Battery string welding method

Abstract

The application provides a battery string welding method. The battery string welding method comprises the following steps: preparing a plurality of battery pieces (1) of a same battery string; preparing at least one continuous welding strip; making the continuous welding strip sequentially contact and weld with the same surface of the plurality of battery pieces (1) through one or more continuous pulling of the continuous welding strip to form a conductive path; and completing the welding of the whole battery string; wherein the continuous welding strip is not bent during the welding process and keeps a continuous extension state after the welding is completed. The battery string welding method can reduce the problem of hidden cracks of the welding strip, avoid the risk of less welding strips, improve the welding capacity, improve the production efficiency, and improve the battery performance.

Description

Technical Field

[0001] This invention relates to the field of battery manufacturing technology, and more specifically, to a method for welding battery strings. Background Technology

[0002] In photovoltaic modules, solar cells are connected in series to form a cell string. In traditional processes, the solder strips are bent into a "Z" shape and overlapped on the front and back of adjacent cells. Welding is done using segmented solder strips, with each segment corresponding to the spacing between one or two cells. The welding process involves a traction mechanism that sequentially cuts and pulls the solder strips to a fixed position. Cells are then placed one by one onto the solder strips by a feeding mechanism. A fixed heating lamp box then presses down, covering the area of ​​two cells for thermal welding. This process is repeated multiple times to complete the connection of the entire cell string. Simultaneously, the connection between the cell string and the busbar is done using a stacking welding machine. A section of the busbar is pulled from the roll material (usually slightly longer than the width of one or two cells), cut, and pulled to the end of the corresponding cell string before welding. Multiple cell strings require repeated cutting, pulling, and welding processes to form multiple independent busbar connection structures.

[0003] In the aforementioned traditional technologies, the "Z"-bending process of the welding strip not only increases the complexity of the mechanism and the cost of equipment, but also easily causes microcracks due to stress concentration at the bending point, affecting the electrical performance and reliability of the battery cells. At the same time, the multiple traction and cutting of the segmented welding strip increases the welding cycle time, reduces production efficiency, and poses a risk of missed welding or insufficient welding due to missing or misaligned welding strips. Summary of the Invention

[0004] The main objective of this invention is to provide a battery string welding method that can reduce the problem of microcracks in the solder strip, avoid the risk of insufficient solder strip, increase welding capacity, improve production efficiency, and enhance battery performance.

[0005] To achieve the above objectives, according to one aspect of the present invention, a battery string welding method is provided, comprising:

[0006] Prepare multiple cells from the same battery string;

[0007] Prepare at least one continuous welding strip;

[0008] By continuously pulling the continuous welding strip once or multiple times, the continuous welding strip is brought into contact with the same surface of multiple battery cells in sequence and welded to form a conductive path.

[0009] Complete the welding of the entire battery string;

[0010] The continuous welding strip is not bent during the welding process and remains in a continuous extended state after welding is completed.

[0011] Furthermore, the continuous solder strip includes an upper solder strip and a lower solder strip. The step of forming a conductive path by repeatedly pulling the continuous solder strip to sequentially contact and weld it to the same surface of multiple solar cells includes:

[0012] Pull the lower layer of welding strip to a first preset length;

[0013] A first preset number of battery cells are placed on a lower layer of solder strip of a first preset length;

[0014] The upper welding strip of the first preset length is stretched to correspond to the first preset number of placed battery cells;

[0015] Perform welding of the first preset number of battery cells to the lower and upper solder strips;

[0016] Pull the lower layer of welding strip to a second preset length;

[0017] A second preset number of battery cells are placed on the lower layer of solder strip of a second preset length;

[0018] The upper welding strip of the second preset length is stretched to correspond to the second preset number of placed battery cells;

[0019] Perform welding of a second preset number of battery cells to the lower and upper solder strips;

[0020] In this manner, the lower layer of solder strips is soldered to the first side of all the cells in the same battery string, and the upper layer of solder strips is soldered to the second side of all the cells in the same battery string.

[0021] Furthermore, the step of welding a first predetermined number of battery cells to the lower and upper solder strips includes:

[0022] The pressure roller mechanism is controlled to descend to a distance of 0.5mm~3mm from the surface of the battery cell;

[0023] Control the welding strip tooling to press and position the upper welding strip;

[0024] Control the welding mechanism to move to the position to be welded and perform welding.

