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 surface displacement amount of a sealing body, and a precision-required surface of the sealing body can be corrected within a reference value. In a method for manufacturing a power storage device provided with a correction step for correcting a sealing body, the sealing body has a precision-requiring surface, and when it is determined that the surface position of the precision-requiring surface is located further toward the inner side than a support point, the surface position of the precision-requiring surface is displaced in advance to the front surface side. In a state in which the sealing body, which displaces the surface position of the precision-required surface to the surface side, is inserted into the opening, it is determined whether or not the surface displacement amount of the precision-required surface with respect to the support point satisfies a required reference value. In the correction step, when it is determined that the surface displacement amount does not satisfy the reference value, a load is applied to the inside of the precision required surface until a correction deformation amount is generated, said correction deformation amount being obtained by adding the surface displacement amount and an elastic deformation amount at which the sealing body is restored to a normal position at which the surface displacement amount becomes zero by means of the elastic force of the sealing body. And releasing the load.

Description

Technical Field

[0001] The disclosed technology relates to a manufacturing method of a power storage device. Background Art

[0002] Conventionally, in a power 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) and a current collecting terminal, etc., an external force is applied to the current collecting terminal, resulting in a phenomenon of deformation of the current collecting terminal. Moreover, due to the deformation of the current collecting terminal, etc., there is a case where the sealing body of the case, which has positive and negative current collecting terminals joined at both ends in the long side direction, has a surface displacement amount that is displaced asymmetrically in the front-back direction 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 collecting terminal with respect to an external force by increasing the rigidity of the current collecting 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 collecting terminal is increased, since the rigidity of the sealing body is usually lower than that of the current collecting terminal, the external force applied to the current collecting terminal is almost directly transmitted to the sealing body to which the current collecting terminal is joined, and thus the surface displacement amount of the sealing body cannot be sufficiently suppressed. In addition, regarding the surface displacement amount of the sealing body, there is a problem that the magnitude of the surface displacement amount varies depending on each manufactured power 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 power storage device, and it is necessary to ensure a better surface position accuracy compared to other parts and to guarantee the surface position accuracy of this precision requirement surface within the required reference value. Summary of the Invention

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

[0009] One aspect of the disclosed technology for solving the above problems is a method for manufacturing a power storage device including a correction process, which 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 surface position measurement process for measuring the surface position of the precision requirement surface in the front-back direction of the sealing body; a surface position determination process for determining whether the surface position of the precision requirement surface measured by the surface position measurement process is located on the surface side or the inner side of the support point of the sealing body when inserted into the opening; a surface position change process for displacing the surface position of the precision requirement surface to a position on the surface side of the support point when it is determined by the surface position determination process that the surface position of the precision requirement surface is located on the inner side of the support point; a surface displacement amount measurement process for measuring the surface displacement amount in the front-back direction of the surface position of the precision requirement surface relative to the support point in a state where the sealing body determined by the surface position determination process to have the surface position of the precision requirement surface located on the surface side of the support point or the sealing body whose surface position of the precision requirement surface is displaced to the surface side of the support point by the surface position change process is inserted into the opening; and a surface displacement amount determination process for determining whether the surface displacement amount measured by the surface displacement amount measurement process satisfies a required reference value. In the correction process, when it is determined by the surface displacement amount determination process that the surface displacement amount does not satisfy the reference value, a load is applied to the inner side of the sealing body until a correction deformation amount obtained by adding the surface displacement amount and an elastic deformation amount that causes the sealing body to return to a normal position where the surface displacement amount becomes zero by its own elastic force is generated, and then the load is released. (2)

[0011] In the method for manufacturing a power storage device described in (1), it is preferable that the precision requirement surface is formed to be able to contact a temperature sensor for monitoring the temperature of the power storage device. (3)

[0013] In the method for manufacturing the electrical storage device described in (1) or (2), it is preferable that: the surface of the sealing body has a plurality of the surfaces with precision requirements, in the surface position measurement step, the surface positions of the respective surfaces with precision requirements are measured, and in the case where, in the surface position determination step, it is determined that the surface positions of at least one of the surfaces with precision requirements are located on the inner side relative to the support point, in the surface position change step, the surface positions of all the surfaces with precision requirements are displaced to the position on the surface side relative to the support point. (4)

[0015] In the method for manufacturing the electrical storage device described in (1) or (2), it is preferable that: the surface of the sealing body has a plurality of the surfaces with precision requirements, in the surface displacement amount measurement step, the surface displacement amounts of the respective surfaces with precision requirements are measured, and in the correction step, in the case where, in the surface displacement amount determination step, it is determined that the surface displacement amount of at least one of the surface displacement amounts does not satisfy the required reference value, after applying a load to each of the surfaces with precision requirements until a position where an average value of the correction deformation amounts obtained by adding the surface displacement amounts measured in the surface displacement amount measurement step and the elastic deformation amounts of each is generated, the load is released. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0020] Figure 5 is a flowchart showing Figure 1 the method for manufacturing the electrical storage device shown.

