Back contact cell assembly and photovoltaic system

Abstract

The application relates to the technical field of solar cells, and provides a back contact cell assembly and a photovoltaic system. The back contact cell assembly is composed of a first cell string unit and a second cell string unit connected in series. Each cell string unit comprises one parallel cell string. The cell piece in the cell string is a one-third cut cell. A first output bus bar serves as a positive output end of the assembly, a second output bus bar serves as a negative output end of the assembly, a series bus bar connects the first cell string unit and the second cell string unit in series, at least one of the three bus bars is arranged on the back surface of the cell piece of the cell string, and a bypass diode is connected between the first output bus bar and the second output bus bar. In this way, the power loss of the assembly can be reduced, and the power generation per unit area of the back contact cell assembly is improved.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and more particularly to a back-contact battery module and photovoltaic system. Background Technology

[0002] Back-contact solar modules typically consist of arrays of back-contact cells, comprising several strings of back-contact cells. In related technologies, as cell size increases, the short-circuit current of the cells and the module continuously rises, leading to a significant increase in internal power loss. Simultaneously, larger cells are more prone to microcracks, affecting the module's reliability and lifespan. Furthermore, the current busbar configuration in existing photovoltaic systems has significant drawbacks, requiring dedicated space on the module for busbar installation. This not only increases the overall module size but also reduces the power generation efficiency per unit area. Utility Model Content

[0003] This application provides a back-contact battery module and a photovoltaic system.

[0004] This application is implemented as follows: the back contact battery assembly in the embodiments of this application includes:

[0005] The first battery string unit and the second battery string unit are arranged along a first direction. The first battery string unit includes three battery strings arranged along the first direction and connected in parallel with each other. The second battery string unit also includes three battery strings arranged along the first direction and connected in parallel with each other. Each battery string includes multiple battery cells arranged along a second direction and connected in series. The battery cells are sliced ​​batteries formed by cutting or splitting back-contact battery cells into three equal parts. The first direction and the second direction intersect.

[0006] A first output bus, a second output bus, and a series bus are provided. The first output bus is connected to the positive terminal of the first battery string unit, the second output bus is connected to the negative terminal of the second battery string unit, and the series bus is connected to both the negative terminal of the first battery string unit and the positive terminal of the second battery string unit.

[0007] A bypass diode, one end of which is connected to the first output busbar and the other end of which is connected to the second output busbar;

[0008] At least one of the first output busbar, the second output busbar, and the series busbar is disposed on the back side of the battery cell.

[0009] In some embodiments, in the battery string, a plurality of battery cells are connected in series via positive and negative electrode solder strips. The back contact battery assembly has a first edge and a second edge opposite to each other in the second direction. The positive terminal of the first battery string unit and the negative terminal of the second battery string unit are disposed near the first edge, and the negative terminal of the first battery string unit and the positive terminal of the second battery string unit are disposed near the second edge. The first output busbar and the second output busbar are disposed near the first edge, and the series busbar is disposed near the second edge.

[0010] In some embodiments, the battery strings in both the first battery string unit and the second battery string unit include first battery cells located at both ends of the battery string in the second direction;

[0011] The first output busbar is disposed on the back of the first battery cell near the first edge in the first battery string unit, and a first insulating layer is provided between the first output busbar and the negative electrode solder strip on the first battery cell; and / or

[0012] The second output busbar is disposed on the back of the first battery cell near the first edge in the second battery string unit, and a second insulating layer is provided between the second output busbar and the positive electrode solder strip on the first battery cell; and / or

[0013] The series busbar is disposed on the back side of the first battery cell near the second edge in the first battery string unit and on the back side of the first battery cell near the second edge in the second battery string unit. A third insulating layer is provided between the series busbar and the positive electrode solder strip on the first battery cell near the second edge in the first battery string unit and the negative electrode solder strip on the first battery cell near the second edge in the second battery string unit.

[0014] In some embodiments, the battery strings in the first battery string unit and the second battery string unit each include a first battery cell located at both ends of the battery string in the second direction and a second battery cell adjacent to the first battery cell;

[0015] The first output busbar is disposed on the back of the second battery cell near the first edge in the first battery string unit and is provided with a first insulating strip between it and the second battery cell. The first output busbar is connected to the positive electrode solder strip on the first battery cell; and / or

[0016] The second output busbar is disposed on the back of the second battery cell near the first edge in the second battery string unit, and a second insulating strip is provided between the second output busbar and the second battery cell. The second output busbar is connected to the negative electrode solder strip on the first battery cell; and / or

[0017] The series busbar is disposed on the back of the second battery cell near the second edge in the first battery string unit and on the back of the second battery cell near the second edge in the second battery string unit, and a third insulating strip is provided between the series busbar and the second battery cell. The series busbar is connected to the negative electrode solder strip on the first battery cell near the second edge in the first battery string unit and the positive electrode solder strip on the first battery cell near the second edge in the second battery string unit.

