Pallet and lead welding device including same

Abstract

The present invention relates to a pallet, on which an electrode assembly is mounted and conveyed, and a lead welding device including same and, more particularly, to a pallet and a lead welding device capable of protecting an electrode lead during a conveying process. According to an embodiment of the present invention, provided are a pallet and a lead welding device including the pallet, the pallet comprising: an outer support provided to support the electrode assembly at a position spaced a certain distance inward from an end of the electrode assembly in the longitudinal direction, and thereby expose the end of the electrode assembly and the electrode tab to the open air; an inner support that supports the electrode assembly at a position spaced inward from the outer support; and a windscreen that extends out from the outer support in the longitudinal direction of the electrode assembly and covers the front of the electrode tabs.

Description

Pallet and lead welding device including the same

[0001] The present invention relates to a pallet in which an electrode assembly is supported and transported, and a lead welding device including the same. More specifically, it relates to a pallet capable of protecting electrode leads during the transport process, and a lead welding device including the same.

[0002] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, technological development in fields related to such mobile devices is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for expanded development of secondary batteries is increasing.

[0003] Secondary batteries can be provided in pouch, prismatic, and cylindrical types depending on the type and shape of the battery case.

[0004] Currently commercialized rechargeable batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium-ion batteries. Among these, lithium-ion batteries are receiving the most attention due to their advantages of free charging and discharging, low self-discharge rate, and high energy density.

[0005] A lithium secondary battery is manufactured in the order of an electrode process for manufacturing an electrode, an assembly process for manufacturing an electrode assembly by interposing the electrode and a separator and embedding it in a secondary battery case together with an electrolyte to manufacture a secondary battery, and an activation process for shipping the manufactured secondary battery.

[0006] The assembly process may include a lamination and stacking process for manufacturing an electrode assembly by sequentially stacking an anode, a separator, and a cathode, and a lead welding process for bonding electrode leads to the electrode assembly.

[0007] The lead welding process may include detailed processes such as a pre-welding process for assembling and temporarily joining bundles of electrode tabs, a cutting process for aligning and trimming electrode tabs, and a main welding process for welding electrode leads to electrode tabs.

[0008] The above detailed processes are, for example, not performed only on the cathode but also on the anode. In many cases, the anode is located in the opposite direction to the cathode; for example, in the case of a stacking-type electrode assembly, the anode is provided on one side in the longitudinal direction and the cathode is provided on the other side. Therefore, the detailed processes for cathode lead welding and the detailed processes for anode lead welding are not performed simultaneously but can be performed sequentially.

[0009] For this reason, a single electrode assembly can be transported over a very long distance while seated on a pallet until the lead welding process is completed on that electrode assembly.

[0010] The lead welding process is performed on the electrode tabs extending from the body, rather than on the body of the electrode assembly. Therefore, the pallet supports only the body of the electrode assembly while the electrode tab portions are exposed to the air, and the electrode assembly is rapidly transported in the width direction together with the pallet.

[0011] At this time, folding or bending of the electrode tabs may occur during the process of transporting the pallet and the electrode assembly, and especially when the leads are attached to the electrode tabs, there is a risk of damage to the joint portion of the leads due to the flapping of the electrode tabs.

[0012] To increase production efficiency, it is necessary to increase the pallet transfer speed. Additionally, it is necessary to minimize the defect rate in lead welding. However, increasing the pallet transfer speed can cause damage to electrode tabs and leads, which may lead to lead welding defects.

[0013] Therefore, it is necessary to explore ways to prevent damage to electrode tabs and leads and to improve lead welding efficiency, even while increasing the pallet transfer speed or maintaining the current transfer speed.

[0014] The present invention aims to solve the problems of conventional pallets and lead welding devices.

[0015] Through one embodiment of the present invention, we aim to provide a pallet and lead welding device that can effectively prevent folding, bending of electrode tabs and damage to leads that may occur in conventional pallet and lead welding devices.

[0016] Through one embodiment of the present invention, a windbreak structure that can be easily modified or added to current or conventional pallets is provided. Through this, a significantly enhanced manufacturing cost reduction effect is provided relative to additional costs.

