A battery assembly and photovoltaic system

Abstract

The application provides a battery assembly and a photovoltaic system. The battery assembly comprises a busbar and a battery string; the busbar comprises a main body part and a plurality of connecting parts, the main body part extends along a second direction, the connecting parts extend along a first direction, and the plurality of connecting parts are arranged at intervals along the second direction; one end of the connecting part is connected to the main body part, and the end of the connecting part of the same busbar which is not connected to the main body part is located on the same side of the main body part; an insulating strip is further arranged between the main body part and the battery string, and the vertical projection of the main body part on the surface of the battery string is located within the vertical projection of the insulating strip on the surface of the battery string; the connecting part comprises a first sub-part and a second sub-part, the vertical projection of the first sub-part on the surface of the battery string is located within the insulating strip, and the vertical projection of the second sub-part on the surface of the battery string is located outside the insulating strip; and the ratio of the length of the second sub-part to the length of the first sub-part is greater than 0.2. The application can improve the reliability of the assembly.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and more particularly to a battery module and a photovoltaic system. Background Technology

[0002] Photovoltaic modules consist of multiple cell strings, which are connected in parallel via busbars. In existing photovoltaic modules, the installation of busbars is complex, resulting in lower module reliability. Summary of the Invention

[0003] This invention provides a battery module and a photovoltaic system to improve module reliability.

[0004] According to one aspect of the present invention, a battery assembly is provided, comprising: Busbars and battery strings; The busbar includes a main body and a plurality of connecting portions connected to the main body. The main body extends along a second direction, and the connecting portions extend along a first direction. The plurality of connecting portions are spaced apart along the second direction, and the first direction and the second direction intersect each other. One end of each connecting portion is connected to the main body, and the ends of the connecting portions of the same busbar that are not connected to the main body are located on the same side of the main body. The main body is disposed on one side surface of the battery string, and an insulating strip is also disposed between the main body and the battery string. The vertical projection of the main body on the surface of the battery string is located within the vertical projection of the insulating strip on the surface of the battery string. The connecting portion includes a first sub-part and a second sub-part. The vertical projection of the first sub-part onto the surface of the battery string is located within the vertical projection of the insulating strip onto the surface of the battery string, and the vertical projection of the second sub-part onto the surface of the battery string is located outside the vertical projection of the insulating strip onto the surface of the battery string. Along the first direction, the ratio of the length of the second sub-part to the length of the first sub-part is greater than 0.2.

[0005] Optionally, along the first direction, the length of the second sub-part is greater than 3 mm and less than 60 mm.

[0006] Optionally, each battery string includes a plurality of solar cells arranged sequentially along the first direction; the busbar includes an edge busbar for connecting adjacent battery strings along the second direction; The main body of the edge busbar is disposed on the surface of the second battery or the surface of the first battery in the battery string; the second sub-part of the connecting part is connected to the solder strip on the first battery of the battery string, the first battery being the outermost solar cell of the battery string, and the second battery being the solar cell adjacent to the first battery.

[0007] Optionally, when the main body of the edge busbar is disposed on the surface of the second battery of the battery string, the minimum distance between the edge of the main body adjacent to the edge of the first battery and the edge of the second battery adjacent to the edge of the main body is 3mm-20mm.

[0008] Optionally, when the main body of the edge busbar is disposed on the second battery surface of the battery string, the insulating strip extends at least partially from the second battery surface to the first battery surface.

[0009] Optionally, when the main body of the edge busbar is disposed on the surface of the second battery of the battery string, the vertical projection of the second sub-part on the surface of the first battery at least covers the first pad of the first battery surface that is closest to the second battery; wherein, the first battery includes a plurality of first pads, the plurality of first pads are connected with solder strips, and the connecting part is welded to the corresponding solder strip.

[0010] Optionally, when the main body of the edge busbar is disposed on the surface of the first battery of the battery string, the ratio of the distance between the main body and the two opposite edges of the first battery along the first direction is greater than 1 / 2 and less than 2.

