A back contact cell, cell assembly and photovoltaic system without a main grid

Abstract

The application is suitable for the technical field of solar cells, and provides a main-grid-free back contact cell, a cell module and a photovoltaic system. The main-grid-free back contact cell comprises a silicon substrate, a plurality of first-polarity thin grids and a plurality of second-polarity thin grids arranged on the silicon substrate, extending along a first direction and arranged along a second direction, the first direction intersecting the second direction, and the first-polarity thin grids and the second-polarity thin grids being arranged at intervals; and a plurality of first connecting structures for connecting a stringing element, located at an edge region of the silicon substrate in the second direction, arranged along the first direction, the first connecting structure connecting a plurality of first-polarity thin grids adjacent in the second direction and being spaced apart from the second-polarity thin grids. In this way, the risk of the partial thin grids collecting current being difficult to export due to broken grids and missing printing in the edge region is reduced, and the photoelectric conversion efficiency of the cell is improved.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, and particularly relates to a gridless back contact cell, cell module and photovoltaic system. Background Technology

[0002] Solar cell power generation is a sustainable and clean energy source that utilizes the photovoltaic effect of semiconductor pn junctions to convert sunlight into electrical energy. A cell without a main grid and with fine grids of two polarities located on the same side of the cell is called a gridless back-contact cell. However, the fine grids at the edges of gridless back-contact cells are prone to breakage and missing markings, making it difficult to dissipate some of the current collected by the grids and resulting in poor photoelectric conversion efficiency.

[0003] Therefore, how to reduce the risk of broken grids or missing prints at the edge of the non-main grid battery causing the current collected by some fine grids to be difficult to discharge has become an urgent problem to be solved. Utility Model Content

[0004] This application provides a gridless back-contact cell, cell module, and photovoltaic system, aiming to solve the problem of how to reduce the risk of broken or missing grids at the edge of the gridless back-contact cell, which makes it difficult to discharge the current collected by some fine grids.

[0005] The gridless back contact battery provided in this application includes: Silicon substrate; A plurality of first polarity gates and a plurality of second polarity gates are disposed on the silicon substrate, extending along a first direction and arranged along a second direction, the first direction intersecting the second direction, and the first polarity gates and the second polarity gates are spaced apart. A plurality of first connection structures for connecting serial members are located at the edge region of the silicon substrate in the second direction and arranged along the first direction. The first connection structures connect a plurality of first polar fine gates that are adjacent in the second direction and are spaced apart from the second polar fine gates.

[0006] Specifically, the first connecting structure is solid.

[0007] Specifically, the dimension of the first connecting structure in the first direction is 0.5mm-10mm.

[0008] Specifically, the first fine grid of the gridless back contact battery is the first polar fine grid at the outermost edge of the silicon substrate in the second direction, which is connected to the first connection structure.

[0009] Specifically, the first fine grid is continuous.

[0010] Specifically, the first polar fine gate includes a second fine gate, the second polar fine gate includes a third fine gate, the first fine gate, the third fine gate and the second fine gate are arranged sequentially along the second direction, and the third fine gate is broken at the first connecting structure and spaced apart from the first connecting structure.

[0011] Specifically, the gridless back contact battery includes a plurality of second connection structures for connecting series members, arranged along the first direction. The second connection structures connect a plurality of second polar fine grids adjacent in the second direction and are spaced apart from the first polar fine grids.

[0012] Specifically, along the first direction, the first connecting structure and the second connecting structure are arranged alternately.

[0013] Specifically, in the second direction, the first polar fine gate connected by the first connection structure is the first fine gate and the second fine gate, respectively; the first connection structure extends beyond the first fine gate, and / or the first connection structure extends beyond the second fine gate.

[0014] The battery assembly provided in this application includes any of the above-mentioned gridless back contact batteries.

[0015] The photovoltaic system provided in this application includes the battery modules described above.

