Back contact cell, photovoltaic module and photovoltaic system

Abstract

The utility model 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 utility model relates to photovoltaic technology field especially relates to a back contact cell, photovoltaic module and photovoltaic system. BACKGROUND

[0002] The back contact cell will form slurry nodes near the main grid in the process of printing the grid line. In the photovoltaic module, the slurry nodes will be conductive with the solder strip, causing the power loss of the photovoltaic module and increasing the defective rate of the photovoltaic module.

[0003] Therefore, how to reduce the defective rate of the photovoltaic module has become a problem to be solved. SUMMARY

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

[0005] The utility model embodiment is realized in this way, and the utility model provides a back contact cell, photovoltaic module and photovoltaic system. A back contact cell includes cell substrate, the cell substrate includes series connection area and non series connection area, the series connection area is the area of back contact cell and solder strip electric connection;Multiple main grids are arranged in the series connection area, the main grid extends along the first direction and is arranged along the second direction interval, the first direction and the second direction cross;A plurality of slurry nodes, a plurality of slurry nodes are formed in the series connection area;Multiple first insulating pieces are arranged in the series connection area, the first insulating piece is arranged in correspondence with the main grid, the first insulating piece is arranged along the first direction, the first insulating piece covers the slurry node, in the first direction, the first gap is formed between the adjacent two first insulating pieces, and part of the main grid is exposed from the first gap.

[0006] Further, the thickness of the first insulating piece is 5 to 50 microns.

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

[0008] Further, in the second direction, at least one first insulating piece is continuously arranged and completely covers the main grid.

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

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

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

[0012] Further, the first insulating part partially covers the pads.

[0013] Further, the size of the first insulating part is 0.2mm to 50mm in the first direction.

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

[0015] Further, a plurality of fine grids are further included, the fine grids are arranged on the battery substrate, the fine grids extend along the second direction and are arranged at intervals along the first direction, the fine grids are connected with the main grids of the same polarity, and the fine grids are spaced apart from the main grids of different polarities.

[0016] Further, a plurality of second insulating parts are further included, the second insulating parts are arranged correspondingly to the fine grids, and the second insulating parts partially cover the fine grids.

[0017] The utility model embodiment further provides a photovoltaic module, the photovoltaic module includes the back contact cell as described above.

[0018] The utility model embodiment further provides a photovoltaic system, the photovoltaic system includes the photovoltaic module as described above.

[0019] In the back contact cell in the application, the first insulating part arranged correspondingly to the main grid is arranged in the series connection area and covers the paste junction, the first gap is arranged between the two adjacent first insulating parts, and the main grid is partially exposed from the first gap, so that the first insulating part can be arranged in blocks, thereby reducing the fluidity of the first insulating part, increasing the thickness of the first insulating part, making the insulation effect of the series connection area better, avoiding the conduction between the paste junction of the series connection area and the solder strip, and reducing the defective rate of the photovoltaic module. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments in the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0021] Figure 1 It is the module schematic view of the photovoltaic system provided by an embodiment of the utility model;

[0022] Figure 2It is a module schematic view of the photovoltaic module provided by the embodiment of the utility model;

[0023] Figure 3 It is an electrode structure schematic view of the back contact cell provided by the embodiment of the utility model;

[0024] Figure 4 It is an insulation piece structure schematic view of the photovoltaic module provided by the embodiment of the utility model;

[0025] Figure 5 It is a partial structure schematic of the back contact cell provided by the embodiment of the utility model;

[0026] Figure 6 It is a partial structure schematic of the back contact cell provided by the another embodiment of the utility model.

[0027] Main element symbol explanation: 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, paste node;50, first insulation piece;60, second insulation piece;D1, first gap;D2, second gap;501, insulation block;201, solder pad. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the following will be further described in detail by combining with the drawings and embodiments. The embodiments described below by referring to the drawings are exemplary, and are only used to explain the utility model, and cannot be understood as the limitation of the utility model. In addition, it should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model.

[0029] In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "length", "width", "upper", "lower", "top", "bottom", "transverse", "longitudinal" and the like is the orientation or position relationship based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.

