Battery and method for manufacturing the same

Abstract

The present disclosure relates to a battery and a method for manufacturing the battery. The method for manufacturing the battery comprises: a joining step of joining overlapping peripheral portions of an outer casing containing an electrode body therein, and sandwiching and welding one end portion of a hollow member between the peripheral portions; and a supply step of supplying an electrolyte from a supply path of the hollow member to the interior of the outer casing.

Description

Technical Field

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

[0002] A method for manufacturing a battery in which an electrolyte is injected from an injection port formed of an unsealed portion of a laminated outer casing and then the injection port is sealed by welding is conventionally known (for example, see Japanese Patent Application Laid-Open No. 2000-285882). Summary of the invention

[0003] However, if the injection port for injecting the electrolyte solution is constituted by an unsealed portion of the laminated outer casing, a step of removing the adhering matter adhering to the injection port is required.

[0004] Therefore, an object of the present disclosure is to provide a battery and a method for manufacturing the battery in which an electrolyte solution can be easily injected into an exterior body.

[0005] Means for solving problems

[0006] In order to achieve the above-mentioned purpose, the battery of the first scheme involved in the present disclosure comprises: an outer casing, which accommodates the electrode body inside and the overlapping peripheral portions are joined; and a hollow member made of resin, which has a supply path for supplying electrolyte to the interior of the outer casing, is sandwiched between the overlapping peripheral portions of the outer casing and is welded to the peripheral portions.

[0007] According to the battery of the first aspect, the resin hollow member having a supply path for supplying the electrolyte to the interior of the outer casing is sandwiched between the overlapping peripheral portions of the outer casing that accommodates the electrode body inside, and is welded to the peripheral portions. Therefore, compared with the case where the injection port is constituted by the unsealed portion of the outer casing, the operation of injecting the electrolyte into the interior of the outer casing becomes easier.

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

[0009] According to the battery of the second aspect, the melting point of the resin material constituting the hollow member is higher than the melting point of the peripheral edge of the outer casing. Therefore, when the peripheral edge of the outer casing is joined, the hollow member does not melt.

[0010] In addition, the manufacturing method of the battery of the third scheme involved in the present disclosure includes: a joining process, joining the overlapping peripheral portions of the outer casing that accommodates the electrode body inside, and clamping and welding one end portion of the hollow member between the peripheral portions; and a supply process, supplying electrolyte from the supply path of the hollow member to the interior of the outer casing.

[0011] According to the manufacturing method of the battery of the third aspect, the electrolyte is supplied to the interior of the outer casing from the supply path of the hollow member whose one end is sandwiched between the peripheral edge portions of the outer casing that accommodates the electrode body and is welded. Therefore, compared with the case where the injection port is constituted by the unsealed portion of the outer casing, the operation of injecting the electrolyte into the interior of the outer casing becomes easier.

[0012] In addition, the manufacturing method of the battery of the fourth scheme involved in the present disclosure is based on the manufacturing method of the battery of the third scheme, wherein, in the joining process, the hollow member is welded between the peripheral portions in a state where the rod-shaped member is inserted into the supply path including the one end portion, and after welding, the rod-shaped member is pulled out.

[0013] According to the manufacturing method of the battery of the fourth aspect, when the one end of the hollow member is welded between the peripheral portions, the welding is performed with the rod-shaped member inserted through the supply path including the one end. And after welding, the rod-shaped member is pulled out. Therefore, the supply path of the hollow member is properly ensured, and the inside and outside of the outer body are properly connected.

[0014] Furthermore, a fifth method of manufacturing a battery according to the present disclosure is the method of manufacturing a battery according to the fourth method, further comprising a decompression step of decompressing the interior of the exterior body after the rod-shaped member is pulled out.

[0015] According to the battery manufacturing method of the fifth aspect, after the rod-shaped member is pulled out, the interior of the outer casing is depressurized. Therefore, in the subsequent supply step, the electrolyte is smoothly supplied to the interior of the outer casing.

[0016] In addition, the manufacturing method of the battery of the 6th scheme involved in the present disclosure is a manufacturing method of the battery according to any one of the 3rd to 5th schemes, which comprises: a cutting process, after supplying the electrolyte to the interior of the outer body, cutting off the hollow member protruding from the peripheral portion; and a sealing process, flattening and welding the one end portion of the hollow member remaining between the peripheral portions to seal the outer body.

