Photovoltaic module backsheet and photovoltaic module

Abstract

A photovoltaic module backsheet, comprising: a metal layer, which comprises a first surface and a second surface arranged opposite each other in the direction of thickness thereof; and an insulating enclosure layer, which comprises a first insulating cover layer arranged on the first surface of the metal layer and a second insulating cover layer arranged on the second surface of the metal layer, wherein the edges of the first insulating cover layer and the second insulating cover layer both protrude beyond the edge of the metal layer, and the portions of the first insulating cover layer and the second insulating cover layer that protrude beyond the edge of the metal layer are connected together, thus enclosing the metal layer between the first insulating cover layer and the second insulating cover layer, each of the first insulating cover layer and the second insulating cover layer comprising at least one first insulating layer.

Description

Photovoltaic module backsheet and photovoltaic module

[0001] Related applications

[0002] This application claims priority to Chinese patent application number 202311438774.8, filed on November 1, 2023, entitled “Photovoltaic Module Backsheet and Photovoltaic Module,” the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application relates to the field of photovoltaic module technology, and in particular to a photovoltaic module backplane and a photovoltaic module. Background Art

[0004] Solar cells are devices that directly convert light energy into electrical energy through the photoelectric or photochemical effect. During the solar cell assembly process, the edges of the laminate formed by stacking the cover plate, cell, and metal backplane (such as an aluminum backplane) are trimmed. The trimmed laminate is then framed with a silicone-filled metal frame to complete the assembly. Although silicone is used for filling, there is no guarantee that the silicone will completely fill the entire metal frame cavity. There is still a risk of contact between the edge of the laminate and the metal frame. In actual use, the metal frame may come into contact with the metal in the metal backplane, resulting in leakage and high-voltage resistance.

[0005] Summary of the Invention

[0006] According to various embodiments of the present application, a photovoltaic module backsheet and a photovoltaic module are provided.

[0007] In a first aspect of the present application, a photovoltaic module backsheet is provided, the photovoltaic module backsheet comprising:

[0008] a metal layer, the metal layer comprising a first surface and a second surface disposed opposite to each other along a thickness direction of the metal layer;

[0009] An insulating coating layer, the insulating coating layer comprising: a first insulating covering layer arranged on the first surface of the metal layer and a second insulating covering layer arranged on the second surface of the metal layer, the edges of the first insulating covering layer and the second insulating covering layer both extend beyond the edge of the metal layer, and the portions of the first insulating covering layer and the second insulating covering layer extending beyond the edge of the metal layer are connected together, so that the metal layer is coated between the first insulating covering layer and the second insulating covering layer, and the first insulating covering layer and the second insulating covering layer both include at least one first insulating layer.

[0010] In some embodiments, the photovoltaic module backsheet further includes: a first adhesive layer disposed between the first insulating cover layer and a portion of the second insulating cover layer that extends beyond an edge of the metal layer.

[0011] In some embodiments, the thickness of the first adhesive layer is about 3 μm to 20 μm.

[0012] In some embodiments, the material of the first adhesive layer includes at least one of polyester glue and acrylic glue.

[0013] A first insulating layer is provided on both the front side and the back side of the metal layer, the orthographic projection of the metal layer on the first insulating covering layer and the second insulating covering layer is located inside the edges of the first insulating covering layer and the second insulating covering layer, and there is a gap between the edge of the metal layer and the edges of the first insulating covering layer and the second insulating covering layer.

[0014] In some embodiments, the gap is about 3 mm to 7 mm.

[0015] In some embodiments, the thickness of each first insulating layer is about 5 μm to 50 μm.

[0016] In some embodiments, the material of each first insulating layer includes at least one of polyethylene terephthalate, polypropylene, polyethylene, modified polyamide, fluorocarbon coating, polyvinylidene fluoride, and polyvinyl fluoride.

[0017] In some embodiments, at least one of the first insulating cover layer and the second insulating cover layer includes at least two first insulating layers.

[0018] In some embodiments, the photovoltaic module backsheet further includes: a second adhesive layer disposed between two adjacent first insulating layers included in at least one of the first insulating covering layer and the second insulating covering layer.

[0019] In some embodiments, the second adhesive layer has a thickness of about 3 μm to 20 μm.

[0020] In some embodiments, the material of the second adhesive layer includes at least one of polyester glue and acrylic glue.

[0021] In some embodiments, the photovoltaic module backsheet further includes: a third adhesive layer disposed between the metal layer and at least one of the first insulating cover layer and the second insulating cover layer.

[0022] In some embodiments, the third adhesive layer has a thickness of about 3 μm to 20 μm.

