Electrode body, solid battery, and method for manufacturing electrode body

Abstract

To provide: an electrode body in which even if a member exposed on a side face is bent, cutting of the member and peeling of a material contained in the member hardly occur; a solid-state battery; and a manufacturing method of the electrode body.SOLUTION: An electrode body comprises: a laminate principal part in which a first collector, a first active material layer, an electrolyte layer, a second active material layer and a second collector are laminated in this order; and an extension part extending from the laminate principal part and having a width smaller than a width of the laminate principal part. The extension part includes: a collector extension part extending from the first collector; and an extension part mixture layer which is laminated on the collector extension part and includes at least one selected from among the first active material layer, the electrolyte layer and the second active material layer. A Young's modulus of the extension part is 0.5 GPa or more and 3.0 GPa or less and a Young's modulus of the laminate principal part is 6.0 GPa or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an electrode body, a solid battery, and a method for manufacturing an electrode body.

Background Art

[0002] In an electrode body, in order to be electrically connected to an external device or the like, when observed in the thickness direction of the electrode body, there is a case where a member for electrically connecting to an external device or the like is exposed on the side surface of the electrode body. For example, Patent Document 1 proposes "an electrode of a laminated battery having an electrode current collector foil, an electrode composite layer formed on the electrode current collector foil, and a separator formed on the electrode composite layer, wherein the electrode has an electrode laminate portion and an electrode terminal portion protruding from the electrode laminate portion, and the electrode composite layer is exposed when the electrode terminal portion is viewed from the lamination direction of the electrode."

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, when an electrode body having a member exposed on the side surface is housed in a battery, it may be necessary to bend the exposed member. In this case, the member exposed on the side surface may be cut when the member is bent, and peeling of the material contained in the member exposed on the side surface may occur, which may reduce the degree of freedom in the shape of the battery. Therefore, in an electrode body having a member exposed on the side surface, development of an electrode body in which the exposed member has bending resistance is required.

[0005] The problem to be solved by one embodiment of the present disclosure is to provide an electrode body in which even when a member exposed on the side surface (i.e., the extending portion in the electrode body according to the present disclosure) is bent, cutting of the member and peeling of the material contained in the member (i.e., the extending portion composite layer in the electrode body according to the present disclosure) are less likely to occur. Another problem to be solved by one embodiment according to the present disclosure is to provide a solid-state battery including an electrode body in which even when a member exposed on the side surface is bent, cutting of the member and peeling of the material contained in the member are less likely to occur. Another problem to be solved by one embodiment according to the present disclosure is to provide a method for manufacturing an electrode body in which an electrode body in which even when a member exposed on the side surface is bent, cutting of the member and peeling of the material contained in the member are less likely to occur can be obtained.

Means for Solving the Problem

[0006] The means for solving the above problems include the following means. <1> A main body of a laminate in which a first current collector, a first active material layer, an electrolyte layer, a second active material layer, and a second current collector are laminated in this order, and an extending portion extending from the main body of the laminate and having a width smaller than the width of the main body of the laminate, wherein the extending portion is laminated with a current collector extending portion extending from the first current collector and an extending portion composite layer including at least one selected from the group consisting of the first active material layer, the electrolyte layer, and the second active material layer on the current collector extending portion, the Young's modulus of the extending portion is 0.5 GPa or more and 3.0 GPa or less, and the Young's modulus of the main body of the laminate is 6.0 GPa or more. <2> The electrode body according to <1>, wherein the filling rate of the extending portion composite layer in the extending portion is 75% or less. <3> A solid-state battery including the electrode body according to <1> or <2>. <4> A step of obtaining a laminate by laminating a base material, a first active material layer, an electrolyte layer, and a second active material layer in this order, applying a linear pressure of 3 t / cm to the laminate 2The step of applying the following pressure, and A method for manufacturing an electrode body having

Advantages of the Invention

[0007] The problem to be solved by one embodiment of the present disclosure is to provide an electrode body in which even when a member exposed on the side surface is bent, cutting of the member and peeling of the material contained in the member are less likely to occur. Another problem to be solved by one embodiment of the present disclosure is to provide a solid-state battery including an electrode body in which even when a member exposed on the side surface is bent, cutting of the member and peeling of the material contained in the member are less likely to occur. Another problem to be solved by one embodiment of the present disclosure is to provide a method for manufacturing an electrode body in which an electrode body in which even when a member exposed on the side surface is bent, cutting of the member and peeling of the material contained in the member are less likely to occur can be obtained.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0009] Hereinafter, an embodiment which is an example of the present disclosure will be described. These descriptions and examples are illustrative of the embodiments and do not limit the scope of the invention. In the numerical ranges described step by step in this specification, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Further, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

[0010] Each component may contain a plurality of corresponding substances. When referring to the amount of each component in the composition, when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the plurality of substances present in the composition. The term "step" includes not only independent steps, but also cases where it cannot be clearly distinguished from other steps, as long as the intended action of the step is achieved.

