A back-contact battery module and photovoltaic system

Abstract

This utility model applies to the field of photovoltaic technology, providing a back-contact battery module and photovoltaic system. The back-contact battery module includes: a plurality of battery strings, each battery string including a plurality of battery cells, each battery cell including a first battery cell located at one end of the battery string and a second battery cell adjacent to the first battery cell. The first battery cell includes a first edge and a second edge, the first edge being located further away from the second battery cell than the second edge; an insulating strip located on the back of the battery cell or in the gap between adjacent battery cells; and a busbar disposed on the insulating strip. The back of the first battery cell has a first solder strip, the first solder strip including a main body and a bent portion connected to the main body. The connection between the bent portion and the main body is located near the first edge, and the bent portion is bent relative to the main body toward the direction of the busbar and connected to the busbar. The insulating strip of the back-contact battery module of this utility model does not require openings, which can reduce the processing difficulty of the battery module.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a back contact battery module and photovoltaic system. Background Technology

[0002] Solar cells, also known as photovoltaic cells, are devices that directly convert light energy into direct current using the photovoltaic effect. In related technologies, multiple solar cells are connected in series and then laminated to form a solar module. The resulting solar module typically includes a back glass or backsheet, a first encapsulating film, a string of cells, a second encapsulating film, and a front glass, all stacked sequentially.

[0003] In related technologies, edge busbars are usually placed in the edge area of ​​the battery module, while center busbars are usually placed in the middle area. Both require a certain amount of space to be reserved on the module, which reduces the effective light-receiving area of ​​the module, affects the conversion efficiency, and also affects the aesthetics of the module.

[0004] In existing technologies, to address the aforementioned issues, busbars and insulating strips are typically positioned on the back of the end cells of the battery string. An insulating strip is placed between the end cell and the busbar, and a hole is drilled in the insulating strip corresponding to the position of the first solder strip. This allows the first solder strip on the end cell to make electrical contact with the busbar, while other polarity solder strips and grid lines on the end cell are insulated from the busbar by the insulating strip. However, the hole-drilling process for the insulating strip is complex and requires high precision, leading to significant difficulties in battery module manufacturing and impacting production costs and efficiency. Utility Model Content

[0005] This utility model provides a battery assembly that aims to solve the problem that existing battery assemblies require holes in the insulating strip, which makes the battery assembly difficult to process and affects the production cost and efficiency of the battery assembly.

[0006] This invention is implemented by providing a back contact battery assembly, comprising:

[0007] A plurality of battery strings, wherein the battery strings include a plurality of battery cells connected in series along a first direction, wherein the plurality of battery cells in the battery strings include a first battery cell disposed at the end of the battery string and a second battery cell adjacent to the first battery cell, wherein the first battery cell includes a first edge and a second edge disposed opposite to each other along the first direction, and the first edge is disposed further away from the second battery cell than the second edge.

[0008] An insulating strip extending along a second direction, the insulating strip being located on the back of at least one of the battery cells or in the gap between two adjacent battery cells, the first direction intersecting the second direction; and

[0009] A busbar is disposed on the insulating strip and extends along the second direction. The back of the first battery cell is provided with a first solder strip connected to the busbar. The first solder strip includes a main body portion located on the first battery cell and a bent portion connected to the main body portion. The connection between the bent portion and the main body portion is disposed near the first edge. The bent portion is bent relative to the main body portion toward the direction of the busbar and is connected to the busbar.

[0010] Preferably, the back of the first battery cell is further provided with a second solder strip, the first solder strip and the second solder strip are arranged alternately along the second direction, and the second solder strip connects the first battery cell and the second battery cell.

[0011] Preferably, the insulating strip and the busbar are located on the back of the first battery cell, and the insulating strip is located on the first solder strip and the second solder strip.

[0012] Preferably, the insulating strip and the busbar are located on the back of the second battery cell. The back of the second battery cell is provided with a third welding strip and a fourth welding strip arranged alternately along the second direction. The third welding strip corresponds one-to-one with the first welding strip, and the fourth welding strip corresponds one-to-one with the second welding strip and is connected to it. The insulating strip is located on the third welding strip and the fourth welding strip.

[0013] Preferably, the insulating strip and the busbar are located in the gap between the first battery cell and the second battery cell, and the insulating strip is located on the second solder strip.

[0014] Preferably, the bent portion bends relative to the main body portion toward the busbar at a position near the first edge, and the bent portion is at least partially connected to the side of the busbar facing away from the insulating strip.

[0015] Preferably, the angle between the orthographic projection of the bent portion on the first battery cell and the orthographic projection of the main body portion on the first battery cell is 0° to 80°.

[0016] Preferably, the ratio of the overlap length between the bent portion and the busbar to the total length of the bent portion is 40% to 100%.

[0017] Preferably, the bent portion includes a first end connected to the main body and a second end disposed away from the main body, the second end being connected to the busbar, and the second end not extending beyond the edge of the busbar near the second battery cell.

[0018] Preferably, the connection between the bent portion and the main body portion is located on the outer side of the first edge.

[0019] Preferably, the main body and the bent portion are connected by an arc-shaped connecting portion, which is located on the outside of the first edge.