[0016] The gridless back-contact cell, cell module, and photovoltaic system of this application embodiment, since the first connection structure located in the edge region of the silicon substrate in the second direction connects several adjacent first polar fine grids in the second direction and is spaced apart from the second polar fine grids, multiple first polar fine grids can be conducted in the edge region through several first connection structures, reducing the risk that the current collected by some fine grids is difficult to be discharged due to broken grids or missing printing in the edge region, which is beneficial to improving the photoelectric conversion efficiency of the cell. Attached Figure Description

[0017] Figure 1 This is a partial structural schematic diagram of a gridless back contact battery according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a gridless back contact battery according to an embodiment of this application; Figure 3 This is a partial structural schematic diagram of a gridless back contact battery according to an embodiment of this application; Figure 4 This is a partial structural schematic diagram of a gridless back contact battery according to an embodiment of this application; Explanation of key component symbols: A gridless back contact cell 10, a silicon substrate 101, a first polar fine grid 11, a first fine grid 111, a second fine grid 112, a second polar fine grid 12, a third fine grid 121, a fourth fine grid 122, a first connection structure 13, a first connection gate 130, a second connection structure 14, and a second connection gate 140. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0019] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0024] Please see Figure 1 and Figure 2 The gridless back contact battery 10 of this application embodiment includes: Silicon substrate 101; A plurality of first polar fine gates 11 and a plurality of second polar fine gates 12 are disposed on a silicon substrate 101, extending along a first direction and arranged along a second direction, the first direction and the second direction intersecting, and the first polar fine gates 11 and the second polar fine gates 12 are disposed at intervals. A plurality of first connection structures 13 for connecting serial members are located in the edge region of the silicon substrate 101 in the second direction and are arranged along the first direction. The first connection structures 13 connect a plurality of first polar fine gates 11 adjacent in the second direction and are spaced apart from second polar fine gates 12.

[0025] In the embodiment of this application, the gridless back contact battery 10 has a first connection structure 13 located in the edge region of the silicon substrate 101 in the second direction that connects a plurality of adjacent first polar fine grids 11 in the second direction and is spaced apart from the second polar fine grids 12. Therefore, multiple first polar fine grids 11 can be turned on in the edge region through a plurality of first connection structures 13, reducing the risk that the current collected by some fine grids is difficult to be discharged due to grid breakage or missing printing in the edge region, which is beneficial to improving the photoelectric conversion efficiency of the battery.

[0026] Specifically, the gridless back contact battery 10 refers to a back contact battery without a grid. The gridless back contact battery 10 can be a sliced ​​battery formed by cutting a whole battery cell. For example, Figure 2 A half-cell battery is formed by cutting a whole cell in half. The gridless back contact cell 10 can also be an uncut whole cell. The whole gridless back contact cell 10 may include slicing grooves, along which the whole cell can be cut to obtain... Figure 2 The sliced ​​battery shown. The whole gridless back contact battery 10 can be asymmetrical or symmetrical along the slice groove.

[0027] Specifically, the silicon substrate 101 may include a silicon substrate, a first polar doped layer, a second polar doped layer, and a dielectric film layer. Further, the silicon substrate may be a P-type silicon substrate or an N-type silicon substrate; it may be a monocrystalline silicon substrate or a polycrystalline silicon substrate. The specific form of the silicon substrate is not limited here. Further, the first polar doped layer and the second polar doped layer are disposed on the silicon substrate. The first polar doped layer and the second polar doped layer have different doping polarities. The two doped layers can be formed by diffusion into the silicon substrate or by deposition of films on the silicon substrate. It can be understood that, in the thickness direction of the gridless back contact cell 10, the first polar doped layer is stacked on the silicon substrate, and the second polar doped layer is stacked on the silicon substrate. On a plane perpendicular to the thickness direction of the gridless back contact cell 10, the first polar doped layer and the second polar doped layer are distributed in regions, corresponding to the first polar doped region and the second polar doped region, respectively.

[0028] Furthermore, a dielectric film can be applied over the first polar doped layer and the second polar doped layer. A first polar fine gate 11 penetrates the dielectric film to contact the first polar doped layer, and a second polar fine gate 12 penetrates the dielectric film to contact the second polar doped layer. In this way, the dielectric film achieves electrical isolation between the first polar doped layer and the second polar doped layer, while also reducing light reflection and recombination. The dielectric film can also be disposed between at least one pair of adjacent first polar doped regions and second polar doped regions to electrically isolate the first polar doped region and the second polar doped region.

[0029] Specifically, the first polar fine gate 11 and the second polar fine gate 12 may be distributed over the entire area of ​​the silicon substrate 101; or the first polar fine gate 11 and the second polar fine gate 12 may be distributed over a portion of the silicon substrate 101.

[0030] Specifically, the first polarity fine gate 11 and the second polarity fine gate 12 have different polarities. The first polarity fine gate 11 corresponds to the first polarity doped layer and the first polarity doped region. The second polarity fine gate 12 corresponds to the second polarity doped layer and the second polarity doped region.

