Solder strip, photovoltaic module and photovoltaic system

Abstract

The invention provides a solder strip, a photovoltaic module and a photovoltaic system, the solder strip comprises a light receiving section and a backlight section, and the light receiving section is used for being fixed on a light receiving surface of a first battery piece; the backlight section is used for being fixed to the backlight face of the second battery piece and comprises a plurality of sub welding strips. One backlight section corresponds to one light receiving section, and the plurality of sub welding strips in one backlight section are connected to one end of the corresponding light receiving section. In a battery string formed by connecting the solder strips in series, the number of light receiving sections of the battery string is relatively small, front shading of the battery piece can be reduced, the front light incidence rate can be improved, meanwhile, the number of the sub-solder strips on the back face of the battery piece is relatively large, current shared by each sub-solder strip is reduced, the current density is reduced, and therefore resistance loss is reduced, and the service life of the battery piece is prolonged. And the output power of the battery string is improved. Besides, the less the current shared by each sub-welding strip is, the less the generated heat is, the heat accumulation and the working temperature of the battery piece are reduced, and the service life of the battery piece is prolonged.

Description

Technical Field

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

[0002] In the photovoltaic field, multiple cells can be connected to form a battery assembly through welding ribbons. Usually, the welding ribbons are connected to different electrodes of adjacent cells to achieve the series connection of the cells. However, the resistance loss of the existing battery assembly formed by connecting cells with welding ribbons is relatively obvious, resulting in the overall power of the battery string not meeting the demand. Summary of the invention

[0003] The embodiments of the present application provide a welding strip, a photovoltaic module and a photovoltaic system to solve or alleviate one or more technical problems in the prior art.

[0004] A first aspect of an embodiment of the present application provides a welding strip, including:

[0005] A light receiving segment, used for being fixed on the light receiving surface of the first battery cell;

[0006] A backlight segment, used for being fixed on the backlight surface of the second battery cell, the backlight segment comprising a plurality of sub-welding strips;

[0007] Among them, one of the backlight segments corresponds to one of the light-receiving segments, and a plurality of sub-welding strips in one of the backlight segments are connected to one end of the corresponding light-receiving segment.

[0008] Optionally, the plurality of sub-welding strips include a first sub-welding strip and a second sub-welding strip;

[0009] There is a non-zero angle between the first sub-welding strip and the second sub-welding strip.

[0010] Optionally, projections of the first sub-welding strip and the light receiving segment in the thickness direction of the second solar cell are not on the same straight line; and / or

[0011] The projections of the second sub-welding strip and the light receiving segment in the thickness direction of the second battery cell are not on the same straight line.

[0012] Optionally, a projection of the first sub-welding strip in a thickness direction of the second battery cell is a first projection;

[0013] The projection of the second sub-welding ribbon in the thickness direction of the second battery cell is a second projection;

[0014] The first projection and the second projection are axially symmetric with respect to the projection of the light receiving segment on the second battery sheet.

[0015] Optionally, projections of the first sub-welding strip and the light receiving segment in a thickness direction of the second battery cell are on the same straight line.

[0016] Optionally, an angle formed by the first welding strip and the second welding strip is 1° to 30°.

[0017] Optionally, the plurality of sub-welding strips include a first sub-welding strip and a second sub-welding strip, the backlight segment further includes a connecting segment, the connecting segment is located on a side of the backlight surface close to the first battery cell, and the connecting segment extends along a side of the second battery cell close to the first battery cell;

[0018] The connecting section is connected to the light receiving section, and is connected to the same end of the first sub-welding strip and the second sub-welding strip;

[0019] Wherein, the first sub-welding strip and the second sub-welding strip are arranged in parallel and at intervals.

[0020] Optionally, the connecting section intersects the first sub-welding strip and the second sub-welding strip perpendicularly.

[0021] Optionally, the cross-sectional area of ​​any of the sub-welding strips is not greater than the cross-sectional area of ​​the light receiving segment.

[0022] Optionally, the cross section of any of the light receiving segments is triangular or circular;

[0023] A cross section of any one of the first sub-welding strips or any one of the second sub-welding strips is triangular, circular or rectangular.

[0024] A second aspect of an embodiment of the present application provides a welding strip, including:

[0025] A plurality of light receiving segments, wherein the plurality of light receiving segments are arranged at intervals on the light receiving surface of the first battery cell;

[0026] A backlight segment, used to be fixed on the backlight surface of the second battery cell, the backlight segment includes a connecting segment and a plurality of sub-welding strips, the number of the plurality of sub-welding strips is greater than the number of the plurality of light-receiving segments, and each of the sub-welding strips includes a first end and a second end opposite to each other;

[0027] Among them, the connecting section is located on the side of the backlight surface close to the first battery cell, and the connecting section extends along the side of the second battery cell close to the first battery cell; the connecting section connects each of the light receiving sections and the first end of each of the sub-solder strips, and the second end of each of the sub-solder strips is away from the connecting section.

