Back contact battery assembly and photovoltaic system

Abstract

The utility model is suitable for the technical field of solar cells, and provides a back contact cell module and a photovoltaic system. The back contact battery assembly comprises a battery string, a welding strip and a black film layer, the battery string comprises a first battery piece and a second battery piece which are adjacent to each other, the first battery piece and the second battery piece are distributed in the first direction and are arranged at an interval, and interval areas are formed; the welding strip is connected with the first fine grid of the first battery piece and the second fine grid of the second battery piece, and the black film layer is arranged on the light-facing side of the welding strip and located in the interval area. Therefore, the black film layer can cover the exposed part of the solder strip in the interval area, so that the front surface of the whole back contact battery assembly can display black, and the color integrity is improved.

Description

Technical Field

[0001] This application belongs to the technical field of solar cells, and particularly relates to a back-contact battery module and a photovoltaic system. Background Art

[0002] Solar energy is a sustainable source of clean energy. Solar cells can convert solar energy into electrical energy by utilizing the photovoltaic effect of the semiconductor p-n junction. Currently, a back-contact battery refers to a solar cell in which the light-facing surface of the cell has no electrodes, and the positive and negative electrodes are both arranged on the backlight side of the cell, thereby reducing the shielding of the electrodes to the cell and increasing the short-circuit current of the cell, improving the energy conversion efficiency of the cell. In the related art, multiple solar cells are electrically connected through solder tapes to form a battery string, and the battery string is encapsulated to form a battery module. However, the color difference between the solder tape and the solar cell is large, resulting in poor color consistency of the battery string. Summary of the Utility Model

[0003] This application provides a back-contact battery module and a photovoltaic system, aiming to solve the problem of how to improve the color consistency of the battery string.

[0004] The back-contact battery module provided by this application includes a battery string, a solder tape, and a black film layer. The battery string includes adjacent first and second battery cells. The first and second battery cells are arranged along the first direction, with a gap between them. First fine grids and second fine grids are formed on the back surfaces of the first and second battery cells. The first and second fine grids extend along the second direction and are alternately arranged along the first direction. The first and second fine grids have opposite polarities. An interval region is formed between the first battery cell and the second battery cell. The solder tape connects the first fine grid of the first battery cell and the second fine grid of the second battery cell. The black film layer is disposed on the light-facing side of the solder tape and within the interval region.

[0005] Furthermore, the black film layer is a black coating, or a black inkjet layer, or a black adhesive strip.

[0006] Furthermore, the length of the black film layer along the first direction is 560 μm - 600 μm.

[0007] Furthermore, the length of the black film layer in the first direction is less than the distance between adjacent two battery cells.

[0008] Furthermore, the width of the black film layer in the second direction is greater than the width of the solder tape in the second direction.

[0009] Furthermore, the thickness of the black film layer is 0.1 μm - 100 μm.

[0010] Further, the thickness of the black film layer is 3 μm - 15 μm.

[0011] Further, the first fine grids of the first cell and the second fine grids of the second cell are arranged in one-to-one correspondence. The solder ribbon includes a first solder ribbon and a second solder ribbon. The first solder ribbon connects the first fine grid of the first cell and the second fine grid of the second cell, and the second solder ribbon connects the first fine grid of the second cell and the component to be connected.

[0012] Further, the component to be connected is the second fine grid or the bus bar of another adjacent first cell.

[0013] Further, in the second direction, the width of the black film layer is equal to the width of the solder ribbon.

[0014] Further, in the second direction, the width of the solder ribbon is greater than or equal to the width of the fine grid; or

[0015] in the second direction, the width of the solder ribbon is less than the width of the fine grid.

[0016] The photovoltaic system provided by the embodiment of the present application includes the back contact battery assembly described in any of the above embodiments.

