Back contact battery assembly and photovoltaic system

Abstract

The utility model relates to the technical field of solar cells, and particularly discloses a back contact cell assembly and a photovoltaic system, the cell assembly comprises a cell substrate, the back surface of the cell substrate is provided with a first grid line and a second grid line which are arranged in a staggered manner along a first direction and have opposite polarities; the confluence pieces comprise first confluence pieces and second confluence pieces, the first confluence pieces and the second confluence pieces are arranged in a staggered mode in the second direction, the first confluence pieces are electrically connected with the first grid lines, and the second confluence pieces are electrically connected with the second grid lines; the bus bar is electrically connected with the first bus member, and an insulating block is arranged between the bus bar and the second bus member; the insulating glue layer is arranged between the second grid line and the first bus piece, and in the second direction, the insulating glue layer comprises a first insulating part which continuously extends from the first bus piece to the direction of the adjacent second bus piece, and in the second direction, the insulating glue layer comprises a second insulating part which continuously extends from the second bus piece to the adjacent second bus piece; the sum of the distance from one end, away from the second bus piece, of the insulating block to the second bus piece and the width of the first insulating part is larger than the distance between the adjacent first bus piece and second bus piece. The reliability of the battery assembly can be improved, and meanwhile the production difficulty is reduced.

Description

Technical Field

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

[0002] In some back-contact battery assemblies, the busbar is mounted on the back of the battery substrate, and an insulating strip is set between the busbar and the battery substrate. The insulating strip needs to be set as an intermittently arranged insulating block to achieve the effect of the busbar being able to contact the same polarity solder strip on the battery substrate, while being insulated from the opposite polarity solder strip and fine grid on the battery substrate. This setting method requires high accuracy in the arrangement of the insulating blocks. In actual production, short circuits can easily occur due to positional displacement of the insulating blocks during lamination. Utility Model Content

[0003] The purpose of this invention is to provide a back contact battery module and photovoltaic system in response to the existing technological status quo.

[0004] This invention can prevent short circuits between the busbar and its heterogeneous grid lines caused by the offset of the insulating block layer, thereby improving the reliability of the battery module. At the same time, it can effectively reduce the accuracy requirements for the position of the insulating block during the production process and reduce the production difficulty.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This utility model provides a back contact battery assembly, including:

[0007] A battery substrate, wherein the back side of the battery substrate is provided with a first grid line and a second grid line arranged alternately along a first direction and having opposite polarities, the first grid line and the second grid line extend along a second direction, and the first direction and the second direction intersect each other;

[0008] The busbar includes a first busbar and a second busbar arranged alternately along a second direction. Both the first busbar and the second busbar extend along a first direction. The first busbar is electrically connected to the first gate line, and the second busbar is electrically connected to the second gate line.

[0009] A busbar, which is electrically connected to the first busbar, and an insulating block is provided between the busbar and the second busbar;

[0010] An insulating adhesive layer is disposed between the second grid line and the first busbar, and in the second direction, the insulating adhesive layer includes a first insulating portion that extends continuously from the first busbar to the adjacent second busbar;

[0011] Furthermore, in the second direction, the sum of the distance from the end of the insulating block away from the second busbar to the second busbar and the width of the first insulating portion is greater than the distance between the adjacent first busbar and the second busbar.

[0012] In some embodiments, in the second direction, both ends of the insulating block are provided with widened sections extending beyond the edge of the second busbar, wherein in the region between the same adjacent first busbar and second busbar, L < W + D < L * 2.

[0013] In the formula, D and W are the widths of the adjacent first insulating portion and the widened section in the second direction, respectively, and L is the distance between the adjacent first busbar and the second busbar in the second direction.

[0014] In some embodiments, in the region between the first busbar and the second busbar in the same adjacent area, L*1.05≤W+D≤L*1.8.

[0015] In the formula, D and W are the widths of the adjacent first insulating portion and the widened section in the second direction, respectively, and L is the distance between the adjacent first busbar and the second busbar in the second direction.

