Back contact cell, photovoltaic module and photovoltaic system

Abstract

The invention provides a back contact battery, a photovoltaic module and a photovoltaic system. The back contact battery comprises a battery substrate, a plurality of main grids, a plurality of slurry nodes and a plurality of first insulating parts. The battery substrate comprises a tandem connection area and a non-tandem connection area; a plurality of slurry nodes are formed in the cascading area; the first insulating parts are arranged in the serial connection area, the first insulating parts and the main grids are correspondingly arranged, the first insulating parts are arranged in the first direction, the first insulating parts cover the slurry nodes, in the first direction, a first gap is formed between every two adjacent first insulating parts, and part of the main grids are exposed out of the first gaps. Therefore, the first insulating parts corresponding to the main grids are arranged in the serial connection area and cover the slurry nodes, the first gaps are formed between the two adjacent first insulating parts, and the main grids are partially exposed from the first gaps, so that the first insulating parts can be arranged in blocks, the thickness of the first insulating parts is increased, the slurry nodes in the serial connection area are prevented from being conducted with the welding strip, and the reliability of the welding strip is improved. And the reject ratio of the photovoltaic module is reduced.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a back contact cell, a photovoltaic module and a photovoltaic system. Background Art

[0002] When printing the grid lines of back-contact cells, paste nodes will be formed near the main grid. In photovoltaic modules, the paste nodes will be connected to the solder strips, causing power loss in the photovoltaic modules and increasing the defective rate of photovoltaic modules.

[0003] Based on this, how to reduce the defective rate of photovoltaic modules has become an urgent problem to be solved. Summary of the invention

[0004] The present invention provides a back contact cell, a photovoltaic module and a photovoltaic system to solve the technical problem of how to reduce the defective rate of the photovoltaic module.

[0005] The embodiment of the present invention is implemented as follows: the present invention provides a back-contact cell, a photovoltaic module, and a photovoltaic system. A back-contact cell includes a cell substrate, the cell substrate includes a series connection area and a non-series connection area, the series connection area is the area where the back-contact cell is electrically connected to the welding strip; a plurality of main grids are arranged in the series connection area, the main grids extend along a first direction and are arranged at intervals along a second direction, and the first direction intersects with the second direction; a plurality of slurry nodes, a plurality of the slurry nodes are formed in the series connection area; a plurality of first insulating members are arranged in the series connection area, the first insulating members are arranged corresponding to the main grids, the first insulating members are arranged along the first direction, the first insulating members cover the slurry nodes, and a first gap is formed between two adjacent first insulating members in the first direction, and a portion of the main grid is exposed from the first gap.

[0006] Furthermore, the thickness of the first insulating member is 5 μm to 50 μm.

[0007] Furthermore, a size of the first gap is 0.5 mm to 1 mm.

[0008] Further, in the second direction, at least one of the first insulating members is continuously arranged to completely cover the main grid.

[0009] Furthermore, the first insulating member includes a plurality of insulating blocks, and in the second direction, adjacent insulating blocks form a second gap, and a portion of the main grid is exposed from the second gap.

[0010] Furthermore, a size of the second gap is less than or equal to 5 mm.

[0011] Furthermore, the main grid is provided with a plurality of pads, and in the second direction, the size of the pads is greater than or equal to the size of the second gap.

[0012] Furthermore, the first insulating member partially covers the pad.

[0013] Further, in the first direction, a dimension of the first insulating member is 0.2 mm to 50 mm.

[0014] Further, in the second direction, a size of the first insulating member is 0.2 mm to 50 mm.

[0015] Furthermore, it also includes a plurality of fine grids, which are arranged on the battery substrate, extend along the second direction, and are arranged at intervals along the first direction, are connected to the main grid of the same polarity, and are spaced from the main grid of different polarities.

[0016] Furthermore, it also includes a plurality of second insulating members, wherein the second insulating members are arranged corresponding to the fine grids, and the second insulating members partially cover the fine grids.

[0017] An embodiment of the present invention further provides a photovoltaic module, which includes the back contact cell as described above.

