Electrode center position identification method and electrode center position identification device

Abstract

This electrode center position identification method is for identifying, after rolling, the center position of an electrode mixture layer of a laminate in which a current collector foil, the electrode mixture layer, and a solid electrolyte layer are laminated in the stated order. At least three reference parts are provided in a region on a surface of the current collector foil where the electrode mixture layer is not formed. A control unit: measures, on the basis of imaged data by an imaging device, the positions of the reference parts and a relative position of the center point of the electrode mixture layer formed on the surface of the current collector foil with respect to the reference parts; after formation of the solid electrolyte layer on the surface, of the electrode mixture layer, opposite from the current collector foil and after the rolling, measures positional change amounts of the reference parts on the basis of imaged data by the imaging device; and identifies the position of the center point of the electrode mixture layer after the rolling by using the positional change amounts.

Description

Method for Specifying Electrode Center Position and Device for Specifying Electrode Center Position

[0006]

[0001] The present invention relates to a method for specifying an electrode center position and a device for specifying an electrode center position.

[0002] As a secondary battery used for a power source of a vehicle or the like, a laminated battery is known. The laminated battery is manufactured by sequentially laminating each layer including a positive electrode layer and a negative electrode layer. In order to ensure the quality of the battery, it is necessary to minimize the displacement of each electrode plate. As a method therefor, WO2021 / 171946A1 discloses a method in which infrared rays are irradiated from the separator side to a laminate in which a separator and an electrode plate are adhered, the infrared rays transmitted through the separator and reflected by the electrode plate are imaged by a camera, and the position of the electrode plate is detected based on the captured image.

[0003] However, the method described in the above document is effective for a battery using a separator through which infrared rays easily pass, such as a conventional secondary battery using an electrolytic solution, but is not applicable to an all-solid-state battery using a solid electrolyte layer through which infrared rays hardly pass.

[0004] Therefore, an object of the present invention is to provide a method capable of detecting the position of an electrode plate even in an all-solid-state battery.

[0005] According to an aspect of the present invention, there is provided an electrode center position specifying method for specifying the center position of a rolled electrode mixture layer in a laminate in which a current collector foil, an electrode mixture layer, and a solid electrolyte layer are laminated in this order. In this method, at least three reference portions are provided at portions on the surface of the current collector foil where the electrode mixture layer is not formed, and a control unit measures, based on imaging data obtained by an imaging device, the position of the reference portion and the relative position of the center point of the electrode mixture layer formed on the surface of the current collector foil with respect to each reference portion. After forming and rolling a solid electrolyte layer on the surface of the electrode mixture layer opposite to the current collector foil, the amount of change in the position of each reference portion is measured based on imaging data obtained by the imaging device, and the position of the center point of the rolled electrode mixture layer is specified using the amount of change in the position.

[0006] Figure 1 is a diagram showing a part of the manufacturing process of a laminate constituting an all-solid-state battery. Figure 2 is a schematic configuration diagram of the apparatus according to this embodiment of the present invention. Figure 3 is a view (plan view) of the positive electrode current collector foil and the positive electrode layer laminated on the positive electrode current collector foil, viewed from above in the lamination direction. Figure 4A is a plan view of the positive electrode current collector foil and positive electrode layer before the solid electrolyte layer is laminated. Figure 4B is a plan view of the positive electrode current collector foil and positive electrode layer after roll pressing. Figure 5 is a diagram showing the region where the reference part is provided. Figure 6 is a diagram showing a method for identifying the center point of the positive electrode current collector foil before rolling according to the first modification. Figure 7 is a diagram showing a method for identifying the center point C01 of the positive electrode current collector foil 1 before rolling according to the second modification. Figure 8 is a diagram showing a method for identifying the center point C01 of the positive electrode current collector foil 1 before rolling according to the third modification. Figure 9 is a diagram for explaining a method for identifying the center point of the positive electrode current collector foil before rolling according to the fourth modification. Figure 10 is a diagram illustrating a method for identifying the center point of the positive electrode current collector foil before rolling, according to the fifth modified example.

[0007] Embodiments of the present invention will be described below with reference to the drawings.