[0016] In some embodiments, in the region between the first busbar and the second busbar in the same adjacent area, L*0.5≤W<L,

[0017] In the formula, W is the width of the widened segment in the second direction, and L is the distance between adjacent first and second busbars in the second direction.

[0018] In some embodiments, the width H of the insulating block in the first direction is greater than the width l of the busbar.

[0019] In some embodiments, l < H < 3*l

[0020] In the formula, H is the width of the insulating block in the first direction, and l is the width of the busbar.

[0021] In some embodiments, 1.2*l ≤ H ≤ 2.5*l,

[0022] In the formula, H is the width of the insulating block in the first direction, and l is the width of the busbar.

[0023] In some embodiments, the first busbar and the second busbar are main gates or solder strips.

[0024] In some embodiments, an insulating adhesive layer is provided between the first grid line and the second busbar, and in a second direction, the insulating adhesive layer extends continuously from at least part of the edge of the second busbar toward the adjacent first busbar.

[0025] In some embodiments, between adjacent first and second busbars, the insulating adhesive layer and the projected portion of the insulating adhesive material layer in a first direction coincide.

[0026] In some embodiments, the insulating block at least partially covers the overlapping area.

[0027] In some embodiments, the insulating block includes an insulating substrate, which is any one of PET substrate, PI substrate, POE substrate, EVA substrate, and PVB substrate.

[0028] This utility model also provides a photovoltaic system, including the aforementioned back contact battery assembly.

[0029] The beneficial effects of the present invention are:

[0030] In this invention, the busbar is disposed on the back side of the battery substrate. An insulating block isolates the busbar from its non-standard busbar (second busbar). A first insulating portion is provided on the non-standard grid line (second grid line), extending continuously from the first busbar towards the adjacent second busbar. The portion of the non-standard grid line (second grid line) between the first and second busbars achieves electrical isolation from the busbar through the cooperation between the insulating block and the insulating adhesive layer. Furthermore, in a second direction, the distance from the end of the insulating block away from the second busbar to the second busbar is equal to the width of the first insulating portion. The sum of the degrees is greater than the distance between the adjacent first busbar and the second busbar, that is, there is an overlapping area between the insulating block and the first insulating part, which allows the insulating block to have a certain degree of offset during the manufacturing process. Even if the position of the insulating block is offset during the product manufacturing process, the first insulating part is still on the exposed irregular grid line (second grid line) due to the offset of the insulating block. Thus, under the action of the first insulating part, the busbar and its irregular grid line are prevented from conducting and short-circuiting, thereby improving the reliability of the battery module. At the same time, it can effectively reduce the accuracy requirements of the insulating block position during the manufacturing process and reduce the manufacturing difficulty. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of one embodiment of a back contact battery assembly according to this utility model.

[0032] Figure 2 for Figure 1 A magnified view of a portion of the image. Detailed Implementation

[0033] 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. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this utility model and are not intended to limit this utility model.

[0034] In the description of this utility model, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., 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.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] In this application, unless otherwise expressly specified and limited, the term "above" or "below" a second feature may include direct contact between the first and second features, or contact between the first and second features not in direct contact but through another feature between them.

[0037] It is understandable that the busbar 3 and the busbar component themselves do not have polarity. In this utility model, for ease of description, the polarity of the busbar 3 and the busbar component refers to their polarity on a certain battery substrate. The polarity of the busbar 3 and the busbar component on a certain battery substrate is consistent with the polarity of the grid lines collected on that battery substrate. Correspondingly, the grid lines of the opposite polarity are the grid lines on the battery substrate with the opposite polarity to the grid lines collected. For example, if the busbar component is welded to the grid lines of the positive electrode on a certain battery substrate, then the polarity of the busbar component on that battery substrate is the positive electrode, and correspondingly, the grid lines of the opposite polarity are the grid lines of the negative electrode.