[0020] Preferably, the radius of the arc of the arc-shaped connection is 0.3 to 1.2 mm.

[0021] Preferably, the distance from the busbar to the first edge is 1 to 3 millimeters.

[0022] Preferably, adjacent battery cells within the battery string are partially overlapped.

[0023] Preferably, the projected length of the overlapping area of ​​adjacent battery cells in the battery string along the first direction is 0.1 to 1 mm.

[0024] Preferably, the dimension of the insulating strip along the first direction is greater than the dimension of the busbar along the first direction, and the dimension of the insulating strip along the second direction is greater than the dimension of the busbar along the second direction.

[0025] This invention provides a photovoltaic system, including the aforementioned back contact battery assembly.

[0026] This utility model provides a back-contact battery module by configuring the first solder strip on the first cell located at the end of the battery string as a main body portion on the back of the first cell and a bent portion connected to the main body portion. The connection between the bent portion and the main body portion is located on the outer side of the first edge. The bent portion is bent relative to the main body portion towards the direction of the busbar and is connected to the busbar. By bending the first solder strip to form the bent portion and connecting the bent portion to the busbar, the connection between the first solder strip and the busbar can be achieved without opening holes in the insulating strip. This reduces the processing difficulty of the battery module, lowers the production cost of the battery module, and improves the production efficiency of the battery module. Moreover, it avoids the problem of short circuits caused by excessively large openings in the insulating strip, which could lead to contact between the busbar and the grid lines or solder strips on the cell, greatly improving the production yield of the photovoltaic module. Furthermore, it avoids the opening of the insulating strip from damaging the fixing film covering the first solder strip, thereby ensuring that the first solder strip is stably fixed to the first cell and guaranteeing the structural stability of the battery module. Attached Figure Description

[0027] Figure 1 A plan view of a back contact battery assembly provided for an embodiment of this utility model;

[0028] Figure 2 A schematic diagram of the structure of a series battery string of a back contact battery assembly provided in an embodiment of this utility model;

[0029] Figure 3A schematic diagram of the structure of a parallel battery string group of a back contact battery assembly provided in an embodiment of this utility model;

[0030] Figure 4 A schematic diagram of a partial structure of a back contact battery assembly provided in an embodiment of this utility model;

[0031] Figure 5 for Figure 4 A magnified view of part A in the middle;

[0032] Figure 6 This is a partial schematic diagram of another embodiment of a back contact battery assembly provided by this utility model.

[0033] Figure 7 This is a partial schematic diagram of yet another embodiment of a back contact battery assembly provided by this utility model. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Examples of 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 the present utility model, and should not be construed as limiting the present utility model. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0035] In the description of this utility model, it should be understood that the terms "upper", "lower", "back", "front", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0036] In this invention, unless otherwise explicitly 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.

[0037] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. 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 the invention. 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, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0038] Please refer to Figures 1-5 The present invention provides a back contact battery assembly 100, comprising:

[0039] A plurality of battery strings 1, each battery string 1 including a plurality of battery pieces 11 connected in series along a first direction Y, each battery piece 11 including a first battery piece 111 disposed at the end of the battery string 1 and a second battery piece 112 adjacent to the first battery piece 111, each first battery piece 111 including a first edge 1111 and a second edge 1112 disposed opposite to each other along the first direction Y, the first edge 1111 being disposed further away from the second edge 1112 than the second edge 1112, the back of the first battery piece 111 having a first solder strip 21 and a second solder strip 22 arranged alternately along the second direction X, the second solder strip 22 connecting the first battery piece 111 and the second battery piece 112;

[0040] An insulating strip 3 is disposed on the back side of the first battery cell 111. The insulating strip 3 is located on the back side of at least one battery cell 11 or in the gap between two adjacent battery cells 11. The insulating strip 3 extends along the second direction X, and the first direction Y intersects the second direction X.

[0041] A busbar 4 is disposed on the insulating strip 3 and extends along the second direction X. A first solder strip 21 connected to the busbar 4 is provided on the back of the first battery cell 111. The first solder strip 21 includes a main body 211 located on the back of the first battery cell 111 and a bent portion 212 connected to the main body 211. The connection between the bent portion 212 and the main body 211 is located near the first edge 1111. The bent portion 212 is bent relative to the main body 211 toward the direction where the busbar 4 is located, and the bent portion 212 is connected to the busbar 4.

[0042] In this embodiment of the invention, the battery assembly 100 may include a plurality of battery strings 1 and a plurality of busbars 4. Each battery string 1 includes a plurality of battery cells 11 connected in series along a first direction Y, and the plurality of battery cells 11 in each battery string 1 are connected in series by solder strips. Specifically, the battery cells 11 are back-contact solar cells.

