Battery and method for manufacturing the same

Abstract

To obtain a battery and a method for manufacturing the same that facilitate the work of pouring electrolyte into the interior of an outer body.SOLUTION: A method for manufacturing a battery 20 comprises: a joint step of joining overlapping peripheral edges 28 of an outer body 22 with an electrode body housed inside, and welding one end 32 of a hollow member 30 between the peripheral edges 28; and a supply step of supplying electrolyte from a supply channel of the hollow member 30 to the interior of the outer body 22.SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] 2. Description of the Related Art A method for manufacturing a battery in which an electrolyte is injected through a liquid injection hole formed in an unsealed portion of a laminate exterior body and then the liquid injection hole is sealed by welding has been conventionally known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-285882 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the injection port for injecting the electrolyte is formed in an unsealed portion of the laminate exterior body, a step of removing any material adhering to the injection port becomes necessary.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a battery that allows easy injection of an electrolyte into the exterior body, and a method for manufacturing the same. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a battery of a first aspect of the present invention comprises an outer casing that houses an electrode body and has overlapping peripheral portions joined together, and a hollow resin member that has a supply path for supplying an electrolyte to the inside of the outer casing, and is sandwiched between the overlapping peripheral portions of the outer casing and welded to the peripheral portions.

[0007] According to the first aspect of the invention, a hollow resin member having a supply path for supplying an electrolyte solution to the inside of the exterior body is sandwiched between overlapping peripheral parts of the exterior body housing the electrode assembly therein and welded to the peripheral parts, which makes it easier to inject an electrolyte solution into the interior of the exterior body compared to when the injection port is formed in an unsealed part of the exterior body.

[0008] A battery according to a second aspect of the present invention is the battery according to the first aspect, wherein the melting point of the resin material constituting the hollow member is higher than the melting point of the peripheral portion.

[0009] According to the second aspect of the invention, the melting point of the resin material constituting the hollow member is higher than the melting point of the peripheral portion of the exterior body, so there is no risk of the hollow member melting when the peripheral portion of the exterior body is joined.

[0010] In addition, a third aspect of the battery manufacturing method according to the present invention includes a joining process for joining overlapping peripheral portions of an outer casing that houses an electrode body therein and sandwiching and welding one end of a hollow member between the peripheral portions, and a supply process for supplying an electrolyte from a supply path of the hollow member to the inside of the outer casing.

[0011] According to the third aspect of the invention, the electrolyte is supplied to the inside of the exterior body from a supply path of a hollow member, one end of which is sandwiched and welded between the periphery of the exterior body that houses the electrode body inside. This makes it easier to inject the electrolyte into the interior of the exterior body compared to when the injection port is formed in the unsealed part of the exterior body.

[0012] Furthermore, a fourth aspect of the battery manufacturing method according to the present invention is the battery manufacturing method of the third aspect, wherein in the joining process, the hollow member is welded between the peripheral portions with a rod-shaped member inserted into the supply path including the one end, and after welding, the rod-shaped member is removed.

[0013] According to the fourth aspect of the invention, when one end of the hollow member is welded between the peripheral parts, the weld is performed with a rod-shaped member inserted into the supply passage including the one end. After welding, the rod-shaped member is removed. Therefore, the supply passage for the hollow member is properly secured, and the inside and outside of the exterior body are properly connected.

[0014] A fifth aspect of the battery manufacturing method according to the present invention is the battery manufacturing method according to the fourth aspect, further comprising a decompression step of reducing the pressure inside the exterior body after removing the rod-shaped member.

[0015] According to the fifth aspect of the invention, the pressure inside the exterior body is reduced after the rod-shaped member is removed, so that the electrolyte is smoothly supplied into the interior of the exterior body in the subsequent supplying step.

[0016] In addition, a sixth aspect of the battery manufacturing method according to the present invention is a battery manufacturing method according to any one of the third to fifth aspects, and includes a cutting process of cutting the hollow member protruding from the peripheral portion after supplying the electrolyte into the inside of the outer casing, and a sealing process of crushing and welding the one end of the hollow member remaining sandwiched between the peripheral portions to seal the outer casing.