[0025] Furthermore, the continuous solder strip includes an upper solder strip and a lower solder strip. The step of forming a conductive path by continuously pulling the continuous solder strip to sequentially contact and weld it to the same surface of multiple solar cells includes:

[0026] The lower layer of welding strips is pulled to a first preset length, which is greater than the length of the battery string;

[0027] All the cells of the same battery string are placed on the lower layer of solder strip of the first preset length;

[0028] The upper solder strip is stretched to a first preset length for the corresponding placed battery cell;

[0029] Welding of the battery cells to the lower and upper solder strips is carried out.

[0030] Furthermore, the steps for welding the solar cells to the lower and upper solder strips include:

[0031] Control the welding strip tooling to press and position the upper welding strip;

[0032] Control the welding mechanism to move to the position to be welded and perform welding.

[0033] Furthermore, the steps of controlling the welding mechanism to move to the position to be welded and performing welding include:

[0034] Determine the coverage area of ​​the welding facility;

[0035] Control the welding mechanism to move to the position to be welded, and perform welding of the weld strip within the coverage area;

[0036] Control the welding mechanism to move away from the welding position;

[0037] Control the welding mechanism to shift the distance of one coverage area towards the unwelded area;

[0038] The welding mechanism is controlled to move to the welding position in the unwelded area and to weld the weld strips within the covered area;

[0039] Continue in this manner to complete the welding of all positions to be welded.

[0040] Furthermore, the battery string welding method also includes:

[0041] After welding all the battery strings, place all the battery strings in the grid.

[0042] A busbar is drawn out from each of the two protruding ends of the battery string;

[0043] This ensures that all solder strips located at the same end are welded to the busbar at that end;

[0044] The busbars are cut so that all the battery strings are connected in series.

[0045] Further, the step of cutting the busbars to form a series structure of all battery strings includes:

[0046] A laser cutting mechanism is used to cut at preset cutting positions, with each position cut twice, so that the scrap material is completely cut off and there is a preset length interval between two adjacent busbars.

[0047] Further, the step of cutting the busbars to form a series structure of all battery strings includes:

[0048] Use a double-edged cutter to make one cut at each cutting point; or,

[0049] A single-blade cutter is used to make two cuts at each cutting position.

[0050] Furthermore, the step of cutting the busbars to form a series structure of all battery strings also includes:

[0051] A base plate is installed at the bottom of the busbar to support it;

[0052] An adsorption structure is installed on the base plate to adsorb the busbars.

[0053] In embodiments of this invention, multiple battery cells from the same battery string and at least one continuous welding strip are prepared. Through one or more continuous traction methods, the continuous welding strip sequentially contacts and welds to the same surface of multiple battery cells without any bending, thereby forming a continuous and stable conductive path on the entire battery string. This method eliminates the step of repeatedly bending the welding strip to accommodate the spacing between battery cells, fundamentally eliminating the risk of mechanical stress concentration and microcracks in the battery caused by welding strip bending. Simultaneously, by maintaining the welding strip in a continuously extended state during and after welding, the entire welding strip can be welded in one go without segmented cutting, repeated positioning, or traction. This significantly shortens the welding cycle time, improves welding consistency, and avoids defects such as missing welding strips, poor overlap, or uneven welding strength caused by segmented welding. This effectively increases welding capacity, production efficiency, and battery performance. Attached Figure Description

[0054] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0055] Figure 1 This is a flowchart illustrating the welding process of battery cells and solder strips in the battery string welding method of this invention.

[0056] Figure 2 This is a flowchart illustrating the welding process of the welding strip and busbar in the battery string welding method of this invention.

[0057] Figure 3 This is a welding structure diagram of the solder strip and the battery cell according to an embodiment of the present invention;

[0058] Figure 4 This is a diagram illustrating the welding process between a battery cell and a solder strip according to an embodiment of the present invention.

[0059] Figure 5 This is a diagram illustrating the welding process between a battery cell and a solder strip according to an embodiment of the present invention.

[0060] Figure 6 This is a diagram illustrating the welding process of the solder strip and the busbar according to an embodiment of the present invention;

[0061] Figure 7 This is a schematic diagram of the cutting structure of a busbar according to an embodiment of the present invention;

[0062] Figure 8 This is a schematic diagram of the cutting structure of a busbar according to an embodiment of the present invention;

[0063] Figure 9 This is a schematic diagram of the overall structure of a battery string after the busbar is welded, according to an embodiment of the present invention.

