Preparation method of photovoltaic module and photovoltaic module

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a preparation method of a photovoltaic module and the photovoltaic module, and the preparation method comprises the steps: providing at least two battery pieces and a plurality of welding strips, placing the welding strips in preset areas of the battery pieces, and enabling the parts, located in the preset areas, of the battery pieces to be provided with conductive parts; a pre-bonding film is provided, the side, facing the battery piece, of the pre-bonding film is provided with a plurality of positioning grooves, and each welding strip at least corresponds to one positioning groove; covering one side, far away from the battery piece, of the welding strip with a pre-bonding film, wherein at least part of the welding strip is accommodated in the positioning groove; a pressing plate is provided, the pressing plate is arranged on the side, away from the battery pieces, of the pre-bonding film, the welding strip is bonded to the preset area through the pre-bonding film through the pressing plate, and the multiple battery pieces are connected into a to-be-welded battery string; the to-be-welded battery string is sent to a laminating stage, and the laminating temperature is larger than or equal to the melting point of the outer layer of the welding strip, so that alloying of the welding strip and the conductive part is achieved. The embodiment of the invention is at least beneficial to reducing the risk of warping of the battery piece while avoiding the deviation of the welding strip.

Description

Technical Field

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

[0002] At present, in the preparation process of photovoltaic modules, the welding strip and the battery cell are usually welded at high temperature by infrared or laser, and the instantaneous high temperature is used to achieve alloy welding of the welding strip and the electrode paste on the battery cell. However, due to the high welding temperature, the thermal expansion coefficients of different objects are different, which makes the shrinkage of the welding strip much greater than that of the battery cell. Since the welding strip and the battery cell have been welded and fixed and cannot change in displacement, the welding strip shrinks and pulls the battery cell to form a single-sided warping, which is also easy to cause defects such as hidden cracks in the battery cell in subsequent processes.

[0003] In addition, before the alloying welding between the soldering ribbon and the electrode paste on the battery cell is achieved, the soldering ribbon is easily offset on the battery cell, resulting in inaccurate positioning of the soldering ribbon and the grid lines on the battery cell, causing a virtual connection between the soldering ribbon and the battery cell.

[0004] Therefore, the current preparation process of photovoltaic modules still needs to be improved. Summary of the invention

[0005] The embodiments of the present disclosure provide a method for preparing a photovoltaic module and a photovoltaic module, which are at least beneficial for reducing the risk of warping of a cell while avoiding deviation of a welding strip.

[0006] According to some embodiments of the present disclosure, on the one hand, the embodiments of the present disclosure provide a method for preparing a photovoltaic module, comprising: providing at least two battery cells and multiple welding strips, and placing the welding strips in a preset area of ​​the battery cell, the portion of the battery cell located in the preset area having a conductive portion; providing a pre-bonding film, the pre-bonding film having multiple positioning grooves on a side facing the battery cell, a single welding strip corresponding to at least one of the positioning grooves; covering the pre-bonding film on a side of the welding strip away from the battery cell, the positioning groove accommodating at least a portion of the welding strip; providing a pressing plate, arranging the pressing plate on a side of the pre-bonding film away from the battery cell, and applying pressure to the pre-bonding film through the pressing plate, so that the pre-bonding film bonds the welding strip to the preset area, and connects multiple battery cells into a battery string to be welded; sending the battery string to be welded into a lamination stage, the lamination temperature of the lamination stage being greater than or equal to the melting point of the material constituting the outer layer of the welding strip, so as to achieve alloying of the welding strip and the conductive portion.

[0007] In some embodiments, the positioning groove is a long strip-shaped groove extending along a first direction, the positioning groove corresponds to the welding strip one by one, and the first direction is the extension direction of the welding strip.

[0008] In some embodiments, the conductive portion is a soldering pad, and a single soldering strip is opposite to a plurality of soldering pads arranged at intervals along a first direction along a second direction, the first direction is an extension direction of the soldering strip, and the second direction is a thickness direction of the battery cell; the pre-bonding film includes a main body portion and a positioning portion, the positioning portion is located on a side of the main body portion close to the battery cell, and the positioning portion has a positioning groove therein, and the positioning groove and the soldering pad are opposite one by one along the second direction.

[0009] In some embodiments, along a third direction, a distance between the welding strip and the positioning groove is 0.1 mm to 0.3 mm, and the third direction is perpendicular to an extending direction of the welding strip.

[0010] In some embodiments, the pressing plate has a protrusion on one side facing the pre-bonding film, and a single protrusion is directly opposite to at least one positioning groove along a second direction, and the second direction is a thickness direction of the battery cell.

[0011] In some embodiments, the protrusions are long strip-shaped protrusions extending along the first direction, and the protrusions correspond to the welding strips one by one.

[0012] In some embodiments, the plurality of raised portions are arranged in an array along the first direction and a third direction, and the third direction is perpendicular to the extension direction of the welding strip; a single welding strip is directly opposite to the plurality of positioning portions arranged at intervals along the first direction along the second direction.

[0013] In some embodiments, the material constituting the outer layer of the solder strip includes tin, the lamination temperature is 140° C. to 170° C.; and / or the duration of the lamination stage is 4 min to 5 min.

[0014] In some embodiments, the preparation method also includes: providing a base plate, the base plate is used to support the side of the battery cell away from the welding strip, the base plate has a first heating part or the pressure plate has a second heating part; in the step of applying pressure to the pre-adhesive film through the pressure plate, the battery cell, the welding strip and the pre-adhesive film are heated by the first heating part or the second heating part.

[0015] According to some embodiments of the present disclosure, on the other hand, embodiments of the present disclosure further provide a photovoltaic component, comprising: a photovoltaic component formed by the method for preparing a photovoltaic component as described in any one of the above items.

[0016] The technical solution provided by the embodiments of the present disclosure has at least the following advantages:

[0017] First, the pre-adhesive film is designed to have multiple positioning grooves on the side facing the battery cell, and a single solder strip corresponds to at least one positioning groove. When the pre-adhesive film is subsequently covered on the side of the solder strip away from the battery cell, it is beneficial for the positioning groove to accommodate at least part of the solder strip. In other words, after the solder strip is placed in the preset area of ​​the battery cell, not only the top surface of the solder strip is in contact and connection with the pre-adhesive film, but also the two sides of the solder strip are in contact and connection with the pre-adhesive film. In this way, in the subsequent stage of applying force and lamination to the pre-adhesive film using a pressure plate, the pre-adhesive film located on both sides of the solder strip can not only effectively avoid the deviation of the solder strip, but also can be bonded to the battery cell based on the pressure applied by the pressure plate, so that the solder strip can be locked in the preset area with the help of the bonding between the pre-adhesive film and the battery cell, ensuring that the solder strip is in contact and connection with the conductive part on the preset area.

