Metal wire assembly preparation method, battery piece preparation method and battery string forming method

Abstract

The invention provides a metal wire assembly preparation method, a battery piece preparation method and a battery string method, and the metal wire assembly preparation method comprises the steps: clamping the head end of a metal wire from a material coil, and pulling out the metal wire, the head end of the pulled-out metal wire penetrates through the space between the N first pull rods and the M second pull rods and then is kept at the preset position; the N first pull rods and the M second pull rods are controlled to move relatively, the N first pull rods and the M second pull rods penetrate through each other in the second direction and then continue to move, and in the process, the N first pull rods and the M second pull rods are matched to continuously pull out the metal wires from the material coil; clamping the tail end of the metal wire; and the tail end of the clamped metal wire is cut off, and the metal wire assembly composed of a plurality of metal wire sections which extend in the second direction and are connected end to end is obtained. According to the preparation method of the metal wire assembly, only one material roll needs to be installed on equipment, so that the occupied space of the equipment is reduced, and the daily maintenance of the equipment and the material roll replacement workload are reduced.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic cell production, and specifically to a method for preparing a wire assembly, a method for preparing a cell, and a method for stringing cells. Background Art

[0002] For a conventional cell, the main grid lines thereon are formed by screen printing silver paste. In order to reduce the usage amount of silver paste and lower the production cost of the cell, an entirely new structure of cell has been proposed in the industry. The main grid lines are no longer printed, and dozens to hundreds of metal wires can be fixedly connected to the cell body, using the metal wires to replace the silver main grid lines to collect the photo-generated current generated by the cell body.

[0003] However, since the number of metal wires required is too large, if the conventional method of pulling out one metal wire from each coil is used, then coils equal in number to the required metal wires, that is, dozens to hundreds of coils, need to be installed on the equipment to achieve the simultaneous parallel feeding of a large number of metal wires. However, the installation of a large number of coils not only occupies a large amount of space on the equipment, but also is not convenient for the daily maintenance of the equipment and the replacement of the coils. Therefore, there is an urgent need for a method that can adapt to actual production to conductively connect metal wires to cells. Summary of the Invention

[0004] In view of the above technical problems, the first aspect of the present application provides a method for preparing metal wires, and its detailed technical solution is as follows:

[0005] A method for preparing a wire assembly, comprising:

[0006] Clamp the head end of the metal wire from the coil, and pull out the metal wire along the first direction, so that the head end of the pulled-out metal wire passes between N first pull rods and M second pull rods and remains at a predetermined position, wherein the N first pull rods are arranged at intervals along the first direction, the M second pull rods are arranged at intervals along the first direction, and the N first pull rods and the M second pull rods are staggered in the first direction; N = M, or N = M + 1, or M = N + 1;

[0007] Control the N first pull rods and the M second pull rods to move relative to each other along the second direction. The N first pull rods and the M second pull rods pass through each other along the second direction and continue to move. During this process, the N first pull rods and the M second pull rods cooperate to continuously pull out the metal wire from the coil, wherein the second direction is perpendicular to the first direction;

[0008] Clamp the tail end of the metal wire;

[0009] Cut off the tail end of the clamped metal wire to obtain a wire assembly composed of several metal wire segments connected end to end.

[0010] The method for preparing a wire assembly provided by this application first clamps the head end of the wire from a wire coil and pulls the wire in a first direction, so that the head end of the wire passes between N first pull rods and M second pull rods and remains at a predetermined position. Subsequently, the N first pull rods and the M second pull rods move relative to each other in a second direction perpendicular to the first direction, pass through each other and continue to move. During this process, the wire is continuously pulled out of the wire coil and bent. Subsequently, after clamping the tail end of the wire, the tail end of the wire is cut off, thereby obtaining a wire assembly composed of several wire segments connected end to end.

[0011] It can be seen that by using the method for preparing a wire assembly provided by the embodiments of this application, only one wire coil needs to be installed on the device. After pulling out the wire from the wire coil, this application can bend the wire to prepare a wire assembly composed of a predetermined number of wire segments connected end to end. After the wire assembly is fixedly connected to the battery cell body subsequently, the wire assembly can collect the photo-generated current in the battery cell body. Compared with the existing wire preparation method, the method for preparing a wire assembly of this application can reduce the floor space of the device and reduce the workload of daily maintenance of the device and replacement of the wire coil.

[0012] In some embodiments, before clamping the tail end of the wire, the method for preparing a wire assembly further includes: pulling the tail end of the wire away from the first pull rod or the second pull rod closest to the tail end of the wire, so that the tail end of the wire is collinear with the N first pull rods or the M second pull rods; and / or, pulling the clamped head end of the wire away from the first pull rod or the second pull rod closest to the head end of the wire, so that the head end of the wire is collinear with the N first pull rods or the M second pull rods; the wire assembly is composed of N + M + 1 wire segments.

[0013] By pulling the tail end of the wire and / or the head end of the wire, it is ensured that the tail end and the head end of the wire are respectively collinear with the N first pull rods or the M second pull rods, thereby ensuring that the wire assembly is composed of N + M + 1 wire segments of equal length.

[0014] In some embodiments, controlling the N first pull rods and the M second pull rods to move relative to each other in the second direction is: fixing the N first pull rods and controlling the M second pull rods to move in the second direction towards the N first pull rods; or, fixing the M second pull rods and controlling the N first pull rods to move in the second direction towards the M second pull rods; or, controlling the N first pull rods and the M second pull rods to move towards each other in the second direction simultaneously.

