Photovoltaic module

Abstract

The embodiment of the utility model relates to the field of photovoltaic technology, and provides a photovoltaic module, the photovoltaic module comprises a battery string, an insulating layer, a bus bar and a welding strip, and the battery string comprises battery pieces; the insulating layer is arranged on the back surface of the battery piece, a first bonding layer is arranged between the insulating layer and the battery piece, and the insulating layer and the battery piece are bonded and fixed through the first bonding layer; the bus bar is arranged on one side of the insulating layer away from the battery piece; the welding strip is conductively connected with the bus bar and the battery piece. The embodiment of the utility model at least can solve the problem that the bus bar slips after being laminated.

Description

TECHNICAL FIELD

[0001] The embodiment of the present disclosure relates to the technical field of photovoltaic, in particular to a photovoltaic module. BACKGROUND

[0002] The existing photovoltaic cell hides the bus bar by bus bar hiding technology, which can improve the maximum output power of the cell module. However, in order to prevent short circuit, an insulating pad is needed to be introduced between the cell and the bus bar when the bus bar is hidden at the back of the cell, and the bus bar will slip after lamination of the cell module. CONTENT

[0003] The embodiment of the present disclosure provides a photovoltaic module, which at least solves the problem of bus bar slipping after lamination of the existing cell module using bus bar hiding technology.

[0004] According to some embodiments of the present disclosure, the embodiment of the present disclosure provides a photovoltaic module, which comprises:

[0005] A cell string, wherein the cell string comprises a cell;

[0006] An insulating layer, wherein the insulating layer is arranged at the back of the cell, and a first adhesive layer is arranged between the insulating layer and the cell to bond and fix the insulating layer and the cell through the first adhesive layer;

[0007] A bus bar, wherein the bus bar is arranged at the side of the insulating layer away from the cell;

[0008] A solder strip, wherein the solder strip is electrically connected to the bus bar and the cell.

[0009] In some embodiments, the solder strip comprises:

[0010] A first connecting section, wherein the first connecting section is arranged on the cell;

[0011] A second connecting section, wherein the second connecting section is arranged on the bus bar;

[0012] A bending section, wherein two ends of the bending section are connected to the first connecting section and the second connecting section respectively, and the bending section is located at one side of the cell, the insulating layer and the bus bar in the width direction of the bus bar.

[0013] In some embodiments, the length of the bending section is 2-4mm.

[0014] In some embodiments, the sum of the length of the bending section and the length of the second connecting section is 7-12mm.

[0015] In some embodiments, the length of the second connecting section is 3-8mm.

[0016] In some embodiments, the second connecting section is arranged on the surface of the busbar away from the battery piece.

[0017] In some embodiments, the first connecting section is arranged on the front surface of the battery piece.

[0018] In some embodiments, the busbar and the insulating layer are fixed by spot welding.

[0019] In some embodiments, the insulating layer comprises a buffer layer and an insulating spacing layer arranged in a stack, the buffer layer is fixed with the busbar by spot welding, and the insulating spacing layer is arranged on the side of the buffer layer away from the busbar.

[0020] In some embodiments, the sum of the thicknesses of the insulating layer and the first adhesive layer is 0.4-0.8 mm.

[0021] In some embodiments, a second adhesive layer is arranged between the insulating layer and the busbar to bond and fix the insulating layer and the busbar through the second adhesive layer.

[0022] In some embodiments, the sum of the thicknesses of the first adhesive layer and the second adhesive layer is 0.6-1.0 mm.

[0023] In some embodiments, the insulating layer is an insulating pad strip, wherein:

[0024] The length of the insulating pad strip is not less than 1128 mm; and / or,

[0025] The width of the insulating pad strip is 10-30 mm.

