Back contact battery assembly and photovoltaic system

Abstract

The utility model provides a back contact battery assembly and a photovoltaic system. The back contact battery assembly comprises a battery string; the first bus bar is arranged on the backlight surface of the Nth battery piece; a first solder strip; a second solder strip; the first insulating part is used for isolating the second welding strip from the first bus bar; and in the second direction, the second welding strip and the extension section are arranged at an interval, and the extension line of the first main body section and the second welding strip are at least partially overlapped. According to the utility model, after the first welding strip is welded with the first battery piece, the first welding strip can be directly connected with the first bus bar without trepanning the first insulating part, so that the short circuit or pseudo soldering of the welding strip caused by position offset when the first insulating part is trepanned can be avoided.

Description

Technical Field

[0001] This utility model relates to the field of back contact battery module technology, and in particular to a back contact battery module and a photovoltaic system. Background Technology

[0002] In existing back-contact battery module manufacturing processes, users typically place the busbars at the edge of the module to connect adjacent cells. Furthermore, users need to install an insulating strip between the busbar and the cell, and this insulating strip is perforated to allow the busbar to contact the same-polarity solder strip on the cell while insulating it from solder strips of different polarities. However, perforating the insulating strip requires high-precision machining and positioning, which can easily lead to positional misalignment, causing short circuits or poor solder joints.

[0003] Therefore, how to reduce the risk of short circuits or poor soldering in the back contact battery assembly has become an urgent problem to be solved. Utility Model Content

[0004] This invention provides a back-contact battery module and a photovoltaic system to solve the technical problem of how to reduce the risk of short circuits or poor soldering in back-contact battery modules.

[0005] This utility model is implemented as follows: This utility model provides a back-contact battery module and a photovoltaic system. A back-contact battery module includes: a battery string comprising a plurality of battery cells arranged sequentially along a first direction, the battery string including opposing first and second edges, the first and second edges extending along a second direction, the second direction intersecting the first direction; a first busbar extending along the second direction, the first busbar being disposed on the back surface of an Nth battery cell, the Nth battery cell being the Nth cell in the battery string along the first direction, N being greater than or equal to 3, and in the first direction, the distance from the first busbar to the first edge being less than the distance from the first busbar to the second edge; a first solder strip disposed on the back surface of a first battery cell, the first battery cell being the first cell in the battery string along the first direction; and a second solder strip disposed on... The backlight surface of the second to the Nth battery cells, wherein the second battery cell is the second battery cell in the battery string along the first direction; a first insulating member, disposed between the first busbar and the Nth battery cell, the first insulating member being used to isolate the second solder strip and the first busbar; wherein the first solder strip includes a first main body segment electrically connected to the first battery cell, an extension segment electrically connected to the first busbar, and a second main body segment insulated from the second to the (N-1)th battery cells by the first insulating member, wherein the (N-1)th battery cell is the (N-1)th battery cell in the battery string along the first direction; in the second direction, the second solder strip and the extension segment are spaced apart, and the extension line of the first main body segment is at least partially overlapped with the second solder strip.

[0006] Furthermore, along the second direction, the second main body segment and the second welding strip are spaced apart.

[0007] Furthermore, along the second direction, the second main body segment and the second welding strip are arranged collinearly.

[0008] Furthermore, along the first direction, the first insulating element at least partially covers the second to the (N-1)th battery cells.

[0009] Furthermore, along the first direction, the first insulating member completely covers the second to the (N-1)th battery cells.

[0010] Furthermore, there are multiple first welding strips, which are arranged along the second direction. The first insulating component includes multiple insulating strips arranged at intervals along the second direction, and the insulating strips are correspondingly arranged with respect to the second main body segment.

[0011] Furthermore, in the second direction, the width of the insulating strip is greater than or equal to the width of the second main body segment.

[0012] Furthermore, in the second direction, the spacing between two adjacent insulating strips is 1 mm to 10 mm.

[0013] Furthermore, along the first direction, the first insulating member includes a first insulating portion and a second insulating portion arranged in sequence, the first insulating portion being located between the second main body segment and the second battery cell to the (N-1)th battery cell; the second insulating portion being located between the second solder strip and the first busbar.

[0014] Furthermore, in the second direction, the distance between the second solder strip and the adjacent epitaxial segment is 0.1 mm to 1 mm.

[0015] Furthermore, in the first direction, two adjacent battery cells partially overlap.

[0016] This utility model embodiment also provides a photovoltaic system, which includes the back contact battery assembly as described above.

[0017] In the back contact battery assembly of this utility model embodiment, after the first solder strip is soldered to the first battery cell, it can be directly connected to the first busbar without the need to open the first insulating component. During assembly, the first insulating component only needs to be placed on the Nth battery cell. This can avoid short circuits or poor soldering caused by positional displacement when the first insulating component is opened, increase the product yield of the back contact battery assembly, and effectively reduce the precision requirements and production difficulty of the back contact battery assembly.

