Welding method, welded product, and battery module

Abstract

The present invention relates to a welding method, a welded product, and a battery module. The welding method according to the present invention comprises: a positioning process of positioning a plurality of base materials to be in contact with each other; and a welding process of forming a predetermined welding pattern by welding the plurality of base materials to each other, wherein in the welding process, the welding pattern is welded to be formed in a shape in which a plurality of spiral patterns are connected without overlapping each other.

Description

Welding methods, welded parts and battery modules

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0033203, filed March 8, 2024, and Korean Patent Application No. 10-2025-0028016, filed March 5, 2025, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a welding method, a welded product, and a battery module.

[0005] Conventional spiral pattern welds often involve significant spatter generation at the start / end points and a notch effect due to the bead shape at the end of the spiral pattern. Furthermore, when combined with real-time weld quality inspection, this can reduce the likelihood of inspection.

[0006] In addition, the continuous fusion of the welding jig due to the generation of a large amount of spatter has a disadvantageous effect on maintenance / repair.

[0007] The notch effect at the end of the spiral pattern acts as a factor that can deteriorate the mechanical properties under repeated loads.

[0008] If the weld diameter is small or the welding speed is high, which shortens the welding time, there is a problem that reduces the possibility of real-time welding quality inspection.

[0009]

[0010] One aspect of the present invention is to provide a welding method, a welded product, and a battery module capable of reducing spatter and increasing mechanical properties.

[0011] A welding method according to an embodiment of the present invention includes a positioning process of positioning a plurality of base materials so as to be in contact with each other; and a welding process of welding the plurality of base materials to form a predetermined welding pattern, wherein the welding process welds the welding pattern in a form in which a plurality of spiral patterns are connected without overlapping.

[0012] In addition, a welded product according to an embodiment of the present invention includes a plurality of base materials positioned in contact with each other; and a predetermined welding pattern formed by welding the plurality of base materials together, wherein the welding pattern forms a plurality of spiral patterns, and the plurality of spiral patterns do not overlap and are connected.

[0013] In addition, a battery module according to an embodiment of the present invention includes a welded product according to the embodiment of the present invention.

[0014] According to the present invention, when a plurality of parent materials are welded together to form a welding pattern in the form of a plurality of spiral patterns being connected, by welding continuously without overlapping welding lines, spatter is reduced, mechanical properties are improved, space utilization is increased, and the possibility of real-time welding quality inspection is increased.

[0015] Furthermore, according to the present invention, multiple spiral pattern welding lines are welded so as to be continuous without overlapping, thereby preventing deterioration of the mechanical and material properties of the welded portion due to high heat generated when the welding lines overlap. In addition, the notch effect that occurs when multiple spiral patterns are individually formed into a single pattern can be significantly reduced.

[0016] In addition, according to the present invention, the plurality of spiral patterns include a first spiral pattern and a second spiral pattern, and by welding such that welding starts at the center of the first spiral pattern and ends at the center of the second spiral pattern, the two spiral patterns are formed into one non-overlapping continuous pattern, thereby ensuring mechanical properties capable of withstanding a similar load even if the diameter of the welded portion (welding pattern) is reduced.

[0017] Figure 1 is a plan view showing a welding process in a welding method according to an embodiment of the present invention.

[0018] Figure 2 is a reference diagram showing a welding pattern formed through a welding process of a welding method according to an embodiment of the present invention.

[0019] FIG. 3 is a perspective view showing an example of a welded product welded using a welding method according to an embodiment of the present invention.

[0020] FIG. 4 is a plan view exemplarily showing a welding portion of an example of a welded product welded through a welding method according to an embodiment of the present invention.

[0021] FIG. 5 is a plan view showing an enlarged view of a welded portion of another example of a welded product welded using a welding method according to an embodiment of the present invention.

[0022] FIG. 6 is a cross-sectional view showing a secondary battery applied to another example of a welded product welded by a welding method according to an embodiment of the present invention.

[0023] Fig. 7 is a perspective view showing another example of a welded product welded using a welding method according to an embodiment of the present invention.

[0024] Fig. 8 is an external photograph showing the fractured state of a welded product welded using a welding method according to a comparative example.

