Secondary battery sealing method

Abstract

The sealing method for a secondary battery of the present invention is a method for sealing an electrode lead and a battery case of a secondary battery, and includes the steps of providing a heater in front of a sealing machine, providing an electrode lead between an upper sealer and a lower sealer included in the sealing machine, heating the electrode lead with the heater, sealing the electrode lead and the battery case with the sealing machine, photographing the sealing machine around the heater with a camera arranged in front of the heater to obtain shape information, measuring the temperature of the sealing machine around the heater with a temperature sensor to obtain temperature information, obtaining thermal expansion data according to the temperature of the sealing machine using the shape information, temperature information, and material information about the sealing machine, and measuring the temperature of the electrode lead with the temperature sensor and then predicting the thermal expansion value of the sealing machine at the electrode lead blocked by the heater using the thermal expansion data.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0137564, filed on October 16, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a sealing method for a secondary battery, and more particularly to a sealing method for a secondary battery that can predict the amount of thermal deformation of a gap of a sealer in an invisible area during a sealing process and adjust the gap of the sealer accordingly. [Background technology]

[0003] The sealing thickness of the electrode lead is one of the main quality items (CTQ, Critical to Quality) of secondary batteries, and the gap adjustment of the sealing machine is one of the CTP (Critical to Process) related to the sealing thickness. In other words, in order for the electrode lead of a secondary battery to be sealed to the appropriate thickness, it is important to adjust the gap between the upper and lower sealing parts included in the sealing machine.

[0004] Conventionally, as shown in Figure 1, sealed secondary batteries 10 are sampled at regular intervals, and the thickness of the pouch sealing area around the electrode lead 11 is measured at multiple points through self-inspection, and the gap of the sealing machine is adjusted accordingly. However, this method requires a full inspection to confirm that the product is good when a defect occurs, which results in material, human, and time losses. Therefore, there is an increasing need for a method to measure and manage the gap of the sealing machine in-line during the sealing process without separating the sample during the process, and research into this is underway.

[0005] Previously, attempts were made to introduce smart cameras into the process for in-line production, but the position of the sealing machine, which serves as the measurement reference, was blocked by the heater, making it difficult to take camera images from the front.In addition, there were problems with pallet transfer at the rear, where the heater was not located, making it difficult to take camera images.

[0006] This has led to a demand for the development of a method for measuring and controlling the gap of a sealing machine when the position of the sealing machine serving as a measurement reference is in a non-visible area. Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE INVENTION An object of the present invention is to provide a sealing method for predicting the amount of thermal deformation of a sealing machine in an in-line non-visible area and adjusting the gap of the sealing machine.

[0008] SUMMARY OF THE INVENTION An object of the present invention is to provide a sealing method with improved reliability by adjusting the gap of a sealing machine in-line. [Means for solving the problem]

[0009] a sealing method for a secondary battery according to the present invention for sealing an electrode lead and a battery case of a secondary battery, the method including the steps of: providing a heater in front of a sealing machine; providing the electrode lead between an upper sealer and a lower sealer included in the sealing machine; heating the electrode lead with the heater; sealing the electrode lead and the battery case with the sealing machine; photographing the sealing machine around the heater with a camera arranged in front of the heater to obtain shape information; measuring the temperature of the sealing machine around the heater with a temperature sensor to obtain temperature information; obtaining thermal expansion data according to the temperature of the sealing machine using the shape information, the temperature information, and material information about the sealing machine; and measuring the temperature of the electrode lead with the temperature sensor and then predicting a thermal expansion value of the sealing machine at the electrode lead blocked by the heater using the thermal expansion data.

[0010] In one embodiment, the method may further include adjusting the distance between the upper sealer and the lower sealer according to the predicted thermal expansion value.

[0011] In one embodiment, the camera, the heater, and the sealing machine are aligned in a first direction, and the sealing machine can extend in a second direction perpendicular to the first direction.

[0012] In one embodiment, in the step of predicting the thermal expansion value, the temperature sensor may measure the temperature at a central position of the electrode lead, and the central position may be a central position of the electrode lead in the second direction.

[0013] In one embodiment, the camera may be located in front of the sealing machine.

[0014] In one embodiment, the shape information may be a height measurement along the longitudinal direction of the sealing machine.

