Photovoltaic module

Abstract

The embodiment of the invention 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 conductive bridging part, the battery string comprises a plurality of battery pieces, the back surface of each battery piece is provided with a welding strip, and the plurality of battery pieces are connected in series through the welding strips; the insulating layer is arranged on one side, far away from the battery piece, of the welding strip, and the insulating layer is provided with an avoiding area, so that part of the welding strip is exposed from the avoiding area to form a welding strip exposing part; the bus bar is arranged on one side of the insulating layer away from the solder strip; and the conductive bridging part is arranged at the avoiding area and is arranged between the bus bar and the welding strip exposing part, so that the bus bar is conductively connected with the welding strip exposing part through the conductive bridging part. The embodiment of the invention is at least beneficial to improving the maximum output power of the back contact battery assembly.

Description

Cross-references to related applications

[0001] This application is a divisional application of Chinese invention patent application filed on November 7, 2024, with application number 202411586830.7 and invention title "Photovoltaic Module". Technical Field

[0002] This disclosure relates to the field of photovoltaic technology, and in particular to a photovoltaic module. Background Technology

[0003] Back-contact (BC) cells have no grid lines obstructing the front, maximizing the utilization of incident light, reducing optical losses, and exhibiting higher short-circuit current, thereby increasing the maximum output power of back-contact cell modules. In existing back-contact cell modules, visible busbars still exist on the front, occupying part of the module area, reducing the cell placement area, and severely limiting the maximum output power of the back-contact cell module. Summary of the Invention

[0004] This disclosure provides a photovoltaic module that at least helps to increase the maximum output power of a back-contact battery module.

[0005] According to some embodiments of this disclosure, one aspect of this disclosure provides a photovoltaic module, including: A battery string, comprising multiple battery cells, each battery cell having a solder strip on its back side to connect multiple battery cells in series via the solder strip; An insulating layer is disposed on the side of the solder ribbon away from the battery cell, and the insulating layer is provided with a clearance area so that a portion of the solder ribbon is exposed from the clearance area to form a solder ribbon exposure portion; A busbar, the busbar being disposed on the side of the insulating layer away from the solder strip; A conductive bridging portion is disposed at the avoidance area and between the busbar and the exposed solder strip, so as to electrically connect the busbar and the exposed solder strip through the conductive bridging portion.

[0006] In some embodiments, the conductive bridging portion includes a bridging connector and / or conductive adhesive.

[0007] In some embodiments, the bridging connector and the exposed solder strip are integrally formed.

[0008] In some embodiments, the width of the bridging connector is greater than the width of the solder strip.

[0009] In some embodiments, the height difference between the busbar and the solder strip is equal to the thickness of the conductive bridging portion.

[0010] In some embodiments, the length of the conductive bridging portion is less than or equal to the length of the exposed solder strip portion.

[0011] In some embodiments, the insulating layer includes a coating layer disposed on the battery string, the coating layer covering the back side of the battery cell and the solder strip, the coating layer having openings that form the clearance area.

[0012] In some embodiments, the coating layer is an insulating film.

[0013] In some embodiments, the coating layer is applied to the back of the battery cell using a low-temperature coating technique.

[0014] In some embodiments, the insulating layer further includes an insulating spacer layer disposed between the coating layer and the busbar, the insulating spacer layer having a clearance structure communicating with the opening.

[0015] In some embodiments, an insulating adhesive is provided between the solder ribbon and the back surface of the battery cell, wherein the dimension of the insulating adhesive in the width direction of the solder ribbon is greater than or equal to the dimension of the opening in the width direction of the solder ribbon, so that the projection of the opening on the back surface of the battery cell is located on the insulating adhesive.

[0016] In some embodiments, the coating layer extends along the length of the battery string, and the dimension of the coating layer in the length direction of the battery string is equal to the length of the battery string; or... The coating layer includes multiple coating sub-layers, and the multiple coating sub-layers are arranged in a one-to-one correspondence with the multiple battery cells in the battery string. Each coating sub-layer covers the back of a corresponding battery cell.

[0017] In some embodiments, the insulating spacer layer is provided in the form of a strip extending along the length direction of the busbar, and the insulating spacer layer is provided with a clearance hole corresponding to the opening, the clearance hole forming the clearance structure.