[0018] An embodiment of the present invention further provides a photovoltaic system, which includes the photovoltaic assembly as described above.

[0019] In the back-contact battery in the present application, since the first insulating member corresponding to the main grid is arranged in the series connection area and covers the paste nodes, there is a first gap between two adjacent first insulating members, and the main grid is partially exposed from the first gap, the first insulating member can be arranged in blocks, thereby reducing the fluidity of the first insulating member and increasing the thickness of the first insulating member, so that the insulation effect of the series connection area is better, avoiding the paste nodes in the series connection area from being connected to the welding strips, and reducing the defective rate of photovoltaic modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a schematic diagram of a module of a photovoltaic system provided by an embodiment of the present invention;

[0022] Figure 2is a schematic diagram of a module of a photovoltaic assembly provided by an embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of the electrode structure of a back contact battery provided by an embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of the insulating structure of a photovoltaic module provided by an embodiment of the present invention;

[0025] Figure 5 is a schematic diagram of a partial structure of a back contact battery provided by an embodiment of the present invention;

[0026] Figure 6 It is a schematic diagram of the partial structure of a back contact battery provided in yet another embodiment of the present invention.

[0027] Explanation of main component symbols: 1000, photovoltaic system; 1001, photovoltaic module; 100, back contact cell; 10, cell substrate; 101, series connection area; 102, non-series connection area; 20, main grid; 30, fine grid; 40, slurry node; 50, first insulating member; 60, second insulating member; D1, first gap; D2, second gap; 501, insulating block; 201, welding pad. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "top", "bottom", "lateral", "longitudinal" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 invention.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use scenarios of other materials.

[0033] See also Figure 1 and Figure 2 The photovoltaic system 1000 in the embodiment of the present invention may include the photovoltaic module 1001 in the embodiment of the present invention. The photovoltaic module 1001 in the embodiment of the present invention may include a plurality of back-contact cells 100. The plurality of back-contact cells 100 may be connected in series in sequence through welding strips to form a cell string. The cell strings in the photovoltaic module 1001 may be connected in series, in parallel, or in series-parallel combination to realize current bus output. For example, the connection between the cell strings may be realized through a bus bar.

[0034] In this embodiment, the photovoltaic system 1000 can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system 1000 are not limited to this, that is, the photovoltaic system 1000 can be applied in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system 1000 may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple battery components. For example, multiple battery components may form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter to convert it into the alternating current required by the mains power grid and then connected to the mains network to realize solar power supply.

[0035] The drawings provided in this application are schematic diagrams, and some elements are not shown in the drawings. The purpose is to clearly describe the technical solution and highlight the key points of the invention. It is not intended to limit the technical solution to not include these unshown elements. In other words, the drawings are only examples and do not represent a limitation on the specific form of the back contact battery 100.

[0036] like Figures 3 to 6 As shown, the back contact battery 100 in the embodiment of the present invention includes: a battery substrate 10, a plurality of main grids 20, a plurality of paste nodes 40, and a plurality of first insulating members 50. The battery substrate 10 includes a series connection area 101 and a non-series connection area 102, wherein the series connection area 101 is an area where the back contact battery 100 is electrically connected to the welding strip; the main grid 20 is arranged in the series connection area 101, the main grid 20 extends along a first direction, and is arranged at intervals along a second direction, and the first direction intersects with the second direction; a plurality of paste nodes 40 are formed in the series connection area 101; the first insulating member 50 is arranged in the series connection area 101, the first insulating member 50 is arranged corresponding to the main grid 20, the first insulating member 50 is arranged along the first direction, the first insulating member 50 covers the paste nodes 40, and in the first direction, a first gap D1 is formed between two adjacent first insulating members 50, and a portion of the main grid 20 is exposed from the first gap D1. Specifically, the first insulating member 50 can be an insulating glue.

