Back-contact solar cell string, cell module and photovoltaic system

Abstract

The present application applies to the technical field of solar cells. Provided are a back-contact solar cell string (100), a cell module (200) and a photovoltaic system (100). In the back-contact solar cell string (100), a spacing region (101) is provided between every two adjacent back-contact solar cells (10). P-type doped layers (11) and N-type doped layers (12) of each back-contact solar cell (10) are each provided with a first electrically conductive connector (20). The first electrically conductive connectors (20) on the P-type doped layers (11) are fixedly and conductively connected to all the P-type doped layers (11) of each back-contact solar cell (10), and the first electrically conductive connectors (20) on the N-type doped layers (12) are fixedly and conductively connected to all the N-type doped layers (12) of each back-contact solar cell (10). A second electrically conductive connector (80) is provided at each spacing region (101), the second electrically conductive connector (80) being connected to all the first electrically conductive connectors (20). At corresponding positions on each spacing region (101), in an M-th first electrically conductive connector (20), the portion that is located on one side of the second electrically conductive connector (80) is cut off; in an (M+1)th first electrically conductive connector (20), the portion that is located on the other side of the second electrically conductive connector (80) is cut off. Each cut-off first electrically conductive connector (20) forms, at the spacing region (101), a suspended segment (21) which is not connected to the second electrically conductive connector (80), the length (L1) of the suspended segment (21) being less than the distance (L2) between two adjacent first electrically conductive connectors (20).

Description

Back-contact solar cell strings, modules, and photovoltaic systems

[0001] Priority information

[0002] This application claims priority and benefits of patent application No. 202420065535.6 filed with the State Intellectual Property Office of China on January 9, 2024, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to the technical field of solar cells, and in particular to a back-contact solar cell string, a cell assembly, and a photovoltaic system. Background Art

[0004] In related technologies, when forming a string of back-contact solar cells, a secondary grid and a main grid are typically formed on the cells using patterning techniques. The cells are then connected in series by welding ribbon to the main grid to form the string. This technical solution requires the installation of a separate main grid to collect current, and then welding ribbon to the main grid to connect the cells in series, which is costly.

[0005] To address this technical issue, a busbar can be omitted. Instead, a wire can be placed directly in contact with the P-type and N-type regions of the cell, and then the cells can be connected in series. This approach involves cutting off a wire every other time. However, this approach leaves a portion of the wire hanging loose when it is cut. This hanging portion can easily bend and come into contact with adjacent wires, leading to a short circuit. Summary of the Invention

[0006] The present application provides a back-contact solar cell string, a cell assembly, and a photovoltaic system.

[0007] The present application is implemented as follows: a back-contact solar cell string according to an embodiment of the present application includes:

[0008] A plurality of back-contact solar cells arranged along a first direction, wherein a back-light surface of each back-contact solar cell has a P-type doped layer and an N-type doped layer alternately arranged in sequence along a second direction, the second direction intersecting the first direction, a spacer being provided between two adjacent back-contact solar cells, and wherein the P-type doped layer of one of the two adjacent back-contact solar cells corresponds to the P-type doped layer of the other in the first direction, and the N-type doped layer of one of the two adjacent back-contact solar cells also corresponds to the N-type doped layer of the other in the first direction;

[0009] a plurality of first conductive connectors, the first conductive connectors being arranged parallel to the P-type doped layer and the N-type doped layer, the plurality of first conductive connectors being arranged at intervals along the second direction, and the first conductive connectors being provided on the P-type doped layer and the N-type doped layer of each back-contact solar cell;

[0010] The first conductive connector on the P-type doped layer is fixedly and conductively connected to all the P-type doped layers corresponding to each back-contact solar cell in the first direction, and the first conductive connector on the N-type doped layer is fixedly and conductively connected to all the N-type doped layers corresponding to each back-contact solar cell in the first direction;

[0011] a plurality of second conductive connecting members, the second conductive connecting members extending along the second direction and each of the spacers correspondingly having one second conductive connecting member, the second conductive connecting members being connected to all the first conductive connecting members;

[0012] At a position corresponding to the spacer, in the Mth first conductive connector, a portion located on one side of the second conductive connector is cut off, and in the M+1th first conductive connector, a portion located on the other side of the second conductive connector is cut off, thereby connecting a plurality of the back-contact solar cells in series into a back-contact solar cell string, where M is a positive integer;

[0013] The truncated first conductive connection forms a suspended segment not connected to the second conductive connection at the spacing area, and the length of the suspended segment is smaller than the distance between two adjacent first conductive connections.