[0011] Optionally, the battery string includes a first battery string and a second battery string, both of which include a plurality of solar cells arranged sequentially along the first direction; The busbar includes a central busbar for connecting a first battery string and a second battery string that are adjacent along a first direction; the main body of the central busbar is disposed on the surface of a third battery in the first battery string, and the third battery is a solar cell in the first battery string that is adjacent to the second battery string. The first sub-section of the central busbar includes a first region, and the second sub-section of the central busbar includes a second region and a third region. The first region is disposed on the surface of the main body, and the second and third regions are disposed on the side of the main body adjacent to the second battery string. The second region is connected to the solder strip on the surface of the third battery, and the third region is connected to the solder strip on the surface of the fourth battery in the second battery string. The fourth battery is a solar cell in the second battery string that is adjacent to the first battery string.

[0012] Optionally, the insulating strip exposes at least the second pad of the third battery closest to the fourth battery on its surface; wherein the third battery includes a plurality of second pads, the plurality of second pads being connected to solder strips, and the connecting portion being welded to the corresponding solder strips.

[0013] Optionally, the distance between the edge of the insulating strip adjacent to the second pad and the edge of the second pad adjacent to the insulating strip is greater than 2 mm.

[0014] According to another aspect of the present invention, a photovoltaic system is provided, including the battery module described in any embodiment of the present invention.

[0015] This invention, through its embodiment, sets a busbar comprising a main body and multiple connecting portions connected to the main body. The connecting portions connect to the solder ribbon on the surface of the solar cell, allowing the solder ribbon to be pre-set on the solar cell surface without needing to be set together with the busbar. When setting the busbar, only the main body and the solar cell need to be aligned simultaneously, and the connecting portions and the solder ribbon. Furthermore, because the connecting portions can be relatively short and the solder ribbon is relatively wide, the alignment difficulty between the connecting portions and the solder ribbon is reduced. Therefore, this embodiment can reduce the alignment difficulty between the busbar and the solder ribbon, improve alignment accuracy, and enhance module reliability. Moreover, by setting the end of the connecting portion not connected to the main body to be located on the same side of the main body, the connecting portion only needs to be fixed on one side of the main body, reducing manufacturing complexity. Furthermore, by setting the ratio of the length of the second sub-part to the length of the first sub-part along the first direction to be greater than 0.2, the second sub-part has a larger contact area with the solder ribbon, further improving module reliability.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a battery assembly provided in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of a busbar.

[0020] Figure 3 This is a schematic diagram of another battery assembly provided in an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram showing the position of the main body provided in an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of another battery assembly provided in an embodiment of the present invention.

[0023] Figure 6This is a cross-sectional view of a battery assembly provided in an embodiment of the present invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] This invention provides a battery assembly. Figure 1 This is a schematic diagram of a battery assembly provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of a busbar, for reference. Figure 1 and Figure 2 The battery assembly includes: Busbar 10 and battery string 100; The busbar 10 includes a main body 11 and a plurality of connecting parts 12 connected to the main body 11. The main body 11 extends along a second direction Y, and the connecting parts 12 extend along a first direction X. The plurality of connecting parts 12 are spaced apart along the second direction Y, and the first direction X and the second direction Y intersect each other. One end of the connecting part 12 is connected to the main body 11, and the ends of the connecting parts 12 of the same busbar 10 that are not connected to the main body 11 are located on the same side of the main body 11. The main body 11 is disposed on one side surface of the battery string 100, and an insulating strip 30 is also disposed between the main body 11 and the battery string 100. The vertical projection of the main body 11 on the surface of the battery string 100 is located within the vertical projection of the insulating strip 30 on the surface of the battery string 100. The connecting portion 12 includes a first sub-portion 121 and a second sub-portion 122. The vertical projection of the first sub-portion 121 on the surface of the battery string 100 is located within the vertical projection of the insulating strip 30 on the surface of the battery string 100, and the vertical projection of the second sub-portion 122 on the surface of the battery string 100 is located outside the vertical projection of the insulating strip 30 on the surface of the battery string 100. Along the first direction, the ratio of the length of the second sub-portion 122 to the length of the first sub-portion 121 is greater than 0.2.