[0015] Three ways to control the relative movement of N first pull rods and M second pull rods are provided, all of which can cooperate to continuously pull out the wire from the wire coil and bend the wire. Among them, controlling the N first pull rods and the M second pull rods to move towards each other simultaneously in the second direction can, on the one hand, improve the pulling and bending efficiency of the wire, and on the other hand, make the forces on both sides of the wire balanced, reducing the risk of the wire being broken.

[0016] In some embodiments, the second pull rod has the same diameter as the first pull rod, and the distance between adjacent wire segments in the wire assembly is equal to the diameter of the first pull rod.

[0017] Ensure that the distances between adjacent wire segments in the wire assembly are all equal.

[0018] In some embodiments, the method for preparing the wire assembly further includes: performing extrusion shaping on all wire segments of the wire assembly to change the cross-sectional shape of the wire segments.

[0019] By performing extrusion shaping on all wire segments of the wire assembly, the adjustment of the cross-sectional shape of the wire segments can be realized, so as to meet the different performance requirements of the battery cells.

[0020] In some embodiments, an extrusion die is used to perform extrusion shaping on all wire segments of the wire assembly. The extrusion die includes a bearing plate and an extrusion member, wherein: there are V-shaped grooves on the bearing plate corresponding one by one to the wire segments of the wire assembly; the extrusion member is configured to press the wire segments of the wire assembly into the V-shaped grooves one by one to extrude the cross-section of each wire segment into a triangle.

[0021] Since the cross-section of the wire segments of the wire assembly is triangular. Therefore, when the wire assembly is fixedly connected to the battery cell body, the vertically incident light and the obliquely incident light irradiated on the wire segments can be reflected by the wire segments to the battery cell body, thereby maximizing the light absorption effect of the battery cell body and finally increasing the photocurrent of the battery cell body.

[0022] The second aspect of the present application provides a method for preparing a battery cell, and its detailed technical solution is as follows:

[0023] A method for preparing a battery cell includes:

[0024] Providing a first wire assembly, a second wire assembly and a battery cell body, wherein both the first wire assembly and the second wire assembly are prepared by the method for preparing the wire assembly described in any one of the above.

[0025] Fix the first wire assembly to the first surface of the cell body, and fix the second wire assembly to the second surface of the cell body to obtain a cell, wherein the same ends of the wire segments of the first wire assembly extend out of the cell body to form a series connection end.

[0026] By fixing the first wire assembly and the second wire assembly to the first surface and the second surface of the cell body respectively, a cell with wires on its surface is obtained. Subsequently, only by electrically connecting the first wire assembly of one of the adjacent cells to the second wire assembly of the other cell, the series connection of the cells can be implemented to obtain a cell string. In addition, since the first wire assembly of the cell has a series connection end extending out of the cell body, it facilitates the series connection of adjacent cells.

[0027] In some embodiments, fixing the first wire assembly to the first surface of the cell body and fixing the second wire assembly to the second surface of the cell body includes:

[0028] Weld the first wire assembly to the first surface of the cell body, and weld the second wire assembly to the second surface of the cell body;

[0029] Or it includes:

[0030] Apply glue to the first wire assembly to bond the first wire assembly to the first surface of the cell body, and apply glue to the second wire assembly to bond the second wire assembly to the second surface of the cell body;

[0031] Or it includes:

[0032] Weld the first wire assembly to the first surface of the cell body, and weld the second wire assembly to the second surface of the cell body;

[0033] Apply glue to the first wire assembly to bond the first wire assembly to the first surface of the cell body, and apply glue to the second wire assembly to bond the second wire assembly to the second surface of the cell body;

[0034] Or it includes:

[0035] Bond the first wire assembly and the second wire assembly to the first surface and the second surface of the cell body respectively through a diaphragm; the diaphragm covers all the wire segments of the first wire assembly or the second wire assembly.

[0036] Several implementation methods are provided for fixedly connecting the first wire assembly and the second wire assembly to the battery cell, all of which can form an electrical connection between the first wire assembly, the second wire assembly and the battery cell. Among them, the fixed connection method of welding can form a stable metallized connection between the first wire assembly, the second wire assembly and the battery cell. For the main-grid-free battery cell body, the fixed connection method of applying glue can ensure a firm and stable connection between the first wire assembly, the second wire assembly and the battery cell body. The double connection method of welding and applying glue can further improve the connection strength between the first wire assembly, the second wire assembly and the battery cell body. The method of bonding with a diaphragm can conveniently and quickly fixedly connect the first wire assembly and the second wire assembly to the battery cell body, improving the fixed connection efficiency.

[0037] In some embodiments, the method of applying glue to the second wire assembly is the same as that to the first wire assembly. The method of applying glue to the first wire assembly includes:

[0038] Apply a number of glue strips to the first wire assembly at intervals. Among them, the glue strips are perpendicular to the wire segments of the first wire assembly, and each glue strip is bonded to all the wire segments of the first wire assembly.

[0039] Bonding the first wire assembly to the battery cell body through a number of glue strips bonded to all the wire segments of the first wire assembly can ensure that all the wire segments in the first wire assembly form a stable connection with the battery cell body.

[0040] In some embodiments, before fixedly connecting the first wire assembly to the first surface of the battery cell body and the second wire assembly to the second surface of the battery cell body, the battery cell preparation method further includes: pressing the first wire assembly against the first surface of the battery cell body and pressing the second wire assembly against the second surface of the battery cell body.

[0041] Before fixedly connecting the first wire assembly and the second wire assembly to the battery cell body, pressing the first wire assembly and the second wire assembly against the battery cell body can improve the fixed connection effect between the first wire assembly, the second wire assembly and the battery cell body and prevent virtual connection.

