Method for manufacturing power storage device

Abstract

Provided is a method for manufacturing a power storage device, wherein a correction deformation amount can be changed in accordance with a warpage displacement amount of a sealing body, and a precision-requiring surface of the sealing body can be corrected within a reference value. The method includes a correction step for correcting the sealing body. The seal body has a precision requirement surface, and is provided with: a database formation step for storing related chart data, the graph data is the correlation graph data of the warping displacement amount of the precision requirement surface relative to the supporting point of the sealing body in the surface-to-surface direction and the correction deformation amount of the precision requirement surface in the direction opposite to the surface-to-surface direction until the precision requirement surface can return to the normal position through the elastic force of the precision requirement surface. A surface displacement measurement step for measuring the amount of warpage displacement; and a displacement amount determination step for determining whether or not the warping displacement amount satisfies a reference value, and in the correction step, a load is applied to the precision requirement surface determined to be unqualified until a correction deformation amount when the warping displacement amount measured in the surface displacement measurement step coincides with the warping displacement amount in the correlation chart data is generated, and the correction deformation amount is released.

Description

Technical Field

[0001] The disclosed technology relates to a method for manufacturing an electricity storage device. Background Art

[0002] Conventionally, in an electricity storage device having an electrode body in a case, when joining the end portion of the electrode body (non-coated portion of the active material) to a current collector terminal or the like, an external force is applied to the current collector terminal, resulting in deformation of the current collector terminal. Further, due to the deformation of the current collector terminal or the like, the sealing body of the case in which positive and negative current collector terminals are joined at both end portions in the long side direction sometimes warps and displaces in the front-back direction in an asymmetric manner left and right.

[0003] Regarding this point, for example, in Patent Document 1 and Patent Document 2, technologies for reducing the deformation of the current collector terminal with respect to an external force by increasing the rigidity of the current collector terminal are disclosed.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2009-26705

[0005] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2019-125486

[0006] However, there are the following problems: Even if the rigidity of the current collector terminal is increased, since the rigidity of the sealing body is generally lower than that of the current collector terminal, the external force applied to the current collector terminal is almost directly transmitted to the sealing body to which the current collector terminal is joined, and thus warping of the sealing body cannot be sufficiently suppressed. In addition, regarding the warping displacement amount of the sealing body, there is a problem that the magnitude of the warping displacement amount varies depending on each manufactured electricity storage device. Moreover, generally, on the surface of the sealing body, for example, there is a precision requirement surface, such as a sensor contact surface formed to be able to contact a temperature sensor for monitoring the temperature of the electricity storage device, which requires ensuring better surface position accuracy compared to other parts, and it is necessary to ensure the surface position accuracy of this precision requirement surface within the required reference value. Summary of the Invention

[0007] The disclosed technology has been completed in view of this problem, and its object is to provide a method for manufacturing a highly reliable electricity storage device that can change the amount of corrective deformation according to the amount of warping displacement and correct the precision requirement surface of the sealing body within the reference value even when the warping displacement amount of the sealing body varies depending on each manufactured electricity storage device and the warping displacement amount is asymmetric left and right. (1)

[0009] One aspect of the present disclosure technology for solving the above problems is a method for manufacturing a power storage device, which includes a correction process that corrects a sealing body before a sealing body welding process of welding the sealing body that seals an opening of a housing containing an electrode body to the opening. Here, a precision requirement surface that requires a required surface position accuracy is provided on the surface of the sealing body. The method for manufacturing the power storage device includes: a database formation process for pre-storing relevant chart data, where the relevant chart data is the warpage displacement amount of the precision requirement surface of the sealing body inserted into the opening in the front-back direction with respect to a support point, and the correction deformation amount for correcting the precision requirement surface displaced by the warpage displacement amount to a position where it can return to a normal position where the warpage displacement amount becomes zero through its own elastic force in the front-back opposite direction opposite to the displacement direction of the precision requirement surface with respect to the support point; a surface displacement measurement process for measuring the warpage displacement amount of the precision requirement surface after inserting the sealing body into the opening; and a displacement amount determination process for determining whether the warpage displacement amount of the precision requirement surface measured by the surface displacement measurement process meets a required reference value. In the correction process, when it is determined by the displacement amount determination process that the warpage displacement amount does not meet the required reference value, a load is applied to the precision requirement surface until it reaches a position where the warpage displacement amount measured by the surface displacement measurement process is the same as the warpage displacement amount in the relevant chart data, and then the load is released. (2)