[0027] The battery assembly includes multiple battery strings 100, and each battery string 100 includes multiple solar cells 20 arranged sequentially along a first direction X. The solar cells 20 can be back-contact solar cells, and each solar cell 20 may include a silicon substrate and a doped layer and grid lines disposed on one side of the silicon substrate. The doped layer may include a first doped layer and a second doped layer, and the grid lines may include a first grid line and a second grid line. The first grid line is disposed on the side of the first doped layer away from the silicon substrate, and the second grid line is disposed on the side of the second doped layer away from the silicon substrate. The first and second doped layers have different doping types; for example, one of the first and second doped layers is an N-type doped layer, and the other is a P-type doped layer. Busbars are used for current collection, enabling series and parallel connections between adjacent battery strings 100. The connecting portion 12 and the main body 11 may be an integral structure or not. When the connecting portion 12 and the main body 11 are not an integral structure, the connecting portion 12 may be disposed on the side of the main body 11 away from the insulating strip 30.

[0028] Specifically, the insulating strip 30 is used to insulate the main body 11 and the solder ribbon 40 on the surface of the solar cell 20, preventing short circuits between the main body 11 and the solder ribbon 40 of different polarities. The dimension of the insulating strip 30 along the first direction X is larger than the dimension of the main body 11 along the first direction X, and the dimension of the insulating strip 30 along the second direction Y is larger than the dimension of the main body 11 along the second direction Y. The portion of the connecting portion 12 extending out of the insulating strip 30 (the second sub-part 122) is the part where the connecting portion 12 connects to the solder ribbon 30. If the length S2 of the second sub-part 122 is too small, the contact area between the connecting portion 12 and the solder ribbon 30 will be too small, which may easily cause the connecting portion 12 to detach from the solder ribbon 40, affecting the reliability of the module. By setting the ratio of the length S2 of the second sub-part 122 to the length S1 of the first sub-part 121 along the first direction X to be greater than 0.2, the second sub-part 122 has a larger length and a larger contact area with the solder ribbon 40, ensuring that the module has high reliability. For example, along the first direction X, the ratio of the length S2 of the second sub-part 122 to the length S1 of the first sub-part 121 can be 0.3, 0.5, 0.8, 1, 2 or 3, etc.

[0029] In related technologies, the solder ribbon 40 of the solar cell 20 that needs to be connected to the busbar is usually connected together with the busbar to form a busbar assembly. The entire busbar assembly is placed on the surface of the cell string. Since the solder ribbon 40 is relatively long, and the busbar is placed between two adjacent solar cells, it is necessary to align the busbar with the solar cell 20, fix the solder ribbon 40 connected to the busbar, and align it with the grid lines on the surface of the solar cell 20. The alignment is difficult, which makes the installation of the busbar assembly difficult. In addition, the solder ribbon 40 is prone to displacement, which affects the reliability of the assembly.

[0030] By configuring the busbar 10 to include an interconnected main body 11 and a connecting part 12, the solder ribbon 40 can be pre-positioned on the surface of the solar cell 20 via the connecting part 12. The length of the connecting part 12 can be much shorter than the length of the solder ribbon 40, eliminating the need for fixing the connecting part 12. When configuring the busbar 10, it is only necessary to align the main body 11 with the solar cell 20 and simultaneously align the connecting part 12 with the solder ribbon 40. Furthermore, since the connecting part 12 can be relatively short and the solder ribbon 40 is relatively wide, the alignment between the connecting part 12 and the solder ribbon 40 is less difficult. Therefore, this embodiment can reduce the difficulty of aligning the busbar 10 with the solder ribbon 40, improve alignment accuracy, and enhance module reliability. Moreover, by positioning the connecting part 12 on the same side of the main body 11, it is only necessary to fix the connecting part 12 on one side of the main body 11, reducing the manufacturing complexity.

