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 and a bus bar, 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 exposed part; the bus bar is arranged on the side, away from the welding strip, of the insulating layer, the bus bar is provided with an abutting part in a protruding mode towards the welding strip exposing part, and the abutting part abuts against the welding strip exposing part so that the bus bar can be conductively connected with the welding strip. The embodiment of the invention is at least beneficial to improving the maximum output power of the back contact battery assembly.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of photovoltaic technology, and in particular to a photovoltaic module. Background Art

[0002] The front of the back contact (BC) cell is free of grid lines, which can maximize the use of incident light, reduce optical losses, and have a higher short-circuit current, thereby increasing the maximum output power of the back contact cell module. In existing back contact cell modules, there are still visible bus bars on the front of the back contact cell module, which occupy part of the module area, reduce the laying area of ​​the battery cells, and severely limit the maximum output power of the back contact cell module. Summary of the invention

[0003] The embodiments of the present disclosure provide a photovoltaic module, which is at least beneficial for improving the maximum output power of the back-contact battery module.

[0004] According to some embodiments of the present disclosure, on one hand, a photovoltaic assembly is provided, including:

[0005] A battery string, the battery string comprising a plurality of battery cells, a welding strip being arranged on the back of each battery cell, so as to connect the plurality of battery cells in series through the welding strip;

[0006] An insulating layer, the insulating layer is arranged on a side of the soldering strip away from the battery cell, and the insulating layer is provided with an avoidance area so that a portion of the soldering strip is exposed from the avoidance area to form a soldering strip exposed portion;

[0007] A bus bar is arranged on a side of the insulating layer away from the welding strip, and the bus bar is provided with an abutment portion protruding toward the exposed portion of the welding strip, and the abutment portion abuts against the exposed portion of the welding strip to conductively connect the bus bar to the welding strip.

[0008] In some embodiments, a portion of the bus bar is recessed toward the welding strip exposed portion relative to a portion adjacent to the portion, and the recessed portion of the bus bar forms the abutting portion.

[0009] In some embodiments, the abutting portion is arranged in an arc shape.

[0010] In some embodiments, a dimension of the abutment portion in a width direction of the bus bar is equal to a width of the bus bar.

[0011] In some embodiments, a conductive adhesive is disposed between the abutting portion and the solder strip exposed portion, so that at least a portion of the abutting portion abuts against the solder strip exposed portion through the conductive adhesive.

[0012] In some embodiments, the battery string is formed with a plurality of the solder strip exposed portions arranged at intervals along the length direction of the bus bar, and the bus bar is provided with a plurality of the abutment portions corresponding to the plurality of solder strip exposed portions in the battery string, and each solder strip exposed portion abuts against a corresponding one of the abutment portions.

[0013] In some embodiments, the plurality of battery strings are arranged along the length direction of the bus bar, and the plurality of battery strings are connected in series through the bus bar.

[0014] In some embodiments, the insulating layer includes a coating layer, the coating layer is disposed on the battery string, the coating layer covers the back side of the battery cell and the welding strip, the coating layer is provided with an opening, and the opening forms the avoidance area.

[0015] In some embodiments, the insulating layer further includes an insulating spacer layer, the insulating spacer layer is disposed between the coating layer and the bus bar, and the insulating spacer layer is provided with a avoidance structure communicating with the opening.

[0016] In some embodiments, the insulating spacer layer is arranged in a strip shape extending along the length direction of the busbar, and the insulating spacer layer is provided with an avoidance hole corresponding to the opening, the avoidance hole forms the avoidance structure, the abutment portion extends into the avoidance hole, and the abutment portion abuts against the inner hole wall of the avoidance hole in the length direction of the busbar.

[0017] In some embodiments, the insulating spacing layer includes a plurality of insulating sublayers spaced apart along the length direction of the busbar, the opening is located between two adjacent insulating sublayers to form the avoidance structure between the two adjacent insulating sublayers, the abutting portion extends between the two adjacent insulating sublayers, and the abutting portion abuts against the two adjacent insulating sublayers in the length direction of the busbar.