[0042] The third aspect of this application provides a battery stringing method, and its detailed technical solution is as follows:

[0043] A battery stringing method, which includes:

[0044] Provide N battery cells, and the battery cells are the battery cells prepared by using the battery cell preparation method described in any one of the above.

[0045] The series connection end of the second wire assembly of the (i + 1)-th cell is welded to the series connection end of the first wire assembly of the i-th cell through a conductive bar to obtain a cell string, where the conductive bar is perpendicular to the wire segments of the second wire assembly and the first wire assembly, and is welded to each wire segment, 1 ≤ i ≤ N - 1.

[0046] By connecting the first wire assembly and the second wire assembly of two adjacent cells through a conductive bar, the series connection of the cells is realized. In addition, since the conductive bar is perpendicular to the wire segments of the second wire assembly and the first wire assembly, and is welded to each wire segment, all wire segments in the first wire assembly and the second wire assembly of two adjacent cells can be ensured to achieve conductive connection.

[0047] In some embodiments, the conductive bar is a conductive copper bar coated with a tin layer.

[0048] The copper bar as the base material enables the conductive bar to have excellent electrical conductivity and improves the quality of cell string formation. The surface of the copper bar is coated with a tin layer. Tin has good oxidation resistance and corrosion resistance, can effectively protect the copper bar from oxidation or corrosion, and can be used as a solder to realize the welding connection between the conductive copper bar and the wire assembly.

[0049] In some embodiments, the width of the conductive bar along the extension direction of the cell string ≤ 2 mm, the thickness of the conductive bar is 10 μm - 30 μm, and the thickness of the tin layer is 3 μm - 10 μm.

[0050] By setting the width and thickness of the conductive bar, on the premise of realizing the conductive connection of adjacent cells, the amount of the conductive bar is reduced, the cost is saved, and the conductive bar has high flexibility, which is suitable for scenarios that require bending or folding. By setting the thickness of the tin layer, the tin layer is sufficient to provide good oxidation resistance, corrosion resistance and welding performance, and will not significantly increase the overall thickness of the conductive bar. Description of the Drawings

[0051] Figure 1 It is a schematic diagram of the state after the wire to be pulled passes through between N first pull rods and M second pull rods;

[0052] Figure 2 It is a schematic diagram of the state after N first pull rods and M second pull rods complete the pulling and bending of the wire;

[0053] Figure 3 It is a schematic diagram of the extrusion and shaping of the wire assembly by an extrusion die from one perspective;

[0054] Figure 4 It is a schematic diagram of the structure of the extrusion die from another perspective;

[0055] Figure 5 The partial enlarged view of area A of Figure 4 ;

[0056] Figure 6 The structural schematic diagram of a cell formed by fixedly connecting a first wire assembly, a second wire assembly and a cell body;

[0057] Figure 7 The schematic diagram of gluing the first wire assembly to the cell body through a plurality of rubber strips;

[0058] Figure 8 The schematic diagram of gluing the first wire assembly to the cell body through a diaphragm;

[0059] Figure 9 The schematic diagram of pressing the first wire assembly and the second wire assembly against the cell body through a first press tool and a second press tool;

[0060] Figure 10 The structural schematic diagram of a cell string.

[0061] Figures 1 to 10 It includes:

[0062] A first pull rod 1, a second pull rod 2, a first chuck 3, a second chuck 4, a bearing plate 5, an extrusion member 6, a V-shaped groove 7, a first press tool 8, a second press tool 9;

[0063] A wire 100, a wire assembly 200, a wire segment 201, a first wire assembly 200a, a second wire assembly 200b, a series connection end 200c, a cell body 300, a conductive strip 400, a rubber strip 500, a diaphragm 600. Specific embodiments

[0064] To make the above objects, features and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0065] As described in the background art section, in order to obtain the wires required to collect the photo-generated current generated by the cell body. The existing processing method is to install on the equipment the same number of material rolls as the number of wires required for the cell body, and pull out one wire from each material roll, that is, dozens to hundreds of material rolls, so as to realize the simultaneous parallel feeding of a large number of wires. However, the installation of a large number of material rolls not only occupies a large amount of space on the equipment, but also is not convenient for the daily maintenance of the equipment and the replacement of the material rolls. Therefore, there is an urgent need for a method that can adapt to actual production to conductively connect the wires to the cells.

[0066] In order to solve the above problems existing in the existing wire preparation method, the present application provides a method for preparing a wire assembly.

[0067] The method for preparing the wire assembly of the present application includes the following steps:

[0068] S11. Clamp the head end of the wire from the wire reel and pull out the wire in the first direction, so that the head end of the pulled-out wire passes between N first pull rods and M second pull rods and remains at a predetermined position. Among them, the N first pull rods are arranged at intervals in the first direction, the M second pull rods are arranged at intervals in the first direction, and the N first pull rods and the M second pull rods are staggered in the first direction. Among them, N = M, or N = M + 1, or M = N + 1. That is to say, the number of the first pull rods is equal to the number of the second pull rods, or the number of the first pull rods is one more than that of the second pull rods, or the number of the second pull rods is one more than that of the first pull rods, so that the first pull rods and the second pull rods can be staggered in the first direction.

[0069] S12. Control the N first pull rods and the M second pull rods to move relatively in the second direction. The N first pull rods and the M second pull rods pass through each other in the second direction and continue to move. During this process, the N first pull rods and the M second pull rods cooperate to continuously pull out the wire from the wire reel. Among them, the second direction is perpendicular to the first direction.

[0070] S13. Clamp the tail end of the wire.

[0071] S14. Cut off the tail end of the clamped wire to obtain a wire assembly composed of several wire segments connected end to end.

