Back contact solar cell with no busbars, photovoltaic module

Abstract

The application relates to a kind of main gridless back contact cells and photovoltaic modules, can save silver prize, main gridless back contact cell, comprising: cell substrate, the cell substrate has first soldering area and second soldering area alternately arranged along the first direction;Located in the cell substrate first fine grid line and multiple second fine grid lines, the first fine grid line and the second fine grid line are different in polarity, multiple first fine grid lines and multiple second fine grid lines are sequentially arranged alternately along the second direction, the first fine grid line has first disconnected area on the first soldering area, the end of the first fine grid line on the both sides of the first disconnected area is provided with first thickening section, the second fine grid line has second disconnected area on the second soldering area, the end of the first fine grid line on the both sides of the second disconnected area is provided with second thickening section.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a gridless back contact cell, and also to a photovoltaic module. Background Technology

[0002] Conventional gridless (OBB) back-contact batteries have alternating fine grids for N and P polarities. By eliminating the main grid, solder joints are retained at the points requiring soldering to connect with the solder ribbon. To ensure a good connection, relatively large solder joints are needed, resulting in higher silver paste consumption and costs. Utility Model Content

[0003] Therefore, it is necessary to provide a gridless back contact cell to address the problem of excessive silver paste consumption, and a photovoltaic module is also proposed.

[0004] The first aspect of this application discloses a gridless back contact battery, comprising: a battery substrate having a first welding area and a second welding area alternately arranged along a first direction; a first fine grid line and a plurality of second fine grid lines located on the battery substrate, the first fine grid line and the second fine grid line having different polarities, the plurality of first fine grid lines and the plurality of second fine grid lines being alternately arranged sequentially along a second direction, the first fine grid line having a first break area on the first welding area, the ends of the first fine grid line on both sides of the first break area having a first thickened section, the second fine grid line having a second break area on the second welding area, the ends of the first fine grid line on both sides of the second break area having a second thickened section.

[0005] In some embodiments, the size of the first thickened segment is 0.1mm-0.2mm in the first direction and 0.01mm-0.1mm in the second direction; and / or, the size of the second thickened segment is 0.1mm-0.2mm in the first direction and 0.01mm-0.1mm in the second direction.

[0006] In some embodiments, a first adhesive dot is provided within the first disconnection zone.

[0007] In some embodiments, in the first direction, the size of the first break area is 0.2mm-0.8mm, and the size of the first adhesive dot is 0.05-0.4mm.

[0008] In some embodiments, a second adhesive dot is provided within the second disconnection zone.

[0009] In some embodiments, in the first direction, the size of the second break zone is 0.2 mm to 0.8 mm, and the size of the second adhesive dot is 0.05 mm to 0.4 mm.

[0010] In some embodiments, the first fine grid line has a first spacing in the second welding area, and in the first direction, the width of the first spacing is greater than the width of the second break area.

[0011] In some embodiments, the second fine grid line has a second spacing in the first welding area, and in the first direction, the width of the second spacing is greater than the width of the first break area.

[0012] A second aspect of this application provides a photovoltaic module, including the aforementioned gridless back contact cell; a first solder strip located in the first welding area and disposed along the second direction, the first solder strip connecting to the first thickened section and electrically insulated from the second fine grid line; and a second solder strip located in the second welding area and disposed along the second direction, the second solder strip connecting to the second thickened section and electrically insulated from the first fine grid line.

[0013] In some embodiments, the widths of the first and second solder strips in the first direction are 0.2 mm to 1 mm.

[0014] In some embodiments, the first thickened segment extends beyond the edge of the first solder strip along a first direction and away from the first break region; and / or, the second thickened segment extends beyond the edge of the second solder strip along a first direction and away from the second break region.

[0015] In some embodiments, the first fine grid line has a first spacing in the second welding area, and in the first direction, the width of the first spacing is greater than the width of the second solder strip; or, the first fine grid line and the second solder strip are electrically insulated from each other by a first insulator.

