Manufacturing method of photovoltaic module

Abstract

The invention relates to the technical field of solar cells, in particular to a manufacturing method of a photovoltaic module. In the embodiment of the invention, a plurality of welding strips, a plurality of glue points and a covering film are arranged on the target side of a battery piece according to a preset sequence in the process of forming a battery string, each welding strip corresponds to at least one glue point, and the covering film at least covers the sides, deviating from the battery piece, of the plurality of welding strips. Therefore, the plurality of welding strips can be relatively fixed with the battery piece through the glue points and the covering film, the welding connection reliability of the welding strips and the battery piece is improved, and the reliability of the photovoltaic module is further improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a method for manufacturing a photovoltaic module. Background Art

[0002] In the process of manufacturing photovoltaic modules, multiple cells need to be connected to form a cell string with the help of welding ribbons, and then lamination, framing and other related processes are performed to form photovoltaic modules. The reliability of the connection between the welding ribbon and the corresponding cell will affect the reliability of the photovoltaic module. Therefore, the reliability of the connection between the welding ribbon and the corresponding cell needs to be further improved. Summary of the invention

[0003] Based on this, it is necessary to provide a method for manufacturing a photovoltaic module to improve the connection reliability between the welding ribbon and the battery cell, thereby improving the reliability of the photovoltaic module.

[0004] The present application provides a method for manufacturing a photovoltaic module, comprising:

[0005] Provide battery cells;

[0006] Connect multiple battery cells to form a battery string according to a preset stringing method;

[0007] wherein, in forming the battery string, a plurality of solder strips, a plurality of glue spots and a covering film are provided on a target side of the battery cell in a preset sequence;

[0008] For the same target side, the covering film is located on the side of the solder strip away from the battery cell, and the orthographic projection of the covering film on the reference plane has overlapping projections with the orthographic projections of multiple solder strips on the reference plane; each solder strip corresponds to at least one glue point, and the orthographic projection of the glue point on the reference plane has overlapping projections with the orthographic projection of the corresponding solder strip on the reference plane; the target side of the battery cell is at least one side of the battery cell along a first direction, the first direction is the thickness direction of the battery cell, and the reference plane is a plane perpendicular to the first direction.

[0009] In one of the embodiments, for all glue points on the same target side of the same cell sheet, there is a first target glue point;

[0010] Along the first direction, at least a portion of the first target glue point is located between the corresponding solder strip and the battery cell.

[0011] In one of the embodiments, for the same target side of the same battery cell, there is at least one first target glue point whose orthographic projection on the reference surface has an overlapping projection with the orthographic projection of the corresponding coating on the reference surface; and / or

[0012] For the same target side of the same battery cell, there is at least one orthographic projection of a first target glue point on the reference surface and an orthographic projection of the corresponding coating on the reference surface that do not overlap with each other.

[0013] In one of the embodiments, there is a second target glue point for all glue points on the same target side of all cells;

[0014] Along the first direction, at least a portion of the second target glue point is located between the corresponding soldering strip and the corresponding covering film.

[0015] In one embodiment, for all glue points on the same target side of all battery cells, there is a third target glue point; along the first direction, at least part of the third target glue point is located on a side of the corresponding coating away from the battery cell; and / or

[0016] For all glue points on the same target side of all battery cells, there is a fourth target glue point; along the first direction, at least part of the fourth target glue point is located on a side of the corresponding solder strip away from the battery cell.

[0017] In one of the embodiments, for the same target side of all the cells, the covering film is provided with a projection where the orthographic projection of at least part of the welding strip on the reference surface has an overlapping projection with the orthographic projection of the corresponding covering film on the reference surface; or

[0018] For the same target side of all the cells, multiple covering films are provided, each covering film covers at least one cell, and all covering films do not overlap with each other, and the orthographic projection of at least part of the welding strip on the reference surface has an overlapping projection with the orthographic projection of the corresponding covering film on the reference surface; or

[0019] For the same target side of all battery cells, multiple covering films are provided, and all covering films and all battery cells are arranged one-to-one, and the orthographic projection of at least part of the welding strip on the reference surface has an overlapping projection with the orthographic projection of the corresponding covering film on the reference surface.

[0020] In one embodiment, each solder strip corresponds to a plurality of glue dots;

[0021] The orthographic projections of the plurality of glue dots on the reference surface and the orthographic projections of the corresponding solder strips on the reference surface respectively have overlapping projections.

[0022] In one embodiment, the welding strip has a first end and a second end disposed opposite to each other along the longitudinal direction of the welding strip;

[0023] For the multiple glue dots, the orthographic projection of one of the glue dots on the reference surface has an overlapping projection with the orthographic projection of the first end of the corresponding solder strip on the reference surface; the orthographic projection of another glue dot on the reference surface has an overlapping projection with the orthographic projection of the second end of the corresponding solder strip on the reference surface.

[0024] In one embodiment, the coating is configured as a single-layer structure, and the pre-crosslinking degree of the coating is 20% to 50%; or

[0025] The coating is configured as a multi-layer structure, and the coating includes a plurality of sub-films stacked together, and the pre-crosslinking degree of the sub-film closest to the battery cell among the plurality of sub-films is 20% to 50%.

[0026] In one of the embodiments, for the same target side of the same battery cell, the orthographic projection of each welding strip on the reference surface has an overlapping projection with the orthographic projection of the corresponding covering film on the reference surface; and / or

[0027] The minimum torque value ML of the coating satisfies: 0.1≤ML≤0.8; and / or

[0028] The coating temperature of the coating is 100°C to 135°C; and / or

[0029] The thickness of the coating is between 50µm and 500µm; and / or

[0030] The process of forming the battery string includes curing the glue points, and the degree of cross-linking of the glue points after curing is greater than 90%; and / or

[0031] The Tg of the glue point is ≥59.40°C; Tg is the temperature at which the glue point changes from a glassy state to a high-condensation state; and / or

[0032] The welding strip includes at least one of a round wire welding strip, a triangular welding strip, a flat welding strip, and a special-shaped welding strip.

[0033] In the manufacturing method of the above-mentioned photovoltaic module, during the process of forming a battery string, multiple welding strips, multiple glue points and covering films are arranged on the target side of the battery cell in a preset order, and each welding strip corresponds to at least one glue point, and the covering film is at least covered on the side of the multiple welding strips away from the battery cell, so that the multiple welding strips can be relatively fixed to the battery cell via the glue points and the covering film, thereby improving the reliability of the welding connection between the welding strips and the battery cell, thereby improving the reliability of the photovoltaic module.

[0034] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the embodiments below. The accompanying drawings are only for the purpose of illustrating the embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0036] Figure 1 A schematic diagram of a process for manufacturing a photovoltaic module provided in some embodiments of the present application;

[0037] Figure 2A schematic diagram of a side cross-sectional structure of a partial structure of a soldering strip, a glue point, a covering film and a battery cell provided in some embodiments of the present application;

[0038] Figure 3 A schematic diagram of a top view of a partial structure of a solder strip, a glue point, and a battery cell provided in some embodiments of the present application;

[0039] Figure 4 A schematic diagram of a top view of a partial structure of a welding strip, a glue point, a covering film and a battery cell provided in some embodiments of the present application;

[0040] Figure 5 A schematic diagram of a top view of a partial structure of a welding strip, a glue point, a covering film and a battery cell provided in some other embodiments of the present application;

[0041] Figure 6 A schematic diagram of a top view of a partial structure of a welding strip, a glue point, a covering film and a battery cell provided in some embodiments of the present application;

[0042] Figure 7 A schematic diagram of a side cross-sectional structure of a partial structure of a welding strip, a glue point, a covering film and a battery cell provided in other embodiments of the present application;

[0043] Figure 8 A schematic diagram of a side cross-sectional structure of a partial structure of a soldering strip, a glue point, a covering film and a battery cell provided in some embodiments of the present application;

[0044] Fig. 9 A schematic diagram of a top view of a partial structure of a welding strip, a glue point, a covering film and a battery cell provided in some embodiments of the present application;

[0045] Fig.10 A schematic diagram of a side cross-sectional structure of a partial structure of a soldering strip, a glue point, a covering film and a battery cell provided in some other embodiments of the present application;

[0046] Fig.11 A schematic diagram of a top view of a partial structure of a welding strip, a glue point, a covering film and a battery cell provided in some other embodiments of the present application;

[0047] Fig.12 A schematic diagram of a side cross-sectional structure of a partial structure of a welding strip, a glue point, a covering film and a battery cell provided in some embodiments of the present application;

[0048] Fig.13 A schematic diagram of a top view of a partial structure of a welding strip, a glue point, a covering film and a battery cell provided in some other embodiments of the present application;

[0049] Fig.14A schematic diagram of a top view of a partial structure of a welding strip, a glue point, a covering film and a battery cell provided in some other embodiments of the present application;

[0050] Fig.15 A schematic diagram of a top view structure of a covering film and a plurality of battery cells provided in some embodiments of the present application;

[0051] Fig.16 A schematic diagram of a top view structure of a coating and a plurality of battery cells in cooperation with each other provided in some embodiments of the present application;

