Fastening method of laminate cell in laminate cell battery

Abstract

To provide a fastening method of a laminate cell battery, capable of preventing damages of a cell by preventing a cell terminal from applying a rotational torque at a fastening.SOLUTION: A fastening method of a laminate cell is a fastening method of a laminate cell, provided to the laminate cell in a laminate cell battery in which the plurality of laminate cells are arranged in a thickness direction, and are assembled, and comprises: a temporal fastening step of temporally fastening both of terminals for fastening, provided to the laminate cell by using a bolt and a nut; and a fastening step of fastening the nut in a state where a fixture for rotary stopping the bolt and each terminal after the temporal fastening step.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for fastening laminate cells in a laminate cell battery pack. [Background technology]

[0002] Conventionally, in a battery pack in which a plurality of laminate cells are arranged in the thickness direction, a method for connecting the plurality of laminate cells by fastening them with bolts and nuts has been known, as described in Patent Document 1. In the method described in Patent Document 1, the plurality of laminate cells are connected by fastening cell terminals extending from the main bodies of the plurality of laminate cells to each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-11128 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the fastening method described in Patent Document 1, when a fastening torque is applied to the cell terminal during fastening, a corresponding stress is also applied to the base of the cell terminal, i.e., the part close to the main body of the laminated cell, which poses the risk of damaging the laminated cell. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] According to one embodiment of the present disclosure, there is provided a method for fastening laminate cells in a laminate cell assembled battery in which a plurality of laminate cells are arranged in a thickness direction, the method including a temporary fastening step of temporarily fastening fastening terminals of the laminate cells with bolts and nuts, and a fastening step of fastening the nuts after the temporary fastening step in a state in which a jig for preventing the bolts and the terminals from rotating is set. According to this embodiment, in the fastening step, the nut is fastened in a state in which the bolt and the terminal are prevented from rotating by the jig, so that no rotational torque is applied to the terminal when the nut is fastened, and damage to the laminate cell can be suppressed. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a perspective view for illustrating a state before a jig is set on the laminated cell assembled battery in the first embodiment of the present disclosure. [Diagram 2] FIG. 2 is a perspective view for illustrating a state after a jig has been set on the laminated cell assembled battery in the first embodiment of the present disclosure. [Diagram 3] FIG. 13 is a side view showing a schematic state of the laminated cell battery pack after the jig has been set thereon. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A. First embodiment: A1. Configuration of laminated cell battery 1: Fig. 1 is a perspective view for explaining a state before a jig 20 is set on a laminate cell assembled battery 1 in the first embodiment of the present disclosure. Fig. 2 is a perspective view for explaining a state after a jig 20 is set on a laminate cell assembled battery 1 in the first embodiment of the present disclosure. As shown in Figs. 1 and 2, the laminate cell assembled battery 1 is an assembled battery in which a plurality of laminate cells 10 are arranged in the thickness direction. The laminate cell 10 is not particularly limited, but it is preferable to use a lithium ion battery, in particular an all-solid-state lithium ion battery including a solid electrolyte.

[0009] The thickness direction coincides with the direction in which the X-axis extends in each of Figures 1 to 3. In the following description, one side in the thickness direction is also referred to as the "X-axis negative side" and the other side in the thickness direction is also referred to as the "X-axis positive side". The Y-axis is perpendicular to the X-axis and coincides with the up-down direction in each of the figures. Hereinafter, the Y-axis positive side is also referred to as the "upper" side, and the Y-axis negative side is also referred to as the "lower" side.

[0010] 1 and 2 show a schematic diagram of a laminate cell 10 that is generally used in a battery pack. The laminate cell 10 is a plate-shaped assembly of electrodes (not shown) that is wrapped in a laminate film made of a metal foil such as aluminum coated with a synthetic resin, and the periphery is sealed. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and, in some cases, a separator sheet or the like interposed between them. The laminate cell 10 is provided at its end with two fastening terminals (a first terminal 11 and a second terminal 12) that protrude to the outside. The jig 20 is used to connect the terminals of adjacent laminate cells 10 to each other.

