Back contact photovoltaic module

Abstract

The utility model relates to a back contact photovoltaic module, and the module comprises a photovoltaic laminated part which comprises a plurality of battery pieces, a backboard, a welding strip, and a bus bar, the plurality of battery pieces are connected through the welding strip to form a battery string, the battery string and the backboard are stacked, and the battery string is connected with the bus bar; wherein a lead hole is formed in the back plate in a penetrating manner; at least one bus bar comprises a first part arranged between the back side of the battery piece and the back plate and a second part connected with the first part, and the second part penetrates through the lead hole; the first portion has a first width, the second portion has a second width, and the second width is smaller than the first width. The problem that the backboard has the fragment risk can be solved or improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cell manufacturing, and in particular to a back contact photovoltaic module. BACKGROUND

[0002] Solar energy, as a new energy, has the advantages of inexhaustibility, cleanness and environmental protection compared with traditional fossil fuels. At present, a main way of solar energy utilization is to convert received light energy into electrical energy output through a solar cell module, which can be a large-area cell module formed by packaging and arranging in a square matrix after a plurality of solar cells (or photovoltaic cells, or photovoltaic modules) are connected in series. Among them, the solar cell absorbs light energy, and the accumulation of opposite charges appears at both ends of the cell, that is, a "photovoltaic effect" is generated. Under the action of the photovoltaic effect, an electromotive force is generated at both ends of the solar cell, thereby converting light energy into electrical energy. In the photovoltaic module, the function of the solder strip and the busbar is to guide the current collected by the cell into the junction box, and the busbar, as the current lead-out wire in the solar module, plays an important role.

[0003] However, in the prior art, the lead hole on the back plate causes the problem of the risk of breaking the back plate. SUMMARY

[0004] Therefore, it is necessary to provide a back contact photovoltaic module for the problem of the risk of breaking the back plate caused by the lead hole on the back plate.

[0005] In a first aspect, the present application provides a back contact photovoltaic module, comprising:

[0006] a photovoltaic laminate comprising a plurality of cell pieces, a back plate, a solder strip and a busbar, the plurality of cell pieces being connected by the solder strip to form a cell string, the cell string and the back plate being stacked, and the cell string being connected with the busbar;

[0007] wherein the back plate is provided with a lead hole penetrating therethrough;

[0008] At least one of the busbars comprises a first part arranged between the back side of the cell piece and the back plate, and a second part connected with the first part, and the second part is arranged through the lead hole;

[0009] The first part has a first width, and the second part has a second width, and the second width is smaller than the first width;

[0010] The first width refers to the size of the first part along the width direction of the first part, and the width direction of the first part, the longitudinal extension direction of the first part and the thickness direction of the first part are perpendicular to each other;

[0011] The second width refers to a dimension of the second portion along a width direction of the second portion, the width direction of the second portion, the longitudinal extension direction of the second portion, and the thickness direction of the second portion being perpendicular to each other.

[0012] In some embodiments, in a direction perpendicular to the longitudinal extension direction of the first portion, the cross-sectional area of the first portion is a first area.

[0013] In a direction perpendicular to the longitudinal extension direction of the second portion, the cross-sectional area of the second portion is a second area, which is less than or equal to the first area.

[0014] In some embodiments, the second area is less than the first area.

[0015] The first portion has a first thickness along a thickness direction of the first portion, and the second portion has a second thickness along a thickness direction of the second portion, the first thickness being equal to the second thickness.

[0016] In some embodiments, relative to the first portion, at least one notch is provided on the bus bar on at least one side of the second portion along the width direction of the second portion.

[0017] In some embodiments, along the width direction of the second portion, the second portion includes a folding line on at least one side of the second portion.

[0018] In some embodiments, along the thickness direction of the second portion, the second portion includes a main body portion, and two folding portions respectively located on both sides of the main body portion along the thickness direction of the second portion.

[0019] In some embodiments, the first width is greater than 8 mm; and / or,

[0020] The second width is less than 8 mm.

[0021] In some embodiments, the cross-sectional area of the first portion is greater than 1.8 mm 2 ; and / or,

[0022] The cross-sectional area of the second portion is less than 1.8 mm 2 .

