Method for bending lead of battery

Abstract

A method for bending a lead, according to the present invention, is a method for bending a first lead protruding from a battery cell stack positioned on one side of a first direction of a bus bar frame assembly including a bus bar and a bus bar frame for accommodating the bus bar, to the other side of the first direction of the bus bar frame assembly. The method includes the steps of: positioning a bending tool on one side of the first lead in a second direction perpendicular to the first direction; tilting the first lead to the other side in the second direction by pressing the first lead by moving the bending tool to the other side in the second direction; adhering the first lead to the bus bar frame assembly by pressing the first lead by moving the bending tool to one side in the first direction; sliding the bending tool with respect to the first lead by moving the bending tool to the other side in the second direction; and moving the bending tool to the other side in the first direction.

Description

How to bend battery leads

[0001] The present invention relates to a method for bending a lead of a battery.

[0002] Secondary batteries, which can be recharged and discharged, are widely used in mobile devices such as digital cameras, mobile phones, and laptops. They have recently attracted attention as an energy source for electric vehicles and energy storage systems (ESS). Meanwhile, as electric vehicles and ESS demand large capacity and high output, medium- to large-sized battery devices, such as battery modules housing multiple secondary batteries within a housing or battery packs comprising multiple battery modules, are becoming widely used.

[0003] Since mid- to large-sized battery devices are preferably manufactured with the smallest possible size and weight, square and pouch-shaped battery cells, which can be stacked with high integration and have a small weight-to-capacity ratio, are primarily used as battery cells (unit cells). In particular, pouch-shaped battery cells, which utilize aluminum laminate sheets as external components, have recently attracted significant attention due to their advantages, including light weight, low manufacturing costs, and ease of shape modification.

[0004] Meanwhile, to electrically connect the battery cells that make up these medium- to large-sized battery devices, the battery cell leads are welded to busbars. Before welding the battery cell leads to the busbars, the battery cell leads are bent to ensure they adhere tightly to the busbars.

[0005] However, if bending is performed using a conventional bending method, there is a risk of various problems such as deformation of the battery and deterioration of bending quality.

[0006] The present invention was created in consideration of the above-described problems, and relates to a method for bending a battery lead, and more particularly, to provide a method for bending a battery lead that can minimize deformation of the battery due to the bending process.

[0007] A battery lead bending method according to one embodiment of the present invention is a method of bending a first lead protruding from a battery cell laminate located on one side of a busbar frame assembly in the first direction, which includes a busbar and a busbar frame accommodating the busbar, to the other side of the busbar frame assembly in the first direction,

[0008] The method comprises the steps of: positioning a bending tool on one side of a second direction perpendicular to the first direction of a first lead; pressing the first lead by moving the bending tool to the other side of the second direction to tilt the first lead to the other side of the second direction; pressing the first lead by moving the bending tool to one side of the first direction to bring the first lead into close contact with the busbar frame assembly; sliding the bending tool to the other side of the second direction to the first lead; and moving the bending tool to the other side of the first direction.

[0009] The step of positioning the bending tool on one side of the second direction of the first lead may be such that the distance along the first direction between the bending tool and the busbar frame assembly may be half the length of the first lead protruding to the other side of the busbar frame assembly in the first direction.

[0010] In the step of tilting the first lead toward the second direction by pressing the first lead by moving the bending tool toward the second direction, the bending tool can be moved to a position where the front end surface of the bending tool and the bending start point of the first lead at least partially overlap.

[0011] In the step of tilting the first lead toward the second direction by pressing the first lead by moving the bending tool toward the second direction, the bending tool can be moved to a position where the center of the second direction end face of the bending tool overlaps with the bending start point of the first lead.

[0012] In the step of pressing the first lead by moving the bending tool to one side in the first direction to bring the first lead into close contact with the busbar frame assembly, the bending tool can press the busbar frame assembly so that the busbar frame assembly is elastically deformed to one side in the first direction.

[0013] In the step of moving the bending tool to the first direction side, the busbar frame assembly can be at least partially elastically restored as the bending tool is retracted to the first direction side.