[0025] Figure 9 is an external photograph showing a broken state of a welded product welded using a welding method according to a manufacturing example.

[0026] Figure 10 is a graph showing the tensile load of a welded product welded using a welding method according to a comparative example.

[0027] Figure 11 is a graph showing the tensile load of a welded product welded using a welding method according to a manufacturing example.

[0028] The objects, specific advantages, and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In this specification, when reference numerals are given to components in each drawing, it should be noted that, as far as possible, identical components are given the same reference numerals even if they are shown in different drawings. Furthermore, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

[0029]

[0030] Welding method according to the embodiment

[0031]

[0032] FIG. 1 is a plan view showing a welding process in a welding method according to an embodiment of the present invention, and FIG. 2 is a reference view showing a welding pattern formed through a welding process of a welding method according to an embodiment of the present invention.

[0033]

[0034] Referring to FIGS. 1 and 2, a welding method according to an embodiment of the present invention can manufacture a welded product (100) by including a positioning process of positioning a plurality of base materials (130) so as to be in contact with each other and a welding process of forming a predetermined welding pattern (160) by welding a plurality of base materials (130).

[0035]

[0036] In more detail, the positioning process can position a plurality of parent materials (130) so that they are in contact with each other.

[0037] In addition, during the positioning process, the plurality of parent materials (130) can be positioned so that the width (w1) of the plurality of parent materials (130) in contact with each other is 8 to 15 mm. Here, the plurality of parent materials (130) include a first parent material (110) and a second parent material (120), and the width (w1) of the overlapping section of the first parent material (110) and the second parent material (120) can be, for example, 8 to 15 mm. Here, the width (w1) of the plurality of parent materials (130) in contact with each other can be, for example, a width (w1) in a direction parallel to the width direction (W) of the welding pattern (160) that is perpendicular to the longitudinal (extension) direction (G) of the welding pattern (160).

[0038]

[0039] The welding process welds multiple parent materials (130) in multiple spiral patterns. At this time, the welding process welds the welding pattern (160) so that the multiple spiral patterns are connected without overlapping.

[0040] In addition, the welding process can weld in multiple spiral patterns (140, 150) in which two or more spiral patterns are connected.

[0041] In addition, the welding process can be performed in a manner that the welding lines (L) do not overlap and are continuously connected during welding in multiple spiral patterns (140, 150).

[0042] The plurality of spiral patterns (140, 150) may include a first spiral pattern (140) and a second spiral pattern (150).

[0043] Here, the welding process can be performed such that welding starts at the center (141) of the first spiral pattern (140) and ends at the center (151) of the second spiral pattern (150).

[0044] The welding process can be performed by irradiating a laser beam onto the base material (130) using a laser device. Here, the welding process can be performed by, for example, irradiating the base material (130) with laser light having a wavelength of 1030 nm to 1070 nm using a laser device. Accordingly, by irradiating the laser light having a wavelength of 1030 nm to 1070 nm during welding, it is possible to secure a welding quality that can withstand a high separation load that separates multiple welded base materials (130).

[0045] The welding process can form a first spiral pattern (140) by irradiating laser light counterclockwise, and a second spiral pattern (150) by irradiating laser light clockwise. That is, the welding process can form a first spiral pattern (140) that faces from the inside to the outside as a welding pattern (160), and then form a second spiral pattern (150) that faces from the outside to the inside by connecting the welding line (L).

[0046] The welding line (L) may include a first welding line (La) of the first spiral pattern (140), a second welding line (Lb) of the second spiral pattern (150), and a third welding line (Lc) connecting the first spiral pattern (140) and the second spiral pattern (150). Here, the first welding line (La) and the second welding line (Lb) may be formed in a curved shape to form a spiral pattern, and the second welding line (Lb) may be formed in a straight line to be connected to the first welding line (La) and the second welding line (Lb).