[0008] Figure 1 shows a part of the manufacturing process for the laminate that makes up an all-solid-state battery. Note that the shape and thickness of each layer are set for convenience and are not limited to these.

[0009] First, a slurry containing the positive electrode active material, binder, etc., is coated onto the positive electrode current collector foil 1 and dried (Figure 1(a)). The positive electrode current collector foil 1 is made of a metal material such as aluminum foil. From the viewpoint of miniaturizing the all-solid-state battery, it is desirable that the thickness of the positive electrode current collector foil 1 be 20 μm or less.

[0010] Next, a slurry of solid electrolyte, binder, etc., is coated onto stainless steel foil or the like, and dried to create a solid electrolyte layer 7. This solid electrolyte layer 7 is then placed on the upper surface of the positive electrode layer 2 and roll-pressed (Figures 1(b) and 1(c)).

[0011] Next, a slurry containing a mixture of negative electrode active material, binder, etc., is applied to the negative electrode current collector and dried to create a negative electrode layer 8, which is then placed on the upper surface of the solid electrolyte layer 7 (Figure 1(d)). Finally, this is roll-pressed to create a laminate.

[0012] In the process described above, each operation, such as coating and lamination, is performed by manufacturing equipment.

[0013] Incidentally, from the standpoint of ensuring battery performance, it is desirable that the positive electrode layer 2 and the negative electrode layer 8 be stacked without any misalignment. To achieve this, it is necessary to determine the precise position of the positive electrode layer 2 using an imaging device such as a camera before stacking the negative electrode layer 8. However, when stacking the negative electrode layer 8, there is a solid electrolyte layer 7 on the upper surface of the positive electrode layer 2, so it is not possible to image the position of the positive electrode layer 2 from above. Imaging from above is possible before stacking the solid electrolyte layer 7 (Figure 1(a)), but when stacking the negative electrode layer 8, the positive electrode layer 2 is deformed by the roll press, so the position data from before stacking the solid electrolyte layer 7 cannot be used.

[0014] Therefore, in this embodiment, the position of the positive electrode layer 2 is determined when stacking the negative electrode layer 8 using the method described below.

[0015] Figure 2 is a schematic diagram of the apparatus according to this embodiment. Figure 3 is a view (plan view) of the positive electrode current collector foil 1 and the positive electrode layer 2 laminated on the positive electrode current collector foil 1, viewed from above in the lamination direction. In this embodiment, the workpiece movement direction during roll pressing is from the bottom to the top of the paper (Y direction).

[0016] As shown in Figure 2, a digital camera 21, which serves as an imaging device, is positioned above the workpiece in the stacking direction, such as the positive electrode layer 2. The imaging data from the digital camera (hereinafter also simply referred to as "camera") 21 is read by the control unit 20. Note that the imaging device is not limited to a camera 21; for example, a line sensor may also be used.

[0017] The control unit 20 includes a pre-rolling measurement unit 20A, a post-rolling measurement unit 20B, and a center position identification unit 20C. Based on the imaging data, it identifies the position of the positive electrode layer 2 by a method described later, and based on that position, it operates an actuator (e.g., a robot arm) 22 to stack and arrange the negative electrode layer 8 on the upper surface of the solid electrolyte layer 7.

[0018] Identifying the position of the positive electrode layer 2 specifically means identifying the position of the center of the positive electrode layer 2. Since the position of the center of the negative electrode layer 8 can be confirmed by camera 21, if the position of the center of the positive electrode layer 2 is known, the positive electrode layer 2 and the negative electrode layer 8 can be stacked without misalignment by stacking them so that the center of the negative electrode layer 8 coincides with the center of the positive electrode layer 2. The method for identifying the center position of the positive electrode layer 2 will be explained below.

[0019] As shown in Figure 3, the positive electrode current collector foil 1 is equipped with four reference sections 3-6. Note that there should be at least three reference sections. The reference sections 3-6 can be any shape that can be recognized by the camera 21; for example, they may be holes punched out, or marks created by laser processing or coating. Also, while the reference sections 3-6 are circular in Figure 3, they are not limited to this; they may be triangular, square, or cross-shaped, for example. However, it is desirable that they be symmetrical along a line or point. This is because if a part is missing for any reason, the center of the reference section can be calculated from the shape of the remaining part.

