Back contact battery assembly and photovoltaic system

Abstract

The utility model relates to the technical field of solar cells, and provides a back contact cell assembly and a photovoltaic system, a first bus bar of the back contact cell assembly is arranged on a first edge cell piece of a cell string and is welded with a first welding strip on the first edge cell piece, and a first composite insulating layer is arranged between the first bus bar and a second welding strip; the first composite insulating layer comprises a first insulating adhesive layer and a first aerogel layer stacked on the first insulating adhesive layer. Therefore, the arrangement of the first composite insulating layer can ensure the insulation between the first bus bar and the second welding strip on the first edge battery piece. Meanwhile, the first aerogel layer in the first composite insulating layer has a high impedance value and low conductivity, and the first aerogel layer has low density and thermal conductivity, so that when the first bus bar is welded, the existence of the first aerogel layer can prevent a large amount of heat from being diffused to the battery piece, and the welding quality of the battery piece is improved. And therefore, hidden cracks and blackening of the back contact battery piece can be effectively avoided, and the yield of the assembly can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cell, in particular to a back contact cell string, a cell module and a photovoltaic system. BACKGROUND

[0002] The back contact cell module is generally composed of an array of back contact cell pieces, which includes a plurality of back contact cell strings. At present, in the back contact cell module, the edge bus bar and the middle bus bar are usually arranged in the blank area without cell pieces. In the module, space is required to place the bus bar, which reduces the effective light receiving area of the module and affects the appearance of the module. In some products, in order to solve this technical problem, the bus bar is arranged on the back of the cell piece, and an insulating strip is arranged between the bus bar and the cell piece to isolate the heteropolar solder strip. However, since the bus bar is arranged on the cell piece, in the process of welding the bus bar and the solder strip, the cell piece is easily caused by high temperature due to high welding temperature, thereby causing the cell piece to appear hidden crack and blackening phenomenon. CONTENT OF THE UTILITY MODEL

[0003] The present application provides a back contact cell module and a photovoltaic system.

[0004] The present application is implemented in this way. The back contact cell module of the embodiment of the present application comprises:

[0005] A cell string, the cell string comprises a plurality of back contact cell pieces arranged along a first direction, and the plurality of back contact cell pieces comprise a first edge cell piece located at one end of the cell string; each of the back contact cell pieces is provided with a plurality of first solder strips and a plurality of second solder strips, the first solder strips and the second solder strips are alternately and spaced arranged along a second direction and extend along the first direction, and the second direction intersects the first direction;

[0006] A first bus bar arranged on the first edge cell piece, the first bus bar extends along the second direction and is welded with the first solder strip on the first edge cell piece; and

[0007] A first composite insulating layer, the first composite insulating layer is arranged at least between the first bus bar and the second solder strip on the first edge cell piece to insulate and separate the first bus bar and the second solder strip, and the first composite insulating layer comprises a first insulating adhesive layer and a first aerogel layer stacked on the first insulating adhesive layer.

[0008] In some embodiments, the first composite insulating layer is an intermittent structure in the second direction to form a plurality of first insulating portions spaced from each other along the second direction, and each of the second solder strips has the first insulating portion between the first bus bar.

[0009] In some embodiments, the first composite insulating layer continuously extends along the second direction and is located on a side of the first solder strip and the second solder strip away from the first edge cell piece, all the first solder strips and the second solder strips on the first edge cell piece cross the first composite insulating layer, and the first bus bar is arranged on the first composite insulating layer.

[0010] The back contact cell assembly further comprises a first auxiliary soldering piece, the first auxiliary soldering piece extends along the second direction, one end of the first auxiliary soldering piece is soldered with the first bus bar, and the other end of the first auxiliary soldering piece extends out of the edge of the first composite insulating layer and is soldered with the first solder strip.

[0011] In some embodiments, the number of the first auxiliary soldering pieces is plural and corresponds to the number of the first solder strips on the first edge cell piece, and the plural first auxiliary soldering pieces are arranged at intervals along the second direction.

[0012] In some embodiments, the length of the first auxiliary soldering piece in the second direction is greater than or equal to the length of the first solder strip in the second direction.

[0013] In some embodiments, on the first edge cell piece, the first composite insulating layer extends along the second direction and is located on a side of the second solder strip away from the first edge cell piece, the first bus bar is arranged on the first composite insulating layer, and the first solder strip is arranged on a side of the first composite insulating layer away from the first edge cell piece and crosses and is soldered with the first bus bar.

[0014] In some embodiments, the several back contact cell pieces include a second edge cell piece located at the other end of the cell string; the back contact cell assembly further comprises:

[0015] a second bus bar arranged on the second edge cell piece, the second bus bar extends along the second direction and is soldered with the second solder strip on the second edge cell piece; and

[0016] a second composite insulating layer, the second composite insulating layer is arranged at least between the second bus bar and the first solder strip on the second edge cell piece to insulate and separate the second bus bar and the first solder strip, and the second composite insulating layer comprises a second insulating adhesive layer and a second aerogel layer arranged on the second insulating adhesive layer in a stack.

[0017] In some embodiments, the second composite insulating layer is discontinuous in the second direction to form several second insulating portions spaced from each other along the second direction, and each of the first solder strips has the second insulating portion between the first solder strip and the second bus bar.

