Electrode tab welding apparatus and electrode tab welding method

Abstract

According to one embodiment of the present invention, provided is a welding apparatus for welding a plurality of electrode tabs of an electrode assembly, the electrode tab welding apparatus comprising: a tab guide unit including an upper tab guide block and a lower tab guide block provided to be vertically movable so as to collect the plurality of electrode tabs; an air spray unit that sprays air to collect the plurality of electrode tabs; and a welding unit provided to weld a collected portion of the plurality of electrode tabs.

Description

Electrode tab welding device and electrode tab welding method

[0001] The present invention relates to an electrode tab welding device and an electrode tab welding method, and more specifically, to an electrode tab welding device and an electrode tab welding method that effectively increase the replacement time of a tab guide part by preventing damage to a tab guide part that gathers electrode tabs.

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0011262, filed January 24, 2024, the entire contents of which are incorporated herein by reference.

[0003] Recently, rechargeable secondary batteries have been widely used as a power source for wireless mobile devices. Furthermore, secondary batteries are also attracting attention as a potential energy source for electric and hybrid electric vehicles, which are being proposed as a solution to air pollution caused by existing gasoline and diesel vehicles that use fossil fuels. Consequently, the applications that utilize secondary batteries are diversifying significantly due to their advantages, and it is expected that secondary batteries will be applied to a wider range of fields and products in the future.

[0004] In general, secondary batteries are classified into cylindrical and prismatic batteries in which the electrode assembly is built into a cylindrical or prismatic metal can, and pouch-type batteries in which the electrode assembly is built into a pouch-type case made of aluminum laminate sheet, depending on the shape of the battery case. The electrode assembly built into the battery case is a power generator capable of charging and discharging, consisting of a positive electrode, a negative electrode, and a separator structure interposed between the positive and negative electrodes. It is classified into a jelly-roll type in which a separator is interposed between long sheet-shaped positive and negative electrodes coated with an active material and wound, and a stack type in which a plurality of positive and negative electrodes of a predetermined size are sequentially stacked while being interposed between separators.

[0005] Pouch-type secondary batteries are widely used as lithium secondary batteries, in which the electrode assembly is sealed in a pouch made of aluminum. The electrode assembly of a pouch-type secondary battery is housed in a pouch case, which is a sealing material. The pouch type houses the electrode assembly in a pouch made of a flexible polymer material with an irregular shape.

[0006] Figure 1 is an exploded perspective view schematically illustrating the components of a typical pouch-type secondary battery. Figure 2 is a cross-sectional view schematically illustrating the electrode assembly of a conventional pouch-type secondary battery. For reference, the electrode assembly in Figure 2 is shown prior to the process of welding the ends of multiple electrode tabs.

[0007] Referring to FIGS. 1 and 2, the pouch (21), which is a case of a pouch-type secondary battery (30), includes pouch films (21a, 21b) made of a flexible material. The pouch films (21a, 21b) are composed of multiple layers, such as an outer covering layer, a metal barrier layer, and an inner adhesive layer. The pouch film (21b) is formed with a cup-shaped receiving portion (21b1) that receives an electrode assembly (20).

[0008] A pouch-type secondary battery (30) includes an electrode assembly (20) accommodated in a receiving portion (21b1) of a pouch (21). The electrode assembly (20) includes a plurality of electrodes (22) having electrode active materials applied to electrode plates, and electrode tabs (25) connected to each of the electrodes (22). The electrodes include a positive electrode and a negative electrode. The electrode assembly (20) includes a separator (10) interposed between the positive electrode (22a) and the negative electrode (22b).

[0009] A pouch-type secondary battery (30) includes an electrode lead (26). The electrode lead (26) is divided into a positive lead (26a) and a negative lead (26b) according to polarity. The electrode lead (26) is provided with a lead film (27) for electrical insulation of the portion that matches the pouch (21).

[0010] And, the manufacturing process of the pouch-type secondary battery (30) is composed of a receiving step of receiving the electrode assembly (20) in a receiving portion (21b1) formed in a lower pouch film (21b), a sealing step of sealing the remaining edge portions of the pouch except for one side by heat-melting, a liquid injection step of injecting an electrolyte while the electrode assembly (20) is received in the receiving portion (21b1), an activation step of performing initial charging and discharging of the battery, and a sealing step of sealing the edge portions (21b2) of the upper pouch film (21a) and the lower pouch film (21b) by heat-melting.

[0011] Figure 3 is a cross-sectional view schematically showing the welding of electrode tabs of an electrode assembly of a pouch-type secondary battery of the prior art.

[0012] Referring to FIGS. 1 to 3, in the manufacturing process of a secondary battery (30), before the electrode lead (26) and the plurality of electrode tabs (25) are welded together, pre-welding is performed through a welding part (60) while the ends of the plurality of electrode tabs (25) are brought together so that they overlap each other. Therefore, prior to performing the pre-welding, a process of bringing the ends of the electrode tabs together to form a bundle is necessary.