[0018] In some embodiments, the insulating spacer layer includes a plurality of insulator layers spaced apart along the length of the busbar, and the opening is located between two adjacent insulator layers to form the clearance structure between the two adjacent insulator layers.

[0019] In some embodiments, a plurality of openings are provided at intervals along the length direction of the busbar, and each opening is provided with an insulator layer on both sides of the busbar along the length direction.

[0020] In some embodiments, the thermoplasticity of the coating layer is superior to that of the insulating spacer layer.

[0021] In some embodiments, an insulating adhesive is provided between the solder ribbon and the back surface of the battery cell, wherein the dimension of the insulating adhesive in the width direction of the solder ribbon is greater than or equal to the dimension of the opening in the width direction of the solder ribbon, so that the projection of the opening on the back surface of the battery cell is located on the insulating adhesive.

[0022] The technical solution provided in this disclosure has at least the following advantages: The busbars of the photovoltaic module are hidden on the back of the solar cells, so they do not occupy the area on the front of the photovoltaic module. This maximizes the area of ​​solar cells that can be laid, increases the light-receiving area on the front of the photovoltaic module, and thus improves the maximum output power of the photovoltaic module. In addition, a conductive bridging part is added to the contact area between the busbar and the solder ribbon. This not only effectively reduces the risk of microcracks and fragmentation of the solar cells during the subsequent lamination process, but also reduces the possibility of poor soldering between the busbar and the solder ribbon. Attached Figure Description

[0023] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a back-contact battery assembly in the prior art. Figure 2 This is a schematic diagram of the structure of a photovoltaic module provided in one embodiment of the present disclosure; Figure 3 for Figure 2 A cross-sectional view of a photovoltaic module; Figure 4 for Figure 3 A magnified view of a section at point A in the middle; Figure 5 for Figure 2 A schematic diagram of the structure of a photovoltaic module after the busbars have been removed; Figure 6 for Figure 2 A schematic diagram of the structure of a photovoltaic module after removing the busbars and insulating spacer layer; Figure 7This is a schematic diagram of the structure of another photovoltaic module provided in an embodiment of the present disclosure; Figure 8 for Figure 7 A schematic diagram of the structure of a photovoltaic module after the busbars have been removed; Figure 9 This is a schematic diagram of the structure of an opening in a photovoltaic module according to an embodiment of the present disclosure. Detailed Implementation

[0025] As can be seen from the background technology, reference Figure 1 In the existing back-contact battery module 1000A, the front side of the back-contact battery module 1000A still has visible head and tail busbars 100A and middle busbar 200A. Thus, with the size of the back-contact battery module 1000A fixed, the head and tail busbars 100A and middle busbar 200A occupy part of the front area of ​​the back-contact battery module 1000A, thereby reducing the laying area of ​​the battery cells 300A and severely limiting the maximum output power of the back-contact battery module 1000A.

[0026] This disclosure provides a photovoltaic module in which the busbars are hidden on the back of the solar cells, and the busbars do not occupy the area on the front of the photovoltaic module. This maximizes the area of ​​solar cell installation and the illumination area on the front of the photovoltaic module, thereby improving the maximum output power of the photovoltaic module. Furthermore, the addition of a conductive bridging part in the contact area between the busbars and the solder strips can not only effectively reduce the risk of microcracks and fragmentation of the solar cells during subsequent lamination, but also reduce the possibility of poor soldering between the busbars and the solder strips.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0030] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. For example, if the device or element in the illustration is inverted, then the element described as "below," "under," "below," or "bottom" of other elements or features will be oriented "above" or "top" of said other elements or features. Therefore, the term "below" may cover both above and below orientation depending on the context in which the term is used, which will be obvious to those skilled in the art. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0031] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] Figures 2 to 9 The diagram shows the structure of various photovoltaic modules provided in the embodiments of this disclosure.

