Battery manufacturing method

Abstract

To improve the ease of battery assembly. [Solution] Multiple cells 10 and multiple cushioning materials 11 are stacked by engaging the guided portion of the cell 10 and the guided portion of the cushioning material 11 with the guide. When stacking the cells 10 and cushioning materials 11, the multiple cells 10 and multiple cushioning materials 11 are divided into multiple groups, including a first group and a second group. The cells 10 and cushioning materials 11 of the first group are stacked along the guide, a guide module is connected to the guide to extend the guide in the stacking direction, and the cells 10 and cushioning materials 11 of the second group are stacked along the extended guide.

Description

Technical Field

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

Background Art

[0002] In recent years, in order to enable more people to access affordable, reliable, sustainable and advanced energy, research and development on secondary batteries that contribute to energy efficiency has been carried out.

[0003] The pressure device for battery cells described in Patent Document 1 includes a plurality of battery cells arranged in the thickness direction, a plurality of pressure bags arranged between the plurality of battery cells and capable of pressurizing the battery cells by pressurized fluid supplied therein, and a housing that houses the plurality of battery cells and the plurality of pressure bags. The housing has guide shafts inserted into guide holes provided at the four corners of the pressure bag, and holds the pressure bag slidable in the thickness direction.

[0004] The method for manufacturing a fuel cell described in Patent Document 2 sequentially fits cylindrical intermediate adapters into through holes of single cells and separator plates to form unit blocks. Next, a shaft is inserted into the through hole of the intermediate adapter, a plurality of unit blocks are stacked, and the stacked plurality of unit blocks are tightened around the shaft.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] For example, in batteries installed in electric vehicles such as electric cars, the number of stacked cells tends to increase in response to the demand for larger capacity and / or higher voltage batteries. As the number of cells increases, when the stacked cells and the cushioning material sandwiching the cells are compressed, misalignment in the direction perpendicular to the stacking direction is more likely to occur in the cells and cushioning material in the middle of the stacking direction.

[0007] While the use of guides can suppress misalignment, a guide of considerable length is required when there are many stacked cells. Furthermore, when inserting the guide through the holes in the cells and / or cushioning material, it is particularly time-consuming to move the cells and / or cushioning material located on the lower layers along the guide. One of the objectives of the present invention is to improve the ease of assembly of batteries. [Means for solving the problem]

[0008] A method for manufacturing a battery according to one aspect of the present invention is a method for manufacturing a battery in which a plurality of cushioning materials and a plurality of cells arranged between two adjacent cushioning materials are stacked, The multiple cells and the multiple cushioning materials are stacked by engaging the guided portion of each cell and the guided portion of each cushioning material with guides that extend in the stacking direction of the multiple cells and the multiple cushioning materials, When stacking the plurality of cells and the plurality of cushioning materials, The plurality of cells and the plurality of cushioning materials, A first group comprising one or more of the aforementioned cells and two or more of the aforementioned cushioning materials, A second group comprising one or more of the aforementioned cells and two or more of the aforementioned cushioning materials, Divide into several groups including, The cells and cushioning material of the first group are stacked along the guide, A guide module is connected to the guide to extend the guide in the stacking direction, The cells and cushioning material of the second group are stacked on top of the cells and cushioning material of the first group along the extended guide. [Effects of the Invention]

[0009] According to the present invention, the battery assembly property can be improved.

Brief Description of Drawings

[0010] [Figure 1] FIG. 1 is a front view schematically showing an example of a battery for explaining an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of a cell included in the battery of FIG. 1. [Figure 3] FIG. 3 is a plan view of a cushioning material included in the battery of FIG. 1. [Figure 4] FIG. 4 is a diagram showing an example of a manufacturing method of the battery of FIG. 1 in order. [Figure 5] FIG. 5 is a diagram showing an example of a manufacturing method of the battery of FIG. 1 in order. [Figure 6] FIG. 6 is a diagram showing an example of a manufacturing method of the battery of FIG. 1 in order. [Figure 7] FIG. 7 is a diagram showing an example of a manufacturing method of the battery of FIG. 1 in order. [Figure 8] FIG. 8 is a diagram showing an example of a manufacturing method of the battery of FIG. 1 in order. [Figure 9] FIG. 9 is a diagram showing another example of a manufacturing method of the battery of FIG. 1 in order. [Figure 10] FIG. 10 is a diagram showing another example of a manufacturing method of the battery of FIG. 1 in order. [Figure 11] FIG. 11 is a diagram showing another example of a manufacturing method of the battery of FIG. 1 in order.