[0020] Before laminating the solid electrolyte layer 7, the control unit 20 measures the position of the reference section 3-6 and the relative position of the center point of the positive electrode layer 2 formed on the surface of the positive electrode current collector foil 1 with respect to the reference section 3-6, based on the imaging data from the camera 21. Specifically, it identifies the position of the reference section 3-6 and the position of the center point of the positive electrode layer 2 based on the imaging data from the camera 21, and further calculates the relative position of the center point of the positive electrode layer 2 with respect to the reference section 3-6. The center point of the positive electrode layer 2 can be identified based on the imaging data. Specific examples of data used to identify the relative position will be described later, but any data that can identify the positional relationship between the reference section 3-6 and the center point of the positive electrode layer 2 is acceptable and is not particularly limited.

[0021] After the above measurements are completed, the solid electrolyte layer 7 is stacked and roll-pressed, and the amount of positional change of the reference section 3-6 is measured based on the imaging data from the camera 21. This amount of positional change is then used to determine the center position of the positive electrode layer 2 after rolling.

[0022] The method for determining the center position of the positive electrode layer 2 after rolling will be explained with reference to Figures 4A and 4B.

[0023] Figure 4A is a plan view of the positive electrode current collector foil 1 and positive electrode layer 2 before lamination of the solid electrolyte layer 7, and Figure 4B is a plan view of the positive electrode current collector foil 1 and positive electrode layer 2 after roll pressing. In Figures 4A and 4B, the short direction of the positive electrode current collector foil 1 and positive electrode layer 2 is the X direction, and the long direction is the Y direction. Note that the solid electrolyte layer 7 is omitted in Figure 4B for explanatory purposes.

[0024] Furthermore, the four reference sections 3-6 are designated as the first reference section 3, the second reference section 4, the third reference section 5, and the fourth reference section 6. The four reference sections 3-6 are arranged so that each reference section 3-6 is a vertex of a rectangle. Note that there may be three reference sections, from the first reference section 3 to the third reference section 5. In that case, the line connecting the first reference section 3 and the third reference section 5 must be parallel to the line perpendicular to the line connecting the first reference section 3 and the second reference section 4. The reason for this will be explained later.

[0025] First, let's explain Figure 4A.

[0026] The intersection of a line perpendicular to the midpoint of the line connecting the center of the first reference section 3 and the center of the second reference section 4, and a line perpendicular to the midpoint of the line connecting the center of the first reference section 3 and the center of the third reference section 5, is defined as the pre-rolling center point C01 of the positive electrode current collector foil 1. On the other hand, the center point of the positive electrode layer 2 is defined as the pre-rolling center point Ca1.

[0027] Then, the distance in the X direction between the pre-rolling center point C01 and the pre-rolling center point Ca1 is defined as dx1, and the distance in the Y direction is defined as dy1. Also, the distance in the X direction between the first reference section 3 and the second reference section 4 is defined as Lx1, and the distance in the Y direction between the first reference section 3 and the third reference section 5 is defined as Ly1.

[0028] In Figure 4B, as in Figure 4A, the intersection of a line perpendicular to the midpoint of the line connecting the center of the first reference section 3 and the center of the second reference section 4, and a line perpendicular to the midpoint of the line connecting the center of the first reference section 3 and the center of the third reference section 5, is defined as the rolled center point C02 of the positive electrode current collector foil 1. On the other hand, the center point of the positive electrode layer 2 is defined as the rolled center point Ca2. The distance in the X direction between the rolled center point C02 and the rolled center point Ca2 is defined as dx2, and the distance in the Y direction is defined as dy2. The distance in the X direction between the first reference section 3 and the second reference section 4 is defined as Lx1, and the distance in the Y direction between the first reference section 3 and the third reference section 5 is defined as Ly1.