[0052] Fig.17 A schematic diagram of a top view structure of a covering film and a plurality of battery cells provided in other embodiments of the present application;

[0053] Fig.18 A schematic diagram of a top view of a partial structure of a soldering strip, a glue point and a battery cell provided in some other embodiments of the present application;

[0054] Fig.19 A schematic diagram of a side cross-sectional structure of a partial structure of a solder strip, a glue point and a battery cell provided in some embodiments of the present application;

[0055] Fig. 20 A schematic diagram of a top view of a partial structure of a solder strip and a glue point in cooperation with each other provided in some embodiments of the present application;

[0056] Fig.21 A schematic diagram of a side cross-sectional structure of a partial structure of a solder strip, a glue point and a battery cell provided in some other embodiments of the present application;

[0057] Fig. 22 A schematic diagram of a top view of a partial structure of a solder strip and a glue point in cooperation with each other provided in some other embodiments of the present application;

[0058] Fig.23 A schematic diagram of the structure of a photovoltaic module provided in some embodiments of the present application;

[0059] Fig.24 A schematic diagram of the structure of the cooperation between the welding strip and the battery cell provided in some embodiments of the present application;

[0060] Fig.25 A schematic diagram of the structure of a battery string provided in some embodiments of the present application;

[0061] Fig.26 A schematic diagram of the structure of a battery string provided in some other embodiments of the present application;

[0062] Fig. 27 A schematic diagram of the structure of a battery string provided in some other embodiments of the present application;

[0063] Fig.28A schematic diagram of the structure of a battery string provided in some other embodiments of the present application;

[0064] Fig.29 A schematic diagram of the structure of the cooperation between the welding strip and the battery cell provided in other embodiments of the present application;

[0065] Fig.30 A schematic diagram of the structure of a battery string provided in some embodiments of the present application;

[0066] Fig.31 Schematic diagram of the structure of battery strings provided in some other embodiments of the present application.

[0067] Description of reference numerals:

[0068] Photovoltaic module 10;

[0069] Battery string 100;

[0070] Battery cell 110, welding strip 120, first end e1, second end e2, glue point 130, first sub-glue point 131, second sub-glue point 132, first target glue point 130a, second target glue point 130b, third target glue point 130c, fourth target glue point 130d, covering film 140;

[0071] Encapsulation layer 200;

[0072] Cover plate 300;

[0073] Steps S110, S120. DETAILED DESCRIPTION

[0074] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0075] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0076] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0077] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. It is worth noting that in the following description, "electrical connection" between one feature and another feature not only includes one feature directly contacting another feature to form an electric energy transmission or current transmission channel, but also includes an intermediate feature between one feature and another feature, and the one feature, the other feature and the intermediate feature between them form an electric energy transmission channel or a current transmission channel to achieve electric energy transmission or transmission. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0078] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0079] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0080] When using photovoltaic modules, different illumination on the surface of the cell may lead to different local power generation efficiency and cause local overtemperature. In this case, due to the different thermal expansion coefficients of the solder ribbon and the cell, stress will be generated at the connection interface between the solder ribbon and the cell. Long-term stress will cause the bond between the solder and the cell or the solder ribbon at the welding point to gradually loosen. The good intermetallic compound connection originally formed by the solder may be destroyed, making the electrical contact between the solder ribbon and the cell unstable, resulting in a cold solder joint, resulting in obstruction of current transmission between the cells, reducing the power generation efficiency of the photovoltaic module, and may even cause safety hazards such as local overheating, thereby reducing the reliability of the photovoltaic module.

[0081] Based on this, the embodiments of the present application improve the reliability of the connection between the welding ribbon and the battery cell by improving the manufacturing method of the photovoltaic module, thereby improving the reliability of the photovoltaic module.

[0082] Figure 1 A schematic flow chart of a method for manufacturing a photovoltaic module provided in some embodiments of the present application is shown; for ease of explanation, only contents related to the embodiments of the present application are shown.

[0083] Please refer to Figure 1 The present invention provides a method for manufacturing a photovoltaic module, comprising the following steps:

[0084] Step S110, providing a battery cell;

[0085] Step S120, connecting multiple battery cells to form a battery string in accordance with a preset stringing method; wherein, in the process of forming the battery string, multiple welding strips, multiple glue points and a coating are arranged on the target side of the battery cell in a preset order; for the same target side, the coating is located on the side of the welding strip away from the battery cell, and the orthographic projection of the coating on the reference plane has overlapping projections with the orthographic projections of the multiple welding strips on the reference plane; each welding strip corresponds to at least one glue point, and the orthographic projection of the glue point on the reference plane has overlapping projections with the orthographic projection of the corresponding welding strip on the reference plane; the target side of the battery cell is at least one side of the battery cell along a first direction, the first direction is the thickness direction of the battery cell, and the reference plane is a plane perpendicular to the first direction.

[0086] In step S110, the battery cell can be configured according to actual use requirements. Exemplarily, the battery cell can be a TOPCon (Tunnel Oxide Passivating Contacts) battery, a BC (Back Contact) battery, an HJT (Heterojunction with Intrinsic Thin-layer) battery, a perovskite battery or a stacked battery, and the stacked battery can be a perovskite battery superimposed with a TOPCon battery, a BC battery or a HJT battery. No specific restrictions are made here. The battery cell can be a whole cell, a half cell, or a smaller cell, and no specific restrictions are made here.

[0087] In step S120, the preset stringing method refers to a pre-designed connection method for multiple battery cells, which can be combined so that the current and voltage generated by the multiple battery cells can meet the power requirements and electrical characteristics requirements of the photovoltaic module. The preset stringing method includes, but is not limited to, the electrical connection method of the battery cells, the arrangement method of the battery cells, the placement method of the welding strips, and the arrangement method of the welding strips. The connection method of the battery cells in the battery string can be that the front electrode of a battery cell is electrically connected to the back electrode of the adjacent battery cell through a welding strip (for example, a TOPCon battery), or the back electrode of a battery cell is electrically connected to the back electrode of the adjacent battery cell through a welding strip (for example, a BC battery). The multiple battery cells can be connected in series, in parallel, or in a mixed series-parallel connection, and no specific restrictions are made here.

[0088] The target side of the cell may be the front side of the cell or the back side of the cell. For example, when the cell is a TOPCon cell, the target side of the cell may be at least one of the front side and the back side of the cell. For another example, when the cell is a BC cell, the target side of the cell may be the back side of the cell. The target side may be configured accordingly according to the type and usage of the cell.

[0089] It can be understood that the front of the cell is the light-receiving surface, and the back of the cell is the backlight surface. The light-receiving surface and the backlight surface are relative. The light-receiving surface is specifically the surface on the cell in the photovoltaic module where sunlight mainly shines. With the development of solar cell technology, the backlight surface will also receive energy from sunlight, mainly from reflected light or scattered light in the surrounding environment.

[0090] Solder ribbon is a strip used for electronic components. Solder ribbon is mainly used to connect battery cells to form a good electrical connection between battery cells, so as to collect and conduct the current generated by each battery cell. Solder ribbon is generally a strip-shaped component, which usually has a certain flexibility and is convenient for welding between battery cells. The material of the solder ribbon includes but is not limited to tin-lead alloy, lead-free alloy (such as tin-silver-copper alloy), etc. The coating is a film covering the surface of the battery cell. The material of the coating includes but is not limited to one or more of EVA (Ethylene-Vinyl Acetate, polyethylene-polyvinyl acetate copolymer), POE (Polyolefin Elastomer, polyolefin elastomer), TPO (Thermoplastic Polyolefin, polyolefin thermoplastic elastomer), TPU (Thermoplastic Polyurethane, polyurethane thermoplastic elastomer). Glue point is a component formed by a material with a certain adhesive ability. The material of the glue point includes at least one of acrylic acid, epoxy resin, and conductive glue.

[0091] A plurality of solder strips, a plurality of glue dots and a coating are arranged on the target side of the battery cell in a preset order, that is, the solder strips, the glue dots and the coating may be arranged sequentially, or the glue dots, the solder strips and the coating may be arranged sequentially, or the solder strips, the coating and the glue dots may be arranged sequentially. Of course, the solder strips and the glue dots may be arranged alternately, and then the coating may be arranged. The arrangement order of the plurality of solder strips, the glue dots and the coating may be configured according to the specific arrangement situation, and no specific limitation is made here.

[0092] The orthographic projection of the covering film on the reference surface has an overlapping projection with the orthographic projection of the plurality of welding strips on the reference surface, that is, the orthographic projection of the covering film on the reference surface and the orthographic projection of the plurality of welding strips on the reference surface may completely overlap or may not completely overlap. As long as the covering film and at least part of the welding strips are arranged correspondingly in the thickness direction of the battery cell, no specific limitation is made here.