[0018] Secondly, before realizing the alloying of the soldering tape and the conductive part, the soldering tape is first bonded to the preset area of ​​the battery cell by using the cooperation of the pre-bonding film and the pressing plate to ensure that the soldering tape is in contact with the conductive part on the preset area, so as to avoid the soldering tape being offset relative to the battery cell in the subsequent lamination stage, thereby avoiding the problem of virtual connection between the soldering tape and the battery cell in the lamination stage. In addition, based on the advance bonding and pressing of the soldering tape, the offset of the soldering tape is avoided. On this basis, the lamination stage does not require the aid of instantaneous high-temperature welding. As long as the lamination temperature in the lamination stage is greater than or equal to the melting point of the material constituting the outer layer of the soldering tape, the alloying of the soldering tape and the conductive part can be realized, which is conducive to reducing the risk of warping of the battery cell by lowering the welding temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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.

[0020] Figure 1 A schematic diagram of a process for preparing a photovoltaic module provided in one embodiment of the present disclosure;

[0021] Figure 2 A schematic diagram of a partial top view of the structure of a cell in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure;

[0022] Figure 3 Another partial top view structural schematic diagram of a cell in the method for preparing a photovoltaic module provided in one embodiment of the present disclosure;

[0023] Figure 4 A schematic diagram of a partial cross-sectional structure of a welding strip in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure;

[0024] Figure 5 A schematic diagram of a partial upward-facing structure of a pre-bonding film in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure;

[0025] Figure 6 A schematic diagram of a first partial cross-sectional structure in which the pre-bonding film is not bonded to the welding ribbon and the solar cell in the method for preparing a photovoltaic module provided by an embodiment of the present disclosure;

[0026] Figure 7 A schematic diagram of a second partial cross-sectional structure in which the pre-bonding film is not bonded to the welding ribbon and the solar cell in the method for preparing a photovoltaic module provided by an embodiment of the present disclosure;

[0027] Figure 8 A schematic diagram of another partial upward-facing structure of a pre-bonding film in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure;

[0028] Fig. 9 A schematic diagram of a third partial cross-sectional structure in which the pre-bonding film is not bonded to the welding ribbon and the solar cell in the method for preparing a photovoltaic module provided by an embodiment of the present disclosure;

[0029] Fig.10 A schematic diagram of a first partial cross-sectional structure in which a pressing plate is not pressed down onto a pre-bonding film in a method for preparing a photovoltaic module provided by an embodiment of the present disclosure;

[0030] Fig.11 A schematic diagram of a second partial cross-sectional structure in which a pressing plate is not pressed down onto a pre-bonding film in a method for preparing a photovoltaic module provided by an embodiment of the present disclosure;

[0031] Fig.12 A schematic diagram of a third partial cross-sectional structure in which a pressing plate is not pressed down onto a pre-bonding film in a method for preparing a photovoltaic module provided by an embodiment of the present disclosure;

[0032] Fig.13 A schematic diagram of a partial upward-facing structure of a pressure plate in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure;

[0033] Fig.14 A schematic diagram of another partial upward-facing structure of a pressure plate in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure;

[0034] Fig.15 A schematic diagram of a partial three-dimensional structure of a photovoltaic assembly provided by another embodiment of the present disclosure;

[0035] Fig.16 for Fig.15A schematic diagram of a local cross-sectional structure along a first cross-sectional direction AA1;

[0036] Fig.17 for Fig.15 A schematic diagram of a local cross-sectional structure along the second cross-sectional direction BB1. DETAILED DESCRIPTION

[0037] As can be seen from the background technology, the preparation process of photovoltaic modules still needs to be improved to improve the warping risk of solar cells and the problem of virtual connection between solder strips and solar cells.

[0038] The present disclosure provides a method for preparing a photovoltaic module and a photovoltaic module. In the preparation method, first, a pre-adhesive film is designed to have a plurality of positioning grooves on the side facing the battery cell, and a single solder strip corresponds to at least one positioning groove. When the pre-adhesive film is subsequently covered on the side of the solder strip away from the battery cell, it is beneficial for the positioning groove to accommodate at least part of the solder strip, so that not only the top surface of the solder strip is in contact with the pre-adhesive film, but also the two sides of the solder strip are in contact with the pre-adhesive film. In this way, in the subsequent stage of applying force to the pre-adhesive film and laminating, the pre-adhesive film on both sides of the solder strip can also be bonded to the battery cell based on the pressure applied by the press plate, so as to lock the solder strip in a preset area and ensure that the solder strip is in contact with the conductive part on the preset area. Secondly, before realizing the alloying of the soldering tape and the conductive part, the soldering tape is first bonded to a preset area of ​​the battery cell by using the cooperation of the pre-bonding film and the pressing plate to avoid the soldering tape being offset relative to the battery cell in the subsequent lamination stage. On this basis, the lamination stage does not require the aid of instantaneous high-temperature welding. The alloying of the soldering tape and the conductive part can be realized as long as the lamination temperature in the lamination stage is greater than or equal to the melting point of the material constituting the outer layer of the soldering tape, which is beneficial to reduce the risk of warping of the battery cell by lowering the welding temperature.

[0039] In the description of the embodiments of the present disclosure, 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 disclosure, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0040] 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 disclosure. The appearance of the phrase in various places 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.

[0041] In the description of the embodiments of the present disclosure, 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 may 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.

[0042] In the description of the embodiments of the present disclosure, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0043] In the description of the embodiments of the present disclosure, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present disclosure and simplifying the description. They do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the embodiments of the present disclosure.

[0044] In the description of the embodiments of the present disclosure, 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 disclosure can be understood according to the specific circumstances.

[0045] In the accompanying drawings corresponding to the embodiments of the present disclosure, the thickness and area of ​​the layers are magnified for better understanding and ease of description. When describing a component (such as a layer, a film, a region or a substrate) on another component or on the surface of another component, the component may be "directly" located on the surface of the other component, or a third component may be present between the two components. On the contrary, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component as being "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.

[0046] In the description of the embodiments of the present disclosure, when a component "includes" another component, unless otherwise specified, other components are not excluded, and other components may be further included. In addition, when a component such as a layer, a film, a region, or a plate is referred to as being "on / located on" another component, it may be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may exist in between. In addition, when a component such as a layer, a film, a region, a plate, etc. is "directly located on" another component, or when a component such as a layer, a film, a region, a plate, etc. is located on the surface of another component, it means that no other components are located in between.

[0047] 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.

[0048] 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 embodiments of 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 embodiments of the present disclosure can be implemented.