[0031] This embodiment of the invention provides a busbar 10 comprising a main body 11 and multiple connecting portions 12 connected to the main body 11. The connecting portions 12 connect to the solder ribbon on the surface of the solar cell 20. The solder ribbon 40 can be pre-set on the surface of the solar cell 20, eliminating the need to set it together with the busbar. When setting the busbar 10, the connecting portions 12 and solder ribbon 40 only need to be aligned simultaneously with the main body 11 and the solar cell 20. Furthermore, since the connecting portions 12 can be relatively short and the solder ribbon 40 is relatively wide, the alignment of the connecting portions 12 and solder ribbon 40 is less difficult. Therefore, this embodiment reduces the difficulty of aligning the busbar 10 with the solder ribbon 40, improves alignment accuracy, and enhances module reliability. Moreover, by setting the end of the connecting portion 12 not connected to the main body 11 to be on the same side of the main body 11, the connecting portion 12 only needs to be fixed on one side of the main body 11, reducing the manufacturing complexity. Furthermore, by setting the ratio of the length S2 of the second sub-part 122 to the length S1 of the first sub-part 121 along the first direction X to be greater than 0.2, the second sub-part 122 and the solder strip 40 have a larger contact area, thereby improving the reliability of the component.

[0032] Based on the above embodiments, optionally, the length S2 of the second sub-part 122 along the first direction X is greater than 3mm and less than 60mm.

[0033] Specifically, if the length S2 of the second sub-part 122 is too small, the welding area between the connecting part 12 and the solder strip 40 is small, which can easily lead to poor soldering and desoldering, reducing the reliability of the battery module. If the length S2 of the second sub-part 122 is too long, the connecting part 12 is prone to misalignment and twisting, reducing the reliability of the battery module and the yield after lamination. By setting the length S2 of the second sub-part 122 to be greater than 3mm and less than 60mm, it is possible to ensure that the connecting part 12 and the solder strip 30 have sufficient welding area while reducing material waste in the connecting part 12, reducing the risk of misalignment and twisting in the connecting part 12, and improving the reliability of the battery module and the yield after lamination. For example, the length S2 of the second sub-part 122 can be 5mm, 10mm, 30mm, or 55mm, etc.

[0034] Figure 3 This is a schematic diagram of another battery assembly provided in an embodiment of the present invention, see reference. Figures 1-3 Based on the above embodiments, optionally, each battery string 100 includes a plurality of solar cells 20 arranged sequentially along the first direction X; the bus bar 10 includes an edge bus bar 101, which is used to connect adjacent battery strings 100 along the second direction Y. The main body 11 of the edge busbar 101 is disposed on the surface of the second battery 202 of the battery string 100. Figure 3 ) or the surface of the first battery 201 ( Figure 1 The second sub-part 122 of the connecting part 12 is connected to the solder strip 40 on the first battery 201 of the battery string 100. The first battery 201 is the outermost solar cell of the battery string 100, and the second battery 202 is the solar cell adjacent to the first battery 201.

[0035] For details, please refer to Figure 1 When the main body 11 of the edge busbar 101 is disposed on the surface of the first battery 201 of the battery string 100, the second sub-part 122 may be located on the side of the main body 11 adjacent to the second battery 202, or on the side of the main body 11 away from the second battery 202. The second sub-part 122 is connected to the solder strip 40 on the surface of the first battery 201.

[0036] refer to Figure 3 When the main body 11 of the edge busbar 101 is disposed on the surface of the second battery 202, the second sub-part 122 is disposed on the side of the main body 11 adjacent to the first battery 201, and the second sub-part 122 is connected to the solder strip 40 on the surface of the first battery 201.

[0037] By setting the end of the connecting part 12 that is not connected to the main body part 11 to be located on the same side of the main body part 11, the main body part 11 of the edge busbar 101 can be set on the surface of the first battery 201 or on the surface of the second battery 202, making the setting method of the edge busbar 101 more flexible.

[0038] Figure 4 This is a schematic diagram showing the position of the main body 11 provided in an embodiment of the present invention, with reference to... Figure 3 and Figure 4 Based on the above embodiments, optionally, when the main body 11 of the edge busbar 101 is disposed on the surface of the second battery 202 of the battery string 100, the minimum distance S3 between the edge of the main body 11 adjacent to the edge of the first battery 201 and the edge of the second battery 202 adjacent to the edge of the main body 11 is 3mm-20mm.