[0015] In one embodiment, the temperature sensor may include any one of a resistance temperature sensor (RTD), a thermocouple temperature sensor, and an infrared temperature sensor.

[0016] In one embodiment, the steps of heating and sealing the electrode lead may be performed simultaneously.

[0017] In one embodiment, the sealing material may include at least one of BeCu, WC, AlBe, Inconel 718, and Ni-Be.

[0018] In one embodiment, the secondary battery may include an electrode assembly housed in the battery case, and the electrode leads may protrude from the electrode assembly at both ends of the battery case. [Effects of the Invention]

[0019] The present invention can reliably predict the amount of thermal deformation for a sealing machine at a measurement position in a non-visible area.

[0020] When the sealing method of the present invention is applied, the gap of the sealing machine is measured and controlled during the in-line sealing process, thereby providing a sealing method with improved reliability and process efficiency. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram showing a conventional method for evaluating sealing thickness. [Figure 2] FIG. 2 is a perspective view showing the front surface of the sealing device of the embodiment. [Figure 3] FIG. 2 is a plan view showing the front surface of the sealing device of the embodiment. [Figure 4] 1A-1C illustrate steps in a sealing method according to one embodiment. [Figure 5] 1 is a perspective view showing a secondary battery according to an embodiment; [Figure 6]10 is a graph showing the results of a thermal expansion simulation of an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention may be embodied in various different forms and is not limited to the embodiments set forth herein.

[0023] In order to clearly explain the present invention, parts that are not necessary for the explanation will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0024] 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 various layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0025] Furthermore, when a layer, film, region, plate, or other part is said to be "above" another part, this includes not only the case where it is "directly above" that part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Furthermore, being "above" a reference part means being located above or below the reference part, and does not necessarily mean being "above" in the opposite direction of gravity.

[0026] Furthermore, throughout the specification, when a part "comprises" a certain element, this means that it can further include other elements, but not excluding other elements, unless specifically stated to the contrary.

[0027] 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.

[0028] Although terms indicating directions such as front, back, left, right, up, and down are used, these terms are merely for the convenience of explanation and may vary depending on the position of the object of interest, the position of the observer, etc.

[0029] Preferred examples are presented below to aid in understanding the present invention, but the following examples are merely for illustrative purposes and are not intended to limit the present invention.

[0030] FIG. 2 is a perspective view showing the front of the sealing device of one embodiment.

[0031] FIG. 3 is a plan view showing the front surface of the sealing device of one embodiment.

[0032] FIG. 4 illustrates a step in a sealing method according to one embodiment.

[0033] 2, 3, and 4, a sealing apparatus 1000 according to one embodiment includes a camera 100, a sealing machine 200, a heater 300, a lead device 400, and a temperature sensor 500. The sealing apparatus 1000 further includes a first rail 101, a second rail 102, and a basket 103 for movement of the camera 100.

[0034] The camera 100 can be a known camera including a vision sensor. The camera 100 can directly measure the measurement value of the object being photographed. Specifically, the camera 100 can convert the distance in the detection area (FOV, Field of Vision) into an actual measurement value and express it. The camera 100 can also measure the object being photographed at multiple points, and distance conversion software can be used for the camera 100, lens, lighting, and number of pixels.

[0035] The camera 100 can stably capture the target sealing machine 200 from the front. For example, the camera 100 may be housed in a basket 103 and stably fixed, or may be stably moved on a rail to adjust its position.

[0036] In the present invention, the camera 100 is housed in a basket 103 and can move on a first rail 101 or a second rail 102. The first rail 101 extends in a first direction DR1, and the second rail 102 extends in a second direction DR2 perpendicular to the first direction DR1. The second direction DR2 is defined as a direction parallel to the extension direction of the sealing machine 200.

[0037] The camera 100 can move along the first rail 101 in the direction of transfer of the secondary battery in the sealing machine 200. In addition, the camera 100 can adjust the distance from the sealing machine 200, which is a heat source, and adjust the focus on the detection field of view (FOV) by moving along the second rail 102.

[0038] The first rail 101 and the second rail 102 may be, for example, a long bar-shaped LM rail, but the types of the first rail 101 and the second rail 102 are not limited to this.