[0037] In this way, the back-contact battery 100 in the embodiment of the present invention, since the first insulating member 50 corresponding to the main grid 20 is arranged in the series connection area 101 and covers the paste node 40, there is a first gap D1 between two adjacent first insulating members 50, and the main grid 20 is partially exposed from the first gap D1, so the first insulating member 50 can be arranged in blocks, thereby reducing the fluidity of the first insulating member 50 and increasing the thickness of the first insulating member 50, so that the insulation effect of the series connection area 101 is better, thereby avoiding the paste node 40 in the series connection area 101 from being connected to the welding strip, thereby reducing the defective rate of the photovoltaic module 1001.

[0038] At the same time, since there is a first gap D1 between two adjacent first insulating members 50, the main grid 20 is partially exposed from the first gap D1, so that when the welding ribbon is connected to the back contact battery 100, the effective connection area between the welding ribbon and the main grid 20 can be increased, thereby improving the welding ribbon's ability to collect current on the main grid 20, thereby improving the power generation efficiency of the photovoltaic module 1001.

[0039] Specifically, the back contact cell 100 may be a whole cell, or may be a half cell, a third cell, or a cell with other proportions divided from a whole cell.

[0040] Specifically, the cell substrate 10 includes a front side and a back side, the front side faces the sun and mainly receives direct sunlight, and the back side faces the mounting surface of the cell assembly and mainly receives sunlight reflected by the mounting surface, such as the ground, the roof, etc. In other words, the back side is the side where the grid lines of the back contact cell 100 are provided.

[0041] Specifically, the back side of the battery substrate 10 includes a series connection area 101 and a non-series connection area 102. The series connection area 101 of the battery substrate 10 is specifically the area of ​​the battery substrate 10 covered by the welding ribbon when the welding ribbon is connected. The non-series connection area 102 is the area outside the series connection area 101 on the back side of the battery substrate 10.

[0042] Furthermore, the series connection areas 101 and the non-series connection areas 102 are alternately distributed on the back side of the battery substrate 10. In other words, a non-series connection area 102 is formed between two adjacent series connection areas 101, and a series connection area 101 is formed between two adjacent non-series connection areas 102.

[0043] Furthermore, the series connection area 101 has two polarities, namely, a first series connection area and a second series connection area, and the first series connection area and the second series connection area are alternately distributed. In other words, a second series connection area is formed between two adjacent first series connection areas, and a first series connection area is formed between two adjacent second series connection areas. Furthermore, one of the first series connection area and the second series connection area is a positive series connection area, and the other of the first series connection area and the second series connection area is a negative series connection area.

[0044] Further, the series connection area 101 includes a welding area and / or a conductive adhesive area. Further, the welding area may be provided with a conductive material. The conductive material is, for example, solder such as solder paste. Further, the conductive adhesive area may be provided with a conductive adhesive. In other words, the main grid 20 of the series connection area 101 may be connected to the welding strip through solder; may also be electrically bonded to the welding strip through conductive adhesive; may also be connected to the welding strip through bonding of solder and conductive adhesive.

[0045] Specifically, the busbar 20 is disposed in the series connection area 101 . In other words, in a direction perpendicular to the back side of the battery substrate 10 , the projection of the busbar 20 on the back side of the battery substrate 10 is located in the series connection area 101 .

[0046] Further, the main grid 20 has two polarities, namely, a first main grid 20 and a second main grid 20, and the first main grid 20 and the second main grid 20 are staggered. In other words, a second main grid 20 is formed between two adjacent first main grids 20, and a first main grid 20 is formed between two adjacent second main grids 20. Furthermore, one of the first main grid 20 and the second main grid 20 is a positive main grid 20, and the other of the first main grid 20 and the second main grid 20 is a negative main grid 20.

[0047] Furthermore, the arrangement direction of the series area 101 and the non-series area 102 is perpendicular to the arrangement direction of the main gate 20. It can be understood that in other embodiments, the arrangement direction of the series area 101 and the non-series area 102 is perpendicular to the arrangement direction of the main gate 20 or at an angle, which is not limited here.

[0048] Specifically, a paste node 40 is formed in the series connection area 101. The paste node 40 is specifically a node formed in the process of printing the gate line. In addition to being formed in the series connection area 101, in other embodiments, the paste node 40 can also be formed in the non-series connection area 102, which is not limited here.