[0017] According to the method for manufacturing a battery of the sixth aspect, after supplying the electrolyte into the interior of the outer casing, the hollow member protruding from the peripheral portion thereof is cut off, and then one end of the hollow member remaining sandwiched between the peripheral portions is flattened and welded to seal the outer casing. Therefore, the manufactured battery maintains space saving as before.

[0018] As described above, according to the present disclosure, the work of injecting the electrolyte into the interior of the outer casing can be easily performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Typical embodiments of the present disclosure will be described in detail based on the following drawings.

[0020] Figure 1 This is a schematic plan view showing an electric vehicle including a battery according to the present embodiment.

[0021] Figure 2 It is a schematic perspective view showing the structure of a battery module according to the present embodiment.

[0022] Figure 3 It is a schematic plan view showing the configuration of the battery module according to the present embodiment with the upper cover removed.

[0023] Figure 4 It is a schematic front view showing the configuration of a battery cell accommodated in the battery module according to the present embodiment, as viewed from the thickness direction.

[0024] Figure 5 It is a schematic cross-sectional view showing the manufacturing process of the battery according to the present embodiment.

[0025] Figure 6 It is a schematic cross-sectional view showing the manufacturing process of the battery according to the present embodiment.

[0026] Figure 7 It is a schematic cross-sectional view showing the manufacturing process of the battery according to the present embodiment.

[0027] Figure 8 It is a schematic cross-sectional view showing the manufacturing process of the battery according to the present embodiment.

[0028] Fig. 9 It is a schematic cross-sectional view showing the manufacturing process of the battery according to the present embodiment. DETAILED DESCRIPTION

[0029] Hereinafter, the embodiments of the present disclosure will be described in detail based on the accompanying drawings. In addition, for the convenience of description, the arrow UP appropriately shown in each figure is set as the vehicle upper direction, the arrow FR is set as the vehicle front direction, and the arrow LH is set as the vehicle left direction. Therefore, in the following description, when the up-down, front-back, and left-right directions are recorded without special description, the up-down direction of the vehicle upper-lower direction, the front-back direction of the vehicle front-back direction, and the left-right direction of the vehicle left-right direction (vehicle width direction) are indicated. In addition, the left-right direction is synonymous with the vehicle width direction.

[0030] In addition, the size of the components in each figure is conceptual, and the relative relationship between the sizes of the components is not limited thereto. In addition, in the present embodiment, the term "process" is not only an independent process, but also includes this term as long as the desired purpose of the process can be achieved even if it cannot be clearly distinguished from other processes.

[0031] In addition, in the present embodiment, the numerical range represented by "to" means a range including the numerical values ​​before and after "to" as the minimum value and the maximum value, respectively. In addition, in the numerical range recorded in the present embodiment in stages, the upper limit or lower limit recorded in a certain numerical range may also be replaced by the upper limit or lower limit of the numerical range recorded in other stages.

[0032] like Figure 1 As shown, the vehicle 100 according to the present embodiment is, as an example, an electric vehicle (BEV) having a battery pack 10 mounted under the floor. That is, the battery 20 according to the present embodiment is mounted on the vehicle 100. In the following description, the "battery 20" may be referred to as a "battery unit 20".

[0033] In vehicle 100, DC / DC converter 102, electric compressor 104, and PTC (Positive Temperature Coefficient) heater 106 are arranged in front of battery pack 10. Also, motor 108, gear box 110, inverter 112, and charger 114 are arranged in the rear of battery pack 10.

[0034] Therefore, the DC current output from battery pack 10 is regulated in voltage by DC / DC converter 102 and then supplied to electric compressor 104, PTC heater 106, inverter 112, etc. Furthermore, by supplying power to motor 108 via inverter 112, the rear wheels rotate and vehicle 100 travels.

[0035] A charging port 116 is provided at the right side of the rear portion of the vehicle 100 . Therefore, by connecting a charging plug of an external charging device (not shown) to the charging port 116 , electric power is stored in the battery pack 10 via the charger 114 .

