Photovoltaic module

Abstract

The photovoltaic module comprises a battery unit and a back plate, the battery unit is arranged on the back plate, the battery unit comprises a plurality of battery strings, the plurality of battery strings are electrically connected through a bus member, and the bus member extends along a first direction and is provided with a first long edge extending along the first direction; the confluence piece closest to the edge of the back plate in the first direction is a first confluence piece, one end, facing the edge, of the first confluence piece is provided with a first chamfer part, and the first chamfer part is provided with a bent edge smoothly connected with the first long edge. Therefore, the sharp degree of the end part of the confluence piece can be reduced, so that local stress concentration of the end part of the confluence piece can be reduced in an assembly lamination process, the risk that the edge of the back plate is damaged or even punctured is reduced, meanwhile, the problem of point discharge at the end part of the confluence piece can be avoided by arranging the first chamfer part, and the reliability of the assembly is improved. Therefore, the yield and the safety performance of the photovoltaic module can be improved.

Description

Technical Field

[0001] This application belongs to the field of photovoltaic technology, specifically relating to a photovoltaic module. Background Technology

[0002] In photovoltaic module manufacturing, multiple solar cells are arranged in a specific structure to form a cell string. Busbars connect these strings in series and parallel to form a cell unit. A front panel and a back panel are then installed on either side of the cell unit for encapsulation. However, the ends of the busbars are typically right angles or have sharp corners. During module lamination, the laminating frame surrounds the entire circumference of the module. Stress concentration at the right angles or sharp corners of the busbar ends can easily damage the back panel, leading to encapsulation failure. Furthermore, during module operation, the right angles or sharp corners at the ends of the busbars in the cell unit can cause point discharge, resulting in leakage problems. Summary of the Invention

[0003] This application aims to provide a photovoltaic module that can solve the problems in existing photovoltaic modules where stress concentration at right angles or sharp corners at the end of the busbar can easily lead to damage to the backsheet, and where tip discharge at the end of the busbar can cause leakage during module operation.

[0004] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, this application provides a photovoltaic module, including: a battery cell and a backsheet, wherein the battery cell is disposed on the backsheet, the battery cell includes a plurality of battery strings, the plurality of battery strings are electrically connected by a busbar, and the busbar extends along a first direction and has a first long side extending along the first direction. The busbar closest to the edge of the back plate in the first direction is the first busbar. The first busbar has a first chamfer at one end facing the edge, and the first chamfer has a curved edge that is smoothly connected to the first long side.

[0005] In the embodiments of this application, a first chamfer is provided at one end of the busbar near the edge of the backsheet. The edge of the first chamfer is smoothly connected to the first long side of the busbar. This reduces the sharpness of the end of the busbar, thereby reducing local stress concentration at the end of the busbar during the module lamination process. This reduces the risk of damage or even puncture at the edge of the backsheet. At the same time, providing the first chamfer also avoids the problem of tip discharge at the end of the busbar, thus helping to improve the yield and safety performance of the photovoltaic module.

[0006] Secondly, embodiments of this application propose a photovoltaic module, comprising: a battery cell, the battery cell comprising a plurality of battery strings, the battery strings comprising a plurality of battery cells and interconnecting members, the plurality of battery cells being arranged along a second direction, the interconnecting members extending along the second direction and electrically connecting two adjacent battery cells; the interconnecting members having a second long side extending along the second direction, and at least one end of the interconnecting members along the second direction having a second chamfer, the second chamfer having a curved edge smoothly connected to the second long side.

[0007] In the embodiments of this application, by providing a second chamfer at at least one end of the interconnect along the second direction, and the edge of the second chamfer forming a smooth connection with the second long side, the sharpness of the end of the interconnect can be reduced. When using the interconnect to connect the cells in series, the risk of the end of the interconnect piercing the insulating layer on the surface of the cell and causing a short circuit can be avoided. At the same time, the problem of tip discharge at the end of the interconnect can also be avoided, thereby helping to improve the yield and safety performance of the photovoltaic module.

[0008] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below, wherein: Figure 1 This is a schematic diagram of a photovoltaic module in the prior art; Figure 2 This is a schematic diagram of a photovoltaic module according to an embodiment of this application; Figure 3 yes Figure 2 An enlarged view of a structure at part A, shown in the middle circle; Figure 4 yes Figure 2 An enlarged view of another structure at part A, shown in the middle circle; Figure 5 This is a partial structural schematic diagram of an interconnecting component according to an embodiment of this application; Figure 6 This is a partial structural schematic diagram of another interconnect component according to an embodiment of this application; Figure 7 yes Figure 2 Enlarged view of section B shown in the middle circle; Figure 8 yes Figure 7 Enlarged view of section C shown in the middle circle; Figure 9 This is a partial structural diagram of the junction box corresponding to the photovoltaic module according to an embodiment of this application; Figure 10 This is a schematic diagram of another photovoltaic module according to an embodiment of this application; Figure 11 yes Figure 10 An enlarged view of a structure at part D, shown in the middle circle; Figure 12 yes Figure 10 An enlarged view of another structure at part D, shown in the middle circle; Figure 13 This is a cross-sectional view of a busbar according to an embodiment of this application; Figure 14 This is a cross-sectional view of another busbar according to an embodiment of this application; Figure 15 This is another photovoltaic module according to an embodiment of this application. Figure 2 The center circle shows an enlarged view of section A; Figure 16 This is a partial schematic diagram of an interconnecting component according to an embodiment of this application.

