Insulation resistance measurement method

Abstract

To provide an insulation resistance measurement method capable of measuring an insulation resistance by suppressing a cost in a battery having an ion conductor.SOLUTION: The present invention provides an insulation resistance measurement method of lamination bodies (1, 2, and 100) as a negative electrode deposition type battery in which an ion moves in an ion conductive layer (30) or their intermediate body, containing: positive electrodes (10 and 11); a negative electrode (12); and the ion conductive layer (30) between each positive electrode and the negative electrode. This insulation resistance measurement method includes steps of: connecting a high-potential side of an insulation resistance measurement device (101) to a negative electrode side of the lamination bodies (1, 2, and 100) in a state where the ion and their reductant are not contained in the negative electrode side of the lamination bodies (1, 2, and 100); and measuring the insulation resistance of each lamination body by connecting a low-potential side to the positive electrode side of the lamination bodies (1, 2, and 100).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an insulation resistance measuring method. [Background technology]

[0002] Conventionally, a method for measuring the insulation resistance of a cell (battery) is known in which a voltage is applied to the cell (battery) before the electrolyte is poured in and the current value is measured. According to this method, if there is a defective part such as a pinhole in the insulator (separator) between the positive and negative electrodes, applying a high voltage causes electrons to flow to the defective part, making it possible to identify the defective cell.

[0003] However, for example, in an all-solid-state battery having an all-solid-state electrolyte or a semi-solid-state battery having a gel electrolyte, the electrolyte (ion conductor) is ion-conductive, and therefore the above-mentioned measurement method cannot be applied as is.

[0004] Patent Document 1 discloses an inspection method for detecting defects in an all-solid-state battery by applying a voltage to the all-solid-state battery. In this inspection method, the all-solid-state battery is cooled (freezing treatment) to suppress ion conductivity and increase resistance, and then a voltage is applied to measure insulation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7119925 Summary of the Invention [Problem to be solved by the invention]

[0006] The inspection method (insulation resistance measuring method) described in Patent Document 1 includes a step of cooling the all-solid-state battery, which may complicate the process and increase costs.

[0007] The present invention has been made in consideration of the above problems, and has an object to provide an insulation resistance measurement method that can measure the insulation resistance of a battery having an ion conductor while suppressing costs. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided a method for measuring the insulation resistance of an anode deposition type battery or a laminate which is an intermediate thereof, the battery having a positive electrode, a negative electrode, and an ion conductive layer between the positive electrode and the negative electrode, in which ions move through the ion conductive layer. In this insulation resistance measuring method, the insulation resistance of the laminate is measured by connecting the high potential side of an insulation resistance measuring device to the negative electrode side of the laminate and the low potential side to the positive electrode side of the laminate in a state in which the negative electrode side of the laminate does not contain ions and their reduced forms. Effect of the Invention

[0009] According to the present invention, in a state in which the negative electrode side does not contain ions or their reduced forms, the high potential side of the insulation resistance measuring device is connected to the negative electrode side of the laminate (battery) and the low potential side is connected to the positive electrode side of the laminate to measure the insulation resistance of the laminate. In this way, since the high potential side of the insulation resistance measuring device is connected to the negative electrode side that does not contain ions, the ion conducting layer of the laminate does not conduct ions. Therefore, the insulation resistance of the laminate can be easily measured without performing any additional processing. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of an all-solid-state battery to which an insulation resistance measuring method according to one embodiment of the present invention is applied. [Diagram 2] FIG. 2 is a diagram showing the state in which an insulation resistance measuring device is connected to an all-solid-state battery. [Diagram 3] FIG. 3 is a diagram showing an all-solid-state battery in a state where it is pressed to atmospheric pressure. [Figure 4] FIG. 4 is a diagram showing an all-solid-state battery in a pressurized state. [Diagram 5] FIG. 5 is a diagram showing the state in which an insulation resistance measuring device is connected to a single cell. [Figure 6] FIG. 6 is a diagram showing the connection portion. [Figure 7] FIG. 7 is a diagram showing a modified example of the connection portion. [Figure 8] FIG. 8 is a diagram showing a modified example of the connection portion. [Figure 9] FIG. 9 is a diagram showing a modified example of the connection portion. [Figure 10] FIG. 10 is a diagram showing a state in which an insulation resistance measuring device is connected to the intermediate body (laminate). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] [Embodiment] Fig. 1 is a schematic configuration diagram of an all-solid-state battery 100 to which an insulation resistance measuring method according to one embodiment of the present invention is applied, and is a cross-sectional view of the all-solid-state battery 100. Note that Fig. 1 is a diagram of the all-solid-state battery 100 in an uncharged state (including during manufacture).