[0037] refer to Figures 2 to 4 The photovoltaic module 1000 includes a cell string 100, an insulating layer 300, a busbar 400, and a conductive bridging portion 500. The cell string 100 includes multiple cells 110, and each cell 110 has a solder ribbon 200 on its back side to connect multiple cells 110 in series. The insulating layer 300 is disposed on the side of the solder ribbon 200 away from the cell 110, and the insulating layer 300 has a clearance area 310 to expose a portion of the solder ribbon 200 from the clearance area 310 to form a solder ribbon exposure portion 210. The busbar 400 is disposed on the side of the insulating layer 300 away from the solder ribbon 200. The conductive bridging portion 500 is disposed between the busbar 400 and the solder ribbon exposure portion 210 to electrically connect the busbar 400 and the solder ribbon exposure portion 210.

[0038] Specifically, the photovoltaic module 1000 is a back-contact solar module, comprising multiple series-connected cell strings 100, each cell string 100 comprising multiple series-connected solar cells 110. The solar cells 110 are typically sheet-like structures, having a front (or light-absorbing) side and a back side opposite each other in the thickness direction. The front side of the solar cell 110 absorbs light energy and converts it into electrical energy. The back side of the solar cell 110 is provided with a first grid line and a second grid line, one of which is a positive grid line and the other a negative grid line. Each battery cell 110 has multiple solder ribbons 200 on its back side. The solder ribbons 200 extend along the length of the battery string 100 (i.e., the arrangement direction of the multiple battery cells 110 in the battery string 100). The multiple solder ribbons 200 include multiple first solder ribbons 200a and multiple second solder ribbons 200b, which are alternately arranged on the back side of the battery cell 110 along the width direction of the battery string 100. The first solder ribbons 200a are electrically connected to the first grid line, and the second solder ribbons 200b are electrically connected to the second grid line. In this way, the current of the first grid line can be conducted through the first solder ribbons 200a, and the current of the second grid line can also be conducted through the second solder ribbons 200b. The multiple battery cells 110 in the battery string 100 are connected in series through the first solder ribbons 200a and the second solder ribbons 200b.

[0039] An insulating layer 300 is disposed on the side of the solder ribbon 200 away from the solar cell 110. The insulating layer 300 has a clearance area 310. The portion of the solder ribbon 200 and the clearance area 310 opposite each other in the thickness direction of the solar cell 110 is the exposed portion 210 of the solder ribbon. The clearance area 310 exposes the exposed portion 210 of the solder ribbon 200, meaning that the exposed portion 210 of the solder ribbon is not covered by the insulating layer 300, while the portion of the solder ribbon 200 other than the exposed portion 210 is covered by the insulating layer 300. A busbar 400 is disposed on the side of the insulating layer 300 away from the solder ribbon 200. A portion of the busbar 400 is spaced apart from the exposed portion 210 of the solder ribbon in the thickness direction of the solar cell 110. A conductive bridging portion 500 is provided at the clearance area 310 of the insulating layer 300, and the conductive bridging portion 500 is located between the exposed solder ribbon 210 and the busbar 400. The conductive bridging portion 500 conductively connects the exposed solder ribbon 210 and the busbar 400, thereby conductively connecting the busbar 400 and the solder ribbon 200. By adding a conductive bridging portion 500 at the contact point between the busbar 400 and the solder ribbon 200, the contact point between the busbar 400 and the solder ribbon 200 becomes flat, thereby improving stress concentration and localized deformation of the solar cell 110 during subsequent lamination.

[0040] The busbar 400 is electrically connected to the solder strip 200, specifically by the busbar 400 being electrically connected to one of the first solder strip 200a and the second solder strip 200b. For example, refer to... Figures 2 to 4 In some embodiments, the insulating layer 300 has a clearance area 310 corresponding to the first solder strip 200a, and the busbar 400 is electrically connected to the first solder strip 200a through the conductive bridging portion 500. In other embodiments, the insulating layer 300 has a clearance area 310 corresponding to the second solder strip 200b, and the busbar 400 is electrically connected to the second solder strip 200b through the conductive bridging portion 500. The following description will use the example of the busbar 400 being electrically connected to the first solder strip 200a through the conductive bridging portion 500.