[0043] In this embodiment of the invention, the insulating strip 3 can be disposed on the back side of the battery cell 11, that is, both the busbar 4 and the insulating strip 3 are on the back side of the battery cell 11. For example, the busbar 4 and the insulating strip 3 can be disposed on the back side of the first battery cell 111, and the busbar 4 and the insulating strip 3 can also be disposed on the back side of the second battery cell 112. Of course, the busbar 4 and the insulating strip 3 can also be disposed on the back side of other battery cells 11 besides the first battery cell 111 and the second battery cell 112. Figures 1-5 The schematic diagram shows that the busbar 4 and the insulating strip 3 are located on the back of the first battery cell 11; Figure 6 The schematic diagram shows the busbar 4 and insulating strip 3 located on the back of the second battery cell 11.

[0044] In addition, such as Figure 7 As shown, a gap 113 can be provided between two adjacent battery cells 11 in the battery string 1, that is, there is a gap between two adjacent battery cells 11 in the battery string 1. The busbar 4 and the insulating strip 3 can be set at the gap 113 between two adjacent battery cells 11. For example, the busbar 4 and the insulating strip 3 can be set at the gap 113 between the first battery cell 111 and the second battery cell 112.

[0045] In this embodiment of the present invention, the connection between the bent portion 212 and the main body 211 is also the bending position of the first welding strip 21. The first welding strip 21 extends to the outside of the first edge 1111, and the first welding strip 21 bends near the first edge 1111 of the first battery cell 111 to form the bent portion 212. The connection between the bent portion 212 and the main body 211 is located near the first edge 1111 of the first battery cell 111. That is, the connection between the bent portion 212 and the main body 211 is adjacent to the first edge 1111 of the first battery cell 111. Alternatively, the connection between the bent portion 212 and the main body 211 can be located on the first battery cell 111 and near the first edge 1111, or it can be located on the outside of the first battery cell 111 and near the first edge 1111.

[0046] This utility model provides a back-contact battery assembly by configuring the first solder strip 21 on the first battery cell 111 as including a main body 211 located on the back of the first battery cell 111 and a bent portion 212 connected to the main body 211. The connection between the bent portion 212 and the main body 211 is located near the first edge 1111 of the first battery cell 111. The bent portion 212 is bent relative to the main body 211 towards the direction of the busbar 3, and the bent portion 212 is connected to the busbar 4. It can be understood that the first solder strip 21 extends outward to the outside of the first edge 1111 of the first battery cell 111, and then the first solder strip 21 is bent towards the direction of the busbar 4, so that the bent portion 212 is connected to the busbar 4, realizing the connection between the first solder strip 21 and the busbar 4. The connection of the first solder strip 21 to the busbar 4 is simple, achieved by bending and connecting the first solder strip 21 to the busbar 4. The insulating strip 3 does not require openings to connect the first solder strip 21 to the busbar 4, reducing the processing difficulty of the battery module 100, lowering production costs, and improving production efficiency. Furthermore, it avoids the problem of short circuits caused by excessively large openings in the insulating strip 3, which could lead to contact between the busbar 4 and the irregular grid lines or solder strips. Additionally, since the insulating strip 3 does not require openings, it avoids damaging the fixing film covering the first solder strip 21, maintaining the integrity of the fixing film and ensuring the first solder strip 21 remains stably fixed to the first battery cell 111, thus guaranteeing the structural stability of the battery module 100. In this embodiment, the length of the first solder strip 21 is greater than the dimension of the first battery cell 111 along the first direction Y. In practical applications, along the first direction Y, the first solder strip 21 extends beyond the edge of the first battery cell 111. The portion of the first solder strip 21 extending beyond the edge of the first battery cell 111 bends towards the direction of the busbar 4 to form a bent portion 212, and the bent portion 212 contacts the busbar 4, thus achieving an electrical connection between the busbar 4 and the first solder strip 21. Specifically, the main body 211 of the first solder strip 21 is a straight line arranged along the first direction Y, and the bent portion 212 can also be a straight line.

[0047] As an embodiment of the present invention, the back side of the first battery cell 111 is also provided with a second welding strip 22. The first welding strip 21 and the second welding strip 22 are arranged alternately along the second direction X, and the second welding strip 22 connects the first battery cell 111 and the second battery cell 112.

[0048] In the battery string 1, a plurality of battery cells 11 include a first battery cell 111 located at one end of the battery string 1, and a second battery cell 112 adjacent to the first battery cell 111. Specifically, the ends of the battery string 1 refer to the two ends of the battery string 1 in the first direction Y, that is, at least one of the battery cells located at the two ends of the battery string 1 is a first battery cell 111. The back of the first battery cell 111 is provided with a first solder strip 21 and a second solder strip 22 arranged alternately along the second direction X, and the polarities of the first solder strip 21 and the second solder strip 22 are opposite. The first solder strip 21 is the end output terminal of the battery string 1, used to connect to the bus bar 4. The second solder strip 22 is used to connect the first battery cell 111 and the second battery cell 112.

[0049] like Figures 1-5 As shown in one embodiment of the present invention, the insulating strip 3 and the busbar 4 are located on the back side of the first battery cell 111, and the insulating strip 3 is located on the first solder strip 21 and the second solder strip 22. In this embodiment of the present invention, the busbar 4 is disposed on the back side of the first battery cell 111, and the busbar 4 is connected to the first solder strip 21 to realize the current output of the battery string 1. The busbar 4 extends along a second direction X, which intersects with a first direction Y. The first direction Y is the stringing direction of the battery cells 11 in each battery string 1, and the second direction X is preferably perpendicular to the first direction Y. Specifically, the first direction Y and the second direction X can be the longitudinal direction and the transverse direction of the battery assembly 100, respectively. Of course, in some possible embodiments, the second direction X may not be perpendicular to the first direction Y, and this is not limited here. The busbar 4 can be an end busbar of the battery assembly 100 or a middle busbar of the battery assembly.