[0014] The lead bending method is, after the step of moving the bending tool to the first direction,

[0015] The step of bending the second lead protruding from the second direction other side of the first lead to the first direction other side of the busbar frame assembly may be further included.

[0016] The step of bending the second lead protruding from the second direction other side of the first lead to the first direction other side of the busbar frame assembly may include the steps of: positioning a bending tool on the second direction other side of the second lead; moving the bending tool to one side in the second direction to pressurize the second lead and tilt the second lead to one side in the second direction; moving the bending tool to one side in the first direction to pressurize the second lead to bring the second lead into close contact with the busbar frame assembly; and further moving the bending tool to one side in the second direction to slide it relative to the first lead.

[0017] In the step of positioning the bending tool on the second direction side of the second lead, the distance in the first direction between the bending tool and the busbar frame assembly may be greater than the distance in the first direction between the end of the first lead and the busbar frame assembly caused by elastic restoration of the first lead.

[0018] The first lead may have a length protruding from the busbar frame assembly that is less than the distance between the first lead and the second lead.

[0019] The first lead may have a length protruding from the busbar frame assembly that is less than the distance between the first lead and the second lead minus half the width of the bending tool in the second direction.

[0020] The bending tool may be insulated.

[0021] According to one aspect of the present invention, a bending tool can reduce the force required to tilt a first lead and at the same time ensure stability during the tilting process. The force required to tilt the first lead can be proportional to the minimum stress required to bend the first lead divided by the distance between the bending tool and the point where the first lead is bent. Therefore, the closer the bending tool is to the busbar frame assembly, the closer the bending tool is to the point where the first lead is bent, and thus the greater the force applied by the bending tool to tilt the first lead. Therefore, the busbar frame assembly can be pushed due to the repulsive force of the first lead during the tilting process. However, the farther the bending tool is from the busbar frame assembly, the greater the risk that the first lead may escape the constraints of the bending tool during the tilting process. Therefore, in the above-mentioned steps, the bending tool can reduce the force required to tilt the first lead and at the same time ensure stability.

[0022] According to another aspect of the present invention, in the step of pressing the first lead to bring the first lead into close contact with the busbar frame assembly, the first lead can be easily bent because the point where the first lead is to be bent is pressed by the leading edge of the bending tool. In particular, when the center of the leading edge along the second direction presses the point where the first lead is to be bent, the first lead can be bent most easily. Therefore, the problem of the first lead being lifted off the busbar frame assembly due to the restoring force of the first lead can be minimized.

[0023] According to another aspect of the present invention, the first lead can be prevented from being separated due to elastic restoration of the busbar frame assembly.

[0024] According to another aspect of the present invention, the first lead and the second lead may be bent in a direction that brings them closer to each other, and in particular, may be provided so that at least one area overlaps them. This may contribute to preventing deformation of the battery cell.

[0025] According to another aspect of the present invention, in the step of tilting the second lead by pressing the second lead, the elastically restored first lead can be pressed by the second lead and brought back into close contact with the busbar frame assembly.

[0026] Fig. 1 illustrates a battery cell stack including a lead bent by a lead bending method according to the present invention.

[0027] FIG. 2 is a drawing showing a battery cell stack and busbar frame assembly including a lead bent by a lead bending method according to the present invention.

[0028] Figure 3 is a drawing showing a bending tool and a lead used in a lead bending method according to the present invention.

[0029] Figures 4 to 18 are drawings showing steps included in a lead bending method according to the present invention.

[0030] Before going into the detailed description of the present invention, it should be noted that the terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted with meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term in order to explain his own invention in the best way. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of ​​the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of this application.

[0031] The same reference numbers or symbols used in each drawing attached to this specification represent parts or components that perform substantially the same functions. For convenience of explanation and understanding, the same reference numbers or symbols may be used in different embodiments. In other words, even if components with the same reference numbers are depicted in multiple drawings, they do not necessarily represent a single embodiment.