Embodiments for Carrying Out the Invention

[0011] An example of a battery and its manufacturing method for explaining an embodiment of the present invention will be described based on the accompanying drawings.

[0012] The battery 1 shown in FIG. 1 includes a plurality of cells 10 and a plurality of cushioning materials 11. The cells 10 and the cushioning materials 11 are flat or planar and are laminated in the thickness direction. The cells 10 are disposed between two adjacent cushioning materials 11. Further, the battery 1 further includes a set of end plates 3 that sandwich a laminate 12 of the plurality of cells 10 and the plurality of cushioning materials 11 in the lamination direction, and a frame 4 that restrains the set of end plates 3 from each other. The frame 4 fixes the interval between the set of end plates 3.

[0013] FIG. 2 shows an example of the cell 10. The cell 10 is a so-called laminated cell in which a positive electrode, a negative electrode, a separator, and an electrolyte are enclosed in a pack of laminated films. Generally, compared with a can cell in which materials such as a positive electrode are enclosed in a cylindrical or rectangular metal container, the laminated cell has a higher energy density per volume and excellent heat dissipation.

[0014] A plurality of guide holes 20 are provided at the edge of the outer periphery of the cell 10. In the example shown in FIG. 2, the cell 10 is formed in a substantially rectangular shape in the thickness direction, and the guide holes 20 are provided at the four corners of the cell 10. Note that the cell is not limited to a rectangular shape, and the positions of the guide holes 20 are not limited to the four corners. Further, a holder for holding the cell 10 may be provided, and the guide holes 20 may be provided in the holder.

[0015] The cell 10 may be a lithium-ion battery or a nickel-metal hydride battery using a liquid electrolyte, or may be an all-solid-state battery using a solid electrolyte. In the all-solid-state battery, the solid electrolyte also serves as a separator. Generally, compared with a lithium-ion battery or the like using a liquid electrolyte, the all-solid-state battery has excellent temperature resistance and a long service life.

[0016] In both cells using liquid electrolytes and cells using solid electrolytes, the negative electrode may be made of a material with excellent energy density but large expansion, such as metallic lithium or alloys containing metallic lithium, or silicon (Si). For example, lithium is deposited on the surface of a negative electrode made of metallic lithium due to repeated charging and discharging. If there is variation in the pressure distribution within the plane of cell 10, uneven deposition of lithium may occur. Uneven deposition of lithium promotes the growth of the deposited lithium into protrusions, and there is a concern that these may reach the positive electrode and cause a short circuit. Therefore, it is necessary to apply uniform pressure to all parts of the plane of cell 10 with an appropriate load.

[0017] Furthermore, in cells using solid electrolytes, it is crucial to densify the solid electrolyte and improve the adhesion between the electrodes and the solid electrolyte in order to facilitate ion movement between electrodes. Therefore, it is necessary to apply uniform pressure to various points within the plane of cell 10 with an appropriate load.

[0018] Figure 3 shows an example of a cushioning material 11. The cushioning material 11 is a pouch in which a fluid such as gas or liquid is sealed in an insulating bag-shaped packaging material. Based on the isotropy of the fluid pressure inside the cushioning material 11, the load acting on each point in the plane of the cell 10 sandwiched between two adjacent cushioning materials 11 is equalized. Note that the cushioning material 11 is not limited to the above-described pouch, as long as it has cushioning and pressure equalization properties.

[0019] Multiple guide holes 30 are provided on the outer edge of the cushioning material 11. In the laminate 12, each guide hole 30 of the cushioning material 11 is aligned in the stacking direction with one of the multiple guide holes 20 of the cell 10. In the example shown in Figure 3, the cushioning material 11 is formed in a substantially rectangular shape when viewed in the thickness direction, corresponding to the substantially rectangular cell 10 shown in Figure 2, and the guide holes 30 are provided at the four corners of the cushioning material 11.