[0038] See Figures 1 to 2As shown, this embodiment discloses a back contact battery assembly, including:

[0039] A battery substrate, wherein the back side of the battery substrate is provided with a first grid line 11 and a second grid line 12 arranged alternately along a first direction and having opposite polarities, the first grid line 11 and the second grid line 12 extending along a second direction, and the first direction and the second direction intersecting each other;

[0040] The busbar includes a first busbar 21 and a second busbar 22 arranged alternately along a second direction. Both the first busbar 21 and the second busbar 22 extend along a first direction. The first busbar 21 is electrically connected to the first grid line 11, and the second busbar 22 is electrically connected to the second grid line 12.

[0041] Busbar 3, which is electrically connected to the first busbar 21, and an insulating block 5 is provided between the busbar 3 and the second busbar 22;

[0042] An insulating adhesive layer 4 is disposed between the second grid line 12 and the first busbar 21, and in the second direction, the insulating adhesive layer 4 includes a first insulating portion 41 that extends continuously from the first busbar 21 toward the adjacent second busbar 22;

[0043] Furthermore, in the second direction, the sum of the distance from the end of the insulating block 5 away from the second busbar 22 to the second busbar 22 and the width of the first insulating portion 41 is greater than the distance between the adjacent first busbar 21 and the second busbar 22.

[0044] In this embodiment, the busbar 3 is disposed on the back side of the battery substrate. The busbar 3 is isolated from its non-standard busbar (second busbar 22) by an insulating block 5. A first insulating portion 41 is provided on the non-standard grid line (second grid line 12) extending continuously from the first busbar 21 to the adjacent second busbar 22. The portion of the non-standard grid line (second grid line 12) between the first busbar 21 and the second busbar 22 can be electrically isolated from the busbar 3 through the cooperation between the insulating block 5 and the insulating adhesive layer 4. In the second direction, the distance from the end of the insulating block 5 away from the second busbar 22 to the second busbar 22 is different from the distance of the first insulating block 5. The sum of the widths of the first insulating part 41 is greater than the distance between the adjacent first busbar 21 and second busbar 22. That is, there is an overlapping area between the insulating block 5 and the first insulating part 41, which allows the insulating block 5 to have a certain degree of offset during the manufacturing process. Even if the position of the insulating block 5 is offset during the product manufacturing process, the first insulating part 41 is still on the exposed irregular grid line (second grid line 12) due to the offset of the insulating block 5. Thus, under the action of the first insulating part 41, the busbar 3 and its irregular grid line are prevented from conducting and short-circuiting, thereby improving the reliability of the battery assembly. At the same time, it can effectively reduce the accuracy requirements of the position of the insulating block 5 during the manufacturing process and reduce the manufacturing difficulty.

[0045] Understandably, on the same battery substrate, all first grid lines 11 have the same polarity, all second grid lines 12 have the same polarity, and the polarities of the first grid lines 11 and the second grid lines 12 are opposite. Between different battery substrates, the polarities of the first grid lines 11 can be the same or different, and correspondingly, the polarities of the second grid lines 12 can be the same or different.

[0046] For example, in the first embodiment, to connect the first battery string and the second battery string in series via the same busbar 3 (where the busbar 3 is the end busbar 3), on the battery substrate where the busbar 3 is located in the first battery string, the first grid line 11 is the positive electrode and the second grid line 12 is the negative electrode, and the first busbar 21 is connected to the first grid line 11 of the positive electrode on the battery substrate. Similarly, on the battery substrate where the busbar 3 is located in the second battery string, the first grid line 11 is the negative electrode and the second grid line 12 is the positive electrode, and the first busbar 21 is connected to the first grid line 11 of the negative electrode on the battery substrate.

[0047] For example, in the second embodiment, in order to enable the third battery string and the fourth battery string to be connected in parallel through the same bus bar 3 (at this time, the bus bar 3 is the middle bus bar 3), on the battery substrate where the bus bar 3 is located in the third battery string and the fourth battery string, the first grid line 11 is the positive electrode and the second grid line 12 is the negative electrode, and the first bus member 21 is connected to the first grid line 11 of the positive electrode on the battery substrate where the bus bar 3 is located.