[0047] Meanwhile, the welding process can be performed so that the diameters (R1, R2) of the plurality of spiral patterns (140, 150) are each formed to be 1.5 to 3.0 (π). That is, the welding process can be performed so that the diameters (R1, R2) of the first spiral pattern (140) and the second spiral pattern (150) are each formed to be 1.5 to 3.0 (π). Accordingly, the diameters (R1, R2) of the first spiral pattern (140) and the second spiral pattern (150) are each welded to be 1.5 to 3.0 (π), thereby providing an effect that can function as an effective welding pattern (160) from a mechanical and material viewpoint within a narrow area. At this time, the diameters (R1, R2) of the first spiral pattern (140) and the second spiral pattern (150) are formed to be greater than the lower limit of 1.5 (π), so that there is an effect of preventing excessive heat input due to heat input overlap of the welding line (L) in the direction from the outside to the inside (out->in) of the spiral pattern (140, 150).

[0048] Meanwhile, the welding process can be performed so that the interval (d1, d2) between the welding lines (L) in the plurality of spiral patterns (140, 150) is 0.2 to 0.4 mm. That is, the welding process can be performed so that the interval (d1, d2) between the welding lines (L) in the first spiral pattern (140) and the second spiral pattern (150) is 0.2 to 0.4 mm. Accordingly, the interval (d1, d2) between the welding lines (L) in the first spiral pattern (140) and the second spiral pattern (150) is formed to be 0.2 mm or more, which is the lower limit, so that there is an effect of preventing the occurrence of a decrease in the strength of the weld joint due to excessive heat input when the interval (d1, d2) between the welding lines (L) is too narrow. In addition, the spacing (d1, d2) between the welding lines (L) in the first spiral pattern (140) and the second spiral pattern (150) is formed to be less than the upper limit of 0.4 mm, so that there is an effect of preventing the formation of a weld with weak strength when the spacing (d1, d2) between the welding lines (L) is too wide.

[0049]

[0050] FIG. 3 is a perspective view showing an example of a welded product welded using a welding method according to an embodiment of the present invention.

[0051] Meanwhile, referring to FIG. 3, a plurality of parent materials (130) may be electrode leads (E) and bus bars (B) in a battery module including a cell stack in which a plurality of secondary batteries (10) having electrode leads (E) are stacked, and a bus bar (B) connecting the electrode leads (E) of the plurality of secondary batteries (10).

[0052]

[0053] The welding method according to the embodiment of the present invention, which is configured as described above, forms a welding pattern (160) in a form in which a plurality of spiral patterns (140, 150) are connected by welding a plurality of base materials, and by continuously welding so that the welding lines (L) do not overlap, spatter is reduced, mechanical properties are increased, space utilization is increased, and the possibility of real-time welding quality inspection can be increased. That is, when one spiral pattern is formed, a large amount of spatter is generated at the welding start point and a large amount of cracks are generated at the welding end point, but the welding method according to the embodiment of the present invention forms a welding pattern (160) in a form in which a plurality of spiral patterns are connected, so that spatter generated at the welding start point and cracks generated at the welding end point can be significantly reduced.

[0054] In addition, the welding method according to an embodiment of the present invention can prevent defects from occurring in the welded portion due to high heat and overheating that occur when the welding lines (L) of a plurality of spiral patterns (140, 150) are welded so that they do not overlap but are continuously connected. In addition, the notch effect that occurs when the plurality of spiral patterns (140, 150) are each formed into one pattern can be significantly reduced. In addition, when welding with a square-shaped pattern, the notch effect that occurs at the corners can be prevented. That is, by eliminating the notch effect, the mechanical properties under repeated loads can be improved.

[0055] In addition, the welding method according to an embodiment of the present invention includes a plurality of spiral patterns (140, 150), including a first spiral pattern (140) and a second spiral pattern (150), and by welding starting from the central portion (141) of the first spiral pattern (140) and ending at the central portion (151) of the second spiral pattern (150), the two spiral patterns (140, 150) are formed into a single non-overlapping continuous pattern, thereby ensuring mechanical properties capable of withstanding a similar load even if the diameter of the welded portion (welding pattern) is reduced. Accordingly, space utilization is increased, and the possibility of real-time welding quality inspection can be increased. That is, when two spiral patterns (140, 150) are formed into one non-overlapping continuous pattern, the welding length is increased compared to when two are formed into one spiral pattern, and even if the diameter is reduced, mechanical properties that can withstand a similar load can be secured. (Welding length increase 41.1%)

[0056]

[0057] Welded product according to the embodiment

[0058]

[0059] Below, a welded product according to an embodiment of the present invention will be described.