[0018] In some embodiments, the second composite insulating layer extends continuously along the second direction and is located on the side of the first and second solder strips away from the second edge cell, all the first and second solder strips on the second edge cell intersect with the second composite insulating layer, and the second busbar is disposed on the second composite insulating layer;

[0019] The back contact battery assembly also includes a second auxiliary welding component, which extends along the second direction. One end of the second auxiliary welding component is welded to the second busbar, and the other end extends to the edge of the second composite insulation layer and is welded to the second welding strip.

[0020] In some embodiments, the number of the second auxiliary welding components is multiple and corresponds to the number of the second welding strips on the second edge battery cell, and the multiple second auxiliary welding components are spaced apart along the second direction.

[0021] In some embodiments, the second auxiliary welding member covers a portion of the second welding strip, and the length of the second auxiliary welding member in the second direction is greater than or equal to the length of the second welding strip in the second direction.

[0022] In some embodiments, on the second edge cell, the second composite insulating layer extends along the second direction and is located on the side of the second solder strip opposite to the second edge cell, the second busbar is disposed on the second composite insulating layer, and the first solder strip is disposed on the side of the second composite insulating layer opposite to the second edge cell and intersects with and is welded to the second busbar.

[0023] This application also provides a photovoltaic system, which includes the back contact battery assembly described in any of the above claims.

[0024] In the back contact battery assembly and the photovoltaic system in the embodiments of the present application, the first busbar is arranged on the first edge cell of the cell string and welded with the first solder strip on the first edge cell, a first composite insulation layer is arranged between the first busbar and the second solder strip, and the first composite insulation layer comprises a first insulation adhesive layer and a first aerogel layer arranged on the first insulation adhesive layer. In this way, the arrangement of the first composite insulation layer can ensure the insulation between the first busbar and the second solder strip on the first edge cell. Meanwhile, the first aerogel layer in the first composite insulation layer has a large number of micro voids and polarization areas inside the aerogel, so that the first aerogel layer has a high impedance value and a very low conductivity, and has a good insulation effect. In addition, the first aerogel layer has a low density and a low thermal conductivity, and when the first busbar is welded, the first aerogel layer can isolate a large amount of heat from spreading to the cell, effectively protecting the back contact cell, thereby effectively avoiding the occurrence of hidden cracks and blackening of the back contact cell, and improving the yield of the assembly.

[0025] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a schematic diagram of a module of a photovoltaic system provided by the embodiments of the present application;

[0027] Figure 2 is a schematic diagram of a back contact battery assembly provided by the embodiments of the present application;

[0028] Figure 3 is a schematic diagram of a cell string, a busbar and a composite insulation layer provided by the embodiments of the present application;

[0029] Figure 4 is another schematic diagram of a cell string, a busbar and a composite insulation layer provided by the embodiments of the present application;

[0030] Figure 5 is still another schematic diagram of a cell string, a busbar and a composite insulation layer provided by the embodiments of the present application;

[0031] Figure 6 is a schematic diagram of a first composite insulation layer and a second composite insulation layer of a back contact battery assembly provided by the embodiments of the present application.

[0032] Main element symbol explanation: photovoltaic system 1000, back contact cell assembly 100, cell string 10, back contact cell piece 11, first edge cell piece 111, second edge cell piece 112, first solder strip 12, second solder strip 13, first busbar 20, first composite insulating layer 30, first insulating adhesive layer 31, first aerogel layer 32, first insulating part 33, first auxiliary soldering part 40, second busbar 50, second composite insulating layer 60, second insulating adhesive layer 61, second aerogel layer 62, second insulating part 63, second auxiliary soldering part 70. DETAILED DESCRIPTION

[0033] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The examples of the embodiments are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation to the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0034] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation to the present application.

[0035] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0036] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0039] Please see Figures 1-5 The photovoltaic system 1000 in this application embodiment may include the back contact battery module 100 in this application embodiment. The back contact battery module 100 in this application embodiment may include a battery string 10, a first bus bar 20 and a first composite insulation layer 30.

[0040] The battery string 10 may include a plurality of back-contact battery sheets 11 arranged along a first direction. Each back-contact battery sheet 11 is provided with a plurality of first solder strips 12 and a plurality of second solder strips 13. The first solder strips 12 and the second solder strips 13 are arranged alternately and at intervals along a second direction and both extend along the first direction. The back-contact battery sheets 11 in the battery string 10 are connected in series through the first solder strips 12 and the second solder strips 13. The second direction intersects the first direction, and the first direction is the connection direction of the battery string 10. Preferably, the first direction is perpendicular to the second direction. The plurality of back-contact battery sheets 11 include a first edge battery sheet 111 located at one end of the battery string 10.

[0041] like Figures 2-5 As shown, the first busbar 20 is disposed on the first edge battery cell 111. The first busbar 20 extends along the second direction and is welded to the first welding strip 12 on the first edge battery cell 111. The first busbar 20 can be directly welded to the first welding strip 12, or it can be indirectly welded through other auxiliary welding parts. No specific restrictions are imposed here.

[0042] The first composite insulation layer 30 is arranged at least between the first bus bar 20 and the second solder strip 13 on the first edge cell piece 111 to insulate and separate the first bus bar 20 and the second solder strip 13. As shown in the drawings, Figure 6 The first composite insulation layer 30 includes a first insulation adhesive layer 31 and a first aerogel layer 32 arranged on the first insulation adhesive layer 31.