[0032] In the following description, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "comprises" or "comprises" should be understood to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0033] In addition, in the description below, expressions such as top, upper, lower, lower, side, front, and rear are expressed based on the direction shown in the drawing, and it is noted in advance that they may be expressed differently if the direction of the object in question changes.

[0034] Additionally, terms including ordinal numbers, such as "first," "second," etc., may be used in this specification and claims to distinguish between components. These ordinal numbers are used to distinguish identical or similar components from each other, and the use of these ordinal numbers should not be interpreted in a limited manner. For example, components associated with these ordinals should not be interpreted in a restricted manner, such as in the order of use or arrangement, based on their numbers. If necessary, each ordinal number may be used interchangeably.

[0035] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. However, the spirit of the present invention is not limited to the presented embodiments. For example, those skilled in the art who understand the spirit of the present invention may propose other embodiments within the spirit of the present invention by adding, modifying, or deleting components, etc., but such embodiments will also be considered to be within the spirit of the present invention. The shapes and sizes of elements in the drawings may be exaggerated for clarity.

[0036] FIG. 1 illustrates a battery cell stack (20) including leads (201, 202) bent by a lead bending method according to the present invention.

[0037] Referring to FIG. 1, a battery cell stack (20) may include a plurality of battery cells (200). The battery cell stack (20) may have a plurality of battery cells (200) stacked in one direction. The battery cells (200) may be pouch cells.

[0038] A pouch battery cell may include an electrode assembly, an electrolyte, and a pouch outer case. The electrode assembly may be formed by folding or winding a laminate including a first electrode, a second electrode, and a separator. The pouch battery cell may include a first lead (201) electrically connected to a first electrode of the electrode assembly and protruding outward from the pouch outer case, and a second lead (202) electrically connected to a second electrode of the electrode assembly and protruding outward from the pouch outer case. The first lead (201) and the second lead (202) may protrude in both directions as illustrated in FIG. 1, but may also protrude in one direction. The first lead (201) may be made of copper. The first lead (201) may have a negative electrode. The second lead (202) may be made of aluminum. The second lead (202) may have a positive electrode.

[0039] FIG. 2 is a drawing showing a battery cell stack (20) and a busbar frame assembly (10) including a lead bent by a lead bending method according to the present invention.

[0040] Referring to FIG. 2, the busbar frame assembly (10) may include a busbar (110) and a busbar frame (130).

[0041] A plurality of battery cells (200) constituting a battery cell stack (20) may be electrically connected by a bus bar (110). The plurality of battery cells (200) constituting the battery cell stack (20) may be connected in series and / or in parallel depending on the connection method of the bus bar (110). The bus bar (110) may be provided between each of the plurality of battery cells (200). The bus bar (110) may be in contact with the leads of the battery cells (200). The bus bar (110) and the leads of the battery cells (200) may be joined by welding. The bus bar (110) may include a conductive metal.

[0042] The busbar frame (130) can accommodate the busbar (110). The busbar frame (130) can be provided on one side and / or the other side of the battery cell stack (20). The busbar frame (130) can be provided in a direction in which the leads of the battery cells (200) protrude. The busbar frame (130) can include an electrically insulating material. The busbar frame (130) can accommodate a first external terminal (T1) and a second external terminal (T2).

[0043] As illustrated in Fig. 2, in order for the battery cell stack (20) and the busbar (110) to be stably joined, welding of the lead and the busbar (110) is required. In order to weld the lead and the busbar (110), the lead must be bent at an angle of approximately 90 degrees so that it makes surface contact with the busbar (110) or the busbar frame.

[0044] Below, the lead bending method will be described in more detail using FIGS. 3 to 18.

[0045] FIG. 3 is a drawing showing a bending tool (300) and a first lead (201) used in a lead bending method according to the present invention.

[0046] Referring to FIG. 3, a method of bending the first lead (201) using a bending tool (300) will be schematically described.