[0026] The technical solutions provided by the embodiments of the present disclosure have at least the following advantages:

[0027] The busbar of the photovoltaic module is hidden on the back surface of the battery piece, the insulating layer is arranged between the busbar and the battery piece, the first adhesive layer is added on the insulating layer, the first adhesive layer is bonded with the battery piece, and the insulating layer is fixed with the busbar. This fixing method of the busbar can improve the problem of busbar slipping after lamination of the photovoltaic module. There is no bubble at the first adhesive layer of the laminated photovoltaic module, and the appearance is normal. Moreover, this fixing method of the busbar is convenient and fast, which is conducive to realizing mass production of photovoltaic modules through equipment. BRIEF DESCRIPTION OF DRAWINGS

[0028] One or more embodiments are illustrated by way of example in the drawings and described herein in connection with the enumerated embodiments. These embodiments are not intended to limit the scope of the disclosure, but rather, particular embodiments are to serve as teaching devices to provide further instruction to those of ordinary skill in the art in view of the present disclosure. The present disclosure is intended to cover any and all modifications and equivalents. For the purpose of comprehension of the present disclosure, certain technical terms are defined below.

[0029] Figure 1 A structural schematic diagram of a photovoltaic module in the prior art;

[0030] Figure 2 A structural schematic diagram of a photovoltaic module provided by an embodiment of the present disclosure;

[0031] Figure 3 A structural schematic diagram of a photovoltaic module provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0032] As can be known from the background, reference is made to Figure 1 In the process of manufacturing the busbar hidden module 1000A, the insulating film 100A is arranged between the busbar 200A and the cell 300A, the busbar 200A and the cell 300A are conductively connected through the solder strip 400A, and the busbar 200A will slip after lamination.

[0033] The present disclosure provides a photovoltaic module, the busbar of the photovoltaic module is hidden at the back of the cell, an insulating layer is arranged between the busbar and the cell, a first adhesive layer is added on the insulating layer, the first adhesive layer is bonded with the cell, and the insulating layer is fixed with the busbar. The fixing mode of the busbar can improve the problem of busbar slipping after lamination of the photovoltaic module, there is no bubble at the first adhesive layer of the photovoltaic module after lamination, and the appearance is normal. The fixing mode of the busbar is convenient and fast, and is conducive to realizing mass production of the photovoltaic module through equipment.

[0034] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited. Similarly, "a plurality of groups" means two or more groups (including two groups), and "a plurality of pieces" means two or more pieces (including two pieces).

[0035] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be incorporated into any other embodiment in a manner known to those of ordinary skill in the art.

[0036] In the description of the embodiments of the present application, the term“and / or” is merely used to describe associated objects, and can represent that there can be three types of relationships, for example, A and / or B can represent that there are A, A and B, and B. In addition, the character“ / ” in this article generally represents that the front and rear associated objects are a“or” relationship.

[0037] In the description of the embodiments of the application, the technical terms“center”,“longitudinal”,“transverse”,“length”,“width”,“thickness”,“upper”,“lower”,“front”,“rear”,“left”,“right”,“vertical”,“horizontal”,“top”,“bottom”,“inner”,“outer”,“clockwise”,“counterclockwise”,“axial”,“radial”,“circumferential” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the application and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the application. For example, if the device or element in the drawing is inverted, the element described as“below” or“under” or“lower” or“bottom” of the other element or feature will be oriented“above” or“top” of the other element or feature. Therefore, the term“below” can cover both upward and downward orientations depending on the context in which the term is used, which will be apparent to those of ordinary skill in the art. The material can be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatially relative descriptors used herein can be interpreted accordingly.

[0038] In the description of the embodiments of the application, unless otherwise explicitly specified and limited, the technical terms“mounting”,“connecting”,“connecting”,“fixing” and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the embodiments of the application can be understood according to the specific circumstances.

[0039] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. Furthermore, when describing a component as "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0040] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. The formation or provision of a second component above or on a first component, or on the surface of a first component, or on one side of a first component, may include embodiments where the first and second components are in direct contact, and may also include embodiments where an additional component may be present between the first and second components, thereby preventing direct contact between the first and second components. For simplicity and clarity, various components may be drawn at different scales. In the drawings, some layers / components may be omitted for simplicity. Unless otherwise specified, the formation or provision of a second component on the surface of a first component refers to direct contact between the first and second components. The term "component" may refer to a layer, film, region, portion, structure, etc.

[0041] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0042] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0043] Figure 2 and Figure 3 The diagram shows the structure of various photovoltaic modules provided in the embodiments of this disclosure.