[0017] Through one embodiment of the present invention, we aim to provide a pallet and a lead welding device that can be easily changed to a windbreak structure with different lengths and heights as the specifications of the electrode assembly vary in a current or conventional pallet.

[0018] Through one embodiment of the present invention, we aim to provide a lead welding device capable of significantly increasing productivity by increasing the transfer speed of an electrode assembly while simultaneously preventing lead damage.

[0019] To achieve the aforementioned objective, according to one embodiment of the present invention, a pallet is provided on which the electrode assembly is placed and which moves in the width direction of the electrode assembly during a lead welding process in which the electrode tabs of the electrode assembly are joined with leads. Here, the pallet includes a windbreak provided to cover the front of the electrode tabs. Additionally, according to one embodiment of the present invention, a lead welding device including the pallet is provided.

[0020] The above pallet is configured to transport a mounted electrode assembly, wherein the electrode assembly mounted on the pallet is transported in the width direction of the electrode assembly, and the pallet also moves in the width direction of the pallet.

[0021] Specifically, the pallet may include an outer support provided to support the electrode assembly at a position spaced inward by a predetermined length from the longitudinal end of the electrode assembly, thereby exposing the end of the electrode assembly and the electrode tab to the air.

[0022] In other words, interference with the pallet can be eliminated when accessing the end and electrode tab of the electrode assembly from the outside. In particular, a point where the outer support supports the electrode assembly can be pre-set so as to exclude access to the end and electrode tab of the electrode assembly in the vertical direction. This support point setting may be reconfigured as the size of the electrode assembly changes.

[0023] The windbreak may be provided to extend outwardly in the longitudinal direction from the outer support of the electrode assembly to cover the front of the electrode tabs. For example, the windbreak may be a vertical wall erected in front of the electrode tabs.

[0024] That is, the windbreak can be detachably mounted on an outer support. This means that the windbreak is configured independently of the support of the electrode assembly. Therefore, even when the specifications of the electrode assembly change (for example, when the length or height of the electrode assembly changes), a windbreak having a suitable length and height can be easily mounted.

[0025] The above pallet may include an inner support that supports the electrode assembly at a position spaced inward from the outer support.

[0026] The above electrode assembly can be stably supported through an inner support and an outer support, however, the electrode tab portion may be unsupported and exposed to the air so that the lead welding process can be performed.

[0027] It is preferable that the windbreak be provided at the front end of the outer support. The outer support may be formed to be elongated in the width direction of the electrode assembly, corresponding to the width of the electrode assembly. Furthermore, if the transport direction of the pallet is from left to right, the right side can be referred to as the front and the left side as the rear. Accordingly, the right end of the outer support can be referred to as the front end and the left end as the rear end. In other words, it is preferable that the windbreak be provided in the direction from which the wind is blowing.

[0028] Pallets and electrode assemblies can repeatedly transfer and stop within the lead welding device, and can be transported at very high speeds. Pallets and electrode assemblies can be transported in the width direction rather than the length direction. Therefore, during rapid transfer, electrode tabs placed in the air may experience very high air resistance. In other words, the electrode tabs are inevitably exposed to headwinds. These headwinds can be blocked by a windbreak before reaching the electrode tabs.

[0029] It is preferable that the height of the windbreak is greater than the thickness of the electrode assembly.

[0030] It is preferable that the windbreak extends beyond the point where the electrode tabs and the electrode lead are joined. However, it is preferable that the windbreak does not extend to the end of the electrode lead. This is because as the length of the windbreak increases, there is a possibility of interference with the lead insertion device that inserts the electrode lead.

[0031] It may include a stopper provided on the outer support to support the front side of the electrode assembly based on the transfer direction of the electrode assembly.

[0032] The stopper may be provided to determine the mounting position in the width direction of the electrode assembly. The windbreak may be provided integrally with the stopper. Therefore, by changing the height of the stopper and the extension length of the stopper, it may be possible to implement the functions of the stopper and the windbreak through a single configuration.

[0033] The rear surface of the windbreak may form the same surface as the rear surface of the stopper or be located in front.

