Multipurpose jig for secondary battery manufacturing and method for setting manufacturing equipment using the same

Abstract

A multi-purpose jig for setting a secondary battery manufacturing apparatus according to an embodiment of the invention includes a main body portion, a first measuring portion protruding from one end of the main body portion in a longitudinal direction, and a second measuring portion formed to have a step at the other end of the main body portion in the longitudinal direction.

Description

[Technical Field]

[0001] Cross-reference to related application(s) This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0182734 dated December 20, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a multipurpose jig for manufacturing secondary batteries, more particularly to a jig that can be used for setting a secondary battery manufacturing apparatus, and to a method for setting a secondary battery manufacturing apparatus using such a multipurpose jig. [Background technology]

[0003] The rapid increase in the use of fossil fuels has led to an increasing demand for alternative and clean energy sources, and one of the most actively researched fields in this area is the field of electrochemical power generation and storage.

[0004] Currently, a typical example of an electrochemical element that utilizes such electrochemical energy is a secondary battery, and the range of its use is expanding day by day.

[0005] Recently, with the increasing technological development and demand for portable devices such as portable computers, mobile phones, and cameras, the demand for secondary batteries as energy sources has increased dramatically. Of these, lithium secondary batteries, which exhibit high energy density and working potential, long cycle life, and low self-discharge rate, have been the subject of much research and are now commercially available and widely used.

[0006] In addition, with growing concern about environmental issues, much research is being conducted into electric vehicles and hybrid electric vehicles that can replace vehicles that use fossil fuels such as gasoline and diesel vehicles, which are one of the main causes of air pollution. Nickel-metal hydride secondary batteries are mainly used as the power source for such electric vehicles and hybrid electric vehicles, but active research is being conducted into the use of lithium secondary batteries, which have high energy density and discharge voltage, and some of them are already in the commercialization stage.

[0007] Generally, a secondary battery has a structure in which an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode is housed in a case such as a can or a pouch.

[0008] When manufacturing such a secondary battery, an electrode assembly including a positive electrode, a negative electrode, and a separator may be manufactured through a pre-welding process in which electrode tabs of a plurality of positive electrodes and a plurality of negative electrodes are connected to each other, a cutting process in which the pre-welded electrode tabs are cut to a predetermined length, and a main-welding process in which leads are welded to the welded electrode tabs.

[0009] The equipment for this can only produce a good secondary battery if it accurately sets the positions of the welds taking into account the configuration of the secondary battery to be manufactured, for example, the positions of the multiple tabs to be welded in the stacked electrode assembly.

[0010] Usually, such settings are performed using an actual secondary battery.

[0011] However, when using an actual product, the state of the secondary battery can easily change depending on the surrounding environment, and there are problems with inefficiency in accuracy and required time due to the existence of deviations between each secondary battery. Also, there is a problem with deviations occurring between multiple pieces of equipment within the same process depending on the state of the secondary batteries used, making it impossible to proceed with the process accurately. Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention provides a multipurpose jig for manufacturing secondary batteries, which allows convenient and accurate setting of a secondary battery manufacturing apparatus and allows all assembly equipment settings during the process to be performed through a single jig, and a method for setting the manufacturing apparatus using the same.

[0013] However, the problems to be solved by the embodiments of the present invention are not limited to the above problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0014] A multipurpose jig for manufacturing a secondary battery according to an embodiment of the present invention is a multipurpose jig for setting an apparatus for manufacturing a secondary battery, the multipurpose jig including a main body, a first measuring portion protruding from one end of the main body in a longitudinal direction, (also called "Part 1") and a second measuring section formed to have a step at the other end of the main body in the longitudinal direction. (also called "Second Part") Includes:

[0015] The first measurement portion may protrude from the center of the main body portion in the thickness direction.

[0016] The position of the first measuring unit may correspond to the position of electrode tabs connected to a plurality of electrodes included in the secondary battery.

[0017] The thickness of the first measuring part may correspond to the thickness of electrode tabs connected to a plurality of electrodes included in the secondary battery.

[0018] A scale portion formed on a protruding portion that protrudes further outward from the step may be positioned on a side surface of the second measuring portion.