[0028] Optionally, the solder strip further satisfies at least one of the following characteristics:

[0029] (1) Multiple sub-welding strips are parallel and evenly spaced;

[0030] (2) Each of the sub-welding strips intersects the connecting section perpendicularly;

[0031] (3) Multiple light-receiving segments are distributed in parallel and evenly spaced intervals;

[0032] (4) The projections of each of the light receiving segments and the connecting segments in the thickness direction of the second battery cell intersect vertically;

[0033] (5) The ratio of the number of the light receiving segments to the number of the sub-welding strips is 2 to 10.

[0034] A third aspect of the embodiments of the present application provides a photovoltaic assembly, the photovoltaic assembly comprising:

[0035] At least two battery cells;

[0036] For the soldering strip as described in the first or second aspect above, the light-receiving section of the soldering strip is connected to the light-receiving surface of one battery cell, and the backlight section of the soldering strip is connected to the backlight surface of another battery cell.

[0037] A fourth aspect of an embodiment of the present application provides a photovoltaic system, comprising the photovoltaic assembly as described above.

[0038] The above technical solution adopted in the embodiment of the present application may have the following advantages:

[0039] The light-receiving segment on the light-receiving surface can correspond to multiple sub-welding strips on the backlight surface. Under the condition of ensuring electrical performance, the number of light-receiving segments used on the front side of the battery string can be reduced, thereby reducing the shading area on the front side of the battery cell and improving the light-incoming rate on the front side of the battery cell. At the same time, since one light-receiving segment can be connected to multiple sub-welding strips, the number of sub-welding strips on the back side of the battery cell is relatively large, and the current shared by each sub-welding strip is relatively reduced, and the current density is reduced, thereby reducing resistance loss, and then improving the output power of the battery string connected in series. In addition, the less current each sub-welding strip shares, the less heat it generates, thereby reducing heat accumulation, lowering the operating temperature of the battery cell, and extending the service life of the battery cell.

[0040] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present application will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] 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.

[0042] Figure 1 A schematic diagram of the structure of a welding strip according to an embodiment of the present application;

[0043] Figure 2 Another structural schematic diagram of the welding strip of the embodiment of the present application;

[0044] Figure 3 This is another structural schematic diagram of the welding strip of the embodiment of the present application;

[0045] Figure 4 This is another structural schematic diagram of the welding strip of the embodiment of the present application;

[0046] Figure 5 This is another structural schematic diagram of the welding strip of the embodiment of the present application;

[0047] Figure 6 for Figure 5 A partial enlarged schematic diagram in the middle;

[0048] Figure 7 This is another structural schematic diagram of the welding strip according to the embodiment of the present application.

[0049] Description of reference numerals:

[0050] Light receiving section 11; backlight section 12; first sub-welding strip 121; second sub-welding strip 122; third sub-welding strip 123; connecting section 125; connecting section 127; sub-welding strip 128; first battery cell 21; second battery cell 22. DETAILED DESCRIPTION

[0051] 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. 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 limiting the present application.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] The embodiment of the present application provides a welding strip, a photovoltaic module and a photovoltaic system technical solution. Based on this, the battery module formed by the series-connected battery cells is prone to packaging loss. See below for details.

[0057] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0058] See also Figures 1 to 6 The embodiment of the present application provides a solder strip, which includes a light receiving segment 11 and a backlight segment 12. The following is a detailed description:

[0059] The light receiving segment 11 is used to be fixed on the light receiving surface of the first battery cell 21. In the present embodiment, the cross section of the light receiving segment 11 may be circular or triangular. The circular cross section of the light receiving segment 11 can reduce the contact area between the light receiving segment 11 and the battery cell, reduce the contact resistance, and the surface area of ​​the cylindrical light receiving segment 11 is relatively large, which has a better heat dissipation effect. If the cross section of the light receiving segment 11 is triangular, the light incident on the light receiving segment 11 can be reflected to the surface of the battery cell, thereby improving the light utilization rate and thus improving the output power of the component, wherein one side of the triangular cross section can be used to connect to the battery cell, and the other two oblique sides can be used to reflect light.

[0060] The backlight segment 12 is used to be fixed on the backlight surface of the second battery cell 22. The backlight segment 12 includes a plurality of sub-welding strips. The cross section of the backlight segment 12 can be circular, triangular, rectangular, etc. In practical applications, it can be selected according to whether the battery string pursues bifaciality (the ratio of bifacial power generation to monofacial power generation). In the case of pursuing bifacial power generation, the cross section of the backlight segment 12 is preferably triangular or circular.

[0061] In this embodiment, one backlight segment 12 corresponds to (is connected to) one light receiving segment 11, and a plurality of sub-welding strips in one backlight segment 12 are connected to one end of the corresponding light receiving segment 11. By way of example, adjacent cells in a cell string can be connected in series through a plurality of parallel welding strips, each welding strip comprising a light receiving segment 11 and a backlight segment 12, that is, a plurality of light receiving segments 11 are fixed to the light receiving surface of one cell, and a plurality of backlight segments 12 are fixed to the backlight surface of another cell.

