Cell string, cell module and photovoltaic system

Abstract

The present application applies to the technical field of solar cells. Provided are a cell string (100), a cell module (200) and a photovoltaic system (1000). In the cell string (100), several back-contact solar cells (10) are arranged at intervals in a first direction; the back surface of each back-contact solar cell (10) is provided with P-type doped layers (11) and N-type doped layers (12) which are alternately arranged in sequence in a second direction, the P-type doped layers (11) and the N-type doped layers (12) both extending in the first direction; a spacing region (101) is provided between every two adjacent back-contact solar cells (10); and between every adjacent back-contact solar cells (10), the P-type doped layers (11) of one cell correspond to the N-type doped layers (12) of the other cell in the first direction. Each electrically conductive connector (20) is fixedly and conductively connected to both a P-type doped layer (11) and an N-type doped layer (12). At each spacing region (101), in the second direction, every other electrically conductive connector (20) is cut off. Each cut-off electrically conductive connector (20) forms a suspended segment (21) at the spacing region (101), the length (L1) of the suspended segment (21) being less than the distance (L2) between two adjacent electrically conductive connectors (20).

Description

Battery strings, battery panels and photovoltaic systems

[0001] Priority information

[0002] This application claims priority and benefits of patent application No. 202420051820.2 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 battery string, a battery assembly and a photovoltaic system. Background Art

[0004] Solar cells are a sustainable source of clean energy, converting sunlight into electricity through the photovoltaic effect of a semiconductor pn junction. Back-contact solar cells are designed with both the emitter and base contact electrodes located on the back (non-light-receiving) side of the cell. This leaves the light-receiving side unobstructed by any metal electrodes, effectively increasing the cell's short-circuit current.

[0005] When forming a string of back-contact solar cells, a secondary grid and a main grid are typically formed on the cell 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.

[0006] In related technologies, to address this technical issue, a busbar is omitted. Instead, a wire is placed directly in contact with the P-type and N-type regions of the cell, and then the cells are connected in series. This method involves cutting off one wire every other time. However, this solution 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, causing a short circuit. Summary of the Invention

[0007] The present application provides a battery string, a battery assembly and a photovoltaic system.

[0008] The present application is implemented as follows: the battery string of the embodiment of the present application includes:

[0009] A plurality of back-contact solar cells arranged along a first direction, wherein a back-light surface of the back-contact solar cells has a P-type doped layer and an N-type doped layer alternately arranged in sequence along a second direction, the P-type doped layer and the N-type doped layer having opposite polarities, and the second direction intersecting the first direction;

[0010] There is a spacer between two adjacent back-contact solar cells, and in the two adjacent back-contact solar cells, the P-type doped layer of one and the N-type doped layer of the other are arranged correspondingly in the first direction;

[0011] a plurality of conductive connectors, the conductive connectors extending along the first direction, and the conductive connectors being spaced apart along the second direction, each of the conductive connectors being located above the P-type doped layer and the N-type doped layer and being fixed and conductively connected to the P-type doped layer and the N-type doped layer, and each of the P-type doped layer and each of the N-type doped layers corresponding to one conductive connector;

[0012] At a position corresponding to the spacing area, in the second direction, every other conductive connection is cut off;

[0013] The truncated conductive connecting member forms a suspended segment at the spacing area, and the length of the suspended segment is smaller than the distance between two adjacent conductive connecting members.

[0014] Furthermore, the number of the back-contact solar cells is greater than two, and in two adjacent spacing regions, the interrupted conductive connections are different.

[0015] Furthermore, in the second direction, the distance between two adjacent conductive connecting members is 0.3 mm-1.2 mm.

[0016] Furthermore, in the first direction, the distance between two adjacent back-contact solar cells is 0.3 mm-1.2 mm.

[0017] Furthermore, the back-contact solar cell also includes a plurality of metal grid lines arranged corresponding to the P-type doped layer and the N-type doped layer, the metal grid lines on the P-type doped layer are in ohmic contact with the P-type doped layer, the metal grid lines on the N-type doped layer are in ohmic contact with the N-type doped layer, and the conductive connectors are fixedly connected to the metal grid lines.

[0018] Furthermore, the length of the suspended segment is smaller than the distance between the conductive connection and the metal grid line adjacent to the conductive connection in the second direction.

[0019] Furthermore, at a corresponding position of the spacer area, a shielding layer is provided on a side of the conductive connector facing the light-receiving surface of the back-contact solar cell, and the color of the shielding layer corresponds to the color of the back-contact solar cell.