[0018] In some embodiments, the battery strings in the first battery string unit and the second battery string unit each include a first battery cell located at both ends of the battery string in the second direction and a second battery cell adjacent to the first battery cell;

[0019] The first output busbar overlaps with both the first and second battery cells near the first edge in the first battery string unit, and a first insulating strip is provided between the first output busbar and the first and second battery cells. The first output busbar is connected to the positive electrode solder strip on the first battery cell; and / or

[0020] The second output busbar overlaps with both the first and second battery cells near the first edge in the second battery string unit, and a second insulating strip is provided between the second output busbar and the first and second battery cells. The second output busbar is connected to the negative electrode solder strip on the first battery cell; and / or

[0021] The series busbar overlaps with both the first and second battery cells near the second edge in the first battery string unit, and also overlaps with both the first and second battery cells near the second edge in the second battery string unit. A third insulating strip is provided between the series busbar and the first and second battery cells. The series busbar is connected to the negative electrode solder strip on the first battery cell near the second edge in the first battery string unit and the positive electrode solder strip on the first battery cell near the second edge in the second battery string unit.

[0022] In some embodiments, in at least one of the battery strings in the first battery string unit and the second battery string unit, two adjacent battery cells partially overlap.

[0023] In some embodiments, the length of the overlapping portion of two adjacent battery cells in the second direction is 0.2 mm to 0.5 mm.

[0024] In some embodiments, in the first battery string unit, two adjacent battery strings partially overlap in the first direction; and / or

[0025] In the second battery string unit, two adjacent battery strings partially overlap in the first direction.

[0026] In some embodiments, two adjacent battery strings in the first battery string unit partially overlap in the first direction, and the length of the overlapping portion of the two adjacent battery strings in the first direction is 0.2mm-0.5mm; and / or

[0027] In the second battery string unit, two adjacent battery strings partially overlap in the first direction, and the length of the overlapping portion of the two adjacent battery strings in the first direction is 0.2mm-0.5mm.

[0028] In some embodiments, the first battery string unit and the second battery string unit partially overlap in the first direction.

[0029] This application also provides a photovoltaic system, which includes the back contact battery assembly described in any of the above claims.

[0030] In the back-contact solar module and photovoltaic system of this application embodiment, the back-contact solar module consists of a first cell string unit and a second cell string unit connected in series. Each cell string unit includes three parallel cell strings. The cells in the cell strings are one-third sliced ​​cells. A first output bus bar serves as the positive output terminal of the module, and a second output bus bar serves as the negative output terminal of the module. A series bus bar connects the first cell string unit and the second cell string unit in series. At least one of the three bus bars is located on the back side of the cell in the cell string. A bypass diode is connected between the first output bus bar and the second output bus bar. Thus, on the one hand, by using one-third sliced ​​cells in the cell string, and through the parallel connection of cell strings within the cell string unit and the series connection between cell string units, the power loss of the module can be reduced while maintaining the final output voltage and current of the module essentially the same as that of a conventional module. Furthermore, the one-third sliced ​​cells are relatively small in size, which enhances the resistance to microcracks and reduces the risk of microcracks. Meanwhile, at least one of the first output busbar, the second output busbar, and the series busbar is located on the back of the battery cell, which can hide the busbar and thus improve the power generation efficiency per unit area of ​​the back contact battery module, that is, improve the power density of the back contact battery module.

[0031] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a photovoltaic system module provided in an embodiment of this application;

[0033] Figure 2 This is a schematic diagram of the structure of the back contact battery assembly provided in the embodiments of this application;

[0034] Figure 3 This is another structural schematic diagram of the back contact battery assembly provided in the embodiments of this application;

[0035] Figure 4 This is another structural schematic diagram of the back contact battery assembly provided in the embodiments of this application;

[0036] Figure 5 This is another structural schematic diagram of the back contact battery assembly provided in the embodiments of this application;

[0037] Figure 6 This is another structural schematic diagram of the back contact battery assembly provided in the embodiments of this application.

[0038] Explanation of key component symbols:

[0039] Photovoltaic system 1000, back contact battery module 100, first battery string unit 11, second battery string unit 12, battery string 110, battery cell 111, first battery cell 1111, second battery cell 1112, positive electrode solder ribbon 112, negative electrode solder ribbon 113, first output bus bar 20, second output bus bar 30, series bus bar 40, bypass diode 60, first insulating layer 70, second insulating layer 80, third insulating layer 90, first insulating strip 120, second insulating strip 130, third insulating strip 140. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0041] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0043] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0044] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0045] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0046] Please see Figure 1 The photovoltaic system 1000 in this application embodiment may include at least one back contact battery module 100 as described in this application embodiment. In the photovoltaic system 1000, the back contact battery modules 100 may be electrically connected in parallel or in series, depending on actual needs.