[0018] The technical solution provided by the embodiments of the present disclosure has at least the following advantages:

[0019] The busbar of the photovoltaic module is hidden on the back of the battery cell, and the busbar does not occupy the area on the front of the photovoltaic module. This can maximize the laying area of ​​the battery cell and increase the illuminated area on the front of the photovoltaic module, thereby improving the maximum output power of the photovoltaic module. At the same time, by changing the shape of the busbar, an abutment portion is formed on the busbar, and the abutment portion of the busbar is abutted with the exposed portion of the welding strip. In this way, the busbar and the welding strip are welded through the abutment portion and the exposed portion of the welding strip. Not only can the displacement of the busbar caused by sudden local force be reduced during the welding process, but the busbar can also better contact with the welding strip, thereby effectively reducing the risk of hidden cracks and fragments of the battery cell in the subsequent lamination process, and reducing the possibility of poor welding between the busbar and the welding strip. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings, and these exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the structure of a back contact battery assembly in the prior art;

[0022] Figure 2 A schematic diagram of the structure of a photovoltaic module provided by an embodiment of the present disclosure;

[0023] Figure 3 for Figure 2 A cross-sectional view of a photovoltaic module;

[0024] Figure 4 for Figure 3 A partial enlarged view of the middle A;

[0025] Figure 5 for Figure 2 Schematic diagram of the structure of the photovoltaic module after removing the busbar;

[0026] Figure 6 for Figure 2 Schematic diagram of the structure of the photovoltaic module after removing the busbar and insulating spacer layer;

[0027] Figure 7 A schematic diagram of the structure of another photovoltaic module provided by an embodiment of the present disclosure;

[0028] Figure 8 for Figure 7 Schematic diagram of the structure of the photovoltaic module after removing the busbar;

[0029] Fig. 9 A schematic diagram of the structure of an opening in another photovoltaic module provided by an embodiment of the present disclosure;

[0030] Fig.10 A cross-sectional view of an abutment portion in another photovoltaic assembly provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0031] As can be seen from the background technology, reference Figure 1In the existing back contact battery assembly 1000A, the head and tail bus bars 100A and the middle bus bar 200A are still visible on the front of the back contact battery assembly 1000A. In this way, when the size of the back contact battery assembly 1000A is fixed, the head and tail bus bars 100A and the middle bus bar 200A occupy part of the front area of ​​the back contact battery assembly 1000A, thereby reducing the laying area of ​​the battery cell 300A, which seriously limits the maximum output power of the back contact battery assembly 1000A.

[0032] The present disclosure implements a photovoltaic module, in which the bus bar of the photovoltaic module is hidden on the back side of the battery cell, and the bus bar does not occupy the area of ​​the front side of the photovoltaic module, so that the laying area of ​​the battery cell can be maximized, and the illumination area of ​​the front side of the photovoltaic module can be increased, thereby improving the maximum output power of the photovoltaic module; at the same time, by changing the shape of the bus bar, an abutment portion is formed on the bus bar, and the abutment portion of the bus bar is abutted with the exposed portion of the welding strip, so that the bus bar and the welding strip are welded through the abutment portion and the exposed portion of the welding strip, which can not only reduce the displacement of the bus bar caused by sudden local force during the welding process, but also the bus bar can better contact with the welding strip, thereby effectively reducing the risk of hidden cracks and fragments of the battery cell in the subsequent lamination process, and reducing the possibility of poor welding between the bus bar and the welding strip.

[0033] 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 "multiple" is more than two, unless otherwise clearly and specifically defined. Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0036] In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. For example, if the device or element in the figure is inverted, then the element described as being "below" or "below" or "below" or "bottom" of other elements or features will be oriented "above" or "top" of the other elements or features. Therefore, the term "below" may cover both the above and below orientations depending on the context in which the term is used, which will be obvious to a person 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.

[0037] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0038] In the accompanying drawings corresponding to the embodiments of the present application, the thickness and area of ​​the layers are exaggerated for better understanding and ease of description. In addition, when describing that a component is "substantially" 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 partial edge of the entire surface.

[0039] In the description of the embodiments of the present application, when a certain component "includes" another component, unless otherwise specified, other components are not excluded, and other components may be further included. A second component is formed or provided above or on the first component, or a second component is formed or provided on the surface of the first component, or a second component is formed or provided on one side of the first component, which may include an embodiment in which the first component and the second component are in direct contact, and may also include an embodiment in which an additional component may be provided between the first component and the second component, so that the first component and the second component may not be in direct contact. For the sake of simplicity and clarity, various components may be drawn arbitrarily in different proportions. In the accompanying drawings, some layers / components may be omitted for simplicity. Unless otherwise specified, a second component is formed or provided on the surface of the first component, which means that the first component is in direct contact with the second component. Among them, the above-mentioned "component" may refer to a layer, a film, an area, a part, a structure, etc.

[0040] The terms used in the description of the various embodiments described herein are only used to describe specific embodiments and are not intended to be limiting. As used in the description of the various embodiments described and in the appended claims, "the components" are also intended to include plural forms unless the context clearly indicates otherwise. Among them, components include components such as layers, films, regions, or plates.

[0041] The following will describe the various embodiments of the present disclosure in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present disclosure, many technical details are provided in order to enable the reader to better understand the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present disclosure can be implemented.

