Manufacturing method for battery

Abstract

To provide a manufacturing method for a battery capable of suppressing electrolyte leakage under a reduced pressure environment before sealing a filling port.SOLUTION: The manufacturing method for a battery 1 includes a step for injecting electrolyte into a structure 10 via a filling frame 20 having a filling port 23 communicating with a through hole 15a formed in the structure 10, in which a battery cell is provided internally. Furthermore, the manufacturing method for the battery 1 includes the steps for deforming an end portion 22a in a direction perpendicular to the direction of extension of the filling frame 20 by heating the end portion 22a, which is opposite the through hole 15a of the filling frame 20, with a heater 3, placing a sealing material 30 on the end portion 22a, depressurizing the environment surrounding the structure 10, and fusing the sealing material 30 to the end portion 22a.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a battery. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2018-101486 (Patent Document 1) discloses an energy storage module including a stack of multiple battery cells, each including an electrode plate, and a frame that holds the electrode plate on a side surface of the stack. The frame is provided with a liquid injection port for injecting an electrolyte into the stack. After the electrolyte is injected, the liquid injection port is sealed with a sealant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-101486 Summary of the Invention [Problem to be solved by the invention]

[0004] Before sealing the injection hole, the stack and the frame are placed in a reduced pressure environment, which allows gas to be expelled from the frame. However, some of the electrolyte may leak out along with the gas.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a method for manufacturing a battery that can suppress leakage of electrolyte in a reduced pressure environment before sealing the filling port. [Means for solving the problem]

[0006] A method for manufacturing a battery according to an aspect of the present disclosure includes the steps of injecting an electrolyte into a structure through a liquid filling frame having a liquid filling port communicating with a through-hole formed in the structure inside which a battery cell is provided, and further including the steps of heating an end of the liquid filling frame opposite the through-hole with a heater to deform the end in a direction perpendicular to the extension direction of the liquid filling frame, arranging a sealant at the end, reducing the pressure in the environment around the structure, and welding the sealant to the end.

[0007] According to the present disclosure, the end portion is deformed in a direction perpendicular to the extension direction of the liquid filling frame, so that the end portion has a portion that protrudes in the direction perpendicular to the extension direction of the liquid filling frame. This protruding portion blocks the electrolyte that has passed through the through hole and reached the liquid filling port. This prevents leakage of the electrolyte in a reduced-pressure environment before the liquid filling port is sealed. [Effects of the Invention]

[0008] According to the method for manufacturing a battery of the present disclosure, leakage of the electrolyte can be suppressed in a reduced pressure environment before the filling port is sealed. [Brief explanation of the drawings]

[0009] [Figure 1] 3A to 3C are diagrams illustrating a first step and a second step of a method for manufacturing a battery according to an embodiment. [Figure 2] 5A and 5B are diagrams illustrating a third step and a fourth step of the battery manufacturing method according to the embodiment. [Figure 3] 6A and 6B are diagrams illustrating the fifth and sixth steps of the battery manufacturing method according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0011] A method for manufacturing a battery according to an embodiment will be described with reference to Figures 1 to 3. Figure 1 is a diagram illustrating first and second steps of the method for manufacturing a battery according to an embodiment. Figure 2 is a diagram illustrating third and fourth steps of the method for manufacturing a battery according to an embodiment. Figure 3 is a diagram illustrating fifth and sixth steps of the method for manufacturing a battery according to an embodiment.

[0012] The battery 1 manufactured by the manufacturing method according to the embodiment is used in various vehicles, such as forklifts, hybrid vehicles, electric vehicles, etc. The battery 1 may also be used in devices other than vehicles.

[0013] 1 to 3, the battery 1 includes a structure 10, a liquid filling frame 20, and a sealing material 30. The battery 1 is, for example, a bipolar type electricity storage module.

[0014] The structure 10 includes a plurality of battery cells 10a (only three are shown in FIG. 1) and a fixing member 15. The plurality of battery cells 10a are stacked in a certain direction (hereinafter referred to as the "stacking direction").

[0015] Each of the plurality of battery cells 10a includes a current collector 11, a positive electrode active material layer 12, a negative electrode active material layer 13, and a separator 14. The battery cell 10a is composed of a laminate in which the current collector 11, the positive electrode active material layer 12, the separator 14, the negative electrode active material layer 13, and the current collector 11 are laminated in this order.

[0016] The fixing member 15 fixes the peripheral edges of the current collectors 11 together. The fixing member 15 is made of, for example, resin. The fixing member 15 has a plurality of through holes 15a. In the example shown in FIG. 1, the plurality of through holes 15a are provided at positions corresponding to the plurality of battery cells 10a, respectively.

[0017] The liquid filling frame 20 is a member for injecting an electrolyte solution into the internal space 10b of the structure 10. The liquid filling frame 20 is made of resin. The liquid filling frame 20 has a plurality of walls 22 standing on a side surface 16 that is parallel to the stacking direction of the structure 10. That is, the plurality of walls 22 extend in a direction perpendicular to the side surface 16. The plurality of walls 22 may be provided at an angle relative to the direction perpendicular to the side surface 16.

[0018] The space between two adjacent walls 22 constitutes a liquid filling port 23 that communicates with the through-hole 15a. In the example shown in Fig. 1, the liquid filling frame 20 has a plurality of liquid filling ports 23 that communicate with the plurality of through-holes 15a, respectively.