[0036] In addition, the illustrated vehicle 100 is a rear-wheel drive vehicle with the motor 108 mounted at the rear, but the present invention is not limited thereto, and the vehicle may be a front-wheel drive vehicle with the motor 108 mounted at the front. In addition, the vehicle may be a vehicle with a pair of motors 108 mounted at the front and rear, or a vehicle may be a vehicle with a hub motor at each wheel. In other words, the arrangement and structure of the components constituting the vehicle 100 are not limited to the above-described configuration.

[0037] The battery pack 10 is configured to include a plurality of battery modules 11. In the present embodiment, as an example, 10 battery modules 11 are provided. Specifically, five battery modules 11 are arranged on the right side of the vehicle 100 with the thickness direction facing the front-rear direction, and five battery modules 11 are arranged on the left side of the vehicle 100 with the thickness direction facing the front-rear direction. In addition, each battery module 11 is electrically connected.

[0038] like Figure 2 As shown, the battery module 11 is formed into a substantially rectangular parallelepiped shape with the vehicle width direction as the length direction. In addition, 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 castings at both ends of an aluminum alloy extrusion by laser welding or the like.

[0039] A pair of voltage terminals 12 and a connector 14 are provided at both ends of the battery module 11 in the vehicle width direction. A flexible printed circuit board 21 described later is connected to the connector 14. Bus bars (not shown) are welded to both ends of the battery module 11 in the vehicle width direction.

[0040] The battery module 11 has a length MW in the vehicle width direction of, for example, 350 mm to 600 mm, a length ML in the front-rear direction of, for example, 150 mm to 250 mm, and a height MH in the up-down direction of, for example, 80 mm to 110 mm.

[0041] like Figure 3 As shown, a plurality of battery cells (batteries) 20 are arranged and housed in the battery module 11 with the thickness direction oriented in the front-rear direction. In the present embodiment, as an example, 24 battery cells 20 are arranged with the thickness direction oriented in the front-rear direction and bonded to each other.

[0042] A flexible printed circuit (FPC) 21 is disposed above the battery cell 20 and in the center in the front-rear direction. The flexible printed circuit 21 is formed in a strip shape with the vehicle width direction as the length direction, and thermistors 23 are provided at both ends of the flexible printed circuit 21. The thermistor 23 is not bonded to the battery cell 20, but is pressed toward the battery cell 20 by the upper cover of the battery module 11.

[0043] In addition, one or more buffers (not shown) are accommodated inside the battery module 11. The buffer is, for example, a thin plate-shaped member that can be elastically deformed, and is arranged between adjacent battery cells 20 with the arrangement direction of the battery cells 20 as the thickness direction. In this embodiment, as an example, buffers are arranged at both ends in the longitudinal direction and the central part in the longitudinal direction of the battery module 11.

[0044] like Figure 4As shown, the battery cell 20 is formed in a substantially rectangular plate shape, and an electrode body (not shown) is housed therein. The electrode body is formed by laminating electrodes (negative and positive electrodes) and separators disposed between the electrodes, and is sealed by a laminate film 22 as an outer body.

[0045] As the electrode, for example, an electrode having a layer containing an electrode active material formed on one or both sides of a current collector is used. As the separator, for example, a microporous film made of a resin such as polyethylene is used. The laminate film 22 is a laminate having a metal layer containing a metal such as aluminum and a heat seal layer.

[0046] In this embodiment, as an example, the electrode body receiving portion is formed by folding and sticking together a sheet-shaped laminate film 22 that has been embossed (embossed). In addition, the laminate film 22 can be a single cup embossed structure with one embossed portion and a double cup embossed structure with two embossed portions. Figure 4 In FIG. 8 , a single cup embossing structure with a drawing depth of about 8 mm to 10 mm is shown.

[0047] in addition, Figure 4 The upper end of the battery cell 20 shown in the longitudinal direction is bent, and the upper end of the battery cell 20 is also bent to be continuous with the bent portion. A fixing band 24 is wound around the upper end of the battery cell 20 along the longitudinal direction.

[0048] In addition, terminals (tabs) 26 are provided at both ends in the longitudinal direction of the battery cell 20. In the present embodiment, as an example, each terminal 26 is provided at a position offset downward from the center portion in the vertical direction of the battery cell 20. Each terminal 26 is joined to a bus bar (not shown) by laser welding or the like.