[0042] Figures 2 to 9 Schematic diagram of the structures of various photovoltaic modules provided in the embodiments of the present disclosure.

[0043] refer to Figures 2 to 4 The photovoltaic module 1000 includes a battery string 100, an insulating layer 300 and a bus bar 400. The battery string 100 includes a plurality of battery cells 110. A welding strip 200 is arranged on the back of each battery cell 110 so as to connect the plurality of battery cells 110 in series through the welding strip 200. The insulating layer 300 is arranged on a side of the welding strip 200 away from the battery cell 110. The insulating layer 300 is provided with an avoidance area 310 so as to allow part of the welding strip 200 to be exposed from the avoidance area 310 to form a welding strip exposed portion 210. The bus bar 400 is arranged on a side of the insulating layer 300 away from the welding strip 200. The bus bar 400 is provided with a contact portion 410 protruding toward the welding strip exposed portion 210. The contact portion 410 contacts the welding strip exposed portion 210 so as to conductively connect the bus bar 400 with the welding strip 200.

[0044] Specifically, the photovoltaic module 1000 is a back contact battery module, and the photovoltaic module 1000 includes a plurality of battery strings 100 connected in series, and each battery string 100 includes a plurality of battery cells 110 connected in series. The battery cell 110 is generally a sheet structure, and the battery cell 110 has a front side (or light absorbing side) and a back side that are opposite to each other in the thickness direction of the battery cell 110. The front side of the battery cell 110 can absorb light energy and convert the light energy into electrical energy. The back side of the battery cell 110 is provided with a first grid line and a second grid line, and one of the first grid line and the second grid line is a positive grid line, and the other is a negative grid line. A plurality of welding strips 200 are arranged on the back of each battery cell 110, and the welding strips 200 are extended along the length direction of the battery string 100 (i.e., the arrangement direction of the plurality of battery cells 110 in the battery string 100), and the plurality of welding strips 200 include a plurality of first welding strips 200a and a plurality of second welding strips 200b, and the plurality of first welding strips 200a and the plurality of second welding strips 200b are alternately arranged on the back of the battery cell 110 along the width direction of the battery string 100. The first welding strip 200a is conductively connected to the first grid line, and the second welding strip 200b is conductively connected to the second grid line, so that the current of the first grid line can be conducted by the first welding strip 200a, and the current of the second grid line can also be conducted by the second welding strip 200b, and the plurality of battery cells 110 in the battery string 100 are connected in series through the first welding strip 200a and the second welding strip 200b.

[0045] The insulating layer 300 is arranged on the side of the soldering tape 200 away from the battery cell 110, and the insulating layer 300 is provided with an avoidance area 310, and the portion of the soldering tape 200 and the avoidance area 310 that are opposite to each other in the thickness direction of the battery cell 110 is the soldering tape exposed portion 210, and the avoidance area 310 exposes the soldering tape exposed portion 210 of the soldering tape 200, that is, the soldering tape exposed portion 210 is not covered by the insulating layer 300, while the portion of the soldering tape 200 except the soldering tape exposed portion 210 is covered by the insulating layer 300. The bus bar 400 is arranged on a side of the insulating layer 300 away from the welding strip 200. By changing the shape of the portion of the bus bar 400 opposite to the welding strip exposed portion 210 in the thickness direction of the battery cell 110, a contact portion 410 is formed on the bus bar 400 corresponding to the welding strip exposed portion 210. The contact portion 410 and the welding strip exposed portion 210 are opposite to each other in the thickness direction of the battery cell 110, and at least a portion of the contact portion 410 extends into the avoidance area 310 of the insulating layer 300 and abuts against the welding strip exposed portion 210, so that the bus bar 400 and the welding strip 200 can be welded through the contact portion 410 and the welding strip exposed portion 210.

[0046] The bus bar 400 is electrically connected to the welding strip 200, specifically, the bus bar 400 is electrically connected to one of the first welding strip 200a and the second welding strip 200b. Figures 2 to 4In some embodiments, the insulating layer 300 is provided with a avoidance area 310 corresponding to the first welding strip 200a, the first welding strip 200a forms a welding strip exposed portion 210, and the bus bar 400 and the first welding strip 200a are conductively connected to the welding strip exposed portion 210 through the abutting portion 410. For another example, in other embodiments, the insulating layer 300 is provided with a avoidance area 310 corresponding to the second welding strip 200b, the second welding strip 200b forms a welding strip exposed portion 210, and the bus bar 400 and the second welding strip 200b are conductively connected to the welding strip exposed portion 210 through the abutting portion 410. The following will take the bus bar 400 and the first welding strip 200a being conductively connected to the welding strip exposed portion 210 through the abutting portion 410 as an example.

