Photovoltaic module

Abstract

The present disclosure relates to a photovoltaic module, which comprises a plurality of cell strings and a plurality of bus electrodes, each cell string comprising first cells and second cells arranged alternately, the positive electrode of the first cell and the negative electrode of the second cell being arranged on the same plane, the negative electrode of the first cell and the positive electrode of the second cell being arranged on the same plane, from the starting end to the tail end of the cell string, the positive electrode and the negative electrode of adjacent cells are sequentially connected by alternating back welding strips and front welding strips, and the cell at the starting end of the cell string is connected with the back welding strip; the plurality of bus electrodes comprises a first bus electrode, which is arranged on the back side of the cell string and connected with the back welding strip at the starting end of the cell string. The effective area of the photovoltaic module can be improved, which is conducive to improving the overall efficiency of the module.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic technology, in particular to a photovoltaic module. BACKGROUND

[0002] Tunnel Oxide Passivated Contact (TOPCON) cell is the mainstream cell in the field of TOPCON cell photovoltaic. The existing TOPCON module is sequentially connected by multiple TOPCON cells through solder strips. The solder strips of adjacent cells are led out from different surfaces of the cells and interconnected. Such connection design requires that the cell pieces must be spaced apart by a certain distance to ensure that the connection of the solder strips does not interfere with each other, resulting in a reduction in the effective area of the module, thereby affecting the overall performance of the module. Moreover, the solder strips of adjacent cells are led out from different surfaces of the cells, which also brings potential hidden crack risk to the cells, which is not conducive to the long-term stability and reliability of the module. SUMMARY

[0003] Therefore, it is necessary to provide a photovoltaic module to solve the problem that the solder strips of adjacent cells are led out from different surfaces of the cells and interconnected, resulting in a reduction in the effective area of the module, thereby affecting the overall performance of the module, and bringing potential hidden crack risk to the cells.

[0004] The present disclosure provides a photovoltaic module, comprising a plurality of cell strings and a plurality of bus electrodes, each of the cell strings comprising first cells and second cells arranged alternately, the positive electrode of the first cell and the negative electrode of the second cell being arranged on the same surface, the negative electrode of the first cell and the positive electrode of the second cell being arranged on the same surface, the positive electrode and the negative electrode of adjacent cells being sequentially connected by alternating back surface solder strips and front surface solder strips from the starting end to the tail end of the cell string, and the cell at the starting end of the cell string being connected with the back surface solder strip.

[0005] The plurality of bus electrodes comprises a first bus electrode, the first bus electrode being arranged on the back side of the cell string, and the first bus electrode being connected with the back surface solder strip at the starting end of the cell string.

[0006] In one embodiment, each cell comprises a grid line area and a fish-tail line area arranged on both sides of the grid line area, and the first bus electrode is arranged on the back surface of the fish-tail line area.

[0007] In one embodiment, the width d1 of the fish-tail line area ranges from 3mm to 10mm, the spacing d2 between the edge of the fish-tail line area and the edge of the cell ranges from 0mm to 2mm, and the width d3 of the first bus electrode is d1-d2.

[0008] In one of the embodiments, the back solder strip is connected to the side of the cell away from the starting end of the first busbar along the thickness direction of the photovoltaic module.

[0009] In one of the embodiments, at least two cell groups are included, and the at least two cell groups are arranged at intervals along a first direction, each of the cell groups including at least two cell strings arranged along a second direction, and the cell strings in the same group are connected in series by the same first busbar.

[0010] The plurality of busbars further includes a plurality of second busbars, and two cell strings adjacent along the first direction are connected by the second busbar, and the two cell strings belong to two cell groups respectively.

[0011] In one of the embodiments, the tail ends of the two cell strings adjacent along the first direction are arranged opposite to each other, and the tail ends of the two cell strings are connected by the second busbar.

[0012] In one of the embodiments, the number of cells in the cell string is odd, and the starting end cell and the tail end cell of the cell string are the first cell or the second cell, and the tail end cell of the cell string is connected to the front solder strip.

[0013] The second busbar is arranged between the two cell groups, and the front solder strip of the tail end of the two cell strings adjacent along the first direction is connected to the second busbar.

[0014] In one of the embodiments, the number of cells in the cell string is even, and one of the starting end cell and the tail end cell of the cell string is the first cell and the other is the second cell, and the tail end cell of the cell string is connected to the back solder strip.