[0010] Figure label: 1: Battery cell; 11: Battery string; 11a: First side; 11b: Second side; 111: Battery cell; 111a: Edge battery cell; 112: Interconnector; 1120: Second chamfer; 1121: Second long side; 112a: Edge interconnector; 12: Busbar; 12a: Substrate; 12b: Bonding layer; 120: First busbar; 1201: First chamfer; 1202: First long side; 1203: First short side; A1: Centerline; 121: Middle busbar; 121a: Lead wire; 1211: Bending part; 1212: Connecting part; 2: Backplate; 201: Edge; 21: Lead hole; 3: Junction box; 31: Connecting terminal; 32: Bonding material layer; X: First direction; Y: Second direction. Detailed Implementation

[0011] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0012] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0013] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0014] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0015] Before providing a detailed description of the photovoltaic modules provided in the embodiments of this application, the application scenarios of the photovoltaic modules will be explained first: In the photovoltaic (PV) module manufacturing process, multiple solar cells are connected in series and / or parallel to form a cell string using interconnecting components (such as solder ribbons). Busbars are then placed at the middle and both ends of the PV module to connect the cell strings in series and parallel, forming cell units. A front panel and a back panel are then placed on both sides of the cell unit. A laminating frame is then used to laminate the entire module, resulting in a PV module. Figure 1 As shown, in existing photovoltaic modules, the end positions of the busbar 12 are mostly right angles or have sharp corners (e.g., acute angles). During the lamination process, this structure of the busbar 12 results in localized gravitational concentration at the right angles or sharp corners, which can easily lead to lamination damage to the backsheet 2 or even puncture of the backsheet (e.g.,...). Figure 1 The location indicated by the middle arrow M) causes packaging failure. Furthermore, as... Figure 1 As shown, the leftmost right angle or sharp corner of the busbar 12 will produce a point discharge phenomenon, resulting in leakage.

[0016] Therefore, this application provides a photovoltaic module to solve some or all of the technical problems existing in the prior art. The photovoltaic module provided in this application will be described in detail below with reference to the accompanying drawings and specific embodiments and application scenarios.

[0017] like Figures 2 to 6 As shown, a photovoltaic module according to some embodiments of this application includes a battery cell 1 and a backsheet 2. The battery cell 1 is disposed on the backsheet 2 and includes a plurality of battery strings 11. The plurality of battery strings 11 are electrically connected by a busbar 12. The busbar 12 extends along a first direction X and has a first long side 1202 extending along the first direction X. The busbar 12 closest to the edge 201 of the backsheet 2 in the first direction X is a first busbar 120. The first busbar 120 has a first chamfer 1201 at one end facing the edge 201. The first chamfer 1201 has a curved edge that is smoothly connected to the first long side 1202.

[0018] The photovoltaic module may also include a cover plate, with the battery cell 1 disposed between the back sheet 2 and the cover plate and sealed by an encapsulation layer between the back sheet 2 and the cover plate. The encapsulation layer material may be one or more of EVA, POE, etc., in a stacked structure.

[0019] In this embodiment, a first chamfer 1201 is provided at one end of the busbar 12 near the edge 201 of the backsheet 2. The edge of the first chamfer 1201 is smoothly connected to the first long side 1202 of the busbar 12. This reduces the sharpness of the end of the busbar 12, thereby reducing local stress concentration at the end of the busbar 12 during the module lamination process. This reduces the risk of damage or even puncture to the edge 201 of the backsheet 2. At the same time, the first chamfer 1201 also avoids the problem of tip discharge at the end of the busbar 12, thus helping to improve the yield and safety performance of the photovoltaic module.

[0020] It is understandable that, such as Figure 1 As shown, the current collector 12 in the prior art has two first long sides 1202 and two first short sides 1203 arranged opposite to each other. The connection between the first short side 1203 and the first long side 1202 is at a right angle or an acute angle, which makes the end of the current collector 12 have a sharp corner. In the module lamination process, the lamination frame is laminated around the four edges of the module. The sharp corner at the end of the current collector 12 can easily cause damage to the back sheet 2, or even puncture the back sheet 2, causing the back sheet 2 to fail to encapsulate the battery cell 1. Furthermore, during the operation of the photovoltaic module, the sharp corner at the end of the current collector 12 has a tip discharge phenomenon, which can easily lead to leakage problems.

[0021] Therefore, such as Figure 3As shown, in this application, for the first busbar 120 near the edge 201 of the back panel 2, the end of the first busbar 120 facing the edge 201 of the back panel 2 is chamfered to form a first chamfered portion 1201 at the end of the first busbar 120 facing the edge 201 of the back panel 2. The first chamfered portion 1201 has a curved edge and can be smoothly connected to the first long side 1202 of the first busbar 120, thereby reducing the sharpness of the end of the first busbar 120 facing the edge 201 of the back panel 2.

[0022] Specifically, the first chamfered portion 1201 can be formed by chamfering the end of the first busbar 120. The chamfering process includes, but is not limited to, straight chamfering, arc chamfering, and curved chamfering, so as to form a curved edge at the edge 201 of the first busbar 120 facing the back plate 2, and the curved edge forms a smooth transition connection with the first long side 1202.