[0014] The present application also provides a battery assembly, which includes several of the above-mentioned back-contact solar cell strings.

[0015] The present application also provides a photovoltaic system, which includes the above-mentioned battery assembly.

[0016] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a module schematic diagram of a photovoltaic system provided in an embodiment of the present application.

[0018] FIG2 is a module schematic diagram of a battery assembly provided in an embodiment of the present application.

[0019] FIG3 is a schematic diagram of a planar structure of a back-contact solar cell string provided in an embodiment of the present application;

[0020] FIG4 is another planar structural diagram of a back-contact solar cell string provided in an embodiment of the present application;

[0021] FIG5 is another schematic plan view of the structure of a back-contact solar cell string according to an embodiment of the present application;

[0022] FIG6 is another schematic plan view of the back-contact solar cell string provided in an embodiment of the present application;

[0023] 7 is a schematic cross-sectional view of a back-contact solar cell string provided by an embodiment of the present application at the position of a first conductive connector along a first direction;

[0024] 8 is another cross-sectional schematic diagram of a back-contact solar cell string provided by an embodiment of the present application at the position of the first conductive connector along the first direction;

[0025] FIG9 is another schematic cross-sectional view of the back-contact solar cell string provided by an embodiment of the present application at the position of the first conductive connector along the first direction.

[0026] Description of main component symbols:

[0027] Photovoltaic system 1000, battery assembly 200, back-contact solar cell string 100, back-contact solar cell 10, P-type doped layer 11, N-type doped layer 12, spacer 101, first conductive connector 20, suspended section 21, first bus bar 30, second bus bar 40, metal grid line 50, first shielding layer 60, insulating coating 70, second conductive connector 80. Modes for Carrying Out the Invention

[0028] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. It should be noted that the embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and are not to be construed as limiting the present application. In addition, it should be understood that the specific embodiments described herein are merely used to explain the present application and are not intended to limit the present application.

[0029] In the description of this application, it should be understood that the terms "up", "down", "left", "right", "horizontal", "longitudinal", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They 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 direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on this application.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of this application, "several" means two or more, unless otherwise specifically defined.

[0031] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

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

[0033] Example 1

[0034] 1 and 2 , the photovoltaic system 1000 in the embodiment of the present application may include the battery assembly 200 in the embodiment of the present application, and the battery assembly 200 in the embodiment of the present application may include several back-contact solar cell strings 100 in the embodiment of the present application.

[0035] 3 to 6 , a back-contact solar cell string 100 in an embodiment of the present application may include a plurality of back-contact solar cells 10 , a plurality of first conductive connectors 20 , and a plurality of second conductive connectors 80 .

[0036] A plurality of back-contact solar cells 10 may be arranged at intervals along a first direction. The backlight surface of the back-contact solar cell 10 has a P-type doped layer 11 and an N-type doped layer 12 alternately arranged in sequence along a second direction. The P-type doped layer 11 and the N-type doped layer 12 both extend along the first direction, and the first direction intersects the second direction.

[0037] The first direction may be the string connection direction of the back-contact solar cell string 100 (ie, the lateral direction in FIG. 3 ), and the second direction may be a direction perpendicular to the string connection direction (ie, the longitudinal direction in FIG. 4 ), and the two directions are perpendicular to each other.

[0038] As shown in Figures 3 to 6, there is a spacer 101 between two adjacent back-contact solar cells 10. In the two adjacent back-contact solar cells 10, the P-type doped layer 11 of one corresponds to the P-type doped layer 11 of the other in the first direction, and the N-type doped layer 12 of one also corresponds to the N-type doped layer 12 of the other in the first direction.

[0039] That is, in the entire back-contact solar cell string 100, the arrangement of the P-type doped layer 11 and the N-type doped layer 12 in all the back-contact solar cells 10 is the same, the P-type doped layer 11 of the previous back-contact solar cell 10 and the P-type doped layer 11 of the next back-contact solar cell 10 are basically located on the same straight line in the first direction, and the N-type doped layer 12 of the previous back-contact solar cell 10 and the N-type doped layer 12 of the next back-contact solar cell 10 are also basically located on the same straight line in the first direction.