[0017] In the back contact battery assembly and the photovoltaic system of the embodiment of the present application, the back contact battery assembly includes a battery string, a solder ribbon, and a black film layer. The battery string includes adjacent first cells and second cells. The first cells and the second cells are arranged along the first direction and are spaced apart. First fine grids and second fine grids are formed on the back surfaces of the first cells and the second cells. The first fine grids and the second fine grids extend along the second direction and are alternately arranged along the first direction. The first fine grids and the second fine grids have opposite polarities. An interval region is formed between the first cell and the second cell. The solder ribbon connects the first fine grid of the first cell and the second fine grid of the second cell. The black film layer is disposed on the light-facing side of the solder ribbon and is located within the interval region. In this way, the black film layer can cover the exposed portion of the solder ribbon located in the interval region, so that the entire front surface of the back contact battery assembly can display black, improving the color integrity. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of a back contact battery assembly according to an embodiment of the present application;

[0019] Figure 2 is a partial structural schematic diagram of a back contact battery assembly according to an embodiment of the present application;

[0020] Figure 3It is a schematic cross-sectional structure diagram of a back-contact battery module according to an embodiment of the present application;

[0021] Figure 4 It is a schematic module structure diagram of a back-contact battery module according to an embodiment of the present application;

[0022] Figure 5 It is a schematic structure diagram of a photovoltaic system according to an embodiment of the present application.

[0023] Main element symbol description:

[0024] 100, back-contact battery module; 10, battery string; 11, first battery cell; 12, second battery cell; 21, first fine grid; 22, second fine grid; 30, solder ribbon; 31, first solder ribbon; 32, second solder ribbon; 40, black film layer; 50, component to be connected; 51, bus bar; 60, spacer area; 200, photovoltaic system. Detailed implementation manners

[0025] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present application and should not be construed as limiting the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.

[0027] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality of" means two or more unless otherwise specifically defined.

[0028] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" 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, an electrical connection, or a connection that allows for mutual communication; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0029] In the present application, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the horizontal height of the first feature is lower than that of the second feature.

[0030] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use scenarios of other materials.

[0031] In the related art, multiple solar cells are electrically connected through solder ribbons to form a battery string, and the battery string forms a battery module after encapsulation. However, there is a large color difference between the solder ribbons and the solar cells, resulting in poor color consistency of the battery string. In the present application, a black film layer can be provided at the position of the solder ribbon exposed between the gaps of the solar cells. The black film layer can cover the exposed part of the solder ribbon in the spaced area, so that the entire front surface of the back-contact battery module can display black, improving the color integrity.

[0032] Embodiment 1

[0033] Please refer to Figures 1 to 3, in the back-contact battery module 100 according to the embodiment of the present application, the back-contact battery module 100 includes a battery string 10, a welding tape 30, and a black film layer 40. The battery string 10 includes adjacent first battery cells 11 and second battery cells 12. The first battery cells 11 and the second battery cells 12 are arranged along a first direction, and the first battery cells 11 and the second battery cells 12 are spaced apart. First fine grids 21 and second fine grids 22 are formed on the back surfaces of the first battery cells 11 and the second battery cells 12. The first fine grids 21 and the second fine grids 22 extend along the first direction and are alternately arranged along a second direction. The first fine grids 21 and the second fine grids 22 have opposite polarities. An interval region 60 is formed between the first battery cells 11 and the second battery cells 12. The welding tape 30 connects the first fine grid 21 of the first battery cell 11 and the second fine grid 22 of the second battery cell 12. The black film layer 40 is disposed on the light-facing side of the welding tape 30 and is located within the interval region 60.