[0013] 1, the all-solid-state battery 100 is constructed by sealing a single cell (laminated battery, laminate) 1, which is formed by stacking a solid electrolyte layer (ion conducting layer) 30 between a positive electrode layer 10, a positive electrode current collector foil 11, and a negative electrode current collector foil 21, in an exterior body 40. A positive electrode tab 12 connected to the positive electrode current collector foil 11 and a negative electrode tab 22 connected to the negative electrode current collector foil 21 protrude from the exterior body 40.

[0014] The positive electrode layer 10 contains a positive electrode active material, and is laminated on one surface in the lamination direction of the solid electrolyte layer 30 (the upper surface in FIG. 1). The positive electrode layer 10 is produced by mixing NMC (lithium nickel manganese cobalt oxide), a solid electrolyte, a conductive additive, and a binder, drying the mixture, and then press-molding the mixture, and contains lithium ions and lithium metal. In this embodiment, the positive electrode layer 10 is formed using NMC as the main raw material of the positive electrode active material, but the present invention is not limited thereto, and the positive electrode layer 10 may be formed using any known material used as a positive electrode active material.

[0015] The positive electrode current collector foil 11 is a thin plate made of a metal material such as aluminum, nickel, stainless steel (SUS), or an alloy thereof, but is not limited thereto and may be any material having a current collecting function. The positive electrode current collector foil 11 is pressure-bonded to the surface of the positive electrode layer 10 opposite to the surface in contact with the solid electrolyte layer 30, and the positive electrode layer 10 and the positive electrode current collector foil 11 constitute the positive electrode of the all-solid-state battery 100. A positive electrode tab 12 connected to the positive electrode current collector foil 11 is attached to the positive electrode current collector foil 11.

[0016] The negative electrode current collector foil 21 is a thin plate made of a metal material such as aluminum, nickel, stainless steel (SUS), or an alloy thereof, but is not limited thereto and may be any material having a current collecting function. The positive electrode current collector foil 11 and the negative electrode current collector foil 21 may be made of the same material or different materials. The negative electrode current collector foil 21 is laminated on the surface (lower surface in FIG. 1) opposite to the side on which the positive electrode layer 10 is laminated in the lamination direction of the solid electrolyte layer 30, and constitutes the negative electrode of the all-solid-state battery 100. When the all-solid-state battery 100 is charged, lithium metal is precipitated on the negative electrode current collector foil 21, and a lithium metal layer is formed on the negative electrode. A negative electrode tab 22 connected to the negative electrode current collector foil 21 is attached to the negative electrode current collector foil 21.

[0017] The solid electrolyte layer 30 is an ion-conductive layer (ion-conducting layer) containing a solid electrolyte as a main component, and is interposed between the positive electrode layer 10 and the negative electrode current collector foil 21. The solid electrolyte layer 30 is produced by mixing a sulfide solid electrolyte as a solid electrolyte with a binder, drying the mixture, and then press-molding the mixture. Note that, although a sulfide solid electrolyte is used as the solid electrolyte in this embodiment, the present invention is not limited thereto, and any known solid electrolyte may be used. For example, an oxide solid electrolyte may be used.

[0018] The single cell (laminated battery, laminate) 1 is produced by stacking and press-molding a positive electrode layer 10 and a positive electrode current collector foil 11 pressure-bonded to the positive electrode layer 10 on one surface in the stacking direction of a solid electrolyte layer 30, and then stacking and press-molding a negative electrode current collector foil 21 on top of the positive electrode layer 10. That is, the single cell 1 is configured by fixing a positive electrode (the positive electrode layer 10 and the positive electrode current collector foil 11) and a negative electrode (the negative electrode current collector foil 21) to the solid electrolyte layer 30. The single cell 1 is vacuum-sealed in an exterior body 40 with a positive electrode tab 12 connected to the positive electrode current collector foil 11 and a negative electrode tab 22 connected to the negative electrode current collector foil 21 protruding to the outside.