[0016] In some embodiments, the second fine grid line has a second spacing in the first welding area, and in the first direction, the width of the second spacing is greater than the width of the first solder strip; and / or, the second fine grid line is electrically insulated from the first solder strip by a second insulator.

[0017] In this application, when the first fine grid line is welded to the first solder strip, the first fine grid line has a first break zone in the first welding area, which can save solder paste when welding with the first solder strip. The first thickened sections on both sides of each first break zone have a large contact area with the first solder strip in the second direction, ensuring conductivity. The second fine grid line has a second break zone in the second welding area, which can save solder paste when welding with the second solder strip. The second thickened sections on both sides of each second break zone have a large contact area with the second solder strip in the second direction, ensuring conductivity. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the structure of a gridless back contact battery according to an embodiment of this application.

[0019] Figure 2 for Figure 1 A magnified view of part A in the middle.

[0020] Figure 3 for Figure 1 A magnified view of part B in the middle section.

[0021] Figure 4 for Figure 1 A schematic diagram of a photovoltaic module formed by gridless back-contact cells.

[0022] Figure 5 for Figure 4 A magnified view of part C in the middle.

[0023] Figure 6 for Figure 4 A magnified view of part D in the middle.

[0024] Figure label:

[0025] 100. Gridless back contact battery; 10. Battery substrate; 110. First welding area; 120. Second welding area; 20. First fine grid line; 210. First break area; 220. First thickened section; 230. First adhesive dot; 240. First spacer; 30. Second fine grid line; 310. Second break area; 320. Second thickened section; 330. Second adhesive dot; 340. Second spacer; 40. First solder strip; 50. Second solder strip; 60. First insulating component; 70. Second insulating component; X, first direction; Y, second direction. Detailed Implementation

[0026] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0027] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0028] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0029] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0031] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, 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 possible implementation.

[0032] See Figures 1 to 3 This application proposes a grid-less back-contact cell 100, which can be used to form a photovoltaic module. For example, multiple grid-less back-contact cells 100 are connected in series via solder strips to form a photovoltaic module. Figure 4 The cells in a photovoltaic module are connected in strings to form the photovoltaic module. Figure 2 The example shown is only exemplarily illustrated when two gridless back contact batteries 100 are connected in series, but it should be understood that the number of gridless back contact batteries 100 in the battery string is not limited to two.

[0033] refer to Figures 1 to 3 An embodiment of the gridless back contact battery 100 of this application includes a battery substrate 10, a plurality of first fine grid lines 20 and a plurality of second fine grid lines 30 disposed on the battery substrate 10. The battery substrate 10 has a first welding area 110 and a second welding area 120 alternately arranged along a first direction X. The first fine grid lines 20 and the second fine grid lines 30 have different polarities. The plurality of first fine grid lines 20 and the plurality of second fine grid lines 30 are arranged alternately along a second direction Y. The first fine grid lines 20 have a first break area 210 on the first welding area 110. The ends of the first fine grid lines 20 on both sides of the first break area 210 are provided with a first thickened section 220. The second fine grid lines 30 have a second break area 310 on the second welding area 120. The ends of the first fine grid lines 20 on both sides of the second break area 310 are provided with a second thickened section 320.

[0034] The first direction X is along the left-right direction, and the second direction Y is along the up-down direction. The first fine grid line 20 and the second fine grid line 30 both extend along the first direction X, but the multiple first fine grid lines 20 and the multiple second fine grid lines 30 are arranged alternately along the second direction Y.

[0035] The first welding area 110 and the second welding area 120 are arranged alternately along the first direction X, and are used to connect the first solder strip 40 and the second solder strip 50, respectively. In this application, the first welding area 110 refers to the area on the battery substrate 10 in the first direction X used to set the first solder strip 40. The second welding area 120 refers to the area on the battery substrate 10 in the first direction X used to set the second solder strip 50.

