Photovoltaic module

Abstract

The invention relates to the technical field of solar cells, in particular to a photovoltaic module. The photovoltaic module at least comprises a bus bar, a battery string and a first welding strip, in the first direction, the bus bar is located on at least one side of the battery string, the two sides of the first welding strip are welded and fixed to the bus bar and the battery string respectively, and the connecting glue is bonded and fixed to the bus bar and the first welding strip. The first welding strip comprises a welding surface and a bonding surface, in the third direction, the welding surface and the bonding surface are located on the two sides of the first welding strip respectively, the welding surface and the bus bar are welded and fixed, the bonding surface and the connecting glue are bonded and fixed, and the projection of the welding surface and the projection of the bonding surface coincide. On the basis that the first welding strip and the bus bar are welded and fixed, the first welding strip and the bus bar are bonded and fixed through the connecting glue, and the drawing force of the first welding strip on the bus bar is improved. And the connection glue reinforces the connection between the first welding strip and the bus bar at the welding position, so that the drawing force of the first welding strip on the bus bar is further improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a photovoltaic module. Background Art

[0002] The photovoltaic module includes a battery string and a bus bar. The battery string and the bus bar are electrically connected by welding strips to achieve series and parallel connection of adjacent battery strings.

[0003] Typically, the soldering ribbon and the bus bar are fixed by welding, but due to the size of the soldering ribbon and the bus bar, the fixing effect of the soldering ribbon and the bus bar is poor, resulting in a small pull-out force of the soldering ribbon.

[0004] Therefore, how to improve the fixing effect between the soldering ribbon and the busbar is an important issue that needs to be solved in this field. Summary of the Invention

[0005] The present application provides a photovoltaic assembly that can improve the fixing effect of welding ribbons and bus bars.

[0006] The present application provides a photovoltaic module, which includes at least a busbar, a cell string, and a first welding ribbon. In a first direction, the busbar is located on at least one side of the cell string. In the first direction, both sides of the first welding ribbon are welded and fixed to the busbar and the cell string, respectively. The photovoltaic module also includes a connecting adhesive, which is bonded and fixed to the busbar and the first welding ribbon, respectively. The first welding ribbon includes a welding surface and an adhesive surface. In a third direction, the welding surface and the adhesive surface are located on both sides of the first welding ribbon, respectively. The welding surface is welded and fixed to the busbar, and the adhesive surface is bonded and fixed to the connecting adhesive. In the third direction, the projections of the welding surface and the adhesive surface overlap.

[0007] In the present application, on the basis of welding and fixing the first welding ribbon and the bus bar, a connecting glue is added, and the first welding ribbon and the bus bar are bonded and fixed by the connecting glue, thereby improving the connection stability between the first welding ribbon and the bus bar, reducing the risk of the first welding ribbon being separated from the bus bar under the action of external force, and improving the pulling force of the first welding ribbon on the bus bar, so as to improve the stability of the photovoltaic module.

[0008] There is an overlapping part between the projections of the welding surface and the bonding surface, so that the connecting glue strengthens the connection between the first welding strip and the bus bar at the welding position, so that the adhesion force of the connecting glue on the first welding strip and the bus bar and the welding force of the first welding strip and the bus bar are concentrated at the same position, so that the connection force between the first welding strip and the bus bar is concentrated, further improving the pulling force of the first welding strip on the bus bar.

[0009] In some possible designs, the bonding area between the connecting glue and the first soldering tape is S1, 0.02mm 2 ≤S1≤4mm 2The bonding area between the connecting glue and the busbar is S2, 0.2mm 2 ≤S2≤8mm 2 .

[0010] In some possible designs, there is one connecting adhesive on one first soldering ribbon. Alternatively, there are multiple connecting adhesives on one first soldering ribbon, and the multiple connecting adhesives are arranged along the first direction and / or the second direction.

[0011] In some possible designs, there are multiple connecting adhesives on a first soldering strip, and adjacent connecting adhesives are in contact. Alternatively, there are multiple connecting adhesives on a first soldering strip, and gaps are left between adjacent connecting adhesives.

[0012] In some possible designs, a plurality of connecting adhesives are provided on a first soldering strip, with gaps between adjacent connecting adhesives. In the arrangement direction of the connecting adhesives, the size of the gap is L, and L is ≤ 1 mm.

[0013] In some possible designs, there are multiple connecting adhesives on one first welding strip, and the multiple connecting adhesives are evenly arranged.

[0014] In some possible designs, the connecting adhesive includes a first connecting portion and a second connecting portion, wherein at least a portion of the first connecting portion is bonded and fixed to the first soldering ribbon, and at least a portion of the second connecting portion is bonded and fixed to the busbar. In the third direction, the first connecting portion and the second connecting portion have the same thickness.