[0019] The multi-purpose jig can be constructed using a 3D printer.

[0020] A method for setting up a secondary battery manufacturing apparatus according to another embodiment of the present invention is a method for setting up a secondary battery manufacturing apparatus using the multi-purpose jig for manufacturing the above-mentioned secondary battery, and includes a step of moving the multi-purpose jig to a setting location for setting in the manufacturing apparatus so that the first measuring unit faces the setting location, and a step of setting the position of the setting location based on the first measuring unit.

[0021] The setting portion may include an upper device and a lower device based on electrode tabs connected to a plurality of electrodes included in the secondary battery, and the step of setting the position of the setting portion may include the step of confirming whether at least one of the upper device and the lower device contacts at least one of an upper surface and a lower surface of the first measuring portion.

[0022] A method for setting up a secondary battery manufacturing apparatus according to another embodiment of the present invention is a method for setting up a secondary battery manufacturing apparatus using the multi-purpose jig for manufacturing the above-mentioned secondary battery, and includes a step of moving the multi-purpose jig to a setting location for setting in the manufacturing apparatus so that the second measuring unit faces the setting location, and a step of setting the position of the setting location based on the second measuring unit.

[0023] The setting portion may include an upper device and a lower device based on electrode tabs connected to a plurality of electrodes included in the secondary battery, and the step of setting the position of the setting portion may include the step of confirming, through the second measuring unit, whether the upper device and the lower device are aligned and spaced the same distance from each other from a workbench on which the secondary battery is placed.

[0024] A scale portion formed on a protruding portion that protrudes further outward from the step may be positioned on a side surface of the second measuring portion.

[0025] The step of checking using the second measuring unit may include the steps of: bringing an end of the protrusion into contact with the upper device and measuring a first distance between the work table and the upper device using the scale; turning the multipurpose jig over and bringing the end of the protrusion into contact with the lower device and measuring a second distance between the work table and the lower device using the scale; and checking whether the first distance and the second distance are the same and correcting the setting portion so that they are the same.

[0026] The step of checking using the second measuring unit may include the steps of: placing a secondary battery on the workbench such that an electrode tab is disposed between the upper device and the lower device; placing the multi-purpose jig on the secondary battery such that a side of the secondary battery and the scale are parallel; and setting the gap between an end of a separator of the secondary battery and the upper device to a predetermined value using the scale. [Effects of the Invention]

[0027] The multi-purpose jig for manufacturing secondary batteries according to the embodiment allows an operator to set up at multiple positions during the manufacturing process of a manufacturing device using a single jig, thereby minimizing deviations between processes and improving the precision of setting up, while also shortening the time required to set up the manufacturing device, thereby improving productivity.

[0028] Furthermore, the secondary battery manufactured according to the embodiment can be manufactured as a high-quality product without manufacturing defects by using a device that is always set to a constant state.

[0029] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned above will be clearly understood by those skilled in the art from the description of the claims. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a perspective view showing a multipurpose jig for manufacturing a secondary battery according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional view of the multipurpose jig of FIG. 1 taken along line II-II. [Figure 3] 2 is an enlarged front view of part III of the multipurpose jig of FIG. 1. [Figure 4] 2 is a view illustrating a first example of use in which the multipurpose jig of FIG. 1 is used for setting a secondary battery manufacturing apparatus; [Figure 5] 10 is a view for explaining a second example of use in which the multipurpose jig of FIG. 1 is used for setting a secondary battery manufacturing apparatus; [Figure 6a] 10 is a view for explaining a third example of use in which the multipurpose jig of FIG. 1 is used for setting a secondary battery manufacturing apparatus. [Figure 6b] 10 is a view for explaining a third example of use in which the multipurpose jig of FIG. 1 is used for setting a secondary battery manufacturing apparatus. [Figure 7] 10 is a view for explaining a fourth example of use in which the multipurpose jig of FIG. 1 is used for setting a secondary battery manufacturing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may be embodied in various different forms and is not limited to the embodiments set forth herein.