[0036] Specifically, refer to Figure 1 , Figure 4 The first welding area 110 is defined by a plurality of first fine grid lines 20, and the first solder strip 40 is welded to the plurality of first fine grid lines 20 in the first welding area 110, while being electrically insulated from the second fine grid lines 30. The second welding area 120 is defined by a plurality of second fine grid lines 30, and the second solder strip 50 is welded to the plurality of second fine grid lines 30 in the second welding area 120, while being electrically insulated from the first fine grid lines 20.

[0037] In this application, for example, the first fine gate line 20 is a P-gate line and the second fine gate line 30 is an N-gate line. That is, when the first solder ribbon 40 is soldered to the P-gate line, the first solder ribbon 40 is electrically insulated from the N-gate line. When the second solder ribbon 50 is soldered to the N-gate line, the second solder ribbon 50 is electrically insulated from the P-gate line.

[0038] refer to Figure 4 The connection method of multiple gridless back-contact batteries 100 connected in series via a first solder strip 40 and a second solder strip 50 is as follows. For example, Figure 4 Only two non-main grid back contact batteries 100 are shown in the image.

[0039] In the battery string, two adjacent gridless back-contact cells 100 are placed with opposite polarities. Specifically, two adjacent gridless back-contact cells 100 are defined as the first cell (the gridless back-contact cell 100 located at the top in the figure) and the second cell (the gridless back-contact cell 100 located at the bottom in the figure). (Reference) Figure 1 and Figure 4 Each first welding area 110 on the first battery cell corresponds one-to-one with each second welding area 120 on the second battery cell in the second direction Y. The first solder strip 40 is connected to the corresponding second solder strip 50 on the second battery cell, and so on, with multiple gridless back-contact batteries 100 connected in series to form a battery string. In a specific implementation, the first solder strip 40 and the corresponding second solder strip 50 on adjacent battery cells can be integrally formed.

[0040] refer to Figure 2 The ends of the first fine grid lines 20 on both sides of the first break zone 210 are provided with first thickened sections 220. The ends of the second fine grid lines 30 on both sides of the second break zone are provided with second thickened sections 320. Here, "thickened" means that the width of the first thickened section 220 in the second direction Y is greater than the width of other parts of the first fine grid line 20. Similarly, the width of the second thickened section 320 in the second direction Y is greater than the width of other parts of the second fine grid line 30.

[0041] In this application, when the first fine grid line 20 is welded to the first solder strip 40, the first fine grid line 20 has a first break zone 210 on the first welding area 110, which can save solder paste when welding with the first solder strip 40. The first thickened section 220 on both sides of each first break zone 210 has a large contact area with the first solder strip 40 in the second direction Y, ensuring the conductivity effect.

[0042] The second fine grid line 30 has a second break zone 310 on the second welding area 120, which can save solder paste when welding with the second solder strip 50. The second thickened section 320 on both sides of each second break zone 310 has a large contact area with the second solder strip 50 in the second direction Y, ensuring the conductivity effect.

[0043] In some embodiments, the size of the first thickened segment 220 is 0.1mm-0.2mm in the first direction X and 0.01mm-0.1mm in the second direction Y; and / or, the size of the second thickened segment 320 is 0.1mm-0.2mm in the first direction X and 0.01mm-0.1mm in the second direction Y.

[0044] For example, in the first direction X, the dimensions of the first thickened segment 220 are 0.1mm, 0.12mm, 0.15mm, and 0.2mm. For example, in the first direction X, the dimensions of the second thickened segment 320 are 0.1mm, 0.12mm, 0.15mm, and 0.2mm. For example, in the second direction Y, the dimensions of the first thickened segment 220 are 0.01mm, 0.02mm, 0.04mm, 0.06mm, and 0.1mm. For example, in the second direction Y, the dimensions of the second thickened segment 320 are 0.01mm, 0.02mm, 0.04mm, 0.06mm, and 0.1mm.

