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 first grid lines and second grid lines which are staggered along a first direction and opposite in polarity, and the first grid lines and the second grid lines extend along a second direction. First areas and second areas are arranged on the back face of the battery substrate in a staggered mode in the second direction, the first direction and the second direction are arranged in a crossed mode, the confluence pieces comprise first confluence pieces and second confluence pieces which are arranged in a staggered mode in the second direction, and the first confluence pieces are electrically connected with the parts, located in the first areas, of the first grid lines; the insulating rubber layer comprises a first insulating part and a second insulating part, the first insulating part covers the part, located in the second area, of the first grid line, the second insulating part covers the part, located in the second area, of the second grid line, the bus bar is electrically connected with the first bus piece, and the bus bar is electrically connected with the second bus piece. An insulating block is arranged between the bus bar and the second bus piece, and the breakdown voltage resistance of the insulating block is larger than that of the insulating adhesive layer. The battery assembly is high in reliability, and the production difficulty can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to solar cell technical field especially relates to a back contact battery assembly and photovoltaic system. BACKGROUND

[0002] In some back contact battery assemblies, the bus bar is installed on the back of the cell piece, and an insulating strip is arranged between the bus bar and the cell piece, the insulating strip needs to be treated with hole opening or the bus bar is arranged as an insulating block with intermittent arrangement, so that the bus bar can contact the same polarity ribbon on the cell piece, and the reverse polarity ribbon and the fine grid on the cell piece are insulated, the setting mode is high in requirement for the hole opening precision of the insulating strip and the arrangement position precision of the insulating block, in the actual production process, the position deviation of the insulating strip during hole opening or the position deviation of the insulating block during lamination can cause short circuit / virtual welding. SUMMARY

[0003] The utility model discloses a back contact battery assembly and photovoltaic system, the battery assembly of the utility model is high in reliability, can avoid the position deviation of the insulating strip during hole opening or the position deviation of the insulating block during lamination to cause short circuit / virtual welding, and can effectively reduce the precision requirement of the position of the insulating block in the production preparation process, and reduce the production difficulty.

[0004] To achieve the above object, the utility model adopts the following technical scheme:

[0005] On the one hand, the utility model provides a back contact battery assembly, comprising:

[0006] The back of the cell substrate is provided with first grid lines and second grid lines staggered in a first direction and opposite in polarity, the first grid lines and the second grid lines are arranged in a second direction, the back of the cell substrate is staggered in the second direction and has first areas and second areas,

[0007] The bus bar includes first bus bars and second bus bars staggered in the second direction, the first bus bars are electrically connected with the first grid lines in the first areas, and the second bus bars are electrically connected with the second grid lines in the first areas,

[0008] The insulating adhesive layer includes first insulating parts and second insulating parts, the first insulating parts cover the first grid lines in the second areas, and the second insulating parts cover the second grid lines in the second areas,

[0009] 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.

[0010] In some embodiments, the insulating adhesive layer further comprises a third insulating portion and a fourth insulating portion, both of which are arranged in the first region, the third insulating portion is arranged between the first bus member and the second gate line and connected with the adjacent second insulating portion, and the fourth insulating portion is arranged between the second bus member and the first gate line and connected with the adjacent first insulating portion.

[0011] In some embodiments, the breakdown voltage capacity of the insulating block is at least 2 times the breakdown voltage capacity of the insulating adhesive layer.

[0012] In some embodiments, in the second direction, the insulating block at least partially overlaps with the second insulating portion.

[0013] In some embodiments, in the first direction, both sides of the insulating block are respectively provided with an overhanging segment overhanging the edge of the second bus member, and in a single second region, the width of the overhanging segment is less than the width of the second insulating portion, and the width of the overhanging segment is at least 0.5 times the width of the second insulating portion.

[0014] In some embodiments, the insulating block comprises an insulating substrate, which is any one of a PET substrate, a PI substrate, a POE substrate, an EVA substrate, and a PVB substrate.