[0023] In some embodiments, the orthographic projection trajectory of the edge of the first chamfered portion 1201 onto the back plate 2 is a straight line, a circular arc, an elliptical arc, or a parabola, or a combination of two or more of these. For example, this can be achieved by chamfering the connection between the first short side 1203 and the first long side 1202 of the first busbar 120, so that the straight chamfered edge at the chamfer and the remaining portion of the first short side 1203 form the curved edge, which smoothly connects to the first long side 1202. Alternatively, as... Figure 3 As shown, by rounding the corners at the connection between the first short side 1203 and the first long side 1202, the curved edge is formed by the rounded chamfered edge and the remaining part of the first short side 1203, and the curved edge is smoothly connected to the first long side 1202.

[0024] It should be noted that the orthographic projection trajectory of the edge of the first chamfered portion 1201 on the back plate 2 is set as the first trajectory, and the orthographic projection trajectory of the first long side 1202 on the back plate 2 is set as the first straight line. As long as it can be ensured that the angle between the tangent of the first trajectory at the intersection with the first straight line and the first straight line is obtuse, the specific structure of the first chamfered portion 1201 and the corresponding processing method can be flexibly set according to actual needs, and are not limited here.

[0025] In practical applications, photovoltaic modules have a first direction X and a second direction Y that are perpendicular to each other. The first direction X can be the width direction of the photovoltaic module, and the second direction Y is the length direction of the photovoltaic module. For example... Figure 2 As shown, the battery unit 1 includes multiple battery cells 111. The multiple battery cells 111 are arranged along the second direction Y and connected in series by interconnecting member 112 to form a battery string 11. The multiple battery strings 11 are arranged along the first direction X and the second direction Y. Then, the multiple battery strings 11 are connected in series and parallel by bus member 12 to finally form battery unit 1.

[0026] Among them, such as Figure 2 and Figure 10 As shown, along the second direction Y, two or three rows of busbars 12 can be set in the photovoltaic module. The ones located at both ends of the photovoltaic module are edge busbars, and the ones located in the middle of the photovoltaic module are middle busbars. The edge busbars can connect at least two adjacent battery strings 11 along the first direction X in series, and the middle busbars can connect at least two opposite battery strings 11 along the second direction Y in parallel.

[0027] For example, such as Figure 2 As shown, three edge busbars are provided at one end of the photovoltaic module along the second direction Y. Each edge busbar is approximately the same length, and two battery strings 11 arranged along the first direction X can be connected in series through the edge busbars. Four intermediate busbars are provided in the middle of the photovoltaic module, with the two intermediate busbars on the two sides being relatively shorter and the two intermediate busbars in the middle being relatively longer. At least two battery strings 11 arranged along the second direction Y can be connected in parallel through the intermediate busbars.

[0028] In some embodiments, such as Figures 2 to 4 As shown, the first busbar 120 is disposed at one end of the photovoltaic module along the second direction Y, and the first busbar 120 connects at least two adjacent battery strings 11 along the first direction X. That is, the first busbar 120 is the edge busbar referred to in the above embodiment. The first busbar 120 can connect at least two battery strings 11 arranged along the first direction X in series. By providing a first chamfer 1201 at the end of the edge busbar near the edge 201, the risk of damage to the edge 201 of the back sheet 2 near both ends can be reduced.

[0029] In other embodiments, such as Figure 2 and Figure 7 As shown, the first busbar 120 is positioned near the center of the photovoltaic module along the second direction Y, and connects at least two battery strings 11 that are opposite each other along the second direction Y. That is, the first busbar 120 is the intermediate busbar referred to in the above embodiment, which connects at least two battery strings 11 that are opposite each other along the second direction Y in parallel. By providing a first chamfer 1201 at one end of the intermediate busbar near the edge 201, the risk of damage to the edge 201 of the back sheet 2 near the center can be reduced.

[0030] It should be noted that multiple busbars 12 are provided in the photovoltaic module. Other busbars 12 besides the first busbar 120 may also have a first chamfer 1201 at their ends. This can avoid the problem of tip discharge at the ends of the corresponding busbars 12. The end structure of other busbars 12 can refer to the first busbar 120, and will not be described again here. For example, such as Figure 2 As shown, the busbar 12 is spaced apart from the battery cells 111 at the end of the battery string 11 along the second direction Y. The interconnecting member 112 extends from the edge of the battery cells 111 at the end of the battery string 11 and is electrically connected to the busbar 12. Alternatively, as... Figure 10 As shown, the busbar 12 can be disposed on the back of the battery cell 111 at the end of the battery string 11, that is, the busbar 12 overlaps with the battery cell 111 at the end of the battery string 11, so as to achieve a hidden arrangement of the busbar 12. The arrangement position and number of busbars 12 can be flexibly set as needed, and are not limited here.

[0031] In some embodiments, such as Figure 4 As shown, the battery cell 111 in this embodiment can be a bifacial battery, such as a TOPCON battery, a PERC battery, an HJT battery, etc. Electrodes are provided on both the front and back sides of the battery cell 111. The battery cell 111 located at the end of the battery string 11 is designated as the end battery cell. The electrodes on the front or back of the end battery cell are electrically connected to the busbar 12.

[0032] In other embodiments, such as Figure 3 As shown, the battery cell 111 in this embodiment can be a single-sided battery, such as a BC battery. Both the positive and negative electrodes are located on the back side of the battery cell 111. The back side of the battery cell 111 at the end of the battery string 11 has two interconnecting members 112 of opposite conductivity types. The busbar 12 is electrically connected to one type of interconnecting member 112 and disconnected from the other type of interconnecting member 112, or, as... Figure 10 As shown, when the busbar 12 is located on the back of the battery cell 111, the busbar 12 is insulated from the interconnecting member 112 of the opposite wire type by the insulating layer.