[0047] Fig. 3 shows a bending tool (300) positioned on one side of the first lead (201). The bending tool (300) can move to the other side of the first lead (201) to bend the first lead (201). After the bending tool (300) bends the first lead (201), the first lead (201) can be pressed against the bus bar (110) by applying pressure to the first lead (201) with the front end surface (S) of the bending tool (300).

[0048] The bending tool (300) may be insulated. The bending tool (300) may be insulated to prevent the risk of short circuits between products. For example, the bending tool (300) may be made of a material such as ceramic or PEEK.

[0049] The bending tool (300) may be provided to be larger than the width of the lead in order to apply uniform pressure across the entire width direction of the lead. The length of the front end face (S) of the bending tool (300) along the Z-axis may be larger than the width of the lead.

[0050] The width of the leading edge (S) of the bending tool (300) along the Y-axis may be 5 mm or more. If the length of the leading edge (S) of the bending tool (300) along the Y-axis is 5 mm or less, it may be difficult to align the bending start point of the lead (201) and the leading edge (S) of the bending tool (300) at a position where they can at least partially overlap with respect to the Y-axis, and the pressure point of the bending tool (300) may become small, which may cause damage to the lead (201) or the busbar frame assembly (10).

[0051] The corners of the bending tool (300) can be rounded. This can prevent the lead from being damaged by the corners of the bending tool (300) when the bending tool (300) comes into contact with the lead.

[0052] FIGS. 4 to 18 are drawings showing steps included in a lead bending method according to the present invention. In FIGS. 4 to 18, the busbar frame (130) and the battery cell stack (20) that accommodate the busbar (110) are omitted to more easily explain the lead bending method. The first lead (201) and the second lead (202) in FIGS. 4 to 18 may refer to leads of adjacent battery cells (200). In FIGS. 4 to 18, the busbars (110) illustrated in the positive and negative Y-axis directions respectively are cross-sections of one busbar (110), and may be cross-sections of one busbar (110) having an approximately hollow center. Therefore, adjacent battery cells (200) may be electrically connected by the busbars (110). The lead bending method illustrated in FIGS. 4 to 18 can be performed in one direction and / or both directions in which the leads of the battery cell stack (20) protrude.

[0053] A lead bending method according to the present invention may be a method of bending a first lead (201) protruding from a battery cell stack (20) provided on one side (positive direction of the X-axis) of a busbar frame assembly (10) in the first direction to the other side (negative direction of the X-axis) of the busbar frame assembly (10). The battery cell stack (20) may be one in which a plurality of battery cells (200) are stacked in a second direction (parallel direction to the Y-axis) that is a direction perpendicular to the first direction.

[0054] The lead bending method may include a step of positioning the bending tool (300) on one side (positive Y-axis direction) in a second direction that is perpendicular to the first direction (parallel to the X-axis) of the first lead (201). FIG. 4 shows that the bending tool (300) is positioned on the other side (negative Y-axis direction) in the second direction of the first lead (201), and FIGS. 5 and 6 show that the bending tool (300) is positioned on one side (positive Y-axis direction) in the second direction of the first lead (201).

[0055] The lead bending method may include a step of tilting the first lead (201) in the second direction (negative Y-axis direction) by pressing the first lead (201) by moving the bending tool (300) in the second direction (negative Y-axis direction). Fig. 7 shows an example of the bending tool (300) pressing the first lead (201) to tilt the first lead (201) in the second direction (negative Y-axis direction).

[0056] The lead bending method may include a step of pressing the first lead (201) by moving the bending tool (300) in one direction (positive direction of the X-axis) to bring the first lead (201) into close contact with the busbar frame assembly (10). FIG. 8 is a view showing the first lead (201) being pressed by moving the bending tool (300) in one direction (positive direction of the X-axis) to bring the first lead (201) into close contact with the busbar frame assembly (10).

[0057] The lead bending method may include a step of sliding the bending tool (300) relative to the first lead (201) by moving it in the second direction (negative Y-axis direction). FIG. 10 illustrates a bending tool (300) sliding relative to the first lead (201) by moving it in the second direction (negative Y-axis direction).