[0043] In the back contact cell module 100 and the photovoltaic system 1000 of the embodiments of the present application, the first bus bar 20 is arranged on the first edge cell piece 111 of the cell string 10 and welded with the first solder strip 12 on the first edge cell piece 111, and the first composite insulation layer 30 is arranged between the first bus bar 20 and the second solder strip 13. The first composite insulation layer 30 includes the first insulation adhesive layer 31 and the first aerogel layer 32 arranged on the first insulation adhesive layer 31. In this way, the arrangement of the first composite insulation layer 30 can ensure the insulation between the first bus bar 20 and the second solder strip 13 on the first edge cell piece 111. Meanwhile, the first aerogel layer 32 in the first composite insulation layer 30 has a large number of micro voids and polarization areas in the aerogel, which can make the first aerogel layer 32 have a high impedance value and a very low conductivity, thus achieving a good insulation effect. In addition, the first aerogel layer 32 has a low density and a low thermal conductivity, and the presence of the first aerogel layer 32 can isolate a large amount of heat from spreading to the cell piece when the first bus bar 20 is welded, thus effectively protecting the back contact cell piece 11 and avoiding the occurrence of hidden cracks and blackening of the back contact cell piece 11, and improving the yield of the module.

[0044] Specifically, in the embodiments of the present application, the first insulation adhesive layer 31 can be made of epoxy resin adhesive, epoxy polyester adhesive or other high molecular polymer adhesive, and the first aerogel layer 32 can be a silica aerogel layer or a graphene aerogel layer, which has good insulation and heat insulation properties. In the present application, in the first composite insulation layer 30, the first insulation adhesive layer 31 can be arranged on the side facing the first edge cell piece 111, and the first aerogel layer 32 can be arranged on the side of the first insulation adhesive layer 31 away from the first edge cell piece 111. Alternatively, the first aerogel layer 32 can be arranged on the side facing the first edge cell piece 111, and the first insulation adhesive layer 31 can be arranged on the side of the first aerogel layer 32 away from the first edge cell piece 111. The specific arrangement is not limited herein.

[0045] In the cell string 10, the first solder strip 12 and the second solder strip 13 can be positive and negative solder strips respectively. When the first solder strip 12 is a positive solder strip, the first solder strip 12 on the first edge cell piece 111 is a positive output terminal of the cell string 10. When the first solder strip 12 is a negative solder strip, the first solder strip 12 on the first edge cell piece 111 is a negative output terminal of the cell string 10.

[0046] Please continue to readFigures 3-5 In some embodiments, the several back contact cell pieces 11 can also include a second edge cell piece 112 located at the other end of the cell string 10. The back contact cell assembly 100 further includes a second bus bar 50 and a second composite insulation layer 60.

[0047] The second bus bar 50 is arranged on the second edge cell piece 112, and the second bus bar 50 extends along the second direction and is welded with the second solder strip 13 on the second edge cell piece 112. The second composite insulation layer 60 is arranged at least between the second bus bar 50 and the first solder strip 12 on the second edge cell piece 112 to insulate and separate the second bus bar 50 and the first solder strip 12, as shown in Figure 6 The second composite insulation layer 60 can include a second insulating adhesive layer 61 and a second aerogel layer 62 arranged on the second insulating adhesive layer 61, as shown.

[0048] In this way, the arrangement of the second composite insulation layer 60 can ensure the insulation between the second bus bar 50 and the first solder strip 12 of the second edge cell piece 112. Meanwhile, the second aerogel layer 62 in the second composite insulation layer 60 has a large number of micro voids and polarization regions inside the aerogel, which can make the second aerogel layer 62 have a high impedance value and a very low electrical conductivity, thus having a good insulation effect. The second aerogel layer 62 has a low density and a low thermal conductivity, and the presence of the second aerogel layer 62 can isolate a large amount of heat from spreading to the cell pieces when welding the second bus bar 50, thus effectively protecting the back contact cell piece 11 and effectively avoiding the occurrence of hidden cracks and blackening of the back contact cell piece 11.

[0049] Specifically, in the embodiments of the present application, the material of the second insulating adhesive layer can also be a high polymer adhesive such as epoxy resin adhesive or epoxy polyester adhesive, and the second aerogel layer 62 can also be a silica aerogel layer or a graphene aerogel layer, etc. which has good insulation and heat insulation properties. In the present application, in the second composite insulation layer 60, the second insulating adhesive layer 61 can be located on the side facing the second edge cell piece 112, and the second aerogel layer 62 can be arranged on the side of the second insulating adhesive layer 61 away from the second edge cell piece 112, or the second aerogel layer 62 can be located on the side facing the second edge cell piece 112, and the second insulating adhesive layer 61 can be arranged on the side of the second insulating adhesive layer 61 away from the back contact cell piece 11, and the specific arrangement is not limited herein.

[0050] In such embodiments, the first bus bar 20 is welded with the first solder strip 12 on the first edge cell piece 111, and the second bus bar 50 is welded with the second solder strip 13 on the second edge cell piece 112, and the polarities of the two bus bars are opposite, one being positive and the other being negative. It is not difficult to understand that in such a case, the number of back contact cell pieces 11 in the cell string 10 is even.

