Method for manufacturing solid-state battery, and solid-state battery

Abstract

To provide a method for manufacturing a solid-state battery in which peeling of an insulating layer during hot pressing is suppressed.SOLUTION: A method for manufacturing a solid-state battery includes the steps of: preparing a solid-state battery 20 having an electrode body that has a positive electrode layer 8, a solid-state electrolyte layer 6, a negative electrode layer 4, and an insulating layer 10, in which the positive electrode layer 8, the solid electrolyte layer 6, and the negative electrode layer 4 are stacked in order, and the insulating layer 10 is arranged so as to be in contact with a surface of the positive electrode layer 8 side of the solid-state electrolyte layer 6 in a stacking direction and in contact with a side surface of the positive electrode layer 8 in a stacking direction and a direction orthogonal to a longitudinal direction of the electrode body; and heat pressing the solid-state battery 20 from both sides in the stacking direction. The insulating layer 10 includes a first binding material whose reaction force at a temperature of heat pressing is 0.60 N / mm2 to 1.50 N / mm2. The positive electrode layer 8 and the solid-state electrolyte layer 6 include a second binding material whose reaction force at a temperature of heat pressing is 0.01 N / mm2 to 0.40 N / mm2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART Conventionally, solid-state batteries have been used that have an electrode assembly in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked in this order.

[0003] For example, Patent Document 1 discloses a solid-state battery in which an insulating layer is arranged so as to be in contact with a positive electrode layer, specifically, an all-solid-state battery including an electrode body in which a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil are laminated in this order, and in which an insulating layer is arranged on the surface of the positive electrode current collector foil facing the positive electrode layer at least in portions facing the ends of the solid electrolyte layer and the negative electrode layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-104123 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in a solid-state battery having an electrode body in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked in this order, and an insulating layer is disposed so as to be in contact with the side surface of the positive electrode layer in a direction perpendicular to the stacking direction and the longitudinal direction of the electrode body, peeling of the insulating layer may occur when hot pressing is performed from both sides in the stacking direction during the manufacturing process.

[0006] The present disclosure has been made in consideration of the above-described circumstances, and aims to provide a method for manufacturing a solid-state battery in which peeling of an insulating layer during heat pressing is suppressed, and a solid-state battery in which peeling of an insulating layer is suppressed. [Means for solving the problem]

[0007] <1> preparing a solid-state battery having an electrode body having a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and an insulating layer, wherein the positive electrode layer, the solid electrolyte layer, and the negative electrode layer are stacked in this order, and the insulating layer is arranged so as to be in contact with a surface of the solid electrolyte layer facing the positive electrode layer in a stacking direction and in contact with a side surface of the positive electrode layer in a direction perpendicular to the stacking direction and a longitudinal direction of the electrode body; and hot pressing the solid-state battery from both sides in the stacking direction, The insulating layer has a reaction force of 0.60 N / mm at the temperature of the heat press. 2 ~1.50N / mm 2 The first binder is The positive electrode layer and the solid electrolyte layer have a reaction force of 0.01 N / mm at the temperature of the heat press. 2 ~0.40N / mm 2 The second binder is How solid-state batteries are manufactured. <2> The reaction force of the first binder at the temperature of the heat press is 5 times or more the reaction force of the second binder at the temperature of the heat press. <1> 10. A method for manufacturing the solid state battery according to claim 9. <3> The first binder is a styrene-ethylene-butylene-styrene block copolymer, and the second binder is a styrene-butadiene rubber. <1> or <2> 10. A method for manufacturing the solid state battery according to claim 9. <4> The filling rate of the insulating layer after the heat pressing step is 70% to 80%. <1> ~ <3> 10. A method for producing the solid state battery according to claim 9. <5> an electrode assembly having a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and an insulating layer; the positive electrode layer, the solid electrolyte layer, and the negative electrode layer are stacked in this order; the insulating layer is disposed so as to be in contact with a surface of the solid electrolyte layer on the positive electrode layer side in the stacking direction and to be in contact with a side surface of the positive electrode layer in a direction perpendicular to the stacking direction and the longitudinal direction of the electrode body, The insulating layer has a reaction force of 1.00 N / mm at 120°C. 2 ~1.50N / mm 2 The first binder is The positive electrode layer and the solid electrolyte layer have a reaction force of 0.01 N / mm at 120°C. 2 ~0.40N / mm 2 The second binder is solid state battery. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a method for manufacturing a solid-state battery in which peeling of an insulating layer during heat pressing is suppressed, and a solid-state battery in which peeling of an insulating layer is suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic top view illustrating a configuration of a solid-state battery according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic cross-sectional view taken along the line XX in FIG. [Figure 3] FIG. 10 is a schematic top view illustrating the configuration of a solid-state battery according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] The manufacturing method of a solid-state battery and the solid-state battery according to the present disclosure will be described in detail below with reference to the drawings. The drawings are schematic diagrams, and the size and shape of each part are appropriately exaggerated for ease of understanding.