[0049] An embodiment of the present disclosure provides a method for preparing a photovoltaic module. The method for preparing a photovoltaic module provided by an embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0050] refer to Figures 1 to 14 , Figure 1 A schematic diagram of a process for preparing a photovoltaic module according to an embodiment of the present disclosure is provided. Figures 2 to 14 As will be described later, the method for preparing a photovoltaic module includes at least the following steps:

[0051] S1: providing at least two battery cells 100 and a plurality of solder strips 101 , and placing the solder strips 101 in a predetermined area 110 of the battery cell 100 , wherein the portion of the battery cell 100 located in the predetermined area 110 has a conductive portion 120 .

[0052] S2: providing a pre-bonding film 102 , wherein the pre-bonding film 102 has a plurality of positioning grooves 112 on a side facing the battery cell 100 , and a single welding strip 101 corresponds to at least one positioning groove 112 .

[0053] S3: Cover the pre-bonding film 102 on the side of the soldering ribbon 101 away from the battery cell 100 , and the positioning groove 112 accommodates at least a portion of the soldering ribbon 101 .

[0054] S4: Provide a pressing plate 103, set the pressing plate 103 on the side of the pre-bonding film 102 away from the battery cell 100, and apply pressure to the pre-bonding film 102 through the pressing plate 103, so that the pre-bonding film 102 bonds the welding strip 101 to the preset area 110, and connects multiple battery cells 100 into a battery string to be welded.

[0055] S5: sending the battery string to be welded into a lamination stage, wherein the lamination temperature of the lamination stage is greater than or equal to the melting point of the material constituting the outer layer 111 of the welding strip 101 , so as to achieve alloying of the welding strip 101 and the conductive part 120 .

[0056] It is worth noting that before alloying the soldering tape 101 and the conductive part 120 through step S5, steps S2 to S4 are designed first, and the soldering tape 101 is bonded to the preset area 110 of the battery cell 100 in advance by utilizing the cooperation of the pre-bonding film 102 and the pressing plate 103, to ensure that the soldering tape 101 is in contact and connected with the conductive part 120 on the preset area 110, thereby avoiding the soldering tape 101 from being offset relative to the battery cell 100 in the subsequent lamination stage, i.e., step S5, for example, avoiding the soldering tape 101 from being offset to not being in contact with the conductive part 120, thereby avoiding the problem that the soldering tape 101 cannot be alloyed and welded with the conductive part 120 during the lamination stage, i.e., the soldering tape 101 and the battery cell 100 are virtually connected.

[0057] Furthermore, in step S2, the pre-adhesive film 102 is designed to have a plurality of positioning grooves 112 on the side facing the battery cell 100, and a single solder strip 101 corresponds to at least one positioning groove 112. This is conducive to allowing the positioning groove 112 in step S3 to accommodate at least a portion of the solder strip 101, that is, the solder strip 101 is clamped by the positioning groove 112. In other words, after the solder strip 101 is placed in the preset area 110 of the battery cell 100, not only the top surface of the solder strip 101 is in contact and connected with the pre-adhesive film 102, but also the two sides of the solder strip 101 are in contact and connected with the pre-adhesive film 102. In this way, in step S4, the pre-adhesive film 102 located on both sides of the soldering tape 101 can not only effectively prevent the deviation of the soldering tape 101, but also can be bonded to the battery cell 100 based on the pressure applied by the pressure plate 103. Therefore, the soldering tape 101 can be locked on the preset area 110 with the help of the bonding between the pre-adhesive film 102 and the battery cell 100, ensuring that the soldering tape 101 is in contact and connected with the conductive part 120 on the preset area 110.

[0058] In addition, based on the bonding, fixing and pressing process of the soldering strip 101 in steps S2 to S4, the deviation of the soldering strip 101 is avoided, and the soldering strip 101 is ensured to be in contact with the conductive part 120 on the preset area 110. On this basis, in the lamination stage, i.e., step S5, there is no need to resort to instantaneous high-temperature welding. As long as the lamination temperature in the lamination stage is greater than or equal to the melting point of the material constituting the outer layer 111 of the soldering strip 101, the soldering strip 101 and the conductive part 120 can be alloyed to weld the soldering strip 101 to the battery cell 100, which is conducive to reducing the risk of warping of the battery cell 100 by lowering the welding temperature.

[0059] It should be noted that, in order to illustrate the preset area 110 on the battery cell 100, Figure 1 In the figure, a dotted line is used to divide a preset area 110 on the battery cell 100 .

[0060] The steps in the method for preparing a photovoltaic module provided in one embodiment of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0061] The conductive portion 120 of the portion of the battery cell 100 provided in step S1 located in the predetermined area 110 includes at least the following two embodiments.

[0062] In some embodiments, reference Figure 2 , Figure 2 A partial top view of a cell in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure is provided, wherein the cell 100 is a BC cell (Back Contact) without a main grid. Based on this, the conductive portion 120 of the cell 100 located in the preset area 110 can be a pad 120a for welding with the welding strip 101.

[0063] In other embodiments, reference Figure 3 , Figure 3 Another partial top view structural diagram of a cell in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure, the cell 100 is a cell with a main grid, and the conductive portion 120 of the portion of the cell 100 located in the preset area 110 can be a main grid 120b welded to the welding ribbon 101. In some examples, the cell with a main grid includes but is not limited to one of a BC cell (Back Contact), a PERC cell (Passivated Emitter Rear Cell), a TOPCon cell (Tunnel Oxide Passivated Contact), or a HIT / HJT cell (Heterojunction Technology).

[0064] In the above two embodiments, the BC battery includes an IBC battery (Interdigitated Back Contact), an HBC battery (Heterojunction Back Contact), a TBC battery (TOPCon Back Contact) or an HPBC battery (Hybrid Passivated Back Contact), etc.

[0065] In some embodiments, reference Figure 4 , Figure 4 A schematic diagram of a partial cross-sectional structure of a soldering tape in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure, wherein the material constituting the outer layer 111 of the soldering tape 101 includes tin, and the lamination temperature is 140°C to 170°C. For example, the lamination temperature may be 143°C, 145°C, 148°C, 150°C, 152°C, 155°C, 157°C, 160°C, 162°C, 165°C or 168°C, etc.

[0066] It is worth noting that in step S5, i.e., the lamination stage, in order to achieve alloying of the soldering ribbon 101 and the conductive part 120, the lamination temperature in the lamination stage is lower than that in high-temperature welding by infrared or laser, and only needs to be greater than or equal to the melting point of the material constituting the outer layer 111 of the soldering ribbon 101. Moreover, the soldering ribbon used in step S5 is different from the soldering ribbon used in high-temperature welding by infrared or laser, etc. The melting point of the outer layer material of the soldering ribbon used in high-temperature welding by infrared or laser is generally higher than 180°C, but the melting point of the outer layer of the soldering ribbon used in step S5 is lower, which is conducive to further reducing the lamination temperature in the lamination stage, so that the lamination temperature is 140°C to 170°C, thereby helping to reduce the risk of warping of the battery cell 100 by lowering the welding temperature.