[0031] Specifically, the number of first polar fine gates 11 can be 1, 2, 3, 4, or other numbers. The number of second polar fine gates 12 can be 1, 2, 3, 4, or other numbers. No limitation is made here. The number of first polar fine gates 11 and the number of second polar fine gates 12 can be the same or different.

[0032] Specifically, the first polar fine gate 11 and the second polar fine gate 12 extend along the first direction, meaning that the overall extension direction is the first direction. This does not represent a limitation on the specific shape of the first polar fine gate 11 and the second polar fine gate 12. In this embodiment, the first polar fine gate 11 and the second polar fine gate 12 are straight lines, and the extension direction of the first polar fine gate 11 and the second polar fine gate 12, that is, the first direction, is the length direction of the first polar fine gate 11 and the second polar fine gate 12. In other embodiments, the first polar fine gate 11 may be wavy, zigzag, or other shapes. The second polar fine gate 12 may be wavy, zigzag, or other shapes.

[0033] Specifically, the first polar fine gate 11 and the second polar fine gate 12 are arranged along the second direction, which can be alternating or non-alternating along the second direction; they can be arranged at equal intervals or at unequal intervals along the second direction. No limitation is made here.

[0034] Specifically, the first polar fine gate 11 and the second polar fine gate 12 are arranged at intervals, meaning that a gap is formed between adjacent first polar fine gates 11 and second polar fine gates 12. The gap can be filled with an insulating element or can be an air gap.

[0035] Specifically, the first connecting structure 13 is used to connect the serial connector. The first connecting structure 13 and the serial connector can be electrically connected through at least one of the following methods: conductive adhesive bonding, direct soldering, solder paste soldering, or physical contact. No limitation is made here. Furthermore, the entire area of ​​the first connecting structure 13 is connected to the serial connector. This results in a larger connection area, which is beneficial for improving connection stability. It is understood that in other embodiments, a portion of the first connecting structure 13 may also be connected to the serial connector. Further, the serial connector includes at least one of solder strip and conductive wire. This document uses solder strip as an example to illustrate the serial connector.

[0036] Specifically, the first connection structure 13 includes at least one of a pad and a gate line segment.

[0037] Specifically, the number of the first connecting structures 13 can be 2, 3, 4, or other numbers. No limitation is made here.

[0038] Specifically, the first connection structure 13 is located at the edge region of the silicon substrate 101 in the second direction and is arranged along the first direction. Thus, by providing the first connection structure 13 for connecting the serial connector in the edge region of the silicon substrate 101, the connection between the serial connector and the battery can be made more stable, reducing the risk of the serial connector detaching from the battery.

[0039] Specifically, the first connection structure 13 connects several adjacent first polar fine gates 11 in the second direction and is spaced apart from the second polar fine gates 12. In this way, multiple first polar fine gates 11 can be conducted in the edge region through several first connection structures 13, reducing the risk that the current collected by some fine gates will be difficult to discharge due to broken gates or missing printing in the edge region, which is beneficial to improving the photoelectric conversion efficiency of the battery.

[0040] exist Figure 1 In the example, the first connection structure 13 connects two adjacent first polar fine gates 11 in the second direction. Figure 3 In the example, the first connection structure 13 connects three adjacent first polarity gates 11 in the second direction. It is understood that in other examples, the first connection structure 13 connects four, five, or other numbers of adjacent first polarity gates 11 in the second direction. The number of adjacent first polarity gates 11 connected to the first connection structure 13 in the second direction is not limited here.

[0041] Specifically, the second polar fine gate 12 can be broken at the first connecting structure 13 to form a gap and avoid the first connecting structure 13.

[0042] Please see Figure 1 In some embodiments, in the second direction, the first and last first polar fine grids 11 connected by the first connection structure 13 are respectively the first fine grid 111 and the second fine grid 112. The back contact battery 10 without a main grid includes a plurality of first connection grids 130, which intersect with the first fine grid 111 and the second fine grid 112 to form the first connection structure 13.

[0043] Thus, by using the first polar fine gate 11 to form part of the first connection structure 13, the amount of paste used to form the first connection structure 13 can be reduced, which helps to reduce costs. Moreover, the first connection gate 130 intersects with the first fine gate 111 and the second fine gate 112, so that the first connection gate 130 is connected to the first fine gate 111 and the second fine gate 112, which can improve conductivity.