[0050] In this embodiment of the invention, the insulating strip 3 is disposed on the back side of the first battery cell 111. The insulating strip 3 is used to insulate and isolate the busbar 4 from the second solder strip 22 and the irregular grid lines on the first battery cell 111, preventing the busbar 4 from contacting the second solder strip 22 and the irregular grid lines on the first battery cell 111, and preventing short circuits caused by contact between the busbar 4 and the second solder strip 22 or the irregular grid lines on the first battery cell 111. The extending direction of the insulating strip 3 is the same as the extending direction of the busbar 4, and both the insulating strip 3 and the busbar 4 extend along the second direction X.

[0051] Please refer to Figure 4 and Figure 5 As an embodiment of the present invention, the first battery cell 111 includes a first edge 1111 and a second edge 1112 disposed opposite to each other along the first direction Y. The first edge 1111 is disposed away from the second battery cell 112 relative to the second edge 1112. The bent portion 212 extends to the outside of the first edge 1111 and bends relative to the main body portion 211 toward the busbar 4 so that the bent portion 212 is connected to the busbar 4.

[0052] In this embodiment, before the bent portion 212 is connected to the busbar 4, a portion of the bent portion 212 extends along the first direction Y to the outer side of the first edge 1111. The bent portion 212 bends relative to the main body 211 toward the busbar 4, and the bent portion 212 contacts the busbar 4, thereby achieving an electrical connection between the first solder strip 21 and the busbar 4. Figure 4 and Figure 5 The dotted line portion of the main body 211 is the part of the main body 211 covered by the insulating strip 1.

[0053] As an embodiment of the present invention, the bent portion 212 is bent toward the busbar 4 relative to the main body portion 211 at a position near the first edge 1111, and the bent portion 212 is at least partially connected to the side of the busbar 4 away from the insulating strip 3.

[0054] In this embodiment, the bent portion 212 overlaps the side of the busbar 4 facing away from the insulating strip 3, which facilitates the processing and forming of the bent portion 212 and ensures stable contact between the bent portion 212 and the busbar 4. Of course, the bent portion 212 can also partially connect to the side surface of the busbar 4, that is, the bent portion 212 can wrap around the side surface of the busbar 4, which can further improve the contact reliability between the bent portion 212 and the busbar 4.

[0055] As an embodiment of the present invention, the orthographic projection of the bent portion 212 on the first battery cell 111 does not overlap with the orthographic projection of the main body portion 211 on the first battery cell 111.

[0056] In this embodiment, the orthographic projection of the bent portion 212 on the first battery cell 111 does not overlap with the orthographic projection of the main body portion 211 on the first battery cell 111. That is, the bent portion 212 and the main body portion 211 do not overlap in the thickness direction of the busbar 4, which avoids the battery assembly 100 being too thick at the position of the main body portion 211, making the thickness distribution of the battery assembly 100 more uniform and reducing the risk of microcracks in the lamination process of the battery assembly 100.

[0057] As an embodiment of the present invention, the angle B between the orthographic projection of the bent portion 212 on the first battery cell 111 and the orthographic projection of the main body portion 211 on the first battery cell 111 is 0° to 80°.

[0058] In this embodiment, the orthographic projection of the bent portion 212 on the first battery cell 111 is the projection of the bent portion 212 onto the back surface of the first battery cell 111 along a direction perpendicular to the first battery cell 111. The orthographic projection of the main body portion 211 on the first battery cell 111 is the projection of the main body portion 211 onto the back surface of the first battery cell 111 along a direction perpendicular to the first battery cell 111. The angle between the orthographic projection of the bent portion 212 on the first battery cell 111 and the orthographic projection of the main body portion 211 on the first battery cell 111 is 0° to 80°. When the bent portion 212 on the first battery cell 111... When the angle between the orthographic projection of the bent portion 212 on the first battery cell 111 and the orthographic projection of the main body 211 on the first battery cell 111 is 0°, the orthographic projection of the bent portion 212 on the first battery cell 111 overlaps with the orthographic projection of the main body 211 on the first battery cell 111. When the angle between the orthographic projection of the bent portion 212 on the first battery cell 111 and the orthographic projection of the main body 211 on the first battery cell 111 is greater than 0° and less than 80°, the orthographic projection of the bent portion 212 on the first battery cell 111 does not overlap with the orthographic projection of the main body 211 on the first battery cell 111. By controlling the angle between the orthographic projection of the bent portion 212 on the first battery cell 111 and the orthographic projection of the main body 211 on the first battery cell 111 to be between 0° and 80°, a good overlap between the bent portion 212 and the busbar 4 can be ensured. Preferably, the angle between the orthographic projection of the bent portion 212 on the first battery cell 111 and the orthographic projection of the main body portion 211 on the first battery cell 111 is 30° to 60°, which allows the bent portion 212 to overlap well with the busbar 4. Moreover, the bent portion 212 and the main body portion 211 do not overlap in the thickness direction of the busbar 4, which can reduce the risk of microcracks in the battery cell 11 during the lamination process of the battery assembly 100.