[0019] 1, the manufacturing method of the battery 1 includes a first step S1 of injecting an electrolyte solution 50 into the structure 10 through a liquid filling frame 20 having a liquid filling port 23 that communicates with a through-hole 15a formed in the structure 10 inside which the battery cell 10a is provided. As a result, the electrolyte solution 50 is filled into the internal space 10b of the structure 10 through the liquid filling port 23 and the through-hole 15a.

[0020] The method for manufacturing the battery 1 next includes a second step S2 in which the structure 10 and the liquid filling frame 20 are placed in the decompression chamber 2. A heater 3 is also placed in the decompression chamber 2. The heater 3 is arranged so as to face the end of the liquid filling frame 20 on the opposite side from the through-hole 15a. Specifically, the heater 3 is arranged so as to face the end 22a of each of the multiple walls 22 of the liquid filling frame 20 on the opposite side from the side surface 16 of the structure 10. In the second step S2, the inside of the decompression chamber 2 is maintained at atmospheric pressure.

[0021] 2 , the manufacturing method of the battery 1 includes, as a next step, a third step S3 in which an end 22a of the liquid filling frame 20 on the opposite side to the through-hole 15a is heated with a heater 3 to deform the end 22a in a direction perpendicular to the extension direction of the liquid filling frame 20. By performing the third step S3, the end 22a of each wall 22 of the liquid filling frame 20 includes a protruding portion 22b that protrudes in a direction perpendicular to the wall 22. The protruding portion 22b is a mass formed by the heat of the heater 3 melting and solidifying part of the resin of the end 22a.

[0022] The manufacturing method of the battery 1 next includes a fourth step S4 in which a sealant 30 is placed on the end 22a of the liquid filling frame 20. The sealant 30 is, for example, a sheet-like resin material. In the fourth step S4, the sealant 30 is temporarily attached to the end 22a of the liquid filling frame 20. Therefore, a small gap exists between the sealant 30 and the end 22a. In the third step S3 and the fourth step S4, the inside of the reduced pressure chamber 2 is maintained at atmospheric pressure.

[0023] 3, the manufacturing method of the battery 1 next includes a fifth step S5 of reducing the pressure of the environment around the structure 10. Specifically, the pressure inside the decompression chamber 2 is reduced. As a result, the gas 40 remaining in the internal space 10b of the structure 10 passes through the through-hole 15a, the liquid filling port 23, and the gap between the end 22a of the liquid filling frame 20 and the sealing material 30, in that order, and is discharged to the outside.

[0024] When the environment around the structure 10 is decompressed, part of the electrolyte solution 50, along with the gas 40, can pass through the through-holes 15a and reach the pouring port 23. As described above, by performing the third step S3, the end 22a of each wall 22 of the pouring frame 20 includes a protrusion 22b that protrudes in a direction perpendicular to the wall 22. Therefore, even if the electrolyte solution 50 reaches the pouring port 23, the electrolyte solution 50 is blocked by the protrusion 22b. As a result, leakage of the electrolyte solution 50 to the outside from the gap between the end 22a of the pouring frame 20 and the sealing material 30 is suppressed.

[0025] If the protrusion 22b were not formed, the battery would need to be tilted so that the sealing material 30 is on top in order to prevent the electrolyte 50 from leaking from the gap between the end 22a of the liquid filling frame 20 and the sealing material 30. In this case, a space is required to tilt the battery. However, in the manufacturing method according to this embodiment, the protrusion 22b is formed on the end 22a, so there is no need to prepare such a space in advance.

[0026] The manufacturing method of the battery 1 next includes a sixth step S6 in which the heater 3 is pressed against the sealing material 30 to weld the sealing material 30 to the end 22a of the liquid filling frame 20. As a result, the sealing material 30 seals the liquid filling port 23. After the sixth step S6 is completed, the pressure inside the reduced pressure chamber 2 is returned to atmospheric pressure.

[0027] As described above, in this embodiment, the third step S3 is performed in which the end 22a of the liquid filling frame 20 opposite the through-hole 15a is heated by the heater 3 to deform the end 22a in a direction perpendicular to the extension direction of the liquid filling frame 20. As a result, in the fifth step S5, the pressure inside the decompression chamber 2 is reduced, and even if a portion of the electrolyte solution 50 reaches the liquid filling port 23 through the through-hole 15a together with the gas 40, the electrolyte solution 50 is blocked by the protruding portion 22b. As a result, leakage of the electrolyte solution 50 to the outside from the gap between the end 22a of the liquid filling frame 20 and the sealing material 30 is suppressed.

[0028] In the above embodiment, the liquid filling ports 23 are provided to correspond to the through holes 15a, respectively, but the present disclosure is not limited to this. For example, the liquid filling frame 20 may have one liquid filling port 23 that communicates with two or more through holes 15a.

[0029] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0030] 1 battery, 2 vacuum chamber, 3 heater, 10 structure, 10a battery cell, 10b internal space, 11 current collector, 12 positive electrode active material layer, 13 negative electrode active material layer, 14 separator, 15 fixing member, 15a through hole, 16 side surface, 20 liquid filling frame, 22 wall, 22a end, 22b protrusion, 23 liquid filling port, 30 sealant, 40 gas, 50 electrolyte.

Claims

[Claim 1] A method for manufacturing a battery, comprising: a step of injecting an electrolyte into the structure through a liquid injection frame having a communication port that communicates with a through-hole formed in the structure in which the battery cell is provided; a step of heating an end portion of the liquid filling frame opposite to the through hole with a heater to deform the end portion in a direction perpendicular to the extending direction of the liquid filling frame; placing a sealant on the edge; reducing the pressure in the environment surrounding the structure; and welding the sealing material to the end portion.

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