[0015] In some possible designs, the connecting adhesive includes a first connecting portion and a second connecting portion, wherein at least a portion of the first connecting portion is bonded and fixed to the first welding ribbon, and at least a portion of the second connecting portion is bonded and fixed to the busbar. The first connecting portion includes a first surface, which is located on a side of the first connecting portion facing away from the first welding ribbon in a third direction. The second connecting portion includes a second surface, which is located on a side of the second connecting portion facing away from the busbar in the third direction. The first surface and the second surface are located in the same plane perpendicular to the third direction, such that the thickness of the second connecting portion is greater than the thickness of the first connecting portion.

[0016] In some possible designs, the connecting glue is a conductive glue or an insulating glue.

[0017] In some possible designs, the cross-section of the first welding ribbon is circular or rectangular.

[0018] In some possible designs, the cell string includes at least a first cell and a second cell. In a first orientation, the first cell is positioned between a bus bar and the second cell. A first welding ribbon is welded to the first cell. The photovoltaic module further includes a second welding ribbon. In the first orientation, two sides of the second welding ribbon are welded to the first cell and the second cell, respectively, to electrically connect the first cell and the second cell. Both the first welding ribbon and the second welding ribbon are welded to the backlight surface of the first cell.

[0019] It should be understood that the foregoing general description and the following detailed description are merely illustrative and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 A cross-sectional view of the structure of a photovoltaic module provided in this application in some embodiments; Figure 2 A schematic diagram of the connection structure of battery layers in some embodiments; Figure 3 for Figure 2 Schematic diagram of the connection structure of the battery cell and the welding ribbon; Figure 4 for Figure 2 Schematic diagram of the connection structure of bus bars, welding ribbons and battery cells in some embodiments; Figure 5 is a schematic diagram of the connection structure of battery layers in other embodiments; Figure 6 for Figure 5 Schematic diagram of the connection structure of the battery cell and the welding ribbon; Figure 7 for Figure 5 Schematic diagram of the connection structure of bus bars, welding ribbons and battery cells in some embodiments; Figure 8 Schematic diagram of the connection structure of busbars, welding ribbons and battery strings provided in this application in other embodiments; Figure 9 for Figure 8 Left side view of the connection locations of the center busbar, solder ribbon, and battery string; Figure 10 for Figure 8 A left side view of the connection position of the bus bar, welding ribbon and battery string in another embodiment; Figure 11 for Figure 8 A left side view of the connection position of the bus bar, welding ribbon and battery string in another embodiment; Figure 12 Schematic diagram of the connection structure of the busbar, welding ribbon and connecting adhesive provided in this application in some embodiments; Figure 13 Schematic diagram of the connection structure of the busbar, welding ribbon and connecting adhesive provided in this application in other embodiments.

[0022] Reference numerals: 100-photovoltaic module; 110-cover plate; 120-encapsulation layer; 130 - battery layer; 131 - battery string; 131A - battery cell; 131A1 - first battery cell; 131A2 - second battery cell; 131A3 - first battery cell; 131A4 - second battery cell; 131B - soldering strip; 131B1 - first soldering strip; 131B2 - second soldering strip; 131B3 - soldering surface; 131B4 - bonding surface; 132 - bus bar; 133 - connection adhesive; 133A - first connection portion; 133B - second connection portion; 133C - first surface; 133D - second surface; X-first direction; Y-second direction; Z-third direction. DETAILED DESCRIPTION

[0023] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0024] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0025] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0026] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0027] The embodiment of the present application provides a photovoltaic module, Figure 1 FIG is a cross-sectional view of the structure of a photovoltaic module in some embodiments. Figure 1 As shown, the photovoltaic module 100 includes a cover plate 110 , an encapsulation layer 120 and a cell layer 130 .

[0028] The cover plate 110 may be made of a rigid material such as tempered glass, PET (Polyethylene Terephthalate), or PC (Polycarbonate).

[0029] Alternatively, the cover plate 110 may be made of a flexible material such as PVF (Polyvinyl Fluoride), ETFE (Ethylene-Tetra-Fluoro-Ethylene), or PVDF (Polyvinylidene Fluoride).

[0030] The encapsulation layer 120 is located between the cover plate 110 and the battery layer 130. The encapsulation layer 120 is used to achieve encapsulation and fixation of the battery layer 130 and the cover plate 110. The material of the encapsulation layer 120 is one of polyolefins such as EVA (Ethylene-Vinyl Acetate Copolymer), POE (Polyolefin Elastomer), PVB (Polyvinyl Butyral), etc. The above materials have high light transmittance, which is beneficial to improving the photoelectric conversion efficiency of photovoltaic modules.

[0031] The encapsulation layer 120 may also be an EPE film (EVA-POE-EVA co-extruded structure) or an EP film (EVA-POE co-extruded structure).

