A battery assembly and photovoltaic system

Abstract

The utility model is suitable for photovoltaic technical field provides a kind of battery component and photovoltaic system, battery component includes: several cell strings, cell string includes the several cell piece connected in series by welding band, and the several cell piece includes the first cell piece located at the end of cell string, the second cell piece adjacent to first cell piece;Busbar is set on the back of second cell piece;Along first direction, second cell piece includes oppositely arranged first edge and second edge, and second edge is set away from first cell piece compared with first edge, and the back of second cell piece is provided with several thin grids;The distance of busbar to first edge is d1, and 0.1mm The utility model discloses a battery component can reduce the risk of cell piece hidden crack and crack in lamination process, and can reduce short-circuit risk, to improve battery component production yield.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a battery module and a 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 and encapsulated to form a solar module. The resulting solar module typically includes a back glass, a first encapsulating film, a cell string, a second encapsulating film, and a front glass, which are stacked sequentially.

[0003] In related technologies, edge busbars are typically placed in the edge area of ​​battery modules, while center busbars are typically placed in the middle area. Both require a certain amount of space to be reserved on the module for placement. This reduces the effective light-receiving area of ​​the module, affecting its conversion efficiency and aesthetics.

[0004] In related technologies, to address the aforementioned issues, busbars can be positioned on the back of the cells in a battery string. For example, the busbar can be placed on a cell adjacent to the end cell of the battery string, and then the solder strips on the end cell are welded to the busbar to achieve concealment and current output. However, since the distance between the busbar and the edge of the cell is typically not controlled, if the busbar contacts the edge of the cell, microcracks and cell splits are likely to occur during lamination, posing a significant risk. Conversely, if the distance between the busbar and the edge of the cell is too large, the solder strips connecting the busbar to the end cell are prone to short-circuiting with the fine grid on the cell containing the busbar, thus affecting the yield of the battery module. Utility Model Content

[0005] This utility model provides a battery assembly that aims to solve the problems of existing battery assemblies, such as the easy occurrence of microcracks and cracks in the battery cells, and the easy contact and short circuit between the solder strips on the end battery cells that connect to the busbars and the fine grids on the battery cells where the busbars are located.

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

[0007] A plurality of battery strings, each battery string comprising a plurality of battery cells connected in series along a first direction, the plurality of battery cells being connected in series by solder strips, each battery cell comprising a first battery cell located at one end of the battery string and a second battery cell adjacent to the first battery cell; and

[0008] A busbar is disposed on the back of the second battery cell, the busbar extending along a second direction, the second direction intersecting the first direction; the solder strip includes a first solder strip and a second solder strip, the first battery cell and the second battery cell are connected by the first solder strip, the first battery cell and the busbar are connected by the second solder strip, and the first solder strip is spaced apart from the busbar;

[0009] Along the first direction, the second battery cell includes a first edge and a second edge disposed opposite to each other, the second edge being disposed further away from the first edge than the first battery cell, and a plurality of fine grids spaced sequentially along the first direction are disposed on the back side of the second battery cell; wherein, the distance from the busbar to the first edge is d1, 0.1mm < d1 ≤ 3mm, and the number of fine grids on the second battery cell located between the first edge and the busbar is 1 to 10.

[0010] Preferably, the length of the second solder strip is greater than or equal to half the length of the first solder strip, and the length of the second solder strip is less than or equal to two-thirds the length of the first solder strip.

[0011] Preferably, the width of the busbar is D, and the overlap length between the second welding strip and the busbar is S, where 0.25D≦S≤D.

[0012] Preferred options also include:

[0013] An insulating strip is located between the busbar and the second battery cell, and the busbar is insulated from the first solder strip by the insulating strip.

[0014] Preferably, the distance from the insulating strip to the first edge is d2, where d2 < d1.

[0015] Preferably, along the second direction, the second battery cell includes a third edge and a fourth edge disposed opposite to each other, the third edge being disposed near the end of the busbar, and the distance from the end of the busbar to the third edge being d3, where d3 is 2mm to 10mm.

[0016] Preferably, the spacing between two adjacent fine grids is 0.2 to 0.5 mm.

[0017] Preferably, the battery assembly includes at least one series battery string group, the series battery string group including two battery strings arranged along the second direction, and in the same series battery string group, the same bus bar extends from the second battery cell in one battery string to the second battery cell in the other battery string to connect the two battery strings in the series battery string group in series.