[0064] The above figures include the following reference numerals:

[0065] 1. Battery cell; 2. Lower layer welding strip; 3. Upper layer welding strip; 4. Pressure roller mechanism; 5. Welding mechanism; 6. Welding strip tooling; 7. Busbar; 8. Laser cutting mechanism; 9. Double-edged cutter; 10. Scrap material; 11. Feeding mechanism; 12. Transmission mechanism; 13. Welding strip traction mechanism; 14. Moving load-bearing mechanism. Detailed Implementation

[0066] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0067] See also Figures 1 to 9 As shown, according to an embodiment of the present invention, the battery string welding method includes: preparing multiple battery cells 1 of the same battery string; preparing at least one continuous welding strip; by continuously pulling the continuous welding strip once or multiple times, the continuous welding strip is brought into sequential contact with the same surface of the multiple battery cells 1 and welded to form a conductive path; completing the welding of the entire battery string; wherein, the continuous welding strip is not bent during the welding process and remains in a continuously extended state after the welding is completed.

[0068] Applying the technical solution of this embodiment, the battery string welding method involves preparing multiple battery cells 1 and at least one continuous welding strip from the same battery string. One or more continuous traction operations are used to sequentially contact the continuous welding strip with the same surface of the multiple battery cells 1, completing the welding and forming a continuous conductive path. This solution eliminates the need for any bending of the continuous welding strip during the welding process, ensuring that the welding strip maintains a straight extension throughout the entire welding process. This avoids the problems of stress concentration, increased risk of microcracks, and increased equipment complexity caused by welding strip bending in traditional processes. Furthermore, since the continuous welding strip maintains its continuous extension after welding, there is no need for segmented cutting, repositioning, or multiple traction operations. This achieves continuous welding of the entire welding strip to the entire string of battery cells 1 on the same surface, effectively solving the defects of insufficient welding, missed welding, long welding cycle time, and poor welding stability caused by segmented welding strips in existing technologies. This effectively improves welding capacity, production efficiency, and battery performance.

[0069] The battery string welding method described in this embodiment is applicable to photovoltaic cells with single-sided electrode structures, such as P-type PERC cells or Al-BSF cells; it is also compatible with bifacial cell structures that generate electricity on both sides, such as bifacial PERC cells or bifacial TOPCon cells; and it is also applicable to HJT cells and XBC cells (IBC and cells formed by combining IBC technology with other cell technologies, abbreviated as XBC. For example, the combination of TOPCON and IBC technology is called TBC).

[0070] See also Figure 4 As shown, in one embodiment, the continuous welding strip includes an upper welding strip 3 and a lower welding strip 2. The step of forming a conductive path by repeatedly pulling the continuous welding strip to sequentially contact and weld the continuous welding strip with the same surface of multiple battery cells 1 includes: pulling the lower welding strip 2 to a first preset length; placing a first preset number of battery cells 1 on the lower welding strip 2 to the first preset length; stretching the upper welding strip 3 to the first preset length corresponding to the placed first preset number of battery cells 1; welding the first preset number of battery cells 1 with the lower welding strip 2 and the upper welding strip 3; pulling the lower welding strip 2 to a second preset length; placing a second preset number of battery cells 1 on the lower welding strip 2 to the second preset length; stretching the upper welding strip 3 to the second preset length corresponding to the placed second preset number of battery cells 1; welding the second preset number of battery cells 1 with the lower welding strip 2 and the upper welding strip 3; and so on, to complete the welding of the lower welding strip 2 with the first surface of all battery cells 1 in the same battery string, and the welding of the upper welding strip 3 with the second surface of all battery cells 1 in the same battery string.

[0071] In this embodiment, the continuous welding strip includes an upper welding strip 3 and a lower welding strip 2. Through a step-by-step traction and welding process, firstly, a first preset length of the lower welding strip 2 is traction, and a first preset number of battery cells 1 are placed on it. Then, the first preset length of the upper welding strip 3 is simultaneously stretched to align it with the battery cells 1, completing the welding of the first group of battery cells 1 to the upper and lower welding strips 2. Next, a second preset length of the lower welding strip 2 is traction, and a second preset number of battery cells 1 are placed on it. Then, the second preset length of the upper welding strip 3 is stretched accordingly to weld the second group of battery cells 1. This process... By analogy, continuous welding of the lower welding strip 2 to the first side of all the battery cells 1 in the battery string is achieved, while simultaneous welding of the upper welding strip 3 to the second side of all the battery cells 1 is performed. This batch-by-batch, segmented traction and welding structure effectively reduces the heat input and welding strip tension fluctuations during a single welding operation, avoiding problems such as thermal stress concentration, welding strip misalignment, or uneven welding caused by placing all battery cells 1 at once. This ensures that the upper welding strip 3 and the lower welding strip 2 maintain a continuous extension throughout the entire string welding process without bending, significantly improving welding stability and the consistency of the conductive path. The first preset quantity is, for example, 2 to 4, or even 5 or more, depending on the machine size or the number of cells.