[0030] In addition, the terms "first", "second" are only used for description purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0031] In the description of the utility model, it needs to explain, unless another explicit provision and limitation, term " install " " link " " connection " should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected;Can be mechanical connection, also can be electric connection or can communicate with each other;It can be directly connected, also can be indirectly connected through intermediate medium, can be the communication or the interaction relationship of two elements inside two elements.For ordinary skilled in the art, the above-mentioned terms can be understood according to the specific meaning of the utility model.

[0032] The following disclosure provides many different embodiments or examples for implementing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the utility model. In addition, the utility model can refer to the same number and / or reference letter in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0033] Please refer to Figure 1 And Figure 2 The photovoltaic system 1000 in the embodiment of the utility model can include the photovoltaic assembly 1001 in the embodiment of the utility model, and the photovoltaic assembly 1001 in the embodiment of the utility model can include a plurality of back contact cells 100. The plurality of back contact cells 100 can be sequentially connected in series through a solder strip to form a cell string. Each cell string in the photovoltaic assembly 1001 can be connected in series, parallel, or a combination of series and parallel to realize the current output of the bus, for example, the connection between each cell string can be realized through a bus bar.

[0034] In this embodiment, the photovoltaic system 1000 can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy for power generation, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system 1000 are not limited to these; that is, the photovoltaic system 1000 can be applied in all fields that require solar energy for power generation. Taking a photovoltaic power generation system network as an example, the photovoltaic system 1000 may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0035] The accompanying 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 features of the utility model. It is not intended to limit the technical solution to exclude these unshown elements. That is to say, the drawings are merely 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 this embodiment of the present invention includes: a battery substrate 10, a plurality of main grids 20, a plurality of slurry 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. The series connection area 101 is the area where the back contact battery 100 is electrically connected to the solder strip. The main grids 20 are disposed in the series connection area 101, extending along a first direction and arranged at intervals along a second direction, the first direction intersecting the second direction. A plurality of slurry nodes 40 are formed in the series connection area 101. The first insulating members 50 are disposed in the series connection area 101, corresponding to the main grids 20. The first insulating members 50 are arranged along the first direction and cover the slurry nodes 40. 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. Specifically, the first insulating member 50 can be insulating adhesive.

[0037] Therefore, the back contact battery 100 in the embodiment of the utility model, because the first insulating piece 50 corresponding to the main grid 20 is arranged in the series connection area 101 and covers the paste junction 40, the first insulating piece 50 is divided into blocks, thereby the flowability of the first insulating piece 50 can be reduced, the thickness of the first insulating piece 50 is increased, the insulation effect of the series connection area 101 is better, thereby the paste junction 40 of the series connection area 101 is prevented from being conducted with the solder strip, and the failure rate of the photovoltaic module 1001 is reduced.

[0038] Meanwhile, because the first gap D1 is formed between the two adjacent first insulating pieces 50, the main grid 20 is partially exposed from the first gap D1, when the back contact battery 100 is connected with the solder strip, the effective connection area of the solder strip and the main grid 20 can be increased, thereby the current collecting capacity of the solder strip on the main grid 20 is improved, and the power generation efficiency of the photovoltaic module 1001 is improved.

[0039] Specifically, the back contact battery 100 can be a whole piece of battery, or can be a half piece, a third piece or other proportion of battery divided from the whole piece of battery.

[0040] Specifically, the back contact battery 100 includes a front surface and a back surface, the front surface faces the sun and mainly receives the direct sunlight, and the back surface faces the mounting surface of the battery module and mainly receives the sunlight reflected by the mounting surface, for example, the ground, the roof and the like. Alternatively, the back surface is the surface provided with the grid lines of the back contact battery 100.

[0041] Specifically, the back surface of the battery substrate 10 specifically includes the series connection area 101 and the 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 solder strip when the solder strip is connected. The non-series connection area 102 is the area of the back surface of the battery substrate 10 except the series connection area 101.

[0042] Further, the series connection area 101 and the non-series connection area 102 are staggered on the back surface of the battery substrate 10. In other words, one non-series connection area 102 is formed between two adjacent series connection areas 101, and one series connection area 101 is formed between two adjacent non-series connection areas 102.

[0043] Further, the polarity of the series connection area 101 has two types, which are the first series connection area and the second series connection area, and the first series connection area and the second series connection area are staggered. In other words, one second series connection area is formed between two adjacent first series connection areas, and one first series connection area is formed between two adjacent second series connection areas. Further, 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 comprises a solder area and / or a conductive adhesive area. Further, the solder area can be provided with a conductive material. The conductive material is, for example, solder such as tin paste. Further, the conductive adhesive area can be provided with a conductive adhesive. In other words, the main grid 20 of the series connection area 101 can be connected to the bonding wire by solder; can be electrically and adhesively connected to the bonding wire by the conductive adhesive; and can be adhesively connected to the bonding wire by solder and the conductive adhesive.

