Battery

Abstract

To provide a battery capable of reducing a residual quantity of an electrolyte in a liquid injection space of a liquid injection frame.SOLUTION: A battery comprises: a laminate 15 including a plurality of electrodes 16, 20 and 25; a liquid injection frame 45 which is provided on an outer periphery side of the laminate and includes a communication hole 48 communicating with an internal space V of the laminate and a liquid injection space 47 of an internal space communicating with the communication hole and to which a liquid injection device 60 capable of injecting an electrolyte to the liquid injection space is connectable; and a sleeve member 50 which includes an outer peripheral surface 53 in a shape corresponding to an inner surface of the liquid injection frame and an inner peripheral surface 54 on which water repellent processing is performed, and in which a through hole 52 communicating with the communication hole is formed. The inner surface of the liquid injection frame includes a plurality of planes and a connection which connects ends of the plurality of planes crossing each other. A portion corresponding to the connection in the inner peripheral surface of the sleeve member is composed of a curved surface 54-1.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to 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 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] A portion of the electrolyte injected from the injection device into the injection space may remain in the injection space without moving into the internal space of the laminate. The electrolyte exerts a predetermined function in the internal space of the laminate. Therefore, it is preferable that the amount of electrolyte remaining in the injection space is small.

[0005] In consideration of the above, an object of the present invention is to provide a battery capable of reducing the amount of electrolyte remaining in the filling space of the filling frame. [Means for solving the problem]

[0006] A first aspect of the battery includes: a laminate having a plurality of electrodes; a liquid filling frame that is provided on the outer periphery of the laminate and has a communication hole that communicates with the internal space of the laminate; and a liquid filling space that is an internal space that communicates with the communication hole, and to which a liquid filling device can be connected that can inject electrolyte into the liquid filling space; and a sleeve member that has an outer periphery surface that corresponds to the internal shape of the liquid filling frame and an inner periphery surface that has been treated to be water repellent, and in which a through hole that communicates with the communication hole is formed, wherein the internal surface of the liquid filling frame has a plurality of flat surfaces and connecting portions that connect end portions of the plurality of flat surfaces that intersect with each other, and the portion of the internal surface of the sleeve member that corresponds to the connecting portion is formed by a curved surface.

[0007] The battery of the first embodiment includes a laminate having a plurality of electrodes, a liquid filling frame provided on the outer periphery of the laminate and having a communication hole communicating with the internal space of the laminate and a liquid filling space that is an internal space communicating with the communication hole, and a sleeve member having an outer periphery surface shaped to correspond to the internal surface of the liquid filling frame and an internal surface treated with a water repellent coating, and having a through hole formed therein that communicates with the communication hole. Furthermore, a liquid filling device capable of injecting electrolyte into the liquid filling space can be connected to the liquid filling frame. Therefore, electrolyte injected from the liquid filling device into the liquid filling space (internal space of the sleeve member) is injected into the internal space of the laminate via the through hole in the sleeve member and the communication hole in the liquid filling frame.

[0008] The inner circumferential surface of the sleeve member is treated to be water-repellent. Furthermore, the portion of the inner circumferential surface of the sleeve member that corresponds to the connection portion of the liquid filling frame is configured as a curved surface. Therefore, the electrolyte injected into the internal space of the sleeve member is less likely to remain in the internal space of the sleeve member (liquid filling space of the liquid filling frame). Therefore, the battery of the first embodiment can reduce the amount of electrolyte remaining in the liquid filling space of the liquid filling frame.

[0009] Furthermore, since the portion of the inner circumferential surface of the sleeve member that corresponds to the connecting portion of the liquid filling frame is configured as a curved surface, stress is less likely to concentrate at the portion of the inner circumferential surface of the sleeve member that corresponds to the connecting portion of the liquid filling frame when force is applied to the liquid filling frame from the liquid filling device, for example, and the sleeve material is less likely to deform.

[0010] In the battery of the second aspect, in addition to the battery of the first aspect, the sleeve member is made of resin.

[0011] Since the sleeve member of the battery of the second aspect is made of resin, the sleeve member has good moldability and can be manufactured inexpensively.

[0012] In a third aspect of the battery, the cross section of the curved surface is C-shaped.