[0048] For example, in the third embodiment, in order to connect adjacent battery substrates in the same battery string, the first grid line 11 / second grid line 12 of adjacent battery substrates have opposite polarities. Taking the Nth, N+1th, and N+2th battery substrates arranged adjacently in the same battery string as an example, the first grid line 11 on the Nth battery substrate is the positive electrode and the second grid line 12 is the negative electrode; the first grid line 11 on the N+1th battery substrate is the negative electrode and the second grid line 12 is the positive electrode; the first grid line 11 on the N+2th battery substrate is the positive electrode and the second grid line 12 is the negative electrode. The same first busbar 21 is connected to the first grid line 11 of the positive electrode on the Nth battery substrate and the first grid line 11 of the negative electrode on the N+1th battery substrate, respectively. The same second busbar 22 is connected to the second grid line 12 of the positive electrode on the N+1th battery substrate and the second grid line 12 of the negative electrode on the N+2th battery substrate, respectively.

[0049] In some embodiments, the insulating adhesive layer 4 can be prepared by printing a pattern on a battery substrate and then curing it (e.g., thermosetting) to form the insulating adhesive layer 4. It is understood that the insulating adhesive material layer 6 described below can also be prepared in this way, and will not be described in detail hereafter.

[0050] In some embodiments, see Figures 1 to 2 As shown, in the second direction, both ends of the insulating block 5 are provided with widened sections 51 extending beyond the edge of the second busbar 22 (that is, the insulating block 5 has widened sections 51A and 51B), wherein, in the region between the same adjacent first busbar 21 and second busbar 22,

[0051] L < W + D < L * 2,

[0052] In the formula, D and W are the widths of adjacent first insulating portions 41 and widened segments 51 in the second direction, respectively; L is the distance between adjacent first busbars 21 and second busbars 22 in the second direction. It can be understood that W here is the width of the widened segment 51 between a single adjacent first busbar 21 and second busbar 22 in the second direction, for example, the width of a single widened segment 51A or a single widened segment 51B in the second direction; and D is the width of the first insulating portion 41 between a single adjacent first busbar 21 and second busbar 22 in the second direction.

[0053] Both ends of the insulating block 5 are provided with widened sections 51 extending beyond the edge of the second busbar 22. On the one hand, this allows the second busbar 22 and the busbar 3 to still be electrically isolated through the insulating block 5 even if the insulating block 5 shifts within a certain range during the manufacturing process. On the other hand, the portion of the non-standard grid line (second grid line 12) between the first busbar 21 and the second busbar 22 can be electrically isolated from the busbar 3 through the cooperation between the widened section 51 and the first insulating part 41 of the insulating adhesive layer 4. The presence of the widened section 51 and the width setting of the widened section 51 and the first insulating part 41 mean that the insulating adhesive layer 4 does not need to completely cover the entire portion of the non-standard grid line (second grid line 12) located between the first busbar 21 and the second busbar 22. This also effectively avoids short circuits caused by the busbar 3 and its non-standard grid line due to positional shift during the manufacturing process of the insulating block 5. This reduces the use of insulating adhesive material, lowers material costs, and avoids the problem of battery substrate warping caused by excessive coating of insulating adhesive material, ensuring the overall flatness of the battery substrate.

[0054] In some embodiments, more preferably, in the region between the first busbar 21 and the second busbar 22 of the same adjacent type, L*1.05≤W+D≤L*1.8.

[0055] In the formula, D and W are the widths of the adjacent first insulating portion 41 and the widened segment 51 in the second direction, respectively, and L is the distance between the adjacent first busbar 21 and the second busbar 22 in the second direction.

[0056] Since the offset of insulating block 5 during the manufacturing process is usually within a certain range, when W+D is controlled within the range of L*1.05≤W+D≤L*1.8, it can ensure that the battery module will not cause a short circuit due to the offset of insulating block 5 during the manufacturing process, and it can also avoid the problem of battery substrate warping caused by excessive coating of insulating adhesive material. The battery module can have better reliability, lower production precision requirements, lower production costs and higher flatness, with better overall performance, which is conducive to product manufacturing and widespread application.