[0018] Furthermore, in the back contact battery assembly of this utility model embodiment, the first busbar is set along the Nth battery cell of the battery string in the first direction, where N is greater than or equal to 3. This also allows the first busbar to be located at a position relatively far from the edge of the back contact battery assembly, thereby reducing the stress on the edge of the back contact battery, reducing the risk of poor soldering, and also reducing the risk of microcracks and fragments in the battery cells. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a photovoltaic system module provided in one embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of a back contact battery assembly provided in one embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of a back contact battery assembly provided in another embodiment of the present invention;

[0023] Figure 4 yes Figure 2 A partial structural schematic diagram of the back contact battery assembly shown in the figure;

[0024] Figure 5 yes Figure 3 A partial structural schematic diagram of the back contact battery assembly shown in the figure;

[0025] Figure 6 This is a cross-sectional schematic diagram of a portion of the back contact battery assembly structure provided in one embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram of the structure of a back contact battery assembly provided in another embodiment of the present invention;

[0027] Figure 8 This is a schematic diagram of the structure of a back contact battery assembly provided in another embodiment of the present invention.

[0028] Key component symbols: 1000, Photovoltaic system; 100, Back contact battery module; 101, First edge; 102, Second edge; 10, Battery string; 20, First solder strip; 30, Second solder strip; 40, First insulating component; 50, First busbar; 60, Third solder strip; 11, First cell; 12, Second cell; 13, Third cell; 14, (N-1)th cell; 15, Nth cell; 16, (N+1)th cell; 21, First main body segment; 22, Second main body segment; 23, Extension segment; 24, Connecting segment; 41, Insulating strip; 42, First insulating part; 43, Second insulating part. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as limiting the present utility model. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0030] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "top", "bottom", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0031] 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 utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. 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 the invention. 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, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0034] Please see Figure 1The photovoltaic system 1000 in this embodiment of the present invention may include a back-contact battery module 100. The back-contact battery module 100 may include multiple battery strings 10, and each battery string 10 may include multiple battery cells. These battery cells can be sequentially connected together via solder strips to form the battery strings 10. The battery strings 10 in the back-contact battery module 100 can be connected in series, in parallel, or in a series-parallel combination to achieve current collection and output. For example, busbars can be used to connect the various battery strings 10.

[0035] In this embodiment, the photovoltaic system 1000 can be applied in back-contact battery module 100 power stations, such as ground-mounted power stations, rooftop power stations, and floating power stations. It can also be applied to equipment or devices that utilize solar energy for power generation, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system 1000 are not limited to these; that is, the photovoltaic system 1000 can be applied in all fields that require solar energy for power generation. Taking the back-contact battery module 100 power generation system network as an example, the photovoltaic system 1000 may include a back-contact battery module 100 array, a combiner box, and an inverter. The back-contact battery module 100 array can be a combination of multiple battery modules. For example, multiple battery modules can form multiple back-contact battery module 100 arrays. The back-contact battery module 100 array is connected to the combiner box, which can collect the current generated by the back-contact battery module 100 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.

[0036] The accompanying drawings provided in this application are schematic diagrams, and some elements are not shown in the drawings. The purpose is to clearly describe the technical solution and highlight the key features of the utility model. It is not intended to limit the technical solution to exclude these unshown elements. That is to say, the drawings are merely examples and do not represent a limitation on the specific form of the back contact battery assembly 100.

[0037] like Figures 2 to 8As shown, the back-contact battery assembly 100 in this embodiment of the present invention includes: a battery string 10, a first busbar 50, a first solder strip 20, a second solder strip 30, and a first insulating member 40. The battery string 10 includes a plurality of battery cells arranged sequentially along a first direction. The battery string 10 includes opposing first edges 101 and second edges 102, which extend along a second direction and intersect the first direction. Specifically, the first edges 101 and second edges 102 are two opposing boundary lines arranged along the first direction in the battery string 10. The battery string 10 may include two battery cells connected in series, three battery cells connected in series, or a greater number of battery cells. The specific number of battery cells to be connected in series can be determined according to the actual usage, and this application does not impose any limitations on this. Furthermore, the grid lines on the battery cells are not shown in the figures. The grid lines on the battery cells can be arranged according to the actual situation; for example, they can be battery cells with main grids or battery cells without main grids.

[0038] The first busbar 50 extends along the second direction and is disposed on the backlight surface of the Nth battery cell 15, which is the Nth battery cell in the battery string 10 along the first direction, where N is greater than or equal to 3. In the first direction, the distance from the first busbar 50 to the first edge 101 is less than the distance from the first busbar 50 to the second edge 102. The second direction intersects the first direction. The first solder strip 20 is disposed on the backlight surface of the first battery cell 11, which is the first battery cell in the battery string 10 along the first direction. The second solder strip 30 is disposed on the backlight surfaces of the second battery cell 12 to the Nth battery cell 15, which is the second battery cell in the battery string 10 along the first direction. The first insulating member 40 is disposed between the first busbar 50 and the Nth battery cell 15, and is used to isolate the second solder strip 30 from the first busbar 50.