[0067] In some embodiments, the duration of the lamination stage may be 4 to 5 minutes. For example, the duration of the lamination stage may be 245 seconds, 250 seconds, 255 seconds, 260 seconds, 265 seconds, 270 seconds, 275 seconds, 280 seconds, 285 seconds, 290 seconds or 295 seconds. In this way, when the lamination temperature in the lamination stage is low, it is beneficial to fully alloy the welding ribbon 101 and the conductive part 120 on the battery cell 100 through a long and slow lamination time, so as to further improve the welding efficiency between the welding ribbon 101 and the conductive part 120, thereby facilitating the improvement of the yield of the photovoltaic module finally formed.

[0068] In some cases, the soldering ribbon 101 further includes an inner layer 121 wrapped by the outer layer 111. In some examples, the material of the outer layer 111 and the material of the inner layer 121 may be different, and the material of the inner layer 121 may be a conductive material such as copper, silver, or aluminum; in other examples, the material of the outer layer and the material of the inner layer may be the same.

[0069] It should be noted that, in order to illustrate the outer layer 111 and the inner layer 121 in the welding strip 101, Figure 4 The outer layer 111 and the inner layer 121 are divided by dashed lines; in addition, Figure 4 The cross-sectional shape of the soldering ribbon 101 is only taken as an example to be circular. In practical applications, the cross-sectional shape of the soldering ribbon may also be rectangular or triangular, etc. The present disclosure does not limit the cross-sectional shape of the soldering ribbon in an embodiment. To facilitate the description of the positioning groove 112, the cross-sectional shape of the soldering ribbon 101 is circular in the subsequent drawings to illustrate the pre-bonding film 102.

[0070] The following describes in detail the situation where a single soldering ribbon 101 corresponds to at least one positioning groove 112 in the pre-adhesive film 102 .

[0071] In some embodiments, in conjunction with reference Figure 5 and Figure 6 , or refer to Figure 7 The positioning groove 112 may be a long strip-shaped groove extending along the first direction X. The positioning groove 112 corresponds to the solder strip 101 one by one, and the first direction X is the extending direction of the solder strip 101. In this way, after the pre-bonding film 102 is covered on the solder strip 101 in step S3, one positioning groove 112 engages one solder strip 101, and the solder strip 101 can be quickly fixed on the preset area 110 of the battery cell 100, and the solder strip 101 is prevented from being offset relative to the battery cell 100.

[0072] in, Figure 5 A schematic diagram of a partial upward structure of a pre-bonding film in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure is shown. Figure 6 This is a schematic diagram of a first partial cross-sectional structure in which the pre-bonding film is not bonded to the soldering tape and the solar cell in the method for preparing a photovoltaic module provided by an embodiment of the present disclosure, Figure 7 A schematic diagram of a second partial cross-sectional structure in which the pre-bonding film is not bonded to the welding ribbon and the solar cell in the method for preparing a photovoltaic module provided in one embodiment of the present disclosure.

[0073] In some cases, along the first direction X, the length of the positioning groove 112 is greater than or equal to the length of the battery cell 100. In other words, the positioning groove 112 passes through the pre-bonding film 102 along the first direction X, so that a single positioning groove 112 can accommodate the entire welding strip 101 located on the battery cell 100, which is also beneficial to reduce the risk of bending of the welding strip 101 due to external force.

[0074] In some examples, combined with reference Figure 5 and Figure 6 The positioning groove 112, which is a long strip-shaped groove, is embedded in the pre-bonding film 102. In other words, along the second direction Y, the thickness of the portion of the pre-bonding film 102 that faces the welding strip 101 is smaller than the thickness of the portion of the pre-bonding film 102 that does not face the welding strip 101.

[0075] In other examples, reference Figure 7 The pre-bonding film 102 includes a film body 142 and a positioning strip 152. The positioning strip 152 extends along the first direction X, and the positioning strip 152 is located on the side of the film body 142 close to the solar cell 100. The positioning groove 112, which is a long strip-shaped groove, is embedded in the positioning strip 152. In other words, different parts of the positioning strip 152 have different thicknesses in the second direction Y to form the positioning groove 112 in the positioning strip 152, and the thickness of the film body 142 is less than the average thickness of the positioning strip 152, which is conducive to fixing the welding strip 101 in the preset area 110 in advance with the help of the pre-bonding film 102, while reducing the amount of glue required for the pre-bonding film 102 as a whole, so as to reduce the preparation cost of the photovoltaic module.

[0076] It should be noted that Figure 7 In the figure, the film body 142 and the positioning strip 152 are divided on the pre-bonding film 102 by a dotted line.

[0077] In other embodiments, reference Figure 2 , the conductive portion 120 is a pad 120a, a single solder strip 101 and a plurality of solder pads 120a arranged at intervals along a first direction X are directly opposite to each other along a second direction Y, the first direction X is the extension direction of the solder strip 101, and the second direction Y is the thickness direction of the battery cell 100; in combination with reference Figure 2 , Figure 8 and Fig. 9 The pre-bonding film 102 includes a main body 122 and a positioning portion 132. The positioning portion 132 is located on a side of the main body 122 close to the battery cell 100, and a positioning groove 112 is provided in the positioning portion 132. The positioning groove 112 and the pad 120a are opposite to each other along the second direction Y.

[0078] in, Figure 8 This is another partial upward-facing structural schematic diagram of a pre-bonding film in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure, Fig. 9 This is a schematic diagram of a third partial cross-sectional structure in which the pre-bonding film is not bonded to the soldering tape and the cell in the method for preparing a photovoltaic module provided by an embodiment of the present disclosure. It should be noted that: Fig. 9 In the figure, the main body portion 122 and the positioning portion 132 are divided on the pre-bonding film 102 by a dotted line.

[0079] It is worth noting that the pre-bonding film 102 has a plurality of positioning grooves 112 arranged at intervals along the first direction X, and has a plurality of positioning grooves 112 arranged at intervals along the arrangement direction of the plurality of solder strips 101, which is conducive to making each solder strip 101 correspond to the plurality of positioning grooves 112. Moreover, the corresponding position of each positioning groove 112 and the solder strip 101 is regarded as a positioning point, and then each solder strip 101 is designed with a plurality of positioning points, and the positioning grooves 112 and the solder pads 120a are designed to face each other along the second direction Y. Then, the plurality of positioning points on each solder strip 101 face each other along the second direction Y, which is conducive to preventing the solder strip 101 from being bent by external force, and making the solder strip 101 contact and connect with the plurality of solder pads 120a more accurately, and effectively avoiding the phenomenon of offset between the solder strip 101 and the solder pad 120a.