[0011] <Electrode body> The electrode body according to the present disclosure has a main laminate part in which a first current collector, a first active material layer, an electrolyte layer, a second active material layer, and a second current collector are laminated in this order, and an extension part that extends from the main laminate part and has a width smaller than the width of the main laminate part. The extension part is laminated with a current collector extension part extending from the first current collector and an extension part composite layer including at least one selected from the group consisting of the first active material layer, the electrolyte layer, and the second active material layer on the current collector extension part. The Young's modulus of the extension part is 0.5 GPa or more and 3.0 GPa or less, and the Young's modulus of the main laminate part is 6.0 GPa or more.

[0012] The electrode body according to the present disclosure provides an electrode body in which, even when the extension part is bent, cutting of the extension part and peeling of the extension part composite layer included in the extension part are less likely to occur. The reason is presumed to be that by setting the Young's modulus of the extension part to 0.5 GPa or more and 3.0 GPa or less and the Young's modulus of the main laminate part to 6.0 GPa or more, the flexibility of the extension part is improved. Hereinafter, the details of the electrode body according to the present disclosure will be described.

[0013] (Laminated structure of electrode body) An example of the laminated structure of the electrode body according to the present disclosure will be described with reference to FIG. 1. FIG. 1 is a schematic perspective view of an embodiment of the electrode body according to the present disclosure, and the electrode body according to the present disclosure is not limited thereto. The electrode body 810 has a main laminated part in which a first current collector 81, a first active material layer 82, an electrolyte layer 83, a second active material layer 84, and a second current collector 85 are laminated in this order. In addition, the electrode body 810 has a current collector extension part 86 extending from the first current collector, and an extension part in which a first active material layer 87, an electrolyte layer 88, and a second active material layer 89 are laminated on the current collector extension part 86.

[0014] Details of the electrode body according to the present disclosure will be described below, and reference numerals may be omitted.

[0015] (Main laminated part) In the electrode body according to the present disclosure, the main laminated part laminates a first current collector, a first active material layer, an electrolyte layer, a second active material layer, and a second current collector in this order.

[0016] - First current collector - The first current collector is a positive electrode current collector or a negative electrode current collector, and is preferably a negative electrode current collector. Examples of the material of the first current collector include metal, carbon, and the like. Examples of the material of the first current collector include stainless steel, aluminum, nickel, iron, titanium, carbon, etc., and aluminum alloy foil or aluminum foil is preferred. The aluminum alloy foil and the aluminum foil may be manufactured using powder. Examples of the shape of the first current collector include a foil shape and a mesh shape, and a foil shape is preferred.

[0017] - First active material layer - Examples of the first active material layer include a positive electrode active material layer and a negative electrode active material layer, and a negative electrode active material layer is preferred.

[0018] The positive electrode active material layer contains at least a positive electrode active material. The positive electrode active material layer may contain a conductive assistant, a solid electrolyte, a binder, and other components as required. Preferably, the positive electrode active material includes a lithium composite oxide. The lithium composite oxide may contain at least one selected from the group consisting of F, Cl, N, S, Br, and I. Further, the lithium composite oxide may have a crystal structure belonging to at least one space group selected from the space groups R-3m, Immm, and P63-mmc (also referred to as P63mc and P6 / mmc). Further, the main arrangement of transition metal, oxygen, and lithium in the lithium composite oxide may be an O2-type structure. Examples of the conductive assistant include carbon materials, metal materials, and conductive polymer materials. Examples of the carbon material include carbon black (e.g., acetylene black, furnace black, ketjen black, etc.), fibrous carbon (e.g., vapor-grown carbon fiber, carbon nanotube, carbon nanofiber, etc.), graphite, and carbon fluoride. Examples of the metal material include metal powder (e.g., aluminum powder, etc.), conductive whiskers (e.g., zinc oxide, potassium titanate, etc.), and conductive metal oxides (e.g., titanium oxide, etc.). Examples of the conductive polymer material include polyaniline, polypyrrole, and polythiophene. The conductive assistant may be used alone or in combination of two or more. Preferably, the solid electrolyte contains at least one solid electrolyte species selected from the group of solid electrolytes consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes. Specific examples of the sulfide solid electrolyte, oxide solid electrolyte, and halide solid electrolyte are the same as those described later. Examples of the binder include vinyl halide resins, rubbers, and polyolefin resins. Examples of the other components include oxide solid electrolytes, halide solid electrolytes, thickeners, surfactants, dispersants, wetting agents, defoamers, and solvents.