[0047] The bus bar 400 of the photovoltaic module 1000 is hidden on the back of the battery cell 110, and the bus bar 400 does not occupy the area of ​​the front of the photovoltaic module 1000, so that the laying area of ​​the battery cell 110 can be maximized, and the illumination area of ​​the front of the photovoltaic module 1000 can be increased, thereby improving the maximum output power of the photovoltaic module 1000; at the same time, by changing the shape of the bus bar 400, abutment portions 410 are formed on the bus bar 400, so that the abutment portions 410 of the bus bar 400 and the photovoltaic module 1000 can be connected to each other. The exposed portion 210 of the welding strip 200 is abutted, so that the bus bar 400 and the welding strip 200 are welded through the abutting portion 410 and the exposed portion 210 of the welding strip. Not only can the displacement of the bus bar 400 caused by sudden local force during the welding process be reduced, but the bus bar 400 can also better contact with the welding strip 200, thereby effectively reducing the risk of hidden cracks and fragments of the battery cell 110 in the subsequent lamination process, and reducing the possibility of poor welding between the bus bar 400 and the welding strip 200.

[0048] The embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0049] The abutment portion 410 is formed on the busbar 400 by changing the shape of the busbar 400. There are many specific ways to form the abutment portion 410. For example, the portion of the busbar 400 opposite to the solder strip exposed portion 210 is thickened to form an abutment boss (i.e., the thickened portion) on the surface of the busbar 400 close to the solder strip exposed portion 210, and the abutment boss is the abutment portion 410; for another example, the portion of the busbar 400 opposite to the solder strip exposed portion 210 is bent and deformed, and the bent and deformed portion is the abutment portion 410.

[0050] refer to Figures 2 to 4 In some embodiments, a portion of the bus bar 400 is recessed toward the welding strip exposed portion 210 relative to a portion adjacent to the portion, and the recessed portion of the bus bar 400 forms an abutting portion 410 .

[0051] Specifically, the portion of the busbar 400 opposite to the exposed portion 210 of the welding strip is recessed toward the exposed portion 210, and the recessed portion of the busbar 400 extends into the avoidance area 310 of the insulating layer 300 and abuts against the exposed portion 210 of the welding strip, so that the recessed portion of the busbar 400 forms the abutting portion 410. This abutting portion 410 can be formed by stamping the existing busbar 400, so that the busbar 400 is partially recessed to form the abutting portion 410, and the processing cost of the busbar 400 with such a special shape is relatively low.

[0052] The specific shape of the concave abutting portion 410 is not particularly limited, and the abutting portion 410 can be set in a square, trapezoidal, or arc shape. Figures 2 to 4 In some embodiments, the abutting portion 410 is arranged in an arc shape. The arc-shaped abutting portion 410 is relatively easy to process and can also avoid stress concentration at the abutting portion 410 .

[0053] The width of the abutting portion 410 is the dimension of the abutting portion 410 in the width direction of the bus bar 400 , and the width of the abutting portion 410 may be less than or equal to the width of the bus bar 400 . Figures 2 to 4 In some embodiments, the dimension of the abutting portion 410 in the width direction of the busbar 400 is equal to the width of the busbar 400. In this way, making the abutting portion 410 as wide as possible can not only reduce the processing difficulty of the abutting portion 410, but also help increase the effective conductive area between the abutting portion 410 and the solder strip exposed portion 210.

[0054] In other embodiments, a conductive adhesive is provided between the abutting portion 410 and the solder strip exposed portion 210, so that at least a portion of the abutting portion 410 abuts against the solder strip exposed portion 210 through the conductive adhesive. Filling the conductive adhesive between the abutting portion 410 and the solder strip exposed portion 210 is beneficial to increase the effective conductive area between the abutting portion 410 and the solder strip exposed portion 210, and reduce the possibility of a cold solder joint between the abutting portion 410 and the solder strip exposed portion 210.

[0055] refer to Figure 2 , Figure 5 and Figure 6 , the battery string 100 is usually provided with a plurality of first welding strips 200a along the width direction of the battery string 100, and the plurality of first welding strips 200a are conductively connected through the bus bar 400. For example, referring to Figure 2 , Figure 5 and Figure 6In some embodiments, the battery string 100 is formed with a plurality of solder strip exposed portions 210 arranged at intervals along the length direction of the bus bar 400, and the bus bar 400 is provided with a plurality of abutment portions 410 corresponding to the plurality of solder strip exposed portions 210 in the battery string 100, and each solder strip exposed portion 210 abuts against a corresponding abutment portion 410. The insulating layer 300 is provided with a plurality of avoidance areas 310 arranged at intervals along the length direction of the bus bar 400, so that the battery string 100 is formed with a plurality of solder strip exposed portions 210 arranged at intervals along the length direction of the bus bar 400, wherein the length direction of the bus bar 400 is perpendicular or approximately perpendicular to the length direction of the solder strip 200. Such a configuration can make the laying method of the battery cell 110 more diverse, which is conducive to increasing the laying area of ​​the battery cell.