[0039] The sealing machine 200 includes an upper sealing machine 210 and a lower sealing machine 220 facing each other, and is mounted on a heating block 230. The upper sealing machine 210 and the lower sealing machine 220 are symmetrical to each other, and the distance between the upper sealing machine 210 and the lower sealing machine 220 is defined as a sealing machine gap. The sealing machine 200 may extend along a second direction DR2.

[0040] Meanwhile, a lead device 400 may be disposed between the upper sealing machine 210 and the lower sealing machine 220. When a secondary battery is installed in the sealing machine 200, the electrode leads of the secondary battery may be provided on the lead device 400. The electrode leads of the secondary battery are placed in the lead device 400 and heated and sealed. Specifically, the electrode leads of the secondary battery are heated by a heater 300 so that they can be sealed at a uniform temperature. For example, the heater 300 may heat the electrode leads to the same temperature as the sealing machine 200, thereby minimizing heat loss due to a temperature difference between the sealing machine 200 and the electrode leads during the sealing process. In addition, the heater 300 is located in front of the sealing machine 200 to minimize heat loss from the electrode leads. In this specification, the front of the sealing machine 200 is defined as the surface of the sealing machine 200 as viewed from the camera 100.

[0041] The heater 300 may include an upper heater 310 and a lower heater 320 that face each other. The upper heater 310 is disposed in front of the upper sealing device 210, and the lower heater 320 is disposed in front of the lower sealing device 220. When the sealing device 1000 is operated, the upper heater 310 and the lower heater 320 move up and down together with the sealing device 200. At this time, the upper heater 310 and the lower heater 320 move up and down with a negative tolerance, so that the heater 300 blocks the lead device 400 and the sealing device 200 in the AA region. The AA region is the region where the lead device 400 is disposed and is used to measure the gap of the sealing device 200, which determines the sealing thickness.

[0042] That is, the heater 300 places the lead device 400 and the sealing machine 200 in the AA region in an invisible area, making direct photography and measurement impossible for the camera 100.

[0043] Therefore, the present invention provides a sealing method for a secondary battery with improved process efficiency by reliably predicting the gap of the sealing machine 200 placed in the AA region.

[0044] a sealing method for a secondary battery according to the present invention for sealing an electrode lead and a battery case of a secondary battery, the method including the steps of: providing a heater in front of a sealing machine; providing the electrode lead between an upper sealer and a lower sealer included in the sealing machine; heating the electrode lead with the heater; sealing the electrode lead and the battery case with the sealing machine; photographing the sealing machine around the heater with a camera arranged in front of the heater to obtain shape information; measuring the temperature of the sealing machine around the heater with a temperature sensor to obtain temperature information; obtaining thermal expansion data according to the temperature of the sealing machine using the shape information, the temperature information, and material information about the sealing machine; and measuring the temperature of the electrode lead with the temperature sensor and then predicting a thermal expansion value of the sealing machine at the electrode lead blocked by the heater using the thermal expansion data.

[0045] Hereinafter, each step of the sealing method for a secondary battery according to the present invention will be described in detail. The same components as those described above are applicable, and detailed description thereof will be omitted.

[0046] The secondary battery in the method for sealing the electrode leads and the battery case of the secondary battery will be described with reference to FIG.

[0047] FIG. 5 is a perspective view showing a secondary battery according to an embodiment.

[0048] FIG. 5 shows a pouch-type battery cell as an example of the secondary battery of the present invention, but the type of secondary battery of the present invention is not limited to this.

[0049] 5, the secondary battery 110 has a structure in which two electrode leads 111 and 112 face each other and protrude from one end 114a and the other end 114b of a battery body 113, respectively. The secondary battery 110 can be manufactured by bonding both ends 114a and 114b of the battery case 114 to one side 114c connecting them, with an electrode assembly (not shown) housed in the battery case 114. In other words, the secondary battery 110 according to this embodiment has a total of three sealing portions 114sa, 114sb, and 114sc, which are sealed by a method such as heat sealing, and the remaining other side may be formed as a connecting portion 115.