[0019] The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer may contain at least one of a solid electrolyte for a negative electrode, a conductive assistant, and a binder, if necessary. Examples of the negative electrode active material include Li-based active materials such as metallic lithium, carbon-based active materials such as graphite, oxide-based active materials such as lithium titanate, and Si-based active materials such as elemental Si. The conductive assistant, solid electrolyte for a negative electrode, and binder used in the negative electrode active material layer are the same as those exemplified as the conductive assistant contained in the positive electrode active material layer, the solid electrolyte contained in the solid electrolyte layer, and the binder.

[0020] -Electrolyte layer- The electrode body according to the present disclosure has an electrolyte layer laminated on the first active material layer. The electrolyte layer contains at least an electrolyte. Examples of the electrolyte include solid electrolytes. In the case of a layer containing a solid electrolyte (solid electrolyte layer), the solid electrolyte layer preferably contains one selected from the group consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes. As the sulfide solid electrolyte, it preferably contains sulfur (S) as the main component of the anion element, and further contains, for example, Li element and A element. The A element is at least one selected from the group consisting of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In. As the oxide solid electrolyte, it contains oxygen (O) as the main component of the anion element, and may contain, for example, Li and Q element (Q represents at least one of Nb, B, Al, Si, P, Ti, Zr, Mo, W, and S). As the halide solid electrolyte, a solid electrolyte containing Li, M, and X (M represents at least one of Ti, Al, and Y, and X represents F, Cl, or Br) is suitable. The solid electrolyte layer may or may not contain a binder. As the binder that can be contained in the solid electrolyte layer, the same binder as described above is applicable.

[0021] -Second active material layer- The electrode body according to the present disclosure has a second active material layer laminated on the electrolyte layer. Examples of the second active material layer include a positive electrode active material layer and a negative electrode active material layer, and a positive electrode active material layer is preferable. The composition and preferred embodiments of the positive electrode active material layer and the negative electrode active material layer are the same as those in the first active material layer.

[0022] - Second current collector - The electrode body according to the present disclosure has a second current collector laminated on the second active material layer. The second current collector is a positive electrode current collector or a negative electrode current collector, and a negative electrode current collector is preferable. Preferred embodiments of the second current collector are the same as those of the first current collector.

[0023] - Young's modulus of the main part of the laminate - From the viewpoint of reducing resistance, the Young's modulus of the main part of the laminate is 6.0 GPa or more, preferably 6.0 GPa or more and 15.0 GPa or less, and more preferably 6.0 GPa or more and 13.0 GPa or less.

[0024] The Young's modulus of the main part of the laminate can be adjusted by changing the pressure in the third step of the method for manufacturing the electrode body described later.

[0025] The Young's modulus of the main part of the laminate is calculated as follows. · Procedure for calculating Young's modulus of the main part of the laminate Measure in the same procedure as the "· Procedure for calculating Young's modulus of the extended part" described later, except for cutting out a measurement sample with dimensions of 5 mm in length and 20 mm in width from the main part of the laminate.

[0026] (Extended part) The electrode body according to the present disclosure has an extended part that extends from the main part of the laminate and has a width smaller than the width of the main part of the laminate. The extended part includes a current collector extended part extending from the first current collector and an extended part composite layer including at least one selected from the group consisting of a first active material layer, an electrolyte layer, and a second active material layer laminated on the current collector extended part.

[0027] - Current collector extension part - The current collector extension part is a member extending from the first current collector, and the material of the current collector extension part is the same as that of the first current collector.