[0023] In some embodiments, the material of the third adhesive layer includes at least one of polyester glue and acrylic glue.

[0024] In some embodiments, the photovoltaic module back panel further includes: at least one lead-out hole provided on the photovoltaic module back panel and a positioning member provided on the photovoltaic module back panel, the at least one lead-out hole being used to lead out a bus bar, the positioning member being provided with at least one positioning hole, the at least one positioning hole corresponding one-to-one to the position of the at least one lead-out hole, and each of the positioning holes being used to clamp and fix the bus bar led out by the lead-out hole corresponding to the positioning hole.

[0025] In some embodiments, a diameter of each positioning hole is smaller than a diameter of an outlet hole corresponding to the positioning hole.

[0026] In some embodiments, the positioning element is a transparent positioning element.

[0027] In some embodiments, the photovoltaic module backplane further includes: a second insulating layer disposed on a hole wall of each of the lead-out holes.

[0028] In some embodiments, the second insulating layer has a thickness of about 1 mm to 3 mm.

[0029] In some embodiments, the material of the second insulating layer includes at least one of ethylene-vinyl acetate copolymer, polyolefin elastic material, polyethylene foam material, and butyl hot melt adhesive.

[0030] In a second aspect, the present application provides a photovoltaic module, which includes a frame and a laminate arranged in the frame, wherein the laminate includes a cover plate, a cell and the photovoltaic module back plate as described in the first aspect, which are stacked in sequence.

[0031] In some embodiments, the photovoltaic module further includes: a third insulating layer disposed around a side surface of the laminate.

[0032] In some embodiments, the third insulating layer is a hot melt adhesive coating; or, the third insulating layer is an insulating tape.

[0033] In some embodiments, the third insulating layer is formed by coating the side of the laminate with hot melt adhesive; or

[0034] The third insulating layer is formed by sealing the side surfaces of the laminate with the insulating tape.

[0035] In some embodiments, the material of the hot melt adhesive coating includes at least one of ethylene-vinyl acetate copolymer, polyolefin elastic material, polyethylene foam material and butyl hot melt adhesive.

[0036] In some embodiments, the material of the insulating tape includes at least one of ethylene-vinyl acetate copolymer, polyolefin elastic material, polyethylene foam material, polyvinyl chloride, polyethylene terephthalate, polyethylene, and flame-retardant silicone rubber.

[0037] In some embodiments, the cell includes a bus bar, and the photovoltaic module back panel includes: at least one lead-out hole opened on the photovoltaic module back panel and a positioning member arranged on the photovoltaic module back panel, the positioning member has at least one positioning hole, and the at least one positioning hole corresponds one-to-one to the position of the at least one lead-out hole, and the bus bar passes through the at least one lead-out hole and is led out by the positioning hole corresponding to each lead-out hole.

[0038] In some embodiments, the photovoltaic module backplane further includes: a fourth insulating layer disposed on a surface of the busbar at an inlet portion of each of the lead-out holes.

[0039] In some embodiments, the fourth insulating layer has a thickness of about 1 mm to 3 mm.

[0040] The details of one or more embodiments of the present application are set forth in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings of the application without creative work.

[0042] FIG1 is a schematic diagram of the cross-sectional structure of a photovoltaic module backplane provided in one embodiment of the present application.

[0043] FIG2 is a schematic diagram of the front structure of a photovoltaic module backplane provided in one embodiment of the present application.

[0044] FIG3 is a schematic diagram of another cross-sectional structure of a photovoltaic module backplane provided in one embodiment of the present application.

[0045] FIG4 is a schematic diagram of a positioning member assembly structure provided in one embodiment of the present application.

[0046] FIG5 is a schematic structural diagram of a positioning member provided in one embodiment of the present application.

[0047] FIG6 is another structural schematic diagram of a positioning member provided in one embodiment of the present application.

[0048] FIG7 is a schematic structural diagram of a laminate provided in one embodiment of the present application.

[0049] FIG8 is a schematic diagram of the structure of the lead-out hole provided in one embodiment of the present application.

[0050] Among them, 100 is the photovoltaic module backplane; 101 is the metal layer; 102 is the first insulating layer; 103a is the first adhesive layer; 103b is the second adhesive layer; 103c is the third adhesive layer; 104 is the positioning piece; 105 is the positioning hole; 106 is the second insulating layer; 300 is the cover plate; 200 is the battery cell; 201 is the bus bar; 400 is the third insulating layer; 202 is the fourth insulating layer. DETAILED DESCRIPTION

[0051] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0053] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, including the two endpoint integers of the numerical range, and each integer between the two endpoints, is equivalent to directly enumerating each integer. When multiple numerical ranges are provided to describe a feature or characteristic, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0054] In this application, the terms "optionally," "optional," and "optional" mean optional or dispensable, i.e., they refer to either option being selected from two parallel options: "with" or "without." If a technical solution contains multiple "optional" clauses, each "optional" clause is independent unless otherwise specified and there are no contradictions or constraints.