[0045] Specifically, the main grid 20 is arranged in the series connection area 101. In other words, the projection of the main grid 20 on the back surface of the battery substrate 10 in the direction perpendicular to the back surface of the battery substrate 10 is located in the series connection area 101.

[0046] Further, the polarity of the main grid 20 is of two types, i.e., a first main grid 20 and a second main grid 20, and the first main grid 20 and the second main grid 20 are arranged alternately. In other words, one second main grid 20 is formed between two adjacent first main grids 20, and one first main grid 20 is formed between two adjacent second main grids 20. Further, 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] Further, the arrangement direction of the series connection area 101 and the non-series connection area 102 is perpendicular to the arrangement direction of the main grid 20. It can be understood that, in other embodiments, the arrangement direction of the series connection area 101 and the non-series connection area 102 can also be at an angle to the arrangement direction of the main grid 20, which is not limited herein.

[0048] Specifically, the slurry node 40 is further formed in the series connection area 101. The slurry node 40 is specifically a node formed in the process of printing the grid line. In other embodiments, the slurry node 40 can also be formed in the non-series connection area 102, which is not limited herein.

[0049] Further, the slurry node 40 can be formed by the non-burn-through slurry as the main grid 20; or the slurry node 40 can be formed by the burn-through slurry as the fine grid 30, which is not limited herein.

[0050] Please refer to Figures 3 to 6 Further, the first insulating member 50 is specifically arranged 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.

[0051] Further, the first insulating member 50 is specifically arranged 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] Further, the polarity of the slurry node 40 is two, which is positive slurry node 40 and negative slurry node 40. The polarity of the slurry node 40 can be the same as the polarity of the main grid 20, or the polarity of the slurry node 40 can be opposite to the polarity of the main grid 20.

[0053] Specifically, when the polarity of the main grid 20 and the slurry node 40 located in the same stringing area 101 is opposite. For example, the main grid 20 is positive, and the slurry node 40 is negative; or the main grid 20 is negative, and the slurry node 40 is positive. When the solder strip is arranged in the stringing area 101, in order to avoid the conduction between the slurry node 40 and the solder strip, damage the back contact battery 100, and cause the photovoltaic module 1001 to be bad, thereby avoiding the conduction between the slurry node 40 of the stringing area 101 and the solder strip, and thereby reducing the failure rate of the photovoltaic module 1001. In the embodiment of the utility model, the first insulating part 50 covers the slurry node 40, and in the first direction, a first gap D1 is formed between the two adjacent first insulating parts 50, and part of the main grid 20 is exposed from the first gap D1.

[0054] It can be understood that the insulating part in the prior art is usually a long strip-shaped insulating glue extending along the extension direction of the main grid 20. The flowability of the long strip-shaped insulating glue is relatively large, and after being arranged, the long strip-shaped insulating glue will flow to the surrounding, causing the thickness of the insulating glue to become thin. Therefore, in the prior art, the insulation between the slurry node 40 and the solder strip is insufficient, and the slurry node 40 can be in conduction with the solder strip.

[0055] However, in the embodiment of the utility model, the first insulating part 50 covers the slurry node 40, and in the first direction, the first insulating part 50 is arranged in blocks. Therefore, the flowability of the first insulating part 50 can be reduced, the thickness of the first insulating part 50 can be increased, and the insulation effect of the stringing area 101 is better. Therefore, the insulation between the slurry node 40 and the solder strip is strengthened, the conduction between the slurry node 40 and the solder strip is avoided, and the failure rate of the photovoltaic module 1001 is reduced.

[0056] It can be understood that "the first insulating part 50 covers the slurry node 40" means that the first insulating part 50 completely covers the slurry node 40, in other words, the first insulating part 50 completely wraps the slurry node 40, and the slurry node 40 has no part exposed from the first insulating part 50.