[0041] The busbar 400 of the photovoltaic module 1000 is hidden on the back of the solar cell 110. The busbar 400 does not occupy the area on the front of the photovoltaic module 1000, thus maximizing the laying area of ​​the solar cell 110 and increasing the light-receiving area on the front of the photovoltaic module 1000, thereby improving the maximum output power of the photovoltaic module 1000. Furthermore, the addition of a conductive bridging part 500 at the contact area between the busbar 400 and the solder ribbon 200 can not only effectively reduce the risk of microcracks and fragmentation of the solar cell 110 during subsequent lamination, but also reduce the possibility of poor soldering between the busbar 400 and the solder ribbon 200.

[0042] The embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings.

[0043] The busbar 400 and the solder strip 200 are electrically connected through the conductive bridging part 500. The conductive bridging part 500 can be configured in various ways. For example, the conductive bridging part 500 can be a section of solder strip or a metal part, etc., as a bridging connector 500a; the conductive bridging part 500 can also be conductive adhesive; the conductive bridging part 500 can also be a combination of the bridging connector 500a and conductive adhesive.

[0044] refer to Figures 3 to 4 In some embodiments, the conductive bridging portion 500 is a bridging connector 500a, and the bridging connector 500a is a piece of solder strip. Using a piece of solder strip as the conductive bridging portion 500 makes this arrangement relatively simple.

[0045] When the conductive bridging part 500 is a bridging connector 500a, the bridging connector 500a and the exposed solder strip part 210 can be integrally formed; the bridging connector 500a and the exposed solder strip part 210 can also be separate parts.

[0046] The thickness of the bridging connector 500a is the dimension of the bridging connector 500a in the thickness direction of the welding strip 200. The height difference between the busbar 400 and the welding strip 200 is equal to or approximately equal to the thickness of the bridging connector 500a, so that the contact position between the busbar 400 and the welding strip 200 can be relatively flat.

[0047] The length of the bridging connector 500a is its dimension along the length of the solder strip 200, and the length of the bridging connector 500a is less than or equal to the length of the exposed portion 210 of the solder strip. (Reference) Figures 3 to 4 In some embodiments, the length of the bridging connector 500a is equal to the length of the exposed solder strip 210. Maximizing the length of the bridging connector 500a not only increases the effective conductive area between the busbar 400 and the solder strip 200, but also prevents gaps from appearing in the length direction of the solder strip 200, resulting in a relatively flat contact area between the busbar 400 and the solder strip 200.

[0048] The width of the bridging connector 500a is its dimension in the width direction of the solder strip 200. The width of the bridging connector 500a can be greater than or equal to the width of the solder strip 200; the width of the bridging connector 500a can also be less than the width of the solder strip 200. (Reference) Figure 3 and Figure 4 In some embodiments, the width of the bridging connector 500a is greater than the width of the solder strip 200. The solder strip 200 is usually of equal width, and the width of the solder strip 200 is the width of the exposed portion 210. This arrangement, where the width of the bridging connector 500a is slightly larger than the width of the exposed portion 210, not only increases the effective conductive area between the busbar 400 and the solder strip 200, but also avoids gaps in the width direction of the solder strip 200, resulting in a relatively flat contact area between the busbar 400 and the solder strip 200.

[0049] refer to Figure 2 , Figure 5 and Figure 6 The battery string 100 typically has multiple first solder strips 200a along its width, and these multiple first solder strips 200a are electrically connected via a busbar 400. For example, see reference... Figure 2 , Figure 5 and Figure 6In some embodiments, the insulating layer 300 is provided with a plurality of clearance areas 310 spaced apart along the length direction of the busbar 400, so that the battery string 100 forms a plurality of exposed solder ribbons 210 spaced apart along the length direction of the busbar 400. Multiple conductive bridging portions 500 are provided corresponding to the plurality of exposed solder ribbons 210 in the battery string 100, and each exposed solder ribbon 210 is conductively connected to the busbar 400 through a corresponding conductive bridging portion 500. The length direction of the busbar 400 is perpendicular or approximately perpendicular to the length direction of the solder ribbons 200. This arrangement allows for more diverse laying methods for the battery cells 110, which is beneficial for increasing the laying area of ​​the battery cells.