[0044] Specifically, in Figure 1 In the example provided, there are two first connecting gates 130. It is understood that in other examples, the number of first connecting gates 130 may be one, three, four, five, or other numbers. No limitation is made here.

[0045] Please see Figure 3 In some embodiments, the first connecting structure 13 may also be solid. This results in a larger contact area between the first connecting structure 13 and the connector, and a more stable connection with the connector.

[0046] Specifically, the width of the first connecting gate 130 is 0.01mm-4mm. For example, it is 0.01mm, 0.05mm, 0.1mm, 1mm, 2mm, 3mm, or 4mm. In this way, the width of the first connecting gate 130 is within a suitable range, which can avoid the gate breaking easily due to its small size, and can also avoid the waste of materials and increased costs due to its large size.

[0047] Please see Figure 1 In some embodiments, the dimension w1 of the first connecting structure 13 in the first direction is 0.5mm-10mm. For example, it is 0.5mm, 0.6mm, 1mm, 2mm, 5.4mm, 8mm, or 10mm. In this way, the dimension w1 of the first connecting structure 13 in the first direction is within a suitable range, which can avoid the unstable connection with the connecting parts caused by the size being too small, and can also avoid the waste of materials and increased costs caused by the size being too large.

[0048] In some embodiments, the dimension of the first connecting structure 13 in the second direction is 0.5mm-5mm. For example, it is 0.5mm, 0.6mm, 1mm, 2.42mm, 2.5mm, 3mm, 4mm, or 5mm. In this way, the dimension of the first connecting structure 13 in the second direction is within a suitable range, which can avoid unstable connection with the connecting parts due to the size being too small, and can also avoid material waste and increased costs due to the size being too large.

[0049] Please see Figure 1 In some embodiments, the first fine grid 111 of the gridless back contact battery 10 is the first polar fine grid 11 at the outermost edge of the silicon substrate 101 in the second direction, and is connected to the first connection structure 13.

[0050] In other words, in the second direction, the first first polar fine gate 11 connected by the first connection structure 13 is the first fine gate 111, and the first fine gate 111 is the fine gate at the outermost edge of the silicon substrate 101 in the second direction.

[0051] In this way, the first connection structure 13 connects to the outermost fine gate of the silicon substrate 101 in the second direction, reducing the risk that the current collected in some fine gates may be difficult to discharge due to gate breakage or missing printing at the outermost fine gate. It can be understood that since the first fine gate 111 is connected to other first polarity fine gates 11 through the first connection structure 13, in the case of multiple segments formed by gate breakage or missing printing of the first fine gate 111, the segments can be connected to other first polarity fine gates 11 through the first connection structure 13, so that the collected current can be transmitted to other first polarity fine gates 11, thereby reducing the risk that the current collected in some fine gates may be difficult to discharge due to gate breakage or missing printing at the outermost fine gate.

[0052] Please see Figure 1 In some embodiments, the first fine gate 111 is continuous.

[0053] In this way, the fine gates at the outermost edge of the silicon substrate 101 in the second direction are continuous, without breaks or divisions, which can reduce the complexity of the edge gate pattern, thereby reducing the risk of broken gates and missing prints caused by poor printing and increasing the fault tolerance rate.

[0054] Specifically, "continuous" means that the first fine grid 111 is not broken or has no breaks.

[0055] Please see Figure 1 In some embodiments, the first polar fine gate 11 includes a second fine gate 112, the second polar fine gate 12 includes a third fine gate 121, the first fine gate 111, the third fine gate 121 and the second fine gate 112 are arranged sequentially along the second direction, and the third fine gate 121 is disconnected at the first connecting structure 13 and spaced apart from the first connecting structure 13.

[0056] Thus, by disconnecting at the first connection structure 13 and avoiding the first connection structure 13, the third fine gate 121 with opposite polarity can avoid contact with the first connection structure 13, which could lead to a short circuit.

[0057] Specifically, the distance d between the third fine gate 121 and the first connecting structure 13 is 0.2mm-5mm. For example, it is 0.2mm, 0.5mm, 1.05mm, 2mm, 3mm, 4mm, or 5mm. This ensures that the distance d between the third fine gate 121 and the first connecting structure 13 is within a suitable range, avoiding the conduction and short circuit caused by structures with opposite polarities due to too small a distance, and also avoiding the poor carrier collection effect caused by too large a distance.