[0044] refer to Figure 2 and Figure 3The photovoltaic module 100 includes a cell string 1, an insulation layer 2, a busbar 4, and a solder strip 5. The cell string 1 includes a cell sheet 11. The insulation layer 2 is arranged on the back surface of the cell sheet 11. A first adhesive layer 3 is arranged between the insulation layer 2 and the cell sheet 11 to adhere and fix the insulation layer 2 to the cell sheet 11 through the first adhesive layer 3. The busbar 4 is arranged on the side of the insulation layer 2 away from the cell sheet 11. The solder strip 5 is electrically connected to the busbar 4 and the cell sheet 11.

[0045] Specifically, the cell string 1, the insulation layer 2, the busbar 4, and the solder strip 5 form a cell sheet layer of the photovoltaic module 100. The cell sheet layer includes one or any combination of a PERC cell (Passivated Emitter Rear Cell), an IBC cell (Interdigitated Back Contact), a TOPCon cell (Tunnel Oxide Passivated Contact), an HIT / HJT cell (Heterojunction Technology), a solar thin-film cell, and a stacked cell. The solar thin-film cell includes, but is not limited to, a perovskite solar thin-film cell, a copper-indium-selenium solar thin-film cell, a gallium arsenide solar thin-film cell, and a cadmium sulfide solar thin-film cell. The stacked cell includes, but is not limited to, a perovskite cell stacked with a crystalline silicon cell, a perovskite cell stacked with a perovskite cell, and a perovskite cell stacked with a thin-film cell. Figure 2 and Figure 3 In some embodiments, the cell sheet layer includes a TOPCon cell. The photovoltaic module 100 generally includes a plurality of cell strings 1 connected in series, and each cell string 1 includes a plurality of cell sheets 11 connected in series. The cell sheet 11 generally has a sheet structure and has a front surface (or a light-absorbing surface) and a back surface opposite to each other in the thickness direction of the cell sheet 11. The front surface of the cell sheet 11 can absorb light energy and convert the light energy into electrical energy.

[0046] Each cell sheet 11 is generally provided with a plurality of solder strips 5 arranged to extend along the length direction of the cell string 1 (i.e., the arrangement direction of the plurality of cell sheets 11 in the cell string 1), so as to connect the plurality of cell sheets 11 in the cell string 1 in series through the plurality of solder strips 5. The insulation layer 2 is arranged on the back surface of the cell sheet 11. The busbar 4 is arranged on the side of the insulation layer 2 away from the cell sheet 11. The busbar 4 is generally arranged to extend along the width direction of the cell string 1. In this way, the insulation layer 2 is arranged to be spaced between the busbar 4 and the cell sheet 11, so as to insulate the busbar 4 and the cell sheet 11 through the insulation layer 2. One end of the solder strip 5 away from the cell sheet 11 is connected to the busbar 4. In this way, the two ends of the solder strip 5 are connected to the busbar 4 and the cell sheet 11, respectively, so as to electrically connect the busbar 4 and the cell sheet 11 through the solder strip 5.

[0047] The insulating layer 2 is provided with a first adhesive layer 3 on the surface close to the cell sheet 11, so that the insulating layer 2 is fixed to the back of the cell sheet 11 through the first adhesive layer 3. Thus, during the lamination of the photovoltaic module 100, the bus bar 4 is not prone to slip relative to the cell sheet 11, because the insulating layer 2 is fixed to the cell sheet 11 through the first adhesive layer 3, and the bus bar 4 is fixed to the insulating layer 2.

[0048] The bus bar 4 of the photovoltaic module 100 is hidden on the back of the cell sheet 11, so that the bus bar 4 does not occupy the area of the front of the photovoltaic module 100, thereby maximizing the laying area of the cell sheet 11 and increasing the light receiving area of the front of the photovoltaic module 100, thereby improving the maximum output power of the photovoltaic module 100. The insulating layer 2 is provided between the bus bar 4 and the cell sheet 11, and the first adhesive layer 3 is provided on the insulating layer 2. The first adhesive layer 3 is adhered to the cell sheet 11, and the insulating layer 2 is fixed to the bus bar 4. This fixing method of the bus bar 4 can improve the problem of the bus bar 4 slipping after the lamination of the photovoltaic module 100. The first adhesive layer 3 of the laminated photovoltaic module 100 is free of bubbles and has no abnormal appearance. Moreover, this fixing method of the bus bar 4 is convenient and fast, and is conducive to the mass production of the photovoltaic module 100 through equipment.

