Method for manufacturing a storage module

Abstract

To provide a method for manufacturing a power storage module capable of improving the welding accuracy of a bus bar to an external terminal while avoiding an increase in the bus bar size.SOLUTION: A method for manufacturing a power storage module includes: a preparation step of preparing a plurality of power storage cells 100; an arrangement step of arranging the plurality of power storage cells 100; a location information storage step of reading location information including the location of an external terminal 120 and a reference location and storing the location information; a mounting step of mounting a bus bar 210 on a pair of the external terminals 120; and a welding step of welding the bus bar 210 to the pair of external terminals 120. A reading index 122 is formed on each of the pair of external terminals 120. In the location information storage step, the location of the reading index 122 is read as the location of the external terminal 120 included in the location information. In the welding step, the bus bar 210 is welded to the pair of external terminals 120 by irradiating the bus bar 210 with a laser L based on the location information.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a power storage module.

Background Art

[0002] For example, Japanese Unexamined Patent Application Publication No. 2013-26191 discloses a power supply device including a plurality of battery cells and a bus bar that electrically connects output terminals of adjacent battery cells to each other. A connection hole for inserting the output terminal is formed in the bus bar. The bus bar is welded to the output terminal with the output terminal inserted into the connection hole.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power supply device described in Japanese Unexamined Patent Application Publication No. 2013-26191, stress concentration is likely to occur in a portion of the bus bar near the connection hole, and there is a concern that the amount of heat generated during energization becomes excessive. Therefore, it is necessary to increase the size of the bus bar, such as increasing the cross-sectional area of the bus bar, and the entire power storage module becomes larger.

[0005] An object of the present disclosure is to provide a method for manufacturing a power storage module capable of improving the welding accuracy of the bus bar to an external terminal while avoiding an increase in the size of the bus bar.

Means for Solving the Problems

[0006] A method for manufacturing a power storage module according to an aspect of the present disclosure includes a preparation step of preparing a plurality of power storage cells each having a case and a pair of external terminals protruding from the case, an arrangement step of arranging the plurality of power storage cells so that the plurality of power storage cells are aligned in one direction, a position information storage step of reading position information including the position of the external terminals in each of the plurality of power storage cells and a preset reference position and storing the position information, a placement step of placing a bus bar on a pair of external terminals adjacent to each other in the one direction, and a welding step of welding the bus bar to the pair of external terminals adjacent to each other in the one direction. Each of the pair of external terminals of each of the power storage cells prepared in the preparation step is formed with a reading index that can be read in the position information storage step. In the position information storage step, the position of the reading index is read as the position of the external terminals included in the position information. In the welding step, the bus bar is welded to the pair of external terminals by irradiating the bus bar with a laser based on the position information.

Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a method for manufacturing a power storage module capable of improving the welding accuracy of a bus bar to an external terminal while avoiding an increase in the size of the bus bar.

Brief Description of the Drawings

[0008]

Figure 1

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Figure 10

Mode for Carrying Out the Invention

[0009] Embodiments of the present disclosure will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same numbers.

[0010] FIG. 1 is a perspective view schematically showing a part of a power storage module manufactured by a method for manufacturing a power storage module according to an embodiment of the present disclosure. This method for manufacturing a power storage module is preferably applied to the manufacture of a power storage module mounted on a vehicle.

[0011] As shown in FIG. 1, the power storage module 1 includes a plurality of power storage cells 100 and a bus bar module 200 (see FIG. 6).

[0012] The plurality of power storage cells 100 are arranged side by side in one direction. Examples of each power storage cell 100 include a lithium-ion battery. As shown in FIGS. 1 to 3, each power storage cell 100 has a case 110 and a pair of external terminals 120.

[0013] The case 110 houses electrodes and the like. The case 110 is made of aluminum or the like. The case 110 is formed in a rectangular parallelepiped shape.

[0014] The pair of external terminals 120 have a shape protruding from the case 110. Each external terminal 120 protrudes upward from the upper surface of the case 110. One of the pair of external terminals 120 is a positive electrode terminal, and the other is a negative electrode terminal.

