Method of manufacturing battery and battery

Abstract

To provide a method of manufacturing a battery capable of injecting an electrolyte from a liquid injection device to a liquid injection space of a liquid injection frame while improving air tightness between the liquid injection device and the liquid injection frame without deforming the liquid injection frame, and a battery.SOLUTION: A method of manufacturing a battery includes: a connection step of making a liquid injection device 60 capable of injecting an electrolyte to a liquid injection space close to an opening provided in a resin liquid injection frame 45 which is provided on an outer periphery side of a laminate 15 including a plurality of electrodes 16, 20 and 25, and includes inside a liquid injection space 47 communicating with an internal space V of the laminate, and bringing an annular packing 63 consisting of an elastic material provided in the liquid injection device into contact with an inner peripheral part or an outer peripheral part of the liquid injection frame; and a liquid injection step of injecting the electrolyte from the liquid injection device to the liquid injection space and injecting the electrolyte to the internal space via the liquid injection space.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] One known example of a battery is one in which the outer periphery of a laminate having multiple electrodes is covered with a resin frame, and a resin liquid-filling frame is provided on a portion of the side of the resin frame. The liquid-filling space, which is the internal space of this liquid-filling frame, communicates with the internal space of the laminate. Furthermore, an opening is provided on an end face of the liquid-filling frame. When an electrolyte is poured from the liquid-filling device into the liquid-filling space while the liquid-filling device is in contact with the end face of the liquid-filling frame, the electrolyte is poured into the internal space of the laminate via the liquid-filling space. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-021544 Summary of the Invention [Problem to be solved by the invention]

[0004] When injecting electrolyte from the injection device into the injection space, it is necessary to increase the airtightness between the injection device and the end face of the injection frame. Therefore, when injecting electrolyte from the injection device into the injection space, it is necessary to contact the injection device with a certain amount of force against the end face of the injection frame. This may cause deformation of the injection frame.

[0005] In consideration of the above, the present invention aims to provide a method for manufacturing a battery and a battery that can inject electrolyte from a liquid injection device into the liquid injection space of the liquid injection frame while increasing the airtightness between the liquid injection device and the liquid injection frame without deforming the liquid injection frame. [Means for solving the problem]

[0006] A manufacturing method of a battery of the first aspect includes a connecting step of bringing a liquid injection device capable of injecting electrolyte into an opening provided in a resin liquid injection frame, the liquid injection frame being provided on the outer periphery of a laminate having a plurality of electrodes and having an injection space therein that communicates with the internal space of the laminate, close to the opening, and bringing an annular gasket made of an elastic material provided in the liquid injection device into contact with the inner or outer periphery of the liquid injection frame, and a liquid injection step of injecting the electrolyte from the liquid injection device into the liquid injection space and injecting the electrolyte into the internal space via the liquid injection space.

[0007] The battery manufacturing method of the first aspect includes a connecting step of bringing a liquid injection device capable of injecting electrolyte into the liquid injection space of the resin liquid injection frame close to the opening of the liquid injection frame and contacting an annular packing made of an elastic material provided on the liquid injection device with the inner or outer periphery of the liquid injection frame. Therefore, the packing can improve the airtightness between the liquid injection device and the liquid injection frame. Furthermore, because the packing ensures airtightness, there is no need to apply a large force to bring the liquid injection device into contact with the end face of the liquid injection frame. Therefore, the battery manufacturing method of the first aspect allows electrolyte to be injected from the liquid injection device into the liquid injection space of the liquid injection frame while improving the airtightness between the liquid injection device and the liquid injection frame without deforming the liquid injection frame.

[0008] In a second aspect of the battery manufacturing method, in the first aspect, the connecting step is a step of contacting the packing with the outer circumferential portion of the liquid filling frame while positioning the inner circumferential portion of the packing in an annular groove formed on the outer circumferential surface of the liquid filling frame.

[0009] In the battery manufacturing method of the second aspect, the packing is brought into contact with the outer periphery of the liquid filling frame while the inner periphery of the packing is positioned in the annular groove formed in the outer periphery of the liquid filling frame, thereby enabling the battery manufacturing method of the second aspect to further improve the airtightness between the liquid filling device and the liquid filling frame.

[0010] A third aspect of the battery manufacturing method is the same as the first aspect, in which the connecting step is a step of bringing the packing into contact with the inner peripheral portion of the liquid filling frame while positioning the outer peripheral portion of the packing in an annular groove formed in the inner peripheral surface of the liquid filling frame.