[0011] <Solid-state battery manufacturing method> -Step of preparing a solid-state battery having an electrode body (preparation step)- FIG. 1 is a schematic top view showing the configuration of a solid-state battery according to an embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view taken along the line XX in FIG. 1 . The solid-state battery shown in FIGS. 1 and 2 is a solid-state battery 20 in which two electrode assemblies, one on each side of a current collector 2, are arranged as a pair. The solid-state battery 20 has a configuration in which an anode layer 4, a solid electrolyte layer 6, and a cathode layer 8 are stacked on each side of the current collector 2 in this order from the current collector 2 side. The solid-state battery 20 also has a configuration in which two insulating layers 10 (four insulating layers 10 in total for the solid-state battery 20) are arranged in contact with the surface of the solid electrolyte layer 6 facing the cathode layer 8 in the stacking direction and in contact with both side surfaces of the cathode layer 8 in a direction (i.e., the vertical direction in FIG. 2 ) perpendicular to the stacking direction (i.e., the vertical direction in FIG. 2 ) and the longitudinal direction of the electrode assemblies (i.e., the vertical direction in FIG. 1 ). A single electrode body is composed of the negative electrode layer 4, the solid electrolyte layer 6, the positive electrode layer 8, and two insulating layers 10 arranged on both sides of the positive electrode layer 8. In other words, in the solid-state battery 20, two electrode bodies are arranged as a pair, one on each side of the current collector 2.

[0012] The solid-state battery in the preparation step contains a binder in the insulating layer, the positive electrode layer, and the solid electrolyte layer. The insulating layer has a reaction force of 0.60 N / mm at the temperature of the heat press. 2 ~1.50N / mm 2 The positive electrode layer and the solid electrolyte layer contain a first binder having a reaction force of 0.01 N / mm at the temperature of the heat press. 2 ~0.40N / mm 2 The second binder is

[0013] -The heat pressing process (heat pressing process)- In the heat pressing step, the solid-state battery 20 is heat pressed from both sides in the stacking direction (i.e., the vertical direction in FIG. 2 ). Examples of the heat pressing method include a method in which the solid-state battery 20 is passed between a pair of rolls rotating in the forward direction (i.e., a roll pair consisting of two rolls rotating in opposite directions), and the rolls apply pressure and heat to the solid-state battery 20.

[0014] The solid-state battery according to the embodiment of the present disclosure has the effect of suppressing peeling of the insulating layer during heat pressing. The reason for this effect is presumed to be as follows.

[0015] In a conventional solid-state battery having an electrode assembly in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked in this order, an insulating layer is arranged so as to contact the side surface of the positive electrode layer in a direction perpendicular to the stacking direction and the longitudinal direction of the electrode assembly, in order to prevent short circuits from occurring in the positive electrode layer. However, when a solid-state battery having an insulating layer arranged on the side surface of the positive electrode layer is subjected to heat pressing from both sides in the stacking direction during the manufacturing process, peeling of the insulating layer sometimes occurs. The reason for peeling of the insulating layer is thought to be that the binder contained in the insulating layer seeps out in the high-temperature environment during heat pressing and adheres to the heat pressing member (e.g., the heat pressing roll), and the binder adhered to the heat pressing member causes peeling of the insulating layer.

[0016] In contrast, in the solid-state battery according to the embodiment of the present disclosure, the insulating layer has a reaction force of 0.60 N / mm at the temperature of the heat press. 2 ~1.50N / mm 2 The positive electrode layer and the solid electrolyte layer contain a first binder having a reaction force of 0.01 N / mm at the temperature of the heat press. 2 ~0.40N / mm 2 The insulating layer contains a second binder having a high reactivity even in high-temperature environments such as those encountered during heat pressing, thereby suppressing the exudation of the binder from the insulating layer during heat pressing. As a result, adhesion of the binder to the heat pressing members is reduced, and peeling of the insulating layer is suppressed. Furthermore, the positive electrode layer and the solid electrolyte layer contain a second binder having a low reactivity in high-temperature environments, in other words, a binder with a strong binding force. This achieves high binding between the positive electrode layer and the insulating layer, between the solid electrolyte layer and the insulating layer, and between the positive electrode layer and the solid electrolyte layer.