[0032] Figure 2 FIG. 1 is a schematic diagram of the connection structure of the battery layer in some embodiments. Figure 2 As shown, the battery layer 130 includes a plurality of battery strings 131, a battery string 131 includes a plurality of battery cells 131A, adjacent battery cells 131A are connected by welding strips 131B, a bus bar 132 is provided on at least one side of the battery string 131, and adjacent battery strings 131 are electrically connected by the bus bar 132 to realize series or parallel connection between adjacent battery strings 131, so as to improve the output power of the photovoltaic module.

[0033] like Figure 2 As shown, the battery layer 130 has a first direction X, a second direction Y and a third direction Z that are perpendicular to each other. The first direction X is parallel to the length direction of the welding ribbon 131B, and the third direction Z is parallel to the thickness direction of the battery cell 131A.

[0034] The types of cell 131A include but are not limited to Passivated Emitter Rear Cell (PERC), Tunnel Oxide Passivated Contact (TOPCon), Heterojunction with Intrinsic Thin-film (HJT), Interdigitated Back Contact (IBC), perovskite cell, etc.

[0035] A PERC cell, along its thickness, consists of a front surface silver electrode, a front surface silicon nitride passivation layer, a phosphorus emitter layer, a P-type silicon substrate layer, a local aluminum back field, a metal aluminum back electrode, and a back passivation layer (Al2O3 / SiNx). PERC cells use a passivation film to passivate the back surface, replacing the all-aluminum back field. This enhances internal back reflection of light from the silicon substrate, reduces the back recombination rate, and increases cell efficiency by 0.5%-1%.

[0036] A TOPCon cell, along its thickness, consists of a silver electrode, a front silicon nitride passivation layer, a boron-doped emitter, an N-type base silicon layer, a diffused doped layer, an ultrathin silicon oxide layer, doped polysilicon, silicon nitride, and a silver electrode. The back of the cell consists of an ultrathin silicon oxide layer (1nm-2nm) and a phosphorus-doped microcrystalline amorphous hybrid silicon thin film, which together form a passivated contact structure. This structure blocks minority carrier-hole recombination, improving the cell's open-circuit voltage and short-circuit current. The ultrathin oxide layer allows majority electrons to tunnel into the polysilicon layer while blocking minority carrier-hole recombination. The excellent passivation effect of the ultrathin silicon oxide and heavily doped silicon film causes surface band bending of the silicon wafer, creating a field passivation effect. This significantly increases the probability of electron tunneling and reduces contact resistance, thereby increasing the cell's open-circuit voltage and short-circuit current, and thus improving the cell's conversion efficiency.

[0037] For HJT cells, along their thickness direction, the HJT cells include a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type base silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode.

[0038] An IBC cell, along its thickness, consists of a silicon nitride inversion layer, an N+ front surface field, an N-type base silicon layer, a P+ emitter, an N+ back field, an aluminum oxide passivation layer, a silicon nitride anti-reflection layer, and a metallic silver electrode. IBC cells utilize ion implantation technology to achieve P and N regions with excellent uniformity and precisely controllable junction depth. The front of the cell is free of grid lines, eliminating current losses from metal electrode shading and maximizing the utilization of incident photons. This improves short-circuit current by approximately 7% compared to conventional solar cells. Due to the back-contact structure, grid line shading is not a concern, allowing for a wider grid line ratio, reducing series resistance and achieving a high fill factor. Surface passivation and surface light trapping structures can be optimized, resulting in a lower front-surface recombination rate and surface reflection.

[0039] A perovskite cell, along its thickness, consists of a substrate material, a conductive film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. Photons absorbed by the perovskite material are converted into electrons, which are easily collected by the electrode with minimal loss. This results in high photogenerated voltage and current, leading to high photoelectric conversion efficiency.

[0040] Figure 2 The example of battery cell 131A is TOPCon battery. On this basis, Figure 3 for Figure 2 Schematic diagram of the connection structure of the battery cell 131A and the welding ribbon 131B, as shown in Figure 3 As shown, the battery cell 131A includes at least a first battery cell 131A1 and a second battery cell 131A2 adjacent to each other, one end of the soldering ribbon 131B is connected to the backlight surface of the first battery cell 131A1, and the other end of the soldering ribbon 131B is connected to the light-facing surface of the second battery cell 131A2, so that the first battery cell 131A1 and the second battery cell 131A2 are electrically connected through the soldering ribbon 131B.

[0041] based on Figure 2 and Figure 3 The structure shown, Figure 4 FIG. 1 is a schematic diagram of the connection structure of busbars, welding ribbons and battery cells in some embodiments. Figure 4As shown, the welding strip 131B includes a first welding strip 131B1 and a second welding strip 131B2. In the first direction X, the two ends of the second welding strip 131B2 are respectively connected to the first battery cell 131A1 and the second battery cell 131A2, the second welding strip 131B2 is connected to the backlight surface of the first battery cell 131A1, and the second welding strip 131B2 is connected to the light-facing surface of the second battery cell 131A2, so that the first battery cell 131A1 and the second battery cell 131A2 are connected in series to form a battery string 131, and the two sides of the first welding strip 131B1 are respectively connected to the bus bar 132 and the battery string 131, so as to realize the series or parallel connection of adjacent battery strings 131.