[0080] In addition, relative to the main body 122, the positioning portion 132 protrudes in the direction close to the solar cell 100, and different parts of the positioning portion 132 have different thicknesses in the second direction Y, so as to form a positioning groove 112 in the positioning portion 132, and the thickness of the film body 142 is less than the average thickness of the positioning portion 132. In other words, the positioning portion 132 is designed only in the area on the pre-bonding film 102 that is directly opposite to the pad 120a along the second direction Y, which is conducive to fixing the soldering strip 101 in the preset area 110 in advance with the help of the pre-bonding film 102, and further reducing the amount of glue required for the pre-bonding film 102 as a whole, so as to further reduce the preparation cost of the photovoltaic module.

[0081] It should be noted that, no matter the cell 100 is a cell without a main grid or a cell with a main grid, the conductive portion 120 can be a pad 120a, but the size of the pad in the cell without a main grid is smaller than that in the cell with a main grid, and the number of pads in the cell without a main grid is greater than that in the cell with a main grid. Figure 3 The pads electrically contacting the main gate 120b are not shown.

[0082] In some embodiments, reference Figure 6 , Figure 7 or Fig. 9 , along the third direction Z, the spacing between the soldering ribbon 101 and the positioning groove 112 may be 0.1 mm to 0.3 mm, and the third direction Z is perpendicular to the extension direction of the soldering ribbon 101. For example, the spacing between the soldering ribbon 101 and the positioning groove 112 may be 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.23 mm, 0.25 mm, 0.26 mm or 0.28 mm.

[0083] In some cases, reference Figure 6 , Figure 7 or Fig. 9The welding strip 101 can be a circular welding strip, that is, the cross-sectional shape of the welding strip 101 in the cross-section perpendicular to the first direction X is circular or elliptical, etc., and the width of the circular welding strip in the third direction Z is 0.2mm~0.4mm, for example, 0.23mm, 0.25mm, 0.26mm, 0.28mm, 0.3mm, 0.32mm, 0.35mm, 0.36mm or 0.39mm, etc.

[0084] In other cases, the welding strip can be a flat welding strip, and the cross-sectional shape of the welding strip in the cross-section perpendicular to the first direction is a rectangle or a rectangle with rounded corners, etc., and the width of the flat welding strip in the third direction is 0.4mm~2mm, for example, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm or 1.9mm, etc.

[0085] In some embodiments, reference Fig.10 or Fig.11 The pressing plate 103 has a protrusion 113 on one side facing the pre-bonding film 102 , and a single protrusion 113 is directly opposite to at least one positioning groove 112 along the second direction Y, where the second direction Y is the thickness direction of the battery cell 100 .

[0086] In this way, a single protrusion 113 is directly opposite to at least one soldering strip 101 along the second direction Y. In step S4, in the process of applying pressure to the pre-bonding film 102 by the pressing plate 103, the pressure applied by the protrusion 113 to the pre-bonding film 102 is greater than the pressure applied by the portion of the pressing plate 103 without the protrusion 113 to the pre-bonding film 102, which is conducive to further ensuring that the soldering strip 101 is closely attached to the preset area 110 of the battery cell 100. Specifically, on the one hand, by means of the pressure applied by the pressing plate 103 to the pre-bonding film 102, the pre-bonding film 102 on the left and right sides of the soldering strip 101 is bonded to the battery cell 100, so as to effectively prevent the soldering strip 101 from deviating to the left and right; on the other hand, by means of the characteristic that the protrusion 113 applies greater pressure to the pre-bonding film 102, the friction between the soldering strip 101 and the battery cell 100 is increased, so as to further prevent the soldering strip 101 from deviating to the left and right, and is conducive to strengthening the connection strength between the soldering strip 101 and the conductive part 120.

[0087] in, Fig.10 A schematic diagram of a first partial cross-sectional structure in which a pressing plate is not pressed down onto a pre-bonding film in a method for preparing a photovoltaic module provided by an embodiment of the present disclosure, Fig.11 A schematic diagram of a second partial cross-sectional structure in which a pressing plate is not pressed down onto a pre-bonding film in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure.

[0088] In some examples, reference Fig.10 or Fig.11 The pressing plate 103 also has a pressing plate body 123, which is located on the side of the protruding portion 113 away from the battery cell 100, and the protruding portion 113 is movably mounted on the pressing plate body 123. It should be noted that Fig.10 and Fig.11 Solid lines are used to divide the protrusion 113 and the pressing plate body 123 in the pressing plate 103.

[0089] It is worth noting that for battery cells 100 of different sizes, the number of welding strips 101 designed on the battery cells 100 and the positions of the welding strips 101 on the battery cells 100 are different. Based on this, the protrusion 113 is designed to be movably installed on the pressure plate body 123, so that the pressure plate 103 can be applicable to battery cells 100 of various sizes, which is beneficial to improve the versatility of the pressure plate 103 and reduce the preparation cost of photovoltaic modules.

[0090] In some cases, the corresponding program can be set in the automation equipment so that the protrusion 113 on the pressing plate 103 is moved to a position directly opposite to the welding strip 101 on the battery cell 100 to be pressed along the second direction Y, which is conducive to avoiding human errors caused by manual operation of the protrusion 113 and reducing the labor cost in the preparation process of photovoltaic modules. In addition, a mapping table of battery cells of different sizes and welding strip positions can be pre-stored in the automation equipment in advance, which is convenient for quickly moving the protrusion 113 on the pressing plate 103 to a position directly opposite to the welding strip 101 on the battery cell 100 to be pressed along the second direction Y, thereby improving the preparation efficiency of photovoltaic modules.

[0091] In some examples, reference Fig.12 , Fig.12 The present invention is a schematic diagram of a third partial cross-sectional structure in which the pressure plate is not pressed down onto the pre-bonding film in the preparation method of a photovoltaic module provided in an embodiment of the present invention, the protrusion 113 is a first pressure needle 113a, and the side of the pressure plate 103 facing the pre-bonding film 102 also has a second pressure needle 133, and the first pressure needle 113a is provided with second pressure needles 133 on opposite sides along the third direction Z, respectively. The third direction Z is perpendicular to the extension direction of the welding strip 101, and the second pressure needle 133 is not directly opposite to the welding strip 101 along the second direction Y, and the pressing depth of the second pressure needle 133 is greater than the pressing depth of the first pressure needle 113a.

[0092] In this way, on the one hand, the friction force between the soldering tape 101 and the battery cell 100 can be increased with the help of the first pressing needle 113a, so as to further avoid the left and right deviation of the soldering tape 101, and it is beneficial to strengthen the connection strength between the soldering tape 101 and the conductive part 120; on the other hand, the pressure applied to the pre-adhesive film 102 on the left and right sides of the soldering tape 101 along the second direction Y can be increased with the help of the second pressing needle 133, so as to further improve the bonding effect between the pre-adhesive film 102 on both sides of the soldering tape 101 and the battery cell 100, and then improve the blocking effect of the pre-adhesive film 102 on both sides of the soldering tape 101 on the soldering tape 101, so as to further ensure that the soldering tape 101 does not deviate.