[0039] The first solder strip 20 includes a first main body segment 21 electrically connected to the first battery cell, an extension segment 23 electrically connected to the first busbar 50, and a second main body segment 22 insulated from the second battery cell 12 to the (N-1)th battery cell 14 by a first insulating member 40. The (N-1)th battery cell 14 is the (N-1)th battery cell in the battery string 10 along the first direction; in the second direction, the second solder strip 30 is spaced apart from the extension segment 23; the extension line of the first main body segment 21 is at least partially overlapped with the second solder strip 30.

[0040] Thus, in this embodiment of the present invention, after the first solder strip 20 of the back contact battery assembly 100 is soldered to the first battery cell 11, it can be directly connected to the first busbar 50. Therefore, the user does not need to perform hole-making on the first insulating component 40; during assembly, the first insulating component 40 can simply be placed entirely on the Nth battery cell 15. This avoids short circuits or incomplete soldering caused by positional misalignment when the first insulating component 40 is made into a hole, increasing the product yield of the back contact battery assembly 100. Simultaneously, it effectively reduces the precision requirements and manufacturing difficulty of the back contact battery assembly 100. Preferably, the first busbar 50 can be located at the end of the Nth battery cell 15 near the (N-1)th battery cell 14. Thus, the extension segment 23 can extend to the edge of the (N-1)th battery cell 14 near the Nth battery cell 15 to achieve electrical connection with the first busbar 50. This reduces the extension length of the extension segment 23 of the first solder strip 20, saving solder strip material and thus reducing costs. Specifically, the first busbar 50 is specifically disposed on the Nth battery cell in the battery string 10 along the first direction, where N is greater than or equal to 3. In the first direction, the distance from the first busbar 50 to the first edge 101 is less than the distance from the first busbar 50 to the second edge 102. On the one hand, the edge area of ​​the back contact battery assembly 100 no longer needs to reserve space for placing the busbar, and the back contact battery assembly 100 can reserve more space to install the battery cells, making the effective light-receiving area of ​​the back contact battery assembly 100 larger and the photoelectric conversion efficiency of the back contact battery assembly 100 higher. On the other hand, this application can hide the first busbar 50 on the back surface of the battery cell, which can further increase the effective light-receiving area of ​​the back contact battery assembly 100, improve the conversion efficiency of the back contact battery assembly 100, and make the overall aesthetics of the back contact battery assembly 100 better.

[0041] Furthermore, it is understood that the stress at the edge of the back contact battery assembly 100 is relatively high, and the stress increases closer to the edge of the back contact battery assembly 100. This can lead to insufficient tensile strength in the welding of the solder strips at the edge of the back contact battery assembly 100, making it prone to incomplete soldering. Additionally, it increases the risk of microcracks and fragmentation of the battery cells during lamination of the back contact battery assembly 100. Therefore, compared to placing the first busbar 50 on the first battery cell 11 or the second battery cell 12 along the first direction in the battery string 10, this application places the first busbar 50 on the Nth battery cell 15 along the first direction in the battery string 10, where N is greater than or equal to 3. This allows the first busbar 50 to be located further away from the edge of the back contact battery assembly 100, thereby reducing the stress at the edge of the back contact battery assembly 100, reducing the risk of incomplete soldering, and also lowering the risk of microcracks and fragmentation of the battery cells, thus improving the stability of the back contact battery assembly 100.

[0042] Specifically, the first busbar 50 can be an end busbar, and the first busbar 50 can be used for series connection between adjacent battery strings 10 in the second direction.

[0043] Specifically, the first busbar 50 can be an intermediate busbar located near the center of the back contact battery assembly 100. The first busbar 50 can be used for parallel connection between adjacent battery strings 10 in the first direction. Specifically, adjacent battery strings 10 can be connected to the first busbar 50 in the first direction to achieve parallel connection of adjacent battery strings 10.

[0044] Specifically, the first welding strip 20 includes a first main body segment 21, a second main body segment 22, and an extension segment 23 arranged sequentially along a first direction. The first main body segment 21 is located on the backlight surface of the first solar cell 11 and is electrically connected to the first solar cell 11; the second main body segment 22 is located on the backlight surface of the second solar cell 12 to the (N-1)th solar cell 14, and the second main body segment 22 is insulated from the second solar cell 12 to the (N-1)th solar cell 14; the extension segment 23 is located on the first busbar 50 and is electrically connected to the first busbar 50. The electrical connection method can be welding, bonding with conductive adhesive, etc., but is not limited to these methods.

[0045] Therefore, by electrically connecting the first solder strip 20 with the epitaxial section 23 and the first busbar 50, and by setting the epitaxial section 23 and the second solder strip 30 at intervals in the second direction, the first insulating strip 41 can be offset to a certain extent in the first direction during the manufacturing process, which effectively reduces the production precision requirements and production difficulty, and can effectively reduce the risk of short circuit. Furthermore, due to the staggered setting of the epitaxial section 23 and the second solder strip 30, the stacking height can be reduced, and the stress on the back contact battery module 100 is smaller during lamination, which can reduce the risk of microcracks and fragments in the battery cells and improve the reliability of the back contact battery module 100.