[0013] To this end, in the prior art, by using tab guide blocks (41, 42) to pressurize a plurality of electrode tabs (25) from both sides, the ends of the plurality of electrode tabs (25) could be made into a bundle shape.

[0014] However, in the prior art, when the tab guide blocks (41, 42) press against the upper and lower portions of the plurality of electrode tabs (25) of the electrode assembly (20), the electrode tabs (25) are formed of a metal material, so the collision portions (C) of the tab guide blocks (41, 42) are easily damaged. Accordingly, when the pressing process of the tab guide blocks (41, 42) is repeated multiple times, the tab guide blocks (41, 42) are deformed or damaged, requiring replacement. Furthermore, the tab guide blocks (41, 42) generally use plastic materials for electrical insulation from the electrode tabs, and the tab guide blocks (41, 42) made of plastic, which has lower rigidity (hardness) than metal, are damaged more quickly due to collision with the electrode tabs (25), which leads to a problem in that the replacement time is shortened.

[0015] To solve these problems, there is a need to develop welding devices and welding methods that can be applied to the manufacturing process of secondary batteries.

[0016] The present invention aims to solve problems occurring in a pre-welding process for forming a bundle of multiple electrode tabs of an electrode assembly of a conventional secondary battery.

[0017] Through one embodiment of the present invention, it is intended to provide an electrode tab welding device and an electrode tab welding method using the same, which can buffer the impact of an electrode tab and a tab guide portion by air pressure of air injected to the electrode tab by including an air injection unit that injects air toward the electrode tab.

[0018] In addition, the present invention aims to provide an electrode tab welding device that can easily maintain the ends of a plurality of electrode tabs in a bundle shape by air injection, and an electrode tab welding method using the same.

[0019] In order to solve the above problem, according to one embodiment of the present invention, an electrode tab welding device is provided, which is a welding device for welding a plurality of electrode tabs of an electrode assembly, comprising: a tab guide unit including an upper tab guide block and a lower tab guide block that are arranged to be able to move up and down to gather the plurality of electrode tabs; an air injection unit that injects air to gather the plurality of electrode tabs; and a welding unit that is arranged to weld the gathered portions of the plurality of electrode tabs.

[0020] In addition, the air injection unit may be provided in the tab guide portion. In addition, the air injection unit may be provided to be movable together with the tab guide portion. For example, the tab guide portion may be moved toward or away from a plurality of electrode tabs, and the air injection unit may be moved toward or away from a plurality of electrode tabs when the tab guide portion moves.

[0021] Additionally, the air injection unit may include a lower air injection nozzle mounted on the lower tap guide block, and a first air supply unit connected to the lower air injection nozzle and supplying air.

[0022] Additionally, the lower air injection nozzle may have a first air injection port configured to inject air toward the lowest electrode tab among the plurality of electrode tabs.

[0023] Additionally, the lower air injection nozzle may be positioned at the bottom of the plurality of electrode tabs and may be configured to inject air toward the lowest electrode tab.

[0024] Additionally, the lower air injection nozzle may be provided to inject air while the lower tab guide block moves (rises) toward the electrode tab.

[0025] In addition, the lower air injection nozzle may include a first adjustment guide for adjusting the direction of air discharged through the first air injection port. For example, the first adjustment guide may be provided within the lower air injection nozzle. The first adjustment guide may be provided to be rotatable, and the first adjustment guide may be provided to be rotatable in both the forward and reverse directions, and a driving source such as a first motor may be connected to the rotational axis of the first adjustment guide. At this time, when the first motor is operated, the first adjustment guide may be rotated and the direction of air discharged through the first air injection port may be adjusted. For example, when the lower tap guide block rises, the first adjustment guide may spray air in a first direction that is approximately parallel to the rising direction of the lower tap guide block, may spray air in a second direction closer to the electrode assembly than the first direction, or may spray air in a third direction that is opposite to the second direction and away from the electrode assembly based on the first direction. In this document, the direction away from the electrode assembly may refer to the direction toward the end of the electrode tab (bundle of electrode tabs) where ultrasonic welding is to be performed. In other words, the direction away from the electrode assembly may refer to the direction away from the electrode of the electrode assembly.

[0026] Additionally, the first adjustment guide may be provided to adjust the direction of air discharged through the first air injection port while the lower tab guide block moves toward the electrode tab.

[0027] Additionally, the air injection unit may include an upper air injection nozzle mounted on the upper tab guide block, and a second air supply unit connected to the upper air injection nozzle and supplying air.

[0028] Additionally, the upper air injection nozzle may have a second air injection port configured to inject air toward the uppermost electrode tab among the plurality of electrode tabs.

[0029] Additionally, the upper air injection nozzle may be provided to inject air while the upper tab guide block moves (descends) toward the electrode tab.