[0028] - Extension part composite layer - The extension part composite layer includes at least one selected from the group consisting of the first active material layer, the electrolyte layer, and the second active material layer. The forms of the first active material layer, the electrolyte layer, and the second active material layer included in the extension part composite layer are the same as those of the first active material layer, the electrolyte layer, and the second active material layer included in the main part of the laminate, and the preferred forms are also the same.

[0029] - Width of the main part of the laminate - The extension part in the electrode body according to the present disclosure has a width smaller than the width of the main part of the laminate. Here, the width means "the length in the direction perpendicular to the direction in which the extension part extends". From the viewpoint of bending resistance, the width of the extension part is preferably 40% or more and 100% or less, more preferably 50% or more and 100% or less, and still more preferably 55% or more and 100% or less with respect to the width of the main part of the laminate.

[0030] - Young's modulus of the extension part - In the electrode body according to the present disclosure, the Young's modulus of the extension part is 0.5 GPa or more and 3.0 GPa or less, preferably 0.5 GPa or more and 2.0 GPa or less, and more preferably 0.5 GPa or more and 1.0 GPa or less.

[0031] The Young's modulus of the extension part can be adjusted by changing the pressure in the second step in the manufacturing method of the electrode body described later.

[0032] The Young's modulus of the extension part is calculated as follows. · Procedure for calculating the Young's modulus of the extension part Cut out a measurement sample with dimensions of 5 mm in length and 20 mm in width from the extension part. When cutting out, place the measurement sample on a table with a width of 10 mm and a tip diameter of 2 mm, and perform a bending test. As the bending tester, for example, the single-column type material tester STB-1125L manufactured by A&D Company can be used. Then, measure the amount of bending deformation and the load required for bending. Based on the obtained results, calculate the Young's modulus from the following formula 1. Formula 1: "Amount of bending deformation (unit: mm)" = "Load required for bending (unit: kN)" × "Width of the table (i.e., 10 mm) (unit: mm)" / (48 × "Young's modulus (unit: GPa)" × "Second moment of area (unit: mm 2 )" Here, the second moment of area is calculated by substituting the height of the measurement sample (the length in the direction perpendicular to the longitudinal and transverse directions of the measurement sample) and the longitudinal length of the measurement sample (i.e., 5 mm) into the following. Formula 2: "Second moment of area (unit: mm 2 )" = "Height of the measurement sample (unit: mm)" × "Longitudinal length of the measurement sample (unit: mm)"

[0033] - Filling rate of the extension part composite material layer - The filling rate of the extension part composite material layer in the extension part is preferably 75% or less, more preferably 60% or more and 75% or less, and even more preferably 65% or more and 75% or less.

[0034] The filling rate of the extension part composite material layer is measured as follows. · Procedure for calculating the filling rate of the extension part composite material layer Measure the total weight of the current collector extension part and the extension part composite material layer in the extension part. Then, using a solvent (e.g., N-methyl-2-pyrrolidone), wipe off the extension part composite material layer in the extension part and measure the weight of the current collector extension part in the extension part. By subtracting the measured value of the weight of the current collector extension part in the extension part from the measured value of the total weight of the current collector extension part and the extension part composite material layer in the extension part, the weight of the extension part composite material layer in the extension part is obtained. Then, measure the total thickness of the current collector extension part and the extension part composite material layer in the extension part. Subsequently, substitute these values into the following formula 3 to calculate the filling rate of the extension part composite material layer. Formula 3: Filling ratio of the extended part composite material layer = "Weight of the extended part composite material layer of the extended part" / "Total thickness of the current collector extended part and the extended part composite material layer of the extended part" / True density × 100 Note that the true density was calculated as the sum of the "weight ratios" of each material / the "weight ratio / true density" of each material.

[0035] <Method for manufacturing an electrode body> The method for manufacturing an electrode body according to the present disclosure includes a step (first step) of obtaining a laminate in which a base material, a first active material layer, an electrolyte layer, and a second active material layer are laminated in this order, and applying a linear pressure of 3 t / cm 2 to the laminate in the following pressure range (second step). It is preferable to have such steps.

[0036] (First step) The first step is a step of obtaining a laminate in which a first current collector, a first active material layer, an electrolyte layer, and a second active material layer are laminated in this order. The laminate may be formed by sequentially applying slurries containing materials constituting the first active material layer, a slurry containing materials constituting the electrolyte layer, and a slurry containing materials constituting the second active material layer on the first current collector. Alternatively, the first active material layer, the electrolyte layer, and the second active material layer may be separately prepared and laminated on the first current collector.