[0020] An example of a manufacturing method for the battery 1 will be explained with reference to Figures 4 to 8. In the following explanation, the stacking direction of the cells 10 and the cushioning material 11 will be described as the vertical direction for convenience.

[0021] First, the multiple cells 10 and multiple cushioning materials 11 are divided into multiple groups, including a first group and a second group. The first group and the second group each contain one or more cells 10 and two or more cushioning materials 11. Here, we will explain assuming that the multiple cells 10 and multiple cushioning materials 11 are divided into two groups, the first group and the second group.

[0022] As shown in Figure 4, the lower end plate 3a of a pair of end plates 3 is placed on the base 40. Multiple rod-shaped guides 41A are installed on the base 40. Each guide 41A extends in the vertical direction, and its lower end 42 is fixed to the base 40. The lower end 42 only needs to be fixed so as not to rotate relative to the base 40, and the method of fixing is not particularly limited.

[0023] The lower end plate 3a is provided with multiple guide holes, and each guide hole is aligned vertically (in the stacking direction) with one of the multiple guide holes 23 of the cell 10 and one of the multiple guide holes 30 of the cushioning material 11. Each guide 41A is inserted through one of the multiple guide holes of the lower end plate 3a, and the lower end plate 3a is moved downward along the guide 41A from the upper end of the guide 41A and installed on the base 40.

[0024] Then, the first group of cells 10 and cushioning material 11 are stacked on the lower end plate 3a. Each guide 41A is inserted through one of the multiple guide holes 20 of the cell 10, and also through one of the multiple guide holes 30 of the cushioning material 11. The cells 10 and cushioning material 11 are moved downward along the guide 41A from the upper end and are sequentially stacked on the lower end plate 3a. The guide 41A and the edges of the guide holes 20 of the cell 10 and the edges of the guide holes 30 of the cushioning material 11 may or may not be in contact with each other. The number of cells 10 and cushioning material 11 in the first group is set according to the length of the guide 41A such that the sum of the thicknesses of the cells 10 and cushioning material 11 when uncompressed is less than the length of the guide 41A.

[0025] Next, as shown in Figure 5, a guide module 44 is connected to the upper end of each guide 41A. An internal thread 43, as an example of a fixing element, is formed on the upper end of the guide 41A, and an external thread 45, as an example of a fixing element, is formed on the lower end of the guide module 44. The guide module 44 is connected to the guide 41A by screwing the internal thread 43 and the external thread 45 together. The guide module 44, together with the guide 41A, constitutes a guide 41B that extends beyond the guide 41A. The method of connecting the guide 41A and the guide module 44 is not particularly limited, as long as the guide module 44 is separable from the guide 41A. For example, they may be connected by fitting multiple protrusions and recesses extending in the connection direction, such as a spline fitting.

[0026] Next, as shown in Figure 6, the second group of cells 10 and cushioning material 11 are stacked on top of the first group of cells 10 and cushioning material 11 that have already been stacked. Each guide 41B is inserted through one of the multiple guide holes 20 of the cell 10 and one of the multiple guide holes 30 of the cushioning material 11, and the cells 10 and cushioning material 11 are moved downward along the guide 41B from the upper end and are sequentially stacked on top of the first group of cells 10 and cushioning material 11 that have already been stacked. The number of cells 10 and cushioning material 11 in the second group is set according to the length of the guide 41B. Note that the third group and subsequent groups of cells 10 and cushioning material 11 may be further stacked. In this case, the guide module 44 is connected to the guide 41B and the guide is extended as appropriate.

[0027] Then, the upper end plate 3b is placed on top of the laminate 12, which is made up of all the cells 10 and cushioning material 11 stacked together. The upper end plate 3b, like the lower end plate 3a, is also provided with multiple guide holes, and each guide 41B is inserted through one of the multiple guide holes of the upper end plate 3b. The upper end plate 3b is moved downward along the guide 41B from the upper end of the guide 41B and placed on top of the laminate 12.