[0060] Referring to FIG. 1, a welded product (100) according to an embodiment of the present invention includes a plurality of base materials (130) positioned in contact with each other and a predetermined welding pattern (160) formed by welding the plurality of base materials (130).

[0061] A welded product (100) according to an embodiment of the present invention relates to a welded product (100) manufactured using a welding method according to the embodiment described above. Therefore, in this embodiment, any content overlapping with the embodiments described above will be omitted or briefly described, and differences will be described.

[0062]

[0063] In more detail, the welding pattern (160) forms a plurality of spiral patterns. Here, the welding lines (L) of the plurality of spiral patterns (140, 150) do not overlap and are connected. At this time, the welding lines (L) of the plurality of spiral patterns (140, 150) do not overlap and may be continuous. The plurality of spiral patterns may include a first spiral pattern (140) and a second spiral pattern (150).

[0064] The welding line (L) may have a starting point where welding begins at the center (141) of the first spiral pattern (140), and an end point where welding ends at the center (151) of the second spiral pattern (150).

[0065] That is, the welding pattern (160) can form a welding line (L) that starts at the center (141) of the first spiral pattern (140) and ends at the center (151) of the second spiral pattern (150).

[0066] The welding line (L) may include a first welding line (La) of the first spiral pattern (140), a second welding line (Lb) of the second spiral pattern (150), and a third welding line (Lc) connecting the first spiral pattern (140) and the second spiral pattern (150). Here, the first welding line (La) and the second welding line (Lb) may be formed in a curved shape to form a spiral pattern, and the second welding line (Lb) may be formed in a straight line to be connected to the first welding line (La) and the second welding line (Lb).

[0067] The width (w1) of the multiple parent materials (130) in contact with each other can be 8 to 15 mm.

[0068] Here, the plurality of parent materials (130) include a first parent material (110) and a second parent material (120), and the overlapping section of the first parent material (110) and the second parent material (120) may be, for example, 8 to 15 mm.

[0069] Meanwhile, the diameters of the plurality of spiral patterns (140, 150) may be formed to be 1.5 to 3.0 (π), respectively. That is, the first spiral pattern (140) and the second spiral pattern (150) may be welded to have diameters of 1.5 to 3.0 (π), respectively. Accordingly, the first spiral pattern (140) and the second spiral pattern (150) are welded to have diameters of 1.5 to 3.0 (π), respectively, so that there is an effect that they can function as effective welding patterns (160) from a mechanical and material perspective within a narrow area. At this time, the diameters of the first spiral pattern (140) and the second spiral pattern (150) are formed to be greater than the lower limit of 1.5 (π), so that there is an effect of preventing excessive heat input due to the overlap of the heat input of the welding line (L) in the direction from the outside to the inside (out->in) of the spiral pattern (140, 150).

[0070] Meanwhile, the spacing (d1, d2) between the welding lines (L) in the plurality of spiral patterns (140, 150) may be 0.2 to 0.4 mm. That is, the first spiral pattern (140) and the second spiral pattern (150) may be welded so that the spacing (d1, d2) between the welding lines (L) is 0.2 to 0.4 mm. Accordingly, the spacing (d1, d2) between the welding lines (L) in the first spiral pattern (140) and the second spiral pattern (150) is formed to be 0.2 mm or more, which is the lower limit, so that there is an effect of preventing the occurrence of a decrease in the strength of the weld joint due to excessive heat input when the spacing (d1, d2) between the welding lines (L) is too narrow. In addition, the spacing (d1, d2) between the welding lines (L) in the first spiral pattern (140) and the second spiral pattern (150) is formed to be less than the upper limit of 0.4 mm, so that there is an effect of preventing the formation of a weld with weak strength when the spacing (d1, d2) between the welding lines (L) is too wide.

[0071]

[0072] FIG. 4 is a plan view exemplarily showing a welding portion of an example of a welded product welded by a welding method according to an embodiment of the present invention, FIG. 5 is a plan view enlargedly showing a welding portion of another example of a welded product welded by a welding method according to an embodiment of the present invention, FIG. 6 is a cross-sectional view showing a secondary battery applied to another example of a welded product welded by a welding method according to an embodiment of the present invention, and FIG. 7 is a perspective view showing another example of a welded product welded by a welding method according to an embodiment of the present invention.