[0019] The exterior body 40 is a bag-shaped case made of a laminate film containing aluminum, and vacuum-seals the single cell 1. The degree of vacuum inside the exterior body 40 is, for example, 5 torr or less, but is not limited to this.

[0020] The positive electrode tab 12 is connected to the positive electrode current collector foil 11 and has one end protruding outside the exterior body 40 , and the negative electrode tab 22 is connected to the negative electrode current collector foil 21 and has one end protruding outside the exterior body 40 .

[0021] In the all-solid-state battery 100 configured as described above, during charging, lithium ions enter the solid electrolyte layer 30 from the positive electrode layer 10, lithium metal is precipitated on the negative electrode current collector foil 21, and a lithium metal layer is formed in the negative electrode. That is, the all-solid-state battery 100 is a negative electrode precipitation type laminated battery (laminate) in which lithium ions and lithium metal are not contained in the negative electrode during discharging, and lithium metal is precipitated in the negative electrode during charging.

[0022] Meanwhile, a method of measuring the insulation resistance of a cell is known as a method of detecting defects in a cell (battery). For example, for a cell that uses an electrolytic solution as an electrolyte, a method is known in which a voltage is applied to the cell before the electrolytic solution is injected, and the current value is measured to measure the insulation. According to this method, if there is a defective part such as a pinhole in the insulator (separator) between the positive and negative electrodes, electrons will flow to the defective part when a high voltage is applied, so that the defective cell can be identified.

[0023] However, in an all-solid-state battery using an all-solid-state electrolyte as an electrolyte or a semi-solid-state battery using a gel electrolyte, the electrolyte (ion conductor) is ionically conductive, and therefore the above method cannot be used as is. For example, when an insulation resistance measuring device is connected to the all-solid-state battery 100 and a voltage is applied, the insulation resistance cannot be measured because the solid electrolyte layer 30 is ionically conductive.

[0024] In addition, there is a method in which the all-solid-state battery is cooled (freezing treatment) to suppress the ionic conductivity and increase the resistance before applying a voltage. However, in this case, since a step of cooling the all-solid-state battery is included, there is a risk that the process will become complicated and the cost will increase.

[0025] Therefore, in this embodiment, in a state in which the negative electrode side does not contain lithium ions and lithium ion metal (hereinafter referred to as lithium ions, etc.), the high potential side of the insulation resistance device is connected to the negative electrode side of the all-solid-state battery 100 (single cell 1) and the low potential side is connected to the positive electrode side, and the insulation resistance of the all-solid-state battery 100 (single cell 1) is measured. In this measurement method, since the high potential side of the insulation resistance measuring device is connected to the negative electrode side that does not contain lithium ions, etc., the solid electrolyte layer 30 of the single cell 1 does not conduct ions. Therefore, the insulation resistance of the all-solid-state battery 100 (single cell 1) can be easily measured without performing a separate process.

[0026] The state not containing lithium ions, etc. may refer not only to a state in which lithium ions, etc. are completely absent, but also to a state in which a small amount of lithium ions, etc. is contained to such an extent that it can be determined that the solid electrolyte layer 30 functions as an insulator when the insulation resistance is measured.

[0027] The insulation resistance measuring method of this embodiment will be described in detail below.

[0028] 2 is a diagram showing a state in which an insulation resistance measuring device 101 is connected to an all-solid-state battery 100. As shown in FIG 2, the insulation resistance measuring device 101 has a high potential (positive) terminal connected to a negative electrode tab 22 and a low potential (negative) terminal connected to a positive electrode tab 12.

[0029] Although not shown, a banana plug, an alligator clip, an alligator clip, a star clip, or the like can be used for the terminals of the insulation resistance measuring device 101, but is not limited to these. In addition, the terminals of the insulation resistance measuring device 101 may be connected to the positive and negative electrode tabs 12, 22 by welding.

[0030] As described above, the all-solid-state battery 100 is a negative electrode deposition type battery, and does not contain lithium ions or the like in the negative electrode during discharge. In addition, the all-solid-state battery 100 does not contain lithium ions or the like in the negative electrode during manufacture (before charging). Therefore, even if a voltage is applied by connecting the high potential side terminal of the insulation resistance measuring device 101 to the negative electrode tab 22 and the low potential side terminal to the positive electrode tab 12 during manufacture or discharge when the negative electrode does not contain lithium ions or the like, there is no ion conduction from the negative electrode side to the positive electrode side because there are no lithium ions or the like on the negative electrode side.