[0040] The first conductive connecting members 20 extend along the first direction. The first conductive connecting members 20 are arranged parallel to the P-type doped layer 11 and the N-type doped layer 12 . A plurality of first conductive connecting members 20 are arranged at intervals along the second direction.

[0041] A first conductive connector 20 is provided on the P-type doped layer 11 and the N-type doped layer 12 of each back-contact solar cell 10, and the number of the first conductive connectors 20 is the same as the sum of the number of the P-type doped layers 11 and the N-type doped layers 12 in each back-contact solar cell 10.

[0042] The first conductive connector 20 on the P-type doped layer 11 is fixed and conductively connected to all the P-type doped layers 11 corresponding to the first direction in each back-contact solar cell 10, and the first conductive connector 20 on the N-type doped layer 12 is fixed and conductively connected to all the N-type doped layers 12 corresponding to the first direction in each back-contact solar cell 10.

[0043] As shown in Figures 3-7 , the first conductive connector 20 on the P-type doped layer 11 sequentially connects to the corresponding P-type doped layer 11 in each back-contact solar cell 10 in the first direction. The first conductive connector 20 on the N-type doped layer 12 sequentially connects to the corresponding N-type doped layer 12 in the first direction in each back-contact solar cell 10. That is, in the first direction, the P-type doped layer 11 of the previous back-contact solar cell 10 is connected to the P-type doped layer 11 of the next back-contact solar cell 10 via the first conductive connector 20, and the N-type doped layer 12 of the previous back-contact solar cell 10 is connected to the N-type doped layer 12 of the next back-contact solar cell 10 via the first conductive connector 20.

[0044] The second conductive connecting members 80 are extended along the second direction and one second conductive connecting member 80 is correspondingly provided at each spacing area 101 . The second conductive connecting members 80 are connected to all the first conductive connecting members 20 .

[0045] As shown in Figures 3 to 7, at the position corresponding to the spacer 101, in the Mth first conductive connector 20, the portion located on one side of the second conductive connector 80 is cut off, and in the M+1th first conductive connector 20, the portion located on the other side of the second conductive connector 80 is cut off, thereby connecting several back-contact solar cells 10 in series into a back-contact solar cell string 100, where M is a positive integer.

[0046] The truncated first conductive connection member 20 forms a suspended segment 21 not connected to the second conductive connection member 80 at the spacing area 101 , and the length L1 of the suspended segment 21 is smaller than the distance L2 between two adjacent first conductive connection members 20 .

[0047] For example, as shown in Figure 3, the first first conductive connector 20 is cut off on the left side of the second conductive connector 80, and the second second conductive connector 20 is cut off on the right side of the second conductive connector 80. Then, from top to bottom, the first conductive connector 20 at the odd position is cut off on the left side of the second conductive connector 80, and the first conductive connector 20 at the even position is cut off on the right side of the second conductive connector 80. That is, each first conductive connector 20 has a suspended segment 21. The difference is that the suspended segments 21 of two adjacent first conductive connectors 20 are respectively located on the left and right sides of the second conductive connector 80.

[0048] It should be noted that, as shown in FIG3 , the severed first conductive connector 20 forms two portions at the spacer region 101: one portion connected to the second conductive connector 80, and the other portion not connected to the second conductive connector 80. The suspended segment 21 refers to the portion of the severed first conductive connector 20 between the endpoint of the portion not connected to the second conductive connector 80 and the fixing point 102 closest to the spacer region 102 between the portion and the P-type doped layer 11 or the N-type doped layer 12 (i.e., the edge fixing point between the first conductive connector 20 and the P-type doped layer 11 or the N-type doped layer 12). The length L1 of the suspended segment 21 is the distance between the endpoint and the fixing point 102.

[0049] At the same time, it should be noted that, in the present application, “the distance between two adjacent first conductive connectors 20 ” refers to the spacing between the two first conductive connectors 20 in the second direction, that is, the spacing between the lower edge of the previous first conductive connector 20 and the upper edge of the next first conductive connector 20 .