[0034] In the back-contact battery module 100 according to the embodiment of the present application, the back-contact battery module 100 includes a battery string 10, a welding tape 30, and a black film layer 40. The battery string 10 includes adjacent first battery cells 11 and second battery cells 12. The first battery cells 11 and the second battery cells 12 are arranged along a first direction, and the first battery cells 11 and the second battery cells 12 are spaced apart. First fine grids 21 and second fine grids 22 are formed on the back surfaces of the first battery cells 11 and the second battery cells 12. The first fine grids 21 and the second fine grids 22 extend along the first direction and are alternately arranged along a second direction. The first fine grids 21 and the second fine grids 22 have opposite polarities. An interval region 60 is formed between the first battery cells 11 and the second battery cells 12. The welding tape 30 connects the first fine grid 21 of the first battery cell 11 and the second fine grid 22 of the second battery cell 12. The black film layer 40 is disposed on the light-facing side of the welding tape 30 and is located within the interval region 60. Thus, the black film layer 40 can cover the exposed portion of the welding tape 30 located in the interval region 60, so that the entire front surface of the back-contact battery module 100 can display black, improving the color integrity.

[0035] Specifically, the first battery cells 11 and the second battery cells 12 may be arranged in sequence in the first direction according to the order of "first battery cell 11, second battery cell 12, first battery cell 11, second battery cell 12...", and the specific number of battery cells is not limited. Moreover, the first battery cells 11 and the second battery cells 12 are spaced apart, and an interval region 60 is formed between the battery cells. The interval region 60 can leave a redundant space for the thermal expansion and contraction of the battery cells, thereby ensuring the safety and service life of the battery cells. At the same time, the interval region 60 helps the heat dissipation of the battery cells, reduces the thermal influence between the battery cells, and can also leave a certain space for welding and installation operations. And the interval region 60 can ensure that each battery cell can work independently, reducing the possible influence between each other.

[0036] Furthermore, first fine grids 21 and second fine grids 22 are formed on the back surfaces of the first cell 11 and the second cell 12, and the first fine grids 21 and the second fine grids 22 extend along the first direction. In this way, while not wasting the position space of the cell in the first direction, it is also beneficial to the connection between the fine grids of the first cell 11 and the second cell 12, making the connection of the fine grids more convenient. The first fine grids 21 and the second fine grids 22 are alternately arranged along the second direction, and can be arranged in the order of "first fine grid 21, second fine grid 22, first fine grid 21, second fine grid 22...". In this way, the position space in the second direction of the cell can be fully utilized, which is beneficial to collecting and transmitting the converted electric energy on the cell. The number of fine grids in a cell in this application is not limited, and the corresponding number of fine grids can be set according to the size of the cell and actual requirements to meet various needs.

[0037] Furthermore, the first fine grids 21 and the second fine grids 22 have opposite polarities. Here, the specific polarities represented by "first" and "second" are not limited, and "first" and "second" are only used to distinguish two different polar fine grids. That is to say, the first fine grid 21 can be the positive electrode or the negative electrode, and the second fine grid 22 can be the positive electrode or the negative electrode. However, when the polarity of the first fine grid 21 is positive, the polarity of the second fine grid 22 is negative; when the polarity of the first fine grid 21 is negative, the polarity of the second fine grid 22 is positive. The distinction of different polarities facilitates the connection between different cells.

[0038] In addition, in the back-contact cell assembly 100 of the embodiment of this application, the solder strip 30 connects the first fine grid 21 of the first cell 11 and the second fine grid 22 of the second cell 12. Since the first fine grid 21 and the second fine grid 22 have opposite polarities, the positive electrode of the first cell 11 and the negative electrode of the second cell 12 can be connected; or the negative electrode of the first cell 11 and the positive electrode of the second cell 12 can be connected. In this way, multiple cells can be connected in series to form a battery string 10.

[0039] Furthermore, since the solder strip 30 is required to connect the first cell 11 and the second cell 12, an interval region 60 is formed between the first cell 11 and the second cell 12. The interval region 60 not only provides space for the thermal expansion and contraction of the cells and installation operations, etc., but also exposes the solder strip 30 from the interval region 60. The color of the solder strip 30 is quite different from that of the cell, and the exposed solder strip 30 causes the inconsistency of the surface color of the battery string 10, affecting the integrity of the color of the battery string 10. In this way, the black film layer 40 is arranged on the light-facing side of the solder strip 30 and within the interval region 60, so that the black film layer 40 can cover the exposed solder strip 30, making the interval region 60 and the battery string 10 present the same color, achieving the visual effect of no solder strip 30, ensuring the integrity of the color of the battery string 10, and improving the aesthetics.