[0021] Figure 6 is a flowchart showing Figure 5 the measurement method for measuring the surface positions of the surfaces with precision requirements in the surface position measurement step of the flowchart shown.

[0022] Figure 7 is a flowchart showing Figure 5Schematic cross-sectional view of a method for changing the surface position in the process shown in the flowchart, which displaces the surface position of the surface with precision requirements towards the surface side relative to the support points.

[0023] Figure 8 It shows that through Figure 5 Schematic cross-sectional view of a measurement method for measuring the surface displacement of the surface with precision requirements in the surface displacement measurement process shown in the flowchart in the front-back direction relative to the support points.

[0024] Figure 9 It is through Figure 5 Schematic cross-sectional view of a correction device that corrects the surface displacement of the surface with precision requirements within a reference value in the correction process shown in the flowchart.

[0025] Figure 10 It is in Figure 9 Brief cross-sectional view when a load is applied in the correction device shown in such a way as to cause a correction deformation of the surface with precision requirements.

[0026] Figure 11 It is in Figure 9 Brief cross-sectional view when the load applied in such a way as to cause a correction deformation of the surface with precision requirements is released in the correction device shown.

[0027] Figure 12 It is in Figure 9 An example of the correlation chart data showing the correlation between the surface displacement of the surface with precision requirements and the correction deformation in the correction device shown.

[0028] Explanation of reference numerals:

[0029] 1... housing; 2... electrode body; 5... temperature sensor; 5S... sensor contact surface; 10... energy storage device; 12... sealing body; 12K, 12K1, 12K2... support points; 12S, 12S1, 12S2... surfaces with precision requirements; 111... opening; 121... surface; DH, DH1, DH2... elastic deformation; F, F1, F2... load; KJ... reference value; MT, MT1, MT2... surface position; P, P1, P1B, P2... correction deformation; Q, Q1, Q1B, Q2... surface displacement; S1... surface position measurement process; S2... surface position determination process; S3... surface position change process; S4... surface displacement measurement process; S5... surface displacement determination process; S6... correction process; S7... sealing body welding process; SK... normal position; SKD, SKD1, SKD2... correlation chart data. Detailed implementation mode

[0030] <Overall description of this energy storage device>

[0031] 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 the present embodiment. Figure 2 Shows Figure 1 A schematic cross-sectional view showing a state in which a temperature sensor is in contact with the sensor contact surface of the sealing body in the A-A cross-sectional view shown. In Figure 3 , a schematic perspective view showing a state in which a part of the electrode body shown in Figure 2 has been unwound is shown. Figure 4 Shows Figure 2 The B-B cross-sectional view 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.

[0032] As Figures 1 to 4 shown, the power storage device 10 manufactured by the manufacturing method of the present power storage device includes a housing 1, an electrode body 2, and a current collecting terminal 4. Here, the housing 1 includes a bottomed square tube-shaped housing 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, an injection port 123 for injecting the electrolyte 8 into the housing 1, a plug body 122 that seals the injection port 123, and a safety valve 124 that cracks when the pressure inside the housing 1 rises above a specified value are provided. Both the housing 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 collecting terminal 4.

[0033] In addition, at the opening 111 of the housing 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 a step portion 111S formed at the lower end of the thin wall portion 111T, which corresponds to the support point 12K of the sealing body 12. In addition, the opening 111 of the housing body 11 has the following structure: there are no thin wall portions on the inner walls of the long side surfaces 11A and 11B, and it is difficult to prevent the central portion of the sealing body 12 from displacing (bending deformation) in the front-back direction (Z direction).

[0034] In addition, as Figures 2 to 4As shown, the electrode body 2 is wound into a flat shape by laminating a positive electrode body 21 and a negative electrode body 22 with a separator 23 interposed therebetween, and is housed in a housing main body 11. The positive electrode body 21 and the negative electrode body 22 each have: an active material non-coated portion 211, 221 where no active material KT1, KT2 is coated on one end portions 21K1, 22K1 of the metal foils 21K, 22K; and an active material coated portion 212, 222 where the active materials KT1, KT2 are coated on the metal foils 21K, 22K. The active material non-coated portion 211 of the positive electrode body 21 and the active material non-coated portion 221 of the negative electrode body 22 are arranged to face each other in the long side direction (X direction) of the sealing body 12. In addition, the active material coated portions 212, 222 are formed on the other end portions 21K2, 22K2 and the intermediate portions 21K3, 22K3 of the metal foils 21K, 22K.