[0030] In addition, the upper air injection nozzle may include a second adjustment guide for adjusting the direction of air discharged through the second air injection port. For example, the second adjustment guide may be provided within the upper air injection nozzle. The second adjustment guide may be provided to be rotatable, and the second adjustment guide may be provided to be rotatable in both the forward and reverse directions, and a driving source such as a second motor may be connected to the rotational axis of the second adjustment guide. At this time, when the second motor is operated, the second adjustment guide may be rotated and the direction of air discharged through the second air injection port may be adjusted. For example, when the upper tab guide block is lowered, the second adjustment guide may inject air in a fourth direction that is approximately parallel to the lowering direction of the upper tab guide block, may inject air in a fifth direction closer to the electrode assembly than the fourth direction, or may inject air in a sixth direction that is opposite to the fifth direction and away from the electrode assembly based on the fourth direction. In this document, the direction away from the electrode assembly may refer to the direction toward the end of the electrode tab (bundle of electrode tabs) where ultrasonic welding is to be performed. In other words, the direction away from the electrode assembly may refer to the direction away from the electrode of the electrode assembly.

[0031] Additionally, the second adjustment guide may be provided to adjust the direction of air discharged through the second air injection port while the upper tab guide block moves toward the electrode tab.

[0032] Additionally, the electrode tab welding device may include a control unit for controlling the operation of the tab guide unit and the air injection unit.

[0033] Additionally, the air injection unit may be provided so that at least one of the flow rate and discharge direction of the air is controlled.

[0034] In addition, the control unit can control the air injection unit so that at least one of the air flow rate and discharge direction is adjusted during the movement of the tap guide unit.

[0035] For example, the control unit can control the flow rate of air discharged through the first air injection port and the second air injection port by controlling the first air supply unit and the second air supply unit, respectively. For example, the control unit can maintain the flow rate of air discharged through the first air injection port and the second air injection port constant when the tap guide unit moves.

[0036] In addition, the control unit can adjust the spray direction of the air discharged through the first air injection port and the second air injection port by controlling the first control guide and the second control guide, respectively. For example, the control unit can adjust the spray direction of the air discharged through the first air injection port and the second air injection port when the tap guide unit moves, and can rotate the first control guide and the second control guide, respectively, so that the air is sprayed in a direction away from the electrode assembly while the tap guide unit moves.

[0037] Additionally, each of the upper tab guide block and the lower tab guide block may include a curved surface on a pressing surface that presses the electrode tab.

[0038] In addition, according to another aspect of the present invention, there is provided an electrode tab welding method for welding a plurality of electrode tabs of an electrode assembly in a bundle form using the electrode tab welding device, the method including a placement step of placing the electrode assembly on a mounting stand so that a plurality of electrode tabs are positioned between the upper tab guide block and the lower tab guide block, a spraying step of spraying air toward the electrode tabs through an air spraying unit while the tab guide unit moves, a pressing step of pressing the plurality of electrode tabs up and down by each of the upper tab guide block and the lower tab guide block so that ends of the plurality of electrode tabs are gathered, and a welding step of welding the gathered ends of the plurality of electrode tabs.

[0039] Additionally, the injection step may include a control step of controlling at least one of the flow rate and the injection direction of air injected through the air injection unit.

[0040] In addition, the above-described adjustment step may be provided so that, while the tab guide part is moving, the direction of the air injected through the air injection part is adjusted toward the ends of the plurality of electrode tabs.

[0041] Additionally, the above adjustment step may be arranged so that the direction of air injected through the air injection unit is adjusted to move away from the electrode assembly while the tap guide unit is moving.

[0042] In addition, according to one embodiment of the present invention, a welding method for welding a plurality of electrode tabs of an electrode assembly in a bundle shape using an electrode tab welding device including a tab guide portion including an upper tab guide block and a lower tab guide block and a welding portion provided to weld the gathered portions of the plurality of electrode tabs, the method comprising: a placing step of placing the electrode assembly on a mounting stand so that the plurality of electrode tabs are positioned between the upper tab guide block and the lower tab guide block; a spraying step in which an air spraying portion provided in the tab guide portion sprays air toward the electrode tabs; a pressing step in which each of the upper tab guide block and the lower tab guide block presses the plurality of electrode tabs so that ends of the plurality of electrode tabs are gathered while the air spraying portion sprays air toward the electrode tabs; and a welding step in which the welding portion welds the gathered ends of the plurality of electrode tabs.

[0043] The above air injection unit may, in the injection step, inject air toward the lowest electrode tab among the plurality of electrode tabs through a lower air injection nozzle provided in the lower tab guide block. The lower air injection nozzle may be provided to inject air toward the lower surface of the lowest electrode tab.

[0044] In the above injection step, the lower air injection nozzle can inject air toward the lower portion of the plurality of electrode tabs through a first air injection port in the shape of a slit formed at the upper portion of the body.

