Photovoltaic module structure

Abstract

The invention relates to a photovoltaic module structure which comprises a plurality of battery strings located between a cover plate and a back plate, the battery strings are connected with a plurality of battery pieces in series, first side faces, second side faces, third side faces and fourth side faces of the battery pieces are opposite, and passivation layers are arranged on edge areas of the front faces and the back faces of the battery pieces. The passivation layer effectively reduces or avoids the current short circuit phenomenon, thereby facilitating the reduction of the spacing between the battery pieces and the spacing between the battery strings, improving the space utilization rate of the photovoltaic module, and further achieving the high-density arrangement of the module. And the passivation layer can also reduce or eliminate the phenomenon of electric leakage at the edge of the battery piece, the recombination rate of the battery is reduced, and the filling factor of the battery is improved, so that the photoelectric conversion efficiency of the battery is improved.

Description

Technical Field

[0001] The invention relates to a photovoltaic module structure. Background Art

[0002] In the photovoltaic field, the performance of the module is closely related to the structural design. As the market's requirements for photovoltaic power generation efficiency and space utilization efficiency continue to increase, high-density modules have become a development direction that has attracted much attention. High-density modules have strong market competitiveness due to their high power generation per unit area and beautiful appearance.

[0003] The existing photovoltaic module structure has obvious limitations, which seriously restricts its development towards high-density packaging. Figure 1 As shown in the schematic diagram of the photovoltaic module structure in the prior art, the photovoltaic module structure includes multiple battery strings 9. In a battery string 9, the distance 1 between two adjacent battery cells 3 is usually greater than 0.8 mm, and the distance 2 between two adjacent battery strings 9 is usually greater than 1.5 mm.

[0004] like Figure 2 As shown in the schematic diagram of the battery cell structure in the prior art, the spacing between the battery cells 3 and the battery strings 9 is mainly set because the four sides 4 of the battery cell 3 are conductive. During the lamination process, the packaging film used to encapsulate the battery cell 3 flows after melting due to heat. The melted and flowing packaging film will cause relative displacement of the battery cells and the battery strings, which can easily cause the edges of the battery cells to contact each other, thereby causing short circuits or leakage, which may cause the electrical performance of the components to fail in severe cases. Therefore, the spacing between the battery cells 3 and the battery strings 9 needs to be greater than a certain value, for example, greater than 0.8mm and 1.5mm respectively.

[0005] Therefore, there is an urgent need for a high-density photovoltaic module that can reduce or avoid short circuit or leakage phenomena. Summary of the invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a high-density photovoltaic module structure that can reduce or avoid short circuit or leakage phenomena.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions.

[0008] A photovoltaic module structure includes a plurality of battery strings located between a cover plate and a back plate, wherein the battery strings include a plurality of battery slices connected in series, wherein the battery slices include two opposite first and second sides, and a passivation layer is provided on the first and second sides.

[0009] Furthermore, the battery cell also includes two opposite third side surfaces and a fourth side surface, and a passivation layer is provided on the third side surface and the fourth side surface.

[0010] Furthermore, the battery cell also includes a front side and a back side opposite to each other, and a passivation layer is provided on an edge region of the front side close to the first side surface, the second side surface, the third side surface, and the fourth side surface.

[0011] Furthermore, a passivation layer is provided on the edge region of the reverse surface close to the first side surface, the second side surface, the third side surface and the fourth side surface.

[0012] Furthermore, the battery cell is rectangular or square.

[0013] Furthermore, the battery cell is rectangular, and the aspect ratio of the rectangle is 2:1, 3:1, 4:1, 5:1 or 6:1.

[0014] Furthermore, the passivation layer includes Al 2 O 3 Thin film, SiO 2 Thin film, SiN x At least one of a thin film, a SiON thin film; or both of Al 2 O 3 Thin films and SiO 2 Thin film or Al 2 O 3 Thin Film and SiN x Thin film; optionally, Al 2 O 3 The thin film is located between the cell and SiO 2 Thin film or SiN x between films.

[0015] Furthermore, an insulating glue layer is provided on the passivation layer.

[0016] Furthermore, the thickness of the passivation layer is less than 300 nm, preferably less than 250 nm, preferably greater than 10 nm, and preferably 50 to 250 nm.