[0047] In the embodiments of this application, the photovoltaic system 1000 can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system 1000 are not limited to these; that is to say, the photovoltaic system 1000 can be applied in all fields that require the use of solar energy to generate electricity.

[0048] Taking a photovoltaic power generation system network as an example, the photovoltaic system 1000 may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules. For example, multiple battery modules may form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can combine the current generated by the photovoltaic array. The combined current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to realize solar power supply.

[0049] Please see Figure 2 and Figure 3 The back contact battery in this application embodiment may include a first battery string unit 11, a second battery string unit 12, a first output bus bar 20, a second output bus bar 30, a series bus bar 40, and a bypass diode 60.

[0050] In the back-contact battery assembly 100, a first battery string unit 11 and a second battery string unit 12 are arranged along a first direction. The first battery string unit 11 includes three battery strings 110 arranged along the first direction, and the three battery strings 110 in the first battery string unit 11 are connected in parallel. The second battery string unit 12 also includes three battery strings 110 arranged along the first direction, and the three battery strings 110 in the second battery string unit 12 are also connected in parallel. Specifically, the battery strings 110 in the first battery string unit 11 can be arranged in parallel, and the battery strings 110 in the second battery string unit 12 can also be arranged in parallel, or all the battery strings 110 can be arranged in parallel along the first direction.

[0051] Each battery string 110 includes a plurality of battery cells 111 arranged and connected in series along a second direction. In some embodiments, in the battery string 110, the plurality of battery cells 111 are connected in series by positive electrode solder strips 112 and negative electrode solder strips 113. The number of battery cells 111 in each battery string 110 may be equal. The battery cells 111 in the battery string 110 are sliced ​​batteries formed by cutting or splitting back-contact battery cells 111 into thirds, that is, the battery cells 111 in the battery string 110 are all one-third sliced ​​batteries. The first direction and the second direction intersect. Specifically, in this application, the first direction may be the lateral direction of the back-contact battery assembly 100, and the second direction may be the longitudinal direction of the back-contact battery assembly 100, and the two are perpendicular to each other.

[0052] The first output busbar 20 is connected to the positive terminal of the first battery string unit 11, the second output busbar 30 is connected to the negative terminal of the second battery string unit 12, and the series busbar 40 is connected to the negative terminal of the first battery string unit 11 and the positive terminal of the second battery string unit 12 to connect the first battery string unit 11 and the second battery string unit 12 in series. That is, in the back contact battery assembly 100, the first output busbar 20 serves as the positive output terminal of the back contact battery assembly 100, the second output busbar 30 serves as the negative output terminal of the back contact battery assembly 100, and the series busbar 40 is used to connect the first battery string unit 11 and the second battery string unit 12 in series.

[0053] One end of the bypass diode 60 is connected to the first output bus 20, and the other end of the bypass diode 60 is connected to the second output bus 30. In some embodiments, the negative terminal of the bypass diode 60 is connected to the first output bus 20, and the positive terminal of the bypass diode 60 is connected to the second output bus 30. The bypass diode 60 is responsible for controlling the first battery string unit 11 and the second battery string unit 12.

[0054] At least one of the first output busbar 20, the second output busbar 30, and the series busbar 40 is disposed on the back of the battery cell 111, thereby achieving the concealment of at least one busbar.

[0055] In the back contact battery module 100 and photovoltaic system 1000 of this application embodiment, the back contact battery module 100 is composed of a first battery string unit 11 and a second battery string unit 12 connected in series. Each battery string 110 group includes three parallel battery strings 110. The battery cells 111 in the battery string 110 are one-third sliced ​​batteries. The first output bus bar 20 serves as the positive output terminal of the module, and the second output bus bar 30 serves as the negative output terminal of the module. The series bus bar 40 connects the first battery string unit 11 and the second battery string unit 12 in series. At least one of the three bus bars is disposed on the back side of the battery cells 111 of the battery string 110. A bypass diode 60 is connected between the first output bus bar 20 and the second output bus bar 30. Thus, on the one hand, the solar cells 111 in the battery string 110 are one-third sliced ​​cells. By connecting the battery strings 110 in parallel within the battery string 110 group and connecting the battery strings 110 groups in series, the power loss of the module can be reduced while keeping the final output voltage and current of the module basically the same as that of a conventional module. Furthermore, the one-third sliced ​​cells 111 are relatively small in size, which enhances the resistance to microcracks and reduces the risk of microcracks. Simultaneously, at least one of the first output busbar 20, the second output busbar 30, and the series busbar 40 is located on the back of the solar cell 111, which allows the busbar to be hidden, thereby improving the power generation efficiency per unit area of ​​the back-contact battery module 100, that is, increasing the power density of the back-contact battery module 100.