[0034] The above windbreak can be provided at both one end position and the other end position in the longitudinal direction of the electrode assembly.

[0035] The above windbreak may be provided at only one of the longitudinal end positions of the electrode assembly and the other end position.

[0036] It is preferable that the above windbreak be positioned at the end where lead welding is performed first, between the one end and the other end in the longitudinal direction of the electrode assembly.

[0037] To achieve the aforementioned objective, according to one embodiment of the present invention, an electrode lead welding device for joining leads to electrode tabs of an electrode assembly comprises: a first pre-welding stage for gathering and temporarily joining a bundle of electrode tabs corresponding to a first electrode; a first main stage for welding a first electrode lead to the bundle of electrode tabs temporarily joined in the first pre-welding stage; a second pre-welding stage for gathering and temporarily joining a bundle of electrode tabs corresponding to a second electrode; a second main stage for welding a second electrode lead to the bundle of electrode tabs temporarily joined in the second pre-welding stage; and a linear moving device for moving the pallet and the electrode assembly in the width direction so that the pallet sequentially passes through the first pre-welding stage, the first main stage, the second pre-welding stage, and the second main stage.

[0038] The above linear movement device may include a pallet and may include components for linearly moving the pallet. The above linear movement device may be referred to as an LMS.

[0039] The above stages may be arranged in a line. Devices for performing the corresponding process may be provided on the respective stages. The pre-welding stage may be equipped with a tab guide device that guides the electrode tab bundles to gather in the center by applying vertical pressure to the electrode tab bundles, and a welding device that temporarily joins the electrode tabs.

[0040] The main stage may be equipped with a welding device for bonding electrode leads to electrode tabs. The welding device performing pre-welding and the welding device performing main welding may be of different forms.

[0041] Various devices, such as a cutting device for cutting the temporarily joined electrode tab and an inspection device for inspecting the electrode tab before main welding, may be provided between the pre-welding stage and the main stage. Separate stages may be provided for the cutting process and the inspection process.

[0042] The pallet is configured to transport electrode assemblies, and the corresponding process can be performed by passing through each stage while the electrode assemblies are sequentially placed on the pallet.

[0043] Specifically, the pallet may include an outer support provided to support the electrode assembly with the end of the electrode assembly, the electrode tabs, and the first electrode exposed to the air, and a windbreak provided to extend outward in the longitudinal direction of the electrode assembly from the outer support to cover the front of the electrode tabs.

[0044] The above windbreak may be provided extending beyond the point where the electrode tabs and the first electrode are joined.

[0045] When the position of the first electrode of the electrode assembly is opposite to the position of the second electrode, bonding processes for the first electrode may be performed first, followed by bonding processes for the second electrode. That is, while the bonding processes for the second electrode are being performed, the bonding process for the first electrode is already completed. Therefore, the electrode tabs and electrode leads of the first electrode may be transported for long periods and long distances while welded, and may be continuously exposed to headwinds. For this reason, it is desirable to provide a windbreak at the location where the electrode tabs corresponding to the first electrode are exposed.

[0046] The height of the windbreak may be equal to or greater than the thickness of the electrode assembly.

[0047] It is preferable that the above windbreak be provided at the front end of the above outer support.

[0048] The above windbreak may be provided extending beyond the point where the electrode tabs and electrode leads are joined.

[0049] A stopper may be provided on the outer support to support the front side of the electrode assembly based on the transport direction of the electrode assembly. It is possible to install the windbreak using such a stopper. The windbreak may be provided integrally with the stopper.

[0050] The stopper can be formed in the shape of a block mounted on the front end of the pallet. Accordingly, it is possible to implement the stopper and the windbreak as a single unit by increasing the length of the block and, if necessary, increasing the height.

[0051] Through one embodiment of the present invention, a pallet and lead welding device can be provided that effectively prevents folding, bending of electrode tabs and damage to leads that may occur in conventional pallet and lead welding devices.

[0052] Through one embodiment of the present invention, a windbreak structure that can be easily modified or added to current or conventional pallets can be provided. Through this, a significantly enhanced manufacturing cost reduction effect compared to additional costs can be provided.