[0093] Each solder strip corresponds to at least one glue point, that is, in the thickness direction of the battery cell, each solder strip is set corresponding to at least one glue point. The orthographic projection of the glue point on the reference surface has an overlapping projection with the orthographic projection of the corresponding solder strip on the reference surface, that is, the orthographic projection of the glue point on the reference surface can be completely located within the orthographic projection range of the corresponding solder strip on the reference surface, or can be partially located within the orthographic projection range of the corresponding solder strip on the reference surface. According to different preset orders and different setting positions, the solder strip and the corresponding glue point may be in contact or not in contact.

[0094] The orthographic projection of the coating on the reference surface and the orthographic projection of the plurality of glue dots on the reference surface may have overlapping projections or may not have overlapping projections, and no specific limitation is made here. In the case where the orthographic projection of the coating on the reference surface and the orthographic projection of the plurality of glue dots on the reference surface do not have overlapping projections, the orthographic projection of the coating on the reference surface and the orthographic projection of the plurality of solder strips on the reference surface partially overlap.

[0095] Therefore, since in the thickness direction of the cell, the soldering tape and the corresponding glue point have the aforementioned overlapping projection, and the covering film and the multiple soldering tapes have the aforementioned overlapping projection, the multiple soldering tapes can be relatively fixed to the cell via the glue point and the covering film, thereby improving the stability between the soldering tape and the cell. Even if the photovoltaic module has a local overtemperature during use, under the limiting effect of the glue point and the covering film, the soldering tape can still maintain good ohmic contact with the cell, thereby improving the reliability of the soldering connection between the soldering tape and the cell, and further improving the reliability of the photovoltaic module.

[0096] In some embodiments, for all glue points on the same target side of the same cell, there is a first target glue point. Along the first direction, at least a portion of the first target glue point is located between the corresponding solder ribbon and the cell.

[0097] Specifically, the first target glue point is first set on the battery cell relative to the solder strip. Figure 2 , Figure 2 The schematic diagram of the side cross-sectional structure of the partial structure of the welding ribbon 120, the glue point 130, the covering film 140 and the battery cell 110 provided in some embodiments of the present application is shown. Figure 2 Only one solder strip 120 is shown in the figure, and a part of the first target glue spot 130a can be located between the solder strip 120 and the battery cell 110, and another part can be located at the side of the solder strip 120. Of course, the first target glue spot 130a can also be located between the solder strip 120 and the battery cell 110. No specific limitation is made here. Figure 3 , Figure 3 The schematic diagram of the top view of the structure of the partial structure of the welding strip 120, the glue point 130 and the battery cell 110 provided in some embodiments of the present application is shown. Figure 3The coating 140 is omitted, and all glue dots 130 on the same target side of the same battery cell 110 may be the first target glue dots 130a. Of course, one glue dot 130 among all glue dots 130 on the same target side of the same battery cell 110 may be the first target glue dot 130a, or some glue dots 130 among all glue dots 130 on the same target side of the same battery cell 110 may be the first target glue dot 130a. In the case where there is a glue dot 130 among all glue dots 130 on the same target side of the same battery cell 110 that is not the first target glue dot 130a, it may be set with reference to some glue dot 130 structures illustrated later, and no specific limitation is made here.

[0098] In this way, by setting the first target glue point, not only can the corresponding solder strip be positioned more accurately, but the corresponding solder strip and the battery cell can also be initially fixed together, which helps to increase the tension between the corresponding solder strip and the battery cell and enhance the structural stability between the corresponding solder strip and the battery cell.

[0099] In some embodiments, for the same target side of the same cell, there is at least one orthographic projection of the first target glue point on the reference surface and the orthographic projection of the corresponding coating on the reference surface with overlapping projections; and / or, for the same target side of the same cell, there is at least one orthographic projection of the first target glue point on the reference surface and the orthographic projection of the corresponding coating on the reference surface that do not overlap with each other. Overlapping projections can be understood with reference to the situations illustrated in some of the aforementioned embodiments, and will not be described in detail here.

[0100] Exemplary, with reference to Figure 4 , Figure 4 The schematic diagram of the top view of the partial structure of the cooperation between the welding strip 120, the glue point 130, the covering film 140 and the battery cell 110 provided in some embodiments of the present application is shown. Figure 4 The dotted line in the figure indicates the structure covered by the coating 140 in the first direction. From the first direction, a portion of the first target glue dots 130a is covered by the coating 140, that is, the orthographic projection of the portion of the first target glue dots 130a on the reference surface is within the orthographic projection range of the coating 140 on the reference surface, and the overlapping projection of the two is the orthographic projection of the portion of the first target glue dots 130a on the reference surface. Figure 4 , viewed from the first direction, another portion of the first target glue dots 130a is not covered by the coating 140, that is, the orthographic projection of the other portion of the first target glue dots 130a on the reference surface is outside the orthographic projection range of the coating 140 on the reference surface.

[0101] Again exemplary, in conjunction with reference Figure 5 , Figure 5FIG. 1 shows a schematic diagram of a top view of a partial structure of a soldering ribbon 120, a glue point 130, a covering film 140 and a battery cell 110 provided in some other embodiments of the present application. Figure 5 The dotted line in FIG. 1 shows the structure covered by the coating 140 in the first direction. From the first direction, all the first target glue dots 130a are not covered by the coating 140. That is, the orthographic projections of all the first target glue dots 130a on the reference surface are outside the orthographic projection range of the coating 140 on the reference surface.

[0102] For example, in conjunction with reference Figure 6 , Figure 6 FIG. 1 shows a schematic diagram of a top view of a partial structure of a soldering ribbon 120, a glue point 130, a covering film 140 and a battery cell 110 provided in some embodiments of the present application. Figure 6 The dotted line in the figure indicates the structure covered by the coating 140 in the first direction. From the first direction, all the first target glue dots 130a are covered by the coating 140. That is, the orthographic projections of all the first target glue dots 130a on the reference surface are within the orthographic projection range of the coating 140 on the reference surface.

[0103] In this way, when the first target glue point is located on the side of the coating facing the battery cell and the two have overlapping projections, the first target glue point, the corresponding coating and the corresponding welding strip have corresponding parts in the first direction, which is not only beneficial for providing a support point for coating, but also for further improving the stability of the electrical connection between the welding strip and the battery cell under the action of the glue point and the coating, but also beneficial for absorbing and dispersing the stress generated by the different thermal expansion coefficients of the battery cell, welding strip and coating when the temperature changes, thereby reducing the occurrence of problems such as battery cell cracking and welding strip loosening, and enhancing the mechanical stability of the photovoltaic module.

[0104] Furthermore, in conjunction with reference Figure 7 , Figure 7 A schematic diagram of a side cross-sectional structure of a partial structure in which the solder ribbon 120, glue point 130, coating 140 and battery cell 110 cooperate with each other provided in some other embodiments of the present application is shown. By controlling the thickness of the first target glue point 130a along the first direction, the coating 140 can be made to contact the side of the solder ribbon 120 that is away from the battery cell 110, and to contact the side of the first target glue point 130a that is away from the battery cell 110. At this time, the first target glue point 130a can not only improve the stability of the connection between the solder ribbon 120 and the battery cell 110, but also further enhance the fixing force of the coating 140 on the solder ribbon 120.

[0105] Therefore, by setting the first target glue point and flexibly configuring the relationship between the first target glue point and the soldering ribbon and the covering film, the reliability of the electrical connection between the soldering ribbon and the battery cell can be further improved, thereby improving the reliability of the photovoltaic module.

[0106] In some embodiments, for all glue points on the same target side of all battery cells, there is a second target glue point. Along the first direction, at least part of the second target glue point is located between the corresponding solder strip and the corresponding cover film. Specifically, the second target glue point is disposed later on the battery cell relative to the solder strip.

[0107] Exemplary, with reference to Figure 8 , Figure 8 The schematic diagram of the side cross-sectional structure of the partial structure of the cooperation between the soldering ribbon 120, the glue point 130, the covering film 140 and the battery cell 110 provided in some other embodiments of the present application is shown, a part of the second target glue point 130b contacts the corresponding soldering ribbon 120, and another part contacts the corresponding covering film 140. Furthermore, another part of the second target glue point 130b can contact the side edge of the soldering ribbon 120.

[0108] Again exemplary, in conjunction with reference Fig. 9 , Fig. 9 The schematic diagram of the top view of the partial structure of the cooperation between the soldering tape 120, the glue point 130, the covering film 140 and the battery cell 110 provided in some embodiments of the present application illustrates the situation that along the first direction, the entire second target glue point 130b is located between the corresponding soldering tape 120 and the corresponding covering film 140. Of course, it is also possible that along the first direction, part of the second target glue point 130b is located between the corresponding soldering tape 120 and the corresponding covering film 140. Fig. 9 In FIG. 1 , the structure covered by the coating 140 in the first direction is indicated by a dotted line.

[0109] In this way, by setting the second target glue point, the fixing force of the film on the welding strip can be further improved, thereby improving the reliability of the electrical connection between the welding strip and the battery cell. In addition, during the production, transportation and use of photovoltaic modules, photovoltaic modules will experience various mechanical stresses (such as pressure during lamination, material expansion and contraction caused by temperature changes, etc.). The second target glue point located between the corresponding welding strip and the corresponding film can serve as a buffer component to absorb and disperse these stresses, thereby improving the peeling or damage caused by stress concentration between the welding strip and the film, and at the same time reducing the impact of stress on the battery cell and reducing the risk of battery cell cracking.