[0031] Here, if there is a defect such as a pinhole in the solid electrolyte layer 30, electrons move within the solid electrolyte layer 30 (pinhole, etc.), causing a short circuit. Therefore, in a state in which the negative electrode side does not contain lithium ions, etc., the high potential side of the insulation resistance measuring device 101 is connected to the negative electrode side of the all-solid-state battery 100, and the low potential side is connected to the positive electrode side, and a voltage is applied, thereby measuring the insulation resistance and detecting defects present in the solid electrolyte layer 30.

[0032] In addition, since the unit cell 1 of the all-solid-state battery 100 is vacuum-sealed by the exterior body 40, the unit cell 1 is pressed to atmospheric pressure as shown in Fig. 3. This improves contact at the interfaces between the layers and elements, and makes it possible to sensitively identify the unit cell 1 having a pinhole or the like.

[0033] Preferably, the insulation resistance is measured while the unit cell 1 is pressurized using a pressurizing device or the like, as shown in Fig. 4. This improves contact at the interfaces between the layers and elements, and makes it possible to more sensitively identify unit cells 1 that have pinholes or the like.

[0034] As described above, in the insulation resistance measuring method of the present embodiment, the high potential side of the insulation resistance measuring device 101 is connected to the negative electrode side that does not contain lithium ions, etc., so that the solid electrolyte layer 30 of the all-solid-state battery 100 does not conduct ions. Therefore, the insulation resistance of the all-solid-state battery 100 can be easily measured without performing a separate process.

[0035] In addition, since the insulation resistance is measured in a state where the unit cell 1 is wrapped in the exterior body 40, that is, for the completed all-solid-state battery 100, it is possible to determine whether there are any defects in the final product.

[0036] The insulation resistance measuring method of the present embodiment can also be used in the manufacturing process of the all-solid-state battery 100. That is, it may be used for the single cell 1 in a state in which the positive electrode and negative electrode tabs 12, 22 are not installed before sealing in the exterior body 40, or for a laminate that is an intermediate body of the all-solid-state battery 100.

[0037] 5 is a diagram showing a state in which an insulation resistance measuring device 101 is connected to a unit cell (laminated battery, laminate) 1 before it is sealed in an exterior body 40. As described above, the unit cell 1 is configured by fixing a positive electrode (positive electrode layer 10 and positive electrode current collector foil 11) and a negative electrode (negative electrode current collector foil 21) to a solid electrolyte layer 30.

[0038] As shown in FIG. 5, the high potential (plus) terminal of the insulation resistance measuring device 101 is connected to the negative electrode current collector foil 21, and the low potential (minus) terminal is connected to the positive electrode current collector foil 11. Here, the all-solid-state battery 100 does not contain lithium ions or the like on the negative electrode side at the time of manufacture. Therefore, even if a voltage is applied to the single cell 1 by the insulation resistance measuring device 101, there is no lithium ion or the like on the negative electrode side, so ion conduction does not occur from the negative electrode side to the positive electrode side. Therefore, if there is no defect such as a pinhole in the solid electrolyte layer 30, no electron transfer occurs. On the other hand, if there is a pinhole or the like in the solid electrolyte layer 30, a short circuit occurs. Therefore, by connecting the high potential side of the insulation resistance measuring device 101 to the negative electrode side that does not contain lithium ions or the like, the insulation resistance of the single cell 1 can be easily measured and defects present in the solid electrolyte layer 30 can be detected.

[0039] In this manner, by measuring the insulation resistance of the laminate (i.e., the single cell 1) in a state in which the positive electrode and the negative electrode are fixed to the solid electrolyte layer 30 (before being sealed in the exterior body 40), it is possible to detect defects present in the solid electrolyte layer 30 at the stage of a battery element (before it becomes the all-solid-state battery 100). This makes it possible to increase the yield of the all-solid-state battery 100.