[0056] It should be noted that the term "hidden" in this article refers to at least partial hiding, unless otherwise stated, such as "completely hidden" as described below.

[0057] Specifically, in this application, the back contact battery assembly 100 further includes a front panel, a front adhesive film, a rear adhesive film, and a back side. The back contact battery assembly 100 can be formed by encapsulating the front panel, front adhesive film, rear adhesive film, and back side together. In the embodiments of this application, the battery cell 111 can be a back contact battery cell 111 with a main grid or a back contact battery cell 111 without a main grid; no specific limitation is made here. In the embodiments of this application, the number of battery cells 111 in each battery string 110 is not limited, and the entire assembly includes 6 battery strings 110.

[0058] Please see Figure 2In the embodiments of this application, the back-contact battery assembly 100 has a first edge 101 and a second edge 102 in a second direction. The positive terminal of the first battery string unit 11 and the negative terminal of the second battery string unit 12 are disposed near the first edge 101, and the negative terminal of the first battery string unit 11 and the positive terminal of the second battery string unit 12 are disposed near the second edge 102. A first output bus bar 20 and a second output bus bar 30 are disposed near the first edge 101. The first output bus bar 20 is connected to the positive terminal of the first battery string unit 11, and the second output bus bar 30 is connected to the negative terminal of the second battery string unit 12. A series bus bar 40 is disposed near the second edge 102 and is connected to the negative terminal of the first battery string unit 11 and the positive terminal of the second battery string unit 12.

[0059] Specifically, such as Figure 2 As shown, in the back-contact battery assembly 100, the polarities of each battery string 110 in the first battery string unit 11 are oriented in the same direction, with the positive terminal facing one end of the first edge 101 and the negative terminal facing one end of the second edge 102. That is, the positive terminal of the first battery string unit 11 is closer to the first edge 101, and the negative terminal of the first battery string unit 11 is closer to the second edge 102. The polarities of the two ends of the second battery string unit 12 are opposite to those of the two ends of the first battery string unit 11. That is, the polarities of each battery string 110 in the second battery string unit 12 are oriented in the same direction, with the positive terminal facing one end of the second edge 102 and the negative terminal facing one end of the first edge 101. This allows the series busbar 40 to connect the negative terminal of the first battery string unit 11 and the positive terminal of the second battery string unit 12, thereby achieving series connection between the two. The first output busbar 20, the second output busbar 30, and the series busbar 40 all extend along the first direction.

[0060] Please see Figure 2 In some embodiments, the battery strings 110 in the first battery string unit 11 and the second battery string unit 12 each include first battery pieces 1111 located at both ends of the battery string 110 in the second direction.

[0061] The first output busbar 20 is disposed on the back side of the first battery cell 1111 near the first edge 101 in the first battery string unit 11, and a first insulating layer 70 is provided between the first output busbar 20 and the negative electrode solder strip 113 on the first battery cell 1111.

[0062] In this way, the first output busbar 20 can be hidden, increasing the power generation per unit area of ​​the module and improving the aesthetics of the module. At the same time, the first insulating layer 70 can prevent short circuits caused by conductive contact between the first output busbar 20 and the opposite polarity negative electrode solder strip 113.

[0063] Specifically, in this embodiment, the first output busbar 20 is connected to the positive electrode solder strip 112 on the first battery cell 1111 near the first edge 101 of the three battery strings 110 in the first battery string unit 11, while it is isolated from the negative electrode solder strip 113 on the first battery cell 1111 by a first insulating layer 70. In this embodiment, during the manufacturing process, a whole layer of the first insulating layer 70 can be first set at the location where the first output busbar 20 is set, and then the positive electrode solder strip 112 on the first battery cell 1111 can be exposed by making holes in the first insulating layer 70 to achieve the welding of the positive electrode solder strip 112 on the first battery cell 1111 to the first output busbar 20.

[0064] It is easy to understand that the positive electrode solder strip 112 on the first battery cell 1111 near the first edge 101 in the battery string 110 of the first battery string unit 11 is a short solder strip. That is, the positive electrode solder strip 112 on the first battery cell 1111 near the first edge 101 in the battery string 110 of the first battery string unit 10 is the positive output terminal of the battery string 110. The negative electrode solder strip 113 on the first battery cell 1111 near the second edge 102 in the battery string 110 of the first battery string unit 11 is a short solder strip. That is, the negative electrode solder strip 113 on the first battery cell 1111 near the second edge 102 in the battery string 110 of the first battery string unit 10 is the negative output terminal of the battery string 110.