[0050] The connecting portion 115 is a region extending elongatedly along one edge of the secondary battery 110, and a protrusion 110p of the secondary battery 110 may be formed at an end of the connecting portion 115. The protrusion 110p may be formed on at least one of both ends of the connecting portion 115 and may protrude in a direction perpendicular to the extension direction of the connecting portion 115. The protrusion 110p may be located between the connecting portion 115 and one of the sealing portions 114sa, 114sb on both ends 114a, 114b of the battery case 114.

[0051] The battery case 114 generally has a laminate structure of a resin layer / a metal thin film layer / a resin layer.

[0052] The sealing method for a secondary battery of the present invention is for forming sealing portions 114sa and 114sb at both ends of the aforementioned secondary battery 110. Specifically, the sealing method for a secondary battery of the present invention can be applied to a method for forming sealing portions 114sa and 114sb by sealing electrode leads 111 and 112 and both ends 114a and 114b of a battery case 114. However, application examples of the present invention are not limited thereto.

[0053] As an example, the secondary battery described below will be understood to be the secondary battery 110 described above in FIG.

[0054] A method for sealing an electrode lead and a battery case of a secondary battery, comprising: The step of providing a heater on the front surface of the sealing machine is a step of providing the heater 300 on the front surface of the sealing machine 200 in order to reduce heat loss in the electrode leads. The upper heater 310 of the heater 300 is disposed on the front surface of the upper sealing machine 210, and the lower heater 320 of the heater 300 is disposed on the front surface of the lower sealing machine 220.

[0055] The step of providing the electrode leads between the upper and lower sealing units included in the sealing machine is a step of providing electrode leads of the secondary battery on a lead device 400 disposed between the upper and lower sealing units 210 and 220. The secondary battery may be provided at the rear surface of the sealing unit 200, and the electrode leads of the secondary battery may be disposed on the lead device 400. Meanwhile, the provided secondary battery is transported along the second direction DR2 of the sealing unit 200.

[0056] The step of heating the electrode lead with the heater is a step of heating the electrode lead placed on the lead device 400 with the heater 300. The heater 300 heats the electrode lead at a uniform temperature to ensure uniform sealing. In addition, the heater 300 heats the electrode lead at the same temperature as the sealing device 200, thereby preventing heat loss due to a temperature difference between the electrode lead and the sealing device 200.

[0057] The step of sealing the electrode leads and the battery case with the sealing machine includes a step of sealing the electrode leads 111 and 112 and both ends 114a and 114b of the battery case 114, as described above in FIG. 5, to form sealing portions 114sa and 114sb. Referring to FIGS. 3 and 4 together, during the sealing step, the gap between the upper sealer 210 and the lower sealer 220 narrows, and the upper heater 310 and the lower heater 320 come into contact, blocking the lead device 400 from view from the front. At this time, the sealer 200 in the AA region where the lead device 400 is located is also blocked by the heater 300. Meanwhile, the sealing step is performed simultaneously with the heating step described above.

[0058] The step of photographing the sealing device around the heater with a camera disposed in front of the heater to obtain shape information includes photographing the sealing device 200 in the BB region with the camera 100 to obtain the shape information. Because the lead device 400 and the sealing device 200 in the AA region cannot be directly photographed or measured with the camera 100, the camera 100 photographs the sealing device 200 in the BB region adjacent to the AA region to obtain the shape information. The BB region may be adjacent to the AA region in the second direction DR2. For example, the BB region may be adjacent to both sides of the AA region in the second direction DR2. In one embodiment, the shape information is a value obtained by measuring the height of the sealing device 200 in the BB region along the longitudinal direction. The shape of the sealing device 200 may change depending on the temperature. Specifically, the sealing device 200 may be thermally deformed, causing its shape to change depending on the temperature. The camera 100 may photograph the shape of the sealing device 200 at a specific temperature to provide the shape information. The shape information thus obtained is used to predict the shape of the AA region at a specific temperature by carrying out a thermal expansion simulation together with temperature information (to be described later) and material information of the sealing machine 200. Related details will be described later.