[0042] At this time, the first cell 131A1 is located between the second cell 131A2 and the bus bar 132, one of the first and second welding strips 131B1 and 131B2 is connected to the light-facing surface of the first cell 131A1, and the other is connected to the backlight surface of the first cell 131A1.

[0043] Figure 5 is a schematic diagram of the connection structure of the battery layer in some other embodiments, Figure 5 The example of battery cell 131A is an IBC battery. On this basis, Figure 6 for Figure 5 Schematic diagram of the connection structure of the battery cell 131A and the welding ribbon 131B, as shown in Figure 6 As shown, the battery cell 131A includes at least an adjacent first battery cell 131A3 and a second battery cell 131A4, one end of the soldering ribbon 131B is connected to the backlight surface of the first battery cell 131A3, and the other end of the soldering ribbon 131B is connected to the backlight surface of the second battery cell 131A4, so that the first battery cell 131A3 and the second battery cell 131A4 are electrically connected through the soldering ribbon 131B.

[0044] based on Figure 5 and Figure 6 The structure shown, Figure 7 FIG. 1 is a schematic diagram of the connection structure of busbars, welding ribbons and battery cells in some embodiments. Figure 7 As shown, the welding strip 131B includes a first welding strip 131B1 and a second welding strip 131B2. In the first direction X, the two ends of the second welding strip 131B2 are respectively connected to the backlight surface of the first battery cell 131A3 and the backlight surface of the second battery cell 131A4, so that the first battery cell 131A3 and the second battery cell 131A4 are connected in series to form a battery string 131. The two sides of the first welding strip 131B1 are respectively connected to the bus bar 132 and the battery string 131 to realize the series or parallel connection of adjacent battery strings 131.

[0045] At this time, the first cell 131A3 is located between the second cell 131A4 and the bus bar 132 , and the first welding ribbon 131B1 and the second welding ribbon 131B2 are both connected to the backlight surface of the first cell 131A3 .

[0046] The embodiment of the present application does not specifically limit the specific type of the battery cell 131A. Figure 5 、 Figure 6 and Figure 7 The structure shown discusses the specific structure of the photovoltaic module in detail.

[0047] Typically, the first welding ribbon 131B1 is fixed to the bus bar 132 by welding, and the welding area between the first welding ribbon 131B1 and the bus bar 132 is limited by the size of the first welding ribbon 131B1 and the bus bar 132, resulting in a poor fixing effect of the first welding ribbon 131B1 and the bus bar 132, resulting in a small pulling force of the first welding ribbon 131B1, and there is a risk of the first welding ribbon 131B1 being separated from the bus bar 132 under the action of external force.

[0048] In view of this, Figure 8 FIG. 1 is a schematic diagram of the connection structure of busbars, welding ribbons and battery strings in some embodiments. Figure 8 As shown, the photovoltaic module further includes a connection adhesive 133 , which is bonded and fixed to the bus bar 132 and the first welding ribbon 131B1 , respectively.

[0049] Figure 9 for Figure 8 Left view of the connection position of the bus bar, welding ribbon and battery string, as shown in Figure 9 As shown, the first welding strip 131B1 includes a welding surface 131B3 and a bonding surface 131B4. In the third direction Z, the welding surface 131B3 and the bonding surface 131B4 are respectively located on both sides of the first welding strip 131B1. The welding surface 131B3 is welded and fixed to the bus bar 132, and the bonding surface 131B4 is bonded and fixed to the connecting glue 133. In the third direction Z, the projections of the welding surface 131B3 and the bonding surface 131B4 overlap.

[0050] In this embodiment, on the basis of welding and fixing the first welding ribbon 131B1 to the bus bar 132, a connecting glue 133 is added. The connecting glue 133 allows the first welding ribbon 131B1 to be bonded and fixed to the bus bar 132, thereby improving the connection stability between the first welding ribbon 131B1 and the bus bar 132 and reducing the risk of the first welding ribbon 131B1 being separated from the bus bar 132 under the action of external force, thereby increasing the pulling force of the first welding ribbon 131B1 on the bus bar 132, thereby improving the stability of the photovoltaic module.

[0051] There is an overlapping part between the projections of the welding surface 131B3 and the bonding surface 131B4, so that the connecting glue 133 strengthens the connection between the first welding strip 131B1 and the bus bar 132 at the welding position, so that the adhesion force of the connecting glue 133 on the first welding strip 131B1 and the bus bar 132 and the welding force of the first welding strip 131B1 and the bus bar 132 are concentrated at the same position, so that the connection force between the first welding strip 131B1 and the bus bar 132 is concentrated, thereby further improving the pulling force of the first welding strip 131B1 on the bus bar 132.