[0018] Preferably, the battery assembly includes at least one parallel battery string group, the parallel battery string group including a first battery string and a second battery string arranged along a first direction;

[0019] In the parallel battery string group, the first battery string includes a first battery cell located closest to the second battery string, and the second battery string includes a third battery cell, which is the battery cell in the second battery string closest to the first battery string. The first battery cell of the first battery string and the third battery cell of the second battery string are connected in parallel by the second solder strip.

[0020] This utility model also provides a photovoltaic system, including the above-mentioned battery components.

[0021] This utility model provides a battery assembly that controls the distance d1 from the busbar to the first edge of the second battery cell to satisfy 0.1mm < d1 ≤ 3mm. This ensures that the busbar does not contact the edge of the second battery cell, maintaining a certain distance between them. This reduces the risk of microcracks and cell breakage in the second battery cell during lamination. Simultaneously, controlling the distance from the busbar to the first edge to be less than or equal to 3mm prevents excessive distance between the busbar and the first edge of the second battery cell, reducing the risk of fine grid joints between the second solder strip and the first edge of the second battery cell during lamination. The risk of short circuits is reduced; moreover, controlling the number of fine grids between the first edge of the second cell and the busbar to 1 to 10 can avoid an excessive number of fine grids between the first edge of the second cell and the busbar, which can further reduce the risk of short circuits between the second solder ribbon and the fine grids on the second cell during the lamination process, thereby improving the production yield of the battery module; in addition, controlling the number of fine grids between the first edge of the second cell and the busbar to 1 to 10 ensures that the number of fine grids in the second cell is set within a reasonable range, which can effectively collect charge carriers, reduce the risk of short circuits between fine grids, and avoid wasting fine grid paste. Attached Figure Description

[0022] Figure 1 A plan view of a battery assembly provided for an embodiment of this utility model;

[0023] Figure 2 A schematic diagram of a series battery string of a battery assembly provided in an embodiment of this utility model;

[0024] Figure 3 A schematic diagram of the structure of a parallel battery string group of a battery assembly provided for an embodiment of this utility model;

[0025] Figure 4 This is a partial structural schematic diagram of a battery assembly provided in an embodiment of the present utility model. Detailed Implementation

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] Please refer to Figures 1-4 The present invention provides a battery assembly 100, comprising:

[0031] A plurality of battery strings 1, each battery string 1 comprising a plurality of battery cells 11 connected in series along a first direction Y, the plurality of battery cells 11 being connected in series via solder strips 2, each battery cell 11 comprising 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; and

[0032] The busbar 3 is disposed on the back of the second battery cell 112. The busbar 3 extends along the second direction X, which intersects with the first direction Y. The solder strip 2 includes a first solder strip 21 and a second solder strip 22. The first battery cell 111 and the second battery cell 112 are connected by the first solder strip 21. The first battery cell 111 is connected to the busbar 3 by the second solder strip 22. The first solder strip 21 and the busbar 3 are spaced apart.

[0033] Along the first direction Y, the second battery cell 112 includes a first edge 1121 and a second edge 1122 disposed opposite to each other. The second edge 1122 is disposed away from the first edge 1121 from the first battery cell 111. The back side of the second battery cell 112 is provided with a plurality of fine grids 1101 spaced apart along the first direction Y. The distance from the busbar 3 to the first edge 1121 is d1, 0.1mm < d1 ≤ 3mm. The number of fine grids 1101 located between the first edge 1121 and the busbar 3 in the second battery cell 112 is 1 to 10.

[0034] In this embodiment of the invention, the battery assembly 100 may include a plurality of battery strings 1 and a busbar 3. Each battery string 1 includes a plurality of battery cells 11 connected in series along a first direction Y, with adjacent battery cells 11 connected in series by a solder strip 2. Specifically, each battery cell 11 may be a back-contact solar cell. In the battery string 1, the 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 both ends of the battery string 1 in the first direction Y; that is, at least one of the battery cells 11 located at the two ends of the battery string 1 is a first battery cell 111. The second solder strip 22 is the end output of the battery string 1, used to connect to the busbar 3.