[0057] In some embodiments, see Figure 2 As shown, in the region between the first busbar 21 and the second busbar 22, which are adjacent to each other, L*0.5≤W<L.

[0058] In the formula, W is the width of the widened segment 51 in the second direction, and L is the distance between the adjacent first busbar 21 and second busbar 22 in the second direction.

[0059] When the widened section 51 is too narrow, the first insulating part 41 of the insulating adhesive layer 4 needs to be longer, which can easily increase the warping of the battery substrate. When the widened section 51 is too large, the edge of the widened section 51 is too close to the adjacent first busbar 21, which can easily interfere with the welding of the first busbar 21 and increase the risk of poor welding.

[0060] In some embodiments, see Figure 2 As shown, the width H of the insulating block 5 in the first direction is greater than the width l of the busbar 3.

[0061] Preferably, the width of the insulating block 5 in the first direction is greater than the width of the busbar 3, allowing the insulating block 5 to shift to a certain extent during the manufacturing process. This avoids short circuit between the busbar 3 and the second busbar 22 due to the width shift of the insulating block 5 during placement, and reduces the production precision requirements for the placement of the insulating block 5 during the manufacturing process.

[0062] In some embodiments, see Figure 2 As shown, l < H < 3*l,

[0063] In the formula, H is the width of the insulating block 5 in the first direction, and l is the width of the busbar 3.

[0064] Within this range, sufficient offset can be provided for the insulating block 5 during the preparation process, while avoiding unnecessary shading of the battery substrate due to the excessive width of the insulating block 5, which would lead to a decrease in the bifaciality.

[0065] In some embodiments, preferably, 1.2*l ≤ H ≤ 2.5*l.

[0066] In the formula, H is the width of the insulating block 5 in the first direction, and l is the width of the busbar 3.

[0067] In some embodiments, the first busbar 21 and the second busbar 22 are main gates or solder strips.

[0068] In some embodiments, see Figures 1 to 2 As shown, an insulating adhesive layer 6 is provided between the first grid line 11 and the second busbar 22. In the second direction, the insulating adhesive layer 6 extends continuously from the edge of the second busbar 22 toward the adjacent first busbar 21. The insulating adhesive layer 6 can effectively prevent two adjacent first grid lines 11 and second grid lines 12 with opposite polarities from being connected by conductive debris, thereby further improving the production yield of the battery module.

[0069] In some embodiments, see Figure 2As shown, between adjacent first busbars 21 and second busbars 22, the projection portions of the insulating adhesive layer 4 and the insulating adhesive material layer 6 in the first direction overlap, further reducing the risk of two adjacent first grid lines 11 and second grid lines 12 with opposite polarities being connected by conductive debris, further improving the production yield of the battery assembly. At the same time, while ensuring the aforementioned effects, the amount of insulating adhesive material used is reduced, avoiding the problem of battery substrate warping that is easily caused by excessive coating of insulating adhesive material.

[0070] In some embodiments, see Figure 2 As shown, the insulating block 5 at least partially covers the overlapping area, further improving the production yield and reliability of the battery assembly.

[0071] In some embodiments, see Figures 1 to 2 As shown, the insulating adhesive layer 4 also has a second insulating portion 42, which extends continuously between the second grid line 12 and the first busbar 21, and is connected to the adjacent first insulating portion 41.

[0072] And / or, the insulating adhesive material layer 6 is further provided with a third insulating portion 61, which extends continuously between the first grid line 11 and the second busbar 22.

[0073] To prevent short circuits caused by contact between the busbar and its non-standard grid line, in this embodiment, a second insulating part 42 is provided between the first busbar 21 and its non-standard grid line (second grid line 12), and a third insulating part 61 is provided between the second busbar 22 and its non-standard grid line (first grid line 11), which effectively ensures the electrical isolation between the busbar and its non-standard grid line and further improves the reliability of the battery assembly.

[0074] In some embodiments, the insulating block 5 includes an insulating substrate, which is any one of PET substrate, PI substrate, POE substrate, EVA substrate, and PVB substrate.