[0045] In some embodiments, reference is made to Figure 2 A first adhesive dot 230 is provided within the first disconnection zone 210. The first adhesive dot 230 is positioned between the two first thickened sections 220. When the first solder ribbon 40 is connected to each first fine grid line 20, the first solder ribbon 40 is welded to the two first thickened sections 220 on both sides and bonded to the first adhesive dot 230. The provision of the first adhesive dot 230 increases the reliability of the first solder ribbon 40 when connected to the battery substrate 10. The first adhesive dot 230 can pre-fix the first solder ribbon 40 and avoid incomplete soldering.

[0046] Furthermore, in the first direction X, the size of the first break area 210 is 0.2mm-0.8mm, and the size of the first adhesive dot 230 is 0.05-0.4mm.

[0047] It is easy to understand that, in the first direction X, the first adhesive dot 230 is located within the first break region 210, and the size of the first adhesive dot 230 is smaller than the size of the first break region 210. The size of the first solder strip 40 is generally 0.2-1mm. Correspondingly, the first direction dimension of the first break region 210, i.e., its width D1, is set to 0.2mm-0.8mm. In this way, the first solder strip 40 can contact the two first thickened sections 220 on both sides of the first break region 210, thereby facilitating welding; or at least partially covering the two first thickened sections 220, thereby increasing the welding area.

[0048] For example, the dimensions of the first disconnection zone 210 are 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, and 0.8mm. The dimensions of the first adhesive dot 230 are 0.05mm, 0.1mm, 0.2mm, and 0.4mm.

[0049] In some embodiments, reference is made to Figure 2 A second adhesive dot 330 is provided within the second disconnection zone 310. In the first direction X, the size of the second disconnection zone 310 is 0.2mm-0.8mm, and the size of the second adhesive dot 330 is 0.05mm-0.4mm.

[0050] Similar to the setting of the first adhesive dot 230, the setting of the second adhesive dot 330 increases the reliability of the second solder ribbon 50 when it is connected to the battery substrate 10. The second adhesive dot 330 can pre-fix the second solder ribbon 50 to avoid poor soldering.

[0051] The size of the first solder strip 40 is typically 0.2-1mm. For example, the width d1 of the second disconnection zone 310 is 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, or 0.8mm. The size of the second adhesive dot 330 is 0.05mm, 0.1mm, 0.2mm, or 0.4mm.

[0052] As described above, the first solder strip 40 is soldered to multiple first fine grid lines 20 in the first soldering area 110, while being electrically insulated from the second fine grid lines 30. The second solder strip 50 is soldered to multiple second fine grid lines 30 in the second soldering area 120, while being electrically insulated from the first fine grid lines 20.

[0053] In order to make the second solder strip 50 electrically insulated from the first fine grid line 20, in some embodiments, the gridless back contact battery 100 is further configured as follows.

[0054] refer to Figure 1 , Figure 2The first fine grid line 20 has a first interval 240 in the second welding area 120. In the first direction X, the width D2 of the first interval 240 is greater than the width d1 of the second disconnection area 310. When the second solder strip 50 is connected to the second fine grid line 30, the second solder strip 50 extends in the second direction Y and passes through the first interval 240, thereby avoiding contact with the first fine grid line 20 and thus achieving electrical insulation with the first fine grid line 20.