[0017] Furthermore, the edge region is a strip region, and the width of the strip region is less than 2 mm, preferably less than 1.5 mm, preferably greater than 0.5 mm, preferably greater than 1 mm, and preferably 1 to 1.5 mm.

[0018] Furthermore, the photovoltaic module structure also includes a front adhesive film and a rear adhesive film; the front adhesive film is arranged between the cover plate and the battery string; the rear adhesive film is arranged between the battery string and the back plate.

[0019] Furthermore, the photovoltaic module structure also includes an adhesive material, and the adhesive material is used to fix the battery string.

[0020] Further, the bonding material is a tape, and the tape is one of a transparent UV-resistant tape or a black tape;

[0021] Alternatively, the bonding material is glue, and the glue is UV-cured UV glue or one of acrylic glue, silicone-based glue, and epoxy glue that are cured by heat.

[0022] Furthermore, the distance between two adjacent groups of battery strings is less than 1.8 mm, preferably less than 1.6 mm, preferably greater than -0.9 mm, and preferably -0.8 to 1.5 mm.

[0023] Furthermore, the distance between two adjacent groups of battery strings is 0 mm.

[0024] Furthermore, the battery cell is a battery with positive and negative electrodes on one surface, and the distance between two adjacent battery cells in the battery string is less than 0.8 mm, preferably less than 0.6 mm, preferably greater than -0.8 mm, and preferably -0.8 to 0.5 mm.

[0025] Furthermore, the battery cell is a battery with positive and negative electrodes on one surface, the distance between two adjacent groups of the battery strings is 0 mm, and the distance between two adjacent battery cells in the battery string is 0 mm.

[0026] The technical solution of the present invention has the following advantages:

[0027] (1) Enhanced stability: Passivation layers are set on the sides and edges of the front and back of the sliced ​​cells to effectively reduce or avoid current short circuits, reducing cell damage and component failure caused by short circuits. In addition, using inorganic materials as passivation layers is more stable, harder, more resistant to wear, and has better insulation than insulating glue, thereby improving the stability and reliability of photovoltaic modules.

[0028] (2) Improving battery efficiency: A passivation layer is set on the battery cell to passivate the surface activity of the battery cell, thereby reducing or eliminating leakage at the edge of the battery cell, reducing the recombination rate of the battery, and increasing the fill factor (FF) of the battery, thereby improving the photoelectric conversion efficiency of the battery.

[0029] (3) Improving power density: By reducing the spacing between cells and between cell strings, more cells can be accommodated per unit area, thereby improving the space utilization of photovoltaic modules, thereby achieving high-density arrangement of modules and increasing the power of photovoltaic modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of a photovoltaic module in the prior art;

[0031] Figure 2It is a schematic diagram of the battery cell structure in the prior art;

[0032] Figure 3 is a top view of the first photovoltaic module structure;

[0033] Figure 4 is a schematic diagram of the cross-sectional structure of the first photovoltaic module;

[0034] Figure 5 It is a schematic diagram of the structure of the battery cell in the first photovoltaic module structure;

[0035] Figure 6 for Figure 5 AA cross-sectional structure diagram of the battery cell;

[0036] Figure 7 is a top view of the second photovoltaic module structure;

[0037] Figure 8 is a schematic diagram of the cross-sectional structure of the second photovoltaic module;

[0038] Fig. 9 It is a schematic diagram of the structure of the battery cell in the second photovoltaic module structure;

[0039] Fig.10 for Fig. 9 Schematic diagram of the BB cross-section structure of a battery cell.

[0040] Among them, 1-the distance between adjacent battery cells in a battery string; 2-the distance between adjacent battery strings; 3-battery cell; 301-the first side of the battery cell; 302-the second side of the battery cell; 303-the third side of the battery cell; 304-the fourth side of the battery cell; 305-the front side of the battery cell; 306-the back side of the battery cell; 3051-the edge area of ​​the front side of the battery cell; 3061-the edge area of ​​the back side of the battery cell; 4-the side of the battery cell; 5-passivation layer; 6-solder strip; 7-cover plate; 8-front adhesive film; 9-battery string; 10-adhesive tape; 11-glue; 12-rear adhesive film; 13-back plate; 14-insulating adhesive layer. DETAILED DESCRIPTION

[0041] Hereinafter, the technical solution of the present invention will be described in detail.