[0023] In some embodiments, at least one of the bus bars including the first portion and the second portion is a middle bus bar, and a plurality of the battery pieces include a first battery piece and a second battery piece arranged adjacently, and the at least one middle bus bar is arranged at a middle position of the first battery piece and the second battery piece.

[0024] In some embodiments, the intermediate busbar is stacked with the first cell in a thickness direction of the first cell, and the back contact photovoltaic module further comprises an insulating film arranged between the intermediate busbar and the first cell, the first cell comprising a first electrode and a second electrode on a back surface of the first cell;

[0025] The insulating film has a plurality of openings, and the intermediate busbar is electrically connected to the first electrode on the back surface of the first cell through the openings; or,

[0026] The insulating film comprises a plurality of insulating strips arranged at intervals and a gap part between two adjacent insulating strips, the insulating strips covering the second electrode on the back surface of the first cell, and the intermediate busbar being electrically connected to the first electrode on the back surface of the first cell through the gap part

[0027] In the embodiments of the present application, the first part has a first width, and the second part has a second width smaller than the first width. By reducing the width of the second part relative to the first part, the width of the lead hole through which the second part passes can be reduced, thereby reducing the risk of breakage of the back plate. At the same time, after reducing the width of the second part, the width of the first part can be increased, and the thickness of the first part can be reduced, thereby reducing the risk of breakage of the back plate and the cell sheet while ensuring to reduce the resistance of the first part. Therefore, the present application has the effect of reducing the risk of breakage of the back plate and the cell sheet, and improves the reliability of the photovoltaic module. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments or exemplary embodiments of the present application, the drawings needed to be used in the description of the embodiments or exemplary embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0029] Figure 1 A cross-sectional structure schematic diagram of a back contact photovoltaic module according to some embodiments of the present application.

[0030] Figure 2 A first planar structure schematic diagram of a busbar of a back contact photovoltaic module according to some embodiments of the present application.

[0031] Figure 3 A second planar structure schematic diagram of a busbar of a back contact photovoltaic module according to some embodiments of the present application.

[0032] Figure 4 A first top view schematic diagram of a back contact photovoltaic module provided for some embodiments of the present application.

[0033] Figure 5 A second top view schematic diagram of a back contact photovoltaic module provided for some embodiments of the present application. DETAILED DESCRIPTION

[0034] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many different ways other than those described herein, and one of ordinary skill in the art can make similar improvements without departing from the spirit of the present application, and therefore the present application is not limited to the specific embodiments disclosed below.

[0035] In the description of the present application, it should be understood that if these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0036] In addition, if these terms "first", "second" appear, these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "a plurality of" appears, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0037] In the present application, unless otherwise explicitly specified and limited, if the terms "mounting", "connecting", "connecting", "fixing" and the like appear, these terms should be understood in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] In this application, unless otherwise explicitly specified and limited, if there is a description of "on" or "under" or similar description of the first feature and the second feature, it means that the first and second features are in direct contact or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "on", "above" and "over" the second feature can be that the first feature is directly above or obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

[0039] It should be noted that if an element is referred to as being "fixed" or "set" on another element, it can be directly on the other element or there can be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there can be an intermediate element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are only for illustrative purposes and do not represent the only implementation.

[0040] Referring to Figures 1 to 5 . Figure 1 A schematic diagram of a cross-sectional structure of a back contact photovoltaic module provided for some embodiments of the present application. Figure 2 A first schematic diagram of a busbar of a back contact photovoltaic module provided for some embodiments of the present application. Figure 3 A second schematic diagram of a busbar of a back contact photovoltaic module provided for some embodiments of the present application. Figure 2 And Figure 3 A schematic diagram of the shape of the first and second parts of the busbar before or without bending.