[0011] The first terminal 11 and the second terminal 12 are provided at ends of the laminate cell 10 in the thickness direction (X-axis direction) and spaced apart from each other. The first terminal 11 is provided at an end of the laminate cell 10 on the +X-axis side. The second terminal 12 is provided at an end of the laminate cell 10 on the -X-axis side. The first terminal 11 and the second terminal 12 are formed with an insertion hole 110 through which the bolt 2 is inserted. When a plurality of laminate cells 10 are arranged in the thickness direction, the first terminal 11 of one of the adjacent laminate cells 10 and the second terminal 12 of the other of the adjacent laminate cells 10 are positioned opposite each other in the X-axis direction. When assembled, the position of the insertion hole 110 of the first terminal 11 corresponds to the position of the insertion hole of the second terminal 12.

[0012] When assembling a plurality of laminate cells 10, the bolt 2 is inserted from the negative side of the X-axis of the first terminal 11, and the nut 3 is placed on the positive side of the X-axis of the second terminal 12 and temporarily fastened. The first terminal 11 corresponds to the "bolt side terminal". The second terminal 12 corresponds to the "nut side terminal". Hereinafter, the "first terminal 11" is also referred to as the "bolt side terminal 11". The "second terminal 12" is also referred to as the "nut side terminal 12". Then, the nut 3 is fastened with the jig 20 preventing each terminal 11, 12 from rotating, thereby connecting adjacent laminate cells 10 to each other.

[0013] A2. Configuration of jig 20: Fig. 3 is a side view showing a schematic state after the jig 20 is set on the laminated cell battery pack 1. Fig. 3 is a view seen from the protruding direction of the terminals 11, 12. When the nut is fastened, the jig 20 receives the rotation of the bolt 2 which rotates together with the jig 2, and receives a reaction force acting on the terminals 11, 12 by contacting the nut-side terminal 12 and the bolt-side terminal 11. That is, the jig 20 has a bolt rotation stopper 21, a nut-side terminal rotation stopper 23, and a bolt-side terminal rotation stopper 22.

[0014] As shown in each of Figs. 1 to 3, the jig 20 includes a shaft portion 24 and a head portion 25, and has a so-called wrench shape as a whole. In the following, the "axial direction" refers to the direction in which the shaft portion 24 extends. The head portion 25 is integrally connected to the tip of the shaft portion 24. The head portion 25 includes two base portions (a first base portion 26 and a second base portion 27) that are spaced apart in the axial direction. The first base portion 26 is formed at one end of the head portion 25 that is away from the shaft portion 24. The second base portion 27 is formed at one end of the head portion 25 that is adjacent to the shaft portion 24. The first base portion 26 and the second base portion 27 are disposed so as to face each other in the axial direction. The surfaces facing each other are also referred to as the "inner surfaces" of the base portions 26 and 27. The spaced portion in the axial direction between the first base portion 26 and the second base portion 27 is formed as an opening 30.

[0015] 3, in each of the bases 26, 27, a bolt rotation preventing portion 21 is provided on part of the inner surface at one end side in the thickness direction (the negative X-axis side when set). By sandwiching the bolt 2 between the inner surfaces of the bases 26, 27, rotation of the bolt 2 is prevented.

[0016] A bolt-side terminal rotation stopper 22 is provided near the axial upper end of first base 26. Bolt-side terminal rotation stopper 22 is an inner surface of a rectangular parallelepiped portion 28 formed integrally with first base 26. Rectangular parallelepiped portion 28 may be formed integrally with first base 26, or may be a separate member that is attached by welding, adhesion, or the like. The upper surface of bolt-side terminal 11 abuts against this bolt-side terminal rotation stopper 22, thereby preventing co-rotation of bolt-side terminal 11 when the nut is fastened.