[0040] Fig. 6 is a diagram showing a connection portion between the single cell 1 and a terminal of an insulation resistance measuring device 101. As shown in Fig. 6, terminals 102 of the insulation resistance measuring device 101 are connected to current collector foils 11, 21 via metal body 103 having a flat surface that contacts current collector foils 11, 21. For terminals 102 of the insulation resistance measuring device 101, banana plugs, alligator clips, alligator clips, star clips, etc. can be used, but are not limited to these. Furthermore, terminals 102 and metal body 103 may be connected by welding.

[0041] Furthermore, the method of connecting the unit cell 1 and the terminal of the insulation resistance measuring device 101 is not limited to the above. For example, a metal body 103 may be placed on conductive rubber 104 in contact with the current collecting foils 11, 21, and a terminal 102 of the insulation resistance measuring device 101 may be connected to the metal body 103 (FIG. 7). Also, for example, the terminal 102 of the insulation resistance measuring device 101 may be connected to the current collecting foils 11, 21 via a metal body or conductive rubber 105 (FIG. 8) having a surface that contacts the entire current collecting foils 11, 21, or a metal body or conductive rubber 106 (FIG. 9) having a jagged surface that contacts the current collecting foils 11, 21.

[0042] FIG. 10 is a diagram showing a state in which an insulation resistance measuring device 101 is connected to a laminate 2 made up of a positive electrode (positive electrode layer 10 and positive electrode current collector foil 11) and a solid electrolyte layer 30. In FIG.

[0043] In the laminate 2, only the positive electrode (positive electrode layer 10 and positive electrode current collector foil 11) is fixed to the solid electrolyte layer 30, and the laminate 2 does not have a negative electrode (negative electrode current collector foil 21). That is, the laminate 2 is an intermediate body prior to forming the negative electrode of the all-solid-state battery 100. A foil 107 connected to an insulation resistance measuring device 101 is in contact with a surface (hereinafter also referred to as the negative electrode side) of the laminate 2 opposite to the side to which the positive electrode is fixed in the stacking direction of the solid electrolyte layer 30.

[0044] The foil 107 is a metal foil (nickel foil) made of nickel. As described above, the solid electrolyte layer 30 uses a sulfide solid electrolyte as a solid electrolyte and contains sulfur. Sulfur is highly reactive and easily reacts with many metals, but does not easily react with nickel. Therefore, even if the foil 107 is brought into contact with the solid electrolyte layer 30, it hardly reacts with the sulfur contained in the solid electrolyte layer 30.

[0045] As shown in FIG. 10, the low potential (negative) terminal of the insulation resistance measuring device 101 is connected to the positive electrode current collector foil 11. On the other hand, the high potential (positive) terminal of the insulation resistance measuring device 101 is connected to the foil 107 that contacts the negative electrode side of the laminate 2. That is, the high potential side of the insulation resistance measuring device 101 is connected to the negative electrode side of the laminate 2 via the foil 107. As described above, the all-solid-state battery 100 does not contain lithium ions or the like on the negative electrode side at the time of manufacture. That is, the laminate 2 does not contain lithium ions or the like on the negative electrode side. Therefore, even if a voltage is applied to the laminate 2 by the insulation resistance measuring device 101, there is no ion conduction from the negative electrode side to the positive electrode side because there are no lithium ions or the like on the negative electrode side. Therefore, when there is no defect such as a pinhole in the solid electrolyte layer 30, no movement of electrons occurs even if a voltage is applied to the laminate 2 by the insulation resistance measuring device 101. On the other hand, when a pinhole or the like is present, when a voltage is applied to the laminate 2, electrons move through the pinhole or the like, causing a short circuit. Therefore, by connecting the high potential side of the insulation resistance measuring device 101 to the negative electrode side that does not contain lithium ions or the like, the insulation resistance of the laminate 2 can be easily measured.

[0046] Furthermore, the high potential side of the insulation resistance measuring device 101 is connected to the negative electrode side of the laminate 2 via the foil 107, but as described above, the foil 107 is made of nickel, which does not easily react with sulfur. Therefore, by bringing the foil 107 connected to the high potential side of the insulation resistance measuring device 101 into contact with the negative electrode side, the insulation resistance of the laminate 2 before forming the negative electrode of the all-solid-state battery 100 can be measured in a state in which the solid electrolyte and the foil 107 do not react with each other.