[0011] In the method for manufacturing a power storage device described in the above (1), it is preferable that:

[0012] The precision requirement surface is formed to be in contact with a temperature sensor that monitors the temperature of the power storage device, i.e., a sensor contact surface. (3)

[0014] In the method for manufacturing a power storage device described in the above (1) or (2), it is preferable that:

[0015] A plurality of the precision requirement surfaces are provided on the surface of the sealing body. In the surface displacement measurement process, the warpage displacement amount of each precision requirement surface is measured. In the correction process, when it is determined by the displacement amount determination process that at least one of the warpage displacement amounts does not meet the required reference value, a load is applied to each precision requirement surface until it reaches a position where the average value of the correction deformation amounts when the warpage displacement amounts measured by the surface displacement measurement process are the same as the warpage displacement amounts in the relevant chart data, and then the load is released. Description of the Drawings

[0016] Figure 1 It is a schematic top view of a power storage device manufactured by the manufacturing method of a power storage device according to one aspect of the present embodiment.

[0017] Figure 2 It is Figure 1 The A-A cross-sectional view shown is a schematic cross-sectional view of the state where the temperature sensor is in contact with the sensor contact surface of the sealing body.

[0018] Figure 3 It represents Figure 2 A schematic perspective view of a state in which a part of the electrode body shown is unwound.

[0019] Figure 4 It is Figure 2 The B-B cross-sectional view shown.

[0020] Figure 5 It represents Figure 1 A flowchart of the manufacturing method of the power storage device shown.

[0021] Figure 6 It is in Figure 5 An example of relevant chart data stored in the database formation process of the flowchart shown.

[0022] Figure 7 It represents Figure 5 A schematic cross-sectional view of a measurement method for measuring the warpage displacement amount of a precision required surface in the database formation process and the surface displacement measurement process of the flowchart shown.

[0023] Figure 8 It is in Figure 5 A schematic cross-sectional view of a correction device for correcting the warpage displacement amount of a precision required surface in the correction process of the flowchart shown.

[0024] Figure 9 It is in Figure 8 A schematic cross-sectional view when a load is applied to the correction device shown in such a way as to cause a correction deformation amount on the precision required surface.

[0025] Figure 10 It is in Figure 8 A schematic cross-sectional view when the load applied in such a way as to cause a correction deformation amount on the precision required surface is released in the correction device shown.

[0026] Explanation of reference numerals:

[0027] 1... housing; 2... electrode body; 5... temperature sensor; 5S... sensor contact surface; 10... power storage device; 12... sealing body; 12K, 12K1, 12K2... support points; 12S, 12S1, 12S2... precision requirement surfaces; 111... opening; 121... surface; F, F1, F2... loads; KJ... reference value; P, P1, P1B, P2... correction deformation amounts; Q, Q1, Q1B, Q2... warpage displacement amounts; S1... database formation process; S2... surface displacement measurement process; S3... displacement amount determination process; S4... correction process; S5... sealing body welding process; SK... normal position; SKD, SKD1, SKD2... related chart data. Detailed implementation

[0028] <Overall description of this power storage device>

[0029] Next, with reference to the drawings, the overall structure of the power storage device manufactured by the manufacturing method of the power storage device according to one aspect of the above-disclosed technology will be described in detail. Figure 1 A schematic top view showing the power storage device manufactured by the manufacturing method of the power storage device according to one aspect of this embodiment. Figure 2 Indicates Figure 1 The cross-sectional view taken along the line A-A shown is a schematic cross-sectional view of the state where the temperature sensor is in contact with the sensor contact surface of the sealing body. In Figure 3 It shows a schematic perspective view of the state where a part of the electrode body shown in Figure 2 has been unwound. Figure 4 Indicates Figure 2 The cross-sectional view taken along the line B-B shown. In addition, the X direction shown in each figure represents the long side direction of the sealing body, the Y direction represents the short side direction of the sealing body, and the Z direction represents the front-back direction (thickness direction) of the sealing body.