[0040] Example Two

[0041] Please refer to Figure 1 , in some alternative embodiments, the black film layer 40 is a black coating, or a black inkjet layer, or a black adhesive strip.

[0042] Specifically, the black film layer 40 can be a black coating, and a solid continuous film can be obtained by one-time application, which is used to coat the light-facing side of the solder tape 30 exposed in the spacer region 60 between two adjacent solar cells, and the operation is simple; alternatively, the black film layer 40 can also be a black inkjet layer, and the black film layer 40 is formed by spraying tiny ink dots, which is used to spray on the light-facing side of the solder tape 30 exposed in the spacer region 60 between two adjacent solar cells, and precise three-dimensional dimensions of the black film layer 40 can be obtained by inkjet; or the black film layer 40 can also be a black adhesive strip, which can be a black film 40 with an adhesive effect on one side prepared in advance, and is used to paste on the light-facing side of the solder tape 30 exposed in the spacer region 60 between two adjacent solar cells, and the operation is simple. In this way, the solder tape 30 and the solar cell can present the same black color, ensuring the color consistency of the solar cell string 10 and achieving the effect of no visible solder tape 30 visually. In this way, while ensuring the color consistency of the solar cell string 10, the preparation process can be simplified, the process difficulty can be reduced, and the process precision can be increased, etc. At the same time, the light-facing side of the black film layer 40 is also the side impacted by rainwater. The setting of the black film layer 40 can improve the color of the solar cell string 11 while enhancing the wear resistance, corrosion resistance, light-facing side insulation performance, etc. of the solder tape 30 in the spacer region 60.

[0043] Further, after the black film layer 40 is set on the solder tape 30 by means of coating or inkjet layer, natural drying or heating and drying may be required to ensure good curing effect of the black film layer 40 and increase the durability and firmness of the black film layer 40. If necessary, further treatment can also be performed on the surface of the black film layer 40, such as multi-layer coating or multi-layer spraying, etc., in order to obtain a better color effect and more precisely control the three-dimensional dimensions of the length, width and thickness of the black film layer 40. Of course, different surface types of the black film layer 40, such as matte or shiny surface, can also be obtained through different processes, improving the overall visual appearance. The application does not limit the coating and spraying processes and the number of times of the black film layer 40 to meet various requirements.

[0044] Example Three

[0045] Please refer to Figures 1 to 3 , in some alternative embodiments, the length of the black film layer 40 in the first direction is 560μm - 600μm. For example, the length of the black film layer 40 in the first direction can be 560μm, 565μm, 570μm, 575μm, 580μm, 585μm, 590μm, 595μm, 600μm.

[0046] In this way, the length of the black film layer 40 is within a suitable range, which can avoid exposing the welding tape 30 in the interval region 60 between the first solar cell 11 and the second solar cell 12 due to too small a length, which is beneficial to ensuring the color consistency of the battery string 10, and can also avoid the relatively high cost caused by too large a length.

[0047] Exemplarily, the length of the black film layer 40 in the first direction can be 580 μm. At this time, the coating of the black film layer 40 can be sprayed on the welding tape 30 with a width of 560 μm, so that the width of the black film layer 40 in the first direction is within the range of 540 μm - 580 μm, avoiding affecting the welding of the welding tape 30 and the solar cell.

[0048] Of course, in other embodiments, the coating of the black film layer 40 can be sprayed on the welding tape 30 in as many ways as possible, that is, the width of the black film layer 40 in the first direction is greater than the width of the interval region 60 in the first direction, avoiding the exposure of the non-black part of the interval region 60.