[0020] Furthermore, an insulating coating is coated on the end of the suspended segment, and the insulating coating wraps the end of the suspended segment.

[0021] Furthermore, the color of the insulating coating corresponds to the color of the back contact solar cell.

[0022] The present application also provides a battery assembly, which includes several of the above-mentioned battery strings.

[0023] The present application also provides a photovoltaic system, which includes the above-mentioned battery assembly.

[0024] In the cell strings, cell assemblies, and photovoltaic systems of the embodiments of the present application, a spacer region is provided between two adjacent back-contact solar cells in the cell string. In the two adjacent back-contact solar cells, the P-type doped layer of one and the N-type doped layer of the other are arranged correspondingly in a first direction. Each conductive connector is located above the P-type doped layer and the N-type doped layer and is fixedly and conductively connected to the P-type doped layer and the N-type doped layer. At the position corresponding to the spacer region, in the second direction, every other conductive connector is interrupted. The interrupted conductive connector forms a suspended segment at the spacer region, and the length of the suspended segment is less than the distance between the two adjacent conductive connectors. In this way, the individual back-contact solar cells can be directly connected in series via the conductive connectors to form a cell string. By interrupting every other conductive connector at the spacer region, short circuits can be avoided. The length of the suspended segment formed by the interrupted conductive connector is less than the distance between the two adjacent conductive connectors, which prevents the suspended segment from bending and contacting the adjacent conductive connector, causing leakage, thereby ensuring the stability and reliability of the cell string.

[0025] 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

[0026] FIG1 is a module schematic diagram of a photovoltaic system provided in an embodiment of the present application.

[0027] FIG2 is a module schematic diagram of a battery assembly provided in an embodiment of the present application.

[0028] FIG3 is a schematic diagram of a planar structure of a battery string provided in an embodiment of the present application;

[0029] FIG4 is another planar structural diagram of a battery string provided in an embodiment of the present application;

[0030] FIG5 is another schematic plan view of the structure of a battery string according to an embodiment of the present application;

[0031] FIG6 is another schematic plan view of the structure of a battery string according to an embodiment of the present application;

[0032] FIG7 is a schematic cross-sectional view of a battery string provided by an embodiment of the present application at the location of a conductive connector along a first direction;

[0033] FIG8 is another cross-sectional schematic diagram of a battery string provided by an embodiment of the present application at the location of a conductive connector along the first direction;

[0034] FIG9 is another schematic cross-sectional view of a battery string provided by an embodiment of the present application at the location of a conductive connector along the first direction.

[0035] Description of main component symbols:

[0036] Photovoltaic system 1000, battery assembly 200, battery string 100, back-contact solar cell 10, P-type doped layer 11, N-type doped layer 12, spacer 101, conductive connector 20, suspended section 21, first bus bar 30, second bus bar 40, metal grid line 50, shielding layer 60, insulating coating 70. Modes for Carrying Out the Invention

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] Example 1

[0043] 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 battery strings 100 in the embodiment of the present application.

[0044] 3 to 6 , a cell string 100 in an embodiment of the present application may include a plurality of back-contact solar cells 10 and a plurality of conductive connectors 20 .

[0045] 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. The polarities of the P-type doped layer 11 and the N-type doped layer 12 are opposite, and the first direction intersects the second direction.

[0046] Specifically, the first direction may be the connection direction of the battery string 100 (ie, the transverse direction in FIG. 3 ), and the second direction may be a direction perpendicular to the connection direction (ie, the longitudinal direction in FIG. 4 ), and the two directions are perpendicular to each other.

[0047] As shown in FIG3-6 , a spacer 101 is provided 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 and the N-type doped layer 12 of the other are arranged correspondingly in the first direction.

[0048] The conductive connector 20 extends along the first direction, and several conductive connectors 20 are arranged at intervals along the second direction. Each conductive connector 20 is located above the P-type doped layer 11 and the N-type doped layer 12 and is fixed to and conductively connected to the P-type doped layer 11 and the N-type doped layer 12. Each P-type doped layer 11 and each N-type doped layer 12 corresponds to a conductive connector 20. That is, as shown in Figures 3-6, for each conductive connector 20, it alternately connects several P-type doped layers 11 and several N-type doped layers 12 in the first direction.

[0049] As shown in Figures 3-6 , at the position corresponding to the spacing region 101, every other conductive connector 20 in the second direction is cut off. The cut conductive connector 20 forms a suspended segment 21 at the spacing region 101, and the length L1 of the suspended segment 21 is less than the distance L2 between two adjacent conductive connectors 20.