[0058] Please see Figure 4 In some embodiments, in the second direction, the first polar fine gate 11 connected by the first connecting structure 13 is a first fine gate 111 and a second fine gate 112, respectively; the first connecting structure 13 extends beyond the first fine gate 111, and / or the first connecting structure 13 extends beyond the second fine gate 112.

[0059] This makes the first connecting structure 13 larger in area and the contact area with the serial connector larger, making the connection between the first connecting structure 13 and the serial connector more stable.

[0060] exist Figure 4 In the example, the first connection structure 13 extends beyond the first fine gate 111, and the first connection structure 13 extends beyond the second fine gate 112. It can be understood that in other examples, the first connection structure 13 may extend beyond the first fine gate 111 but not beyond the second fine gate 112; or the first connection structure 13 may not extend beyond the first fine gate 111 but extends beyond the second fine gate 112.

[0061] Please see Figure 1 In some embodiments, the gridless back contact battery 10 includes a plurality of second connection structures 14 for connecting series members, arranged along a first direction, wherein the second connection structures 14 connect a plurality of second polar fine grids 12 adjacent in a second direction and are spaced apart from the first polar fine grids 11.

[0062] In this way, multiple second polar fine grids 12 can be turned on through several second connection structures 14, reducing the risk that the current collected by some fine grids will be difficult to discharge due to broken grids or missing prints, which is beneficial to improving the photoelectric conversion efficiency of the battery.

[0063] Please see Figure 1 In some embodiments, the first connection structure 13 and the second connection structure 14 are arranged alternately along the first direction. In this way, the two types of series connectors that connect the first connection structure 13 and the second connection structure 14 are arranged alternately, which can better collect charge carriers and form a battery string.

[0064] Specifically, the second polar fine gate 12 includes a fourth fine gate 122, which is a second polar fine gate 12 adjacent to the third fine gate 121 that is disconnected at the first connecting structure 13. The second connecting structure 14 connects the third fine gate 121 and the fourth fine gate 122.

[0065] Please see Figure 1 In some embodiments, the gridless back contact battery 10 includes a plurality of second connection gates 140, which intersect with the third fine gate 121 and the fourth fine gate 122 to form a second connection structure 14.

[0066] This reduces the amount of paste used to form the second connection structure 14, thus lowering costs. Furthermore, the second connection gate 140 intersects with the third fine gate 121 and the fourth fine gate 122, allowing for better electrical conductivity.

[0067] Further explanations and descriptions regarding the second connecting gate 140 can be found in the previous explanations and descriptions regarding the first connecting gate 130. To avoid redundancy, they will not be repeated here.

[0068] Please see Figure 1 In some embodiments, the dimension w2 of the second connecting structure 14 in the first direction is 0.5mm-8mm. For example, it is 0.5mm, 0.6mm, 1mm, 2mm, 3.6mm, 5mm, 7mm, or 8mm. In this way, the dimension w2 of the second connecting structure 14 in the first direction is within a suitable range, which can avoid unstable connection with the connecting parts due to the size being too small, and can also avoid material waste and increased costs due to the size being too large.

[0069] In some embodiments, the dimension of the second connecting structure 14 in the second direction is 0.5mm-5mm. For example, it is 0.5mm, 0.6mm, 1mm, 2.42mm, 2.5mm, 3mm, 4mm, or 5mm. In this way, the dimension of the second connecting structure 14 in the second direction is within a suitable range, which can avoid the unstable connection with the connecting element caused by the size being too small, and can also avoid the waste of materials and increased costs caused by the size being too large.

[0070] For further explanations and descriptions of the second connection structure 14, please refer to the explanations and descriptions of the first connection structure 13 above. To avoid redundancy, they will not be repeated here.

[0071] The battery assembly of this application embodiment includes the gridless back contact battery 10 of any of the above-mentioned embodiments.

[0072] In the battery assembly of this application embodiment, since the first connection structure 13 located in the edge region of the silicon substrate 101 in the second direction connects several adjacent first polar fine grids 11 in the second direction and is spaced apart from the second polar fine grids 12, multiple first polar fine grids 11 can be conducted in the edge region through several first connection structures 13, reducing the risk that the current collected by some fine grids is difficult to be discharged due to broken grids or missing printing in the edge region, which is beneficial to improving the photoelectric conversion efficiency of the battery.