[0065] Similarly, in the second battery string unit 12, the negative electrode solder strip 113 on the first battery cell 1111 near the first edge 101 in the battery string 110 is a short solder strip, that is, the negative electrode solder strip 113 on the first battery cell 1111 near the first edge 101 in the battery string 110 is the negative output terminal of the battery string 110. The positive electrode solder strip 112 on the first battery cell 1111 near the second edge 102 in the battery string 110 is a short solder strip, that is, the positive electrode solder strip 112 on the first battery cell 1111 near the second edge 102 in the battery string 110 is the positive output terminal of the battery string 110.

[0066] Please continue reading. Figure 2 In some embodiments, the second output busbar 30 is disposed on the back side of the first battery cell 1111 near the first edge 101 in the second battery string unit 12, and a second insulating layer 80 is provided between the second output busbar 30 and the positive electrode solder strip 112 on the first battery cell 1111.

[0067] In this way, the second output busbar 30 can be hidden, increasing the power generation per unit area of ​​the module and improving the aesthetics of the module. At the same time, the second insulating layer 80 can prevent short circuits caused by conductive contact between the second output busbar 30 and the opposite polarity positive electrode solder strip 112.

[0068] Specifically, in this embodiment, the second output busbar 30 is connected to the negative electrode solder strip 113 on the first battery cell 1111 near the first edge 101 of the three battery strings 110 in the second battery string unit 12, while it is isolated from the corresponding positive electrode solder strip 112 on the first battery cell 1111 by a second insulating layer 80. In this embodiment, during the manufacturing process, a whole layer of second insulating layer 80 can be first set at the location where the second output busbar 30 is set, and then the negative electrode solder strip 113 on the first battery cell 1111 can be exposed by making holes in the second insulating layer 80 to achieve the welding of the negative electrode solder strip 113 on the first battery cell 1111 to the first output busbar 20.

[0069] Please continue reading. Figure 2 In some embodiments, a series busbar 40 is disposed on the back side of the first battery cell 1111 near the second edge 102 in the first battery string unit 11 and on the back side of the first battery cell 1111 near the second edge 102 in the second battery string unit 12. A third insulating layer 90 is provided between the series busbar 40 and the positive electrode solder strip 112 on the first battery cell 1111 near the second edge 102 in the first battery string unit 11 and the negative electrode solder strip 113 on the first battery cell 1111 near the second edge 102 in the second battery string unit 12.

[0070] In this way, the series busbar 40 can be hidden, increasing the power generation per unit area of ​​the module and improving the aesthetics of the module. At the same time, the third insulation layer 90 can prevent short circuits caused by conductive contact between the second output busbar 30 and the solder strip of opposite polarity.

[0071] Specifically, in such an embodiment, the series busbar 40 is connected to the negative electrode solder strip 113 on the first battery cell 1111 near the second edge 102 of the three battery cells 110 in the first battery cell unit 11, and to the positive electrode solder strip 112 on the first battery cell 1111 near the second edge 102 of the three battery cells 110 in the second battery cell unit 12. At the same time, the series busbar 40 is isolated from the positive electrode solder strip 112 on the first battery cell 1111 near the second edge 102 of the three battery cells 110 in the first battery cell unit 11 and the negative electrode solder strip 113 on the first battery cell 1111 near the second edge 102 of the three battery cells 110 in the second battery cell unit 12 by a third insulating layer 90. In such an embodiment, during the manufacturing process, a third insulating layer 90 can be first set at the location where the series busbar 40 is set. Then, by making holes in the third insulating layer 90, the negative electrode solder strip 113 on the first battery cell 1111 near the second edge 102 in the first battery string unit 11 and the positive electrode solder strip 112 on the first battery cell 1111 near the second edge 102 in the second battery string unit 12 are exposed. This achieves the series connection between the first battery string unit 11 and the second battery string unit 12 while concealing the series busbar 40.

[0072] exist Figure 2 In the example shown, the first output busbar 20, the second output busbar 30, and the series busbar 40 are all hidden on the back of the corresponding first battery cell 1111. It should be noted that in this application, it is also possible that only one or both of the first output busbar 20, the second output busbar 30, and the series busbar 40 are hidden on the back of the first battery cell 1111. There is no specific limitation here, but it is preferable that all the busbars are hidden.

[0073] Please see Figure 3 In some embodiments, the battery strings 110 in the first battery string unit 11 and the second battery string unit 12 each include a first battery piece 1111 located at both ends of the battery string 110 in the second direction and a second battery piece 1112 adjacent to the first battery piece 1111.

[0074] The first output busbar 20 is disposed on the back side of the second battery cell 1112 near the first edge 101 in the first battery string unit 11, and a first insulating strip 120 is provided between the first output busbar 20 and the second battery cell 1112. The first output busbar 20 is connected to the positive electrode solder strip 112 on the first battery cell 1111.