[0050] It should be noted that, as shown in FIG3 , a truncated conductive connector 20 forms two endpoints 22, which together form two suspended segments 21. One of the two suspended segments 21 is the portion between one of the endpoints 22 formed by the truncation of the conductive connector 20 and the fixing point 102 between the conductive connector 20 and the P-type doped layer 11 closest to the spacer 102 (i.e., the edge fixing point between the conductive connector 20 and the P-type doped layer 11). The other is the portion between the other endpoint 22 formed by the truncation of the conductive connector 20 and the fixing point 102 between the conductive connector 20 and the N-type doped layer 12 closest to the spacer 102 (i.e., the edge fixing point between the conductive connector 20 and the N-type doped layer 12). The length L1 of the suspended segment 21 is the distance between the endpoint 22 and the fixing point 102.

[0051] In the cell string 100, cell assembly 200, and photovoltaic system 1000 of the embodiment of the present application, a spacer 101 is provided between two adjacent back-contact solar cells 10 of the cell string 100. In the two adjacent back-contact solar cells 10, the P-type doped layer 11 of one and the N-type doped layer 12 of the other are arranged correspondingly in the first direction. Each conductive connector 20 is located above the P-type doped layer 11 and the N-type doped layer 12 and is fixed and conductively connected to the P-type doped layer 11 and the N-type doped layer 12. At the position corresponding to the spacer 101, in the second direction, every other conductive connector 20 is cut off. The cut conductive connector 20 forms a suspended section 21 at the spacer 101, and the length L1 of the suspended section 21 is less than the distance L2 between the two adjacent conductive connectors 20. In this way, each back-contact solar cell 10 can be directly connected in series through the conductive connector 20 to form a cell string 100. By cutting off one conductive connector 20 at the spacer area 101 for every other conductive connector 20, short circuit can be avoided. The length L1 of the suspended section 21 formed by the cut-off conductive connector 20 is less than the distance L2 between two adjacent conductive connectors 20, which can prevent the cut-off suspended section 21 from bending and contacting the adjacent conductive connector 20 to cause leakage, thereby ensuring the stability and reliability of the cell string 100.

[0052] Specifically, in the present application, the number of conductive connectors 20 corresponds to the sum of the number of P-type doped layers 11 and N-type doped layers 12 in each back-contact solar cell 10. For example, if the sum of the number of P-type doped layers 11 and N-type doped layers 12 in the back-contact solar cell 10 is 50, then the number of conductive connectors 20 is also 50.

[0053] 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 strips to form a cell string. Instead, a continuous conductive connector 20 is first used to directly connect each P-type doped layer 11 of a back-contact solar cell 10 to the corresponding N-type doped layer 12 of the next back-contact solar cell 10, and then every other conductive connector 20 is cut off in the spacer area 101 between the two back-contact solar cells 10, thereby forming a cell string 100.

[0054] It should be noted that “in two adjacent back-contact solar cells 10, the P-type doped layer 11 of one and the N-type doped layer 12 of the other are arranged correspondingly in the first direction” can be understood as, in two adjacent back-contact solar cells 10, the P-type doped layer 11 of one and the N-type doped layer 12 of the other are basically located on the same straight line in the first direction.

[0055] The phrase "at the position corresponding to the spacer 101, in the second direction, every other conductive connector 20 is interrupted" can be understood to mean that the Mth conductive connector 20 is continuous and uninterrupted at the spacer 101, while the M+1th conductive connector 20 is interrupted at the spacer 101, where M is a positive integer. For example, in the second direction, if the first conductive connector 20 is interrupted and the second conductive connector 20 is not, then, from top to bottom, the conductive connectors 20 at odd-numbered positions are interrupted, while the conductive connectors 20 at even-numbered positions are not. In other words, every other conductive connector 20 is interrupted, thereby forming two suspended segments 21.

[0056] Similarly, if the first conductive connection 20 is not cut off and the second conductive connection 20 is cut off, then, from top to bottom, the conductive connections 20 at even-numbered positions are cut off, while the conductive connections 20 at odd-numbered positions are not cut off.

[0057] At the same time, it should be noted that in this application, "the distance between two adjacent conductive connectors 20" refers to the spacing between the two conductive connectors 20 in the second direction, that is, the spacing between the lower edge of the previous conductive connector 20 and the upper edge of the next conductive connector 20.

[0058] Referring to FIG. 5 and FIG. 6 , in some embodiments, the number of back-contact solar cells 10 is greater than two, and the conductive connections 20 that are cut off in two adjacent spacers 101 are different.