[0059] As an embodiment of the present invention, the bending portion 212 includes a first end 2121 connected to the main body portion 211 and a second end 2122 disposed away from the main body portion 211. The second end 2122 is connected to the busbar 4, and the second end 2122 does not extend beyond the edge of the busbar 4 near the second battery cell 112.

[0060] In this embodiment, the second end 2122 is controlled not to exceed the edge of the busbar 4 near the second battery cell 112, so as to avoid the bent portion 212 and the busbar 4 exceeding the edge of the busbar 4 near the second battery cell 112. This can improve the isolation effect between the bent portion 212 and the second solder strip 22 and the irregular grid line below the busbar 4, and reduce the short circuit risk between the bent portion 212 and the second solder strip 22 and the irregular grid line below the busbar 4.

[0061] As one embodiment of the present invention, the ratio of the overlap length of the bent portion 212 and the busbar 4 to the total length of the bent portion 212 is 40% to 100%.

[0062] In this embodiment, the ratio of the overlap length between the bent portion 212 and the busbar 4 to the total length of the bent portion 212 is controlled to be 40% to 100%. This avoids the overlap length between the bent portion 212 and the busbar 4 being too small, ensuring a good overlap between the bent portion 212 and the busbar 4 and achieving good electrical contact between them. The total length of the bent portion 212 is the distance from the first end 2121 to the second end 2122.

[0063] As an embodiment of the present invention, the connection between the bent portion 212 and the main body portion 211 is located on the outer side of the first edge 1111.

[0064] In this embodiment, the connection between the bent portion 212 and the main body portion 211 is located on the outside of the first edge 1111, which facilitates the bending of the bent portion 212 and prevents the first solder strip 21 from falling off the first battery cell 111, thus ensuring a stable connection between the first solder strip 21 and the first battery cell 111.

[0065] As an embodiment of the present invention, the main body 211 and the bent part 212 are connected by an arc-shaped connecting part 213, which is located on the outside of the first edge 1111.

[0066] In this embodiment, the arc-shaped connecting part 213 is specifically an arc-shaped structure. The main body 211 and the bent part 212 are connected by the arc-shaped connecting part 213, which can prevent the bent part 212 from breaking at the connection between the bent part 212 and the main body 211, and can reduce the stress at the connection between the bent part 212 and the main body 211.

[0067] As one embodiment of this utility model, the arc radius of the arc-shaped connecting part 213 is 0.3 to 1.2 mm.

[0068] In this embodiment, the radius of the arc of the arc-shaped connecting part 213 is controlled to be 0.3 to 1.2 mm, which can further prevent the connection between the bent part 212 and the main body 211 from breaking and further reduce the stress at the connection between the bent part 212 and the main body 211.

[0069] As an embodiment of this utility model, the distance D1 from the busbar 4 to the first edge 1111 is 1 to 3 millimeters.

[0070] In this embodiment, when the busbar 4 is disposed on the first battery cell 111, the distance from the busbar 4 to the first edge 1111 is 1 to 3 millimeters. This avoids the distance from the busbar 4 to the first edge 1111 being too large or too small. A distance that is too small can easily lead to the first battery cell 111 cracking, while a distance that is too large would require a longer first solder strip 21, thus reducing production costs. Of course, in some embodiments, the distance from the busbar 4 to the first edge 1111 can be less than 1 millimeter or greater than 3 millimeters.

[0071] In one embodiment of this utility model, adjacent battery cells 11 within the battery string 1 are partially overlapped.

[0072] In this embodiment, there is no spacing between adjacent cells 11 in the battery string 1, and the adjacent cells 11 in the battery string 1 have overlapping areas, which can increase the proportion of cell area on the front of the battery module and improve the power generation efficiency of the module.

[0073] As an embodiment of the present invention, the projection length of the overlapping area of ​​adjacent battery cells 11 in the battery string 1 along the first direction Y is 0.1 to 1 mm.

[0074] In this embodiment, the projection length of the overlapping area of ​​adjacent battery cells 11 in the battery string 1 along the first direction Y is controlled to be 0.1 to 1 mm. This can prevent the length of the overlapping area of ​​adjacent battery cells 11 from being too large or too small, thus achieving a gapless relationship between adjacent battery cells 11 in the battery string 1, reducing the area of ​​the non-battery cell area on the front of the battery module 100, increasing the area ratio of battery cells 11 on the front of the battery module 100, and improving the power generation efficiency of the battery module 100. Moreover, it can prevent the overlapping area of ​​adjacent battery cells 11 from being too large, thus ensuring a good power generation efficiency for each battery cell 11.

[0075] As one embodiment of this utility model, the dimension of the insulating strip 3 along the first direction Y is greater than the dimension of the busbar 4 along the first direction Y, and the dimension of the insulating strip 3 along the second direction X is greater than the dimension of the busbar 4 along the second direction X.