[0041] Figure 4 A first schematic diagram of a back contact photovoltaic module provided for some embodiments of the present application. Figure 5 A second schematic diagram of a back contact photovoltaic module provided for some embodiments of the present application. Figure 4 And

[0042] The application provides a back contact photovoltaic module 100, which comprises a photovoltaic laminate 101, the photovoltaic laminate 101 comprising a plurality of cell pieces 10, a back plate 30, a solder strip 12 and a bus bar 20, the plurality of cell pieces 10 being connected by the solder strip 12 to form a cell string 102, the cell string 102 being stacked with the back plate 30, and the cell string 102 being connected with the bus bar 20; wherein the back plate 30 is provided with a lead hole 31 penetrating therethrough; at least one bus bar 20 comprises a first part 21 arranged between the back side of the cell piece 10 and the back plate 30, and a second part 22 connected with the first part 21, the second part 22 being arranged through the lead hole 31; the first part 21 has a first width d1, and the second part 22 has a second width d2, the second width d2 being smaller than the first width d1; the first width d1 refers to the size of the first part 21 along the width direction of the first part, the width direction of the first part, the longitudinal extension direction of the first part and the thickness direction of the first part being perpendicular to each other in pairs; the second width d2 refers to the size of the second part 22 along the width direction of the second part, the width direction of the second part, the longitudinal extension direction of the second part and the thickness direction of the second part being perpendicular to each other in pairs.

[0043] For example, in some embodiments, the composition of the photovoltaic module 100 comprises a laminate 101 and a frame, the laminate 101 comprising a cover plate, a first adhesive film, a plurality of photovoltaic module strings, a second adhesive film and a back plate 30, the photovoltaic module string comprising a plurality of cell pieces 10 arranged in series (cell string 102), the cover plate, the first adhesive film, the plurality of photovoltaic module strings, the second adhesive film and the back plate 30 being laminated to obtain the laminate 101, and the laminate 101 and the frame being assembled to form the photovoltaic module 100, but the structure of the photovoltaic module 100 is not limited thereto.

[0044] For example, in some embodiments, the first adhesive film and the second adhesive film can be ethylene-vinyl acetate copolymer (EVA) adhesive film, polyethylene octene copolymer (POE) adhesive film or polyethylene terephthalate (PET) adhesive film, and can also be PVB adhesive film, EPE adhesive film (EVA and POE three-layer co-extrusion adhesive film), EP adhesive film (EVA and POE two-layer co-extrusion adhesive film), or other types of adhesive film, which can be selected according to actual needs, and is not limited herein.

[0045] For example, in some embodiments, the cover plate is arranged on the side of the first adhesive film away from the cell piece 10, and the cover plate can use transparent materials such as glass or high polymer materials, and when the cover plate uses glass, it is also called "photovoltaic glass", which has good light transmission and high hardness, and can adapt to large diurnal temperature difference and harsh weather environment after being covered on the first adhesive film, thereby protecting the cell piece. The glass used for the cover plate can be super-white photovoltaic embossed glass, super-white processed float glass or TCO glass, and can also be other types of front plate glass, which can be selected according to actual needs, and is not limited herein.

[0046] For example, in some embodiments, the back plate 30 is arranged on the side of the second adhesive film away from the battery piece 10. The back plate 30 also protects and supports the battery piece, has good weather resistance, water resistance, corrosion resistance, and insulation, etc., can isolate the photovoltaic module 100 from the surrounding photovoltaic environment, and effectively protect and support the battery piece 10, thereby increasing the impact strength of the photovoltaic module 100. The back plate 30 can be made of glass material (for example, calendaring glass or super white calendaring glass), TPT (polyvinyl fluoride composite film), or TPE (thermoplastic elastomer), etc.

[0047] For example, as shown in Figure 4 and Figure 5 The back contact photovoltaic module 100 can include a plurality of battery strings 102.

[0048] For example, the front side of the battery piece 10 refers to the side of the battery piece 10 that receives solar radiation, or the side that mainly receives solar radiation.

[0049] For example, the back side of the battery piece 10 refers to the side away from the sunlight.

[0050] For example, the back side of the battery piece 10 can be provided with a first electrode 111 and a second electrode 112. The first electrode 111 can be one of the positive grid and the negative grid, and the second electrode 112 can be the other of the positive grid and the negative grid.