[0075] More preferably, the insulating substrate is a PET substrate or a PI substrate. PET substrates possess excellent insulation properties, mechanical properties, temperature and weather resistance, and are environmentally friendly and recyclable, while PI substrates have lower costs, effectively reducing material costs.

[0076] In some embodiments, the insulating adhesive layer 4 and the insulating adhesive material layer 6 may be made of transparent material to increase the double-sidedness.

[0077] This utility model also provides a photovoltaic system, including the aforementioned back contact battery assembly.

[0078] In this embodiment, the photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0079] In the description of this specification, 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 the present invention. 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.

[0080] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A back-contact battery assembly, characterized in that, include: A battery substrate, wherein the back side of the battery substrate is provided with a first grid line and a second grid line arranged alternately along a first direction and having opposite polarities, the first grid line and the second grid line extend along a second direction, and the first direction and the second direction intersect each other; The busbar includes a first busbar and a second busbar arranged alternately along a second direction. Both the first busbar and the second busbar extend along a first direction. The first busbar is electrically connected to the first gate line, and the second busbar is electrically connected to the second gate line. A busbar, which is electrically connected to the first busbar, and an insulating block is provided between the busbar and the second busbar; An insulating adhesive layer is disposed between the second grid line and the first busbar, and in the second direction, the insulating adhesive layer includes a first insulating portion that extends continuously from the first busbar to the adjacent second busbar; Furthermore, in the second direction, the sum of the distance from the end of the insulating block away from the second busbar to the second busbar and the width of the first insulating portion is greater than the distance between the adjacent first busbar and the second busbar.

2. The back contact battery assembly according to claim 1, characterized in that, In the second direction, both ends of the insulating block are provided with widened sections extending beyond the edge of the second busbar, wherein in the region between the same adjacent first busbar and second busbar, L < W + D < L * 2, In the formula, D and W are the widths of the adjacent first insulating portion and the widened section in the second direction, respectively, and L is the distance between the adjacent first busbar and the second busbar in the second direction.

3. A back-contact battery assembly according to claim 2, characterized in that, In the same adjacent area between the first busbar and the second busbar, L*1.05≤W+D≤L*1.8 In the formula, D and W are the widths of the adjacent first insulating portion and the widened section in the second direction, respectively, and L is the distance between the adjacent first busbar and the second busbar in the second direction.

4. A back-contact battery assembly according to claim 2, characterized in that, In the same adjacent area between the first busbar and the second busbar, L*0.5≤W<L, In the formula, W is the width of the widened segment in the second direction, and L is the distance between adjacent first and second busbars in the second direction.

5. A back-contact battery assembly according to claim 1, characterized in that, The width H of the insulating block in the first direction is greater than the width l of the busbar.

6. A back-contact battery assembly according to claim 5, characterized in that, l＜H＜3*l， In the formula, H is the width of the insulating block in the first direction, and l is the width of the busbar.

7. A back-contact battery assembly according to claim 6, characterized in that, 1.2*l≤H≤2.5*l， In the formula, H is the width of the insulating block in the first direction, and l is the width of the busbar.

8. A back-contact battery assembly according to claim 1, characterized in that, The first busbar and the second busbar are main grids or solder strips.

9. A back-contact battery assembly according to claim 1, characterized in that, An insulating adhesive layer is provided between the first grid line and the second busbar, and in the second direction, the insulating adhesive layer extends continuously from at least part of the edge of the second busbar toward the adjacent first busbar.

10. A back-contact battery assembly according to claim 9, characterized in that, Between adjacent first and second busbars, the insulating adhesive layer and the projected portion of the insulating adhesive material layer in the first direction coincide.

11. A back-contact battery assembly according to claim 10, characterized in that, The insulating block at least partially covers the overlapping area.

12. A back-contact battery assembly according to claim 1, characterized in that, The insulating block includes an insulating substrate, which is any one of PET substrate, PI substrate, POE substrate, EVA substrate, and PVB substrate.

13. A photovoltaic system, characterized in that, Includes the back contact battery assembly according to any one of claims 1 to 12.

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