[0028] Next, as shown in Figure 7, the laminate 12 is compressed. The pressure jig 46 is placed on top of the upper end plate 3b. The pressure jig 46 is provided with multiple guide holes, and each guide 41B is inserted into one of the multiple guide holes of the pressure jig 46. The pressure jig 46 is moved downward along the guide 41B from the upper end of the guide 41B and placed on top of the upper end plate 3b. Then, the base 40 is supported by the compression device, the pressure jig 46 is pushed down, and the laminate 12 is compressed until it reaches a predetermined thickness.

[0029] Next, as shown in Figure 8, the base 40 and the pressure jig 46 are restrained from each other by appropriate fixing jigs 47. The distance between the base 40 and the pressure jig 46 is fixed, and the laminate 12 remains compressed even after the pressure on the pressure jig 46 is released. After this, the compressed laminate 12 and the pair of end plates 3 that sandwich the laminate 12 are removed from the compression device together with the base 40 and the pressure jig 46, and the frame 4 is assembled to the pair of end plates 3 to form the battery 1.

[0030] After the frame 4 is assembled to the pair of end plates 3, the restraint between the base 40 and the pressure jig 46 by the fixing jig 47 is released, and the pressure jig 46 is removed. Then, the battery 1 is lifted along the guide 41B and removed from the base 40.

[0031] In the manufacturing method shown in Figures 4 to 8, the first group of cells 10 and cushioning material 11 are arranged on the lower layer side in the stacked battery 1 12. The guide 41A used when stacking the first group of cells 10 and cushioning material 11 is shorter than the guide 41B required to stack all the cells 10 and cushioning material 11. Therefore, the effort required to move the first group of cells 10 and cushioning material 11 along the guide 41A to the predetermined position on the lower layer side is reduced. This improves the ease of assembly of the battery 1.

[0032] Furthermore, when the laminate 12 is compressed, the cells 10 and cushioning material 11 constituting the laminate 12 are prevented from shifting in a direction intersecting the lamination direction by engaging with the guides 41B inserted through the guide holes 20 and 30. This allows the laminate 12 to be compressed while the cells 10 and cushioning material 11 remain aligned in the lamination direction, making it easier to assemble the frame 4.

[0033] Furthermore, by compressing the laminate 12 while maintaining the alignment of the cells 10 and the cushioning material 11 in the stacking direction, it becomes possible to uniformly press various points in the plane intersecting the thickness direction of the cells 10. This is useful when the cells 10 are cells using a solid electrolyte, and also when the cells 10 include a negative electrode formed from metallic lithium or the like.

[0034] Figures 9 to 11 show modified examples of the manufacturing method for battery 1. In the manufacturing method described below, each time a group of cells 10 and cushioning material 11 are stacked along the guide, the stacked body consisting of the cells 10 and cushioning material 11 is compressed.

[0035] First, as shown in Figure 9, the lower end plate 3a is placed on the base 40, and the first group of cells 10 and cushioning material 11 are placed on the lower end plate 3a. Furthermore, an intermediate plate 13 is placed on top of the laminated structure consisting of the first group of cells 10 and cushioning material 11. The intermediate plate 13 is provided with multiple guide holes, and each guide 41A is inserted through one of the multiple guide holes in the intermediate plate 13.

[0036] Then, the compression device supports the base 40 and pushes down the intermediate plate 13, compressing the laminate consisting of the first group of stacked cells 10 and cushioning material 11 until it reaches a predetermined thickness. After compression, the intermediate plate 13 is fixed in position relative to the base 40 by an appropriate method. For example, a bolt may be inserted from the side of the intermediate plate 13 through a screw hole that reaches the guide hole of the intermediate plate 13, and the bolt may be engaged with the guide 41A.

[0037] Next, as shown in Figure 10, a guide module 48 is connected to the upper end of each guide 41A. The guide module 48, together with the guide 41A, forms a guide 41C that is extended beyond the guide 41A.