[0050] In the back-contact solar cell string 100, solar cell assembly 200, and photovoltaic system 1000 of the embodiments of the present application, a spacer 101 is provided between two adjacent back-contact solar cells 10 in the back-contact solar cell string 100. In the two adjacent back-contact solar cells 10, the P-type doped layer 11 of one is arranged correspondingly with the P-type doped layer 11 of the other, and the N-type doped layer 12 of one is arranged correspondingly with the N-type doped layer 12 of the other in the first direction. A plurality of first conductive connectors 20 are arranged in a spaced relationship along a second direction. First conductive connectors 20 are provided on both the P-type doped layer 11 and the N-type doped layer of each back-contact solar cell 10. The number of first conductive connectors 20 is equal to the sum of the number of P-type doped layers 11 and the number of N-type doped layers 12 in each back-contact solar cell 10. The first conductive connectors 20 on the P-type doped layers 11 are fixedly and conductively connected to all corresponding P-type doped layers 11 in each back-contact solar cell 10 in the first direction. The first conductive connectors 20 on the N-type doped layers 12 are fixedly and conductively connected to all corresponding N-type doped layers 12 in each back-contact solar cell 10 in the first direction. At the location corresponding to the spacer 101, the portion of the Mth first conductive connector 20 located on one side of the second conductive connector 80 is cut off, and the portion of the M+1th first conductive connector 20 located on the other side of the second conductive connector 80 is cut off, thereby connecting several back-contact solar cells 10 in series to form a back-contact solar cell string 100, where M is a positive integer. The cut first conductive connectors 20 have a suspended segment 21 at the spacer 101 that is not connected to the second conductive connector 80. The length L1 of the suspended segment 21 is less than the distance L2 between two adjacent first conductive connectors 20.

[0051] In this manner, by providing a plurality of first conductive connectors 20 and a plurality of second conductive connectors 80 in a back-contact solar cell string 100, the portion of the Mth first conductive connector 20 located on one side of the second conductive connector 80 is cut off, and the portion of the M+1th first conductive connector 20 located on the other side of the second conductive connector 80 is cut off. By cutting off the first conductive connectors 20, the back-contact solar cells 10 can be directly connected in series to form a back-contact solar cell string 100. The length L1 of the suspended segment 21 formed by the cut first conductive connector 20, which is not in contact with the second conductive connector 80, is less than the distance L2 between two adjacent first conductive connectors 20. This prevents the suspended segment 21 formed by the cut first conductive connector 20 from bending and contacting an adjacent first conductive connector 20, which could cause leakage, thereby ensuring the stability and reliability of the back-contact solar cell string 100.

[0052] It can be understood that the present application is different from the prior art in which the main grid is used to realize current convergence and then the main grid is connected by welding ribbons to form a cell string. Instead, each P-type doped layer 11 of a back-contact solar cell 10 is directly connected to the corresponding P-type doped layer 11 of the next back-contact solar cell 10 using a continuous first conductive connector 20, and each N-type doped layer 12 of a back-contact solar cell 10 is directly connected to the corresponding N-type doped layer 12 of the next back-contact solar cell 10 using a continuous first conductive connector 20. Then, a second conductive connector 80 conductively connected to the first conductive connector 20 is provided in the spacer area 101 between the two back-contact solar cells 10, and then the first conductive connector 20 is cut off by the cutting method described above to form a back-contact solar cell string 100.

[0053] Referring to FIG. 5 and FIG. 6 , in some embodiments, the number of back-contact solar cells 10 is greater than two, and the same first conductive connection 20 is cut off at the same position in two adjacent spacers 101 .

[0054] That is to say, if in the first spacing area 101, the portion of the Mth first conductive connection 20 located on the right side of the second conductive connection 80 is cut off, and the portion of the M+1th first conductive connection 20 located on the left side of the second conductive connection 80 is cut off, then, in the second spacing area 101, the portion of the Mth first conductive connection 20 located on the right side of the second conductive connection 80 is also cut off, and the portion of the M+1th first conductive connection 20 located on the left side of the second conductive connection 80 is also cut off.

[0055] For example, as shown in Figures 5 and 6, in the examples shown in Figures 5 and 6, there are two spacers 101. In the first spacer 101, from top to bottom, the first conductive connector 20 at the odd position is cut off on the right side of the second conductive connector 80, and the first conductive connector 20 at the even position is cut off on the left side of the second conductive connector 80. Then, in the second spacer, the first conductive connector 20 at the odd position is also cut off on the right side of the second conductive connector 80, and the first conductive connector 20 at the even position is also cut off on the right side of the second conductive connector 80, and so on.