[0015] The second busbar is arranged on the back side of the cell string, and the back solder strip of the tail end of the two cell strings adjacent along the first direction is connected to the second busbar.

[0016] In one of the embodiments, the projection of the second busbar on the tail end cell of the cell string at least partially overlaps with a fish-tail line area of the tail end cell, the width of the fish-tail line area is d1, and the width of the second busbar is d1

[0017] In one of the embodiments, the spacing between the adjacent cell strings is less than 0.5 cm.

[0018] The welding band connecting the first cell and the second cell of the photovoltaic module of the present disclosure does not need to be bent at the spacing between the first cell and the second cell, the spacing between the first cell and the second cell can be reduced, the side of the first cell and the side of the second cell can be pasted together, the distance between the cells can be shortened to the minimum, the effective area of the photovoltaic module can be improved, and the overall performance of the module can be improved. And the first cell and the second cell are led out by the welding band on the same side, the surface of the cell string is flat, the surface of the photovoltaic module is not uneven, which is beneficial to reduce the risk of hidden cracks of the photovoltaic module in the lamination process, and improves the long-term stability and reliability of the photovoltaic module; the first bus electrode at the starting end of each cell string is "hidden" at the back side of the cell at the starting end, which can save the area of the side of the starting end of the cell string for setting the first bus electrode, reduce the redundant area occupied by the first bus electrode in the photovoltaic module, further improve the effective area of the photovoltaic module, and improve the overall performance of the module. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 The layout schematic diagram of the photovoltaic module provided in an exemplary embodiment of the present application;

[0021] Figure 2 The layout schematic diagram of the photovoltaic module provided in another exemplary embodiment of the present application;

[0022] Figure 3 The schematic diagram of the cell string provided in an exemplary embodiment of the present application;

[0023] Figure 4 The circuit diagram of the cell string provided in an exemplary embodiment of the present application.

[0024] Explanation of reference signs:

[0025] 100, cell group; 10, cell string; 11, first cell; 12, second cell; 101, grid line area; 102, fork line area; 133, welding block; 20, bus electrode; 120, first bus electrode; 220, second bus electrode; 31, front welding band; 32, back welding band; 40, diode; 50, connecting line;

[0026] D1, first direction; D2, second direction. DETAILED DESCRIPTION

[0027] For the purposes of this application, a more complete description of the application will be presented with reference to the associated drawings. The drawings provided herein are intended to explain the best implementation of the application. However, the application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the application is more complete and thorough.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0029] It will be understood that when an element or layer is referred to as being "on" or "adjacent" or "connected" or "coupled" to another element or layer, it can be directly on, adjacent, connected or coupled to the other element or layer or one or more intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on," "directly adjacent," "directly connected" or "directly coupled" to another element or layer, then there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.

[0030] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can also be oriented in the other direction (e.g., rotated 90 degrees or at other orientations) and the included spatial description terminology is interpreted accordingly.

[0031] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Also, as used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0032] According to an exemplary embodiment, the present embodiment provides a photovoltaic module, as shown in Figure 1 , Figure 2 , Figure 3 , Figure 4 The photovoltaic module includes a plurality of cell strings 10 and a plurality of bus electrodes 20. Each cell string 10 includes first cells 11 and second cells 12 arranged alternately. The positive electrode of the first cell 11 is arranged on the same plane as the negative electrode of the second cell 12, and the negative electrode of the first cell 11 is arranged on the same plane as the positive electrode of the second cell 12. From the starting end to the tail end of the cell string 10, the positive electrode and the negative electrode of adjacent cells are sequentially connected by alternating back surface welding ribbons 32 and front surface welding ribbons 31. The cell at the starting end of the cell string 10 is connected with the back surface welding ribbon 32. The plurality of bus electrodes 20 includes a first bus electrode 120. The first bus electrode 120 is arranged on the back side of the cell string 10 and connected with the back surface welding ribbon 32 at the starting end of the cell string 10.