[0033] Specifically, the battery cell 111 in this application can be a whole cell, a half cell, a third cell, a quarter cell, or other multi-cell cells. Among them, a half cell refers to dividing a whole cell into two equal parts, and the same applies to other multi-cell cells.

[0034] It should be noted that the total number of solar cells 111 in the photovoltaic module of this application can be 108, 132, 138, 144, 150, 156, 162, etc., or an integer multiple of the above numbers. For example, as shown... Figure 2 As shown, the photovoltaic module has six rows of solar cells 111 arranged along the first direction X. Each row of solar cells 111 includes two strings of cells 11, one above the other. The two strings of cells 11 are connected in parallel via a busbar 12, while two adjacent strings of cells 11 are connected in series via a busbar 12. Of course, the number of solar cells 111 in the photovoltaic module can be flexibly set and is not limited here.

[0035] In some embodiments, multiple solar cells 111 are arranged along the second direction Y and connected in series by interconnecting members 112 to form a solar cell string 11. In a solar cell string 11, two adjacent solar cells 111 along the second direction Y can be spaced apart, for example, the spacing between two solar cells 111 along the second direction Y is set to 0.5mm-2mm. Alternatively, the edges of two adjacent solar cells 111 along the second direction Y can at least partially overlap, that is, a stacked structure is adopted. For example, the width of the overlapping part is 0.2mm-1mm, so as to make the arrangement of solar cells 111 more compact, thereby making full use of the space of the photovoltaic module.

[0036] Optionally, such as Figure 3 and Figure 4 As shown, the battery string 11 includes multiple battery cells 111 arranged along the second direction Y. The battery cell 111 closest to the edge 201 in the first direction X is the edge battery cell 111a, and the side of the edge battery cell 111a facing the edge 201 is the first side 11a. The orthographic projection of the first chamfered portion 1201 along the second direction Y is located within the orthographic projection of the edge battery cell 111a along the second direction Y, and the distance d1 between the first chamfered portion 1201 and the first side 11a along the first direction X is greater than or equal to 1 mm. That is, along the first direction X, the first chamfered portion 1201 is located between the edge interconnect 112a and the first side 11a.

[0037] In this embodiment, the orthographic projection of the first chamfered portion 1201 along the second direction Y falls within the orthographic projection of the edge cell 111a along the second direction Y. That is, in the first direction X, the first chamfered portion 1201 does not extend beyond the first side 11a of the edge cell 111a, and the distance d1 between the first chamfered portion 1201 and the first side 11a is greater than or equal to 1 mm. This avoids the end of the first busbar 120 being too close to the edge 201 of the backsheet 2, which could easily lead to cracking of the edge 201 of the backsheet 2 during lamination. At the same time, it also increases the creepage distance of the photovoltaic module, thereby improving the safety performance of the photovoltaic module.

[0038] Specifically, the spacing d1 can be set to: 1 mm, 3 mm, 5 mm, 8 mm, etc.

[0039] It is understandable that, such as Figure 3 and Figure 4 As shown, the surface of the battery cell 111 (including the front and back sides) is provided with a plurality of interconnects 112 arranged at intervals along the first direction X. When the first busbar 120 is electrically connected to the outermost interconnect 112 on the battery cell 111 at one end facing the edge 201 of the back plate 2, the spacing d1 can be set to a range of 1mm-5mm. This can both prevent the end of the first busbar 120 from being too close to the edge 201 of the back plate 2, thus affecting the creepage distance, and prevent the end of the first busbar 120 from being too far from the first side 11a of the battery cell 111, thus affecting the current collection capability of the interconnect 112 for the edge region of the battery cell 111.

[0040] In some embodiments, such as Figure 3 As shown, the first busbar 120 has a first chamfer 1201 at both ends along the first direction X. By providing the first chamfer 1201 at both ends of the first busbar 120, on the one hand, when connecting and using the first busbar 120, it is not necessary to specifically distinguish the structures at both ends of the first busbar 120, which facilitates actual connection and improves processing efficiency; on the other hand, it can simultaneously avoid the problem of tip discharge at both ends of the first busbar 120, which can further improve the safety of the photovoltaic module.

[0041] In other embodiments, such as Figure 5 and Figure 6 As shown, the first busbar 120 has a centerline A1 extending along the first direction X, and the first busbar 120 has an axisymmetric structure about the centerline A1. By setting the first busbar 120 to have an axisymmetric structure in this application, the upper and lower parts of the end of the first busbar 120 in the second direction Y can be made to have the same structure. In this way, the stress distribution at different positions of the end of the first busbar 120 can be balanced during the lamination process, thereby further reducing the risk of damage to the back plate 2.

[0042] Optionally, such as Figure 3 and Figure 5 As shown, in the second direction Y, the battery cell 111 located at the end of the battery string 11 is electrically connected to the first busbar 120 through the interconnect 112. Among the multiple interconnects 112 that are electrically connected to the first busbar 120, the outermost interconnect 112 (i.e., the edge interconnect 112a) along the first direction X is offset from the first chamfer 1201.