[0045] The above lower air injection nozzle can inject air so that air flows between the lowermost electrode tab and the lower tab guide block during the injection step.

[0046] In the above pressurizing step, each of the upper tab guide block and the lower tab guide block can press the electrode tab with a pressurizing surface including a curved surface.

[0047] The above air injection unit can inject air toward the uppermost electrode tab of the plurality of electrode tabs through an upper air injection nozzle mounted on the upper tab guide block in the injection step. The upper air injection nozzle can be configured to inject air toward the upper surface of the uppermost electrode tab.

[0048] In the above injection step, the upper air injection nozzle can inject air toward the upper portion of the plurality of electrode tabs through a second air injection port in the shape of a slit formed at the lower portion of the body.

[0049] The upper air injection nozzle can inject air so that the air flows between the uppermost electrode tab and the upper tab guide block during the injection step.

[0050] As described above, the electrode tab welding device and the electrode tab welding method using the same according to one embodiment of the present invention have the following effects.

[0051] In order to improve the problems in the prior art, an air injection unit that injects air toward the electrode tab when the tab guide unit moves is included, so that the impact between the electrode tab and the tab guide unit can be cushioned by the air pressure of the air injected to the electrode tab.

[0052] In addition, it can reduce manufacturing costs by increasing the life of the upper and lower tab guide blocks, and can help the ends of multiple electrode tabs to be easily formed into a bundle shape by air injection, and can improve the gathered shape of multiple electrode tabs during welding.

[0053] Figure 1 is an exploded perspective view schematically showing the configuration of a typical pouch-type secondary battery.

[0054] Figure 2 is a cross-sectional view schematically showing the appearance of an electrode assembly of a pouch-type secondary battery of the prior art.

[0055] Figure 3 is a cross-sectional view schematically showing the welding of electrode tabs of an electrode assembly of a pouch-type secondary battery of the prior art.

[0056] Figure 4 is a conceptual diagram conceptually illustrating the configurations of an electrode tab welding device according to one embodiment of the present invention.

[0057] FIGS. 5 and 6 are front views schematically showing some components of an electrode tab welding device according to one embodiment of the present invention.

[0058] FIG. 7 is a plan view schematically showing some components of an electrode tab welding device according to one embodiment of the present invention.

[0059] Fig. 8 is a front view schematically showing some components of an electrode tab welding device according to another embodiment of the present invention.

[0060] FIG. 9 is a plan view schematically showing some components of an electrode tab welding device according to another embodiment of the present invention.

[0061] FIG. 10 is a flowchart showing steps of a method for pre-welding an electrode tab using an electrode tab welding device according to one embodiment of the present invention.

[0062] Hereinafter, an electrode tab welding device and a welding method using the same according to one embodiment of the present invention will be described in detail with reference to the attached drawings.

[0063] In addition, regardless of the drawing symbol, identical or corresponding components are given identical or similar reference numbers and redundant descriptions thereof are omitted, and for the convenience of explanation, the size and shape of each component depicted may be exaggerated or reduced.

[0064] Fig. 4 is a conceptual diagram conceptually illustrating the configurations of an electrode tab welding device (100) according to one embodiment of the present invention. In addition, Figs. 5 and 6 are front views schematically illustrating some configurations of an electrode tab welding device (100) according to one embodiment of the present invention.

[0065] Referring to FIGS. 4 to 6, an electrode tab welding device (100) according to an embodiment of the present invention is a welding device (100) for pre-welding a plurality of electrode tabs (25) of an electrode assembly (20). In addition, the electrode tab welding device (100) of the present invention includes a tab guide part (110). The tab guide part (110) is provided to gather a plurality of electrode tabs (25). The tab guide (110) performs a function of gathering a plurality of electrode tabs (25) to form an electrode tab bundle (25c). To this end, the tab guide part (110) includes an upper tab guide block (112) and a lower tab guide block (114) that are provided to be able to move up and down. When forming the electrode tab bundle (25c), the upper tab guide block (112) moves downward, and the lower tab guide block (114) moves upward. In this document, the z-axis may represent the rising / falling direction of the upper tab guide block (112) and the lower tab guide block (114), and the y-axis may represent the direction in which the plurality of electrode tabs extend.

[0066] In addition, the tab guide unit (110) of the electrode tab welding device (100) of the present invention may include an upper moving unit (118) and a lower moving unit (119) provided to move the upper tab guide block (112) and the lower tab guide block (114) in the up-and-down direction, respectively. Each of the upper moving unit (118) and the lower moving unit (119) may include, for example, a hydraulic piston (not shown) or a servo cylinder (not shown). However, the application of the moving unit is not necessarily limited to this configuration, and all moving technologies generally used for moving blocks in a manufacturing process may be applied.