[0059] Thus, if the number of back-contact solar cells 10 in the cell string 100 exceeds two, the conductive connections 20 cut off in two adjacent spacers 101 are different, which can achieve smooth current collection to avoid short circuits.

[0060] Specifically, as shown in Figures 5 and 6, in two adjacent spacing areas 101, the Mth conductive connection 20 in one of the spacing areas 101 is cut off, and the M+1th conductive connection 20 is not cut off. Then, in the other spacing area 101, the M+1th conductive connection 20 is cut off, and the Mth conductive connection 20 is not cut off, where M is a positive integer.

[0061] As shown in Figures 4 and 6, in an embodiment of the present application, the battery string 100 also includes a first bus bar 30 and a second bus bar 40 respectively located at both ends of the battery string 100. Among the plurality of conductive connectors 20, every other conductive connector 20 is electrically connected to the first bus bar 30 and the second bus bar 40, thereby realizing the bus output of the battery string 100.

[0062] Specifically, as shown in Figures 4 and 6, a first bus bar 30 and a second bus bar 40 are respectively provided at both ends of the battery string 100. The conductive connector 20 that is cut off at the interval 101 closest to the first bus bar 30 is connected to the first bus bar 30, and the remaining conductive connectors 20 are not in contact with the first bus bar 30. The conductive connector 20 that is cut off at the interval 101 closest to the second bus bar 40 is connected to the second bus bar 40, and the remaining conductive connectors 20 are not in contact with the second bus bar 40.

[0063] For example, as shown in FIG4 , a cell string 100 includes two back-contact solar cells 10 and only one spacer 101. In spacer 101, if the conductive connectors 20 at even-numbered positions are cut off, the conductive connectors 20 at even-numbered positions are connected to the first bus bar 30, while the conductive connectors 20 at odd-numbered positions are not in contact with the first bus bar 30. Similarly, the conductive connectors 20 at even-numbered positions are connected to the second bus bar 40, while the conductive connectors 20 at odd-numbered positions are not in contact with the second bus bar 40. Conversely, if the conductive connectors 20 at odd-numbered positions are cut off, the conductive connectors 20 at odd-numbered positions are connected to the first bus bar 30 and the second bus bar 40, while the conductive connectors 20 at even-numbered positions are not in contact with the first bus bar 30 and the second bus bar 40.

[0064] For another example, as shown in FIG6 , a cell string 100 includes three back-contact solar cells 10. In the spacing region 101 closest to the first bus bar 30, the conductive connectors 20 at even-numbered positions are cut off. Consequently, the conductive connectors 20 at even-numbered positions are connected to the first bus bar 30, while the conductive connectors 20 at odd-numbered positions are not in contact with the first bus bar 30. In the spacing region 101 closest to the second bus bar 40, the conductive connectors 20 at odd-numbered positions are cut off. Consequently, the conductive connectors 20 at odd-numbered positions are connected to the second bus bar 40, while the conductive connectors 20 at even-numbered positions are not in contact with the second bus bar 40.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] Example 2

[0070] In some embodiments, in the second direction, the distance L2 between two adjacent conductive connectors 20 may be 0.3 mm-1.2 mm.

[0071] In this way, it is possible to avoid the distance L2 between two adjacent 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 conductive connector 20 being increased; it is also possible to avoid the distance L2 between two adjacent conductive connectors 20 being too large, which would result in a small number of conductive connectors 20 and a reduced carrier collection effect.

[0072] Specifically, in such an embodiment, the distance L2 between two adjacent 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.

[0073] Example 3

[0074] 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.

[0075] 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 cut off the 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 reduce the number of back-contact solar cells 10 in a single cell string 100 of the same size.

[0076] 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.

[0077] Example 4

[0078] 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 conductive connector 20 is fixedly connected to the metal grid lines 50.

[0079] The portion between the end point 22 formed by the cut-off conductive connection 20 and the fixing point 102 of the cut-off conductive connection 20 and the metal gate line 50 closest to the spacer 101 is the suspended segment 21 .

[0080] In this way, by welding the conductive connector 20 to the metal grid line 50 , the connection stability and reliability of the conductive connector 20 can be improved, and the conductive connector 20 can be effectively prevented from falling off.

[0081] 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 conductive connector 20, and finally realized bus output through the above-mentioned first bus bar 30 and second bus bar 40.

[0082] 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 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.

