in accordance with the displacement of the electrode body and absorbs the expansion and contraction, thereby making it possible to manufacture an all-solid-state battery that can absorb the displacement of the surface properties of the exterior member and the displacement of the electrode body.

[0071] 9. In the above embodiment, the formation of the plurality of steps includes: a first step formed in the center in the stacking direction; a second step formed in a direction away from the central portion in the stacking direction and located more inward than the first step; a third step formed in a direction away from the central portion in the stacking direction and located more inward than the second step; A fourth step is formed in a direction further away from the central portion in the stacking direction and is formed more inward than the third step.

[0072] For example, if the fourth step is formed first and then the third step is formed, a jig is required that prevents the fourth step from being deformed when the material for exterior member 18 is pressed with jig 303. Similarly, if the second step is formed after the third step is formed, a jig is required that prevents the third and fourth steps from being deformed when the material for exterior member 18 is pressed with jig 302. Furthermore, if the first step is formed after the second step is formed, a jig is required that prevents the second, third, and fourth steps from being deformed when the material for exterior member 18 is pressed with jig 301. In this way, if the step close to the second side surface of the electrode (fourth step 182d) is formed first and then the steps are formed sequentially in a direction away from the second side surface of the electrode (third step, second step, first step), a separate jig is required to prevent deformation of the steps that have already been formed.

[0073] According to this embodiment, by forming the first step, the second step, the third step, and the fourth step in that order among the plurality of steps, a jig for preventing deformation of the formed steps is not required, and a method for manufacturing the all-solid-state battery 1 with excellent work efficiency can be provided.

[0074] Although the embodiments of the invention have been described above, the invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]

[0075] 1: all-solid-state battery, 2: electrode body, 18: exterior member, 182a to 182d: steps

Claims

1. an electrode body in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked; An all-solid-state battery comprising: an exterior member that houses the electrode body; The exterior member is a first region facing the lamination surface of the outermost layer of the electrode body, and a second region formed between an end of the first region and a peripheral edge of the exterior member, a displacement absorbing portion capable of absorbing displacement of the electrode body is provided in the second region; The displacement absorbing portion has a plurality of steps formed therein, the plurality of steps are formed at different inclination angles with respect to a normal to a surface formed in the first region, Among the plurality of steps, a step formed in a direction away from a center portion in the stacking direction of the electrode body is formed at an inclination angle that is smaller than an inclination angle of a step formed in the center portion.

2. an electrode body in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked; An all-solid-state battery comprising: an exterior member that houses the electrode body; The exterior member is a first region facing the lamination surface of the outermost layer of the electrode body, and a second region formed between an end of the first region and a peripheral edge of the exterior member, a displacement absorbing portion capable of absorbing displacement of the electrode body is provided in the second region; The displacement absorbing portion has a plurality of steps formed therein, the plurality of steps are formed at different inclination angles with respect to a normal to a surface formed in the first region, At least a portion of the step formed near the surface of the electrode body among the plurality of steps abuts against a side surface of the electrode body housed in the exterior member.

3. 3. The all-solid-state battery according to claim 1, wherein, when the electrode body is housed in the exterior member, a lamination surface of the outermost layer of the electrode body abuts against a region surface formed in the first region.

4. 4. The all-solid-state battery according to claim 3, wherein the area surface formed in the first area is parallel to a lamination surface of the outermost layer of the electrode body.

5. an electrode body in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked; an exterior member that houses the electrode body, the exterior member having a first region facing a lamination surface of the outermost layer of the electrode body, and a second region formed between an end of the first region and a peripheral edge of the exterior member, the second region being provided with a displacement absorbing portion that can absorb displacement of the electrode body; A method for manufacturing an all-solid-state battery comprising: By pressing the material of the exterior member, a plurality of steps are formed in the displacement absorbing portion, the plurality of steps are formed at different inclination angles with respect to a normal to a surface formed in the first region, a step formed in a direction away from a center portion in a stacking direction of the electrode body among the plurality of step differences is formed at an inclination angle smaller than an inclination angle of the step formed in the center portion.

6. An electrode body in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked; an exterior member that houses the electrode body, the exterior member having a first region facing a lamination surface of the outermost layer of the electrode body, and a second region formed between an end of the first region and a peripheral edge of the exterior member, the second region being provided with a displacement absorbing portion that can absorb displacement of the electrode body; A method for manufacturing an all-solid-state battery comprising: By pressing the material of the exterior member, a plurality of steps are formed in the displacement absorbing portion, the plurality of steps are formed at different inclination angles with respect to a normal to a surface formed in the first region, a step formed near a surface of the electrode body among the plurality of steps, at least a portion of which abuts against a side surface of the electrode body housed in the exterior member.

7. In forming the plurality of steps, a first step formed at a center portion in the stacking direction of the electrode body; a second step formed in a direction away from the central portion in the stacking direction and located more inward than the first step; a third step formed in a direction away from the central portion in the stacking direction and located more inward than the second step; a fourth step formed in a direction further away from the central portion in the stacking direction and located more inward than the third step, the method for manufacturing an all-solid-state battery according to claim 5 or 6,

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