[0017] According to the sixth aspect of the invention, after supplying the electrolyte to the inside of the exterior body, the hollow member protruding from the periphery is cut off, and then one end of the hollow member remaining sandwiched between the periphery is crushed and welded to seal the exterior body. Therefore, the manufactured battery maintains the same space-saving feature as before. Effect of the Invention

[0018] As described above, according to the present invention, the operation of injecting the electrolyte into the exterior body can be easily performed. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic plan view showing an electric vehicle equipped with a battery according to an embodiment of the present invention. [Diagram 2]1 is a schematic perspective view showing a configuration of a battery module according to an embodiment of the present invention. [Diagram 3] 1 is a schematic plan view showing the configuration of a battery module according to an embodiment of the present invention with a top cover removed. [Figure 4] 2 is a schematic front view showing the configuration of a battery cell accommodated in the battery module according to the embodiment, as viewed in the thickness direction. FIG. [Diagram 5] 3A to 3C are schematic cross-sectional views showing a manufacturing process of a battery according to the present embodiment. [Figure 6] 3A to 3C are schematic cross-sectional views showing a manufacturing process of a battery according to the present embodiment. [Figure 7] 3A to 3C are schematic cross-sectional views showing a manufacturing process of a battery according to the present embodiment. [Figure 8] 3A to 3C are schematic cross-sectional views showing a manufacturing process of a battery according to the present embodiment. [Figure 9] 3A to 3C are schematic cross-sectional views showing a manufacturing process of a battery according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. For the sake of convenience, the arrow UP shown in each drawing indicates the vehicle upward direction, the arrow FR indicates the vehicle forward direction, and the arrow LH indicates the vehicle leftward direction. Therefore, in the following description, when the directions of up / down, front / rear, and left / right are described without special mention, they refer to up / down in the vehicle up / down direction, front / rear in the vehicle front / rear direction, and left / right in the vehicle left / right direction (vehicle width direction). In addition, the left / right direction is synonymous with the vehicle width direction.

[0021] In addition, the sizes of the members in each drawing are conceptual, and the relative relationship between the sizes of the members is not limited to this. In addition, in this embodiment, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0022] In the present embodiment, a numerical range indicated using "to" means a range including the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in the present embodiment, the upper limit or lower limit described in a certain numerical range may be replaced with the upper limit or lower limit of another numerical range described in stages.

[0023] 1, a vehicle 100 according to this embodiment is, as an example, an electric vehicle (BEV: Battery Electric Vehicle) that has a battery pack 10 mounted under the floor. In other words, the vehicle 100 is equipped with a battery 20 according to this embodiment. In the following description, the "battery 20" may be referred to as a "battery cell 20."

[0024] In the vehicle 100, a DC / DC converter 102, an electric compressor 104, and a PTC (Positive Temperature Coefficient) heater 106 are disposed in front of the battery pack 10. In addition, a motor 108, a gear box 110, an inverter 112, and a charger 114 are disposed behind the battery pack 10.

[0025] Therefore, the DC current output from the battery pack 10 is supplied to the electric compressor 104, the PTC heater 106, the inverter 112, etc. after the voltage is adjusted by the DC / DC converter 102. In addition, power is supplied to the motor 108 via the inverter 112, causing the rear wheels to rotate and the vehicle 100 to run.

[0026] A charging port 116 is provided on the right side at the rear of the vehicle 100. Therefore, when a charging plug of an external charging facility (not shown) is connected to the charging port 116, power is stored in the battery pack 10 via the charger 114.

[0027] The vehicle 100 shown in the figure is a rear-wheel drive vehicle with the motor 108 mounted at the rear, but is not limited to this and may be a front-wheel drive vehicle with the motor 108 mounted at the front. Also, the vehicle may be equipped with a pair of motors 108 mounted at the front and rear, or may be equipped with an in-wheel motor on each wheel. In other words, the arrangement and structure of each component constituting the vehicle 100 are not limited to the configuration described above.

[0028] The battery pack 10 includes a plurality of battery modules 11. In the present embodiment, as an example, ten battery modules 11 are provided. Specifically, five battery modules 11 are arranged on the right side of the vehicle 100 with their thickness directions extending in the front-rear direction, and five battery modules 11 are arranged on the left side of the vehicle 100 with their thickness directions extending in the front-rear direction. The battery modules 11 are electrically connected to each other.