[0039] Specifically, if the main body 11 is too close to the edge of the second battery 202 adjacent to the main body 11, the edge of the second battery 202 will be subjected to excessive pressure during lamination, which may easily cause microcracks. By setting the minimum distance S3 between the edge of the main body 11 adjacent to the first battery 201 and the edge of the second battery 202 adjacent to the main body 11 to be 3mm-20mm, the risk of microcracks at the edge of the second battery 202 can be reduced, and electrical losses can be reduced.

[0040] Based on the above embodiments, optionally, when the main body 11 of the edge busbar 101 is disposed on the surface of the second battery 202 of the battery string 100, the insulating strip 50 extends at least from the surface of the second battery 202 to the surface of the first battery 201.

[0041] Specifically, the insulating strip 30 at least covers the gap between the first solar cell 201 and the second solar cell 202, allowing the connecting portion 12 to extend to the surface of the first solar cell 201 via a relatively flat surface. This prevents the connecting portion 12 from deforming at the gap between the two solar cells 20, thus affecting the reliability of the connection between the connecting portion 12 and the solder ribbon 40. For example, the insulating strip 30 may extend from the surface of the second solar cell 202 to the surface of the first solar cell 201, covering a portion of the edge area of ​​the first solar cell 201.

[0042] Based on the above embodiments, optionally, when the main body 11 of the edge busbar 101 is disposed on the surface of the second battery 202 of the battery string 100, the vertical projection of the second sub-part 122 on the surface of the first battery 201 at least covers the first pad 51 of the first battery 201 that is closest to the second battery 202; wherein, the first battery 201 includes a plurality of first pads 51, and solder strips 40 are connected to the plurality of first pads 51, and the connecting part is welded to the corresponding solder strips 40.

[0043] Specifically, the surface of the solar cell 20 is also provided with pads, which are connected to the first or second grid line. When the solder ribbon 40 is placed on the surface of the solar cell 20, it is soldered to the pads. Since the pads are wider than the grid lines, the soldering area between the solder ribbon 40 and the pads is larger, making the solder ribbon 40 and the pads more firmly soldered and less likely to fall off, thus improving the soldering reliability. The first pad 51 is the pad on the surface of the first cell 201.

[0044] When the main body 11 of the edge busbar 101 is disposed on the surface of the second battery 202, the second sub-part 122 is connected to the solder ribbon 40 on the surface of the first battery 201. The area between the first solder pad 51 at the outermost edge of the first battery 201 and the edge of the first battery 201 is the edge area of ​​the first battery 201. In this area, the solder ribbon 40 is prone to twisting. If the end of the connecting part 12 is located in this area, it is easy to misalign with the solder ribbon 40, resulting in a small contact area and easy desoldering. By setting the vertical projection of the second sub-part 122 on the surface of the first battery 201 to at least cover the first solder pad 51 closest to the second battery 202 on the surface of the first battery 201, the welding area between the second sub-part 122 and the solder ribbon 40 of the first battery 201 is larger, the welding is stronger, and the reliability of the component is improved.

[0045] Based on the above embodiments, optionally, refer to the following: Figure 1 When the main body 11 of the edge busbar 101 is disposed on the surface of the first battery 201 of the battery string 100, the ratio of the distance between the two opposite edges of the main body 12 and the first battery 201 along the first direction X is greater than 1 / 2 and less than 2.

[0046] Specifically, along the first direction X, the ratio of the distance between the main body 11 of the edge busbar 101 and the two sides of the first battery 201 is L1 / L2. If this ratio is too small, the current collection in the edge busbar 50 will be uneven, increasing the electrical transmission loss of the battery assembly and reducing its power. By setting the ratio of the distance between the main body 12 and the two opposite edges of the first battery 201 along the first direction X to be greater than 1 / 2 and less than 2, the uniformity of current collection in the edge busbar 100 can be ensured, reducing the electrical transmission loss of the battery assembly and increasing its power. For example, the ratio of the distance between the main body 12 and the two opposite edges of the first battery 201 along the first direction X can be as large as 1 / 2, 1, or 2, etc.