[0058] The lead bending method may include a step of moving the bending tool (300) in the first direction (the negative X-axis direction). Fig. 11 shows the bending tool (300) moved in the first direction (the negative X-axis direction).

[0059] Referring again to FIG. 6, in the step of positioning the bending tool (300) on one side of the second direction (positive Y-axis direction) of the first lead (201), the distance (X / 2) along the first direction between the bending tool (300) and the busbar frame assembly (10) may correspond to approximately half of the length (X) of the first lead (201) protruding to the other side of the first direction (negative X-axis direction) of the busbar frame assembly (10).

[0060] According to this step of the present invention, in the step of tilting the first lead (201) in the second direction (negative Y-axis direction), the bending tool (300) can reduce the force required to tilt the first lead (201) and at the same time provide stability in the tilting. The force required to tilt the first lead (201) can be proportional to the value obtained by dividing the minimum stress required to bend the first lead (201) by the distance from the bending tool (300) to the point where the first lead (201) is bent. Accordingly, the closer the bending tool (300) is to the busbar frame assembly (10), the closer the bending tool (300) is to the point where the first lead (201) is bent, and the greater the force applied by the bending tool (300) to tilt the first lead (201), the more the busbar frame assembly (10) may be pushed due to the repulsive force of the first lead (201) in the process of tilting the first lead (201). Conversely, the farther the bending tool (300) is to the busbar frame assembly (10), the greater the risk that the first lead (201) may escape the restraint of the bending tool (300) in the process of tilting the first lead (201) by the bending tool (300). Therefore, setting the distance in the first direction between the bending tool (300) and the busbar frame assembly (10) in the above step can reduce the force required for the bending tool (300) to tilt the first lead (201) while at the same time providing stability in operation.

[0061] Referring back to FIG. 7, in the step of tilting the first lead (201) to the second direction other side (Y-axis negative direction) by pressing the first lead (201) by moving the bending tool (300) in the second direction other side, the bending tool (300) can be moved to a position where the leading edge (S) of the bending tool (300) and the bending start point of the first lead (201) at least partially overlap. That is, the bending tool (300) can be moved until the leading edge (S) of the bending tool (300) and the bending start point of the first lead (201) at least partially overlap in the first direction. Here, 'overlapping in the first direction' means that the two configurations are arranged at a position where they overlap each other when viewed in the first direction.

[0062] In the step where the first lead (201) is pressed and the first lead (201) is tilted in the second direction (the negative direction of the Y-axis) as the bending tool (300) moves in the second direction (the negative direction of the Y-axis), the center of the cutting edge (S) of the bending tool (300) along the second direction (the direction parallel to the Y-axis) can be moved to a position where it overlaps with the bending start point of the first lead (201).

[0063] The bending start point of the first lead (201) may be the start point where the first lead (201) protrudes from the busbar frame assembly (10).

[0064] According to this step of the present invention, in the step of pressing the first lead (201) to bring the first lead (201) into close contact with the busbar frame assembly (10), the point where the first lead (201) is bent is pressed by the front end surface (S) of the bending tool (300), so that the first lead (201) can be easily bent. In particular, when the center of the front end surface (S) along the second direction presses the point where the first lead (201) is bent, the first lead (201) can be bent most easily. Therefore, the problem of the first lead (201) being lifted off from the busbar frame assembly (10) due to the restoring force of the first lead (201) can be minimized.

[0065] Referring again to FIG. 8, in the step of pressing the first lead (201) by moving the bending tool (300) in one direction (positive direction of the X-axis) to bring the first lead (201) into close contact with the busbar frame assembly (10), the bending tool (300) may press the busbar frame assembly (10) so that the busbar frame assembly (10) is elastically deformed in one direction (positive direction of the X-axis). The amount of movement (h) of the elastically deformed busbar frame assembly (10) may be less than or equal to the thickness of the first lead (201). For example, the busbar frame assembly (10) may be elastically deformed by approximately 0.5 mm to 1 mm by the pressing of the bending tool (300).