[0049] The embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0050] The insulating layer 2 is fixed to the back of the cell sheet 11 through the first adhesive layer 3. The first adhesive layer 3 can be a double-sided adhesive tape or a glue layer, for example, the first adhesive layer 3 can be a tearable adhesive layer such as a double-sided adhesive tape. Alternatively, in some embodiments, the first adhesive layer 3 is a first insulating adhesive layer. The first adhesive layer 3 is an insulating adhesive, so that the first adhesive layer 3 has insulating properties. The insulating layer 2 is fixed to the cell sheet 11 through the first insulating adhesive layer, which is conducive to ensuring the insulation between the bus bar 4 and the cell sheet 11.

[0051] The insulating layer 2 is provided on the back of the cell sheet 11. The specific style of the insulating layer 2 can be set according to actual conditions. For example, the insulating layer 2 can be an insulating film, which is provided on the back of the cell sheet 11. Alternatively, the insulating layer 2 can be an insulating strip. Figure 2 and Figure 3 In some embodiments, the insulating layer 2 is an insulating pad strip 2a. Thus, the insulating layer 2 is provided in the form of a strip extending along the length direction of the bus bar 4 to form the insulating pad strip 2a. Providing the insulating layer 2 in the form of the insulating pad strip 2a can reduce the consumption of insulating materials. The insulating layer 2 will be described below as an example of the insulating pad strip 2a.

[0052] The length of the insulation pad strip 2a is generally longer than the length of the busbar 4. Optionally, in some embodiments, the length of the insulation pad strip 2a is not less than 1128mm.

[0053] Specifically, the length of the insulation pad strip 2a is greater than or equal to 1128mm, for example, the length of the insulation pad strip 2a can be 1128mm, 1130mm, 1135mm, 1140mm, 1145mm, 1150mm, 1155mm, 1160mm, 1165mm, 1170mm, 1175mm, 1180mm, 1185mm, 1190mm, 1195mm or 1200mm, etc. By thus preferably selecting the length of the insulation pad strip 2a, the two ends of the insulation pad strip 2a in the length direction of the busbar 4 can both extend beyond the busbar 4 and the battery sheet 11, thereby facilitating insulation of the busbar 4 from the battery sheet 11 by the insulation pad strip 2a.

[0054] The width of the insulation pad strip 2a is generally wider than the width of the busbar 4. Optionally, in some embodiments, the width of the insulation pad strip 2a is 10-30mm.

[0055] Specifically, the width of the insulation pad strip 2a is 10-30mm, for example, the width of the insulation pad strip 2a can be 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm or 30mm, etc. By thus preferably selecting the width of the insulation pad strip 2a, not only can the width of the insulation pad strip 2a be generally wider than the width of the busbar 4, thereby facilitating insulation of the busbar 4 from the battery sheet 11 by the insulation pad strip 2a, but also can avoid the problem of waste of insulation material caused by excessively wide insulation pad strip 2a.

[0056] Optionally, referring to Figure 2 and Figure 3 In some embodiments, the insulation layer 2 comprises a buffer layer 21 and an insulation spacing layer 22 arranged in layers, and the insulation spacing layer 22 is arranged on the side of the buffer layer 21 away from the busbar 4.

[0057] Specifically, the buffer layer 21 can be an EVA (ethylene-vinyl acetate copolymer) layer or the like, and the insulating spacing layer 22 can be a PET (polyethylene terephthalate) layer or the like. The buffer layer 21 is mainly used for shock absorption and buffering, and can reduce the possibility of hidden cracks of the photovoltaic module 100 in the lamination process. The insulating spacing layer 22 mainly plays an insulating role, and can reduce the possibility of excessive contact between the bus bar 4 and the cell sheet 11, resulting in short circuit and the like. Therefore, the insulating layer 2 can simultaneously play the roles of insulation and buffering, and the following will be described by taking the insulating layer 2 including the buffer layer 21 and the insulating spacing layer 22 as an example.