[0015] As shown in FIGS. 1 and 3, a reading index 122 is formed on each external terminal 120. In the present embodiment, the reading index 122 is constituted by a recess that is recessed downward. For example, the recess may be constituted by a caulked portion of the external terminal 120. The outer shape of the reading index 122 is formed in a circular shape. However, the outer shape of the reading index 122 is not limited to a circular shape.

[0016] Each power storage cell 100 may be a battery having a liquid electrolyte housed in a case 110, or may be a battery (all-solid-state battery) having a solid electrolyte housed in a cell case 110.

[0017] As shown in FIG. 5, a frame body 130 made of an insulating material (such as resin) is disposed between a pair of power storage cells 100 adjacent to each other. In FIG. 1, the illustration of the frame body 130 is omitted. Further, as shown in FIG. 6, end plates 140 are provided on both sides of a plurality of power storage cells 100 in one direction. An insert nut 142 is provided on the end plate 140. In FIG. 6, the illustration of the frame body 130 is omitted.

[0018] The bus bar module 200 is connected to a plurality of power storage cells 100. The bus bar module 200 has a plurality of bus bars 210 and a holder 220.

[0019] Each bus bar 210 electrically connects a pair of external terminals 120 adjacent to each other in one direction. Each bus bar 210 electrically connects the positive terminal of one power storage cell 100 and the negative terminal of a power storage cell 100 adjacent to the one power storage cell 100. That is, the plurality of power storage cells 100 are connected in series by each bus bar 210.

[0020] As shown in FIG. 1, each bus bar 210 has a welded portion 212 to be welded to the external terminal 120. The welded portion 212 is formed in a flat plate shape. The welded portion 212 is welded to the external terminal 120 in a state of covering the reading index 122. No through hole or notch is formed in the welded portion 212.

[0021] The holder 220 holds the plurality of bus bars 210 such that the plurality of bus bars 210 are arranged in one direction. The holder 220 is made of a synthetic resin or the like. In FIG. 1, the illustration of the holder 220 is omitted.

[0022] Next, with reference to FIGS. 4 to 10, a method for manufacturing the power storage module 1 will be described. In this manufacturing method, a positioning jig 10, a laser condenser (PFO: Programmable Focusing Optics) 20, an arm 30, a reading device 40, a storage device 50, a displacement meter 60, and a pressing jig 70 are used.

[0023] The positioning jig 10 is a jig for positioning a plurality of power storage cells 100. As shown in FIG. 4, the positioning jig 10 positions the plurality of power storage cells 100 from both sides in a direction (a direction orthogonal to the paper surface in FIG. 4) and a direction orthogonal to both the up-and-down direction and the one direction (the left-right direction in FIG. 4).

[0024] The laser condenser 20 can irradiate a laser L for welding the bus bar 210 to the external terminal 120.

[0025] The arm 30 holds the laser condenser 20. The arm 30 can move the laser condenser 20 three-dimensionally.

[0026] The reading device 40 is composed of a CCD camera or the like. The reading device 40 reads the position information of all the external terminals 120 in the plurality of power storage cells 100. More specifically, the reading device 40 reads the position information of the reading indicators 122 of all the external terminals 120. The reading device 40 also reads a preset reference position. In the present embodiment, the reference position is constituted by an insert nut 142 provided on the end plate 140. The reading device 40 is fixed to the laser condenser 20.

[0027] The memory device 50 stores the position information (the position of the reading index 122 and the reference position) read by the reading device 40.

[0028] The displacement meter 60 measures the distance between the laser concentrator 20 and the surface of the welded portion 212 of the bus bar 210.

[0029] The pressing jig 70 presses the bus bar 210 toward the external terminal 120. As shown in FIGS. 8 and 9, the pressing jig 70 presses each welded portion 212 against the external terminal 120. The pressing load of the bus bar 210 by the pressing jig 70 is controlled to be within a preset load range.