[0046] Furthermore, in the second direction, the extension line of the first main body segment 21 in the first solder strip 20 at least partially overlaps with the second solder strip 30. This facilitates the user's positioning of the first solder strip 20, making it easier to set its position. In addition, it makes the solder strip wiring simpler and clearer, and reduces the difficulty and complexity of solder strip wiring in the back contact battery assembly 100.

[0047] It is worth noting that "in the second direction, the extension line of the first main body segment 21 in the first solder strip 20 at least partially overlaps with the second solder strip 30" means that in the second direction, the extension line of the first main body segment 21 partially or completely covers the second solder strip 30. It can be understood that "the second cell 12 to the (N-1)th cell 14" refers to all the cells in the battery string 10 from the second cell in the first direction to the (N-1)th cell 14 in the first direction. For example, when N=3, "the second cell 12 to the (N-1)th cell 14" refers to the second cell in the first direction of the battery string 10. For example, when N=4, "the second cell 12 to the (N-1)th cell 14" refers to the second cell and the third cell in the first direction of the battery string 10. For example, when N=5, "the second cell 12 to the (N-1)th cell 14" refers to the second cell of the battery string 10 in the first direction, the third cell of the battery string 10 in the first direction, and the fourth cell of the battery string 10 in the first direction. It can be understood that "the second cell 12 to the (N-1)th cell 14" includes the second cell 12, the (N-1)th cell 14, and all cells between the second cell 12 and the (N-1)th cell 14 along the first direction.

[0048] like Figures 2 to 8 As shown, in this embodiment of the present invention, N = 3 and (N-1) = 2 are used for explanation. In other words, the (N-1)th battery cell 14 is the second battery cell 12; the Nth battery cell 15 is the third battery cell 13.

[0049] Furthermore, the second main body segment 22 of the first solder strip 20 may span one or more solar cells. Moreover, to prevent a short circuit caused by electrical connection between the second main body segment 22 of the first solder strip 20 and solar cells other than the first solar cell 11, a first insulating member 40 is provided in this application. The first insulating member 40, in addition to isolating the second solder strip 30 and the first busbar 50, also isolates the second main body segment 22 of the first solder strip 20 from the second solar cells 12 to the (N-1)th solar cells 14. Therefore, a portion of the first insulating member 40 is located between the second main body segment 22 and the second solar cells 12 to the (N-1)th solar cells 14.

[0050] Furthermore, the first solder strip 20 includes a first main body segment 21 electrically connected to the first battery cell 11 and an extension segment 23 electrically connected to the first busbar 50. Specifically, in the second direction, the extension segment 23 and the second solder strip 30 are spaced apart. This is such that the extension segment 23 extending to the Nth battery cell 15 does not overlap with the second solder strip 30 on the Nth battery cell 15 in the thickness direction of the first busbar 50. This avoids excessive stress caused by partial overlap of the extension segment 23 and the second solder strip 30 on the first busbar 50, thereby reducing the risk of microcracks in the battery cells during the lamination process of the back-contact battery assembly 100.

[0051] For example, the thickness of the first busbar 50 can be between 0.06 mm and 0.3 mm, and the width can be between 8 mm and 20 mm. The material of the first busbar 50 can be a tin-plated copper busbar, conductive copper foil, or aluminum-based copper strip.

[0052] For example, the first insulating element 40 can be an insulating adhesive, or a non-conductive tape or insulating film, such as a PET or PI tape with acrylic or silicone, or a PET or PI substrate coated on one or both sides with ethylene-vinyl acetate copolymer or hot melt adhesive. It is understood that the first insulating element 40 may comprise materials such as ethylene-vinyl acetate copolymer, resin materials, polyimide, polypropylene, or polyethylene, and may also include an acrylic adhesive layer.

[0053] It should be noted that the thickness of the first insulating element 40 cannot be too thick or too thin. If the first insulating strip 41 is too thin, it is inconvenient to apply, easily deformed by pulling, and there is a risk of breakage during long-term insulation. If it is too thick, it will increase the height difference, generate greater stress during the lamination process, easily cause fragmentation, and increase the risk of poor soldering. Based on this, in this embodiment, the thickness of the first insulating element 40 can be set between 0.05 mm and 0.8 mm. In this way, the first insulating element 40 is neither too thin nor too thick. For example, the thickness of the first insulating element 40 can be 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, or 0.8 mm.

[0054] Furthermore, there are multiple first solder ribbons 20, which are spaced apart along the second direction on the backlight surface of the first solar cell 11, and each first solder ribbon 20 extends from the first solar cell 11 to the (N-1)th solar cell 14. There are multiple second solder ribbons 30, which are spaced apart along the second direction, and extend from the second solar cell 12 to the backlight surface of the Nth solar cell 15. The multiple first solder ribbons 20 and the multiple second solder ribbons 30 are arranged in a one-to-one correspondence.