[0072] Among them, the specific values of the number N of the first pull rods and the number M of the second pull rods in step S11 are selected and set according to the number of wire segments required for the wire assembly to be obtained.

[0073] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the following will be combined with Figures 1 to 2 to describe in more detail the specific implementation process of the method for preparing the wire assembly of the present application in an embodiment.

[0074] First, as Figure 1 shown, control the first chuck 3 to clamp the head end of the wire 100 from the wire reel and pull out the wire 100 in the first direction (such as the X direction), so that the head end of the pulled-out wire 100 passes between N first pull rods 1 and M second pull rods 2 and remains at a predetermined position a.

[0075] Next, control the N first pull rods 1 and the M second pull rods 2 to move relative to each other in the second direction (such as the Y-axis direction). The N first pull rods 1 and the M second pull rods 2 continue to move after passing through each other in the second direction. During this process, the N first pull rods 1 and the M second pull rods 2 cooperate to continuously pull out the wire 100 from the wire reel, and reciprocally bend the pulled-out wire 100.

[0076] Next, control the second chuck 4 to clamp the tail end of the wire 100.

[0077] Finally, control the cutting tool to cut off the tail end of the clamped wire 100, so as to obtain Figure 2 the wire assembly 200 shown in the figure, which is composed of several wire segments 201 connected end to end.

[0078] It can be seen that by using the method for preparing a wire assembly provided in the embodiment of the present application, only one wire reel needs to be installed on the device. After pulling out the wire 100 from the wire reel, the wire 100 can be bent to prepare the wire assembly 200 composed of a predetermined number of wire segments 201 connected end to end. After the wire assembly 200 is fixedly connected to the surface of the battery cell body subsequently, the wire assembly 200 can collect the photo-generated current in the battery cell body. Compared with the existing wire preparation method, the method for preparing a wire assembly of the present application can reduce the floor space of the device, and reduce the workload of daily maintenance of the device and replacement of the wire reel.

[0079] As Figures 1 to 2 shown in the figure, optionally, controlling the N first pull rods and the M second pull rods to move relative to each other in the second direction in step S12 is:

[0080] Control the N first pull rods 1 and the M second pull rods 2 to move towards each other simultaneously in the second direction.

[0081] In this way, on the one hand, the pulling and bending efficiency of the wire 100 can be improved, and on the other hand, the forces on both sides of the wire 100 are balanced, thereby reducing the risk of the wire 100 being broken.

[0082] Of course, it is also possible to fix the N first pull rods 1 and control the M second pull rods 2 to move towards the N first pull rods 1 in the second direction to perform the pulling and bending of the wire 100. Or, it is also possible to fix the M second pull rods 2 and control the N first pull rods 1 to move towards the M second pull rods 2 in the second direction to perform the pulling and bending of the wire 100.

[0083] Optionally, the second pull rod 2 has the same diameter as the first pull rod 1. With such a setting, on the one hand, the distance between adjacent wire segments 201 in the finally obtained wire assembly 200 is equal to the diameters of the first pull rod 1 and the second pull rod 2.

[0084] As shown Figures 1 to 2 in the figure, this is the case where N first pull rods 1 and M second pull rods 2 move towards each other simultaneously in the second direction. The N first pull rods 1 and the M second pull rods 2 cooperate to continuously draw out the wire 100 from the wire coil. After completing the reciprocating bending of the drawn wire 100, the N first pull rods 1 switch from the first side of the pulling path L of the first chuck 3 for the wire 100 to the second side of the pulling path L, and the M second pull rods 2 switch from the second side of the pulling path L to the first side of the pulling path L, and the distances between the N first pull rods 1, the M second pull rods 2 and the pulling path L increase.

[0085] However, as shown Figure 2 in the figure, at this time, the first chuck 3 is still located at the predetermined position a on the pulling path L, resulting in a large angle between the wire segment between the leading end of the wire and the nearest second pull rod 2 (such as the left dotted line segment in Figure 2 the figure) and the second direction, and this wire segment is shorter than the other bent wire segments 201. Similarly, there is a large angle between the wire segment between the trailing end of the wire and the nearest first pull rod 1 (such as the right dotted line segment in Figure 2 the figure) and the second direction, and this wire segment is also shorter than the lengths of the other bent wire segments 201.

[0086] To solve the above problems, optionally, before clamping the trailing end of the wire in step S13, the method for preparing the wire assembly of the present application further includes: pulling the trailing end of the wire away from the first pull rod 1 or the second pull rod 2 closest to the trailing end of the wire, so that the trailing end of the wire is collinear with the N first pull rods 1 or the M second pull rods 2; and / or pulling the leading end of the clamped wire away from the first pull rod 1 or the second pull rod 2 closest to the leading end of the wire, so that the leading end of the wire is collinear with the N first pull rods 1 or the M second pull rods 2.

[0087] Still taking the wire in the embodiment shown Figures 1 to 2 in the figure as an example, before clamping the trailing end of the wire, pull the trailing end of the wire away from the first pull rod 1 closest to the trailing end of the wire, so that the trailing end of the wire is collinear with the M second pull rods 2, and pull the leading end of the clamped wire away from the second pull rod 2 closest to the leading end of the wire, so that the leading end of the wire is collinear with the N first pull rods 1. The pulling directions of the trailing end and the leading end of the wire are as shown by the dotted arrows in Figure 2 the figure.

[0088] In this way, when the trailing end of the wire is cut off, it can be ensured that a wire assembly 200 composed of N + M + 1 wire segments 201 with equal lengths can be obtained.