[0029] In the actual manufacturing process, the center point Ca2 of the positive electrode layer 2 after rolling cannot be identified by the camera 21. However, if the relationship between the X-direction distance dx1 and Y-direction distance dy1 before the roll press and the X-direction distance dx2 and Y-direction distance dy2 after the roll press (i.e., the change in the X-direction distance and Y-direction distance before and after the roll press) is known in advance, the center point Ca2 of the positive electrode layer 2 after rolling can be calculated from the center point C02 of the positive electrode current collector foil 1 after rolling. Specifically, the change in position of the reference section 3-6 before and after the roll press can be obtained from the position of the reference section 3-6 before and after the roll press, and furthermore, the change in position from the center point C01 before rolling to the center point C02 after rolling can be calculated. Furthermore, by using the amount of positional change of the center of the positive electrode current collector foil 1 and the relationship between the X-direction distance dx1 and Y-direction distance dy1 before roll pressing and the X-direction distance dx2 and Y-direction distance dy2 after roll pressing, the center point Ca2 of the positive electrode layer 2 after rolling can be determined from the center point C02 of the positive electrode current collector foil 1 after rolling.

[0030] Therefore, in this embodiment, the relationship between the X-direction distance dx1 and Y-direction distance dy1 before roll pressing and the X-direction distance dx2 and Y-direction distance dy2 after roll pressing is determined in advance by experimentation or other means. Then, before laminating the solid electrolyte layer 7, the position of the reference section 3-6 and the position of the center point Ca1 of the positive electrode layer 2 are acquired based on the imaging data of the camera 21, and the center point Ca2 of the positive electrode layer 2 after rolling is determined by the method described above.

[0031] Once the center point Ca2 of the positive electrode layer 2 after rolling is identified, the control unit 20 controls the actuator 22 based on the data of that position to stack the negative electrode layers 8 so that their centers coincide with the center point Ca2 after rolling.

[0032] Incidentally, since the reference section 3-6 is imaged by the camera 21, it is assumed that it is placed in a region where the positive electrode layer 2 of the positive electrode current collector foil 1 is not formed. More specifically, it is desirable that it be placed within that region, in a plan view, within the range that would be covered if the positive electrode layer 2 were extended in the longitudinal direction (Y direction), or within the range that would be covered if the positive electrode layer 2 were extended in the short direction (X direction). The reason for this will be explained with reference to Figure 5.

[0033] Figure 5 shows the area where the reference section 3-6 is provided. The shaded areas A1 and A2 represent the area covered when the positive electrode layer 2 is extended in the longitudinal direction (Y direction), and the shaded areas A3 and A4 represent the area covered when the positive electrode layer 2 is extended in the short direction (X direction).

[0034] During roll pressing, the positive electrode current collector foil 1 is transported along the Y direction from the bottom to the top in the figure, and only the portion where the positive electrode layer 2 is formed is pressed. The portion where the positive electrode layer 2 is formed stretches in the X and Y directions when pressed. If the elongation rate in the X direction and the elongation rate in the Y direction are different, the region B1-B4, excluding the shaded area A1-A4, will experience a rotational deformation as shown by the thick arrow in the figure due to the combined elongation in the X and Y directions. The amount of this deformation is difficult to predict. If reference section 3-6 is placed in such a location, the shape of reference section 3-6 may deform significantly, or the positional relationship of the four reference sections 3-6 may change significantly, which may worsen the accuracy of estimating the center point Ca2 of the positive electrode layer 2 after rolling. In contrast, in the shaded area A1-A4, the elongation in either the X or Y direction is dominant, so the deterioration of the estimation accuracy can be suppressed.

[0035] Next, modifications of the above embodiments will be described. Each of the following modifications also falls within the technical scope of the present invention, similar to the above embodiments.

[0036] [First Modified Example] Figure 6 shows a method for identifying the center point C01 of the positive electrode current collector foil 1 before rolling, according to the first modified example. The same method applies to the center point C02 after rolling.

[0037] The arrangement of the four reference sections 3-6 is the same as in the above embodiment, with each section located at a vertex of the rectangle. However, in this modified example, the pre-rolling center point C01 is defined as the intersection of the lines connecting the diagonally opposite reference sections, i.e., the first reference section 3 and the fourth reference section 6, and the second reference section 4 and the third reference section 5. This method of identification also allows for accurate identification of the pre-rolling center point C01.