[0093] In addition, the pressing depth of the second pressing needle 133 is designed to be greater than the pressing depth of the first pressing needle 113a, which can compensate for the height difference between the pressure plate body 123 and the protruding portion 113 to a certain extent, thereby ensuring that the second pressing needle 133 applies a greater pressure to the pre-bonding film 102 located on the left and right sides of the solder strip 101, so as to ensure a good bonding effect between the pre-bonding film 102 located on the left and right sides of the solder strip 101 and the battery cell 100.

[0094] In some cases, at least one of the first pressing needle 113a and the second pressing needle 133 may have a heating function. In the process of applying pressure to the pre-adhesive film 102 by the pressing plate 103 in step S4, the pre-adhesive film 102 can be pre-melted under the dual effects of pressurization and heating, thereby improving the deformability and adhesion of the pre-adhesive film 102, facilitating the bonding of the inner wall of the positioning groove 112 formed on the pre-adhesive film 102 with the welding tape 101, and facilitating the bonding of the pre-adhesive film 102 in other areas with the battery cell 100. Based on the all-round wrapping of the welding tape 101 by the pre-adhesive film 102 and the battery cell 100, the deviation of the welding tape 101 is avoided, and the internal stability of the battery string to be welded by multiple battery cells 100 is improved.

[0095] The situation where a single protrusion 113 and at least one positioning groove 112 are directly opposite to each other along the second direction Y will be described in detail below.

[0096] In some embodiments, reference Fig.13 , Fig.13 A schematic diagram of a partial upward structure of a pressure plate in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure, wherein the protrusion 113 may be a long strip-shaped protrusion extending in the first direction X, and the protrusion 113 corresponds to the welding strip 101 one by one. In this way, after applying pressure to the pre-bonding film 102 by the pressure plate 103 in step S4, a protrusion 113 is directly opposite to a welding strip 101 in the second direction Y, so as to increase the pressure applied to the welding strip 101, thereby facilitating the increase of the friction between the welding strip 101 and the battery cell 100, further avoiding the left-right deviation of the welding strip 101, and facilitating the strengthening of the connection between the welding strip 101 and the conductive part 120.

[0097] In some cases, along the first direction X, the length of the raised portion 113 which is a long strip of protrusion is greater than or equal to the length of the battery cell 100, so that a single raised portion 113 can be directly opposite to the entire welding strip 101 located on the battery cell 100 along the second direction Y, which is beneficial for making the various parts of the welding strip 101 along the first direction X to be subjected to uniform force, thereby helping to reduce the risk of bending of the welding strip 101 due to external force.

[0098] In some examples, combined with reference Figure 6 and Fig.13 , or, combined with reference Figure 7 and Fig.13 , the positioning groove 112 is a long strip-shaped groove extending along the first direction X, and the positioning groove 112 corresponds to the welding strip 101 one by one. Since the protrusion 113, which is a long strip-shaped protrusion, also corresponds to the welding strip 101 one by one, after the pressure is applied to the pre-bonding film 102 by the pressing plate 103 in step S4, the protrusion 113 and the positioning groove 112 are one by one opposite to each other along the second direction Y. On this basis, in step S4, the protrusion 113, which is a long strip-shaped protrusion, can make the pre-bonding film 102 located on the top side of the welding strip 101 partially squeezed to the left and right sides of the welding strip 101, so that the pre-bonding film 102 located on the left and right sides of the welding strip 101 is closely attached to the battery cell 100 downward under the dual effects of the pressure and squeezing force applied by the pressing plate 103, thereby facilitating the improvement of the bonding strength between the pre-bonding film 102 and the battery cell 100.

[0099] In other examples, combined with reference Fig. 9 and Fig.13 The pre-bonding film 102 includes a main body 122 and a positioning portion 132. The positioning portion 132 is located on a side of the main body 122 close to the battery cell 100, and the positioning portion 132 has a positioning groove 112 therein. The positioning groove 112 and the solder pad 120a are aligned one by one along the second direction Y. Since the long strip-shaped protrusions 113 correspond one by one to the solder strips 101, after the pressure is applied to the pre-bonding film 102 by the pressing plate 103 in step S4, a single protrusion 113 and a plurality of positioning grooves 112 corresponding to a single solder strip 101 are aligned one by one along the second direction Y.

[0100] On this basis, in step S4, the protruding portion 113 which is a long strip protrusion can at least make the outer contour of the positioning groove 112 in the positioning portion 132 be subjected to greater pressure, and further squeezed to the left and right sides of the welding strip 101, so that the pre-bonding film 102 located on the left and right sides of the welding strip 101 is pressed downwardly and tightly attached to the battery cell 100 under the dual effects of the pressure and extrusion force applied by the pressing plate 103, thereby facilitating the improvement of the bonding strength between the pre-bonding film 102 and the battery cell 100. Moreover, the positioning groove 112 and the pad 120a are aligned one by one along the second direction Y, and a single protruding portion 113 which is a long strip protrusion can be aligned with multiple pads 120a corresponding to a single welding strip 101 along the second direction Y, which is also conducive to making the welding strip 101 and the pad 120a more closely attached.

[0101] In other embodiments, in combination with reference Fig. 9 and Fig.14 , Fig.14 A schematic diagram of another partial upward-facing structure of a pressure plate in a method for preparing a photovoltaic module provided in an embodiment of the present disclosure, wherein a plurality of protrusions 113 are arranged in an array along a first direction X and a third direction Z, and the third direction Z is perpendicular to the extension direction of the welding strip 101; a single welding strip 101 is directly opposite to a plurality of positioning portions 132 arranged at intervals along the first direction X along the second direction Y.

[0102] It is worth noting that, combined with reference Figure 2 , Fig. 9 and Fig.14 , a single welding strip 101 is in contact with and connected to a plurality of conductive parts 120 arranged at intervals along the first direction X, and a part of the single welding strip 101 does not need to be directly opposite to the conductive part 120 along the second direction Y. Generally, in order to ensure the performance of the photovoltaic module finally formed, an insulating layer is generally provided between the part of the welding strip 101 that is not directly opposite to the conductive part 120 along the second direction Y and the solar cell 100. On this basis, the single welding strip 101 is designed to be directly opposite to a plurality of positioning parts 132 arranged at intervals along the first direction X along the second direction Y. The raised part 113 can be used to apply a greater pressure to the part of the welding strip 101 that is directly opposite to the conductive part 120 along the second direction Y to ensure the contact connection between the welding strip 101 and the conductive part 120. The pressure applied by the pressing plate 103 to the part of the welding strip 101 that is not directly opposite to the conductive part 120 along the second direction Y can also be appropriately reduced to avoid damage to the insulating layer, thereby ensuring the good electrical performance of the photovoltaic module finally formed.

