Solar cell module and photovoltaic system

Abstract

The embodiment of the invention provides a solar cell module and a photovoltaic system. The solar cell module comprises at least two cell strings, each cell string comprises a plurality of cell pieces which are connected in series through a welding strip, each cell string comprises a head-end cell piece and a tail-end cell piece, the head-end cell piece is a first cell piece, the tail-end cell piece is a second cell piece, and the first cell piece and the second cell piece are connected in series. The polarities of the first battery piece and the second battery piece are opposite; two adjacent battery strings are arranged side by side in the direction perpendicular to the series connection direction of the battery strings, and the polarities of two adjacent head-end battery pieces and / or two adjacent tail-end battery pieces in the two adjacent battery strings are opposite. The solar cell module provided by the embodiment of the invention has relatively high photoelectric conversion efficiency and relatively small module area.

Description

Technical Field

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

[0002] With the widespread application of solar energy, the solar photovoltaic panel industry has also flourished. The conventional component manufacturing process uses welding ribbons to connect the positive and negative electrodes of the cells into strings, and then arranges and welds them into components in a certain arrangement. Usually, the welding ribbons are used to alternately weld the front and back sides of two adjacent cells to achieve the purpose of connecting the positive and negative electrodes.

[0003] However, in the process of connecting multiple heterojunction solar cells in series to form a photovoltaic module, there is a lot of blank space between the series-connected heterojunction cells of the heterojunction solar cell photovoltaic module, and the bus bar also occupies part of the area of ​​the module, resulting in a reduction in the area of ​​the module occupied by the cells of the entire module, affecting the light-receiving area of ​​the module body, thereby resulting in low module conversion efficiency.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0005] The embodiments of the present application provide a solar cell module and a photovoltaic system to solve or alleviate the problem of low module conversion efficiency mentioned above.

[0006] According to a first aspect of an embodiment of the present application, a solar cell assembly is provided, comprising: at least two cell strings, each of the cell strings comprising a plurality of cell sheets connected in series via welding strips, the cell strings comprising a head-end cell sheet and a tail-end cell sheet, the head-end cell sheet being a first cell sheet, the tail-end cell sheet being a second cell sheet, the first cell sheet and the second cell sheet having opposite polarities; in a direction perpendicular to the series connection of the cell strings, two adjacent cell strings are arranged side by side, and the polarities of two adjacent head-end cell sheets and / or two adjacent tail cell sheets in two adjacent cell strings are opposite.

[0007] The solar cell module of the embodiment of the present application has a high photoelectric conversion efficiency and a small module area. Specifically, the polarity of the head cell and the end cell in each cell string is opposite, so that the welding strips of the head cell and the end cell are both drawn out from the back of the cell. When the welding strips drawn out from the back are subsequently connected to the bus bar, the bus bar can be hidden on the back of the photovoltaic module, which in turn helps to improve the module conversion effect.

[0008] According to an embodiment of the present application, in the series connection direction of the battery strings, the photovoltaic module includes at least two of the battery strings, and two adjacent battery strings are connected in series via welding strips, and two adjacent battery cells in the two adjacent battery strings have the same polarity.

[0009] According to an embodiment of the present application, the photovoltaic component also includes: a first bus bar and a second bus bar, in a series connection direction perpendicular to the battery string, the first bus bar is located on the head end battery cell of the adjacent battery string, and the second bus bar is located on the end battery cell of the adjacent battery string.

[0010] According to an embodiment of the present application, the first bus bar is located in the middle of the backlight surface of the head-end battery cell, and the second bus bar is located in the middle of the backlight surface of the end battery cell.

[0011] According to an embodiment of the present application, the first bus bars include at least two, and among two adjacent first bus bars, one first bus bar and the other first bus bar are staggered or collinear in an extension direction.

[0012] According to an embodiment of the present application, the second bus bars include at least two, and among two adjacent second bus bars, one second bus bar and the other second bus bar are staggered or collinear in an extension direction.

[0013] According to an embodiment of the present application, the photovoltaic module also includes: a first bus bar, a second bus bar and a third bus bar. In the series connection direction perpendicular to the battery string, the first bus bar is located on the head end battery cell of the adjacent battery string, and the second bus bar is located on the end battery cell of the adjacent battery string; in the series connection direction of the battery string, the third bus bar is located on two adjacent battery cells in two adjacent battery strings or in the gap between two adjacent battery cells.