[0053] Through one embodiment of the present invention, a pallet and a lead welding device can be provided that allow for easy modification to windbreak structures of different lengths and heights as the specifications of the electrode assembly vary from current or conventional pallets.

[0054] Through one embodiment of the present invention, a lead welding device can be provided that can significantly increase productivity by increasing the transfer speed of the electrode assembly while simultaneously preventing lead damage.

[0055] FIG. 1 is a layout diagram of a lead welding apparatus applicable to an embodiment of the present invention,

[0056] FIG. 2 is a front view of a pallet according to an embodiment of the present invention,

[0057] FIG. 3 is a plan view of the pallet shown in FIG. 2,

[0058] FIG. 4 is a perspective view of the palette shown in FIG. 2,

[0059] FIG. 5 is a front view of a pallet according to another embodiment of the present invention,

[0060] FIG. 6 is a plan view of the pallet shown in FIG. 5, and

[0061] Figure 7 is a perspective view of the palette shown in Figure 5.

[0062] Hereinafter, a lead welding device and a pallet according to an embodiment of the present invention will be described in detail with reference to the attached drawings.

[0063] Figure 1 shows the layout of the entire lead welding apparatus.

[0064] The lead welding device (100) can be described as a device that welds multiple electrode tabs of an electrode assembly together with a single electrode lead. Multiple positive tabs are welded to the positive lead and multiple negative tabs are welded to the negative lead, thereby completing the manufacture of the electrode assembly.

[0065] The electrode assembly, in which lead welding is completed in the lead welding device (100), can be transferred to a device for subsequent processes such as a packaging process that combines with a battery case such as a pouch, an electrolyte injection process, and an activation process.

[0066] Before the lead welding process, electrode assemblies can be manufactured by stacking them using an electrode assembly stacking device. After multiple monocells are stacked in the stacking device, halfcells can be stacked last. Additionally, taping can be performed on the outer surface of the electrode assembly in the stacking device. Electrode assemblies that pass the visual inspection after taping can then be fed into the lead welding process. In other words, a lamination and stacking process can be performed before the lead welding process.

[0067] The electrode assembly (10) that has been laminated in the lamination device can be transferred to the lead welding device (100). To this end, the lead welding device (100) may include a loader (A). The lamination device may include the loader (A). Here, the loader may be a device that feeds the electrode assembly into the welding device and may be a part of the lead welding device (100).

[0068] The electrode assembly (10), which has been stacked in the stacking device, can be moved to the welding stage (B) via the loading device (A). The electrode assembly can be transferred from the loading device (A) to the welding stage (B), specifically the anode pre-welding stage (B1), using a pick-and-place device. That is, the electrode assembly can be moved from the stacking stage to the welding stage via a pick-and-place (PNP) device.

[0069] In the welding stage (B) above, a welding process in which the positive lead and the negative lead are welded can be performed. The welding stage (B) above can be considered the main component of the lead welding device (100).

[0070] The welding process can be performed in multiple detailed processes, and each detailed process can be performed at a different stage.

[0071] The detailed process may include anode pre-welding, anode main-welding, cathode pre-welding, and cathode main-welding. These detailed processes may be performed through the detailed device (110) at individual stages. The individual stages may be arranged in a row.

[0072] Here, pre-welding may include a tab guide process that presses multiple electrode tabs up and down to gather them in the center. After the tab guide process is completed, welding is performed via ultrasonic welding so that the electrode tabs are electrically connected and fixed. This can be referred to as pre-welding.

[0073] To facilitate main welding after pre-welding, a cutting process can be performed to align and cut the electrode tabs.

[0074] Main welding can be described as a process of welding electrode leads so that they are electrically connected and fixed to pre-welded electrode tabs. Therefore, a single electrode lead can be electrically connected and fixed to multiple electrode tabs.

[0075] In the anode pre-welding stage (B1), the anode electrode tabs of the electrode assembly are pre-welded, and then the electrode assembly can be moved to the main welding stage (B2). In the main welding stage (B2), the anode lead can be welded.