[0089] Of course, in other embodiments, according to the movement of the N first pull rods 1 and the M second pull rods 2 in the second direction, and according to the specific structure of the wire assembly 200 finally required to be obtained, before clamping the tail end of the wire, it is possible to choose to only pull the tail end of the wire away from the first pull rod 1 or the second pull rod 2 closest to the tail end of the wire, so that the tail end of the wire is collinear with the M second pull rods 2 or the N first pull rods 1. Or choose to only pull the head end of the clamped wire away from the first pull rod 1 or the second pull rod 2 closest to the head end of the wire, so that the head end of the wire is collinear with the M second pull rods 2 or the N first pull rods 1.

[0090] Optionally, the method for preparing the wire assembly in the embodiment of the present application further includes: performing extrusion shaping on all wire segments 210 of the wire assembly 200 to change the cross-sectional shape of the wire segment 201. With such a setting, different performance requirements of the battery cell can be met, such as enabling the wire assembly 200 to more effectively collect the photo-generated current generated by the battery cell body.

[0091] As Figures 3 to 5 As shown, optionally, an extrusion die is used to perform extrusion shaping on all wire segments 201 of the wire assembly 200. The extrusion die includes a bearing plate 5 and an extrusion member 6, wherein: there are V-shaped grooves 7 on the bearing plate 5 corresponding one-to-one to the wire segments 201 of the wire assembly 200. The extrusion member 6 is configured to press the wire segments 201 of the wire assembly 200 into the V-shaped grooves 7 one-to-one, so as to extrude the cross-section of each wire segment 201 into a triangle, wherein the original cross-sectional shape of the wire is circular.

[0092] Since the cross-section of the wire segment 201 of the wire assembly 200 is triangular, when the wire assembly 200 is fixedly connected to the battery cell body, both the vertically incident light and the obliquely incident light irradiated on the wire segment 201 can be reflected by the wire segment 201 onto the battery cell body, thereby maximizing the light absorption effect of the battery cell body and ultimately increasing the photo-generated current of the battery cell body.

[0093] As Figure 3As shown in the figure, an optional extrusion and shaping method is as follows: After cutting the tail end of the wire to obtain the wire assembly 200, the first pull rod 1, the second pull rod 2, the first chuck 3 and the second chuck 4 maintain the support and tension of the wire assembly 200. Subsequently, the bearing plate 5 and the extrusion member 6 translate towards the wire assembly 200, so that the wire assembly 200 enters between the bearing plate 5 and the extrusion member 6, and it is ensured that each wire segment 201 in the wire assembly 200 is aligned with the corresponding V-shaped groove 7. Control the extrusion member 6 to press the wire segments 201 of the wire assembly 200 into the V-shaped grooves 7 one by one, and the cross-section of each wire segment 201 can be extruded into a triangle. In actual extrusion, the bearing plate 5 can be located above the extrusion member 6 or below the extrusion member 6.

[0094] Of course, after cutting the tail end of the wire to obtain the wire assembly 200, it is also possible to control the first chuck 3 and the second chuck 4 to release both ends of the wire assembly 200 and remove the wire assembly 200 from the N first pull rods 1 and the M second pull rods 2. Subsequently, the wire assembly 200 is placed on the bearing plate 5, and it is ensured that each wire segment 201 in the wire assembly 200 is aligned with the corresponding V-shaped groove 7. Subsequently, control the extrusion member 6 to press the wire segments 201 of the wire assembly 200 into the V-shaped grooves 7 one by one, and the cross-section of each wire segment 201 can be extruded into a triangle.

[0095] The extrusion member 6 can be a pressing plate or a pressing roller. When the pressing plate is used as the extrusion member 6, controlling the pressing plate to press tightly against the bearing plate 5 can press all the wire segments 201 of the wire assembly 200 into the corresponding V-shaped grooves 7 on the bearing plate 5 at one time, thereby improving the extrusion and shaping efficiency of the wire assembly 200. When the pressing roller is used as the extrusion member 6, controlling the pressing roller to roll reciprocally on the bearing plate 5 and pressing the wire segments 201 of the wire assembly 200 into the corresponding V-shaped grooves 7 on the bearing plate 5 can make the wire segments 201 fully pressed, and the material of the wire segments 201 can be more fully pressed into the V-shaped grooves 7, thereby improving the extrusion and shaping effect of the wire assembly 200.

[0096] Based on the same inventive concept, the present application also provides a method for preparing a battery cell. As Figures 6 to 9 shown, the method for preparing a battery cell in the embodiment of the present application includes the following steps:

[0097] S21. Provide a first wire assembly 200a, a second wire assembly 200b and a battery cell body 300, wherein both the first wire assembly 200a and the second wire assembly 200b are prepared by the wire assembly preparation method in any of the above embodiments.

[0098] S22. Fix the first wire assembly 200a to the first surface (e.g., the front surface) of the cell body 300, and fix the second wire assembly 200b to the second surface (e.g., the back surface) of the cell body 300 to obtain a cell, wherein the same ends of the wire segments 201 of the first wire assembly 200a extend outward from the cell body 300 to form a series connection end 200c.

[0099] In other words, except for the series connection end 200c where the first wire assembly 200a extends outward from the cell body 300, the rest of the first wire assembly 200a is located on the first surface of the cell body 300, and the second wire assembly 200b is completely located on the second surface of the cell body 300 (as Figure 6 shown).