[0051] For example, different battery pieces 10 can be connected in series by a solder strip 12 to form a battery string 102. For example, the second electrode 112 of the first battery piece is connected to the first electrode 111 of the second battery piece by the solder strip 12. The structure of the battery string is not limited thereto.

[0052] For example, Figure 1 The battery piece 10, the first part 21 of the bus bar 20, and the back plate 30 are arranged in layers.

[0053] For example, the material of the back plate 30 can be a glass substrate, but is not limited thereto. The back plate 30 can protect the battery piece.

[0054] For example, the side of the back plate 30 away from the battery piece 10 is provided with a junction box 40. The current generated by the plurality of battery pieces 10 can be converged to the junction box 40 by the bus bar 20.

[0055] For example, in the back contact photovoltaic module, the surface of the battery piece 10 facing the back plate 30 and the junction box 40 is the back side. The first electrode 111 and the second electrode 112 are arranged on the back side of the battery piece 10.

[0056] For example, the back plate 30 is provided with a lead hole 31, and the second portion 22 of the bus bar 20 is bent relative to the first portion 21, and the second portion 22 of the bus bar passes through the lead hole 31 to electrically connect the terminal box 40.

[0057] For example, in combination with Figures 1 to 5 , the first portion 21 of the bus bar 20 extends on the surface side of the battery sheet 10, and thus the width direction of the first portion is perpendicular to the longitudinal extension direction of the first portion and parallel to the plane on which the battery sheet 10 is located, the second direction Y is the width direction of the first portion, and the first portion 21 has a first width d1.

[0058] For example, in combination with Figures 1 to 5 , the thickness direction of the first portion is perpendicular to the plane on which the battery sheet 10 is located, the third direction Z is the thickness direction of the first portion 21, and the first portion 21 has a first thickness h1.

[0059] For example, in combination with Figures 1 to 5 , the second portion 22 of the bus bar 20 is bent or curved relative to the first portion 21, for example, the longitudinal extension direction of the second portion of the bus bar 20 is perpendicular to the direction of the plane on which the battery sheet 10 is located, and in some embodiments, the width direction of the second portion 22 is perpendicular to the longitudinal extension direction of the second portion and parallel to the plane on which the battery sheet 10 is located, the width direction of the second portion is parallel to the width direction of the first portion, and the second portion 22 has a second width d2.

[0060] For example, in combination with Figures 1 to 5 , the second portion 22 of the bus bar 20 is bent or curved relative to the first portion 21, for example, the longitudinal extension direction of the second portion of the bus bar 20 is perpendicular to the direction of the plane on which the battery sheet 10 is located, and in some embodiments, the thickness direction of the second portion is perpendicular to the longitudinal extension direction of the second portion and parallel to the plane on which the battery sheet 10 is located, the width of the second portion is perpendicular to the width direction of the first portion, and the second portion 22 has a second thickness h2.

[0061] In the embodiment of the present application, the first portion 21 has a first width d1, and the second portion 22 has a second width d2, the second width d2 being less than the first width d1. The width of the second portion 22 is reduced relative to the first portion 21, so that the width of the lead hole 31 through which the second portion 22 passes can be reduced, thereby reducing the risk of the back plate 30 being broken. At the same time, the width of the second portion 22 is reduced, and the width of the first portion 21 can be increased, and the thickness of the first portion 21 can be reduced, thereby reducing the risk of the back contact photovoltaic module 100 being subjected to an external force and the cell sheet 10 being broken into pieces, while ensuring that the resistance of the first portion 21 is reduced. Therefore, the present application has the effect of reducing the risk of the back plate 30 and the cell sheet 10 being broken into pieces, and improves the reliability of the photovoltaic module.

[0062] In some embodiments, in a direction perpendicular to the longitudinal extension direction of the first portion, the cross-sectional area of the first portion 21 is a first area; and in a direction perpendicular to the longitudinal extension direction of the second portion, the cross-sectional area of the second portion 22 is a second area, the second area being less than or equal to the first area.