[0030] As Figures 1 to 4 shown, the power storage device 10 manufactured by the manufacturing method of this power storage device includes a housing 1, an electrode body 2, and a current collector terminal 4. Here, as Figure 1 , Figure 2 shown, the housing 1 includes a bottomed square tube-shaped housing main body 11 having a rectangular opening 111, and a long and flat sealing body 12 that seals the opening 111. For the sealing body 12, it includes an injection port 123 for injecting the electrolyte 8 into the housing 1, a plug body 122 for sealing the injection port 123, and a safety valve 124 that cracks when the pressure inside the housing 1 rises above a specified value. Both the housing main body 11 and the sealing body 12 are made of aluminum, but due to the necessity of improving the opening performance of the safety valve 124, the sealing body 12 can use a material that is softer and more easily deformable than the current collector terminal 4.

[0031] In addition, at the opening 111 of the housing main body 11, thin wall portions 111T are formed only on the inner walls of the short side surfaces 11C and 11D. Therefore, both end portions 12R in the long side direction (X direction) of the sealing body 12 inserted into the opening 111 are supported by the step portions 111S formed at the lower ends of the thin wall portions 111T, which serve as the support points 12K of the sealing body 12. In addition, at the opening 111 of the housing main body 11, the structure is such that there are no thin wall portions on the inner walls of the long side surfaces 11A and 11B, making it difficult to prevent displacement (warpage deformation) of the central portion of the sealing body 12 in the front-back direction (Z direction).

[0032] In addition, as Figures 2 to 4 shown, the electrode body 2 is formed by laminating a positive electrode body 21 and a negative electrode body 22 with a separator 23 interposed therebetween, wound into a flat shape, and housed in the housing main body 11. The positive electrode body 21 and the negative electrode body 22 each have non-coated active material portions 211 and 221 where no active materials KT1 and KT2 are coated on one end portions 21K1 and 22K1 of the metal foils 21K and 22K, and active material coated portions 212 and 222 where the active materials KT1 and KT2 are coated on the metal foils 21K and 22K. The non-coated active material portion 211 of the positive electrode body 21 and the non-coated active material portion 221 of the negative electrode body 22 are arranged on opposite sides in the long side direction (X direction) of the sealing body 12. In addition, the active material coated portions 212 and 222 are formed on the other end portions 21K2 and 22K2 and the intermediate portions 21K3 and 22K3 of the metal foils 21K and 22K.

[0033] The power storage device 10 refers to the entire power storage device capable of extracting electric energy, and includes, for example, primary batteries, secondary batteries, electric double layer capacitors, etc. For example, in a lithium ion secondary battery, the metal foil 21K of the positive electrode body 21 can be, for example, an aluminum foil, and the active material KT1 coated thereon can be, for example, a lithium transition metal oxide (LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, LiNiO2, etc.). In addition, the metal foil 22K of the negative electrode body 22 can be, for example, a copper foil, and the active material KT2 coated thereon can be, for example, graphite, hard carbon, soft carbon, etc. In addition, the separator 23 can be, for example, a porous sheet such as polypropylene or polyethylene. In addition, the electrolytic solution 8 can be a known non-aqueous electrolytic solution.

[0034] In addition, for the current collecting terminals 4, there are a positive current collecting terminal 4A and a negative current collecting terminal 4B. The positive current collecting terminal 4A is made of aluminum, for example, and the negative current collecting terminal 4B is made of copper, for example. Generally, since the tensile strength of the aluminum positive current collecting terminal 4A is less than that of the copper negative current collecting terminal 4B, and the conductivity of the positive current collecting terminal 4A is less than that of the negative current collecting terminal 4B, in order to equalize the strength and allowable current of the positive current collecting terminal 4A and the negative current collecting terminal 4B, the plate thickness of the positive current collecting terminal 4A is made larger than that of the negative current collecting terminal 4B. The positive and negative current collecting terminals 4 each have a base portion 41, a base adjacent portion 42, and a lead portion 43 formed integrally.

[0035] The base portion 41 is joined to the external connection portions 45 (45A, 45B) on the surface side of the sealing body 12, for example, by a riveting pin 46 or the like. The central portion of the sealing body 12 may be displaced in the front-back direction (Z direction) due to the external force when the base portion 41, the external connection portion 45, and the sealing body 12 are joined by the riveting pin 46 or the like. In addition, an insulating member 3 that also serves as an unsealed material is interposed between the riveting pin 46 and the external connection portion 45 and the sealing body 12. The insulating member 3 can use polyphenylene sulfide (PPS) resin, for example. When connecting a plurality of the power storage devices 10, a connecting bus bar (not shown) is connected to the external connection portions 45 (45A, 45B).