[0073] In addition, referring to FIGS. 3 to 7, a plurality of parent materials (130) may be electrode terminals (T, T') and bus bars (B, B') in a battery module including a cell assembly (S, S') in which a plurality of secondary batteries (10, 10') having electrode terminals are arranged, and a bus bar (B, B') connecting the electrode terminals (T, T') of the plurality of secondary batteries (10, 10').

[0074]

[0075] Meanwhile, as an example, referring to FIGS. 3 and 4, the secondary battery (10) may be provided as a pouch-type secondary battery (10) in which an electrode assembly is accommodated in a pouch (11). Here, the electrode terminal (T) may include an electrode lead (E) that is connected to the electrode assembly and extends to the outside of the pouch (11). At this time, a plurality of base materials (130) may include the electrode leads (E). And, for example, the contact width (w1) of the first base material, the electrode lead (E), and the second base material, the bus bar (B), may be 8 to 15 mm. Here, specifically, for example, the contact width (w1) of the first base material, the electrode lead (E), and the second base material, the bus bar (B) may be 8 to 15 mm. And, the bus bar (B) may include various shapes, such as a straight portion or an "ㅁ"-shaped portion in which a bus bar hole (B1) is formed in the center.

[0076]

[0077] Meanwhile, as another example, referring to FIGS. 5 to 7, the secondary battery (10') may be provided as a cylindrical secondary battery (10') in which an electrode assembly (A) is accommodated in a can (20'). The electrode terminal (T') may include a positive terminal (T1') located at the center of the outer end of the can (20') and a negative terminal (T2') located around the positive terminal (T1') at the outer end of the can (20'). Here, a plurality of parent materials (130) may include positive terminals (T1') and negative terminals (T2'). In addition, the contact width (w2) of the electrode terminal (T'), which is the first parent material, and the bus bar (B'), which is the second parent material, may be 8 to 15 mm. At this time, the positive terminal (T1') can be connected to the positive tab (12) extended from the positive pole of the electrode assembly (A), and the negative terminal (T2') can be connected to the negative tab (13) extended from the negative pole of the electrode assembly (A).

[0078]

[0079] Battery module according to the embodiment

[0080] Meanwhile, referring to FIGS. 1, 3, 5, and 7, a battery module (M, M') can be configured by including a welded product (100, 100') according to an embodiment of the present invention configured as described above.

[0081] The welded product (100, 100') includes a plurality of base materials (130) positioned in contact with each other and a predetermined welding pattern (160) formed by welding the plurality of base materials (130), and the welding pattern (160) forms a plurality of spiral patterns (140, 150), and the welding lines (L) of the plurality of spiral patterns (140, 150) do not overlap and are continuous.

[0082] Here, the plurality of parent materials (130) may be electrode terminals (T, T') and bus bars (B, B') in a battery module (M, M') including a cell assembly (S, S') in which a plurality of secondary batteries (10, 10') having electrode terminals (T, T') are arranged, and a bus bar (B, B') connecting the electrode terminals (T, T') of the plurality of secondary batteries (10, 10').

[0083] That is, the battery module (M, M') includes a cell assembly (S, S') in which secondary batteries (10, 10') are arranged and a welded product (100, 100'), and the welded product (100, 100') may include an electrode terminal (T, T') which is a first base material (110), a bus bar (B, B') which is a second base material (120), and a welding pattern (160).

[0084]

[0085] < Manufacturing Example >

[0086] A plurality of parent materials (130) were welded together so that a welding pattern (160) was formed in the form of multiple spiral patterns being connected, and a welded product was manufactured by welding continuously so that the welding lines did not overlap when welding multiple spiral patterns.

[0087] At this time, the diameter (D2) of the spiral pattern was formed as 2.3pi (π).

[0088] Here, a plurality of parent materials (130) were used, including a first parent material (110) made of aluminum and a second parent material (120) made of steel.

[0089] And, the welding pattern (160) was formed by laser welding. At this time, the laser power was 550 W, and the welding speed was 300 mm / s.

[0090]

[0091] < Comparative example >

[0092] A welded product was manufactured by welding multiple parent materials (130) together and forming each spiral pattern as one without connecting them using a welding pattern (P).