[0076] In this embodiment, the dimension of the insulating strip 3 along the first direction Y is greater than the dimension of the busbar 4 along the first direction Y, and the dimension of the insulating strip 3 along the second direction X is greater than the dimension of the busbar 4 along the second direction X. This can be understood as the width of the insulating strip 3 being greater than the width of the busbar 4, and the length of the insulating strip 3 being greater than the length of the busbar 4. This allows the insulating strip 3 to better isolate the busbar 4 from the second solder strip 22 and grid lines on the first battery cell 111, further reducing the risk of short circuits. Of course, the dimensions of the insulating strip 3 and the busbar 4 can also be equal, that is, the edges of the insulating strip 3 and the busbar 4 can be flush. Alternatively, the insulating strip 3 can also be flush with the edge of the battery cell 11.

[0077] like Figure 6 As shown, in another embodiment of this utility model, the insulating strip 3 and the busbar 4 are located on the back side of the second battery cell 112. The back side of the second battery cell 112 is provided with a third welding strip 23 and a fourth welding strip 24 arranged alternately along the second direction X. The third welding strip 23 corresponds one-to-one with the first welding strip 21, and the fourth welding strip 24 corresponds one-to-one with the second welding strip 22 and is connected to it. The insulating strip 3 is located on the third welding strip 23 and the fourth welding strip 24. The fourth welding strip 24 and the second welding strip 22 can be an integral structure or separate structures connected to form an integral structure.

[0078] In this embodiment, the insulating strip 3 is disposed on the back side of the second battery cell 112, and the busbar 4 is located on the insulating strip 3. The busbar 4 is insulated from the third solder strip 23 and the fourth solder strip 24 and the irregular grid lines on the second battery cell 112 by the insulating strip 3. The bent portion 212 of the first solder strip 21 extends towards the second battery cell 112, and the bent portion 212 extends above the busbar 4 and connects with the busbar 4. In this embodiment, a gap may or may not be provided between two adjacent battery cells 11 within the battery string 1.

[0079] In this embodiment, the insulating strip 3 and the busbar 4 are disposed on the back of the second battery cell 112, and the first welding strip 21 is bent and connected to the busbar 4. The insulating strip 3 does not need to be opened to connect the first welding strip 21 to the busbar 4, which can reduce the processing difficulty of the battery assembly 100.

[0080] like Figure 7 As shown, in another embodiment of the present invention, the insulating strip 3 and the busbar 4 are located at the gap 113 between the first battery cell 111 and the second battery cell 112, and the insulating strip 3 is located on the second welding strip 22.

[0081] In this embodiment, a gap 113 is provided between two adjacent battery cells 11 in the battery string 1, that is, there is a gap between two adjacent battery cells 11 in the battery string 1. The busbar 4 and the insulating strip 3 can be set at the gap position between two adjacent battery cells 11.

[0082] In this embodiment, the busbar 4 and the insulating strip 3 can be positioned at the gap 113 between the first battery cell 111 and the second battery cell 112. The bent portion 212 of the first solder strip 21 extends into the gap 113 between the first battery cell 111 and the second battery cell 112, and extends above the busbar 4 and connects to it. The insulating strip 3 is located above the second solder strip 22, and the busbar 4 is located above the insulating strip 3. The busbar 4 is insulated from the second solder strip 22 by the insulating strip 3. Alternatively, the busbar 4 and the insulating strip 3 can also be positioned at gaps between other adjacent battery cells 11.

[0083] In this embodiment, the insulating strip 3 and the busbar 4 are positioned at the gap 113 between the first battery cell 111 and the second battery cell 112, and the first welding strip 21 is bent and connected to the busbar 4. The insulating strip 3 does not need to be opened to connect the first welding strip 21 to the busbar 4, which can reduce the processing difficulty of the battery assembly 100.

[0084] Please refer to this again. Figure 1 As an embodiment of this utility model, the back contact battery assembly 100 also includes a frame 5, and a plurality of battery strings 1 are disposed within the frame 5. In addition, the front of the plurality of battery strings 1 is encapsulated by an upper adhesive film and a front glass, and the back of the plurality of battery strings 1 is encapsulated by a lower adhesive film and a back plate.

[0085] In some embodiments, the battery assembly 100 may include a plurality of battery strings 1. Specifically, the battery assembly 100 may include twelve battery strings 1, which are arranged in six columns in the second direction X, with each column including two battery strings 1 arranged in the first direction Y. The number of battery cells 11 included in each battery string 1 is not limited; for example, the number of battery cells 11 included in each battery string 1 may be 3 to 20. Figure 1 The diagram only shows that each battery string 1 has 7 battery cells. Specifically, as shown... Figure 1 As shown, the battery assembly 100 is divided into an upper half and a lower half in the first direction Y (as shown in the figure). Figure 1 The center line L is the boundary.