[0036] In addition, the base portion 41 is joined with the insulating member 3 interposed on the inner side of both end portions 12R in the long side direction (X direction) of the sealing body 12. In addition, the base adjacent portion 42 is adjacent to the base portion 41 and abuts against the insulating member 3. The upper end portion 43a of the lead of the lead portion 43 is bent from the base adjacent portion 42 toward the inside of the housing (Z direction), and the metal foils 21K, 22K of the non-coated portions 211, 221 of the active material of the electrode body 2 are welded and joined to the lower end portion 43b of the lead in a current collecting foil state. When welding the electrode body 2 and the lower end portion 43b of the lead, an external force that easily displaces the lower end portion 43b of the lead in the long side direction (X direction) of the sealing body 12 is likely to be generated due to the sliding of the lower end portion 43b of the lead relative to the metal foils 21K, 22K in the middle of the current collecting foil. Sometimes this external force is transmitted to the sealing body 12, causing the central portion of the sealing body 12 to be displaced in the front-back direction (Z direction).

[0037] In addition, on the surface 121 of the sealing body 12, there are two precision-required surfaces 12S (12S1, 12S2) that require the desired surface position accuracy. Here, the precision-required surfaces 12S (12S1, 12S2) are formed as sensor contact surfaces 5S that can come into contact with the temperature sensor 5 for monitoring the temperature of the power storage device 10, but are not necessarily limited to the sensor contact surfaces 5S. The temperature sensor 5 can use, for example, a thermistor, a thermocouple, etc. The temperature sensor 5 is held by the holding case 51 fixed to the mounting bracket 53 and is biased by the spring member 52 etc. against the sensor contact surface 5S. However, considering various manufacturing errors, in order to ensure the measurement accuracy of the temperature sensor 5, it is required that the surface position accuracy of the sensor contact surface 5S meet the required reference value KJ.

[0038] In addition, when a plurality of the power storage devices 10 are connected in series to form a battery pack, usually, the long side surfaces 11A, 11B of the housing main body 11 are arranged close to each other, so the external connection portions 45A of the positive electrodes and the external connection portions 45B of the negative electrodes are alternately arranged in the same direction. Therefore, there are cases where the sensor contact surface 5S is formed as the precision-required surface 12S (12S1) close to the external connection portion 45A of the positive electrode ( Figure 2 the case shown), and cases where the sensor contact surface 5S is formed as the precision-required surface 12S (12S2) close to the external connection portion 45B of the negative electrode. It is required that the surface position accuracy of both precision-required surfaces 12S (12S1, 12S2) meet the required reference value KJ.

[0039] <Manufacturing method of the power storage device>

[0040] Next, with reference to the drawings, the manufacturing method of the power storage device according to the present embodiment will be described in detail. In Figure 5 it shows a flowchart showing Figure 1 the manufacturing method of the power storage device shown. In Figure 6 it shows an example of the related chart data stored in the database formation process in the flowchart shown in Figure 5 In Figure 7 it shows a schematic cross-sectional view of the measurement method for measuring the warpage displacement amount of the precision-required surface in the database formation process and the surface displacement measurement process in the flowchart shown in Figure 5 In Figure 8 it shows a schematic cross-sectional view of the correction device for correcting the warpage displacement amount of the precision-required surface in the correction process in the flowchart shown in Figure 5 In Figure 9 it shows a brief cross-sectional view when a load is applied to the correction device shown in Figure 8 in such a way as to cause a correction deformation amount on the precision-required surface. In Figure 10 it shows in Figure 8A schematic cross-sectional view when the load applied in a manner that causes a corrective deformation amount to occur on the precision requirement surface is released in the shown corrective device.