[0055] In this application, the terms "first," "second," etc., in "the first aspect," "the second aspect," etc., are used for descriptive purposes only and should not be understood as indicating or implying relative importance or quantity, nor as implicitly indicating the importance or quantity of the technical features indicated. Furthermore, "first," "second," "third," "fourth," etc., are only used for non-exhaustive enumeration and description purposes and should be understood not to constitute closed-ended limitations on quantity.

[0056] In response to the problem in the related art that the chamfered laminate is framed with a metal frame filled with silicone, the first aspect of the present application provides a photovoltaic module backplane, as shown in Figures 1 and 2, the photovoltaic module backplane 100 includes a metal layer 101 and an insulating coating layer, wherein the metal layer 101 includes a first surface and a second surface arranged opposite to each other along its thickness direction; the insulating coating layer includes: a first insulating covering layer arranged on the first surface of the metal layer 101 and a second insulating covering layer arranged on the second surface of the metal layer 101, the edges of the first insulating covering layer and the second insulating covering layer both exceed the edge of the metal layer 101, and the parts of the first insulating covering layer and the second insulating covering layer exceeding the edge of the metal layer 101 are connected together, and the metal layer 101 is coated between the first insulating covering layer and the second insulating covering layer, and the first insulating covering layer and the second insulating covering layer both include at least one layer of first insulating layer 102.

[0057] In the photovoltaic module backsheet provided in the embodiment of the present application, by setting the photovoltaic module backsheet 100 to a structure in which the insulating coating layer covers the metal layer 101, when it is stacked with the cell and the cover plate to form a laminate and the edge is chamfered, the portion of the first insulating coating layer and the second insulating coating layer that exceeds the edge of the metal layer 101 can be used to make the edge redundancy, that is, after the edge is chamfered, the portion of the first insulating coating layer and the second insulating coating layer that exceeds the edge of the metal layer 101 will not be completely removed, and the metal layer 101 will still be formed into an insulating edge. Therefore, during the photovoltaic module assembly process, on the one hand, no silicone filling is required, and on the other hand, the metal layer 101 will not be in contact with the metal frame, causing leakage and other problems. This can solve the problem of poor filling of silicone in the related art, which easily leads to contact between the metal layer 101 and the metal frame, causing leakage, etc. For example, in the related art, when silicone is used for filling, it cannot be guaranteed that the silicone completely fills the cavity of the entire metal frame, and there is still a risk of contact between the edge of the laminate and the metal frame. In actual use, the metal frame may contact the metal layer, resulting in leakage and high voltage resistance.

[0058] In some embodiments, the photovoltaic module backsheet further includes: a first adhesive layer 103 a disposed between the first insulating cover layer and a portion of the second insulating cover layer that extends beyond the edge of the metal layer 101 .

[0059] In some embodiments, the thickness of the first adhesive layer 103 a is about 3 μm to 20 μm.

[0060] In some embodiments, the material of the first adhesive layer 103a includes at least one of polyester glue and acrylic glue.

[0061] In some embodiments, the metal layer 101 in the present application may be, for example, aluminum foil.

[0062] In some embodiments, the orthographic projection of the metal layer 101 on the first insulating cover layer and the second insulating cover layer is located inside the edges of the first insulating cover layer and the second insulating cover layer, and there is a gap between the edge of the metal layer 101 and the edges of the first insulating cover layer and the second insulating cover layer.

[0063] This application uses a first insulating covering layer and a second insulating covering layer whose planar dimensions are larger than the metal layer 101 for covering, so that the edges of the metal layer 101 are wrapped with insulating material, thereby avoiding problems such as leakage caused by contact between the metal layer and other structural parts such as a metal frame.

[0064] In some embodiments of the present application, the metal layer 101 is centrally disposed on the first insulating cover layer and the second insulating cover layer.

[0065] In some embodiments, the gap may be approximately 3 mm to 7 mm, for example, 3.0 mm, 3.4 mm, 3.8 mm, 4.2 mm, 4.6 mm, 5.0 mm, 5.4 mm, 5.8 mm, 6.2 mm, 6.6 mm, or 7.0 mm.