[0032] In order to clearly explain the present invention, parts unnecessary for the explanation are omitted, and the same reference numerals are used throughout the specification to refer to the same or similar components.

[0033] Furthermore, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses are exaggerated to clearly show multiple layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0034] Furthermore, when a layer, film, region, plate, or other part is said to be "on" another part, this does not only mean that it is "directly on" that other part, but also includes cases where there are other parts in between. Conversely, when a part is said to be "directly on" another part, it means that there are no other parts in between. Furthermore, being "on" a reference part means being located above or below the reference part, and does not necessarily mean being "on" in the opposite direction of gravity.

[0035] Furthermore, throughout the specification, when a part is said to "comprise" a certain element, this does not mean that it excludes other elements and may further include other elements, unless specifically stated to the contrary.

[0036] Also, throughout the specification, "on a plane" means when the subject part is viewed from above, and "on a cross section" means when the subject part is cut vertically and viewed from the side.

[0037] Hereinafter, a multipurpose jig for manufacturing a secondary battery according to an embodiment of the present invention will be described with reference to FIGS.

[0038] FIG. 1 is a perspective view showing a multipurpose jig for manufacturing a secondary battery according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the multipurpose jig of FIG. 1 taken along II-II, and FIG. 3 is an enlarged front view of part III of the multipurpose jig of FIG. 1.

[0039] The multi-purpose jig according to the embodiment is configured to allow multiple portions of a secondary battery manufacturing apparatus to be set using a single jig. The secondary battery manufacturing apparatus according to the embodiment may be an apparatus for manufacturing a pouch-type secondary battery. For example, the secondary battery manufacturing apparatus may be an apparatus for performing a so-called pre-welding process in which a plurality of positive electrode tabs or negative electrode tabs provided on a plurality of positive electrodes or negative electrodes, respectively, constituting an electrode assembly in a pouch-type secondary battery are fixed by welding, a cutting process in which a portion of the welded positive electrode tabs or negative electrode tabs is cut, or a so-called main welding process in which a lead is attached to the welded positive electrode tabs or negative electrode tabs.

[0040] 1, the multipurpose jig 10 includes a main body 100, a first measuring part 200 protruding from one end of the main body 100 in the longitudinal direction, and a second measuring part 300 formed to have a step at the other end of the main body 100 in the longitudinal direction. Here, the longitudinal direction of the main body 100 may be the y-axis direction in the drawing, and the one end where the first measuring part 200 is formed may be the negative end in the y-axis direction, and the other end where the second measuring part 300 is formed may be the positive end in the y-axis direction.

[0041] The body 100 may be in the form of a rectangular tube including an upper surface 120 and a lower surface 130 formed at the upper (+) and lower (-) ends in the z-axis direction, respectively, and a side surface 110 connecting them. The body 100 may have a size and shape corresponding to the portion where the electrodes and separators of the electrode assembly of the secondary battery are stacked. That is, the thickness a of the body 100 may be the thickness of the portion where the electrodes and separators of the electrode assembly are stacked, and the length b of the body 100 may be the thickness of the portion where the electrodes and separators of the electrode assembly are stacked.

[0042] The first measuring portion 200, which is integrally formed with the body 100 and protrudes from one end of the body 100 in the longitudinal direction, may have a shape similar to an electrode tab in an electrode assembly of a secondary battery. That is, as shown in FIG. 2, the first measuring portion 200 includes an inclined portion 220 extending from the body 100 and a tab-shaped portion 210 protruding from the inclined portion 220. The tab-shaped portion 210 is formed to protrude from the center of the body 100 in the thickness direction. That is, the height h1 between the upper surface 120 of the body 100 and the tab-shaped portion 210 is the same as the height h2 from the lower surface 130 of the body 100 to the tab-shaped portion 210. Therefore, the center of a manufacturing device can be set using the tab-shaped portion 210, as will be described in detail below.

[0043] Meanwhile, the thickness d of the tab-shaping portion 210 may be formed to correspond to the thickness of the electrode tab. Since the thickness of the electrode tab may vary depending on the specifications of the secondary battery to be manufactured, when manufacturing the multi-purpose jig 10 for each secondary battery, by making the thickness d of the tab-shaping portion 210 the same as the thickness of each electrode tab of the secondary battery, it is possible to set the upper and lower devices to appropriate heights in equipment related to the electrode tab, such as a tab guide or electrode tab cutter used in a welding process. Specific examples of this will also be described later.