[0043] In this embodiment, the first busbar 120 is electrically connected to the battery cell 111 at the end of the battery string 11 via the interconnect 112. Among the multiple interconnects 112 electrically connected to the first busbar 120, the outermost interconnect 112 is staggered from the first chamfer 1201. That is, the outermost interconnect 112 and / or its extension do not pass through the first chamfer 1201 at the end of the first busbar 120. In this way, the impact of the first chamfer 1201 on the connection area of ​​the first busbar 120 can be reduced, and the connection performance between the first busbar 120 and the outermost interconnect 112 can be ensured.

[0044] Optionally, such as Figure 5 and Figure 6 As shown, the width of the first busbar 120 is W1, and the width of the first chamfered portion 1201 in the first direction X is D1, satisfying: 0.5mm≤D1≤0.5*W1. For example, the width D1 can be set to: 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 0.1*W1, 0.3*W1, 0.5*W1, etc.

[0045] In this embodiment, the width range of the first chamfered portion 1201 in the first direction X is reasonably set based on the width W1 of the first busbar 120. On the one hand, this avoids the width D1 of the first chamfered portion 1201 being too small, so as not to effectively improve the sharpness of the end of the first busbar 120. On the other hand, it avoids the width D1 of the first chamfered portion 1201 being too large, so that the first chamfered portion 1201 needs to occupy a lot of volume at the end of the first busbar 120, which is not conducive to the connection between the end of the first busbar 120 and the interconnecting member 112.

[0046] It should be noted that the width W1 of the first busbar 120 refers to the straight-line distance between the two first long sides 1202 of the first busbar 120 along the second direction Y. The width D1 of the first chamfer 1201 refers to the straight-line distance from the end of the first chamfer 1201 away from the first long side 1202 along the first direction X to the junction of the first chamfer 1201 and the first long side 1202.

[0047] In some embodiments, the width of the busbar 12 can be set to 3mm-12mm, and the thickness of the busbar 12 can be set to 0.2mm-0.6mm. Here, the busbar 12 includes a first busbar 120. Specifically, the busbar 12 includes an edge busbar and a middle busbar. The width of the edge busbar is smaller than the width of the middle busbar. For example, the width of the edge busbar can be set to 3mm-8mm, and the width of the middle busbar can be set to 5mm-12mm. The specific dimensions of the busbar 12 can be flexibly set according to actual needs and are not limited here.

[0048] Optionally, such as Figure 2 , Figure 7 and Figure 8 As shown, the busbar 12 includes an intermediate busbar 121 disposed near the center of the photovoltaic module. There are at least two intermediate busbars 121, which are arranged at intervals along the first direction X. The back plate 2 is provided with a lead hole 21, which is located between two adjacent intermediate busbars 121. One end of the intermediate busbar 121 facing the lead hole 21 is bent to form a lead wire 121a. The lead wire 121a passes through the lead hole 21, and the end of the lead wire 121a is provided with a first chamfer 1201.

[0049] In the embodiments of this application, such as Figures 7 to 9 As shown, the end of the intermediate busbar 121 near the lead hole 21 is bent to form a lead wire 121a. The lead wire 121a passes through the lead hole 21 and is electrically connected to the junction box 3 provided on the back panel 2 to conduct the internal current of the photovoltaic module. Furthermore, a first chamfer 1201 is provided at the end of the lead wire 121a. In this way, during the operation of passing the lead wire 121a out of the lead hole 21 of the back panel 2, the first chamfer 1201 can play a guiding role, which facilitates the passing of the lead wire 121a. In addition, it can also reduce the problem of the end of the lead wire 121a scratching the back panel 2 around the lead hole 21.

[0050] It should be noted that, as Figure 7 As shown, the photovoltaic module has multiple intermediate busbars 121 arranged at intervals along a first direction X. Among them, the intermediate busbar 121 closest to the edge 201 of the backsheet 2 is designated as the first busbar 120. The end of the first busbar 120 near the edge 201 has a first chamfer 1201, and the end of the first busbar 120 away from the edge 201 is bent to form a lead wire 121a. The end of the lead wire 121a also has a first chamfer 1201. The two ends of the intermediate busbars 121 other than the first busbar 120 can also have first chamfers 1201, so that the two ends of the corresponding intermediate busbar 121 can be bent and pass through the lead wire hole 21.

[0051] Optionally, such as Figure 8 and Figure 9As shown, the photovoltaic module also includes a junction box 3, which is installed on the side of the back panel 2 away from the solar cell 111. The junction box 3 is provided with a connection terminal 31. The lead wire 121a includes a bent portion 1211 and a connecting portion 1212 connected to each other. The bent portion 1211 passes through the lead wire hole 21, and the connecting portion 1212 is electrically connected to the connection terminal 31. The end of the connecting portion 1212 away from the bent portion 1211 is provided with a first chamfer 1201. Along the first direction X, the length of the overlapping portion of the connecting portion 1212 and the connecting terminal 31 is L, and the width of the first chamfer 1201 at the end of the lead wire 121a is D2, satisfying: L≥5*D2.

[0052] In this embodiment, the intermediate busbar 121 has a lead wire 121a at its end. The lead wire 121a includes a bent portion 1211 and a connecting portion 1212 that are connected to each other. The connecting portion 1212 at least partially overlaps with the connecting terminal 31 in the junction box 3 to form an electrical connection. Furthermore, by setting the ratio between the length L of the overlapping portion of the connecting portion 1212 and the connecting terminal 31 and the width D2 of the first chamfer portion 1201 at the end of the lead wire 121a, the width D2 of the first chamfer portion 1201 at the end of the lead wire 121a is not too large, which would affect the connection area between the connecting portion 1212 and the connecting terminal 31, thereby ensuring the reliability of the connection between the lead wire 121a and the connecting terminal 31.