[0041] As Figures 1 to 10 shown, the manufacturing method of this power storage device is a manufacturing method of the power storage device 10 having a corrective process S4. This corrective process S4 corrects the sealing body 12 that seals the opening 111 of the housing 1 containing the electrode body 2 before the sealing body welding process S5 of welding the sealing body 12 to the opening 111. Among them, on the surface 121 of the sealing body 12, there is a precision requirement surface 12S that requires the required surface position accuracy. Moreover, the manufacturing method of this power storage device includes a database formation process S1, a surface displacement measurement process S2, a displacement amount determination process S3, a corrective process S4, and a sealing body welding process S5. The sealing body welding process S5 is a process of welding the outer periphery of the sealing body 12 whose warpage displacement amount Q of the precision requirement surface 12S is determined to meet the reference value KJ by the displacement amount determination process S3 or the sealing body 12 whose warpage displacement amount Q of the precision requirement surface 12S is corrected within the reference value KJ by the corrective process S4 to the opening 111 by using laser welding or the like. In addition, in Figures 7 to 10 , the electrode body 2 is omitted, but as Figure 2 shown, the electrode body 2 is coupled to the sealing body 12 via the current collector terminal 4.

[0042] Here, the precision requirement surface 12S is illustrated by an example of being formed as a sensor contact surface 5S that can contact the temperature sensor 5 for monitoring the temperature of the power storage device 10. As Figure 1 , Figure 2 , Figure 6 , Figure 7 shown, the sensor contact surface 5S is a flat quadrilateral surface, and is formed as the precision requirement surface 12S (12S1) close to the external connection portion 45A of the positive electrode and the precision requirement surface 12S (12S2) close to the external connection portion 45B of the negative electrode. It is required that the surface position accuracy of both precision requirement surfaces 12S (12S1, 12S2) meets the required reference value KJ.

[0043] In addition, the reference value KJ refers to the allowable value of the warpage displacement amount Q in which the surface position of the precision requirement surface 12S (12S1, 12S2) is displaced in the front-back direction (Z direction) of the sealing body 12 with respect to the support point 12K of the sealing body 12. The reference value KJ is, for example, on the order of ±0.2 to 0.3 mm. The displacement toward the upper side in the Z direction on the surface side in the front-back direction of the sealing body 12 ( Figures 7 to 10 in the upper side of the Z direction in Figures 7 to 10 is represented by +, and the displacement toward the lower side in the front-back direction of the sealing body 12 ( Figure 6The related chart data SKD shown is an example when the surface position of the precision requirement surface 12S (12S1, 12S2) is displaced toward the surface side (the upper side in the Z direction) of the sealing body 12. Since the precision requirement surface 12S is formed as a sensor contact surface 5S that can contact the temperature sensor 5 for monitoring the temperature of the power storage device 10, the measurement accuracy of the temperature sensor 5 can be improved, and an excessive temperature rise of the power storage device 10 can be avoided. Therefore, the safety and reliability of the power storage device 10 can be further improved.

[0044] In addition, the database formation process S1 is a process of pre-storing the related chart data SKD, where the above-mentioned related chart data SKD is the warpage displacement amount Q in the front-back direction (Z direction) of the precision requirement surface 12S (12S1, 12S2), and the precision requirement surface 12S (12S1, 12S2) displaced by the warpage displacement amount Q is corrected and deformed in the direction opposite to the displacement direction of the precision requirement surface 12S relative to the support points 12K (12K1, 12K2), that is, the front-back opposite direction (above or below in the Z direction), until it can return to the normal position SK where the warpage displacement amount Q becomes zero through its own elastic force, and the related chart data of the correction deformation amount P.

[0045] The related chart data SKD is made, for example, in the following order. First, the sealing body 12 combined with the electrode body 2 via the current collector terminal 4 is inserted into the opening 111 of the housing main body 11. Next, as Figure 7 shown, the surface positions of the precision requirement surfaces 12S (12S1, 12S2) of the sealing body 12 in the front-back direction (Z direction) of the sealing body 12 are measured. The measuring device for the surface position is preferably a non-contact measuring device 6 having laser rangefinders 61 and 62. Here, the laser of the laser rangefinders 61 and 62 is irradiated on the central part of the precision requirement surfaces 12S (12S1, 12S2) to measure the surface position. The measuring device 6 calculates the difference between the surface positions of the respective precision requirement surfaces 12S (12S1, 12S2) measured by the laser rangefinders 61 and 62 and the surface position of the reference support point 12K as the warpage displacement amount Q in the front-back direction (Z direction). Then, the surface positions of the precision requirement surfaces 12S (12S1, 12S2) of the sealing bodies 12 with different warpage displacement amounts Q are measured, and various warpage displacement amounts Q are transferred to Figure 8 the database of the correction device 7 shown.