[0050] refer to Figure 2 , Figure 5 and Figure 6 A photovoltaic module 1000 typically includes multiple cell strings 100, which are connected in series via a busbar 400. For example, see reference... Figure 2 , Figure 5 and Figure 6 In some embodiments, multiple battery strings 100 are arranged along the length of the busbar 400, and the multiple battery strings 100 are connected in series through the busbar 400. This arrangement allows for more diverse ways of laying the battery cells 110, which is beneficial for increasing the laying area of ​​the battery cells.

[0051] An insulating layer 300 is provided between the busbar 400 and the solder strip 200, which insulates the busbar 400 from the second solder strip 200b and the second grid line of the battery cell 110. Since the insulating layer 300 has a clearance area 310 corresponding to the first solder strip 200a, the busbar 400 can be electrically connected to the first solder strip 200a through the conductive bridging portion 500 provided at the clearance area 310.

[0052] There are various ways to specifically install the insulating layer 300; for example, the insulating layer 300 can be insulating adhesive, insulating tape, or insulating film, etc. (See reference) Figure 2 , Figure 5 and Figure 6 In some embodiments, the insulating layer 300 includes a coating layer 320 disposed on the battery string 100, the coating layer 320 covering the back of the battery cell 110 and the solder strip 200, and the coating layer 320 having an opening 321 forming a clearance area 310.

[0053] Specifically, the coating layer 320 is an insulating film, and the coating layer 320 is provided with multiple openings 321, which respectively form multiple clearance areas 310. The specific shape of the openings 321 is not particularly limited, and the openings 321 can be square, circular, or diamond-shaped, etc. For example, see reference. Figure 5 and Figure 6In some embodiments, the opening 321 is a square hole.

[0054] The coating layer 320 can be applied to the back of the solar cell 110 using a low-temperature coating technique. For example, a coating layer 320 is first laid down and perforated; after positioning, solder ribbons 200 are placed on the coating layer 320; then the solar cell 110 is placed; finally, heating and pressurizing are applied to fix the solder ribbons 200 to the solar cell 110 by the coating layer 320. Using a low-temperature coating technique to apply the coating layer 320 to the back of the solar cell 110 can reduce warping of the solar cell 110, and the coating layer 320 can protect most of the grid area of ​​the solar cell 110, thus preventing short circuits caused by solder splatter during the soldering of the busbar 400. The specific material of the coating layer 320 can be set according to the actual situation. For example, the coating layer 320 can be an EVA (ethylene-vinyl acetate copolymer) film, a POE (polyethylene octene coelastomer) film, an EP film (a two-layer co-extruded film of EVA and POE), or an EPE film (a three-layer co-extruded film of EVA and POE), etc.

[0055] The coating layer 320 covers the back side of each battery cell 110 in the battery string 100, and there are various specific arrangements for the coating layer 320. For example, see reference... Figure 6 In some embodiments, the coating layer 320 includes multiple coating sub-layers 322, which are arranged in a one-to-one correspondence with multiple battery cells 110 in the battery string 100. Each coating sub-layer 322 covers the back side of a corresponding battery cell 110. The shape and size of the coating sub-layers 322 are adapted to the shape and size of the battery cells 110. The multiple coating sub-layers 322 are respectively covered on the back side of the multiple battery cells 110 in the battery string 100. The multiple coating sub-layers 322 are not connected into a whole. In this way, the coating layer 320 is formed by multiple sheet-like coating sub-layers 322, which can reduce the setting area of ​​the coating layer 320 and reduce the amount of coating layer 320 used.

[0056] For example, in other embodiments, the coating layer 320 extends along the length of the battery string 100, and the dimension of the coating layer 320 in the length direction of the battery string 100 is equal to the length of the battery string 100. The length of the coating layer 320 is equal to or approximately equal to the length of the battery string 100. This not only helps to ensure that the back side of each battery cell 110 in the battery string 100 can be completely covered by the coating layer 320, but also allows the solder ribbon 200 connecting two adjacent battery cells 110 to be completely covered by the coating layer 320.

[0057] refer to Figures 2 to 4In some embodiments, the insulating layer 300 further includes an insulating spacer layer 330, which is disposed between the coating layer 320 and the busbar 400. The insulating spacer layer 330 is provided with a clearance structure 331 communicating with the opening 321.