[0057] It can be understood that "in the first direction, a first gap D1 is formed between the two adjacent first insulating parts 50" means that the plurality of first insulating parts 50 are arranged in the first direction with a spacing, and there is a spacing between the two adjacent first insulating parts 50, and part of the main grid 20 is exposed from the gap between the two adjacent first insulating parts 50.

[0058] Please refer to Figures 3 to 6In a possible implementation, the back contact cell 100 further comprises a plurality of fine grids 30, the fine grids 30 are arranged on the cell substrate 10, the fine grids 30 extend along the second direction and are arranged in intervals along the first direction, the fine grids 30 are connected with the main grids 20 of the same polarity, and the fine grids 30 are spaced apart from the main grids 20 of different polarity.

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

[0060] Further, the fine grids 30 are connected with the main grids 20 of the same polarity, and the fine grids 30 are spaced apart from the main grids 20 of different polarity. In other words, the fine grids 30 are connected with the main grids 20 of the same polarity, and the fine grids 30 are spaced apart from the main grids 20 of different polarity. For example, the positive fine grids 30 are connected with the positive main grids 20, and the positive fine grids 30 are spaced apart from the negative main grids 20, the negative fine grids 30 are connected with the negative main grids 20, and the negative fine grids 30 are spaced apart from the positive main grids 20.

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

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

[0063] Please refer to Figures 3 to 6In a possible implementation, the back contact cell 100 comprises a plurality of second insulating pieces 60, which are arranged in correspondence with the fine grids 30 and partially cover the fine grids 30. In this way, the insulation of the main grids 20 and the fine grids 30 of different polarities can be achieved, and the short circuit of the back contact cell 100 can be prevented.

[0064] Specifically, the "second insulating piece 60 partially covers the fine grid 30" means that the second insulating piece 60 does not completely cover the fine grid 30, and part of the fine grid 30 is exposed from the second insulating piece 60, so as to realize the connection of the fine grid 30 and the main grid 20 of the same polarity and the insulation of the fine grid 30 and the main grid 20 of different polarities.

[0065] In a possible implementation, the size t of the first gap D1 is 0.5 mm to 1 mm. For example, it is 0.5 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm. In this way, the first insulating piece 50 can be arranged in blocks, and the thickness of the first insulating piece 50 can be increased while avoiding the conduction between the main grid 20 and the fine grid 30 of different polarities.

[0066] It can be understood that, in the first direction, the spacing between adjacent first insulating pieces 50 should be greater than the spacing between two adjacent fine grids 30 of the same polarity, so as to avoid the conduction between the main grid 20 and the fine grid 30 of different polarities.

[0067] In a possible implementation, the thickness of the first insulating piece 50 is 5 μm to 50 μm. For example, it is 5 μm, 6 μm, 10 μm, 15 μm, 20 μm, 22 μm, 25 μm, 30 μm, 35 μm, 40 μm, or 50 μm. In this way, the insulation of the polar slurry and the solder strip can be increased while avoiding the waste of material and the increase of cost caused by the excessive thickness of the first insulating piece 50.

[0068] Preferably, the thickness of the first insulating piece 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 piece 50 can be a certain constant value within 5 μm to 50 μm, or can fluctuate within 5 μm to 50 μm.

[0070] Please refer to Figures 3 to 6 In a possible implementation, in the second direction, at least one first insulating piece 50 is arranged continuously and covers the main grid 20 completely. In this way, in the second direction, the main grid 20 can be completely insulated by the continuous arrangement of the first insulating piece 50, and the accidental electrical contact of the main grid 20 can be avoided, so as to ensure that the main grid 20 will not be short-circuited or current leakage will not occur, and the safety and reliability of the back contact cell 100 can be effectively improved.

[0071] Specifically, the "first insulating member 50 is continuously arranged" means that, in the second direction, the first insulating member 50 is continuously arranged 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] Please refer to Figures 3 to 6 In a possible implementation, the first insulating member 50 includes a plurality of insulating blocks 501, and in the second direction, adjacent insulating blocks 501 are formed with a second gap D2, and part 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, the thickness of each insulating block 501 can be effectively increased, the insulation between the solder joints 40 and the solder strips can be increased, and the total amount of the first insulating member 50 can be saved, thereby saving costs.

[0073] Specifically, the first insulating member 50 can 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 turn, the effective connection area of the solder strip and the main grid 20 can be further increased, thereby further improving the current collection capability of the solder strip on the main grid 20, thereby improving the power generation efficiency of the photovoltaic module 1001.