[0038] Next, as shown in Figure 11, the second group of cells 10 and cushioning material 11, as well as the upper end plate 3b, are stacked on the intermediate plate 13. After this, as shown in Figures 7 and 8, the pressure jig 46 is placed on the upper end plate 3b, and the base 40 is supported by the compression device, the pressure jig 46 is pushed down, and the laminate 12 is compressed until it reaches a predetermined thickness. Then, the base 40 and the pressure jig 46 are restrained from each other by appropriate fixing jigs 47, and the frame 4 is assembled to the compressed laminate 12 and a pair of end plates 3 that sandwich the laminate 12, thereby forming the battery 1.

[0039] According to the manufacturing method shown in Figures 9 to 11, when the first group of cells 10 and cushioning material 11 are stacked, the stacked body consisting of these cells 10 and cushioning material 11 is compressed. The guide 41C required to stack all the cells 10 and cushioning material 11, including the second group of cells 10 and cushioning material 11 that are stacked afterward, can be shortened compared to the guide 41B. This makes it possible to miniaturize the compression device.

[0040] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and modifications, improvements, etc., can be made as appropriate. This specification includes at least the following matters. Note that the components etc. in parentheses indicate those corresponding to the above embodiments, but the invention is not limited thereto.

[0041] (1) A method for manufacturing a battery (battery 1) in which a plurality of cushioning materials (cushioning material 11) and a plurality of cells (cells 10) arranged between two adjacent cushioning materials are stacked, The multiple cells and the multiple cushioning materials are stacked by engaging the guided portion (guide hole 20) of each cell and the guided portion (guide hole 30) of each cushioning material with guides (guides 41A, 41B) that extend in the stacking direction of the multiple cells and the multiple cushioning materials. When stacking the plurality of cells and the plurality of cushioning materials, The plurality of cells and the plurality of cushioning materials, A first group comprising one or more of the aforementioned cells and two or more of the aforementioned cushioning materials, A second group comprising one or more of the aforementioned cells and two or more of the aforementioned cushioning materials, Divide into several groups including, The cells and cushioning material of the first group are stacked along the guide, A guide module (guide module 44) is connected to the guide to extend the guide in the stacking direction. The cells and cushioning material of the second group are stacked on top of the cells and cushioning material of the first group along the extended guide. Battery manufacturing method.

[0042] According to the battery manufacturing method described in (1) above, the guide used when stacking the first group of cells and cushioning material is shorter than the guide required to stack all the cells and cushioning material. Therefore, the effort required to move the first group of cells and cushioning material along the guide to a predetermined position on the lower layer is reduced. This improves the ease of assembly of the battery. Furthermore, when the laminate is compressed, the cells and cushioning material constituting the laminate are prevented from shifting in the direction intersecting the stacking direction by engaging with the guide. This allows the laminate to be compressed while the cells and cushioning material remain aligned in the stacking direction, and enables uniform pressing of various points in the plane intersecting the thickness direction of the cells.

[0043] (2) A method for manufacturing the battery described in (1) above, Fixing elements (female thread 43, male thread 45) that are fixed to each other are formed at one end of the guide (guide 41A) to which the guide module is connected, and at one end of the guide module that is connected to the guide. Battery manufacturing method.

[0044] According to the battery manufacturing method described in (2) above, the connection between the guide and the guide module is easy.

[0045] (3) A method for manufacturing the battery described in (2) above, The other end of the guide is fixed to a base (base 40) that supports the plurality of cells and the plurality of cushioning materials in the stacking direction. Battery manufacturing method.

[0046] According to the battery manufacturing method described in (3) above, the configuration of the jig, including the guide, can be simplified.

[0047] (4) A method for manufacturing the battery described in (1) above, The guided portion of each cell and the guided portion of each cushioning material are holes through which the guide is inserted. Battery manufacturing method.

[0048] According to the battery manufacturing method described in (4) above, the engagement between the cell, the cushioning material and the guide can be reliably achieved.

[0049] (5) A method for manufacturing the battery described in (1) above, The cells and cushioning material of the second group are stacked on top of the cells and cushioning material of the first group. The cells and cushioning material of the first group, and the cells and cushioning material of the second group are compressed in the stacking direction. Battery manufacturing method.

[0050] According to the battery manufacturing method described in (5) above, the compression process can be reduced.