[0051] Of course, it is understood that in some embodiments, the number of back contact cell pieces 11 in the battery string 10 is even, in which case the second busbar 50 can be welded with the first tab 12 on the second edge cell piece 112, and the polarities of the two busbars are the same, both being positive or negative. Hereinafter, it is assumed that the number of back contact cell pieces 11 in the battery string 10 is even, the first busbar 20 is welded with the first tab 12 on the first edge cell piece 111, and the second busbar 50 is welded with the second tab 13 on the second edge cell piece 112.

[0052] It is understood that, as shown in FIG. 1, in some embodiments, in the battery string 10 of the back contact cell assembly 100, in the stringing direction, the first tab 12 on the first edge cell piece 111 is an independent tab, which is welded with the first busbar 20 as one output terminal of the battery string 10, that is, the first tab 12 on the first edge cell piece 111 is a short tab. The second tab 13 on the first edge cell piece 111 can be connected with the first tab 12 on the second back contact cell piece 13, and the two can be in an integral structure to form a long tab, and the second tab 13 on the second back contact cell piece 13 is connected with the first tab 12 on the third back contact cell piece 13, and so on, so as to form the stringing between the back contact cell pieces 11. On the second edge cell piece 112, the second tab 13 on the second edge cell piece 112 is an independent tab, which is welded with the second busbar 50 as the other output terminal of the battery string 10, that is, the second tab 13 on the second edge cell piece 112 is a short tab. Figures 3-5 It is understood that, as shown in FIG. 1, in some embodiments, in the battery string 10 of the back contact cell assembly 100, in the stringing direction, the first tab 12 on the first edge cell piece 111 is an independent tab, which is welded with the first busbar 20 as one output terminal of the battery string 10, that is, the first tab 12 on the first edge cell piece 111 is a short tab. The second tab 13 on the first edge cell piece 111 can be connected with the first tab 12 on the second back contact cell piece 13, and the two can be in an integral structure to form a long tab, and the second tab 13 on the second back contact cell piece 13 is connected with the first tab 12 on the third back contact cell piece 13, and so on, so as to form the stringing between the back contact cell pieces 11. On the second edge cell piece 112, the second tab 13 on the second edge cell piece 112 is an independent tab, which is welded with the second busbar 50 as the other output terminal of the battery string 10, that is, the second tab 13 on the second edge cell piece 112 is a short tab.

[0053] Figure 2 It is understood that, as shown in FIG. 1, in some embodiments, in the battery string 10 of the back contact cell assembly 100, in the stringing direction, the first tab 12 on the first edge cell piece 111 is an independent tab, which is welded with the first busbar 20 as one output terminal of the battery string 10, that is, the first tab 12 on the first edge cell piece 111 is a short tab. The second tab 13 on the first edge cell piece 111 can be connected with the first tab 12 on the second back contact cell piece 13, and the two can be in an integral structure to form a long tab, and the second tab 13 on the second back contact cell piece 13 is connected with the first tab 12 on the third back contact cell piece 13, and so on, so as to form the stringing between the back contact cell pieces 11. On the second edge cell piece 112, the second tab 13 on the second edge cell piece 112 is an independent tab, which is welded with the second busbar 50 as the other output terminal of the battery string 10, that is, the second tab 13 on the second edge cell piece 112 is a short tab. Figure 2 It is understood that, as shown in FIG. 1, in some embodiments, in the battery string 10 of the back contact cell assembly 100, in the stringing direction, the first tab 12 on the first edge cell piece 111 is an independent tab, which is welded with the first busbar 20 as one output terminal of the battery string 10, that is, the first tab 12 on the first edge cell piece 111 is a short tab. The second tab 13 on the first edge cell piece 111 can be connected with the first tab 12 on the second back contact cell piece 13, and the two can be in an integral structure to form a long tab, and the second tab 13 on the second back contact cell piece 13 is connected with the first tab 12 on the third back contact cell piece 13, and so on, so as to form the stringing between the back contact cell pieces 11. On the second edge cell piece 112, the second tab 13 on the second edge cell piece 112 is an independent tab, which is welded with the second busbar 50 as the other output terminal of the battery string 10, that is, the second tab 13 on the second edge cell piece 112 is a short tab.

[0054] Figure 2 It is understood that, as shown in FIG. 1, in some embodiments, in the battery string 10 of the back contact cell assembly 100, in the stringing direction, the first tab 12 on the first edge cell piece 111 is an independent tab, which is welded with the first busbar 20 as one output terminal of the battery string 10, that is, the first tab 12 on the first edge cell piece 111 is a short tab. The second tab 13 on the first edge cell piece 111 can be connected with the first tab 12 on the second back contact cell piece 13, and the two can be in an integral structure to form a long tab, and the second tab 13 on the second back contact cell piece 13 is connected with the first tab 12 on the third back contact cell piece 13, and so on, so as to form the stringing between the back contact cell pieces 11. On the second edge cell piece 112, the second tab 13 on the second edge cell piece 112 is an independent tab, which is welded with the second busbar 50 as the other output terminal of the battery string 10, that is, the second tab 13 on the second edge cell piece 112 is a short tab.