[0110] In some embodiments, for all glue points on the same target side of all battery cells, there is a third target glue point; along the first direction, at least part of the third target glue point is located on the side of the corresponding coating away from the battery cell; and / or, for all glue points on the same target side of all battery cells, there is a fourth target glue point; along the first direction, at least part of the fourth target glue point is located on the side of the corresponding solder strip away from the battery cell. Specifically, the third target glue point is set on the battery cell later than the coating. The fourth target glue point is set on the battery cell later than the solder strip. The fourth target glue point can be set before the coating or after the coating, and is not specifically limited here.

[0111] Exemplary, with reference to Fig.10 and Fig.11 , Fig.10 The figure shows a schematic side cross-sectional structure diagram of a partial structure of the cooperation between the solder strip 120, the glue point 130, the covering film 140 and the battery cell 110 provided in some other embodiments of the present application. Fig.11 The schematic diagram of the top view of the partial structure of the cooperation between the welding ribbon 120, the glue point 130, the covering film 140 and the battery cell 110 provided in some other embodiments of the present application is shown. Along the first direction, the third target glue point 130c is completely located on the side of the corresponding covering film 140 away from the battery cell 110. Of course, along the first direction, the third target glue point 130c can also be partially located on the side of the corresponding covering film 140 away from the battery cell 110, and the other part is in contact with the welding ribbon 120 or the battery cell 110. In this case, the third target glue point 130c is located at the edge area of ​​the covering film 140.

[0112] Again exemplary, in conjunction with reference Fig.12 and Fig.13 , Fig.12 The figure shows a schematic side cross-sectional structure diagram of a partial structure of the cooperation between the solder strip 120, the glue point 130, the covering film 140 and the battery cell 110 provided in some embodiments of the present application. Fig.13 The schematic diagram of the top view of the partial structure of the cooperation between the welding strip 120, the glue point 130, the covering film 140 and the battery cell 110 provided in some other embodiments of the present application is shown. The fourth target glue point 130d can be located on the side of the welding strip 120 and contact the battery cell 110. The fourth target glue point 130d and the corresponding covering film 140 are independent of each other. Of course, in other embodiments, the covering film 140 can also cover the fourth target glue point 130d, and the fourth target glue point 130d is away from the side of the battery cell 110 and contacts the covering film 140. No specific limitation is made here.

[0113] In this way, by setting the third target glue point, the coating and the welding strip can be fixed at the same time, so that the coating can be combined with the coating to further enhance the fixing force of the coating on the welding strip, thereby improving the reliability of the electrical connection between the welding strip and the battery cell. In addition, during the production, transportation and use of photovoltaic modules, photovoltaic modules will experience various mechanical stresses (such as pressure during lamination, material expansion and contraction caused by temperature changes, etc.). The third target glue point can be used in conjunction with the coating as a support point to absorb and disperse these stresses, thereby improving the situation where the welding strip moves due to false welding and desoldering between the welding strip and the battery cell. By setting the fourth target glue point, not only can the setting order of the glue point and the coating be more flexible, so that the production of photovoltaic modules can be more flexible, but also the reliability of the welding strip and the battery cell can be improved. In addition, when the fourth target glue point and the coating are independent of each other, photovoltaic modules of different thicknesses can also be obtained by controlling the size of the fourth target glue point and the coating in the first direction.

[0114] Therefore, through the first target glue point, second target glue point, third target glue point and fourth target glue point illustrated in some of the above embodiments, the solder strip, glue point and coating can be set in different preset orders, thereby forming a fixed structure that can improve the position stability of the solder strip to different degrees and in different ways.

[0115] It is understandable that at least two of the first target glue point, the second target glue point, the third target glue point and the fourth target glue point can be used in conjunction with each other. Fig.14 For example, Fig.14 The top view of the structure of the partial structure of the cooperation of the solder strip, glue point, coating and battery cell provided in some other embodiments of the present application is shown. The second target glue point and the fourth target glue point can be used in combination. No specific restrictions are made here. In this way, the cooperation of different types of target glue points is conducive to the cooperation in different ways to form a more reliable structure as a whole.

[0116] In some embodiments, for the same target side of all battery cells, one coating is provided, and the orthographic projection of at least part of the welding strip on the reference surface has an overlapping projection with the orthographic projection of the corresponding coating on the reference surface; or, for the same target side of all battery cells, multiple coatings are provided, each coating covers at least one battery cell, and all coatings do not overlap with each other, and the orthographic projection of at least part of the welding strip on the reference surface has an overlapping projection with the orthographic projection of the corresponding coating on the reference surface; or, for the same target side of all battery cells, multiple coatings are provided, all coatings and all battery cells are arranged one by one, and the orthographic projection of at least part of the welding strip on the reference surface has an overlapping projection with the orthographic projection of the corresponding coating on the reference surface.

[0117] Exemplary, with reference to Figures 15 to 17, in order to facilitate the illustration of the relationship between the cover film 140 and the plurality of battery cells 110, Figures 15 to 17 The solder strip 120 and the glue point 130 are omitted. Fig.15 The diagram shows a case where a coating 140 is provided on the same target side. Fig.16 The diagram shows a situation where a plurality of coating films 140 corresponding to a plurality of battery cells 110 are provided on the same target side. Fig.17 The diagram shows a case where one coating film 140 is coated on one battery cell 110 and one coating film 140 is coated on three battery cells 110 on the same target side. Fig.16 In the illustrated case, the soldering tape 120, the glue point 130 and the covering film 140 may be arranged in a preset order for each cell 110, or the soldering tape 120 and the glue point 130 may be arranged for each cell 110, and then the covering film 140 may be arranged together. The glue point 130 may be arranged in accordance with its structure and position, and no specific limitation is made here.

[0118] When multiple cells share a film, when they are subjected to external forces or internal stresses (such as material expansion and contraction caused by temperature changes), the shared film can distribute these forces more evenly to multiple cells, so that the pressure on each cell is relatively small, reducing the risk of damage to a single cell due to excessive local force. At the same time, it can also save steps in the production of photovoltaic modules and improve production efficiency.

[0119] In the case where each battery cell is covered with a corresponding film, the independent film on each battery cell can independently buffer and disperse external forces. This independent buffering mechanism enables each battery cell to respond to external forces according to the characteristics and state of its own film, reducing the probability of damage to the battery cell. For example, even if the film on a battery cell is partially deformed after being hit, the films of other battery cells and the battery cell itself can still work normally and will not be greatly affected. When facing internal stresses (such as thermal expansion and contraction of battery cells due to temperature changes), independent films can also better adapt to the changes of each battery cell. Since the films of each battery cell are independent, they can be adjusted accordingly according to the size changes of the battery cell itself, which can reduce the concentration of internal forces caused by differences in thermal expansion coefficients between battery cells and reduce the risk of damage caused by squeezing or pulling between battery cells.

[0120] In the case where there is a film covering multiple battery cells and a film covering one battery, the advantages of the above-mentioned situation of "multiple battery cells sharing one film" and the situation of "each battery cell is covered with a film" can be taken into account.

[0121] In this way, different coating methods can be flexibly configured or combined according to specific usage conditions, so that the stress conditions at different positions can be improved, and no specific restrictions are made here.

[0122] In some embodiments, each solder strip corresponds to a plurality of glue dots, and the orthographic projections of the plurality of glue dots on the reference surface and the orthographic projections of the corresponding solder strips on the reference surface respectively have overlapping projections.

[0123] Exemplary, with reference to Figures 3 to 6 , Fig. 9 , Fig.11 , Fig.13 and Fig.14 , illustrating the situation where each solder strip 120 corresponds to two glue dots 130 .

[0124] In this way, the fixing effect of the soldering ribbon can be further improved through multiple glue points, thereby further improving the reliability of the electrical connection between the soldering ribbon and the battery cell.

[0125] In some embodiments, the solder strip has a first end and a second end that are disposed opposite to each other along the longitudinal direction of the solder strip. For the plurality of glue points, an orthographic projection of one of the glue points on the reference surface has an overlapping projection with an orthographic projection of the first end of the corresponding solder strip on the reference surface; and an orthographic projection of another glue point on the reference surface has an overlapping projection with an orthographic projection of the second end of the corresponding solder strip on the reference surface.

[0126] Exemplary, with reference to Figures 3 to 6 , Fig. 9 , Fig.11 , Fig.13 and Fig.14 , illustrating a situation where each solder strip 120 corresponds to two glue dots 130, and the two glue dots 130 are respectively located at the corresponding first end e1 and the corresponding second end e2. The longitudinal direction of the solder strip 120 is the second direction illustrated in the figure, and the second direction and the first direction are perpendicular to each other.

