Battery string and photovoltaic module

Abstract

The utility model discloses a battery string and a photovoltaic module, and belongs to the technical field of photovoltaic modules. The battery string comprises battery pieces, and the surfaces of the battery pieces are provided with first grid lines extending in the first direction; the welding strip extends in the second direction and is connected to the first grid line, the width of the welding strip is d in the first direction, and the second direction intersects with the first direction; wherein the connection part of the first grid line and the welding strip is provided with a thickened section, the thickened section extends along the first direction, the length of the thickened section along the first direction is l, and l is more than or equal to 1.5 d and less than or equal to 2.5 d.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic components, in particular to a battery string and a photovoltaic component. Background Art

[0002] As the core component of photovoltaic modules, the battery string can convert solar energy into electrical energy. The battery string usually includes battery cells and welding strips. The surface of the battery cell has a main grid and a secondary grid arranged in an intersecting manner. The secondary grid collects the current generated by the battery cell, and the main grid collects the current collected by the secondary grid. During the processing of the battery string, the welding strip needs to be laid on the top of the main grid, and the welding strip is welded to the surface of the battery cell by spot welding, so that the current collected by the main grid is transmitted to the external circuit through the welding strip.

[0003] In order to reduce the production cost of the battery string, the prior art usually sets the welding strip, the main grid and the auxiliary grid to be relatively thin. The connection between the welding strip and the battery cell is relatively reliable only at the welding point of the welding strip, and the other positions of the welding strip are prone to relative displacement with the battery cell, thereby affecting the reliability of the connection between the welding strip and the main grid, and further affecting the photoelectric conversion efficiency of the photovoltaic module. Utility Model Content

[0004] The utility model discloses a battery string and a photovoltaic module, so as to solve or at least partially solve the problem existing in the prior art that the area where the welding strip is not welded to the surface of the battery cell is prone to relative displacement with the battery cell, thereby affecting the reliability of the connection between the welding strip and the main grid, and further affecting the photoelectric conversion efficiency of the photovoltaic module.

[0005] In order to solve the above technical problems, the utility model is achieved as follows:

[0006] In a first aspect, the utility model discloses a battery string, comprising a battery cell, wherein the surface of the battery cell has a first grid line extending along a first direction; a welding strip, wherein the welding strip extends along a second direction and is connected to the first grid line, wherein the width of the welding strip is d along the first direction, and the second direction intersects with the first direction; wherein a thickened section is provided at the connection between the first grid line and the welding strip, wherein the thickened section extends along the first direction, and wherein the length of the thickened section is l along the first direction, satisfying 1.5d≤l≤2.5d.

[0007] Optionally, the thickened segment is a rectangular structure, and along the second direction, the width of the thickened segment is k, satisfying k<l.

[0008] Optionally, the surface of the battery cell further has a second grid line extending along the second direction, the second grid line intersects the first grid line perpendicularly, and the welding strip is arranged above the second grid line.

[0009] Optionally, the first gate lines include a plurality of first gate lines, and the plurality of first gate lines are arranged at intervals along the second direction; the welding strip has two connection points with two adjacent first gate lines, and only one of the two connection points is provided with the thickened section.

[0010] Optionally, the welding strips also include a plurality of strips, and the plurality of welding strips are arranged at intervals along the first direction; the first gate line has two connecting points with two adjacent welding strips, and only one of the two connecting points is provided with the thickened section.

[0011] Optionally, the surface of the battery cell further has a soldering pad, and the soldering strip is arranged at the connection between the first gate line and the soldering strip; along the first direction, the length of the soldering pad is greater than or equal to the length of the thickened section.

[0012] Optionally, along the first direction, a length of the pad is greater than or equal to 0.5 mm and less than or equal to 1.0 mm.

[0013] Optionally, along the second direction, there is at least one thickened segment between two adjacent pads.

[0014] Optionally, a connection between the pad and the first gate line further comprises a contact segment, and along the second direction, a width of the contact segment is greater than a width of the first gate line, and a width of the contact segment is less than a width of the pad.

[0015] In a second aspect, the utility model discloses a photovoltaic module, wherein the photovoltaic module comprises the battery string described in the first direction, wherein the battery string comprises a plurality of battery strings, and the plurality of battery strings are arranged at intervals.