[0055] ​​like Figure 2 As shown, in some embodiments, in all battery strings 10 located in the upper half, the first edge battery cell 111 is provided with a first bus bar 20 and the second edge battery cell 112 is provided with a second bus bar 50. In all battery strings 10 located in the lower half, only the first edge battery cell 111 is provided with a first bus bar 20, while the second edge battery cell 112 is not provided with a second bus bar 50. In this case, the second solder strip 13 on the second edge battery cell 112 in the lower half can be directly connected to the second bus bar 50 on the second edge battery cell 112 in the upper half to realize the parallel connection of the upper and lower half.

[0056] Of course, in other embodiments, in all the battery strings 10 located in the lower half, the first edge battery cell 111 may be provided with a first bus bar 20, and the second edge battery cell 112 may also be provided with a second bus bar 50. In this case, in the upper and lower half, two adjacent second bus bars 50 can be connected together by a connector or the two can be directly integrated into a single structure, thereby realizing the parallel connection between the upper and lower half. The specific details are not limited here.

[0057] In other words, in the embodiments of this application, in the back contact battery assembly 100, all the first edge battery pieces 111 of the battery strings 10 may have a first bus bar 20 (i.e., edge bus bar), and some of the second edge battery pieces 112 of the battery strings 10 may have a second bus bar 50 (i.e., middle bus bar). Alternatively, all the first edge battery pieces 111 of the battery strings 10 may have a first bus bar 20 (i.e., edge bus bar), and all the second edge battery pieces 112 of the battery strings 10 may have a second bus bar 50 (i.e., middle bus bar), and the specific configuration is not limited here.

[0058] Please see Figure 3 In some embodiments, the first composite insulating layer 30 may be a discontinuous structure in the second direction to form a plurality of first insulating portions 33 spaced apart from each other in the second direction, and each second solder strip 13 has a first insulating portion 33 between it and the first busbar 20.

[0059] Thus, by setting the first composite insulation layer 30 as an intermittent structure, the first busbar 20 can be directly welded to the first solder strip 12 between the two first insulation parts 33, without the need to set other intermediate welding parts to achieve the connection with the first solder strip 12.

[0060] Specifically, such as Figure 3As shown, in such embodiments, the first bus bar 20 is welded with the first solder ribbon 12 at the broken part of the first composite insulating layer 30, and the welding position is located between two adjacent first insulating parts 33, which can block the heat generated by the welding from spreading to the areas on both sides of the welding position, effectively reducing the risk of hidden cracks.

[0061] As shown in FIG. 1, the back contact battery assembly 100 can further include a first composite insulating layer 30, which extends along the second direction and is located on the side of the first edge cell 111 away from the first solder ribbon 12 and the second solder ribbon 13. The first composite insulating layer 30 can be a continuous structure along the second direction, and all the first solder ribbons 12 and the second solder ribbons 13 on the first edge cell 111 can cross the first composite insulating layer 30. The first bus bar 20 can be arranged on the first composite insulating layer 30. Figure 4 In some embodiments, the first composite insulating layer 30 can extend continuously along the second direction (i.e., the first composite insulating layer 30 is a continuous structure along the second direction) and be located on the side of the first edge cell 111 away from the first solder ribbon 12 and the second solder ribbon 13. All the first solder ribbons 12 and the second solder ribbons 13 on the first edge cell 111 can cross the first composite insulating layer 30, and the first bus bar 20 can be arranged on the first composite insulating layer 30. In such cases, the orthographic projection of the first bus bar 20 on the first composite insulating layer 30 along the thickness direction is completely located within the first composite insulating layer 30 or coincides with the first composite insulating layer 30, i.e., the first bus bar 20 is completely arranged on the first composite insulating layer 30.

[0062] In such cases, as shown in FIG. 2, the back contact battery assembly 100 can further include a first auxiliary soldering member 40, which extends along the second direction. One end of the first auxiliary soldering member 40 is welded with the first bus bar 20, and the other end extends out of the edge of the first composite insulating layer 30 and is welded with the first solder ribbon 12. The welding position of the first auxiliary soldering member 40 and the first bus bar 20 is located on the first composite insulating layer 30. Figure 4 In such cases, as shown in FIG. 2, the back contact battery assembly 100 can further include a first auxiliary soldering member 40, which extends along the second direction. One end of the first auxiliary soldering member 40 is welded with the first bus bar 20, and the other end extends out of the edge of the first composite insulating layer 30 and is welded with the first solder ribbon 12. The welding position of the first auxiliary soldering member 40 and the first bus bar 20 is located on the first composite insulating layer 30.

[0063] In such cases, as shown in FIG. 2, the back contact battery assembly 100 can further include a first auxiliary soldering member 40, which extends along the second direction. One end of the first auxiliary soldering member 40 is welded with the first bus bar 20, and the other end extends out of the edge of the first composite insulating layer 30 and is welded with the first solder ribbon 12. The welding position of the first auxiliary soldering member 40 and the first bus bar 20 is located on the first composite insulating layer 30.

[0064]

[0065] ​In addition, it is understood that, in such an embodiment, if the first composite insulating layer 30 is not provided, but only a common insulating layer having only the first insulating adhesive layer 31 is provided, in order to avoid the influence of the high-temperature heat generated when the first auxiliary soldering member 40 is soldered to the first bus bar 20 on the first edge cell 111, the first auxiliary soldering member 40 and the first bus bar 20 need to be soldered together before the first bus bar 20 and the first auxiliary soldering member 40 are placed, and then the soldering between the first auxiliary soldering member 40 and the first solder strip 12 is performed in an overall manner. In this case, the soldering needs to be performed in two steps during the entire assembly manufacturing process.