[0011] In the battery manufacturing method of the third aspect, the packing is brought into contact with the inner peripheral portion of the liquid filling frame while the outer peripheral portion of the packing is positioned in an annular groove formed in the inner peripheral surface of the liquid filling frame, thereby enabling the battery manufacturing method of the third aspect to further improve the airtightness between the liquid filling device and the liquid filling frame.

[0012] The battery of the fourth aspect includes a laminate having a plurality of electrodes, and a liquid filling frame having an internal liquid filling space provided on the outer periphery of the laminate and communicating with the internal space of the laminate, the internal liquid filling frame having an annular groove formed on its inner or outer periphery in which a part of an annular packing made of an elastic material can be positioned. The annular groove is provided in a liquid filling device capable of injecting electrolyte into the liquid filling space. [Effects of the Invention]

[0013] As described above, the battery manufacturing method and battery according to the present invention have the excellent effect of being able to inject electrolyte from the injection device into the injection space of the injection frame while increasing the airtightness between the injection device and the injection frame without deforming the injection frame. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view of a battery manufactured by applying a battery manufacturing method according to an embodiment. [Figure 2] 2 is a schematic cross-sectional view taken along the arrow line 2-2 in FIG. 1 when a liquid filling device is connected to a liquid filling frame of a battery. [Figure 3] 1 is a flowchart showing the steps of a manufacturing method according to an embodiment. [Figure 4] FIG. 3 is a cross-sectional view of a first modified example, corresponding to FIG. 2. [Figure 5] FIG. 10 is a cross-sectional view of a second modified example, corresponding to FIG. 2. [Figure 6] FIG. 10 is a cross-sectional view of a third modified example, corresponding to FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0015] 1 and 2 show a battery (bipolar battery) 10 manufactured using a battery manufacturing method according to an embodiment (hereinafter referred to as the manufacturing method). The battery 10 can be installed in a variety of devices. For example, the battery 10 can be installed in an electric vehicle (BEV: Battery Electric Vehicle) and supply power to an electric motor that serves as a drive source. The arrows UP, FR, and LH in the drawings indicate the upper side in the up-down direction, the front side in the fore-and-aft direction, and the left side in the left-right direction, respectively.

[0016] Before describing the manufacturing method, the basic configuration of the battery 10 will be described with reference to Figures 1 and 2. The battery 10 of this embodiment includes a laminate 15, a sealant 33, a spacer 35, a resin frame 40, a liquid injection frame 45, and a cover member 50.

[0017] The stack 15 includes a plurality of battery cells 12. Because the configuration of the stack 15 is well known, the following description of the stack 15 will be simplified. The stack 15 includes one negative terminal electrode (electrode) 16, one positive terminal electrode (electrode) 20, a plurality of bipolar electrodes (electrodes) 25 positioned between the negative terminal electrode 16 and the positive terminal electrode 20, and a plurality of separators 30 positioned between adjacent positive terminal electrodes 20, negative terminal electrodes 16, and bipolar electrodes 25.

[0018] The negative electrode terminal electrode 16 includes a current collector 17 and a negative electrode active material layer 18 provided on one side of the current collector 17. The positive electrode terminal electrode 20 includes a current collector 17 and a positive electrode active material layer 21 provided on one side of the current collector 17. Each bipolar electrode 25 includes a current collector 17 and a negative electrode active material layer 18 and a positive electrode active material layer 21 provided on both sides of the current collector 17, respectively. The laminate 15 is formed by stacking the negative electrode terminal electrode 16, the positive electrode terminal electrode 20, multiple bipolar electrodes 25, and multiple separators 30 in a stacking direction LD. In FIGS. 1 and 2, the stacking direction LD is parallel to the vertical direction. In this embodiment, the negative electrode terminal electrode 16, the positive electrode terminal electrode 20, the bipolar electrodes 25, and the separators 30 have rectangular planar shapes. Therefore, the planar shape of the laminate 15 is rectangular. Each separator 30 and the negative electrode active material layer 16 and positive electrode active material layer 21 positioned above and below the separator 30 are components of the battery cell 12.

[0019] As shown in FIG. 2, a resin sealant 33 is provided on the outer periphery of each current collector 17. The sealant 33 is a frame-shaped body having a rectangular planar shape, and a groove is provided on the entire inner periphery of the sealant 33. The sealant 33 is welded to the current collector 17 with the outer periphery of the current collector 17 inserted into the groove. Furthermore, a resin spacer 35 is provided on the outer periphery of each separator 30. The spacer 35 is a frame-shaped body having a rectangular planar shape. The outer periphery of the separator 30 and the spacer 35 are welded (spot welded) to the adjacent sealant 33.