[0056] In this way, the current can be smoothly collected to avoid short circuit through such a cutoff method.

[0057] As shown in Figures 4 and 6, in an embodiment of the present application, the back-contact solar cell string 100 further includes a first bus bar 30 and a second bus bar 40 respectively located at both ends of the back-contact solar cell string 100. Among the plurality of first conductive connectors 20, every other first conductive connector 20 is electrically connected to the first bus bar 30 and the second bus bar 40, thereby realizing bus output of the back-contact solar cell string 100.

[0058] It is understood that in the embodiments of the present application, the battery assembly 200 may further include a metal frame, a backsheet, photovoltaic glass, and an adhesive film (not shown). The adhesive film may be filled between the front surface and photovoltaic glass, the back surface and the backsheet, and adjacent cells of the back-contact solar cell 10. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the adhesive film may be EVA film or POE film. The specific choice may be based on actual conditions and is not limited here.

[0059] Photovoltaic glass can cover the adhesive film on the front surface of the back-contact solar cell 10. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and excellent physical, mechanical, and optical properties. For example, ultra-clear glass can have a light transmittance of over 92%, protecting the back-contact solar cell 10 while minimizing the impact on the efficiency of the back-contact solar cell 10. The adhesive film can also bond the photovoltaic glass and the back-contact solar cell 10 together, providing sealing, insulation, and waterproofing of the back-contact solar cell 10.

[0060] A backsheet can be attached to the film on the back of the back-contact solar cell 10. The backsheet protects and supports the back-contact solar cell 10, providing reliable insulation, water resistance, and aging resistance. A variety of backsheet options are available, typically including tempered glass, organic glass, and aluminum alloy TPT composite film. The specific configuration depends on the specific situation and is not limited here. The entire assembly consisting of the backsheet, back-contact solar cell 10, film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the primary external support structure for the entire battery assembly 200 and provides stable support and installation for the battery assembly 200. For example, the metal frame can be used to install the battery assembly 200 in the desired location.

[0061] Furthermore, in this embodiment, the photovoltaic system 1000 can be applied in photovoltaic power stations, such as ground-based power stations, rooftop power stations, and water-based power stations. It can also be applied to equipment or devices that use 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 1000 are not limited to these. In other words, the photovoltaic system 1000 can be applied in all fields that require solar 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 assemblies 200. For example, multiple battery assemblies 200 may form multiple photovoltaic arrays. The photovoltaic arrays are connected to a combiner box, which can combine the current generated by the photovoltaic arrays. The combined current flows through the inverter to convert it into the AC power required by the mains power grid and then connects to the mains power grid to achieve solar power supply.

[0062] Example 2

[0063] In some embodiments, in the second direction, a distance L2 between two adjacent first conductive connectors 20 may be 0.3 mm-1.2 mm.

[0064] In this way, it is possible to avoid the distance L2 between two adjacent first conductive connectors 20 being too small, which would result in the length of the truncated suspended section 21 being too short and the process difficulty of truncating the first conductive connector 20 being increased; it is also possible to avoid the distance L2 between two adjacent first conductive connectors 20 being too large, which would result in a small number of first conductive connectors 20 and a reduced carrier collection effect.

[0065] Specifically, in such an embodiment, the distance L2 between two adjacent first conductive connecting members 20 may be, for example, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, or 1.2 mm.

[0066] Example 3

[0067] In some embodiments, in the first direction, the distance between two adjacent back-contact solar cells 10 (ie, the width of the spacer 101 in the first direction) may be 0.3 mm-1.2 mm.

[0068] In this way, it is possible to avoid the distance between two adjacent back-contact solar cells 10 being too small, which would make it inconvenient to operate when cutting off the first conductive connector 20; and it is also possible to avoid the distance between two adjacent back-contact solar cells 10 being too large, which would result in a smaller number of back-contact solar cells 10 in a single back-contact solar cell string 100 of the same size.

[0069] Specifically, in such an embodiment, the distance between two adjacent back-contact solar cells 10 may be, for example, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, or 1.2 mm.

[0070] Example 4

[0071] Please refer to Figure 7. In some embodiments, the back-contact solar cell 10 also includes a plurality of metal grid lines 50 arranged corresponding to the P-type doped layer 11 and the N-type doped layer 12. The metal grid lines 50 on the P-type doped layer 11 are in ohmic contact with the P-type doped layer 11, and the metal grid lines 50 on the N-type doped layer 12 are in ohmic contact with the N-type doped layer 12. The first conductive connector 20 is fixedly connected to the metal grid lines 50.