[0049] Further, the paste node 40 may be formed of a non-burn-through paste like the main grid 20 ; or, the paste node 40 may be formed of a burn-through paste like the fine grid 30 , which is not limited here.

[0050] See also Figures 3 to 6 A first insulating member 50 is further disposed in the series connection region 101 . The first insulating member 50 is arranged along a first direction. In other words, the first insulating member 50 is arranged along an extension direction of the main grid 20 .

[0051] Furthermore, the first insulating member 50 is specifically disposed corresponding to the main grid 20. In other words, the position of the first insulating member 50 specifically matches the position of the main grid 20.

[0052] Furthermore, there are two polarities of the slurry nodes 40, namely, positive electrode slurry nodes 40 and negative electrode slurry nodes 40. The polarity of the slurry nodes 40 may be the same as that of the main grid 20, or may be opposite to that of the main grid 20.

[0053] Specifically, when the polarities of the main grid 20 and the paste node 40 located in the same series connection area 101 are opposite. For example, the main grid 20 is a positive electrode and the paste node 40 is a negative electrode; or, the main grid 20 is a negative electrode and the paste node 40 is a positive electrode. When the welding strip is arranged in the series connection area 101, in order to avoid the paste node 40 and the welding strip from being connected, damaging the back contact cell 100, and thus causing the photovoltaic module 1001 to be defective, the paste node 40 in the series connection area 101 is prevented from being connected to the welding strip, thereby reducing the defective rate of the photovoltaic module 1001. In an embodiment of the present invention, the first insulating member 50 covers the paste node 40, and in the first direction, a first gap D1 is formed between two adjacent first insulating members 50, and part of the main grid 20 is exposed from the first gap D1.

[0054] It is understandable that the insulating member in the prior art is usually a long strip of insulating glue extending along the extension direction of the main grid 20. The long strip of insulating glue has a large fluidity, and after being set, it will flow to the surroundings, causing the thickness of the insulating glue to become thinner. Therefore, in the prior art, the insulation between the paste node 40 and the welding strip is insufficient, and the paste node 40 will be conductive with the welding strip.

[0055] However, in the embodiment of the present invention, the first insulating member 50 is arranged in blocks in the first direction while covering the paste node 40. This can reduce the fluidity of the first insulating member 50, increase the thickness of the first insulating member 50, and make the insulation effect of the series connection area 101 better. In this way, the insulation between the paste node 40 and the welding strip is strengthened, and the conduction between the paste node 40 and the welding strip is avoided, thereby reducing the defective rate of the photovoltaic module 1001.

[0056] It can be understood that “the first insulating member 50 covers the slurry node 40 ” means that the first insulating member 50 completely covers the slurry node 40 . In other words, the first insulating member 50 completely wraps the slurry node 40 , and there is no part of the slurry node 40 exposed from the first insulating member 50 .

[0057] It can be understood that “in the first direction, a first gap D1 is formed between two adjacent first insulating members 50 ” means that a plurality of first insulating members 50 are arranged at intervals along the first direction, there is a gap between two adjacent first insulating members 50 , and part of the main grid 20 is exposed from the gap between two adjacent first insulating members 50 .

[0058] See also Figures 3 to 6 In a possible implementation, the back contact battery 100 further includes a plurality of fine grids 30, which are disposed on the battery substrate 10, extend along the second direction, and are arranged at intervals along the first direction, the fine grids 30 are connected to the main grids 20 of the same polarity, and the fine grids 30 are spaced apart from the main grids 20 of different polarities.

[0059] Specifically, the main grid 20 has two polarities, namely, a first main grid 20 and a second main grid 20, and the first main grid 20 and the second main grid 20 are staggered. In other words, a second main grid 20 is formed between two adjacent first main grids 20, and a first main grid 20 is formed between two adjacent second main grids 20. Furthermore, one of the first main grid 20 and the second main grid 20 is a positive main grid 20, and the other of the first main grid 20 and the second main grid 20 is a negative main grid 20.