[0066] However, in the embodiment of the present application, by providing the first composite insulating layer 30, most of the heat generated when the first bus bar 20 is soldered to the first auxiliary soldering member 40 can be isolated, so that the soldering between the first auxiliary soldering member 40 and the first bus bar 20 and the first solder strip 12 can be completed in one soldering process, thereby simplifying the manufacturing process of the assembly and improving the production efficiency.

[0067] Further, in such an embodiment, the number of the first auxiliary soldering members 40 is multiple and corresponds to the number of the first solder strips 12 on the first edge cell 111, and the multiple first auxiliary soldering members 40 are arranged in the second direction at intervals.

[0068] In this way, by providing multiple first auxiliary soldering members 40, each first solder strip 12 can be connected to the first bus bar 20.

[0069] Specifically, in such an embodiment, the first auxiliary soldering member 40 can be arranged in parallel with the first solder strip 12, and the interval of the adjacent two first auxiliary soldering members 40 in the second direction can be equal to the interval of the adjacent two first solder strips 12 in the first direction. The material of the first auxiliary soldering member 40 can be the same as or different from the material of the first solder strip 12 and the second solder strip 13, as long as it has excellent electrical conductivity and soldering performance, which is not limited here.

[0070] Please refer to Figure 4 In some embodiments, the length of the first auxiliary soldering member 40 in the second direction (i.e., the width of the first auxiliary soldering member 40) is greater than or equal to the length of the first solder strip 12 in the second direction (i.e., the width of the first solder strip 12).

[0071] In this way, the first auxiliary soldering piece 40 is set to have the same width as the first solder strip 12 or a width larger than that of the first solder strip 12, so that the first auxiliary soldering piece 40 has a relatively large soldering area with the first solder strip 12, thereby improving the soldering stability between the first auxiliary soldering piece 40 and the first solder strip 12 and reducing the probability of the first auxiliary soldering piece 40 and the first solder strip 12 being separated due to an external force impact on the assembly.

[0072] Referring to Figure 5 In some embodiments, the first composite insulating layer 30 is discontinuous in the second direction to form a plurality of first insulating portions 31 that are spaced apart from each other in the second direction. In this case, each of the first solder strips 12 and the first bus bar 20 is arranged on one of the first insulating portions 31.

[0073] In this way, by arranging the second solder strip 13 on the first edge cell 111 below the first composite insulating layer 30 and arranging the first solder strip 12 on the first composite insulating layer 30, the first bus bar 20 is directly insulated from the second solder strip 13 by the first composite insulating layer 30, and the first solder strip 12 and the first bus bar 20 have only one soldering point on the first composite insulating layer 30. The first composite insulating layer 30 can isolate most of the heat generated by soldering, thereby reducing the risk of hidden cracks without the need to arrange the first auxiliary soldering piece 40 as described above.

[0074] Specifically, in such embodiments, the first composite insulating layer 30 continuously extends in the second direction, and the first solder strip 12 can be arranged above the first bus bar 20 or below the first bus bar 20. Preferably, the first solder strip 12 is arranged below the first bus bar 20, so as to avoid a large height difference between the first solder strip 12 and the soldering position on the electrode (main grid or fine grid) on the back of the first edge cell 111, which can cause a virtual soldering.

[0075] Referring to Figure 3 In some embodiments, the second composite insulating layer 60 can also be discontinuous in the second direction to form a plurality of second insulating portions 63 that are spaced apart from each other in the second direction. Each of the first solder strips 12 and the second bus bar 50 has a second insulating portion 63 therebetween.

[0076] In this way, by arranging the second composite insulating layer 60 in an intermittent structure, the second bus bar 50 can be directly welded with the second solder rib 13 between two second insulating portions 63 without the need of arranging other intermediate welding members to realize the connection with the second solder rib 13.

[0077] Specifically, as shown in Figure 3 In such an embodiment, the second bus bar 50 is welded with the second solder rib 13 at the broken part of the second composite insulating layer 60, and the welding position is located between two adjacent second insulating portions 63, which can block the heat generated by the welding from spreading to the areas on both sides of the welding position, effectively reducing the risk of hidden cracks.

[0078] Please refer to Figure 4 In some embodiments, the second composite insulating layer 60 can extend continuously along the second direction (i.e., the second composite insulating layer 60 is in a continuous structure along the second direction) and is located on the side of the second solder rib 13 and the first solder rib 12 away from the second edge cell 112, all the second solder rib 13 and the first solder rib 12 on the second edge cell 112 intersect with the second composite insulating layer 60, and the second bus bar 50 is arranged on the second composite insulating layer 60. In this case, the orthographic projection of the second bus bar 50 on the second composite insulating layer 60 along the thickness direction is completely located in the second composite insulating layer 60 or coincides with the second composite insulating layer 60, i.e., the second bus bar 50 is completely arranged on the second composite insulating layer 60.

[0079] In this case, as shown in Figure 4 The back contact battery assembly 100 can further include a second auxiliary welding member 70 extending along the second direction, one end of the second auxiliary welding member 70 is welded with the second bus bar 50, and the other end extends out of the edge of the second composite insulating layer 60 and is welded with the second solder rib 13, and the welding point of the second auxiliary welding member 70 and the second bus bar 50 is located on the second composite insulating layer 60.