[0103] In some examples, the conductive portion 120 is a pad 120a, a single solder strip 101 is directly opposite to a plurality of pads 120a arranged at intervals along the first direction X along the second direction Y, and the raised portions 113 and the pads 120a are directly opposite to each other along the second direction Y. In this way, each raised portion 113 can specifically press the solder strip 101 down onto the pad 120a, so that the pressing plate 103 can better press the solder strip 101 and the battery cell 100, and improve the alignment accuracy between the solder strip 101 and the pad 120a.

[0104] In some embodiments, the process of applying pressure to the pre-bonding film 102 by the pressing plate 103 in step S4 may further include a heating process, which is described in detail below.

[0105] In some embodiments, reference Figures 10 to 12 The method for preparing a photovoltaic module may further include: providing a base plate (not shown in the figure), the base plate is used to support the side of the battery cell 100 away from the welding ribbon 101, and the base plate has a first heating part (not shown in the figure); in the step of applying pressure to the pre-bonding film 102 by the pressing plate 103, the battery cell 100, the welding ribbon 101 and the pre-bonding film 102 are heated by the first heating part.

[0106] In this way, after the positioning groove 112 is used to clamp the welding tape 101, while applying greater pressure to the positioning groove 112 through the pressure plate 103, the pre-adhesive film 102 is also heated by the first heating unit, so that under the dual effects of pressurization and heating, the pre-adhesive film 102 is pre-melted, and the deformability and adhesion of the pre-adhesive film 102 are improved, which makes it easier for the inner wall of the positioning groove 112 formed by the pre-adhesive film 102 to be bonded to the welding tape 101, and for the pre-adhesive film 102 in other areas to be bonded to the battery cell 100. Based on the all-round wrapping of the welding tape 101 by the pre-adhesive film 102 and the battery cell 100, the deviation of the welding tape 101 is avoided, and the internal stability of multiple battery cells 100 connected into a battery string to be welded is improved.

[0107] In some examples, the heating temperature of the battery cell 100 by the first heating unit can be 70°C to 130°C, for example, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C or 125°C.

[0108] In other embodiments, reference Figures 10 to 12 The method for preparing a photovoltaic module may further include: the pressing plate 103 has a second heating unit; in the step of applying pressure to the pre-bonding film 102 by the pressing plate 103, the battery cell 100, the soldering tape 101 and the pre-bonding film 102 are heated by the second heating unit.

[0109] It is worth noting that the second heating portion may be at least one of the first pressing pin or the second pressing pin described in the aforementioned embodiment, or may be an additional component in the pressing plate 103 that is different from the first pressing pin or the second pressing pin.

[0110] In some examples, the heating temperature of the second heating unit on the battery cell 100 can be 70°C to 130°C, for example, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C or 125°C, etc.

[0111] In some embodiments, after the polarization step S5, i.e., the lamination stage, the battery strings to be welded have been welded into battery strings, and the method for preparing a photovoltaic module may further include: assembling a plurality of battery strings in sequence with components such as adhesive films, bus bars, junction boxes, and cover plates, thereby forming a photovoltaic module. It should be noted that an embodiment of the present disclosure does not impose too many restrictions on the step of assembling a plurality of battery strings in sequence with components such as adhesive films, bus bars, junction boxes, and cover plates, and can be achieved by various known technical means.

[0112] In summary, the pre-bonding film 102 is first designed to have a plurality of positioning grooves 112 on the side facing the battery cell 100, and a single solder strip 101 corresponds to at least one positioning groove 112. When the pre-bonding film 102 is subsequently covered on the side of the solder strip 101 away from the battery cell 100, it is beneficial for the positioning groove 112 to accommodate at least part of the solder strip 101, so that not only the top surface of the solder strip 101 is in contact and connection with the pre-bonding film 102, but also the two sides of the solder strip 101 are in contact and connection with the pre-bonding film 102. In this way, in the subsequent stage of applying force and laminating the pre-bonding film 102 using the pressing plate 103, the pre-bonding film 102 on both sides of the solder strip 101 can also be bonded to the battery cell 100 based on the pressure applied by the pressing plate 103, so as to lock the solder strip 101 on the preset area 110, and ensure that the solder strip 101 is in contact and connection with the conductive part 120 on the preset area 110. Secondly, before realizing the alloying of the soldering tape 101 and the conductive part 120, the soldering tape 101 is first bonded to the preset area 110 of the battery cell 100 in advance by utilizing the cooperation of the pre-bonding film 102 and the pressing plate 103, so as to avoid the soldering tape 101 being offset relative to the battery cell 100 in the subsequent lamination stage. On this basis, the lamination stage does not require the aid of instantaneous high-temperature welding, and the lamination temperature of the lamination stage only needs to be greater than or equal to the melting point of the material constituting the outer layer 111 of the soldering tape 101 to realize the alloying of the soldering tape 101 and thus help to reduce the risk of warping of the battery cell 100 by lowering the welding temperature.

[0113] Another embodiment of the present disclosure further provides a photovoltaic module, which is formed by the method for preparing the photovoltaic module provided by the above embodiment. The photovoltaic module provided by another embodiment of the present disclosure will be described in detail below in conjunction with the accompanying drawings. It should be noted that the parts that are the same or corresponding to the above embodiment will not be repeated here.

[0114] The photovoltaic module includes: a photovoltaic module formed by the method for preparing the photovoltaic module provided in the above embodiment.

[0115] In some embodiments, in conjunction with reference Figure 1 , Figures 15 to 17 , the photovoltaic module may include: a battery string, formed by steps S1 to S5 in the method for preparing the photovoltaic module provided in the above embodiment; a packaging film 41, used to cover the surface of the battery string; a cover plate 42, used to cover the surface of the packaging film 41 away from the battery string. The battery cell 100 is electrically connected in the form of a whole piece or multiple pieces to form a plurality of battery strings, and the plurality of battery strings are electrically connected in series and / or in parallel. The battery cell 100 can be a whole cell or a sliced ​​cell, and a sliced ​​cell refers to a cell formed by a complete whole cell through a cutting process.

[0116] in, Fig.15 A partial three-dimensional structural schematic diagram of a photovoltaic assembly provided by another embodiment of the present disclosure is shown. Fig.16 for Fig.15 A schematic diagram of a local cross-sectional structure along the first cross-sectional direction AA1, Fig.17 for Fig.15 A schematic diagram of a local cross-sectional structure along the second cross-sectional direction BB1.

[0117] It should be noted that in the step of covering the surface of the battery string with the packaging film 41, if the material of the pre-bonding film 102 is the same as the material of the packaging film 41, there will be no obvious boundary between the two in the final photovoltaic module. Fig.16 and Fig.17 The dotted line in the encapsulation film 41 indicates the approximate area where the pre-bonding film 102 is located. In practical applications, the material of the pre-bonding film and the material of the encapsulation film may be different, and there may be a clear boundary between the pre-bonding film and the encapsulation film in the final photovoltaic module.