[0060] Further, the fine grid 30 is connected to the main grid 20 of the same polarity, and the fine grid 30 is spaced from the main grid 20 of different polarity. In other words, the fine grid 30 is connected to the main grid 20 of the same polarity, and the fine grid 30 is spaced from the main grid 20 of different polarity. For example, the positive electrode fine grid 30 is connected to the positive electrode main grid 20, the positive electrode fine grid 30 is spaced from the negative electrode main grid 20, the negative electrode fine grid 30 is connected to the negative electrode main grid 20, and the negative electrode fine grid 30 is spaced from the positive electrode main grid 20.

[0061] In a possible implementation, in the first direction, the size of the first insulating member 50 is 0.2 mm to 50 mm. For example, it is 0.2 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm. In this way, the insulation of the first insulating member 50 can be ensured while the first insulating member 50 is divided into blocks, thereby increasing the thickness of the first insulating member 50. It is understood that in the first direction, the size of the first insulating member 50 can be a constant value within the range of 0.2 mm to 50 mm, or it can fluctuate within the range of 0.2 mm to 50 mm.

[0062] In a possible implementation, in the second direction, the size of the first insulating member 50 is 0.2 mm to 50 mm. For example, it is 0.2 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm. In this way, the insulation of the first insulating member 50 can be ensured while the first insulating member 50 is divided into blocks, thereby increasing the thickness of the first insulating member 50. It is understood that in the second direction, the size of the first insulating member 50 can be a constant value within the range of 0.2 mm to 50 mm, or it can fluctuate within the range of 0.2 mm to 50 mm.

[0063] See also Figures 3 to 6 In a possible implementation, the back contact battery 100 includes a plurality of second insulating members 60, which are arranged corresponding to the fine grids 30, and the second insulating members 60 partially cover the fine grids 30. In this way, the insulation between the main grid 20 and the opposite fine grids 30 can be achieved, and a short circuit can be prevented in the back contact battery 100.

[0064] Specifically, "the second insulating member 60 partially covers the fine gate 30" means that the second insulating member 60 does not completely cover the fine gate 30, and part of the fine gate 30 is exposed from the second insulating member 60 to connect the fine gate 30 with the main gate 20 of the same polarity and to insulate the fine gate 30 from the main gate 20 of a different polarity.

[0065] In a possible implementation, the size t of the first gap D1 is 0.5 mm to 1 mm, for example 0.5 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm. In this way, the first insulating member 50 can be divided into blocks, the thickness of the first insulating member 50 can be increased, and the main grid 20 can be prevented from being turned on with the fine grids 30 of different polarities.

[0066] It is understandable that, in the first direction, the spacing between adjacent first insulating members 50 should be greater than the spacing between two adjacent fine gates 30 of the same polarity, so as to avoid conduction between the main gate 20 and the fine gate 30 of the opposite polarity.

[0067] In a possible implementation, the thickness of the first insulating member 50 is 5 μm to 50 μm, for example, 5 μm, 6 μm, 10 μm, 15 μm, 20 μm, 22 μm, 25 μm, 30 μm, 35 μm, 40 μm, 50 μm. In this way, the insulation of the polar paste and the solder strip can be increased while avoiding the waste of materials and increased costs caused by the excessive thickness of the first insulating member 50.

[0068] Preferably, the thickness of the first insulating member 50 is 20 μm to 50 μm. In this way, the overall effect of insulation and saving is the best.

[0069] It can be understood that the thickness of the first insulating member 50 can be a constant value within a range of 5 μm to 50 μm, or can fluctuate within a range of 5 μm to 50 μm.

[0070] See also Figures 3 to 6 In a possible implementation, in the second direction, at least one first insulating member 50 is continuously disposed to completely cover the main grid 20. In this way, in the second direction, by continuously disposing the first insulating member 50 to completely cover the main grid 20, complete insulation protection of the main grid 20 on the second side can be ensured, accidental electrical contact of the main grid 20 can be avoided, and the main grid 20 will not be short-circuited or have current leakage, thereby effectively improving the safety and reliability of the back contact battery 100.