[0016] The utility model discloses a battery string and a photovoltaic module, wherein the battery string comprises a battery cell and a welding strip. The surface of the battery cell has a first grid line extending along a first direction, and the welding strip extends along a second direction and is connected to the first grid line. Along the first direction, the width of the welding strip is d, and a thickened section is provided at the connection between the first grid line and the welding strip, the thickened section extends along the first direction, and along the first direction, the length of the thickened section is l, and the length l is set to be greater than or equal to 1.5 times the width d of the welding strip and less than or equal to 2.5 times the width d of the welding strip.

[0017] The thickened section in the embodiment of the utility model can increase the friction between the welding strip and the thickened section along the first direction, and reduce the displacement of the welding strip in the first direction. Furthermore, when the welding strip is displaced along the first direction, the thickened section can also form an effective connection with the welding strip to avoid whitening. Thereby improving the reliability of the connection between the welding strip and the first grid line, reducing the power loss of the photovoltaic module, and improving the photoelectric conversion efficiency of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram showing the structure of the battery string described in the embodiment of the utility model;

[0019] Figure 2 A partial enlargement of the battery string in the embodiment of the utility model is shown Figure 1 ;

[0020] Figure 3 A partial enlargement of the battery string in the embodiment of the utility model is shown Figure 2 ;

[0021] Figure 4 A partial enlargement of the battery string in the embodiment of the utility model is shown Figure 3 ;

[0022] Figure 5 A partial enlargement of the battery string in the embodiment of the utility model is shown Figure 4 .

[0023] Reference numerals:

[0024] 10: battery cell; 11: first grid line; 12: second grid line;

[0025] 20: welding strip;

[0026] 30: bold paragraph;

[0027] 40: pad;

[0028] 50: contact section;

[0029] A: first direction; B: second direction; DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the fixed scope of the utility model.

[0031] It should be understood that the references to "one embodiment" or "an embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present invention. Therefore, the references to "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0032] Reference Figure 1, showing a schematic diagram of the structure of the battery string in the embodiment of the utility model; referring to Figure 2 , showing a partial enlargement of the battery string described in the embodiment of the utility model Figure 1 ;reference Figure 3 , showing a partial enlargement of the battery string described in the embodiment of the utility model Figure 2 ;reference Figure 4 , showing a partial enlargement of the battery string described in the embodiment of the utility model Figure 3 ;reference Figure 5 , showing a partial enlargement of the battery string described in the embodiment of the utility model Figure 4 .

[0033] like Figures 1 to 5 As shown, a battery string is disclosed in an embodiment of the utility model, which includes a battery cell 10, and the surface of the battery cell 10 has a first grid line 11 extending along a first direction A; a welding strip 20, the welding strip 20 extends along a second direction B and is connected to the first grid line 11, along the first direction A, the width of the welding strip 20 is d, and the second direction B intersects with the first direction A; wherein, a thickened section 30 is provided at the connection between the first grid line 11 and the welding strip 20, the thickened section 30 extends along the first direction A, and along the first direction A, the length of the thickened section 30 is l, satisfying 1.5d≤l≤2.5d.

[0034] The battery string disclosed in the embodiment of the utility model can be used in a photovoltaic module, and the solar energy is converted into electrical energy through the battery string. Generally, a photovoltaic module includes multiple battery strings, and the multiple battery strings are arranged at intervals. The following will take one of the battery strings as an example for relevant description.

[0035] like Figures 1 to 5 As shown, the battery string disclosed in the embodiment of the utility model includes a battery cell 10 and a welding strip 20. Among them, the battery cell 10 is the core component of the battery string, which can convert solar energy into electrical energy. The surface of the battery cell 10 has a first grid line 11 extending along a first direction A. The current generated on the surface of the battery cell 10 is collected by the first grid line 11.

[0036] Exemplarily, when the battery cell 10 is a rectangular battery cell, the length direction of the battery cell 10 can be set as the first direction A, and the width direction of the battery cell 10 can be set as the second direction B. A first gate line 11 is set on the surface of the battery cell 10 along the length direction of the battery cell 10 to collect the current generated by the battery cell 10 through the first gate line 11.

[0037] Of course, the above method of setting the battery cell 10 as a rectangular battery cell is only an individual example of the present invention. The battery cell 10 in the embodiment of the utility model can be a rectangular structure, a square structure, or a special-shaped structure. In this regard, the embodiment of the utility model does not make specific restrictions. In actual applications, technicians can set it as needed.