[0093] At this time, the spiral pattern diameter (D1) was formed to 3.0pi (π). Here, a plurality of parent materials (130) were used as the same products as in the manufacturing example. In addition, the welding pattern (160) was formed by laser welding as in the manufacturing example. At this time, the laser power (Power) was 600W, and the welding speed (Welding speed) was 300 mm / s to perform the welding.

[0094]

[0095] Fig. 8 is an external photograph showing a fractured state of a welded product welded by a welding method according to a comparative example, and Fig. 9 is an external photograph showing a fractured state of a welded product welded by a welding method according to a manufacturing example. Here, Figs. 8 and 9 are photographs showing a state in which a second base material (120) is fractured due to a tensile load being applied to the first base material (110). At this time, Figs. 8 and 9 show a state in which the first base material (110) and the second base material (120) are fractured centered on the welding pattern (P, 160), but are fractured along fracture lines (L1, L2) formed along the outer lines of the welding pattern (P, 160).

[0096] In addition, Fig. 10 is a graph showing the tensile load of a welded product welded using a welding method according to a comparative example, and Fig. 11 is a graph showing the tensile load of a welded product welded using a welding method according to a manufacturing example.

[0097]

[0098] <Experimental Example>

[0099] Welded products of manufacturing examples and comparative examples were each manufactured, and a tensile force was applied to the welded products in which multiple parent materials (130) were welded together so that multiple parent materials (130) were separated from each other, and the maximum tensile load at the time of fracture was measured. The results of the manufacturing example were shown in the graph of Fig. 10, and the results of the comparative example were shown in the graph of Fig. 11.

[0100] Then, welded products of manufacturing examples and comparative examples were manufactured, and a tensile load was applied to measure the tensile load at the time of fracture. Then, the fractured parent material (130) was welded again to measure the recognized load of the welded product. This process was repeated several times, as shown in Figs. 10 and 11.

[0101] Here, the unit of the vertical axis of FIGS. 10 and 11 is LOAD (N) representing tensile force, and the unit of the horizontal axis is DISP [mm] representing displacement. FIG. 10 is a graph showing the maximum tensile load when a weldment (A) welded by a welding method according to a comparative example as illustrated in FIG. 8 is broken, and FIG. 11 is a graph showing the maximum tensile load when a weldment (B) welded by a welding method according to a manufacturing example as illustrated in FIG. 9 is broken.

[0102] As shown in Fig. 10, the maximum tensile load of the welded product (A) of the comparative example is about 1000 N on average, and as shown in Fig. 11, the maximum tensile load of the welded product (B) of the manufacturing example is about 1033 N on average.

[0103] Accordingly, it can be seen that the maximum tensile load is similar when the welding pattern (P) of the comparative example is formed as a spiral pattern having a single 3.0pi(π) diameter (D1) during welding, and when the welding pattern (160) of the manufacturing example is formed as two spiral patterns having a non-overlapping 2.3pi(π) diameter (D2) connected.

[0104] Therefore, when welding as in the manufacturing example, two spiral patterns are formed without overlapping, and the maximum tensile load is similar even though they are formed smaller than the spiral patterns formed as one each in the comparative example, it can be seen that it is possible to reduce the size of the welding pattern (160) as in the manufacturing example under an appropriate maximum tensile load.

[0105] In the end, it can be seen that when the welding pattern (160) is formed into two spiral patterns without overlapping, as in the manufacturing example, it is possible to secure mechanical properties capable of withstanding a similar load even if the size of the welding pattern (160) is reduced, compared to when two welding patterns (P) are formed into one spiral pattern, as in the comparative example.

[0106]

[0107] While the present invention has been described in detail through specific examples, these are intended to illustrate the invention in detail and are not intended to be limiting. Those skilled in the art will appreciate that various implementations are possible within the technical scope of the present invention.

[0108] Additionally, the specific scope of protection of the invention will be made clear by the appended claims.