[0071] Specifically, “the first insulating member 50 is continuously disposed” means that in the second direction, the first insulating member 50 is continuously disposed when covering the main grid 20. In the second direction, the first insulating member 50 completely covers the main grid 20, and the main grid 20 is not exposed from the insulating member.

[0072] See also Figures 3 to 6In a possible implementation, the first insulating member 50 includes a plurality of insulating blocks 501. In the second direction, adjacent insulating blocks 501 form a second gap D2, and a portion of the main grid 20 is exposed from the second gap D2. In this way, the first insulating member 50 can be further divided into blocks, which can effectively increase the thickness of each insulating block 501, increase the insulation between the paste node 40 and the welding strip, and can also save the total amount of the first insulating member 50, thereby saving costs.

[0073] Specifically, the first insulating member 50 may also be arranged in blocks. The first insulating member 50 includes a plurality of insulating blocks 501, and adjacent insulating blocks 501 are arranged at intervals. Part of the main grid 20 is exposed from the gap between adjacent insulating blocks 501. In this way, the effective connection area between the welding strip and the main grid 20 can be further increased, thereby further improving the welding strip's ability to collect current on the main grid 20, thereby improving the power generation efficiency of the photovoltaic module 1001.

[0074] It is understandable that, for each first insulating member 50, the first insulating member 50 may be completely continuously arranged, or completely divided into blocks, or both divided first insulating members 50 and continuous first insulating members 50 may be arranged, and this is not limited here.

[0075] In a possible implementation, the size p of the second gap D2 is less than or equal to 5 mm, for example, 0.5 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm. In this way, the insulating block 501 can be divided into blocks, and the thickness of the insulating block 501 can be increased while preventing the main grid 20 from being turned on with the fine grids 30 of different polarities.

[0076] It is understandable that the size p of the second gap D2 cannot be too large. If the second gap D2 is too large, the main grid 20 may be connected to the fine grid 30 of different polarities, thereby causing a short circuit in the back contact battery 100.

[0077] In a possible implementation, the main grid 20 is provided with a plurality of pads 201, and in the second direction, the size of the pads 201 is greater than or equal to the size p of the second gap D2, so as to avoid the pads 201 from being conductively connected to the fine grids 30 of different polarities.

[0078] Specifically, a plurality of pads 201 are provided on the main grid 20, and the pads 201 are used to realize the connection between the main grid 20 and the welding strip. The size of the pads 201 cannot be too small. If the size of the pads 201 is too small, the welding strip may not be able to fully contact the pads 201, or the contact may be uneven, which may easily lead to cold soldering.

[0079] Meanwhile, the size p of the second gap D2 cannot be too large. If the size p of the second gap D2 is too large, the insulation between the pad 201 and the heterogeneous fine gate 30 may be insufficient, resulting in a short circuit.

[0080] Preferably, the size p of the second gap D2 is 3 mm to 5 mm. In this way, the thickness of the insulating block 501 can be increased while preventing the pad 201 from being electrically connected to the heterogeneous fine gate 30 .

[0081] In a possible implementation manner, the first insulating member 50 partially covers the pad 201. In this way, it is possible to prevent the pad 201 from being further connected to the fine gates 30 of different polarities.

[0082] In some optional embodiments, the first insulating member 50 is a transparent insulating member, so that the first insulating member 50 can reduce the shielding of sunlight, so that more sunlight can be absorbed by the back contact, which is beneficial to improve the photoelectric conversion efficiency.

[0083] Please note that transparent means that the transmittance of the first insulating member 50 to visible light is greater than or equal to 70% at a thickness of micrometers. It is understood that in other embodiments, the first insulating member 50 may be a non-transparent insulating member. This is not limited here.

[0084] In some optional embodiments, the second insulating member 60 is a transparent insulating member, so as to further reduce the shielding of sunlight by the insulating member, which is conducive to further improving the photoelectric conversion efficiency.