[0049] Embodiment 4

[0050] Please refer to Figures 1 to 3 , in some alternative embodiments, the length of the black film layer 40 in the first direction is less than the spacing between two adjacent solar cells.

[0051] Specifically, the black film layer 40 is disposed in the interval region 60 between two adjacent solar cells. The length of the black film layer 40 in the first direction should be less than the length of the interval region 60, so as to leave a redundant space, increase the operation error tolerance rate, and further avoid the black film layer 40 from blocking light. At the same time, it is avoided that the length of the black film layer 40 exceeds the interval region 60 between two adjacent solar cells after thermal expansion and contraction, causing occlusion of the light-facing surface of the solar cell and affecting the performance of the solar cell.

[0052] Embodiment 5

[0053] Please refer to Figures 1 to 3 , in some alternative embodiments, the width of the black film layer 40 in the second direction is greater than the width of the welding tape 30 in the second direction.

[0054] Specifically, since the solar panel is mostly placed obliquely during use, in order to make the black film layer 40 block the edge part of the welding tape 30 in the second direction on the light-facing side as much as possible and avoid the edge of the welding tape 30 in the second direction from being exposed, the width of the black film layer 40 should be greater than the width of the welding tape 30 in the second direction. So that the welding tape 30 is completely blocked in the second direction on the light-facing side, and the welding tape 30 will not be exposed even if the solar panel is placed obliquely.

[0055] Embodiment 6

[0056] Please refer to Figures 1 to 3 In some alternative embodiments, the thickness of the black film layer 40 is 0.1 μm - 100 μm. For example, the thickness of the black film layer 40 can be 0.1 μm, 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm.

[0057] In this way, by making the thickness of the black film layer 40 within a suitable range, it is possible to avoid the color of the black film layer 40 being too light due to too small a thickness of the black film layer 40, which exposes the solder strip 30 and affects the color consistency. It is also possible to avoid the relatively high cost caused by too large a thickness of the black film layer 40.

[0058] Embodiment Seven

[0059] Please refer to Figures 1 to 3 In some alternative embodiments, the thickness of the black film layer 40 is 3 μm - 15 μm. For example, the thickness of the black film layer 40 can be 3 μm, 5 μm, 7 μm, 9 μm, 11 μm, 13 μm, 15 μm.

[0060] In this way, preferably, the thickness of the black film layer 40 is 3 μm - 15 μm, so that the thickness of the black film layer 40 is in a more suitable range. On the premise of ensuring color consistency, the reliability of the black film layer 40 is increased, the cost is better controlled, and the overall effect is better.

[0061] Embodiment Eight

[0062] Please refer to Figure 1 and Figure 2 In some alternative embodiments, the first fine grid 21 of the first solar cell 11 and the second fine grid 22 of the second solar cell 12 are arranged in one-to-one correspondence. The solder strip 30 includes a first solder strip 31 and a second solder strip 32. The first solder strip 31 connects the first fine grid 21 of the first solar cell 11 and the second fine grid 22 of the second solar cell 12, and the second solder strip 32 connects the first fine grid 21 of the second solar cell 12 and the component to be connected 50.

[0063] Specifically, if the cell is divided into multiple regions of the same size from top to bottom in the second direction (e.g., region 1, region 2, region 3, region 4...), the first fine grid 21 of the first cell 11 can be located in the odd-numbered regions of the first cell 11 (e.g., region 1, region 3...). Since the first fine grid 21 of the first cell 11 and the second fine grid 22 of the second cell 12 are arranged in one-to-one correspondence, the second fine grid 22 of the second cell 12 should be located in the odd-numbered regions of the second cell 12 (e.g., region 1, region 3...). In this way, it is more convenient to connect the first fine grid 21 of the first cell 11 and the second fine grid 22 of the second cell 12 by the first solder strip 31, and the operation is simple and reliable. At the same time, since the polarities of the first fine grid 21 and the second fine grid 22 are opposite, the first cell 11 and the second cell 12 are connected in series through the solder strip 30.