[0014] According to an embodiment of the present application, the gap is no greater than 14 mm.

[0015] According to an embodiment of the present application, the third bus bar is located in the middle of the gap, and the third bus bar is not in contact with the two battery cells.

[0016] According to an embodiment of the present application, the first bus bars include at least two, and among two adjacent first bus bars, one first bus bar and the other first bus bar are staggered or collinear in an extension direction.

[0017] According to an embodiment of the present application, the second bus bars include at least two, and among two adjacent second bus bars, one second bus bar and the other second bus bar are staggered or collinear in an extension direction.

[0018] According to an embodiment of the present application, the third bus bars include at least two, and among two adjacent third bus bars, one third bus bar and the other third bus bar are staggered or collinear in their extension direction.

[0019] The second aspect of the embodiment of the present application provides a photovoltaic system, characterized in that the photovoltaic system includes the solar cell assembly described in the first aspect. The photovoltaic system also has the advantages of the photovoltaic assembly, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0021] Figure 1 is a schematic diagram of the structure of a solar cell assembly in some embodiments; Figure 2 is a schematic structural diagram of the back side of the bus bar welded at the middle position of some embodiments; Figure 3 is a schematic diagram of a structure in which the first bus bar is hidden in the backlight surface in some embodiments; Figure 4 is a schematic diagram of a structure in which the first bus bar is hidden in the backlight surface in some other embodiments; Figure 5 It is a schematic diagram of the back side of the structure in which the second bus bar is hidden on the backlight surface in some embodiments.

[0022] Description of reference numerals: 1: welding strip; 2: second battery cell; 3: third bus bar; 4: spacing; 5: first bus bar; 6: second bus bar; 7: first battery cell. DETAILED DESCRIPTION

[0023] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0024] 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 and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. When the second element, component, region, layer or part is discussed, it does not indicate that the present application necessarily has the first element, component, region, layer or part.

[0025] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0028] There is a lot of white space in the heterojunction photovoltaic module as a whole. The middle and upper and lower bus bars occupy part of the module area, resulting in a reduction in the area of ​​the module occupied by the battery cells of the entire module, affecting the light-receiving area of ​​the module body and causing low module conversion efficiency.

[0029] Based on this, a first aspect of an embodiment of the present application provides a solar cell assembly, comprising: at least two cell strings, each of the cell strings comprising a plurality of cell sheets connected in series through welding ribbons, the cell strings comprising a head-end cell sheet and a tail-end cell sheet, the head-end cell sheet is a first cell sheet, the tail-end cell sheet is a second cell sheet, and the polarities of the first cell sheet and the second cell sheet are opposite; in a direction perpendicular to the series connection of the cell strings, two adjacent cell strings are arranged side by side, and the polarities of two adjacent head-end cell sheets and / or two adjacent tail cell sheets in two adjacent cell strings are opposite.

[0030] The solar cell module of the embodiment of the present application has a high photoelectric conversion efficiency and a small module area. Specifically, the polarity of the head cell and the end cell in each cell string is opposite, so that the welding strips of the head cell and the end cell are both drawn out from the back of the cell. When the welding strips drawn out from the back are subsequently connected to the bus bar, the bus bar can be hidden on the back of the photovoltaic module, which in turn helps to improve the module conversion effect.

[0031] In some embodiments, the solar cell assembly includes a plurality of solar cells connected in series and / or in parallel; wherein the solar cell is a heterojunction solar cell or a tunneling oxide passivated contact solar cell (TOPcon).

[0032] Furthermore, the first battery cell and the second battery cell have opposite polarities, which means that the first battery cell is a battery cell obtained by flipping the second battery cell, so that the electrodes of the first battery cell and the second battery cell on the same straight line have opposite polarities.

[0033] In some embodiments, in a solar cell assembly, the phosphorus-doped layer of the first cell is located on the light-receiving surface, and the boron-doped layer of the second cell is located on the light-receiving surface. The front / back surface of the first cell and the front / back surface of the second cell have the same film color, electrode, and grid line. This makes the solar cell assembly look beautiful.

[0034] In some embodiments, the photovoltaic module further includes: a first bus bar and a second bus bar, wherein the first bus bar is located on the head end cell of the adjacent cell string in a direction perpendicular to the series connection of the cell string, and the second bus bar is located on the end cell of the adjacent cell string. The first bus bar and the second bus bar located on the backlight side can avoid blocking the light of the entire module, thereby increasing the absorption of solar energy by the entire module. In addition, the second bus bar located on the backlight side can also reduce the area of ​​the entire photovoltaic module.

