Photovoltaic module

Abstract

The photovoltaic module comprises a plurality of battery strings and a plurality of bus electrodes, each battery string comprises first batteries and second batteries which are alternately arranged, the positive electrodes of the first batteries and the negative electrodes of the second batteries are arranged on the same plane, the negative electrodes of the first batteries and the positive electrodes of the second batteries are arranged on the same plane, and the first batteries and the second batteries are arranged from the starting ends to the tail ends of the battery strings. Positive electrodes and negative electrodes of adjacent batteries are sequentially connected through alternate back welding strips and front welding strips, and the battery at the starting end of the battery string is connected with the back welding strips; the plurality of bus electrodes comprise a first bus electrode, the first bus electrode is arranged on the back side of the battery string, and the first bus electrode is connected with the back welding strip at the starting end of the battery string. The effective area of the photovoltaic module can be increased, and the overall efficiency of the module can be improved.

Description

Technical Field

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

[0002] Tunnel Oxide Passivated Contact (TOPCON) cells are the mainstream cells in the photovoltaic field. Existing TOPCON modules are composed of multiple TOPCON cells connected in sequence through welding ribbons. The welding ribbons of adjacent cells are led out from different surfaces of the cells and interconnected. Such a connection design requires that the cells must be spaced a certain distance apart to ensure that the connections of the welding ribbons do not interfere with each other, resulting in a reduction in the effective area of ​​the module, which in turn affects the overall performance of the module. Moreover, the welding ribbons of adjacent cells are led out from different surfaces of the cells, which will also bring potential risks of hidden cracks to the cells, which is not conducive to the long-term stability and reliability of the module. Summary of the invention

[0003] Based on this, it is necessary to provide a photovoltaic module to address the problem in the prior art that the welding 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, which in turn affects the overall performance of the module and brings potential risks of hidden cracks to the cells.

[0004] The present disclosure provides a photovoltaic module, comprising a plurality of battery strings and a plurality of busbars, each of the battery strings comprising a first battery and a second battery arranged alternately, the positive electrode of the first battery and the negative electrode of the second battery being arranged on the same surface, the negative electrode of the first battery and the positive electrode of the second battery being arranged on the same surface, the positive electrode and the negative electrode of the first battery being connected in sequence from the starting end to the tail end of the battery string through alternating back welding strips and front welding strips, and the battery at the starting end of the battery string being connected to the back welding strip;

[0005] The plurality of busbar electrodes include a first busbar electrode, which is disposed on the back side of the battery string and connected to the back welding strip at the starting end of the battery string.

[0006] In one embodiment, each battery includes a gate line region and a harpoon line region disposed on both sides of the gate line region; the first bus electrode is disposed on the back side of the harpoon line region.

[0007] In one embodiment, the width d1 of the harpoon line area is in the range of 3mm-10mm; the distance d2 between the edge of the harpoon line area and the edge of the battery is in the range of 0mm-2mm; and the width d3 of the first bus electrode is equal to d1-d2.

[0008] In one of the embodiments, along the thickness direction of the photovoltaic module, the back welding strip is connected to a side of the battery of the first bus electrode away from the starting end.

[0009] In one embodiment, at least two battery groups are included, at least two of the battery groups are spaced apart along a first direction, each of the battery groups 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;

[0010] The plurality of bus electrodes further include a plurality of second bus electrodes, two battery strings adjacent to each other along the first direction are connected via the second bus electrodes, and the two battery strings belong to two battery groups respectively.

[0011] In one of the embodiments, the tail ends of two battery strings adjacent to each other along the first direction are arranged opposite to each other, and the tail ends of the two battery strings are connected through the second bus electrode.

[0012] In one embodiment, the number of cells in the cell string is an odd number, the starting cell and the tail cell of the cell string are both the first cell, or both are the second cell, and the tail cell of the cell string is connected to the front welding strip;

[0013] The second bus electrode is disposed between two groups of the battery groups, and the front welding strips at the tail ends of two adjacent battery strings along the first direction are connected to the second bus electrode.

[0014] In one embodiment, the number of cells in the cell string is an even number, one of the starting cell and the tail cell of the cell string is the first cell, and the other is the second cell, and the tail cell of the cell string is connected to the back welding strip;

[0015] The second bus electrode is disposed on the back side of the battery string, and the back welding strips at the tail ends of two adjacent battery strings along the first direction are connected to the second bus electrode.

[0016] In one embodiment, the projection of the second bus electrode on the tail battery of the battery string at least partially overlaps with the harpoon line area of ​​the tail battery, the width of the harpoon line area is d1, and the width of the second bus electrode is d1<d4<2d1.