[0062] In the battery string formed by connecting the battery cells in series with the welding strips in this embodiment, a light-receiving segment located on the light-receiving surface can correspond to multiple sub-welding strips located on the backlight surface. Under the condition of ensuring electrical performance, the number of light-receiving segments used on the front side of the battery string can be reduced, thereby reducing the shading area on the front side of the battery cell and improving the light incident rate on the front side of the battery cell. At the same time, since one light-receiving segment can be connected to multiple sub-welding strips, the number of sub-welding strips on the back side of the battery cell is relatively large, and the current shared by each sub-welding strip is relatively reduced, and the current density is reduced, thereby reducing resistance loss, and then improving the output power of the battery string connected in series. In addition, the less current each sub-welding strip shares, the less heat it generates, thereby reducing heat accumulation, lowering the operating temperature of the battery cell, and extending the service life of the battery cell.

[0063] The material of the backlight segment 12 can be copper as the main material of the backlight segment 12. Copper has high electrical conductivity, can effectively reduce resistance loss, improve current transmission efficiency, and has good mechanical strength and toughness. In addition, copper has a higher cost performance than other highly conductive materials (such as silver), can control costs while ensuring performance, and is suitable for large-scale production and application.

[0064] Specifically, tin-lead can also be plated on the surface of copper. Tin-lead has a lower melting point and can achieve good connection between the soldering ribbon and the battery cell at a lower temperature, thereby reducing thermal stress and thermal damage to the battery cell.

[0065] In one embodiment, see Figure 1 The plurality of sub-welding strips include a first sub-welding strip 121 and a second sub-welding strip 122. A non-zero angle is formed between the first sub-welding strip 121 and the second sub-welding strip 122. The projections of the first sub-welding strip 121 and the second sub-welding strip 122 on the battery cell are both linear.

[0066] The non-zero angle arrangement between the sub-welding strips can optimize the current collection path and reduce the resistance loss in current transmission. The carriers generated on the cell can converge with the sub-welding strip closest to it, reducing the carrier transmission path and thus reducing the carrier movement loss.

[0067] Specifically, the included angle between the first sub-welding strip 121 and the second sub-welding strip 122 may be 1° to 180°, so that the two sub-welding strips extend toward the side away from the light receiving section 11 without being separated from the second battery cell 22 .

[0068] In this embodiment, the main grid on the cell can be redesigned to match the structure of the cell with the backlight segment 12. For example, the main grid is divided into two sections to correspond to the first sub-welding strip 121 and the second sub-welding strip 122 respectively, so that the carriers on the cell can be directly converged to the corresponding sub-welding strips through the main grid.

[0069] In an optional embodiment, the projections of the first sub-welding strip 121 and the light receiving segment 11 in the thickness direction of the second battery cell 22 are not on the same straight line; and / or the projections of the second sub-welding strip 122 and the light receiving segment 11 in the thickness direction of the second battery cell 22 are not on the same straight line.

[0070] In one embodiment, see Figures 1 to 3 , the projections of the first sub-weld strip 121 and the second sub-weld strip 122 on the second cell 22 may be V-shaped. The light receiving section 11 partially extends out of the first cell 21 and extends to the second cell 22 to connect with the first sub-weld strip 121 and the second sub-weld strip 122, and the projections are not in a straight line. The first sub-weld strip 121, the second sub-weld strip 122 and the light receiving section 11 are connected at one place and extend in different directions, which can more evenly distribute the stress of the second cell 22, reduce stress concentration, improve the connection stability between the first cell 21 and the second cell 22, and improve the overall mechanical strength of the photovoltaic module, thereby extending the service life of the photovoltaic module.

[0071] In some embodiments, the main grid on the second battery cell 22 can be set corresponding to the backlight segment 12, that is, the main grid can be divided into two to correspond to the first sub-welding strip 121 and the second sub-welding strip 122 respectively, so as to more evenly distribute and collect the current generated by the battery cell and improve the current transmission efficiency.

[0072] In one embodiment, if Figure 2 As shown, the projections of the first sub-welding strip 121 and the light receiving segment 11 in the thickness direction of the second battery cell 22 are on the same straight line. This arrangement does not require changing the grid line layout of the battery cell. The second sub-welding strip 122 can be arranged corresponding to the back main grid, and the first sub-welding strip 121 can be arranged crosswise with multiple back main grids.

[0073] In an alternative embodiment, if Figure 3As shown, the projection of the first sub-welding strip 121 in the thickness direction of the second battery cell 22 is the first projection; the projection of the second sub-welding strip 122 in the thickness direction of the battery cell is the second projection. The first projection and the second projection are axially symmetrical with the projection of the light-receiving segment 11 on the second battery cell 22 as the axis, that is, the projections of the light-receiving segment 11 and the backlight segment 12 on the second battery cell 22 can be Y-shaped.