[0035] Furthermore, the first bus bar is located in the middle of the backlight surface of the first end cell, and the second bus bar is located in the middle of the backlight surface of the end cell. The first bus bar and the second bus bar located in the middle make the current drawn from both sides consistent, reducing the photoelectric performance loss caused by the current adaptation of the solar cell module.

[0036] In some embodiments, the first bus bars include at least two, and among two adjacent first bus bars, one first bus bar is staggered or collinear with another first bus bar in the extension direction; and / or, the second bus bars include at least two, and among two adjacent second bus bars, one second bus bar is staggered or collinear with another second bus bar in the extension direction.

[0037] In some embodiments, in the series connection direction of the battery strings, the photovoltaic module includes at least two of the battery strings, and two adjacent battery strings are connected in series via welding strips, and two adjacent battery cells in the two adjacent battery strings have the same polarity.

[0038] In some other embodiments, the photovoltaic module further includes: a first bus bar, a second bus bar and a third bus bar; in a direction perpendicular to the series connection of the battery strings, the first bus bar is located on the head end battery cell of the adjacent battery strings, and the second bus bar is located on the end battery cell of the adjacent battery strings; in the series connection direction of the battery strings, the third bus bar is located on two adjacent battery cells in two adjacent battery strings or in a gap between two adjacent battery cells.

[0039] In some specific embodiments, reference Figure 1-3 The solar cell assembly includes at least two battery strings, each of which includes a plurality of battery cells connected in series through a welding ribbon 1, the head end battery cell is a first battery cell 7, the end battery cell is a second battery cell 2, and the polarities of the first battery cell 7 and the second battery cell 2 are opposite. The first bus bar 5 is located on the head end battery cell of the adjacent battery string, and the second bus bar 6 is located on the end battery cell of the adjacent battery string. The third bus bar 3 is located on the adjacent two battery cells in the two adjacent battery strings or on the gap 4 between the adjacent two battery cells.

[0040] In some embodiments, reference Figure 2 In the structure of the light-receiving surface of the solar cell module, the third bus bar 3 is hidden on the backlight surface, and in the series connection direction of the battery string, the photovoltaic module includes at least two battery strings, and two adjacent battery strings are connected in series through welding strips, and the polarity of the adjacent two battery cells in the two adjacent battery strings is the same. In this way, the welding strips do not need to be staggered and welded on the front and back sides of the two adjacent cells to achieve the positive and negative connection effect. The welding strips do not contact the sides of the battery cells, so there is no stress, and there is no hidden cracking caused by stress, thereby improving the life of the module. In addition, this design is conducive to the first bus bar being hidden on the back, thereby improving the overall photoelectric conversion efficiency of the module.

[0041] In some embodiments, reference Figure 2 The third bus bar 3 is located in the middle of the spacing and does not contact the backlight surface of the solar cell module. The first bus bar located in the middle allows the currents on both sides of the welding strip connected to it to be consistent, so as to reduce the photoelectric performance loss of the solar cell module caused by current mismatch.

[0042] In other embodiments, reference Figure 3 In the series connection direction of the battery string, there is a gap 4 between two adjacent battery cells in each adjacent battery string. The third bus bar is located above the gap, so that the third bus bar is located on the backlight surface, so that the distance between two adjacent battery cells is reduced.

[0043] Optionally, the spacing is not greater than 14 mm. This is because the third bus bar is located on the backlight side, so that the spacing between the two central cells is reduced, and can even reach zero spacing, which is beneficial to reducing the overall area of ​​the photovoltaic module and reducing the packaging material cost.

[0044] Furthermore, the third bus bar is located in the middle of the gap, so that the cells led out of the welding strips on both sides of the third bus bar can remain consistent, avoiding losses caused by current mismatch of the photovoltaic module.

[0045] In some embodiments, reference Figure 4In the structure of the light-receiving surface of the solar cell assembly, the third bus bar 3 is located and hidden on the backlight surface, and the first bus bar is located in the middle of the spacing. In the series connection direction of the battery strings, and in the series connection direction of the battery strings, the photovoltaic assembly includes at least two of the battery strings, and two adjacent battery strings are connected in series through welding strips. The polarity of two adjacent battery cells in two adjacent battery strings is the same, so that the welding strips do not need to be staggered and welded on the front and back sides of two adjacent cells to achieve the positive and negative pole connection effect. The welding strips do not contact the side of the battery cell, so there is no stress, and there is no hidden cracking problem caused by stress, thereby improving the life of the assembly.