[0038] like Figure 3 As shown, the welding strip 20 in the embodiment of the utility model extends along the second direction B and is connected to the first grid line 11. The current collected by the first grid line 11 is collected by the welding strip 20, and the current is transmitted so that the current is transmitted to the external circuit. Exemplarily, in the case where the battery cell 10 is a rectangular battery cell, the length direction of the battery cell 10 can be set to the first direction A, and the width direction of the battery cell 10 can be set to the second direction B. The welding strip 20 is laid on the surface of the battery cell 10 along the width direction of the battery cell 10 so that the welding strip 20 intersects with the first grid line 11 and is connected to the first grid line 11.

[0039] It should be noted that the welding strip 20 in the embodiment of the utility model can be a round welding strip, a square welding strip, a flat welding strip, or a special-shaped welding strip. In the embodiment of the utility model, there are no excessive restrictions on the specific structure of the welding strip 20, and any welding strip 20 with a strip structure can be used. In actual applications, technicians can select a suitable welding strip 20 as needed.

[0040] like Figures 1 to 5 As shown, along the first direction A, the width of the soldering strip 20 is d. The connection between the first gate line 11 and the soldering strip 20 has a thickened section 30, which extends along the first direction A. And along the first direction A, the length of the thickened section 30 is l. Wherein, l is greater than or equal to 1.5d and less than or equal to 2.5d.

[0041] For example, when the welding strip 20 is a circular welding strip, the diameter of the circular welding strip can be set to 0.35 mm. That is, along the first direction A, the width of the circular welding strip is 0.35 mm. Then, along the first direction A, the length of the thickened section 30 can be set to be greater than or equal to 0.525 mm and less than or equal to 0.875 mm. For example, along the first direction A, the length of the thickened section 30 can be set to 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, etc.

[0042] It should be noted that, in the embodiment of the present invention, the width of the thickened section 30 can be set to be greater than or equal to 30 μm and less than or equal to 40 μm along the second direction B. For example, along the second direction B, the width of the thickened section 30 can be set to 30 μm, 32 μm, 34 μm, 36 μm, 38 μm, or 40 μm.

[0043] In addition, the first gate line 11 and the thickened segment 30 in the embodiment of the utility model are both conductive. Specifically, the metal paste can be printed on the surface of the battery cell 10 by screen printing to form the first gate line 11 and the thickened segment 30 on the surface of the battery cell 10.

[0044] The thickened section 30 in the embodiment of the utility model can increase the friction between the welding strip 20 and the thickened section 30 along the first direction A, and reduce the displacement of the welding strip 20 in the first direction A. Furthermore, when the welding strip 20 is displaced along the first direction A, the thickened section 30 can also form an effective connection with the welding strip 20 to avoid whitening. Thereby, the reliability of the connection between the welding strip 20 and the first grid line 11 is improved, the power loss of the photovoltaic module is reduced, and the photoelectric conversion efficiency of the photovoltaic module is improved.

[0045] Alternatively, if Figures 1 to 5 As shown, the thickened section 30 in the embodiment of the present invention is a rectangular structure. Along the second direction B, the width of the thickened section 30 is k, satisfying k<l.

[0046] like Figures 1 to 5 As shown, the thickened section 30 in the embodiment of the utility model is a rectangular structure. And along the second direction B, the width of the thickened section 30 is k, where k<l. That is, the length direction of the thickened section 30 extends along the first direction A, and the width direction is set along the second direction B.

[0047] In the embodiment of the utility model, the length direction of the thickened section 30 is extended along the first direction A, and the width direction of the thickened section 30 is arranged along the second direction B. This further increases the effective friction area between the welding strip 20 and the thickened section 30 along the first direction A, thereby reducing the displacement of the welding strip 20 in the first direction A.

[0048] Alternatively, if Figures 1 to 5 As shown, the surface of the battery cell 10 in the embodiment of the utility model further has a second grid line 12 extending along the second direction B. The second grid line 12 intersects the first grid line 11 perpendicularly, and the welding strip 20 is arranged above the second grid line 12 .

[0049] In the embodiment of the utility model, a second grid line 12 extending along the second direction B is arranged on the surface of the battery cell 10, so that the second grid line 12 intersects the first grid line 11 perpendicularly, and the welding strip 20 is arranged above the second grid line 12. Thus, the current collected by the first grid line 11 is collected by the second grid line 12, and the current collected by the second grid line 12 is transmitted to the welding strip 20, and the current is transmitted to the external circuit through the welding strip 20.