[0033] In the present embodiment, the first cell 11 and the second cell 12 can be TOPCon cells. For the TOPCon cell, along the thickness direction, the TOPCon cell includes, in sequence, a metal silver electrode, a front surface silicon nitride passivation layer, a boron-doped emitter, an N-type base silicon layer, a diffusion-doped layer, an ultra-thin silicon oxide, a doped polysilicon, a silicon nitride, and a metal silver electrode. The back surface of the cell is composed of an ultra-thin silicon oxide layer (1 nm-2 nm) and a phosphorus-doped microcrystalline and amorphous mixed Si thin film, which together form a passivation contact structure. This structure can block the recombination of minority carriers, and improve the open-circuit voltage and short-circuit current of the cell. The ultra-thin oxide layer allows the tunneling of majority carriers into the polysilicon layer while blocking the recombination of minority carriers. The good passivation effect of the ultra-thin silicon oxide and the heavily doped silicon thin film causes the energy band of the silicon wafer surface to bend, thereby forming a field passivation effect. The probability of electron tunneling is greatly increased, the contact resistance is reduced, and the open-circuit voltage and short-circuit current of the cell are improved, thereby improving the conversion efficiency of the cell.

[0034] In each battery string 10, the positive electrode of the first battery 11 is arranged on the same plane as the negative electrode of the second battery 12, the negative electrode of the first battery 11 is arranged on the same plane as the positive electrode of the second battery 12, and from the start end of the battery string 10 to the tail end, the positive electrode of the first battery 11 is connected to the negative electrode of the next second battery 12 arranged in sequence by the front welding strip 31, and the positive electrode of the second battery 12 is connected to the negative electrode of the next first battery 11 arranged in sequence by the back welding strip 32.

[0035] In this way, the welding strip connecting the first battery 11 and the second battery 12 does not need to be bent at the spacing between the first battery 11 and the second battery 12, the spacing between the first battery 11 and the second battery 12 can be reduced, the side of the first battery 11 and the side of the second battery 12 can be attached together, the distance between the batteries can be shortened to a minimum, the effective area of the photovoltaic module can be improved, and the overall performance of the module can be improved. At the same time, the front welding strip 31 and the back welding strip 32 are both flat metal conductors, which can reduce the consumption of welding strips, reduce the loss of welding strips, and help to improve production costs.

[0036] In addition, the first battery 11 and the second battery 12 are led out on the same side by the welding strip, the surface of the battery string 10 is flat, and the surface of the photovoltaic module is not uneven, which helps to reduce the risk of hidden cracks in the photovoltaic module during the lamination process, and improves the long-term stability and reliability of the photovoltaic module.

[0037] The battery at the start end of each battery string 10 can be a first battery 11 or a second battery 12, but the battery at the start end is connected to the back welding strip 32, and the first bus electrode 120 is arranged on the back side of the battery at the start end. The first bus electrode 120 is connected to the back welding strip 32 at the start end.

[0038] In this way, the first bus electrode 120 at the start end of each battery string 10 is "hidden" on the back side of the battery at the start end, which can save the area of the side of the start end of the battery string 10 for arranging the first bus electrode 120, reduce the excess area occupied by the first bus electrode 120 in the photovoltaic module, and further improve the effective area of the photovoltaic module, which helps to improve the overall performance of the module.

[0039] In some embodiments, as shown in FIGS. 1A and 1B, each battery string 10 includes a plurality of batteries 11 and 12 arranged in sequence, and a first bus electrode 120 arranged on the back side of the battery at the start end of the battery string 10. Figure 1 Figure 2 As shown in FIGS. 1A and 1B, each battery includes a grid line area 101 and a fish line area 102 arranged on both sides of the grid line area 101; and the first bus electrode 120 is arranged on the back of the fish line area 102. The grid line area 101 is the power generation area of the battery, and the fish line area 102 is the area for connecting the welding strip.

[0040] In this embodiment, the first bus electrode 120 is arranged on the back of the fish line area 102, which not only ensures smooth transmission of current, but also ensures the structural integrity and reliability of the battery.​

[0041] In some embodiments, the width d1 of the fish-tail region 102 ranges from 3mm to 10mm, for example, the width d1 of the fish-tail region 102 can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm.

[0042] The distance d2 between the edge of the fish-tail region 102 and the edge of the battery ranges from 0mm to 2mm, for example, the distance d2 between the edge of the fish-tail region 102 and the edge of the battery can be 0mm, 0.5mm, 1mm, 1.5mm or 2mm.

[0043] The width d3 of the first busbar 120 is d1-d2. For example, d1=3mm, d2=0, the width d3 of the first busbar 120 is 3mm. Or, d1=10mm, d2=3mm, the width d3 of the first busbar 120 is 7mm.

[0044] In some embodiments, along the thickness direction of the photovoltaic module, the back surface solder strip 32 of the starting end is connected to the side of the first busbar 120 away from the battery of the starting end.