[0067] The above electrode tab welding device (100) includes an air injection unit (120) that injects air to gather the plurality of electrode tabs (25). The air injection unit (120) may be provided to inject air toward at least one of the uppermost electrode tab (25b) and the lowermost electrode tab (25a) to gather the plurality of electrode tabs.

[0068] In addition, the electrode tab welding device (100) includes a welding part (130) provided to weld a gathered portion (25c, electrode tab bundle) of the plurality of electrode tabs (25).

[0069] In addition, the electrode tab welding device (100) of the present invention may include a control unit (140) that controls the operation of the tab guide unit (110), the air injection unit (120), the upper moving unit (118), the lower moving unit (119), and the welding unit (130). For example, the control unit (140) may perform on / off control to control the start and end of air injection of the air injection unit (120). For example, the control unit (140) may perform welding operation control to control the start and end of welding of the welding unit (130). For example, the control unit (140) may control the operation of the upper moving unit (118) and the lower moving unit (119) to control the movement of the tab guide unit blocks (112, 114) in the up and down direction.

[0070] In addition, the control unit (140) may include a microprocessor, a programmable logic controller (PLC), a digital signal processor (DSP), or another central control unit (CCU). The control unit (140) may communicate with each component of the welding device (100) to control synchronized movements and operations, and may collect information from sensors to optimize control of the components during operation. The control unit (140) may include hardware, software, and the like. The control unit (140) may be provided so that a user can smoothly access it through a user interface (UI) and easily perform operation control.

[0071] In addition, the electrode tab welding device (100) of the present invention includes an air injection unit (120). The air injection unit (120) may be provided on one side of the tab guide unit (110). For example, the air injection unit (120) may be mounted on the tab guide unit (110). The air injection unit (120) may be provided to inject air toward one or more of the plurality of electrode tabs (25).

[0072] In addition, the electrode tab welding device (100) of the present invention includes a welding part (130). The welding part (130) is provided to weld the gathered portions of a plurality of electrode tabs (25). The welding part (130) may include a horn (131) and an anvil (132). The horn (131) and the anvil (132) are components for ultrasonic welding. Here, ultrasonic welding refers to a process of welding by bringing two materials into contact with each other and applying energy converted into ultrasonic vibration. Ultrasonic vibration generates heat between the two materials to be joined, and utilizes the principle that the materials melt and fuse due to this heat. The horn (131) serves to transmit ultrasonic vibration to the materials. The horn (131) may include a metal material. The anvil (132) serves to support the materials. The anvil (132) may include a metal material. The size of the anvil (132) may be equal to or larger than the size of the horn (131). For example, the horn (131) and the anvil (132) may have surfaces formed with small protrusions.

[0073] In addition, the welding part (130) may be arranged to perform ultrasonic welding while the horn (131) and the anvil (132) pressurize the ends of a plurality of electrode tabs (25) gathered by the tab guide part (110). At this time, the horn (131) transmits ultrasonic waves to the ends of the electrode tabs (25), so that the bundle (25c) of electrode tabs (25) can be melted and joined by the heat generated.

[0074] The electrode tab welding device (100) of the present invention includes an air injection unit (120) provided in the tab guide unit (110) and injecting air toward the electrode tab (25), thereby buffering an impact between the electrode tab (25) and the lower tab guide block (114) by the air pressure of the air injected to the electrode tab (25). In addition, the present invention can not only increase the lifespan of the lower tab guide block (114) and reduce manufacturing costs, but also help the ends of the plurality of electrode tabs (25) to better have a bundle shape by the air injection, thereby improving the gathered shape of the plurality of electrode tabs (25).

[0075] FIG. 7 is a plan view schematically showing some components of an electrode tab welding device according to one embodiment of the present invention.

[0076] Referring to FIGS. 4 to 6 and 7, the air injection unit (120) may include a lower air injection nozzle (122). The lower air injection nozzle (122) may be coupled to one surface of the lower tab guide block (114). The lower air injection nozzle (122) may be provided to inject air toward the lower portion of the lowest electrode tab (25a) among the plurality of electrode tabs (25). The lower air injection nozzle (122) may have a first air injection port (122h) in the shape of a slit formed at the upper portion of the body. At this time, the slit shape may have a shape that extends long in the width direction of the electrode tab (25).

[0077] The electrode tab welding device (100) of the present invention includes a lower air injection nozzle (122) in which a slit-shaped first air injection port (122h) is formed, so that air can be evenly injected in the width direction according to the width size of the electrode tab (25), thereby maintaining a shape in which the ends of the plurality of electrode tabs (25) are evenly gathered. In addition, air can be evenly injected between the lower tab guide block (114) and the lowest electrode tab (25a), thereby exerting a balanced buffering effect against the collision between the plurality of electrode tabs (25) and the lower tab guide block (114).