[0056] refer to Figure 2 , Figure 5 and Figure 6 , the photovoltaic module 1000 generally includes a plurality of battery strings 100, and the plurality of battery strings 100 are connected in series through a bus bar 400. For example, referring to Figure 2 , Figure 5 and Figure 6 In some embodiments, multiple battery strings 100 are arranged along the length direction of the bus bar 400, and multiple battery strings 100 are connected in series through the bus bar 400. Such an arrangement can make the laying method of the battery sheet 110 more diverse, which is conducive to increasing the laying area of ​​the battery sheet.

[0057] An insulating layer 300 is provided between the bus bar 400 and the welding strip 200, and the insulating layer 300 can insulate the bus bar 400 from the second welding strip 200b and the second grid line of the battery cell 110. Since the insulating layer 300 is provided with an avoidance area 310 corresponding to the welding strip exposed portion 210 of the first welding strip 200a, the abutting portion 410 of the bus bar 400 can extend into the avoidance area 310 and abut against the welding strip exposed portion 210 of the first welding strip 200a, thereby conductively connecting the bus bar 400 to the first welding strip 200a.

[0058] There are many specific ways to set the insulating layer 300. For example, the insulating layer 300 can be an insulating glue, an insulating tape, or an insulating film. Figure 2 , Figure 5 and Figure 6 In some embodiments, the insulating layer 300 includes a coating layer 320 , which is disposed on the battery string 100 , and covers the back side of the battery cell 110 and the welding strip 200 . The coating layer 320 is provided with an opening 321 , and the opening 321 forms an avoidance area 310 .

[0059] Specifically, the coating layer 320 is an insulating film, and the coating layer 320 is provided with a plurality of openings 321, and the plurality of openings 321 respectively form a plurality of avoidance areas 310. The specific shape of the openings 321 may not be particularly limited, and the openings 321 may be provided in the shape of a square hole, a circular hole, or a diamond hole. Figure 5 and Figure 6 In some embodiments, the opening 321 is a square hole.

[0060] The coating layer 320 can be disposed on the back of the battery cell 110 by low-temperature coating technology. For example, a layer of coating layer 320 is first laid and the coating layer 320 is perforated; the welding tape 200 is placed on the coating layer 320 after positioning; the battery cell 110 is then placed; and finally heating and pressurizing are performed so that the welding tape 200 is fixed on the battery cell 110 by the coating layer 320. The coating layer 320 is disposed on the back of the battery cell 110 by the low-temperature coating technology, which can reduce the warping of the battery cell 110, and the coating layer 320 can protect most of the grid line area of ​​the battery cell 110, so as to prevent the tin explosion caused by the welding of the bus bar 400 from short-circuiting the battery cell 110. Among them, the specific material of the coating layer 320 can be set according to actual conditions. For example, the coating layer 320 can be EVA (ethylene-vinyl acetate copolymer) film, POE (polyethylene octene elastomer) film, EP film (EVA and POE two-layer co-extruded film) or EPE film (EVA and POE three-layer co-extruded film), etc.

[0061] The coating layer 320 covers the back side of each battery cell 110 in the battery string 100, and there are many specific configuration methods for the coating layer 320. Figure 6 In some embodiments, the coating layer 320 includes a plurality of coating sub-layers 322, and the plurality of coating sub-layers 322 are arranged in a one-to-one correspondence with the plurality of battery cells 110 in the battery string 100, and each coating sub-layer 322 covers the back side of a corresponding battery cell 110. The shape and size of the coating sub-layer 322 are adapted to the shape and size of the battery cell 110, and the plurality of coating sub-layers 322 are respectively covered on the back side of the plurality of battery cells 110 in the battery string 100, and the plurality of coating sub-layers 322 are not connected into a whole. Thus, the coating layer 320 is formed by a plurality of sheet-shaped coating sub-layers 322, so that the setting area of ​​the coating layer 320 can be reduced, and the amount of the coating layer 320 used can be reduced.

[0062] For example, in other embodiments, the coating layer 320 is extended along the length direction of the battery string 100, and the size 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, which is not only conducive to ensuring 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 welding ribbon 200 connecting two adjacent battery cells 110 to be completely covered by the coating layer 320.

[0063] refer to Figures 2 to 4 In some embodiments, the insulating layer 300 further includes an insulating spacer layer 330 , which is disposed between the coating layer 320 and the bus bar 400 , and the insulating spacer layer 330 is provided with a avoidance structure 331 communicating with the opening 321 .