[0058] The bus bar 4 is fixed with the insulating layer 2, and there are various specific fixing modes between the bus bar 4 and the insulating layer 2. For example, the bus bar 4 and the insulating layer 2 can be fixed by spot welding, and this fixing mode of the bus bar 4 and the insulating layer 2 is relatively simple. Alternatively, referring to Figure 2 In some embodiments, the buffer layer 21 and the bus bar 4 are fixed by spot welding.

[0059] Specifically, the buffer layer 21 of the insulating layer 2 and the bus bar 4 are fixed by spot welding, so as to fix the bus bar 4 and the insulating layer 2 by spot welding, and since the insulating layer 2 is provided with the buffer layer 21, the problem of the insulating spacing layer 22 being welded through can be avoided.

[0060] Alternatively, referring to Figure 2 In some embodiments, the sum of the thicknesses of the insulating layer 2 and the first adhesive layer 3 is 0.4-0.8 mm.

[0061] Specifically, the buffer layer 21, the insulating spacing layer 22 and the first adhesive layer 3 form a three-layer insulating structure, which is defined as an insulating strip below, and the insulating strip is a “sandwich” structure. The total thickness of the three-layer insulating strip is 0.4-0.8 mm, for example, the total thickness of the three-layer insulating strip can be 0.4 mm, 0.42 mm, 0.44 mm, 0.46 mm, 0.48 mm, 0.5 mm, 0.52 mm, 0.54 mm, 0.56 mm, 0.58 mm, 0.6 mm, 0.62 mm, 0.64 mm, 0.66 mm, 0.68 mm, 0.7 mm, 0.72 mm, 0.74 mm, 0.76 mm, 0.78 mm or 0.8 mm, etc. Therefore, by optimizing the thickness range of the three-layer insulating strip, not only the bus bar 4 and the cell sheet 11 can be insulated by the insulating strip, but also the problem of waste of insulating material caused by the insulating strip being too thick can be avoided, and the possibility of hidden cracks of the photovoltaic module 100 in the lamination process can be reduced.

[0062] Alternatively, referring to Figure 3In some embodiments, the second adhesive layer 6 is arranged between the insulation layer 2 and the bus bar 4 to bond and fix the insulation layer 2 and the bus bar 4 through the second adhesive layer 6.

[0063] Specifically, the second adhesive layer 6 is arranged on the surface of the insulation layer 2 away from the battery piece 11, that is, the buffer layer 21 is arranged on the surface of the insulation layer 2 away from the battery piece 11, and the bus bar 4 is directly bonded and fixed on the surface of the insulation layer 2 away from the battery piece 11 through the second adhesive layer 6. This fixing mode of the bus bar 4 and the insulation layer 2 is relatively simple.

[0064] The second adhesive layer 6 can be a double-sided adhesive tape or a glue layer, for example, the second adhesive layer 6 can be a tearable adhesive layer such as a double-sided adhesive tape. Alternatively, in some embodiments, the second adhesive layer 6 is a second insulation adhesive layer. The second adhesive layer 6 is an insulating glue, so that the second adhesive layer 6 has insulation, and the bus bar 4 and the insulation layer 2 are bonded and fixed through the second insulation adhesive layer, which is conducive to ensuring that the bus bar 4 is insulated from the battery piece 11.

[0065] Alternatively, with reference to Figure 3 In some embodiments, the sum of the thicknesses of the insulation layer 2, the first adhesive layer 3, and the second adhesive layer 6 is 0.6-1.0 mm.