[0064] Furthermore, the first fine grid 21 of the second cell 12 can be located in the even-numbered regions (e.g., region 2, region 4...), and the second solder strip 32 connects the first fine grid 21 of the second cell 12 and the component to be connected 50. Similarly, the second fine grid 22 of the first cell 11 can also be located in the even-numbered regions (e.g., region 2, region 4...), and the second solder strip 32 can connect the second fine grid 22 of the first cell 11 and the component to be connected 50. The component to be connected 50 can be another cell, or other external circuits, etc. There are various situations. The component to be connected 50 can be selected according to the actual situation. The type of the component to be connected 50 is not limited in this application to meet various requirements.

[0065] Embodiment Nine

[0066] Please refer to Figure 1 and Figure 2 In some alternative embodiments, the component to be connected 50 is the second fine grid 22 or the bus bar 51 of another adjacent first cell 11.

[0067] Specifically, the first fine grid 21 of the second cell 12 can be connected to the second fine grid 22 of another adjacent first cell 11 through the solder strip 30 to increase the number of cells in the battery string 10 and improve the performance of the battery string 10; or the first fine grid 21 of the second cell 12 can be connected to the bus bar 51 through the solder strip 30, so that the current generated in the cell converges through the solder strip 30 and then through the bus bar 51, and then is transmitted to the connected external battery pack or power grid. Of course, other battery strings 10 can also be connected through the bus bar 51, or other circuits can be connected. The circuit connected to the bus bar 51 is not limited in this application to meet various requirements.

[0068] Embodiment Ten

[0069] Please refer to Figures 1 to 3, in some alternative embodiments, the width of the black film layer 40 in the second direction is equal to the width of the solder tape 30.

[0070] Thus, the black film layer 40 with the same width as the solder tape 30 in the second direction can completely cover the color of the solder tape 30 itself while reducing the use of the material of the black film layer 40. While ensuring the color consistency of the battery string 10, the production cost is controlled.

[0071] Embodiment Eleven

[0072] Please refer to Figures 1 to 3 , in some alternative embodiments, in the second direction, the width of the solder tape 30 is greater than or equal to the width of the fine grid; or

[0073] In the second direction, the width of the solder tape 30 is less than the width of the fine grid.

[0074] Specifically, the width of the solder tape 30 can be set accordingly according to actual requirements. When the power of the solar cell is large, a wider solder tape 30 may be required to transmit more current. At this time, the width of the solder tape 30 can be greater than the width of the fine grid; when the power of the solar cell is moderate, a solder tape 30 with an appropriate width may be required. At this time, the width of the solder tape 30 can be equal to the width of the fine grid, reducing the preparation cost while meeting the current transmission; when the power of the solar cell is small, a narrower solder tape 30 may be required to transmit less current. At this time, the width of the solder tape 30 can be less than the width of the fine grid to reduce the production cost. The present application does not limit the width of the solder tape 30 to meet various requirements.

[0075] Embodiment Twelve

[0076] Please refer to Figure 1 , Figure 4 and Figure 5 , the photovoltaic system 200 provided by the implementation manner of the present application includes the back contact battery assembly 100 of any one of the above implementation manners.

[0077] In the back-contact battery assembly 100 and the photovoltaic system 200 according to the embodiments of the present application, the back-contact battery assembly 100 includes a battery string 10, a solder ribbon 30, and a black film layer 40. The battery string 10 includes adjacent first and second battery cells 11 and 12, which are arranged along a first direction with a gap therebetween. On the back surfaces of the first and second battery cells 11 and 12, a first fine grid 21 and a second fine grid 22 are formed. The first and second fine grids 21 and 22 extend along the first direction and are alternately arranged along a second direction, with opposite polarities. An interval region 60 is formed between the first battery cell 11 and the second battery cell 12. The solder ribbon 30 connects the first fine grid 21 of the first battery cell 11 and the second fine grid 22 of the second battery cell 12. The black film layer 40 is disposed on the light-facing side of the solder ribbon 30 and within the interval region 60. Thus, the black film layer 40 can cover the exposed portion of the solder ribbon 30 within the interval region 60, making the entire front surface of the back-contact battery assembly 100 appear black and improving the color integrity.