[0017] In one embodiment, the spacing between adjacent battery strings is less than 0.5 cm.

[0018] In the photovoltaic module disclosed in the present invention, the welding strip connecting the first battery and the second battery does not need to be bent at the gap between the first battery and the second battery, so the gap between the first battery and the second battery can be reduced, the side of the first battery and the side of the second battery can be attached together, and the distance between the battery cells can be shortened to a minimum, which can increase the effective area of ​​the photovoltaic module and help improve the overall efficiency of the module. In addition, the first battery and the second battery are led out from the same side through the welding strip, the surface of the battery string is flat, and the surface of the photovoltaic module has no ups and downs, which is conducive to reducing the risk of hidden cracks in the lamination process of the photovoltaic module and improving the long-term stability and reliability of the photovoltaic module; the first bus electrode at the starting end of each battery string is "hidden" on the back side of the battery at the starting end, which can save the area of ​​the side of the starting end of the battery string for setting the first bus electrode, can reduce the redundant area occupied by the first bus electrode in the photovoltaic module, can further increase the effective area of ​​the photovoltaic module, and help improve the overall efficiency of the module. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

[0021] Figure 2 A schematic diagram of the layout of a photovoltaic assembly provided in another exemplary embodiment of the present application;

[0022] Figure 3 A schematic diagram of a battery string provided in an exemplary embodiment of the present application;

[0023] Figure 4 It is a circuit diagram of a battery string provided in an exemplary embodiment of the present application.

[0024] Description of reference numerals:

[0025] 100, battery pack; 10, battery string; 11, first battery; 12, second battery; 101, gate line area; 102, harpoon line area; 133, welding block; 20, busbar electrode; 120, first busbar electrode; 220, second busbar electrode; 31, front welding strip; 32, back welding strip; 40, diode; 50, connecting wire;

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

[0027] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0029] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers, doping types and / or parts, these elements, components, regions, layers, doping types and / or parts should not be limited by these terms. These terms are only used to distinguish an element, component, region, layer, doping type or part from another element, component, region, layer, doping type or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer, doping type or part discussed below can be represented as a second element, component, region, layer or part.

[0030] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0031] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that when the terms "consisting of" and / or "comprising" are used in this specification, the presence of the features, integers, steps, operations, elements and / or parts can be determined, but the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups is not excluded. At the same time, when used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0032] According to an exemplary embodiment, this embodiment provides a photovoltaic assembly, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the photovoltaic module includes a plurality of battery strings 10 and a plurality of bus electrodes 20, each battery string 10 includes a first battery 11 and a second battery 12 arranged alternately, the positive electrode of the first battery 11 is arranged on the same surface as the negative electrode of the second battery 12, and the negative electrode of the first battery 11 is arranged on the same surface as the positive electrode of the second battery 12, and the positive electrode and negative electrode of the adjacent battery are connected in sequence from the starting end to the tail end of the battery string 10 through alternating back welding strips 32 and front welding strips 31, and the battery at the starting end of the battery string 10 is connected to the back welding strip 32; the plurality of bus electrodes 20 include a first bus electrode 120, the first bus electrode 120 is arranged on the back side of the battery string 10, and the first bus electrode 120 is connected to the back welding strip 32 at the starting end of the battery string 10.

[0033] Among them, the first battery 11 and the second battery 12 in the embodiment of the present application can be TOPCon batteries. For TOPCon batteries, along the thickness direction, the TOPCon battery includes a metal silver electrode, a front surface silicon nitride passivation layer, a boron-doped emitter, an N-type base silicon layer, a diffused doped layer, an ultra-thin silicon oxide, doped polysilicon, silicon nitride, and a metal silver electrode. The back of the battery is composed of a layer of ultra-thin silicon oxide (1nm~2nm) and a layer of phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivation contact structure. This structure can block the recombination of minority carrier holes and increase the open circuit voltage and short-circuit current of the battery. The ultra-thin oxide layer can allow the majority electrons to tunnel into the polysilicon layer while blocking the recombination of minority carrier holes. The good passivation effect of ultra-thin silicon oxide and heavily doped silicon film causes the surface energy band of the silicon wafer to bend, thereby forming a field passivation effect, greatly increasing the probability of electron tunneling, and reducing the contact resistance, which increases the open circuit voltage and short-circuit current of the battery, thereby improving the battery conversion efficiency.