[0017] The second base 27 is formed with a nut-side terminal rotation stopper 23. As shown in FIG. 1, the nut-side terminal rotation stopper 23 is the bottom surface of a recess 29 formed on the inner surface of the second base 27. The recess 29 has a rectangular shape when viewed in the axial direction. As shown in FIG. 3, the lower surface of the nut-side terminal 12 abuts against the nut-side terminal rotation stopper 23, thereby suppressing the nut-side terminal 12 from rotating together when the nut is fastened. The bolt-side terminal rotation stopper 22 and the nut-side terminal rotation stopper 23 are arranged to face each other in the axial direction of the shaft 24. In addition, the axial distance between the bolt-side terminal rotation stopper 22 and the nut-side terminal rotation stopper 23 is slightly longer than the axial length of each of the terminals 11 and 12.

[0018] A3. Fastening method of laminated cell 10: Next, a method of fastening the laminate cell 10 will be described. First, the bolt side terminal 11 and the nut side terminal 12 are temporarily fastened together using the bolt 2 and the nut 3 (see FIG. 1). This temporary fastening process corresponds to the "temporary fastening process". After the temporary fastening, the jig 20 is prepared. Then, the jig 20 is attached so that the opening 30 of the head portion 25 approaches each of the terminals 11, 12 and the first base portion 26 and the second base portion 27 sandwich each of the terminals 11, 12 from above and below (see FIG. 2). In the example of each figure, the jig 20 is set in a state in which the extension direction of the shaft portion 24 and the extension direction of the X-axis are approximately aligned. When the jig is set, the bolt rotation stopper 21, the bolt side terminal rotation stopper 22, and the nut side terminal rotation stopper 23 are positioned in this order from the negative side in the X-axis direction.

[0019] At this time, bolt side terminal rotation stopper 22 formed on first base 26 abuts against bolt side terminal 11 from above. Additionally, nut side terminal rotation stopper 23 formed on second base 27 abuts against nut side terminal 12 from below. Bolt 2 is sandwiched from above and below by bolt rotation stopper 21. At this time, it is advisable to enlarge the outer dimensions of terminals 11, 12 so that terminals 11, 12 reliably come into contact with rotation stopper 22, 23.

[0020] After the jig 20 is set, the nut 3 is rotated in the R direction using a known nut tightening tool 4 to perform final tightening, as shown in Fig. 2. This final tightening process corresponds to the "fastening process".

[0021] As the nut 3 rotates, a reaction force in the Rb direction, which is the same direction as the R direction, acts on the bolt-side terminal 11, and a reaction force in the Rn direction, which is opposite to the R direction, acts on the nut-side terminal 12. The Rb direction and the Rn direction have different directions. At this time, the reaction force in the Rb direction acting on the bolt-side terminal 11 is received by the bolt-side terminal rotation stopper 22. Moreover, the reaction force in the Rn direction acting on the nut-side terminal 12 is received by the nut-side terminal rotation stopper 23.

[0022] Therefore, according to the method for fastening the laminate cell 10 of the above embodiment, since no rotational torque is applied to the bolt side terminal 11 and the nut side terminal 12 when the nut is fastened, damage to the laminate cell 10 can be suppressed.

[0023] The present disclosure is not limited to the above-mentioned embodiments, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in each embodiment corresponding to the technical features in each form described in the Summary of the Invention column can be appropriately replaced or combined in order to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0024] 1...Laminated cell battery pack, 2...Bolt, 3...Nut, 4...Nut fastening tool, 10...Laminated cell, 11...First terminal (bolt side terminal), 12...Second terminal (nut side terminal), 20...Jig, 21...Bolt rotation stopper, 22...Bolt side terminal rotation stopper, 23...Nut side terminal rotation stopper, 24...Shaft, 25...Head, 26...First base, 27...Second base, 28...Rectangular parallelepiped portion, 29...Recess, 30...Opening

Claims

[Claim 1] A method for fastening laminate cells in a laminate cell battery pack in which a plurality of laminate cells are arranged in a thickness direction, comprising the steps of: a temporary fastening step of temporarily fastening fastening terminals of the laminate cells to each other using bolts and nuts; a fastening step of fastening the nut in a state in which a jig for preventing the bolt and the terminal from rotating is set after the temporary fastening step; A method for fastening laminate cells in a laminate cell battery pack comprising:

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