[0074] It can be understood that for each first insulating member 50, the first insulating member 50 can be completely continuously arranged, or completely arranged in blocks, or both the first insulating member 50 arranged in blocks and the first insulating member 50 continuously arranged, which 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 blocks 501 can be arranged in blocks, and while increasing the thickness of the insulating blocks 501, the main grid 20 and the fine grid 30 of different polarities can be prevented from being conductive.

[0076] It can be understood that the size p of the second gap D2 cannot be too large. When the second gap D2 is too large, the main grid 20 can be conductive with the fine grid 30 of different polarities, thereby causing the back contact cell 100 to be short-circuited.

[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 pad 201 is greater than or equal to the size p of the second gap D2. In this way, the pad 201 and the fine grid 30 of different polarities can be prevented from being conductive.

[0078] Specifically, a plurality of pads 201 are arranged on the main grid 20, and the pads 201 are used to realize the connection between the main grid 20 and the solder ribbon. The size of the pad 201 cannot be too small. If the size of the pad 201 is too small, the solder ribbon can not fully contact the pad 201, or the contact is uneven, which can easily cause the soldering to be loose.

[0079] At the same time, the size p of the second gap D2 cannot be too large. When the second gap D2 is too large, it can cause insufficient insulation between the pad 201 and the fine grid 30 of different polarity, resulting in short circuit.

[0080] Preferably, the size p of the second gap D2 is 3mm to 5mm. In this way, the thickness of the insulating block 501 can be increased while avoiding the conduction between the pad 201 and the fine grid 30 of different polarity.

[0081] In a possible implementation, the first insulating member 50 partially covers the pad 201. In this way, further conduction between the pad 201 and the fine grid 30 of different polarity can be avoided.

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

[0083] Please note that transparent means that the first insulating member 50 has a light transmittance of greater than or equal to 70% for visible light at a thickness of microns. It can be understood that in other embodiments, the first insulating member 50 can 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. In this way, the second insulating member 60 can further reduce the blocking of sunlight, which is conducive to further improving the photoelectric conversion efficiency.

[0085] Please note that transparent means that the second insulating member 60 has a light transmittance of greater than or equal to 70% for visible light at a thickness of microns. It can be understood that in other embodiments, the second insulating member 60 can 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 irradiation of a light source of a corresponding wavelength, thereby facilitating the detection of the position of the first insulating member 50, and being conducive to improving the accuracy of the first insulating member 50 arranged on the back contact cell 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 irradiation of a light source of a corresponding wavelength, thereby facilitating the detection of the position of the second insulating member 60, and being conducive to improving the accuracy of the second insulating member 60 arranged on the back contact cell 100.

[0088] Please note that the explanation and description of the second insulation member 60 as a transparent fluorescent insulation member are similar to those of the first insulation member 50, and the relevant content of the first insulation member 50 can be referred to herein.

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

[0090] Specifically, the transparent insulation 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 insulation glue is a transparent insulation member, the shading of sunlight can be reduced, and more sunlight can be absorbed by the back contact cell, which is conducive to improving the photoelectric conversion efficiency. At the same time, since the transparent insulation glue includes the fluorescent agent with a mass percentage of greater than or equal to 0.1% and less than 1%, the transparent insulation glue will emit light under the irradiation of light sources with corresponding wavelengths, which facilitates the detection of the position of the transparent insulation glue and improves the accuracy of the setting of the transparent insulation glue on the back contact cell 100.

[0091] Specifically, the transparent insulation glue can be set on the back contact cell 100 by means of screen printing, spray valve, coating, etc.

[0092] Specifically, the transparent insulation glue has a coverage area ratio of greater than 10% on the back contact cell 100.

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

[0094] Specifically, the mass percentage of the inorganic filler is, for example, 5%, 6%, 8%, 10%, 11%, 14%, or 15%. In this way, the inorganic filler, which is relatively inexpensive, can be used to reduce the amount of resin component, thereby reducing the cost of the transparent insulation glue. Moreover, the inorganic filler can enhance the mechanical properties of the transparent insulation glue, making the insulation glue easier to set and adhere.

[0095] Specifically, the mass percentage of the curing agent is, for example, 5%, 8%, 10%, 11%, 14%, or 15%. In this way, the transparent insulation glue 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, the solvent can dissolve other materials in the transparent insulation glue and adjust the viscosity of the transparent insulation glue.