[0066] In these embodiments, sufficient chamfering dimensions may be reserved to prevent the metal layer of the photovoltaic module backsheet from being exposed after the chamfering.

[0067] In some embodiments, the thickness of each first insulating layer 102 may be approximately 5 μm to 50 μm, for example, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm.

[0068] In some embodiments, the thickness of the metal layer 101 is about 10 μm to 30 μm, for example, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, or 30 μm.

[0069] In some embodiments, the material of each first insulating layer 102 includes at least one of polyethylene terephthalate (PET), polypropylene, polyethylene, modified polyamide, fluorocarbon coating, polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF).

[0070] In some embodiments, as shown in FIG3 , at least one of the first insulating cover layer and the second insulating cover layer includes at least two first insulating layers 102. Providing multiple layers of first insulating layers 102 can improve the insulation performance of the photovoltaic module backsheet during use. In particular, on the side of the photovoltaic module backsheet closest to the solar cells 200, a multi-layered first insulating layer 102 can improve the insulation performance between the photovoltaic module backsheet and the solar cells.

[0071] It should be noted that the thickness and material of each first insulating layer in the present application may be the same or different, and those skilled in the art may make reasonable choices based on actual needs.

[0072] In some embodiments, the photovoltaic module backsheet further includes: a second adhesive layer 103b disposed between two adjacent first insulating layers included in at least one of the first insulating covering layer and the second insulating covering layer.

[0073] In some embodiments, two first insulating layers 102 are provided on the surface of the metal layer 101 near the battery cell, and the second adhesive layer 103b is provided between the two first insulating layers 102. Optionally, the first insulating layer 102 near the metal layer 101 is a PET layer.

[0074] In some embodiments, the thickness of the second adhesive layer 103b may be approximately 3 μm to 20 μm, for example, 3 μm, 4 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, or 20 μm.

[0075] In some embodiments, the material of the second adhesive layer 103b includes at least one of polyester glue and acrylic glue.

[0076] It can be understood that the materials and thicknesses of any two different second adhesive layers 103b in the present application may be the same or different.

[0077] In some embodiments, the photovoltaic module backsheet 100 may further include: a third adhesive layer 103 c disposed between the metal layer 101 and at least one of the first insulating cover layer and the second insulating cover layer.

[0078] In some embodiments, the third adhesive layer 103 c has a thickness of about 3 μm to 20 μm.

[0079] In some embodiments, the material of the third adhesive layer 103c includes at least one of polyester glue and acrylic glue.

[0080] It can be understood that, similar to the above-mentioned second adhesive layer, the materials and thicknesses of any two different third adhesive layers 103b in the present application may also be the same or different.

[0081] In some embodiments, as shown in Figure 4, the photovoltaic module back panel 100 may also include: at least one lead-out hole opened on the photovoltaic module back panel and a positioning member arranged on the photovoltaic module back panel, at least one lead-out hole is used to lead out a bus bar, and at least one positioning hole 105 is opened on the positioning member 104, at least one positioning hole 105 corresponds to the position of at least one lead-out hole one-to-one, and each positioning hole 105 is used to clamp and fix the bus bar led out by the lead-out hole corresponding to the positioning hole 105.

[0082] During the assembly of photovoltaic modules, the battery strings are connected into series-parallel circuits through busbars. Finally, the lead-out wires composed of the busbars are led out through the lead-out holes on the back panel, and then form a path with the connection box. The busbars can be copper busbars. Since the opening of the lead-out holes will cause the metal layer 101 in the back panel to be exposed, if the busbar makes a single-point contact with the metal layer 101 during the lead-out process, a leakage channel will be formed, posing a safety hazard; if multiple points of contact occur, a short circuit will be formed, causing power loss of the module. However, the present application provides a positioning member 104, and the lead-out busbar is fixed by the positioning hole 105, which can avoid the busbar from contacting the metal layer 101 exposed in the lead-out hole, thereby preventing the lead-out busbar from having problems such as leakage and short circuit.

[0083] In some embodiments, as shown in Figures 5 and 6 , the positioning member 104 includes a substrate and at least one positioning hole 105 defined in the substrate. The substrate is located on the outer surface of the metal layer 101 facing away from the cell. Optionally, a positioning pin is provided in the positioning member 104 at the location of each lead-out hole. The provision of positioning pins in this application allows for quick positioning of the positioning member 104. Furthermore, the positioning hole 105 may be formed through the positioning pin.

[0084] In some embodiments, the diameter of each positioning hole 105 is smaller than the diameter of the lead-out hole corresponding to the positioning hole 105 .