[0072] In one embodiment, the steps of welding a first preset number of battery cells 1 to the lower welding strip 2 and the upper welding strip 3 include: controlling the pressure roller mechanism 4 to descend to a distance of 0.5mm to 3mm from the surface of the battery cell 1; controlling the welding strip tooling 6 to press and position the upper welding strip 3; and controlling the welding mechanism 5 to move to the position to be welded and perform welding.

[0073] In this embodiment, when the pressure roller mechanism 4 descends to a distance of 0.5mm to 3mm from the surface of the battery cell 1, it can apply a moderate pre-pressure to the upper welding strip 3, so that it initially adheres to the surface of the battery cell 1, suppressing the elastic lifting or lateral displacement of the welding strip during the traction process. Subsequently, the welding strip tooling 6 precisely presses and positions the upper welding strip 3, further fixing its relative position in the welding area, ensuring that the contact surface between the upper welding strip 3 and the battery cell 1 is stable and without gaps. On this basis, the welding mechanism 5 moves from the upper and lower sides to the position to be welded and performs welding, so that heat energy is applied to the contact area between the positioned upper welding strip 3 and the battery cell 1, as well as the contact area between the lower welding strip 2 and the battery cell 1. Thus, without bending the continuous welding strip, it achieves a high degree of consistency in the welding point position and stability in the fusion strength, effectively solving the problems of false welding, misaligned welding and uneven welding points caused by welding strip displacement, and ensuring the reliability and consistency of the electrical conductivity of the entire battery string in the continuous welding process.

[0074] See also Figure 4As shown, in one embodiment, the welding device used in the above welding method includes a pressure roller mechanism 4, a welding mechanism 5, a welding strip clamping fixture 6, a feeding mechanism 11, a transmission mechanism 12, and a welding strip traction mechanism 13. The welding mechanism 5 is fixedly installed; the transmission mechanism 12 uses a belt for transmission and operates in a cyclical manner; the welding strip traction mechanism 13 moves left and right, with a certain range of motion; the pressure roller mechanism 4 is movable up and down, used to fix the position of the upper welding strip 3; after the lower welding strip 2 is pulled to the fixed position, it is fixed by a fixing device to prevent displacement. After the upper welding strip 3 is pulled to the fixed position, it is pressed down by the welding strip clamping fixture 6 to prevent the welding strip from deviating.

[0075] In one embodiment, the welding mechanism 5 is, for example, a heating lamp box.

[0076] In one embodiment, the process of welding the welding strip to the battery cell 1 using the above-mentioned welding device is as follows:

[0077] First, the welding strip traction mechanism 13 pulls the lower welding strip 2 out to a first preset length, which is greater than the width of three whole battery cells. Here, the width of a whole battery cell refers to the dimension of the cell along the length of the battery string. The first preset length can also be greater than the width of two or four whole battery cells, or other dimensions, depending on the size of the machine itself. The robotic arm places three whole battery cells on the lower welding strip 2 at a time (two segments equal six cells; three segments equal nine cells, and so on).

[0078] Afterwards, the welding strip traction mechanism 13 pulls the upper welding strip 3 for approximately the width of three full battery cells and then pauses. At this time, the pressure roller mechanism 4 descends to about 1mm from the battery surface, and the distance between the pressure rollers of the pressure roller mechanism 4 and the heating lamp box is such that the pressure rollers do not interfere with the downward welding. The pressure rollers are preferably positioned on the third battery cell, that is, the battery cell furthest from the welding strip traction mechanism 13. Then, a special robot arm moves the welding strip fixture 6 onto the upper welding strip 2, ensuring that the upper welding strip 2 does not deviate. The heating lamp box is lowered to cover the distance between the two batteries and the heating welding begins. After welding is completed, the heating lamp box rises, and the special robot arm removes the welding strip fixture 6 from the upper welding strip 2. The transmission mechanism 12 drives the battery cells forward via the conveyor belt; the welding strip traction mechanism 13 holds the welding strip and keeps it in place, so that the welding strip moves forward synchronously and continuously, stopping at a distance of two full battery cells. The robotic arm then places two more battery cells in succession and pauses; the dedicated robotic arm then moves the welding strip fixture 6 over and lowers the heating lamp box for welding, repeating the welding process in sequence to complete the welding of the entire battery string.