[0078] In addition, the air injection unit (120) may include a first air supply unit (124). The first air supply unit (124) may be provided to supply compressed air. The first air supply unit (124) may be connected to the lower air injection nozzle (122) via an air hose (128), etc. The first air supply unit (124) may be provided to generate compressed air. For example, the first air supply unit (124) may be a piston-type air compressor, a screw-type air compressor, a disk-type air compressor, etc. In addition, the first air supply unit (124) may be provided with an air tank for storing compressed air.

[0079] In addition, the lower air injection nozzle (122) can inject air so that air flows between the lowermost electrode tab (25a) and the lower tab guide block (114) while the lower tab guide block (114) moves toward the plurality of electrode tabs (25). That is, the air injection unit (120) can generate a predetermined air pressure between the lower tab guide block (114) and the lowermost electrode tab (25a). This air pressure can buffer the pressing force when the lower tab guide block (114) collides with the lowermost electrode tab (25), thereby effectively preventing damage to the lower tab guide block (114) due to the collision between the electrode tab (25) and the lower tab guide block (114).

[0080] Additionally, each of the upper tab guide block (112) and the lower tab guide block (114) may include a curved surface (B) on the pressing surface that presses the electrode tab (25). This curved surface (B) can reduce the frictional force between the tab guide block and the electrode tab (25), thereby effectively reducing damage to the tab guide block due to pressing.

[0081] The above lower air injection nozzle (122) may include a first adjustment guide (123) for adjusting the direction of air discharged through the first air injection port (122h).

[0082] In addition, the first adjustment guide (123) is provided to adjust the direction of air discharged through the first air injection port (122h) while the lower tab guide block (114) moves toward the electrode tab.

[0083] FIG. 8 is a front view schematically showing some components of an electrode tab welding device (100) according to another embodiment of the present invention, and FIG. 9 is a plan view schematically showing some components of an electrode tab welding device according to another embodiment of the present invention.

[0084] The electrode tab welding device (100) of FIG. 8 may have similar or identical configurations to or different from the electrode tab welding device (100) of FIG. 5, except that it additionally includes an upper air injection nozzle (126).

[0085] Referring to FIGS. 8 and 9, the air injection unit (120) of the electrode tab welding device (100) according to another embodiment of the present invention may include an upper air injection nozzle (126). The upper air injection nozzle (126) may be coupled to one surface of the upper tab guide block (112). The upper air injection nozzle (126) may be provided to inject air toward the upper portion of the uppermost electrode tab (25b) of the plurality of electrode tabs (25). In addition, the air injection unit (120) may include a second air supply unit (127) that is connected to the upper air injection nozzle (126) and supplies air. The second air supply unit (127) may be provided to supply compressed air. The second air supply unit (127) may be connected to the upper air injection nozzle (126) through an air hose (128), etc. The second air supply unit (127) may be configured to generate compressed air. For example, the second air supply unit (127) may be a piston-type air compressor, a screw-type air compressor, a disc-type air compressor, etc. In addition, the second air supply unit (127) may be equipped with an air tank for storing compressed air.

[0086] The above air injection unit (120) may include two air supply units (124, 128) that independently supply air to the lower air injection nozzle (122) and the upper air injection nozzle (126), or may be provided to simultaneously supply air to the lower air injection nozzle (122) and the upper air injection nozzle (126) with a single air supply unit.

[0087] Additionally, a second air injection port (126h) in the shape of a slit for injecting air toward a plurality of electrode tabs (25) at the lower part of the body may be formed in the upper air injection nozzle (126). The slit shape may have a shape that extends long in the width direction of the electrode tabs (25).

[0088] The electrode tab welding device (100) of the present invention includes an upper air injection nozzle (126) in which a slit-shaped second air injection port (126h) is formed, so that air can be evenly injected in the width direction according to the width size of the electrode tab (25), thereby maintaining a shape in which the ends of the plurality of electrode tabs (25) are appropriately gathered. In addition, air can be evenly injected between the upper tab guide block (112) and the uppermost electrode tab (25b), thereby exerting a balanced buffering effect against the collision between the plurality of electrode tabs (25) and the upper tab guide block (112).

[0089] In addition, the upper air injection nozzle (126) can inject air so that air flows between the uppermost electrode tab (25b) among the plurality of electrode tabs (25) and the upper tab guide block (112) while the upper tab guide block (112) moves (descended) toward the plurality of electrode tabs (25). That is, the air injection unit (120) can generate a predetermined air pressure between the upper tab guide block (112) and the uppermost electrode tab (25b). This air pressure can buffer the pressing force when the upper tab guide block (112) collides with the electrode tab (25), thereby effectively preventing damage to the upper tab guide block (112).

[0090] FIG. 10 is a flowchart showing the steps of a method for pre-welding an electrode tab (25) using an electrode tab welding device (100) according to one embodiment of the present invention.

[0091] Referring to FIGS. 3 to 9 and 10, the present invention provides a welding method for welding a plurality of electrode tabs (25) of an electrode assembly (20) in a bundle form using an electrode tab welding device (100).