[0085] In the present application, the size of the positioning hole 105 is smaller than the size of the lead-out hole, ensuring that the positioning hole 105 is engaged and fixed to the bus bar.

[0086] In some embodiments, the cross-sectional shape of the positioning hole 105 includes a rectangle, a square, an ellipse, a triangle, or a circle.

[0087] In some embodiments, the positioning member 104 is a transparent positioning member 104 .

[0088] In the present application, a transparent positioning member 104 is used so that the position of the lead-out bus bar inside the lead-out hole can be observed, and the position of the lead-out bus bar can be adjusted to prevent the bus bar from contacting the hole wall of the lead-out hole and causing leakage.

[0089] In some embodiments, the photovoltaic module backsheet may further include: a second insulating layer 106 disposed on the hole wall of each lead-out hole.

[0090] In the present application, a second insulating layer 106 is provided on the hole wall of the lead-out hole, and the second insulating layer 106 is used to shield the exposed metal layer 101 after the lead-out hole is opened, thereby avoiding the problem of contact leakage between the bus bar and the metal layer 101 in the lead-out hole.

[0091] Optionally, the second insulating layer 106 has a thickness of about 1 mm to 3 mm, for example, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm or 3.0 mm.

[0092] Optionally, the material of the second insulating layer 106 includes at least one of ethylene-vinyl acetate copolymer, polyolefin elastic material, polyethylene foam material and butyl hot melt adhesive.

[0093] A second aspect of the present application provides a photovoltaic module, which includes a frame and a laminate arranged in the frame. As shown in Figure 7, the laminate includes a cover plate 300, a cell 200 and the photovoltaic module back plate 100 as described in the first aspect, which are stacked in sequence.

[0094] In some embodiments, as shown in FIG. 7 , the photovoltaic module further includes a third insulating layer 400 disposed around a side surface of the laminate.

[0095] In some embodiments, the third insulating layer 400 is a hot melt adhesive coating; or the third insulating layer is an insulating tape.

[0096] In some embodiments, the third insulating layer 400 is formed by coating the side of a laminate with hot melt adhesive; or, the third insulating layer 400 is formed by sealing the side of a laminate with insulating tape.

[0097] The present application adopts the method of edge sealing with tape or coating with hot melt adhesive to form the third insulating layer 400. The material of hot melt adhesive and tape is the same as that of the first insulating layer 102, has good adhesion, is not prone to delamination or stratification problems, and the selected materials have good volume resistivity and low water permeability. For example, the volume resistivity of EVA, EPE and POE materials is greater than about 1015Ω·cm, and the water permeability of POE is less than about 5g / m 2 ·day, EPE water permeability < about 8g / m2 ·day, EVA water permeability < about 30g / m 2 This makes the back panel low in water permeability and has insulation and high-voltage resistance effects.

[0098] In some embodiments, the material of the hot melt adhesive includes at least one of ethylene vinyl acetate copolymer (EVA), polyolefin elastomer (POE), polyethylene foam (EPE) and butyl hot melt adhesive.

[0099] In some embodiments, the material of the insulating tape includes at least one of ethylene-vinyl acetate copolymer, polyolefin elastic material, polyethylene foam material, polyvinyl chloride, polyethylene terephthalate, polyethylene, and flame-retardant silicone rubber.

[0100] In some embodiments, as shown in Figures 5, 6 and 8, the battery cell 200 includes a busbar 201, and the photovoltaic module backplane 100 includes: at least one lead-out hole opened on the photovoltaic module backplane 100 and a positioning member 104 arranged on the photovoltaic module backplane 100, the positioning member 104 is provided with at least one positioning hole 105, and the at least one positioning hole 105 corresponds to the position of the at least one lead-out hole one-to-one. The busbar 201 passes through the at least one lead-out hole and is led out by the positioning hole 105 corresponding to each lead-out hole, and the positioning holes 105 position and fix the busbar 201.

[0101] In some embodiments, the photovoltaic module backsheet further includes: a fourth insulating layer 202 disposed on the surface of the bus bar 201 at the inlet portion of each lead-out hole.

[0102] The present application sets a fourth insulating layer 202 on the surface of the bus bar 201 at the entrance of the lead-out hole. Since the bus bar 201 will bend at the entrance of the lead-out hole, the bent part is likely to come into contact with the hole wall of the lead-out hole and cause contact leakage. The fourth insulating layer 202 is used to isolate the bus bar 201. Even if the bus bar 201 is close to the hole wall of the lead-out hole, it will be supported and isolated by the fourth insulating layer 202, further avoiding the problem of leakage of the lead-out line.