[0100] By fixing the first wire assembly 200a and the second wire assembly 200b to the first surface and the second surface of the cell body 300 respectively, a cell with wires on its surface is obtained. The wires can collect the photo-generated current generated by the cell body 300. Subsequently, only by electrically connecting the first wire assembly 200a of one of the adjacent cells to the second wire assembly 200b of the other cell, the series connection of the cells can be implemented to obtain a cell string. In addition, since the first wire assembly 200a of the cell has a series connection end 200c that extends out of the cell body 300, it is convenient to series-connect adjacent cells.

[0101] In step S22, fixing the first wire assembly to the first surface of the cell body and fixing the second wire assembly to the second surface of the cell body can be implemented by, but not limited to, the following four implementation manners.

[0102] The first implementation manner

[0103] Weld the first wire assembly 200a to the first surface of the cell body 300, and weld the second wire assembly 200b to the second surface of the cell body 300.

[0104] By using the fixed connection method of welding, a stable metallization connection can be formed between the first wire assembly 200a, the second wire assembly 200b and the cell body 300, ensuring the collection effect of the first wire assembly 200a and the second wire assembly 200b on the photo-generated current.

[0105] Optionally, in order to improve the welding effect, the outer surface of the wire is coated with solder and flux is applied.

[0106] The second implementation manner

[0107] Apply glue to the first wire assembly 200a to bond the first wire assembly 200a to the first surface of the cell body 300, and apply glue to the second wire assembly 200b to bond the second wire assembly 200b to the second surface of the cell body 300.

[0108] For a main-gridless cell body without main grid lines on its surface, the fixed connection method of applying glue for bonding can ensure a firm and stable connection between the first wire assembly 200a, the second wire assembly 200b and the cell body 300, and ensure the collection effect of the first wire assembly 200a and the second wire assembly 200b on the photo-generated current.

[0109] The third implementation method

[0110] Weld the first wire assembly 200a to the first surface of the cell body 300, and weld the second wire assembly 200b to the second surface of the cell body 300.

[0111] Apply glue to the first wire assembly 200a to bond the first wire assembly 200a to the first surface of the cell body 300, and apply glue to the second wire assembly 200b to bond the second wire assembly 200b to the second surface of the cell body 300.

[0112] It should be noted that the welding operation of the first wire assembly 200a and the second wire assembly 200b can be carried out before the glue-bonding operation or after the glue-bonding operation, and there is no strict sequence between the two.

[0113] Adopting the double connection method of welding and glue-bonding can further improve the connection strength between the first wire assembly 200a, the second wire assembly 200b and the cell body 300.

[0114] Optionally, the glue application method for the second wire assembly 200b is the same as that for the first wire assembly 200a. Taking the glue application to the first wire assembly 200a as an example, as Figure 7 shown, the glue application method is: apply a number of (for example Figure 7 6 in

[0115] The first wire assembly 200a is adhered to the main body 300 of the solar cell by a plurality of adhesive strips 500 adhered to all wire segments 201 of the first wire assembly 200a, so as to ensure that all wire segments 201 in the first wire assembly 200a form a stable connection with the main body 300 of the solar cell.

[0116] The fourth implementation

[0117] As Figure 8 shown, the first wire assembly 200a and the second wire assembly 200b are respectively adhered to the first surface and the second surface of the main body 300 of the solar cell by a diaphragm 600. The diaphragm 600 covers all wire segments 201 of the first wire assembly 200a or the second wire assembly 200b.

[0118] By adopting the diaphragm adhesion method, the first wire assembly 200a and the second wire assembly 200b can be fixedly connected to the main body 300 of the solar cell conveniently and quickly, and the fixing connection efficiency of the first wire assembly 200a and the second wire assembly 200b is improved.

[0119] Optionally, before fixedly connecting the first wire assembly 200a to the first surface of the main body 300 of the solar cell and fixedly connecting the second wire assembly 200b to the second surface of the main body 300 of the solar cell, the method for preparing a solar cell in the embodiment of the present application further includes: pressing the first wire assembly 200a on the first surface of the main body 300 of the solar cell, and pressing the second wire assembly 200b on the second surface of the main body 300 of the solar cell.

[0120] Before fixedly connecting the first wire assembly 200a and the second wire assembly 200b to the main body 300 of the solar cell, pressing the first wire assembly 200a and the second wire assembly 200b onto the main body 300 of the solar cell first can improve the fixing connection effect between the first wire assembly 200a and the second wire assembly 200b and the main body 300 of the solar cell, and prevent virtual connection.

[0121] As Figure 9 shown, an optional method for pressing the first wire assembly 200a and the second wire assembly 200b onto the main body 300 of the solar cell is as follows.

[0122] The first wire assembly 200a and the second wire assembly 200b are synchronously prepared by the wire assembly preparation method in the above embodiment, and the first wire assembly 200a and the second wire assembly 200b are arranged up and down. In particular, the first pull rod 1, the second pull rod 2, the first chuck 3 and the second chuck 4 maintain the support and tension of the first wire assembly 200a and the second wire assembly 200b.

[0123] Move the battery cell body 300 between the first wire assembly 200a and the second wire assembly 200b.

[0124] Control the first press tool 8 and the second press tool 9 to move to the upper side of the first wire assembly 200a and the lower side of the second wire assembly 200b respectively. Subsequently, control the first press tool 8 to press down until the first wire assembly 200a is pressed off from the first pull rod 1 and the second pull rod 2, and is finally pressed by the first press tool 8 onto the first surface of the battery cell body 300. At the same time, control the second press tool 9 to press up until the second wire assembly 200b is pressed off from the first pull rod 1 and the second pull rod 2, and is finally pressed by the second press tool 9 onto the second surface of the battery cell body 300.