[0013] In the battery of the third aspect, the cross section of the curved surface of the sleeve member is C-shaped. This improves the ability of the electrolyte to slide down the curved surface of the sleeve member. Therefore, the battery of the third aspect can further reduce the amount of electrolyte remaining in the filling space of the filling frame. [Effects of the Invention]

[0014] As described above, the battery according to the present invention has the excellent effect of reducing the amount of electrolyte remaining in the filling space of the filling frame. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a battery according to an embodiment. [Figure 2] 2 is a schematic cross-sectional view of the battery and the sleeve member separated forward from the battery, taken along the arrow 2-2 in FIG. 1. FIG. [Figure 3] 1 is a flowchart showing the steps of a manufacturing method according to an embodiment. [Figure 4] 3 is a cross-sectional view of the battery in a liquid injection step, corresponding to FIG. 2. FIG. [Figure 5] FIG. 3 is a cross-sectional view corresponding to FIG. 2 of the battery in a sealing step. DETAILED DESCRIPTION OF THE INVENTION

[0016] 1, 2, 4, and 5 show a battery (bipolar battery) 10 according to an embodiment. 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. Note that the arrows UP, FR, and LH shown in each drawing 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.

[0017] 1 and 2, the basic configuration of a battery 10 will be described. 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, a sleeve member 50, and a cover member 58.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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).

[0022] 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).

[0023] The inner peripheral surface of the liquid filling frame 45 has a first plane (plane) 45S1 in which the communication hole 48 is formed, a second plane (plane) 45S2 which is the left side of the inner peripheral surface, a third plane (plane) 45S3 which is the upper part of the inner peripheral surface, a fourth plane (plane) 45S4 which is the lower part of the inner peripheral surface, and a fifth plane (plane) (not shown) which is the right side of the inner peripheral surface. The first plane 45S1 is perpendicular to the front-to-rear direction, the second plane 45S2 and the fifth plane are perpendicular to the left-to-right direction, and the third plane 45S3 and the fourth plane 45S4 are perpendicular to the up-down direction. Therefore, the connecting portions 46-2, 46-3, and 46-4 connecting the outer peripheral edge of the first plane 45S1 to the rear edges of the second plane 45S2, the third plane 45S3, and the fourth plane 45S4 that intersect with the first plane 45S1, and the connecting portion (not shown) connecting the outer peripheral edge of the first plane 45S1 to the rear edge of the fifth plane that intersects with the first plane 45S1, are configured by curved surfaces. That is, the cross-sectional shapes of these connecting portions are C-shaped. Furthermore, the cross-sectional shapes of the connecting portions 46-23 and 46-24 connecting the second plane 45S2 to the third plane 45S3 and the fourth plane 45S4 are also C-shaped. Furthermore, the cross-sectional shapes of the two connecting portions (not shown) connecting the fifth plane to the third plane 45S3 and the fourth plane 45S4 are also C-shaped.

[0024] 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.

[0025] A sleeve member 50 shown in FIG. 2 is attached to the liquid filling frame 45. The sleeve member 50 is made of resin and can be manufactured, for example, by injection molding using a mold. The resin material constituting the sleeve member 50 is an insulating and heat-resistant material (e.g., polyethylene). The sleeve member 50 is a hollow body with an open front. A bottom plate portion 51 of the sleeve member 50 is formed with multiple through holes 52 (only one is shown in FIG. 2). The outer peripheral surface 53 of the sleeve member 50 has a shape corresponding to the inner peripheral surface of the liquid filling frame 45. That is, the outer peripheral surface 53 is formed with multiple outer peripheral curved portions 53-1 corresponding to each connecting portion of the liquid filling frame 45. Each outer peripheral curved portion 53-1 has a C-shaped cross section. Furthermore, multiple inner peripheral curved portions (curved surfaces) 54-1 having a C-shaped cross section are formed at portions of the inner peripheral surface 54 of the sleeve member 50 corresponding to each outer peripheral curved portion 53-1 (each connecting portion of the liquid filling frame 45).

[0026] As shown in Figure 4, the sleeve member 50 is inserted into the filling space 47 of the filling frame 45, and the outer peripheral surface 53 of the sleeve member 50 is fixed to the inner peripheral surface of the filling frame 45. When the filling frame 45 and the sleeve member 50 are fixed, each through hole 52 communicates with the corresponding communication hole 48 in an airtight and liquidtight state. The filling frame 45 and the sleeve member 50 are fixed with, for example, a heat-resistant adhesive. When the sleeve member 50 is fixed to the filling frame 45, the front end surfaces of the filling frame 45 and the sleeve member 50 are flush with each other, as shown in Figures 4 and 5.

[0027] Furthermore, the entire inner circumferential surface 54 of the sleeve member 50 is subjected to a water-repellent treatment (surface treatment). That is, the inner circumferential surface 54 has a higher slipperiness (against the electrolyte) than before the water-repellent treatment was applied. This water-repellent treatment may be applied before the sleeve member 50 is fixed to the liquid filling frame 45, or may be applied after the sleeve member 50 is fixed to the liquid filling frame 45.