[0015] In some embodiments, the thickness of the insulating adhesive layer is 10-80 μm, and the thickness of the insulating block is 85-300 μm.

[0016] In some embodiments, the insulating blocks are arranged at intervals along the second direction.

[0017] In some embodiments, the battery assembly comprises an insulating strip arranged to extend along the second direction, the insulating strip is provided with a relief hole for exposing the first bus member, and the insulating blocks are formed between adjacent relief holes.

[0018] In some embodiments, the first bus member and the second bus member are main gates or solder strips.

[0019] In another aspect, the utility model also provides a photovoltaic system comprising the back contact battery assembly.

[0020] The utility model has the advantages of:

[0021] In this invention, the busbar is positioned on the back of the battery substrate, and an insulating block isolates the busbar from the non-standard busbar (second busbar). The portion of the non-standard grid line (second grid line) located in the second region is completely covered by a second insulating portion, ensuring that the non-standard grid line, except for the first region, is electrically isolated from the busbar. This prevents short circuits caused by the busbar and non-standard grid line from conducting during product manufacturing, even if the insulating block shifts. Furthermore, the insulation block has a higher breakdown voltage than the insulating adhesive layer, providing more stable and better insulation. However, the insulation block is relatively thick; if its edges are too close to the first busbar, during product manufacturing... If the insulating block is misaligned, it can easily lift and obstruct the first busbar, causing unevenness in the first busbar and affecting its welding, resulting in a cold solder joint. However, the insulating adhesive layer is made of insulating adhesive material and is thin, so the first insulating part can cover the position of the opposite grid line near the first busbar without affecting the welding of the first busbar. This avoids cold solder joints caused by the misalignment of the insulating block, resulting in better reliability of the battery module. It can effectively reduce the accuracy requirements for the position of the insulating block during the production process and reduce the production difficulty. At the same time, this utility model also completely covers the first insulating part on the part of the first grid line located in the second region, preventing two adjacent first grid lines and second grid lines with opposite polarities from being connected by conductive debris, further improving the production yield of the battery module. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model.

[0023] Figure 2 for Figure 1 A magnified view of a portion of the image.

[0024] Figure 3 This is a structural schematic diagram of Embodiment 2 of the present invention. Detailed Implementation

[0025] 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.

[0026] In the description of the utility model, the terms "first", "second", "third", "fourth" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second", "third", "fourth" and the like can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "multiple" is two or more than two, unless otherwise specifically limited.

[0027] It can be understood that the bus bar and the bus member do not have polarity, in the utility model, for the convenience of description, the polarity of the bus bar and the bus member refers to its polarity on a certain battery piece, the polarity of the bus bar and the bus member on a certain battery piece is consistent with the polarity of the grid line collected on the battery piece, and correspondingly, the opposite grid line is the grid line opposite to the grid line collected on the battery piece, for example, the bus member is welded with the grid line of the positive pole on a certain battery piece, and the polarity of the bus member on the battery piece is the positive pole, and correspondingly, the opposite grid line is the grid line of the negative pole.

[0028] Embodiment 1

[0029] Referring to Figures 1 to 2 The embodiment discloses a back contact battery assembly, which comprises:

[0030] A battery substrate, the back surface of the battery substrate is provided with first grid lines 11 and second grid lines 12 staggered in a first direction and opposite in polarity, the first grid lines 11 and the second grid lines 12 are arranged in extension in a second direction, the back surface of the battery substrate is staggered in the second direction and provided with a first area 61 and a second area 62, the first direction and the second direction are cross arranged,

[0031] A bus member, comprising first bus members 21 and second bus members 22 staggered in the second direction, the first bus members 21 are electrically connected with the part of the first grid lines 11 located in the first area 61, and the second bus members 22 are electrically connected with the part of the second grid lines 12 located in the first area 61, it can be understood that the first bus members 21 and the second bus members 22 are arranged in the first area 61, one first area 61 is provided with one first bus member 21 or second bus member 22, and the first bus members 21 and the second bus members 22 are staggered in the adjacent two first areas 61,