[0063] For example, the second width d2 is less than the first width d1, and the second area is less than or equal to the first area, that is, the second area is not increased but is reduced or even further reduced based on the reduction of the second width d2, so that the area of the lead hole 31 through which the second portion 22 passes can be better reduced, thereby better reducing the risk of the back plate 30 being broken.

[0064] In some embodiments, as shown in Figure 1 and Figure 2 , the second area is less than the first area; the first portion 21 has a first thickness in the thickness direction of the first portion, and the second portion 22 has a second thickness in the thickness direction of the second portion, and the first thickness is equal to the second thickness.

[0065] For example, as shown in Figure 1 and Figure 2 , the second width d2 is less than the first width d1, the second area is less than the first area, and the first thickness h1 is equal to the second thickness h2, that is, only the width of the second portion 22 is reduced, and the thickness of the second portion 22 is not increased, so that the area of the lead hole 31 through which the second portion 22 passes can be better reduced, thereby better reducing the risk of the back plate 30 being broken.

[0066] In some embodiments, as shown in Figure 1 and Figure 2 , relative to the first portion 21, a cutout 221 is provided on the bus bar 20 at least on one side of the second portion 22 in the width direction of the second portion.

[0067] For example, as shown in Figure 1and Figure 2 As shown in FIG. 2, the second portion 22 can be provided with a cutout 221 at least one side of the second portion 22, for example, the cutout 221 can be formed by cutting some parts of the second portion 22 to reduce the width of the second portion 22.

[0068] For example, as shown in FIG. 2, the second portion 22 can be provided with a cutout 221 at both sides of the second portion 22; for example, the cutouts 221 at both sides of the second portion 22 can be symmetrically arranged along the width direction of the second portion 22. Figure 1 and Figure 2 For example, as shown in FIG. 2, the second portion 22 can be provided with a cutout 221 at both sides of the second portion 22; for example, the cutouts 221 at both sides of the second portion 22 can be symmetrically arranged along the width direction of the second portion 22.

[0069] In some embodiments, as shown in FIG. 2, along the width direction of the second portion 22, the second portion 22 comprises a folding line at least one side of the second portion 22. Figure 1 and Figure 3 In some embodiments, as shown in FIG. 2, along the width direction of the second portion 22, the second portion 22 comprises a folding line at least one side of the second portion 22.

[0070] For example, as shown in FIG. 2, the second portion 22 can be provided with a folding line 222 at least one side of the second portion 22, and the parts on both sides of the folding line 222 can be folded relative to each other, so as to reduce the width of the second portion 22. Figure 1 and Figure 3 For example, as shown in FIG. 2, the second portion 22 can be provided with a folding line 222 at least one side of the second portion 22, and the parts on both sides of the folding line 222 can be folded relative to each other, so as to reduce the width of the second portion 22.

[0071] In some embodiments, as shown in FIG. 2, along the thickness direction of the second portion 22, the second portion 22 comprises a main body part 223, and two folding parts 224 respectively located at both sides of the main body part 223 along the thickness direction of the second portion 22. Figure 1 and Figure 3 In some embodiments, as shown in FIG. 2, along the thickness direction of the second portion 22, the second portion 22 comprises a main body part 223, and two folding parts 224 respectively located at both sides of the main body part 223 along the thickness direction of the second portion 22.

[0072] For example, as shown in FIG. 2, the folding part 224 can be folded relative to the main body part 223. Figure 3 As shown in FIG. 2, the folding part 224 is shown in a state before being folded relative to the main body part 223.

[0073] For example, as shown in FIG. 2, the second portion 22 can be provided with a folding line 222 at both sides of the second portion 22, and the folding parts 224 on both sides of the two folding lines 222 can be folded relative to the main body part 223 on both sides of the main body part 223. Figure 1 and Figure 3 For example, as shown in FIG. 2, the second portion 22 can be provided with a folding line 222 at both sides of the second portion 22, and the folding parts 224 on both sides of the two folding lines 222 can be folded relative to the main body part 223 on both sides of the main body part 223.

[0074] For example, as shown in FIG. 2, compared with the first portion 21, the second portion 22 is folded relative to the main body part 223 through the folding part 224, so as to reduce the width of the second portion 22. Figure 1 and Figure 3 For example, as shown in FIG. 2, compared with the first portion 21, the second portion 22 is folded relative to the main body part 223 through the folding part 224, so as to reduce the width of the second portion 22.