[0053] For example, the ratio L / D2 of the length L to the width D2 can be set to any value such as 5, 6, 7, 8, 9, or any position between two values.

[0054] It should be noted that the width D2 in this embodiment and the width D1 in the previous embodiment can be set to be equal or unequal. They can be flexibly set according to actual needs and are not limited here.

[0055] Specifically, such as Figure 8 and Figure 9 As shown, the lead wire 121a extends from the lead wire hole 21 and bends towards the side of the connecting terminal 31 away from the back plate 2 to form a connecting part 1212 on the side of the connecting terminal 31 away from the back plate 2. The connecting part 1212 can be connected and fixed to the connecting terminal 31 by welding or other means. A bonding material layer 32 can be provided on the connecting part 1212 and the connecting terminal 31 to increase the connection performance between the connecting part 1212 and the connecting terminal 31. By setting the ratio of the length L to the width D2, L / D2, to be greater than or equal to 5, the connection area between the connecting part 1212 and the connecting terminal 31 is ensured, thereby ensuring the connection performance.

[0056] Optionally, such as Figure 10As shown, the battery string 11 includes multiple battery cells 111 arranged along a second direction Y, which is perpendicular to the first direction X; a busbar 12 is disposed on the back of the battery cells 111, and at least one first busbar 120 spans along the first direction X and electrically connects two adjacent battery cells 111; as shown Figure 11 and Figure 12 As shown, the back of the battery cell 111 is provided with two types of interconnects 112 with opposite conductivity. The two types of interconnects 112 with opposite conductivity are arranged alternately along the first direction X. The first busbar 120 is electrically connected to some of the interconnects 112. The interconnects 112 closest to the two sides of the battery cell 111 are designated as edge interconnects 112a. Both ends of the first busbar 120 have a first chamfer 1201.

[0057] In one embodiment, such as Figure 11 As shown, the two edge interconnects 112a on two adjacent battery cells 111 that are close to each other have opposite conductivity types. The two ends of the first busbar 120 are electrically connected to the two edge interconnects 112a on the two battery cells 111 that are opposite to each other, and the first chamfer 1201 is staggered from the corresponding edge interconnect 112a.

[0058] In this embodiment, by placing the busbar 12 on the back of the solar cell 111, the purpose of hiding the busbar 12 is achieved, thereby improving the surface space utilization of the photovoltaic module. The first busbar 120 spans and electrically connects two adjacent solar cells 111 along the first direction X. The two ends of the first busbar 120 are respectively electrically connected to two mutually opposite edge interconnects 112a on the two solar cells 111. The first chamfered portions 1201 at both ends of the first busbar 120 are staggered from the corresponding edge interconnects 112a. This avoids the backsheet breakage problem caused by the excessively sharp ends of the first busbar 120, and also ensures the firmness of the connection between the two ends of the first busbar 120 and the edge interconnects 112a.

[0059] In other embodiments, such as Figure 12 As shown, the two edge interconnects 112a that are close to each other on two adjacent battery cells 111 have the same conductivity type. One end of the first busbar 120 is electrically connected to the edge interconnect 112a on one of the battery cells 111, and the other end of the first busbar 120 does not overlap with the edge interconnect 112a on the other battery cell 111.

[0060] In this embodiment, by electrically connecting one end of the first busbar 120 to the edge interconnect 112a on one of the battery cells 111, and ensuring that the other end of the first busbar 120 does not overlap with the edge interconnect 112a on the other battery cell 111, a certain distance can be maintained between the other end of the first busbar 120 and the corresponding edge interconnect 112a. Furthermore, a first chamfer 1201 is provided at the end of the first busbar 120 to prevent tip discharge between the end of the first busbar 120 and the edge interconnect 112a of the opposite conductivity type.

[0061] In some embodiments, such as Figure 13 and Figure 14 As shown, the busbar 12 includes a substrate 12a and a bonding layer 12b disposed on at least one side of the substrate 12a; the thickness of the bonding layer 12b is D3, which satisfies the condition: 0.01mm ≤ D3 ≤ 0.03mm. For example, the thickness D3 can be set to: 0.01 mm, 0.015 mm, 0.02 mm, 0.025 mm, 0.03 mm, etc.

[0062] In this embodiment, the connectivity of the busbar 12 is improved by providing a bonding layer 12b on the substrate 12a. The thickness D3 of the bonding layer 12b on the substrate 12a ranges from 0.01mm to 0.03mm. This ensures that the substrate 12a has a bonding layer 12b of a certain thickness to improve the connectivity of the busbar 12, while avoiding the bonding layer 12b being too thick, which would cause the resistivity of the busbar 12 to increase and affect the power of the photovoltaic module.

[0063] In some embodiments, the substrate 12a may be made of a metallic material with good electrical conductivity, such as pure copper, brass, aluminum alloy, or copper-aluminum composite material. The bonding layer 12b may be made of a tin alloy or similar material to improve the solderability of the bus 12. The specific materials of the substrate 12a and the bonding layer 12b can be flexibly set as needed and are not limited here.