[0042] Figure 3-6 This is a first photovoltaic module structure provided by an embodiment of the present invention.

[0043] like Figure 3 A top view of the first photovoltaic module structure and Figure 4As shown in the schematic diagram of the cross-sectional structure of the first photovoltaic module, the photovoltaic module structure of this embodiment may include a welding strip 6, a cover plate 7, a battery string 9 and a back plate 13, the front adhesive film 8 is arranged between the cover plate 7 and the battery string 9, the rear adhesive film 12 is arranged between the battery string 9 and the back plate 13, and the battery string 9 may include a plurality of battery cells 3 connected in series.

[0044] Generally speaking, the battery cell 3 has a regular shape, and this embodiment takes a square battery cell as an example. Figure 5 As shown in the schematic diagram of the structure of the battery cell in the first photovoltaic module structure, the battery cell 3 may include a first side surface 301 and a second side surface 302, a third side surface 303 and a fourth side surface 304, and a passivation layer 5 may be provided on the first side surface 301, the second side surface 302, the third side surface 303 and the fourth side surface 304. By providing the passivation layer 5, the surface activity of the battery cell is passivated, and even if the sides of two battery cells 3 are in contact with each other, a current short circuit phenomenon will not be caused, which lays a good foundation for the subsequent combination and high-density arrangement of the battery cells 3.

[0045] like Figure 5 Schematic diagram of the structure of the battery cell in the first photovoltaic module structure and Figure 6 As shown in the AA cross-sectional structural diagram of the battery cell, the battery cell 3 of the present embodiment may further include a front side 305 and a back side 306 relative to each other, and a passivation layer 5 may be provided on an edge area 3051 of the front side 305 close to the first side 301, the second side 302, the third side 303, and the fourth side 304 and on an edge area 3061 of the back side 306 close to the first side 301, the second side 302, the third side 303, and the fourth side 304.

[0046] The passivation layer 5 may be prepared by atomic layer deposition, plasma enhanced chemical vapor deposition, etc., and the present application does not limit the preparation method of the passivation layer. The passivation layer 5 may include Al 2 O 3 Thin film, SiO 2 Thin film, SiN x In this embodiment, the passivation layer 5 can be prepared by atomic layer deposition method. 2 O 3 Thin films and SiO 2 Thin film, and Al 2 O 3 The film can be located between the cell 3 and SiO 2 Using inorganic materials as the passivation layer makes the cell more stable, harder, more resistant to wear, and has better insulation.

[0047] The thickness of the passivation layer 5 may be 10 nm to 250 nm, preferably 50 to 250 nm. The edge region 3051 and the edge region 3061 may be strip regions, and their width may be 0.5 mm to 2 mm, preferably 0.8 to 1.6 mm.

[0048] In this embodiment, the battery cell 3 may be a bifacial battery with positive and negative electrodes located on the front and back sides, such as a TOPCon battery or a PERC battery. Figure 3 As shown in the top view of the first photovoltaic module structure, the edges of the cells 3 of this bifacial cell are difficult to fit closely together in physical structure due to the presence of welding strips 6 between the cells 3. However, this structure can achieve a special arrangement of zero string distance, thereby achieving a high-density arrangement layout of the cell strings 9, where the zero string distance means that the distance between two adjacent groups of cell strings 9 can be zero.

[0049] For the above-mentioned cells, during the preparation of the photovoltaic module, the distance between two adjacent groups of cell strings 9 can meet -0.9 mm to 1.5 mm, preferably -0.8 to 1.5 mm. In addition, when the distance between two adjacent groups of cell strings 9 is a negative number, it means that the cell edges between the cell strings 9 overlap each other. As an example, the distance between two adjacent groups of cell strings 9 can be 0 mm.

[0050] In the preparation process of the photovoltaic module of this embodiment, the cell string 9 can also be fixed by an organic adhesive material. The organic adhesive material can be a tape 10. As an example, it can include a transparent UV-resistant tape or a black tape. When there is a small gap between two adjacent groups of cell strings 9, the black tape can be used to improve the appearance of the photovoltaic module.