[0125] When the first wire assembly 200a and the second wire assembly 200b are fixedly connected to the battery cell body 300 by welding, hollow parts can be provided on the first press tool 8 and the second press tool 9, and the welding mechanism can heat the first wire assembly 200a and the second wire assembly 200b through the hollow parts, so that the first wire assembly 200a and the second wire assembly 200b are welded to the battery cell body 300.

[0126] When the first wire assembly 200a and the second wire assembly 200b are fixedly connected to the battery cell body 300 by gluing, hollow parts can be provided on the first press tool 8 and the second press tool 9. After the first press tool 8 and the second press tool 9 cooperate to press the first wire assembly 200a and the second wire assembly 200b onto the battery cell body 300, glue is applied to the wire assemblies through the above-mentioned hollow parts by a glue application mechanism.

[0127] When the first wire assembly 200a and the second wire assembly 200b are fixedly connected to the battery cell body 300 by film bonding, films can be pre-applied to the first wire assembly 200a and the second wire assembly 200b. Then control the first press tool 8 and the second press tool 9 to move to the upper side of the first wire assembly 200a and the lower side of the second wire assembly 200b respectively. In this way, while the first press tool 8 and the second press tool 9 press the first wire assembly 200a and the second wire assembly 200b onto the battery cell body 300, the first wire assembly 200a and the second wire assembly 200b are glued to the battery cell body 300.

[0128] In another pressing method, the prepared first wire assembly 200a and second wire assembly 200b can also be first detached from the corresponding first pull rod 1 and second pull rod 2.

[0129] After stacking the first wire assembly 200a, the second wire assembly 200b and the cell body 300, a press is used to tightly compress the stacked first wire assembly 200a, second wire assembly 200b and cell body 300 from above, so that the first wire assembly 200a and the second wire assembly 200b are respectively compressed onto the first surface and the second surface of the cell body 300.

[0130] Based on the same inventive concept, the present application also provides a method for stringing cells. As Figure 10 shown, the method for stringing cells in the embodiments of the present application includes the following steps:

[0131] Provide N cell pieces, and the cell pieces are cell pieces prepared by using the cell piece preparation method of any one of the above embodiments.

[0132] Weld the series connection end 200c of the second wire assembly 200b of the (i + 1)-th cell piece and the first wire assembly 200a of the i-th cell piece through a conductive bar 400 to obtain a cell string, where the conductive bar 400 is perpendicular to the wire segments of the second wire assembly 200b and the first wire assembly 200a, and is welded to each wire segment, 1 ≤ i ≤ N - 1.

[0133] For example, taking the total number of cell pieces to be strung as 4 (of course, the number of cell pieces included in an actual cell string is generally greater than 4) as an example, the specific stringing method is as follows:

[0134] Provide 4 cell pieces, counting from the front to the back:

[0135] Weld the series connection end 200c of the second wire assembly 200b of the second cell piece and the first wire assembly 200a of the first cell piece through a conductive bar 400.

[0136] Weld the series connection end 200c of the second wire assembly 200b of the third cell piece and the first wire assembly 200a of the second cell piece through a conductive bar 400.

[0137] Weld the series connection end 200c of the second wire assembly 200b of the fourth cell piece and the first wire assembly 200a of the fifth cell piece through a conductive bar 400.

[0138] It can be seen that by connecting the first wire assembly 200a and the second wire assembly 200b of adjacent two solar cells through the conductive bar 400, the series connection of the solar cells into a string is achieved. In addition, since the conductive bar 400 is perpendicular to the wire segments of the second wire assembly 200b and the first wire assembly 200a, and is welded to each wire segment, all the wire segments in the first wire assembly 200a and the second wire assembly 200b of adjacent two solar cells can be ensured to achieve conductive connection.

[0139] Optionally, a conductive copper bar coated with a tin layer is used as the conductive bar 400. The copper bar as the base material enables the conductive bar 400 to have excellent electrical conductivity, improving the quality of the series connection of the solar cells. The surface of the copper bar is coated with a tin layer. Tin has good oxidation resistance and corrosion resistance, which can effectively protect the copper bar from oxidation or corrosion, and can be used as a solder to achieve the welded connection between the conductive copper bar and the wire assembly.

[0140] Optionally, the width of the conductive bar 400 along the extension direction of the solar cell string is ≤ 2 mm, such as 0.5 mm, 1 mm, 2 mm, etc. The thickness of the conductive bar is 10 μm - 30 μm, such as 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, etc. The thickness of the tin layer is 3 μm - 10 μm, such as 3 μm, 5 μm, 7 μm, 9 μm, 10 μm, etc.

[0141] By setting the width and thickness of the conductive bar 400 as above, on the premise of achieving the conductive connection of adjacent solar cells, the amount of the conductive bar is reduced, the cost is saved, and the conductive bar has high flexibility, which is suitable for scenarios that require bending or folding. By setting the thickness of the tin layer as above, the tin layer is sufficient to provide good oxidation resistance, corrosion resistance and welding performance, and at the same time will not significantly increase the overall thickness of the conductive bar.

[0142] The above has described the present application in sufficient detail with a certain particularity. Those of ordinary skill in the art should understand that the description in the embodiments is only exemplary, and all changes made without departing from the true spirit and scope of the present application should fall within the protection scope of the present application. The scope of protection required by the present application is defined by the claims described, rather than by the above description in the embodiments.