[0064] like Figure 14 As shown, a bonding layer 12b can be provided on the surface of the substrate 12a that is connected to the interconnect 112, while no bonding layer 12b is provided on the side of the busbar 12 facing away from the interconnect 112. This way, while utilizing the bonding layer 12b to improve the connection performance between the busbar 12 and the interconnect 112, the amount of material used in the bonding layer 12b can be reduced, thereby lowering production costs. Furthermore, the bonding layer 12b can extend to cover the side surface of the substrate 12a to improve the adhesion between the bonding layer 12b and the substrate 12a.

[0065] Or, such as Figure 13As shown, the bonding layer 12b can be covered on the outer peripheral surface of the substrate 12a. This can increase the connection area between the bonding layer 12b and the substrate 12a, improve the bonding force between the bonding layer 12b and the substrate 12a, and at the same time, facilitate processing and use, and improve production efficiency.

[0066] Optionally, such as Figure 15 and Figure 16 As shown in the embodiment of this application, another photovoltaic module is also provided, including: a battery unit 1, the battery unit 1 including a plurality of battery strings 11, the battery strings 11 including a plurality of battery cells 111 and interconnecting members 112, the plurality of battery cells 111 being arranged along a second direction Y, the interconnecting members 112 extending along the second direction Y and electrically connecting two adjacent battery cells 111; the interconnecting member 112 having a second long side 1121 extending along the second direction Y, and at least one end of the interconnecting member 112 along the second direction Y having a second chamfer 1120, the second chamfer 1120 having a curved edge smoothly connected to the second long side 1121.

[0067] In this embodiment, by providing a second chamfer 1120 at at least one end of the interconnect 112 along the second direction Y, and the edge of the second chamfer 1120 forming a smooth connection with the second long side 1121, the sharpness of the end of the interconnect 112 can be reduced. When the interconnect 112 is used to connect the solar cells 111 in series, the risk of the end of the interconnect 112 piercing the insulating layer on the surface of the solar cells 111 and causing a short circuit can be avoided. At the same time, the problem of tip discharge at the end of the interconnect 112 can also be avoided, thereby helping to improve the yield and safety performance of the photovoltaic module.

[0068] In some embodiments, a second chamfered portion 1120 can be formed by chamfering the end of the interconnect 112. The chamfering process includes, but is not limited to, straight chamfering, circular chamfering, and curved chamfering, to form a second chamfered portion 1120 with a curved edge on the interconnect 112, where the curved edge forms a smooth transition connection with the second long side 1121. In some embodiments, the orthographic projection trajectory of the edge of the second chamfered portion 1120 onto the battery cell 111 is one or a combination of two or more of the following: a straight line, a circular arc, an elliptical arc, and a parabola.

[0069] It should be noted that the structure and beneficial effects of the second chamfered portion 1120 at the end of the interconnecting member 112 in this embodiment can be understood by referring to the structure of the first chamfered portion 1201 of the first busbar 120 in the foregoing embodiment, and will not be repeated here.

[0070] Optionally, such as Figure 16As shown, the width of the interconnect 112 is W2, and the width of the second chamfer 1120 in the second direction Y is D4, satisfying: 0.5mm≤D4≤0.5*W2. For example, the width D4 can be set to: 0.5 mm, 0.7 mm, 1 mm, 1.2 mm, 1.5 mm, 2 mm, 0.1*W2, 0.3*W2, 0.5*W2, etc.

[0071] In this embodiment, the width range of the second chamfered portion 1120 in the second direction Y is reasonably set based on the width W2 of the interconnect 112. On the one hand, this avoids the width D4 of the second chamfered portion 1120 being too small, so as not to effectively improve the sharpness of the end of the first busbar 120. On the other hand, it avoids the width D4 of the second chamfered portion 1120 being too large, so that the second chamfered portion 1120 requires a large volume at the end of the interconnect 112, which is not conducive to the effective connection between the interconnect 112 and the electrode on the surface of the battery cell 111.

[0072] It should be noted that the width W2 of the interconnect 112 refers to the straight-line distance between the two second long sides 1121 of the interconnect 112 along the first direction X. The width D4 of the second chamfer 1120 refers to the straight-line distance from the end of the second chamfer 1120 away from the second long side 1121 along the second direction Y to the junction of the second chamfer 1120 and the second long side 1121.

[0073] In some embodiments, the interconnecting member 112 has a second chamfer 1120 at each of its opposite ends along the second direction Y. By providing a second chamfer 1120 at both ends of the interconnecting member 112, on the one hand, when connecting and using the interconnecting member 112, it is not necessary to specifically distinguish the structures at both ends of the interconnecting member 112, which facilitates actual connection and improves processing efficiency; on the other hand, it can simultaneously avoid the problem of tip discharge at both ends of the interconnecting member 112, which can further improve the safety of the photovoltaic module.

[0074] In other embodiments, the cross-sectional outer contour of the interconnect 112 is rectangular, elliptical, racetrack-shaped, etc. For example, the interconnect 112 can be a flat solder strip with a width of 0.3 mm-2.5 mm and a thickness of 0.05 mm-0.6 mm. The interconnect 112 includes a conductive core and a cladding layer. The conductive core is made of a metallic material, such as a copper core or a copper-clad aluminum core. The cladding layer covers at least a portion of the outer peripheral surface of the conductive core and can be made of a soldering flux such as a tin alloy.