[0083] It is not difficult to understand that the welding point 51 closest to the spacer area 101 is the fixed point 102 closest to the spacer area 101 in this article, and the part between the fixed point 102 and the end point 22 formed by the truncated conductive connector 20 is the suspended section 21 of the conductive connector 20. The length of the suspended section 21 is less than the distance between the two adjacent conductive connectors 20. In this way, no matter how the suspended section 21 bends and deforms, it will not contact the adjacent conductive connector 20, thereby avoiding short circuit.

[0084] In some embodiments, the length of the suspended segment 21 is smaller than the distance between the conductive connection 20 and the metal gate line 50 adjacent to the conductive connection 20 in the second direction.

[0085] In this way, the suspended segment 21 can be prevented from bending and contacting the adjacent metal gate line 50 of different polarity, thereby preventing leakage.

[0086] Specifically, the "spacing between the conductive connector 20 and the metal grid line 50 adjacent to the conductive connector 20 in the second direction" refers to the distance between two opposing edges of the 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 conductive connector 20. In such cases, the 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 conductive connector 20 and the adjacent metal grid line 50.

[0087] Example 5

[0088] Referring to Figure 8 , in some embodiments, a shielding layer 60 is coated on the side of the conductive connector 20 facing the light-receiving surface (i.e., the bottom surface in Figure 8 ) of the back-contact solar cell 10 at a corresponding position in the spacer 101. The color of the shielding layer 60 corresponds to the color of the back-contact solar cell 10. For example, if the back-contact solar cell 10 is blue, the shielding layer 60 may also be blue; and if the back-contact solar cell 10 is gold, the shielding layer 60 may also be gold.

[0089] Thus, coating the area of ​​the conductive connector 20 exposed from the spacer 101 with a shielding layer 60 of the same color as the back-connected solar cell can prevent the conductive connector 20 of a different color from being seen from the front at the spacer 101, thereby ensuring an aesthetically pleasing appearance.

[0090] Example 6

[0091] Referring to FIG. 9 , in some embodiments, an insulating coating 70 is coated on the end of the suspended segment 21 , and the insulating coating 70 wraps the end of the suspended segment 21 .

[0092] In this way, the provision of the insulating coating 70 can prevent the conductive connector 20 from unexpectedly causing conductive contact between the two ends after being cut, thereby improving the reliability of the battery string 100.

[0093] 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 cell string 100 can be ensured.

[0094] 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.

[0095] 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 cell string, comprising:a plurality of back-contact solar cells arranged in a first direction, a backlight surface of each of the back-contact solar cells having a P-type doped layer and an N-type doped layer which are alternately arranged in sequence in a second direction, the P-type doped layer and the N-type doped layer having opposite polarities, and the second direction intersecting the first direction;a spacer region provided between two adjacent back-contact solar cells, in the adjacent back-contact solar cells, a P-type doped layer of one back-contact solar cell corresponding to an N-type doped layer of the other back-contact solar cell in a first direction;a plurality of conductive connectors, wherein the conductive connectors extend in the first direction, the plurality of conductive connectors are arranged at intervals in a second direction, each of the conductive connectors is located above the P-type doped layer and the N-type doped layer, and is fixedly and conductively connected to the P-type doped layer and the N-type doped layer, and each of the P-type doped layers and each of the N-type doped layers correspond to one of the conductive connectors;at a position corresponding to the spacer region, in the second direction, every other conductive connector is cut off in a second direction,wherein a suspended segment is formed at the spacer region of the cut-off conductive connectors, and the length of the suspended segment is less than a distance between two adjacent conductive connectors.

2. The cell string according to claim 1, wherein a number of the back-contact solar cells is greater than two, and the cut-off conductive connectors are different in two adjacent spacer regions.

3. The cell string according to claim 1, wherein in the second direction, a distance between two adjacent conductive connectors is 0.3mm to 1.2mm.

4. The cell string according to claim 1, wherein in the first direction, a distance between twoadjacent back-contact solar cells is 0.3 mm to 1.2 mm.

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

6. The cell string according to claim 5, wherein a length of the suspended segment is less than a distance between the conductive connector and the metal grid line adjacent to the conductive connector in the second direction.

7. The cell string according to claim 1, wherein at a position corresponding to the spacer region, a shield layer is provided on the side of the conductive connector facing a light-receiving surface of the back-contact solar cell, and the color of the shield layer corresponds to that of the back-contact solar cell.

8. The cell string according to claim 1, wherein an end portion of the suspended segment is coated with an insulating coating, and the insulating coating wraps around the end portion of the suspended segment.

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

10. A cell assembly, comprising several cell strings according to any one of claims 1 to 9.

11. A photovoltaic system, comprising the cell assembly according to claim 10.

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