[0046] In other embodiments, in the structure of the light-receiving surface of the solar cell module, the first bus bar is hidden on the backlight surface, and the first bus bar is located in the middle of the spacing, in the cell cell adjacent to the middle cell cell in the series connection direction of the cell string. This design is conducive to hiding the bus bar on the back side, thereby improving the overall photoelectric conversion efficiency of the module.

[0047] In some embodiments, reference Figure 5 The solar cell assembly includes at least two of the subassemblies, and the solar cell assembly also includes a first bus bar 5. The first bus bar is located on the backlight side of the end cell sheet in the adjacent subassembly. The first bus bar located on the backlight side can avoid blocking the light of the entire assembly, thereby increasing the absorption of solar energy by the entire assembly. In addition, the first bus bar located on the backlight side can also reduce the area of ​​the entire photovoltaic assembly.

[0048] In some other embodiments, there is only one subassembly in the solar cell assembly, and the solar cell assembly further includes a first bus bar, which is located on the backlight side of the end cell in the subassembly. The first bus bar located on the backlight side can avoid blocking the light of the entire assembly, thereby increasing the absorption of solar energy by the entire assembly. In addition, the second bus bar located on the backlight side can also reduce the area of ​​the entire photovoltaic assembly and make the solar cell assembly more beautiful in appearance.

[0049] In some embodiments, the solar cell assembly includes at least two of the subassemblies, and in the series connection direction of the battery string, the end battery cells in the subassembly include a head battery cell and an end battery cell, the first bus bar is located on the backlight surface of the head battery cell in the adjacent subassembly, and the second bus bar is located on the backlight surface of the end battery cell in the adjacent subassembly.

[0050] In some other embodiments, there is only one sub-component in the solar cell assembly, and in the series connection direction of the battery string, the end battery cells in the sub-component include a head battery cell and an end battery cell, the second bus bar is located on the backlight surface of the head battery cell in the sub-component, and the second bus bar is located on the backlight surface of the end battery cell in the adjacent sub-component.

[0051] In some embodiments, the solar cell assembly includes at least two of the subassemblies, and the second bus bar is located in the middle of the backlight surface of the head end cell in the adjacent subassembly, and in the middle of the backlight surface of the end cell in the adjacent subassembly. The bus bar located in the middle allows the current drawn from both sides to remain consistent, reducing the photoelectric performance loss caused by the current adaptation of the solar cell assembly.

[0052] In other embodiments, there is only one subassembly in the solar cell assembly, and the second bus bar is located in the middle of the backlight surface of the head end cell in the subassembly, and in the middle of the backlight surface of the end cell in the subassembly. The bus bar located in the middle allows the current drawn from both sides to remain consistent, reducing the photoelectric performance loss caused by the current adaptation of the solar cell assembly.

[0053] Exemplarily, each battery series subassembly includes a first bus bar and a second bus bar. The number of the first bus bar and the second bus bar is not particularly limited and can be designed according to the size of the actual assembly, such as 3, 5, 60, etc. For example, there are 3 first bus bars, so there are 6 subassemblies connected in series.

[0054] In some embodiments, the first busbars include at least two, and among two adjacent first busbars, one first busbar and another first busbar are staggered or collinear in their extension direction. In this way, the welding terminals in the junction box can be better matched in the subsequent process without the need for special design of the junction box.

[0055] In some embodiments, the second busbars include at least two, and among two adjacent second busbars, one second busbar and another second busbar are staggered or collinear in their extension direction. In this way, the welding terminals in the junction box can be better matched in the subsequent process without the need for special design of the junction box.

[0056] In some embodiments, in the extension direction of the third bus bar, one of the adjacent battery cells connected to the third bus bar is a first battery cell and the other is a second battery cell; in the extension direction of the third bus bar, one of the adjacent battery cells connected to the third bus bar is a first battery cell and the other is a second battery cell. This design is conducive to placing the third bus bar behind the battery cells and hiding the function of the bus bar.