[0051] (6) A method for manufacturing the battery described in (1) above, The cells and cushioning material of the first group stacked along the guide are compressed in the stacking direction. The cells and cushioning material of the second group are stacked on top of the compressed cells and cushioning material of the first group, and compressed in the stacking direction. Battery manufacturing method.

[0052] According to the battery manufacturing method described in (6) above, the length of the guide required to stack all the cells and cushioning material is shortened, and the compression device can be miniaturized.

[0053] (7) A method for manufacturing a battery as described in any one of (1) to (6) above, The cell contains a solid electrolyte. Battery manufacturing method.

[0054] (8) A method for manufacturing a battery according to any one of the above (1) to (6), The negative electrode of the cell comprises metallic lithium or an alloy containing metallic lithium. Battery manufacturing method.

[0055] (9) A method for manufacturing a battery, any one of the above (1) to (6), The negative electrode of the cell contains silicon, Battery manufacturing method.

[0056] (10) A method for manufacturing a battery according to any one of the above (1) to (6), The cushioning material contains a fluid sealed in the packaging material. Battery manufacturing method. [Explanation of Symbols]

[0057] 1 Battery 3 End Plates 4 frames 10 cells 11 Cushioning material 12-layer structure 13 Intermediate plate 20 guide holes 30 guide holes 40 bases 41A Guide 41B Guide 41C Guide 42 Lower end 43 Female thread 44 Guide Pages 45 Male screw 46 Pressurizing jig 47 Fixing fixture

Claims

1. A method for manufacturing a battery in which multiple cushioning materials and multiple cells, each placed between two adjacent cushioning materials, are stacked, The multiple cells and the multiple cushioning materials are stacked by engaging the guided portion of each cell and the guided portion of each cushioning material with guides that extend in the stacking direction of the multiple cells and the multiple cushioning materials, When stacking the plurality of cells and the plurality of cushioning materials, The plurality of cells and the plurality of cushioning materials, A first group comprising one or more of the aforementioned cells and two or more of the aforementioned cushioning materials, A second group comprising one or more of the aforementioned cells and two or more of the aforementioned cushioning materials, Divide into several groups including, The cells and cushioning material of the first group are stacked along the guide, A guide module is connected to the guide to extend the guide in the stacking direction, The cells and cushioning material of the second group are stacked on top of the cells and cushioning material of the first group along the extended guide. Battery manufacturing method.

2. A method for manufacturing a battery according to claim 1, A fixing element is formed at one end of the guide to which the guide module is connected, and at one end of the guide module connected to the guide, so that they are fixed to each other. Battery manufacturing method.

3. A method for manufacturing a battery according to claim 2, The other end of the guide is fixed to a base that supports the plurality of cells and the plurality of cushioning materials in the stacking direction. Battery manufacturing method.

4. A method for manufacturing a battery according to claim 1, The guided portion of each cell and the guided portion of each cushioning material are holes through which the guide is inserted. Battery manufacturing method.

5. A method for manufacturing a battery according to claim 1, The cells and cushioning material of the second group are stacked on top of the cells and cushioning material of the first group. The cells and cushioning material of the first group, and the cells and cushioning material of the second group are compressed in the stacking direction. Battery manufacturing method.

6. A method for manufacturing a battery according to claim 1, The cells and cushioning material of the first group stacked along the guide are compressed in the stacking direction. The cells and cushioning material of the second group are stacked on top of the compressed cells and cushioning material of the first group, and compressed in the stacking direction. Battery manufacturing method.

7. A method for manufacturing a battery according to any one of claims 1 to 6, The cell contains a solid electrolyte. Battery manufacturing method.

8. A method for manufacturing a battery according to any one of claims 1 to 6, The negative electrode of the cell comprises metallic lithium or an alloy containing metallic lithium. Battery manufacturing method.

9. A method for manufacturing a battery according to any one of claims 1 to 6, The negative electrode of the cell contains silicon, Battery manufacturing method.

10. A method for manufacturing a battery according to any one of claims 1 to 6, The cushioning material contains a fluid sealed in the packaging material. Battery manufacturing method.

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