[0028] Next, a manufacturing method of the battery 10 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.

[0029] The manufacturing method of this embodiment is carried out using a vacuum sealing device (not shown) having a chamber that is a box-shaped member, a suction device, and a heating device 65.

[0030] When carrying out the manufacturing method using the vacuum sealing device, the liquid injection step is carried out first as shown in FIG.

[0031] The liquid injection step is performed using a liquid injection device 60 shown in Fig. 4. The liquid injection device 60 includes a main body 61 and an annular connector 62 fixed to the rear surface of the main body 61. The main body 61 is capable of storing an electrolyte therein and is also capable of discharging the stored electrolyte into the internal space of the annular connector 62. The annular connector 62 is made of rubber.

[0032] As shown in Figure 4, 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 rear surface of the annular connecting part 62 is brought into contact with the front end surfaces of the liquid injection frame 45 and the sleeve member 50. At this time, in order to improve the airtightness and liquid tightness between the rear surface of the annular connecting part 62 and the front end surfaces of the liquid injection frame 45 and the sleeve member 50, the rear surface of the annular connecting part 62 is brought into contact with the front end surfaces of the liquid injection frame 45 and the sleeve member 50 with a certain amount of force. In this state, when the main body part 61 discharges the electrolyte into the internal space of the sleeve member 50, the discharged electrolyte is injected into the internal space V of each battery cell 12 via the through-holes 52, communication holes 48, and communication holes 42.

[0033] Next, a carrying-in step is carried out. That is, after separating the liquid pouring device 60 from the liquid pouring frame 45, an integrated body including the laminate 15, the seal material 33, the spacer 35, the resin frame 40, the liquid pouring frame 45, and the sleeve member 50 is inserted into the chamber.

[0034] Next, a covering step is carried out. That is, as shown in FIG. 5, a cover member 58 is placed over the front end surface of the liquid pouring frame 45. The cover member 58 is a substantially rectangular film-like member. The cover member 58 is made of an insulating material. Furthermore, adhesive temporary tape (not shown) is used to temporarily attach the cover member 58 to the liquid pouring frame 45 at multiple locations. This temporary tape is made of a highly heat-resistant material.

[0035] Next, a depressurization step is carried out. That is, the suction device connected to the chamber is activated. As a result, some of the gas present inside the integrated body (for example, at least one of the internal space V of the battery cell 12, the communication holes 42, the communication holes 48, and the through-holes 52) is sucked by the suction device through the gap between the portion of the cover member 58 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.

[0036] Next, the sealing step is carried out. That is, as shown in Fig. 5, a heating device 65, which is provided in the chamber and heated to a predetermined temperature, is moved and brought into contact with the cover member 58 for a predetermined time. As a result, heat transferred from the heating device 65 to the liquid filling frame 45 via the cover member 58 deforms a part (for example, the front part) of the liquid filling frame 45 and heat-welds it to the cover member 58. As a result, the front end opening of the liquid filling frame 45 is sealed airtight by the cover member 58.

[0037] Subsequently, the sealing completion step is carried out. That is, when the temperature of the heating device 65 falls below the melting temperature of the liquid filling frame 25 due to the lapse of this predetermined time, the heating device 65 is moved away from the cover member 58.

[0038] 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.

[0039] 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 58.

[0040] As described above, the inner circumferential surface 54 of the sleeve member 50 of the battery 10 of this embodiment is subjected to a water-repellent treatment. Furthermore, inner circumferential curved portions 54-1 with a C-shaped cross section are formed on the inner circumferential surface 54 of the sleeve member 50 at locations corresponding to the outer circumferential curved portions 53-1 (connecting portions of the liquid filling frame 45). The electrolyte injected into the internal space of the sleeve member 50 slides down the inner circumferential surface 54 more easily than when the inner circumferential surface 54 is not subjected to a water-repellent treatment and the cross section of the portion of the inner circumferential surface 54 where the inner circumferential curved portions 54-1 are provided is a right angle (L-shaped). Therefore, the electrolyte injected into the internal space of the sleeve member 50 is less likely to remain in the internal space of the sleeve member 50 (liquid filling space 47 of the liquid filling frame 45). Therefore, after the electrolyte is injected into each internal space V of the battery 10 via the liquid filling frame 45, the amount of electrolyte remaining in the internal space of the sleeve member 50 (liquid filling space 47 of the liquid filling frame 45) can be reduced. Therefore, after the liquid pouring device 60 is separated from the liquid pouring frame 45, there is little risk of the electrolyte adhering to the front end surface of the liquid pouring frame 45. Therefore, the cover member 58 can be reliably welded to the front end surface of the liquid pouring frame 45 using the heating device 65.