[0055] It should be understood that, given that the width of the first interval 240 is greater than the width of the second break zone 310, the specific dimensions of the first interval 240 and the second break zone 310 should be determined in conjunction with the dimensions of the second solder strip 50, with the ultimate goal of ensuring that the width of the second solder strip 50 is less than the width of the first interval 240. In this application, in the first direction X, the width of the first interval 240 is greater than the dimension of the second solder strip 50, ensuring that they are insulated from each other. Based on this, the dimension of the second solder strip 50 is 0.2-1 mm, and the width of the first interval 240 is 0.3-1.2 mm. For example, the dimension of the second solder strip 50 is 0.2 mm, and the width of the first interval 240 is 0.3 mm; the dimension of the second solder strip 50 is 0.5 mm, and the width of the first interval 240 is 0.8 mm; the dimension of the second solder strip 50 is 0.8 mm, and the width of the first interval 240 is 1 mm; the dimension of the second solder strip 50 is 1 mm, and the width of the first interval 240 is 1.2 mm. (Reference) Figure 1 , Figure 3 In order to ensure that the second solder strip 50 is electrically insulated from the first fine grid line 20, the first fine grid line 20 may not have a first gap 240 provided in the second welding area 120. In this case, the first fine grid line 20 and the second solder strip 50 are isolated by the first insulating member 60 (see...). Figure 5 ).

[0056] refer to Figure 2 In order to ensure that the first solder strip 40 is electrically insulated from the second fine grid line 30, the gridless back contact battery 100 is further configured as follows: The second fine grid line 30 has a second spacing 340 in the first soldering area 110, and in the first direction X, the width d2 of the second spacing 340 is greater than the width D1 of the first disconnection area 210.

[0057] When the first solder strip 40 is connected to the first fine grid line 20, the first solder strip 40 extends in the second direction Y and passes through the second gap, thereby avoiding contact with the second fine grid line 30 and achieving electrical insulation with the second fine grid line 30. It should be understood that, provided that the width D2 of the second gap is greater than the width d1 of the first break region 210, the specific dimensions of the second gap and the first break region 210 should be determined in conjunction with the dimensions of the first solder strip 40, with the ultimate goal of ensuring that the width of the first solder strip 40 is less than the width of the second gap.

[0058] In this application, in the first direction X, the width of the second gap 340 is greater than the size of the first solder strip 40, ensuring that the two are insulated from each other. Based on this, the size of the first solder strip 40 is 0.2-1 mm, and the width of the second gap 340 is 0.3-1.2 mm. For example, the size of the first solder strip 40 is 0.2 mm, and the width of the second gap 340 is 0.3 mm; the size of the first solder strip 40 is 0.5 mm, and the width of the second gap 340 is 0.8 mm; the size of the first solder strip 40 is 0.8 mm, and the width of the second gap 340 is 1 mm; the size of the first solder strip 40 is 1 mm, and the width of the second gap 340 is 1.2 mm.

[0059] refer to Figure 1 and Figure 2 In order to make the first solder strip 40 electrically insulated from the second fine grid line 30, the second fine grid line 30 may not be provided with a second spacing 340 in the first welding area 110. In this case, the second fine grid line 30 and the first solder strip 40 are isolated by a second insulating member 70.

[0060] A second aspect of this application proposes a photovoltaic module. (Reference) Figure 1 , Figure 4 The photovoltaic module includes a gridless back contact cell 100, a first solder strip 40 located in a first welding area 110 and arranged along the second direction Y, the first solder strip 40 being connected to a first thickened section 220 and electrically insulated from a second fine grid line 30; and a second solder strip 50 located in a second welding area 120 and arranged along the second direction Y, the second solder strip 50 being connected to the second thickened section 320 and electrically insulated from the first fine grid line 20.

[0061] A photovoltaic module typically includes multiple grid-less back-contact cells 100, which are arranged along a second direction Y. (Reference) Figure 4 The connection method for multiple gridless back contact batteries 100 connected in a string via first solder ribbon 40 and second solder ribbon 50 is as follows. Adjacent gridless back contact batteries 100 in the battery string are placed with opposite polarities. Specifically, two adjacent gridless back contact batteries 100 are defined as a first cell (the gridless back contact battery 100 at the top of the figure) and a second cell (the gridless back contact battery 100 at the bottom of the figure). Each first welding area 110 on the first cell corresponds one-to-one with each second welding area 120 on the second cell in the second direction Y. The first solder ribbon 40 is connected to the corresponding second solder ribbon 50 on the second cell, and so on, with multiple gridless back contact batteries connected in series to form a battery string. In specific implementations, the first solder ribbon 40 and the corresponding second solder ribbon 50 can be integrally formed.