[0092] Specifically, the welding method of the present invention uses the electrode tab welding device (100) described above. The electrode tab welding device (100) includes a tab guide part (110) including an upper tab guide block (112) and a lower tab guide block (114). The electrode tab welding device (100) includes a welding part (130) provided to weld the gathered portions of a plurality of electrode tabs (25).

[0093] In addition, the above welding method includes a placement step (M01). The placement step (M01) is a step of placing the electrode assembly (20) on the mounting base (180) so that a plurality of electrode tabs (25) are positioned between the upper tab guide block (112) and the lower tab guide block (114). At this time, the ends of the plurality of electrode tabs (25) may be placed between the horn (131) and the anvil (132) of the welding portion (130).

[0094] In addition, the above welding method includes an injection step (M02). The injection step (M02) may be provided such that an air injection unit (120) that injects air injects air toward the electrode tab (25). The air injection unit (120) may be provided in a form coupled to the tab guide unit (110). At this time, the injected air serves to cushion the collision between the tab guide unit (110) and the electrode tab (25).

[0095] In addition, the welding method includes a pressurizing step (M03). The pressurizing step (M03) is a step in which the upper tab guide block (112) and the lower tab guide block (114) each pressurize the plurality of electrode tabs (25) so that the ends of the plurality of electrode tabs (25) are gathered while the air injection unit (120) sprays air toward the electrode tabs (25). That is, the upper tab guide block (112) located above the plurality of electrode tabs (25) can move downward toward the electrode tabs (25). The lower tab guide block (114) located below the plurality of electrode tabs (25) can move upward toward the electrode tabs (25). In the pressurizing step (M03), the upper tab guide block (112) and the lower tab guide block (114) can each pressurize the plurality of electrode tabs (25) while the air injection unit (120) sprays air toward the electrode tabs (25).

[0096] In addition, the above welding method includes a welding step (M04). The welding step (M04) may be a step in which the welding part (130) welds the gathered ends of a plurality of electrode tabs (25). For example, in the welding step (M04), the welding part (130) may perform ultrasonic welding.

[0097] Accordingly, the welding method of the electrode tab related to one embodiment of the present invention includes an injection step (M02) in which the air injection unit (120) provided in the tab guide unit (110) injects air toward the electrode tab (25), thereby buffering the impact between the electrode tab (25) and the tab guide unit (110) by the air pressure of the air injected to the electrode tab (25). In addition, the present invention not only increases the lifespan of the tab guide unit (110) and reduces the manufacturing cost, but also helps the ends of the plurality of electrode tabs (25) to better have a bundle shape according to the air injection, thereby improving the gathered shape of the plurality of electrode tabs (25), thereby effectively increasing the weldability of the bundle of electrode tabs (25).

[0098] Additionally, the air injection unit (120) may be arranged to inject air toward the lower portion of the plurality of electrode tabs (25) through a lower air injection nozzle (122) coupled to one surface of the lower tab guide block (114) in the injection step (M02).

[0099] Additionally, in the injection step (M02), the lower air injection nozzle (122) can inject air to the lower portion of the plurality of electrode tabs (25) through the first air injection port (122h) in the shape of a slit formed in the upper portion of the body.

[0100] Additionally, the lower air injection nozzle (122) can inject air so that air flows between the electrode tab (25) and the lower tab guide block (114) in the injection step (M02).

[0101] Additionally, in the pressurizing step (M03), each of the upper tab guide block (112) and the lower tab guide block (114) can press the electrode tab (25) with a pressurizing surface including a curved surface (B).

[0102] In addition, the air injection unit (120) can inject air toward the upper portion of the plurality of electrode tabs (25) through the upper air injection nozzle (126) coupled to one surface of the upper tab guide block (112) in the injection step (M02).

[0103] Additionally, in the injection step (M02), the upper air injection nozzle (126) can inject air to the upper portion of the plurality of electrode tabs (25) through the second air injection port (126h) in the shape of a slit formed at the lower portion of the body.

[0104] In addition, the upper air injection nozzle (126) can inject air so that air flows between the upper tab guide block (112) and the upper tab guide block (112) at the uppermost electrode tab (25b) among the plurality of electrode tabs (25) in the injection step (M02).

[0105] In addition, the above injection step may include a control step of controlling at least one of the flow rate and injection direction of air injected through the air injection unit (120).

[0106] In addition, the above-described adjustment step may be provided so that, while the tab guide unit (110) is moving, the direction of the air injected through the air injection unit (120) is adjusted to move away from the electrode assembly. In this document, the direction away from the electrode assembly may mean the direction toward the end of the electrode tab (bundle of electrode tabs) where ultrasonic welding is to be performed. In other words, the direction away from the electrode assembly may mean the direction away from the electrode of the electrode assembly.