[0044] 1 and 3, the second measuring unit 300, which is integrally formed with the main body 100 and formed with a step at the other end of the main body 100 in the longitudinal direction, may include a protrusion 310 that protrudes in the same direction as the length of the main body 100 to form the step, and a scale 320 that is formed on the side surface 110 of the main body 100 and extends to a portion corresponding to the protrusion 310. Additionally, a sub-scale 321 may be further included on the side surface 110 of the non-protruding portion. While the step is shown as a staircase shape in this embodiment, this is merely an example and is not limited thereto, and may have a slanted shape, etc., but is not particularly limited thereto. The second measuring unit 300 can be used to check whether the alignment of an appliance having separate upper and lower units is accurate and to set it up. This will be described later with specific examples of use.

[0045] The multi-purpose jig 10 of the embodiment configured as described above can be manufactured using a 3D printer and includes resin as a material, which allows the multi-purpose jig 10 to be manufactured so as to be lightweight and have an accurate size.

[0046] Hereinafter, with reference to FIGS. 4 to 7, an example of using the multipurpose jig according to the embodiment for setting up a secondary battery manufacturing apparatus will be described.

[0047] Figure 4 is a drawing shown to explain a first use example in which the multipurpose jig of Figure 1 is used to set up a secondary battery manufacturing apparatus, Figure 5 is a drawing shown to explain a second use example in which the multipurpose jig of Figure 1 is used to set up a secondary battery manufacturing apparatus, Figures 6a and 6b are drawings shown to explain a third use example in which the multipurpose jig of Figure 1 is used to set up a secondary battery manufacturing apparatus, and Figure 7 is a drawing shown to explain a fourth use example in which the multipurpose jig of Figure 1 is used to set up a secondary battery manufacturing apparatus.

[0048] 4, the center of the electrode tab cutter 30 can be set using the multipurpose jig 10. That is, the electrode tab cutter 30 can include an upper blade 31 and a lower blade 32 centered on the portion where the electrode tab is located, and the upper blade 31 and the lower blade 32 must be accurately positioned around the electrode tab to perform the cutting operation accurately.

[0049] To do this, first, the lower blade 32 is raised to its operating position, the multipurpose jig 10 is placed on the work table 20, and the tab-shaped portion 210 of the first measuring unit 200 is inserted into the portion where the lower blade 32 will be located. If interference occurs between the lower blade 32 and the tab-shaped portion 210, the electrode tab cutter 30 is determined to be set in the correct position. On the other hand, if the lower blade 32 protrudes higher than the tab-shaped portion 210 or if the tab-shaped portion 210 and the lower blade 32 do not come into contact and interfere with each other, it is determined that the electrode tab cutter 30 is not set in the correct position, and the device must be reset. Setting the position of the electrode tab cutter 30 using the multipurpose jig 10 in this manner reduces the reject rate during the cutting process. Furthermore, since the shape of the multipurpose jig 10 remains constant even after repeated setting, it can be reset to the correct position, allowing for accurate and quick setting.

[0050] Meanwhile, in this example, the setting of the center of an electrode tab cutter has been described as an example, but the present invention is not limited to this. The multipurpose jig 10 of this embodiment can also be used to set the upper and lower positions of other devices that place electrode tabs between them to adjust the height of the upper and lower parts, such as an electrode tab press.

[0051] Referring to FIG. 5, the multipurpose jig 10 can be used to set the upper and lower guides 41 and 42 of the tab guide 40 during welding.

[0052] That is, welding may be performed to connect a plurality of positive electrode tabs or a plurality of negative electrode tabs connected to a plurality of positive electrodes or a plurality of negative electrodes included in an electrode assembly of a pouch-type secondary battery, and at this time, a tab guide 40 may be used to gather and secure the plurality of electrode tabs. The electrode tabs secured by the tab guide 40 may be welded using a welding device 50, which may include a welding table (or anvil) 51 and a welding machine (or horn) 52.