[0076] Afterwards, the cathode electrode tabs of the electrode assembly are pre-welded in the cathode pre-welding stage (B3), and then the electrode assembly can be moved to the main welding stage (B4). In the main welding stage (B4), the cathode lead can be welded.

[0077] That is, pre-welding and main welding of the cathode can be performed after pre-welding and main welding of the anode. Of course, pre-welding and main welding of the anode can be performed after pre-welding and main welding of the cathode.

[0078] In the above plurality of stages (B1 to B4), the electrode assembly (10) can be transported through a linear motion system or a linear moving system (20, LMS). The above linear motion system can be referred to as a linear moving device. It includes a plurality of pallets (30), and the electrode assembly (10) can be placed on the pallets. That is, the electrode assembly (10) moves sequentially through the stages while positioned on the pallets, and through this, the first electrode lead and the second electrode lead are sequentially welded so that the welding process is completed overall.

[0079] The electrode assembly, after the welding process is completely finished, is transferred to the unloading machine (C) via a pick-and-place device.

[0080] The above welding machine (B) is equipped with a linear motion system, so that multiple pallets move linearly. That is, electrode assemblies placed on the pallets move linearly in sequence through the linear motion system.

[0081] A linear motion system can be described as a system in which multiple pallets (20) are arranged at regular intervals on a circular track, and multiple pallets simultaneously move and stop at regular intervals.

[0082] The electrode assembly (10) can be transferred from the welding stage (B) to the unloading machine (C) using a pick-and-place device. In particular, it can be transferred from the cathode main welding stage (B4) to the unloading machine (C). The electrode assembly (10) is positioned at the transfer location (P, first point) of the welding stage (B) immediately before being transferred to the unloading machine (C). Here, the transfer location (P) can be described as the location where the electrode assembly is placed on a pallet immediately before being transferred to the unloading machine (C) after the welding process of the electrode assembly is completely completed.

[0083] The unloading machine (C) may be equipped with a shuttle (Q, R) device for transporting the electrode assembly. The shuttle device can be described as a device for transporting the electrode assembly from a specific location to a specific location while moving back and forth.

[0084] First, the shuttle (Q, R) device may include a first shuttle (Q) and a second shuttle (R). The first shuttle (Q) is configured to receive an electrode assembly transferred from the welding stage (B), and the second shuttle (R) is configured to receive an electrode assembly transferred from the first shuttle (Q). The second shuttle may be configured to transfer multiple electrode assemblies as a single unit after multiple electrode assemblies have been received.

[0085] The lead welding device (100) includes a wide variety of detailed devices (100), so it can also be called a lead welding facility.

[0086] As illustrated in FIG. 1, the electrode assembly (10) is positioned to move in the width direction in the welding device (100). The electrode assembly (10) moves in a straight line in the welding device (100). If the electrode assembly (10) has a rectangular shape, the pallet (30) may also have an overall rectangular shape, and the pallet also moves in the width direction.

[0087] FIGS. 2 to 4 illustrate an electrode assembly (10) placed on a pallet (30) that can be applied to the present invention.

[0088] FIG. 3 shows a plan view in which an electrode assembly (10) is seated on a support of a pallet, and the electrode assembly (10) is shown with a dotted line.

[0089] The electrode assembly (10) may include a body (11) formed by sequentially stacking an anode, a separator, and a cathode, with a separator provided on the outermost layer (top layer and bottom layer), electrode tabs (13, 15) protruding from the end of the body, and electrode leads (14, 15) joined to the electrode tabs.

[0090] The electrode assembly (10) may have a body (11) formed in the shape of a flat plate, and the shape of the body may be rectangular. A first electrode lead (14) and a second electrode lead (16) may be provided on both sides of the short side.

[0091] A single electrode and a single electrode tab are formed through an aluminum foil or a copper foil. Thus, the single electrode tab has a very thin thickness. The electrode tabs (13, 15) protruding from the body (11) form a bundle, and these electrode tab bundles are gathered and temporarily joined. Main welding can be performed by joining electrode leads (14, 16) to the temporarily joined electrode tabs (13, 15).