[0020] When the stack 15 is constructed as shown in FIG. 2, the outer periphery of the stack 15 is surrounded by a plurality of sealants 33 and spacers 35. When the stack 15, the plurality of sealants 33, and the plurality of spacers 35 are placed in a mold (not shown), and the sealants 33 and spacers 35 are heated, portions of the sealants 33 and spacers 35 melt to form a resin frame 40, which is a frame-shaped body that is rectangular in plan view. In other words, the sealants 33 and spacers 35 before heating are larger than the shape shown in FIG. 2. At this time, a plurality of communication holes 42 are formed in the front portions of the sealants 33, spacers 35, and resin frame 40, which communicate airtightly and liquidtightly with the front ends of the internal spaces V of each battery cell 12 (only one communication hole 42 formed in the resin frame 40 is shown in FIG. 2; communication holes in the sealants 33 and spacers 35 are not shown).

[0021] Furthermore, a resin liquid filling frame 45 is integrally formed on the front end surface of the resin frame 40 by injection molding using a molding die (not shown). As shown in FIGS. 1 and 2, the liquid filling frame 45 has a rectangular parallelepiped shape. A liquid filling space 47 is formed inside the liquid filling frame 45, and the front end of the liquid filling frame 45 is open. A plurality of communication holes 48 are formed in the bottom plate portion (rear plate portion) of the liquid filling frame 45, which communicate with each of the communication holes 42 in an airtight and liquidtight state (only one communication hole 48 is shown in FIG. 2).

[0022] The sealing material 33, the spacer 35, the resin frame 40, and the liquid filling frame 45 are made of an insulating resin material, such as polypropylene, polyethylene, polystyrene, ABS resin, acid-modified polypropylene, acid-modified polyethylene, or acrylonitrile-styrene resin.

[0023] Next, the manufacturing method of this embodiment will be described with reference to Fig. 3. As shown in Fig. 3, the manufacturing method of this embodiment includes a liquid injection step, a carrying step, a covering step, a depressurization step, a sealing step, a sealing completion step, and a depressurization completion step. By repeatedly performing each of these steps, a plurality of batteries 10 are manufactured.

[0024] The manufacturing method of this embodiment is carried out using a vacuum sealing device (not shown) that has a chamber, which is a box-shaped member, a suction device, and a heating device.

[0025] When carrying out the manufacturing method using the vacuum sealing device, the liquid injection step is carried out first as shown in FIG.

[0026] The liquid injection process is performed using a liquid injection device 60 shown in FIG. 2. The liquid injection device 60 includes a main body 61 and a cylindrical connecting part 62 fixed to the rear surface of the main body 61. The main body 61 is capable of storing an electrolyte therein and discharging the stored electrolyte into the internal space of the cylindrical connecting part 62. The cylindrical connecting part 62 is a hollow body having a rectangular parallelepiped outer shape, and its entire rear surface is open. Furthermore, the vertical dimension of the inner surface of the cylindrical connecting part 62 is larger than the vertical dimension of the outer surface of the liquid injection frame 45, and the lateral dimension of the inner surface of the cylindrical connecting part 62 is larger than the lateral dimension of the outer surface of the liquid injection frame 45. Furthermore, the outer peripheral portion of a ring-shaped packing 63 made of an elastic material (e.g., rubber) is fixed to the inner peripheral surface of the cylindrical connecting part 62. When the packing 63 is in a free state, the vertical dimension of the inner peripheral portion of the packing 63 is smaller than the vertical dimension of the outer peripheral surface of the liquid injection frame 45. When the packing 63 is in a free state, the left-right dimension of the inner periphery of the packing 63 is smaller than the left-right dimension of the outer periphery of the liquid filling frame 45 .

[0027] 2, the liquid injection device 60 is brought close from the front to the liquid injection frame 45 of the battery 10, which is located outside the chamber of the vacuum sealing device, and the tubular connecting portion 62 is positioned on the outer periphery of the liquid injection frame 45. This causes the packing 63 to elastically deform and come into airtight and liquidtight contact with the outer periphery of the liquid injection frame 45. In this state, when the main body 61 discharges the electrolyte into the internal space of the tubular connecting portion 62, the discharged electrolyte is injected into the internal space V of each battery cell 12 via the communication holes 48 and 42.

[0028] Next, a carrying-in step is carried out. That is, after separating the liquid pouring device 60 from the liquid pouring frame 45, the integrated body including the laminate 15, the seal material 33, the spacer 35, the resin frame 40, and the liquid pouring frame 45 is inserted into the chamber.