[0049] In addition, the length CW1 of the battery unit 20 in the vehicle width direction is, for example, 530mm~600mm, 600mm~700mm, 700mm~800mm, 800~900mm, 1000mm or more, and the length CW2 of the area accommodating the electrode body is, for example, 500mm~520mm, 600mm~700mm, 700mm~800mm, 800~900mm, 1000mm or more.

[0050] The height CH of the battery cell 20 is, for example, 80 mm to 110 mm, 110 mm to 140 mm, the thickness of the battery cell 20 is 5.0 mm to 7.0 mm, 7.0 mm to 9.0 mm, 9.0 mm to 11.0 mm, and the height TH of the terminal 26 is 40 mm to 50 mm, 50 mm to 60 mm, 60 mm to 70 mm.

[0051] Next, a method for manufacturing the battery (battery cell) 20 having the above-described structure will be described. Figures 5 to 9 The battery 20 shown schematically shows Figure 4 A plan cross-section of a battery cell 20 is shown.

[0052] The battery 20 manufactured by the manufacturing method according to the present embodiment is a so-called laminated battery (laminated battery) using a laminate film 22 as an outer body. First, the laminate film 22 is folded into two after accommodating an electrode body (not shown) inside, and the heat-sealed layers at the overlapping peripheral portions 28 are joined (welded).

[0053] At this time, if Figure 5 As shown in FIG. 1 , one end 32 of a hollow member 30 formed into a cylindrical shape by a low-melting-point resin material is sandwiched and fused between the heat-sealing layers at the overlapping peripheral portions 28 of the laminated film 22 (joining step). At this time, the hollow member 30 is fused between the heat-sealing layers at the peripheral portions 28 of the laminated film 22 in a state where a metal rod-shaped member 40 having a length exceeding the entire length of the supply path 30A including the one end 32 is inserted. Then, as shown in FIG. Figure 6 As shown, after welding, the rod-shaped member 40 is pulled out.

[0054] When the inside and outside of the laminate film 22 are connected through the hollow member 30, as shown in FIG. Figure 7 As shown, for example, two hollow extension members 34 are connected to the hollow member 30. Then, first, the air inside the laminate film 22 is extracted from the opening 36 on one side to reduce the pressure inside the laminate film 22 (decompression process). Then, an electrolyte (not shown) is injected from the opening 38 on the other side (differential pressure injection). That is, the supply path 30A (see FIG. 1 ) of the hollow member 30 is connected to the hollow member 30. Figure 5 ) The electrolyte is supplied to the interior of the laminate film 22 (supplying step).

[0055] After the electrolyte is supplied to the interior of the laminate film 22, the hollow extension member 34 is removed from the hollow member 30. Figure 8 As shown, a portion of the hollow member 30 protruding from the peripheral portion 28 of the laminate film 22 (the remaining portion except one end portion 32) is cut from the root (in a manner that it becomes coplanar with the cut surface of the peripheral portion 28, that is, the end surface 28A) (cutting step).

[0056] Afterwards, if Fig. 9 As shown, one end portion 32 of the hollow member 30 remaining sandwiched between the heat seal layers at the peripheral edge 28 of the laminate film 22 is crushed and welded (closing the supply path 30A), and the laminate film 22 is sealed (sealing step). The battery 20 is manufactured in the above manner.

[0057] In addition, the low melting point resin material used in the hollow member 30 is a resin material having a melting point higher than the melting point of the heat seal layer (e.g., low density polyethylene layer) at the peripheral portion 28 of the laminate film 22, and for example, polypropylene can be cited. In addition, the outer diameter of the rod-shaped member 40 is substantially the same as the inner diameter of the hollow member 30. Therefore, in the joining process, the outer peripheral surface of the one end portion 32 of the hollow member 30 is welded to the heat seal layer at the peripheral portion 28 of the laminate film 22 in a close contact state. In addition, the above-mentioned manufacturing method can also be applied to the case where the electrolyte is injected in multiple times or the case of additional injection.

[0058] Next, the operation of the battery 20 and the method for manufacturing the battery 20 according to the present embodiment having the above-described configuration will be described.

[0059] As described above, one end portion 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 accommodates the electrode body inside. Therefore, the electrolyte can be supplied to the inside of the laminate film 22 from the supply path 30A of the hollow member 30. Therefore, compared with the case where the injection port is constituted by the unsealed portion of the laminate film 22, there is no need to remove the attachments attached to the injection port, and the operation of injecting the electrolyte into the laminate film 22 can be easily performed.