[0066] At this stage, the first lead (201) must be bent securely so as not to be separated from the busbar frame assembly (10). If the bending tool (300) is moved too quickly, the first lead (201) may not be properly plasticized and may be elastically restored. Therefore, a speed of the bending tool (300) that minimizes the restoration of the first lead (201) may be applied. A step for deriving this speed may be added prior to the bending process.

[0067] Additionally, when the bending process is performed simultaneously in both directions in which the leads of the battery cell stack (20) protrude, the speed of the bending tool can be matched to prevent the battery cell (200) from being pushed or twisted to one side.

[0068] Referring back to FIG. 9, the step of moving the bending tool (300) in the first direction (negative X-axis direction) may further include a step of retracting the bending tool (300) in the first direction (negative X-axis direction) so that the busbar frame assembly (10) is at least partially elastically restored. For example, the bending tool (300) may be retracted in the first direction (negative X-axis direction) by a thickness of the first lead (201). Alternatively, the bending tool (300) may be retracted in the first direction (negative X-axis direction) by half the thickness of the first lead (201).

[0069] By having this retreat process of the bending tool (300), the deformation of the first lead (201) due to the subsequent movement of the bending tool (300) in the second direction can be minimized. That is, if the bending tool (300) moves in the other direction (negative Y-axis direction) while excessively pressing the first lead (201), an area of ​​the first lead (201) that is pressed and then released by the bending tool (300) may not be in close contact with the busbar frame assembly (10) and may spread apart, or the bending may be released. Therefore, by this retreat step of the bending tool (300), the bending tool (300) can slide while properly contacting the first lead (201).

[0070] Referring again to FIGS. 12 to 18, the lead bending method may further include a step of bending the second lead (202) protruding from the second direction other side (Y-axis negative direction) of the first lead (201) to the first direction other side (X-axis negative direction) of the busbar frame assembly (10).

[0071] In the present invention, the first lead (201) and the second lead (202) may be bent in a direction that brings them closer to each other, and in particular, may be provided so that at least one area overlaps. This may contribute to preventing deformation of the battery cell (200).

[0072] The lead bending method includes a step of bending a second lead (202) protruding from the second direction other side (Y-axis negative direction) of the first lead (201) to the first direction other side (X-axis negative direction) of the busbar frame assembly (10), including the steps of: positioning a bending tool (300) on the second direction other side (Y-axis negative direction) of the second lead (202); pressing the second lead (202) by moving the bending tool (300) to one side in the second direction (Y-axis positive direction) to tilt the second lead (202) to one side in the second direction (Y-axis positive direction); pressing the second lead (202) by moving the bending tool (300) to one side in the first direction (X-axis positive direction) to bring the second lead (202) into close contact with the busbar frame assembly (10); And it may include a step of sliding the bending tool (300) with respect to the first lead (201) by further moving it in the second direction (positive Y-axis direction). These steps may be performed in a similar manner to the method of bending the first lead (201) described above.

[0073] After the bending of the first lead (201) is completed, the bending tool (300) can move in the second direction (negative direction of the Y-axis) as shown in FIG. 12 to bend the second lead (202), and then move in the first direction (positive direction of the X-axis) as shown in FIG. 13.

[0074] Referring to FIG. 13, in the step of positioning the bending tool (300) on the second side (negative Y-axis direction) of the second lead (202), the distance (y2) along the first direction (parallel to the X-axis) between the bending tool (300) and the busbar frame assembly (10) may be greater than the distance (y1) along the first direction (parallel to the X-axis) between the end of the first lead (201) and the busbar frame assembly (10) caused by elastic restoration of the first lead (201).

[0075] According to this step of the present invention, in the step of pressing the second lead (202) to tilt the second lead (202) in the second direction (positive Y-axis direction), the elastically restored first lead (201) can be pressed by the second lead (202) and brought into close contact with the busbar frame assembly (10) again. This is because, when the second lead (202) is pressed by moving the bending tool (300) in the second direction (positive Y-axis direction) while the distance in the first direction between the bending tool (300) and the busbar frame assembly (10) is smaller than the distance in the first direction between the end of the first lead (201) and the busbar frame assembly (10) caused by the elastic restoration of the first lead (201), the elastically restored first lead (201) may be separated from the busbar frame assembly (10) by the second lead (202) or may be damaged.