[0046] Next, as Figure 9As shown, the working parts 71 and 72 of the correction device 7 operate. After applying a load F to the accuracy requirement surfaces 12S (12S1, 12S2) that have been displaced by respective warpage displacement amounts Q in the opposite front-back direction (Z direction) to the displacement direction of the accuracy requirement surfaces 12S relative to the support points 12K (12K1, 12K2) to cause them to undergo correction deformation until they can return to the normal position SK where the warpage displacement amount Q becomes zero by their own elastic force, as Figure 10 shown, the working parts 71 and 72 return to their original positions, thereby releasing the load F. The working parts 71 and 72 of the correction device 7 are preferably configured to be driven by an encoder servo motor or the like and can accurately control the movement amount. In addition, the working parts 71 and 72 of the correction device 7 can also repeatedly perform correction deformation and release in multiple times, gradually increasing the deformation amount until it reaches the specified correction deformation amount P.

[0047] Moreover, as Figure 6 shown, the correction device 7 creates correlation chart data SKD (SKD1, SKD2) of the warpage displacement amount Q transferred from the measurement device 6 and the correction deformation amount P when the correction deformation is performed by applying the load F, and stores it in the database. In addition, the working parts 71 and 72 of the correction device 7 are preferably configured to be able to switch to a structure (such as an adsorption structure or a hooking structure, etc.) that can apply the load F in the displacement direction of the accuracy requirement surface 12S and the opposite front-back direction (Z direction) even when the accuracy requirement surface 12S (12S1, 12S2) has been displaced to the inner side of the sealing body 12.

[0048] Here, the correlation chart data SKD1 is a correlation curve representing the correlation between the warpage displacement amount Q and the correction deformation amount P of the accuracy requirement surface 12S (12S1) of the external connection part 45A near the positive electrode. In addition, the correlation chart data SKD2 is a correlation curve representing the correlation between the warpage displacement amount Q and the correction deformation amount P of the accuracy requirement surface 12S (12S2) of the external connection part 45B near the negative electrode. Figure 6 The shown correlation chart data SKD1 and SKD2 are represented by a line graph, but it can also be represented by a curve graph by increasing the measurement data.

[0049] As Figure 6As shown, according to the relevant chart data SKD1 and the relevant chart data SKD2, in the region where the warpage displacement Q is within the reference value KJ, the difference in the respective warpage displacements Q for the same correction deformation amount P is small. However, in the region where the warpage displacement Q exceeds the reference value KJ, the difference in the respective warpage displacements Q for the same correction deformation amount P increases. It is inferred that this is because the injection port 123 and the safety valve 124, which are important factors causing the strength reduction of the sealing body 12, exist on the side where the precision requirement surface 12S (12S1) of the external connection part 45A near the positive electrode is located. However, in the manufactured storage battery device 10, even when the warpage displacement Q of the sealing body 12 varies between the positive electrode side and the negative electrode side according to each manufactured storage battery device 10, based on the relevant chart data SKD (SKD1, SKD2) stored in the database formation process S1, the correction deformation amount P for correcting the warpage displacement Q can be simply and correctly obtained. In addition, since the relevant chart data SKD (SKD1, SKD2) stored in the database formation process S1 varies according to the size, type, etc. of the storage battery device 10, the relevant chart data SKD (SKD1, SKD2) can be pre-made for each storage battery device 10 respectively and stored in the database.

[0050] In addition, as Figure 5 shown, in the surface displacement measurement process S2, after the sealing body 12 is inserted into the opening 111, the warpage displacements Q (Q1, Q2) of the precision requirement surfaces 12S (12S1, 12S2) are measured. And in the displacement amount determination process S3, it is determined whether the warpage displacements Q (Q1, Q2) of the precision requirement surfaces 12S (12S1, 12S2) measured in the surface displacement measurement process S2 meet the required reference value KJ. In the surface displacement measurement process S2, the method for measuring the warpage displacements Q (Q1, Q2) of the precision requirement surface 12S is as described above, and is performed by the Figure 7 measurement device 6 shown.