[0052] The cross-sectional profile of the first welding ribbon 131B1 may be circular or rectangular. Figure 9 The cross section of the first welding ribbon 131B1 here refers to the cross section obtained by cutting the first welding ribbon 131B1 along the plane surrounded by the second direction Y and the third direction Z. Figure 9 In the example, the outline shape of the cross section of the first welding ribbon 131B1 is a circle.

[0053] Figure 10 for Figure 8 A left view of the connection position of the busbar, welding ribbon and battery string in another embodiment, Figure 10 The cross-sectional profile of the first welding ribbon 131B1 is shown as a rectangle.

[0054] In addition, the cross-sectional profile of the first welding ribbon 131B1 may also be a triangle, a trapezoid, or other shapes. The embodiment of the present application does not impose any special limitation on the cross-sectional profile of the first welding ribbon 131B1.

[0055] The bonding area between the connecting glue 133 and the first soldering strip 131B1 is S1, 0.02mm 2 ≤S1≤4mm 2 For example, the bonding area between the connecting adhesive 133 and the first soldering ribbon 131B1 can be 0.02mm 2 , 0.5mm 2 , 1mm 2 , 1.5mm 2 , 2mm 2 , 2.5mm 2 , 3mm 2 , 3.5mm 2 , 4mm 2 wait.

[0056] If the bonding area between the connection adhesive 133 and the first soldering ribbon 131B1 is small, the bonding stability between the connection adhesive 133 and the first soldering ribbon 131B1 is poor.

[0057] If the bonding area between the connection adhesive 133 and the first soldering ribbon 131B1 is larger, the cost of the connection adhesive 133 is higher.

[0058] Therefore, 0.02mm 2 ≤S1≤4mm 2 , which can improve the bonding stability between the connecting adhesive 133 and the first welding ribbon 131B1 and reduce the size of the connecting adhesive 133 , thereby reducing the material cost of the connecting adhesive 133 .

[0059] For example, 0.02 mm 2 ≤S1≤2mm 2 The bonding area between the connecting glue 133 and the first soldering tape 131B1 can be 0.02mm 2 , 0.04mm 2 , 0.06mm 2 , 0.08mm 2 , 0.1mm 2 , 0.12mm 2 , 0.14mm 2 , 0.16mm 2 , 0.18mm 2 , 0.2mm 2 , 0.22mm 2 , 0.24mm 2 , 0.26mm 2 , 0.28mm 2 , 0.3mm 2 , 0.32mm 2 , 0.34mm 2 , 0.36mm 2 , 0.38mm 2 , 0.4mm 2 , 0.42mm 2 , 0.44mm 2 , 0.46mm 2 , 0.48mm 2 , 0.5mm 2 , 0.52mm 2 , 0.54mm 2 , 0.56mm 2 , 0.58mm 2 , 0.6mm 2 , 0.62mm 2 , 0.64mm 2 , 0.66mm 2 , 0.68mm 2 , 0.7mm 2 , 0.72mm 2 , 0.74mm 2 , 0.76mm 2 , 0.78mm 2 , 0.8mm 2 , 0.82mm2 , 0.84mm 2 , 0.86mm 2 , 0.88mm 2 , 0.9mm 2 , 0.92mm 2 , 0.94mm 2 , 0.96mm 2 , 0.98mm 2 , 1mm 2 , 1.2mm 2 , 1.4mm 2 , 1.6mm 2 , 1.8mm 2 , 2mm 2 wait.

[0060] For example, 2 mm 2 ≤S1≤4mm 2 The bonding area between the connecting glue 133 and the first welding strip 131B1 can be 2mm 2 , 2.2mm 2 , 2.4mm 2 , 2.6mm 2 , 2.8mm 2 , 3mm 2 , 3.2mm 2 , 3.4mm 2 , 3.6mm 2 , 3.8mm 2 , 4mm 2 wait.

[0061] The bonding area between the connecting glue 133 and the bus bar 132 is S2, 0.2mm 2 ≤S2≤8mm 2 The bonding area between the connecting glue 133 and the bus bar 132 can be 0.02mm 2 , 0.5mm 2 , 1mm 2 , 1.5mm 2 , 2mm 2 , 2.5mm 2 , 3mm 2 , 3.5mm 2 , 4mm 2 , 4.5mm 2 , 5mm 2 , 5.5mm 2 , 6mm 2 , 6.5mm 2 , 7mm 2 , 7.5mm 2 , 8mm 2 wait.

[0062] If the bonding area between the connection adhesive 133 and the bus bar 132 is small, the bonding stability between the connection adhesive 133 and the bus bar 132 is poor.

[0063] If the bonding area between the connection adhesive 133 and the bus bar 132 is larger, the cost of the connection adhesive 133 is higher.

[0064] Therefore, 0.2mm 2 ≤S2≤8mm 2 , which can improve the bonding stability between the connecting glue 133 and the bus bar 132 and reduce the size of the connecting glue 133 , thereby reducing the material cost of the connecting glue 133 .