[0072] The portion between the end point of the cut first conductive connection 20 not connected to the second conductive connection 80 and the fixed point 102 of the metal gate line 50 closest to the spacer 101 is the suspended segment 21 .

[0073] In this way, by welding the first conductive connector 20 to the metal grid line 50 , the connection stability and reliability of the first conductive connector 20 can be improved, and the first conductive connector 20 can be effectively prevented from falling off.

[0074] Specifically, in such an embodiment, the metal gate line 50 is a metal sub-gate electrode, the metal gate line 50 on the P-type doped layer 11 is a P-type sub-gate electrode, and the metal gate line 50 on the N-type doped layer 12 is an N-type sub-gate electrode. The metal gate line 50 is used to collect currents in the P-type region and the N-type region, and then connected in series through the first conductive connector 20, and finally realized bus output through the above-mentioned first bus bar 30 and second bus bar 40.

[0075] In such an embodiment, the metal grid line 50 can be formed on the P-type doped layer 11 and the N-type doped layer 12 by printing and sintering, and the first conductive connector 20 can be connected to the metal grid line 50 by welding. For example, as shown in FIG7 , the metal grid line 50 can have a plurality of welding points 51, and the conductive connector 20 can be welded to the metal grid line 50 via the welding points 51. It is easy to understand that the welding point 51 closest to the spacer 101 is the fixing point 102 closest to the spacer 101 in this document.

[0076] In some embodiments, the length of the suspended segment 21 is smaller than the distance between the first conductive connection 20 and the metal gate line 50 adjacent to the first conductive connection 20 in the second direction.

[0077] In this way, the suspended segment 21 can be prevented from bending and contacting the adjacent metal gate line 50 of different polarity.

[0078] Specifically, the "spacing between the first conductive connector 20 and the metal grid line 50 adjacent to the first conductive connector 20 in the second direction" refers to the distance between two opposing edges of the first conductive connector 20 and the metal grid line 50 in the second direction. It will be appreciated that in some embodiments, the width of the metal grid line 50 in the second direction may be greater than the width of the first conductive connector 20. In such cases, the first conductive connector 20 does not completely cover the metal grid line 50. Therefore, to prevent the suspended segment 21 from bending and contacting the edge of the adjacent metal grid line 50, thereby causing a short circuit, the length of the suspended segment 21 may be set to be less than the spacing between the first conductive connector 20 and the adjacent metal grid line 50.

[0079] Example 5

[0080] Referring to FIG. 8 , in some embodiments, at the corresponding position of the spacer 101 , the first shielding layer 60 is coated on the side of the first conductive connector 20 facing the light-receiving surface (ie, the bottom surface in FIG. 8 ) of the back-contact solar cell 10 .

[0081] Thus, coating the first shielding layer 60 on the area where the first conductive connection 20 is exposed from the spacer 101 can shield the first conductive connection 20 and prevent the first conductive connection 20 from being directly exposed and affecting the appearance.

[0082] Furthermore, in such an embodiment, the color of the first shielding layer 60 may be the same as the color of the back-contact solar cell 10. For example, when the back-contact solar cell 10 is blue, the color of the first shielding layer 60 may also be blue; and when the back-contact solar cell 10 is gold, the color of the first shielding layer 60 may also be gold.

[0083] In this way, the color of the first conductive connector 20 is unified with the color of the back contact solar cell 10, which can avoid the first conductive connector 20 of different colors being seen from the front at the spacer 101, thereby ensuring an aesthetic appearance.

[0084] In some embodiments, a second shielding layer (not shown) may be provided on the side of the second conductive connector 80 facing the light-receiving surface of the back contact solar cell 10. Thus, the second shielding layer prevents the second conductive connector 80 from being directly exposed and affecting the appearance.

[0085] In such an embodiment, the color of the second shielding layer may also be the same as the color of the back contact solar cell 10 .

[0086] Example 6

[0087] Please refer to FIG. 9 . In some embodiments, at the corresponding position of the spacer 101 , the end of the suspended segment 21 is coated with an insulating coating 70 , and the insulating coating 70 wraps the end of the suspended segment 21 .