[0017] The reason why a large amount of binder does not adhere from the positive electrode layer to the heat press member during heat pressing, even when the binder contained in the positive electrode layer is a second binder with a low repulsive force in a high-temperature environment, is thought to be as follows: That is, the positive electrode layer is positioned toward the center of the insulating layer (e.g., toward the center in the left-right direction in FIGS. 1 and 2), and when pressed by the heat press member, the binder has a strong tendency to flow toward the side of the positive electrode layer (e.g., in the left-right direction in FIGS. 1 and 2), making it difficult for the binder to seep out toward the heat press member.

[0018] (binding material) ·reaction force In the preparation process, the solid-state battery is subjected to a reaction force of 0.60 N / mm at the temperature of the heat press on the insulating layer. 2 ~1.50N / mm 2 The reaction force of the first binder at the temperature of the hot press is further 0.70 N / mm 2 ~1.30N / mm 2 Preferably, it is 0.80 N / mm 2 ~1.20N / mm 2 It is more preferable that the repulsive force of the first binder at the heat-pressing temperature is equal to or greater than the lower limit, thereby suppressing exudation of the binder from the insulating layer during the heat-pressing, and thus suppressing peeling of the insulating layer. The repulsive force of the first binder at the heat-pressing temperature is equal to or less than the upper limit, thereby achieving high binding strength between the insulating layer and each layer in contact with the insulating layer.

[0019] The positive electrode layer and the solid electrolyte layer have a reaction force of 0.01 N / mm at the heat press temperature. 2 ~0.40N / mm 2 The reaction force of the second binder at the temperature of the hot press is further 0.02 N / mm 2 ~0.30N / mm 2 Preferably, it is 0.03N / mm 2 ~0.25N / mm 2It is more preferable that the reaction force of the second binder at the heat press temperature is equal to or greater than the above lower limit, so that the binder does not melt excessively even in the high-temperature environment during heat pressing, and the binding properties are maintained in the high-temperature environment. When the reaction force of the second binder at the heat press temperature is equal to or less than the above upper limit, high binding properties are achieved between the positive electrode layer and the insulating layer, between the solid electrolyte layer and the insulating layer, and between the positive electrode layer and the solid electrolyte layer.

[0020] Reaction force ratio The reaction force of the first binder at the heat-pressing temperature is preferably at least five times the reaction force of the second binder at the heat-pressing temperature. The ratio of the reaction forces of the first binder and the second binder at the heat-pressing temperature (first binder / second binder) is more preferably at least eight times, and even more preferably at least ten times. When the ratio of the reaction forces of the first binder and the second binder at the heat-pressing temperature (first binder / second binder) is within the above range, peeling of the insulating layer during heat-pressing is suppressed, and high binding strength is achieved between the positive electrode layer and the insulating layer, between the solid electrolyte layer and the insulating layer, and between the positive electrode layer and the solid electrolyte layer.

[0021] Reaction force measurement The reaction force of the first binder contained in the insulating layer and the second binder contained in the positive electrode layer and solid electrolyte layer is measured using the following method. A binder measurement sample is compressed from above and below by applying pressure and heat until the thickness of the measurement sample is reduced by 25%, and then left for 10,000 minutes, and the change in reaction force from the measurement sample is measured. The binder measurement sample is a sample consisting only of the binder to be measured, measuring 20 mm in diameter and 5 mm in thickness. The reaction force is measured using an A&D Tensilon universal testing machine, model RTC-1350A (equipped with a high-temperature measurement chamber (TKC), capable of measuring up to 270°C). The load is in compression mode, and the sample is held at a height where the thickness is 3.75 mm for the specified time. The value on the load cell at that time is recorded as the reaction force. The measurement temperature is set to the maximum temperature reached during heat pressing when measuring "reaction force at heat press temperature," and to 120°C when measuring "reaction force at 120°C," and measurements are taken in an environment where the entire device is at the set temperature. From the obtained change in reaction force, the average value over 10 to 20 seconds is calculated and used as the reaction force.