[0074] Specifically, the axially symmetrical layout of the first sub-welding strip 121 and the second sub-welding strip 122 can ensure that the current collected by the two sub-welding strips on the battery cell is relatively uniform, reducing current loss. In addition, the light-receiving section 11 of the welding strip, the first sub-welding strip 121, and the second sub-welding strip 122 are connected to the same point of the second battery cell 22, which can provide a more stable structure, improve the firmness of the connection point, reduce the risk of the welding strip and the battery cell falling off, and thus improve the overall reliability of the photovoltaic module.

[0075] Specifically, the angle formed by the first welding strip and the second welding strip can be 1° to 30°. Specifically, the angle can be 1°, 3°, 5°, 10°, 15°, 20°, 25°, 30°, etc.

[0076] By way of example, the first battery cell 21 and the second battery cell 22 can be connected in series via a plurality of welding strips, and the angle formed by the first sub-welding strip 121 and the second sub-welding strip 122 of each welding strip backlight segment 12 is 30°. This angle can reduce the overlap of the current collection areas of the first sub-welding strip 121 and the second sub-welding strip 122, thereby improving the current collection efficiency.

[0077] The angle between the first sub-welding strip 121 and the light receiving segment 11 and the angle between the second sub-welding strip 122 and the light receiving segment 11 may be different. The backlight segments 12 of adjacent welding strips may not intersect, so that the current can be directly collected to the current output end along the backlight segments 12, reducing the current from the backlight segment 12 of one welding strip to the backlight segment 12 of another welding strip and increasing the current transmission path.

[0078] In some embodiments, the backlight segment 12 may further include other numbers of sub-welding strips, such as three, four, or ten.

[0079] For an exemplary illustration, see Figure 4 The backlight segment 12 includes three sub-welding strips: a first sub-welding strip 121, a second sub-welding strip 122 and a third sub-welding strip 123. The three sub-welding strips are connected to the same end of the light receiving segment 11 and are distributed in a scattered manner.

[0080] The projection of the first sub-weld belt 121 on the second battery cell 22 and the projection of the light receiving segment 11 on the second battery cell 22 can be on the same straight line, and the angle between the first sub-weld belt 121 and the second sub-weld belt 122 and the angle between the first sub-weld belt 121 and the third sub-weld belt 123 can be the same, that is, the first sub-weld belt 121 and the third sub-weld belt 123 can be arranged symmetrically with the second sub-weld belt 122 as the axis. Such an arrangement can, on the one hand, allow the current on the battery cell to be collected according to the sub-weld belt closest to it, thereby improving the current collection efficiency, reducing the amount of current distributed by each sub-weld belt, and reducing current loss, and on the other hand, increase the mechanical strength of the connection between the welding belt and the battery cell.

[0081] For example, when the backlight segment 12 includes four sub-welding strips: a first sub-welding strip, a second sub-welding strip, a third sub-welding strip, and a fourth sub-welding strip, the first sub-welding strip and the third sub-welding strip can be arranged symmetrically with the projection of the light-receiving segment 11 on the second battery cell 22, and the second sub-welding strip and the fourth sub-welding strip can be arranged symmetrically with the projection of the light-receiving segment 11 on the second battery cell 22, and the four sub-welding strips are connected to the same end of the light-receiving segment 11 in a scattered manner. The effect of this structure is similar to the structure in which the backlight segment 12 includes three sub-welding strips, and will not be repeated here.

[0082] In an alternative embodiment, see Figure 5 and Figure 6 The plurality of sub-welding strips include a first sub-welding strip 121 and a second sub-welding strip 122. The backlight segment 12 further includes a connecting segment 125. The connecting segment 125 is located on the side of the backlight surface close to the first battery cell 21, and the connecting segment 125 extends along the side of the second battery cell 22 close to the first battery cell 21. The connecting segment 125 is connected to the light receiving segment 11 and is connected to the same end of the first sub-welding strip 121 and the second sub-welding strip 122, and the first sub-welding strip 121 and the second sub-welding strip 122 are spaced apart and arranged in parallel.

[0083] In this embodiment, the connecting section 125 connects the light receiving section 11 and the first sub-welding strip 121 and the second sub-welding strip 122, providing a low-impedance current transmission path, reducing the loss in current transmission, and improving the overall efficiency.

[0084] Furthermore, the first sub-welding strip 121 and the second sub-welding strip 122 are arranged in parallel at intervals, so that the spacing between each sub-welding strip and its adjacent sub-welding strips is more uniform, reducing the overlap of the current collection areas corresponding to adjacent sub-welding strips and improving the current collection efficiency of each sub-welding strip.

[0085] Furthermore, in this embodiment, the connecting section 125 intersects the first sub-welding strip 121 and the second sub-welding strip 122 perpendicularly. Preferably, the first sub-welding strip 121 and the second sub-welding strip 122 are symmetrically arranged with respect to the projection of the light receiving section 11 on the second battery cell 22. The vertical intersection of the sub-welding strip and the connecting section 125 can enhance the firmness of the welding point between the backlight section 12 and the battery cell and reduce the risk of welding point falling off.