[0038] [Second Modification] Figure 7 shows a method for identifying the center point C01 of the positive electrode current collector foil 1 before rolling, according to the second modification. The same method applies to the center point C02 after rolling.

[0039] The four reference sections 3-6 are arranged so that each is located at one of the vertices of a trapezoid. In this modified example, the pre-rolling center point C01 is defined as the intersection of a line perpendicular to the midpoint of the line connecting the first reference section 3 and the second reference section 4, and a line that intersects the midpoint of the line connecting the first reference section 3 and the third reference section 5 and extends in the X direction. With this identification method, even if the X-direction positions of the first reference section 3 and the third reference section 5 are misaligned, the pre-rolling center point C01 can be identified using orthogonal coordinates with the longitudinal and transverse directions of the positive electrode current collector foil 1 as axes.

[0040] This modified example can also be applied when the four reference sections 3-6 are arranged so that each is located at a vertex of the rectangle. In this case, since the X-direction positions of the first reference section 3 and the third reference section 5 are the same, the resulting identification method is the same as in the above embodiment.

[0041] [Third Modification] Figure 8 shows a method for identifying the center point C01 of the positive electrode current collector foil 1 before rolling, according to the third modification. The same method applies to the center point C02 after rolling.

[0042] Similar to the second modified example, the four reference sections 3-6 are arranged so that each is located at one of the vertices of a trapezoid. In this modified example, the pre-rolling center point C01 is defined as the intersection of a line extending in the Y direction that intersects the midpoint of the line connecting the first reference section 3 and the second reference section 4, and a line perpendicular to the midpoint of the line connecting the first reference section 3 and the third reference section 5. This identification method allows the pre-rolling center point C01 to be identified using orthogonal coordinates with the longitudinal and transverse directions of the positive electrode current collector foil 1 as axes, even if the Y-direction positions of the first reference section 3 and the second reference section 4 are misaligned. This modified example can also be applied when the four reference sections 3-6 are arranged so that each is located at one of the vertices of a rectangle. In this case, since the Y-direction positions of the first reference section 3 and the second reference section 4 are the same, the identification method is ultimately the same as in the above embodiment.

[0043] [Fourth Modification] Figure 9 is a cross-sectional view of a laminate to which the method for identifying the pre-rolling center point C01 of the positive electrode current collector foil 1 according to the fourth modification is applied.

[0044] In the laminate in the above embodiment, the positive electrode layer 2, the solid electrolyte layer 7, and the negative electrode layer 8 are laminated only on one surface (upper surface) of the positive electrode current collector foil 1. However, in this modified example, the positive electrode layer 2, the solid electrolyte layer 7, and the negative electrode layer 8 are also laminated on the other surface (lower surface) of the positive electrode current collector foil 1. Then, the control unit 20 measures the relative position and the amount of position change for each of the two positive electrode layers 2 on the upper surface side and the lower surface side, and specifies the center point C02 after rolling.

[0045] When the thickness and material of the positive electrode layer 2 are different between the upper surface side and the lower surface side, the amount of deformation is different even with the same pressing load. Even in this case, according to this modified example, since the center point C02 after rolling of the positive electrode layer two is specified according to the amount of deformation on each of the upper surface side and the lower surface side, the negative electrode layer 8 can be laminated on both the upper surface side and the lower surface side without deviation.

[0046] [Fifth Modified Example]FIG. 10 is a diagram showing a method for specifying the center point C01 before rolling of the positive electrode current collector foil 1 according to the fifth modified example. The same applies to the center point C02 after rolling.

[0047] When measuring the position using an imaging device such as a camera 21 or a line sensor, there may be a deviation between the measurement result and the actual position due to the inherent instrumental error of the device used. For example, although the center point before rolling of the actual positive electrode current collector foil 1 is C01R, the measurement result may be C01C. Therefore, in this modified example, the deviations in the X direction and the Y direction between the actual position due to the instrumental error and the position calculated as the measurement result are obtained in advance by experiments or the like, and this is set as an offset value. The method for measuring the center point C01 before rolling may be any of the methods in the above embodiment and the first to fourth modified examples.