[0075] In some embodiments, the first width d1 is greater than 8 mm; and / or, the second width d2 is less than 8 mm.

[0076] For example, the first width d1 is greater than 8 mm, avoiding excessively increasing the thickness of the first portion 21 to reduce the resistance of the busbar 20, reducing the risk of the battery sheet 10 breaking, and making the resistance of the busbar 20 smaller; after the second portion 22 passes through the lead hole 31, since the lead hole 31 has a larger width, the back plate 30 is prone to breaking and other risks, so the second width d2 needs to be reduced, and the second width d2 is less than 8 mm, thereby reducing the risk of the back plate 30 and the battery sheet 10 breaking and other effects, improving the reliability of the photovoltaic module.

[0077] For example, the first thickness h1 is less than 0.2 mm to reduce the risk of the battery sheet 10 breaking.

[0078] In some embodiments, the cross-sectional area of the first portion 21 is greater than 1.8 mm 2 ; and / or, the cross-sectional area of the second portion 22 is less than 1.8 mm 2 .

[0079] For example, the cross-sectional area of the first portion 21 is greater than 1.8 mm 2 , so that the resistance of the busbar 20 is smaller, and the cross-sectional area of the second portion 22 is less than 1.8 mm 2 , so that the area of the lead hole 31 is also smaller, thereby reducing the risk of the back plate 30 and the battery sheet 10 breaking and other effects, improving the reliability of the photovoltaic module.

[0080] In some embodiments, as shown in Figure 4 and Figure 5 , the at least one busbar 20 including the first portion 21 and the second portion 22 is a middle busbar 20z, the plurality of battery sheets 10 includes a first battery sheet 11a and a second battery sheet 11b arranged adjacent to each other, and the at least one middle busbar 20z is arranged at a middle position of the first battery sheet 11a and the second battery sheet 11b.

[0081] For example, the current of the plurality of battery sheets 10 is converged to the junction box 40 by the middle busbar 20z, which can reduce the current transmission path and reduce transmission loss, thereby improving the photoelectric conversion efficiency.

[0082] For example, the middle busbar 20z is located on the back surface of the middle part of the battery sheet 10, so that the battery sheet 10 and the back plate 30 are more prone to breaking and other risks, and any one of the above embodiments needs to be adopted to reduce the risk of the back plate 30 and the battery sheet 10 breaking and other effects, thereby improving the reliability of the photovoltaic module.

[0083] In some embodiments, as shown in Figure 4 , please refer to Figure 1As shown, the intermediate busbar 20z and the first solar cell 11a are stacked in the thickness direction of the first solar cell 11a. The back contact photovoltaic module 100 also includes an insulating film 60, which is disposed between the intermediate busbar 20z and the first solar cell 11a. The first solar cell 11a includes a first electrode 111 and a second electrode 112 located on the back surface of the first solar cell 11a. The insulating film 60 has a plurality of openings 601, and the intermediate busbar 20z is electrically connected to the first electrode 111 on the back surface of the first solar cell 11a through the openings 601.

[0084] For example, a busbar 20 is disposed on the back side of the first battery cell 11a. The back side of the first battery cell 11a is provided with a first electrode 111 and a second electrode 112. The busbar 20 needs to be electrically connected to the first electrode 111 and insulated from the second electrode 112. An insulating film 60 is used to insulate the busbar 20 from the second electrode 112. The busbar 20 is electrically connected to the first electrode 111 on the back surface of the first battery cell 11a through an opening 601.

[0085] In some implementations, such as Figure 5 As shown, please refer to Figure 1 As shown, the intermediate busbar 20z and the first solar cell 11a are stacked in the thickness direction of the first solar cell 11a. The back contact photovoltaic module 100 also includes an insulating film 60, which is disposed between the intermediate busbar 20z and the first solar cell 11a. The first solar cell 11a includes a first electrode 111 and a second electrode 112 located on the back surface of the first solar cell 11a. The insulating film 60 includes a plurality of spaced insulating strips 602 and a gap 603 located between two adjacent insulating strips 602. The insulating strips 602 cover the second electrode 112 on the back surface of the first solar cell 11a. The intermediate busbar 20z is electrically connected to the first electrode 111 on the back surface of the first solar cell 11a through the gap 603.