[0088] Thus, the provision of the insulating coating 70 can prevent the first conductive connector 20 from unexpectedly causing conductive contact between the two ends after being cut, thereby improving the reliability of the back-contact solar cell string 100 .

[0089] Furthermore, in such an embodiment, the color of the insulating coating 70 corresponds to the color of the back-contact solar cell 10. In this way, the aesthetic appearance of the entire back-contact solar cell string 100 can be ensured.

[0090] Throughout this specification, reference to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations 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 any one or more embodiments or examples.

[0091] 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 replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A back-contact solar cell string, characterized in that, Comprising: A plurality of back-contact solar cells arranged in a first direction. The backlight surface of the back-contact solar cell has a P-type doping layer and an N-type doping layer arranged alternately in a second direction in sequence. The second direction intersects the first direction. There is a spacing area between two adjacent back-contact solar cells. Among two adjacent back-contact solar cells, the P-type doping layer of one of them corresponds to the P-type doping layer of the other in the first direction, and the N-type doping layer of one of them also corresponds to the N-type doping layer of the other in the first direction; A plurality of first conductive connectors, the first conductive connectors are arranged parallel to the P-type doping layer and the N-type doping layer, and the plurality of first conductive connectors are arranged at intervals in the second direction. The first conductive connectors are provided on both the P-type doping layer and the N-type doping layer of each back-contact solar cell; The first conductive connectors on the P-type doping layer are fixedly and conductively connected to all the P-type doping layers corresponding to each other in the first direction in each back-contact solar cell, and the first conductive connectors on the N-type doping layer are fixedly and conductively connected to all the N-type doping layers corresponding to each other in the first direction in each back-contact solar cell; A plurality of second conductive connectors, the second conductive connectors are arranged to extend in the second direction and one second conductive connector is correspondingly provided at each spacing area, and the second conductive connectors are connected to all the first conductive connectors; At the position corresponding to the spacing area, in the Mth first conductive connector, the part located on one side of the second conductive connector is truncated, and in the (M + 1)th first conductive connector, the part located on the other side of the second conductive connector is truncated, so as to connect a plurality of the back-contact solar cells in series into a back-contact solar cell string, where M is a positive integer; Wherein, the truncated first conductive connector forms a suspended segment that is not connected to the second conductive connector at the spacing area, and the length of the suspended segment is less than the distance between two adjacent first conductive connectors.

2. The back-contact solar cell string according to claim 1, wherein The number of the back-contact solar cells is greater than two, and the positions where the same first conductive connector is truncated in two adjacent spacing areas are the same.

3. The back-contact solar cell string according to claim 1, wherein In the second direction, the distance between two adjacent first conductive connectors is 0.3 mm - 1.2 mm.

4. The back-contact solar cell string according to claim 1, characterized in that, In the first direction, the distance between two adjacent back-contact solar cells is 0.3 mm - 1.2 mm.

5. The back-contact solar cell string according to claim 1, wherein The back-contact solar cell further includes a plurality of metal grid lines corresponding to the P-type doping layer and the N-type doping layer. The metal grid lines on the P-type doping layer are in ohmic contact with the P-type doping layer, the metal grid lines on the N-type doping layer are in ohmic contact with the N-type doping layer, and the first conductive connectors are fixedly connected to the metal grid lines.

6. The battery string according to claim 5, characterized in that, The length of the suspended segment is less than the spacing between the first conductive connector and the metal grid line adjacent to the first conductive connector in the second direction.

7. The back-contact solar cell string according to claim 1, characterized in that, At a corresponding position of the spacer region, a first shielding layer is provided on a side of the first conductive connection member facing the light-receiving surface of the back-contact solar cell, and the color of the first shielding layer corresponds to the color of the back-contact solar cell; and / or A second shielding layer is provided on a side of the second conductive connection member facing the light-receiving surface of the back-contact solar cell, and the color of the first shielding layer corresponds to the color of the back-contact solar cell.

8. The back-contact solar cell string according to claim 1, wherein, An insulating coating is applied at an end of the suspended section, and the insulating coating wraps the end of the suspended section.

9. The back-contact solar cell string according to claim 8, wherein, The color of the insulating coating corresponds to the color of the back-contact solar cell.

10. A battery assembly, characterized in that, Comprising a back-contact solar cell string according to any one of claims 1-9.

11. A photovoltaic system, characterized in that, Comprising the battery module according to claim 10.

Images