[0022] ·Type of binder From the viewpoint of controlling the repulsive force within the above range, examples of the first binder contained in the insulating layer include styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-butadiene-styrene block copolymer (SBS), and styrene-isoprene-styrene block copolymer (SIS). Among these, styrene-ethylene-butylene-styrene block copolymer is preferred.

[0023] From the viewpoint of controlling the repulsive force within the above range, examples of the second binder contained in the positive electrode layer and the solid electrolyte layer include elastomers that are not block copolymers, such as styrene butadiene rubber (SBR), PVdF, BR, and NBR, and acrylic resins, such as PMMA. Among these, styrene butadiene rubber is preferred.

[0024] Binder content The content of the first binder in the insulating layer is preferably 2% by mass to 6% by mass, and more preferably 3% by mass to 5% by mass, of the entire insulating layer. When the content of the first binder in the insulating layer is equal to or greater than the above-mentioned lower limit, high binding strength is achieved between the insulating layer and each layer in contact with the insulating layer. When the content of the first binder in the insulating layer is equal to or less than the above-mentioned upper limit, seepage of the binder from the insulating layer during heat pressing is suppressed, and peeling of the insulating layer is suppressed.

[0025] The content of the second binder in the positive electrode layer and the solid electrolyte layer is preferably 0.5% by mass to 3% by mass, and more preferably 1% by mass to 2% by mass, of the entire positive electrode layer or the entire solid electrolyte layer. When the content of the second binder in the positive electrode layer and the solid electrolyte layer is equal to or greater than the above-mentioned lower limit, high binding strength is achieved between the positive electrode layer and the insulating layer, between the solid electrolyte layer and the insulating layer, and between the positive electrode layer and the solid electrolyte layer. When the content of the second binder in the positive electrode layer and the solid electrolyte layer is equal to or less than the above-mentioned upper limit, performance other than binding strength required for the positive electrode layer and the solid electrolyte layer is more easily maintained.

[0026] (Other conditions) Heat press temperature The heat press temperature in the heat pressing step, i.e., the maximum temperature reached during heat pressing, is preferably 110°C to 180°C, and more preferably 120°C to 170°C. When the heat press temperature is equal to or higher than the above lower limit, high binding strength of each layer is achieved. When the heat press temperature is equal to or lower than the above upper limit, exudation of the binder from the insulating layer during heat pressing is suppressed, and peeling of the insulating layer is suppressed. The heat press temperature refers to the maximum temperature reached during heat pressing on the surface of the heat press member (e.g., the heat press roll).

[0027] Filling rate of the insulating layer After the hot pressing step, the filling rate of the insulating layer is preferably 70% to 80%, and more preferably 72% to 78%. When the filling rate of the insulating layer is equal to or higher than the lower limit, peeling of the insulating layer is suppressed. When the filling rate of the insulating layer is equal to or lower than the upper limit, defects at the edge (i.e., side) of the insulating layer, such as breakage at the edge, are suppressed. The filling rate of the insulating layer means the proportion of the area other than voids in the insulating layer. The filling rate of the insulating layer is measured using the following method. The mass of the insulating layer is measured using an electronic balance to punch out a specified area. The thickness of the insulating layer is measured using a microscope (Keyence VHX series) from an image of the cut surface. The filling rate of the insulating layer is calculated from the measurement results of the mass and thickness.

[0028] Modifications 1 and 2 show a configuration in which two insulating layers 10 are arranged in the electrode body so as to contact both side surfaces of the positive electrode layer 8 in the direction perpendicular to the stacking direction and the longitudinal direction of the electrode body. However, this is not limited to this, and for example, as shown in FIG. 3, an insulating layer 10B may be arranged so as to contact both side surfaces of the positive electrode layer 8 in the longitudinal direction of the electrode body (i.e., the up-and-down direction in FIG. 1) in addition to both side surfaces of the positive electrode layer 8 in the direction perpendicular to the stacking direction and the longitudinal direction of the electrode body. In other words, a configuration in which one insulating layer 10B is arranged so as to surround the side surfaces of the positive electrode layer 8 may be used.