[0080] In this way, by arranging the second composite insulating layer 60 in a continuous structure, the need for punching or etching and cutting processes on the first composite layer can be saved, saving the process.

[0081] In addition, in the process of manufacturing the assembly, the second auxiliary welding piece 70 can be directly placed first, and then the second auxiliary welding piece 70 is welded with the second bus bar 50 and the second welding strip 13 respectively. The welding point of the second auxiliary welding piece 70 and the second bus bar 50 is directly located on the second composite insulating layer 60. The second composite insulating layer 60 can insulate most of the heat generated at the welding position, avoid excessive heat from spreading to the second edge cell 112, and reduce the probability of hidden cracks. Moreover, the arrangement of the second composite insulating layer 60 can also avoid excessive heat generated by welding the second auxiliary welding piece 70 and the second welding strip 13 from spreading to the area of the second edge cell 112 covered by the second composite insulating layer 60, and can also reduce the probability of hidden cracks.

[0082] In addition, it is not difficult to understand that in such an embodiment, if the second composite insulating layer 60 is not arranged, but only an ordinary insulating layer with only the second insulating adhesive layer 61 is arranged, in order to avoid the high-temperature heat generated by welding the second auxiliary welding piece 70 and the second bus bar 50 from affecting the second edge cell 112, the second auxiliary welding piece 70 and the second bus bar 50 need to be welded together before the second bus bar 50 and the second auxiliary welding piece 70 are placed, and then the whole is placed and the welding between the second auxiliary welding piece 70 and the second welding strip 13 is performed. In this case, the welding needs to be performed in two steps during the whole manufacturing process of the assembly.

[0083] However, in the embodiment of the present application, through the arrangement of the second composite insulating layer 60, most of the heat generated by welding the second bus bar 50 and the second auxiliary welding piece 70 can be insulated, so that the welding between the second auxiliary welding piece 70, the second bus bar 50 and the second welding strip 13 can be completed in one welding process, thereby simplifying the manufacturing process of the assembly and improving the production efficiency.

[0084] Further, in such an embodiment, the number of the second auxiliary welding pieces 70 is multiple and corresponds to the number of the second welding strips 13 on the second edge cell 112, and the multiple second auxiliary welding pieces 70 are arranged at intervals along the second direction.

[0085] In this way, by arranging multiple second auxiliary welding pieces 70, each second welding strip 13 can be connected with the second bus bar 50.

[0086] Specifically, in such an embodiment, the second auxiliary welding piece 70 can be arranged in parallel with the second welding strip 13, and the interval of the second auxiliary welding piece 70 in the second direction can be equal to the interval of the second welding strip 13 in the first direction. The material of the second auxiliary welding piece 70 can be the same as or different from the material of the second welding strip 13 and the first welding strip 12, as long as it has excellent conductivity and welding performance, which is not limited here.

[0087] Please see Figure 4 In some embodiments, the length of the second auxiliary welding member 70 in the second direction (i.e. the width of the second auxiliary welding member 70) is greater than or equal to the length of the second welding strip 13 in the second direction (i.e. the width of the second welding strip 13).

[0088] Thus, by setting the width of the second auxiliary welding component 70 to be the same as or wider than the width of the second welding strip 13, the welding area between the second auxiliary welding component 70 and the second welding strip 13 can be relatively large, thereby improving the welding stability between the second auxiliary welding component 70 and the second welding strip 13 and reducing the probability of the second auxiliary welding component 70 and the second welding strip 13 separating due to external impact on the component.

[0089] Please see Figure 5 In other embodiments, on the second edge cell 112, a second composite insulating layer 60 extends along a second direction and is located on the side of the first solder strip 12 opposite to the second edge cell 112. A second busbar 50 is disposed on the second composite insulating layer 60, and a second solder strip 13 is disposed on the side of the second composite insulating layer 60 opposite to the second edge cell 112, intersecting and being welded to the second busbar 50. The welding point between the second solder strip 13 and the second busbar 50 is located on the second composite insulating layer 60. In this case, the orthographic projection of the second busbar 50 along the thickness direction onto the second composite insulating layer 60 is completely within the second composite insulating layer 60 or coincides with the second composite insulating layer 60; that is, the second busbar 50 is completely disposed on the second composite insulating layer 60.

[0090] Thus, by placing the first solder strip 12 on the second edge battery cell 112 below the second composite insulating layer 60 and placing the second solder strip 13 above the second composite insulating layer 60, the second busbar 50 can be directly insulated from the first solder strip 12 through the second composite insulating layer 60. This also allows the second busbar 50 and the second solder strip 13 to have only one welding point located on the second composite insulating layer 60. The second composite insulating layer 60 can isolate most of the heat generated during welding, thereby reducing the risk of microcracks, without the need for the second auxiliary welding component 70 mentioned above.

[0091] Specifically, in such an embodiment, the second composite insulating layer 60 extends continuously along the second direction, and the second solder strip 13 can be located above or below the second busbar 50. Preferably, the second solder strip 13 is located below the second busbar 50, which can avoid excessive height difference between the second solder strip 13 and the welding position on the electrode (main grid or fine grid) on the back of the second edge cell 112, which could cause poor soldering.