[0064] Specifically, an insulating spacer layer 330 is provided between the coating layer 320 and the bus bar 400, so that the thickness of the insulating layer 300 at the connection between the bus bar 400 and the welding strip 200 is the sum of the thickness of the coating layer 320 and the thickness of the insulating spacer layer 330, which is conducive to ensuring that the insulating layer 300 has sufficient thickness at the connection between the bus bar 400 and the welding strip 200, thereby ensuring the insulation effect of the insulating layer 300. Among them, the insulating spacer layer 330 can be an insulating glue, an insulating tape or an insulating film.

[0065] The thermoplasticity of the coating layer 320 is usually better than that of the insulating spacer layer 330, which not only ensures that the coating layer 320 has a good coating effect, but also helps to ensure that the insulating layer 300 has a sufficient thickness at the connection between the bus bar 400 and the welding ribbon 200 through the provision of the insulating spacer layer 330. The specific material of the insulating spacer layer 330 can be set according to actual conditions, for example, the insulating spacer layer 330 can be a PET (polyethylene terephthalate) film or a PI (polyimide) film.

[0066] The insulating spacer layer 330 is used to ensure that the insulating layer 300 has sufficient thickness at the connection between the bus bar 400 and the welding ribbon 200, and the specific thickness of the insulating spacer layer 330 can be set according to actual conditions. In some embodiments, the thickness of the insulating spacer layer 330 is 0.03-0.2 mm.

[0067] Specifically, the thickness of the insulating spacer layer 330 is 0.03 to 0.2 mm. For example, the thickness of the insulating spacer layer 330 can be 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm or 0.2 mm, etc. In this way, by optimizing the value range of the thickness of the insulating spacer layer 330, it is possible to ensure that the insulating layer 300 has sufficient thickness at the connection between the bus bar 400 and the welding strip 200. This can not only prevent the thickness of the insulating spacer layer 330 from being too thin, making it inconvenient to operate when pasting the insulating spacer layer 330, and it is easy to deform when pulling, and there is a risk of damage during long-term insulation. It can also prevent the thickness of the insulating spacer layer 330 from being too thick, resulting in a large height difference between the bus bar 400 and the welding strip 200, causing the risk of hidden cracks and fragments of the battery cell 110 during the subsequent lamination process.

[0068] The insulating spacer layer 330 is disposed between the coating layer 320 and the busbar 400 . The insulating spacer layer 330 is generally arranged along the length direction of the busbar 400 . The dimension of the insulating spacer layer 330 in the width direction of the busbar 400 is greater than or equal to the width of the busbar 400 .

[0069] refer to Figure 2 and Figure 5 In some embodiments, the insulating spacer layer 330 includes a plurality of insulating sublayers 332 spaced apart along the length direction of the busbar 400 , and the opening 321 is located between two adjacent insulating sublayers 332 to form an avoidance structure 331 between the two adjacent insulating sublayers 332 .

[0070] Specifically, a single insulating sublayer 332 is arranged in a block shape, and a plurality of insulating sublayers 332 are arranged at intervals along the length direction of the busbar 400 to form an insulating spacer layer 330, and the plurality of insulating sublayers 332 and the plurality of openings 321 of the coating layer 320 are arranged alternately along the length direction of the busbar 400, and the gap between the two insulating sublayers 332 on both sides of each opening 321 forms an avoidance structure 331, so that the insulating spacer layer 330 forms a plurality of avoidance structures 331 corresponding to the plurality of openings 321 of the coating layer 320, and the spacing between two adjacent insulating sublayers 332 is greater than or equal to the size of the opening 321 in the length direction of the busbar 400. In this way, by forming the insulating spacer layer 330 with a plurality of insulating sublayers 332, the setting area of ​​the insulating spacer layer 330 can be reduced, and the amount of the insulating spacer layer 330 can be reduced.

[0071] The number of insulating sublayers 332 may be less than the number of openings 321; the number of insulating sublayers 332 may be equal to the number of openings 321; the number of insulating sublayers 332 may be greater than the number of openings 321. Figure 2 and Figure 5 In some embodiments, a plurality of openings 321 are arranged at intervals along the length direction of the busbar 400 , and each opening 321 is provided with insulating sublayers 332 on both sides of the busbar 400 in the length direction.

[0072] Specifically, the number of insulating sublayers 332 is greater than the number of openings 321, so that two insulating sublayers 332 can be distributed on both sides of each opening 321. In this way, the insulating sublayers 332 are arranged on both sides of each opening 321, which can reduce the gap between the bus bar 400 and the coating layer 320, so that the contact position between the bus bar 400 and the welding strip 200 can be relatively flat.