[0045] The front surface solder strip 31 is connected to the front surface grid line of the grid region 101 of the battery through the solder block 133, and the back surface solder strip 32 is connected to the back surface grid line of the grid region 101 of the battery through the solder block 133. The first busbar 120 is arranged on the back side of the battery of the starting end of the battery string 10, and the first busbar 120 is arranged against the back surface of the battery of the starting end. The back surface solder strip 32 of the starting end is connected to the back surface grid line of the grid region 101 of the battery of the starting end through the solder block 133, and the back surface solder strip 32 of the starting end is arranged on the first busbar 120 close to the side of the starting end of the battery string 10 and electrically connected to the first busbar 120.

[0046] In some embodiments, as shown in Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 The photovoltaic module includes at least two battery groups 100, and the at least two battery groups 100 are arranged at intervals along a first direction D1. Each battery group 100 includes at least two battery strings 10 arranged along a second direction D2, and the battery strings 10 in the same group are connected in series through the same first busbar 120. The plurality of busbars 20 further includes a plurality of second busbars 220, and two battery strings 10 adjacent along the first direction D1 are connected through the second busbar 220, and the two battery strings 10 belong to two battery groups 100 respectively.

[0047] At least two battery groups 100 are connected with diodes 40 respectively, the battery strings 10 in each battery group 100 are arranged along the second direction D2, each battery string 10 is connected by the first battery 11 and the second battery 12 along the first direction D1 in turn, and the battery strings 10 in the same battery group 100 are connected by the first bus bar 120 to transmit the current.

[0048] The two battery strings 10 adjacent along the first direction D1 and belonging to two different battery groups 100 are connected with the second bus bar 220 and the diodes 40, and the second bus bar 220 is used to collect the current generated by the two battery strings 10 and export the current to the external circuit.

[0049] The first bus bar 120 and the second bus bar 220 together form the current collection and export circuit of the photovoltaic module, which ensures the efficient transmission of the current in the battery group 100 and between the battery groups 100, thereby improving the power generation efficiency and stability of the photovoltaic module.

[0050] The tail ends of the two battery strings 10 adjacent along the first direction D1 are arranged oppositely, and the tail ends of the two battery strings 10 are connected by the second bus bar 220. The two battery strings 10 adjacent along the first direction D1 are connected by the same second bus bar 220.

[0051] In the following, the battery is taken as a half-cut cell as an example for detailed comparison and description, of course, the half-cut cell here is only for the convenience of description, and does not constitute a limitation on the photovoltaic module of the present application.

[0052] Figure 4 The photovoltaic module shown in FIG. 12 includes 12 battery strings 10 and 3 diodes 40, and the 12 battery strings 10 are arranged into two rows along the second direction D2, and each row has 6 battery strings 10, and the two rows of battery strings 10 are spaced along the first direction D1. The battery strings 10 in the same row are connected in pairs to form 3 battery groups 100, and there are 6 battery groups 100 in total. The two battery groups 100 spaced along the first direction D1 are connected with the diodes 40 respectively.

[0053] In some embodiments, each battery string group 100 includes first battery strings and second battery strings arranged alternately along the second direction D2; the number of batteries in the first battery strings and the second battery strings is equal. The first battery string has a first battery 11 as the head-end battery, and the second battery string has a second battery 12 as the head-end battery. The head-end battery of the first battery string is connected to the head-end battery of the second battery 12 through a first busbar 120, the tail-end battery of the first battery string is connected to the tail-end battery of the first battery string of another battery string group 100 through the same second busbar 220, and is connected to a diode 40 through a connecting wire 50. The tail-end battery of the second battery string is connected to the tail-end battery of the second battery string of another battery string group 100 through the same second busbar 220, and is connected to the diode 40 through the connecting wire 50. The diode is output to the outside of the module through the junction box.

[0054] In some embodiments, as shown in FIG. 1, the number of batteries in the battery string 10 is even, one of the head-end battery and the tail-end battery of the battery string 10 is the first battery 11, and the other is the second battery 12. The tail-end battery of the battery string 10 is connected to the back solder strip 32. The second busbar 220 is arranged on the back side of the battery string 10, and the back solder strips 32 at the tail ends of two adjacent battery strings 10 along the first direction D1 are connected to the second busbar 220. Figure 1

[0055] The number of batteries in the battery string 10 is even, and the head-end battery and the tail-end battery of the battery string 10 are different types of batteries. Specifically, when the head-end battery is the first battery 11, the tail-end battery is the second battery 12; and vice versa. Since the tail-end battery of the battery string 10 is connected to the back solder strip 32. The back solder strip 32 at the tail end is usually located on the back of the tail-end battery, and the second busbar 220 is arranged on the back side of the battery string 10. The second busbar 220 connects the back solder strips 32 at the tail ends of two adjacent battery strings 10 along the first direction D1.