[0053] The tab guide 40 includes an upper guide 41 and a lower guide 42, and is set so that the electrode tab can be placed between these upper and lower guides 41, 42. To this end, the multipurpose jig 10 is placed on the workbench 20, and the tab-shaped portion 210 of the first measuring unit 200 is positioned between the upper guide 41 and the lower guide 42. At this time, it is most preferable that the upper guide 41 and the lower guide 42 are each set to a position where they come into contact with the tab-shaped portion 210, and it is preferable that the gap between the tab-shaped portion 210 and each of the guides 41, 42 is at least 0.5 mm or less.

[0054] In addition, although the present embodiment has been described with reference to setting the position of the tab guide 40, the present invention is not limited to this and the multipurpose jig 10 can be used to directly set the position of the welding device 50, or to set and inspect the positions of other devices, including upper and lower devices, by placing the electrode tabs therebetween. By using the multipurpose jig 10 to set the upper and lower positions of devices used in welding, it is possible to minimize the occurrence of defects such as poor welding and broken electrode tabs, and to improve the efficiency of the manufacturing process by enabling quick and accurate device setting.

[0055] 6a and 6b, the multipurpose jig 10 can be used to set the relative alignment of the upper and lower guides 41, 42 of the tab guide 40 during welding.

[0056] 5, the heights of the upper and lower guides 41, 42 based on the tab-shaped portion 210 are set using the first measuring unit 200. In this example, the y-axis positions of the upper and lower guides 41, 42 are set using the second measuring unit 300. First, as shown in FIG. 6a, the multipurpose jig 10 is positioned on the work table 20 so that the end of the protrusion 310 contacts the upper guide 41. Then, the scale 320 is checked to position the upper guide 41 so that there is a predetermined distance between the end of the work table 20 and the upper guide 41.

[0057] 6b, the multipurpose jig 10 is turned over and positioned so that the end of the protrusion 310 contacts the lower guide 42. Then, checking the scale 320, the lower guide 42 is positioned so that the end of the work table 20 and the lower guide 42 have the same gap as the predetermined gap in the upper guide 41. At this time, because the scale 320 is checked with only the upper and lower guides 41 and 42 contacting the protrusion 310, interference that may occur in areas other than those in contact with the protrusion 310 can be prevented even if the multipurpose jig 10 is thick enough overall to have the same thickness as the secondary battery. Therefore, the gap can be measured in a securely intimate state through the scale 320.

[0058] This allows the upper and lower guides 41 and 42 to be aligned at the same position without error. Therefore, by accurately positioning the tab guide 40 at a predetermined position in the length direction of the secondary battery, i.e., in the y-axis direction, it is possible to accurately support the electrode tabs during welding. Furthermore, by aligning the upper and lower guides 41 and 42 at the same position without error, it is possible to prevent welding errors due to improper support of the electrode tabs during welding.

[0059] Although only the tab guide 40 has been described as an example in this embodiment, it can be applied to the setting of various devices that require alignment based on the length direction of the secondary battery, and the auxiliary scale portion 321 formed inside the step together with the scale portion 320 allows setting in various positions and postures.

[0060] Referring to FIG. 7, the multipurpose jig 10 can be used to set the gap between the electrode assembly 60 of the secondary battery and the tab guide 40 while the electrode assembly 60 is placed during welding.

[0061] That is, the electrode assembly 60 is placed on the workbench 20 so that the electrode tab 61 of the electrode assembly 60 is interposed between the upper guide 41 and the lower guide 42. The second measuring unit 300 of the multipurpose jig 10, i.e., the protrusion 310, is then placed above the electrode assembly 60, with the protrusion 310 facing the upper guide 41. The scale 320 can then be used to check whether the gap e between the edge of the separator membrane of the electrode assembly 60 and the upper guide 41 is equal to or less than a predetermined gap, for example, 1 mm, and the position of the electrode assembly 60 can be adjusted to meet this condition. Generally, whether the electrode assembly 60 is inserted in the correct position is determined by simply checking the approximate position with the naked eye before performing a process. However, when the multipurpose jig 10 is used as in this embodiment, the position can be set more precisely using the scale 320, making it possible to accurately set the device in the same position even during multiple processes.