[0086] like Figure 1 As shown, the upper half of the battery assembly 100 has six battery strings 1 arranged along the second direction X, and the lower half also has six battery strings 1 arranged along the second direction X. In the battery assembly 100, the busbar 4 may include an edge busbar located at the edge of the battery assembly 100 and an intermediate busbar located in the middle of the battery assembly 100.

[0087] In other words, in Figure 1In the upper half of the battery assembly 100, if the battery cell 11 closest to the upper edge of the battery string 1 is the first battery cell 111, then the bus bar 4 is an end bus bar, used to connect two adjacent battery strings 1 in the upper half. In the upper half, if the battery cell 11 closest to the lower edge of the battery string 1 is the first battery cell 111, then the bus bar 4 is an intermediate bus bar, used to connect the battery string 1 in parallel with the battery string 1 in the lower half. In the upper half, if both battery cells 11 at both ends of the battery string 1 are first battery cells 111, then the bus bar 4 closest to the upper edge is an end bus bar, and the bus bar 4 closest to the lower edge is an intermediate bus bar.

[0088] Similarly, such as Figure 1 As shown, in the lower half of the battery assembly 100, if the battery cell 11 closest to the lower edge of the battery string 1 is the first battery cell 111, then the busbar 4 is an end busbar, used to connect two adjacent battery strings 1 in the lower half. In the lower half, if the battery cell 11 closest to the upper edge of the battery string 1 is the first battery cell 111, then the busbar 4 is an intermediate busbar, used to connect the battery string 1 in parallel with the battery string 1 in the upper half. In the lower half, if both battery cells 11 at both ends of the battery string 1 are first battery cells 111, then the busbar 4 closest to the lower edge is an end busbar, and the busbar 4 closest to the upper edge is also an end busbar.

[0089] like Figure 1 As shown, in the battery assembly 100, if the battery cell 11 closest to the lower edge of the battery string 1 in the upper half is the first battery cell 111, then the bus bar 4 is the middle bus bar, and the battery cell 11 closest to the upper edge of the battery string 1 in the lower half is not the first battery cell 111. In this case, the battery cell 11 is the third battery cell 1211 mentioned below.

[0090] In an embodiment of the present invention, the battery assembly 100 includes at least one series battery string group 110, which includes two battery strings 1 arranged along the second direction X. In the same series battery string group 110, the same bus bar 4 extends from the second battery cell 112 of one battery string 1 to the second battery cell 112 of the other battery string 1 to connect the two battery strings 1 in series in the series battery string group 110.

[0091] Thus, in the series battery string group 110, two battery strings 1 can be connected in series through the same bus bar 4, without the need to set two different bus bars 4 to connect the battery strings 1 in the series battery string group 110.

[0092] Specifically, in such an embodiment, the busbar 4 used to connect two battery strings 1 in series in the series battery string group 110 is an end busbar of the battery assembly 100. The number of end busbars is equal to the number of series battery string groups 110 in the battery assembly 100. For example, as Figure 1 As shown, the upper half has 6 battery strings 1 and 3 series-connected battery string groups 110, and the lower half also has 6 battery strings 1 and 3 series-connected battery string groups 110. Therefore, the upper half has 3 end busbars and the lower half also has 3 end busbars.

[0093] It is easy to understand that in the series battery string group 110, the first battery cells 111 in the two battery strings 1 correspond to each other (i.e., are basically aligned in the second direction X). In order to realize the series connection of the two battery strings 1, the polarity of the first solder strips 21 on the first battery cells 111 in the two battery strings 1 is opposite. That is, in the two battery strings 1 in the series battery string group 110, the first solder strip 21 of the first battery cell 111 in one battery string 1 is electrically connected to the negative main grid and / or negative fine grid on the corresponding first battery cell 111, and the first solder strip 21 on the other first battery cell 111 is electrically connected to the positive main grid and / or positive fine grid on the corresponding first battery cell 111.

[0094] In an embodiment of the present invention, the battery assembly 100 includes at least one parallel battery string group 120, the parallel battery string group 120 including a first battery string 1201 and a second battery string 1202 arranged along a first direction Y, the first battery string 1201 being located in the upper half of the assembly, and the second battery string 1202 being located in the lower half of the assembly.

[0095] In the parallel battery string group 120, the first battery cell 111 includes the battery cell 11 located in the first battery string 1201 that is closest to the second battery string 1202. The second battery string 1202 includes a third battery cell 1211, which is the battery cell in the second battery string 1202 that is closest to the first battery string 1201. The first solder strip 21 connects the first battery cell 111 and the third battery cell 1211, thereby connecting the first battery string 1201 and the second battery string 1202 in parallel to achieve parallel output of the two battery strings 1.

[0096] In this case, when the first battery cell 111 includes the battery cell 11 located in the first battery string 1201 that is closest to the second battery string 1202, the busbar 4 on the second battery cell 112 adjacent to the first battery cell 111 is the intermediate busbar.