[0065] For example, 0.02 mm 2 ≤S2≤2mm 2 The bonding area between the connecting glue 133 and the bus bar 132 can be 0.02mm 2 , 0.04mm 2 , 0.06mm 2 , 0.08mm 2 , 0.1mm 2 , 0.12mm 2 , 0.14mm 2 , 0.16mm 2 , 0.18mm 2 , 0.2mm 2 , 0.22mm 2 , 0.24mm 2 , 0.26mm 2 , 0.28mm 2 , 0.3mm 2 , 0.32mm 2 , 0.34mm 2 , 0.36mm 2 , 0.38mm 2 , 0.4mm 2 , 0.42mm 2 , 0.44mm 2 , 0.46mm 2 , 0.48mm 2 , 0.5mm 2 , 0.52mm 2 , 0.54mm 2 , 0.56mm 2 , 0.58mm 2 , 0.6mm 2 , 0.62mm 2 , 0.64mm 2 , 0.66mm 2 , 0.68mm2 , 0.7mm 2 , 0.72mm 2 , 0.74mm 2 , 0.76mm 2 , 0.78mm 2 , 0.8mm 2 , 0.82mm 2 , 0.84mm 2 , 0.86mm 2 , 0.88mm 2 , 0.9mm 2 , 0.92mm 2 , 0.94mm 2 , 0.96mm 2 , 0.98mm 2 , 1mm 2 , 1.2mm 2 , 1.4mm 2 , 1.6mm 2 , 1.8mm 2 , 2mm 2 wait.

[0066] For example, 2 mm 2 ≤S2≤4mm 2 The bonding area between the connecting glue 133 and the bus bar 132 can be 2mm 2 , 2.2mm 2 , 2.4mm 2 , 2.6mm 2 , 2.8mm 2 , 3mm 2 , 3.2mm 2 , 3.4mm 2 , 3.6mm 2 , 3.8mm 2 , 4mm 2 wait.

[0067] For example, 4mm 2 ≤S2≤6mm 2 The bonding area between the connecting glue 133 and the bus bar 132 can be 4mm 2 , 4.2mm 2 , 4.4mm 2 , 4.6mm 2 , 4.8mm 2 , 5mm 2 , 5.2mm 2 , 5.4mm 2 , 5.6mm 2 , 5.8mm 2 , 6mm2 wait.

[0068] For example, 6mm 2 ≤S2≤8mm 2 The bonding area between the connecting glue 133 and the bus bar 132 can be 6mm 2 , 6.2mm 2 , 6.4mm 2 , 6.6mm 2 , 6.8mm 2 , 7mm 2 , 7.2mm 2 , 7.4mm 2 , 7.6mm 2 , 7.8mm 2 , 8mm 2 wait.

[0069] Continue to refer Figure 10 The connecting adhesive 133 includes a first connecting portion 133A and a second connecting portion 133B. At least a portion of the first connecting portion 133A is bonded and fixed to the first welding ribbon 131B1, and at least a portion of the second connecting portion 133B is bonded and fixed to the busbar 132. In the third direction Z, the first connecting portion 133A and the second connecting portion 133B have the same thickness, resulting in a height difference between the surface of the connecting adhesive 133 facing away from the busbar 132.

[0070] In this embodiment, the first connection portion 133A and the second connection portion 133B have the same thickness, so that the thickness of the connection adhesive 133 at each position remains consistent, which can reduce the processing cost of the connection adhesive 133 .

[0071] Figure 11 for Figure 8 The left side view of the connection position of the bus bar, welding ribbon and battery string in another embodiment. Figure 11 As shown, the first connection portion 133A includes a first surface 133C. In the third direction Z, the first surface 133C is located on the side of the first connection portion 133A facing away from the first welding ribbon 131B1. The second connection portion 133B includes a second surface 133D. In the third direction Z, the second surface 133D is located on the side of the second connection portion 133B facing away from the bus bar 132. The first surface 133C and the second surface 133D are located in the same plane perpendicular to the third direction Z, so that the thickness of the second connection portion 133B is greater than that of the first connection portion 133A.

[0072] In this embodiment, the thickness of the second connecting portion 133B is greater than the thickness of the first connecting portion 133A, so that the surface of the connecting glue 133 facing away from the bus bar 132 is a flat surface perpendicular to the third direction Z, thereby improving the flatness of the surface of the connecting glue 133, so as to improve the lamination quality in the subsequent lamination process.

[0073] On one first welding ribbon 131B1 , the number of the connecting adhesive 133 may be one or more.

[0074] Reference again Figure 8 , Figure 8 The example shows that the number of the connecting adhesive 133 on the first welding ribbon 131B1 is one, thereby reducing the difficulty of attaching the connecting adhesive 133 to the surfaces of the first welding ribbon 131B1 and the bus bar 132 .