[0066] Specifically, the second adhesive layer 6+the buffer layer 21+the insulation spacing layer 22+the first adhesive layer 3 form a four-layer insulation strip, and the total thickness of the four-layer insulation strip is 0.6-1.0 mm, for example, the total thickness of the four-layer insulation strip can be 0.6 mm, 0.62 mm, 0.64 mm, 0.66 mm, 0.68 mm, 0.7 mm, 0.72 mm, 0.74 mm, 0.76 mm, 0.78 mm, 0.8 mm, 0.82 mm, 0.84 mm, 0.86 mm, 0.88 mm, 0.9 mm, 0.92 mm, 0.94 mm, 0.96 mm, 0.98 mm, or 1.0 mm, etc. Therefore, by optimizing the thickness range of the four-layer insulation strip, not only is the insulation of the bus bar 4 from the battery piece 11 through the insulation strip facilitated, but also the problem of waste of insulation material caused by excessive thickness of the insulation strip is avoided, and the possibility of hidden cracks in the photovoltaic module 100 during lamination is reduced.

[0067] The solder strip 5 is conductively connected to the bus bar 4 and the battery piece 11, and the specific arrangement mode of the solder strip 5 can be set according to actual conditions. Alternatively, with reference to Figure 2 and Figure 3In some embodiments, the solder strip 5 comprises a first connecting segment 51, a second connecting segment 52, and a bending segment 53, the first connecting segment 51 is arranged on the battery piece 11; the second connecting segment 52 is arranged on the bus bar 4; the two ends of the bending segment 53 are connected to the first connecting segment 51 and the second connecting segment 52 respectively, and the bending segment 53 is located on one side of the battery piece 11, the insulating layer 2, and the bus bar 4 in the width direction of the bus bar 4.

[0068] Specifically, the first connecting segment 51 of the solder strip 5 is welded on the battery piece 11 first, and the second connecting segment 52 and the bending segment 53 of the solder strip 5 exceed the edge of the battery piece 11; then the second connecting segment 52 of the solder strip 5 is welded on the bus bar 4; finally, the bus bar 4 is folded from one side of the battery piece 11 to the back of the battery piece 11, so that the bending segment 53 is bent and formed. The first connecting segment 51 can be arranged on the front or back of the battery piece 11, and similarly, the second connecting segment 52 can be arranged on the surface of the bus bar 4 away from the battery piece 11 or the surface of the bus bar 4 close to the battery piece 11.

[0069] Optionally, referring to Figure 2 and Figure 3 In some embodiments, the sum of the length of the bending segment 53 and the length of the second connecting segment 52 is 7-12 mm.

[0070] Specifically, the sum of the length of the bending segment 53 and the length of the second connecting segment 52 is the length of the solder strip 5 relative to the battery piece 11, and the length of the solder strip 5 is 7-12 mm, for example, the length of the solder strip 5 can be 7 mm, 7.2 mm, 7.4 mm, 7.6 mm, 7.8 mm, 8 mm, 8.2 mm, 8.4 mm, 8.6 mm, 8.8 mm, 9 mm, 9.2 mm, 9.4 mm, 9.6 mm, 9.8 mm, 10 mm, 10.2 mm, 10.4 mm, 10.6 mm, 10.8 mm, 11 mm, 11.2 mm, 11.4 mm, 11.6 mm, 11.8 mm, or 12 mm, etc. By optimizing the length of the solder strip 5, the problem of hidden cracks in the solder strip 5 can be avoided when the bus bar 4 is folded.

[0071] Optionally, referring to Figure 2 and Figure 3 In some embodiments, the length of the bending segment 53 is 2-4 mm.

[0072] Specifically, the length of the bending section 53 is the distance between the welding strip 5 and the battery sheet 11, and the distance between the welding strip 5 and the battery sheet 11 is 2-4 mm. For example, the distance between the welding strip 5 and the battery sheet 11 can be 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, or 4 mm, etc. In this way, by optimizing the value range of the distance between the welding strip 5 and the battery sheet 11, the problem of hidden cracks in the welding strip 5 can be avoided when the bus bar 4 is folded.

[0073] Optionally, with reference to Figure 2 and Figure 3 In some embodiments, the length of the second connecting section 52 is 3-8 mm.

[0074] Specifically, the length of the second connecting section 52 is the length of the welding strip 5 on the bus bar 4, and the length of the welding strip 5 on the bus bar 4 is 3-8 mm, for example, the length of the welding strip 5 on the bus bar 4 can be 3 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm, 5 mm, 5.2 mm, 5.4 mm, 5.6 mm, 5.8 mm, 6 mm, 6.2 mm, 6.4 mm, 6.6 mm, 6.8 mm, 7 mm, 7.2 mm, 7.4 mm, 7.6 mm, 7.8 mm, or 8 mm. In this way, by optimizing the value range of the length of the welding strip 5 on the bus bar 4, the problem of hidden cracks in the welding strip 5 can be avoided when the bus bar 4 is folded.