[0034] In each battery string 10, the positive electrode of the first battery 11 is arranged on the same surface as the negative electrode of the second battery 12, and the negative electrode of the first battery 11 is arranged on the same surface as the positive electrode of the second battery 12. From the starting end to the tail end of the battery string 10, the positive electrode of the first battery 11 is connected to the negative electrode of the next second battery 12 arranged in sequence through 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 through 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 gap between the first battery 11 and the second battery 12, which can reduce the gap between the first battery 11 and the second battery 12, and can put the side of the first battery 11 and the side of the second battery 12 together, shortening the distance between the batteries to a minimum, which can increase the effective area of ​​the photovoltaic module and help improve the overall efficiency of the module. At the same time, the front welding strip 31 and the back welding strip 32 are both straight metal conductors, which can reduce welding strip consumables and welding strip loss, which is conducive to improving production costs.

[0036] In addition, the first cell 11 and the second cell 12 are led out on the same side through the welding strip, the surface of the cell string 10 is flat, and the surface of the photovoltaic module has no unevenness, which is beneficial to reducing the risk of hidden cracks in the photovoltaic module during the lamination process and improving the long-term stability and reliability of the photovoltaic module.

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

[0038] In this way, the first bus electrode 120 at the starting end of each battery string 10 is "hidden" on the back side of the battery at the starting end, which can save the area on the side of the starting end of the battery string 10 for setting the first bus electrode 120, reduce the redundant area occupied by the first bus electrode 120 in the photovoltaic module, further increase the effective area of ​​the photovoltaic module, and help improve the overall performance of the module.

[0039] In some embodiments, Figure 1 , Figure 2 As shown, each battery includes a gridline area 101 and a harpoon line area 102 disposed on both sides of the gridline area 101; a first bus electrode 120 is disposed on the back of the harpoon line area 102. The gridline area 101 is the power generation area of ​​the battery, and the harpoon line area 102 is the area for connecting with the welding strip.

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

[0041] In some embodiments, the width d1 of the harpoon line area 102 ranges from 3 mm to 10 mm. For example, the width d1 of the harpoon line area 102 may be 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm.

[0042] The distance d2 between the edge of the harpoon line area 102 and the edge of the battery ranges from 0 mm to 2 mm. For example, the distance d2 between the edge of the harpoon line area 102 and the edge of the battery can be 0 mm, 0.5 mm, 1 mm, 1.5 mm or 2 mm.

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

[0044] In some embodiments, along the thickness direction of the photovoltaic module, the backside welding ribbon 32 at the starting end is connected to a side of the first bus electrode 120 away from the battery at the starting end.

[0045] The front welding strip 31 is connected to the front grid line of the grid line area 101 of the battery through the welding block 133, and the back welding strip 32 is connected to the back grid line of the grid line area 101 of the battery through the welding block 133. The first bus electrode 120 is arranged on the back side of the battery at the starting end of the battery string 10, and the first bus electrode 120 is arranged close to the back of the battery at the starting end. The back welding strip 32 at the starting end is connected to the back grid line of the grid line area 101 of the battery at the starting end through the welding block 133, and the back welding strip 32 at the starting end is placed on the first bus electrode 120 on the side close to the starting end of the battery string 10 and is electrically connected to the first bus electrode 120.

[0046] In some embodiments, Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the photovoltaic module includes at least two battery groups 100, at least two of which are arranged at intervals along the first direction D1, and each battery group 100 includes at least two battery strings 10 arranged along the second direction D2, and the battery strings 10 in the same group are connected in series through the same first bus electrode 120; the multiple bus electrodes 20 also include multiple second bus electrodes 220, and two adjacent battery strings 10 along the first direction D1 are connected through the second bus electrode 220, and the two battery strings 10 belong to two battery groups 100 respectively.

[0047] At least two battery groups 100 are respectively connected to the diode 40, and the multiple battery strings 10 of each battery group 100 are arranged along the second direction D2. Each battery string 10 is composed of a first battery 11 and a second battery 12 connected in series in the first direction D1. The multiple battery strings 10 in the same battery group 100 transmit current through the first bus electrode 120.

[0048] Two battery strings 10 adjacent to each other along the first direction D1 and belonging to two different battery groups 100 are connected to the second bus electrode 220 and connected to the diode through the second bus electrode 220. The second bus electrode 220 is used to collect the current generated by the two battery strings 10 and output it to the external circuit.

[0049] The first bus electrode 120 and the second bus electrode 220 together constitute a current collection and derivation circuit of the photovoltaic module, ensuring efficient transmission of current within the battery pack 100 and between battery packs 100, thereby improving the power generation efficiency and stability of the photovoltaic module.

[0050] The tail ends of two battery strings 10 adjacent to each other in the first direction D1 are arranged opposite to each other, and the tail ends of the two battery strings 10 are connected through the second bus electrode 220. The two battery strings 10 adjacent to each other in the first direction D1 are connected through the same second bus electrode 220.