[0075] Thus, by setting the first output busbar 20 on the second battery cell 1112 near the first edge 101 in the first battery string unit 11, and then using a whole first insulating strip 120 to achieve insulation between the first output busbar 20 and the positive electrode solder strip 112 and the negative electrode solder strip 113 on the second battery cell 1112, without the need to make holes in the first insulating strip 120, the manufacturing process can be simplified and the process difficulty reduced.

[0076] Specifically, in such an embodiment, the positive electrode solder strip 112 on the first battery cell 1111 adjacent to the second battery cell 1112 on which the first output busbar 20 is provided can extend to the first output busbar 20 and be soldered to the first output busbar 20 to serve as the positive output terminal of the component.

[0077] Of course, in some embodiments, the first output busbar 20 may also be disposed between the first battery cell 1111 and the second battery cell 1112, and overlap with both. In this case, the first output busbar 20 overlaps with both the first battery cell 1111 and the second battery cell 1112 near the first edge 101 in the first battery string unit 11, and a first insulating strip 120 is provided between the first output busbar 20 and the first battery cell 1111 and the second battery cell 1112. The first output busbar 20 is connected to the positive electrode solder strip 112 on the first battery cell 1111. In this way, the first output busbar 20 can also be hidden.

[0078] Please continue reading. Figure 3 In some embodiments, the second output busbar 30 is disposed on the back side of the second battery cell 1112 near the first edge 101 in the second battery string unit 12 and a second insulating strip 130 is provided between the second battery cell 1112 and the second output busbar 30 is connected to the negative electrode solder strip 113 on the first battery cell 1111.

[0079] Thus, by setting the second output busbar 30 on the second battery cell 1112 near the first edge 101 in the second battery string unit 12, and then using a whole second insulating strip 130 to achieve insulation between the second output busbar 30 and the positive electrode solder strip 112 and the negative electrode solder strip 113 on the second battery cell 1112, the manufacturing process can be simplified and the process difficulty reduced without having to make holes in the second insulating strip 130.

[0080] Specifically, in such an embodiment, the negative electrode solder strip 113 on the first battery cell 1111 adjacent to the second battery cell 1112 on which the second output busbar 30 is provided can extend to the second output busbar 30 and be soldered to the second output busbar 30 to serve as the negative electrode output terminal of the component.

[0081] Of course, in some embodiments, the second output busbar 30 may also be disposed between the first battery cell 1111 and the second battery cell 1112, and overlap with both. In this case, the second output busbar 30 overlaps with both the first battery cell 1111 and the second battery cell 1112 near the first edge 102 in the second battery cell 12, and a second insulating strip 130 is provided between the second output busbar 30 and the first battery cell 1111 and the second battery cell 1112. The second output busbar 30 is connected to the negative electrode solder strip 113 on the first battery cell 1111. In this way, the second output busbar 30 can also be hidden.

[0082] Please continue reading. Figure 3 In some embodiments, the series busbar 40 is disposed on the back side of the second battery cell 1112 near the second edge 102 in the first battery string unit 11 and on the back side of the second battery cell 1112 near the second edge 102 in the second battery string unit 12, and a third insulating strip 140 is provided between the series busbar 40 and the second battery cell 1112. The series busbar 40 is connected to the negative electrode solder strip 113 on the first battery cell 1111 near the second edge 102 in the first battery string unit 11 and the positive electrode solder strip 112 on the first battery cell 1111 near the second edge 102 in the second battery string unit 12.

[0083] Thus, by setting the series busbar 40 on the second battery cell 1112 near the second edge 102 in the first battery string unit 11 and the second battery cell 1112 near the second edge 102 in the second battery string unit 12, and then using a whole third insulating strip 140 to achieve insulation between the series busbar 40 and the positive electrode solder strip 112 and negative electrode solder strip 113 on each second battery cell 1112, without the need to make holes in the third insulating strip 140, the manufacturing process can be simplified and the process difficulty reduced.

[0084] Specifically, in such an embodiment, the negative electrode solder strip 113 on the first battery cell 1111 adjacent to the second battery cell 1112 provided with the series busbar 40 in the first battery string unit 11 can extend to the series busbar 40 and be welded to the series busbar 40, and the positive electrode solder strip 112 on the first battery cell 1111 adjacent to the second battery cell 1112 provided with the series busbar 40 in the second battery string unit 12 can extend to the series busbar 40 and be welded to the series busbar 40, thereby realizing the series connection between the first battery string unit 11 and the second battery string unit 12.

[0085] Of course, in some embodiments, the series busbar 40 can also be disposed between the first battery cell 1111 and the second battery cell 1112, and overlap with both. In this case, the series busbar 40 overlaps with both the first battery cell 1111 and the second battery cell 1112 near the second edge 102 in the first battery string unit 11, and also overlaps with both the first battery cell 1111 and the second battery cell 1112 near the second edge 102 in the second battery string unit 12. A third insulating strip 140 is provided between the series busbar 40 and the first battery cell 1111 and the second battery cell 1112. The series busbar 40 is connected to the negative electrode solder strip 113 on the first battery cell 1111 near the second edge 102 in the first battery string unit 11 and the positive electrode solder strip 112 on the first battery cell 1111 near the second edge 102 in the second battery string unit 12. In this way, the series busbar 40 can also be hidden.