[0085] Please note that transparent means that the transmittance of the second insulating member 60 to visible light is greater than or equal to 70% at a thickness of micrometers. It is understood that in other embodiments, the second insulating member 60 may be a non-transparent insulating member. This is not limited here.

[0086] In some optional embodiments, the first insulating member 50 is a transparent fluorescent insulating member. In this way, the first insulating member 50 will emit light under the illumination of a light source of a corresponding wavelength, thereby facilitating detection of the position of the first insulating member 50 and improving the accuracy of setting the first insulating member 50 on the back contact battery 100.

[0087] In some optional embodiments, the second insulating member 60 is a transparent fluorescent insulating member. In this way, the second insulating member 60 will emit light under the illumination of a light source of a corresponding wavelength, thereby facilitating detection of the position of the second insulating member 60 and improving the accuracy of setting the second insulating member 60 on the back contact battery 100.

[0088] Please note that the explanation and description of the second insulating member 60 as a transparent fluorescent insulating member is similar to that of the first insulating member 50 , and reference may be made to the relevant contents of the first insulating member 50 , which will not be repeated here.

[0089] In this embodiment, the transparent fluorescent insulating member is made of transparent insulating glue.

[0090] Specifically, the transparent insulating glue includes: a resin component, with a mass percentage of 60%-80%; an inorganic filler, with a mass percentage of 5%-15%; a curing agent, with a mass percentage of 5%-15%; a solvent, with a mass percentage of less than 10%; and a fluorescent agent, with a mass percentage of greater than or equal to 0.1% and less than 1%. In this way, since the insulating glue is a transparent insulating member, it can reduce the shielding of sunlight, so that more sunlight is absorbed by the back contact electricity, which is beneficial to improving the photoelectric conversion efficiency. At the same time, since the transparent insulating glue includes a fluorescent agent with a mass percentage greater than or equal to 0.1% and less than 1%, it will emit light under the irradiation of a light source of a corresponding wavelength, thereby facilitating the detection of the position of the transparent insulating glue, which is beneficial to improving the accuracy of setting the transparent insulating glue for the back contact battery 100.

[0091] Specifically, the transparent insulating adhesive can be applied to the back contact battery 100 by screen printing, spray valve, coating, etc.

[0092] Specifically, the coverage ratio of the transparent insulating glue on the back contact battery 100 is greater than 10%.

[0093] Specifically, the mass percentage of the resin component is, for example, 60%, 62%, 65%, 70%, 73%, 75%, 78%, 80%. In this way, the mass percentage of the resin component is within a suitable range, which can reduce the brittleness of the insulating member formed by curing the insulating glue and improve the bending and impact resistance of the insulating member.

[0094] Specifically, the mass percentage of the inorganic filler is, for example, 5%, 6%, 8%, 10%, 11%, 14%, and 15%. In this way, the use amount of the resin component can be reduced by using the relatively cheap inorganic filler, thereby reducing the cost of the transparent insulating adhesive. Moreover, the inorganic filler can enhance the mechanical properties of the transparent insulating adhesive, making the insulating adhesive easier to set and adhere.

[0095] Specifically, the mass percentage of the curing agent is, for example, 5%, 8%, 10%, 11%, 14%, or 15%, so that the transparent insulating adhesive can be cured within a predetermined process time.

[0096] Specifically, the mass percentage of the solvent is, for example, 9.99%, 9%, 7%, 5%, 4%, 2%, or 0.1%. In this way, other materials in the transparent insulating adhesive can be dissolved to adjust the viscosity of the transparent insulating adhesive.

[0097] Specifically, the mass percentage of the fluorescent agent is, for example, 0.99%, 0.95%, 0.8%, 0.6%, 0.5%, 0.3%, and 0.1%. The fluorescent agent will whiten, and a mass percentage greater than or equal to 1% will affect the light transmittance of the transparent insulating glue itself. When the mass percentage of the fluorescent agent is greater than or equal to 0.1% and less than 1%, the light transmittance of the insulating glue itself can be better, which is beneficial to ensure the photoelectric conversion efficiency. Moreover, when the mass percentage of the fluorescent agent is greater than or equal to 0.1% and less than 1%, it will not lead to excessively high costs, which is beneficial to ensure that the insulating glue can be detected while ensuring the normal operation of the solar cell and reducing the cost of the back contact cell 100.