[0075] Figure 12 FIG. 1 is a schematic diagram of the connection structure of busbars, welding strips and connecting adhesive in some embodiments. Figure 12 As shown, there are multiple connecting adhesives 133 on a first welding ribbon 131B1, and the multiple connecting adhesives 133 are arranged along the first direction X and / or the second direction Y, that is, the connecting adhesive 133 can be arranged only along the first direction X, or only along the second direction Y, or along both the first direction X and the second direction Y.

[0076] Figure 12 In this example, there are two connecting adhesives 133 on a first welding ribbon 131B1 , and the two connecting adhesives 133 are arranged along the second direction Y.

[0077] Figure 13 Schematic diagram of the connection structure of busbars, welding ribbons and connecting adhesive in other embodiments. Figure 13 In this example, the number of the connecting adhesives 133 on a first welding ribbon 131B1 is four, a portion of the connecting adhesives 133 is arranged along the first direction X, and another portion of the connecting adhesives 133 is arranged along the second direction Y.

[0078] The embodiment of the present application does not impose any special limitation on the specific number and arrangement of the connecting adhesive 133 .

[0079] When there are multiple connecting adhesives 133 on one first welding ribbon 131B1 , adjacent connecting adhesives 133 may be in contact with each other or have gaps therebetween, that is, the distance between adjacent connecting adhesives 133 may be 0 or greater than 0.

[0080] When adjacent connection adhesives 133 on a first welding ribbon 131B1 come into contact, the arrangement density of the connection adhesive 133 can be increased, thereby increasing the force exerted by the connection adhesive 133 on the first welding ribbon 131B1 and thereby increasing the pulling force between the first welding ribbon 131B1 and the bus bar 132 .

[0081] When gaps are left between adjacent connection adhesives 133 on a first welding ribbon 131B1 , it can reduce the difficulty of attaching the connection adhesive 133 to the first welding ribbon 131B1 and help improve the smoothness of attaching the connection adhesive 133 to the first welding ribbon 131B1 .

[0082] like Figure 13 As shown, when a gap is left between adjacent connecting adhesives 133 on a first welding strip 131B1, the size of the gap is L in the arrangement direction of the connecting adhesive 133, L≤1mm. For example, the gap between adjacent connecting adhesives 133 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc.

[0083] If the gap between adjacent connecting adhesives 133 is large, the number of connecting adhesives 133 provided in the preset covering area of ​​the connecting adhesive 133 is small, and the force exerted by the connecting adhesive 133 on the first welding strip 131B1 is relatively dispersed, resulting in a poor effect of enhancing the pulling force of the connecting adhesive 133 on the first welding strip 131B1.

[0084] Therefore, L≤1mm can increase the number of connection adhesives 133 set in the preset area and concentrate the force of the connection adhesive 133 on the first welding strip 131B1, thereby improving the pulling force of the first welding strip 131B1, so as to further improve the pulling force of the first welding strip 131B1 on the bus bar 132.

[0085] Exemplarily, L≤0.5mm, the gap between adjacent connecting glues 133 can be 0.02mm, 0.04mm, 0.06mm, 0.08mm, 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm, 0.22mm, 0.24mm, 0.26mm, 0.28mm, 0.3mm, 0.32mm, 0.34mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.44mm, 0.46mm, 0.48mm, 0.5mm, etc.

[0086] Exemplarily, 0.5mm≤L≤1mm, the gap between adjacent connecting glue 133 can be 0.5mm, 0.52mm, 0.54mm, 0.56mm, 0.58mm, 0.6mm, 0.62mm, 0.64mm, 0.66mm, 0.68mm, 0.7mm, 0.72mm, 0.74mm, 0.76mm, 0.78mm, 0.8mm, 0.82mm, 0.84mm, 0.86mm, 0.88mm, 0.9mm, 0.92mm, 0.94mm, 0.96mm, 0.98mm, 1mm, etc.

[0087] When there are multiple connection adhesives 133 on one first welding ribbon 131B1 , the connection adhesives 133 may be evenly distributed or unevenly distributed on the first welding ribbon 131B1 .

[0088] In this embodiment, the connection adhesive 133 is evenly distributed on the first welding strip 131B1 , which reduces the difficulty of attaching the connection adhesive 133 to the first welding strip 131B1 .

[0089] Based on the above structure, the connecting glue 133 can be a conductive glue. The connecting glue 133 made of conductive glue can increase the conductive area between the first welding ribbon 131B1 and the bus bar 132, thereby improving the current transmission efficiency between the first welding ribbon 131B1 and the bus bar 132, so as to improve the output power of the photovoltaic module.

[0090] The connecting glue 133 can also be insulating glue. The connecting glue 133 made of insulating glue covers the electrical connection position between the first welding ribbon 131B1 and the bus bar 132, thereby reducing the risk of short circuit between the first welding ribbon 131B1 and the bus bar 132, so as to improve the working stability of the photovoltaic module.