[0092] The pallet (30) may include a base (31), a support member (33) that supports the lower surface of the electrode assembly (10), and a post (32) that supports the support member (33) with respect to the base (31). The base, the support member, and the post are provided to be movable as a single unit. As the base (31) moves through a transfer device such as a transfer rail or conveyor of the LMS, the entire pallet (30) can move.

[0093] The support member (33) may include an inner support member (33a) provided on both sides at the center of the electrode assembly body (11) and an outer support member (33b) that supports the end portions of the body (11). The outer support member may be provided to support only one end portion of either end or to support both ends.

[0094] The support portion (33) may be formed as a single plate, and the inner support portion (33a) and the outer support portion (33b) may be provided to correspond to the width of the electrode assembly body (11). The entire width of the electrode assembly body (11) may be supported through the inner support portion and the outer support portion. A recess (33c) that narrows in width may be provided between the inner support portion and the inner support portion, and between the inner support portion and the outer support portion. Accordingly, the recess (33c) also supports the electrode assembly body (11), but only a part of the entire width.

[0095] The inner support member (33a) is provided in two places to support both sides at the center of the electrode assembly, and a post (32) is positioned between the inner support member (33a) and the base (31).

[0096] As the rapid transport and stopping of the pallet (30) are repeated, the alignment of the electrode assembly (10) may become misaligned. Additionally, when the electrode assembly is initially placed on the pallet (30), the alignment position of the electrode assembly needs to be accurately set. For this reason, stoppers (34a, 34b) may be provided to prevent movement of the electrode assembly (10) in the width direction.

[0097] The stoppers (34a, 34b) may include an inner stopper (34a) provided to protrude upward from the front and / or rear end of the inner support member and an outer stopper (34b) provided to protrude upward from the front and / or rear end of the outer support member.

[0098] The stoppers (34a, 34b) may protrude upward from the upper surface of the support member (33). For example, when the side of the electrode assembly (10) comes into contact with both the inner stopper (34a) and the outer stopper (34b), the electrode assembly may be aligned in the width direction.

[0099] The stoppers (34a, 34b) may be formed in a block shape and may be detachably provided on the support member (33). That is, the size and height of the stoppers may change as the size of the electrode assembly varies.

[0100] As described above, in an electrode assembly (10) moving along a welding stage (B), welding for the first electrode is first performed in a pre-welding stage (B1) and a welding stage (B2), and subsequently, welding for the second electrode is performed in a pre-welding stage (B3) and a welding stage (B4). The detailed device configurations for performing the process in B1 and B2 may be identical to the detailed device configurations (110) for performing the process in B3 and B4.

[0101] As illustrated, in the electrode assembly (10), the first electrode lead (14) is positioned opposite to the second electrode lead (16). That is, it has a 180-degree phase.

[0102] At this time, the detailed device configurations may be positioned on the upper side in the y direction at B1 and B2, and the detailed device (110) configurations may be positioned on the lower side in the y direction at B3 and B4. In this case, welding of the first electrode may be performed on the upper side and welding of the second electrode may be performed on the lower side. Therefore, a change in the orientation or a 180-degree change in position of the electrode assembly is not required.

[0103] In order to configure an efficient layout of the lead welding device (100), it may be desirable to place all the detailed devices (110) for performing pre-welding, temporary bonding, cutting, and main welding on one side, for example, on the upper side in the y direction. However, in this case, it is desirable to rotate the electrode assembly (10) 180 degrees in the xy plane between B2 and B3.

[0104] Accordingly, the first electrode is adjacent to the detailed device (110) in B1 and B2, and the second electrode is adjacent to the detailed device (110) in B3 and B4 by 180-degree inversion of the electrode assembly.

[0105] As described, the pallet provided in the welding device does not support the entire length of the electrode assembly (10). The outer support (33b) may be provided to support the area near the end of the electrode assembly with the end of the electrode assembly and the electrode tabs (13, 15) exposed to the air.

[0106] Accordingly, the temporary joining, cutting, and main welding of the electrode tabs (13, 15) can be performed without interference from the pallet (20). Additionally, the electrode leads (14, 16) after the main welding are also exposed to the air. In particular, since the outer support (33b) supports the electrode assembly at a predetermined distance inward from the end of the electrode assembly, a longitudinal clearance and an upward / downward clearance can be secured so that the detailed device (110) can access the electrode tabs.