[0055] In the first direction, the second welding strip 30 can be a single welding strip or it can be composed of multiple welding strips spaced apart, which is not limited here.

[0056] Furthermore, the back contact battery assembly 100 also includes a third solder ribbon 60, which is disposed on the back surface of the Nth battery cell 15 and extends from the Nth solder ribbon to the (N+1)th battery cell 16. In a first direction, the third solder ribbon 60 and the second solder ribbon 30 are arranged alternately. The first insulating member 40 isolates the second solder ribbon 30 and the first busbar 50, while also isolating the third solder ribbon 60 and the first busbar 50.

[0057] In one possible implementation, the second body segment 22 and the second solder strip 30 are collinear along the second direction. It is understood that the second body segment 22 and the second solder strip 30 can be arranged collinearly. This makes the solder strip wiring simpler and clearer, and also reduces the difficulty and complexity of solder strip wiring in the back contact battery assembly 100. It is understood that due to existing manufacturing processes, the second body segment 22 and the second solder strip 30 may not be geometrically absolutely collinear. For example, if the second body segment 22 and the second solder strip 30 are misaligned by within 1 mm in the second direction, they can also be considered collinear. In one possible implementation, the second body segment 22 and the second solder strip 30 are spaced apart along the second direction. It is understandable that, in the thickness direction of the back contact battery assembly 100, in order to avoid the second main body segment 22 from overlapping with the second solder strip 30, by setting the second main body segment 22 and the second solder strip 30 to be spaced apart in the second direction, the problem of excessive stress caused by the partial overlap of the second main body segment 22 and the second solder strip 30 on the battery cell can be avoided, thereby further reducing the risk of microcracks in the battery cell during the lamination process of the back contact battery assembly 100.

[0058] Specifically, in the second direction, the second main body segment 22 and the outer extension segment 23 can be configured to be collinear. This makes the wiring of the solder strip simpler and clearer, and also reduces the difficulty and complexity of wiring the solder strip in the back contact battery assembly 100. Understandably, due to existing manufacturing processes, the second main body segment 22 and the outer extension segment 23 may not be perfectly collinear in a geometric sense. For example, if the second main body segment 22 and the outer extension segment 23 are misaligned by less than 1 mm in the second direction, they can also be considered collinear.

[0059] Therefore, in this embodiment of the utility model, the position of the second main body segment 22 can be set in various ways. For example, as Figure 2 and Figure 4 As shown, the second main body segment 22 is set to be collinear with the first main body segment 21. Alternatively, it can be set as follows: Figure 3 and Figure 5 As shown, the second main body segment 22 and the extension segment 23 are set to be collinear.

[0060] Furthermore, the first welding strip 20 also includes a connecting segment 24, which connects the second main body segment 22 and the extension segment 23; or, the connecting segment 24 connects the first main body segment 21 and the second main body segment 22.

[0061] like Figure 2 and Figure 4 As shown, the connecting segment 24 can be used to realize the electrical conduction of the second main body segment 22 and the epitaxial segment 23, so that the first main body segment 21 can transmit the charge carriers on the first battery cell 11 through the second main body segment 22 and the connecting segment 24 to the epitaxial segment 23 and then into the first busbar 50, thereby completing the collection of charge carriers on the first battery cell 11.

[0062] Or, such as Figure 3 and Figure 5 As shown, the connecting segment 24 can be used to realize the electrical conduction of the first main body segment 21 and the second main body segment 22, so that the first main body segment 21 can transmit the charge carriers on the first battery cell 11 through the connecting segment 24 to the second main body segment 22 and the epitaxial segment 23 and then into the first busbar 50, thus completing the collection of charge carriers on the first battery cell 11.

[0063] Furthermore, in the second direction, the connecting segment 24 is bent relative to the second main body segment 22 and the first main body segment 21. This allows for the staggered arrangement of the epitaxial segment 23 and the second solder strip 30, reducing the stacking height and avoiding excessive stress caused by the partial overlap of the epitaxial segment 23 and the second solder strip 30 on the first busbar 50. Consequently, the stress on the back contact battery assembly 100 is lower during lamination, reducing the risk of microcracks and fragmentation of the battery cells and improving the reliability of the back contact battery assembly 100.

[0064] like Figure 2and Figure 4 As shown, further, the second main body segment 22 and the connecting segment 24 may be smoothly connected, and / or, the extension segment 23 and the connecting segment 24 may be smoothly connected. More specifically, in the embodiments of this application, the first main body segment 21 and the second main body segment 22 are smoothly connected, the second main body segment 22 and the connecting segment 24 are smoothly connected, and the connecting segment 24 and the extension segment 23 are smoothly connected.

[0065] Understandably, the connecting segment 24 is bent relative to the second main body segment 22, and the extension segment 23 is bent relative to the connecting segment 24, which is equivalent to the first weld strip 20 being continuously bent to form the connecting segment 24 and the extension segment 23. Because stress concentration often occurs at the bending point of the first weld strip 20, leading to cracks or even breakage, the smooth transition design can effectively disperse these stresses, reducing the risk of breakage or detachment of the first weld strip 20 due to stress concentration. Furthermore, the smooth transition also gives the connecting part of the first weld strip 20 a better aesthetic appearance, enhancing the overall visual effect and texture of the product.