[0091] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A photovoltaic module, characterized in that: The photovoltaic assembly comprises at least a bus bar (132), a battery string (131) and a first welding strip (131B1); in a first direction (X), the bus bar (132) is located on at least one side of the battery string (131); in the first direction (X), two sides of the first welding strip (131B1) are respectively welded and fixed to the bus bar (132) and the battery string (131); The photovoltaic assembly further comprises a connecting adhesive (133), wherein the connecting adhesive (133) is bonded and fixed to the bus bar (132) and the first welding strip (131B1) respectively; The first welding strip (131B1) comprises a welding surface (131B3) and an adhesive surface (131B4); in a third direction (Z), the welding surface (131B3) and the adhesive surface (131B4) are respectively located on two sides of the first welding strip (131B1); the welding surface (131B3) is welded and fixed to the bus bar (132); and the adhesive surface (131B4) is adhesively fixed to the connecting glue (133); In the third direction (Z), projections of the welding surface (131B3) and the bonding surface (131B4) have overlapping portions.

2. The photovoltaic module according to claim 1, characterized in that The bonding area between the connecting glue (133) and the first welding strip (131B1) is S1, 0.02 mm 2 ≤S1≤4mm 2 ; The bonding area between the connecting glue (133) and the busbar (132) is S2, 0.2 mm 2 ≤S2≤8mm 2 .

3. The photovoltaic module according to claim 2, characterized in that On one of the first welding strips (131B1), the number of the connecting glue (133) is one; Alternatively, on one of the first welding strips (131B1), there are a plurality of the connection adhesives (133), and the plurality of the connection adhesives (133) are arranged along the first direction (X) and / or the second direction (Y).

4. The photovoltaic module according to claim 3, characterized in that On one of the first welding strips (131B1), there are a plurality of connecting adhesives (133), and adjacent connecting adhesives (133) are in contact; Alternatively, on one of the first welding strips (131B1), there are a plurality of the connecting adhesives (133), and gaps are left between adjacent connecting adhesives (133).

5. The photovoltaic module according to claim 4, characterized in that: On one of the first welding strips (131B1), the number of the connecting adhesives (133) is plural, and gaps are left between adjacent connecting adhesives (133); In the arrangement direction of the connecting glue (133), the size of the gap is L, and L≤1mm.

6. The photovoltaic module according to claim 3, characterized in that On one of the first welding strips (131B1), there are a plurality of the connection adhesives (133), and the plurality of the connection adhesives (133) are evenly arranged.

7. The photovoltaic module according to any one of claims 1 to 6, characterized in that: The connecting glue (133) comprises a first connecting portion (133A) and a second connecting portion (133B), at least a portion of the structure of the first connecting portion (133A) is bonded and fixed to the first welding strip (131B1), and at least a portion of the structure of the second connecting portion (133B) is bonded and fixed to the bus bar (132); In the third direction (Z), the first connecting portion (133A) and the second connecting portion (133B) have the same thickness.

8. The photovoltaic module according to any one of claims 1 to 6, characterized in that: The connecting glue (133) comprises a first connecting portion (133A) and a second connecting portion (133B), at least a portion of the structure of the first connecting portion (133A) is bonded and fixed to the first welding strip (131B1), and at least a portion of the structure of the second connecting portion (133B) is bonded and fixed to the bus bar (132); The first connecting portion (133A) comprises a first surface (133C), and in the third direction (Z), the first surface (133C) is located on a side of the first connecting portion (133A) facing away from the first welding strip (131B1); The second connecting portion (133B) includes a second surface (133D), and in the third direction (Z), the second surface (133D) is located on a side of the second connecting portion (133B) facing away from the bus bar (132); The first surface (133C) and the second surface (133D) are located in the same plane perpendicular to the third direction (Z), so that the thickness of the second connecting portion (133B) is greater than the thickness of the first connecting portion (133A).

9. The photovoltaic module according to any one of claims 1 to 6, characterized in that: The connecting glue (133) is conductive glue or insulating glue.

10. The photovoltaic module according to any one of claims 1 to 6, characterized in that: The cross-sectional profile of the first welding strip (131B1) is circular or rectangular.

11. The photovoltaic module according to any one of claims 1 to 6, characterized in that: The battery string (131) comprises at least a first battery cell (131A3) and a second battery cell (131A4); in the first direction (X), the first battery cell (131A3) is located between the bus bar (132) and the second battery cell (131A4); The first welding strip (131B1) is welded and fixed to the first battery cell (131A3); The photovoltaic assembly further comprises a second welding strip (131B2), and in the first direction (X), two sides of the second welding strip (131B2) are respectively welded and fixed to the first cell piece (131A3) and the second cell piece (131A4), so as to electrically connect the first cell piece (131A3) and the second cell piece (131A4); The first welding strip (131B1) and the second welding strip (131B2) are both welded and fixed to the backlight surface of the first battery cell (131A3).

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