[0075] Optionally, with reference to Figure 2 and Figure 3 In some embodiments, the photovoltaic module 100 further comprises a front cover plate 6, a front encapsulation layer 7, a back encapsulation layer (not shown in the figure), and a back cover plate (not shown in the figure).

[0076] Specifically, as introduced above, the battery string 1, the insulating layer 2, the bus bar 4, the welding strip 5, etc. form a battery sheet layer, the front cover plate 6, the front encapsulation layer 7, the battery sheet layer, the back encapsulation layer, and the back cover plate are sequentially stacked, the front cover plate 6 and the front encapsulation layer 7 are close to the front of the battery sheet 11, and the back encapsulation layer and the back cover plate are close to the back of the battery sheet 11.

[0077] The main function of the front cover plate 6 is to avoid damage to the battery sheet layer, to ensure that the photovoltaic module 100 can adapt to harsh weather environment, and has good photoelectric conversion efficiency. Therefore, the front cover plate 6 has high hardness and transparency, wherein the transparency represents the transmittance of the front cover plate 6 to light of a specific wavelength. Therefore, the front cover plate 6 can be a glass cover plate, a plastic cover plate, or the like, which has good light transmission function and is not easy to be damaged.

[0078] The main function of the back cover plate is to protect the battery sheet layer. Therefore, in order to ensure that the back cover plate has good sealing, insulation, waterproof, or aging resistance, etc., the back cover plate can be a glass cover plate, a plastic cover plate, or the like, which is not easy to be damaged. For example, the back cover plate can adopt a cover plate composed of a polyvinyl fluoride film (PVF) + a polyester film (PET) + a PVF three-layer film, which is referred to as a TPT cover plate. The outer protective layer PVF has good environmental erosion resistance, the middle layer PET has good insulation performance, and the inner layer PVF has good adhesion performance after surface treatment and encapsulation film 130. For another example, the back cover plate can also adopt a cover plate composed of a thermoplastic elastomer (TPE) having high elasticity, high strength, and recyclability.

[0079] The front encapsulation layer 7 is located between the front cover plate 6 and the battery sheet layer, and the main function of the front encapsulation layer 7 is to act as a medium to bond the front cover plate 6 and the battery sheet layer. The back encapsulation layer is located between the back cover plate and the battery sheet layer, and the main function of the back encapsulation layer is to act as a medium to bond the back cover plate and the battery sheet layer. The front encapsulation layer 7 and the back encapsulation layer also have good transparency, and the front encapsulation layer 7 and the back encapsulation layer can be an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene copolymer (POE) film, a polyethylene terephthalate (PET) film, or a polyvinyl butyral (PVB) film.

[0080] The preparation method of the photovoltaic module 100 can be: 1. stacking the front cover plate 7, the front encapsulation layer 8 and the cell sheet 11 in a predetermined order, welding the bus bar 4 at the edge solder strip 5 of the cell sheet 11, wherein the length of the solder strip 5 is 7-12 mm, the distance between the solder strip 5 and the cell sheet 11 is 2-4 mm, and the length of the solder strip 5 on the bus bar 4 is 3-8 mm; 2. carefully folding the bus bar 4 with the welded solder strip 5 to avoid hidden cracks, and folding to the back of the cell sheet 11; 3. placing an insulating strip with a length of not less than 1128 mm between the bus bar 4 and the cell sheet 11, the width of the insulating strip is 10-30 mm, the insulating strip has a sandwich structure (buffer layer 21 + insulating spacing layer 22 + first adhesive layer 3), the total thickness of the three layers is 0.4-0.8 mm, the first adhesive layer 3 is insulating glue, and the first adhesive layer 3 of the insulating strip faces the cell sheet 11, and the buffer layer 21 is fixed with the bus bar 4 by spot pressing; 4. laying the back encapsulation layer and the back cover plate, and laminating according to fixed laminating parameters, and there is no bubble after laminating.