[0079] See also Figure 5As shown, in one embodiment, the continuous welding strip includes an upper welding strip 3 and a lower welding strip 2. The step of forming a conductive path by continuously pulling the continuous welding strip to sequentially contact and weld the continuous welding strip with the same surface of multiple battery cells 1 includes: pulling the lower welding strip 2 of a first preset length, the first preset length being greater than the length of the battery string; placing all battery cells 1 of the same battery string on the lower welding strip 2 of the first preset length; stretching the upper welding strip 3 of the first preset length corresponding to the placed battery cells 1; and welding the battery cells 1 with the lower welding strip 2 and the upper welding strip 3.

[0080] In this embodiment, the continuous welding strip consists of an upper welding strip 3 and a lower welding strip 2. Through a continuous traction action, the lower welding strip 2 of a first preset length is first stretched and fixed. This first preset length is greater than the total length of the entire string of battery cells 1, ensuring that the lower welding strip 2 can completely cover the same surface of all battery cells 1. Then, all battery cells 1 of the same battery string are placed on the lower welding strip 2 that has been pulled into place at once, achieving precise positioning. Next, corresponding to the placed battery cells 1, the upper welding strip 3 of the first preset length is stretched synchronously, so that it extends parallel to the lower welding strip 2 and covers the same surface above the battery cells 1. The two together clamp the entire string of battery cells 1 in a straight state without bending. Finally, through the welding process, the battery cells 1 simultaneously form stable electrical contact with both the lower welding strip 2 and the upper welding strip 3, constructing a complete conductive path. This sequential traction and positioning mechanism ensures that the upper and lower welding strips are synchronously bonded to the entire string of battery cells 1 under straight conditions without bending, avoiding offset, incomplete welding, or poor contact caused by segmented traction or misaligned placement, significantly improving welding consistency and conductivity reliability.

[0081] In one embodiment, the steps of welding the battery cell 1 to the lower welding strip 2 and the upper welding strip 3 include: controlling the pressure welding fixture 6 to press and position the upper welding strip 3; and controlling the welding mechanism 5 to move to the position to be welded and to perform welding.

[0082] In this embodiment, when welding the battery cell 1 to the lower welding strip 2 and the upper welding strip 3, the upper welding strip 3 is pressed and positioned by controlling the welding strip tool 6, so that the upper welding strip 3 adheres tightly to the surface of the battery cell 1 after traction and remains stable, effectively avoiding poor contact caused by loose or displaced welding strips. At the same time, the welding mechanism 5 is controlled to move to the position to be welded and perform welding, ensuring that the welding heat energy is accurately applied to the contact area between the battery cell 1 and the upper welding strip 3 and between the battery cell 1 and the lower welding strip 2, realizing one-time traction and continuous same-side welding. The welding strip does not need to be bent during the entire process and maintains a continuous extension state. The welding quality is stable and reliable, significantly reducing the risk of off-center welding and incomplete welding, and improving the conductivity consistency and structural reliability of the entire battery string.

[0083] In one embodiment, the step of controlling the welding mechanism 5 to move towards the position to be welded and to perform welding includes: determining the coverage area of ​​the welding mechanism 5; controlling the welding mechanism 5 to move towards the position to be welded and to weld the weld strip within the coverage area; controlling the welding mechanism 5 to move away from the welding position; controlling the welding mechanism 5 to shift to an unwelded area by the distance of the coverage area; controlling the welding mechanism 5 to move towards the position to be welded in the unwelded area and to weld the weld strip within the coverage area; and so on, to complete the welding of all positions to be welded.

[0084] In this embodiment, the welding mechanism 5 achieves precise control over the contact area between the continuous welding strip and the same surface of the battery cell 1 by determining its own coverage area. After the welding mechanism 5 moves to the position to be welded and welds the welding strip in the coverage area, it first retreats away from the welding position, then moves along the unwelded area by the distance of one coverage area, and then repositions itself to the next position to be welded and repeats the welding action. This cyclic process can achieve continuous welding of the entire string of battery cells 1 on the same surface without bending the welding strip. Through this collaborative mechanism of segmented displacement and repeated welding, the welding mechanism 5 can still completely cover the welding path of the entire string of battery cells 1 in the fixed installation state, ensuring that the contact area between each segment of welding strip and the battery cell 1 obtains a consistent hot-press welding effect, significantly improving welding consistency and production efficiency. At the same time, the continuous welding strip maintains an overall extended state after welding, avoiding stress concentration and the risk of strip breakage caused by traditional segmented traction and bending, making the conductive path of the battery string more stable and reliable.