[0109]

[0110] [Explanation of symbols]

[0111] 10,10': Secondary battery

[0112] 11: Pouch

[0113] 100,100': Welded product

[0114] 110: First Mother Material

[0115] 120: Second Mother Material

[0116] 130: Mother material

[0117] 140: First Spiral Pattern

[0118] 141: Central

[0119] 150: Second Spiral Pattern

[0120] 151: Central

[0121] 160: Welding pattern

[0122] B,B': bus bar

[0123] B1: Bus Bar Hall

[0124] E: Electrode lead

[0125] S,S': Cell assembly

[0126] C: Central side

[0127] T,T': electrode terminals

[0128] T1,T1': negative terminal

[0129] T2,T2': positive terminal

[0130] G pattern extension (length) direction

[0131] W pattern width direction

[0132] w1, w2: width

Claims

1. A positioning process in which multiple parent materials are placed in contact with each other; and It includes a welding process of welding a plurality of base materials to form a predetermined welding pattern, The above welding process is a welding method in which the welding pattern is welded in a form in which multiple spiral patterns are connected without overlapping.

2. In claim 1, The above welding process is a welding method in which the welding lines are continuously connected without overlapping when welding in the above multiple spiral patterns.

3. In claim 2, The above plurality of spiral patterns include a first spiral pattern and a second spiral pattern, The above welding process is a welding method in which welding starts at the center of the first spiral pattern and ends at the center of the second spiral pattern.

4. In claim 3, The above welding process is a welding method that uses a laser device to irradiate laser light to the base material to weld it.

5. In claim 4, The above welding process The above first spiral pattern is formed by irradiating the laser light counterclockwise, A welding method for forming the second spiral pattern by irradiating the laser light in a clockwise direction.

6. In claim 1, A welding method in which the plurality of parent materials are positioned so that the width of contact between them is 8 to 15 mm during the above positioning process.

7. In claim 1, The above multiple parent materials are, A method for welding electrode terminals and bus bars in a battery module, the method comprising: a cell assembly in which a plurality of secondary batteries having electrode terminals are arranged; and a bus bar connecting the electrode terminals of the plurality of secondary batteries.

8. In claim 1, The above welding process A welding method for forming multiple spiral patterns with diameters of 1.5 to 3.0 (π).

9. In claim 2, The above welding process A welding method for welding in which the interval between the welding lines in the above multiple spiral patterns is 0.2 to 0.4 mm.

10. In claim 1, The above welding process is a welding method that uses a laser device to irradiate the base material with laser light having a wavelength of 1030 nm to 1070 nm to weld.

11. A plurality of parent materials positioned in contact with each other; and It includes a predetermined welding pattern formed by welding the above multiple parent materials together, The above welding pattern forms multiple spiral patterns, The above multiple spiral patterns are not overlapping and are connected welded parts.

12. In claim 11, A welded product in which the welding lines of the above multiple spiral patterns do not overlap and are continuously connected.

13. In claim 12, The above multiple spiral patterns include a first spiral pattern and a second spiral pattern, The above welding line is a welded product in which a starting point where welding begins is located at the center of the first spiral pattern, and an end point where welding ends is located at the center of the second spiral pattern.

14. In claim 11, A welded product in which the width of the plurality of base materials in contact with each other is 8 to 15 mm.

15. In claim 11, The above multiple parent materials are, A battery module comprising a cell assembly in which a plurality of secondary batteries having electrode terminals are arranged, and a bus bar connecting the electrode terminals of the plurality of secondary batteries, wherein the electrode terminals and the bus bar are welded.

16. In claim 15, The above secondary battery is provided as a pouch-type secondary battery in which an electrode assembly is accommodated in a pouch, The electrode terminal includes an electrode lead connected to the electrode assembly and extending to the outside of the pouch, The above plurality of parent materials are welded products including the electrode leads.

17. In claim 15, The above secondary battery is provided as a cylindrical secondary battery in which an electrode assembly is accommodated in a can, The electrode terminal includes a positive terminal located at the center of the outer end of the can and a negative terminal located around the positive terminal at the outer end of the can. The above plurality of parent materials are welded products including the positive terminal and the negative terminal.

18. In claim 11, A welded product in which the diameters of the above multiple spiral patterns are each 1.5 to 3.0 (π).

19. In claim 12, A welded product having a spacing between the welding lines of the above multiple spiral patterns of 0.2 to 0.4 mm.

20. A battery module comprising a welded product as described in any one of claims 11 to 19.

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