[0056] In this way, the second busbar 220 can also be "hidden" on the back side of the battery string 10, the spacing between two adjacent battery strings 10 along the first direction D1 can be reduced, the area on the back side of the tail end of the battery string 10 for arranging the second busbar 220 can be further saved, the redundant area occupied by the second busbar 220 in the photovoltaic module can be reduced, and the effective area of the photovoltaic module can be further improved, which is conducive to improving the overall performance of the module.

[0057] In addition, in the present embodiment, the first busbar 120 and the second busbar 220 are both arranged on the back side of the battery string 10, and the surface of the battery string 10 is flat, which is conducive to reducing the risk of hidden cracks of the photovoltaic module during the lamination process and improving the long-term stability and reliability of the photovoltaic module.

[0058] In some embodiments, as shown in FIG. 1, the number of batteries in the battery string 10 is even, one of the head-end battery and the tail-end battery of the battery string 10 is the first battery 11, and the other is the second battery 12. The tail-end battery of the battery string 10 is connected to the back solder strip 32. The second busbar 220 is arranged on the back side of the battery string 10, and the back solder strips 32 at the tail ends of two adjacent battery strings 10 along the first direction D1 are connected to the second busbar 220. Figure 1 ​As shown, the projection of the second busbar 220 on the tail-end cell of the battery string 10 has at least a partial overlap with the fish-tail region 102 of the tail-end cell. The width of the fish-tail region 102 is d1, and the width of the second busbar 220 is d4 < d1 < 2d1. For example, the width d1 of the fish-tail region 102 can be in the range of 3mm-10mm, and the width d4 of the second busbar 220 can be in the range of 3mm-20mm.

[0059] In this embodiment, the projection of the second busbar 220 on the tail-end cell of the battery string 10 has at least a partial overlap with the fish-tail region 102 of the tail-end cell. This allows the second busbar 220 to have sufficient contact area with the back side tab 32 of the tail-end cell, so that the second busbar 220 has good electrical transmission effect with the back side tab 32 of the tail-end cell.

[0060] The width d4 of the second busbar 220 is greater than the width d1 of the fish-tail region 102. That is, the width of the second busbar 220 is at least as wide as the fish-tail region 102, or even wider, to ensure that the width of the second busbar 220 is wide enough to have sufficient overlap with the tail-end cell of both battery strings 10, so that the second busbar 220 can achieve good electrical connection with both battery strings 10.

[0061] The width d4 of the second busbar 220 is less than twice the width 2d1 of the fish-tail region 102, to ensure that the width of the second busbar 220 does not exceed the fish-tail region 102 of the tail-end cell of the battery string 10, avoiding occupying the position of the back side tab 32 of the tail-end cell connected to the grid region 101 of the tail-end cell through the solder block 133.

[0062] In this way, the width of the second busbar 220 matches the fish-tail region 102 of the tail-end cell, which is beneficial for optimizing the current collection efficiency of the battery string 10, and also ensures the compactness and rationality of the structure layout of the back side of the tail-end cell, which is beneficial for the stability and reliability of the photovoltaic module.

[0063] In some embodiments, the spacing between adjacent battery strings 10 along the first direction D1 is less than 0.5cm. For example, the spacing between adjacent battery strings 10 along the first direction D1 can be 0.5cm, 0.4cm, 0.3cm, 0.2cm, 0.1cm, or 0cm.

[0064] In some embodiments, as shown in FIG. 1, the second busbar 220 is arranged on the back side of the tail-end cell of the battery string 10. Figure 2As shown, the number of batteries in the battery string 10 is odd. The starting and ending batteries of the battery string 10 are either the first battery 11 or the second battery 12. The ending battery of the battery string 10 is connected to the front solder strip 31. The second bus electrode 220 is located between the two battery groups 100. The front solder strip 31 of the two adjacent battery strings 10 along the first direction D1 is connected to the second bus electrode 220.

[0065] The number of batteries in the battery string 10 is odd, and the batteries at the beginning and end of the battery string 10 are of the same type. Specifically, when the starting battery is the first battery 11, the ending battery is also the first battery 11; and vice versa. The ending battery of the battery string 10 is connected to the front solder strip 31. A second bus electrode 220 is disposed between the two battery groups 100, and the second bus electrode 220 connects to the front solder strip 31 at the end of the adjacent battery string 10.