[0066] Furthermore, the first main body segment 21 and the second main body segment 22 are directly connected. This allows the first main body segment 21 to transfer charge carriers from the first solar cell 11 to the second main body segment 22. Optionally, the first main body segment 21 and the second main body segment 22 can be connected with a smooth transition.

[0067] Or, such as Figure 3 and Figure 5 As shown, further, the first main body segment 21 and the connecting segment 24 may be smoothly connected, and / or, the connecting segment 24 and the second main body segment 22 may be smoothly connected. More specifically, in the embodiments of this application, the first main body segment 21 and the connecting segment 24 are smoothly connected, the connecting segment 24 and the second main body segment 22 are smoothly connected, and the second main body segment 22 and the extension segment 23 are smoothly connected.

[0068] Understandably, the first main body segment 21 is bent relative to the connecting segment 24, and the second main body segment 22 is bent relative to the connecting segment 24, which is equivalent to the first weld strip 20 being continuously bent to form the connecting segment 24 and the second main body segment 22. Because stress concentration often occurs at the bending point of the first weld strip 20, leading to cracks or even breakage, the smooth transition design can effectively disperse these stresses, reducing the risk of breakage or detachment of the first weld strip 20 due to stress concentration. Furthermore, the smooth transition also gives the connection part of the first weld strip 20 a better aesthetic appearance, enhancing the overall visual effect and texture of the product.

[0069] Furthermore, the second main body segment 22 and the epitaxial segment 23 are directly connected. This allows the second main body segment 22 to transfer charge carriers from the second cell 12 to the (N-1)th cell 14 to the epitaxial segment 23. Optionally, the second main body segment 22 and the epitaxial segment 23 can be connected with a smooth transition.

[0070] In one possible implementation, such as Figure 2 and Figure 5 As shown, the first main body segment 21, the second main body segment 22, the connecting segment 24, and the extension segment 23 of the first welding strip 20 can be integrally stamped from a single welding strip, or they can be formed by splicing multiple welding strips together. This application does not impose any restrictions on this.

[0071] Optionally, the first welding strip 20 is formed by integral stamping of a single welding strip, which eliminates redundant processes such as welding when manufacturing the first welding strip 20, reduces manpower consumption, and avoids phenomena such as incomplete welding and burrs caused by manual welding during the welding process.

[0072] Optionally, the first welding strip 20 can also be formed by splicing multiple welding strips together, which can make it possible to produce and assemble the various parts of the first welding strip 20 separately, thereby improving the assembly accuracy of the first welding strip 20 and reducing the manufacturing difficulty of the first welding strip 20.

[0073] In this embodiment, the connecting segment 24 has a line segment or bend shape. This is not specifically limited in this application; it is sufficient that the extension segment 23 and the second solder strip 30 are spaced apart along the length of the first busbar 50. Preferably, the connecting segment 24 is a straight line segment structure, which can avoid the strength reduction caused by repeated bending of the solder strip, preventing breakage or detachment.

[0074] In one possible implementation, such as Figure 2 , Figure 3 and Figure 7 As shown, along the first direction, the first insulating member 40 at least partially covers the second battery cell 12 to the (N-1)th battery cell 14. In this way, the second main body segment 22 in the first solder strip 20 can be isolated from the battery other than the first battery cell 11, and the second main body segment 22 can be electrically connected to the second battery cell 12 to the (N-1)th battery cell 14.

[0075] Specifically, the second main body segment 22 of the first welding strip 20 extends from the second battery cell 12 to the (N-1) battery cell 14 in the first direction. The second main body segment 22 can be effectively isolated from the second battery cell 12 to the (N-1) battery cell 14 by at least partially covering the second battery cell 12 to the (N-1) battery cell 14 by the first insulating member 40.

[0076] It is understood that "the first insulating member 40 at least partially covers the second battery cell 12 to the (N-1) battery cell 14" means that the first insulating member 40 may completely cover the second battery cell 12 to the (N-1) battery cell 14 along the first direction; or it may partially cover the second battery cell 12 to the (N-1) battery cell 14 according to the size and arrangement of the second main body segment 22, which is not limited here.

[0077] Furthermore, in one possible implementation, such as Figure 2 and Figure 3 As shown, along the first direction, the first insulating member 40 completely covers the second battery cell 12 to the (N-1)th battery cell 14. This increases the electrical isolation between the second main body segment 22 and the second battery cell 12 to the (N-1)th battery cell 14, preventing potential short circuits between the second main body segment 22 and the second battery cell 12 to the (N-1)th battery cell 14, while also improving the overall safety and stability of the back contact battery assembly 100.