[0073] refer to Fig.10 In some embodiments, the abutting portion 410 extends between two adjacent insulating sub-layers 332 , and the abutting portion 410 abuts against the two adjacent insulating sub-layers 332 in the length direction of the busbar 400 .

[0074] Specifically, the dimension of the abutment portion 410 in the length direction of the busbar 400 is the length of the abutment portion 410, and the length of the longest part of the abutment portion 410 is equal to or approximately equal to the spacing between two adjacent insulating sub-layers 332, so that the abutment portion 410 can abut against the two adjacent insulating sub-layers 332 in the length direction of the busbar 400, thereby reducing the displacement of the busbar 400 in the length direction of the busbar 400 due to sudden local force.

[0075] refer to Figure 7 and Figure 8 In 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 avoidance holes 331 a corresponding to the openings 321 , and the avoidance holes 331 a form an avoidance structure 331 .

[0076] 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 arranged in a long strip shape. 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 a plurality of avoidance holes 331a corresponding to the plurality of openings 321 of the coating layer 320, and each avoidance hole 331a is connected to a corresponding opening 321. The size of the avoidance hole 331a may be greater than or equal to the size of the opening 321, and the shape of the avoidance hole 331a is generally adapted to the shape of the opening 321. For example, refer to Figure 7 and Figure 8 In some embodiments, the avoidance hole 331a and the opening 321 are both square holes. By setting the insulating spacer layer 330 in a strip shape, a gap between the bus bar 400 and the coating layer 320 can be avoided, so that the contact position between the bus bar 400 and the welding strip 200 can be relatively flat.

[0077] refer to Fig.10 In some embodiments, the abutting portion 410 extends into the avoidance hole 331 a , and the abutting portion 410 abuts against the inner hole wall of the avoidance hole 331 a in the length direction of the busbar 400 .

[0078] Specifically, the dimension of the avoidance hole 331a in the width direction of the welding strip 200 (i.e., the length direction of the busbar 400) is the width of the avoidance hole 331a. The longest length of the abutment portion 410 is equal to or approximately equal to the width of the avoidance hole 331a, so that the abutment portion 410 can abut against two inner hole walls of the avoidance hole 331a opposite to each other in the length direction of the busbar 400, thereby reducing the displacement of the busbar 400 in the length direction of the busbar 400 due to sudden local force.

[0079] In other embodiments, the abutting portion 410 extends into the avoidance hole 331 a , and the abutting portion 410 abuts against an inner hole wall of the avoidance hole 331 a in the width direction of the busbar 400 .

[0080] Specifically, the dimension of the avoidance hole 331a in the length direction of the welding strip 200 (i.e., the width direction of the busbar 400) is the length of the avoidance hole 331a. The width of the widest part of the abutment portion 410 is equal to or approximately equal to the length of the avoidance hole 331a, so that the abutment portion 410 can abut against two inner hole walls of the avoidance hole 331a opposite to each other in the width direction of the busbar 400, thereby reducing the displacement of the busbar 400 in the width direction of the busbar 400 due to sudden local force.

[0081] The thickness of the soldering tape 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 soldering tape 200 may be less than the thickness of the coating layer 320; the thickness of the soldering tape 200 may also be equal to the thickness of the coating layer 320; the thickness of the soldering tape 200 may also be greater than the thickness of the coating layer 320. Figure 4 In some embodiments, the surface of the exposed portion 210 of the solder strip away from the battery cell 110 is located on the side of the coating layer 320 close to the insulating spacer layer 330 , and the surface of the insulating spacer layer 330 close to the bus bar 400 is located on the side of the exposed portion 210 of the solder strip away from the battery cell 110 .

[0082] Specifically, the thickness of the welding ribbon 200 may be less than the thickness of the coating layer 320, so that the surface of the welding ribbon exposed portion 210 away from the battery cell 110 is located on the side of the coating layer 320 close to the insulating spacer layer 330, that is, the welding ribbon exposed portion 210 extends out of the opening 321 of the coating layer 320 toward the bus bar 400. The thickness of the welding 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 close to the bus bar 400 is located on the side of the welding ribbon exposed portion 210 away from the battery cell 110, that is, the portion of the welding ribbon exposed portion 210 extending out of the opening 321 is located within the avoidance structure 331 of the insulating spacer layer 330.

[0083] refer to Fig. 9 The back of the cell 110 is usually provided with an insulating glue 120, which can insulate the first grid line and the second grid line of the cell 110. Since the back of the cell 110 is provided with a coating layer 320, the coating layer 320 can protect most of the grid line area of ​​the cell 110, so that the amount of the insulating glue 120 can be reduced.