[0048] The actuator 22 that receives the coordinate data of the center point Ca2 after rolling of the positive electrode layer 2 from the control unit 20 laminates the negative electrode layer 8 with the coordinates obtained by adding the offset value to the received coordinate data as the target coordinates. Note that the control unit may be made to store the offset value, and the value obtained by adding the offset value to the measurement result may be used as the coordinate data to be transmitted to the actuator 22.

[0049] As described above, this embodiment provides an electrode center position identification method for identifying the center position of the positive electrode layer 2 after rolling, in a laminate in which a positive electrode current collector foil (current collector foil) 1, a positive electrode layer (electrode mixture layer) 2, and a solid electrolyte layer 7 are laminated in this order. In this method, at least three reference sections 3-6 are provided on the surface of the positive electrode current collector foil 1 in areas where the positive electrode layer 2 is not formed. The control unit 20 measures the positions of the reference sections 3-6 and the relative positions of the center point C01 of the positive electrode layer 2 formed on the surface of the positive electrode current collector foil 1 with respect to each reference section 3-6 based on imaging data from a camera (imaging device) 21. After forming the solid electrolyte layer 7 on the surface of the positive electrode layer 2 opposite to the positive electrode current collector foil 1 and performing roll pressing (rolling), the amount of position change of each reference section 3-6 is measured based on imaging data from the camera 21, and the position Ca2 of the center point of the positive electrode layer 2 after rolling is identified using the amount of position change. This makes it possible to accurately pinpoint the center position of the positive electrode layer 2 after roll pressing, even in all-solid-state batteries where the positive electrode layer 2 is deformed by roll pressing during the manufacturing process. As a result, the negative electrode layer 8 can be laminated relative to the positive electrode layer 2 without any misalignment.

[0050] In this embodiment, the reference portion 3-6 has a line-symmetric or point-symmetric shape. As a result, even if the reference portion 3-6 is damaged during the manufacturing process, the center position of the reference portion 3-6 can be determined from the remaining portion, and thus the center position of the positive electrode layer 2 can be determined.

[0051] In this embodiment, the reference portion 3-6 is provided within the area (A1, A2) that would be covered if the positive electrode layer 2 were extended in the Y direction (longitudinal direction) in a plan view, or within the area (A3, A4) that would be covered if the positive electrode layer 2 were extended in the X direction (short direction), in a portion where the positive electrode layer 2 is not formed. Since this area is less affected by deformation due to the roll press, the position of the center of the positive electrode layer 2 can be accurately determined.

[0052] In this embodiment, when at least three reference sections 3-6 are designated as the first reference section 3, the second reference section 4, and the third reference section 5, the first reference section 3, the second reference section 4, and the third reference section 5 are positioned such that the line connecting the first reference section 3 and the third reference section 5 is parallel to the line perpendicular to the line connecting the first reference section 3 and the second reference section 4. This allows for more accurate measurements, as each position and distance can be measured in a coordinate system where the X and Y axes are orthogonal.

[0053] In a modified version of this embodiment, a positive electrode layer 2 and a solid electrolyte layer 7 are laminated in this order on both sides of the positive electrode current collector foil 1, and the control unit 20 measures the relative position and the amount of positional change for each of the two positive electrode layers 2 to determine the center position after roll pressing. This makes it possible to laminate the negative electrode layer 8 without misalignment relative to the positive electrode layer 2, even when the thickness or material of the positive electrode layer 2 differs on the two sides.

[0054] In this embodiment, the imaging device is a digital camera 21 or a line sensor (not shown). With these, the measurement results can be saved as digital data on a storage medium. Furthermore, since measurements can be taken without human intervention, a fully automated manufacturing facility can be constructed.

[0055] In this embodiment, it is desirable that the positive electrode current collector foil 1 be made of a metal material with a thickness of 20 μm or less. This makes it possible to make the all-solid-state battery more compact. The thinner the positive electrode current collector foil 1 is, the lower its resistance to external forces and the greater the amount of deformation by roll pressing. However, with the method of this embodiment, the center position of the positive electrode current collector foil 1 after roll pressing can be accurately determined. As a result, the center position of the positive electrode layer 2 after roll pressing can also be accurately determined.