[0107] The illustrated reference numeral 17 is a lead tape. With the lead tape (17) attached to the electrode lead, the electrode lead can be main welded to the electrode tab.

[0108] Hereinafter, an embodiment of a pallet equipped with a windbreak will be described in detail with reference to FIGS. 5 to 7. Descriptions that overlap with the previously described embodiment will be omitted.

[0109] Based on the pallet and electrode assembly shown in Fig. 6, the pallet and electrode assembly can move linearly from left to right. Therefore, the right end can be called the front end and the left end the rear end.

[0110] As described above, in this embodiment, a pallet (30) equipped with a windbreak (46) may be provided. The windbreak (46) may be provided to cover the front of the electrode tabs. That is, when the pallet (30) moves, the windbreak may be provided to block the headwind before the headwind reaches the electrode tab (13).

[0111] The above windbreak (46) needs to be mounted or installed on the pallet (30). That is, it is preferable that it be provided to move integrally with the pallet as part of the pallet's configuration.

[0112] It is preferable that the windbreak (46) extends outward in the longitudinal direction from the outer support (33b) of the electrode assembly (10) to cover the electrode tab (13). In particular, it is preferable that the windbreak (46) be provided at the front end of the outer support (33b).

[0113] It is preferable that the height of the windbreak (46) be equal to or greater than the thickness of the electrode assembly.

[0114] It is preferable that the windbreak (46) be provided extending beyond the point where the electrode tabs and electrode lead (14) are joined. The electrode tabs are joined to a single electrode lead at the point where they are gathered and in close contact. The electrode tabs are formed by a thin sheet. Therefore, the electrode tabs may flap due to the headwind at the point where the electrode tabs and electrode lead (14) are joined. This may reduce the bonding strength at the joining point. In particular, when the electrode assembly is transported at a very high speed, it is possible for the electrode tabs to separate at the joining point due to a strong headwind. This may cause performance degradation and defects in the secondary battery.

[0115] For this reason, it is preferable to provide a windbreak (46) that covers the entire electrode tabs and even covers the point where it is joined to the electrode lead.

[0116] A stopper (34b) may be provided on the outer support (33b) to support the front side of the electrode assembly (10) based on the direction of transport of the electrode assembly. The windbreak (46) may be mounted using the stopper (34b).

[0117] In the case where the stopper is configured to be mounted on the outer support (33b), the windbreak can be formed integrally with the stopper. That is, the windbreak (46) can additionally perform the function of the stopper.

[0118] The rear surface of the windbreak (46) may form the same surface as the rear surface of the stopper (34b) or be located in front.

[0119] The above windbreak (46) can be provided at both one end position and the other end position in the longitudinal direction of the electrode assembly (10).

[0120] The position of the electrode assembly can be maintained until lead welding for both the first electrode and the second electrode is completed. That is, a 180-degree inversion may not be performed. In this case, the windbreak (46) may be provided on both outer supports. The windbreak may be provided on the front of both outer supports.

[0121] After lead welding for the first electrode is completed, the electrode assembly can be inverted 180 degrees. Subsequently, lead welding for the second electrode can be performed. Based on the electrode assembly (10) shown in FIG. 7, the first electrode can be denoted by reference numeral 14 and the second electrode by reference numeral 17.

[0122] In this case, the windbreak (46) may be provided on only one outer support, rather than on both outer supports. That is, it is preferable that the windbreak (46) be provided on the outer support (33b) supporting the area near the first electrode when lead welding is performed on the second electrode. That is, it is preferable that the windbreak (46) be located at the end where lead welding is performed first, between the one end and the other end in the longitudinal direction of the electrode assembly (10).

[0123] As illustrated in FIG. 7, a welding machine (50) may be provided for electrode lead welding. The welding machine (50) may include a feeder for feeding electrode leads (16) into electrode tabs and a welder for welding after contact between the electrode tabs and the electrode leads.