[0086] exist Figure 3 In the example shown, the first output bus 20, the second output bus 30, and the series bus 40 are all hidden on the back of the corresponding second battery cell 1112. It should be noted that in this application, only one or both of the first output bus 20, the second output bus 30, and the series bus 40 may be hidden on the back of the second battery cell 1112. There is no specific limitation here, but it is preferable that all the busbars are hidden.

[0087] Please see Figures 4-6 ( Figures 4-6 (Components such as solder strips and insulating layers are not shown). In some embodiments, in at least one battery string 110 of the first battery string unit 11 and the second battery string unit 12, two adjacent battery cells 111 partially overlap. That is, in the battery string 110, two adjacent battery cells 111 arranged in series along the second direction have an overlapping portion in the second direction.

[0088] In this way, the spacing between the cells 111 within the battery string 110 can be eliminated, thereby increasing the unit light-receiving area of ​​the back-contact battery assembly 100.

[0089] like Figure 4 As shown, in Figure 4 In the embodiment shown, all adjacent battery cells 111 in all battery strings 110 partially overlap in the second direction.

[0090] In some embodiments, the length of the overlapping portion of two adjacent battery cells 111 in the second direction is 0.2mm-0.5mm, such as any value between 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm or 0.2mm-0.5mm.

[0091] Please see Figure 5 In some embodiments, in the first battery string unit 11, two adjacent battery strings 110 partially overlap in the first direction, and in the second battery string unit 12, two adjacent battery strings 110 partially overlap in the first direction. That is, in the first battery string unit 11, two adjacent battery strings 110 arranged along the first direction have an overlapping portion in the first direction, and in the second battery string unit 12, two adjacent battery strings 110 arranged along the first direction have an overlapping portion in the first direction.

[0092] In this way, the spacing between the battery strings 110 in the first battery string unit 11 and the second battery string unit 12 can be eliminated, thereby increasing the unit light-receiving area of ​​the back contact battery assembly 100.

[0093] In some embodiments, the length of the overlapping portion of two adjacent battery strings 110 in the first battery string unit 11 in the first direction is 0.2mm-0.5mm, for example, any value between 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm or 0.2mm-0.5mm.

[0094] In some embodiments, the length of the overlapping portion of two adjacent battery strings 110 in the second battery string unit 12 in the first direction is 0.2mm-0.5mm, for example, any value between 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm or 0.2mm-0.5mm.

[0095] Of course, it should be noted that in some possible embodiments, adjacent battery strings 110 may only partially overlap in the first direction within the first battery string unit 11. In other possible embodiments, adjacent battery strings 110 may only partially overlap in the first direction within the second battery string unit 12.

[0096] Please see Figure 6 In some embodiments, the first battery string unit 11 and the second battery string unit 12 partially overlap in a first direction. That is, in the first battery string unit 11 and the second battery string unit 12, the battery string 110 closest to the second battery string unit 12 in the first battery string unit 11 and the battery string 110 closest to the first battery string unit 11 in the second battery string unit 12 partially overlap in a first direction.

[0097] In this way, the gap between adjacent first battery string units 11 and second battery string units 12 can be eliminated, thereby increasing the unit light-receiving area of ​​the back contact battery assembly 100.

[0098] It is not difficult to understand that, as Figure 6 As shown, when the first battery string unit 11 and the second battery string unit 12 partially overlap, the busbars can be completely hidden when the first output busbar 20, the second output busbar 30 and the series busbar 40 are located on the back of the battery cell 111.

[0099] In the description of this specification, the use of terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., refers to specific features, structures, materials, or characteristics described in connection with the embodiments or examples, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0100] Furthermore, the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A back-contact battery assembly, characterized in that, include: The first battery string unit and the second battery string unit are arranged along a first direction. The first battery string unit includes three battery strings arranged along the first direction and connected in parallel with each other. The second battery string unit also includes three battery strings arranged along the first direction and connected in parallel with each other. Each battery string includes multiple battery cells arranged along a second direction and connected in series. The battery cells are sliced ​​batteries formed by cutting or splitting back-contact battery cells into three equal parts. The first direction and the second direction intersect. A first output bus, a second output bus, and a series bus. The first output bus is connected to the positive terminal of the first battery string unit, the second output bus is connected to the negative terminal of the second battery string unit, and the series bus is connected to the negative terminal of the first battery string unit and the positive terminal of the second battery string unit. and A bypass diode, one end of which is connected to the first output busbar and the other end of which is connected to the second output busbar; At least one of the first output busbar, the second output busbar, and the series busbar is disposed on the back side of the battery cell.