[0097] In addition, combined Figures 1-3As can be seen, in the battery assembly 100 of this embodiment, the battery cell 11 closest to the second battery cell 1202 in the first battery string 1201 is the first battery cell 111, and the battery cell 11 located at the end of the first battery string 1201 away from the second battery string 1202 is also the first battery cell 111. In the second battery string 1202, the battery cell 11 closest to the first battery string 1201 is the third battery cell 1211, and the battery cell 11 located at the end of the second battery string 1202 away from the first battery string 1201 is also the first battery cell 111. That is to say, in this embodiment, the battery cells 11 at both ends of the first battery string 1201 are both first battery cells 111, the battery cell 11 at one end of the second battery string 1202 is the first battery cell 111, and the battery cell 11 at the other end of the second battery string 1202 is the third battery cell 1211.

[0098] In an embodiment of this utility model, in the battery assembly 100, the busbar 4 includes an end busbar and an intermediate busbar, and the specific type of the busbar 4 depends on the specific location where the busbar 4 is set.

[0099] This utility model embodiment also provides a photovoltaic system, which includes the battery module of the above embodiment. It should be noted that this photovoltaic system has the same or similar beneficial effects as the back contact battery module described above, and the related parts between the two can be referred to each other. To avoid repetition, they will not be described again here.

[0100] In this embodiment, the photovoltaic system 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 are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple back-contact battery modules. For example, multiple back-contact battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected 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 achieve solar power supply.

[0101] In the description of this specification, the references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0102] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A back-contact battery assembly, characterized in that, include: A plurality of battery strings, wherein the battery strings include a plurality of battery cells connected in series along a first direction, wherein the plurality of battery cells in the battery strings include a first battery cell disposed at the end of the battery string and a second battery cell adjacent to the first battery cell, wherein the first battery cell includes a first edge and a second edge disposed opposite to each other along the first direction, and the first edge is disposed further away from the second battery cell than the second edge. An insulating strip extends along a second direction and is located on the back of at least one of the battery cells or in the gap between two adjacent battery cells, wherein the first direction intersects the second direction; and A busbar is disposed on the insulating strip and extends along the second direction. The back of the first battery cell is provided with a first solder strip connected to the busbar. The first solder strip includes a main body portion located on the first battery cell and a bent portion connected to the main body portion. The connection between the bent portion and the main body portion is disposed near the first edge. The bent portion is bent relative to the main body portion toward the direction of the busbar and is connected to the busbar.

2. The back contact battery assembly according to claim 1, characterized in that, The back of the first battery cell is also provided with a second solder strip, and the first solder strip and the second solder strip are arranged alternately along the second direction, and the second solder strip connects the first battery cell and the second battery cell.

3. The back contact battery assembly according to claim 2, characterized in that, The insulating strip and the busbar are located on the back of the first battery cell, and the insulating strip is located on the first solder strip and the second solder strip.

4. The back contact battery assembly according to claim 2, characterized in that, The insulating strip and the busbar are located on the back of the second battery cell. The back of the second battery cell is provided with a third welding strip and a fourth welding strip arranged alternately along the second direction. The third welding strip corresponds to the first welding strip, and the fourth welding strip corresponds to the second welding strip and is connected to it. The insulating strip is located on the third welding strip and the fourth welding strip.

5. The back contact battery assembly according to claim 2, characterized in that, The insulating strip and the busbar are located in the gap between the first battery cell and the second battery cell, with the insulating strip located on the second solder strip.

6. The back contact battery assembly according to claim 1, characterized in that, The bent portion bends relative to the main body toward the busbar near the first edge, and the bent portion is at least partially connected to the side of the busbar facing away from the insulating strip.

7. The back contact battery assembly according to claim 3, characterized in that, The angle between the orthographic projection of the bent portion on the first battery cell and the orthographic projection of the main body portion on the first battery cell is 0° to 80°.

8. The back contact battery assembly according to claim 3, characterized in that, The ratio of the overlap length between the bent portion and the busbar to the total length of the bent portion is 40% to 100%.

9. The back contact battery assembly according to claim 3, characterized in that, The bent portion includes a first end connected to the main body and a second end disposed away from the main body. The second end is connected to the busbar and does not extend beyond the edge of the busbar near the second battery cell.

10. The back contact battery assembly according to claim 1, characterized in that, The connection between the bent portion and the main body portion is located on the outside of the first edge.

11. The back contact battery assembly according to claim 1 or 10, characterized in that, The main body and the bent portion are connected by an arc-shaped connecting portion, which is located on the outside of the first edge.

12. The back contact battery assembly according to claim 11, characterized in that, The radius of the arc-shaped connection is 0.3 to 1.2 mm.

13. The back contact battery assembly according to claim 3, characterized in that, The distance from the busbar to the first edge is 1 to 3 millimeters.

14. The back contact battery assembly according to claim 3 or 4, characterized in that, The adjacent battery cells within the battery string are partially overlapped.

15. The back contact battery assembly according to claim 14, characterized in that, The projected length of the overlapping area of ​​adjacent battery cells within the battery string along the first direction is 0.1 to 1 mm.

16. The back contact battery assembly according to claim 1, characterized in that, The dimension of the insulating strip along the first direction is greater than the dimension of the busbar along the first direction, and the dimension of the insulating strip along the second direction is greater than the dimension of the busbar along the second direction.

17. A photovoltaic system, characterized in that, Includes the back contact battery assembly as described in any one of claims 1 to 16.

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