[0051] Below, a detailed comparison is made by taking a battery as a half-cut cell as an example. Of course, the half-cut cell here is only for the convenience of explanation and does not constitute a limitation to the photovoltaic module of the present application.

[0052] Figure 4 The photovoltaic assembly shown in the figure includes 12 battery strings 10 and 3 diodes 40. The 12 battery strings 10 are arranged in two rows along the second direction D2, with 6 battery strings 10 in each row, and the two rows of battery strings 10 are spaced apart along the first direction D1. The battery strings 10 in the same row are connected in series in pairs to form three battery groups 100, for a total of 6 battery groups 100. The two battery groups 100 spaced apart along the first direction D1 are respectively connected to the diodes 40.

[0053] In some embodiments, each battery group 100 includes a first battery string and a second battery string alternately arranged along a second direction D2; the number of batteries in the first battery string and the second battery string is equal. The head end battery of the first battery string is the first battery 11, and the head end battery of the second battery string is the second battery 12. The head end battery of the first battery string is connected to the head end battery of the second battery 12 through the first bus electrode 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 group 100 and the same second bus electrode 220, and is connected to the diode 40 through the connecting line 50, and the tail end battery of the second battery string is connected to the tail end battery of the second battery string of another battery group 100 and the same second bus electrode 220, and is connected to the diode 40 through the connecting line 50. It is led out to the junction box through the diode and then output to the outside of the component.

[0054] In some embodiments, Figure 1 As shown, the number of cells in the battery string 10 is an even number, one of the starting cell and the tail cell of the battery string 10 is a first cell 11, and the other is a second cell 12, and the tail cell of the battery string 10 is connected to the back welding strip 32; the second bus electrode 220 is arranged on the back side of the battery string 10, and the back welding strips 32 at the tail ends of two adjacent battery strings 10 along the first direction D1 are connected to the second bus electrode 220.

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

[0056] In this way, the second bus electrode 220 can also be "hidden" on the back side of the battery string 10, which can reduce the distance between two adjacent battery strings 10 along the first direction D1, further reduce and save the area on the side of the tail end of the battery string 10 for setting the second bus electrode 220, and reduce the redundant area occupied by the second bus electrode 220 in the photovoltaic module, which can further increase the effective area of ​​the photovoltaic module, which is beneficial to improving the overall performance of the module.

[0057] In addition, in this embodiment, the first bus electrode 120 and the second bus electrode 20 are both arranged on the back side of the battery string 10. The surface of the battery string 10 is flat, which is beneficial to reducing the risk of hidden cracks in the photovoltaic module during the lamination process and improving the long-term stability and reliability of the photovoltaic module.

[0058] In some embodiments, Figure 1As shown, the projection of the second bus electrode 220 on the tail battery of the battery string 10 at least partially overlaps with the harpoon line area 102 of the tail battery, the width of the harpoon line area 102 is d1, and the width d1 of the second bus electrode 220 is d4<2d1. For example, the width d1 of the harpoon line area 102 ranges from 3mm to 10mm, and the width d4 of the second bus electrode 220 ranges from 3mm to 20mm.

[0059] In this embodiment, the projections formed by the second bus electrode 220 on the tail end battery of the battery string 10 to which it is connected at least partially overlap with the harpoon line area 102 of the tail end battery, so that the second bus electrode 220 can have a sufficient contact area with the back side welding strip 32 of the tail end battery, so that the second bus electrode 220 and the back side welding strip 32 of the tail end battery have a good electrical transmission effect.

[0060] The width d4 of the second bus electrode 220 is greater than the width d1 of the harpoon line area 102. That is, the width of the second bus electrode 220 is at least as wide as the harpoon line area 102, or even wider, to ensure that the width of the second bus electrode 220 is wide enough so that the tail end batteries of the two battery strings 10 connected to the second bus electrode 220 can have enough overlap area, ensuring that the second bus electrode 220 can achieve good electrical connection with both battery strings 10.

[0061] The width d4 of the second bus electrode 220 is less than twice the width 2d1 of the harpoon line area 102 to ensure that the width of the second bus electrode 220 does not exceed the harpoon line area 102 of the tail end battery of the battery string 10, avoiding occupying the position where the back side welding strip 32 of the tail end is connected to the gate line area 101 of the tail end battery through the welding block 133.

[0062] In this way, the width of the second bus electrode 220 matches the harpoon line area 102 of the tail cell, which is beneficial to optimizing the current collection efficiency of the battery string 10, and also ensures the compactness and rationality of the structural layout on the back side of the tail cell, which is beneficial to 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 0.5 cm. For example, the spacing between adjacent battery strings 10 along the first direction D1 may be 0.5 cm, 0.4 cm, 0.3 cm, 0.2 cm, 0.1 cm or 0 cm.