[0086] For example, the insulating strip 602 covers the second electrode 112 on the back surface of the first battery cell 11a, so that the second electrode 112 is insulated from the busbar 20, and the intermediate busbar 20z is electrically connected to the first electrode 111 on the back surface of the first battery cell 11a through the gap 603.

[0087] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The above embodiments only express several implementation ways of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation to the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A back contact photovoltaic module, characterized by, The photovoltaic laminate comprises a plurality of cell pieces, a back sheet, a solder strip and a busbar, the plurality of cell pieces are connected by the solder strip to form a cell string, the cell string is stacked with the back sheet, and the cell string is connected with the busbar. The back sheet is provided with a lead hole penetrating through the back sheet. At least one of the busbars comprises a first part arranged between the back side of the cell piece and the back sheet, and a second part connected with the first part, and the second part is arranged through the lead hole. The first part has a first width, and the second part has a second width, and the second width is smaller than the first width. The first width refers to the size of the first part along the width direction of the first part, the width direction of the first part, the longitudinal extension direction of the first part and the thickness direction of the first part are perpendicular to each other. The second width refers to the size of the second part along the width direction of the second part, the width direction of the second part, the longitudinal extension direction of the second part and the thickness direction of the second part are perpendicular to each other. In the direction perpendicular to the longitudinal extension direction of the first part, the cross-sectional area of the first part is a first area.

2. The back contact photovoltaic module of claim 1, wherein, In the direction perpendicular to the longitudinal extension direction of the second part, the cross-sectional area of the second part is a second area, and the second area is smaller than or equal to the first area. The second area is smaller than the first area.

3. The back contact photovoltaic assembly of claim 2, wherein, The first part has a first thickness along the thickness direction of the first part, and the second part has a second thickness along the thickness direction of the second part, and the first thickness is equal to the second thickness. With respect to the first part, at least one notch is arranged on the busbar in the width direction of the second part.

4. The back contact photovoltaic assembly of claim 3, wherein, In the width direction of the second part, the second part comprises a folding line on at least one side of the second part.

5. The back contact photovoltaic assembly of claim 2, wherein, In the thickness direction of the second part, the second part comprises a main body part and two folding parts respectively arranged on both sides of the main body part in the thickness direction of the second part.

6. The back contact photovoltaic assembly of claim 5, wherein, The first width is greater than 8mm; and / or, 7. The back contact photovoltaic assembly of claim 1, wherein, The second width is less than 8mm. The busbar comprising the first part and the second part is an intermediate busbar, the plurality of cell pieces comprise a first cell piece and a second cell piece arranged adjacent to each other, and the intermediate busbar is arranged corresponding to the intermediate position of the first cell piece and the second cell piece.

8. The back contact photovoltaic assembly of claim 2, wherein, the first portion has a cross-sectional area greater than 1.8 mm 2 ; and / or, the second portion has a cross-sectional area less than 1.8 mm 2 .

9. The back contact photovoltaic assembly of claim 1, wherein, The intermediate busbar is stacked with the first cell piece in the thickness direction of the first cell piece, the back contact photovoltaic module further comprises an insulating film arranged between the intermediate busbar and the first cell piece, and the first cell piece comprises a first electrode and a second electrode arranged on the back side surface of the first cell piece.

10. The back contact photovoltaic module of claim 9, wherein, The insulating film has a plurality of openings, and the intermediate busbar is electrically connected with the first electrode on the back side surface of the first cell piece through the openings; or, ​ The insulating film comprises a plurality of insulating strips arranged at intervals and gap portions between adjacent two insulating strips, the insulating strips cover the second electrodes on the back surface of the first battery piece, and the intermediate bus bar is electrically connected with the first electrodes on the back surface of the first battery piece through the gap portions.

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