[0076] Referring again to FIGS. 13 to 18, the method of bending the first lead (201) described above will be briefly explained by applying it to the method of bending the second lead (202).

[0077] In the step of positioning the bending tool (300) on the other side of the second lead (202) in the second direction (negative Y-axis direction), the distance between the bending tool (300) and the busbar frame assembly (10) in the first direction may correspond to half of the length of the second lead (202) protruding on the other side of the first direction (negative X-axis direction) of the busbar frame assembly (10).

[0078] By moving the bending tool (300) in one direction (positive Y-axis direction) in the second direction, the second lead (202) is pressed and the second lead (202) is tilted in one direction (positive Y-axis direction), the bending tool (300) can be moved to a position where the leading edge (S) of the bending tool (300) and the bending start point of the second lead (202) at least partially overlap. That is, the bending tool (300) can be moved until the leading edge (S) of the bending tool (300) and the bending start point of the second lead (202) at least partially overlap with respect to the Y-axis.

[0079] In the step of tilting the second lead (202) in the second direction (positive Y-axis direction) by pressing the second lead (202) by moving the bending tool (300) in the second direction, the bending tool (300) may be moved to a position where the center of the end face (S) of the bending tool (300) in the second direction (parallel to the Y-axis) overlaps with the bending start point of the second lead (202).

[0080] The bending start point of the second lead (202) may be the start point where the second lead (202) protrudes from the busbar frame assembly (10).

[0081] In the step of pressing the second lead (202) by moving the bending tool (300) in one direction (positive direction of the X-axis) to bring the second lead (202) into close contact with the busbar frame assembly (10), the busbar frame assembly (10) can be elastically deformed in one direction (positive direction of the X-axis) as the bending tool (300) presses the busbar frame assembly (10). For example, the busbar frame assembly (10) can be elastically deformed by a maximum thickness of the first lead (201) and the thickness of the second lead (202) added together.

[0082] In the step of moving the bending tool (300) in the first direction (negative X-axis direction), the bending tool (300) may be retracted in the first direction (negative X-axis direction) so that the busbar frame assembly (10) is at least partially elastically restored. For example, the bending tool (300) may be retracted in the first direction (negative X-axis direction) by an amount equal to the sum of the thicknesses of the first lead (201) and the second lead (202). Alternatively, the bending tool (300) may be retracted in the first direction (negative X-axis direction) by half the sum of the thicknesses of the first lead (201) and the second lead (202).

[0083] Referring to FIG. 14, the length of the first lead (201) protruding from the busbar frame assembly (10) may be smaller than the distance between the first lead (201) and the second lead (202). In particular, the length of the first lead (201) protruding from the busbar frame assembly (10) may be smaller than the distance between the first lead (201) and the second lead (202) minus half of the width (t) of the venting tool in the second direction.

[0084] According to this configuration of the present invention, in the step where the second lead (202) is bent after the first lead (201) is first bent, the end of the first lead (201) can be prevented from being damaged or crumpled by the bending of the second lead (202).

[0085] In particular, when the second lead (202) is bent while the first lead (201) is not completely in contact with the busbar frame assembly (10), there is a concern that the first lead (201) may interfere with the bending of the second lead (202), and thus this needs to be prevented. For example, if the length of the first lead (201) protruding from the busbar frame assembly (10) is greater than the distance between the first lead (201) and the second lead (202) minus half of the width (t) of the bending tool in the second direction, the second lead (202) may not fold much and may interfere with the first lead (201), and as a result, the first lead (201) may be damaged by receiving a large compressive force in the longitudinal direction.

[0086] While the present invention has been described with reference to the accompanying drawings, focusing on preferred embodiments, it will be apparent to those skilled in the art that numerous obvious modifications can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should be construed as encompassing the many examples of such modifications within the scope of the claims.