[0127] In this way, since two glue points are respectively arranged at the two ends of the welding strip in the longitudinal direction, it can not only more effectively limit the movement of the welding strip in the longitudinal direction, but also reduce the risk of deformation of the welding strip due to thermal stress. When the photovoltaic module is subjected to tensile force in the longitudinal direction of the welding strip, for example, it may be stretched by the mounting structure during the installation of the module or the longitudinal tension may be generated due to improper fixation during transportation, the glue points at both ends of the welding strip can more effectively resist this tensile force. At the same time, the glue points arranged at both ends of the welding strip can also change the stress distribution when subjected to longitudinal force. In the absence of glue points for fixation, the tensile force will be concentrated at the connection between the welding strip and the battery cell, which may easily lead to loose connection or battery cell cracking. With the corresponding glue points, the tensile force will be dispersed to the bonding interface between the glue point and the battery cell, and the glue point and the welding strip. This stress dispersion mechanism reduces the stress in each part and reduces the risk of damage due to stress concentration. In the direction perpendicular to the longitudinal direction of the welding ribbon (for example, the third direction F3 shown in the figure), when the photovoltaic module is subjected to shear force, such as the lateral wind pressure generated on the surface of the module when it is hit by strong winds or the lateral friction force it encounters during transportation, the glue points corresponding to the two ends of the welding ribbon can play an anti-shear role.

[0128] It should be noted that, in conjunction with the reference Figures 3 to 6 , Fig. 9 , Fig.11 , Fig.13 and Fig.14 , the first end e1 and the second end e2 of the soldering ribbon 120 are relative. The glue point 130 corresponding to the first end e1 can be directly opposite to the edge area of ​​the first end e1 in the first direction, or directly opposite to the non-edge area of ​​the first end e1 in the first direction. The glue point 130 corresponding to the second end e2 can also be understood with reference to the glue point 130 corresponding to the first end e1, and will not be elaborated here. Depending on the type of battery cell 110 and the electrical connection method of the battery cell 110, the setting of the soldering ribbon 120 on the battery cell 110 is different. Figures 3 to 6 , Fig. 9 , Fig.11 , Fig.13 and Fig.14, illustrating a situation where a plurality of welding strips 120 are arranged at intervals along the third direction, and the first direction, the second direction and the third direction are perpendicular to each other. Among the plurality of welding strips 120, a portion of the second end e2 of a portion of the welding strips 120 extends out of one side of the battery cell 110 along the second direction, and a portion of the first end e1 of another portion of the welding strips 120 extends out of the other side of the battery cell 110 along the second direction. At this time, for the welding strip 120 whose second end e2 extends out of the battery cell 110, the glue point 130 corresponding to the second end e2 of the welding strip 120 is directly opposite to the non-edge area of ​​the second end e2 in the first direction. For the welding strip 120 whose first end e1 extends out of the battery cell 110, the glue point 130 corresponding to the first end e1 of the welding strip 120 is directly opposite to the non-edge area of ​​the first end e1 in the first direction. The positions of the glue points 130 arranged corresponding to the first end e1 and the second end e2 of the welding strip 120 can be determined according to the position of the welding strip 120 relative to the battery cell 110, and are not specifically limited here.

[0129] Further, in some embodiments, please continue to refer to Figure 3 , the glue dots 130 corresponding to the first end e1 can be arranged at intervals along the third direction, and the glue dots 130 corresponding to the second end e2 can be arranged at intervals along the third direction. At this time, the extending direction of the line connecting the centers of the glue dots 130 corresponding to the first end e1 is parallel to the third direction, and the extending direction of the line connecting the centers of the glue dots 130 corresponding to the second end e2 is parallel to the third direction.

[0130] This arrangement of glue dots is not only conducive to more evenly dispersing stress, but also makes the position change of each solder strip relatively small when subjected to external force, thereby reducing the change in contact resistance caused by solder strip displacement. At the same time, it is also convenient to form glue dots by screen printing.

[0131] Of course, in other embodiments, please refer to Fig.18 , Fig.18 The schematic diagram of the top view of the partial structure of the matching of the welding strip 120, the glue point 130 and the battery cell 110 provided in some other embodiments of the present application is shown. The glue points 130 set corresponding to the first end e1 can be arranged in a staggered manner along the third direction, and the glue points 130 set corresponding to the second end e2 can be arranged in a staggered manner along the third direction. At this time, the line connecting the centers of the glue points 130 corresponding to the first end e1 is generally arranged in a folded line, and the line connecting the centers of the glue points 130 corresponding to the second end e2 is generally arranged in a folded line.

[0132] Such an arrangement of glue points can provide resistance in different directions, so that a mutually restrained structure is formed between the welding ribbons. For example, when subjected to torsional force, some glue points will be subjected to tensile force, while others will be subjected to compressive force. This interaction can effectively offset the torsional force, improve the excessive twisting of the welding ribbon and the battery cell, and protect the structural integrity of the component. In this way, the torsional resistance of the photovoltaic module can be enhanced as a whole. At the same time, the stress can also be dispersed to the surrounding area through different transfer paths, and the local stress can be better dispersed, thereby reducing the risk of battery cell cracking and welding ribbon damage. In addition, it is also beneficial to increase the tension of the connection between the welding ribbon and another battery cell, thereby further reducing the risk of the welding ribbon shifting at the edge of the battery cell.

[0133] In some embodiments, the coating is configured as a single-layer structure, and the pre-crosslinking degree of the coating is 20% to 50%; or, the coating is configured as a multi-layer structure, and the coating includes a plurality of sub-films stacked together, and the pre-crosslinking degree of the sub-film closest to the battery cell is 20% to 50%.

[0134] Among them, the degree of pre-crosslinking refers to the degree of crosslinking reaction during the preparation of the coating. Crosslinking reaction refers to the process in which polymer molecular chains are connected to each other through chemical bonds (such as covalent bonds) to form a three-dimensional network structure. The degree of pre-crosslinking can be intuitively understood as the relative number of crosslinking bonds that have been formed at a specific stage (usually before the final molding of the material) or the degree of perfection of the crosslinking structure. From a molecular level, a high degree of pre-crosslinking means that more molecular chains are connected together through crosslinking bonds to form a relatively tight three-dimensional network. The degree of pre-crosslinking can be expressed by the proportion of functional groups that have reacted to form crosslinking bonds. Assuming that in a polymer system containing double bonds, all double bonds are likely to participate in the crosslinking reaction, there are 100 double bonds in the initial system, and after the reaction, 60 double bonds participate in the crosslinking reaction, then the degree of pre-crosslinking can be expressed as 60%.

[0135] For example, when the coating is configured as a single-layer structure, the pre-crosslinking degree of the coating may be 20%, 30%, 32%, 35%, 37%, 42%, 45%, 48% or 50%, and the pre-crosslinking degree of the coating may be any value between 20% and 50%. When the coating is configured as a multi-layer structure, the pre-crosslinking degree of the sub-film closest to the battery cell among the multiple sub-films may be 20%, 30%, 32%, 35%, 37%, 42%, 45%, 48% or 50%, and the pre-crosslinking degree of the sub-film closest to the battery cell may be any value between 20% and 50%. No specific limitation is made here.

[0136] The degree of pre-crosslinking is closely related to the physical and chemical properties of the coating material. A higher degree of pre-crosslinking usually increases the hardness of the material and reduces its elasticity. This is because the crosslinking structure limits the stretching and deformation of the molecular chain, making the material more rigid. For example, when manufacturing a high-hardness plastic coating, the degree of pre-crosslinking will be appropriately increased. At the same time, the degree of pre-crosslinking will also affect the thermal stability, solvent resistance and other properties of the material. Materials with a high degree of pre-crosslinking are less likely to soften and deform at high temperatures because the crosslinking structure requires a higher temperature to be destroyed.

[0137] In this way, when the coating is configured as a single-layer structure, by controlling the pre-crosslinking degree of the coating, it not only helps the processing operation and shortens the processing time, but also has a good balance of strength and toughness, providing certain support performance and buffering performance. When the coating is configured as a multi-layer structure, by controlling the sub-film closest to the battery cell, good initial mechanical protection can be provided for the battery cell. At the same time, due to its certain flexibility, when the battery cell undergoes slight expansion or contraction (such as caused by temperature changes), it can adapt to such changes and avoid excessive pressure on the battery cell. The remaining sub-films can be configured more flexibly to provide additional protection for the battery cell. For example, the remaining sub-films can have better chemical protection properties such as weather resistance and corrosion resistance, blocking ultraviolet rays, moisture, chemical gases, etc. from damaging the battery cell and the inner layer of the coating. This layered protection mechanism can extend the service life of the entire coating structure and the battery cell. In addition, if a layer of sub-film has quality problems during processing, the multi-layer structure is conducive to isolating the problem. For example, processing defects in the outer film will not directly affect the sub-film closest to the cell and the cell itself, reducing the risk of the entire photovoltaic module being scrapped due to local quality problems and improving the product yield.

[0138] In some embodiments, please refer to Figures 4 to 6 , Fig. 9 , Fig.11 , Fig.13 and Fig.14 For the same target side of the same battery cell 110 , the orthographic projection of each welding strip 120 on the reference surface has an overlapping projection with the orthographic projection of the corresponding covering film 140 on the reference surface.