[0097] Specifically, the mass percentage of the fluorescent agent is, for example, 0.99%, 0.95%, 0.8%, 0.6%, 0.5%, 0.3%, 0.1%. The fluorescent agent can whiten, and a mass percentage greater than or equal to 1% can affect the light transmittance of the transparent insulating glue itself. However, a mass percentage greater than or equal to 0.1% and less than 1% of the fluorescent agent can make the light transmittance of the insulating glue itself better, which is conducive to ensuring the photoelectric conversion efficiency. Moreover, a mass percentage greater than or equal to 0.1% and less than 1% of the fluorescent agent will not result in excessively high cost, which is conducive to ensuring 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 can be understood that in such an embodiment, the photovoltaic module 1001 can further include a frame, a back plate, photovoltaic glass, and a glue film. The glue film can be filled between the front and back surfaces of the cell sheet, the photovoltaic glass, the adjacent cell sheet, etc., and can be a transparent glue with good light transmittance and aging resistance, for example, the glue film can use EVA glue film or POE glue film, which can be selected according to actual conditions, and is not limited herein.

[0099] The photovoltaic glass can be covered on the glue film on the front surface of the cell sheet, and the photovoltaic glass can be super white glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of the super white glass can be more than 92%, which can protect the cell sheet as much as possible without affecting the efficiency of the cell sheet. At the same time, the glue film can bond the photovoltaic glass and the cell sheet together, and the presence of the glue film can seal and insulate the cell sheet and prevent water and moisture.

[0100] The back plate can be attached to the glue film on the back surface of the cell sheet, and the back plate can protect and support the cell sheet, has reliable insulation, water resistance, and aging resistance, and the back plate can have multiple choices, which can be tempered glass, organic glass, aluminum alloy TPT composite glue film, etc., which can be set according to specific conditions, and is not limited herein. The whole composed of the back plate, the cell sheet, the glue film, and the photovoltaic glass can be arranged on the frame, and 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 desired installation position through the frame.

[0101] In the description of the specification, reference to "some embodiments," "certain embodiments," "example," "specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the above expressions in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0102] Moreover, the above-described embodiments are merely descriptive of the application and are not intended to limit the application. Any modification, equivalent replacement, and improvement made within the spirit and principle of the application shall fall within the scope of the application.

Claims

1. A back contact cell, characterized in that, The battery substrate comprises 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 a solder strip; a plurality of main grids are arranged in the series connection area, the main grids extending along a first direction and being arranged at intervals along a second direction, the first direction intersecting the second direction; a plurality of paste 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 being arranged corresponding to the main grids, the first insulating members being arranged along the first direction, the first insulating members covering the paste nodes, and a first gap being formed between two adjacent first insulating members along the first direction, and part of the main grids being exposed from the first gap. The thickness of the first insulating member is 5 μm to 50 μm.

2. The back contact cell of claim 1, wherein, The size of the first gap is 0.5 mm to 1 mm.

3. The back contact cell of claim 1, wherein, In the second direction, at least one first insulating member is arranged continuously and covers the main grid completely.

4. The back contact cell of claim 1, wherein, The first insulating member comprises a plurality of insulating blocks, and a second gap is formed between two adjacent insulating blocks along the second direction, and part of the main grids are exposed from the second gap.

5. The back contact cell of claim 1, wherein, The size of the second gap is less than or equal to 5 mm.

6. The back contact cell of claim 5, wherein, The main grid is provided with a plurality of pads, and the size of the pad is greater than or equal to the size of the second gap along the second direction.

7. The back contact cell of claim 5, wherein, The first insulating member partially covers the pad.

8. The back contact cell of claim 7, wherein, The size of the first insulating member along the first direction is 0.2 mm to 50 mm.

9. The back contact cell of claim 1, wherein, The size of the first insulating member along the second direction is 0.2 mm to 50 mm.

10. The back contact cell of claim 1, wherein, The photovoltaic module comprises the back contact battery according to any one of claims 1 to 12.

11. The back contact cell of claim 1, wherein, The photovoltaic module comprises the back contact battery according to any one of claims 1 to 12.

12. The back contact cell of claim 11, wherein, ​ 13. A photovoltaic module, characterized by ​ 14. A photovoltaic system characterized by, ​

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