[0087] [Explanation of symbols]

[0088] 10 Busbar Frame Assembly

[0089] 110 bus bar

[0090] 130 busbar frame

[0091] 20 battery cell stacks

[0092] 200 battery cells

[0093] 201 First Lead

[0094] 202 Second Lead

[0095] 300 bending tool

[0096] S-section

[0097] T1 terminal 1

[0098] T2 terminal 2

Claims

1. A method of bending a first lead protruding from a battery cell laminate located on one side of a first direction of a busbar frame assembly including a busbar and a busbar frame accommodating the busbar to the other side of the first direction of the busbar frame assembly, A step of positioning the bending tool on one side of a second direction which is perpendicular to the first direction of the first lead; A step of applying pressure to the first lead by moving the bending tool in the second direction to tilt the first lead in the second direction; A step of pressing the first lead by moving the bending tool to one side in the first direction to bring the first lead into close contact with the busbar frame assembly; A step of moving the above bending tool in the second direction to slide it against the first lead; and A lead bending method comprising the step of moving the bending tool toward the first direction.

2. In paragraph 1, The step of positioning the above bending tool on one side of the second direction of the first lead is, A lead bending method, characterized in that the distance in the first direction between the bending tool and the busbar frame assembly is half the length of the first lead protruding toward the other side of the busbar frame assembly in the first direction.

3. In paragraph 1, In the step of pressing the first lead by moving the bending tool in the second direction to the other side, thereby tilting the first lead in the second direction to the other side, A lead bending method characterized by moving the bending tool to a position where the front end surface of the bending tool and the bending start point of the first lead at least partially overlap.

4. In paragraph 1, In the step of pressing the first lead by moving the bending tool in the second direction to the other side, thereby tilting the first lead in the second direction to the other side, A lead bending method characterized in that the bending tool is moved to a position where the center of the cross-section of the bending tool along the second direction overlaps with the bending start point of the first lead.

5. In paragraph 1, In the step of pressing the first lead by moving the bending tool to one side of the first direction to bring the first lead into close contact with the busbar frame assembly, A lead bending method characterized in that the bending tool presses the busbar frame assembly so that the busbar frame assembly is elastically deformed in one direction in the first direction.

6. In paragraph 5, In the step of moving the above bending tool to the first direction side, A lead bending method characterized in that the busbar frame assembly is at least partially elastically restored as the bending tool is retracted toward the first direction.

7. In paragraph 1, The above lead bending method is, After the step of moving the above bending tool to the first direction side, A lead bending method characterized by further comprising a step of bending a second lead protruding from the second direction other side of the first lead to the first direction other side of the busbar frame assembly.

8. In paragraph 7, The step of bending the second lead protruding from the second direction other side of the first lead to the first direction other side of the busbar frame assembly is: A step of positioning the above bending tool on the second direction side of the second lead; A step of applying pressure to the second lead by moving the bending tool to one side in the second direction to tilt the second lead to one side in the second direction; A step of pressing the second lead by moving the bending tool in the first direction to one side to bring the second lead into close contact with the busbar frame assembly; and A lead bending method characterized by including a step of further moving the bending tool to one side in the second direction and sliding it relative to the first lead.

9. In paragraph 8, In the step of positioning the above bending tool on the second direction side of the second lead, A lead bending method, characterized in that the distance along the first direction between the bending tool and the busbar frame assembly is greater than the distance along the first direction between the end of the first lead and the busbar frame assembly caused by elastic restoration of the first lead.

10. In paragraph 7, The above first lead is, A lead bending method, characterized in that the length protruding from the busbar frame assembly is smaller than the distance between the first lead and the second lead.

11. In clause 10, The above first lead is, A lead bending method, characterized in that the length protruding from the busbar frame assembly is smaller than a value obtained by subtracting half of the width of the bending tool in the second direction from the distance between the first lead and the second lead.

12. In paragraph 1, A lead bending method, characterized in that the above bending tool is insulated.

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