[0092] In the description of the specification, reference to "some embodiments", "certain embodiments", "exemplary embodiments", "specific embodiments", or "some examples" etc., indicate that the particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearing of the above-mentioned phrases in various places in the specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0093] Moreover, the above-described embodiments are merely descriptive of the application and are not intended to limit the application. Any modification, equivalent replacement, and improvement made within the spirit and principle of the application shall fall within the scope of the application.

Claims

1. A back contact cell assembly, characterized by, The back contact battery assembly comprises: a battery string comprising a plurality of back contact battery pieces arranged along a first direction, the plurality of back contact battery pieces comprising a first edge battery piece at one end of the battery string; each of the back contact battery pieces is provided with a plurality of first solder strips and a plurality of second solder strips, the first solder strips and the second solder strips are alternately and spacedly arranged along a second direction and extend along the first direction, the second direction being transverse to the first direction; a first busbar provided on the first edge battery piece, the first busbar extending along the second direction and being soldered with the first solder strips on the first edge battery piece; and a first composite insulating layer provided at least between the first busbar and the second solder strips on the first edge battery piece to insulate and separate the first busbar and the second solder strips, the first composite insulating layer comprising a first insulating adhesive layer and a first aerogel layer stacked on the first insulating adhesive layer. The first composite insulating layer is discontinuous in the second direction to form a plurality of first insulating portions spaced from each other along the second direction, each of the first insulating portions being between each of the second solder strips and the first busbar.

2. The back contact solar cell assembly of claim 1, wherein, The first composite insulating layer continuously extends along the second direction and is located on a side of the first solder strips and the second solder strips away from the first edge battery piece, all of the first solder strips and the second solder strips on the first edge battery piece cross the first composite insulating layer, and the first busbar is provided on the first composite insulating layer.

3. The back contact cell assembly of claim 1, wherein, The back contact battery assembly further comprises a first auxiliary soldering member extending along the second direction, one end of the first auxiliary soldering member being soldered with the first busbar, and the other end of the first auxiliary soldering member extending out of an edge of the first composite insulating layer and being soldered with the first solder strips. The number of the first auxiliary soldering members corresponds to the number of the first solder strips on the first edge battery piece, and the plurality of first auxiliary soldering members are spacedly arranged along the second direction.

4. The back contact solar cell assembly of claim 3, wherein, The length of the first auxiliary soldering member in the second direction is greater than or equal to the length of the first solder strip in the second direction.

5. The back contact solar cell assembly of claim 4, wherein, On the first edge battery piece, the first composite insulating layer extends along the second direction and is located on a side of the second solder strips away from the first edge battery piece, the first busbar is provided on the first composite insulating layer, and the first solder strips are provided on a side of the first composite insulating layer away from the first edge battery piece, cross the first busbar, and are soldered.

6. The back contact cell assembly of claim 1, wherein, The plurality of back contact battery pieces comprises a second edge battery piece at the other end of the battery string, and the back contact battery assembly further comprises:

7. The back contact cell assembly of claim 1, wherein, a second busbar provided on the second edge battery piece, the second busbar extending along the second direction and being soldered with the second solder strips on the second edge battery piece; and a second composite insulating layer provided at least between the second busbar and the second solder strips on the second edge battery piece to insulate and separate the second busbar and the second solder strips, the second composite insulating layer comprising a second insulating adhesive layer and a second aerogel layer stacked on the second insulating adhesive layer. A second composite insulating layer is provided at least between the second bus bar and the first solder rib on the second edge cell to insulate and separate the second bus bar and the first solder rib, and the second composite insulating layer comprises a second insulating adhesive layer and a second aerogel layer stacked on the second insulating adhesive layer.

8. The back contact solar cell assembly of claim 7, wherein, The second composite insulating layer is discontinuous in the second direction to form a plurality of second insulating portions spaced from each other in the second direction, and each of the first solder rib and the second bus bar has the second insulating portion therebetween.

9. The back contact solar cell assembly of claim 7, wherein, The second composite insulating layer continuously extends in the second direction and is located on a side of the first solder rib and the second solder rib away from the second edge cell, and all the first solder rib and the second solder rib on the second edge cell cross the second composite insulating layer, and the second bus bar is provided on the second composite insulating layer. The back contact cell assembly further comprises a second auxiliary soldering member extending in the second direction, one end of the second auxiliary soldering member is soldered to the second bus bar, and the other end of the second auxiliary soldering member extends out of the edge of the second composite insulating layer and is soldered to the second solder rib.

10. The back contact solar cell assembly of claim 9, wherein, The number of the second auxiliary soldering members is plural and corresponds to the number of the second solder rib on the second edge cell, and the plurality of second auxiliary soldering members are arranged in the second direction.

11. The back contact solar cell assembly of claim 10, wherein, The second auxiliary soldering member covers part of the second solder rib, and the length of the second auxiliary soldering member in the second direction is greater than or equal to the length of the second solder rib in the second direction.

12. The back contact solar cell assembly of claim 7, wherein, On the second edge cell, the second composite insulating layer extends in the second direction and is located on a side of the second solder rib away from the second edge cell, the second bus bar is provided on the second composite insulating layer, and the first solder rib is provided on a side of the second composite insulating layer away from the second edge cell, crosses and is soldered to the second bus bar.

13. A photovoltaic system characterized by, The back contact cell assembly comprises the back contact cell assembly according to any one of claims 1-12.

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