[0029] 2, the battery module 11 is formed in a substantially rectangular parallelepiped shape with the vehicle width direction as the longitudinal direction. The outer shell of the battery module 11 is formed of an aluminum alloy. For example, the outer shell of the battery module 11 is formed by joining aluminum die-casting to both ends of an aluminum alloy extrusion material by laser welding or the like.

[0030] A pair of voltage terminals 12 and a connector 14 are provided at each of both ends of the battery module 11 in the vehicle width direction. A flexible printed circuit board 21, which will be described later, is connected to the connector 14. In addition, bus bars (not shown) are welded to both ends of the battery module 11 in the vehicle width direction.

[0031] The length MW of the battery module 11 in the vehicle width direction is, for example, 350 mm to 600 mm, the length ML in the front-rear direction is, for example, 150 mm to 250 mm, and the height MH in the up-down direction is, for example, 80 mm to 110 mm.

[0032] 3, a plurality of battery cells (batteries) 20 are arranged with their thickness direction oriented in the front-rear direction and housed inside the battery module 11. In this embodiment, as an example, 24 battery cells 20 are arranged with their thickness direction oriented in the front-rear direction and bonded to one another.

[0033] A flexible printed circuit (FPC) 21 is disposed above the battery cells 20 and at the center in the front-rear direction. The flexible printed circuit 21 is formed in a strip shape with its longitudinal direction aligned with the vehicle width direction, and a thermistor 23 is provided at each end of the flexible printed circuit 21. The thermistor 23 is not bonded to the battery cells 20, and is configured to be pressed toward the battery cells 20 by the upper lid of the battery module 11.

[0034] One or more cushioning materials (not shown) are housed inside the battery module 11. The cushioning materials are, for example, elastically deformable thin plate-like members, and are arranged between adjacent battery cells 20 with the arrangement direction of the battery cells 20 being the thickness direction. In the present embodiment, as an example, cushioning materials are arranged at both ends of the battery module 11 in the longitudinal direction and in the central portion in the longitudinal direction.

[0035] 4, the battery cell 20 is formed in a substantially rectangular plate shape and houses an electrode body (not shown) inside. The electrode body is configured by laminating electrodes (negative and positive electrodes) and a separator disposed between the electrodes, and is sealed with a laminate film 22 as an exterior body.

[0036] The electrode may be, for example, a current collector having a layer containing an electrode active material formed on one or both sides thereof. The separator may be, for example, a microporous membrane made of a resin such as polyethylene. The laminate film 22 is a laminate having a metal layer containing a metal such as aluminum and a heat seal layer.

[0037] In this embodiment, as an example, the housing portion for the electrode body is formed by folding and pasting an embossed sheet-like laminate film 22. Note that both a single cup embossed structure in which embossing is performed at one place and a double cup embossed structure in which embossing is performed at two places can be adopted for the laminate film 22. In Fig. 4, a single cup embossed structure with a drawing depth of about 8 mm to 10 mm is shown.

[0038] 4, the upper ends of both longitudinal ends of the battery cell 20 are folded, and the upper end of the battery cell 20 is also folded so as to be continuous with the folded portions. A fixing tape 24 is wrapped around the upper end of the battery cell 20 along the longitudinal direction.

[0039] Furthermore, terminals (tabs) 26 are provided at both longitudinal ends of the battery cell 20. In this embodiment, as an example, each terminal 26 is provided at a position offset downward from the center in the up-down direction of the battery cell 20. Each terminal 26 is joined to a bus bar (not shown) by laser welding or the like.

[0040] The length CW1 of the battery cell 20 in the vehicle width direction is, for example, 530 mm to 600 mm, 600 mm to 700 mm, 700 mm to 800 mm, 800 to 900 mm, 1000 mm or more, and the length CW2 of the area in which the electrode body is housed is, for example, 500 mm to 520 mm, 600 mm to 700 mm, 700 mm to 800 mm, 800 to 900 mm, 1000 mm or more.

[0041] The height CH of the battery cells 20 is, for example, 80 mm to 110 mm, or 110 mm to 140 mm. The thickness of the battery cells 20 is 5.0 mm to 7.0 mm, 7.0 mm to 9.0 mm, or 9.0 mm to 11.0 mm, and the height TH of the terminals 26 is 40 mm to 50 mm, 50 mm to 60 mm, or 60 mm to 70 mm.