[0139] In this way, each welding ribbon has a corresponding covering film to provide a certain fixing force, thereby further improving the reliability of the electrical connection between the welding ribbon and the battery cell.

[0140] Of course, in some other embodiments, for the same target side of the same cell, the orthographic projection of part of the welding strip on the reference surface and the orthographic projection of the corresponding covering film on the reference surface may have overlapping projections, which is not specifically limited here.

[0141] In some embodiments, the minimum torque value ML of the coating satisfies: 0.1≤ML≤0.8.

[0142] Exemplarily, the minimum torque value ML of the coating may be 0.1, 0.2, 0.3, 0.6 or 0.8. The minimum torque value ML of the coating may be any value between 0.1 and 0.8, and is not specifically limited herein. For example, the minimum torque value ML of the coating satisfies: 0.3≤ML≤0.8.

[0143] The torque value of the coating refers to the magnitude of the torsional moment applied to the coating when the coating is twisted.

[0144] In this way, by controlling the minimum torque value of the film, the film has lower fluidity, so that the film can better provide a fixing force on the solder ribbon, and can also further improve the situation that the packaging film flows between the solder ribbon and the battery cell during the subsequent lamination process, thereby further improving the situation of poor welding. In addition, it can also improve the situation of undissolved bubbles, thereby improving the situation of poor appearance and reliability failure.

[0145] In some embodiments, the coating temperature of the coating is 100° C. to 135° C. For example, the coating temperature may be 100° C., 110° C., 120° C., 130° C. or 135° C. The coating temperature may be any value between 100° C. and 135° C., and is not specifically limited herein.

[0146] In this way, by controlling the coating temperature, the molecular chains of the coating material can be adjusted to a certain extent. This temperature range helps to make the molecular chains of the material more flexible, thereby enhancing the flexibility of the coating. In the subsequent use process, the flexible coating can better adapt to the slight deformation of the battery cell under temperature changes, mechanical stress, etc., and reduce the risk of battery cell damage caused by material rigidity, such as cracking. At the same time, the appropriate temperature can improve the bonding performance between the coating and the battery cell. In this temperature range, the coating material may undergo some physical and chemical changes, thereby improving the fixing force of the coating to the welding strip.

[0147] In some embodiments, the thickness of the coating is 50µm to 500µm. For example, the thickness of the coating can be 50µm, 70µm, 80µm, 90µm, 110µm, 150µm, 200µm, 300µm, 400µm or 500µm. The thickness of the coating can be any value between 50µm and 500µm, and is not specifically limited here.

[0148] In this way, by controlling the thickness of the coating, the coating can be easily manufactured while having certain mechanical properties.

[0149] In some embodiments, the process of forming the battery string includes curing the glue points, and the cross-linking degree of the cured glue points is greater than 90%.

[0150] The glue dots can be set at the corresponding positions by the glue dispensing process. Depending on the glue dots of different materials, the glue dots can be cured by processes such as light curing. The curing process steps can be determined according to the order in which the glue dots are set. For example, in the case where the glue dots are set before the solder strips, the curing process can be performed after the solder strips are set, or after the coating is set, without specific limitation.

[0151] The crosslinking degree of the glue point after curing refers to the degree of the network structure formed by the polymer molecular chains in the glue point being interconnected by chemical bonds (covalent bonds). Exemplarily, the crosslinking degree of the glue point after curing can be 91%, 92%, 93%, 94%, 95%, 96% or 99%.

[0152] In this way, a highly cross-linked network structure is formed between the molecular chains of the glue dots. This structure gives the glue dots higher strength and hardness, and allows them to better withstand external pressure and tension. During the use of photovoltaic modules, for example, when exposed to wind, vibration, temperature changes, etc., highly cross-linked glue dots can firmly fix the soldering ribbon or other components, improve their displacement or falling off, and provide reliable mechanical stability for photovoltaic modules. At the same time, highly cross-linked glue dots have a lower creep tendency, that is, they are not prone to slow deformation under the action of external forces, so that they can more effectively fix the soldering ribbon and improve the reliability of photovoltaic modules.

[0153] In some embodiments, the Tg of the gel point is ≥ 59.40° C. Tg is the temperature at which the gel point changes from a glassy state to a high-condensation state.

[0154] Exemplarily, the Tg of the glue point may be 59.40°C, 60°C, 65°C, 70°C, or 80°C.

[0155] In this way, the glue point can maintain its glassy or near-glassy properties at higher temperatures. This means that the glue point will not soften or flow easily in high temperature environments. For example, in some hot climate conditions or when the temperature inside the photovoltaic module rises due to heat generated during operation, the glue point can still stably fix the solder ribbon or other components.

[0156] In some embodiments, the welding strip includes at least one of a round wire welding strip, a triangular welding strip, a flat welding strip, and a special-shaped welding strip.

[0157] Round wire welding strips have a uniform circular cross-section, which allows the current to be evenly distributed when it is transmitted inside. According to electrical principles, when a circular conductor transmits current, the current density is evenly distributed on the cross-section, which can effectively reduce the current concentration phenomenon and thus reduce resistance loss. For example, in photovoltaic modules, this uniform current transmission helps to improve the electrical connection efficiency between cells, reduce the heating problem caused by excessive local resistance, and improve the overall power generation performance of the module.

[0158] The shape of the triangular welding strip enables it to capture and guide light in photovoltaic modules. When light hits the surface of the module, the edges of the triangle can change the direction of light propagation, reflecting part of the light that would otherwise be reflected or scattered onto the cell, increasing the light receiving area and light absorption efficiency of the cell. The triangular structure makes the contact area between the welding strip and the cell relatively large, and can form a good mechanical bond on the contact surface. This mechanical bonding force helps fix the welding strip on the cell and reduces the possibility of the welding strip shifting during production and use.

[0159] The flat welding strip is generally arranged in a sheet shape. The contact area between the flat welding strip and the battery cell is large, which helps to improve the connection stability between them. In terms of electrical connection, the larger contact area can reduce the contact resistance and ensure that the current can be smoothly transmitted between the battery cell and the welding strip. At the same time, in terms of mechanics, the flat welding strip can better fit the surface of the battery cell, resist displacement under external force, and provide more reliable protection for the connection between the battery cells.

[0160] The shape of the special-shaped solder ribbon can be customized according to specific application requirements. For example, it can be designed with a special reflective or refractive surface to optimize the distribution of light on the cell and improve light absorption efficiency. At the same time, in terms of electrical performance, the current distribution can also be adjusted through the special-shaped structure, such as designing a wider conductive part in the area where high current density is required to meet special electrical connection requirements, thereby improving the overall performance of photovoltaic modules.

[0161] Exemplary, with reference to Figures 2 to 14 , indicating that the welding strip 120 is a flat welding strip 120. Fig.19 , Fig.19 The schematic diagram of the side cross-sectional structure of the partial structure of the welding ribbon 120, the glue point 130 and the battery cell 110 provided in some embodiments of the present application is shown, indicating that the welding ribbon 120 is a round wire welding ribbon 120. Fig.19 The coating 140 is omitted.

[0162] In this way, it can be set according to usage requirements and is not specifically limited here.

[0163] In some embodiments, the glue point includes a first sub-glue point and a second sub-glue point that are independent of each other. The orthographic projection of the first sub-glue point on the reference surface is the first projection, and the orthographic projection of the second sub-glue point on the reference surface is the second projection. The first projection and the second projection corresponding to the same glue point are respectively located on both sides of the central axis of the orthographic projection of the corresponding solder strip on the reference surface, and both have overlapping projections with the orthographic projection of the corresponding solder strip on the reference surface. The extension direction of the central axis of the orthographic projection of the solder strip on the reference surface is parallel to the longitudinal direction of the solder strip.

[0164] Exemplary, with reference to Fig. 20 and Fig.21 ,exist Fig.21 The coating 140 is omitted. Fig. 20 The figure shows the case where the soldering ribbon 120 is a flat soldering ribbon 120. Fig.21 The case where the soldering tape 120 is a round wire soldering tape 120 is shown. Of course, in some other embodiments, the glue dots 130 on the covering film 140 may be configured to include first sub-glue dots 131 and second sub-glue dots 132 that are independent of each other, which is not specifically limited here.

[0165] In this way, since both sides of the soldering ribbon are fixed and limited by the glue points, not only the risk of the soldering ribbon being offset during the lamination process is reduced, but also the reliability of the electrical connection between the soldering ribbon and the cell during the use of the photovoltaic module is further improved. At the same time, since the first sub-glue point and the second sub-glue point roughly correspond to the two sides of the soldering ribbon, when using, for example Fig. 20 and Fig.21 In the case of the arrangement of the glue dots 130 shown, the glue dots are easier to cure, so that the curing time of the glue dots is shorter, which is beneficial to improving the production efficiency of photovoltaic modules. For example, when the glue dots are light-curing glue, the curing time of the UV light-curing glue dots can be shortened.

[0166] In some embodiments, the shape of the orthographic projections of all the glue dots on the reference surface includes at least one of a circle, an ellipse, a rectangle, a strip, and a frame.