[0037] (Second step) The second step is a step of applying a linear pressure of 3 t / cm 2 or less to the laminate. Examples of the method for applying pressure include roll pressing and cold isostatic pressing (CIP).

[0038] The pressure in the second step is 2 3 t / cm or less, preferably 2 1 t / cm or more and 2 3 t / cm or less, more preferably 2 1.5 t / cm or more and 2 2.5 t / cm or less, and even more preferably 2 1.5 t / cm or more and 2It is more preferable that it is as follows.

[0039] (Third step) The method for manufacturing an electrode body according to the present disclosure may have a third step, which is a step of applying further pressure to a portion corresponding to the main part of the electrode body laminate among the laminates after the second step. The pressure in the third step is preferably a linear pressure of 4 t / cm 2 or more, and preferably a linear pressure of 4 t / cm 2 or more and 7 t / cm 2 or less, and preferably a linear pressure of 4 t / cm 2 or more and 6 t / cm 2 or less, more preferably a linear pressure of 4 t / cm 2 or more and 6 t / cm 2 or less, and even more preferably a linear pressure of 4 t / cm

[0040] (Other steps) -Trimming step- The method for manufacturing an electrode body according to the present disclosure may have a step (trimming step) of adjusting the shape of the second active material layer, if necessary. Examples of the method for adjusting the shape of the second active material layer include a method using laser irradiation. -Cutting step- In the method for manufacturing an electrode body according to the present disclosure, it is preferable to cut a part of the laminate in the thickness direction of the laminate to form an extended portion and a main part of the laminate.

[0041] <Solid battery> The solid battery according to the present disclosure includes the electrode body according to the present disclosure. The solid battery uses an inorganic solid electrolyte as an electrolyte, and includes a so-called all-solid battery (the content of the electrolytic solution as the electrolyte is 10% by mass with respect to the total amount of the electrolyte).

[0042] When the electrode body according to the present disclosure is used as a power generation unit, the solid battery may have only one power generation unit or two or more power generation units. When the solid battery has two or more power generation units, these power generation units may be connected in series or in parallel.

Example

[0043] Examples will be described below, but the present invention is not limited to these examples. In the following description, unless otherwise specified, all "parts" and "%" are based on mass.

[0044] <Example 1> (Preparation of Cathode Active Material) Using a rolling fluidized coating device (manufactured by Powrec Co., Ltd.), in an air atmosphere, particles of the cathode active material (particles having Li 1.15 Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O2 as the main phase) were coated with lithium niobate, and fired in an air atmosphere to obtain a cathode active material having a coating layer of lithium niobate.

[0045] (First Step) - Preparation of the Second Active Material Layer (Cathode Active Material Layer)- In a propylene container, polyvinylidene fluoride (PVdF) as a binder, the cathode active material prepared by the above procedure, a sulfide solid electrolyte (Li2S-P2S5-based glass ceramic), and carbon fiber (VGCF-H manufactured by Showa Denko K.K.) as a conductive aid were added, and stirred with an ultrasonic disperser (UH-50 manufactured by SMT Co., Ltd.) for 30 seconds. Next, the container was shaken with a shaker (TTM-1 manufactured by Shibata Scientific Co., Ltd.) for 3 minutes, and further stirred with an ultrasonic disperser for 30 seconds. It was shaken with a shaker for 3 minutes to obtain a slurry. The slurry was applied onto an aluminum foil (the first current collector) by the blade method using an applicator to form a cathode active material layer on the aluminum foil.

[0046] - Preparation of the First Active Material Layer (Anode Active Material Layer)- In a polypropylene container, polyvinylidene fluoride (PVdF) as a binder, Li4Ti50 as an anode active material 12And a sulfide solid electrolyte (Li2S-P2S5-based glass ceramic) was added and stirred with an ultrasonic disperser for 30 seconds. Next, the container was shaken with a shaker (TTM-1 manufactured by Shibata Scientific Technology) for 3 minutes and further stirred with an ultrasonic disperser for 30 seconds. It was shaken with a shaker for 3 minutes to obtain a slurry. The slurry was applied onto an aluminum foil (the first current collector) by the blade method using an applicator to form a negative electrode active material layer on the aluminum foil (the first current collector). Thereafter, a negative electrode active material layer was similarly formed on the back surface.