[0058] Specifically, an insulating spacer layer 330 is provided between the coating layer 320 and the busbar 400. Thus, the thickness of the insulating layer 300 at the junction of the busbar 400 and the solder strip 200 is the sum of the thickness of the coating layer 320 and the thickness of the insulating spacer layer 330. This ensures that the insulating layer 300 has sufficient thickness at the junction of the busbar 400 and the solder strip 200, thereby ensuring the insulating effect of the insulating layer 300. The insulating spacer layer 330 can be insulating adhesive, insulating tape, or insulating film, etc.

[0059] The thermoplasticity of the coating layer 320 is generally better than that of the insulating spacer layer 330. This not only ensures that the coating layer 320 has a better coating effect, but also helps to ensure that the insulating layer 300 has sufficient thickness at the connection between the busbar 400 and the solder strip 200 through the setting of the insulating spacer layer 330. The specific material of the insulating spacer layer 330 can be set according to the actual situation. For example, the insulating spacer layer 330 can be a PET (polyethylene terephthalate) film or a PI (polyimide) film.

[0060] The insulating spacer 330 ensures that the insulating layer 300 has sufficient thickness at the connection between the busbar 400 and the solder strip 200, and the specific thickness of the insulating spacer 330 can be set according to the actual situation. In some embodiments, the thickness of the insulating spacer 330 is 0.03~0.2mm.

[0061] Specifically, the thickness of the insulating spacer layer 330 is 0.03~0.2mm. For example, the thickness of the insulating spacer layer 330 can be 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, or 0.2mm, etc. By optimizing the thickness range of the insulating spacer 330, it is possible to ensure that the insulating layer 300 has sufficient thickness at the connection between the busbar 400 and the welding strip 200. This avoids the situation where the insulating spacer 330 is too thin, making it inconvenient to apply, easy to be deformed by pulling, and risking damage to the insulation over a long period of time. It also avoids the situation where the insulating spacer 330 is too thick, resulting in a large height difference between the busbar 400 and the welding strip 200, which could cause microcracks and fragmentation of the battery cell 110 during subsequent lamination.

[0062] An insulating spacer 330 is disposed between the coating layer 320 and the busbar 400. The insulating spacer 330 is generally arranged along the length of the busbar 400, and the dimension of the insulating spacer 330 in the width direction of the busbar 400 is greater than or equal to the width of the busbar 400.

[0063] refer to Figure 2 and Figure 5 In some embodiments, the insulating spacer layer 330 includes a plurality of insulator layers 332 spaced apart along the length of the busbar 400, and an opening 321 is located between two adjacent insulator layers 332 to form a clearance structure 331 between two adjacent insulator layers 332.

[0064] Specifically, a single insulator layer 332 is arranged in a block shape, and multiple insulator layers 332 are arranged at intervals along the length of the busbar 400 to form an insulating spacer layer 330. Furthermore, the multiple insulator layers 332 and the multiple openings 321 of the coating layer 320 are arranged alternately along the length of the busbar 400. The gap between the two insulator layers 332 on both sides of each opening 321 forms a clearance structure 331, thereby ensuring that the insulating spacer layer 330 forms multiple clearance structures 331 corresponding to the multiple openings 321 of the coating layer 320. The distance between two adjacent insulator layers 332 is greater than or equal to the size of the opening 321 along the length of the busbar 400. By forming the insulating spacer layer 330 with multiple insulator layers 332, the area and quantity of the insulating spacer layer 330 can be reduced.

[0065] The number of insulator layers 332 can be less than the number of openings 321; the number of insulator layers 332 can also be equal to the number of openings 321; the number of insulator layers 332 can also be greater than the number of openings 321. (Reference) Figure 2 and Figure 5 In some embodiments, multiple openings 321 are provided at intervals along the length direction of the busbar 400, and each opening 321 is provided with an insulator layer 332 on both sides of the busbar 400 along the length direction.

[0066] Specifically, the number of insulator layers 332 is greater than the number of openings 321, so that two insulator layers 332 can be distributed on both sides of each opening 321. In this way, the insulator layers 332 are provided on both sides of each opening 321, which can reduce the gap between the busbar 400 and the coating layer 320, so that the contact position between the busbar 400 and the welding strip 200 can be relatively flat.