[0062] As described above, the multi-purpose jig according to an embodiment of the present invention can easily and quickly set multiple parts that require setting in a secondary battery manufacturing apparatus using a single jig. Furthermore, even if the setting is performed repeatedly, the same conditions and positions can be set, thereby enabling manufacturing of secondary batteries without errors.

[0063] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the claims also fall within the scope of the present invention. [Explanation of symbols]

[0064] 10: Multipurpose jig 100: Main body 200: 1st measurement section 210: Tab-shaped portion 300: 2nd measurement section 310:Protrusion 320: Scale

Claims

1. A multipurpose jig for setting up an apparatus for manufacturing a secondary battery, a main body portion having a size and shape corresponding to a portion where a plurality of electrodes and separators of the electrode assembly are stacked; a first portion protruding from one longitudinal end of the body portion and having a position and shape corresponding to an electrode tab of the electrode assembly; a second portion formed to have a step at the other end of the main body in the longitudinal direction, The multipurpose jig for manufacturing a secondary battery is used to set the position of a setting portion using the first and second parts as references.

2. The multipurpose jig for manufacturing a secondary battery according to claim 1 , wherein the first portion protrudes from the center of the body in a thickness direction.

3. The multi-purpose jig for manufacturing a secondary battery according to claim 2 , wherein the thickness of the first portion corresponds to the thickness of electrode tabs connected to a plurality of electrodes included in the secondary battery.

4. The multipurpose jig for manufacturing a secondary battery according to claim 1 , wherein a scale portion is located on a side surface of the second portion, the scale portion being formed on a protrusion that protrudes further outward from the step.

5. A method for manufacturing a multipurpose jig for manufacturing a secondary battery according to any one of claims 1 to 4, comprising: A manufacturing method including constructing by a 3D printer.

6. A method for setting a secondary battery manufacturing apparatus using the multipurpose jig for manufacturing a secondary battery according to any one of claims 1 to 4, comprising: moving the multi-purpose jig toward a setting portion of the secondary battery manufacturing apparatus so that the first portion faces the setting portion; and setting a position of the setting portion based on the first portion, The setting portion includes an upper device and a lower device based on electrode tabs connected to a plurality of electrodes included in the secondary battery, The setting method for a secondary battery manufacturing apparatus, wherein the step of setting the position of the setting portion includes a step of confirming whether at least one of the upper device and the lower device contacts at least one of an upper surface and a lower surface of the first portion.

7. A method for setting a secondary battery manufacturing apparatus using the multipurpose jig for manufacturing a secondary battery according to any one of claims 1 to 4, comprising: moving the multi-purpose jig toward a setting portion of the secondary battery manufacturing apparatus; and setting the position of the setting portion based on the second portion; The setting portion includes an upper device and a lower device based on electrode tabs connected to a plurality of electrodes included in the secondary battery, The step of setting the position of the setting portion includes a step of checking through the second part whether the upper device and the lower device are aligned and spaced the same distance from each other from a work table on which the secondary battery is placed.

8. The method of claim 7 , wherein a scale portion is located on a side surface of the second portion, the scale portion being formed on a protruding portion that protrudes further outward from the step.

9. The step of checking through the second part includes: a step of contacting an end of the protrusion with the upper device and measuring a first distance between the work table and the upper device using the scale; turning the multipurpose jig upside down to bring the end of the protrusion into contact with the lower device and measure a second distance between the work table and the lower device using the scale; and 9. The method of claim 8, further comprising the step of checking whether the first gap and the second gap are equal, and correcting the setting portion so that the first gap and the second gap are equal.

10. The step of checking through the second part includes: placing a secondary battery on the work table such that an electrode tab is disposed between the upper device and the lower device; placing the multi-purpose jig on the secondary battery so that a side surface of the secondary battery and the scale portion are parallel to each other; and 9. The method of claim 8, further comprising: setting a distance between an end of a separator of the secondary battery and the upper device to a predetermined value using the scale.

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