[0084] refer to Fig. 9 In some embodiments, an insulating glue 120 is arranged between the soldering ribbon 200 and the back side of the battery cell 110, and the size of the insulating glue 120 in the width direction of the soldering ribbon 200 is greater than or equal to the size of the opening 321 in the width direction of the soldering ribbon 200, so that the projection of the opening 321 on the back side of the battery cell 110 is located on the insulating glue 120.

[0085] Specifically, the size of the insulating glue 120 in the width direction of the welding strip 200 is the width of the insulating glue 120, and the size of the opening 321 in the width direction of the welding strip 200 is the width of the opening 321. The width of the opening 321 is greater than the width of the welding strip 200, and the width of the insulating glue 120 is greater than or equal to the width of the opening 321, so that the portion of the back of the battery cell 110 exposed from the opening 321 is the insulating glue 120 except for the exposed portion 210 of the welding strip, that is, the area of ​​the back of the battery cell 110 except for the exposed portion 210 of the welding strip is covered by the insulating glue 120 and the coating layer 320. In this way, the coating layer 320 has a hole to expose the exposed portion 210 of the welding strip. As long as the opening position of the coating layer 320 is set in place, the bus bar 400 is protected by the insulating glue 120 and the coating layer 320 after soldering and tinning, and there will be no problem of foreign matter overlapping the grid line of the battery cell 110, causing the battery cell 110 to short-circuit.

[0086] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for realizing the present disclosure, and in practical applications, various changes can be made to them in form and details without departing from the spirit and scope of the present disclosure. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, so the protection scope of the present disclosure shall be based on the scope defined in the claims.

Claims

1. A photovoltaic module, characterized in that: include: A battery string, the battery string comprising a plurality of battery cells, a welding strip being arranged on the back of each battery cell, so as to connect the plurality of battery cells in series through the welding strip; An insulating layer, the insulating layer is arranged on a side of the soldering strip away from the battery cell, and the insulating layer is provided with an avoidance area so that a portion of the soldering strip is exposed from the avoidance area to form a soldering strip exposed portion; A bus bar is arranged on a side of the insulating layer away from the welding strip, and the bus bar is provided with an abutment portion protruding toward the exposed portion of the welding strip, and the abutment portion abuts against the exposed portion of the welding strip to conductively connect the bus bar to the welding strip.

2. The photovoltaic module according to claim 1, characterized in that: A portion of the bus bar is recessed relative to a portion adjacent to the portion toward the welding strip exposed portion, and the recessed portion of the bus bar forms the abutting portion.

3. The photovoltaic module according to claim 2, characterized in that: The abutting portion is arranged in an arc shape.

4. The photovoltaic module according to claim 2, characterized in that: The dimension of the abutment portion in the width direction of the bus bar is equal to the width of the bus bar.

5. The photovoltaic module according to claim 1, characterized in that: Conductive glue is arranged between the abutting portion and the solder strip exposed portion, so that at least a portion of the abutting portion abuts against the solder strip exposed portion through the conductive glue.

6. The photovoltaic module according to claim 1, characterized in that: The battery string is formed with a plurality of the solder strip exposed portions arranged at intervals along the length direction of the bus bar, and the bus bar is provided with a plurality of the abutment portions corresponding to the plurality of solder strip exposed portions in the battery string, and each solder strip exposed portion abuts against a corresponding abutment portion.

7. The photovoltaic module according to claim 1, characterized in that: The plurality of battery strings are arranged along the length direction of the bus bar, and the plurality of battery strings are connected in series through the bus bar.

8. The photovoltaic module according to claim 1, characterized in that: The insulating layer includes a coating layer, which is disposed on the battery string, covers the back side of the battery cell and the welding strip, and is provided with openings, which form the avoidance area.

9. The photovoltaic module according to claim 8, characterized in that: The insulating layer further comprises an insulating spacer layer, wherein the insulating spacer layer is arranged between the coating layer and the bus bar, and the insulating spacer layer is provided with a avoidance structure communicating with the opening.

10. The photovoltaic module according to claim 9, characterized in that: The insulating spacer layer is arranged in a strip shape extending along the length direction of the busbar, the insulating spacer layer is provided with a avoidance hole corresponding to the opening, the avoidance hole forms the avoidance structure, the abutment portion extends into the avoidance hole, and the abutment portion abuts against the inner hole wall of the avoidance hole in the length direction of the busbar; or, The insulating spacer layer includes a plurality of insulating sublayers spaced apart along the length direction of the busbar, the opening is located between two adjacent insulating sublayers to form the avoidance structure between the two adjacent insulating sublayers, the abutting portion extends between the two adjacent insulating sublayers, and the abutting portion abuts against the two adjacent insulating sublayers in the length direction of the busbar.

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