[0078] like Figure 7 As shown, further, in one possible implementation, there are multiple first solder strips 20 arranged along a second direction. The first insulating member 40 includes multiple insulating strips 41 spaced apart along the second direction, with the insulating strips 41 corresponding to the second main body segment 22. Thus, the first insulating member 40 does not need to completely cover the second cell 12 to the (N-1)th cell 14, and the insulating strips 41 are arranged correspondingly to the second main body segment 22, thereby ensuring more precise and effective electrical isolation. Furthermore, the total area of ​​the first insulating member 40 can be reduced, thereby reducing the overall cost of the back contact battery assembly 100.

[0079] It is understandable that "the insulating strip 41 is correspondingly arranged with the second main body segment 22" means that the insulating strip 41 can be arranged at the positions where the second main body segment 22 is arranged on the second cell 12 to the (N-1)th cell 14. Furthermore, in the second direction, the width of the insulating strip 41 can be set to be greater than or equal to the width of the second main body segment 22, thereby isolating the second main body segment 22 from the cell while reducing the total area of ​​the first insulating member 40, thereby reducing the cost of the back contact battery assembly 100.

[0080] Preferably, in the second direction, the width of a single insulating strip 41 can be slightly larger than the width of a single second main body segment 22. This ensures that the insulating strip 41 can adequately isolate the second main body segment 22, and provides sufficient insulation redundancy even with manufacturing tolerances or positional deviations, thereby further improving the electrical safety and reliability of the overall back contact battery assembly 100.

[0081] Furthermore, in one possible implementation, the spacing between two adjacent insulating strips 41 in the second direction is 1mm to 10mm. For example, it is 1mm, 1.2mm, 1.5mm, 2mm, 3mm, 5mm, 7mm, 7.5mm, or 10mm. In this way, it is possible to ensure that the insulating strips 41 fully isolate the corresponding second main body segment 22 without occupying too much space and affecting the compactness of the overall structure.

[0082] like Figure 2 and Figure 3 As shown, in one possible implementation, along a first direction, the first insulating member 40 includes a first insulating portion 42 and a second insulating portion 43 arranged sequentially. The first insulating portion 42 is located between the second main body segment 22 and the second battery cell 12 to the (N-1)th battery cell 14; the second insulating portion 43 is located between the second solder strip 30 and the first busbar 50. Thus, the first insulating portion 42 is specifically positioned between the second main body segment 22 and the second battery cell 12 to the (N-1)th battery cell 14, which can better prevent electrical short circuits or interference between the second battery cell 12 to the (N-1)th battery cell 14 and the second main body segment 22; the second insulating portion 43 is located between the second solder strip 30 and the first busbar 50, effectively isolating the second solder strip 30 and the first busbar 50. In this embodiment of the invention, the first insulating member 40 is divided into two parts, facilitating separate optimized design and dimensional adjustments for insulation requirements in different areas, helping to address manufacturing tolerances and layout requirements, and further improving product consistency and reliability. Optionally, the first insulating portion 42 and the second insulating portion 43 can be integrally formed to reduce the manufacturing difficulty of the first insulating component 40. Optionally, the first insulating portion 42 and the second insulating portion 43 can also be detachable. The detachable design facilitates the separate production and assembly of the first insulating portion 42 and the second insulating portion 43 during the manufacturing process, which helps to improve the assembly accuracy of the first insulating component 40 and reduce the manufacturing difficulty of the first insulating component 40.

[0083] In one possible implementation, in the second direction, the distance between the second solder strip 30 and the adjacent extension segment 23 is 0.1 mm to 1 mm. For example, it is 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm. This ensures that the extension segment 23 and the second solder strip 30 are completely non-overlapping or do not coincide in the length direction of the first busbar 50, achieving the effect of localized stress dispersion in the back contact battery assembly 100.

[0084] In some embodiments, the individual battery cells in the battery string 10 may be disposed on the same plane, with adjacent battery cells spaced apart in the first direction. This provides a buffer space between the individual battery cells, preventing them from contacting each other and being damaged when the back-contact battery assembly 100 is subjected to external forces.

[0085] In some embodiments, two adjacent battery cells partially overlap in a first direction. It is understood that the contact areas between these overlaps are not electrically connected; that is, no conductive adhesive or other bonding agent is needed between the overlapping areas. The battery cells are simply overlapped. Thus, there is no gap between two adjacent battery cells in the first direction, which better conceals the series solder ribbons. There is no need to provide a shielding insulating layer in the gaps between the battery cells to hide the series solder ribbons, thereby reducing the use of shielding insulating layers, lowering the production cost of the back contact battery, and simplifying rework.

[0086] Furthermore, by overlapping adjacent battery cells, the size of the battery string 10 can be reduced, thereby occupying less space. In other words, with a fixed size for the battery string 10, more battery cells can be placed, increasing the power output of the battery string 10 and reducing the cost per watt. Preferably, the local overlap distance between two adjacent battery cells in the first direction is greater than 0 and less than or equal to 1.5 mm.