[0073] In this embodiment, multiple gridless back-contact cells 10 in the battery assembly can be connected in series to form a battery string, thereby achieving series current output. For example, the battery cells can be connected in series by setting solder strips (busbars, interconnecting strips), conductive backplates, etc.

[0074] It is understood that in such embodiments, the battery assembly may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film may be filled between the front and back sides of the gridless back contact battery 10, as well as between the photovoltaic glass, adjacent battery cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film may be an EVA film or a POE film, and the specific choice can be made according to the actual situation, without limitation.

[0075] Photovoltaic glass can be applied to the encapsulating film on the front side of the gridless back contact cell 10. The photovoltaic glass can be ultra-clear glass, possessing high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%. It can protect the gridless back contact cell 10 while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the gridless back contact cell 10 together, providing sealing, insulation, waterproofing, and moisture protection for the gridless back contact cell 10.

[0076] The backsheet can be attached to the adhesive film on the back of the gridless back contact cell 10. The backsheet provides protection and support for the gridless back contact cell 10, and offers reliable insulation, water resistance, and aging resistance. Multiple options are available for the backsheet, typically tempered glass, acrylic glass, aluminum alloy TPT composite adhesive film, etc., and the specific choice depends on the specific circumstances and is not limited here. The backsheet, gridless back contact cell 10, adhesive film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, providing stable support and installation. For example, the battery module can be installed at the desired location using the metal frame.

[0077] The photovoltaic system of this application embodiment includes the battery module described above.

[0078] In the photovoltaic system of this application embodiment, since the first connection structure 13 located in the edge region of the silicon substrate 101 in the second direction connects several adjacent first polar fine grids 11 in the second direction and is spaced apart from the second polar fine grids 12, multiple first polar fine grids 11 can be conducted in the edge region through several first connection structures 13, reducing the risk that the current collected by some fine grids is difficult to be discharged due to grid breakage or missing printing in the edge region, which is beneficial to improving the photoelectric conversion efficiency of the cell.

[0079] In this embodiment, the photovoltaic system 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 to generate electricity, 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 are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system 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.

[0080] In the description of this specification, the references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0081] Furthermore, the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A back contact cell with no busbars, characterized in that, include: Silicon substrate; A plurality of first polarity gates and a plurality of second polarity gates are disposed on the silicon substrate, extending along a first direction and arranged along a second direction, the first direction intersecting the second direction, and the first polarity gates and the second polarity gates are spaced apart. A plurality of first connection structures for connecting serial members are located at the edge region of the silicon substrate in the second direction and arranged along the first direction. The first connection structures connect a plurality of first polar fine gates that are adjacent in the second direction and are spaced apart from the second polar fine gates.

2. The no-lead back-contact cell of claim 1, wherein, The first connecting structure is solid.

3. The gridless back contact cell of claim 1, wherein, The dimensions of the first connecting structure in the first direction are 0.5mm-10mm.

4. The eni -main grid back contact cell of claim 1, wherein, The first fine grid of the gridless back contact battery is the first polar fine grid at the outermost edge of the silicon substrate in the second direction, and is connected to the first connection structure.

5. The eni -main grid back contact cell of claim 4, wherein, The first fine grid is continuous.

6. The eni -main grid back contact cell of claim 4, wherein, The first polar fine gate includes a second fine gate, the second polar fine gate includes a third fine gate, the first fine gate, the third fine gate and the second fine gate are arranged sequentially along the second direction, and the third fine gate is broken at the first connecting structure and spaced apart from the first connecting structure.

7. The gridless back contact cell of claim 1 wherein, The gridless back contact battery includes a plurality of second connection structures for connecting series members, arranged along the first direction. The second connection structures connect a plurality of second polar fine grids adjacent in the second direction and are spaced apart from the first polar fine grids.

8. The eni -main grid back contact cell of claim 7, wherein, Along the first direction, the first connecting structure and the second connecting structure are arranged alternately.

9. The gridless back contact cell of claim 1, wherein, In the second direction, the first polar fine gate connected by the first connection structure is the first fine gate and the second fine gate, respectively; the first connection structure extends beyond the first fine gate, and / or the first connection structure extends beyond the second fine gate.

10. A battery assembly characterized by, Includes the gridless back contact battery as described in any one of claims 1-9.

11. A photovoltaic system characterized by, Includes the battery assembly as described in claim 10.

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