[0056] In this embodiment, an electrode center positioning device is provided for determining the center position of the positive electrode layer 2 after roll pressing of a laminate in which a positive electrode current collector foil 1, a positive electrode layer 2, and a solid electrolyte layer 7 are stacked in this order. At least three reference sections 3-6 are provided on the surface of the positive electrode current collector foil 1 in areas where the positive electrode layer 2 is not formed. In this device, the control unit 20 includes a pre-rolling measurement unit 20A that measures the position of the reference sections 3-6 and the relative position of the center point of the positive electrode layer 2 formed on the surface of the positive electrode current collector foil 1 with respect to each reference section 3-6 based on imaging data from a camera 21; a post-rolling measurement unit 20B that measures the amount of position change of each reference section 3-6 after the solid electrolyte layer 7 is formed on the surface of the positive electrode layer 2 opposite to the positive electrode current collector foil 1 and roll pressing is performed; and a center positioning unit 20C that determines the position of the center point of the positive electrode layer 2 after roll pressing using the amount of position change. This makes it possible to accurately pinpoint the center position of the positive electrode layer 2 after roll pressing, even in all-solid-state batteries where the positive electrode layer 2 is deformed by roll pressing during the manufacturing process. As a result, the negative electrode layer 8 can be laminated relative to the positive electrode layer 2 without any misalignment.

[0057] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Claims

1. An electrode center position determination method for determining the center position of the electrode mixture layer after rolling of a laminate in which a current collector foil, an electrode mixture layer, and a solid electrolyte layer are laminated in this order, wherein at least three reference points are provided on the surface of the current collector foil in a portion where the electrode mixture layer is not formed, a control unit measures the position of the reference points and the relative position of the center point of the electrode mixture layer formed on the surface of the current collector foil with respect to each reference point based on imaging data from an imaging device, after forming the solid electrolyte layer on the surface of the electrode mixture layer opposite to the current collector foil and rolling, the amount of position change of each reference point is measured based on imaging data from the imaging device, and the position of the center point of the electrode mixture layer after rolling is determined using the amount of position change.

2. An electrode center position determination method according to claim 1, wherein the reference portion has a line-symmetric or point-symmetric shape.

3. An electrode center position determination method according to claim 1, wherein the reference portion is provided in a portion of the area where the electrode mixture layer is not formed, within a range that would be covered if the electrode mixture layer were extended in the longitudinal direction or within a range that would be covered if the electrode mixture layer were extended in the short direction, in a plan view.

4. An electrode center position determination method according to claim 1, wherein when the three reference parts are designated as a first reference part, a second reference part, and a third reference part, the first reference part, the second reference part, and the third reference part are in a positional relationship such that the line connecting the first reference part and the third reference part is parallel to the line perpendicular to the line connecting the first reference part and the second reference part.

5. An electrode center position determination method according to claim 1, wherein the electrode mixture layer and the solid electrolyte layer are laminated in this order on both sides of the current collector foil, and the control unit measures the relative position and the amount of position change for each of the two electrode mixture layers to determine the center position after rolling.

6. An electrode center position determination method according to claim 1, wherein the imaging device is a digital camera or a line sensor.

7. An electrode center positioning method according to claim 1, wherein the current collector foil is made of a metal material with a thickness of 20 μm or less.

8. An electrode center positioning device for determining the center position of the electrode mixture layer after rolling of a laminate in which a current collector foil, an electrode mixture layer, and a solid electrolyte layer are laminated in this order, wherein at least three reference points are provided on the surface of the current collector foil in a portion where the electrode mixture layer is not formed, and the control unit comprises: a pre-rolling measurement unit that measures the position of the reference points and the relative position of the center point of the electrode mixture layer formed on the surface of the current collector foil with respect to each reference point based on imaging data from an imaging device; a post-rolling measurement unit that measures the amount of position change of each reference point after the solid electrolyte layer is formed on the surface of the electrode mixture layer opposite to the current collector foil and rolled, based on imaging data from the imaging device; and a center positioning unit that determines the position of the center point of the electrode mixture layer after rolling using the amount of position change.

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