[0057] Exemplarily, the number of the third bus bars is not particularly limited. It can be designed according to the size of the actual component, for example, 1, 3, 60, 100, etc. When the number of sub-components in the solar cell component is 1, the number of the third bus bar is also 1, and the third bus bar is located on the backlight surface of the two middle battery cells. Preferably, the third bus bar is located in the middle of the distance between the two middle battery cells and does not contact the sub-component. When the number of the third bus bars in the solar cell component is greater than 1, the third bus bar is located on two adjacent battery cells in two adjacent battery strings or on the gap between two adjacent battery cells.

[0058] In some embodiments, among two adjacent third bus bars, one third bus bar and the other third bus bar are collinear in their extension direction.

[0059] Furthermore, among two adjacent third bus bars, one third bus bar and another third bus bar are collinear in their extension direction, and the third bus bars are located in the middle of the spacing. This can greatly reduce the loss caused by the current mismatch of the solar cell module.

[0060] The second aspect of the embodiment of the present application provides a photovoltaic system, comprising the photovoltaic module in any embodiment of the first aspect. The photovoltaic system also has the advantages of the photovoltaic module, which will not be repeated here.

[0061] In some embodiments, the above-mentioned photovoltaic system has a wide range of applications, not only limited to photovoltaic power stations, such as ground power stations, rooftop power stations and water power stations, but also includes various equipment and devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars and solar buildings. Of course, it is understandable that the application scenarios of photovoltaic systems are not limited to this, that is to say, photovoltaic systems can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components can form multiple photovoltaic arrays. The photovoltaic array is connected to a junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0062] It should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0063] It should also be noted that the "some embodiments", "other embodiments", "embodiments", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0064] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0065] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A photovoltaic module, characterized in that: include: At least two battery strings, each of which includes a plurality of battery cells connected in series through a welding ribbon, the battery string includes a head-end battery cell and a tail-end battery cell, the head-end battery cell is a first battery cell, the tail-end battery cell is a second battery cell, and the first battery cell and the second battery cell have opposite polarities, In a direction perpendicular to the series connection of the battery strings, two adjacent battery strings are arranged side by side, and the polarities of two adjacent head-end battery sheets and / or two adjacent end battery sheets in two adjacent battery strings are opposite.

2. The photovoltaic module according to claim 1, characterized in that: In the series connection direction of the battery strings, the photovoltaic module includes at least two battery strings, and two adjacent battery strings are connected in series through welding strips. The polarities of two adjacent battery cells in two adjacent battery strings are the same.

3. The photovoltaic module according to claim 1 or 2, characterized in that: Also includes: a first bus bar and a second bus bar, In a direction perpendicular to the series connection of the battery strings, the first bus bar is located on the head-end battery slice of the adjacent battery string, and the second bus bar is located on the end battery slice of the adjacent battery string.

4. The photovoltaic module according to claim 3, characterized in that: The first bus bar is located in the middle of the backlight surface of the first-end battery cell. The second bus bar is located in the middle of the backlight surface of the terminal battery cell.

5. The photovoltaic module according to claim 3, characterized in that: The first bus bars include at least two, and among two adjacent first bus bars, one first bus bar and another first bus bar are staggered or collinear in their extension direction; And / or, the second bus bars include at least two, and among two adjacent second bus bars, one second bus bar and another second bus bar are staggered or collinear in their extension direction.

6. The photovoltaic module according to claim 2, characterized in that: Also includes: a first bus bar, a second bus bar and a third bus bar, In a direction perpendicular to the series connection of the battery strings, the first bus bar is located on the head end battery sheet of the adjacent battery string, and the second bus bar is located on the end battery sheet of the adjacent battery string; In the series connection direction of the battery strings, the third bus bar is located on two adjacent battery cells in two adjacent battery strings or on a gap between two adjacent battery cells.

7. The photovoltaic module according to claim 6, characterized in that: The gap is no greater than 14 mm.

8. The photovoltaic module according to claim 6, characterized in that: The third bus bar is located in the middle of the gap, and the third bus bar is not in contact with the two battery cells.

9. The photovoltaic module according to claim 6, characterized in that: The first bus bars include at least two, and among two adjacent first bus bars, one first bus bar and another first bus bar are staggered or collinear in their extension direction; And / or, the second bus bars include at least two, and among two adjacent second bus bars, one second bus bar and another second bus bar are staggered or collinear in their extension direction; And / or, the third bus bars include at least two, and among two adjacent third bus bars, one third bus bar and another third bus bar are staggered or collinear in their extension direction.

10. A photovoltaic system, characterized in that: The photovoltaic system comprises the photovoltaic assembly according to any one of claims 1 to 9.

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