[0050] The provision of the second grid line 12 in the embodiment of the utility model can further improve the reliability of the connection between the welding strip 20 and the first grid line 11, reduce the power loss of the photovoltaic module, and improve the photoelectric conversion efficiency of the photovoltaic module.

[0051] It should be noted that the second gate lines 12 in the embodiment of the utility model are also conductive. Specifically, metal paste can be printed on the surface of the battery cell 10 by screen printing to form the second gate lines 12 on the surface of the battery cell 10 .

[0052] Alternatively, if Figures 1 to 5 As shown, the first gate lines 11 in the embodiment of the utility model include multiple first gate lines 11, and the multiple first gate lines 11 are arranged at intervals along the second direction B; the welding strip 20 has two connecting points with two adjacent first gate lines 11, and only one of the two connecting points is provided with a thickened section 30.

[0053] like Figures 1 to 5 As shown, the surface of the cell 10 has a plurality of first grid lines 11, which extend along a first direction A and are arranged at intervals along a second direction B. Each welding strip 20 has two connections with two adjacent first grid lines 11, and only one of the two connections is provided with a thickened section 30.

[0054] That is to say, when the first direction A is perpendicular to the second direction B, one welding strip 20 has one connection with each first gate line 11 along the second direction B. If a thickened section 30 is provided at the connection between a first gate line 11 and the welding strip 20, then the connection between two first gate lines 11 adjacent to the first gate line 11 and the welding strip 20 is no longer provided with a thickened section 30.

[0055] In the embodiment of the utility model, the thickened section 30 is provided at only one of the two connection points between the welding strip 20 and the two adjacent first grid lines 11. This can reduce the power loss of the photovoltaic module, improve the photoelectric conversion efficiency of the photovoltaic module, and avoid the excessive cost of the photovoltaic module. Furthermore, it can also avoid the wet weight of the battery cell being too high, which affects the quality of the battery cell.

[0056] Alternatively, if Figures 1 to 5As shown, the welding strips 20 in the embodiment of the utility model also include multiple strips, and the multiple welding strips 20 are arranged at intervals along the first direction A; the first gate line 11 and the two adjacent welding strips 20 have two said connection points, and only one of the two said connection points is provided with a thickened section 30.

[0057] like Figures 1 to 5 As shown, a plurality of welding strips 20 are arranged on the surface of the cell 10, and the plurality of welding strips 20 extend along the second direction B and are arranged at intervals along the first direction A. Each first grid line 11 has two connections with two adjacent welding strips 20, and only one of the two connections is provided with a thickened section 30.

[0058] That is to say, when the first direction A is perpendicular to the second direction B, one first grid line 11 and each welding strip 20 have a connection along the first direction A. If a thickened section 30 is provided at the connection between a welding strip 20 and the first grid line 11, the connection between two welding strips 20 adjacent to the welding strip 20 and the first grid line 11 is no longer provided with a thickened section 30.

[0059] In the embodiment of the utility model, the thickened section 30 is provided at only one of the two connection points between the first grid line 11 and the two adjacent welding strips 20. This can reduce the power loss of the photovoltaic module, improve the photoelectric conversion efficiency of the photovoltaic module, and avoid the cost of the photovoltaic module being too high. Furthermore, it can also avoid the wet weight of the battery cell being too high, which affects the quality of the battery cell.

[0060] Alternatively, if Figures 1 to 5 As shown, in the embodiment of the utility model, the surface of the battery cell 10 also has a pad 40, which is arranged at the connection between the first grid line 11 and the welding strip 20; along the first direction A, the length of the pad 40 is greater than or equal to the length of the thickened section 30.

[0061] like Figures 1 to 5 As shown, the surface of the cell 10 also has a pad 40, which is arranged at the connection between the first grid line 11 and the welding strip 20. And along the first direction A, the width of the pad 40 is set to be greater than or equal to the length of the thickened section 30. In the process of welding, the contact area between the welding strip 20 and the cell 10 is increased by the pad 40, and the whitening is reduced. Thereby, the reliability of welding between the welding strip 20 and the cell 10 is improved, the power loss of the photovoltaic module is reduced, and the photoelectric conversion efficiency of the photovoltaic module is improved.

[0062] It should be noted that the pad 40 in the embodiment of the utility model can be a square structure, a rectangular structure, or a special-shaped structure. In the embodiment of the utility model, there are no excessive restrictions on the specific structure of the pad 40. In actual applications, technicians can set it as needed.