[0035] The back of the first battery cell 111 is provided with a second solder strip 22. The first battery cell 111 is connected to the busbar 3 through the second solder strip 22. A portion of the first solder strip 22 is located on the back of the first battery cell 111, and the other portion is located on the back of the second battery cell 112. The first battery cell 111 and the second battery cell 112 are connected through the first solder strip 21. The solder strip 21 also includes a third solder strip 23 located on the back of the second battery cell 112. The second battery cell 112 is connected to other adjacent battery cells 11 through the third solder strip 23, and other adjacent battery cells 11 in each battery string 1 are connected in series through the solder strip 2. The first solder strip 21 and the third solder strip 23 on the back of the second battery cell 112 are spaced apart from the busbar 3.

[0036] In this embodiment of the invention, the second edge 1122 of the second battery cell 112 is disposed away from the first battery cell 111, and the first edge 1121 of the second battery cell 112 is disposed closer to the first battery cell 111 than the second edge 1122. Optionally, two adjacent battery cells 11 in the battery string 1 partially overlap, that is, the first battery cell 111 and the second battery cell 112 partially overlap, and the first battery cell 111 and the second battery cell 112 overlap to form an overlapping area, so that the first edge 1121 of the second battery cell 112 overlaps with the first battery cell 111, and the size of the overlapping area along the first direction Y is not limited.

[0037] In this embodiment of the invention, the busbar 3 is disposed on the back side of the second battery cell 112. The busbar 3 is connected to the second solder strip 22, and the busbar 3 is insulated from the first solder strip 21 and other solder strips 2 on the back side of the second battery cell 112 to achieve the current output of the battery string 1. The busbar 3 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. 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 a limitation. The busbar 3 can be an end busbar 3 of the battery assembly or a middle busbar 3 of the battery assembly.

[0038] In this embodiment of the present invention, the distance from the busbar 3 to the first edge 1121 of the second battery cell 112 is d1, where 0.1mm < d1 ≤ 3mm. Specifically, d1 can be any value among 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.4mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.86mm, 0.9mm, 0.96mm, 1.0mm, 1.1mm, 1.4mm, 1.5mm, 1.7mm, 1.8mm, 2.0mm, 2.2mm, 2.5mm, 2.8mm, 2.9mm, and 3.0mm.

[0039] In this embodiment of the invention, each battery cell 11 has a plurality of fine grids 1101 spaced apart along the first direction Y on its back side. The fine grids 1101 include the positive and negative fine grids of the second battery cell 112, which are spaced apart along the first direction Y. A main grid can be provided on the battery cell 11 to connect to the fine grids of the corresponding polarity, and the solder ribbon 2 can be connected to the corresponding main grid. Alternatively, a main grid may not be required on the battery cell 11, and the solder ribbon 2 can be directly connected to the fine grids of the corresponding polarity. The number of fine grids 1101 on the second battery cell 112 between the first edge 1121 and the busbar 3 is 1 to 10. This can be understood as the area on the back of the second battery cell 112 between the first edge 1121 and the busbar 3 having 1 to 10 fine grids 1101. Specifically, the number of fine grids 1101 on the second battery cell 112 between the first edge 1121 and the busbar 3 can be any number from 1, 2, 3, 4, 5, 6, 7, 8, 9, to 10. The number of fine grids 1101 on the second battery cell 112 between the first edge 1121 and the busbar 3 can be set according to the distance d1 from the busbar 3 to the first edge 1121 and the spacing between two adjacent fine grids 1101. Figure 4 The diagram shows that the second battery cell 112 has four fine grids 1101 located between the first edge 1121 and the busbar 3.

[0040] In this embodiment of the present invention, the distance from the fine grid 1101 closest to the first edge 1121 of the second battery cell 112 to the first edge 1121 is less than the distance from the busbar 3 to the first edge 1121. That is, there is at least one fine grid 1101 between the first edge 1121 of the second battery cell 112 and the busbar 3, so that there is a certain distance between the busbar 3 and the first edge 1121 of the second battery cell 112, which can reduce the risk of microcracks and cracks in the second battery cell 112 during the lamination process of the battery assembly 100.