[0047] -Fabrication of the electrolyte layer- To a polypropylene container, heptane, a butadiene rubber-based binder as a binder, and a sulfide solid electrolyte (Li2S-P2S5-based glass ceramic) were added. The polypropylene container was shaken with a shaker (TTM-1 manufactured by Shibata Scientific Technology) for 30 minutes, stirred with an ultrasonic disperser (UH-50 manufactured by SMT) for 30 seconds, and further shaken with a shaker for 3 minutes to obtain a slurry. The slurry was applied onto an aluminum foil by the blade method using an applicator. Thereafter, the coating film was air-dried and dried on a hot plate at 100 °C for 30 minutes to fabricate an electrolyte layer on the aluminum foil.

[0048] -Fabrication of the laminate- The negative electrode active material layer and the solid electrolyte layer were bonded together so that they were in direct contact, and pressed at 0.3 t / cm 2 Then, the aluminum foil on the solid electrolyte side was peeled off. And the positive electrode active material layer and the solid electrolyte layer were bonded together so that they were in direct contact and pressed at 0.3 t / cm 2 Then, the aluminum foil on the positive electrode active material layer side was peeled off to obtain a laminate as shown in Fig. 2. In Fig. 2, the unit of dimension is mm. Fig. 2(a) is a schematic top view of the laminate obtained by the above procedure. Fig. 2(b) is a cross-sectional view taken along the line A-A of Fig. 2(a).

[0049] (The second step) A pressure of 1.5 t / cm 2 in line pressure was applied to the entire surface of the laminate obtained by the above procedure at 175 °C.

[0050] (Step 3) Starting from the position 30 mm from the end of the aluminum foil of the laminate, at 175 °C, a linear pressure of 4 t / cm 2 was applied (Step 3 was performed in the region marked with "*2" in Figure 2).

[0051] (Other steps) -Trimming step- The positive electrode active material layer of the laminate was laser-trimmed with a width of 5 mm only in the region surrounded by the dotted line in Figure 3 (Figure 3 is a schematic top view of the laminate). -Cutting step- The region surrounded by the dotted line in Figure 4 (Figure 4 is a schematic top view of the laminate after the trimming step) of the laminate was cut in the thickness direction. -Finishing- Acetylene black and an acrylic binder were weighed and mixed so that the volume ratio of acetylene black:acrylic binder = 40:60. Then, ethyl acetate was added to prepare a carbon coating composition. Next, the carbon coating composition was applied to a range of 65 mm in length and 65 mm in width on an aluminum foil with a length of 65 mm and a width of 90 mm to a film thickness of 2 μm, and dried at 100 °C for 1 hour to prepare a positive electrode current collector (second current collector). The positive electrode current collector was bonded and pressed at 5 MPa under the condition of 140 °C so that the region coated with the carbon coating composition did not protrude from the positive electrode active material layer of the laminate that had undergone the above cutting step, thereby obtaining an electrode body. Through the above procedure, the electrode body shown in Figure 5 was obtained. Note that Figure 5(a) is a schematic top view of the electrode body, and Figure 5(b) is a cross-sectional view taken along the line A-A of Figure 5(a). The reference numerals in Figure 5 are the same as those in Figure 1.

[0052] (Fabrication of solid-state battery) Thereafter, 20 electrode bodies were stacked to obtain a stack of electrode bodies. The extending portions of the stacked electrode bodies were bent and welded to the terminals for connection. Also, the second current collector was welded and connected to the terminals, and this was covered with a laminate film to obtain a solid-state battery.

[0053] <Examples 2, 3, Comparative Examples 1 - 4> A solid battery was obtained in the same procedure as in Example 1, except that the line pressure in the second and third steps was changed as shown in Table 1.

[0054] <Comparative Example 5> The line pressure in the second and third steps was changed as shown in Table 1. Also, (other steps) were changed as follows. The other procedures were the same as in Example 1.

[0055] (Other steps) A carbon coating composition was prepared in the same procedure as in Example 1. Next, the carbon coating composition was applied to a range of 65 mm in length and 77.5 mm in width on an aluminum foil of 65 mm in length and 90 mm in width so that the film thickness was 2 μm, and dried at 100 °C for 1 hour to prepare a positive electrode current collector (second current collector). The positive electrode current collector was bonded so that the region coated with the carbon coating composition did not protrude from the positive electrode active material layer of the laminate that had undergone the above cutting process. Then, only the region surrounded by the dotted line in Figure 3 of the positive electrode active material layer of the laminate was laser - trimmed with a width of 5 mm so that the area of the positive electrode active material layer was 70 mm × 70 mm. Then, the same range as the region surrounded by the dotted line in Figure 3 of the laminate was cut out in the thickness direction.