[0107] For example, referring to FIG. 5, when the lower tab guide block (114) starts to rise, air may be sprayed in a first direction that is approximately parallel to the rising direction (z-axis direction) of the lower tab guide block (114) by the first adjustment guide (123). In addition, referring to FIGS. 6 and 8, when the lower tab guide block (114) comes into contact with the lowermost electrode tab (25a), air may be sprayed in a third direction away from the electrode assembly as the first adjustment guide (123) rotates. The third direction may be a direction toward the contact point between the lower tab guide block (114) and the lowermost electrode tab (25a).

[0108] Likewise, when the upper tab guide block (112) starts to descend, air may be sprayed in a fourth direction (z-axis direction) that is approximately parallel to the descending direction of the upper tab guide block (112) by the second adjustment guide (129). In addition, referring to Fig. 8, when the upper tab guide block (112) comes into contact with the uppermost electrode tab (25b), air may be sprayed in a sixth direction away from the electrode assembly as the second adjustment guide (129) rotates. The sixth direction may be a direction toward the contact point between the upper tab guide block (112) and the uppermost electrode tab (25b).

[0109] The preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art having ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following claims.

[0110] According to an electrode tab welding device and an electrode tab welding method using the same related to one embodiment of the present invention, the impact of the electrode tab and the tab guide can be cushioned by the air pressure of the air sprayed to the electrode tab.

Claims

1. A welding device for welding multiple electrode tabs of an electrode assembly, A tab guide unit including an upper tab guide block and a lower tab guide block that are arranged to be able to move up and down to collect the plurality of electrode tabs; An air injection unit that injects air toward the electrode tabs to collect the plurality of electrode tabs; and An electrode tab welding device including a welding part provided to weld the gathered portions of the plurality of electrode tabs.

2. In paragraph 1, An electrode tab welding device characterized in that the air injection unit includes a lower air injection nozzle mounted on the lower tab guide block, and a first air supply unit connected to the lower air injection nozzle and supplying air.

3. In paragraph 2, An electrode tab welding device characterized in that the lower air injection nozzle has a first air injection port configured to inject air toward the lowest electrode tab among the plurality of electrode tabs.

4. In paragraph 2, An electrode tab welding device characterized in that the lower air injection nozzle is provided to inject air while the lower tab guide block moves toward the electrode tab.

5. In paragraph 3, The above lower air injection nozzle is an electrode tab welding device including a first adjustment guide for adjusting the direction of air discharged through the first air injection port.

6. In paragraph 5, The above first adjustment guide is an electrode tab welding device provided to adjust the direction of air discharged through the first air injection port while the lower tab guide block moves toward the electrode tab.

7. In paragraph 1, An electrode tab welding device characterized in that the air injection unit includes an upper air injection nozzle mounted on the upper tab guide block, and a second air supply unit connected to the upper air injection nozzle and supplying air.

8. In paragraph 7, An electrode tab welding device characterized in that the upper air injection nozzle has a second air injection port configured to inject air toward the uppermost electrode tab among the plurality of electrode tabs.

9. In paragraph 7, An electrode tab welding device characterized in that the upper air injection nozzle is provided to inject air while the upper tab guide block moves toward the electrode tab.

10. In paragraph 8, An electrode tab welding device in which the upper air injection nozzle includes a second adjustment guide for adjusting the direction of air discharged through the second air injection port.

11. In paragraph 10, The above second adjustment guide is an electrode tab welding device provided to adjust the direction of air discharged through the second air injection port while the upper tab guide block moves toward the electrode tab.

12. In paragraph 1, It additionally includes a control unit for controlling the operation of the above tab guide unit and air injection unit, The above air injection unit is provided so that at least one of the air flow rate and discharge direction is controlled, The above control unit is an electrode tab welding device that controls an air injection unit so that at least one of the air flow rate and discharge direction is adjusted during the movement of the tab guide unit.

13. A welding method for welding multiple electrode tabs of an electrode assembly in a bundle form using an electrode tab welding device according to Article 1, A placement step of placing the electrode assembly on a mounting stand so that a plurality of electrode tabs are positioned between the upper tab guide block and the lower tab guide block; A spraying step of spraying air toward the electrode tab through an air spraying unit during movement of the above tab guide unit; A pressing step in which each of the upper tab guide block and the lower tab guide block presses the plurality of electrode tabs up and down so that the ends of the plurality of electrode tabs are gathered; and An electrode tab welding method characterized by including a welding step of welding the gathered ends of the plurality of electrode tabs.

14. In paragraph 13, An electrode tab welding method, wherein the above injection step includes a control step for controlling at least one of the flow rate and injection direction of air injected through an air injection unit.

15. In paragraph 14, The above adjustment step is an electrode tab welding method in which the direction of air injected through the air injection unit is adjusted toward the ends of a plurality of electrode tabs while the tab guide unit is moving.

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