[0078] In this embodiment, the photovoltaic system 200 can be applied in a photovoltaic power station, such as a ground power station, a rooftop power station, a water surface power station, etc., or in devices or apparatuses that use solar energy for power generation, such as a user solar power supply, a solar street lamp, a solar vehicle, a solar building, etc. Of course, it can be understood that the application scenarios of the photovoltaic system 200 are not limited thereto, that is to say, the photovoltaic system 200 can be applied in all fields that require solar power generation. Taking a photovoltaic power generation system network as an example, the photovoltaic system 200 may include a photovoltaic array, a busbar box, and an inverter. The photovoltaic array can be an array combination of multiple battery assemblies. For example, multiple battery assemblies can form multiple photovoltaic arrays. The photovoltaic array is connected to the busbar box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into alternating current required by the commercial power grid and then connected to the commercial power grid to achieve solar power supply.

[0079] In the description of this specification, the description with reference to terms such as "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0080] In addition, the above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A back-contact battery assembly, characterized in that, Comprising: A battery string, including adjacent first and second battery cells, the first and second battery cells being arranged along a first direction, the first and second battery cells being spaced apart, first fine grids and second fine grids being formed on the back surfaces of the first and second battery cells respectively, the first fine grids and the second fine grids extending along a second direction and being alternately arranged along the first direction, the first fine grids and the second fine grids having opposite polarities; A solder strip, the solder strip extending along the first direction and connecting the back surfaces of the first and second battery cells, an interval region being formed between the first and second battery cells, the solder strip connecting the first fine grid of the first battery cell and the second fine grid of the second battery cell; A black film layer, the black film layer being disposed on the light-facing side of the solder strip and within the interval region.

2. The back-contact battery assembly according to claim 1, wherein The black film layer is a black coating, or a black inkjet layer, or a black adhesive strip.

3. The back-contact battery assembly according to claim 1, wherein, The length of the black film layer along the first direction is from 560 μm to 600 μm.

4. The back-contact battery assembly according to claim 1, wherein The length of the black film layer in the first direction is less than the distance between adjacent two of the battery cells.

5. The back-contact battery assembly according to claim 1, characterized in that, The width of the black film layer in the second direction is greater than the width of the solder strip in the second direction.

6. The back-contact battery assembly according to claim 1, characterized in that, The thickness of the black film layer is from 0.1 μm to 100 μm.

7. The back-contact battery assembly according to claim 6, wherein, The thickness of the black film layer is from 3 μm to 15 μm.

8. The back-contact battery component according to claim 1, characterized in that, The first fine grids of the first battery cell and the second fine grids of the second battery cell are arranged in one-to-one correspondence, the solder strip includes a first solder strip and a second solder strip, the first solder strip connecting the first fine grid of the first battery cell and the second fine grid of the second battery cell, and the second solder strip connecting the first fine grid of the second battery cell and a component to be connected.

9. The back-contact battery assembly according to claim 8, wherein, The component to be connected is the second fine grid or a bus bar of another adjacent first battery cell.

10. The back-contact battery assembly according to claim 1, characterized in that, In the second direction, the width of the black film layer is equal to the width of the solder strip.

11. The back contact battery assembly according to claim 1, characterized in that, In the second direction, the width of the solder strip is greater than or equal to the width of the fine grid; or In the second direction, the width of the solder strip is less than the width of the fine grid.

12. A photovoltaic system, characterized in that, Comprising a back-contact battery assembly according to any one of claims 1-11.

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