[0066] In this embodiment, the second bus electrode 220 is disposed between two adjacent battery strings 10, and the second bus electrode 220 is disposed on one side of the front of the battery string 10.

[0067] In this embodiment, the width of the second bus electrode 220 is smaller than the spacing between two adjacent battery strings 10. Along the first direction D1, the spacing between the side of the second bus electrode 220 and the end batteries of the two connected battery strings 10 is greater than 0. For example, the width of the second bus electrode 220 is 10mm, the spacing between two adjacent battery strings 10 can be 12mm, and the spacing between the side of the second bus electrode 220 and the end batteries of the two connected battery strings 10 is 1mm.

[0068] This ensures that current passing through the second bus electrode 220 does not directly contact the end cells of the battery string 10, thus avoiding unnecessary electrical connections or short circuits. This improves the electrical safety of the module and also helps reduce errors during manufacturing and installation. Furthermore, the spacing helps buffer thermal expansion stress or mechanical stress, thereby improving the long-term stability and reliability of the module.

[0069] The photovoltaic module of this application improves the effective area and current transmission efficiency of the photovoltaic module by optimizing the layout and connection method. It can maximize the effective area, improve the current transmission efficiency, enhance electrical safety, and improve the overall performance of the photovoltaic module. The photovoltaic module has excellent overall performance and long-term stability.

[0070] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A photovoltaic module, characterized in that, It includes multiple battery strings and multiple bus electrodes. Each battery string includes alternating first and second batteries. The positive electrode of the first battery and the negative electrode of the second battery are arranged on the same side, and the negative electrode of the first battery and the positive electrode of the second battery are arranged on the same side. From the beginning to the end of the battery string, the positive and negative electrodes of adjacent batteries are sequentially connected by alternating back solder strips and front solder strips. The battery at the beginning of the battery string is connected to the back solder strip. The plurality of bus electrodes include a first bus electrode, which is disposed on the back side of the battery string and is connected to the back solder strip at the starting end of the battery string. Each battery includes a grid area and harpoon line areas on both sides of the grid area; the first bus electrode is located on the back side of the harpoon line area; The width of the harpoon line area is d1; the distance between the edge of the harpoon line area and the edge of the battery is d2; the width of the first bus electrode is d3 = d1 - d2.

2. The photovoltaic module according to claim 1, characterized in that, The range of d1 is 3mm-10mm; the range of d2 is 0mm-2mm.

3. The photovoltaic module according to claim 1, characterized in that, Along the thickness direction of the photovoltaic module, the back solder strip is connected to the side of the cell away from the starting end of the first bus electrode.

4. The photovoltaic module according to claim 1, characterized in that, It includes at least two battery packs, the at least two battery packs are spaced apart along a first direction, each battery pack includes at least two battery strings arranged along a second direction, and the battery strings in the same group are connected in series through the same first bus electrode; The plurality of bus electrodes also include a plurality of second bus electrodes, and two adjacent battery strings along the first direction are connected through the second bus electrodes, and the two battery strings belong to two battery packs respectively.

5. The photovoltaic module according to claim 4, characterized in that, The tail ends of two adjacent battery strings along the first direction are arranged opposite each other, and the tail ends of the two battery strings are connected through the second bus electrode.

6. The photovoltaic module according to claim 5, characterized in that, The number of batteries in the battery string is odd. The starting battery and the ending battery of the battery string are both the first battery or both the second battery. The ending battery of the battery string is connected to the front solder strip. The second bus electrode is disposed between the two sets of battery packs, and the front solder strips of the two adjacent battery strings along the first direction are connected to the second bus electrode.

7. The photovoltaic module according to claim 5, characterized in that, The number of batteries in the battery string is even. One of the starting and ending batteries of the battery string is the first battery and the other is the second battery. The ending battery of the battery string is connected to the back solder strip. The second bus electrode is located on the back side of the battery string, and the back solder strips of two adjacent battery strings along the first direction are connected to the second bus electrode.

8. The photovoltaic module according to claim 7, characterized in that, The projection of the second bus electrode onto the end battery of the battery string has at least a partial overlap with the forklift area of ​​the end battery, and the width of the second bus electrode is d1 < d4 < 2d1.

9. The photovoltaic module according to claim 7, characterized in that, The spacing between adjacent battery strings is less than 0.5 cm.

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