[0086] In other embodiments, the multiple sub-solder strips may also include other numbers of sub-solder strips, such as three, four, or ten. The multiple sub-solder strips are all connected to the light receiving segment 11 through a connecting segment, and the multiple sub-solder strips are spaced apart and arranged in parallel. The specific number of sub-solder strips of the backlight segment 12 can be selected according to requirements such as the size of the battery cell.

[0087] In an optional embodiment, the cross-sectional area of ​​any sub-welding strip of the backlight segment 12 is not greater than the cross-sectional area of ​​the light-receiving segment 11 .

[0088] Preferably, the cross-sectional area of ​​any sub-welding strip of the backlight segment 12 is smaller than the cross-sectional area of ​​the light-receiving segment 11. When the cross-sections of the light-receiving segment 11 and the backlight segment 12 are both circular, the diameter of the sub-welding strip of the backlight segment 12 is not greater than the diameter of the light-receiving segment 11. Accordingly, since the size of the backlight segment 12 is reduced, the thickness of the encapsulation film used on the back of the cell can be reduced while maintaining a sufficient encapsulation effect, thereby saving the amount of encapsulation film used to achieve the saving of the use cost of the encapsulation film.

[0089] For example, the first cell 21 and the second cell 22 are connected in series through twelve spaced-apart solder strips, the light receiving section 11 of the solder strip has a diameter of 0.27 mm, and the diameter of any sub-solder strip of the backlight section 12 of the solder strip is 0.2 mm. The front side of the first cell 21 (corresponding to the light receiving section 11 of the solder strip) is made of 400 g / m 2 The back side of the second battery sheet 22 (corresponding to the backlight segment 12 area of ​​the welding strip) can be encapsulated from the original 400 g / m 2 The film weight is reduced to 330 g / m 2 The encapsulation effect of the encapsulation film remains basically unchanged, which greatly reduces the use cost of the encapsulation film. In some embodiments, the encapsulation film can also be a mixture of EVA film and POE film, such as a three-layer stacked structure of EVA film-POE film-EVA film.

[0090] The present application also provides a soldering strip, which is described by taking the soldering strip connecting the first battery cell 21 and the second battery cell 22 in series as an example. The soldering strip of the present application includes a plurality of light receiving segments 11 and a backlight segment 12, which are described in detail below:

[0091] See also Figure 7, a plurality of light receiving segments 11 are arranged at intervals on the light receiving surface of the first battery cell 21. One light receiving segment 11 can be arranged corresponding to one main grid of the first battery cell 21.

[0092] The backlight segment 12 is used to be fixed on the backlight surface of the second battery cell 22. The backlight segment 12 includes a connecting segment 127 and a plurality of sub-welding strips 128. The number of the plurality of sub-welding strips 128 is greater than the number of the plurality of light-receiving segments 11. Each sub-welding strip 128 includes a first end and a second end opposite to each other. The back side of the second battery cell 22 can be provided with a main grid according to the number of sub-welding strips 128, so that each back main grid corresponds to one sub-welding strip 128; or each back main grid corresponds to a plurality of sub-welding strips 128, and a plurality of sub-welding strips 128 are spaced between every two adjacent back main grids.

[0093] Among them, the connecting section 127 is located on the side of the backlight surface close to the first battery cell 21, and the connecting section 127 extends along the side of the second battery cell 22 close to the first battery cell 21; the connecting section 127 connects each light receiving section 11 and the first end of each sub-solder strip 128, and the second end of each sub-solder strip 128 is away from the connecting section 127.

[0094] The connecting section 127 is used to concentrate the current collected by all the sub-welding strips 128, and by increasing the number of sub-welding strips 128, the distribution of current on each sub-welding strip 128 is reduced, and the current density on each sub-welding strip 128 is reduced, thereby reducing resistance loss and improving the overall current conduction efficiency.

[0095] Furthermore, the structure of connecting the connecting section 127 and the plurality of sub-welding strips 128 can make the stress distribution of the cell more uniform and reduce the stress concentration of the cell. In the TC (Thermal Cycling) test, such a structure can reduce the stress on the cell, thereby reducing the risk of the solder strip desoldering.

[0096] In addition, since the number of sub-welding strips 128 increases, the size of the self-welding strip can be reduced accordingly, that is, the cross-sectional area of ​​any sub-welding strip 128 can be smaller than the cross-sectional area of ​​any light-receiving segment 11. When the cross-sections of the light-receiving segment 11 and the sub-welding strip 128 are both circular, the diameter of the sub-welding strip 128 is not greater than the diameter of the light-receiving segment 11. Accordingly, since the size of the backlight segment 12 is reduced, the thickness of the encapsulation film used on the back of the battery cell can be reduced while maintaining a sufficient encapsulation effect, thereby saving the amount of encapsulation film used to save the cost of using the encapsulation film.