2. The back contact battery assembly according to claim 1, characterized in that, In the battery string, multiple battery cells are connected in series via positive and negative electrode solder strips. The back contact battery assembly has a first edge and a second edge opposite to each other in the second direction. The positive terminal of the first battery string unit and the negative terminal of the second battery string unit are located near the first edge, and the negative terminal of the first battery string unit and the positive terminal of the second battery string unit are located near the second edge. The first output busbar and the second output busbar are located near the first edge, and the series busbar is located near the second edge.

3. The back contact battery assembly according to claim 2, characterized in that, The battery strings in both the first battery string unit and the second battery string unit include first battery cells located at both ends of the battery string in the second direction; The first output busbar is disposed on the back of the first battery cell near the first edge in the first battery string unit, and a first insulating layer is provided between the first output busbar and the negative electrode solder strip on the first battery cell; and / or The second output busbar is disposed on the back of the first battery cell near the first edge in the second battery string unit, and a second insulating layer is provided between the second output busbar and the positive electrode solder strip on the first battery cell; and / or The series busbar is disposed on the back side of the first battery cell near the second edge in the first battery string unit and on the back side of the first battery cell near the second edge in the second battery string unit. A third insulating layer is provided between the series busbar and the positive electrode solder strip on the first battery cell near the second edge in the first battery string unit and the negative electrode solder strip on the first battery cell near the second edge in the second battery string unit.

4. The back contact battery assembly according to claim 2, characterized in that, The battery strings in both the first battery string unit and the second battery string unit include first battery cells located at both ends of the battery string in the second direction and second battery cells adjacent to the first battery cells; The first output busbar is disposed on the back of the second battery cell near the first edge in the first battery string unit and is provided with a first insulating strip between it and the second battery cell. The first output busbar is connected to the positive electrode solder strip on the first battery cell; and / or The second output busbar is disposed on the back of the second battery cell near the first edge in the second battery string unit, and a second insulating strip is provided between the second output busbar and the second battery cell. The second output busbar is connected to the negative electrode solder strip on the first battery cell; and / or The series busbar is disposed on the back of the second battery cell near the second edge in the first battery string unit and on the back of the second battery cell near the second edge in the second battery string unit, and a third insulating strip is provided between the series busbar and the second battery cell. The series busbar is connected to the negative electrode solder strip on the first battery cell near the second edge in the first battery string unit and the positive electrode solder strip on the first battery cell near the second edge in the second battery string unit.

5. The back contact battery assembly according to claim 2, characterized in that, The battery strings in both the first battery string unit and the second battery string unit include first battery cells located at both ends of the battery string in the second direction and second battery cells adjacent to the first battery cells; The first output busbar overlaps with both the first and second battery cells near the first edge in the first battery string unit, and a first insulating strip is provided between the first output busbar and the first and second battery cells. The first output busbar is connected to the positive electrode solder strip on the first battery cell; and / or The second output busbar overlaps with both the first and second battery cells near the first edge in the second battery string unit, and a second insulating strip is provided between the second output busbar and the first and second battery cells. The second output busbar is connected to the negative electrode solder strip on the first battery cell; and / or The series busbar overlaps with both the first and second battery cells near the second edge in the first battery string unit, and also overlaps with both the first and second battery cells near the second edge in the second battery string unit. A third insulating strip is provided between the series busbar and the first and second battery cells. The series busbar is connected to the negative electrode solder strip on the first battery cell near the second edge in the first battery string unit and the positive electrode solder strip on the first battery cell near the second edge in the second battery string unit.

6. The back contact battery assembly according to claim 1, characterized in that, In at least one of the battery strings in the first battery string unit and the second battery string unit, two adjacent battery cells partially overlap.

7. The back contact battery assembly according to claim 6, characterized in that, The length of the overlapping portion of two adjacent battery cells in the second direction is 0.2mm-0.5mm.

8. The back contact battery assembly according to claim 1, characterized in that, In the first battery string unit, two adjacent battery strings partially overlap in the first direction; and / or In the second battery string unit, two adjacent battery strings partially overlap in the first direction.

9. The back contact battery assembly according to claim 1, characterized in that, In the first battery string unit, two adjacent battery strings partially overlap in the first direction, and the length of the overlapping portion of the two adjacent battery strings in the first direction is 0.2mm-0.5mm; and / or In the second battery string unit, two adjacent battery strings partially overlap in the first direction, and the length of the overlapping portion of the two adjacent battery strings in the first direction is 0.2mm-0.5mm.

10. The back contact battery assembly according to claim 1, characterized in that, The first battery string unit and the second battery string unit partially overlap in the first direction.

11. A photovoltaic system, characterized in that, Includes the back contact battery assembly as described in any one of claims 1-10.

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