[0063] Optionally, along the first direction A, the length of the pad 40 is greater than or equal to 0.5 mm and less than or equal to 1.0 mm.

[0064] For example, along the first direction A, the length of the pad 40 may be set to 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, etc.

[0065] In the embodiment of the utility model, the length of the pad 40 is set to be greater than or equal to 0.5 mm and less than or equal to 1.0 mm along the first direction A, so that the size of the pad 40 is more appropriate. During the welding process, the pad 40 can increase the contact area between the welding ribbon 20 and the battery cell 10 and reduce whitening. In addition, it will not cause waste of metal slurry.

[0066] Optionally, along the second direction B, there is at least one thickened section 30 between two adjacent pads 40 .

[0067] like Figures 1 to 5 As shown, along the second direction B, each welding strip 20 has a connection with the plurality of first gate lines 11. It can be understood that along the second direction B, each welding strip 20 has a plurality of connections with the plurality of first gate lines 11. However, not every connection among the plurality of connections is provided with a welding pad 40, only a few connections are provided with a welding pad 40. For example, as Figure 1 As shown, among the multiple connection points between each welding strip 20 and the multiple first gate lines 11 , only three connection points are provided with welding pads 40 .

[0068] In the embodiment of the utility model, at least one thickened section 30 is provided between two adjacent pads 40 along the second direction B. The thickened section 30 is used to increase the friction between the welding strip 20 and the thickened section 30 along the first direction A, thereby reducing the displacement of the welding strip 20 in the first direction A. Furthermore, when the welding strip 20 is displaced along the first direction A, the thickened section 30 can also form an effective connection with the welding strip 20 to avoid whitening. Thus, the reliability of the connection between the welding strip 20 and the first grid line 11 is improved, the power loss of the photovoltaic module is reduced, and the photoelectric conversion efficiency of the photovoltaic module is improved.

[0069] During the welding process of the welding ribbon 20, after the welding ribbon 20 on the front side of the cell 10 is laid, the relative position between the welding ribbon 20 and the first grid line 11 is fixed by a fixing component. If the surface of the cell 10 is a light-receiving surface, along the second direction B, two or three thickened sections 30 may be provided between two adjacent pads 40.

[0070] After the soldering tape 20 on the back of the cell 10 is laid, the soldering tape 20 and the cell 10 need to be placed on a conveyor belt for transportation. Friction between the back of the cell 10 and the soldering tape 20 and the conveyor belt may easily cause the soldering tape 20 to deviate. Therefore, if the surface of the cell 10 is the backlight surface, 4, 5 or 6 thickened segments 30 may be provided between two adjacent solder pads 40 along the second direction B.

[0071] Of course, the above is only an example of the number of thickened segments 30 and is not intended to be a limitation of the present invention. In actual applications, technicians can set a suitable number of thickened segments 30 between two adjacent pads 40 as needed.

[0072] Alternatively, if Figures 1 to 5 As shown, the connection between the pad 40 and the first gate line 11 further comprises a contact segment 50 . Along the second direction B, the width of the contact segment 50 is greater than the width of the first gate line 11 , and the width of the contact segment 50 is less than the width of the pad 40 .

[0073] like Figures 1 to 5 As shown, in the embodiment of the utility model, a contact segment 50 is also provided at the connection between the pad 40 and the first grid line 11. And along the second direction B, the width of the contact segment 50 is set to be greater than the width of the first grid line 11, and the width of the contact segment 50 is set to be less than the width of the pad 40. In the process of welding, the contact area between the welding strip 20 and the battery cell 10 is increased by the contact segment 50, and the white exposure is reduced. Thereby improving the reliability of welding between the welding strip 20 and the battery cell 10, reducing the power loss of the photovoltaic module, and improving the photoelectric conversion efficiency of the photovoltaic module. Further, the setting of the contact segment 50 can also avoid damaging the surface of the battery cell 10 during the welding process.

[0074] It should be noted that the contact segment 50 in the embodiment of the utility model can be a rectangular structure, a diamond structure, or a special-shaped structure. In the embodiment of the utility model, there is no limitation on the specific shape of the contact segment 50, and in actual applications, technicians can set it as needed.