[0062] In the photovoltaic module of this application, when the first fine grid line 20 is welded to the first solder strip 40, the first fine grid line 20 has a first break zone 210 on the first welding area 110, which can save solder paste when welding with the first solder strip 40. The first thickened section 220 on both sides of each first break zone 210 has a large contact area with the first solder strip 40 in the second direction Y, ensuring the conduction effect. The second fine grid line 30 has a second break zone 310 on the second welding area 120, which can save solder paste when welding with the second solder strip 50. The second thickened section 320 on both sides of each second break zone 310 has a large contact area with the second solder strip 50 in the second direction Y, ensuring the conduction effect.

[0063] Furthermore, the photovoltaic module also includes a front encapsulation structure, a front encapsulating film, a rear encapsulating film, and a back encapsulation structure. The front encapsulation structure, the front encapsulating film, the gridless back contact cell 100, the rear encapsulating film, and the back encapsulation structure are stacked sequentially. The surface of the gridless back contact cell 100 facing the front encapsulation structure is the light-receiving surface, i.e., the side facing the sun when operating.

[0064] For example, the front and back encapsulation structures can be made of rigid materials such as tempered glass, polyethylene terephthalate (PET), and polycarbonate (PC), or flexible materials such as polyvinyl fluoride (PVF), ethylene-tetrafluoroethylene copolymer (ETFE), and polyvinylidene fluoride (PVDF). These materials have high light transmittance, which can improve the photoelectric conversion efficiency of the photovoltaic module and ensure its power output.

[0065] The front and back adhesive films can be one of the following materials: ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), polyvinyl butyral (PVB), EVA-POE-EVA co-extruded film (EPE), EVA-POE co-extruded film (EP).

[0066] In some embodiments, the widths of the first solder strip 40 and the second solder strip 50 in the first direction X are 0.2mm-1mm. For example, the widths of the first solder strip 40 and the second solder strip 50 are 0.2mm, 0.3mm, 0.5mm, 0.7mm, 0.8mm, and 1mm. Controlling the widths of the first solder strip 40 and the second solder strip 50 within the above range ensures connection with the first fine grid line 20 and the second fine grid line 30 respectively, while also avoiding excessive shading of the fine grid lines and affecting sunlight absorption.

[0067] In some embodiments, reference is made to Figure 2 Along the first direction X and away from the first break zone 210, the first thickened segment 220 extends beyond the edge of the first solder strip 40; and / or, along the first direction X and away from the second break zone 310, the second thickened segment 320 extends beyond the edge of the second solder strip 50.

[0068] The first thickened segment 220 extends beyond the edge of the first solder strip 40 in the first direction X, meaning that the end of each first thickened segment 220 away from the first break zone 210 is not covered by the first solder strip 40. This design reduces the process precision requirements for ensuring that the two ends of the first solder strip 40 can overlap the first thickened portion in the first direction X. The second thickened segment 320 extends beyond the edge of the second solder strip 50, achieving a similar effect.

[0069] In some embodiments, the first fine grid line 20 has a first spacing 240 in the second welding area 120, and the width of the first spacing 240 is greater than the width of the second solder strip 50 in the first direction X; or, the first fine grid line 20 and the second solder strip 50 are electrically insulated from each other by a first insulator 60.

[0070] As described above, each of the first fine grid lines 20 can be broken within the second welding zone 120 to form a first gap 240. The first gap 240 can avoid the second solder strip 50, thus electrically isolating the first fine grid lines 20 from the second solder strip 50. Alternatively, the first fine grid lines 20 may not have the first gap 240; the first fine grid lines 20 and the second solder strip 50 are isolated by a first insulating member 600. Figure 5 As shown.