[0042] Next, a description will be given of a manufacturing method for the battery (battery cell) 20 configured as described above. Note that the battery 20 shown in Figs. 5 to 9 is a schematic cross-sectional view of the battery cell 20 shown in Fig. 4.

[0043] The battery 20 manufactured by the manufacturing method according to this embodiment is a so-called laminate battery that uses a laminate film 22 as an exterior body. First, this laminate film 22 houses an electrode body (not shown) inside, and then is folded in two, and the heat seal layers of the overlapping peripheral portions 28 are joined (welded).

[0044] At this time, as shown in Fig. 5, one end 32 of a hollow member 30 formed into a cylindrical shape from a low-melting resin material is sandwiched and welded between the heat-sealed layers of the overlapping peripheral portion 28 of the laminate film 22 (joining process). At this time, the hollow member 30 is welded between the heat-sealed layers at the peripheral portion 28 of the laminate film 22 with a metal rod-shaped member 40 that exceeds the entire length of the supply path 30A including the one end 32 inserted therein. Then, after welding, the rod-shaped member 40 is removed as shown in Fig. 6.

[0045] Once the inside and outside of the laminate film 22 are thus connected by the hollow member 30, for example, a bifurcated hollow extension member 34 is connected to the hollow member 30 as shown in Fig. 7. Then, first, the air inside the laminate film 22 is removed from one opening 36 side to reduce the pressure inside the laminate film 22 (reducing pressure step). Next, electrolyte (not shown) is injected from the other opening 38 side (differential pressure injection). That is, electrolyte is supplied from the supply path 30A (see Fig. 5) of the hollow member 30 to the inside of the laminate film 22 (supply step).

[0046] After the electrolyte has been supplied to the inside of the laminate film 22, the hollow extension member 34 is removed from the hollow member 30. Then, as shown in Fig. 8, a part of the hollow member 30 protruding from the peripheral portion 28 of the laminate film 22 (the remaining portion excluding one end portion 32) is cut from its base (so as to be flush with the end face 28A, which is the cut surface of the peripheral portion 28) (cutting step).

[0047] 9, one end 32 of the hollow member 30 remaining sandwiched between the heat seal layers at the peripheral portion 28 of the laminate film 22 is crushed and welded (to close the supply path 30A), and the laminate film 22 is sealed (sealing step). In this manner, the battery 20 is manufactured.

[0048] The low-melting-point resin material used in the hollow member 30 is a resin material having a melting point higher than that of the heat-sealed layer (e.g., a low-density polyethylene layer) at the peripheral portion 28 of the laminate film 22, and examples thereof include polypropylene. The outer diameter of the rod-shaped member 40 is approximately the same as the inner diameter of the hollow member 30. Therefore, in the joining step, the outer peripheral surface at one end 32 of the hollow member 30 is welded in a state of being in close contact with the heat-sealed layer at the peripheral portion 28 of the laminate film 22. The above manufacturing method can also be applied to cases where the electrolyte is injected in multiple batches or where additional electrolyte is injected.

[0049] Next, the operation of the battery 20 according to this embodiment and the manufacturing method thereof configured as above will be described.

[0050] As described above, one end 32 of the hollow member 30 is sandwiched and welded between the heat seal layers at the peripheral portion 28 of the laminate film 22 that houses the electrode body. Therefore, the electrolyte can be supplied from the supply path 30A of the hollow member 30 to the inside of the laminate film 22. Therefore, compared to the case where the electrolyte injection port is formed in the unsealed portion of the laminate film 22, a step of removing the deposits adhering to the electrolyte injection port is not required, and the operation of injecting the electrolyte into the laminate film 22 can be easily performed.

[0051] Furthermore, when one end 32 of the hollow member 30 is welded between the heat seal layers at the peripheral portion 28 of the laminate film 22, the weld is performed in a state in which the rod-shaped member 40 is inserted into the supply path 30A including the one end 32. Therefore, with the supply path 30A of the hollow member 30 being appropriately secured, the one end 32 of the hollow member 30 can be welded in a state in which it is in close contact with the heat seal layers at the peripheral portion 28 of the laminate film 22.