[0051] Figure 7-10 This is a second photovoltaic module structure provided by an embodiment of the present invention.

[0052] like Figure 7 The top view of the second photovoltaic module structure and Figure 8 As shown in the schematic diagram of the cross-sectional structure of the second photovoltaic module, the photovoltaic module structure of this embodiment may include a welding strip 6, a cover plate 7, a battery string 9 and a back plate 13, the front adhesive film 8 is arranged between the cover plate 7 and the battery string 9, the rear adhesive film 12 is arranged between the battery string 9 and the back plate 13, and the battery string 9 may include a plurality of battery cells 3 connected in series.

[0053] In this embodiment, taking a rectangular battery cell as an example, the aspect ratio of the rectangle can be 2:1, 3:1, 4:1, 5:1 or 6:1. As an example, the aspect ratio of the rectangular battery cell can be 2:1. Fig. 9As shown in the structural schematic diagram of the battery cell in the second photovoltaic module structure, the battery cell 3 may include a first side 301 and a second side 302, a third side 303 and a fourth side 304 relative to each other, and may have a passivation layer 5 on the first side 301, the second side 302, the third side 303 and the fourth side 304.

[0054] like Fig. 9 The schematic diagram of the structure of the solar cell in the second photovoltaic module structure and Fig.10 As shown in the BB cross-sectional structural diagram of the battery cell, the battery cell 3 of this embodiment further includes a front side 305 and a back side 306 opposite to each other, and a passivation layer 5 may be provided on the edge region 3051 of the front side 305 close to the first side 301, the second side 302, the third side 303, and the fourth side 304, and on the edge region 3061 of the back side 306 close to the first side 301, the second side 302, the third side 303, and the fourth side 304. An insulating glue layer 14 may be provided on the passivation layer 5, so that the insulation of the battery cell can be more effectively improved and the possibility of short circuit can be reduced.

[0055] In this embodiment, the passivation layer 5 can be prepared by plasma enhanced chemical vapor deposition method. 2 O 3 Thin Film and SiN x Thin film, and Al 2 O 3 The film can be located between the cell 3 and the SiN x The thickness of the passivation layer 5 may preferably be 60 to 230 nm, and the width of the edge region 3051 and the edge region 3061 may preferably be 1.1 to 1.4 mm.

[0056] In this embodiment, the battery cell 3 may be a battery with positive and negative electrodes on one surface, which may also be called a single-sided battery, such as a HPBC battery, a TBC battery, or a HBC battery. Figure 7 As shown in the top view of the second photovoltaic module structure, this single-sided battery with both positive and negative electrodes on one side can achieve not only zero string spacing but also zero cell spacing because the welding strips 6 are distributed on the same side of the battery. Here, zero string spacing means that the distance between two adjacent groups of battery strings 9 can be zero, and zero cell spacing means that the distance between two adjacent battery cells 3 in the battery string 9 can be zero.

[0057] For the above-mentioned battery, during the preparation of the photovoltaic module, the distance between two adjacent battery cells 3 in the battery string 9 can meet -0.8mm to 0.8mm, preferably -0.8~0.6mm. When the distance is a negative number, it means that the battery edges between the battery cells 3 overlap each other. The distance between two adjacent groups of battery strings 9 can be preferably -0.6~1.1mm. As an example, the distance between two adjacent battery cells 3 in the battery string 9 can be 0mm, and the distance between two adjacent groups of battery strings 9 can be 0mm.

[0058] In the process of preparing the photovoltaic module of this embodiment, the cell string 9 can also be fixed with glue 11, and the glue 11 can include UV-cured UV glue or one of acrylic glue, silicone-based glue, and epoxy glue that are cured by heat.

[0059] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A photovoltaic module structure, comprising a plurality of battery strings (9) located between a cover plate (7) and a back plate (13), wherein the battery strings (9) comprise a plurality of battery cells (3) connected in series, wherein the battery cells (3) comprise two opposite first side surfaces (301) and a second side surface (302), wherein: A passivation layer (5) is provided on the first side surface (301) and the second side surface (302).