[0035] The power storage device 10 refers to the entire power storage device capable of extracting electric energy, and includes, for example, a primary battery, a secondary battery, an electric double layer capacitor, 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.

[0036] In addition, for the current collecting terminals 4, a current collecting terminal 4A for the positive electrode and a current collecting terminal 4B for the negative electrode are provided. The current collecting terminal 4A for the positive electrode is, for example, made of aluminum, and the current collecting terminal 4B for the negative electrode is, for example, made of copper. Generally, since the tensile strength of the aluminum current collecting terminal 4A for the positive electrode is smaller than that of the copper current collecting terminal 4B for the negative electrode, and the conductivity of the aluminum current collecting terminal 4A for the positive electrode is smaller than that of the copper current collecting terminal 4B for the negative electrode, in order to achieve the uniformity of the strength and the allowable current amount of the current collecting terminal 4A for the positive electrode and the current collecting terminal 4B for the negative electrode, the plate thickness of the current collecting terminal 4A for the positive electrode is made larger than that of the current collecting terminal 4B for the negative electrode. The positive and negative current collecting terminals 4 each have a base portion 41, a base adjacent portion 42, and a wire portion 43 formed integrally.

[0037] The base portion 41 is joined to the external connection portions 45 (45A, 45B) located on the surface side of the sealing body 12, for example, by a rivet 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 an external force when the base portion 41, the external connection portion 45, and the sealing body 12 are joined by the rivet pin 46 or the like. In addition, an insulating member 3 that also serves as a sealing material is interposed between the rivet pin 46 and the external connection portion 45 and the sealing body 12. As the insulating member 3, for example, polyphenylene sulfide (PPS) resin can be used. 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).

[0038] In addition, the base portion 41 is joined by sandwiching the insulating member 3 on the inner side of both end portions 12R in the long side direction (X direction) of the sealing body 12. In addition, a 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 wire of the wire 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 wire in a state of being collected into a foil. When welding the electrode body 2 to the lower end portion 43b of the wire, the lower end portion 43b of the wire slides relative to the metal foils 21K, 22K in the middle of the collected foil, etc., and an external force that causes the lower end portion 43b of the wire to be displaced in the long side direction (X direction) of the sealing body 12 is likely to be generated. Sometimes this external force is transmitted to the sealing body 12, resulting in displacement of the central portion of the sealing body 12 in the front-back direction (Z direction).

[0039] In addition, on the surface 121 of the sealing body 12, there are two precision-required surfaces 12S (12S1, 12S2) that require the required surface position accuracy. Here, the precision-required surfaces 12S (12S1, 12S2) are formed as sensor contact surfaces 5S that can come into contact with a temperature sensor 5 for monitoring the temperature of the power storage device 10, but are not necessarily limited to the sensor contact surfaces 5S. As the temperature sensor 5, for example, a thermistor, a thermocouple, or the like can be used. The temperature sensor 5 is held by a holding case 51 fixed to a mounting bracket 53 and is urged toward the sensor contact surface 5S by a spring member 52 or the like. 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 precision-required surfaces 12S (12S1, 12S2) as the sensor contact surfaces 5S satisfies the required reference value KJ (refer to Figure 9 ).

[0040] In addition, when a plurality of the power storage devices 10 are connected in series to form a battery pack, generally, the long side surfaces 11A and 11B of the housing main body 11 are arranged close to each other. Therefore, 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 on the precision requirement surface 12S (12S1) close to the external connection portion 45A of the positive electrode ( Figure 2 the case shown), and the case where it is formed on the precision requirement surface 12S (12S2) close to the external connection portion 45B of the negative electrode, and the surface position precision of both precision requirement surfaces 12S (12S1, 12S2) is required to satisfy the required reference value KJ.