[0047] Figure 5 This is a schematic diagram of another battery assembly provided in an embodiment of the present invention. Figure 6 This is a cross-sectional view of a battery assembly provided in an embodiment of the present invention, with reference to... Figure 5 and Figure 6Based on the above embodiments, optionally, the battery string includes a first battery string 200 and a second battery string 300, and both the first battery string 200 and the second battery string 300 include a plurality of solar cells 20 arranged sequentially along the first direction X. The busbar 10 includes a central busbar 102, which is used to connect the first battery string 200 and the second battery string 300 adjacent along the first direction X; the main body 11 of the central busbar 102 is disposed on the surface of the third battery 203 of the first battery string 200, and the third battery 203 is a solar cell in the first battery string 200 that is adjacent to the second battery string 300. The first sub-section of the central busbar 102 includes a first region 61, and the second sub-section includes a second region 62 and a third region 63. The first region 61 is disposed on the surface of the main body 11, and the second region 62 and the third region 63 are disposed on the side of the main body 11 adjacent to the second battery string 300. The second region 62 is connected to the solder strip 40 on the surface of the third battery 203, and the third region 63 is connected to the solder strip 40 on the surface of the fourth battery 204 of the second battery string 300. The fourth battery 204 is a solar cell in the second battery string 300 that is adjacent to the first battery string 200.

[0048] Specifically, the connecting portion 12 extends only to one side of the main body 11, and connects to the third battery 203 and the fourth battery 204 on the same side of the main body 11. When setting the central busbar 102, alignment of the connecting portion 12 is only required on one side of the main body 11, reducing alignment difficulty. (See also...) Figure 6 When the connecting part 12 and the main body 11 are not an integral structure, the connecting part 12 is located on the side of the main body 11 away from the insulating strip 30. The connecting part 12 needs to be bent from the surface of the main body 11 to the surface of the solar cell. When the second region 62 and the third region 63 are located on the same side of the main body 11, the connecting part 12 only needs to be bent once, which reduces the probability of stress concentration in the connecting part 12. In addition, the total length of the second region 62 and the third region 63 is relatively long, and the welding area with the solder strip 40 is large, which reduces the probability of the second region 62 and the third region 63 detaching from the solder strip 40 and improves the reliability of the module.

[0049] Based on the above embodiments, optionally, the insulating strip 30 exposes at least the second pad 52 of the third battery 203 that is closest to the fourth battery 204 on the surface of the third battery 203; wherein the third battery 203 includes a plurality of second pads 52, and solder strips 40 are connected to the plurality of second pads 52, and the connecting portion 12 is welded to the corresponding solder strips 40.

[0050] Specifically, the second pad 52 is a pad on the surface of the third battery 203. The area between the second pad 52 at the outermost edge of the third battery 203 and the edge of the third battery 203 is the edge region of the third battery 203. In this region, the solder ribbon 40 is prone to twisting. If the end of the second region 62 is only connected to the solder ribbon 40 in this region, misalignment with the solder ribbon 40 is likely to occur, resulting in a small contact area and easy desoldering. By setting the insulating strip 30 to expose at least the second pad 52 on the surface of the third battery 203 that is closest to the fourth battery 204, the second region 62 is connected to at least the portion of the solder ribbon 40 on the surface of the second pad 52 and the portion located in the edge region of the third battery 203. This results in a larger welding area between the second region 62 and the solder ribbon 40 of the third battery 203, a stronger weld, and improved component reliability.

[0051] Based on the above embodiments, optionally, the distance D between the edge of the insulating strip 30 adjacent to the second pad 52 and the edge of the second pad 52 adjacent to the insulating strip 30 is greater than 2mm.

[0052] This configuration allows for a larger welding area between the second zone 62 and the solder strip 40 of the third battery 203, resulting in a stronger weld and improved component reliability. For example, the distance D between the edge of the insulating strip 30 adjacent to the second pad 52 and the edge of the pad 52 adjacent to the insulating strip 30 can be 2.5mm or 3mm, etc.

[0053] This invention provides a photovoltaic system, which includes the battery module described in the above embodiments.

[0054] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in 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's understandable that the application scenarios of photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be a combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter and is converted into AC power required by the mains grid before being connected to the mains grid to achieve solar power supply.