[0103] In some embodiments, the fourth insulating layer 202 has a thickness of about 1 mm to 3 mm, for example, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, or 3.0 mm.

[0104] Optionally, the material of the fourth insulating layer 202 includes at least one of ethylene-vinyl acetate copolymer, polyolefin elastic material, polyethylene foam material and butyl hot melt adhesive.

[0105] The embodiments of the present application will be described in detail below with reference to the examples. It should be understood that these examples are intended to illustrate the present application only and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance provided in the present application, and can also be based on the experimental manuals or conventional conditions in this area, or according to the conditions recommended by the manufacturer, or with reference to experimental methods known in the art.

[0106] In the following embodiments and comparative examples, the cover plate 300 is made of 3.2 mm thick tempered coated glass, the cell is an N-type Topcon 210 mm × 182 mm cell, and 48 cells are cut into three equal parts and connected in series and parallel to form a photovoltaic module.

[0107] Example 1

[0108] This embodiment provides a photovoltaic module backsheet 100, comprising an aluminum foil. A first adhesive layer, a first PET layer, a second adhesive layer, and a second PET layer are sequentially arranged on the front of the aluminum foil; a third adhesive layer and a third PET layer are sequentially arranged on the back of the aluminum foil. Each layer is 5 mm larger than the aluminum foil (i.e., the gap is 5 mm), and the aluminum foil is located in the center of the backsheet. The aluminum foil is 20 μm thick, the first, second, and third adhesive layers are each 10 μm thick polyester adhesive layers, and the first, second, and third PET layers are each 25 μm thick.

[0109] The photovoltaic module backsheet 100 also has multiple lead-out holes, each with a diameter of 12 mm and a 2 mm thick POE layer on its walls. The photovoltaic module also includes a positioning member 104 comprising a base plate and positioning holes 105 formed therein. The positioning holes 105 correspond to the lead-out holes one-to-one, and each has a diameter of 8 mm.

[0110] This embodiment also provides a photovoltaic module, including a frame and a laminate arranged in the frame, silicone is filled between the laminate and the frame, the laminate includes a cover plate 300, a battery cell 200 and the photovoltaic module back plate 100 stacked in sequence, the bus bar 201 led out from the battery cell 200 passes through the lead-out hole and is fixed by the positioning hole 105.

[0111] Example 2

[0112] This embodiment provides a photovoltaic module backsheet 100 , which differs from Embodiment 1 only in that a 2 mm thick ethylene-vinyl acetate copolymer layer is provided on the hole wall of the lead-out hole.

[0113] This embodiment also provides a photovoltaic module, including a frame and a laminate arranged in the frame, silicone is filled between the laminate and the frame, the laminate includes a cover plate 300, a battery cell 200 and the photovoltaic module back plate 100 stacked in sequence, the bus bar 201 led out from the battery cell 200 passes through the lead-out hole and is fixed by the positioning hole 105.

[0114] Example 3

[0115] This embodiment provides a photovoltaic module backsheet 100 , which differs from Embodiment 1 only in that a 2 mm thick ethylene-vinyl acetate copolymer layer is provided on the hole wall of the lead-out hole.

[0116] This embodiment also provides a photovoltaic module, including a frame and a laminate arranged in the frame, silicone is filled between the laminate and the frame, the laminate includes a cover plate 300, a battery cell 200 and the photovoltaic module back plate 100 stacked in sequence, the bus bar 201 led out from the battery cell 200 passes through the lead-out hole, and the bus bar 201 led out is located at the entrance section of the lead-out hole and is provided with ethylene-vinyl acetate copolymer with a thickness of 2 mm. After the bus bar 201 is led out, it is clamped and fixed by the positioning hole 105.

[0117] Example 4

[0118] This embodiment provides a photovoltaic module backsheet 100 , which is the same as the photovoltaic module backsheet 100 in Embodiment 1.

[0119] This embodiment also provides a photovoltaic module, including a frame and a laminate arranged in the frame, the space between the laminate and the frame is filled with silicone, the laminate includes a cover plate 300, a battery cell 200 and the photovoltaic module back plate 100 stacked in sequence, the side of the laminate is coated with hot melt adhesive to form an ethylene-vinyl acetate copolymer layer with a thickness of 2 mm, the bus bar 201 led out from the battery cell 200 passes through the lead-out hole and is fixed by the positioning hole 105.

[0120] Example 5

[0121] This embodiment provides a photovoltaic module backsheet 100 , which is the same as the photovoltaic module backsheet 100 in Embodiment 1.