[0041] In this embodiment of the invention, the distance from the busbar 3 to the first edge 1121 of the battery assembly 100 is controlled to be d1, where 0.1mm < d1 ≤ 3mm. This ensures that the busbar 3 does not contact the edge of the second battery cell 112, maintaining a distance of at least 0.1mm between the busbar 3 and the first edge 1121 of the second battery cell 112. This reduces the risk of microcracks and cracks in the second battery cell 112 during the lamination process. Simultaneously, controlling the distance d1 from the busbar 3 to the first edge 1121 to be less than or equal to 3mm avoids an excessively large distance between the busbar 3 and the first edge 1121 of the second battery cell 112. This reduces the risk of short circuits caused by the second solder strip 22 contacting the fine grid 1101 between the first edge 1121 of the second battery cell 112 and the busbar 3 during the lamination process. Furthermore, controlling... The number of fine grids 1101 between the first edge 1121 of the second solar cell 112 and the busbar 3 is 1 to 10. This avoids an excessive number of fine grids 1101 between the first edge 1121 of the second solar cell 112 and the busbar 3, and further reduces the risk of short circuit between the second solder ribbon 22 and the fine grids 1101 on the second solar cell 112 during the lamination process, thereby improving the production yield of the solar module. Moreover, under the premise of 0.1mm < d1 ≤ 3mm, controlling the number of fine grids 1101 between the first edge 1121 of the second solar cell 112 and the busbar 3 to 1 to 10 ensures that the number of fine grids 1101 on the second solar cell 112 is set within a reasonable range. This can effectively collect charge carriers, reduce the risk of short circuit between fine grids, and avoid wasting fine grid paste.

[0042] As one embodiment of this utility model, the spacing between two adjacent fine grids 1101 is 0.2 to 0.5 mm.

[0043] In this embodiment, the spacing between two adjacent fine grids 1101 is controlled to be 0.2 to 0.5 mm, which is beneficial to achieve a number of fine grids 1101 between the first edge 1121 of the second battery cell 112 and the busbar 3 of 1 to 10, thereby reducing the risk of short circuit in the module. It is also beneficial to ensure that the distance d1 between the busbar 3 and the first edge 1121 of the second battery cell 112 satisfies 0.1 mm < d1 ≤ 3 mm, which can reduce the risk of microcracks and cracks in the second battery cell 112 during the lamination process of the battery module 100.

[0044] In one embodiment of the present invention, the length L2 of the second solder strip 22 is greater than or equal to half the length L1 of the first solder strip 21, and the length L2 of the second solder strip 22 is less than or equal to two-thirds of the length L1 of the first solder strip 21.

[0045] In this embodiment, the length L2 of the second solder strip 22 is greater than or equal to half the length L1 of the first solder strip 21, which helps to ensure the overlap length between the second solder strip 22 and the busbar 3, and achieve a good electrical connection between the second solder strip 22 and the busbar 3. Moreover, the length of the second solder strip 22 is less than or equal to two-thirds of the length of the first solder strip 21, which avoids the second solder strip 22 from being too long and causing a short circuit between the second solder strip 22 and the solder strip 2 on the second battery cell 112, thereby improving the reliability of the module.

[0046] As an embodiment of this utility model, the width of the busbar 3 is D, the overlap length between the second welding strip 22 and the busbar 3 is S, and 0.25D≦S≤D.

[0047] In this embodiment, the width of the busbar 3 is its dimension along the first direction Y. The overlap length of the second solder strip 22 with the busbar 3 is along the first direction Y. By controlling the overlap length S of the second solder strip 22 and the busbar 3 to be greater than or equal to 0.25D and less than or equal to D, the overlap length of the second solder strip 22 and the busbar 3 can be guaranteed, achieving a good electrical connection between the second solder strip 22 and the busbar 3. Furthermore, it prevents the second solder strip 22 from being too long and extending beyond the edge of the busbar 3, reducing the risk of short circuit between the second solder strip 22 and the solder strip 2 on the second solar cell 112, thereby improving the reliability of the module. Further, 0.25D≦S≤D / 2 can further reduce the risk of short circuit between the second solder strip 22 and the solder strip 2 on the second solar cell 112.

[0048] As one embodiment of this utility model, it also includes:

[0049] Insulating strip 4 is located between busbar 3 and second battery cell 112. Busbar 3 is insulated from first welding strip 21 by insulating strip 4.

[0050] In this embodiment, by setting the insulating strip 4, the busbar 3 and the first solder strip 21 on the second battery cell 112 can form a good insulation isolation to avoid short circuit and leakage.

[0051] Specifically, in such an embodiment, an insulating strip 4 is disposed above the first solder strip 21, and the insulating strip 4 can be continuously extended along the second direction X. The busbar 3 is disposed on the insulating strip 4 to achieve insulation between it and the first solder strip 21.