[0064] In some embodiments, Figure 2As shown, the number of batteries in the battery string 10 is an odd number, the starting battery and the tail battery of the battery string 10 are both first batteries 11, or both are second batteries 12, and the tail battery of the battery string 10 is connected to the front welding strip 31; the second bus electrode 220 is arranged between the two battery groups 100, and the front welding strips 31 at the tail ends of two adjacent battery strings 10 along the first direction D1 are connected to the second bus electrode 220.

[0065] The number of cells in the battery string 10 is an odd number, and the starting cell and the tail cell of the battery string 10 are the same type of cells. Specifically, when the starting cell is the first cell 11, the tail cell is the first cell 11; and vice versa. Since the tail cell of the battery string 10 is connected to the front welding strip 31, the second bus electrode 220 is disposed between the two battery groups 100, and the second bus electrode 220 is connected to the front welding strip 31 of the tail 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 the front side of the battery string 10 .

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

[0068] In this way, it can be ensured that the current will not directly contact the tail battery of the battery string 10 when passing through the second bus electrode 220, thereby avoiding unnecessary electrical connection or short circuit. The electrical safety of the component is improved, and it is also helpful to reduce errors during manufacturing and installation. In addition, the existence of the spacing can also buffer thermal expansion stress or mechanical stress, thereby improving the long-term stability and reliability of the component.

[0069] The photovoltaic module of the present application improves the effective area and current transmission efficiency of the photovoltaic module by optimizing the layout and connection method, 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-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features of the above-described 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 above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A photovoltaic module, characterized in that: The invention comprises a plurality of battery strings and a plurality of busbars, each of the battery strings comprises a first battery and a second battery arranged alternately, the positive electrode of the first battery is arranged on the same surface as the negative electrode of the second battery, and the negative electrode of the first battery is arranged on the same surface as the positive electrode of the second battery, and the positive electrode and the negative electrode of the first battery are sequentially connected from the starting end to the tail end of the battery string through alternating back welding strips and front welding strips, and the battery at the starting end of the battery string is connected to the back welding strip; The plurality of busbar electrodes include a first busbar electrode, which is disposed on the back side of the battery string and connected to the back welding strip at the starting end of the battery string.

2. The photovoltaic module according to claim 1, characterized in that: Each battery comprises a gate line region and harpoon line regions arranged on both sides of the gate line region; the first bus electrode is arranged on the back side of the harpoon line region.

3. The photovoltaic module according to claim 2, characterized in that: The width d1 of the harpoon line area is in the range of 3mm-10mm; the distance d2 between the edge of the harpoon line area and the edge of the battery is in the range of 0mm-2mm; the width d3 of the first bus electrode is = d1-d2.

4. The photovoltaic module according to claim 1, characterized in that: Along the thickness direction of the photovoltaic module, the back welding strip is connected to a side of the battery of the first bus electrode away from the starting end.

5. The photovoltaic module according to claim 1, characterized in that: The battery group comprises at least two battery groups, wherein the at least two battery groups are spaced apart along a first direction, each battery group comprises 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 further include a plurality of second bus electrodes, two battery strings adjacent to each other along the first direction are connected via the second bus electrodes, and the two battery strings belong to two battery groups respectively.

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

7. The photovoltaic module according to claim 6, characterized in that: The number of cells in the cell string is an odd number, the starting cell and the tail cell of the cell string are both the first cell, or both are the second cell, and the tail cell of the cell string is connected to the front welding strip; The second bus electrode is disposed between two groups of the battery groups, and the front welding strips at the tail ends of two adjacent battery strings along the first direction are connected to the second bus electrode.

8. The photovoltaic module according to claim 6, characterized in that: The number of cells in the cell string is an even number, one of the starting cell and the tail cell of the cell string is the first cell, and the other is the second cell, and the tail cell of the cell string is connected to the back welding strip; The second bus electrode is disposed on the back side of the battery string, and the back welding strips at the tail ends of two adjacent battery strings along the first direction are connected to the second bus electrode.

9. The photovoltaic module according to claim 8, characterized in that: The projection of the second bus electrode on the tail battery of the battery string at least partially overlaps with the harpoon line area of ​​the tail battery, the width of the harpoon line area is d1, and the width of the second bus electrode is d1<d4<2d1.

10. The photovoltaic module according to claim 8, characterized in that: The distance between adjacent battery strings is less than 0.5 cm.

Images