[0041] Furthermore, since the liquid filling frame 45 is formed with a plurality of connecting portions 46-1, 46-2, 46-3, 46-23, and 46-24 each having a C-shaped cross section, stress concentration is unlikely to occur at the connecting portions 46-1, 46-2, 46-3, 46-23, and 46-24 when the rear surface of the annular connecting portion 62 comes into contact with the front end surface of the liquid filling frame 45. Similarly, the sleeve member 50 has a plurality of outer circumferential curved portions 53-1 each having a C-shaped cross section formed on its outer circumferential surface 53, and a plurality of inner circumferential curved portions 54-1 each having a C-shaped cross section formed on its inner circumferential surface 54. Therefore, when the rear surface of the annular connecting portion 62 comes into contact with the front end surface of the sleeve member 50, stress concentration is unlikely to occur at the portions of the sleeve member 50 where the outer circumferential curved portions 53-1 and the inner circumferential curved portions 54-1 are formed. Therefore, compared to a case where the connection portions 46-1, 46-2, 46-3, 46-23, 46-24 are not formed in the liquid injection frame 45 and the sleeve member 50 are not formed with the outer circumferential curved portion 53-1 and the inner circumferential curved portion 54-1, when force is applied from the rear surface of the annular connection portion 62 to the front end surfaces of the liquid injection frame 45 and the sleeve member 50, there is less risk of the liquid injection frame 45 and the sleeve member 50 being deformed or damaged.

[0042] Furthermore, the rigidity of the integrated body of the liquid filling frame 45 and the sleeve member 50 is higher than the rigidity of the liquid filling frame 45 alone. Therefore, the risk of the liquid filling frame 45 being deformed or damaged when the liquid filling device 60 (annular connecting portion 62) is pressed against the rear end surface of the integrated body of the liquid filling frame 45 and the sleeve member 50 is smaller than the risk of the liquid filling frame 45 being deformed or damaged when the liquid filling device 60 (annular connecting portion 62) is pressed against the rear end surface of the liquid filling frame 45 when the battery 10 does not include the sleeve member 50.

[0043] Furthermore, since the sleeve member 50 is made of resin, the sleeve member 50 has good moldability and can be manufactured inexpensively.

[0044] The battery 10 according to the embodiment has been described above, but the design can be modified as appropriate within the scope of the present invention.

[0045] For example, the cross-sectional shape of each of the connection portions 46-1, 46-2, 46-3, 46-23, and 46-24 of the infusion frame 45 may be a curved shape other than a C-shape. Similarly, the cross-sectional shape of each of the outer circumferential curved portions 53-1 and each of the inner circumferential curved portions 54-1 of the sleeve member 50 may be a curved shape other than a C-shape.

[0046] The sleeve member 50 may be made of metal.

[0047] The battery cell 12 may include multiple electrodes and separators that do not include bipolar electrodes, i.e., the battery 10 may be a type of battery other than a bipolar battery. [Explanation of symbols]

[0048] 10 Batteries (bipolar batteries) 15 Laminate 16 Negative terminal electrode (electrode) 20 Positive terminal electrode (electrode) 25 Bipolar electrode (electrode) 45 Filling frame 45S1 1st plane (plane) 45S2 2nd plane (plane) 45S3 3rd plane (plane) 45S4 4th plane (plane) 46-1 46-2 46-3 Connection 46-23 46-24 Connection 47 Injection space 48 Communication hole 50 sleeve member 52 Through hole 53 Outer surface 54 Inner surface 54-1 Inner curved part (curved surface) 60 Injection device V interior space

Claims

1. a laminate having a plurality of electrodes; a liquid filling frame provided on the outer periphery of the stack, the liquid filling frame having a communication hole communicating with an internal space of the stack and a liquid filling space which is an internal space communicating with the communication hole, the liquid filling frame being connectable to a liquid filling device which can inject an electrolyte into the liquid filling space; a sleeve member having an outer peripheral surface shaped to correspond to the inner surface of the liquid filling frame and an inner peripheral surface that has been treated to be water repellent, the sleeve member having a through hole formed therein that communicates with the communication hole; Equipped with the inner surface of the liquid filling frame has a plurality of flat surfaces and connecting portions that connect end portions of the plurality of flat surfaces that intersect with each other, A battery in which a portion of the inner circumferential surface of the sleeve member corresponding to the connecting portion is configured as a curved surface.

2. 2. The battery according to claim 1, wherein the sleeve member is made of resin.

3. 3. The battery according to claim 1, wherein the cross section of the curved surface is C-shaped.

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