[0167] For example, in Figures 3 to 6 , Fig. 9 , Fig.11 , Fig.13 , Fig.14 and Fig.18 In the illustrated case, the positive projection shape of the glue dot 130 on the reference surface is a rectangle. Fig. 22 , Fig. 22 The schematic diagram of the top view of the partial structure of the matching of the solder strip 120 and the glue point 130 provided in some other embodiments of the present application is shown. Fig. 22In the embodiment, the glue dot 130 includes a first sub-glue dot 131 and a second sub-glue dot 132, and the shapes of the orthographic projections of the first sub-glue dot 131 and the second sub-glue dot 132 on the reference surface are both long strips. The shapes of the orthographic projections of all glue dots 130 on the reference surface can be one or more, and are not specifically limited here. For example, the frame-shaped glue dot 130 can reduce the amount of glue dot 130 used compared to other forms of glue dot 130.

[0168] In this way, the corresponding glue point structures can be flexibly combined and configured according to the stress conditions of the welding strips at different positions and the use requirements of the photovoltaic module, thereby improving the reliability of the photovoltaic module in different degrees and ways. In the case of using a printing screen to print the glue points, the mesh holes on the printing screen are also set according to the corresponding structures of the glue points, and no specific restrictions are made here.

[0169] In some embodiments, please refer to Figure 3 , the tension between the soldering ribbon 120 , the glue point 130 and the battery cell 110 is greater than or equal to 0.3 N. Specifically, including but not limited to, the corresponding tension can be controlled by configuring the size and material of the glue point 130 .

[0170] For example, Figure 4 For example, when the soldering strip 120 is a flat soldering strip 120, the size of the soldering strip 120 along the third direction can be 0.4 mm to 2 mm, the size of the glue point 130 along the second direction can be 0.4 mm, and the size of the glue point 130 along the third direction can be 1 mm to 4 mm.

[0171] Another example is Fig. 20 For example, the spacing between the first sub-glue dot 131 and the second sub-glue dot 132 along the third direction is greater than or equal to 0.4 mm, the dimensions of the first sub-glue dot 131 and the second sub-glue dot 132 along the second direction can both be 0.4 mm, and the dimensions along the third direction can both be 1 mm to 4 mm. The maximum value of the spacing between the first sub-glue dot 131 and the second sub-glue dot 132 along the third direction can be determined according to the dimensions of the solder ribbon 120, the first sub-glue dot 131, and the second sub-glue dot 132 along the third direction, and is not specifically limited here.

[0172] For example, Fig. 22 For example, the spacing between the first sub-glue dot 131 and the second sub-glue dot 132 along the third direction is greater than or equal to 0.4 mm, the dimensions of the first sub-glue dot 131 and the second sub-glue dot 132 along the second direction can both be 2 mm, and the dimensions along the third direction can both be 4 mm to 10 mm. The maximum value of the spacing between the first sub-glue dot 131 and the second sub-glue dot 132 along the third direction can be determined according to the dimensions of the solder ribbon 120, the first sub-glue dot 131, and the second sub-glue dot 132 along the third direction, and is not specifically limited here.

[0173] Continuing the example, Fig.21 For example, when the soldering ribbon 120 is a round wire soldering ribbon 120, the size of the soldering ribbon 120 along the third direction (that is, the diameter of the soldering ribbon 120) can be 0.18 mm to 0.3 mm. The spacing between the first sub-glue point 131 and the second sub-glue point 132 along the third direction is greater than or equal to 0.2 mm. The maximum value of the spacing between the first sub-glue point 131 and the second sub-glue point 132 along the third direction can be determined according to the size of the soldering ribbon 120, the first sub-glue point 131, and the second sub-glue point 132 along the third direction, and no specific limitation is made here.

[0174] Continuing the example, Fig.19 For example, when the soldering ribbon 120 is a round wire soldering ribbon 120, the size of the soldering ribbon 120 along the third direction (ie, the diameter of the soldering ribbon 120) may be 0.18 mm to 0.3 mm. The size of the glue point 130 along the second direction may be 0.2 mm, and the size of the glue point 130 along the third direction may be 1.5 mm to 3 mm.

[0175] In this way, by controlling the structure and size of the soldering ribbon and the glue point, not only can the soldering ribbon have a certain tensile force, but also the risk of the glue point penetrating between the soldering ribbon and the battery cell and causing a cold solder joint can be reduced.

[0176] In some embodiments, before step S120 , the process includes: printing and curing an insulating adhesive layer on the battery cell.

[0177] Specifically, a corresponding insulation pattern is designed according to the electrode distribution and insulation requirements of the battery cell, and a corresponding screen is made according to the insulation pattern. An insulation adhesive layer is formed at a corresponding position on the battery cell by screen printing. Subsequently, the insulation adhesive layer is cured.

[0178] In this way, short circuits between cells and between cells and other components (such as metal frames, etc.) can be improved. By printing insulating glue at the corresponding positions, an effective insulating barrier can be formed between the conductive areas of the cells, allowing the current to flow along the designed circuit path.

[0179] In some embodiments, before step S120 , the process includes: printing and curing solder on the battery cell.

[0180] Specifically, the solder position is determined according to the electrode distribution of the battery cell, and the corresponding printing template is prepared according to the solder position. The solder can be solder paste, which mainly includes tin alloy powder (such as tin-silver-copper alloy) and flux. The printing template is placed above the battery cell, and the solder paste is scraped on the template with a scraper. After printing, the solder paste will be deposited on the electrode of the battery cell through the opening of the printing template to form a solder paste layer. Subsequently, the solder paste layer is cured.

[0181] In some embodiments, after step S120, the method includes: providing a cover plate and a packaging layer, and processing the cover plate, the packaging layer and the battery string by a lamination process to form a photovoltaic module.

[0182] Specifically, before lamination, the cover plate, the encapsulation layer and the cover plate may be stacked together. Fig.23 The encapsulation layer 200 is used to cover the surface of the battery string 100. The cover plate 300 is used to cover the surface of the encapsulation layer 200 away from the battery string 100. Further, the battery cell 110 is electrically connected in the form of a whole piece or multiple pieces in the manner of forming a battery string 100 in any of the above embodiments to form a plurality of battery strings 100, and the plurality of battery strings 100 are electrically connected in series and / or in parallel. The encapsulation layer 200 covers the front and back sides of the battery cell 110, so that a photovoltaic module 10 can be obtained.

[0183] For example, the encapsulation layer 200 may be an organic encapsulation film such as an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene copolymer (POE) film, or a polyethylene terephthalate (PET) film.

[0184] Exemplarily, the cover plate 300 may be a cover plate having a light-transmitting function such as a glass cover plate or a plastic cover plate.

[0185] For example, the surface of the cover plate 300 facing the encapsulation layer 200 may be a concave-convex surface, so as to increase the utilization rate of the incident light.

[0186] During the lamination process, the lamination temperature may be determined according to the cross-linking temperature of the encapsulation layer and the melting point of the solder mentioned in some of the above embodiments, etc. For example, the lamination temperature may be 100°C to 150°C.

[0187] Thus, during the lamination process, the lamination temperature and lamination pressure can be used to achieve electrical connection between the soldering ribbon and the cell and form a photovoltaic module.

[0188] The following is an illustrative description of the method for manufacturing a photovoltaic module provided in the embodiments of the present application in combination with the processes illustrated in some of the above embodiments, but is not limited thereto.

[0189] Taking the battery cell as a busbar-free battery cell as an example, according to the type of battery cell, one type of battery cell (such as TOPCon battery) is provided with electrodes (also known as secondary grid lines) on the front and back sides, and welding strips are required to be provided on the front and back sides of the battery cell. At this time, the target side of the battery cell is at least one side of the front and back sides of the battery cell; another type of battery cell (such as BC battery) is provided with electrodes (also known as secondary grid lines) on the back side, and welding strips are required to be provided on the back side of the battery cell. At this time, the target side of the battery cell is the back side of the battery cell.

[0190] In an exemplary case, taking the case where electrodes are provided on both the front and back sides of the battery cell, and both the front and back sides of the battery cell are target sides, combined with reference Fig.24 , Fig.24 Only the relationship between the soldering ribbons 120 and the cells 110 is shown in the figure. The first cell 110 is placed on the upper side of the second half of the first soldering ribbon group, the first half of the second soldering ribbon group is placed on the first cell 110, the second cell 110 is placed on the upper side of the second half of the second soldering ribbon group, the first half of the third soldering ribbon group is placed on the second cell 110, the third cell 110 is placed on the upper side of the second half of the third soldering ribbon group, and so on. Each soldering ribbon group includes a plurality of soldering ribbons 120.