[0122] This embodiment also provides a photovoltaic module, including a frame and a laminate arranged in the frame, with silicone filled between the laminate and the frame. The laminate includes a cover plate 300, a battery cell 200 and the photovoltaic module back plate 100 stacked in sequence. The side of the laminate is sealed with tape to form an ethylene-vinyl acetate copolymer layer with a thickness of 2 mm. The bus bar 201 led out from the battery cell 200 passes through the lead-out hole and is fixed by the positioning hole 105.

[0123] Example 6

[0124] This embodiment provides a photovoltaic module backsheet 100 . Compared with the embodiment 1, the embodiment 1 differs in that a 2 mm thick ethylene-vinyl acetate copolymer layer is provided on the hole wall of the lead-out hole.

[0125] This embodiment also provides a photovoltaic module. Compared with Example 1, the side of the laminate is sealed with tape to form an ethylene-vinyl acetate copolymer layer with a thickness of 2 mm, and the bus bar 201 located at the entrance section of the lead-out hole is provided with an ethylene-vinyl acetate copolymer with a thickness of 2 mm.

[0126] Comparative Example 1

[0127] This comparative example provides a photovoltaic module backsheet, which is different from Example 1 in that the plane size of the aluminum foil is the same as that of the other layers.

[0128] This comparative example provides a photovoltaic module, which is different from Example 1 in that the photovoltaic module backplane in Comparative Example 1 is used.

[0129] The photovoltaic modules prepared in the above examples and comparative examples were subjected to formation tests, and the testing method included:

[0130] Module power and EL test: at 25°C, 1000W / m 2 The Pasan machine is used to perform component power testing, and the EL equipment is used to perform EL testing.

[0131] High voltage test: Utilize IEC61730 MST 14 pulse test, 20000V high voltage test.

[0132] The test results are shown in Table 1.

[0133] Table 1

[0134] In comparative example 1, since the busbar contacts the metal layer in the backplane, some of the batteries are short-circuited, the output power is reduced by 1 / 3, and one of the EL strings turns black.

[0135] The above embodiments and comparative examples demonstrate that the backsheet provided by this application effectively addresses edge insulation issues by leaving the internal metal layer 101 uncovered. Furthermore, by providing positioning members 104, insulating the lead-out hole walls, and partially insulating the busbars 201, the problem of power loss caused by contact leakage and short circuits in the busbars 201 leading out of the photovoltaic module is resolved, effectively improving the insulation performance and high-voltage resistance of the photovoltaic module. Furthermore, the selected insulating material exhibits good compatibility, effectively improving sealing performance and achieving low water vapor transmission rates.

[0136] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A photovoltaic module back sheet, wherein: include: A metal layer, the metal layer comprising a first surface and a second surface arranged opposite to each other along a thickness direction thereof; An insulating coating layer, the insulating coating layer comprising: a first insulating covering layer arranged on the first surface of the metal layer and a second insulating covering layer arranged on the second surface of the metal layer, the edges of the first insulating covering layer and the second insulating covering layer both extend beyond the edge of the metal layer, and the portions of the first insulating covering layer and the second insulating covering layer extending beyond the edge of the metal layer are connected together, the metal layer is coated between the first insulating covering layer and the second insulating covering layer, and the first insulating covering layer and the second insulating covering layer both include at least one first insulating layer.

2. The photovoltaic module back sheet according to claim 1, wherein: Also includes: A first adhesive layer is disposed between the first insulating cover layer and a portion of the second insulating cover layer that exceeds an edge of the metal layer.

3. The photovoltaic module back sheet according to claim 2, wherein: The first adhesive layer has a thickness of about 3 μm to 20 μm.

4. The photovoltaic module back sheet according to claim 2 or 3, wherein: The material of the first adhesive layer includes at least one of polyester glue and acrylic glue.

5. The photovoltaic module back sheet according to any one of claims 1 to 4, wherein: The orthographic projection of the metal layer on the first insulating cover layer and the second insulating cover layer is located inside the edges of the first insulating cover layer and the second insulating cover layer, and there is a gap between the edge of the metal layer and the edges of the first insulating cover layer and the second insulating cover layer.

6. The photovoltaic module back sheet according to claim 5, wherein: The gap is about 3 mm to 7 mm.

7. The photovoltaic module back sheet according to any one of claims 1 to 6, wherein: The thickness of each first insulating layer is about 5 μm to 50 μm.

8. The photovoltaic module back sheet according to any one of claims 1 to 7, wherein: The material of each first insulating layer includes at least one of polyethylene terephthalate, polypropylene, polyethylene, modified polyamide, fluorocarbon coating, polyvinylidene fluoride and polyvinyl fluoride.