[0032] An insulating adhesive layer 3, comprising a first insulating part 31 and a second insulating part 32, the first insulating part 31 covers the part of the first grid lines 11 located in the second area 62, and the second insulating part 32 covers the part of the second grid lines 12 located in the second area 62,

[0033] A busbar 4 is electrically connected with the first busbar 21, and an insulating block 5 is arranged between the busbar 4 and the second busbar 22, and the anti-breakdown voltage capacity of the insulating block 5 is greater than the anti-breakdown voltage capacity of the insulating layer 3.

[0034] In the embodiment, the busbar 4 is arranged on the back of the battery substrate, and the busbar 4 and the second busbar 22 are isolated from each other by the insulating block 5, and the second insulating part 32 is entirely covered on the part of the second grid line 12 located in the second area 62, so that the second grid line can be electrically isolated from the busbar 4 except for the first area 61, thereby avoiding the short circuit caused by the conduction between the busbar 4 and the second grid line during the product preparation process. In addition, the anti-breakdown voltage capacity of the insulating block 5 is greater than the anti-breakdown voltage capacity of the insulating layer 3, on the one hand, the insulating block 5 can provide more stable and better insulation effect, but the thickness of the insulating block 5 is relatively large, if the two side edges of the insulating block 5 are too close to the first busbar 21, during the product preparation process, if the position of the insulating block 5 is deviated, the first busbar 21 is easily lifted and hindered, resulting in uneven first busbar 21, affecting the welding of the first busbar 21, causing the problem of virtual welding, and the insulating layer 3 is made of insulating glue material, and the thickness is thin, so the first insulating part 31 can be covered on the position of the second grid line close to the first busbar 21 without affecting the welding of the first busbar 21, avoiding the virtual welding caused by the position deviation of the insulating block 5, and the reliability of the battery assembly is good, which can effectively reduce the precision requirement of the position of the insulating block 5 during the production preparation process, and reduce the production difficulty, and the first insulating part 31 is entirely covered on the part of the first grid line 11 located in the second area 62, avoiding the conduction of the adjacent first grid line 11 and second grid line 12 with opposite polarities by the conductive debris, and further improving the production yield of the battery assembly.

[0035] It can be understood that the polarities of the first grid lines 11 can be the same or different between different battery substrates, and correspondingly, the polarities of the second grid lines 12 can be the same or different. For example, in one embodiment, in order to realize series connection between the first battery string and the second battery string through the same busbar 4 (in this case, the busbar 4 is an end busbar), the first grid line 11 is positive and the second grid line 12 is negative on the battery substrate where the busbar 4 is located in the first battery string, and the first busbar 21 is connected to the positive first grid line 11 on the battery substrate. On the battery substrate where the busbar 4 is located in the second battery string, the first grid line 11 is negative and the second grid line 12 is positive, and the first busbar 21 is connected to the negative first grid line 11 on the battery substrate. In another embodiment, in order to realize parallel connection between the third battery string and the fourth battery string through the same busbar 4 (in this case, the busbar 4 is a middle busbar), the first grid line 11 is positive and the second grid line 12 is negative on the battery substrate where the busbar 4 is located in the third battery string and the fourth battery string, and the first busbar 21 is connected to the positive first grid line 11 on the battery substrate where the busbar 4 is located.

[0036] In some embodiments, the insulating adhesive layer 3 can be prepared by printing a pattern on the battery substrate and then curing and forming.