[0047] In addition, similar to the case of connecting to the tabs 12, 22 and the current collecting foils 11, 21 of the single cell 1, when connecting to the laminate 2, the terminals of the insulation resistance measuring device 101 can be, but are not limited to, banana plugs, alligator clips, alligator clips, star clips, etc. In addition, similar to the case of connecting to the current collecting foils 11, 21 of the single cell 1, when connecting to the laminate 2, the terminals of the insulation resistance measuring device 101 can be, but are not limited to, connected to the positive electrode current collecting foil 11 and foil 107 of the laminate 2 via a metal body having a flat surface, conductive rubber, etc., or by welding.

[0048] In this way, by measuring the insulation resistance of the laminate 2 in a state where only the positive electrode is fixed to the solid electrolyte layer 30 (before the negative electrode is formed), it is possible to detect defects present in the solid electrolyte layer 30 at a stage before the battery (single cell 1) is manufactured. This makes it possible to increase the yield of the all-solid-state battery 100.

[0049] Preferably, in the manufacturing process of the all-solid-state battery 100, the insulation resistance is measured for at least two of the laminates in a state where only the positive electrode is fixed to the solid electrolyte layer 30 (FIG. 10), the laminate in a state where the positive electrode and the negative electrode are fixed to the solid electrolyte layer 30 (single cell 1 before sealing in the exterior body 40, FIG. 5), and the laminate in a state where the single cell 1 is wrapped in the exterior body 40 (all-solid-state battery 100, FIG. 2). This can further increase the yield of the all-solid-state battery 100.

[0050] More preferably, the insulation resistance of the laminate is measured in each of the states where only the positive electrode is fixed to the solid electrolyte layer 30, where the positive electrode and the negative electrode are fixed to the solid electrolyte layer 30, and where the unit cell 1 is wrapped in the exterior body 40. As a result, if there is a defect in the solid electrolyte, the subsequent steps are not performed, and the yield of the all-solid-state battery 100 can be further increased.

[0051] In addition, it is preferable to measure the insulation resistance by the present practical insulation resistance measurement method after measuring the OCV voltage (open circuit voltage) of the all-solid-state battery 100 or an intermediate thereof. By measuring the insulation resistance after judging a defect based on the OCV voltage, the accuracy of determining defects in the solid electrolyte is improved.

[0052] According to the insulation resistance measuring method of the above embodiment, the following effects can be obtained.

[0053] According to the insulation resistance measuring method of the present embodiment, the insulation resistance of an all-solid-state battery 100 of anode deposition type in which ions move through the solid electrolyte layer 30 or a laminate which is an intermediate thereof is measured by connecting the high potential side of the insulation resistance measuring device 101 to the negative electrode side of the laminate and connecting the low potential side to the positive electrode side of the laminate in a state in which lithium ions and lithium metal are not contained on the negative electrode side of the laminate. In this measuring method, the high potential side of the insulation resistance measuring device 101 is connected to the negative electrode side which does not contain lithium ions, etc., so that the solid electrolyte layer 30 does not conduct ions. Therefore, the insulation resistance of the all-solid-state battery 100 or a laminate which is an intermediate thereof can be easily measured without performing a separate process. Therefore, the insulation resistance of a battery having a solid electrolyte layer 30 (ion conductor) can be measured while suppressing costs.

[0054] According to the insulation resistance measuring method of the present embodiment, the insulation resistance is measured for the laminate 2 in a state where only the positive electrode is fixed to the solid electrolyte layer 30. This makes it possible to detect defects present in the solid electrolyte layer 30 before the negative electrode is constructed, that is, before the battery (single cell 1) is manufactured. Therefore, the yield of the all-solid-state battery 100 can be increased.

[0055] According to the insulation resistance measuring method of the present embodiment, the solid electrolyte layer 30 contains sulfur, and a foil 107 made of nickel (nickel foil) is brought into contact with the negative electrode side of the laminate 2 in a state where only the positive electrode is fixed to the solid electrolyte layer 30, and the insulation resistance of the laminate 2 is measured. In this manner, the foil 107 made of nickel, which is less reactive with sulfur, is brought into contact with the solid electrolyte layer 30 containing sulfur, and the negative electrode side of the laminate 2 and the insulation resistance measuring device 101 are connected via the foil 107. Therefore, the insulation resistance of the laminate 2 before forming the negative electrode of the all-solid-state battery 100 can be measured in a state where the solid electrolyte does not react with the foil 107.