[0059] The step of measuring the temperature of the sealing device around the heater with a temperature sensor to obtain temperature information is a step of measuring the temperature of the sealing area of ​​the sealing device 200 with the temperature sensor 500. There is a temperature difference between the non-sealing area and the sealing area in the sealing device 200. For example, the temperature of the non-sealing area of ​​the sealing device 200 may be 180°C to 190°C, and the temperature of the sealing area may be 200°C to 250°C. In this step, the temperature of the sealing device 200 is measured in the BB area within the sealing area to obtain the temperature information. Specifically, the temperature is measured at two or more points in the BB area of ​​the sealing device 200, and the average value is used as the temperature information. The temperature sensor 500 may be disposed on top of the sealing device 200 as shown in FIGS. 2 to 4. However, the embodiment is not limited thereto. For example, the temperature sensor 500 may be disposed separately from the sealing device 200. The temperature sensor 500 may be a contact-type temperature sensor or a non-contact-type temperature sensor. For example, the temperature sensor 500 may include, but is not limited to, any one of a resistance temperature sensor (RTD), a thermocouple temperature sensor, and an infrared temperature sensor.

[0060] The step of acquiring thermal expansion data corresponding to the temperature of the sealing device using the shape information, temperature information, and material information about the sealing device includes a step of conducting a thermal expansion simulation using the shape information, temperature information, and material information of the sealing device 200. The temperature information of the sealing device 200 is obtained by measuring the temperature corresponding to the material of the sealing device 200. For example, the sealing device 200 may include at least one of BeCu, WC, AlBe, Inconel 718, and Ni-Be. Specifically, the sealing device 200 may include any one of BeCu, WC, AlBe, Inconel 718, and Ni-Be, for example, the sealing device 200 may include BeCu. However, the material of the sealing device 200 is not limited thereto.

[0061] As in the above method, the shape information, material information, and temperature information according to the material were collected and a thermal expansion simulation was carried out for the sealing machine of one embodiment. The results are shown in Figure 6.

[0062] FIG. 6 is a graph showing the results of a thermal expansion simulation of one embodiment.

[0063] The results of a thermal expansion simulation performed on the sealing machines of Examples 1 to 4 and the Reference Example are shown in Figure 6. The sealing machines of Examples 1 to 4 and the Reference Example are sealing machines of the same shape but made of different materials.

[0064] Example 1 is a sealing machine containing BeCu, Example 2 is a sealing machine containing AlBe, Example 3 is a sealing machine containing Inconel 718, Example 4 is a sealing machine containing an ultra-light alloy (WC, tungsten carbide), and the reference example is a sealing machine containing BeCu. Meanwhile, the materials correspond to the material information of the sealing machines described above.

[0065] The temperature of the sealing machine in the Reference Example is 23°C. The sealing machines in Examples 1 to 4 were heated to an initial temperature of 23°C and simulated at the following temperatures: 210.6°C for Example 1, 210.6°C for Example 2, 210.2°C for Example 3, and 210.2°C for Example 4. At this time, the average natural convection heat transfer coefficient was 20 W / m 2 Calculated as °C.

[0066] That is, the sealing machines of Examples 1 to 4 were simulated at substantially the same temperature. Meanwhile, the temperature corresponds to the temperature information described above, specifically, the temperature was measured at two or more points in the sealing area of ​​each sealing machine and averaged.

[0067] The sealing machines of Examples 1 to 4 and the Reference Example obtained shape information at the above temperatures, and the shape information was displayed in the graph of FIG.

[0068] In the graph of Figure 6, the x-axis represents the length information of the sealing machine. Specifically, the x-axis is measured from 0 mm, where the sealing area begins, to 210 mm in the second direction (DR2, see Figure 2).

[0069] In the graph of Figure 6, the y-axis represents the height information of the sealing machine. Specifically, the y-axis is based on the height of the end of the sealing machine as 0 mm in the direction perpendicular to the first direction (DR1, see Figure 2) and the second direction (DR2, see Figure 2).

[0070] When performing a simulation using the shape information, temperature information, and sealing machine material information described above, predicted thermal expansion data of the sealing machine 200 in the AA region, which is the invisible region, can be obtained as shown in Fig. 6. Based on this, for sealing machines made of the materials of Examples 1 to 4, the thermal expansion value of the sealing machine 200 in the AA region can be predicted even at temperatures different from the temperature information.

[0071] In this manner, the step of obtaining thermal expansion data according to the temperature of the sealing machine can be performed using the shape information, temperature information, and material information about the sealing machine.