[0030] The manufacturing method of the power storage module 1 includes a preparation step, an arrangement step, a position information storage step, a placement step, and a welding step.

[0031] In the preparation step, a plurality of power storage cells 100 described above are prepared.

[0032] In the arrangement step, the plurality of power storage cells 100 are arranged so that the plurality of power storage cells 100 line up in one direction. In this step, as shown in FIG. 4, the positioning jig 10 is used. In this step, a frame body 130 is arranged between a pair of adjacent power storage cells 100. The plurality of power storage cells 100 arranged in the arrangement step are conveyed to the welding stage. The left end of the power storage cell 100 in FIG. 4 is used as the welding equipment reference.

[0033] In the position information storage step, as indicated by the arrow in FIG. 5, the arm 30 moves the reading device 40, so that the position information including the position of the reading index 122 of the external terminal 120 and the reference position in each power storage cell 100 is read by the reading device 40, and the position information is stored in the memory device 50.

[0034] In the mounting process, as shown in FIG. 7, the bus bar module 200 is mounted on a plurality of power storage cells 100. Specifically, in the mounting process, the bus bar module 200 is mounted on a plurality of power storage cells 100 such that the welded portion 212 of each bus bar 210 covers the reading index 122 of each external terminal 120.

[0035] In the welding process, as shown in FIGS. 8 and 9, while the welded portion 212 of each bus bar 210 is pressed toward the external terminal 120 by the pressing jig 70, the displacement gauge 60 measures the distance between the laser condenser 20 and the surface of the welded portion 212, and while the focal length of the laser L is adjusted according to the distance, the laser L is irradiated from the laser condenser 20 to the welded portion 212 of the bus bar 210 based on the position information, whereby the bus bar 210 is welded to the external terminal 120. This welding process is carried out until the welding of all the bus bars 210 is completed along one direction. In this process, as indicated by the arrow in FIG. 8, the laser condenser 20 and the pressing jig 70 move integrally.

[0036] FIG. 10 is a partial plan view of the power storage module 1 after the welding process. In FIG. 10, a welded portion WP is shown on the welded portion 212. As shown in FIG. 10, in the welding process, among each welded portion 212, the portion adjacent to the portion overlapping the reading index 122 in the thickness direction of the welded portion 212 is welded. In FIG. 10, the illustration of the frame body 130 and the holding body 220 is omitted.

[0037] As described above, in the method for manufacturing a power storage module according to the present embodiment, since the laser L is irradiated based on the position information including the position of the reading index 122 formed on the external terminal 120 of the power storage cell 100, in other words, since the irradiation position of the laser L is determined without depending on the shape of the bus bar 210, the shape of the bus bar 210 can be simplified. Therefore, it is possible to improve the welding accuracy of the bus bar 210 to the external terminal 120 while avoiding an increase in the size of the bus bar 210.

[0038] Those skilled in the art will understand that the above-exemplified embodiments are specific examples of the following aspects.

[0039] The method for manufacturing a power storage module in the above embodiment includes a preparation step of preparing a plurality of power storage cells each having a case and a pair of external terminals protruding from the case, an arrangement step of arranging the plurality of power storage cells so that the plurality of power storage cells are arranged in one direction, a position information storage step of reading position information including the position of the external terminals in each of the plurality of power storage cells and a preset reference position and storing the position information, a placement step of placing a bus bar on a pair of external terminals adjacent to each other in the one direction, and a welding step of welding the bus bar to the pair of external terminals adjacent to each other in the one direction. Each of the pair of external terminals of each of the power storage cells prepared in the preparation step is formed with a reading index readable in the position information storage step. In the position information storage step, the position of the reading index is read as the position of the external terminals included in the position information. In the welding step, the bus bar is welded to the pair of external terminals by irradiating the bus bar with a laser based on the position information.