[0124] Therefore, mechanisms for accessing the electrode tabs can move back and forth and / or up and down. For this reason, sufficient space is required for lead welding. On the other hand, sufficient space is not required for the other electrode (14) where lead welding is completed. For this reason, an outer support (33b) is provided on the side of the electrode lead (14) where lead welding is completed, and the outer support may be omitted on the side of the electrode (16) where lead welding is performed.

[0125] The electrode lead (14) after lead welding is completed travels a long distance until the main welding of another electrode lead (16) is completed. That is, the joint point between the electrode tab and the electrode lead (14) may be exposed to headwinds for a long time and over a long distance. Therefore, such exposure can be prevented in advance through the windbreak (46).

[0126] As described in the detailed description of the invention.

Claims

1. In a lead welding process for joining electrode tabs of an electrode assembly with leads, on a pallet on which the electrode assembly is placed and which moves in the width direction of the electrode assembly, An outer support provided to support the electrode assembly at a position spaced inward by a predetermined length from the longitudinal end of the electrode assembly, thereby exposing the end of the electrode assembly and the electrode tab to the air; An inner support that supports the electrode assembly at a position spaced inward from the outer support; and A pallet comprising a windbreak that extends outwardly in the longitudinal direction of the electrode assembly from the outer support and is provided to cover the front of the electrode tabs.

2. In Paragraph 1, A pallet characterized in that the windbreak is provided at the front of the outer support.

3. In Paragraph 2, A pallet characterized in that the height of the windbreak is greater than the thickness of the electrode assembly.

4. In Paragraph 3, A pallet characterized in that the windbreak is provided extending beyond the point where the electrode tabs and electrode leads are joined.

5. In Paragraph 2, A pallet characterized by including a stopper provided on the outer support to support the front side of the electrode assembly based on the conveying direction of the electrode assembly.

6. In Paragraph 5, A pallet characterized in that the windbreak is integrally provided with the stopper.

7. In Paragraph 6, A pallet characterized in that the rear surface of the above windbreak forms the same surface as the rear surface of the above stopper or is located in front of it.

8. In Paragraph 2, A pallet characterized in that the windbreak is provided at both one end position and the other end position in the longitudinal direction of the electrode assembly.

9. In Paragraph 2, A pallet characterized in that the windbreak is positioned at the end where lead welding is performed first, between one end position and the other end position in the longitudinal direction of the electrode assembly.

10. A lead welding device for joining a lead to an electrode tab of an electrode assembly, A first pre-welding stage for gathering and temporarily joining electrode tab bundles corresponding to the first electrode; A first main stage for welding a first electrode lead to an electrode tab bundle temporarily joined in a first pre-welding stage; A second pre-welding stage for gathering and temporarily joining electrode tab bundles corresponding to the second electrode; A second main stage for welding a second electrode lead to an electrode tab bundle temporarily joined in a second pre-welding stage; and The apparatus includes a pallet on which the electrode assembly is placed, and a linear movement device that moves the pallet and the electrode assembly in the width direction so that the pallet sequentially passes through the first pre-welding stage, the first main stage, the second pre-welding stage, and the second main stage. The above pallet is an electrode lead welding device comprising an outer support provided to support the electrode assembly with the end of the electrode assembly, the electrode tabs, and the first electrode exposed to the air, and a windbreak provided to extend outward in the longitudinal direction of the electrode assembly from the outer support to cover the front of the electrode tabs.

11. In Paragraph 10, The electrode lead welding device is characterized by the above windbreak being provided to extend beyond the point where the electrode tabs and the first electrode are joined.

12. In Paragraph 11, An electrode lead welding device characterized in that the height of the windbreak is greater than the thickness of the electrode assembly.

13. In Paragraph 11, The electrode lead welding device is characterized in that the windbreak is provided at the front end of the outer support.

14. In Paragraph 3, An electrode lead welding device characterized in that the above windbreak is provided extending beyond the point where the electrode tabs and electrode leads are joined.

15. In Paragraph 10, An electrode lead welding device characterized by including a stopper provided on the outer support to support the front side of the electrode assembly based on the transfer direction of the electrode assembly, and the windbreak being provided integrally with the stopper.

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