[0052] The insulating strip 4 can be an insulating adhesive, or a non-conductive tape or insulating film. For example, it can be a PET or PI tape with acrylic or silicone, or a PET or PI substrate coated with ethylene vinyl acetate copolymer or hot melt adhesive on one or both sides. Understandably, the insulating strip 4 can contain materials such as ethylene vinyl acetate copolymer, resin materials, polyimide or polypropylene or polyethylene, and may also contain an acrylic adhesive layer.

[0053] The width of the insulating strip 4 (i.e., its length in the first direction Y) is greater than or equal to the width of the busbar 3 (i.e., its length in the first direction Y). In this way, the insulating strip 4 can completely insulate the busbar 3 from the solder strip 2 on the second battery cell 112.

[0054] As an embodiment of this utility model, the distance from the insulating strip 4 to the first edge 1121 is d2, where d2 < d1.

[0055] In this embodiment, d2 < d1, that is, d2 and d1 increase sequentially, so that the second battery cell 112, insulating strip 4, and busbar 3 are distributed in a stepped manner. The stepped structure formed by the second battery cell 112, insulating strip 4, and busbar 3 can further reduce the edge stress of the second battery cell 112 during the battery module lamination process, and can effectively avoid stress concentration at the edge of the second battery cell 112 during the lamination process. Therefore, it can reduce the risk of microcracks and cell cracks in the battery cell during the lamination process, thereby improving the production yield of the battery module.

[0056] As an embodiment of the present invention, along the second direction X, the second battery cell 112 includes a third edge 1123 and a fourth edge 1124 disposed opposite to each other. The third edge 1123 is disposed near the end of the busbar 3, and the distance from the end of the busbar 3 to the third edge 1123 is d3, where d3 is 2mm to 10mm.

[0057] In this embodiment, the distance d3 from one end of the busbar 3 to the second edge 1122 of the second battery cell 112 is controlled to be 2mm to 10mm, so that the distance d3 from the end of the busbar 3 to the third edge 1123 is controlled within a reasonable range, which can further reduce the risk of microcracks in the battery cell.

[0058] In some embodiments, the battery assembly 100 may include two battery strings 1 arranged along a first direction Y and a plurality of battery strings 1 arranged along a second direction X.

[0059] The battery assembly 100 may include twelve battery strings 1, 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 unlimited; for example, each battery string 1 may include 3 to 20 battery cells 11. Figure 1 The diagram only shows that each battery string 1 has 8 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.

[0060] like Figure 1As 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 3 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.

[0061] In other words, in Figure 1 In 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 busbar 3 is an end busbar, 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 busbar 3 is an intermediate busbar, 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 busbar 3 closest to the upper edge is an end busbar, and the busbar 3 closest to the lower edge is an intermediate busbar.

[0062] 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 3 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 3 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 3 closest to the lower edge is an end busbar, and the busbar 3 closest to the upper edge is also an end busbar.

[0063] 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 busbar 3 is the middle busbar, 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.

[0064] Please see Figures 1-3 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 3 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.

[0065] Thus, in the series battery string group 110, two battery strings 1 can be connected in series through the same bus bar 3, without the need to set two different bus bars 3 to connect the battery strings 1 in the series battery string group 110.

[0066] Specifically, in such an embodiment, the busbar 3 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.

[0067] 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 second solder strips 22 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 second solder strip 22 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 second solder strip 22 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.

[0068] 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.

[0069] 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 11 in the second battery string 1202 that is closest to the first battery string 1201. The second solder strip 22 connects the first battery cell 111 and the third battery cell 1211. The first battery string 1201 and the second battery string 1202 are connected in parallel through the second solder strip 22.

[0070] It is easy to understand that, 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 3 on the second battery cell 112 adjacent to the first battery cell 111 is the intermediate busbar.

[0071] Thus, by setting the battery cell 11 closest to the second battery cell 1202 in the first battery string 1201 of the parallel battery string group 120 as the first battery cell 111, the second solder strip 22 on the first battery cell 111 can connect to the battery cell 11 closest to the first battery string 1201 (i.e. the third battery cell 1211 mentioned above) of the second battery string 1202 at the same time as connecting to the bus bar 3, thereby realizing the parallel connection between the first battery string 1201 and the second battery string 1202.

[0072] In addition, combined Figures 1-3 As 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.