[0029] <Solid battery> A solid state battery according to an embodiment of the present disclosure includes an electrode assembly having a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and an insulating layer, the positive electrode layer, the solid electrolyte layer, and the negative electrode layer being stacked in this order, the insulating layer being disposed so as to contact a surface of the solid electrolyte layer on the positive electrode layer side in the stacking direction and to contact a side surface of the positive electrode layer in a direction perpendicular to the stacking direction and the longitudinal direction of the electrode assembly, and the insulating layer having a reaction force of 1.00 N / mm at 120°C. 2 ~1.50N / mm 2 The positive electrode layer and the solid electrolyte layer contain a first binder having a reaction force of 0.01 N / mm at 120°C. 2 ~0.40N / mm2 The second binder is

[0030] ·reaction force The solid-state battery includes a binder in the insulating layer, the positive electrode layer, and the solid electrolyte layer. The insulating layer has a reaction force of 1.00 N / mm at 120°C. 2 ~1.50N / mm 2 The reaction force of the first binder at 120°C is further 1.05 N / mm 2 ~1.30N / mm 2 Preferably, it is 1.10 N / mm 2 ~1.20N / mm 2 It is more preferable that the reaction force of the first binder at 120°C is equal to or greater than the above lower limit, peeling of the insulating layer during hot pressing is suppressed, and as a result, the binding force of the insulating layer is well maintained. When the reaction force of the first binder in the insulating layer is equal to or less than the above upper limit, high binding strength is achieved between the insulating layer and each layer in contact with the insulating layer.

[0031] The positive electrode layer and solid electrolyte layer have a reaction force of 0.01 N / mm at 120°C. 2 ~0.40N / mm 2 The reaction force of the second binder at 120°C is 0.02 N / mm 2 ~0.30N / mm 2 Preferably, it is 0.03N / mm 2 ~0.25N / mm 2 It is more preferable that the reaction force of the second binder at 120°C is equal to or greater than the above lower limit, the binder does not melt excessively even in the high-temperature environment of hot pressing, and the binding strength in the high-temperature environment is maintained, resulting in good retention of the binding strength between the positive electrode layer and the solid electrolyte layer. The reaction force of the second binder at 120°C is equal to or less than the above upper limit, thereby achieving high binding strength between the positive electrode layer and the insulating layer, between the solid electrolyte layer and the insulating layer, and between the positive electrode layer and the solid electrolyte layer.

[0032] Insulation layer, positive electrode layer, negative electrode layer, solid electrolyte layer The insulating layer includes, for example, an insulating material and a binder. Suitable examples of the binder include those listed above as examples of the first binder. Examples of the insulating material include a solid electrolyte. Examples of the solid electrolyte include the solid electrolyte in the solid electrolyte layer described below.

[0033] The positive electrode layer contains at least a positive electrode active material and may further contain at least one of a conductive material, an electrolyte, and a binder.

[0034] The negative electrode layer contains at least a negative electrode active material and may further contain at least one of a conductive material, an electrolyte, and a binder.

[0035] The solid electrolyte layer is disposed between the positive electrode layer and the negative electrode layer and contains at least one solid electrolyte selected from the group consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes.

[0036] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Example]

[0037] Here, the effects of the solid state battery according to the present disclosure were confirmed through experiments.

[0038] (Examples 1 to 9, Comparative Examples 1 to 6) First, a solid-state battery 20 was prepared in which two electrode assemblies, one on each side of a current collector 2, were arranged as a pair, similar to the configuration shown in Fig. 1. The solid-state battery 20 has a configuration in which an anode layer 4, a solid electrolyte layer 6, and a cathode layer 8 are stacked on both sides of the current collector 2 in this order from the current collector 2 side. The solid-state battery 20 also has a configuration in which two insulating layers 10 are arranged so as to be in contact with the surface of the solid electrolyte layer 6 facing the cathode layer 8 in the stacking direction and in contact with both side surfaces of the cathode layer 8 in a direction perpendicular to the stacking direction and the longitudinal direction of the electrode assemblies.

[0039] The compositions of the positive electrode layer, solid electrolyte layer, negative electrode layer, and insulating layer are shown below. Positive electrode layer (solid content 75%): active material: 74%, solid electrolyte: 23%, conductive additive: 2.5%, binder: 0.5% Solid electrolyte layer (solid content 50%): solid electrolyte: 97%, binder: 3%, Negative electrode layer (solid content 60%): active material: 74%, SE: 25%, binder: 1% Insulation layer (solid content 55%): solid electrolyte: 96%, binder: 4%

[0040] In each example and comparative example, the binder (second binder) used in the positive electrode layer and solid electrolyte layer, and the binder (first binder) used in the insulating layer were those shown in Table 1. The heat pressing temperature (pressing temperature) in each example and comparative example was also those shown in Table 1. Table 1 shows the reaction force of the binder at the heat press temperature, the reaction force at 120°C, the ratio (reaction force ratio) of the reaction force of the binder (first binder) used in the insulating layer to the reaction force of the binder (second binder) used in the positive electrode layer and the solid electrolyte layer at the heat press temperature, and the filling rate of the insulating layer after heat pressing.