[0037] In some embodiments, referring to FIG. 2, the insulating adhesive layer 3 further includes a third insulating portion 33 and a fourth insulating portion 34, both of which are arranged on the first region 61. The third insulating portion 33 is arranged between the first busbar 21 and the second grid line 12 and connected to the adjacent second insulating portion 32. The fourth insulating portion 34 is arranged between the second busbar 22 and the first grid line 11 and connected to the adjacent first insulating portion 31. Figures 1 to 2

[0038] In order to avoid short circuit caused by contact between the busbar and the opposite grid line, in this embodiment, the insulating adhesive layer 3 is arranged between the busbar and the opposite grid line in the first region 61, that is, the third insulating portion 33 is arranged between the first busbar 21 and the second grid line 12, and the fourth insulating portion 34 is arranged between the second busbar 22 and the first grid line 11, which effectively ensures the electrical isolation effect between the busbar and the opposite grid line.

[0039] In some embodiments, the withstand voltage of the insulating block 5 is at least 2 times the withstand voltage of the insulating adhesive layer 3, and the insulating block 5 can provide more stable and better insulation effect.

[0040] In some embodiments, referring to FIG. 2, the insulating adhesive layer 3 further includes a third insulating portion 33 and a fourth insulating portion 34, both of which are arranged on the first region 61. The third insulating portion 33 is arranged between the first busbar 21 and the second grid line 12 and connected to the adjacent second insulating portion 32. The fourth insulating portion 34 is arranged between the second busbar 22 and the first grid line 11 and connected to the adjacent first insulating portion 31. Figure 1 Figure 2 ​​As shown, in the second direction, the insulating block 5 at least partially overlaps the second insulating portion 32.

[0041] In some embodiments, referring to Figure 1 and Figure 2 As shown, in the first direction, both sides of the insulating block 5 are provided with an overhanging section 51 overhanging the edge of the second busbar 22, and the width W of the overhanging section 51 is less than the width L of the second insulating portion 32, and the width W of the overhanging section 51 is at least 0.5 times the width L of the second insulating portion 32.

[0042] The width of the insulating block 5 should not be too large, otherwise the edges of the insulating block 5 are too close to the first busbar 21, and if the position of the insulating block 5 deviates during product preparation, the first busbar 21 is easily lifted and hindered, resulting in unevenness of the first busbar 21, affecting the welding of the first busbar 21, and causing the problem of false welding. The width of the insulating block 5 should not be too small, otherwise the reliability will be reduced.

[0043] In some embodiments, the insulating block 5 comprises an insulating substrate, and the insulating substrate is any one of a PET substrate, a PI substrate, a POE substrate, an EVA substrate, and a PVB substrate.

[0044] Preferably, the insulating substrate is a PET substrate or a PI substrate.

[0045] In some embodiments, the thickness of the insulating adhesive layer 3 is less than the thickness of the insulating adhesive layer 3.

[0046] In some embodiments, the thickness of the insulating adhesive layer 3 is 10-80 μm, and the thickness of the insulating block 5 is 85-300 μm.

[0047] Illustratively, the thickness of the insulating adhesive layer 3 is 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, or 80 μm, but is not limited thereto.

[0048] Exemplarily, the thickness of the insulating block 5 is 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, 150 μm, 155 μm, 160 μm, 165 μm, 170 μm, 175 μm, 180 μm, 185 μm, 190 μm, 195 μm, 200 μm, 205 μm, 210 μm, 215 μm, 220 μm, 225 μm, 230 μm, 235 μm, 240 μm, 245 μm, 250 μm, 255 μm, 260 μm, 265 μm, 270 μm, 275 μm, 280 μm, 285 μm, 290 μm, 295 μm, or 300 μm, but is not limited thereto.

[0049] If the insulating adhesive layer 3 is too thick, the flatness of the busbar is affected, and if the insulating adhesive layer 3 is too thin, the insulating adhesive layer 3 is easily punctured by conductive debris in the preparation process, and both too thick and too thin of the insulating adhesive layer 3 easily increase the risk of hidden cracks.

[0050] If the insulating block 5 is too thick, the welding of the busbar 4 and the busbar is affected, and if the insulating block 5 is too thin, the insulating effect is affected.