[0041] <Method for manufacturing the power storage device>

[0042] Next, with reference to the drawings, the method for manufacturing the power storage device according to the present embodiment will be described in detail. In Figure 5 it shows a Figure 1 flowchart showing the method for manufacturing the power storage device shown. In Figure 6 it shows a Figure 5 schematic cross-sectional view of the measurement method for measuring the surface position of the precision requirement surface by the surface position measurement process of the flowchart shown. In Figure 7 it shows a Figure 5 schematic cross-sectional view of the surface position change method for changing the surface position of the precision requirement surface to a position displaced closer to the surface side than the support point by the surface position change process of the flowchart shown. In Figure 8 it shows a Figure 5 schematic cross-sectional view of the measurement method for measuring the surface displacement amount of the precision requirement surface in the front-back direction with respect to the support point by the surface displacement amount measurement process of the flowchart shown. In Figure 9 it shows a Figure 5 schematic cross-sectional view of the correction device for correcting the surface displacement amount of the precision requirement surface within the reference value by the correction process of the flowchart shown. In Figure 10 it shows a Figure 9 brief cross-sectional view when a load is applied to the correction device shown until a correction deformation amount is generated on the precision requirement surface. In Figure 11 it shows a Figure 9 brief cross-sectional view when the load applied until a correction deformation amount is generated on the precision requirement surface is released in the correction device shown. In Figure 12 it is Figure 9 an example of the correlation chart data showing the correlation between the surface displacement amount and the correction deformation amount of the precision requirement surface used in the correction device shown. In addition, in Figures 6 to 11 the electrode body 2 is omitted, but as Figure 2As shown, the electrode body 2 is combined with the sealing body 12 via the current collecting terminal 4.

[0043] As Figures 1 to 12 shown, the manufacturing method of this power storage device is a manufacturing method of the power storage device 10 having a correction process S6. This correction process S6 corrects the sealing body 12 before the sealing body welding process S7 that welds the sealing body 12 sealing the opening 111 of the housing 1 containing the electrode body 2 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 surface position measurement process S1, a surface position determination process S2, a surface position change process S3, a surface displacement amount measurement process S4, a surface displacement amount determination process S5, a correction process S6, and a sealing body welding process S7. The sealing body welding process S7 is a process of welding the outer periphery of the sealing body 12 whose surface displacement amount Q of the precision requirement surface 12S is determined to satisfy the reference value KJ through the surface displacement amount determination process S5 (S5: satisfied), or the sealing body 12 whose surface displacement amount Q of the precision requirement surface 12S is corrected to within the reference value KJ through the correction process S6 to the opening 111 by using laser welding or the like.

[0044] Here, the precision requirement surface 12S is illustrated by taking the sensor contact surface 5S formed to be able to contact the temperature sensor 5 that monitors the temperature of this power storage device 10 as an example. As Figure 1 、 Figure 2 、 Figures 6 to 12 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 part 45A of the positive electrode and the precision requirement surface 12S (12S2) close to the external connection part 45B of the negative electrode, and the surface position accuracy of both precision requirement surfaces 12S (12S1, 12S2) is required to satisfy the required reference value KJ.

[0045] In addition, the reference value KJ refers to the allowable value of the surface 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 of the sealing body 12 toward the surface side ( Figures 6 to 11 the upper side in the Z direction in Figures 6 to 11 this) in the front-back direction is represented by +, and the displacement of the sealing body 12 toward the inside side ( Figure 9 、 Figure 12The reference value KJ shown is an example where the surface position of the precision requirement surface 12S (12S1, 12S2) is displaced toward the surface side (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, by making the surface displacement amount Q (Q1, Q2) of the precision requirement surface 12S (12S1, 12S2) within the reference value KJ, the measurement accuracy of the temperature sensor 5 can be improved, and thus 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.

[0046] Hereinafter, each process of the manufacturing method of this power storage device will be described in the order of the processes. First, as Figure 6 shown, in the surface position measurement process S1, the surface position MT in the front-back direction (Z direction) of the precision requirement surface 12S of the sealing body 12 is measured. Here, before inserting the sealing body 12 into the opening 111, in a state where both ends in the long side direction (X direction) of the sealing body 12 are supported by a jig (not shown) or the like, the respective surface positions MT (MT1, MT2) of the precision requirement surface 12S (12S1, 12S2) in the front-back direction (Z direction) of the sealing body 12 are measured. The measuring device 6 for the surface position MT (MT1, MT2) is preferably a non-contact measuring device 6 having laser rangefinders 61 and 62, for example. The laser rangefinders 61 and 62 irradiate laser light on the central part of the precision requirement surface 12S (12S1, 12S2) to measure the height of the surface position MT (MT1, MT2). In addition, the surface position measurement process S1 may also measure the surface position MT of the precision requirement surface 12S after inserting the sealing body 12 into the opening 111.

[0047] Next, in the surface position determination process S2, the measuring device 6 compares the surface positions MT (MT1, MT2) of the respective precision requirement surfaces 12S (12S1, 12S2) measured by the laser rangefinders 61 and 62 with the surface position of the reference support point 12K, and determines whether the surface positions MT (MT1, MT2) of the precision requirement surfaces 12S (12S1, 12S2) measured through the surface position measurement process S1 are located on the surface side or the inner side of the support points 12K (12K1, 12K2) of the sealing body 12 when inserted into the opening 111.