[0075] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A photovoltaic module, characterized in that, include: A battery cell and a backplate, wherein the battery cell is disposed on the backplate, the battery cell includes a plurality of battery strings, the plurality of battery strings are electrically connected by a busbar, the busbar extends along a first direction and has a first long side extending along the first direction; The busbar closest to the edge of the back plate in the first direction is the first busbar. The first busbar has a first chamfer at one end facing the edge, and the first chamfer has a curved edge that is smoothly connected to the first long side.

2. The photovoltaic module according to claim 1, characterized in that, The battery string includes multiple battery cells arranged along a second direction, which is perpendicular to the first direction; The battery cell closest to the edge in the first direction is the edge battery cell, and the side of the edge battery cell facing the edge is the first side; the orthographic projection of the first chamfered portion along the second direction is located within the orthographic projection of the edge battery cell along the second direction, and the distance between the first chamfered portion and the first side along the first direction is greater than or equal to 1 mm.

3. The photovoltaic module according to claim 1, characterized in that, The first busbar has the first chamfered portion at both opposite ends along the first direction; And / or, the first busbar has a centerline extending along the first direction, and the first busbar has an axisymmetric structure about the centerline.

4. The photovoltaic module according to claim 1, characterized in that, The battery string includes multiple battery cells arranged along a second direction, which is perpendicular to the first direction; In the second direction, the battery cells located at the end of the battery string are electrically connected to the first busbar via interconnects. Among the plurality of interconnects electrically connected to the first busbar, the outermost interconnect along the first direction is offset from the first chamfered portion.

5. The photovoltaic module according to claim 1, characterized in that, The first busbar is disposed at one end of the photovoltaic module along the second direction, and the first busbar connects at least two adjacent battery strings along the first direction; And / or, the first busbar is disposed near the middle of the photovoltaic module along the second direction, and the first busbar connects at least two battery strings opposite each other along the second direction; wherein, the second direction is perpendicular to the first direction.

6. The photovoltaic module according to claim 1, characterized in that, The width of the first busbar is W1, and the width of the first chamfered portion in the first direction is D1, satisfying: 0.5mm≤D1≤0.5*W1.

7. The photovoltaic module according to any one of claims 1-6, characterized in that, The busbar includes an intermediate busbar disposed near the center of the photovoltaic module, and there are at least two intermediate busbars, which are arranged at intervals along the first direction. The back plate is provided with a lead wire hole, which is located between two adjacent intermediate busbars. One end of the intermediate busbar is bent toward the lead wire hole to form a lead wire. The lead wire passes through the lead wire hole, and the end of the lead wire is provided with the first chamfer.

8. The photovoltaic module according to claim 7, characterized in that, The photovoltaic module also includes a junction box, which is installed on the side of the back panel away from the battery cell, and the junction box is provided with connection terminals; The lead wire includes a bent portion and a connecting portion that are connected to each other. The bent portion passes through the lead wire hole, and the connecting portion is electrically connected to the connecting terminal. The end of the connecting portion away from the bent portion is provided with a first chamfer. Along the first direction, the length of the overlapping portion of the connecting portion and the connecting terminal is L, and the width of the first chamfer at the end of the lead wire is D2, satisfying: L≥5*D2.

9. The photovoltaic module according to claim 1, characterized in that, The battery string includes multiple battery cells arranged along a second direction, which is perpendicular to the first direction; the busbar is disposed on the back of the battery cells, and at least one of the first busbars spans along the first direction and electrically connects two adjacent battery cells; The back of the battery cell is provided with two types of interconnects with opposite conductivity, which are arranged alternately along the first direction. The first busbar is electrically connected to a portion of the interconnects. The interconnects closest to the two edges of the battery cell are designated as edge interconnects, and both ends of the first busbar have the first chamfered portion. The two edge interconnects on two adjacent battery cells that are close to each other have opposite conductivity types. The two ends of the first busbar are electrically connected to the two edge interconnects on the two battery cells that are opposite to each other, and the first chamfered portion is staggered from the corresponding edge interconnect. And / or, the two edge interconnects that are close to each other on two adjacent battery cells have the same conductivity type, one end of the first busbar is electrically connected to the edge interconnect on one of the battery cells, and the other end of the first busbar does not overlap with the edge interconnect on the other battery cell.

10. The photovoltaic module according to claim 1, characterized in that, The busbar includes a substrate and a bonding layer disposed on at least one side of the substrate, wherein the thickness of the bonding layer is D3, satisfying: 0.01mm≤D3≤0.03mm; And / or, the material of the substrate includes one or a combination of two of copper and aluminum.

11. The photovoltaic module according to claim 1, characterized in that, The orthographic projection trajectory of the edge of the first chamfered portion on the back plate is one or a combination of two or more of the following: a straight line, a circular arc, an elliptical arc, and a parabola.

12. A photovoltaic module, characterized in that, include: A battery cell, the battery cell comprising multiple battery strings, each battery string comprising multiple battery cells and interconnects, the multiple battery cells being arranged along a second direction, the interconnects extending along the second direction and electrically connecting two adjacent battery cells; the interconnects having a second long side extending along the second direction, and at least one end of the interconnects along the second direction having a second chamfer, the second chamfer having a curved edge smoothly connected to the second long side.

13. The photovoltaic module according to claim 12, characterized in that, The width of the interconnecting component is W2, and the width of the second chamfer in the second direction is D4, satisfying: 0.5mm≤D4≤0.5*W2.

14. The photovoltaic module according to claim 12, characterized in that, The interconnecting member has a second chamfer at each of its opposite ends along the second direction.

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