[0097] Furthermore, in this embodiment, the solder strip also satisfies at least one of the following characteristics:

[0098] (1) Multiple sub-welding strips 128 are parallel and evenly spaced. The spacing between each sub-welding strip 128 and its adjacent sub-welding strips 128 is relatively uniform, reducing the overlap of the current collection areas corresponding to adjacent sub-welding strips 128, thereby improving the current collection efficiency of each sub-welding strip 128.

[0099] (2) Each sub-welding strip 128 intersects the connecting section 127 vertically. The sub-welding strip 128 intersects the connecting section 127 vertically to enhance the firmness of the welding point between the backlight section 12 and the battery cell and reduce the risk of desoldering.

[0100] (3) The plurality of light receiving segments 11 are parallel and evenly spaced.

[0101] (4) The projections of each light receiving segment 11 and the connecting segment 127 in the thickness direction of the second battery cell 22 intersect vertically. The vertical intersection of the light receiving segment 11 and the connecting segment 127 can make the extension direction of the light receiving segment 11 consistent, improve the connection stability between the light receiving segment 11 and the battery cell, and reduce the risk of desoldering.

[0102] (5) The ratio of the number of light-receiving segments 11 to the number of sub-welding strips 128 is 2 to 10. The ratio of the number of sub-welding strips 128 to the number of light-receiving segments 11 may not be an integer. The more sub-welding strips 128 there are, the smaller the current density of each word welding strip is. Accordingly, the cross-sectional area of ​​the sub-welding strip 128 can be reduced to reduce the amount of packaging film used. However, the sub-welding strip 128 will also block the back light of the battery cell to a certain extent. Therefore, the number of sub-welding strips 128 can be determined based on whether the battery cell has a back light incidence rate, the overall cost of the component, the current transmission efficiency, etc.

[0103] The present application also provides a photovoltaic module, comprising at least two cells and any one of the above-mentioned welding strips, wherein the light-receiving section of the welding strip is connected to the light-receiving surface of one cell, and the backlight section of the welding strip is connected to the backlight surface of another cell.

[0104] Among them, multiple battery cells can form a battery string, and adjacent battery cells can be connected together by series welding.

[0105] Multiple battery strings can be electrically connected in series and / or in parallel to form a more flexible battery organization structure. In order to protect the battery string, the photovoltaic module can also include an encapsulation layer and a cover plate. The encapsulation layer can cover the surface of the battery string, and the cover plate can cover the surface of the encapsulation layer away from the battery string.

[0106] In some embodiments, multiple battery strings can be electrically connected through conductive tapes to achieve a series or parallel arrangement of batteries. The encapsulation layer can be made of an organic encapsulation film, such as an ethylene-vinyl acetate copolymer film, a polyethylene octene co-elastic film, or a polyethylene terephthalate film, to provide protection and isolation functions.

[0107] The advantages possessed by the welding strip in any of the above embodiments are also possessed by the photovoltaic module and will not be elaborated here.

[0108] The following will conduct performance tests on the structure of the photovoltaic module provided in the embodiments of the present application and related comparative examples.

[0109] [Comparative Example 1]

[0110] The 210-66 photovoltaic module has 132 half-cell cells of 210*105mm in size.

[0111] Any two adjacent battery cells are connected in series through 12 conventional welding ribbons, which are circular welding ribbons with a diameter of 0.27 mm.

[0112] [Example 1]

[0113] The 210-66 photovoltaic module has 132 half-cell cells of 210*105mm in size.

[0114] Any two adjacent battery cells are connected in series through 12 welding strips, each welding strip includes a light-receiving segment and a backlight segment, the diameter of the light-receiving segment is 0.27 mm, and each backlight segment includes a first sub-welding strip and a second sub-welding strip, the diameters of the first sub-welding strip and the second sub-welding strip are both 0.27 mm, and the first sub-welding strip and the second sub-welding strip in each backlight segment are symmetrical with respect to the projection of the corresponding light-receiving segment on the second battery cell, and the angle between the first sub-welding strip and the second sub-welding strip is 30°.

[0115] [Example 2]

[0116] It is basically the same as Example 1, except that:

[0117] The first sub-welding strip of each backlight segment and the projection of the light-receiving segment on the second battery cell are in the same straight line, and the angle between the first sub-welding strip and the second sub-welding strip is 30°.

[0118] [Example 3]

[0119] The embodiment is basically the same as the embodiment 1, except that the angle between the first sub-welding strip and the second sub-welding strip is 3°.

[0120] [Example 4]

[0121] It is basically the same as Example 1, except that: each backlight segment includes a first sub-solder strip, a second sub-solder strip, and a third sub-solder strip, the projection of the first sub-solder strip on the second battery cell and the projection of the light-receiving segment on the second battery cell are on the same straight line, and the angle between the first sub-solder strip and the second sub-solder strip, and the angle between the first sub-solder strip and the third sub-solder strip are both 10°.