[0048] Then, in the surface position determination process S2, when it is determined that the surface positions MT (MT1, MT2) of the precision requirement surfaces 12S (12S1, 12S2) are located on the inner side of the support points 12K as Figure 6 shown, as Figure 7As shown, in the surface position changing step S3, the surface positions MT (MT1, MT2) of the precision-required surfaces 12S (12S1, 12S2) are displaced to positions closer to the surface side than the support points 12K. The changing device 6B for the surface positions MT (MT1, MT2) preferably includes, for example, clamping portions 61B1, 62B1 that clamp the sealing body 12 in the thickness direction (Z direction), and the clamping portions 61B1, 62B1 clamp the sealing body 12 at the positions of the precision-required surfaces 12S (12S1, 12S2) and pull it up toward the surface side of the sealing body 12. In addition, preferably in the surface position measuring step S1, after the sealing body 12 is inserted into the opening 111, when measuring the surface position MT of the precision-required surface 12S, the changing device 6B for the surface positions MT (MT1, MT2) is, for example, a device that adsorbs the precision-required surfaces 12S (12S1, 12S2) of the sealing body 12 and can pull up the sealing body 12 toward the surface side.

[0049] Next, in the surface displacement amount measuring step S4, as Figure 8 shown, in a state where the sealing body 12 whose surface positions MT (MT1, MT2) of the precision-required surfaces 12S (12S1, 12S2) are determined to be at positions closer to the surface side than the support points 12K (12K1, 12K2) through the surface position determination step S2, or the sealing body 12 whose surface positions MT (MT1, MT2) of the precision-required surfaces 12S (12S1, 12S2) are displaced to positions closer to the surface side than the support points 12K (12K1, 12K2) through the surface position changing step S3 is inserted into the opening 111, the surface displacement amounts Q (Q1, Q2) in the thickness direction (Z direction) of the surface positions MT (MT1, MT2) of the precision-required surfaces 12S (12S1, 12S2) relative to the support points 12K (12K1, 12K2) are measured. The measuring device 6C for the surface displacement amounts Q (Q1, Q2) is preferably a non-contact measuring device 6C having laser rangefinders 61C, 62C, for example. The laser rangefinders 61C, 62C irradiate laser light onto the central portions of the precision-required surfaces 12S (12S1, 12S2) to measure the surface positions MT (MT1, MT2) of the precision-required surfaces 12S (12S1, 12S2), and calculate the surface displacement amounts Q (Q1, Q2) in the thickness direction (Z direction) of the precision-required surfaces 12S (12S1, 12S2) as the differences between the surface positions MT (MT1, MT2) of the precision-required surfaces 12S (12S1, 12S2) and the surface positions of the support points 12K (12K1, 12K2). Then, the measuring device 6C for the surface displacement amounts Q (Q1, Q2) transfers the calculated surface displacement amounts Q (Q1, Q2) to Figure 9The database of the correction device 7 shown. In addition, the measuring device 6C for the surface displacement amount Q (Q1, Q2) can also serve as the measuring device 6 for the surface position MT (MT1, MT2).

[0050] Next, in the surface displacement amount determination step S5, it is determined whether the surface displacement amount Q (Q1, Q2) measured in the surface displacement amount measurement step S4 satisfies the required reference value KJ. Then, in the correction step S6, when it is determined in the surface displacement amount determination step S5 that the surface displacement amount Q (Q1, Q2) does not satisfy the reference value KJ (S5: NG (not satisfied)), as Figure 10 shown, the working parts 71, 72 of the correction device 7 work, and for the precision required surface 12S (12S1, 12S2), a load F (F1, F2) is applied to the inner side of the sealing body 12 until a correction deformation amount P (P1, P2) obtained by adding the surface displacement amount Q (Q1, Q2) and the elastic deformation amount DH (DH1, DH2) that makes the sealing body 12 return to the normal position SK where the surface displacement amount Q becomes zero by its own elastic force is generated. After that, as Figure 11 shown, the working parts 71, 72 of the correction device 7 are returned to their original positions, thereby releasing the load F. The working parts 71, 72 of the correction device 7 preferably have a structure that can be driven by a servo motor with an encoder or the like to correctly control the movement amount. In addition, the working parts 71, 72 of the correction device 7 can also perform correction deformation and release repeatedly in multiple times, gradually increasing the deformation amount until the specified correction deformation amount P (P1, P2) is reached.