[0040] In this method for manufacturing a power storage module, since laser irradiation is performed based on the position information including the position of the reading index formed on the external terminals of the power storage cells, in other words, since the laser irradiation position is determined without depending on the shape of the bus bar, it is possible to simplify the shape of the bus bar. Therefore, it is possible to increase the welding accuracy of the bus bar to the external terminals while avoiding an increase in the size of the bus bar.

[0041] Further, in the welding step, it is preferable that the bus bar is irradiated with a laser based on the position information in a state where the bus bar is pressed against the pair of external terminals adjacent to each other in the one direction.

[0042] In this way, the adhesion between the bus bar and the external terminals is enhanced, so that the welding accuracy of the bus bar to the external terminals is further increased.

[0043] Further, in the welding process, the distance between the laser condenser that irradiates the laser and the surface of the bus bar is measured, and while the focal length of the laser is adjusted according to the distance, it is preferable that the bus bar is irradiated with the laser based on the position information.

[0044] In this way, the welding accuracy of the external terminal to the bus bar is further improved.

[0045] Further, in the mounting process, the bus bar is mounted on the external terminal so as to cover the reading index, and in the welding process, it is preferable that the laser is irradiated to a portion adjacent to a portion overlapping the reading index in the thickness direction of the bus bar among the bus bars.

[0046] In this case, the reading index formed on the external terminal of each of the power storage cells prepared in the preparation process may be composed of a concave portion that is recessed in the irradiation direction of the laser irradiated in the welding process.

[0047] It should be noted that the embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is shown not by the description of the above embodiments but by the claims, and further includes all modifications within the meaning and scope equivalent to the claims.

Description of Reference Numerals

[0048] 1 Power storage module, 10 Positioning jig, 20 Laser condenser, 30 Arm, 40 Reading device, 50 Storage device, 60 Displacement meter, 70 Pressing jig, 100 Power storage cell, 110 Case, 120 External terminal, 122 Reading index, 130 Frame body, 140 End plate, 142 Insert nut, 200 Bus bar module, 210 Bus bar, 212 Welded portion, 220 Holder, WP Welding portion.

Claims

1. A preparation step of preparing a plurality of power storage cells each having a case and a pair of external terminals protruding from the case, and a pair of end plates; An array step of arranging the plurality of power storage cells so that the plurality of power storage cells are arranged in one direction, and arranging the pair of end plates on both sides of the plurality of power storage cells in the one direction; A position information storage step of reading position information including the position of the external terminal in each of the plurality of power storage cells and a preset reference position, and storing the position information; A placement step of placing a bus bar on a pair of externally adjacent external terminals in the one direction; A welding step of welding the bus bar to a pair of externally adjacent external terminals in the one direction, the method for manufacturing a power storage module comprising: In each of the pair of external terminals of each of the power storage cells prepared in the preparation step, a reading index readable in the position information storage step is formed; On the upper surface of each of the end plates prepared in the preparation step, an insert nut is provided; In the position information storage step, the position of the reading index is read as the position of the external terminal included in the position information, and the position of the insert nut is read as the reference position included in the position information; In the welding step, while pressing the bus bar against a pair of externally adjacent external terminals in the one direction with a pressing jig, the bus bar is welded to the pair of external terminals by irradiating the bus bar with a laser from a laser condenser based on the position information, and the laser condenser and the pressing jig are integrally moved along the one direction.

2. The method for manufacturing a power storage module according to claim 1, wherein in the welding step, the distance between the laser condenser and the surface of the bus bar is measured, and the laser is irradiated onto the bus bar based on the position information while adjusting the focal length of the laser according to the distance.

3. In the placement step, the bus bar is placed on the external terminal so as to cover the reading index; The method for manufacturing a power storage module according to claim 1 or 2, wherein in the welding step, the laser is irradiated onto a portion of the bus bar adjacent to a portion overlapping the reading index in the thickness direction of the bus bar.

4. The manufacturing method of the power storage module according to claim 3, wherein the reading index formed on the external terminal of each of the power storage cells prepared in the preparation step is constituted by a recess that is recessed in the irradiation direction of the laser irradiated in the welding step.

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