[0081] The preparation method of the photovoltaic module 100 can be: 1. stacking the front cover plate 7, the front encapsulation layer 8 and the cell sheet 11 in a predetermined order, welding the bus bar 4 at the edge solder strip 5 of the cell sheet 11, wherein the length of the solder strip 5 is 7-12 mm, the distance between the solder strip 5 and the cell sheet 11 is 2-4 mm, and the length of the solder strip 5 on the bus bar 4 is 3-8 mm; 2. carefully folding the bus bar 4 with the welded solder strip 5 to avoid hidden cracks, and folding to the back of the cell sheet 11; 3. placing an insulating strip with a length of not less than 1128 mm between the bus bar 4 and the cell sheet 11, the width of the insulating strip is 10-30 mm, the insulating strip has a sandwich structure (second adhesive layer 6 + buffer layer 21 + insulating spacing layer 22 + first adhesive layer 3), the total thickness of the four layers is 0.6-1.0 mm, the first adhesive layer 3 and the second adhesive layer 6 are insulating glue, and the first adhesive layer 3 and the second adhesive layer 6 are bonded together with the buffer layer 21 and the insulating spacing layer 22 through coating process, the bus bar 4 is directly bonded on the second adhesive layer 6, and the first adhesive layer 3 contacts the cell sheet 11; 4. laying the back encapsulation layer and the back cover plate, and laminating according to fixed laminating parameters, and there is no abnormality in appearance after laminating.

[0082] Those skilled in the art can understand that the above-mentioned embodiments are specific embodiments for realizing the present disclosure, and in actual application, various changes can be made in form and details without departing from the spirit and scope of the present disclosure. Any person skilled in the art can make various modifications and changes without departing from the spirit and scope of the present disclosure, and therefore the protection scope of the present disclosure should be limited by the scope defined in the claims.

Claims

1. A photovoltaic module, characterized by, The application relates to a battery string, which comprises battery pieces, an insulation layer arranged on the back of the battery pieces, a first adhesive layer arranged between the insulation layer and the battery pieces, a bus bar arranged on the side of the insulation layer away from the battery pieces, and a solder strip electrically connected with the bus bar and the battery pieces. The solder strip comprises a first connecting section arranged on the battery piece, a second connecting section arranged on the bus bar, and a bending section with two ends connected with the first connecting section and the second connecting section respectively, and the bending section is arranged on one side of the battery piece, the insulation layer and the bus bar in the width direction of the bus bar. The length of the bending section is 2-4 mm; the sum of the length of the bending section and the length of the second connecting section is 7-12 mm; and the length of the second connecting section is 3-8 mm. The second connecting section is arranged on the surface of the bus bar away from the battery piece; and the first connecting section is arranged on the front of the battery piece. The bus bar and the insulation layer are fixed by spot welding.

2. The photovoltaic module of claim 1, wherein, The insulation layer comprises a buffer layer and an insulation spacing layer arranged in a stack, the buffer layer is fixed with the bus bar by spot welding, and the insulation spacing layer is arranged on the side of the buffer layer away from the bus bar. The sum of the thickness of the insulation layer and the first adhesive layer is 0.4-0.8 mm. A second adhesive layer is arranged between the insulation layer and the bus bar to fix the insulation layer and the bus bar by the second adhesive layer. The sum of the thickness of the insulation layer, the first adhesive layer and the second adhesive layer is 0.6-1.0 mm.

3. The photovoltaic module of claim 2, wherein, The insulation layer is an insulation pad strip, wherein the length of the insulation pad strip is not less than 1128 mm; and the width of the insulation pad strip is 10-30 mm. ​ ​ 4. The photovoltaic module of claim 2, wherein, ​ ​ 5. The photovoltaic module of claim 1, wherein, ​ 6. The photovoltaic module of claim 5, wherein, ​ 7. The photovoltaic module of claim 5, wherein, ​ 8. The photovoltaic module of claim 1, wherein, ​ 9. The photovoltaic module of claim 8, wherein, ​ 10. The photovoltaic module of claim 1, wherein, ​ ​ ​

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