[0051] As described above, according to the manufacturing method of this electrical storage device, the surface position MT of the precision required surface 12S in the front-back direction (Z direction) of the sealing body 12 is measured by the surface position measurement step S1. When it is determined in the surface position determination step S2 that the surface position MT is located on the inner side of the support point 12K of the sealing body 12 when inserted into the opening 111, the surface position MT of the precision required surface 12S is displaced to a position on the surface side of the support point 12K by the surface position change step S3. Therefore, even if the displacement direction of the sealing body 12 varies for each of the manufactured electrical storage devices 10, the surface position MT of the precision required surface 12S can be unified in such a way that it is temporarily displaced to a position on the surface side of the support point 12K for all the sealing bodies 12.

[0052] Further, in the correction process S6, when it is determined in the surface displacement amount determination process S5 that the surface displacement amount Q does not satisfy the reference value KJ, a load F is applied to the precision required surface 12S on the inner side of the sealing body 12 until a correction deformation amount P obtained by adding the surface displacement amount Q and the elastic deformation amount DH that allows the sealing body 12 to return to the normal position SK where the surface displacement amount Q becomes zero by its own elastic force is generated. After that, the load F is released. Therefore, in the stage immediately before welding the sealing body 12 to the opening 111, it is possible to correct the precision required surface 12S with a surface displacement amount Q that does not satisfy the required reference value KJ by converging it. Further, since the load F is applied to the precision required surface 12S from the surface side of the sealing body 12 toward the inner side (from the upper direction in the Z direction to the lower direction), there is no need to apply the load F from the inner side of the sealing body 12 toward the surface side (from the lower direction in the Z direction to the upper direction), and the precision required surface 12S can be simply and stably corrected within the reference value KJ.

[0053] Further, in the correction process S6, after a load F is applied to the precision required surface 12S on the inner side of the sealing body 12 until a position where a correction deformation amount P obtained by adding the surface displacement amount Q and the elastic deformation amount DH that allows the sealing body 12 to return to the normal position SK where the surface displacement amount Q becomes zero by its own elastic force is generated, the load F is released. Therefore, the plastic deformation amount SH of the precision required surface 12S after correction is consistent with the surface displacement amount Q of the precision required surface 12S, and the precision required surface 12S can be corrected with high precision.

[0054] In addition, the elastic deformation amount DH (DH1, DH2) that allows the sealing body 12 to return to the normal position SK where the surface displacement amount Q becomes zero by its own elastic force can be calculated mechanically using CAE (Computer Aided Engineering), for example. However, it becomes cumbersome because it needs to be calculated every time the surface displacement amount Q (Q1, Q2) changes. Therefore, it is preferable as Figure 12As shown, the relevant chart data SKD is prepared in advance and stored in the database of the correction device 7. The relevant chart data SKD represents the surface displacement amount Q in the front-back direction (Z direction) of the precision requirement surface 12S (12S1, 12S2), and the correction deformation amount P for correcting the precision requirement surface 12S (12S1, 12S2) displaced by the surface displacement amount Q to the opposite direction of the displacement direction of the precision requirement surface 12S (12S1, 12S2), that is, the opposite front-back direction (above or below in the Z direction) until it can return to the normal position SK by its own elastic force. In this case, even without calculating the elastic deformation amounts DH (DH1, DH2) one by one, the correction deformation amounts P (P1, P2) of the points consistent with the surface displacement amounts Q (Q1, Q2) of the precision requirement surfaces 12S (12S1, 12S2) measured by the surface displacement measurement process S4 can be obtained from the relevant chart data SKD (SKD1, SKD2).

[0055] The relevant chart data SKD is prepared, for example, in the following order. First, the sealing body 12 combined with the electrode body 2 via the current collecting terminal 4 is inserted into the opening 111 of the housing main body 11. Next, 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 surface displacement amount Q in the front-back direction (Z direction) is calculated as the difference between the measured surface positions of the respective precision requirement surfaces 12S (12S1, 12S2) and the surface position of the reference support point 12K. Then, the surface positions of the precision requirement surfaces 12S (12S1, 12S2) of the sealing bodies 12 with different surface displacement amounts Q are measured, and various surface displacement amounts Q are stored in the database of the correction device 7.