[0041] [Table 1]

[0042] (Evaluation test) Regarding the solid state batteries obtained in each of the Examples and Comparative Examples, a total of five solid state batteries were subjected to a heat pressing operation in which the solid state batteries were passed through a pair of heat pressing rolls at the pressing temperatures shown in Table 1. After that, the surface of the heat pressing rolls was observed, and the amount of exuded binder (mm) was determined by the following method. For five or more exuded areas around one circumference of the roll, photographs of the exuded areas were taken with a ruler in contact with the roll, and the exuded distance was measured on the image. The average value of the five points was taken as the amount of exuded.

[0043] After the evaluation test, the evaluation was judged based on the following criteria. A (◯): The amount of seepage is small, and neither positive electrode peeling nor insulating layer sticking occurs. B (△): Compared to A (◯), the amount of seepage is the same, the positive electrode does not peel off, and the insulating layer does not stick, but there is a tendency for a slight short circuit in the battery. C (×): There is a large amount of seepage and the insulating layer is sticking, or the positive electrode is peeling off.

[0044] The results are shown in Table 2. The reasons for the defects are also shown in Table 2.

[0045] [Table 2]

[0046] As shown in Table 1, in the examples in which the insulating layer contains a first binder whose reaction force at the heat-press temperature is within the above range, and the positive electrode layer and solid electrolyte layer contain a second binder whose reaction force at the heat-press temperature is within the above range, the amount of binder seepage is reduced compared to the comparative examples that do not satisfy this requirement. Furthermore, in Examples 8 and 9, the amount of seepage was small, and neither positive electrode peeling nor insulating layer sticking occurred. However, in Example 8, cuts occurred at the edge of the insulating layer, and in Example 9, the insulating layer peeled off at the slit. [Explanation of symbols]

[0047] 2 current collector, 4 negative electrode layer, 6 solid electrolyte layer, 8 positive electrode layer, 10, 10B insulating layer, 20 solid-state battery

Claims

1. preparing a solid-state battery having an electrode body having a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and an insulating layer, wherein the positive electrode layer, the solid electrolyte layer, and the negative electrode layer are stacked in this order, and the insulating layer is arranged so as to be in contact with a surface of the solid electrolyte layer facing the positive electrode layer in a stacking direction and in contact with a side surface of the positive electrode layer in a direction perpendicular to the stacking direction and a longitudinal direction of the electrode body; and hot pressing the solid-state battery from both sides in the stacking direction, The insulating layer has a reaction force of 0.60 N / mm at the temperature of the heat press. ２ ~1.50N / mm ２ The first binder is The positive electrode layer and the solid electrolyte layer have a reaction force of 0.01 N / mm at the temperature of the heat press. ２ ~0.40N / mm ２ The second binder is How solid-state batteries are manufactured.

2. The method for manufacturing a solid-state battery according to claim 1 , wherein a reaction force of the first binder at the temperature of the heat press is five times or more larger than a reaction force of the second binder at the temperature of the heat press.

3. 2. The method for manufacturing a solid state battery according to claim 1, wherein the first binder is a styrene-ethylene-butylene-styrene block copolymer, and the second binder is a styrene-butadiene rubber.

4. 2. The method for manufacturing a solid state battery according to claim 1, wherein a packing ratio of the insulating layer after the hot pressing step is 70% to 80%.

5. an electrode assembly having a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and an insulating layer; the positive electrode layer, the solid electrolyte layer, and the negative electrode layer are stacked in this order; the insulating layer is disposed so as to be in contact with a surface of the solid electrolyte layer on the positive electrode layer side in the stacking direction and to be in contact with a side surface of the positive electrode layer in a direction perpendicular to the stacking direction and the longitudinal direction of the electrode body, The insulating layer has a reaction force of 1.00 N / mm at 120°C. ２ ~1.50N / mm ２ The first binder is The positive electrode layer and the solid electrolyte layer have a reaction force of 0.01 N / mm at 120°C. ２ ~0.40N / mm ２ The second binder is solid state battery.

Images