2. The photovoltaic module structure according to claim 1, characterized in that: The battery cell (3) further comprises two opposite third side surfaces (303) and a fourth side surface (304), and a passivation layer (5) is provided on the third side surface (303) and the fourth side surface (304).

3. The photovoltaic module structure according to claim 2, characterized in that: The battery cell (3) also includes a front side (305) and a back side (306) opposite to each other, and a passivation layer (5) is provided on an edge region (3051) of the front side (305) close to the first side (301), the second side (302), the third side (303), and the fourth side (304).

4. The photovoltaic module structure according to claim 2, characterized in that: The battery cell (3) further comprises a front side (305) and a back side (306) opposite to each other, and a passivation layer (5) is provided on an edge region (3061) of the back side (306) close to the first side (301), the second side (302), the third side (303), and the fourth side (304).

5. The photovoltaic module structure according to claim 1, characterized in that: The battery sheet (3) is rectangular or square.

6. The photovoltaic module structure according to claim 5, characterized in that: The battery sheet (3) is rectangular, and the aspect ratio of the rectangle is 2:1, 3:1, 4:1, 5:1 or 6:

1.

7. The photovoltaic module structure according to any one of claims 1 to 6, characterized in that: The passivation layer (5) comprises an Al2O3 film, a SiO2 film, a SiN x At least one of a thin film, a SiON thin film; or at least one of an Al2O3 thin film and a SiO2 thin film, or an Al2O3 thin film and a SiN x Thin film; Optionally, the Al2O3 thin film is located between the battery cell (3) and the SiO2 thin film or SiN x between films.

8. The photovoltaic module structure according to claim 7, characterized in that: An insulating glue layer (14) is provided on the passivation layer (5).

9. The photovoltaic module structure according to any one of claims 1 to 6, characterized in that: The thickness of the passivation layer (5) is less than 300 nm, preferably less than 250 nm, preferably more than 10 nm, and preferably 50 to 250 nm.

10. The photovoltaic module structure according to any one of claims 3 or 4, characterized in that: The edge region (3051) and the edge region (3061) are strip regions, and the width of the strip regions is less than 2 mm, preferably less than 1.5 mm, preferably greater than 0.5 mm, preferably greater than 1 mm, and preferably 1 to 1.5 mm.

11. The photovoltaic module structure according to any one of claims 1 to 6, characterized in that: The photovoltaic module structure also includes a front adhesive film (8) and a rear adhesive film (12); The front adhesive film (8) is arranged between the cover plate (7) and the battery string (9); The rear adhesive film (12) is arranged between the battery string (9) and the back plate (13).

12. The photovoltaic module structure according to claim 11, characterized in that: The photovoltaic module structure also includes a bonding material, and the bonding material is used to fix the battery string (9).

13. The photovoltaic module structure according to claim 12, characterized in that: The adhesive material is an adhesive tape (10), and the adhesive tape (10) is one of a transparent UV-resistant adhesive tape and a black adhesive tape; Alternatively, the bonding material is glue (11), and the glue (11) is UV-cured UV glue or one of acrylic glue, silicone-based glue, and epoxy glue that are cured by heat.

14. The photovoltaic module structure according to claim 12, characterized in that: The distance between two adjacent groups of battery strings (9) is less than 1.8 mm, preferably less than 1.6 mm, preferably greater than -0.9 mm, and preferably -0.8 to 1.5 mm.

15. The photovoltaic module structure according to claim 14, characterized in that: The distance between two adjacent groups of battery strings (9) is 0 mm.

16. The photovoltaic module structure according to claim 14, characterized in that: The battery cell (3) is a battery with positive and negative electrodes on one surface, and the distance between two adjacent battery cells (3) in the battery string (9) is less than 0.8 mm, preferably less than 0.6 mm, preferably greater than -0.8 mm, and preferably -0.8 to 0.5 mm.

17. The photovoltaic module structure according to claim 14, characterized in that: The battery sheet (3) is a battery with positive and negative electrodes on one surface, the distance between two adjacent groups of battery strings (9) is 0 mm, and the distance between two adjacent battery sheets (3) in the battery string (9) is 0 mm.

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