[0191] In this process, when setting the relevant components on the target side of the corresponding battery cell, the target side of the battery cell is set upward. The glue dots can be set first, and then the solder strips can be set, and then the covering film can be set. Alternatively, the solder strips can be set first, and then the glue dots can be set, and then the covering film can be set. Alternatively, the solder strips can be set first, and then the covering film can be set, and then the glue dots can be set. Of course, it is also possible to set the corresponding solder strips, glue dots, and covering films for each battery cell and then arrange the battery cells. It is also possible to set the solder strips and glue dots on all battery cells and then set the covering film together. In this way, the following can be formed: Fig.25 , Fig.26 , Fig. 27 and Fig.28 The different structural forms shown. Among them, Fig.25 In the illustrated situation, both the front side and the back side of the battery cell 110 are target sides, and a covering film 140 is provided on both the front side and the back side of the overall structure; Fig.26 In the illustrated situation, both the front side and the back side of the cell 110 are target sides, a plurality of covering films 140 are provided on the front side of the overall structure, and one covering film 140 is provided on the back side of the overall structure; Fig. 27 In the illustrated situation, both the front side and the back side of the battery cell 110 are target sides, and a plurality of coatings 140 are provided on both the front side and the back side of the overall structure; Fig.28 In the illustrated case, both the front side and the back side of the cell 110 are target sides, a coating 140 is provided on the front side of the overall structure, and multiple coatings 140 are provided on the back side of the overall structure. The matching forms of the welding strip 120, the glue point 130 and the coating 140 can be various cases illustrated in some of the aforementioned embodiments, Figure 25 to Figure 28 The glue dots 130 are omitted. The solder strips 120, the glue dots 130 and the covering film 140 can be arranged according to different matching forms, and no specific limitation is made here.

[0192] In another example, the back side of the battery cell is provided with an electrode, and the back side of the battery cell is taken as the target side. Fig.29 , Fig.29 Only the relationship between the welding ribbon 120 and the battery cell 110 is shown schematically. A plurality of battery cells 110 can be placed on a corresponding carrier device first, with the back of the battery cell 110 facing upward; then, a plurality of welding ribbon groups are placed on the back of the plurality of battery cells 110, each welding ribbon group including a plurality of welding ribbons 120, to form a Fig.29 The structural form shown.

[0193] It should be noted that the placement of the soldering tape 120 includes but is not limited to the above-mentioned situation, and can also be the situation where the front half or the rear half of the soldering tape group is located on the corresponding battery cell 110, that is, the positional relationship between each soldering tape 120 in the soldering tape group and the corresponding battery cell 110 is roughly the same. In this process, the arrangement order of the glue point 130, the soldering tape 120 and the covering film 140 can be understood by referring to the situations illustrated in some of the above-mentioned embodiments, and will not be repeated here. In this way, the following can be formed: Fig.30 and Fig.31 Different structural forms are shown. Fig.30 and Fig.31 In the illustrated case, the back side of the battery cell 110 is the target side. Fig.30 FIG. 1 shows a case where a coating 140 is provided on the back side of the overall structure. Fig.31 FIG. 1 shows a case where a plurality of coatings 140 are provided on the back side of the overall structure. Fig.29 and Fig.30 The glue point 130 is omitted. Figure 25 to Figure 28 , Fig.30 and Fig.31 , the relative position relationship among the soldering ribbon 120 , the covering film 140 and the battery cell 110 is schematically shown.

[0194] It can be understood that when the cell is a main grid-free cell, a photovoltaic module can be manufactured by a low-temperature coating process. The welding strip can be a low-temperature welding strip, and the surface layer of the welding strip can be provided with a low-melting alloy or a metal coating. For example, the melting point of the low-melting alloy or the metal coating can be 140°C. In this process, since the encapsulation layer is a layer with buffering properties, the electrical connection reliability between the welding strip and the cell is affected when the material expands and contracts due to temperature changes. In the embodiment of the present application, by providing a coating with different buffering properties from the encapsulation layer and using glue points in combination, the position stability of the welding strip relative to the cell can be improved, thereby improving the reliability of the electrical connection between the welding strip and the cell. In addition, due to the provision of a coating, the subsequent encapsulation layer can be set thinner, which is also conducive to the thin design of the photovoltaic module. Therefore, in the case of using the manufacturing method illustrated in the above embodiments provided in the embodiments of the present application, the reliability of the photovoltaic module can be improved in the lamination stage, TC (Thermal Cycling, thermal cycle) reliability test, the use process of the photovoltaic module, the transportation process of the photovoltaic module, and the like.

[0195] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0196] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for manufacturing a photovoltaic module, characterized in that: include: Provide battery cells; Connecting a plurality of the battery cells to form a battery string according to a preset stringing method; wherein, in the process of forming the battery string, a plurality of solder strips, a plurality of glue spots and a coating are arranged on a target side of the battery sheet in a preset order; For the same target side, the covering film is located on the side of the solder strip facing away from the battery cell, and the orthographic projection of the covering film on the reference plane has overlapping projections with the orthographic projections of the multiple solder strips on the reference plane; each solder strip corresponds to at least one glue point, and the orthographic projection of the glue point on the reference plane has overlapping projections with the orthographic projection of the corresponding solder strip on the reference plane; the target side of the battery cell is at least one side of the battery cell along a first direction, the first direction is the thickness direction of the battery cell, and the reference plane is a plane perpendicular to the first direction.

2. The method for manufacturing a photovoltaic module according to claim 1, characterized in that: For all the glue points on the same target side of the same battery sheet, there is a first target glue point; Along the first direction, at least a portion of the first target glue point is located between the corresponding welding ribbon and the battery cell.

3. The method for manufacturing a photovoltaic module according to claim 2, characterized in that: For the same target side of the same battery cell, there is at least one orthographic projection of the first target glue point on the reference surface and an orthographic projection of the corresponding coating on the reference surface having an overlapping projection; and / or For the same target side of the same battery cell, there is at least one orthographic projection of the first target glue point on the reference surface and an orthographic projection of the corresponding coating on the reference surface that do not overlap with each other.

4. The method for manufacturing a photovoltaic module according to claim 1, characterized in that: For all of the glue points on the same target side of all of the battery slices, there is a second target glue point; Along the first direction, at least a portion of the second target glue point is located between the corresponding welding strip and the corresponding covering film.

5. The method for manufacturing a photovoltaic module according to claim 1, characterized in that: For all the glue points on the same target side of all the battery cells, there is a third target glue point; along the first direction, at least part of the third target glue point is located on a side of the corresponding coating away from the battery cell; and / or For all the glue points on the same target side of all the battery cells, there is a fourth target glue point; along the first direction, at least part of the fourth target glue point is located on a side of the corresponding solder strip away from the battery cell.

6. The method for manufacturing a photovoltaic module according to any one of claims 1 to 5, characterized in that: For the same target side of all the battery cells, the covering film is provided with a projection where at least a portion of the solder strips have an overlapping projection with the corresponding covering film on the reference surface; or For the same target side of all the battery cells, a plurality of the covering films are provided, each covering film covers at least one battery cell, and all the covering films do not overlap with each other, and the orthographic projection of at least part of the welding strips on the reference surface has an overlapping projection with the orthographic projection of the corresponding covering film on the reference surface; or For the same target side of all the battery cells, a plurality of the covering films are provided, and all the covering films and all the battery cells are arranged one-to-one, and the orthographic projection of at least part of the welding strips on the reference surface has an overlapping projection with the orthographic projection of the corresponding covering film on the reference surface.

7. The method for manufacturing a photovoltaic module according to any one of claims 1 to 5, characterized in that: Each of the welding strips corresponds to a plurality of the glue dots; The orthographic projections of the plurality of glue dots on the reference surface and the orthographic projections of the corresponding solder strips on the reference surface respectively have overlapping projections.

8. The method for manufacturing a photovoltaic module according to claim 7, characterized in that: The welding strip has a first end and a second end that are arranged opposite to each other along the longitudinal direction of the welding strip; For the plurality of glue dots, an orthographic projection of one of the glue dots on the reference surface has an overlapping projection with an orthographic projection of the first end of the corresponding solder strip on the reference surface; The orthographic projection of another of the glue dots on the reference surface has an overlapping projection with the orthographic projection of the corresponding second end of the solder strip on the reference surface.

9. The method for manufacturing a photovoltaic module according to any one of claims 1 to 5, characterized in that: The coating is configured as a single-layer structure, and the pre-crosslinking degree of the coating is 20% to 50%; or The coating is configured as a multi-layer structure, and the coating includes a plurality of sub-films stacked together, wherein the pre-crosslinking degree of the sub-film closest to the battery cell among the plurality of sub-films is 20% to 50%.

10. The method for manufacturing a photovoltaic module according to any one of claims 1 to 5, characterized in that: For the same target side of the same battery cell, the orthographic projection of each welding strip on the reference surface has an overlapping projection with the orthographic projection of the corresponding covering film on the reference surface; and / or The minimum torque value ML of the coating satisfies: 0.1≤ML≤0.8; and / or The coating temperature of the coating is 100°C to 135°C; and / or The thickness of the coating is 50µm to 500µm; and / or The process of forming the battery string includes curing the glue dots, wherein the degree of cross-linking of the glue dots after curing is greater than 90%; and / or The Tg of the glue point is ≥59.40°C; the Tg is the temperature at which the glue point changes from a glassy state to a high-condensation state; and / or The welding strip includes at least one of a round wire welding strip, a triangular welding strip, a flat welding strip, and a special-shaped welding strip.

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