[0051] Therefore, in the stage immediately before welding the sealing body 12 to the opening 111, the surface position of the precision requirement surface 12S (12S1, 12S2) can be measured and its quality can be judged. As a result, various causes of warpage of the sealing body 12 do not need to be considered. In addition, there is no need to measure and judge the quality of the surface positions other than the precision requirement surface 12S. Therefore, the surface displacement measurement process S2 and the displacement amount determination process S3 can be simplified, which helps to improve productivity.

[0052] In addition, as Figure 6 、 Figure 9 、 Figure 10As shown, in the correction process S4, when it is determined in the displacement amount determination process S3 that the warpage displacement amounts Q (Q1, Q2) do not meet the required reference value KJ (S3: does not meet (non-optimal)), a load F (F1, F2) is applied to the precision requirement surfaces 12S (12S1, 12S2) until the correction deformation amount P (P1, P2) is generated when the warpage displacement amounts Q (Q1, Q2) measured by the surface displacement measurement process S2 are consistent with the warpage displacement amounts Q (Q1, Q2) in the relevant chart data SKD (SKD1, SKD2), and then the load F (F1, F2) is released. On the other hand, when it is determined in the displacement amount determination process S3 that the warpage displacement amounts Q (Q1, Q2) meet the required reference value KJ (S3: meets), the sealing body welding process S5 is entered.

[0053] Thus, it is possible to converge the precision requirement surfaces 12S (12S1, 12S2) for which the warpage displacement amounts Q (Q1, Q2) do not meet the required reference value KJ and correct the warpage displacement amounts Q (Q1, Q2). In addition, since the correction deformation amount P (P1, P2) is the deformation amount that enables the precision requirement surfaces 12S (12S1, 12S2) displaced by the warpage displacement amounts Q (Q1, Q2) to return to the normal position SK where the warpage displacement amount Q becomes zero through their own elastic force, the amount obtained by subtracting the elastic deformation amount DH (DH1, DH2) from the correction deformation amount P (P1, P2) becomes the corrected plastic deformation amount SH (SH1, SH2) and is consistent with the warpage displacement amounts Q (Q1, Q2) before correction.

[0054] As described in detail above, the manufacturing method of the power storage device according to the present embodiment is a manufacturing method of the power storage device 10 including a correction process S4, which corrects the sealing body 12 before a sealing body welding process S5 that welds the sealing body 12 sealing the opening 111 of the housing 1 containing the electrode body 2 to the opening 111. Here, on the surface 121 of the sealing body 12, there is a precision requirement surface 12S that requires a required surface position accuracy. The manufacturing method of the power storage device 10 includes: a database formation process S1 in which relevant chart data SKD is pre-stored. The relevant chart data SKD is the warpage displacement amount Q of the precision requirement surface 12S of the sealing body 12 inserted into the opening 111 in the front-back direction (Z direction) with respect to the support points 12K (12K1, 12K2), and the correction deformation amount P for correcting the precision requirement surface 12S displaced by the warpage displacement amount Q to the position where it can be restored to the normal position SK where the warpage displacement amount Q becomes zero by its own elastic force in the opposite front-back direction (Z direction) to the displacement direction of the precision requirement surface 12S with respect to the support points 12K; a surface displacement measurement process S2 in which, after the sealing body 12 is inserted into the opening 111, the warpage displacement amount Q of the precision requirement surface 12S is measured; and a displacement amount determination process S3 in which it is determined whether the warpage displacement amount Q of the precision requirement surface 12S measured by the surface displacement measurement process S2 satisfies the required reference value KJ. In the correction process S4, when it is determined by the displacement amount determination process S3 that the warpage displacement amount Q does not satisfy the required reference value KJ, after applying a load F to the precision requirement surface 12S until the warpage displacement amount Q measured by the surface displacement measurement process S2 coincides with the warpage displacement amount Q in the relevant chart data SKD at the position of the correction deformation amount P, the load F is released.

[0055] Therefore, according to the manufacturing method of the present power storage device 10, even when the warpage displacement amount Q of the sealing body 12 varies for each manufactured power storage device 10 and the warpage displacement amount Q is asymmetric left and right, the correction deformation amount P can be changed according to the warpage displacement amount Q, so that the precision requirement surface 12S of the sealing body 12 can be corrected within the reference value KJ, and a manufacturing method of a highly reliable power storage device can be provided.