[0029] Next, a covering step is carried out. That is, a cover member 50 (see FIG. 1) is placed over the front end surface 45C of the liquid pouring frame 45. The cover member 50 is a substantially rectangular film-like member. The cover member 50 is made of an insulating material. Furthermore, adhesive temporary tape (not shown) is used to temporarily attach the cover member 50 to the liquid pouring frame 45 at multiple locations. This temporary tape is made of a highly heat-resistant material.

[0030] Next, a depressurization step is carried out. That is, a suction device connected to the chamber is activated. As a result, some of the gas present inside the integrated body (for example, the internal space V of the battery cell 12, the communication hole 42, or at least one of the communication holes 48) is sucked by the suction device through the gap between the portion of the cover member 50 where the temporary fixing tape is not provided and the liquid filling frame 45, and through the internal space of the chamber. That is, a depressurization process is carried out inside the integrated body.

[0031] Next, a sealing step is carried out. That is, the heating device, which is provided in the chamber and heated to a predetermined temperature, is moved and brought into contact with cover member 50 for a predetermined period of time. As a result, heat transferred from the heating device to liquid filling frame 45 via cover member 50 deforms a portion (e.g., the front portion) of liquid filling frame 45 and causes it to be thermally welded to cover member 50. As a result, the front end opening of liquid filling frame 45 is sealed airtight by cover member 50.

[0032] Next, the sealing completion step is carried out. That is, when the temperature of the heating device (the temperature of the pouring frame 25) falls below the melting temperature of the pouring frame 25 after the predetermined time has elapsed, the heating device is moved away from the cover member 50.

[0033] Next, the decompression termination step is carried out. That is, the suction device is stopped. This causes the internal space of the chamber to communicate with the external space of the chamber via the suction device. That is, the air pressure in the internal space of the chamber becomes equal to the air pressure in the external space of the chamber. This completes the process using the decompression sealing device. In other words, the battery 10 is completed.

[0034] After this, the worker can remove the battery 10 from inside the chamber to the outside of the chamber. Note that, since the temporary fixing tape is made of a highly heat-resistant material, the temporary fixing tape can be removed from the liquid filling frame 45 and the cover member 50.

[0035] As described above, the manufacturing method of this embodiment includes a connecting step in which the liquid injection device 60 is brought close to the opening of the liquid injection space 47 of the resin liquid injection frame and the annular packing 63 made of an elastic material provided at the cylindrical connecting portion 62 of the liquid injection device 60 is brought into contact with the outer periphery of the liquid injection frame 45 while elastically deforming. Therefore, the packing 63 enhances the airtightness between the liquid injection device 60 and the liquid injection frame 45. Furthermore, because the packing 63 ensures airtightness, it is not necessary to apply a large force to bring the liquid injection device 60 into contact with the end surface 45C of the liquid injection frame 45. Therefore, according to the manufacturing method of this embodiment, electrolyte can be injected from the liquid injection device 60 into the liquid injection space 47 of the liquid injection frame 45 without deforming the liquid injection frame 45 of the battery 10, while enhancing the airtightness between the liquid injection device 60 and the liquid injection frame 45. Therefore, there is almost no risk of the liquid injection frame 45 being deformed or damaged when the liquid injection device 60 is connected to the liquid injection frame 45.

[0036] The manufacturing method of the battery 10 and the battery 10 according to the embodiment have been described above, but these can be modified in design as appropriate within the scope of the present invention.

[0037] For example, the present invention may be embodied in the form of a first modified example shown in FIG. 4. The battery 10A of the first modified example has the same configuration as the battery 10, except that an annular groove 45A is formed on the outer periphery of the liquid filling frame 45. During the liquid filling process, when the cylindrical connecting portion 62 of the liquid filling device 60 is positioned on the outer periphery of the liquid filling frame 45, the packing 63 is elastically deformed and positioned on the outer periphery of the annular groove 45A. The inner periphery of the packing 63 then fits into the annular groove 45A, and the inner periphery of the packing 63 comes into airtight and liquidtight contact with the inner surface of the annular groove 45A. Therefore, according to the first modified example, the airtightness between the liquid filling device 60 and the liquid filling frame 45 can be improved compared to the above embodiment.