[0072] The step of measuring the temperature of the electrode lead with the temperature sensor and then predicting the thermal expansion value of the sealing device at the electrode lead blocked by the heater using the thermal expansion data includes predicting the thermal expansion value of the sealing device 200 at the electrode lead using the thermal expansion data of the AA region obtained in Fig. 6. In order to manage the gap of the sealing device 200, it is necessary to measure the thermal expansion value of the sealing device 200 at the electrode lead blocked by the heater 300 and reflect the result in the process. That is, the step of predicting the thermal expansion value of the sealing device 200 at the AA region using the electrode lead temperature is performed.

[0073] This step includes measuring the temperature of the electrode lead with the temperature sensor 500 and predicting the thermal expansion value of the AA region at the measured electrode lead temperature from the thermal expansion value according to the temperature of the AA region obtained in Fig. 6. At this time, the temperature sensor 500 measures the temperature at the center position of the electrode lead, and the center position means the center position of the electrode lead in the second direction DR2.

[0074] The sealing method for a secondary battery according to the present invention can predict the thermal expansion value of the sealer 200 in the invisible area by carrying out these steps.

[0075] Thereafter, a step of adjusting the gap of the sealer 200, that is, the distance between the upper sealer 210 and the lower sealer 220, may be further performed by reflecting the predicted thermal expansion value in the process.

[0076] The present invention uses the above method to reliably predict the gap of a sealing machine in an invisible area in-line during the sealing process and control the sealing thickness, which is a key quality item, thereby providing a highly reliable and efficient sealing method for secondary batteries.

[0077] 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 following claims also fall within the scope of the present invention. [Explanation of symbols]

[0078] 10 Secondary battery 11 Electrode Lead 100 cameras 101 First Rail 102 Second Rail 103 Basket 110 Secondary battery 110p protrusion 111, 112 Electrode leads 113 Battery body 114 Battery Case 114a, 114b One end 114c One side 114sa, 114sb, 114sc sealing part 115 Connection part 200 Sealing Machine 210 Top Sealing Machine 220 Bottom Sealing Machine 230 Heating Block 300 heater 310 Upper heater 320 Lower heater 400 Lead Device 500 Temperature Sensor 1000 Sealing Device

Claims

1. A method for sealing an electrode lead and a battery case of a secondary battery, comprising: providing a heater in front of the sealing machine; providing the electrode lead between an upper sealer and a lower sealer included in the sealer; heating the electrode lead with the heater; sealing the electrode lead and the battery case with the sealing machine; acquiring shape information by photographing the sealing machine around the heater using a camera disposed in front of the heater; measuring the temperature of the sealing machine around the heater with a temperature sensor to obtain temperature information; obtaining thermal expansion data according to the temperature of the sealing machine using the shape information, the temperature information, and the material information of the sealing machine; measuring the temperature of the electrode lead with the temperature sensor, and then predicting a thermal expansion value of the sealing machine at the electrode lead blocked by the heater using the thermal expansion data.

2. The method of claim 1 , further comprising adjusting a gap between the upper sealer and the lower sealer according to the predicted thermal expansion value.

3. The camera, the heater, and the sealing machine are aligned in a first direction; The method of claim 1 or 2, wherein the sealing device extends in a second direction perpendicular to the first direction.

4. In the step of predicting the thermal expansion value, the temperature sensor measures the temperature at the center of the electrode lead; The sealing method for a secondary battery according to claim 3 , wherein the center position is a center position of the electrode lead in the second direction.

5. The method for sealing a secondary battery according to claim 3 , wherein the camera is disposed in front of the sealing machine.

6. The method of claim 1 , wherein the shape information is obtained by measuring a height along a longitudinal direction of the sealing device.

7. The method of claim 1 , wherein the temperature sensor includes one of a resistance temperature sensor (RTD), a thermocouple temperature sensor, and an infrared temperature sensor.

8. The method of claim 1 , wherein the steps of heating and sealing the electrode lead are performed simultaneously.

9. The method of claim 1 , wherein the sealing material includes at least one of BeCu, WC, AlBe, Inconel 718, and Ni—Be.

10. 2. The method of claim 1, wherein the secondary battery includes an electrode assembly housed in the battery case, and the electrode leads protrude from the electrode assembly at both ends of the battery case.

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