Claims

1. A method for preparing a wire assembly, characterized in that, The method for preparing the wire assembly includes: Clamping the head end of the wire from the wire coil and pulling out the wire along the first direction, so that the head end of the pulled-out wire passes between N first pull rods and M second pull rods and remains at a predetermined position. Among them, the N first pull rods are arranged at intervals along the first direction, the M second pull rods are arranged at intervals along the first direction, and the N first pull rods and the M second pull rods are staggered in the first direction; N = M, or N = M + 1, or M = N + 1; Controlling the N first pull rods and the M second pull rods to move relatively along the second direction. The N first pull rods and the M second pull rods pass through each other along the second direction and continue to move. During this process, the N first pull rods and the M second pull rods cooperate to continuously pull out the wire from the wire coil, where the second direction is perpendicular to the first direction; Clamping the tail end of the wire; Cutting off the tail end of the clamped wire to obtain a wire assembly composed of several wire segments connected end to end.

2. The method for preparing the wire assembly according to claim 1, wherein Before clamping the tail end of the wire, the method for preparing the wire assembly further includes: Pulling the tail end of the wire away from the first pull rod or the second pull rod closest to the tail end of the wire, so that the tail end of the wire is collinear with the N first pull rods or the M second pull rods; and / or, Pulling the head end of the clamped wire away from the first pull rod or the second pull rod closest to the head end of the wire, so that the head end of the wire is collinear with the N first pull rods or the M second pull rods; The wire assembly is composed of N + M + 1 wire segments.

3. The method for preparing a wire assembly according to claim 1, characterized in that, The controlling the N first pull rods and the M second pull rods to move relatively along the second direction is: Fixing the N first pull rods and controlling the M second pull rods to move towards the N first pull rods along the second direction; Or, Fixing the M second pull rods and controlling the N first pull rods to move towards the M second pull rods along the second direction; or, Controlling the N first pull rods and the M second pull rods to move towards each other simultaneously along the second direction.

4. The method for preparing a wire assembly according to claim 1, wherein, The diameter of the second pull rod is equal to that of the first pull rod, and the distance between adjacent wire segments in the wire assembly is equal to the diameter of the first pull rod.

5. The method for preparing a wire assembly according to claim 1, wherein, The method for preparing the wire assembly further includes: Performing extrusion shaping on all wire segments of the wire assembly to change the cross-sectional shape of the wire segments.

6. The method for preparing the wire assembly according to claim 5, characterized in that, Performing extrusion shaping on all wire segments of the wire assembly by using an extrusion die. The extrusion die includes a pressure-bearing plate and an extrusion member, where: There are V-shaped grooves on the pressure-bearing plate corresponding one by one to the wire segments of the wire assembly; The extrusion member is configured to press the wire segments of the wire assembly into the V-shaped grooves one by one to extrude the cross-section of each wire segment into a triangle.

7. A method for preparing a battery cell, characterized in that, The method for preparing the battery cell includes: Provide a first wire assembly, a second wire assembly and a battery cell body, wherein the first wire assembly and the second wire assembly are both prepared by the wire assembly preparation method according to any one of claims 1 to 6; Fix the first wire assembly to the first surface of the battery cell body, and fix the second wire assembly to the second surface of the battery cell body to obtain a battery cell, wherein the same ends of the wire segments of the first wire assembly extend out of the battery cell body to form a series connection end.

8. The method for preparing a battery chip according to claim 7, wherein, Fixing the first wire assembly to the first surface of the battery cell body and fixing the second wire assembly to the second surface of the battery cell body includes: Weld the first wire assembly to the first surface of the battery cell body, and weld the second wire assembly to the second surface of the battery cell body; Or it includes: Apply glue to the first wire assembly to bond the first wire assembly to the first surface of the battery cell body, and apply glue to the second wire assembly to bond the second wire assembly to the second surface of the battery cell body; Or it includes: Weld the first wire assembly to the first surface of the battery cell body, and weld the second wire assembly to the second surface of the battery cell body; Apply glue to the first wire assembly to bond the first wire assembly to the first surface of the battery cell body, and apply glue to the second wire assembly to bond the second wire assembly to the second surface of the battery cell body; Or it includes: Bond the first wire assembly and the second wire assembly to the first surface and the second surface of the battery cell body respectively through a diaphragm; the diaphragm covers all the wire segments of the first wire assembly or the second wire assembly.

9. The method for preparing a battery chip according to claim 8, characterized in that, The method of applying glue to the second wire assembly is the same as the method of applying glue to the first wire assembly. The method of applying glue to the first wire assembly includes: Apply a number of glue strips to the first wire assembly at intervals, wherein the glue strips are perpendicular to the wire segments of the first wire assembly, and each glue strip is bonded to all the wire segments of the first wire assembly.

10. The method for preparing a battery cell according to claim 7, wherein, Before fixing the first wire assembly to the first surface of the battery cell body and fixing the second wire assembly to the second surface of the battery cell body, the battery cell preparation method further includes: Press the first wire assembly against the first surface of the battery cell body, and press the second wire assembly against the second surface of the battery cell body.

11. A method for stringing batteries, characterized in that, The battery stringing method includes: Provide N battery cells, and the battery cells are battery cells prepared by the battery cell preparation method according to any one of claims 7 to 10; The series connection end of the second wire assembly of the (i + 1)-th cell is welded to the series connection end of the first wire assembly of the i-th cell through a conductive bar to obtain a cell string, wherein the conductive bar is perpendicular to the wire segments of the second wire assembly and the wire segments of the first wire assembly, and is welded to each of the wire segments, where 1 ≤ i ≤ N - 1.

12. The battery stringing method according to claim 11, wherein The conductive bar is a conductive copper bar coated with a tin layer.

13. The battery stringing method according to claim 12, characterized in that, The width of the conductive bar along the extension direction of the cell string is ≤ 2 mm, the thickness of the conductive bar is 10 μm to 30 μm, and the thickness of the tin layer is 3 μm to 10 μm.

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