[0056] According to the insulation resistance measuring method of the present embodiment, the insulation resistance is measured for a laminate (i.e., a single cell 1) in a state in which a positive electrode and a negative electrode are fixed to a solid electrolyte layer 30. This makes it possible to detect defects present in the solid electrolyte layer 30 at the stage of a battery element (before it becomes an all-solid-state battery 100). Therefore, the yield of the all-solid-state battery 100 can be increased.

[0057] According to the insulation resistance measuring method of the present embodiment, the insulation resistance is measured for a laminate in a state in which the unit cell 1 is wrapped in the exterior body 40 (i.e., the finished all-solid-state battery 100). This makes it possible to determine whether the final product has any defects.

[0058] In this embodiment, the all-solid-state battery 100 or the laminate which is an intermediate thereof has a configuration having lithium ions in the positive electrode, but is not necessarily limited to this, and may have ions other than lithium or their reduced forms in the positive electrode. For example, the positive electrode may have sodium ions.

[0059] In this embodiment, the insulation resistance of the all-solid-state battery 100 is measured, but the object of the insulation resistance measurement is not necessarily limited to this, and may be any negative electrode deposition type battery in which ions move through an ion conductive layer, or a laminate that is an intermediate therebetween. The object of the insulation resistance measurement may be, for example, a semi-solid battery that uses a gel electrolyte as the ion conductive layer, instead of a solid electrolyte.

[0060] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments. [Explanation of symbols]

[0061] 1: Single cell, 2: Laminate, 10: Positive electrode layer, 11: Positive electrode current collector foil, 21: Negative electrode current collector foil, 30: Solid electrolyte layer (ion conductive layer), 100: All-solid-state battery, 101: Insulation resistance measuring device, 107: Foil (nickel foil)

Claims

1. A method for measuring the insulation resistance of an anode deposition type battery or an intermediate thereof, the battery having a positive electrode, a negative electrode, and an ion conductive layer between the positive electrode and the negative electrode, in which ions move through the ion conductive layer, the method comprising: In a state in which the negative electrode side of the laminate does not contain ions and their reduced products, the high potential side of an insulation resistance measuring device is connected to the negative electrode side of the laminate and the low potential side is connected to the positive electrode side of the laminate, thereby measuring the insulation resistance of the laminate. Insulation resistance measurement method.

2. 2. The insulation resistance measuring method according to claim 1, measuring the insulation resistance of the laminate in a state where only the positive electrode is fixed to the ion conductive layer; Insulation resistance measurement method.

3. 3. The insulation resistance measuring method according to claim 2, the ion conducting layer comprises sulfur; A nickel foil is brought into contact with the negative electrode side of the laminate to measure the insulation resistance of the laminate. Insulation resistance measurement method.

4. 2. The insulation resistance measuring method according to claim 1, measuring the insulation resistance of the laminate in a state in which the positive electrode and the negative electrode are fixed to the ion conductive layer; Insulation resistance measurement method.

5. The insulation resistance measuring method according to claim 4, measuring the insulation resistance of the laminate while the laminate is wrapped in an outer casing; Insulation resistance measurement method.

6. 2. The insulation resistance measuring method according to claim 1, measuring the resistance of the laminate in at least two states among a state in which only the positive electrode is fixed to the ion conductive layer, a state in which the positive electrode and the negative electrode are fixed to the ion conductive layer, and a state in which the laminate is wrapped in an exterior body; Insulation resistance measurement method.

7. 2. The insulation resistance measuring method according to claim 1, measuring an open circuit voltage of the laminate and then measuring a resistance thereof in each of a state in which only the positive electrode is fixed to the ion conductive layer, a state in which the positive electrode and the negative electrode are fixed to the ion conductive layer, and a state in which the laminate is wrapped in an outer casing; Insulation resistance measurement method.

8. 2. The insulation resistance measuring method according to claim 1, The laminate has sodium ions or lithium ions in the positive electrode. Insulation resistance measurement method.

9. 9. The insulation resistance measuring method according to claim 1 , The ion conducting layer is a solid electrolyte. Insulation resistance measurement method.

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