[0056] In addition, in the manufacturing method of this power storage device, it is preferable that: the surface 121 of the sealing body 12 has a plurality of precision required surfaces 12S (12S1, 12S2), in the surface displacement measurement process S2, the warpage displacement amounts Q (Q1B, Q2) of the respective precision required surfaces 12S (12S1, 12S2) are measured, and in the correction process S4, when it is determined in the displacement amount determination process S3 that at least one warpage displacement amount Q (Q2) does not satisfy the required reference value KJ, a load F (F1, F2) is applied to each of the precision required surfaces 12S (12S1, 12S2) until the correction deformation amount P (P1B, P2) corresponding to the warpage displacement amount Q (Q1B, Q2) measured in the surface displacement measurement process S2 and the warpage displacement amount Q (Q1B, Q2) in the related chart data SKD (SKD1, SKD2) shown in Figure 6 coincides, and after reaching the position of the average value (P1B + P2) × 1 / 2 of the correction deformation amount P (P1B, P2), the load F (F1, F2) is released.

[0057] In this case, even if there are a plurality of precision required surfaces 12S (12S1, 12S2), since a load F (F1, F2) is applied until the position of the average value (P1B + P2) × 1 / 2 of the correction deformation amount P (P1B, P2) corresponding to the warpage displacement amount Q (Q1B, Q2) measured in the surface displacement measurement process S2 and the warpage displacement amount Q (Q1B, Q2) in the related chart data SKD (SKD1, SKD2) coincides, and then the load F (F1, F2) is released, there is no need to generate separate correction deformation amounts P (P1B, P2) for the plurality of precision required surfaces 12S (12S1, 12S2), so that the correction device 7 for applying the load F (F1, F2) to the precision required surfaces 12S (12S1, 12S2) can be simplified. Therefore, the precision required surfaces 12S of the sealing body 12 can be corrected within the reference value KJ at a lower cost and in a shorter time.

[0058] <Modification Example>

[0059] As described above in detail, the present embodiment is only a simple illustration and does not limit the disclosed technology in any way. Therefore, the disclosed technology can be variously improved and deformed without departing from its gist.

Claims

1. A method for manufacturing an electric storage device, comprising a correction step of correcting a sealing body before a sealing body welding step of welding a sealing body for sealing an opening of a case accommodating an electrode body to the opening, The method for manufacturing the electric storage device is characterized in that: The sealing body has a surface having a precision-required surface requiring a required surface position accuracy. The method for manufacturing an electric storage device comprises: a database forming step of storing in advance relevant chart data, the relevant chart data being the warping displacement amount of the precision-required surface of the sealing body inserted into the opening in the front-to-back direction relative to the supporting point, and the correction deformation amount of the precision-required surface displaced by the warping displacement amount being correctively deformed in the front-to-back direction opposite to the displacement direction of the precision-required surface relative to the supporting point until the precision-required surface can be restored to a normal position where the warping displacement amount becomes zero by its own elastic force; a surface displacement measuring step of measuring the warping displacement amount of the precision-required surface after the sealing body is inserted into the opening; and a displacement amount determination step of determining whether the warpage displacement amount of the precision-required surface measured in the surface displacement measurement step satisfies a required reference value, In the correction process, when it is determined by the displacement determination process that the warping displacement amount does not satisfy the required reference value, after a load is applied to the precision-required surface until a position of the correction deformation amount is reached where the warping displacement amount measured by the surface displacement measurement process is consistent with the warping displacement amount in the relevant chart data, the load is released.

2. The method for manufacturing an electric storage device according to claim 1, wherein: The accuracy required surface is a sensor contact surface formed to be contactable with a temperature sensor that monitors the temperature of the electrical storage device.

3. The method for manufacturing an electric storage device according to claim 1 or 2, characterized in that: The sealing body has a plurality of precision-required surfaces on its surface. In the surface displacement measuring step, the warping displacement amount of each of the precision-required surfaces is measured. In the correction process, when it is determined by the displacement determination process that at least one of the warping displacement amounts does not satisfy the required reference value, after a load is applied to each of the precision-required surfaces until a position is reached where the average value of the correction deformation amounts when each of the warping displacement amounts measured by the surface displacement measurement process is consistent with the warping displacement amounts in the relevant chart data is reached, the load is released.

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