[0067] refer to Figure 7 and Figure 8In some embodiments, the insulating spacer layer 330 is arranged in a strip shape extending along the length direction of the busbar 400, and the insulating spacer layer 330 is provided with a clearance hole 331a corresponding to the opening 321, the clearance hole 331a forming a clearance structure 331.

[0068] Specifically, the shape of the insulating spacer layer 330 is adapted to the shape of the busbar 400, and the insulating spacer layer 330 is elongated. The length of the insulating spacer layer 330 is greater than or equal to the length of the busbar 400, and the width of the insulating spacer layer 330 is greater than or equal to the width of the busbar 400. For example, the length of the insulating spacer layer 330 may be slightly greater than the length of the busbar 400, and the width of the insulating spacer layer 330 may also be slightly greater than the width of the busbar 400. The insulating spacer layer 330 is provided with multiple clearance holes 331a corresponding to the multiple openings 321 of the coating layer 320, and each clearance hole 331a communicates with a corresponding opening 321. The size of the clearance hole 331a may be greater than or equal to the size of the opening 321, and the shape of the clearance hole 331a is usually adapted to the shape of the opening 321. For example, refer to Figure 7 and Figure 8 In some embodiments, both the clearance hole 331a and the opening 321 are square holes. By making the insulating spacer layer 330 into a long strip shape, gaps can be avoided between the busbar 400 and the coating layer 320, so that the contact position between the busbar 400 and the solder strip 200 can be relatively flat.

[0069] The thickness of the solder strip 200 is less than the sum of the thickness of the coating layer 320 and the thickness of the insulating spacer layer 330, and the thickness of the solder strip 200 can be less than the thickness of the coating layer 320; the thickness of the solder strip 200 can also be equal to the thickness of the coating layer 320; the thickness of the solder strip 200 can also be greater than the thickness of the coating layer 320. (Reference) Figure 4 In some embodiments, the surface of the exposed ribbon 210 away from the cell 110 is located on the side of the coating layer 320 near the insulating spacer layer 330, and the surface of the insulating spacer layer 330 near the busbar 400 is located on the side of the exposed ribbon 210 away from the cell 110.

[0070] Specifically, the thickness of the solder ribbon 200 can be less than the thickness of the coating layer 320, so that the surface of the solder ribbon exposure 210 away from the cell 110 is located on the side of the coating layer 320 near the insulating spacer layer 330, that is, the solder ribbon exposure 210 extends towards the busbar 400 out of the opening 321 of the coating layer 320. The thickness of the solder ribbon 200 is less than the sum of the thickness of the coating layer 320 and the thickness of the insulating spacer layer 330, so that the surface of the insulating spacer layer 330 near the busbar 400 is located on the side of the solder ribbon exposure 210 away from the cell 110, that is, the portion of the solder ribbon exposure 210 extending out of the opening 321 is located within the clearance structure 331 of the insulating spacer layer 330.

[0071] refer to Figure 9 The back of the solar cell 110 is typically provided with insulating adhesive 120, which can insulate the first grid line and the second grid line of the solar cell 110. Since the back of the solar cell 110 is provided with a coating layer 320, the coating layer 320 can protect most of the grid line area of ​​the solar cell 110, thus reducing the amount of insulating adhesive 120 used.

[0072] refer to Figure 9 In some embodiments, an insulating adhesive 120 is provided between the solder ribbon 200 and the back side of the battery cell 110. The dimension of the insulating adhesive 120 in the width direction of the solder ribbon 200 is greater than or equal to the dimension of the opening 321 in the width direction of the solder ribbon 200, so that the projection of the opening 321 on the back side of the battery cell 110 is located on the insulating adhesive 120.

[0073] Specifically, the dimension of the insulating adhesive 120 in the width direction of the solder ribbon 200 is the width of the insulating adhesive 120, and the dimension of the opening 321 in the width direction of the solder ribbon 200 is the width of the opening 321. The width of the opening 321 is greater than the width of the solder ribbon 200, and the width of the insulating adhesive 120 is greater than or equal to the width of the opening 321. This ensures that the portion of the back side of the battery cell 110 exposed from the opening 321, excluding the exposed portion 210 of the solder ribbon, is entirely covered by the insulating adhesive 120 and the coating layer 320. With the opening of the coating layer 320 exposing the exposed portion 210 of the solder ribbon, as long as the opening position of the coating layer 320 is properly set, the insulating adhesive 120 and the coating layer 320 will protect the busbar 400 after soldering failure, preventing foreign objects from contacting the grid lines of the battery cell 110 and causing a short circuit.