[0056] <Evaluation> The following evaluations were performed on the electrode bodies and solid batteries obtained in each example.

[0057] (Young's modulus of the extension part and Young's modulus of the main part of the laminate) The Young's modulus of the extension part and the Young's modulus of the main part of the laminate of the electrode bodies obtained in each example were calculated according to the previously described "· Procedure for calculating the Young's modulus of the extension part" and "· Procedure for calculating the Young's modulus of the main part of the laminate".

[0058] (Filling rate of the extension part composite layer and filling rate of the main part of the laminate) The filling rate of the extension part composite layer of the electrode bodies obtained in each example was calculated in the same procedure as the previously described "· Procedure for calculating the filling rate of the extension part composite layer". The filling rate of the main part of the laminate of the electrode body obtained in each example was calculated by the same procedure as in the above-mentioned "Procedure for calculating the filling rate of the extended part composite layer", except that the measurement target was the main part of the laminate.

[0059] (Short-circuit evaluation during production) After the solid-state battery obtained in each example was left standing for 10 hours after production, the voltage was measured. If the voltage was 0.2 V or less, it was judged to be short-circuited. If the voltage exceeded 0.2 V, it was judged to be qualified. In Table 1, "N" was described when it was short-circuited, and "G" was described when it was qualified.

[0060] (Resistance evaluation) Resistance evaluation was performed in the order of initial charging, followed by voltage adjustment, and then resistance measurement. Initial charging: After charging at 1 C with CCCV (cut-off current 0.01 C) to 2.95 V, discharging at 1 C with CCCV (cut-off current 0.01 C) to 1.50 V was performed. Voltage adjustment: Charging at 1 C with CCCV (cut-off current 0.01 C) to 2.36 V was performed. Resistance measurement: Charging at 2 C for 10 s with CC, and the resistance was calculated from the change in voltage. The ratio of the resistance of each of Examples 1 to 3 and Comparative Examples 1 to 5 to the resistance of Example 1 was used as the resistance evaluation.

[0061] (Short-circuit evaluation after durability) The solid-state battery after the above resistance evaluation was subjected to a vibration test according to the UI transportation regulations under the following measurement conditions. After that, it was left standing for 14 hours. If the voltage drop was 20 mV or more compared to before the vibration test, it was judged to be short-circuited, and if the voltage drop was less than 20 mV compared to before the vibration test, it was judged to be qualified. In Table 1, "N" was described when it was short-circuited, and "G" was described when it was qualified. Measurement conditions: 7 Hz to 200 Hz to 7 Hz in 15 minutes, 12 times in each of the XYZ directions

[0062]

Table 1

[0063] In Examples 1 to 3, when manufacturing the solid battery, since the extension part was bent without causing cutting of the extension part and peeling of the material contained in the extension part, the short-circuit evaluation during manufacturing, the resistance evaluation, and the short-circuit evaluation after durability all showed good results. In Comparative Examples 1 to 5, since cutting of the extension part and peeling of the material contained in the extension part occurred, the results showed the occurrence of short circuit or an increase in resistance.

Explanation of Signs

[0064] 810 Electrode body, 81 First current collector, 82 First active material layer, 83 Electrolyte layer, 84 Second active material layer, 85 Second current collector, 86 Current collector extension part, 87 First active material layer, 88 Electrolyte layer, 89 Second active material layer

Claims

1. A main part of a laminate in which a first current collector, a first active material layer, an electrolyte layer, a second active material layer, and a second current collector are laminated in this order; An extension portion extending from the main part of the laminate and having a width smaller than the width of the main part of the laminate; and Laminating a current collector extension portion where the extension portion extends from the first current collector and an extension portion composite layer including at least one selected from the group consisting of the first active material layer, the electrolyte layer, and the second active material layer on the current collector extension portion; The Young's modulus of the extension portion is 0.5 GPa or more and 3.0 GPa or less; An electrode body in which the Young's modulus of the main part of the laminate is 6.0 GPa or more.

2. The electrode body according to claim 1, wherein the filling rate of the extension portion composite layer in the extension portion is 75% or less.

3. A solid battery including the electrode body according to claim 1 or claim 2.

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