[0118] In some embodiments, reference Fig.15 or Fig.17 , multiple battery cells 100 can be electrically connected through welding strips 101. Fig.15 and Fig.17Only one positional relationship between the battery cells 100 is illustrated, and the battery cells 100 may also be arranged in a manner such that the grid lines of different polarities face the same side, that is, the grid lines of the adjacent multiple battery cells 100 are arranged in the order of the first polarity, the second polarity, and the first polarity, respectively, and the welding strip 101 connects the same side of two adjacent battery cells 100. In other embodiments, the arrangement direction of the electrodes of the same polarity of the battery cells is the same, or the electrodes of each battery cell with positive polarity are arranged toward the same side, so that the welding strips connect different sides of two adjacent battery cells.

[0119] In some embodiments, the encapsulation film 41 includes a first encapsulation layer and a second encapsulation layer, the first encapsulation layer covers one of the front side or the back side of the battery cell 100, and the second encapsulation layer covers the other of the front side or the back side of the battery cell 100. Specifically, at least one of the first encapsulation layer or the second encapsulation layer may be an organic encapsulation film such as a polyvinyl butyral (PVB) film, an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene co-elastomer (POE) film, or a polyethylene terephthalate (PET) film, or at least one of the first encapsulation layer or the second encapsulation layer may also be an EP film, an EPE film, or a PVP film. Among them, EP film refers to a co-extruded film composed of stacked EVA film and POE film, EPE film refers to a co-extruded film formed by stacking EVA film + POE film + EVA film in sequence, and PVP film refers to a co-extruded film formed by stacking POE film + EVA film + POE film. The co-extruded film can be prepared by sequentially extruding one or more raw materials onto another already manufactured film during the film processing process, or bonding different types of already manufactured films together.

[0120] In some cases, there is a boundary between the first encapsulation layer and the second encapsulation layer before lamination. After the lamination process, the photovoltaic module is formed and there is no longer the concept of the first encapsulation layer and the second encapsulation layer, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0121] In some embodiments, the cover plate 42 may be a glass cover plate, a plastic cover plate or the like with a light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulation film 41 may be a concave-convex surface or a velvet surface including a plurality of convex structures, thereby increasing the utilization rate of the incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate is opposite to the first encapsulation layer, and the second cover plate is opposite to the second encapsulation layer.

[0122] In some cases, when the cell 100 is a main grid cell, the surface of the cell 100 has a plurality of main grids arranged at intervals along a first direction X and a plurality of auxiliary grids arranged at intervals along a third direction Z. The main grid includes a main grid connection line and a pad located on the main grid connection line. In the process of constructing a battery string using the cell 100, the welding strip 101 is electrically connected to at least one main grid on each of the two adjacent cell cells 100.

[0123] In other cases, when the battery cell 100 is a main-grid-free battery, the surface of the battery cell 100 has a plurality of auxiliary grids arranged at intervals along a third direction Z. In the process of constructing a battery string using the battery cell 100, the welding strip 101 is electrically connected to the plurality of auxiliary grids on each battery cell 100 of two adjacent battery cells 100.

[0124] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the embodiments 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 embodiments of the present disclosure, so the protection scope of the embodiments of the present disclosure shall be based on the scope defined in the claims.

Claims

1. A method for preparing a photovoltaic module, characterized in that: include: Providing at least two battery cells and a plurality of welding strips, and placing the welding strips in a preset area of ​​the battery cell, wherein a portion of the battery cell located in the preset area has a conductive portion; Providing a pre-bonding film, wherein the pre-bonding film has a plurality of positioning grooves on a side facing the battery cell, and a single welding strip corresponds to at least one of the positioning grooves; Covering the pre-bonding film on a side of the soldering ribbon away from the battery cell, wherein at least a portion of the soldering ribbon is accommodated in the positioning groove; Providing a pressing plate, arranging the pressing plate on a side of the pre-bonding film away from the battery cell, and applying pressure to the pre-bonding film through the pressing plate, so that the pre-bonding film bonds the welding ribbon to the preset area, and connects the plurality of battery cells into a battery string to be welded; The battery string to be welded is sent to a lamination stage, and the lamination temperature of the lamination stage is greater than or equal to the melting point of the material constituting the outer layer of the welding strip, so as to achieve alloying of the welding strip and the conductive part.

2. The preparation method according to claim 1, characterized in that: The positioning grooves are long strip-shaped grooves extending along a first direction. The positioning grooves correspond to the welding strips one by one. The first direction is the extending direction of the welding strips.

3. The preparation method according to claim 1, characterized in that: The conductive part is a solder pad, and a single solder strip is directly opposite to a plurality of solder pads arranged at intervals along a first direction in a second direction, the first direction is an extension direction of the solder strip, and the second direction is a thickness direction of the battery cell; The pre-bonding film comprises a main body and a positioning portion, wherein the positioning portion is located at a side of the main body close to the battery cell, and the positioning portion has the positioning groove therein, and the positioning groove and the pad are opposite to each other one by one along the second direction.

4. The preparation method according to claim 2 or 3, characterized in that: Along the third direction, the spacing between the welding strip and the positioning groove is 0.1 mm to 0.3 mm, and the third direction is perpendicular to the extending direction of the welding strip.

5. The preparation method according to claim 2 or 3, characterized in that: The pressing plate has a protrusion on one side facing the pre-bonding film, and a single protrusion is directly opposite to at least one positioning groove along a second direction, and the second direction is a thickness direction of the battery cell.

6. The preparation method according to claim 5, characterized in that: The protrusions are long strip-shaped protrusions extending along the first direction, and the protrusions correspond to the welding strips one by one.

7. The preparation method according to claim 5, characterized in that: The plurality of protrusions are arranged in an array along the first direction and a third direction, and the third direction is perpendicular to the extension direction of the welding strip; a single welding strip is directly opposite to the plurality of positioning portions arranged at intervals along the first direction along the second direction.

8. The preparation method according to claim 1, characterized in that: The material constituting the outer layer of the solder strip includes tin, the lamination temperature is 140° C. to 170° C.; and / or the duration of the lamination stage is 4 min to 5 min.

9. The preparation method according to claim 1, characterized in that: Also includes: Providing a bottom plate, the bottom plate is used to support the side of the battery sheet away from the welding strip, the bottom plate has a first heating part or the pressing plate has a second heating part; In the step of applying pressure to the pre-adhesive film by the pressing plate, the battery cell, the soldering ribbon, and the pre-adhesive film are heated by the first heating unit or the second heating unit.

10. A photovoltaic module, characterized in that: include: A photovoltaic module formed by the method for preparing a photovoltaic module according to any one of claims 1 to 9.

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