[0098] It is understandable that in such an embodiment, the photovoltaic module 1001 may also include a frame, a back plate, photovoltaic glass and an adhesive film. The adhesive film may be filled between the front and back of the cell and between the photovoltaic glass and adjacent cells, etc. As a filler, it may be a transparent colloid with good light transmission and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film, which may be selected according to actual conditions and is not limited here.

[0099] Photovoltaic glass can cover the adhesive film on the front of the cell. Photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the cell without affecting the efficiency of the cell as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the cell together. The presence of the adhesive film can seal and insulate the cell and make it waterproof and moisture-proof.

[0100] The back plate can be attached to the adhesive film on the back of the cell. The back plate can protect and support the cell and has reliable insulation, water resistance and aging resistance. There are multiple options for the back plate, which can usually be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to the specific situation and is not limited here. The whole composed of the back plate, cell, adhesive film and photovoltaic glass can be set on the frame. The frame serves as the main external support structure of the entire photovoltaic module 1001 and can stably support and install the photovoltaic module 1001. For example, the photovoltaic module 1001 can be installed at the required location through the frame.

[0101] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0102] In addition, the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A back contact battery, characterized in that: include: A battery substrate, the battery substrate comprising a series connection area and a non-series connection area, the series connection area being an area where the back contact battery is electrically connected to the welding strip; A plurality of main grids are arranged in the series connection area, the main grids extend along a first direction and are arranged at intervals along a second direction, and the first direction intersects with the second direction; A plurality of slurry nodes, wherein the plurality of slurry nodes are formed in the series connection area; A plurality of first insulating members are arranged in the series connection area, the first insulating members are arranged corresponding to the main grid, the first insulating members are arranged along the first direction, the first insulating members cover the slurry nodes, and a first gap is formed between two adjacent first insulating members in the first direction, and a portion of the main grid is exposed from the first gap.

2. The back contact cell according to claim 1, characterized in that: The first insulating member has a thickness of 5 μm to 50 μm.

3. The back contact battery according to claim 1, characterized in that: The size of the first gap is 0.5 mm to 1 mm.

4. The back contact cell according to claim 1, characterized in that: In the second direction, at least one of the first insulating members is continuously arranged to completely cover the main grid.

5. The back contact cell according to claim 1, characterized in that: The first insulating member includes a plurality of insulating blocks. In the second direction, adjacent insulating blocks form a second gap, and a portion of the main grid is exposed from the second gap.

6. The back contact cell according to claim 5, characterized in that: The size of the second gap is less than or equal to 5 mm.

7. The back contact battery according to claim 5, characterized in that: The main grid is provided with a plurality of pads, and in the second direction, the size of the pads is greater than or equal to the size of the second gap.

8. The back contact battery according to claim 7, characterized in that: The first insulating member partially covers the pad.

9. The back contact cell according to claim 1, characterized in that: In the first direction, a size of the first insulating member is 0.2 mm to 50 mm.

10. The back contact cell according to claim 1, characterized in that: In the second direction, a size of the first insulating member is 0.2 mm to 50 mm.

11. The back contact cell according to claim 1, characterized in that: It also includes a plurality of fine grids, which are arranged on the battery substrate, extend along the second direction, and are arranged at intervals along the first direction. The fine grids are connected to the main grids of the same polarity, and are spaced apart from the main grids of different polarities.

12. The back contact cell according to claim 11, characterized in that: It also includes a plurality of second insulating members, wherein the second insulating members are arranged corresponding to the fine grids, and the second insulating members partially cover the fine grids.

13. A photovoltaic module, characterized in that: The photovoltaic module comprises the back contact cell according to any one of claims 1 to 12.

14. A photovoltaic system, characterized in that: Comprising the photovoltaic module as claimed in claim 13.

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