[0085] See also Figure 5 As shown, in one embodiment, the welding apparatus used in the above welding method includes a welding mechanism 5, a welding strip tooling 6, a feeding mechanism 11, a transmission mechanism 12, a welding strip traction mechanism 13, and a movable support mechanism 14. The welding mechanism 5 is movably mounted on the movable support mechanism 14 along the extension direction of the welding strip. The movable support mechanism 14 includes a slide block, and the welding mechanism 5 includes a slider, which is slidably disposed on the slide block.

[0086] In one embodiment, the process of welding the welding strip to the battery cell 1 using the above-mentioned welding device is as follows:

[0087] First, the lower welding strip 2 of a first preset length is continuously pulled out from the coil by the welding strip traction mechanism 13. The first preset length is greater than the total length of all the cells in the battery string to be welded along the extension direction, so that the lower welding strip 2 completely covers the expected welding area of ​​the entire battery string.

[0088] Subsequently, a robotic arm places all the battery cells 1 in the entire battery string onto the lower welding strip 2 in one go, aligning the welding area of ​​each battery cell 1 with the position of the lower welding strip 2.

[0089] Next, the welding strip traction mechanism 13 synchronously pulls the upper welding strip 3 to the same length as the lower welding strip 2, and pauses at that position, so that the upper welding strip 3 covers the same surface of all the battery cells 1, forming a structure in which the upper and lower welding strips clamp the battery cells 1.

[0090] After the welding strip is positioned, a special robot arm will move the welding strip fixture 6 in one go and lay it on the surface of the upper welding strip 3, covering the entire area to be welded, so as to ensure that the upper welding strip 3 and the lower welding strip 2 remain stably attached to the battery cell 1 during the subsequent heating process, and prevent the welding strip from shifting or lifting.

[0091] Subsequently, the heating lamp box presses down and covers the welding area of ​​two adjacent battery cells 1, heating and welding the contact points between the welding strips below and the battery cells 1 to achieve local fusion. The effective heating width of the heating lamp box can cover two or more battery cells 1 depending on its structural design, such as... Figure 4 As shown, its heating range corresponds to the combined area of ​​multiple battery cells 1.

[0092] After welding is completed, the heating lamp box rises, and the welding strip fixture 6 is removed by the robot arm.

[0093] Subsequently, the heating lamp box moves a predetermined distance along the extension direction of the battery string, which corresponds to the width spacing between the two battery cells 1; then it is pressed down again to heat and weld the next welding area.

[0094] The above steps are repeated until the solder strip connection areas between all adjacent cells 1 in the entire battery string are completed.

[0095] Throughout the welding process, both the lower welding strip 2 and the upper welding strip 3 remain as continuous, uncut, and unbent structures. The overall positioning is achieved through a single traction action, and the welding area is heated in segments, effectively ensuring the continuity of the welding strips and the consistency of the welding.

[0096] See also Figures 6 to 9 As shown, in one embodiment, the battery string welding method further includes: after welding all battery strings, arranging all battery strings; pulling out a busbar 7 from each of the two protruding ends of the battery string; welding all the solder strips at the same end to the busbar 7 at that end; and cutting the busbar 7 to form a series structure of all battery strings.

[0097] In this embodiment, after welding all battery strings, they are arranged uniformly to achieve neat alignment. Then, a busbar 7 is pulled out from each of the two protruding ends of the welding strips of each battery string, so that all welding strips at the same end simultaneously contact the corresponding busbar 7 and complete the welding in one go. This avoids the problems of increased cycle time and positional displacement caused by traditional segmented traction and segmented welding. After welding, the busbar 7 is cut so that the welding strips between adjacent battery strings are electrically connected through the busbar 7, thereby directly forming a series structure. This process relies on the characteristic of continuous welding strips that do not bend and maintain continuous extension during welding, ensuring uniform stress and no local deformation of the welding strips. Combined with the synchronous welding and precise cutting of the busbar 7, it significantly improves the efficiency and reliability of multi-string battery series connection, while reducing the welding defect rate and the need for manual intervention.

[0098] In this embodiment, when pulling the busbar 7, only one main busbar needs to be cut from the short sides of both ends of the stacking welding machine, making the machine's operation cycle simpler. Since all the welding strips at the same end are welded through a single busbar, the overall appearance remains neat and consistent even after the busbar is cut into N segments. This busbar welding method allows for a single-sided welding structure for the welding strips, eliminating the need for Z-bending, indirectly improving the quality of the battery string, avoiding microcracks caused by welding strip bending, effectively improving hot spot effects, and increasing battery power.