[0038] For example, the present invention may be embodied in the form of a second modified example shown in FIG. 5 . The liquid injection device 60A of the second modified example differs from the liquid injection device 60 of the above embodiment in the structures of the tubular connecting portion 65 and the packing 66. The tubular connecting portion 65 of the liquid injection device 60A is a hollow body having a rectangular parallelepiped outer shape, and the entire rear surface is open. The vertical dimension of the outer peripheral surface of the tubular connecting portion 65 is smaller than the vertical dimension of the inner peripheral surface of the liquid injection frame 45, and the left-to-right dimension of the outer peripheral surface of the tubular connecting portion 65 is smaller than the left-to-right dimension of the inner peripheral surface of the liquid injection frame 45. Furthermore, the inner peripheral portion of a ring-shaped packing 66 made of an elastic material is fixed to the outer peripheral surface of the tubular connecting portion 65. When the packing 66 is in a free state, the vertical dimension of the outer peripheral portion of the packing 66 is larger than the vertical dimension of the inner peripheral surface of the liquid injection frame 45. When the packing 66 is in a free state, the left-to-right dimension of the outer peripheral portion of the packing 66 is larger than the left-to-right dimension of the inner peripheral surface of the liquid injection frame 45.

[0039] In the injection process of the second modified example, the injection device 60A is brought close from the front to the injection frame 45 of the battery 10, which is located outside the chamber of the vacuum sealing device, as shown in Figure 5, and the tubular connecting portion 65 is positioned on the inner circumferential side of the injection frame 45. This causes the packing 66 to elastically deform and come into airtight and liquid-tight contact with the inner circumferential surface of the injection frame 45. In this state, when the main body 61 discharges the electrolyte into the internal space of the tubular connecting portion 65, the discharged electrolyte is injected into the internal space V of each battery cell 12 via the communication holes 48 and 42. Therefore, the second modified example can achieve the same effects as the above embodiment.

[0040] For example, the present invention may be embodied in a third modified example shown in FIG. 6 . The battery 10B of the third modified example has the same configuration as the battery 10, except that an annular groove 45B is formed on the inner periphery of the liquid filling frame 45. During the liquid filling process, when the cylindrical connecting portion 65 of the liquid filling device 60A is positioned on the inner periphery of the liquid filling frame 45, the packing 66 is elastically deformed and positioned on the inner periphery of the annular groove 45B. The outer periphery of the packing 66 then fits into the annular groove 45B, and the outer periphery of the packing 66 comes into airtight and liquidtight contact with the inner surface of the annular groove 45B. Therefore, according to the third modified example, the airtightness between the liquid filling device 60A and the liquid filling frame 45 can be improved compared to the second modified example.

[0041] The battery cell 12 may include multiple electrodes and separators that do not include bipolar electrodes, i.e., the batteries 10, 10A, and 10B may be of a type other than a bipolar battery. [Explanation of symbols]

[0042] 10 10A 10B battery (bipolar battery) 15 Laminate 16 Negative terminal electrode (electrode) 20 Positive terminal electrode (electrode) 25 Bipolar electrode (electrode) 42 Communication hole 45 Filling frame 45A 45B Annular groove 45C end face 47 Injection space 60 60A Injection device 63 Gasket 66 Gasket V interior space

Claims

1. a connecting step of bringing a liquid injection device capable of injecting an electrolyte into an opening provided in a resin liquid injection frame, the opening being provided on the outer periphery of a laminate having a plurality of electrodes and having a liquid injection space therein that communicates with an internal space of the laminate, close to the opening, and bringing an annular packing made of an elastic material provided in the liquid injection device into contact with an inner periphery or an outer periphery of the liquid injection frame; a liquid injection step of injecting the electrolyte solution from the liquid injection device into the liquid injection space and injecting the electrolyte solution into the internal space through the liquid injection space; A method for manufacturing a battery having the above structure.

2. 2. The battery manufacturing method according to claim 1, wherein the connecting step is a step of bringing the packing into contact with the outer circumferential portion of the liquid filling frame while positioning the inner circumferential portion of the packing in an annular groove formed in the outer circumferential surface of the liquid filling frame.

3. 2. The battery manufacturing method according to claim 1, wherein the connecting step is a step of bringing the packing into contact with the inner peripheral portion of the liquid filling frame while positioning the outer peripheral portion of the packing in an annular groove formed in the inner peripheral surface of the liquid filling frame.

4. a laminate having a plurality of electrodes; a liquid filling frame that is provided on the outer circumferential side of the stack and has an internal liquid filling space that communicates with an internal space of the stack, and that has an annular groove formed on its inner or outer circumferential surface in which a part of an annular packing made of an elastic material and provided in a liquid filling device that can inject an electrolyte into the liquid filling space can be positioned; A battery comprising:

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