9. The photovoltaic module back sheet according to any one of claims 1 to 8, wherein: At least one of the first insulating cover layer and the second insulating cover layer includes at least two first insulating layers. layer.

10. The photovoltaic module back sheet according to claim 9, wherein: Also includes: A second bonding layer is disposed between two adjacent first insulating layers included in at least one of the first insulating cover layer and the second insulating cover layer.

11. The photovoltaic module back sheet according to claim 9, wherein: The second adhesive layer has a thickness of about 3 μm to 20 μm.

12. The photovoltaic module back sheet according to claim 10 or 11, wherein: The material of the second adhesive layer includes at least one of polyester glue and acrylic glue.

13. The photovoltaic module back sheet according to any one of claims 1 to 12, wherein: Also includes: A third adhesive layer is disposed between the metal layer and at least one of the first insulating cover layer and the second insulating cover layer.

14. The photovoltaic module back sheet according to claim 13, wherein: The third adhesive layer has a thickness of about 3 μm to 20 μm.

15. The photovoltaic module back sheet according to claim 13 or 14, wherein: The material of the third adhesive layer includes at least one of polyester glue and acrylic glue.

16. The photovoltaic module back sheet according to any one of claims 1 to 15, wherein: It also includes: at least one lead-out hole opened on the back plate of the photovoltaic module and a positioning member arranged on the back plate of the photovoltaic module, the at least one lead-out hole is used to lead out a bus bar, the positioning member is provided with at least one positioning hole, the at least one positioning hole corresponds to the position of the at least one lead-out hole one by one, and each of the positioning holes is used to clamp and fix the bus bar led out by the lead-out hole corresponding to the positioning hole.

17. The photovoltaic module back sheet according to claim 16, wherein: The diameter of each positioning hole is smaller than the diameter of the lead-out hole corresponding to the positioning hole.

18. The photovoltaic module back sheet according to claim 16 or 17, wherein: The positioning piece is a transparent positioning piece.

19. The photovoltaic module back sheet according to any one of claims 16 to 18, wherein: Also includes: A second insulating layer is arranged on the hole wall of each of the lead-out holes.

20. The photovoltaic module back sheet according to claim 19, wherein: The second insulating layer has a thickness of about 1 mm to 3 mm.

21. The photovoltaic module back sheet according to claim 19 or 20, wherein: The material of the second insulating layer includes ethylene-vinyl acetate copolymer, polyolefin elastic material, polyethylene foam At least one of material and butyl hot melt adhesive.

22. A photovoltaic module, wherein: The photovoltaic module comprises a frame and a laminated component arranged in the frame, wherein the laminated component comprises a cover plate, a battery sheet and a photovoltaic module back plate as claimed in any one of claims 1 to 21 which are stacked in sequence.

23. The photovoltaic module according to claim 22, wherein: Also includes: A third insulating layer is disposed around the side of the laminate.

24. The photovoltaic module according to claim 23, wherein: The third insulating layer is a hot melt adhesive coating; or, the third insulating layer is an insulating tape.

25. The photovoltaic module according to claim 24, wherein: The third insulating layer is formed by coating the side of the laminate with hot melt adhesive; or, The third insulating layer is formed by sealing the side surfaces of the laminate with the insulating tape.

26. The photovoltaic module according to claim 24 or 25, wherein: The material of the hot melt adhesive coating includes at least one of ethylene-vinyl acetate copolymer, polyolefin elastic material, polyethylene foam material and butyl hot melt adhesive; The material of the insulating tape includes at least one of ethylene-vinyl acetate copolymer, polyolefin elastic material, polyethylene foam material, polyvinyl chloride, polyethylene terephthalate, polyethylene and flame-retardant silicone rubber.

27. The photovoltaic module according to any one of claims 22 to 26, wherein: The battery cell includes a bus bar, and the photovoltaic module back panel includes: at least one lead-out hole opened on the photovoltaic module back panel and a positioning member arranged on the photovoltaic module back panel, the positioning member is provided with at least one positioning hole, and the at least one positioning hole corresponds to the position of the at least one lead-out hole one by one, and the bus bar passes through the at least one lead-out hole and is led out by the positioning hole corresponding to each lead-out hole.

28. The photovoltaic module according to claim 27, wherein: The photovoltaic module back plate further includes: a fourth insulating layer disposed on the surface of the bus bar at the inlet portion of each of the lead-out holes.

29. The photovoltaic assembly according to claim 28, wherein: The thickness of the fourth insulating layer is about 1 mm to 3 mm.

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