[0099] See also Figure 7 As shown, in one embodiment, the step of cutting the busbar 7 so that all battery strings form a series structure includes: using a laser cutting mechanism 8 to cut at preset cutting positions, cutting twice at each position, so that the scrap material 10 is completely cut off and there is a preset length interval between two adjacent busbar segments 7.

[0100] In this embodiment, when the busbar 7 is cut to form a series structure of all battery strings, the laser cutting mechanism 8 performs two independent cutting actions at a preset cutting position. The two cuts gradually cut from both sides of the busbar 7 towards the center, ensuring that the scrap material 10 located between the two cutting paths is completely separated and completely detached from the main body. This avoids the scrap material 10 remaining micro-connected or burr-overlapping with adjacent busbar 7 segments due to incomplete cutting in a single cut, thereby eliminating potential electrical continuity risks. At the same time, the slit spacing formed by the two cuts is precisely controlled to maintain a preset length of gap between two adjacent busbar segments 7. This gap physically forms a reliable insulation barrier, effectively blocking short-circuit paths between the positive and negative electrodes, and improving the electrical safety and reliability of the battery strings after assembly.

[0101] See also Figure 8As shown, in one embodiment, the step of cutting the busbar 7 so that all battery strings form a series structure includes: using a double-edged cutter 9 to cut once at each cutting position.

[0102] In this embodiment, when the busbar 7 is cut to form a series structure of all battery strings, a double-edged cutter 9 is used to cut each cutting position once. The sharp edges on both sides of the cutter 9 act simultaneously on the two sides of the busbar 7 to completely cut off the scrap material 10 in one go. This avoids material not being broken or burrs remaining due to single-sided cutting, thereby effectively preventing short circuits between the positive and negative electrodes due to residual conductive connections.

[0103] In one embodiment, a single-blade cutter is used to make two cuts at each cutting position.

[0104] A single-blade cutter is used to make two cuts at each cutting position. The first cut enters from one side to the middle of the material, and the second cut enters from the other side and aligns with each other to form a precise break point, ensuring that the scrap 10 is completely separated.

[0105] Both cutting methods significantly improve the reliability of electrical isolation, avoiding the risk of incomplete cutting caused by tool deviation or material toughness in traditional single-cutting, thus ensuring the stability and safety of the battery string structure.

[0106] In one embodiment, the step of cutting the busbar 7 so that all the battery strings form a series structure further includes: setting a base plate at the bottom of the busbar 7 to support the busbar 7; and setting an adsorption structure on the base plate to adsorb the busbar 7.

[0107] In this embodiment, when the busbar 7 is cut to form a series structure of all battery strings, a base plate 21 is set at the bottom of the busbar 7 to support it, so that the busbar 7 maintains a stable planar support state during the cutting process. At the same time, an adsorption structure 22 is set on the base plate 21 to apply an adsorption force to the busbar 7 to fix its position and prevent it from being displaced or deformed under the action of cutting force. This ensures that the cutting path is accurate and the edges are neat, effectively improving the electrical isolation reliability and geometric consistency of the series structure of battery strings. The fixing method of support and adsorption working together ensures that the busbar 7 maintains the preset positioning accuracy before and during the cutting process, avoiding the displacement caused by vibration or tensile stress, thereby ensuring the electrical performance stability and assembly yield of the entire battery string assembly.

[0108] In one embodiment, the width of the scrap material 10 is 2mm to 10mm, and the shape of the scrap material 10 is rectangular or square. After laser or knife cutting, it can be ensured that it is completely separated from the main busbar 7 and there is no risk of electrical connection. At the same time, it is easy to remove efficiently by air blowing or suction nozzle, avoiding short circuits or pollution caused by waste residue, and taking into account both insulation safety and production cleanliness.

[0109] In one embodiment, the cut-off scrap 10 needs to be removed. An air gun blowing mode is preferred, and in air gun mode, the bottom plate of the manifold is activated in suction mode to ensure the main manifold strip is not blown out of position. In some embodiments, a pneumatic suction nozzle can also be used to absorb and remove the scrap 10.

[0110] See also Figure 9 As shown, by using the above-mentioned welding method of solder strip and busbar, multiple battery strings can form a series structure, and multiple battery cells of a single battery string can form a parallel structure.

[0111] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0112] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0113] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for welding battery strings, characterized in that, include: Prepare multiple cells from the same battery string (1); Prepare at least one continuous welding strip; By continuously pulling the continuous welding strip once or multiple times, the continuous welding strip is made to contact and weld with the same surface of multiple battery cells (1) in sequence to form a conductive path; Complete the welding of the entire battery string; The continuous welding strip is not bent during the welding process and remains in a continuous extended state after welding is completed.