[0122] The following is a table showing the difference in component power between test examples 1 to 4 and comparative example 1. The test data is shown in Table 1:

[0123]

[0124] Table 1

[0125] [Comparative Example 2]

[0126] The 210-66 photovoltaic module has 132 half-cell cells of 210*105mm in size.

[0127] Any two adjacent battery cells are connected in series through 18 conventional welding ribbons, which are circular welding ribbons with a diameter of 0.25 mm.

[0128] [Example 5]

[0129] The 210-66 photovoltaic module has 132 half-cell cells of 210*105mm in size.

[0130] Any two adjacent battery cells are connected in series through 18 welding strips, each welding strip includes a light-receiving segment and a backlight segment, the diameter of the light-receiving segment is 0.25 mm, and each backlight segment includes a first sub-welding strip and a second sub-welding strip, the diameters of the first sub-welding strip and the second sub-welding strip are both 0.25 mm, and the first sub-welding strip and the second sub-welding strip in each backlight segment are symmetrical with respect to the projection of the corresponding light-receiving segment on the second battery cell, and the angle between the first sub-welding strip and the second sub-welding strip is 30°.

[0131] [Example 6]

[0132] It is basically the same as Example 5, except that:

[0133] The first sub-welding strip of each backlight segment and the projection of the light-receiving segment on the second battery cell are in the same straight line, and the angle between the first sub-welding strip and the second sub-welding strip is 30°.

[0134] [Example 7]

[0135] The embodiment is basically the same as the embodiment 5, except that the angle between the first sub-welding strip and the second sub-welding strip is 3°.

[0136] [Example 8]

[0137] It is basically the same as Example 5, except that: each backlight segment includes a first sub-solder strip, a second sub-solder strip, and a third sub-solder strip, the projection of the first sub-solder strip on the second battery cell and the projection of the light-receiving segment on the second battery cell are on the same straight line, and the angle between the first sub-solder strip and the second sub-solder strip, and the angle between the first sub-solder strip and the third sub-solder strip are both 10°.

[0138] The following is a table showing the differences in component power between test examples 5 to 8 and comparative example 2. The test data is shown in Table 2:

[0139]

[0140]

[0141] Table 2

[0142] The following will conduct packaging tests on the structure of the photovoltaic module provided in the embodiment of the present application and related comparative examples.

[0143] [Comparative Example 3]

[0144] The 210-66 photovoltaic module has 132 half-cell cells of 210*105mm in size.

[0145] Any two adjacent battery cells are connected in series through 12 conventional welding ribbons, which are circular welding ribbons with a diameter of 0.27 mm.

[0146] The front and back packaging of the components are both 400g / m 2 EVA film for packaging.

[0147] [Example 9]

[0148] The 210-66 photovoltaic module has 132 half-cell cells of 210*105mm in size.

[0149] Any two adjacent cells are connected in series through 12 welding strips, each welding strip includes a light receiving segment and a backlight segment, the diameter of the light receiving segment is 0.27mm, each backlight segment includes a first sub-weld strip and a second sub-weld strip, the diameters of the first sub-weld strip and the second sub-weld strip are both 0.2mm, the first sub-weld strip and the second sub-weld strip in each backlight segment are symmetrical with respect to the projection of the corresponding light receiving segment on the second cell, and the angle between the first sub-weld strip and the second sub-weld strip is 30°. The front package adopts 400g / m 2 The back side is encapsulated with EVA film, and the back side is encapsulated with 330 g / m 2 EVA film for packaging.

[0150] [Example 10]

[0151] It is basically the same as Example 9, except that:

[0152] The first sub-welding strip of each backlight segment and the projection of the light-receiving segment on the second battery cell are in the same straight line, and the angle between the first sub-welding strip and the second sub-welding strip is 30°.

[0153] [Example 11]

[0154] The embodiment is basically the same as the embodiment 9, except that the angle between the first sub-welding strip and the second sub-welding strip is 3°.

[0155] [Example 12]

[0156] It is basically the same as Example 9, except that: each backlight segment includes a first sub-weld belt, a second sub-weld belt, and a third sub-weld belt, the diameters of the first sub-weld belt, the second sub-weld belt, and the third sub-weld belt are all 0.17mm, the projection of the first sub-weld belt on the second battery cell and the projection of the light-receiving segment on the second battery cell are on the same straight line, and the angle between the first sub-weld belt and the second sub-weld belt, and the angle between the first sub-weld belt and the third sub-weld belt are both 10°. The back packaging adopts 300 grams / m 2 EVA film for packaging.

[0157] The following is a table showing the differences in component power between test examples 9 to 12 and comparative example 3. The test data is shown in Table 3:

[0158]

[0159]

[0160] Table 3

[0161] According to Tables 1 and 2 above, the welding strips used in the photovoltaic modules in the embodiments of the present application can significantly increase the output power of the photovoltaic modules. According to Table 3 above, the welding strips used in the photovoltaic modules in the embodiments of the present application can keep the power output of the photovoltaic modules the same as or slightly increase that of the control group while greatly reducing the amount and cost of the back encapsulation film.