[0051] In some embodiments, referring to Figures 1 to 2 as shown, the insulating blocks 5 are arranged at intervals along the second direction.

[0052] In some embodiments, the first busbar 21 and the second busbar 22 are main grids or solder strips.

[0053] The embodiment also discloses a photovoltaic system comprising the back contact cell module.

[0054] Embodiment 2

[0055] The embodiment differs from embodiment 1 in that, referring to Figure 3 as shown, the cell module comprises insulating strips, the insulating strips are arranged along the second direction, the insulating strips are provided with avoiding holes for exposing the first busbar 21, and the insulating blocks 5 are formed between adjacent avoiding holes.

[0056] In the description of the present specification, the description of the terms “some embodiments”, “exemplary embodiments”, “examples”, “specific examples”, or “some examples” and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0057] The above merely describes preferred embodiments of the present application and is not intended to limit the present application in any form. Although the present application has been disclosed with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above-mentioned technical content without departing from the technical solution of the present application, and equivalent embodiments with equivalent changes are obtained. Any simple modification, equivalent change and modification of the above embodiments based on the technical essence of the present application are still within the scope of the present application.

Claims

1. A back contact cell assembly, characterized by, The back contact battery assembly comprises: a battery substrate, a back surface of the battery substrate being provided with first grid lines and second grid lines staggered in a first direction and having opposite polarities, the first grid lines and the second grid lines being arranged in a second direction, a bus member comprising first bus members and second bus members staggered in the second direction, the first bus members being electrically connected to the first grid lines in the first area, and the second bus members being electrically connected to the second grid lines in the first area, an insulating adhesive layer comprising first insulating portions and second insulating portions, the first insulating portions covering the first grid lines in the second area, and the second insulating portions covering the second grid lines in the second area, a bus bar electrically connected to the first bus members, and an insulating block being provided between the bus bar and the second bus members, the insulating block having a breakdown voltage greater than that of the insulating adhesive layer.

2. A back contact solar cell assembly according to claim 1, wherein, The insulating adhesive layer further comprises third insulating portions and fourth insulating portions, the third insulating portions and the fourth insulating portions being provided in the first area, the third insulating portions being provided between the first bus members and the second grid lines and connected to the adjacent second insulating portions, and the fourth insulating portions being provided between the second bus members and the first grid lines and connected to the adjacent first insulating portions.

3. A back contact cell assembly according to claim 1, wherein, The insulating block has a breakdown voltage at least 2 times that of the insulating adhesive layer.

4. A back contact solar cell assembly according to claim 1, wherein, In the second direction, the insulating block at least partially overlaps the second insulating portions.

5. A back contact solar cell assembly according to claim 4, wherein, In the first direction, both sides of the insulating block are respectively provided with overhanging sections extending beyond the edges of the second bus members, and in a single second area, the width of the overhanging sections is less than the width of the second insulating portions, and the width of the overhanging sections is at least 0.5 times the width of the second insulating portions.

6. A back contact solar cell assembly according to claim 1, wherein, The insulating block comprises an insulating base material, which is any one of a PET base material, a PI base material, a POE base material, an EVA base material, and a PVB base material.

7. A back contact solar cell assembly as set forth in Claim 1, wherein, The thickness of the insulating adhesive layer is 10-80 μm, and the thickness of the insulating block is 85-300 μm.

8. A back contact solar cell assembly according to claim 1, wherein, The insulating block is arranged in the second direction at intervals, or The battery assembly comprises an insulating strip arranged in the second direction, the insulating strip being provided with avoiding holes for exposing the first bus members, and the avoiding holes between adjacent avoiding holes forming the insulating block.

9. A back contact solar cell assembly according to claim 1, wherein, The first bus members and the second bus members are main grid lines or solder strips.

10. A photovoltaic system characterized by, The back contact battery assembly comprises any one of the back contact battery assemblies according to claims 1-9.

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