[0052] Then, by removing the rod-shaped member 40 after welding, the inside and outside of the laminate film 22 can be appropriately connected by the hollow member 30. In addition, after removing the rod-shaped member 40, the inside of the laminate film 22 is depressurized. Therefore, the electrolyte can smoothly flow into the inside of the laminate film 22. In other words, the electrolyte can be smoothly supplied to the inside of the laminate film 22.

[0053] Moreover, after the electrolyte is supplied to the inside of the laminate film 22, a part of the hollow member 30 protruding from the peripheral portion 28 is cut off, and then one end 32 of the hollow member 30 remaining sandwiched between the heat seal layers at the peripheral portion 28 is crushed and welded (to close the supply path 30A), thereby sealing the laminate film 22. Therefore, the manufactured battery 20 is configured compactly as before, and space saving when housed in the battery module 11 can be maintained.

[0054] The melting point of the resin material constituting the hollow member 30 is higher than the melting point of the heat seal layer at the peripheral portion 28 of the laminate film 22. Therefore, when joining (welding) the heat seal layer at the peripheral portion 28 of the laminate film 22 with the one end 32 of the hollow member 30 sandwiched therebetween, there is no risk of a defect such as melting of the one end 32 of the hollow member 30.

[0055] In addition, the hollow member 30 is formed of a resin material with a low melting point, such as polypropylene, etc. Therefore, after the electrolyte is supplied to the inside of the laminate film 22, one end 32 of the hollow member 30 can be easily welded (to close the supply path 30A), and the laminate film 22 can be easily sealed.

[0056] Although the battery 20 according to the present embodiment and the manufacturing method thereof have been described above with reference to the drawings, the battery 20 according to the present embodiment and the manufacturing method thereof are not limited to those shown in the drawings, and the design can be appropriately modified within the scope of the present invention. For example, the type of exterior body is not limited to the laminate film 22.

[0057] That is, the exterior body is not particularly limited as long as it can accommodate the electrode body and the melting point of its peripheral portion is lower than the melting point of the hollow member 30. The exterior body may be composed of one member, or may be composed of two or more members. For example, when the exterior body is in a sheet shape, the exterior body may be composed of one sheet, or may be composed of two or more sheets.

[0058] Furthermore, the type and size of the electrode body are not particularly limited and are selected according to the scale and use of the battery 20. Furthermore, the number of electrodes and separators included in the electrode body are also not particularly limited and are selected according to the scale and use of the battery 20. Furthermore, the vehicle 100 is not limited to an electric vehicle. The vehicle 100 may be, for example, a hybrid vehicle (HV) or a plug-in hybrid electric vehicle (PHEV) equipped with an engine. [Explanation of symbols]

[0059] 20 Battery Cells (Batteries) 22 Laminate film (outer body) 28 Periphery 30 Hollow member 30A supply line 40 Rod-shaped member

Claims

1. an exterior body that houses the electrode body therein and has overlapping peripheral portions joined together; a hollow resin member having a supply path for supplying an electrolyte to the inside of the exterior body, the hollow resin member being sandwiched between the overlapping peripheral portions of the exterior body and welded to the peripheral portions; A battery equipped with

2. The battery according to claim 1 , wherein the melting point of the resin material constituting the hollow member is higher than the melting point of the peripheral portion.

3. a joining step of joining overlapping peripheral portions of an exterior body housing the electrode body therein and sandwiching and welding one end of a hollow member between the peripheral portions; a supply step of supplying an electrolyte solution from a supply path of the hollow member to an inside of the exterior body; A method for manufacturing a battery having the above structure.

4. The battery manufacturing method described in claim 3, wherein in the joining process, the hollow member is welded between the peripheral portions with a rod-shaped member inserted into the supply path including the one end, and after welding, the rod-shaped member is removed.

5. The method for producing a battery according to claim 4 , further comprising a depressurizing step of depressurizing the inside of the exterior body after removing the rod-shaped member.

6. a cutting step of cutting the hollow member protruding from the peripheral portion after supplying the electrolyte into the exterior body; a sealing step of crushing and welding the one end of the hollow member remaining sandwiched between the peripheral portions to seal the exterior body; The method for producing a battery according to any one of claims 3 to 5, comprising:

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