[0056] Next, as Figure 10 shown, the working parts 71, 72 of the correction device 7 work. After applying a load F to the precision requirement surfaces 12S (12S1, 12S2) displaced by the respective surface displacement amounts Q in the opposite front-back direction (Z direction) to the displacement direction of the precision requirement surfaces 12S (12S1, 12S2) to make them corrected and deformed until they can return to the normal position SK by their own elastic force, as Figure 11 shown, the working parts 71, 72 are returned to their original positions to release the load F. Then, as Figure 12 shown, the correction device 7 prepares the relevant chart data SKD (SKD1, SKD2) of the initial surface displacement amount Q and the correction deformation amount P during the correction deformation, and stores it in the database. Here, Figure 12The related chart data SKD (SKD1, SKD2) shown is represented by a line graph, but it can also be represented by a curve graph by adding measurement data. In addition, the correction deformation amount P (P1, P2) is the deformation amount that enables the precision requirement surface 12S (12S1, 12S2) displaced by the surface displacement amount Q (Q1, Q2) to return to the normal position SK where the surface displacement amount Q becomes zero through its own elastic force. Therefore, it is consistent with the sum of the elastic deformation amount DH (DH1, DH2) and the plastic deformation amount SH (SH1, SH2) corresponding to the surface displacement amount Q (Q1, Q2) before correction.

[0057] Therefore, even when the surface displacement amount Q (Q1, Q2) of the precision requirement surface 12S (12S1, 12S2) varies for each manufactured power storage device 10 and the surface displacement amount Q (Q1, Q2) is asymmetric left and right, it is possible to simply obtain the appropriate correction deformation amount P (P1, P2) based on Figure 12 the surface displacement amount Q (Q1, Q2) of the related chart data SKD (SKD1, SKD2) shown. In addition, since the related chart data SKD (SKD1, SKD2) varies depending on the size, type, etc. of the power storage device 10, the related chart data SKD (SKD1, SKD2) can be pre-made for each power storage device 10 and stored in a database.

[0058] As described in detail above, the method for manufacturing the power storage device according to the present embodiment is a method for manufacturing the power storage device 10 including a correction step S6. In the correction step S6, before the sealing body welding step S7 of welding the sealing body 12 that seals the opening 111 of the housing 1 containing the electrode body 2 to the opening 111, the sealing body 12 is corrected. Here, on the surface 121 of the sealing body 12, there is a precision requirement surface 12S that requires the required surface position accuracy. The method for manufacturing the power storage device includes: a surface position measurement step S1, in which the surface position MT of the precision requirement surface 12S in the front-back direction (Z direction) of the sealing body 12 is measured; a surface position determination step S2, in which it is determined whether the surface position MT of the precision requirement surface 12S measured by the surface position measurement step S1 is located on the surface side or the inner side of the support point 12K of the sealing body 12 when inserted into the opening 111; a surface position change step S3, in which when it is determined by the surface position determination step S2 that the surface position MT of the precision requirement surface 12S is located on the inner side of the support point 12K, the surface position MT of the precision requirement surface 12S is displaced to a position on the surface side of the support point 12K; a surface displacement amount measurement step S4, in which, in a state where the sealing body 12 determined by the surface position determination step S2 to have the surface position MT of the precision requirement surface 12S located on the surface side of the support point 12K, or the sealing body 12 whose surface position MT of the precision requirement surface 12S is displaced to a position on the surface side of the support point 12K by the surface position change step S3 is inserted into the opening 111, the surface displacement amount Q of the precision requirement surface 12S in the front-back direction (Z direction) relative to the support point 12K is measured; and a surface displacement amount determination step S5, in which it is determined whether the surface displacement amount Q measured by the surface displacement amount measurement step S4 satisfies the required reference value KJ. In the correction step S6, when it is determined by the surface displacement amount determination step S5 that the surface displacement amount Q does not satisfy the reference value KJ (S5: No (not satisfied)), after applying a load F to the precision requirement surface 12S toward the inner side until a correction deformation amount P obtained by adding the surface displacement amount Q and the elastic deformation amount DH that makes the sealing body 12 return to the normal position SK where the surface displacement amount Q becomes zero by its own elastic force is generated, the load F is released.

[0059] Therefore, according to the method for manufacturing the power storage device 10 of the present invention, even when the surface displacement amount Q of the sealing body 12 varies for each manufactured power storage device 10 and the surface displacement amount Q is asymmetric left and right, the correction deformation amount P can be changed according to the surface displacement amount Q, and the precision requirement surface 12S of the sealing body 12 can be corrected within the reference value KJ, thereby providing a method for manufacturing a highly reliable power storage device.

[0060] 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 position measurement step S1, the surface positions MT (MT1, MT2) of the respective precision required surfaces 12S (12S1, 12S2) are measured. When it is determined in the surface position determination step S2 that the surface positions MT (MT1, MT2) of at least one precision required surface 12S (12S1, 12S2) are located on the inner side of the support points 12K (12K1, 12K2), in the surface position change step S3, the surface positions MT of all the precision required surfaces 12S are displaced to the position on the surface side of the support points 12K (12K1, 12K2).