2. The battery string welding method according to claim 1, characterized in that, The continuous solder strip includes an upper solder strip (3) and a lower solder strip (2). The step of forming a conductive path by repeatedly pulling the continuous solder strip to make it sequentially contact and weld with the same surface of multiple battery cells (1) includes: Pull the lower layer of welding strip (2) of the first preset length; A first preset number of battery cells (1) are placed on the lower layer solder strip (2) of the first preset length; The upper welding strip (3) of the first preset length is stretched to the first preset length of the corresponding first preset number of battery cells (1); Welding of a first preset number of battery cells (1) to the lower layer solder strip (2) and the upper layer solder strip (3); Pull the lower layer of welding strip of the second preset length (2); A second preset number of battery cells (1) are placed on the lower layer solder strip (2) of the second preset length; The upper welding strip (3) of the second preset length is stretched to the second preset length of the corresponding second preset number of battery cells (1); Welding of a second preset number of battery cells (1) to the lower layer solder strip (2) and the upper layer solder strip (3) is performed; By analogy, the lower layer solder strip (2) is welded to the first side of all the battery cells (1) in the same battery string, and the upper layer solder strip (3) is welded to the second side of all the battery cells (1) in the same battery string.

3. The battery string welding method according to claim 2, characterized in that, The step of welding a first preset number of battery cells (1) to the lower layer solder strip (2) and the upper layer solder strip (3) includes: The control roller mechanism (4) descends to a distance of 0.5mm to 3mm from the surface of the battery cell (1); The control welding strip tool (6) presses and positions the upper welding strip (3); Control the welding mechanism (5) to move to the position to be welded and perform welding.

4. The battery string welding method according to claim 1, characterized in that, The continuous solder strip includes an upper solder strip (3) and a lower solder strip (2). The step of forming a conductive path by continuously pulling the continuous solder strip to sequentially contact and weld it with the same surface of multiple battery cells (1) in one continuous process includes: The lower welding strip (2) of the first preset length is pulled, and the first preset length is greater than the length of the battery string; All the cells (1) of the same battery string are placed on the lower layer solder strip (2) of the first preset length; The upper welding strip (3) of the corresponding placed battery cell (1) is stretched to a first preset length; Welding of the battery cell (1) to the lower solder strip (2) and the upper solder strip (3) is carried out.

5. The battery string welding method according to claim 4, characterized in that, The steps of welding the battery cell (1) to the lower solder strip (2) and the upper solder strip (3) include: The control welding strip tool (6) presses and positions the upper welding strip (3); Control the welding mechanism (5) to move to the position to be welded and perform welding.

6. The battery string welding method according to claim 5, characterized in that, The steps for controlling the welding mechanism (5) to move to the position to be welded and to perform welding include: Determine the coverage area of ​​the welding mechanism (5); Control the welding mechanism (5) to move to the position to be welded, and perform welding of the welding strip in the coverage area; Control the welding mechanism (5) to move away from the welding position; The welding mechanism (5) is shifted to the unwelded area by a distance covering the area; The welding mechanism (5) is controlled to move to the position to be welded in the unwelded area and to weld the welding strips in the covered area; Continue in this manner to complete the welding of all positions to be welded.

7. The battery string welding method according to any one of claims 1 to 5, characterized in that, The battery string welding method further includes: After welding all the battery strings, place all the battery strings in the grid. A busbar (7) is pulled out from each of the two protruding ends of the battery string. This ensures that all the weld strips located at the same end are welded to the busbar (7) at that end; The busbar (7) is cut so that all the battery strings form a series structure.

8. The battery string welding method according to claim 7, characterized in that, The step of cutting the busbar (7) to form a series structure of all battery strings includes: A laser cutting mechanism (8) is used to cut at a preset cutting position, and each position is cut twice to completely cut off the scrap (10) and to make a preset length interval between two adjacent busbars (7).

9. The battery string welding method according to claim 7, characterized in that, The step of cutting the busbar (7) to form a series structure of all battery strings includes: A double-edged cutter (9) is used to cut once at each cutting position; or, A single-blade cutter is used to make two cuts at each cutting position.

10. The battery string welding method according to claim 8 or 9, characterized in that, The step of cutting the busbar (7) to form a series structure of all battery strings further includes: A base plate is installed at the bottom of the busbar (7) to support the busbar (7); An adsorption structure is set on the base plate to adsorb the busbar (7).

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