[0162] The embodiment of the present application can also provide a photovoltaic system, including the photovoltaic components in any of the above embodiments. The advantages of the above photovoltaic components are also possessed by the photovoltaic system, which will not be repeated here. The above 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 can be understood that the application scenarios of the photovoltaic system are not limited to this, that is to say, the photovoltaic system can be used in all fields where solar energy is required for power generation. 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.

[0163] 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.

[0164] It should also be noted that "one embodiment", "another embodiment", "embodiment", 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. Further, when describing a specific feature, structure or characteristic 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.

[0165] 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.

[0166] 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 welding strip, characterized in that: include: A light receiving segment, used for being fixed on the light receiving surface of the first battery cell; A backlight segment, used for being fixed on the backlight surface of the second battery cell, the backlight segment comprising a plurality of sub-welding strips; Among them, one of the backlight segments corresponds to one of the light-receiving segments, and a plurality of sub-welding strips in one of the backlight segments are connected to one end of the corresponding light-receiving segment.

2. The welding strip according to claim 1, characterized in that: The plurality of sub-welding strips include a first sub-welding strip and a second sub-welding strip; There is a non-zero angle between the first sub-welding strip and the second sub-welding strip.

3. The welding strip according to claim 2, characterized in that: The projections of the first sub-welding strip and the light receiving segment in the thickness direction of the second solar cell are not on the same straight line; and / or The projections of the second sub-welding strip and the light receiving segment in the thickness direction of the second battery cell are not on the same straight line.

4. The welding strip according to claim 2, characterized in that: The projection of the first sub-welding strip in the thickness direction of the second battery cell is a first projection; The projection of the second sub-welding ribbon in the thickness direction of the second battery cell is a second projection; The first projection and the second projection are axially symmetric with respect to the projection of the light receiving segment on the second battery sheet.

5. The welding strip according to claim 2, characterized in that: The projections of the first sub-welding strip and the light receiving segment in the thickness direction of the second battery cell are on the same straight line.

6. The welding strip according to claim 2, characterized in that: The angle formed by the first welding strip and the second welding strip is 1° to 30°.

7. The welding strip according to claim 1, characterized in that: The plurality of sub-welding strips include a first sub-welding strip and a second sub-welding strip, the backlight segment further includes a connecting segment, the connecting segment is located on a side of the backlight surface close to the first battery cell, and the connecting segment extends along a side of the second battery cell close to the first battery cell; The connecting section is connected to the light receiving section, and is connected to the same end of the first sub-welding strip and the second sub-welding strip; Wherein, the first sub-welding strip and the second sub-welding strip are arranged in parallel and at intervals.

8. The welding strip according to claim 7, characterized in that: The connecting section intersects the first sub-welding strip and the second sub-welding strip perpendicularly.

9. The welding strip according to any one of claims 2 to 8, characterized in that: The cross-sectional area of ​​any of the sub-welding strips is not greater than the cross-sectional area of ​​the light receiving section.

10. The welding strip according to any one of claims 2 to 8, characterized in that: The cross section of any of the light receiving segments is triangular or circular; A cross section of any one of the first sub-welding strips or any one of the second sub-welding strips is triangular, circular or rectangular.

11. A welding strip, characterized in that: include: A plurality of light receiving segments, wherein the plurality of light receiving segments are arranged at intervals on the light receiving surface of the first battery cell; A backlight segment, used to be fixed on the backlight surface of the second battery cell, the backlight segment includes a connecting segment and a plurality of sub-welding strips, the number of the plurality of sub-welding strips is greater than the number of the plurality of light-receiving segments, and each of the sub-welding strips includes a first end and a second end opposite to each other; Among them, the connecting section is located on the side of the backlight surface close to the first battery cell, and the connecting section extends along the side of the second battery cell close to the first battery cell; the connecting section connects each of the light receiving sections and the first end of each of the sub-solder strips, and the second end of each of the sub-solder strips is away from the connecting section.

12. The welding strip according to claim 11, characterized in that: Also meets at least one of the following characteristics: (1) Multiple sub-welding strips are parallel and evenly spaced; (2) Each of the sub-welding strips intersects the connecting section perpendicularly; (3) Multiple light-receiving segments are distributed in parallel and evenly spaced intervals; (4) The projections of each of the light receiving segments and the connecting segments in the thickness direction of the second solar cell intersect vertically; (5) The ratio of the number of the light receiving segments to the number of the sub-welding strips is 2 to 10.

13. A photovoltaic module, characterized in that: include: At least two battery cells; The solder strip according to any one of claims 1 to 12, wherein the light-receiving section of the solder strip is connected to the light-receiving surface of one battery cell, and the backlight section of the solder strip is connected to the backlight surface of another battery cell.

14. A photovoltaic system, characterized in that: Comprising the photovoltaic module as claimed in claim 14.

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