[0075] The utility model discloses a battery string, which includes a battery cell and a welding strip. The surface of the battery cell has a first grid line extending along a first direction, and the welding strip extends along a second direction and is connected to the first grid line. Along the first direction, the width of the welding strip is d, and a thickened section is provided at the connection between the first grid line and the welding strip. The thickened section extends along the first direction, and along the first direction, the length of the thickened section is l, and the length l is set to be greater than or equal to 1.5 times the width d of the welding strip and less than or equal to 2.5 times the width d of the welding strip. The setting of the thickened section in the embodiment of the utility model can increase the friction between the welding strip and the thickened section along the first direction, and reduce the displacement of the welding strip in the first direction.

[0076] Furthermore, when the welding strip is displaced along the first direction, the thickened section can also form an effective connection with the welding strip to avoid whitening, thereby improving the reliability of the connection between the welding strip and the first grid line, reducing the power loss of the photovoltaic module, and improving the photoelectric conversion efficiency of the photovoltaic module.

[0077] The utility model also discloses a photovoltaic module in an embodiment. The photovoltaic module includes the battery string described in the above embodiment. The battery string includes a plurality of battery strings, and the plurality of battery strings are arranged at intervals.

[0078] It should be noted that in the embodiment of the utility model, the battery string included in the photovoltaic module has the same structure as the battery string described in the above embodiment, and its beneficial effects are also similar, which will not be described in detail here.

[0079] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0080] Although the optional embodiments of the utility model embodiments have been described, those skilled in the art, once knowing the basic creative concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including optional embodiments and all changes and modifications falling within the scope of the utility model embodiments.

[0081] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity from another entity, and do not necessarily require or imply any such actual relationship or order between these entities. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or terminal device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the article or terminal device including the elements.

[0082] The technical solution provided by the utility model is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation method of the utility model. At the same time, for general technicians in this field, according to the principle and implementation method of the utility model, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the utility model.

Claims

1. A battery string, characterized in that: include: A battery cell (10), wherein a surface of the battery cell (10) has a first grid line (11) extending along a first direction (A); A welding strip (20), the welding strip (20) extending along a second direction (B) and connected to the first gate line (11), the width of the welding strip (20) along the first direction (A) being d, and the second direction (B) intersecting the first direction (A); A thickened section (30) is provided at the connection between the first gate line (11) and the welding strip (20), the thickened section (30) extends along the first direction (A), and along the first direction (A), the length of the thickened section (30) is l, satisfying 1.5d≤l≤2.5d.

2. The battery string according to claim 1, characterized in that: The thickened section (30) is a rectangular structure, and along the second direction (B), the width of the thickened section (30) is k, satisfying k<l.

3. The battery string according to claim 1, characterized in that: The surface of the battery cell also has a second grid line (12) extending along the second direction (B), the second grid line (12) intersects the first grid line (11) perpendicularly, and the welding strip (20) is arranged above the second grid line (12).

4. The battery string according to claim 1, characterized in that: The first gate lines (11) include a plurality of gate lines, and the plurality of gate lines (11) are arranged at intervals along the second direction (B); The welding strip (20) and two adjacent first gate lines (11) have two connection points, and only one of the two connection points is provided with the thickened section (30).

5. The battery string according to claim 1, characterized in that: The welding strip (20) also includes a plurality of strips, and the plurality of welding strips (20) are arranged at intervals along the first direction (A); The first gate line (11) and the two adjacent welding strips (20) have two connection points, and only one of the two connection points is provided with the thickened section (30).

6. The battery string according to claim 1, characterized in that: The surface of the battery cell (10) also has a soldering pad (40), and the soldering pad (40) is arranged at the connection between the first gate line (11) and the soldering strip (20); Along the first direction (A), the length of the pad (40) is greater than or equal to the length of the thickened section (30).

7. The battery string according to claim 6, characterized in that: Along the first direction (A), the length of the pad (40) is greater than or equal to 0.5 mm and less than or equal to 1.0 mm.

8. The battery string according to claim 6, characterized in that: Along the second direction (B), there is at least one thickened section (30) between two adjacent pads (40).

9. The battery string according to claim 6, characterized in that: The connection between the pad (40) and the first gate line (11) also has a contact segment (50); along the second direction (B), the width of the contact segment (50) is greater than the width of the first gate line (11), and the width of the contact segment (50) is less than the width of the pad (40).

10. A photovoltaic module, characterized in that: The battery string comprises the battery string described in any one of claims 1 to 9, wherein the battery string comprises a plurality of battery strings, and the plurality of battery strings are arranged at intervals.

Images