[0071] In some embodiments, the second fine grid line 30 has a second spacing 340 in the first soldering area 110, and the width of the second spacing 340 is greater than the width of the first solder strip 40 in the first direction X; and / or, the second fine grid line 30 is electrically insulated from the first solder strip 40 by a second insulator 70. Figure 6 As shown.

[0072] As described above, each of the second fine grid lines 30 can be broken within the first welding zone 110 to form a second gap 340. The second gap 340 can avoid the first solder strip 40, thereby electrically isolating the second fine grid lines 30 from the first solder strip 40. Alternatively, the second fine grid lines 30 may not have the second gap 340, and the second fine grid lines 30 and the first solder strip 40 may be isolated by a second insulating member 70.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0074] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A gridless back contact battery, characterized in that, include: A battery substrate, the battery substrate having a first welding area and a second welding area alternately arranged along a first direction; The battery substrate has a first fine grid line and a plurality of second fine grid lines. The first fine grid line and the second fine grid line have different polarities. The plurality of first fine grid lines and the plurality of second fine grid lines are arranged alternately along a second direction. The first fine grid line has a first break area on the first welding area. The ends of the first fine grid line on both sides of the first break area are provided with a first thickening section. The second fine grid line has a second break area on the second welding area. The ends of the first fine grid line on both sides of the second break area are provided with a second thickening section.

2. The gridless back contact battery according to claim 1, characterized in that, In the first direction, the size of the first thickened segment is 0.1mm-0.2mm; in the second direction, the size of the first thickened segment is 0.01mm-0.1mm; and / or, In the first direction, the size of the second thickened segment is 0.1mm-0.2mm, and in the second direction, the size of the second thickened segment is 0.01mm-0.1mm.

3. The gridless back contact battery according to claim 1, characterized in that, A first adhesive dot is provided within the first disconnection zone.

4. The gridless back contact battery according to claim 3, characterized in that, In the first direction, the size of the first break zone is 0.2mm-0.8mm, and the size of the first adhesive dot is 0.05-0.4mm.

5. The gridless back contact battery according to claim 1, characterized in that, A second adhesive dot is provided within the second disconnection zone.

6. The gridless back contact battery according to claim 1, characterized in that, In the first direction, the size of the second break zone is 0.2mm-0.8mm, and the size of the second adhesive dot is 0.05mm-0.4mm.

7. The gridless back contact battery according to claim 1, characterized in that, The first fine grid line has a first spacing in the second welding area, and in the first direction, the width of the first spacing is greater than the width of the second break area.

8. The gridless back contact battery according to claim 1, characterized in that, The second fine grid line has a second spacing in the first welding area, and in the first direction, the width of the second spacing is greater than the width of the first break area.

9. A photovoltaic module, characterized in that, include: The gridless back contact battery as described in any one of claims 1-8; The first solder strip is located in the first welding area and is arranged along the second direction. The first solder strip is connected to the first thickened section and is electrically insulated from the second fine grid line. The second welding strip is located in the second welding area and is arranged along the second direction. The second welding strip connects to the second thickened section and is electrically insulated from the first fine grid line.

10. The photovoltaic module according to claim 9, characterized in that, In the first direction, the width of the first and second solder strips is 0.2mm-1mm.

11. The photovoltaic module according to claim 9, characterized in that, Along a first direction and away from the first break zone, the first thickened segment extends beyond the edge of the first solder strip; and / or, along a first direction and away from the second break zone, the second thickened segment extends beyond the edge of the second solder strip.

12. The photovoltaic module according to claim 9, characterized in that, The first fine grid lines have a first spacing in the second welding area, and in the first direction, the width of the first spacing is greater than the width of the second solder strip; or, The first fine grid line and the second solder strip are electrically insulated from each other by a first insulating element.

13. The photovoltaic module according to claim 9, characterized in that, The second fine grid lines have a second spacing in the first welding area, and in the first direction, the width of the second spacing is greater than the width of the first solder strip; and / or, The second fine grid line is electrically insulated from the first solder strip by a second insulating element.

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