[0087] like Figure 8 As shown, in some embodiments, the back contact battery assembly 100 includes at least two sets of battery strings 10 arranged along a second direction. Along this second direction, a first insulating member 40 extends from one of the two sets of battery strings 10 to the other. This allows the first insulating member 40 to be installed in one continuous process between at least two adjacent sets of battery strings 10, simplifying the assembly steps of the battery assembly and improving its production efficiency. It is understood that the back contact battery assembly 100 may include multiple sets of battery strings 10, and the first insulating member 40 may be installed along the entire length of multiple sets of battery strings 10 at once. For example, the back contact battery assembly 100 may include three sets of battery strings 10, and the first insulating member 40 may extend from the first set of battery strings 10 to the third set of battery strings 10.

[0088] It is understood that in such embodiments, the back-contact battery assembly 100 may further include a frame, a backplate, back-contact battery assembly 100 glass, and an encapsulating film. The encapsulating film may be filled between the front and back surfaces of the battery cells, and between the back-contact battery assembly 100 glass, adjacent battery cells, etc. As a filler, it can be a transparent colloid with good light transmittance and aging resistance; for example, the encapsulating film may be EVA film or POE film, and the specific choice can be made according to the actual situation, without limitation.

[0089] Photovoltaic glass can be applied to the encapsulating film on the front of the solar cell. This 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%, protecting the solar cell while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cell together, providing sealing, insulation, and waterproofing / moisture protection for the cell.

[0090] The backsheet can be attached to the adhesive film on the back of the solar cells. The backsheet protects and supports the cells, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, aluminum alloy TPT composite adhesive film, etc., and the specific choice is determined based on the specific circumstances and is not limited here. The backsheet, solar cells, adhesive film, and photovoltaic glass can be integrated into a frame. The frame serves as the main external support structure for the entire back-contact solar module 100, providing stable support and installation. For example, the back-contact solar module 100 can be installed at the desired location via the frame.

[0091] 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.

[0092] Furthermore, the above description is merely a preferred embodiment of this application and is 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 protection scope of this application.

Claims

1. A back contact cell assembly, characterized by, The application relates to a battery string, which comprises a plurality of battery pieces arranged in sequence along a first direction, and a first edge and a second edge opposite to each other and extending along a second direction intersecting the first direction. A first busbar extending along the second direction is arranged on the back surface of an Nth battery piece, the Nth battery piece being the Nth battery piece along the first direction in the battery string, N being greater than or equal to 3, and the distance from the first busbar to the first edge being smaller than the distance from the first busbar to the second edge along the first direction. A first solder strip is arranged on the back surface of a first battery piece, the first battery piece being the first battery piece along the first direction in the battery string. A second solder strip is arranged on the back surface of a second battery piece to the Nth battery piece, the second battery piece being the second battery piece along the first direction in the battery string. A first insulating piece is arranged between the first busbar and the Nth battery piece, and is used for insulating the second solder strip from the first busbar. The first solder strip comprises a first main body segment electrically connected to the first battery piece, an extension segment electrically connected to the first busbar, and a second main body segment insulated from the second battery piece to the (N-1)th battery piece through the first insulating piece, the (N-1)th battery piece being the (N-1)th battery piece along the first direction in the battery string. Along the second direction, the second solder strip is spaced apart from the extension segment, and the extension of the first main body segment at least partially overlaps the second solder strip. Along the second direction, the second main body segment is spaced apart from the second solder strip.

2. The back contact solar cell assembly of claim 1, wherein, Along the second direction, the second main body segment is collinear with the second solder strip.

3. The back contact cell assembly of claim 1, wherein, Along the first direction, the first insulating piece at least partially covers the second battery piece to the (N-1)th battery piece.

4. The back contact solar cell assembly of claim 1, wherein, Along the first direction, the first insulating piece completely covers the second battery piece to the (N-1)th battery piece.

5. The back contact solar cell assembly of claim 4, wherein, The first solder strip is in plurality, and a plurality of the first solder strips are arranged along the second direction; the first insulating piece comprises a plurality of insulating strips arranged along the second direction and corresponding to the second main body segment.

6. The back contact solar cell assembly of claim 4, wherein, Along the second direction, the width of the insulating strip is greater than or equal to the width of the second main body segment.

7. The back contact solar cell assembly of claim 6, wherein, Along the second direction, the interval between two adjacent insulating strips is 1mm to 10mm.

8. The back contact solar cell assembly of claim 6, wherein, Along the first direction, the first insulating piece comprises a first insulating part and a second insulating part arranged in sequence, the first insulating part being arranged between the second main body segment and the second battery piece to the (N-1)th battery piece, and the second insulating part being arranged between the second solder strip and the first busbar.

9. The back contact solar cell assembly of claim 1 wherein, Along the second direction, the interval between the second solder strip and the adjacent extension segment is 0.1mm to 1mm.

10. The back contact solar cell assembly of claim 1 wherein, Along the first direction, two adjacent battery pieces are partially overlapped.

11. The back contact solar cell assembly of claim 1 wherein, ​ 12. A photovoltaic system characterized by, The photovoltaic system comprises a back contact cell assembly according to any one of claims 1 to 11.

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