[0074] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of this disclosure. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure should be determined by the scope defined in the claims.

Claims

1. A photovoltaic module, characterized in that, include: A battery string, comprising multiple battery cells, each battery cell having a solder strip on its back side to connect multiple battery cells in series via the solder strip; An insulating layer is disposed on the side of the solder ribbon away from the battery cell, and the insulating layer is provided with a clearance area so that a portion of the solder ribbon is exposed from the clearance area to form a solder ribbon exposure portion; A busbar, the busbar being disposed on the side of the insulating layer away from the solder strip; A conductive bridging portion is disposed at the avoidance area and between the busbar and the exposed solder strip, so as to electrically connect the busbar and the exposed solder strip through the conductive bridging portion.

2. The photovoltaic module according to claim 1, characterized in that, The conductive bridging portion includes bridging connectors and / or conductive adhesive.

3. The photovoltaic module according to claim 2, characterized in that, The bridging connector and the exposed weld strip are integrally formed; and / or... The width of the bridging connector is greater than the width of the welding strip.

4. The photovoltaic module according to claim 1, characterized in that, The height difference between the busbar and the solder strip is equal to the thickness of the conductive bridging portion; and / or, The length of the conductive bridging portion is less than or equal to the length of the exposed solder strip portion.

5. The photovoltaic module according to claim 1, characterized in that, The insulating layer includes a coating layer disposed on the battery string, the coating layer covering the back of the battery cell and the solder strip, and the coating layer having openings that form the clearance area.

6. The photovoltaic module according to claim 5, characterized in that, The coating layer is an insulating film; and / or, The coating layer is applied to the back of the battery cell using a low-temperature coating technique.

7. The photovoltaic module according to claim 5, characterized in that, The insulating layer further includes an insulating spacer layer disposed between the coating layer and the busbar, and the insulating spacer layer is provided with a clearance structure communicating with the opening.

8. The photovoltaic module according to claim 5, characterized in that, An insulating adhesive is provided between the solder strip and the back of the battery cell. The dimension of the insulating adhesive in the width direction of the solder strip is greater than or equal to the dimension of the opening in the width direction of the solder strip, so that the projection of the opening on the back of the battery cell is located on the insulating adhesive.

9. The photovoltaic module according to claim 5, characterized in that, The coating layer extends along the length of the battery string, and its dimension along the length of the battery string is equal to the length of the battery string; or... The coating layer includes multiple coating sub-layers, and the multiple coating sub-layers are arranged in a one-to-one correspondence with the multiple battery cells in the battery string. Each coating sub-layer covers the back of a corresponding battery cell.

10. The photovoltaic module according to claim 7, characterized in that, The insulating spacer layer is arranged in the shape of a strip extending along the length of the busbar, and the insulating spacer layer is provided with a clearance hole corresponding to the opening, and the clearance hole forms the clearance structure.

11. The photovoltaic module according to claim 7, characterized in that, The insulating spacer layer includes a plurality of insulator layers spaced apart along the length of the busbar, and the opening is located between two adjacent insulator layers to form the clearance structure between two adjacent insulator layers.

12. The photovoltaic module according to claim 11, characterized in that, The openings are provided at intervals along the length of the busbar, and each opening is provided with an insulator layer on both sides of the busbar along the length of the busbar.

13. The photovoltaic module according to claim 7, characterized in that, The thermoplasticity of the coating layer is better than that of the insulating spacer layer.

14. The photovoltaic module according to claim 5, characterized in that, An insulating adhesive is provided between the solder strip and the back of the battery cell. The dimension of the insulating adhesive in the width direction of the solder strip is greater than or equal to the dimension of the opening in the width direction of the solder strip, so that the projection of the opening on the back of the battery cell is located on the insulating adhesive.

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