[0060] In addition, when the one end portion 32 of the hollow member 30 is welded between the heat seal layers at the peripheral portion 28 of the laminate film 22, the rod-shaped member 40 is inserted through the supply path 30A including the one end portion 32. Therefore, the one end portion 32 of the hollow member 30 can be welded in a close contact state between the heat seal layers at the peripheral portion 28 of the laminate film 22 while the supply path 30A of the hollow member 30 is appropriately ensured.

[0061] Furthermore, after welding, by pulling out the rod-shaped member 40, the inside and outside of the laminated film 22 can be properly communicated through the hollow member 30. In addition, after pulling out the rod-shaped member 40, the inside of the laminated film 22 is depressurized. Therefore, the electrolyte can smoothly flow into the inside of the laminated film 22. In other words, the electrolyte can be smoothly supplied to the inside of the laminated film 22.

[0062] After the electrolyte is supplied to the interior of the laminate film 22, a portion of the hollow member 30 protruding from the peripheral portion 28 is cut off, and then one end portion 32 of the hollow member 30 remaining sandwiched between the heat seal layers of the peripheral portion 28 is crushed and welded (closing the supply path 30A), thereby sealing the laminate film 22. Therefore, the manufactured battery 20 is compactly configured as before, and space saving when housed in the battery module 11 can be maintained.

[0063] In addition, 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 the heat seal layer at the peripheral portion 28 of the laminate film 22 is joined (welded) with the one end portion 32 of the hollow member 30 sandwiched therebetween, the one end portion 32 of the hollow member 30 does not melt.

[0064] The hollow member 30 is formed of a low melting point resin material such as polypropylene. Therefore, after supplying the electrolyte into the laminate film 22, the one end 32 of the hollow member 30 can be easily welded (closing the supply path 30A), and the laminate film 22 can be easily sealed.

[0065] The battery 20 and the manufacturing method thereof according to the present embodiment have been described above based on the drawings, but the battery 20 and the manufacturing method thereof according to the present embodiment are not limited to the contents shown in the drawings, and can be appropriately designed and modified within the scope of the present invention. For example, the type of the outer casing is not limited to the laminate film 22.

[0066] That is, the outer casing 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. In addition, the outer casing may be composed of one member or two or more members. For example, when the outer casing is in the form of a sheet, the outer casing may be composed of one sheet or two or more sheets.

[0067] In addition, there is no particular limitation on the type and size of the electrode body, and it is selected according to the scale and purpose of the battery 20. In addition, there is no particular limitation on the number of electrodes and separators contained in the electrode body, and it is selected according to the scale and purpose of the battery 20. In addition, the vehicle 100 is not limited to an electric vehicle. As the vehicle 100, for example, it can also be a hybrid vehicle (HV: Hybrid Vehicle) equipped with an engine or a plug-in hybrid vehicle (PHEV: Plug-in Hybrid Electric Vehicle).

Claims

1. A battery having: An outer casing that accommodates the electrode body inside and has overlapping peripheral portions joined; and The resin hollow member has a supply path for supplying electrolyte to the interior of the outer casing, is sandwiched between the overlapping peripheral edge portions of the outer casing, and is welded to the peripheral edge portions.

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

3. A method for manufacturing a battery, comprising: a joining step of joining overlapping peripheral portions of the outer casings containing the electrode bodies therein, and sandwiching and welding one end portion of the hollow member between the peripheral portions; and The supply step is to supply the electrolyte solution from the supply path of the hollow member to the interior of the outer body.

4. The method for manufacturing a battery according to claim 3, In the joining step, the hollow member is welded between the peripheral portions in a state where a rod-shaped member is inserted through the supply path including the one end portion, and the rod-shaped member is pulled out after the welding.

5. The method for manufacturing a battery according to claim 4, The method includes a decompression step of decompressing the interior of the outer casing after the rod-shaped member is pulled out.

6. The method for manufacturing a battery according to any one of claims 3 to 5, comprising: a cutting step of cutting the hollow member protruding from the peripheral portion after supplying the electrolyte into the interior of the outer body; and In the sealing step, the one end portion of the hollow member remaining sandwiched between the peripheral portions is crushed and welded to seal the outer body.

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