[0061] In this case, even if there are a plurality of precision required surfaces 12S (12S1, 12S2), when it is determined in the surface position determination step S2 that the surface positions MT (MT1, MT2) of at least one precision required surface 12S (12S1, 12S2) are located on the inner side of the support points 12K (12K1, 12K2), in the surface position change step S3, the surface positions MT (MT1, MT2) of all the precision required surfaces 12S (12S1, 12S2) are displaced to the position on the surface side of the support points 12K (12K1, 12K2). Therefore, even if the plurality of precision required surfaces 12S (12S1, 12S2) are displaced in different directions in the front-back direction (in the Z direction, opposite to each other), in the surface position change step S3, the surface positions MT of all the precision required surfaces 12S can be displaced to the position on the surface side of the support points 12K.

[0062] Therefore, it is possible to simplify the changing device 6B that displaces the precision required surface 12S (12S1, 12S2) in the surface position change step S3. In addition, it is possible to simplify the correcting device 7 that applies the load F (F1, F2) to the precision required surface 12S (12S1, 12S2) in the correcting step S6. As a result, the precision required surface 12S of the sealing body 12 can be corrected within the reference value KJ at a lower cost and in a shorter time.

[0063] 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 amount measurement step S4, the surface displacement amounts Q (Q1B, Q2) of the respective precision-required surfaces 12S (12S1, 12S2) are measured. In the correction step S6, when it is determined in the surface displacement amount determination step S5 that at least one surface 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 a correction deformation amount P (P1B, P2) obtained by adding the respective surface displacement amounts Q (Q1B, Q2) measured in the surface displacement amount measurement step S4 and the respective elastic deformation amounts DH (DH1, DH2) is generated, and after reaching the position of the average value (P1B + P2) × 1 / 2, the load F (F1, F2) is released.

[0064] In this case, even if there are a plurality of precision-required surfaces 12S (12S1, 12S2), after applying the load F (F1, F2) until reaching the position of the average value (P1B + P2) × 1 / 2 of the correction deformation amount P (P1B, P2) obtained by adding the respective surface displacement amounts Q (Q1B, Q2) measured in the surface displacement amount measurement step S4 and the respective elastic deformation amounts DH (DH1, DH2), and then releasing the load F (F1, F2), there is no need to generate separate correction deformation amounts P (P1B, P2) for the plurality of precision-required surfaces 12S (12S1, 12S2), and 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.

[0065] <Variant Example>

[0066] As described above in detail, the present embodiment is only a simple example 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 surface position measuring step of measuring the surface position of the precision-required surface in the front-back direction of the sealing body; a surface position determination step of determining whether the surface position of the precision-required surface measured in the surface position determination step is located on the front side or on the back side of the support point of the sealing body when the sealing body is inserted into the opening; a surface position changing step of, when the surface position of the precision required surface is determined to be located at a position on the inner side of the support point by the surface position determining step, shifting the surface position of the precision required surface to a position on the outer side of the support point; a surface displacement amount measuring step of measuring the surface displacement amount of the surface position of the precision required surface in the front-to-back direction relative to the support point, when the sealing body whose surface position of the precision required surface is determined to be located at a position closer to the surface side than the support point by the surface position determining step or the sealing body whose surface position of the precision required surface is displaced to a position closer to the surface side than the support point by the surface position changing step is inserted into the opening; as well as a surface displacement amount determination step of determining whether the surface displacement amount measured by the surface displacement amount measurement step satisfies a required reference value, In the correction step, when it is determined by the surface displacement determination step that the surface displacement does not satisfy the reference value, a load is applied to the accuracy-required surface toward the inner side of the sealing body until a position is generated where a correction deformation amount obtained by adding the surface displacement amount to an elastic deformation amount that causes the sealing body to return to a normal position where the surface displacement becomes zero due to its own elastic force is generated, and then 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 position measuring step, the surface position of each of the precision-required surfaces is measured. When it is determined through the surface position determination step that the surface position of at least one of the precision-required surfaces is located on the inner side of the support point, in the surface position change step, the surface positions of all the precision-required surfaces are shifted to the outer side of the support point.

4. 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 surface displacement of each of the precision-required surfaces is measured. In the correction process, when it is determined by the surface displacement determination process that at least one of the surface displacements does not satisfy the required reference value, after a load is applied to each of the precision-required surfaces until a position is reached in which an average value of a correction deformation obtained by adding each of the surface displacements measured by the surface displacement measurement process to each of the elastic deformations is reached, the load is released.

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