[0055] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0056] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A battery assembly, characterized in that, include: Busbars and battery strings; The busbar includes a main body and a plurality of connecting portions connected to the main body. The main body extends along a second direction, and the connecting portions extend along a first direction. The plurality of connecting portions are spaced apart along the second direction, and the first direction and the second direction intersect each other. One end of each connecting portion is connected to the main body, and the ends of the connecting portions of the same busbar that are not connected to the main body are located on the same side of the main body. The main body is disposed on one side surface of the battery string, and an insulating strip is also disposed between the main body and the battery string. The vertical projection of the main body on the surface of the battery string is located within the vertical projection of the insulating strip on the surface of the battery string. The connecting portion includes a first sub-part and a second sub-part. The vertical projection of the first sub-part onto the surface of the battery string is located within the vertical projection of the insulating strip onto the surface of the battery string, and the vertical projection of the second sub-part onto the surface of the battery string is located outside the vertical projection of the insulating strip onto the surface of the battery string. Along the first direction, the ratio of the length of the second sub-part to the length of the first sub-part is greater than 0.

2.

2. The battery assembly according to claim 1, characterized in that: Along the first direction, the length of the second sub-part is greater than 3 mm and less than 60 mm.

3. The battery assembly according to claim 1, characterized in that: Each battery string includes a plurality of solar cells arranged sequentially along the first direction; the busbar includes an edge busbar for connecting adjacent battery strings along the second direction; The main body of the edge busbar is disposed on the surface of the second battery or the surface of the first battery in the battery string; the second sub-part of the connecting part is connected to the solder strip on the first battery of the battery string, the first battery being the outermost solar cell of the battery string, and the second battery being the solar cell adjacent to the first battery.

4. The battery assembly according to claim 3, characterized in that: When the main body of the edge busbar is disposed on the surface of the second battery of the battery string, the minimum distance between the edge of the main body adjacent to the edge of the first battery and the edge of the second battery adjacent to the edge of the main body is 3mm-20mm.

5. The battery assembly according to claim 3, characterized in that: When the main body of the edge busbar is disposed on the surface of the second battery of the battery string, the insulating strip extends at least partially from the surface of the second battery to the surface of the first battery.

6. The battery assembly according to claim 3, characterized in that: When the main body of the edge busbar is disposed on the surface of the second battery of the battery string, the vertical projection of the second sub-part on the surface of the first battery at least covers the first pad of the first battery surface that is closest to the second battery; wherein, the first battery includes a plurality of first pads, the plurality of first pads are connected with solder strips, and the connecting part is welded to the corresponding solder strip.

7. The battery assembly according to claim 3, characterized in that: When the main body of the edge busbar is disposed on the surface of the first battery of the battery string, the ratio of the distance between the main body and the two opposite edges of the first battery along the first direction is greater than 1 / 2 and less than 2.

8. The battery assembly according to claim 1, characterized in that: The battery string includes a first battery string and a second battery string, both of which include a plurality of solar cells arranged sequentially along the first direction; The busbar includes a central busbar for connecting a first battery string and a second battery string that are adjacent along a first direction; the main body of the central busbar is disposed on the surface of a third battery in the first battery string, and the third battery is a solar cell in the first battery string that is adjacent to the second battery string. The first sub-section of the central busbar includes a first region, and the second sub-section of the central busbar includes a second region and a third region. The first region is disposed on the surface of the main body, and the second and third regions are disposed on the side of the main body adjacent to the second battery string. The second region is connected to the solder strip on the surface of the third battery, and the third region is connected to the solder strip on the surface of the fourth battery in the second battery string. The fourth battery is a solar cell in the second battery string that is adjacent to the first battery string.

9. The battery assembly according to claim 8, characterized in that: The insulating strip exposes at least the second pad of the third battery closest to the fourth battery on its surface; wherein the third battery includes a plurality of second pads, the plurality of second pads being connected to solder strips, and the connecting portion being welded to the corresponding solder strips.

10. The battery assembly according to claim 9, characterized in that: The distance between the edge of the insulating strip adjacent to the second pad and the edge of the second pad adjacent to the insulating strip is greater than 2 mm.

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

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