[0073] In this embodiment, the first battery string 1201 has two first battery cells 111 and two second battery cells 112, each with two corresponding busbars 3. One of the busbars 3 is an end busbar, and the other is a middle busbar. The second battery string 1202 has only one first battery cell 111 and one second battery cell 112, each with one corresponding busbar 3, which is an end busbar 3. It is easy to understand that in this case, in the first battery string 1201, the polarities of the first solder strips 21 on the two first battery cells 111 are opposite. The second solder strip 22 of one first battery cell 111 is electrically connected to the negative main grid and / or negative fine grid on the corresponding first battery cell 111, and the second solder strip 22 of 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. For example, the polarity of the second solder strip 22 on the first battery cell 111 in the second battery string 1202 is opposite to that of the second solder strip 22 on the first battery cell 111 in the first battery string 1201 that is closest to the first battery cell 111 on the second battery string 1202.

[0074] In summary, in the embodiments of this utility model, in the battery assembly 100, the busbar 3 includes an end busbar and an intermediate busbar, and the specific type of the busbar 3 depends on the specific location where the busbar 3 is set.

[0075] This utility model embodiment also provides a photovoltaic system, which includes the battery module 100 of the above embodiment. It should be noted that the photovoltaic system has the same or similar beneficial effects as the battery module, and the related parts between the two can be referred to each other. To avoid repetition, they will not be described again here.

[0076] 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 battery modules; for example, multiple 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.

[0077] In the description of this specification, 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.

[0078] 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 battery assembly, comprising: include: A plurality of battery strings, wherein the battery strings include a plurality of battery cells connected in series along a first direction, the plurality of battery cells being connected in series by solder strips, and the plurality of battery cells including a first battery cell located at the end of the battery string and a second battery cell adjacent to the first battery cell; and A busbar is disposed on the back of the second battery cell, the busbar extending along a second direction, the second direction intersecting the first direction; the solder strip includes a first solder strip and a second solder strip, the first battery cell and the second battery cell are connected by the first solder strip, the first battery cell and the busbar are connected by the second solder strip, and the first solder strip is spaced apart from the busbar; Along the first direction, the second battery cell includes a first edge and a second edge disposed opposite to each other, the second edge being disposed further away from the first edge than the first battery cell, and a plurality of fine grids spaced sequentially along the first direction are disposed on the back side of the second battery cell; wherein, the distance from the busbar to the first edge is d1, 0.1mm < d1 ≤ 3mm, and the number of fine grids on the second battery cell located between the first edge and the busbar is 1 to 10.

2. The battery assembly of claim 1, wherein, The length of the second solder strip is greater than or equal to one-half the length of the first solder strip, and the length of the second solder strip is less than or equal to two-thirds the length of the first solder strip.

3. The battery assembly of claim 1, wherein, The width of the busbar is D, and the overlap length between the second welding strip and the busbar is S, where 0.25D≦S≤D.

4. The battery assembly of claim 1, wherein, Also includes: An insulating strip is located between the busbar and the second battery cell, and the busbar is insulated from the first solder strip by the insulating strip.

5. The battery assembly of claim 4, wherein, The distance from the insulating strip to the first edge is d2, where d2 < d1.

6. The battery assembly according to claim 1, characterized in that, Along the second direction, the second battery cell includes a third edge and a fourth edge disposed opposite to each other, the third edge being disposed near the end of the busbar, and the distance from the end of the busbar to the third edge being d3, where d3 is 2mm to 10mm.

7. The battery assembly according to claim 1, characterized in that, The spacing between two adjacent fine grids is 0.2 to 0.5 mm.

8. The battery assembly according to claim 1, characterized in that, The battery assembly includes at least one series battery string group, the series battery string group including two battery strings arranged along the second direction, in the same series battery string group, the same bus bar extends from the second battery cell in one battery string to the second battery cell in the other battery string to connect the two battery strings in the series battery string group in series.

9. The battery assembly according to claim 1, characterized in that, The battery assembly includes at least one parallel battery string group, which includes a first battery string and a second battery string arranged along the first direction. In the parallel battery string group, the first battery string includes a first battery cell located closest to the second battery string, and the second battery string includes a third battery cell, which is the battery cell in the second battery string closest to the first battery string. The first battery cell of the first battery string and the third battery cell of the second battery string are connected in parallel by the second solder strip.

10. A photovoltaic system, characterized in that, Includes the battery assembly as described in any one of claims 1 to 9.

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